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Sample records for acute reference exposures

  1. Background radiation, electrical work, and some other exposures associated with acute myeloid leukemia in a case-referent study.

    PubMed

    Flodin, U; Fredriksson, M; Persson, B; Hardell, L; Axelson, O

    1986-01-01

    The effect of potential risk factors for acute myeloid leukemia was evaluated in a case-referent study encompassing 59 cases and 354 referents, all of whom were alive. Information on exposure was obtained through a questionnaire mailed to the subjects. The possible effect of background radiation was evaluated by means of a gamma radiation index, which accounted for the differences between cases and referents in this respect, i.e., in time spent in concrete buildings both at home and at work places. In the 20-54 yr old age group, there was an association between leukemia morbidity and index of background radiation. X-ray treatment and electrical work were also associated with increased rate ratios. With regard to solvents, only styrene appeared as a risk factor, but the number of exposed subjects was small. Other exposures were less clearly associated with increased risks.

  2. Acute radiodermatitis from occupational exposure to iridium 192

    SciTech Connect

    Becker, J.; Rosen, T. )

    1989-12-01

    Industrial radiography using the man-made radioisotope iridium 192 is commonplace in the southern states. Despite established procedures and safeguards, accidental exposure may result in typical acute radiodermatitis. We have presented a clinical example of this phenomenon.9 references.

  3. Human health screening level risk assessments of tertiary-butyl acetate (TBAC): calculated acute and chronic reference concentration (RfC) and Hazard Quotient (HQ) values based on toxicity and exposure scenario evaluations.

    PubMed

    Bus, James S; Banton, Marcy I; Faber, Willem D; Kirman, Christopher R; McGregor, Douglas B; Pourreau, Daniel B

    2015-02-01

    A screening level risk assessment has been performed for tertiary-butyl acetate (TBAC) examining its primary uses as a solvent in industrial and consumer products. Hazard quotients (HQ) were developed by merging TBAC animal toxicity and dose-response data with population-level, occupational and consumer exposure scenarios. TBAC has a low order of toxicity following subchronic inhalation exposure, and neurobehavioral changes (hyperactivity) in mice observed immediately after termination of exposure were used as conservative endpoints for derivation of acute and chronic reference concentration (RfC) values. TBAC is not genotoxic but has not been tested for carcinogenicity. However, TBAC is unlikely to be a human carcinogen in that its non-genotoxic metabolic surrogates tertiary-butanol (TBA) and methyl tertiary butyl ether (MTBE) produce only male rat α-2u-globulin-mediated kidney cancer and high-dose specific mouse thyroid tumors, both of which have little qualitative or quantitative relevance to humans. Benchmark dose (BMD)-modeling of the neurobehavioral responses yielded acute and chronic RfC values of 1.5 ppm and 0.3 ppm, respectively. After conservative modeling of general population and near-source occupational and consumer product exposure scenarios, almost all HQs were substantially less than 1. HQs exceeding 1 were limited to consumer use of automotive products and paints in a poorly ventilated garage-sized room (HQ = 313) and occupational exposures in small and large brake shops using no personal protective equipment or ventilation controls (HQs = 3.4-126.6). The screening level risk assessments confirm low human health concerns with most uses of TBAC and indicate that further data-informed refinements can address problematic health/exposure scenarios. The assessments also illustrate how tier-based risk assessments using read-across toxicity information to metabolic surrogates reduce the need for comprehensive animal testing.

  4. Genetics Home Reference: acute promyelocytic leukemia

    MedlinePlus

    ... acute myeloid leukemia, a cancer of the blood-forming tissue ( bone marrow ). In normal bone marrow, hematopoietic ... 7186-203. Review. Citation on PubMed de Thé H, Chen Z. Acute promyelocytic leukaemia: novel insights into ...

  5. In Vivo Nanodetoxication for Acute Uranium Exposure.

    PubMed

    Guzmán, Luis; Durán-Lara, Esteban F; Donoso, Wendy; Nachtigall, Fabiane M; Santos, Leonardo S

    2015-06-15

    Accidental exposure to uranium is a matter of concern, as U(VI) is nephrotoxic in both human and animal models, and its toxicity is associated to chemical toxicity instead of radioactivity. We synthesized different PAMAM G4 and G5 derivatives in order to prove their interaction with uranium and their effect on the viability of red blood cells in vitro. Furthermore, we prove the effectiveness of the selected dendrimers in an animal model of acute uranium intoxication. The dendrimer PAMAM G4-Lys-Fmoc-Cbz demonstrated the ability to chelate the uranyl ion in vivo, improving the biochemical and histopathologic features caused by acute intoxication with uranium.

  6. Acute myelocytic leukemia after exposure to asbestos

    SciTech Connect

    Kishimoto, T.; Ono, T.; Okada, K.

    1988-08-15

    While the carcinogenicity of asbestos has been established in malignant mesotheliomas and lung cancers, and has recently been suspected in several other types of cancer, asbestos has not been implicated in the pathogenesis of acute leukemias. This article includes two cases of acute myelocytic leukemia in individuals with a long history of exposure to asbestos. Significant numbers of asbestos bodies were detected in specimens of their lungs and bone marrow. In addition, the kind of asbestos in both organs was crocidolite, which is implicated in carcinogenesis. No asbestos bodies were detected in the bone marrow specimens from a control group consisting of ten patients with lung cancer with similar occupational histories. The role of asbestos exposure in the development of leukemia requires further study.

  7. Acute radiation syndrome caused by accidental radiation exposure - therapeutic principles.

    PubMed

    Dörr, Harald; Meineke, Viktor

    2011-11-25

    Fortunately radiation accidents are infrequent occurrences, but since they have the potential of large scale events like the nuclear accidents of Chernobyl and Fukushima, preparatory planning of the medical management of radiation accident victims is very important. Radiation accidents can result in different types of radiation exposure for which the diagnostic and therapeutic measures, as well as the outcomes, differ. The clinical course of acute radiation syndrome depends on the absorbed radiation dose and its distribution. Multi-organ-involvement and multi-organ-failure need be taken into account. The most vulnerable organ system to radiation exposure is the hematopoietic system. In addition to hematopoietic syndrome, radiation induced damage to the skin plays an important role in diagnostics and the treatment of radiation accident victims. The most important therapeutic principles with special reference to hematopoietic syndrome and cutaneous radiation syndrome are reviewed.

  8. Regulation of adenosine transport by acute and chronic ethanol exposure

    SciTech Connect

    Nagy, L.E.; Casso, D.; Diamond, I.; Gordon, A.S. )

    1989-02-09

    Chronic exposure to ethanol results in a desensitization of adenosine receptor-stimulated cAMP production. Since adenosine is released by cells and is known to desensitize its own as well as other receptors, it may be involved in ethanol-induced desensitization of adenosine receptor function. Therefore, we have examine the acute and chronic effects of ethanol on the transport of adenosine via the nucleoside transport. Acute exposure to ethanol caused an inhibition of adenosine uptake in S49 lymphoma cells. This decrease in uptake resulted in accumulation of extracellular adenosine after ethanol exposure. The effect of ethanol was specific to nucleoside transport. Uptake of uridine, also transported by the nucleoside transporter, was inhibited by ethanol to the same degree as adenosine uptake, while neither isoleucine nor deoxyglucose uptake was altered by ethanol treatment. Inhibition of adenosine uptake by ethanol was non-competitive and dependent on the concentration of ethanol. After chronic exposure to ethanol, cells became tolerant to the acute effects of ethanol. There was no longer an acute inhibition of adenosine uptake, nor was these accumulation of extracellular adenosine. Chronic ethanol exposure also resulted in a decrease in the absolute rate of adenosine uptake. Binding studies using a high affinity lignad for the nucleoside transporter, nitrobenzylthioinosine (NBMPR), indicate that this decreased uptake was due to a decrease in the maximal number of binding sites. These ethanol-induced changes in adenosine transport may be important for the acute and chronic effects of ethanol.

  9. Proposal for reference concentrations (RfC) for inhalation exposure to methanol.

    PubMed

    Vyskocil; Viau

    2000-12-01

    A tentative reference concentration (RfC) for methanol in ambient air, i.e. an exposure concentration below which adverse effects are not expected to occur, was derived from the analysis of the toxicological data available in the literature. Well-documented studies that correlate environmental levels of methanol with observed toxic effects have not been found in the literature, nor have any long-term epidemiological studies of chronic low-level occupational exposure been found. Assessment of RfC for acute inhalation exposure is based on a human study (n=26 subjects) with a 'tentative' NOAEL of 262 mg/m(3). The calculated RfC for 1 h exposure is 104.8 mg/m(3). The RfC is given a low confidence rating as there was only one methanol concentration used. A well designed study on monkeys served as the basis for the assessment of RfC for chronic inhalation exposure. In this study, 13.1 and 131 mg/m(3) were considered as NOAEL and LOAEL, respectively. The calculated RfC is 0.38 mg/m(3). The overall database is weak, lacking data on reproductive and developmental endpoints in human or non-human primates. Nevertheless, the RfC is given a medium confidence rating because of the strength of the principal study.

  10. USING REGIONAL EXPOSURE CRITERIA AND UPSTREAM REFERENCE DATA TO CHARACTERIZE SPATIAL AND TEMPORAL EXPOSURES TO CHEMICAL CONTAMINANTS

    EPA Science Inventory

    Analyses of biomarkers in fish were used to evaluate exposures among locations and across time. Two types of references were used for comparison, an upstream reference sample remote from known point sources and regional exposure criteria derived from a basline of fish from refere...

  11. USING REGIONAL EXPOSURE CRITERIA AND UPSTREAM REFERENCE DATA TO CHARACTERIZE SPATIAL AND TEMPORAL EXPOSURES TO CHEMICAL CONTAMINANTS

    EPA Science Inventory

    Analyses of biomarkers in fish were used to evaluate exposures among locations and across time. Two types of references were used for comparison, an upstream reference sample remote from known point sources and regional exposure criteria derived from a baseline of fish from refer...

  12. Lung function after acute chlorine exposure

    SciTech Connect

    Jones, R.N.; Hughes, J.M.; Glindmeyer, H.; Weill, H.

    1986-12-01

    Chlorine gas, spreading from a train derailment, caused the deaths of 8 persons and the hospitalization of 23 with sublethal respiratory injuries. Twenty-five others had at least one sign of lower respiratory abnormality but were not hospitalized. One hundred thirteen who were examined for gas effects in the forty-eight hours after exposure, including 20 of 23 of those hospitalized and 21 of 25 of those not hospitalized but with respiratory abnormality, participated in follow-up studies. Probability of admission to hospital was related to distance from the spill, but by 3 wk after exposure there was no detectable difference in lung function relating to distance or apparent severity of injury. In 60 adults tested multiple times over the following 6 yr, longitudinal change in lung function showed expected differences related to smoking but none related to distance or severity of injury. The average annual change in FEV was -34 ml/yr in current smokers and -18 ml/yr in ex and never-smokers. The lack of a discernible chlorine effect in this cohort accords with the findings in most previous studies. Without pre-exposure measurements, a single, lasting reduction in lung function cannot be excluded, but there is no evidence for a persisting abnormal rate of decline.

  13. Development of acute exposure guideline levels for airborne exposures to hazardous substances.

    PubMed

    Krewski, Daniel; Bakshi, Kulbir; Garrett, Roger; Falke, Ernest; Rusch, George; Gaylor, David

    2004-04-01

    Hazardous substances can be released into the atmosphere due to industrial and transportation accidents, fires, tornadoes, earthquakes, and terrorists, thereby exposing workers and the nearby public to potential adverse health effects. Various enforceable guidelines have been set by regulatory agencies for worker and ambient air quality. However, these exposure levels generally are not applicable to rare lifetime acute exposures, which possibly could occur at high concentrations. Acute exposure guideline levels (AEGLs) provide estimates of concentrations for airborne exposures for an array of short durations that possibly could cause mild (AEGL-1), severe, irreversible, potentially disabling adverse health effects (AEGL-2), or life threatening effects (AEGL-3). These levels can be useful for emergency responders and planners in reducing or eliminating potential risks to the public. Procedures and methodologies for deriving AEGLs are reviewed in this paper that have been developed in the United States, with direct input from international representatives of OECD member-countries, by the National Advisory Committee for Acute Exposure Guidelines for Hazardous Substances and reviewed by the National Research Council. Techniques are discussed for the extrapolation of effects across different exposure durations. AEGLs provide a viable approach for assisting in the prevention, planning, and response to acute airborne exposures to toxic agents.

  14. Biomarkers of Acute Respiratory Allergen Exposure: Screening For Sensitization Potential

    EPA Science Inventory

    Rationale: An in vitro assay to identify respiratory sensitizers will provide a rapid screen and reduce animal use. The study goal was to identify biomarkers that differentiate allergen versus non-allergen responses following an acute exposure. Methods: Female BALB/c mice rec...

  15. Health Impacts from Acute Radiation Exposure

    SciTech Connect

    Strom, Daniel J.

    2003-09-30

    Absorbed doses above1-2 Gy (100-200 rads) received over a period of a day or less lead to one or another of the acute radiation syndromes. These are the hematopoietic syndrome, the gastrointestinal (GI) syndrome, the cerebrovascular (CV) syndrome, the pulmonary syndrome, or the cutaneous syndrome. The dose that will kill about 50% of the exposed people within 60 days with minimal medical care, LD50-60, is around 4.5 Gy (450 rads) of low-LET radiation measured free in air. The GI syndrome may not be fatal with supportive medical care and growth factors below about 10 Gy (1000 rads), but above this is likely to be fatal. Pulmonary and cutaneous syndromes may or may not be fatal, depending on many factors. The CV syndrome is invariably fatal. Lower acute doses, or protracted doses delivered over days or weeks, may lead to many other health outcomes than death. These include loss of pregnancy, cataract, impaired fertility or temporary or permanent sterility, hair loss, skin ulceration, local tissue necrosis, developmental abnormalities including mental and growth retardation in persons irradiated as children or fetuses, radiation dermatitis, and other symptoms listed in Table 2 on page 12. Children of parents irradiated prior to conception may experience heritable ill-health, that is, genetic changes from their parents. These effects are less strongly expressed than previously thought. Populations irradiated to high doses at high dose rates have increased risk of cancer incidence and mortality, taken as about 10-20% incidence and perhaps 5-10% mortality per sievert of effective dose of any radiation or per gray of whole-body absorbed dose low-LET radiation. Cancer risks for non-uniform irradiation will be less.

  16. Acute exposure to environmental tobacco smoke and heart rate variability.

    PubMed Central

    Pope, C A; Eatough, D J; Gold, D R; Pang, Y; Nielsen, K R; Nath, P; Verrier, R L; Kanner, R E

    2001-01-01

    Environmental tobacco smoke (ETS) has been associated with cardiovascular mortality. Pathophysiologic pathways leading from ETS exposure to cardiopulmonary disease are still being explored. Reduced cardiac autonomic function, as measured by heart rate variability (HRV), has been associated with cardiac vulnerability and may represent an important pathophysiologic mechanism linking ETS and risk of cardiac mortality. In this study we evaluated acute ETS exposure in a commercial airport with changes in HRV in 16 adult nonsmokers. We conducted ambulatory electrocardiographic (ECG) monitoring for 8-hr periods while participants alternated 2 hr in nonsmoking and smoking areas. Nicotine and respirable suspended particle concentrations and participants' blood oxygen saturation were also monitored. We calculated time and frequency domain measures of HRV for periods in and out of the smoking area, and we evaluated associations with ETS using comparative statistics and regression modeling. ETS exposure was negatively associated with all measures of HRV. During exposure periods, we observed an average decrement of approximately 12% in the standard deviation of all normal-to-normal heart beat intervals (an estimate of overall HRV). ETS exposures were not associated with mean heart rate or blood oxygen saturation. Altered cardiac autonomic function, assessed by decrements in HRV, is associated with acute exposure to ETS and may be part of the pathophysiologic mechanisms linking ETS exposure and increased cardiac vulnerability. PMID:11485870

  17. Genetics Home Reference: cytogenetically normal acute myeloid leukemia

    MedlinePlus

    ... one form of a cancer of the blood-forming tissue (bone marrow) called acute myeloid leukemia. In ... 1 link) PubMed Sources for This Page Döhner H. Implication of the molecular characterization of acute myeloid ...

  18. Gastric acid response to acute exposure to hypergravity

    PubMed Central

    Yoon, Gun; Kim, Hyun-Soo

    2017-01-01

    The influence of environmental stressors on the pathogenesis of gastrointestinal disease has received increased awareness. Stress affects different physiological functions of the gastrointestinal tract, including gastric acid secretion and mucosal blood flow. Repeated exposures of rapid-onset, highly-sustained hypergravity cause severe physical stress in the pilot. Although the effects of exposure to hypergravity on cardiovascular and cerebral functions have been the subjects of numerous studies, crucial information regarding pathophysiological changes in the gastrointestinal tract following hypergravity exposure is lacking. In this study, we investigated the effects of acute exposure to hypergravity on gastric secretory activity and gastrin release. Male Sprague-Dawley rats were exposed to +10Gz three times for 3 min. Gastric juice and blood were collected. The volume and total acidity of gastric juice, and the plasma gastrin level was measured. Acute exposure to +10Gz significantly decreased the gastric juice parameters. The gastric juice volume and total acidity of hypergravity-exposed rats were 3.54 ± 0.32 mL/100 g and 84.90 ± 5.17 mEq/L, respectively, which were significantly lower than those of the nonexposed rats (4.62 ± 0.39 mL/100 g and 97.37 ± 5.42 mEq/L; P < 0.001 and P < 0.001, respectively). In contrast, plasma gastrin level was not significantly altered following hypergravity exposure. We demonstrated that acute exposure to hypergravity led to a significant decrease in the gastric juice volume and acidity but did not alter the plasma gastrin level. PMID:27992379

  19. Human physiological responses to cold exposure: Acute responses and acclimatization to prolonged exposure.

    PubMed

    Castellani, John W; Young, Andrew J

    2016-04-01

    Cold exposure in humans causes specific acute and chronic physiological responses. This paper will review both the acute and long-term physiological responses and external factors that impact these physiological responses. Acute physiological responses to cold exposure include cutaneous vasoconstriction and shivering thermogenesis which, respectively, decrease heat loss and increase metabolic heat production. Vasoconstriction is elicited through reflex and local cooling. In combination, vasoconstriction and shivering operate to maintain thermal balance when the body is losing heat. Factors (anthropometry, sex, race, fitness, thermoregulatory fatigue) that influence the acute physiological responses to cold exposure are also reviewed. The physiological responses to chronic cold exposure, also known as cold acclimation/acclimatization, are also presented. Three primary patterns of cold acclimatization have been observed, a) habituation, b) metabolic adjustment, and c) insulative adjustment. Habituation is characterized by physiological adjustments in which the response is attenuated compared to an unacclimatized state. Metabolic acclimatization is characterized by an increased thermogenesis, whereas insulative acclimatization is characterized by enhancing the mechanisms that conserve body heat. The pattern of acclimatization is dependent on changes in skin and core temperature and the exposure duration.

  20. Factors affecting the estimated probabilistic acute dietary exposure to captan from apple consumption.

    PubMed

    Zentai, A; Sali, J; Szabó, I J; Szeitzné-Szabó, M; Ambrus, A; Vásárhelyi, A

    2013-01-01

    The effect of the number of pesticide residue values below the LOQ/LOD of analytical methods, the variability of residues in individual fruits, mass of fruit units and the number of bootstrap iterations was studied on the probabilistically estimated acute exposure of consumers. The 4720 daily apple consumption data and the results of 1239 apple sample analyses for captan residues, performed within the Hungarian monitoring programme between 2005 and 2011, were used in this study as model matrix. Up to about 95th percentile exposure (µg/(kg bw·day)), simply multiplying each residue in composite samples with each consumption value gave similar estimates to those obtained with the complex procedure taking also into account the mass of and residues in individual fruits. However, the exposure above the 95th percentile calculated with the complex procedure gradually increased with increasing percentile level compared to the simple procedure. Including the high number of non-detects reduced the estimated exposure, which was the highest when only the residues measured in treated fruits were taken into account. The number of bootstrap iterations between 100 and 10,000 did not significantly affect the calculated exposure. The 99.99th percentile exposure amounted to 17.9% of the acute reference dose of 300 µg/(kg bw·day) for women of childbearing age.

  1. Sensory and Cognitive Effects of Acute Exposure to Hydrogen Sulfide

    PubMed Central

    Fiedler, Nancy; Kipen, Howard; Ohman-Strickland, Pamela; Zhang, Junfeng; Weisel, Clifford; Laumbach, Robert; Kelly-McNeil, Kathie; Olejeme, Kelechi; Lioy, Paul

    2008-01-01

    Background Some epidemiologic studies have reported compromised cognitive and sensory performance among individuals exposed to low concentrations of hydrogen sulfide (H2S). Objectives We hypothesized a dose–response increase in symptom severity and reduction in sensory and cognitive performance in response to controlled H2S exposures. Methods In separate exposure sessions administered in random order over three consecutive weeks, 74 healthy subjects [35 females, 39 males; mean age (± SD) = 24.7 ± 4.2; mean years of education = 16.5 ± 2.4], were exposed to 0.05, 0.5, and 5 ppm H2S. During each exposure session, subjects completed ratings and tests before H2S exposure (baseline) and during the final hour of the 2-hr exposure period. Results Dose–response reduction in air quality and increases in ratings of odor intensity, irritation, and unpleasantness were observed. Total symptom severity was not significantly elevated across any exposure condition, but anxiety symptoms were significantly greater in the 5-ppm than in the 0.05-ppm condition. No dose–response effect was observed for sensory or cognitive measures. Verbal learning was compromised during each exposure condition. Conclusions Although some symptoms increased with exposure, the magnitude of these changes was relatively minor. Increased anxiety was significantly related to ratings of irritation due to odor. Whether the effect on verbal learning represents a threshold effect of H2S or an effect due to fatigue across exposure requires further investigation. These acute effects in a healthy sample cannot be directly generalized to communities where individuals have other health conditions and concomitant exposures. PMID:18197303

  2. Acute Lead Exposure Increases Arterial Pressure: Role of the Renin-Angiotensin System

    PubMed Central

    Simões, Maylla Ronacher; Ribeiro Júnior, Rogério F.; Vescovi, Marcos Vinícius A.; de Jesus, Honério C.; Padilha, Alessandra S.; Stefanon, Ivanita; Vassallo, Dalton V.; Salaices, Mercedes; Fioresi, Mirian

    2011-01-01

    Background Chronic lead exposure causes hypertension and cardiovascular disease. Our purpose was to evaluate the effects of acute exposure to lead on arterial pressure and elucidate the early mechanisms involved in the development of lead-induced hypertension. Methodology/Principal Findings Wistar rats were treated with lead acetate (i.v. bolus dose of 320 µg/Kg), and systolic arterial pressure, diastolic arterial pressure and heart rate were measured during 120 min. An increase in arterial pressure was found, and potential roles of the renin-angiotensin system, Na+,K+-ATPase and the autonomic reflexes in this change in the increase of arterial pressure found were evaluated. In anesthetized rats, lead exposure: 1) produced blood lead levels of 37±1.7 µg/dL, which is below the reference blood concentration (60 µg/dL); 2) increased systolic arterial pressure (Ct: 109±3 mmHg vs Pb: 120±4 mmHg); 3) increased ACE activity (27% compared to Ct) and Na+,K+-ATPase activity (125% compared to Ct); and 4) did not change the protein expression of the α1-subunit of Na+,K+-ATPase, AT1 and AT2. Pre-treatment with an AT1 receptor blocker (losartan, 10 mg/Kg) or an ACE inhibitor (enalapril, 5 mg/Kg) blocked the lead-induced increase of arterial pressure. However, a ganglionic blockade (hexamethonium, 20 mg/Kg) did not prevent lead's hypertensive effect. Conclusion Acute exposure to lead below the reference blood concentration increases systolic arterial pressure by increasing angiotensin II levels due to ACE activation. These findings offer further evidence that acute exposure to lead can trigger early mechanisms of hypertension development and might be an environmental risk factor for cardiovascular disease. PMID:21494558

  3. Genetics Home Reference: familial acute myeloid leukemia with mutated CEBPA

    MedlinePlus

    ... terminal C/EBPalpha mutation. Genes Chromosomes Cancer. 2010 Mar;49(3):237-41. doi: 10.1002/gcc. ... EBPalpha), in acute myeloid leukemia. Nat Genet. 2001 Mar;27(3):263-70. Citation on PubMed Renneville ...

  4. Acute effects of cigarette smoke exposure on experimental skin flaps

    SciTech Connect

    Nolan, J.; Jenkins, R.A.; Kurihara, K.; Schultz, R.C.

    1985-04-01

    Random vascular patterned caudally based McFarlane-type skin flaps were elevated in groups of Fischer 344 rats. Groups of rats were then acutely exposed on an intermittent basis to smoke generated from well-characterized research filter cigarettes. Previously developed smoke inhalation exposure protocols were employed using a Maddox-ORNL inhalation exposure system. Rats that continued smoke exposure following surgery showed a significantly greater mean percent area of flap necrosis compared with sham-exposed groups or control groups not exposed. The possible pathogenesis of this observation as well as considerations and correlations with chronic human smokers are discussed. Increased risks of flap necrosis by smoking in the perioperative period are suggested by this study.

  5. Human Physiological Responses to Acute and Chronic Cold Exposure

    NASA Technical Reports Server (NTRS)

    Stocks, Jodie M.; Taylor, Nigel A. S.; Tipton, Michael J.; Greenleaf, John E.

    2001-01-01

    When inadequately protected humans are exposed to acute cold, excessive body heat is lost to the environment and unless heat production is increased and heat loss attenuated, body temperature will decrease. The primary physiological responses to counter the reduction in body temperature include marked cutaneous vasoconstriction and increased metabolism. These responses, and the hazards associated with such exposure, are mediated by a number of factors which contribute to heat production and loss. These include the severity and duration of the cold stimulus; exercise intensity; the magnitude of the metabolic response; and individual characteristics such as body composition, age, and gender. Chronic exposure to a cold environment, both natural and artificial, results in physiological alterations leading to adaptation. Three quite different, but not necessarily exclusive, patterns of human cold adaptation have been reported: metabolic, hypothermic, and insulative. Cold adaptation has also been associated with an habituation response, in which there is a desensitization, or damping, of the normal response to a cold stress. This review provides a comprehensive analysis of the human physiological and pathological responses to cold exposure. Particular attention is directed to the factors contributing to heat production and heat loss during acute cold stress, and the ability of humans to adapt to cold environments.

  6. Endocrine responses in the rhesus monkey during acute cold exposure

    SciTech Connect

    Lotz, W.G.; Saxton, J.L. )

    1991-03-11

    The authors studied five young male rhesus monkeys (Macaca mulatta), 3.4 to 6.7 kg, to determine the relationship between fluid balance hormones and urine production during acute, dry cold exposure. Each monkey served as its own control in duplicate experimental sessions at 6C or 26C. A 6-h experimental session consisted of 120 min equilibration at 26C, 120 min experimental exposure, and 120 min recovery at 26C. Urinary and venous catheters were inserted on the morning of a session. Rectal (Tre) and skin temperatures were monitored continuously. Blood samples were taken at 0, 30, 60 and 120 min of exposure, and at 60 min postexposure. Plasma was analyzed for arginine vasopressin (AVP), atrial natriuretic factor (ANF), plasma renin activity (PRA), plasma aldosterone (PA), and osmolality. Urine samples were analyzed for osmolality, electrolytes, and creatinine. Mean Tre was 1.6C lower after 120 min at 6C than at 26C. Urine volume and osmolality were not altered by cold exposure, as they are in humans and rats. Vasopressin and PA increased sharply, with mean plasma levels in monkeys exposed to cold more than threefold and tenfold, respectively, the levels in monkeys exposed at 26C. In contrast, ANF, PRA, and plasma osmolality were not significantly changed by cold exposure. The absence of a cold-induced diuresis in the monkey may be related to the marked increase in plasma AVP level.

  7. Mitigation Strategies for Acute Radiation Exposure during Space Flight

    NASA Technical Reports Server (NTRS)

    Hamilton, Douglas R.; Epelman, Slava

    2006-01-01

    While there are many potential risks in a Moon or Mars mission, one of the most important and unpredictable is that of crew radiation exposure. The two forms of radiation that impact a mission far from the protective environment of low-earth orbit, are solar particle events (SPE) and galactic cosmic radiation (GCR). The effects of GCR occur as a long-term cumulative dose that results increased longer-term medical risks such as malignancy and neurological degeneration. Unfortunately, relatively little has been published on the medical management of an acute SPE that could potentially endanger the mission and harm the crew. Reanalysis of the largest SPE in August 1972 revealed that the dose rate was significantly higher than previously stated in the literature. The peak dose rate was 9 cGy h(sup -1) which exceeds the low dose-rate criteria for 25 hrs (National Council on Radiation Protection) and 16 hrs (United Nations Scientific Committee on the Effects of Atomic Radiation). The bone marrow dose accumulated was 0.8 Gy, which exceeded the 25 and 16 hour criteria and would pose a serious medical risk. Current spacesuits would not provide shielding from the damaging effects for an SPE as large as the 1972 event, as increased shielding from 1-5 grams per square centimeters would do little to shield the bone marrow from exposure. Medical management options for an acute radiation event are discussed based on recommendations from the Department of Homeland Security, Centers for Disease Control and evidence-based scientific literature. The discussion will also consider how to define acute exposure radiation safety limits with respect to exploration-class missions, and to determine the level of care necessary for a crew that may be exposed to an SPE similar to August 1972.

  8. Mitigation Strategies for Acute Radiation Exposure during Space Flight

    NASA Technical Reports Server (NTRS)

    Hamilton, Douglas R.; Epelman, Slava

    2006-01-01

    While there are many potential risks in a Moon or Mars mission, one of the most important and unpredictable is that of crew radiation exposure. The two forms of radiation that impact a mission far from the protective environment of low-earth orbit, are solar particle events (SPE) and galactic cosmic radiation (GCR). The effects of GCR occur as a long-term cumulative dose that results increased longer-term medical risks such as malignancy and neurological degeneration. Unfortunately, relatively little has been published on the medical management of an acute SPE that could potentially endanger the mission and harm the crew. Reanalysis of the largest SPE in August 1972 revealed that the dose rate was significantly higher than previously stated in the literature. The peak dose rate was 9 cGy h(sup -1) which exceeds the low-dose-rate criteria for 25 hrs (National Council on Radiation Protection) and 16 hrs (United Nations Scientific Committee on the Effects of Atomic Radiation). The bone marrow dose accumulated was 0.8 Gy, which exceeded the 25 and 16 hour criteria and would pose a serious medical risk. Current spacesuits would not provide shielding from the damaging effects for an SPE as large as the 1972 event, as increased shielding from 1-5 gm/cm(sup 2) would do little to shield the bone marrow from exposure. Medical management options for an acute radiation event are discussed based on recommendations from the Department of Homeland Security, Centers for Disease Control and evidence-based scientific literature. The discussion will also consider how to define acute exposure radiation safety limits with respect to exploration-class missions, and to determine the level of care necessary for a crew that may be exposed to an SPE similar to August 1972.

  9. Psychological symptoms and intermittent hypertension following acute microwave exposure

    SciTech Connect

    Forman, S.A.; Holmes, C.K.; McManamon, T.V.; Wedding, W.R.

    1982-11-01

    Two men who were accidently, acutely irradiated with X-band microwave radiation have been followed up clinically for 12 months. Both men developed similar psychological symptoms, which included emotional lability, irritability, headaches, and insomnia. Several months after the incidents, hypertension was diagnosed in both patients. No organic basis for the psychological problems could be found nor could any secondary cause for the hypertension. A similar syndrome following microwave exposure has been described by the East Europeans. The two cases we report, with comparable subjective symptoms and hypertension following a common exposure, provide further strong, circumstantial evidence of cause and effect. A greater knowledge of the mechanisms involved in bioeffects which may be induced by radiofrequency and microwave radiation is definitely needed.

  10. Responses of Hyalella azteca to acute and chronic microplastic exposures.

    PubMed

    Au, Sarah Y; Bruce, Terri F; Bridges, William C; Klaine, Stephen J

    2015-11-01

    Limited information is available on the presence of microplastics in freshwater systems, and even less is known about the toxicological implications of the exposure of aquatic organisms to plastic particles. The present study was conducted to evaluate the effects of microplastic ingestion on the freshwater amphipod, Hyalella azteca. Hyalella azteca was exposed to fluorescent polyethylene microplastic particles and polypropylene microplastic fibers in individual 250-mL chambers to determine 10-d mortality. In acute bioassays, polypropylene microplastic fibers were significantly more toxic than polyethylene microplastic particles; 10-d lethal concentration 50% values for polyethylene microplastic particles and polypropylene microplastic fibers were 4.64 × 10(4) microplastics/mL and 71.43 microplastics/mL, respectively. A 42-d chronic bioassay using polyethylene microplastic particles was conducted to quantify effects on reproduction, growth, and egestion. Chronic exposure to polyethylene microplastic particles significantly decreased growth and reproduction at the low and intermediate exposure concentrations. During acute exposures to polyethylene microplastic particles, the egestion times did not significantly differ from the egestion of normal food materials in the control; egestion times for polypropylene microplastic fibers were significantly slower than the egestion of food materials in the control. Amphipods exposed to polypropylene microplastic fibers also had significantly less growth. The greater toxicity of microplastic fibers than microplastic particles corresponded with longer residence times for the fibers in the gut. The difference in residence time might have affected the ability to process food, resulting in an energetic effect reflected in sublethal endpoints.

  11. Pediatric Acute Lymphoblastic Leukemia and Exposure to Pesticides

    PubMed Central

    Soldin, Offie P.; Nsouly-Maktabi, Hala; Genkinger, Jeanine M.; Loffredo, Christopher A.; Ortega-Garcia, Juan Antonio; Colantino, Drew; Barr, Dana B.; Luban, Naomi L.; Shad, Aziza T.; Nelson, David

    2013-01-01

    Organophosphates are pesticides ubiquitous in the environment and have been hypothesized as one of the risk factors for acute lymphoblastic leukemia (ALL). In this study, we evaluated the associations of pesticide exposure in a residential environment with the risk for pediatric ALL. This is a case–control study of children newly diagnosed with ALL, and their mothers (n = 41 child–mother pairs) were recruited from Georgetown University Medical Center and Children's National Medical Center in Washington, DC, between January 2005 and January 2008. Cases and controls were matched for age, sex, and county of residence. Environmental exposures were determined by questionnaire and by urinalysis of pesticide metabolites using isotope dilution gas chromatography–high-resolution mass spectrometry. We found that more case mothers (33%) than controls (14%) reported using insecticides in the home (P < 0.02). Other environmental exposures to toxic substances were not significantly associated with the risk of ALL. Pesticide levels were higher in cases than in controls (P < 0.05). Statistically significant differences were found between children with ALL and controls for the organophosphate metabolites diethylthiophosphate (P < 0.03) and diethyldithiophosphate (P < 0.05). The association of ALL risk with pesticide exposure merits further studies to confirm the association. PMID:19571777

  12. Acute neurological symptoms during hypobaric exposure: consider cerebral air embolism.

    PubMed

    Weenink, Robert P; Hollmann, Markus W; van Hulst, Robert A

    2012-11-01

    Cerebral arterial gas embolism (CAGE) is well known as a complication of invasive medical procedures and as a risk in diving and submarine escape. In the underwater environment, CAGE is caused by trapped air, which expands and leads to lung vessel rupture when ambient pressure decreases during ascent. Pressure decrease also occurs during hypobaric activities such as flying and, therefore, CAGE may theoretically be a risk in hypobaric exposure. We reviewed the available literature on this subject. Identified were 12 cases of CAGE due to hypobaric exposure. Based on these cases, we discuss pathophysiology, diagnosis, and treatment of CAGE due to hypobaric exposure. The low and slow pressure decrease during most hypobaric activities (as opposed to diving) account for the low incidence of CAGE during these exposures and suggest that severe air trapping must be present to cause barotrauma. This is also suggested by the large prevalence of air filled cysts in the case reports reviewed. We recommend considering CAGE in all patients presenting with acute central neurological injury during or shortly after pressure decrease such as flying. A CT scan of head and chest should be performed in these patients. Treatment with hyperbaric oxygen therapy should be initiated as soon as possible in cases of proven or probable CAGE.

  13. Pediatric acute lymphoblastic leukemia and exposure to pesticides.

    PubMed

    Soldin, Offie P; Nsouli-Maktabi, Hala; Nsouly-Maktabi, Hala; Genkinger, Jeanine M; Loffredo, Christopher A; Ortega-Garcia, Juan Antonio; Colantino, Drew; Barr, Dana B; Luban, Naomi L; Shad, Aziza T; Nelson, David

    2009-08-01

    Organophosphates are pesticides ubiquitous in the environment and have been hypothesized as one of the risk factors for acute lymphoblastic leukemia (ALL). In this study, we evaluated the associations of pesticide exposure in a residential environment with the risk for pediatric ALL. This is a case-control study of children newly diagnosed with ALL, and their mothers (n = 41 child-mother pairs) recruited from Georgetown University Medical Center and Children's National Medical Center in Washington, DC, between January 2005 and January 2008. Cases and controls were matched for age, sex, and county of residence. Environmental exposures were determined by questionnaire and by urinalysis of pesticide metabolites using isotope dilution gas chromatography-high-resolution mass spectrometry. We found that more case mothers (33%) than controls (14%) reported using insecticides in the home (P < 0.02). Other environmental exposures to toxic substances were not significantly associated with the risk of ALL. Pesticide levels were higher in cases than in controls (P < 0.05). Statistically significant differences were found between children with ALL and controls for the organophosphate metabolites diethylthiophosphate (P < 0.03) and diethyldithiophosphate (P < 0.05). The association of ALL risk with pesticide exposure merits further studies to confirm the association.

  14. Effects of Acute Exposures to Carbon Dioxide upon Cognitive Functions

    NASA Technical Reports Server (NTRS)

    Ryder, V. E.; Scully, R. R.; Alexander, D. J.; Lam, C. W.; Young, M.; Satish, U.; Basner, M.

    2017-01-01

    Carbon dioxide (CO2) originates from human metabolism and typically remains about 10-fold higher in concentration on the International Space Station (ISS) than at the earth's surface. There have been recurring complaints by crew members of episodes of "mental viscosity" adversely affecting their performance, and there is evidence from the ISS that associates CO2 levels with reports of headaches by crewmembers. Consequently, flight rules have been employed to control CO2 below 3 mm Hg, which is well below the existing Spacecraft Maximum Allowable Concentration (SMAC) of 10 mm Hg for 24-hour exposures, and 5.3 mm Hg for exposures of 7 to 180 days. Headaches, while sometime debilitating themselves, are also symptoms that can provide evidence that physiological defense mechanisms have been breached, and there is evidence that CO2 has effects at levels below the threshold for headaches. This concern appears to be substantiated in reports that CO2 at concentrations below 2 mm Hg substantially reduced some cognitive functions that are associated with the ability to make complex decisions in conditions that are characterized by volatility, uncertainty, complexity, ambiguity, and delayed feedback. These are conditions that could be encountered by crews in off-nominal situations or during the first missions beyond low earth orbit. Therefore, we set out to determine if decision-making under volatile, uncertain, confusing and ambiguous circumstances, where feedback is delayed or absent, is correlated with low levels of CO2 during acute exposures (several hours) in crew-like subjects and to determine if additional cognitive domains are sensitive to concentrations of CO2 at, or below, current ISS levels by using a test battery that is currently available onboard ISS. We enrolled 22 volunteers (8 females, 14 males) between the ages of 30-55 (38.8 +/- 7.0) years whose training and professional experience reflect that of the astronaut corps. Subjects were divided among 4 study

  15. Change in childhood lead exposure prevalence with new reference level.

    PubMed

    Leafe, Morgan; Irigoyen, Matilde; DeLago, Cynthia; Hassan, Amman; Braitman, Leonard

    2015-06-01

    In 2012, the Centers for Disease Control and Prevention changed the "actionable" reference blood lead level from 10 μg/dL to 5 μg/dL, representing the highest 2.5 percentile of lead levels nationwide. In a high-risk urban community, the prevalence of children classified as lead exposed increased ninefold, from 1% to 9.1% (p < .0001) with the new reference level. This dramatic increase in the prevalence of children newly classified as lead exposed will require additional health care and public health resources for tracking, surveillance, and home lead abatement.

  16. Inhalation exposure system used for acute and repeated-dose methyl isocyanate exposures of laboratory animals.

    PubMed

    Adkins, B; O'Connor, R W; Dement, J M

    1987-06-01

    Laboratory animals were exposed by inhalation for 2 hr/day (acute) or 6 hr/day (four consecutive days, repeated dose) to methyl isocyanate (MIC). Exposures were conducted in stainless steel and glass inhalation exposure chambers placed in stainless steel, wire mesh cages. MIC was delivered with nitrogen via stainless steel and Teflon supply lines. Chamber concentrations ranged from 0 to 60 ppm and were monitored continuously with infrared spectrophotometers to 1 ppm and at 2-hr intervals to 20 ppb with a high performance liquid chromatograph equipped with a fluorescence detector. Other operational parameters monitored on a continuous basis included chamber temperature (20-27 degrees C), relative humidity (31-64%), static (transmural) pressure (-0.3 in.), and flow (300-500 L/min). The computer-assistance system interfaced with the inhalation exposure laboratory is described in detail, including the analytical instrumentation calibration system used throughout this investigation.

  17. Self-reported acute health symptoms and exposure to companion animals

    EPA Science Inventory

    Background: In order to understand the etiological burden of disease associated with acute health symptoms (e.g. gastrointestinal [GI], respiratory, dermatological), it is important to understand how common exposures influence these symptoms. Exposures to familiar and unfamiliar ...

  18. Study of reference waves in single-exposure generalized phase-shifting digital holography.

    PubMed

    Imbe, Masatoshi; Nomura, Takanori

    2013-06-20

    The appropriate reference wave in single-exposure phase-shifting digital holography using a random-complex-amplitude encoded reference wave is experimentally investigated. Although the reference wave is generalized, the quality of reconstructed images depends on it. Furthermore, when the reference wave satisfies a certain condition, reconstructed images cannot be obtained in this method. After the certain condition is presented, the appropriate condition is studied using a speckle property. Experimental results are given to investigate the relations between the quality of reconstructed images and the sizes of speckles of the reference waves. The results prove that the appropriate reference wave exists in this method.

  19. Effect of acute smoke exposure on hepatic protein synthesis.

    PubMed

    Garrett, R J; Jackson, M A

    1979-05-01

    In vivo hepatic protein synthesis was monitored in female rats under control and smoke-exposed conditions. During the 15 min period after i.v. administration of [3H]proline protein synthesis was 206 +/- 35 nmol of proline per mg of DNA for sham-control animals. When animals were subjected to acute exposure to cigarette smoke, protein synthesis was inhibited and the extent of inhibition was positively correlated with the dosage of smoke (32%, 15 puffs; 66%, 60 puffs). The inhibitory effect of whole smoke on protein synthesis was unaltered by passing the smoke through either charcoal or cambridge filters. Carbon monoxide in smoke is not removed by either type of filter. At a level comparable to that in cigarette smoke carbon monoxide depressed hepatic protein synthesis to the same extent as did whole or filtered smoke.

  20. Dental fractures on acute exposure to high altitude.

    PubMed

    Zadik, Yehuda; Einy, Shmuel; Pokroy, Russell; Bar Dayan, Yaron; Goldstein, Liav

    2006-06-01

    There is little in the literature on dental restoration breakage in the aviation environment since reports of problems in combat aviators in War World II. We report two cases of dental fractures during acute exposure to a hypobaric environment. Case 1 was a young officer who suffered an amalgam restoration breakage during a 25,000-ft decompression chamber simulation. Case 2 occurred in an experienced aviator who had a tooth cusp fracture in a molar with a defective amalgam restoration during an unpressurized helicopter flight to 18,000 ft. In both cases, after removing the defective fillings, deep secondary caries were found; both teeth were successfully restored. Because hard-tissue tooth fracture during a high-altitude flight is a rare event, few flight surgeons or dentists are familiar with this phenomenon. We recommend regular dental examinations with careful assessment of previous dental restorations in aircrew subject to decompression.

  1. Infertility after acute salpingitis with special reference to Chlamydia trachomatis.

    PubMed

    Svensson, L; Mårdh, P A; Weström, L

    1983-09-01

    Of 552 women with laparoscopically verified acute salpingitis (AS), 299 were reviewed 2.5 to 7.5 years later. Cervical secretions from these women had been cultured for the presence of Chlamydia trachomatis and Neisseria gonorrhoeae. For 49 of 82 women with visually normal pelvic organs, such cultures were also performed; these women served as control subjects. In women exposing themselves to pregnancy, 50 (23.3%) of 197 AS patients and 2 (6.7%) of 30 control women were infertile for at least 1 year (P less than 0.02). After one episode of AS, women harboring chlamydiae, gonococci, both, or neither of these microorganisms in the cervix on admission seemed to have the same fertility prognosis. Infertility was correlated with the number of AS episodes, the erythrocyte sedimentation rate (millimeters per hour) at admission, and the severity of the inflammatory reactions of the tubes. The use of oral contraceptives at admission was found to be a positive prognostic factor regarding fertility. Oral contraceptives might protect the patient from severe tubal inflammatory reactions.

  2. Acute health effects of accidental chlorine gas exposure

    PubMed Central

    2014-01-01

    Objectives This study was conducted to report the course of an accidental release of chlorine gas that occurred in a factory in Gumi-si, South Korea, on March 5, 2013. We describe the analysis results of 2 patients hospitalized because of chlorine-induced acute health problems, as well as the clinical features of 209 non-hospitalized patients. Methods We analyzed the medical records of the 2 hospitalized patients admitted to the hospital, as well as the medical records and self-report questionnaires of 209 non-hospitalized patients completed during outpatient treatment. Results Immediately after the exposure, the 2 hospitalized patients developed acute asthma-like symptoms such as cough and dyspnea, and showed restrictive and combined pattern ventilatory defects on the pulmonary function test. The case 1 showed asthma-like symptoms over six months and diurnal variability in peak expiratory flow rate was 56.7%. In case 2, his FEV1 after treatment (93%) increased by 25% compared to initial FEV1 (68%). Both cases were diagnosed as chlorine-induced reactive airways dysfunction syndrome (RADS) on the basis of these clinical features. The most frequent chief complaints of the 209 non-hospitalized patients were headache (22.7%), followed by eye irritation (18.2%), nausea (11.2%), and sore throat (10.8%), with asymptomatic patients accounting for 36.5%. The multiple-response analysis of individual symptom revealed headache (42.4%) to be the most frequent symptom, followed by eye irritation (30.5%), sore throat (30.0%), cough (29.6%), nausea (27.6%), and dizziness (27.3%). Conclusions The 2 patients hospitalized after exposure to chlorine gas at the leakage site showed a clinical course corresponding to RADS. All of the 209 non-hospitalized patients only complained of symptoms of the upper airways and mucous membrane irritation. PMID:25852940

  3. Acute arsenic exposure treated with oral D-penicillamine

    SciTech Connect

    Watson, W.A.; Veltri, J.C.; Metcalf, T.J.

    1981-06-01

    Arsenic trioxide (As2O3) is the arsenic compound most commonly implicated in acute toxic exposures. The toxicity of As2O3 is a function of the preparation's particle size and solubility. A 16-month-old female presented at a local emergency room with a history of acute ingestion of As2O3 obtained from a commonly available pesticide. Classic gastrointestinal symptoms of arsenic toxicity were exhibited shortly after ingestion; however, aggressive decontamination followed by early chelation therapy resulted in the cessation of toxic manifestations and an uneventful recovery. Oral chelation therapy with D-penicillamine has rarely been reported as an effective agent in the treatment of arsenic poisoning. The case reported herein is further documentation that D-penicillamine is effective in increasing the mobilization of arsenic. The authors also recommend that products containing arsenic compounds should not be used where children may come in contact with them until the Environmental Protection Agency's child resistant packaging regulations become effective.

  4. Biomarkers of acute respiratory allergen exposure: Screening for sensitization potential

    SciTech Connect

    Pucheu-Haston, Cherie M.; Copeland, Lisa B.; Vallanat, Beena; Boykin, Elizabeth; Ward, Marsha D.W.

    2010-04-15

    Effective hazard screening will require the development of high-throughput or in vitro assays for the identification of potential sensitizers. The goal of this preliminary study was to identify potential biomarkers that differentiate the response to allergens vs non-allergens following an acute exposure in naive individuals. Female BALB/c mice received a single intratracheal aspiration exposure to Metarhizium anisopliae crude antigen (MACA) or bovine serum albumin (BSA) in Hank's Balanced Salt Solution (HBSS) or HBSS alone. Mice were terminated after 1, 3, 6, 12, 18 and 24 h. Bronchoalveolar lavage fluid (BALF) was evaluated to determine total and differential cellularity, total protein concentration and LDH activity. RNA was isolated from lung tissue for microarray analysis and qRT-PCR. MACA administration induced a rapid increase in BALF neutrophils, lymphocytes, eosinophils and total protein compared to BSA or HBSS. Microarray analysis demonstrated differential expression of genes involved in cytokine production, signaling, inflammatory cell recruitment, adhesion and activation in 3 and 12 h MACA-treated samples compared to BSA or HBSS. Further analyses allowed identification of approx 100 candidate biomarker genes. Eleven genes were selected for further assessment by qRT-PCR. Of these, 6 demonstrated persistently increased expression (Ccl17, Ccl22, Ccl7, Cxcl10, Cxcl2, Saa1), while C3ar1 increased from 6-24 h. In conclusion, a single respiratory exposure of mice to an allergenic mold extract induces an inflammatory response which is distinct in phenotype and gene transcription from the response to a control protein. Further validation of these biomarkers with additional allergens and irritants is needed. These biomarkers may facilitate improvements in screening methods.

  5. Injury to skeletal muscle of mice following acute and sub-acute pregabalin exposure

    PubMed Central

    Moshiri, Mohammad; Moallem, Seyed Adel; Attaranzadeh, Armin; Saberi, Zahra; Etemad, Leila

    2017-01-01

    Objective(s): Pregabalin (PGB) is a new antiepileptic drug that has received FDA approval for patient who suffers from central neuropathic pain, partial seizures, generalized anxiety disorder, fibromyalgia and sleep disorders. This study was undertaken to evaluate the possible adverse effects of PGB on the muscular system of mice. Materials and Methods: To evaluate the effect of PGB on skeletal muscle, the animals were exposed to a single dose of 1, 2 or 5 g /kg or daily doses of 20, 40 or 80 mg/kg for 21 days, intraperitoneally (IP). Twaenty-four hr after the last drug administration, all animals were sacrificed. The level of fast-twitch skeletal muscle troponin I and CK-MM activity were evaluated in blood as an indicator of muscle injury. Skeletal muscle pathological findings were also reported as scores ranging from 1 to 3 based on the observed lesion. Results: In the acute and sub-acute toxicity assay IP injection of PGB significantly increased the activity and levels of CK-MM and fsTnI compared to the control group. Sub-acute exposure to PGB caused damages that include muscle atrophy, infiltration of inflammatory cells and cell degeneration. Conclusion: PGB administration especially in long term care causes muscle atrophy with infiltration of inflammatory cells and cell degeneration. The fsTnI and CK-MM are reliable markers in PGB-related muscle injury. The exact mechanisms behind the muscular damage are unclear and necessitate further investigations. PMID:28392896

  6. Transcriptional Response to Acute Thermal Exposure in Juvenile Chinook Salmon Determined by RNAseq

    PubMed Central

    Tomalty, Katharine M. H.; Meek, Mariah H.; Stephens, Molly R.; Rincón, Gonzalo; Fangue, Nann A.; May, Bernie P.; Baerwald, Melinda R.

    2015-01-01

    Thermal exposure is a serious and growing challenge facing fish species worldwide. Chinook salmon (Oncorhynchus tshawytscha) living in the southern portion of their native range are particularly likely to encounter warmer water due to a confluence of factors. River alterations have increased the likelihood that juveniles will be exposed to warm water temperatures during their freshwater life stage, which can negatively impact survival, growth, and development and pose a threat to dwindling salmon populations. To better understand how acute thermal exposure affects the biology of salmon, we performed a transcriptional analysis of gill tissue from Chinook salmon juveniles reared at 12° and exposed acutely to water temperatures ranging from ideal to potentially lethal (12° to 25°). Reverse-transcribed RNA libraries were sequenced on the Illumina HiSeq2000 platform and a de novo reference transcriptome was created. Differentially expressed transcripts were annotated using Blast2GO and relevant gene clusters were identified. In addition to a high degree of downregulation of a wide range of genes, we found upregulation of genes involved in protein folding/rescue, protein degradation, cell death, oxidative stress, metabolism, inflammation/immunity, transcription/translation, ion transport, cell cycle/growth, cell signaling, cellular trafficking, and structure/cytoskeleton. These results demonstrate the complex multi-modal cellular response to thermal stress in juvenile salmon. PMID:25911227

  7. Acute exposure to acid fog. Effects on mucociliary clearance

    SciTech Connect

    Laube, B.L.; Bowes, S.M. III; Links, J.M.; Thomas, K.K.; Frank, R. )

    1993-05-01

    Submicrometric sulfuric acid (H2SO4) aerosol can affect mucociliary clearance without eliciting irritative symptoms or changes in pulmonary function. The effect of larger fog droplets containing H2SO4 on mucociliary clearance is unknown. We quantified mucociliary clearance from the trachea (n = 4) and small airways (n = 7) of young healthy male adults after an acute exposure to H2SO4 fog (MMAD = 10.3 microns; pH = 2.0; liquid water content = 481 +/- 65 mg/m3; osmolarity = 30 mOsm). Acid fog (AF) or saline fog (SF) (10.9 microns; 492 +/- 116 mg/m3; 30 mOsm) was administered for 40 min of unencumbered breathing (no mouth-piece) at rest and for 20 min of exercise sufficient to produce oronasal breathing. Fog exposures were followed by a methacholine (MCh) challenge (a measure of airway reactivity) or inhalation of technetium-99M radioaerosol (MMAD = 3.4 microns) on 2 study days each. Changes in symptoms and forced ventilatory function were also assessed. Clearance was quantified from computer-assisted analyses of gamma camera images of the lower respiratory tract in terms of %removal/min of the radiolabel from the trachea 25 min after inhalation and from the outer zone of the right lung after 1.9 to 3 h. Symptoms, forced ventilatory function, and MCh response were unaffected by either fog. Tracheal clearance was more rapid in four of four subjects after AF (0.83 +/- 1.58% removal/min) compared with that after SF (-0.54 +/- 0.85% removal/min). Outer zone clearance was more rapid in six of seven subjects after AF (0.22 +/- 0.15% removal/min) compared with that after SF (0.01 +/- 0.09% removal/min).

  8. Quantitative Evaluation and Selection of Reference Genes for Quantitative RT-PCR in Mouse Acute Pancreatitis

    PubMed Central

    Yan, Zhaoping; Gao, Jinhang; Lv, Xiuhe; Yang, Wenjuan; Wen, Shilei; Tong, Huan; Tang, Chengwei

    2016-01-01

    The analysis of differences in gene expression is dependent on normalization using reference genes. However, the expression of many of these reference genes, as evaluated by quantitative RT-PCR, is upregulated in acute pancreatitis, so they cannot be used as the standard for gene expression in this condition. For this reason, we sought to identify a stable reference gene, or a suitable combination, for expression analysis in acute pancreatitis. The expression stability of 10 reference genes (ACTB, GAPDH, 18sRNA, TUBB, B2M, HPRT1, UBC, YWHAZ, EF-1α, and RPL-13A) was analyzed using geNorm, NormFinder, and BestKeeper software and evaluated according to variations in the raw Ct values. These reference genes were evaluated using a comprehensive method, which ranked the expression stability of these genes as follows (from most stable to least stable): RPL-13A, YWHAZ > HPRT1 > GAPDH > UBC > EF-1α > 18sRNA > B2M > TUBB > ACTB. RPL-13A was the most suitable reference gene, and the combination of RPL-13A and YWHAZ was the most stable group of reference genes in our experiments. The expression levels of ACTB, TUBB, and B2M were found to be significantly upregulated during acute pancreatitis, whereas the expression level of 18sRNA was downregulated. Thus, we recommend the use of RPL-13A or a combination of RPL-13A and YWHAZ for normalization in qRT-PCR analyses of gene expression in mouse models of acute pancreatitis. PMID:27069927

  9. Acute generalized weakness in patients referred to Amirkola Children’s Hospital from 2005 to 2010

    PubMed Central

    Salehiomran, Mohammad Reza; Naserkhaki, Somayeh; Hajiahmadi, Mahmoud

    2012-01-01

    Background: Diseases that cause acute flaccid paralysis (AFP) often progress rapidly, thus may cause life threatening complications, therefore, their diagnosis and cure are important. This study was carried out to investigate the causes of acute generalized weakness in children referred to Amirkola Children’s Hospital, in Babol, Iran. Methods: In this case series, the epidemiological causes of the disease and clinical features of 15 cases with acute generalized weakness from April 2005 to September 2010 were evaluated. The data were collected and analyzed. Results: The mean age of cases was 4.7±3.5 years. The male/female ratio was 2. Twenty cases had Guillain-Barre syndrome, two with myositis and one with periodic hyperkalemic paralysis. Conclusion: Guillain-Barre syndrome is the most common cause of AFP in children admitted due to acute generalized weakness in Amirkola Children’s Hospital. PMID:24358438

  10. Acute effects of exposure to 56Fe and 16O particles on learning and memory

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although it has been shown that exposure to HZE particles disrupts cognitive performance when tested 2-4 weeks after irradiation, it has not been determined whether exposure to HZE particles can exert acute effects on cognitive performance; i.e., effects within 4-48 hrs after exposure. The present ...

  11. Exhaled nitric oxide concentration upon acute exposure to moderate altitude.

    PubMed

    Caspersen, C; Stang, J; Thorsen, E; Stensrud, T

    2013-03-01

    The purpose of this study was to assess immediate changes in the partial pressure of nitric oxide (NO) in exhaled gas (PE NO ) in healthy trained subjects who were acutely exposed to moderate altitude. One group of nine and another group of 20 healthy subjects were exposed to an ambient pressure of 728 hPa (546 mmHg) corresponding to an altitude of 2800 m for 5 and 90 min, respectively, in an altitude chamber. PE NO was measured offline by sampling exhaled gas in tight metal foil bags at 5, 30, 60, and 90 min. A correction for increased expiratory flow rate due to gas density effects at altitude was performed (PE NO corr). PE NO was significantly decreased by 13-16%, while the fraction of NO in exhaled gas (FE NO) was increased by 16-19% compared to sea level. There was no significant change in PE NO corr after exposure to altitude for 5, 30, 60, and 90 min. We conclude that there was no change in PENO upon arrival at altitude after correcting for gas density effects on expiratory flow rate. Corrections for altitude effects must be done before comparing measurements performed at different altitudes when using measurements of FENO to monitor athletes who have asthma during training at altitude.

  12. Trace element reference intervals in the blood of healthy green sea turtles to evaluate exposure of coastal populations.

    PubMed

    Villa, C A; Flint, M; Bell, I; Hof, C; Limpus, C J; Gaus, C

    2017-01-01

    Exposure to essential and non-essential elements may be elevated for green sea turtles (Chelonia mydas) that forage close to shore. Biomonitoring of trace elements in turtle blood can identify temporal trends over repeated sampling events, but any interpretation of potential health risks due to an elevated exposure first requires a comparison against a baseline. This study aims to use clinical reference interval (RI) methods to produce exposure baseline limits for essential and non-essential elements (Na, Mg, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Mo, Cd, Sb, Ba, and Pb) using blood from healthy subadult turtles foraging in a remote and offshore part of the Great Barrier Reef. Subsequent blood biomonitoring of three additional coastal populations, which forage in areas dominated by agricultural, urban and military activities, showed clear habitat-specific differences in blood metal profiles relative to the those observed in the offshore population. Coastal turtles were most often found to have elevated concentrations of Co, Mo, Mn, Mg, Na, As, Sb, and Pb relative to the corresponding RIs. In particular, blood from turtles from the agricultural site had Co concentrations ranging from 160 to 840 μg/L (4-25 times above RI), which are within the order expected to elicit acute effects in many vertebrates. Additional clinical blood biochemistry and haematology results indicate signs of a systemic disease and the prevalence of an active inflammatory response in a high proportion (44%) of turtles from the agricultural site. Elevated Co, Sb, and Mn in the blood of these turtles significantly correlated with elevated markers of acute inflammation (total white cell counts) and liver dysfunction (alkaline phosphatase and total bilirubin). The results of this study support the notion that elevated trace element exposures may be adversely affecting the health of nearshore green sea turtles.

  13. On the performance of acute toxicity tests using the National Reference Toxicant Database

    SciTech Connect

    Zaidhk, B.

    1995-12-31

    The US National Reference Toxicant Database was used to compile data from 158 Ceriodaphnia dubia, and 187 fathead minnow acute toxicity tests. The data are analyzed using the EPA flow-chart for acute toxicity tests to determine the distribution of test methods selected. The data are reanalyzed using maximum likelihood estimation assuming probit, logit and Gompertz tolerance distributions and non-parametrically using the Spearman-Karber method with and without trimming. The results of these analyses are compared with respect to mean square error for the parametric methods and confidence intervals for the point estimate for all analyses.

  14. Occupational exposure to electromagnetic fields and acute leukaemia: analysis of a case-control study

    PubMed Central

    Willett, E; McKinney, P; Fear, N; Cartwright, R; Roman, E

    2003-01-01

    Aims: To investigate whether the risk of acute leukaemia among adults is associated with occupational exposure to electromagnetic fields. Methods: Probable occupational exposure to electromagnetic fields at higher than typical residential levels was investigated among 764 patients diagnosed with acute leukaemia during 1991–96 and 1510 sex and age matched controls. A job exposure matrix was applied to the self reported employment histories to determine whether or not a subject was exposed to electromagnetic fields. Risks were assessed using conditional logistic regression for a matched analysis. Results: Study subjects considered probably ever exposed to electromagnetic fields at work were not at increased risk of acute leukaemia compared to those considered never exposed. Generally, no associations were observed on stratification by sex, leukaemia subtype, number of years since exposure stopped, or occupation; there was no evidence of a dose-response effect using increasing number of years exposed. However, relative to women considered never exposed, a significant excess of acute lymphoblastic leukaemia was observed among women probably exposed to electromagnetic fields at work that remained increased irrespective of time prior to diagnosis or job ever held. Conclusion: This large population based case-control study found little evidence to support an association between occupational exposure to electromagnetic fields and acute leukaemia. While an excess of acute lymphoblastic leukaemia among women was observed, it is unlikely that occupational exposure to electromagnetic fields was responsible, given that increased risks remained during periods when exposure above background levels was improbable. PMID:12883018

  15. ESTIMATED RATE OF FATAL AUTOMOBILE ACCIDENTS ATTRIBUTABLE TO ACUTE SOLVENT EXPOSURE AT LOW INHALED CONCENTRATIONS

    EPA Science Inventory

    Acute solvent exposures may contribute to automobile accidents because they increase reaction time and decrease attention, in addition to impairing other behaviors. These effects resemble those of ethanol consumption, both with respect to behavioral effects and neurological mecha...

  16. Estrogen Effects after a Crush Muscle Injury and Acute Exposure to Hypobaric Hypoxia

    DTIC Science & Technology

    2015-03-01

    AFRL-SA-WP-TR-2015-0007 Estrogen Effects after a Crush Muscle Injury and Acute Exposure to Hypobaric Hypoxia Dr. Barbara St...after a Crush Muscle Injury and Acute Exposure to Hypobaric Hypoxia 5a. CONTRACT NUMBER FA7014-10-2-0001 5b. GRANT NUMBER 5c. PROGRAM...pressure equivalent to an altitude of 8,000 feet , which is considered high altitude, and lacks abundant supplemental oxygen systems, en route care

  17. Single-exposure phase-shifting digital holography using a random-phase reference wave.

    PubMed

    Nomura, Takanori; Imbe, Masatoshi

    2010-07-01

    We propose a single-exposure phase-shifting digital holography based on a wave-splitting method using a random-phase reference wave. A random-phase reference wave gives random-phase distribution on the digital hologram. Using the amplitude and the phase distributions of the reference wave, the fully complex amplitude of the object wave is obtained. The proposed method requires not devised optical systems but ordinary imaging devices, such as CCD cameras. A preliminary experimental result is given to confirm the proposed method.

  18. Comparison of Acute Health Effects From Exposures to Diesel and Biodiesel Fuel Emissions

    PubMed Central

    Mehus, Aaron A.; Reed, Rustin J.; Lee, Vivien S. T.; Littau, Sally R.; Hu, Chengcheng; Lutz, Eric A.

    2015-01-01

    Objective: To investigate the comparative acute health effects associated with exposures to diesel and 75% biodiesel/25% diesel (B75) blend fuel emissions. Methods: We analyzed multiple health endpoints in 48 healthy adults before and after exposures to diesel and B75 emissions in an underground mine setting—lung function, lung and systemic inflammation, novel biomarkers of exposure, and oxidative stress were assessed. Results: B75 reduced respirable diesel particulate matter by 20%. Lung function declined significantly more after exposure to diesel emissions. Lung inflammatory cells along with sputum and plasma inflammatory mediators increased significantly to similar levels with both exposures. Urinary 8-hydroxydeoxyguanosine, a marker of oxidative stress, was not significantly changed after either exposure. Conclusions: Use of B75 lowered respirable diesel particulate matter exposure and some associated acute health effects, although lung and systemic inflammation were not reduced compared with diesel use. PMID:26147538

  19. REFERENCE VALUES FOR FISH EXPOSURE TO PAH CONTAMINANTS: COMPARISON OF OHIO AND THE MID-ATLANTIC REGION

    EPA Science Inventory

    Reference values for exposure of wildlife to contaminants are needed to cost effectively determine if a site is contaminated and to rank sites that are above background levels. Epidemiological techniques originally developed for clinical chemistry and for determining exposures t...

  20. ACUTE EXPOSURE TO MOLINATE ALTERS NEUROENDOCRINE CONTROL OF OVULATION IN THE RAT

    EPA Science Inventory

    Molinate, a thiocarbamate herbicide, has been shown previously to impair reproductive capability in the male rat. In a two-generation study, molinate exposure to female rats resulted in altered pregnancy outcome. However, published data is lacking on the effects of acute exposure...

  1. AGE-RELATED TOXICITY PATHWAY ANALYSIS IN BROWN NORWAY RAT BRAIN FOLLOWING ACUTE TOLUENE EXPOSURE

    EPA Science Inventory

    The influence of aging on susceptibility to environmental exposures is poorly understood. To investigate-the contribution of different life stages on response to toxicants, we examined the effects of an acute exposure to the volatile organic compound, toluene (0.0 or 1.0 g/kg), i...

  2. ASSESSING THE IMPORTANCE OF THE BEHAVIORAL EFFECT OF ACUTE EXPOSURE TO TOLUENE IN HUMANS.

    EPA Science Inventory

    There is increasing interest in being able to evaluate potential benefit-cost relationships of controlling exposure to toxic substances. Behavioral effects of acute toluene exposure could be subjected to benefit-cost analysis if it's effects were quantitatively compared to tho...

  3. Effects of acute electromagnetic fields exposure on the interhemispheric homotopic functional connectivity during resting state.

    PubMed

    Lv, Bin; Shao, Qing; Chen, Zhiye; Ma, Lin; Wu, Tongning

    2015-08-01

    In this paper, we aimed to investigate the possible effects of acute radiofrequency electromagnetic fields (EMF) on the interhemispheric homotopic functional connectivity with resting state functional magnetic resonance imaging (fMRI) technique. We designed a controllable LTE-related EMF exposure environment at 2.573 GHz and performed the 30 min real/sham exposure experiments on human brain under the safety limits. The resting state fMRI signals were collected before and after EMF exposure. Then voxel-mirrored homotopic connectivity method was utilized to evaluate the acute effects of LTE EMF exposure on the homotopic functional connectivity between two human hemispheres. Based on our previous research, we further demonstrated that the 30 min short-term LTE EMF exposure would modulate the interhemispheric homotopic functional connectivity in resting state around the medial frontal gyrus and the paracentral lobule during the real exposure.

  4. Laboratory facility to create reference radon + thoron atmosphere under dynamic exposure conditions.

    PubMed

    Pressyanov, D; Mitev, K; Georgiev, S; Dimitrova, I; Kolev, J

    2017-01-01

    Radon ((222)Rn) and thoron ((220)Rn) levels in the environment are typically subject to significant random and systematic variations. Creation in the laboratory of reproducible and controlled exposure conditions close to that in the real environment can be useful for testing (222)Rn and (220)Rn detectors and for research. In this report the design and performance of a novel laboratory facility with such functionality is presented. The facility allows the exposure of detectors under controlled dynamic as well as static activity concentrations of (222)Rn and (220)Rn (pure and mixed) and temperature. The temperature is measured and regulated within -15 °C ÷ +60 °C by a dedicated programmable thermostat. Different reference activity concentrations in the exposure vessel are made by regulating the flow-rate of the air that flushes (222)Rn/(220)Rn activity from the sources towards the exposure vessel. Reference atmospheres that contain (222)Rn, (220)Rn or a specified ratio of the two can be created. Pilot experiments that demonstrate the feasibility of the approach are presented. They include follow-up of a pre-defined temperature profile (in the range -5 °C ÷ +35 °C), test of the correspondence between planned and measured (222)Rn and (220)Rn activity concentrations, follow-up of a pre-defined dynamic profile of (220)Rn concentrations and test of the possibility to create mixed (220)Rn/(222)Rn atmospheres (experimentally checked for ratio of the activity concentrations from 0.27 to 4.5). The results from the experimental tests are in agreement with the values obtained by the developed theoretical model. The proposed approach can be used to plan and create stationary and dynamic reference exposure conditions that are close to the real exposure regimes in the environment.

  5. Simulation of acute reference dose (ARfD) settings for pesticides in Japan.

    PubMed

    Yoshida, Midori; Suzuki, Daisetsu; Matsumoto, Kiyoshi; Shirota, Mariko; Inoue, Kaoru; Takahashi, Miwa; Morita, Takeshi; Ono, Atsushi

    2013-01-01

    In order to develop guidelines for setting acute reference doses (ARfDs) for pesticides in Japan, we conducted simulations of ARfD settings based on evaluation reports for 201 pesticides assessed by the Food Safety Commission (FSC) in Japan over the last 8 years. Our conceptual principles were based on the concepts written by Solecki et al. (2005) and were adapted for toxicological data required in Japan. Through this process, we were able to set the ARfDs for over 90% of the 201 pesticides tested. The studies that provided the rationale for ARfD setting were primarily reproductive and developmental toxicity studies, acute neurotoxicity studies, and pharmacology studies. For approximately 30% of the pesticides simulated in the present study, it was not necessary to establish ARfDs. Some of the simulated ARfDs resulting from their endpoints may be conservative estimates, because the evaluation reports were written for acceptable daily intake settings. Thus, it was sometimes difficult to distinguish acute toxic alerts from repeated toxicities. We were unable to set an ARfD for 14 pesticides because of insufficient data on acute toxicities. This could be improved by more complete recordkeeping. Furthermore, we categorized the 201 pesticides by mechanism of action or chemical structure. Our simulation indicates that the conceptual framework presented here can be used as a basis for the development of guidelines on ARfD settings for pesticides in Japan.

  6. Health status of copper refinery workers with specific reference to selenium exposure

    SciTech Connect

    Holness, D.L.; Taraschuk, I.G.; Nethercott, J.R. )

    1989-09-01

    Copper refinery workers exposed to selenium were studied before, during, and after a shutdown period. Urine selenium levels were 83 {plus minus} 30 mumol/mol creatinine and 69 {plus minus} 27 mumol/mol creatinine when measured on two occasions during exposure compared with 56 {plus minus} 17 mumol/mol creatinine when the workers had been free of exposure for 10 wk during a shutdown. The refinery workers reported more nose and eye irritation, indigestion, stomach pain, and fatigue than controls. Garlic-like breath odor was reported to be personally and socially offensive by many of the workers. Reporting of symptoms, pulmonary function indices, and laboratory test results did not change with exposure except for hemoglobin level, which rose during the shutdown. Hemoglobin levels were found to be inversely correlated with the urine selenium level, and there was a positive correlation noted for the interactive effect of urine selenium and urine arsenic levels on hemoglobin.49 references.

  7. Acute Neuroactive Drug Exposures alter Locomotor Activity in Larval Zebrafish

    EPA Science Inventory

    As part of the development of a rapid in vivo screen for prioritization of toxic chemicals, we have begun to characterize the locomotor activity of zebrafish (Danio rerio) larvae by assessing the acute effects of prototypic drugs that act on the central nervous system. Initially,...

  8. A novel antibody-based biomarker for chronic algal toxin exposure and sub-acute neurotoxicity

    USGS Publications Warehouse

    Lefebvre, Kathi A.; Frame, Elizabeth R.; Gulland, Frances; Hansen, John D.; Kendrick, Preston S.; Beyer, Richard P.; Bammler, Theo K.; Farin, Frederico M.; Hiolski, Emma M.; Smith, Donald R.; Marcinek, David J.

    2012-01-01

    The neurotoxic amino acid, domoic acid (DA), is naturally produced by marine phytoplankton and presents a significant threat to the health of marine mammals, seabirds and humans via transfer of the toxin through the foodweb. In humans, acute exposure causes a neurotoxic illness known as amnesic shellfish poisoning characterized by seizures, memory loss, coma and death. Regular monitoring for high DA levels in edible shellfish tissues has been effective in protecting human consumers from acute DA exposure. However, chronic low-level DA exposure remains a concern, particularly in coastal and tribal communities that subsistence harvest shellfish known to contain low levels of the toxin. Domoic acid exposure via consumption of planktivorous fish also has a profound health impact on California sea lions (Zalophus californianus) affecting hundreds of animals yearly. Due to increasing algal toxin exposure threats globally, there is a critical need for reliable diagnostic tests for assessing chronic DA exposure in humans and wildlife. Here we report the discovery of a novel DA-specific antibody response that is a signature of chronic low-level exposure identified initially in a zebrafish exposure model and confirmed in naturally exposed wild sea lions. Additionally, we found that chronic exposure in zebrafish caused increased neurologic sensitivity to DA, revealing that repetitive exposure to DA well below the threshold for acute behavioral toxicity has underlying neurotoxic consequences. The discovery that chronic exposure to low levels of a small, water-soluble single amino acid triggers a detectable antibody response is surprising and has profound implications for the development of diagnostic tests for exposure to other pervasive environmental toxins.

  9. A Novel Antibody-Based Biomarker for Chronic Algal Toxin Exposure and Sub-Acute Neurotoxicity

    PubMed Central

    Lefebvre, Kathi A.; Frame, Elizabeth R.; Gulland, Frances; Hansen, John D.; Kendrick, Preston S.; Beyer, Richard P.; Bammler, Theo K.; Farin, Frederico M.; Hiolski, Emma M.; Smith, Donald R.; Marcinek, David J.

    2012-01-01

    The neurotoxic amino acid, domoic acid (DA), is naturally produced by marine phytoplankton and presents a significant threat to the health of marine mammals, seabirds and humans via transfer of the toxin through the foodweb. In humans, acute exposure causes a neurotoxic illness known as amnesic shellfish poisoning characterized by seizures, memory loss, coma and death. Regular monitoring for high DA levels in edible shellfish tissues has been effective in protecting human consumers from acute DA exposure. However, chronic low-level DA exposure remains a concern, particularly in coastal and tribal communities that subsistence harvest shellfish known to contain low levels of the toxin. Domoic acid exposure via consumption of planktivorous fish also has a profound health impact on California sea lions (Zalophus californianus) affecting hundreds of animals yearly. Due to increasing algal toxin exposure threats globally, there is a critical need for reliable diagnostic tests for assessing chronic DA exposure in humans and wildlife. Here we report the discovery of a novel DA-specific antibody response that is a signature of chronic low-level exposure identified initially in a zebrafish exposure model and confirmed in naturally exposed wild sea lions. Additionally, we found that chronic exposure in zebrafish caused increased neurologic sensitivity to DA, revealing that repetitive exposure to DA well below the threshold for acute behavioral toxicity has underlying neurotoxic consequences. The discovery that chronic exposure to low levels of a small, water-soluble single amino acid triggers a detectable antibody response is surprising and has profound implications for the development of diagnostic tests for exposure to other pervasive environmental toxins. PMID:22567140

  10. Behavioral and neurochemical changes in response to acute stressors: influence of previous chronic exposure to immobilization.

    PubMed

    Pol, O; Campmany, L; Gil, M; Armario, A

    1992-07-01

    The effect of daily (2 h) exposure to immobilization (IMO) for 15 days on the behavioral and neurochemical responses of adult male rats to acute stress caused by 2-h IMO or 2-h tail-shock was studied. The brain areas studied were frontal cortex, hippocampus, hypothalamus, midbrain, and pons plus medulla. Chronic exposure to IMO did not alter noradrenaline (NA), 3-methoxy,4-hydroxyphenyletileneglycol-SO4 (MHPG-SO4), serotonin, or 5-hydroxindoleacetic acid (5-HIAA) concentrations in any brain area as measured approximately 20 h after the last exposure to IMO. Exposure to behavioral tests did not modify neurochemical variables except NA levels in the hypothalamus of nonchronically stressed (control) rats. Both exposure to 2-h IMO or 2-h shock significantly decreased NA levels in hypothalamus and midbrain of nonchronically stressed rats. These decreases in response to the two acute stressors were not observed in chronically stressed rats. However, MHPG-SO4 levels increased to the same extent in control and chronically stressed rats after exposure to the acute stressors. Likewise, increased 5-HIAA concentrations observed in response to acute stressors were similar in control and chronically stressed rats. The inhibition of activity (areas crossed and rearing) in the holeboard caused by acute IMO was less marked in rats previously exposed to the same stressor than in control rats, but the response to shock was similar. In the forced swim test, acute IMO decreased struggling in control rats but tended to increase it in chronically stressed rats. The response to shock followed the same pattern as that to IMO, although it was slight.(ABSTRACT TRUNCATED AT 250 WORDS)

  11. Consequences of acute and chronic exposure to arsenic in children.

    PubMed

    Calderon, Rebecca L; Abernathy, Charles O; Thomas, David J

    2004-07-01

    Arsenic is a toxic chemical and may cause adverse health effects in children and adults. It is known to affect the nervous, gastrointestinal, and hematological systems and cause skin and internal cancers in people exposed to levels greater than 300 ppb in their drinking water. For most people, the major exposure to arsenic comes from food (8 to 14 microg inorganic arsenic per day), but when the arsenic level in water is elevated, drinking water becomes the predominant source of exposure. Because it is very difficult to limit arsenic exposure from food, it would be wise to limit arsenic exposure from those more controllable sources. Pediatricians should ascertain the levels of arsenic in drinking water of patients with high arsenic levels, using the supplier or, in the case of private wells, a professional water-testing laboratory assay. The Safe Drinking Water Act does not cover private wells or those water systems with less than 15 hook-ups or those that serve less than 25 people. Pediatricians should instruct parents to use prepared baby formulas or prepare them using water with the arsenic removed and to curtail playing time for younger children in places that have sand containing large amounts of arsenic. Such procedures will limit arsenic exposure to a minimum.

  12. Prenatal cortisol exposure predicts infant cortisol response to acute stress.

    PubMed

    O'Connor, Thomas G; Bergman, Kristin; Sarkar, Pampa; Glover, Vivette

    2013-03-01

    Experimental animal findings suggest that early stress and glucocorticoid exposure may program the function of the hypothalamic-pituitary-adrenal (HPA) axis in the offspring. The extension of these findings to human development is not yet clear. A prospective longitudinal study was conducted on 125 mothers and their normally developing children. Amniotic fluid was obtained at, on average, 17.2 weeks gestation; infant behavior and cortisol response to a separation-reunion stress was assessed at 17 months. Amniotic fluid cortisol predicted infant cortisol response to separation-reunion stress: infants who were exposed to higher levels of cortisol in utero showed higher pre-stress cortisol values and blunted response to stress exposure. The association was independent of prenatal, obstetric, and socioeconomic factors and child-parent attachment. The findings provide some of the strongest data in humans that HPA axis functioning in the child may be predicted from prenatal cortisol exposure.

  13. Acute and chronic respiratory effects of occupational exposure to ammonia.

    PubMed

    Holness, D L; Purdham, J T; Nethercott, J R

    1989-12-01

    In a soda ash plant, 58 workers exposed to mean airborne ammonia levels of 9.2 +/- 1.4 ppm were compared with 31 control workers with a mean exposure of 0.3 +/- 0.1 ppm. There were no differences between the groups in the reporting of respiratory or cutaneous symptoms, sense of smell, baseline lung function, or change in lung function over a work shift at the beginning and end of a workweek. No relationships between level or length of ammonia exposure and lung function results were demonstrated.

  14. Acute and chronic dietary exposure to domoic acid in recreational harvesters: A survey of shellfish consumption behavior.

    PubMed

    Ferriss, Bridget E; Marcinek, David J; Ayres, Daniel; Borchert, Jerry; Lefebvre, Kathi A

    2017-04-01

    Domoic acid (DA) is a neurotoxin that is naturally produced by phytoplankton and accumulates in seafood during harmful algal blooms. As the prevalence of DA increases in the marine environment, there is a critical need to identify seafood consumers at risk of DA poisoning. DA exposure was estimated in recreational razor clam (Siliqua patula) harvesters to determine if exposures above current regulatory guidelines occur and/or if harvesters are chronically exposed to low levels of DA. Human consumption rates of razor clams were determined by distributing 1523 surveys to recreational razor clam harvesters in spring 2015 and winter 2016, in Washington, USA. These consumption rate data were combined with DA measurements in razor clams, collected by a state monitoring program, to estimate human DA exposure. Approximately 7% of total acute exposures calculated (including the same individuals at different times) exceeded the current regulatory reference dose (0.075mgDA·kgbodyweight(-1)·d(-1)) due to higher than previously reported consumption rates, lower bodyweights, and/or by consumption of clams at the upper range of legal DA levels (maximum 20mg·kg(-1) wet weight for whole tissue). Three percent of survey respondents were potentially at risk of chronic DA exposure by consuming a minimum of 15 clams per month for at 12 consecutive months. These insights into DA consumption will provide an additional tool for razor clam fishery management.

  15. Toxicogenomic identification of biomarkers of acute respiratory exposure sensitizing agents

    EPA Science Inventory

    Allergy induction requires multiple exposures to an agent. Therefore the development of high-throughput or in vitro assays for effective screening of potential sensitizers will require the identification of biomarkers. The goal of this preliminary study was to identify potential ...

  16. Acute Exposure to Particulate Matter (PM) Alters Physiologic ...

    EPA Pesticide Factsheets

    Human exposure to ambient PM from fossil-fuel emissions is linked to cardiovascular disease and death. This association strengthens in people with preexisting cardiopulmonary diseases—especially heart failure (HF). We previously examined the effects of PM on HF by exposing Spontaneously Hypertensive Heart Failure (SHHF) rats to residual oil fly ash (ROFA) after accelerating HF onset via isoproterenol (ISO) infusion. In that study, rats were exposed to PM 2 wks after ISO treatment ceased, which was more than 1 wk after ISO-cessation had induced a 9-d period of hypotension. Epidemiological evidence suggests that effects would be more pronounced if exposure coincided with the HF-like hypotensive period. We hypothesized that PM exposure shortly after cessation of ISO treatment would cause greater cardiopulmonary injury. SHHF rats were infused with ISO (n=24; 1.0 mg/kg/d sc) or saline (n=23) via osmotic pump for 5 wks and then 5 d later exposed by nose-only inhalation for 4 h to either air or 580 µg/m3 of the PM2.5 fraction of a synthetic PM (dried salt solution, MSO4) similar in composition to a well-studied ROFA and consisting of Fe, Ni and V sulfates. In ISO-pretreated rats only, MSO4 decreased pulse pressure (an indirect indicator of cardiac output), decreased systolic and diastolic blood pressures, and increased QA interval (inversely related to myocardial contractility) during inhalation exposure and caused post-inhalation pulmonary inflammation significantl

  17. Acute neuroactive drug exposures alter locomotor activity in larval zebrafish

    EPA Science Inventory

    In an effort to develop a rapid in vivo screen for EPA's prioritization of toxic chemicals, we are characterizing the locomotor activity of zebrafish (Danio rerio) larvae after exposure to prototypic drugs that act on the central nervous system. MPTP (1-methyl-4phenyl- 1 ,2,3,6-...

  18. Mathematical Models of Human Hematopoiesis Following Acute Radiation Exposure

    DTIC Science & Technology

    2014-05-01

    thermochemical) 1.054 350 × 103 joule (J) foot-pound-force (ft lbf) 1.355 818 joule (J) calorie (cal) (thermochemical) 4.184 joule (J) Pressure...approaches zero , τ2I approaches (1 − δmax/2δ0)/δmax = τ2I,min. Thus, the total MK transit time approaches τ2I,min + τ2M = (τmin − τ0/2) + τ0/2 = τmin...Treatment of victims at the zero -energy reactor accident in Vinca,” Diagnosis and Treatment of Acute Radiation Injury: Proceedings of a Scientific Meet

  19. Chronic and Acute Effects of Coal Tar Pitch Exposure and Cardiopulmonary Mortality Among Aluminum Smelter Workers

    PubMed Central

    Friesen, Melissa C.; Demers, Paul A.; Spinelli, John J.; Eisen, Ellen A.; Lorenzi, Maria F.; Le, Nhu D.

    2010-01-01

    Air pollution causes several adverse cardiovascular and respiratory effects. In occupational studies, where levels of particulate matter and polycyclic aromatic hydrocarbons (PAHs) are higher, the evidence is inconsistent. The effects of acute and chronic PAH exposure on cardiopulmonary mortality were examined within a Kitimat, Canada, aluminum smelter cohort (n = 7,026) linked to a national mortality database (1957–1999). No standardized mortality ratio was significantly elevated compared with the province's population. Smoking-adjusted internal comparisons were conducted using Cox regression for male subjects (n = 6,423). Ischemic heart disease (IHD) mortality (n = 281) was associated with cumulative benzo[a]pyrene (B(a)P) exposure (hazard ratio = 1.62, 95% confidence interval: 1.06, 2.46) in the highest category. A monotonic but nonsignificant trend was observed with chronic B(a)P exposure and acute myocardial infarction (n = 184). When follow-up was restricted to active employment, the hazard ratio for IHD was 2.39 (95% confidence interval: 0.95, 6.05) in the highest cumulative B(a)P category. The stronger associations observed during employment suggest that risk may not persist after exposure cessation. No associations with recent or current exposure were observed. IHD was associated with chronic (but not current) PAH exposure in a high-exposure occupational setting. Given the widespread workplace exposure to PAHs and heart disease's high prevalence, even modest associations produce a high burden. PMID:20702507

  20. Cardiac Autonomic Effects of Acute Exposures to Airborne Particulates in Men and Women

    NASA Technical Reports Server (NTRS)

    Howarth, M. S.; Schlegel, T. T.; Knapp, C. F.; Patwardhan, A. R.; Jenkins, R. A.; Ilgner, R. H.; Evans, J. M.

    2007-01-01

    The aim of this research was to investigate cardiac autonomic changes associated with acute exposures to airborne particulates. Methods: High fidelity 12-lead ECG (CardioSoft, Houston, TX) was acquired from 19 (10 male / 9 female) non-smoking volunteers (age 33.6 +/- 6.6 yrs) during 10 minutes pre-exposure, exposure and post-exposure to environmental tobacco smoke (ETS), cooking oil fumes, wood smoke and sham (water vapor). To control exposure levels, noise, subject activity, and temperature, all studies were conducted inside an environmental chamber. Results: The short-term fractal scaling exponent (Alpha-1) and the ratio of low frequency to high frequency Heart Rate Variability (HRV) powers (LF/HF, a purported sympathetic index) were both higher in males (p<0.017 and p<0.05, respectively) whereas approximate entropy (ApEn) and HF/(LF+HF) (a purported parasympathetic index) were both lower in males (p<0.036, and p<0.044, respectively). Compared to pre-exposure (p<0.0002) and sham exposure (p<0.047), male heart rates were elevated during early ETS post-exposure. Our data suggest that, in addition to tonic HRV gender differences, cardiac responses to some acute airborne particulates are gender related.

  1. Acute Air Pollution Exposure and Risk of Suicide Completion

    PubMed Central

    Bakian, Amanda V.; Huber, Rebekah S.; Coon, Hilary; Gray, Douglas; Wilson, Phillip; McMahon, William M.; Renshaw, Perry F.

    2015-01-01

    Research into environmental factors associated with suicide has historically focused on meteorological variables. Recently, a heightened risk of suicide related to short-term exposure to airborne particulate matter was reported. Here, we examined the associations between short-term exposure to nitrogen dioxide, particulate matter, and sulfur dioxide and completed suicide in Salt Lake County, Utah (n = 1,546) from 2000 to 2010. We used a time-stratified case-crossover design to estimate adjusted odds ratios for the relationship between suicide and exposure to air pollutants on the day of the suicide and during the days preceding the suicide. We observed maximum heightened odds of suicide associated with interquartile-range increases in nitrogen dioxide during cumulative lag 3 (average of the 3 days preceding suicide; odds ratio (OR) = 1.20, 95% confidence interval (CI): 1.04, 1.39) and fine particulate matter (diameter ≤2.5 μm) on lag day 2 (day 2 before suicide; OR = 1.05, 95% CI: 1.01, 1.10). Following stratification by season, an increased suicide risk was associated with exposure to nitrogen dioxide during the spring/fall transition period (OR = 1.35, 95% CI: 1.09, 1.66) and fine particulate matter in the spring (OR = 1.28, 95% CI: 1.01, 1.61) during cumulative lag 3. Findings of positive associations between air pollution and suicide appear to be consistent across study locations with vastly different meteorological, geographical, and cultural characteristics. PMID:25673816

  2. Mutagenic potential of acute exposure to organophosphorus and organochlorine compounds.

    PubMed

    Vijayaraghavan, M; Nagarajan, B

    1994-04-01

    The cytogenetic and cytotoxic effects of the pesticides methyl parathion, Bayleton and Hinosan were evaluated in mammalian test systems. The frequency of chromosome aberrations and micronuclei in bone marrow cells and the arginase enzyme profile in the liver tend to show the genotoxicity of organophosphorus and organochlorine pesticides in a single-exposure response study. Methyl parathion was the most hazardous among the three, showing definite pathology in the livers of treated rats.

  3. Acute Radiation Effects Resulting from Exposure to Solar Particle Event-Like Radiation

    NASA Astrophysics Data System (ADS)

    Kennedy, Ann; Cengel, Keith

    2012-07-01

    A major solar particle event (SPE) may place astronauts at significant risk for the acute radiation syndrome (ARS), which may be exacerbated when combined with other space flight stressors, such that the mission or crew health may be compromised. The National Space Biomedical Research Institute (NSBRI) Center of Acute Radiation Research (CARR) is focused on the assessment of risks of adverse biological effects related to the ARS in animal models exposed to space flight stressors combined with the types of radiation expected during an SPE. As part of this program, FDA-approved drugs that may prevent and/or mitigate ARS symptoms are being evaluated. The CARR studies are focused on the adverse biological effects resulting from exposure to the types of radiation, at the appropriate energies, doses and dose-rates, present during an SPE (and standard reference radiations, gamma rays or electrons). The ARS is a phased syndrome which often includes vomiting and fatigue. Other acute adverse biologic effects of concern are the loss of hematopoietic cells, which can result in compromised bone marrow and immune cell functions. There is also concern for skin damage from high SPE radiation doses, including burns, and resulting immune system dysfunction. Using 3 separate animal model systems (ferrets, mice and pigs), the major ARS biologic endpoints being evaluated are: 1) vomiting/retching and fatigue, 2) hematologic changes (with focus on white blood cells) and immune system changes resulting from exposure to SPE radiation with and without reduced weightbearing conditions, and 3) skin injury and related immune system functions. In all of these areas of research, statistically significant adverse health effects have been observed in animals exposed to SPE-like radiation. Countermeasures for the management of ARS symptoms are being evaluated. New research findings from the past grant year will be discussed. Acknowledgements: This research is supported by the NSBRI Center of Acute

  4. DISTRIBUTION OF 14C-ATRAZINE FOLLOWING AN ACUTE LACTATIONAL EXPOSURE IN THE WISTAR RAT.

    EPA Science Inventory

    The purpose of the present study was to examine the distribution of atrazine in the lactating dam and suckling neonate following an acute exposure to either 2 or 4 mg/kg 14C-atrazine (14C-ATR) by gavage. 14C-ATR was administered to the nursing dam on postnatal day 3 by oral gavag...

  5. CARDIOVASCULAR INJURY FROM ACUTE AND REPEATED EXPOSURE TO PARTICULATE MATTER (PM): POTENTIAL ROLE OF ZINC

    EPA Science Inventory

    CARDIOVASCULAR INJURY FROM ACUTE AND REPEATED EXPOSURE TO PARTICULATE MATTER (PM): POTENTIAL ROLE OF ZINC. UP Kodavanti, MC Schladweiler, AD Ledbetter, RH Jaskot, PS Gilmour, DC Christiani, WP Watkinson, DL Costa, JK McGee, A Nyska. NHEERL, USEPA, RTP, NC; CEMALB, UNC, Chapel Hil...

  6. ACUTE BEHAVORIAL EFFECTS FROM EXPOSURE TO TWO-STROKE ENGINE EXHAUST

    EPA Science Inventory

    Benefits of changing from two-stroke to four-stroke engines (and other remedial requirements) can be evaluated (monetized) from the standpoint of acute behavioral effects of human exposure to exhaust from these engines. The monetization process depends upon estimates of the magn...

  7. Neurobehavorial effects of acute exposure to four solvents: meta-abalyses

    EPA Science Inventory

    Meta-and re-analyses of the available data for the neurobehavioral effects of acute inhalation exposure to toluene were reported by Benignus et al. (2007). The present study was designed to test the generality of the toluene results in as many other solvents as possible by furthe...

  8. In Utero Exposure to Lipopolysaccharide Alters the Postnatal Acute Phase Response in Beef Heifers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was designed to determine the potential effect of prenatal lipopolysaccharide (LPS) exposure on the postnatal acute phase response (APR) to an LPS challenge in heifers. Pregnant crossbred cows (n = 50) were separated into prenatal immune stimulation (PIS; n = 25; administered 0.1 microgr...

  9. The effect of chronic ammonia exposure on acute phase proteins, immunoglobulin and cytokines in laying hens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ammonia is a potential health hazard to both humans and animals, causing systemic low-grade inflammation based on its levels and durations. The objective of this study was to examine the effect of 45 weeks of exposure to 30 ppm NH3 on the concentrations of acute phase proteins, immunoglobulins and c...

  10. TOXICITY PATHWAY ANALYSIS IN AGING BROWN NORWAY RAT BRAIN FOLLOWING ACUTE TOLUENE EXPOSURE

    EPA Science Inventory

    The influence of aging on susceptibility to environmental stressors is poorly understood. To investigate the contribution of different life stages on response to toxicants, we examined the effects of acute exposure by oral gavage of the volatile organic solvent toluene (0.00, 0.3...

  11. Self-reported acute health symptoms and exposure to companion animals#

    EPA Science Inventory

    Self-reported acute health symptoms and exposure to companion animalsWhitney S. Krueger1,2, Elizabeth D. Hilborn2, Timothy J. Wade21Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee, USA2Environmental Public Health Division, Office of Research and Development, U...

  12. A Method for Quantifying the Acute Health Impacts of Residential Non-Biological Exposure Via Inhalation

    SciTech Connect

    Logue, Jennifer M.; Sherman, Max H.; Singer, Bret C.

    2014-08-01

    The inability to monetize the health costs of acute exposures in homes and the benefits of various control options is a barrier to justifying policies and approaches that can reduce exposure and improve health.We synthesized relationships between short-term outdoor concentration changes and health outcomes to estimate the health impacts of short-term in-home exposures. Damage and cost impacts of specific health outcomes were taken from the literature. We assessed the impact of vented and non-vented residential natural gas cooking burners on Southern California occupants for two pollutants (NO2 and CO).

  13. Exposure to acute stress is associated with attenuated sweet taste.

    PubMed

    Al'Absi, Mustafa; Nakajima, Motohiro; Hooker, Stephanie; Wittmers, Larry; Cragin, Tiffany

    2012-01-01

    This study examined the effects of stress on taste perception. Participants (N = 38; 21 women) completed two laboratory sessions: one stress (public speaking, math, and cold pressor) and one control rest session. The taste perception test was conducted at the end of each session and included rating the intensity and pleasantness of sweet, salty, sour, and savory solutions at suprathreshold concentrations. Cardiovascular, hormonal, and mood measures were collected throughout the sessions. Participants showed the expected changes in cardiovascular, hormonal, and mood measures in response to stress. Reported intensity of the sweet solution was significantly lower on the stress day than on the rest day. Cortisol level poststress predicted reduced intensity of salt and sour, suggesting that stress-related changes in adrenocortical activity were related to reduced taste intensity. Results indicate that acute stress may alter taste perception, and ongoing research investigates the extent to which these changes mediate effects of stress on appetite.

  14. Exhaled nitric oxide decreases upon acute exposure to high-altitude hypoxia.

    PubMed

    Brown, Daniel E; Beall, Cynthia M; Strohl, Kingman P; Mills, Phoebe S

    2006-01-01

    Nitric oxide (NO) is a vasodilator that plays a role in blood flow and oxygen delivery. Acute hypoxia down regulates NO synthesis, a response that may exacerbate hypoxic stress by decreasing blood flow. This study was designed to test the hypotheses that pulmonary NO decreases upon acute exposure to high-altitude hypoxia and that relatively low levels of NO at altitude are associated with greater stress as reflected in more symptoms of acute mountain sickness (AMS). A sample of 47 healthy, adult, nonsmoking, sea-level residents provided measurements at sea level, at 2,800 m, and at 0-, 2-, and 3-h exposure times at 4,200 m altitude on Mauna Kea, Hawaii. Measurements were made of exhaled NO, oxygen saturation of hemoglobin, heart rate, and reported symptoms of AMS. The partial pressure of NO concentration in exhaled breath decreased significantly from a sea level mean of 4.2 nmHg to 3.8 nmHg at 2,800 m and 3.4 nmHg at 4,200 m. NO concentration in exhaled breath did not change significantly over a 3-h exposure at 4,200 m and recovered to pre-exposure baseline upon return to sea level. There was no significant association between the level of NO exhaled and the number of self-reported symptoms of AMS during this brief exposure.

  15. Effects of Acute Exposure to Sublethal Waterborne Cadmium on Energy Homeostasis in Silver Carp (Hypophthalmichthys molitrix).

    PubMed

    Pi, Jie; Li, Xuelin; Zhang, Ting; Li, Deliang

    2016-10-01

    Effects of acute exposure to sublethal waterborne cadmium (Cd) on energy homeostasis in filter-feeding fishes have rarely been studied. The response patterns of energy substances were investigated in juvenile silver carp (Hypophthalmichthys molitrix) exposed to sublethal waterborne Cd for 96 h. The results showed the 96hLC50 of Cd on juvenile silver carp was 1.723 mg/L. Sublethal acute exposure of Cd significantly affected the energy homeostasis of juvenile silver carp, including increase in plasma glucose and lactate, and decrease in plasma triglyceride, muscle glycogen and triglyceride and liver glycogen. The results indicated that glycogen and triglyceride prior to protein were mobilized to meet the increased demands for detoxication and repair mechanism to sublethal waterborne Cd exposure, and glycogen level depleted faster and restored slower in the liver than in the white muscle in juvenile silver carp.

  16. Acute and Chronic Exposure to CO2 in Space Flight

    NASA Technical Reports Server (NTRS)

    Alexander, D.; Wu, J.; Barr, Y. R.; Watkins, S. D.

    2010-01-01

    Spacecraft and space stations, similar to other habitable confined spaces such as submarines, need to provide a breathable atmosphere for their inhabitants. The inevitable production of CO2 during respiration necessitates life support systems that "scrub" the atmosphere and lower CO2 levels. Due to operational limitations associated with space flight (limited mass, volume, power, and consumables) CO2 is not scrubbed down to its terrestrial equivalent of 0.03% CO2 (ppCO2 of 0.23 mmHg), but is kept below 0.7% (ppCO2 of 5.3 mmHg), a level established in NASA s 180-day mission Spacecraft Maximum Allowable Concentration (SMAC) to be safe and unlikely to cause symptoms. Reports of space flight crewmembers becoming symptomatic with headaches, fatigue, and malaise at levels below those known to cause such symptoms terrestrially has prompted studies measuring the levels of CO2 on both the space shuttle and the space station. Data from cabin atmosphere sampling were collected on space shuttle missions STS-113, STS-122, STS-123, and International Space Station Expeditions 12-15 and 17, and the measured CO2 levels were then correlated to symptoms reported by the crew. The results indicate that a correlation exists between CO2 levels and symptomatology, however causality cannot be established at this time. While the short-term effects of elevated CO2 exposure are well known terrestrially, less is known regarding potential long-term effects of prolonged exposure to a CO2-rich environment or how the physiological changes caused by microgravity may interact with such exposures. Other challenges include limitations in the CO2 monitors used, lack of convection in the microgravity environment, and formation of localized CO2 pockets. As it is unclear if the unique environment of space increases sensitivity to CO2 or if other confounding factors are present, further research is planned to elucidate these points. At the same time, efforts are underway to update the SMAC to a lower level

  17. Structural and Functional Changes of the Human Macula during Acute Exposure to High Altitude

    PubMed Central

    Fischer, M. Dominik; Willmann, Gabriel; Schatz, Andreas; Schommer, Kai; Zhour, Ahmad; Zrenner, Eberhart; Bartz-Schmidt, Karl U.; Gekeler, Florian

    2012-01-01

    Background This study aimed to quantify structural and functional changes at the macula during acute exposure to high altitude and to assess their structure/function relationship. This work is related to the Tuebingen High Altitude Ophthalmology (THAO) study. Methodology/Principal Findings Spectral domain optical coherence tomography and microperimetry were used to quantify changes of central retinal structure and function in 14 healthy subjects during acute exposure to high altitude (4559 m). High-resolution volume scans and fundus-controlled microperimetry of the posterior pole were performed in addition to best-corrected visual acuity (BCVA) measurements and assessment of acute mountain sickness. Analysis of measurements at altitude vs. baseline revealed increased total retinal thickness (TRT) in all four outer ETDRS grid subfields during acute altitude exposure (TRTouter = 2.80±1.00 μm; mean change±95%CI). This change was inverted towards the inner four subfields (TRTinner = −1.89±0.97 μm) with significant reduction of TRT in the fovea (TRTfoveal = −6.62±0.90 μm) at altitude. BCVA revealed no significant difference compared to baseline (0.06±0.08 logMAR). Microperimetry showed stable mean sensitivity in all but the foveal subfield (MSfoveal = −1.12±0.68 dB). At baseline recordings before and >2 weeks after high altitude exposure, all subjects showed equal levels with no sign of persisting structural or functional sequels. Conclusions/Significance During acute exposure to high altitude central retinal thickness is subject to minor, yet statistically significant changes. These alterations describe a function of eccentricity with an increase in regions with relatively higher retinal nerve fiber content and vascular arcades. However, these changes did not correlate with measures of central retinal function or acute mountain sickness. For the first time a quantitative approach has been used to assess these changes during acute, non

  18. Toxicity of white phosphorus to waterfowl: acute exposure in mallards

    USGS Publications Warehouse

    Sparling, D.W.; Gustafson, M.; Klein, P.; Karouna-Renier, N.

    1997-01-01

    As part of an effort to understand extensive, white phosphorus (P4)-induced waterfowl mortality at Eagle River Flats, Fort Richardson, Alaska, we conducted a number of acute toxicity tests using penned mallards (Anas platyrhynchos) in 1993 and 1994. The 24-hr median lethal dose (LD50) for P4 dissolved in oil was 6.46 mg/kg in adult males and 6.96 mg/kg in adult females. Although the median lethal doses were not statistically different, the female dose-response curve had a statistically shallower slope than that of males. The LD50 for the ecologically more relevant pelletized form of P4 in adult males was 4.05 mg/kg. In mallards, one mechanism of P4 toxicity caused rapid (3 to 10 hr) mortality and had signs consistent with anoxia. A second, slower acting mechanism resulted in hepatic and renal pathology including extensive fat deposition in the liver and cellular necrosis. White phosphorus accumulated in adipose tissues, but only for a few days.

  19. Acute myeloid and chronic lymphoid leukaemias and exposure to low-level benzene among petroleum workers

    PubMed Central

    Rushton, L; Schnatter, A R; Tang, G; Glass, D C

    2014-01-01

    Background: High benzene exposure causes acute myeloid leukaemia (AML). Three petroleum case–control studies identified 60 cases (241 matched controls) for AML and 80 cases (345 matched controls) for chronic lymphoid leukaemia (CLL). Methods: Cases were classified and scored regarding uncertainty by two haematologists using available diagnostic information. Blinded quantitative benzene exposure assessment used work histories and exposure measurements adjusted for era-specific circumstances. Statistical analyses included conditional logistic regression and penalised smoothing splines. Results: Benzene exposures were much lower than previous studies. Categorical analyses showed increased ORs for AML with several exposure metrics, although patterns were unclear; neither continuous exposure metrics nor spline analyses gave increased risks. ORs were highest in terminal workers, particularly for Tanker Drivers. No relationship was found between benzene exposure and risk of CLL, although the Australian study showed increased risks in refinery workers. Conclusion: Overall, this study does not persuasively demonstrate a risk between benzene and AML. A previously reported strong relationship between myelodysplastic syndrome (MDS) (potentially previously reported as AML) at our study's low benzene levels suggests that MDS may be the more relevant health risk for lower exposure. Higher CLL risks in refinery workers may be due to more diverse exposures than benzene alone. PMID:24357793

  20. Acute health effects after exposure to chlorine gas released after a train derailment.

    PubMed

    Van Sickle, David; Wenck, Mary Anne; Belflower, Amy; Drociuk, Dan; Ferdinands, Jill; Holguin, Fernando; Svendsen, Erik; Bretous, Lena; Jankelevich, Shirley; Gibson, James J; Garbe, Paul; Moolenaar, Ronald L

    2009-01-01

    In January 2005, a train derailment on the premises of a textile mill in South Carolina released 42 to 60 tons of chlorine gas in the middle of a small town. Medical records and autopsy reports were reviewed to describe the clinical presentation, hospital course, and pathology observed in persons hospitalized or deceased as a result of chlorine gas exposure. Eight persons died before reaching medical care; of the 71 persons hospitalized for acute health effects as a result of chlorine exposure, 1 died in the hospital. The mean age of the hospitalized persons was 40 years (range, 4 months-76 years); 87% were male. The median duration of hospitalization was 4 days (range, 1-29 days). Twenty-five (35%) persons were admitted to the intensive care unit; the median length of stay was 3 days. Many surviving victims developed significant pulmonary signs and severe airway inflammation; 41 (58%) hospitalized persons met PO2/FiO2 criteria for acute respiratory distress syndrome or acute lung injury. During their hospitalization, 40 (57%) developed abnormal x-ray findings, 74% of those within the first day. Hypoxia on room air and PO2/FiO2 ratio predicted severity of outcome as assessed by the duration of hospitalization and the need for intensive care support. This community release of chlorine gas caused widespread exposure and resulted in significant acute health effects and substantial health care requirements. Pulse oximetry and arterial blood gas analysis provided early indications of outcome severity.

  1. Acute phase response, inflammation and metabolic syndrome biomarkers of Libby asbestos exposure

    SciTech Connect

    Shannahan, Jonathan H.; Alzate, Oscar; Winnik, Witold M.; Andrews, Debora; Schladweiler, Mette C.; Ghio, Andrew J.; Gavett, Stephen H.; Kodavanti, Urmila P.

    2012-04-15

    Identification of biomarkers assists in the diagnosis of disease and the assessment of health risks from environmental exposures. We hypothesized that rats exposed to Libby amphibole (LA) would present with a unique serum proteomic profile which could help elucidate epidemiologically-relevant biomarkers. In four experiments spanning varied protocols and temporality, healthy (Wistar Kyoto, WKY; and F344) and cardiovascular compromised (CVD) rat models (spontaneously hypertensive, SH; and SH heart failure, SHHF) were intratracheally instilled with saline (control) or LA. Serum biomarkers of cancer, inflammation, metabolic syndrome (MetS), and the acute phase response (APR) were analyzed. All rat strains exhibited acute increases in α-2-macroglobulin, and α1-acid glycoprotein. Among markers of inflammation, lipocalin-2 was induced in WKY, SH and SHHF and osteopontin only in WKY after LA exposure. While rat strain- and age-related changes were apparent in MetS biomarkers, no LA effects were evident. The cancer marker mesothelin was increased only slightly at 1 month in WKY in one of the studies. Quantitative Intact Proteomic profiling of WKY serum at 1 day or 4 weeks after 4 weekly LA instillations indicated no oxidative protein modifications, however APR proteins were significantly increased. Those included serine protease inhibitor, apolipoprotein E, α-2-HS-glycoprotein, t-kininogen 1 and 2, ceruloplasmin, vitamin D binding protein, serum amyloid P, and more 1 day after last LA exposure. All changes were reversible after a short recovery regardless of the acute or long-term exposures. Thus, LA exposure induces an APR and systemic inflammatory biomarkers that could have implications in systemic and pulmonary disease in individuals exposed to LA. -- Highlights: ► Biomarkers of asbestos exposure are required for disease diagnosis. ► Libby amphibole exposure is associated with increased human mortality. ► Libby amphibole increases circulating proteins involved

  2. Limited inflammatory response in rats after acute exposure to a silicon carbide nanoaerosol

    NASA Astrophysics Data System (ADS)

    Laloy, J.; Lozano, O.; Alpan, L.; Masereel, B.; Toussaint, O.; Dogné, J. M.; Lucas, S.

    2015-08-01

    Inhalation represents the major route of human exposure to manufactured nanomaterials (NMs). Assessments are needed about the potential risks of NMs from inhalation on different tissues and organs, especially the respiratory tract. The aim of this limited study is to determine the potential acute pulmonary toxicity in rats exposed to a dry nanoaerosol of silicon carbide (SiC) nanoparticles (NPs) in a whole-body exposure (WBE) model. The SiC nanoaerosol is composed of a bimodal size distribution of 92.8 and 480 nm. The exposure concentration was 4.91 mg/L, close to the highest recommended concentration of 5 mg/L by the Organisation for Economic Co-operation and Development. Rats were exposed for 6 h to a stable and reproducible SiC nanoaerosol under real-time measurement conditions. A control group was exposed to the filtered air used to create the nanoaerosol. Animals were sacrificed immediately, 24 or 72 h after exposure. The bronchoalveolar lavage fluid from rat lungs was recovered. Macrophages filled with SiC NPs were observed in the rat lungs. The greatest load of SiC and macrophages filled with SiC were observed on the rat lungs sacrificed 24 h after acute exposure. A limited acute inflammatory response was found up to 24 h after exposure characterized by a lactate dehydrogenase and total protein increase or presence of inflammatory cells in pulmonary lavage. For this study a WBE model has been developed, it allows the simultaneous exposure of six rats to a nanoaerosol and six rats to clean-filtered air. The nanoaerosol was generated using a rotating brush system (RBG-1000) and analyzed with an electrical low pressure impactor in real time.

  3. Maintaining the Constant Exposure Condition for an Acute Caenorhabditis elegans Mortality Test Using Passive Dosing

    PubMed Central

    Kwon, Hyuck-Chul; Roh, Ji-Yeon; Lim, Dongyoung; Choi, Jinhee

    2011-01-01

    Objectives Maintaining the constant exposure to hydrophobic organic compouds in acute toxicity tests is one of the most difficult issues in the evaluation of their toxicity and corresponding risks. Passive dosing is an emerging tool to keep constant aqueous concentration because of the overwhelming mass loaded in the dosing phase. The primary objectives of this study were to develop the constant exposure condition for an acute mortality test and to compare the performance of the passive dosing method with the conventional spiking with co-solvent. Methods A custom cut polydimethylsiloxane (PDMS) tubing loaded with benzyl butyl phthalate (BBP) was placed in each well of a 24-well plate containing assay medium. The rate of the release of BBP from PDMS was evaluated by measuring the change in the concentration of BBP in the assay medium. The efficiency of maintaining constant exposure condition was also evaluated using a simple two-compartment mass transport model employing a film-diffusion theory. An acute mortality test using 10 C. elegans in each well was conducted for the evaluation of the validity of passive dosing and the comparative evaluation of the passive dosing method and the conventional spiking method. Results Free concentration in the assay medium reached 95% steady state value within 2.2 hours without test organisms, indicating that this passive dosing method is useful for an acute toxicity test in 24 hours. The measured concentration after the mortality test agreed well with the estimated values from partitioning between PDMS and the assay medium. However, the difference between the nominal and the free concentration became larger as the spiked concentration approached water solubility, indicating the instability of the conventional spiking with a co-solvent. Conclusions The results in this study support that passive dosing provides a stable exposure condition for an acute toxicity test. Thus, it is likely that more reliable toxicity assessment can be

  4. Cancer Events After Acute or Chronic Exposure to Sulfur Mustard: A Review of the Literature

    PubMed Central

    Razavi, Seyed Mansour; Abdollahi, Mohammad; Salamati, Payman

    2016-01-01

    Background: Sulfur mustard (SM) has been considered as a carcinogen in the laboratory studies. However, its carcinogenic effects on human beings were not well discussed. The main purpose of our study is to assess carcinogenesis of SM following acute and/or chronic exposures in human beings. Methods: The valid scientific English and Persian databases including PubMed, Web of Science, Scopus, IranMedex, and Irandoc were searched and the collected papers reviewed. The used keywords were in two languages: English and Persian. The inclusion criteria were the published original articles indexed in above-mentioned databases. Eleven full-texts out of 296 articles were found relevant and then assessed. Results: Studies on the workers of the SM factories during the World Wars showed that the long-term chronic exposure to mustards can cause a variety of cancers in the organs such as oral cavity, larynx, lung, and skin. Respiratory system was the most important affected system. Acute single exposure to SM was assumed as the carcinogenic inducer in the lung and blood and for few cancers including basal cell carcinoma and squamous cell carcinoma. Conclusions: SM is a proven carcinogen in chronic situations although data are not enough to strongly conclude in acute exposure. PMID:27280012

  5. Acute illnesses among Los Angeles County lifeguards according to worksite exposures.

    PubMed Central

    Sullivan, C S; Barron, M E

    1989-01-01

    Due to public concern regarding the potential adverse health effects of exposure to Santa Monica Bay waters, a case-control study of acute illnesses among Los Angeles County lifeguards was conducted. Workers' compensation claimants (N = 112) were matched to healthy lifeguards working in the same year and having the same job classification. Conditional logistic regression showed that the southernmost worksites of the bay were associated with all acute illnesses (OR = 14.4, 95% CI = 4.7, 44.8) and with ear infections (OR = 12.5, 95% CI = 2.9, 53.4). PMID:2817175

  6. Single-exposure phase-shifting digital holography using a random-complex-amplitude encoded reference wave.

    PubMed

    Imbe, Masatoshi; Nomura, Takanori

    2013-01-01

    The improved single-exposure phase-shifting digital holography using a random-phase reference wave is proposed. The algorithm for obtaining a complex amplitude of an object wave is improved. In the proposed algorithm, the reference wave is treated as not a random-phase but a random-complex amplitude. Therefore, the algorithm uses proper amplitude information of the reference wave. Both numerical simulations and experimental results are given to confirm the effectiveness of the proposed algorithm.

  7. Carpal tunnel syndrome (CTS) and exposure to vibration, repetitive wrist movements, and heavy manual work: a case-referent study.

    PubMed Central

    Wieslander, G; Norbäck, D; Göthe, C J; Juhlin, L

    1989-01-01

    Possible connections between carpal tunnel syndrome (CTS) and exposure to vibrating handheld tools, repetitive wrist movements, and heavy manual work were examined in a case-referent study. The cases were 38 men operated on for CTS between 1974 and 1980. For each case, two referents were drawn from among other surgical cases (hospital referents) and two further referents from the population register and telephone directory, respectively (population referents). Thirty four of 38 cases (89%) and 143 of 152 referents (94%) were interviewed by telephone. An increased prevalence of obesity, rheumatoid disease, diabetes, or thyroid disease was observed among the cases but most did not suffer from any of these disorders. CTS was significantly correlated with exposure to vibration from handheld tools and to repetitive wrist movements but showed a weaker correlation with work producing a heavy load on the wrist. A cause-effect relation between CTS and exposures to handheld vibrating tools and to work causing repetitive movements of the wrist seems probable. Some differences between hospital and population referents indicate that a case-referent study of this type could be biased by inappropriate selection of referents. PMID:2920142

  8. 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.

  9. 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.

  10. Chronic health effects of sulphur mustard exposure with special reference to Iranian veterans

    PubMed Central

    Balali-Mood, M; Mousavi, SH; Balali-Mood, B

    2008-01-01

    The widespread use of sulphur mustard (SM) as an incapacitating chemical warfare agent in the past century has proved its long-lasting toxic effects. It may also be used as a chemical terrorist agent. Therefore, all health professionals should have sufficient knowledge and be prepared for any such chemical attack. SM exerts direct toxic effects on the eyes, skin, and respiratory tissue, with subsequent systemic action on the nervous, immunological, haematological, digestive, and reproductive systems. SM is an alkylating agent that affects DNA synthesis, and, thus, delayed complications have been seen since the First World War. Cases of malignancies in the target organs, particularly in haematopoietic, respiratory, and digestive systems, have been reported. Important delayed respiratory complications include chronic bronchitis, bronchiectasis, frequent bronchopneumonia, and pulmonary fibrosis, all of which tend to deteriorate with time. Severe dry skin, delayed keratitis, and reduction of natural killer cells with subsequent increased risk of infections and malignancies are also among the most distressing long-term consequences of SM intoxication. However, despite a lot of research over the past decades on Iranian veterans, there are still major gaps in the SM literature. Immunological and neurological dysfunction, as well as the relationship between SM exposure and mutagenicity, carcinogenicity, and teratogenicity are important fields that require further studies, particularly on Iranian veterans with chronic health effects of SM poisoning. There is also a paucity of information on the medical management of acute and delayed toxic effects of SM poisoning—a subject that greatly challenges health care specialists. PMID:22460216

  11. Micro RNA responses to chronic or acute exposures to low dose ionizing radiation

    PubMed Central

    Chaudhry, M. Ahmad; Omaruddin, Romaica A.; Kreger, Bridget; de Toledo, Sonia M.; Azzam, Edouard I.

    2014-01-01

    Human health risks of exposure to low dose ionizing radiation remain ambiguous and are the subject of intense debate. A wide variety of biological effects are induced after cellular exposure to ionizing radiation, but the underlying molecular mechanism(s) remain to be completely understood. We hypothesized that low dose c-radiation-induced effects are controlled by the modulation of micro RNA (miRNA) that participate in the control of gene expression at the posttranscriptional level and are involved in many cellular processes. We monitored the expression of several miRNA in human cells exposed to acute or chronic low doses of 10 cGy or a moderate dose of 400 cGy of 137Cs γ-rays. Dose, dose rate and time dependent differences in the relative expression of several miRNA were investigated. The expression patterns of many miRNA differed after exposure to either chronic or acute 10 cGy. The expression of miRNA let-7e, a negative regulator of RAS oncogene, and the c-MYC miRNA cluster were upregulated after 10 cGy chronic dose but were downregulated after 3 h of acute 10 cGy. The miR-21 was upregulated in chronic or acute low dose and moderate dose treated cells and its target genes hPDCD4, hPTEN, hSPRY2, and hTPM1 were found to be downregulated. These findings provide evidence that low dose and dose rate c-irradiation dictate the modulation of miRNA, which can result in a differential cellular response than occurs at high doses. This information will contribute to understanding the risks to human health after exposure to low dose radiation. PMID:22367372

  12. Acute and chronic toxicity of sodium sulfate to four freshwater organisms in water-only exposures

    USGS Publications Warehouse

    Wang, Ning; Consbrock, Rebecca A.; Ingersoll, Christopher G.; Hardesty, Douglas K.; Brumbaugh, William G.; Hammer, Edward J.; Bauer, Candice R.; Mount, David R.

    2016-01-01

    The acute and chronic toxicity of sulfate (tested as sodium sulfate) was determined in diluted well water (hardness of 100 mg/L and pH 8.2) with a cladoceran (Ceriodaphnia dubia; 2-d and 7-d exposures), a midge (Chironomus dilutus; 4-d and 41-d exposures), a unionid mussel (pink mucket, Lampsilis abrupta; 4-d and 28-d exposures), and a fish (fathead minnow, Pimephales promelas; 4-d and 34-d exposures). Among the 4 species, the cladoceran and mussel were acutely more sensitive to sulfate than the midge and fathead minnow, whereas the fathead minnow was chronically more sensitive than the other 3 species. Acute-to-chronic ratios ranged from 2.34 to 5.68 for the 3 invertebrates but were as high as 12.69 for the fish. The fathead minnow was highly sensitive to sulfate during the transitional period from embryo development to hatching in the diluted well water, and thus, additional short-term (7- to 14-d) sulfate toxicity tests were conducted starting with embryonic fathead minnow in test waters with different ionic compositions at a water hardness of 100 mg/L. Increasing chloride in test water from 10 mg Cl/L to 25 mg Cl/L did not influence sulfate toxicity to the fish, whereas increasing potassium in test water from 1mg K/L to 3mg K/L substantially reduced the toxicity of sulfate. The results indicate that both acute and chronic sulfate toxicity data, and the influence of potassium on sulfate toxicity to fish embryos, need to be considered when environmental guidance values for sulfate are developed or refined.

  13. Pathogenesis of Acute and Delayed Corneal Lesions after Ocular Exposure to Sulfur Mustard Vapor

    DTIC Science & Technology

    2012-01-01

    2000) Nanoscale topography of the basement membrane underlying the corneal epithelium of the rhesus macaque. Cell Tissue Res 299: 39–46. 28. Pal-Ghosh...DATES COVERED (From - To) 4. TITLE AND SUBTITLE Pathogenesis of acute and delayed corneal lesions after ocular exposure to 5a. CONTRACT NUMBER sulfur...involves a progressive corneal degeneration resulting in chronic ocular discomfort and impaired vision for which clinical interventions have typically

  14. Acute and chronic toxicity of sodium sulfate to four freshwater organisms in water-only exposures.

    PubMed

    Wang, Ning; Dorman, Rebecca A; Ingersoll, Christopher G; Hardesty, Doug K; Brumbaugh, William G; Hammer, Edward J; Bauer, Candice R; Mount, David R

    2016-01-01

    The acute and chronic toxicity of sulfate (tested as sodium sulfate) was determined in diluted well water (hardness of 100 mg/L and pH 8.2) with a cladoceran (Ceriodaphnia dubia; 2-d and 7-d exposures), a midge (Chironomus dilutus; 4-d and 41-d exposures), a unionid mussel (pink mucket, Lampsilis abrupta; 4-d and 28-d exposures), and a fish (fathead minnow, Pimephales promelas; 4-d and 34-d exposures). Among the 4 species, the cladoceran and mussel were acutely more sensitive to sulfate than the midge and fathead minnow, whereas the fathead minnow was chronically more sensitive than the other 3 species. Acute-to-chronic ratios ranged from 2.34 to 5.68 for the 3 invertebrates but were as high as 12.69 for the fish. The fathead minnow was highly sensitive to sulfate during the transitional period from embryo development to hatching in the diluted well water, and thus, additional short-term (7- to 14-d) sulfate toxicity tests were conducted starting with embryonic fathead minnow in test waters with different ionic compositions at a water hardness of 100 mg/L. Increasing chloride in test water from 10 mg Cl/L to 25 mg Cl/L did not influence sulfate toxicity to the fish, whereas increasing potassium in test water from 1 mg K/L to 3 mg K/L substantially reduced the toxicity of sulfate. The results indicate that both acute and chronic sulfate toxicity data, and the influence of potassium on sulfate toxicity to fish embryos, need to be considered when environmental guidance values for sulfate are developed or refined.

  15. Whole Adult Organism Transcriptional Profiling of Acute Metal Exposures in Male Zebrafish

    DTIC Science & Technology

    2014-03-10

    adult organism transcriptional profiling of acute metal exposures in male Zebrafish Naissan Hussainzada1, John A Lewis2, Christine E Baer4, Danielle L...fish were pulverized under liquid nitrogen using a SPEX 6750 freezer mill (SPEX Sample Prep, Metuchen, NJ). Total RNA was isolated from the pulverized...advantages and current limitations. Toxicol Pathol 2003, 31(Suppl):62–87. 3. Carvan MJ III, Dalton TP, Stuart GW, Nebert DW: Transgenic zebrafish as

  16. Acute respiratory effects and endotoxin exposure during wheat harvest in Northeastern Colorado.

    PubMed

    Viet, S M; Buchan, R; Stallones, L

    2001-06-01

    Acute cross-shift respiratory changes were evaluated for workers at 25 farms in northeastern Colorado during the summer of 1994 wheat harvest. Information on workers' respiratory health, past occupational exposures, and smoking status was obtained. Each worker was asked to rank eight acute symptoms before he or she began harvest work for the day. Spirometry was also performed before work began. Each participant wore a high-flow personal air sampling pump for the full shift. At the end of the workshift, spirometry and ranking of the eight acute symptoms were conducted again. Total dust exposure was determined gravimetrically. Total endotoxin was measured by the Limulus amoebocyte lysate (LAL) assay. The 98 harvest workers included in the study ranged in age from 18 to 80. Ten percent of the workers had moderate airway obstruction, as indicated by the pre-shift spirometry test results. Fifty percent of the workers were current or ex-smokers. Despite an unusually poor harvest, total dust exposures ranged from 0.09 to 15.33 mg/m3 (geometric mean 0.83 mg/m3), with 8 percent of workers exposed above the American Conference of Government Industrial Hygienists (ACGIH) threshold limit value (TLV) of 4 mg/m3. Total endotoxin exposures ranged from 4.4 to 744.4 EU/m3 (geometric mean 54.2 EU/m3), with 33 percent of workers exposed above 90 EU/m3, the level suggested as a threshold for acute mucous membrane irritation and pulmonary change among cotton workers. Sixty percent of workers experienced a cross-shift change in at least one respiratory symptom. The respiratory index (sum of cross-shift changes in the eight acute respiratory symptoms) was significantly correlated with both total dust and endotoxin exposure. Cross-shift changes in the spirometric variables were associated with smoking status, age, presence of airway obstruction, and history of chronic respiratory symptoms, but not with dust or endotoxin exposure. Peak expiratory flow rate was found to decrease over the

  17. Exposure to acute stress enhances decision-making competence: Evidence for the role of DHEA.

    PubMed

    Shields, Grant S; Lam, Jovian C W; Trainor, Brian C; Yonelinas, Andrew P

    2016-05-01

    Exposure to acute stress can impact performance on numerous cognitive abilities, but little is known about how acute stress affects real-world decision-making ability. In the present study, we induced acute stress with a standard laboratory task involving uncontrollable socio-evaluative stress and subsequently assessed decision-making ability using the Adult Decision Making Competence index. In addition, we took baseline and post-test saliva samples from participants to examine associations between decision-making competence and adrenal hormones. Participants in the stress induction group showed enhanced decision-making competence, relative to controls. Further, although both cortisol and dehydroepiandrosterone (DHEA) reactivity predicted decision-making competence when considered in isolation, DHEA was a significantly better predictor than cortisol when both hormones were considered simultaneously. Thus, our results show that exposure to acute stress can have beneficial effects on the cognitive ability underpinning real-world decision-making and that this effect relates to DHEA reactivity more than cortisol.

  18. Inhibition of gustatory plasticity due to acute nicotine exposure in the nematode Caenorhabditis elegans.

    PubMed

    Matsuura, Tetsuya; Miura, Hitoshi; Nishino, Asuka

    2013-11-01

    The present study investigated the effect of nicotine exposure on gustatory plasticity in the nematode Caenorhabditis elegans. The chemotactic response of wild-type N2 nematodes pre-exposed to 100mM NaCl with 3.0mM nicotine was almost the same as that of mock-conditioned nematodes unexposed to NaCl; however, the response of N2 nematodes pre-exposed to NaCl without nicotine was significantly lower than that of mock-conditioned nematodes. These results indicate that gustatory plasticity is inhibited by acute nicotine exposure. Inhibition of gustatory plasticity was observed when cat-2 mutants with a defect in dopamine biosynthesis were pre-exposed to NaCl with 3.0mM nicotine. Acute nicotine exposure did not cause inhibition of gustatory plasticity in bas-1 mutants, which had defects in both serotonin and dopamine secretion, and tph-1 mutants, which had a defect in serotonin secretion only. However, inhibition of gustatory plasticity was observed when bas-1 and tph-1 mutants were maintained on a growth plate that included serotonin. These results suggest that serotonin signaling plays an essential role in the modulation of the acute effects of nicotine.

  19. Risk of childhood acute lymphoblastic leukaemia following parental occupational exposure to extremely low frequency electromagnetic fields

    PubMed Central

    Reid, A; Glass, D C; Bailey, H D; Milne, E; de Klerk, N H; Downie, P; Fritschi, L

    2011-01-01

    Background: Earlier studies have reported moderate increases in the risk of acute lymphoblastic leukaemia (ALL) among children whose mothers have been occupationally exposed to extremely low frequency (ELF) electromagnetic fields. Other studies examining parental occupational exposure to ELF and ALL have reported mixed results. Methods: In an Australian case–control study of ALL in children aged <15 years, parents were asked about tasks they undertook in each job. Exposure variables were created for any occupational exposure before the birth of the child, in jobs 2 years before birth, in jobs 1 year before birth and up to 1 year after birth. Results: In all, 379 case and 854 control mothers and 328 case and 748 control fathers completed an occupational history. Exposure to ELF in all time periods was similar in case and control mothers. There was no difference in exposure between case and control fathers. There was no association between maternal (odds ratio (OR)=0.96; 95% CI=0.74–1.25) or paternal (OR=0.78; 95% CI=0.56–1.09) exposure to ELF any time before the birth and risk of childhood ALL. Conclusion: We did not find an increased risk of ALL in offspring of parents with occupational exposure to ELF. PMID:21915123

  20. Disrupted Nitric Oxide Metabolism from Type II Diabetes and Acute Exposure to Particulate Air Pollution.

    PubMed

    Pettit, Ashley P; Kipen, Howard; Laumbach, Robert; Ohman-Strickland, Pamela; Kelly-McNeill, Kathleen; Cepeda, Clarimel; Fan, Zhi-Hua; Amorosa, Louis; Lubitz, Sara; Schneider, Stephen; Gow, Andrew

    2015-01-01

    Type II diabetes is an established cause of vascular impairment. Particulate air pollution is known to exacerbate cardiovascular and respiratory conditions, particularly in susceptible populations. This study set out to determine the impact of exposure to traffic pollution, with and without particle filtration, on vascular endothelial function in Type II diabetes. Endothelial production of nitric oxide (NO) has previously been linked to vascular health. Reactive hyperemia induces a significant increase in plasma nitrite, the proximal metabolite of NO, in healthy subjects, while diabetics have a lower and more variable level of response. Twenty type II diabetics and 20 controls (ages 46-70 years) were taken on a 1.5 hr roadway traffic air pollution exposure as passengers. We analyzed plasma nitrite, as a measure of vascular function, using forearm ischemia to elicit a reactive hyperemic response before and after exposure to one ride with and one without filtration of the particle components of pollution. Control subjects displayed a significant increase in plasma nitrite levels during reactive hyperemia. This response was no longer present following exposure to traffic air pollution, but did not vary with whether or not the particle phase was filtered out. Diabetics did not display an increase in nitrite levels following reactive hyperemia. This response was not altered following pollution exposure. These data suggest that components of acute traffic pollution exposure diminish vascular reactivity in non-diabetic individuals. It also confirms that type II diabetics have a preexisting diminished ability to appropriately respond to a vascular challenge, and that traffic pollution exposure does not cause a further measureable acute change in plasma nitrite levels in Type II diabetics.

  1. Disrupted Nitric Oxide Metabolism from Type II Diabetes and Acute Exposure to Particulate Air Pollution

    PubMed Central

    Pettit, Ashley P.; Kipen, Howard; Laumbach, Robert; Ohman-Strickland, Pamela; Kelly-McNeill, Kathleen; Cepeda, Clarimel; Fan, Zhi-Hua; Amorosa, Louis; Lubitz, Sara; Schneider, Stephen; Gow, Andrew

    2015-01-01

    Type II diabetes is an established cause of vascular impairment. Particulate air pollution is known to exacerbate cardiovascular and respiratory conditions, particularly in susceptible populations. This study set out to determine the impact of exposure to traffic pollution, with and without particle filtration, on vascular endothelial function in Type II diabetes. Endothelial production of nitric oxide (NO) has previously been linked to vascular health. Reactive hyperemia induces a significant increase in plasma nitrite, the proximal metabolite of NO, in healthy subjects, while diabetics have a lower and more variable level of response. Twenty type II diabetics and 20 controls (ages 46–70 years) were taken on a 1.5hr roadway traffic air pollution exposure as passengers. We analyzed plasma nitrite, as a measure of vascular function, using forearm ischemia to elicit a reactive hyperemic response before and after exposure to one ride with and one without filtration of the particle components of pollution. Control subjects displayed a significant increase in plasma nitrite levels during reactive hyperemia. This response was no longer present following exposure to traffic air pollution, but did not vary with whether or not the particle phase was filtered out. Diabetics did not display an increase in nitrite levels following reactive hyperemia. This response was not altered following pollution exposure. These data suggest that components of acute traffic pollution exposure diminish vascular reactivity in non-diabetic individuals. It also confirms that type II diabetics have a preexisting diminished ability to appropriately respond to a vascular challenge, and that traffic pollution exposure does not cause a further measureable acute change in plasma nitrite levels in Type II diabetics. PMID:26656561

  2. Resistin deficiency in mice has no effect on pulmonary responses induced by acute ozone exposure

    PubMed Central

    Razvi, Shehla S.; Richards, Jeremy B.; Malik, Farhan; Cromar, Kevin R.; Price, Roger E.; Bell, Cynthia S.; Weng, Tingting; Atkins, Constance L.; Spencer, Chantal Y.; Cockerill, Katherine J.; Alexander, Amy L.; Blackburn, Michael R.; Alcorn, Joseph L.; Haque, Ikram U.

    2015-01-01

    Acute exposure to ozone (O3), an air pollutant, causes pulmonary inflammation, airway epithelial desquamation, and airway hyperresponsiveness (AHR). Pro-inflammatory cytokines—including IL-6 and ligands of chemokine (C-X-C motif) receptor 2 [keratinocyte chemoattractant (KC) and macrophage inflammatory protein (MIP)-2], TNF receptor 1 and 2 (TNF), and type I IL-1 receptor (IL-1α and IL-1β)—promote these sequelae. Human resistin, a pleiotropic hormone and cytokine, induces expression of IL-1α, IL-1β, IL-6, IL-8 (the human ortholog of murine KC and MIP-2), and TNF. Functional differences exist between human and murine resistin; yet given the aforementioned observations, we hypothesized that murine resistin promotes O3-induced lung pathology by inducing expression of the same inflammatory cytokines as human resistin. Consequently, we examined indexes of O3-induced lung pathology in wild-type and resistin-deficient mice following acute exposure to either filtered room air or O3. In wild-type mice, O3 increased bronchoalveolar lavage fluid (BALF) resistin. Furthermore, O3 increased lung tissue or BALF IL-1α, IL-6, KC, TNF, macrophages, neutrophils, and epithelial cells in wild-type and resistin-deficient mice. With the exception of KC, which was significantly greater in resistin-deficient compared with wild-type mice, no genotype-related differences in the other indexes existed following O3 exposure. O3 caused AHR to acetyl-β-methylcholine chloride (methacholine) in wild-type and resistin-deficient mice. However, genotype-related differences in airway responsiveness to methacholine were nonexistent subsequent to O3 exposure. Taken together, these data demonstrate that murine resistin is increased in the lungs of wild-type mice following acute O3 exposure but does not promote O3-induced lung pathology. PMID:26386120

  3. Acute phase response, inflammation and metabolic syndrome biomarkers of Libby asbestos exposure.

    PubMed

    Shannahan, Jonathan H; Alzate, Oscar; Winnik, Witold M; Andrews, Debora; Schladweiler, Mette C; Ghio, Andrew J; Gavett, Stephen H; Kodavanti, Urmila P

    2012-04-15

    Identification of biomarkers assists in the diagnosis of disease and the assessment of health risks from environmental exposures. We hypothesized that rats exposed to Libby amphibole (LA) would present with a unique serum proteomic profile which could help elucidate epidemiologically-relevant biomarkers. In four experiments spanning varied protocols and temporality, healthy (Wistar Kyoto, WKY; and F344) and cardiovascular compromised (CVD) rat models (spontaneously hypertensive, SH; and SH heart failure, SHHF) were intratracheally instilled with saline (control) or LA. Serum biomarkers of cancer, inflammation, metabolic syndrome (MetS), and the acute phase response (APR) were analyzed. All rat strains exhibited acute increases in α-2-macroglobulin, and α1-acid glycoprotein. Among markers of inflammation, lipocalin-2 was induced in WKY, SH and SHHF and osteopontin only in WKY after LA exposure. While rat strain- and age-related changes were apparent in MetS biomarkers, no LA effects were evident. The cancer marker mesothelin was increased only slightly at 1 month in WKY in one of the studies. Quantitative Intact Proteomic profiling of WKY serum at 1 day or 4 weeks after 4 weekly LA instillations indicated no oxidative protein modifications, however APR proteins were significantly increased. Those included serine protease inhibitor, apolipoprotein E, α-2-HS-glycoprotein, t-kininogen 1 and 2, ceruloplasmin, vitamin D binding protein, serum amyloid P, and more 1 day after last LA exposure. All changes were reversible after a short recovery regardless of the acute or long-term exposures. Thus, LA exposure induces an APR and systemic inflammatory biomarkers that could have implications in systemic and pulmonary disease in individuals exposed to LA.

  4. Acute and chronic effects of erythromycin exposure on oxidative stress and genotoxicity parameters of Oncorhynchus mykiss.

    PubMed

    Rodrigues, S; Antunes, S C; Correia, A T; Nunes, B

    2016-03-01

    Erythromycin (ERY) is a macrolide antibiotic used in human and veterinary medicine, and has been detected in various aquatic compartments. Recent studies have indicated that this compound can exert biological activity on non-target organisms environmentally exposed. The present study aimed to assess the toxic effects of ERY in Oncorhynchus mykiss after acute and chronic exposures. The here adopted strategy involved exposure to three levels of ERY, the first being similar to concentrations reported to occur in the wild, thus ecologically relevant. Catalase (CAT), total glutathione peroxidase (GPx), glutathione reductase (GRed) activities and lipid peroxidation (TBARS levels) were quantified as oxidative stress biomarkers in gills and liver. Genotoxic endpoints, reflecting different types of genetic damage in blood cells, were also determined, by performing analysis of genetic damage (determination of the genetic damage index, GDI, measured by comet assay) and of erythrocytic nuclear abnormalities (ENAs). The results suggest the occurrence of a mild, but significant, oxidative stress scenario in gills. For acutely exposed organisms, significant alterations were observed in CAT and GRed activities, and also in TBARS levels, which however are modifications with uncertain biological interpretation, despite indicating involvement of an oxidative effect and response. After chronic exposure, a significant decrease of CAT activity, increase of GPx activity and TBARS levels in gills was noticed. In liver, significant decrease in TBARS levels were observed in both exposures. Comet and ENAs assays indicated significant increases on genotoxic damage of O. mykiss, after erythromycin exposures. This set of data (acute and chronic) suggests that erythromycin has the potential to induce DNA strand breaks in blood cells, and demonstrate the induction of chromosome breakage and/or segregational abnormalities. Overall results indicate that both DNA damaging effects induced by

  5. Acute mountain sickness: medical problems associated with acute and subacute exposure to hypobaric hypoxia

    PubMed Central

    Clarke, C

    2006-01-01

    This article summarises the medical problems of travel to altitudes above 3000 m. These are caused by chronic hypoxia. Acute mountain sickness (AMS), a self limiting common illness is almost part of normal acclimatisation—a transient condition lasting for several days. However, in <2% of people staying above 4000 m, serious illnesses related to hypoxia develop – high altitude pulmonary oedema and cerebral oedema. These are potentially fatal but can be largely avoided by gradual ascent. Short vacations, pressure from travel companies and peer groups often encourage ascent to 4000 m more rapidly than is prudent. Sensible guidelines for ascent are outlined, clinical features, management and treatment of these conditions. PMID:17099095

  6. [Cutaneous damage after acute exposure to ionizing radiation: decisive for the prognosis of radiation accident victims].

    PubMed

    Dörr, H; Baier, T; Meineke, V

    2013-12-01

    The cutaneous radiation syndrome includes all deterministic effects on the skin and visible parts of the mucosa from ionizing radiation. The Intensity and duration of radiation-induced skin symptoms depend on the kind and quality of ionizing radiation. The aim of this study was the investigation of the importance of the time of the development of radiation induced-skin effects on the prognosis of radiation accident victims. Clinical data about radiation accident victims from the database SEARCH were used. 211 cases with good documentation regarding radiation-induced skin effects were selected. From these 211 patients, 166 survived the acute phase of the acute radiation syndrome, while 45 died during the acute phase. Among those patients who did not survive the acute phase, 82.2 % showed their first documented radiation-induced skin symptoms during the first 3 days after radiation exposure. Of those patients whose first documented radiation-induced skin symptoms appeared on or after day four, 94.2 % survived the acute phase. The time to the occurrence of the first radiation-induced skin effects is diagnostically significant. The skin plays an important role in the clinical course of radiation syndromes and in the development of radiation-induced multi-organ failure. In a retrospective data analysis like this, the quality of data might be a limitation.

  7. Prior exposure to repeated immobilization or chronic unpredictable stress protects from some negative sequels of an acute immobilization.

    PubMed

    Pastor-Ciurana, Jordi; Rabasa, Cristina; Ortega-Sánchez, Juan A; Sanchís-Ollè, Maria; Gabriel-Salazar, Marina; Ginesta, Marta; Belda, Xavier; Daviu, Núria; Nadal, Roser; Armario, Antonio

    2014-05-15

    Exposure to chronic unpredictable stress (CUS) is gaining acceptance as a putative animal model of depression. However, there is evidence that chronic exposure to stress can offer non-specific stress protection from some effects of acute superimposed stressors. We then compared in adult male rats the protection afforded by prior exposure to CUS with the one offered by repeated immobilization on boards (IMO) regarding some of the negative consequences of an acute exposure to IMO. Repeated exposure to IMO protected from the negative consequences of an acute IMO on activity in an open-field, saccharin intake and body weight gain. Active coping during IMO (struggling) was markedly reduced by repeated exposure to the same stressor, but it was not affected by a prior history of CUS, suggesting that our CUS protocol does not appear to impair active coping responses. CUS exposure itself caused a strong reduction of activity in the open-field but appeared to protect from the hypo-activity induced by acute IMO. Moreover, prior CUS offered partial protection from acute IMO-induced reduction of saccharin intake and body weight gain. It can be concluded that a prior history of CUS protects from some of the negative consequences of exposure to a novel severe stressor, suggesting the development of partial cross-adaptation whose precise mechanisms remain to be studied.

  8. Acute and chronic ethanol exposure differentially alters alcohol dehydrogenase and aldehyde dehydrogenase activity in the zebrafish liver.

    PubMed

    Tran, Steven; Nowicki, Magda; Chatterjee, Diptendu; Gerlai, Robert

    2015-01-02

    Chronic ethanol exposure paradigms have been successfully used in the past to induce behavioral and central nervous system related changes in zebrafish. However, it is currently unknown whether chronic ethanol exposure alters ethanol metabolism in adult zebrafish. In the current study we examine the effect of acute ethanol exposure on adult zebrafish behavioral responses, as well as alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) activity in the liver. We then examine how two different chronic ethanol exposure paradigms (continuous and repeated ethanol exposure) alter behavioral responses and liver enzyme activity during a subsequent acute ethanol challenge. Acute ethanol exposure increased locomotor activity in a dose-dependent manner. ADH activity was shown to exhibit an inverted U-shaped curve and ALDH activity was decreased by ethanol exposure at all doses. During the acute ethanol challenge, animals that were continuously housed in ethanol exhibited a significantly reduced locomotor response and increased ADH activity, however, ALDH activity did not change. Zebrafish that were repeatedly exposed to ethanol demonstrated a small but significant attenuation of the locomotor response during the acute ethanol challenge but ADH and ALDH activity was similar to controls. Overall, we identified two different chronic ethanol exposure paradigms that differentially alter behavioral and physiological responses in zebrafish. We speculate that these two paradigms may allow dissociation of central nervous system-related and liver enzyme-dependent ethanol induced changes in zebrafish.

  9. Perchlorate exposure from infant formula and comparisons with the perchlorate reference dose.

    PubMed

    Schier, Joshua G; Wolkin, Amy F; Valentin-Blasini, Lisa; Belson, Martin G; Kieszak, Stephanie M; Rubin, Carol S; Blount, Benjamin C

    2010-05-01

    Perchlorate exposure may be higher in infants compared with older persons, due to diet (infant formula) and body weight versus intake considerations. Our primary objective was to quantitatively assess perchlorate concentrations in commercially available powdered infant formulas (PIFs). Secondary objectives were: (1) to estimate exposure in infants under different dosing scenarios and compare them with the perchlorate reference dose (RfD); (2) estimate the perchlorate concentration in water used for preparing PIFs that would result in a dose exceeding the RfD; and (3) estimate iodine intakes from PIFs. We quantified perchlorate levels in three samples (different lot numbers) of reconstituted PIF (using perchlorate-free water) from commercial brands of PIF in each of the following categories: bovine milk-based with lactose, soy-based, bovine milk-based but lactose-free, and elemental (typically consisting of synthetic amino acids). Exposure modeling was conducted to determine whether the RfD might be exceeded in 48 dosing scenarios that were dependent on age, centile energy intake per unit of body weight, body weight percentile, and PIF perchlorate concentration. We obtained three different samples in each of the five brands of bovine- and soy-based PIF, three different samples in each of the three brands of lactose-free PIF, and three different samples in two brands of elemental PIF. The results were as follows: bovine milk-based with lactose (1.72 microg/l, range: 0.68-5.05); soy-based (0.21 microg/l, range: 0.10-0.44); lactose-free (0.27 microg/l, range: 0.03-0.93); and elemental (0.18 microg/l, range: 0.08-0.4). Bovine milk-based PIFs with lactose had a significantly higher concentration of perchlorate (P<0.05) compared with all. Perchlorate was a contaminant of all commercially available PIFs tested. Bovine milk-based PIFs with lactose had a significantly higher perchlorate concentration perchlorate than soy, lactose-free, and elemental PIFs. The perchlorate Rf

  10. Improvement of cold resistance and performance of broilers by acute cold exposure during late embryogenesis.

    PubMed

    Shinder, D; Ruzal, M; Giloh, M; Druyan, S; Piestun, Y; Yahav, S

    2011-03-01

    The aim of this study was to fine-tune previous acute cold exposure treatments of broiler embryos during late embryogenesis to improve lifelong cold resistance and performance. Six hundred Cobb hatching eggs were incubated under standard conditions and then exposed to 3 treatments: control; cold treatment in which embryos were exposed to 15°C for 30 min on d 18 and 19 of incubation (30 × 2); and cold treatment similar to 30 × 2 but with 60-min exposures (60 × 2). Egg shell temperature (T(egg)) and heart rate (HR) were monitored pre- and posttreatment. Upon hatching, hatchability, body weight, and body temperature were recorded. From 14 to 35 d of age, three quarters of the chickens in each treatment were raised under ascites-inducing conditions (AIC) and the remaining birds were raised under standard brooding conditions (SBC). The T(egg) and HR decreased significantly in response to increased exposure time on d 18 of incubation. On d 19 of incubation, before the second cold exposure, the 30 × 2 group showed greater T(egg) and HR than the controls, and during the second exposure they maintained these parameters better than the 60 × 2 embryos. No treatment effect on hatchability was observed. At 35 d of age ascites incidence among 30 × 2 chickens under AIC was significantly less than that among the controls (P < 0.01), and body weight of these chickens under either SBC or AIC was significantly higher than that of the controls. Under SBC relative breast muscle weight was significantly higher in 60 × 2 chickens, whereas the relative heart weight was higher in both cold-treated groups than in the controls. It can be concluded that repeated short acute cold exposures during late embryogenesis significantly reduced ascites incidence and improved growth rate under either SBC or AIC. These results may be related to a prenatal epigenetic adaptation of the thermoregulatory and cardiovascular systems to low ambient temperature.

  11. Estimated rate of fatal automobile accidents attributable to acute solvent exposure at low inhaled concentrations.

    PubMed

    Benignus, Vernon A; Bushnell, Philip J; Boyes, William K

    2011-12-01

    Acute solvent exposures may contribute to automobile accidents because they increase reaction time and decrease attention, in addition to impairing other behaviors. These effects resemble those of ethanol consumption, both with respect to behavioral effects and neurological mechanisms. These observations, along with the extensive data on the relationship between ethanol consumption and fatal automobile accidents, suggested a way to estimate the probability of fatal automobile accidents from solvent inhalation. The problem can be approached using the logic of the algebraic transitive postulate of equality: if A=B and B=C, then A=C. We first calculated a function describing the internal doses of solvent vapors that cause the same magnitude of behavioral impairment as ingestion of ethanol (A=B). Next, we fit a function to data from the literature describing the probability of fatal car crashes for a given internal dose of ethanol (B=C). Finally, we used these two functions to generate a third function to estimate the probability of a fatal car crash for any internal dose of organic solvent vapor (A=C). This latter function showed quantitatively (1) that the likelihood of a fatal car crash is increased by acute exposure to organic solvent vapors at concentrations less than 1.0 ppm, and (2) that this likelihood is similar in magnitude to the probability of developing leukemia from exposure to benzene. This approach could also be applied to other potentially adverse consequences of acute exposure to solvents (e.g., nonfatal car crashes, property damage, and workplace accidents), if appropriate data were available.

  12. Chromosomal Bands Affected by Acute Oil Exposure and DNA Repair Errors

    PubMed Central

    Zock, Jan-Paul; Giraldo, Jesús; Pozo-Rodríguez, Francisco; Espinosa, Ana; Rodríguez-Trigo, Gema; Verea, Hector; Castaño-Vinyals, Gemma; Gómez, Federico P.; Antó, Josep M.; Coll, Maria Dolors; Barberà, Joan Albert; Fuster, Carme

    2013-01-01

    Background In a previous study, we showed that individuals who had participated in oil clean-up tasks after the wreckage of the Prestige presented an increase of structural chromosomal alterations two years after the acute exposure had occurred. Other studies have also reported the presence of DNA damage during acute oil exposure, but little is known about the long term persistence of chromosomal alterations, which can be considered as a marker of cancer risk. Objectives We analyzed whether the breakpoints involved in chromosomal damage can help to assess the risk of cancer as well as to investigate their possible association with DNA repair efficiency. Methods Cytogenetic analyses were carried out on the same individuals of our previous study and DNA repair errors were assessed in cultures with aphidicolin. Results Three chromosomal bands, 2q21, 3q27 and 5q31, were most affected by acute oil exposure. The dysfunction in DNA repair mechanisms, expressed as chromosomal damage, was significantly higher in exposed-oil participants than in those not exposed (p= 0.016). Conclusion The present study shows that breaks in 2q21, 3q27 and 5q31 chromosomal bands, which are commonly involved in hematological cancer, could be considered useful genotoxic oil biomarkers. Moreover, breakages in these bands could induce chromosomal instability, which can explain the increased risk of cancer (leukemia and lymphomas) reported in chronically benzene-exposed individuals. In addition, it has been determined that the individuals who participated in clean-up of the oil spill presented an alteration of their DNA repair mechanisms two years after exposure. PMID:24303039

  13. Acute lethal toxicity of some reference chemicals to freshwater fishes of Scandinavia

    SciTech Connect

    Oikari, A.O.J.

    1987-07-01

    Relevance of the choice of a test organism intended to be representative for a given environment seems to be under continual debate in aquatic ecotoxicology. For instance, it is commonly argue that acute toxicity tests with rainbow trout, the species most often recommended as a standard cold water teleost, were not representative for Nordic countries because the species is an alien in local faunas. A comparative study with several freshwater species was therefore initiated to clarify the validity of this assumption. As a first approximation, standard LC 50 assays were conducted. The species used were chosen only on the basis of their local availability, i.e, they randomly represented the fish fauna of Nordic inland waters. Furthermore, inter-species variation of toxicity response was compared with certain other, quantitatively more important, intra-species sources of variability affecting the toxicity of chemicals. Use of reference toxicants has been recommended as a means of standardizing bioassays. Compounds, characteristic of effluents from the pulp and paper industry, were selected for the present study. The toxicity of organic acids such a phenols and resin acids, as well as that of pupmill effluents, strongly depends on water pH. Because of the possibility that species differences could exist in this respect, effects of water acidity on toxicity of these types of substances to a randomly selected local species was investigated. Finally, as an example of the biological source of assay variability, the effect of yolk absorption was studied with a subsequent crisis period due to moderate starvation under laboratory conditions.

  14. Development of Toxicological Risk Assessment Models for Acute and Chronic Exposure to Pollutants.

    PubMed

    Reichwaldt, Elke S; Stone, Daniel; Barrington, Dani J; Sinang, Som C; Ghadouani, Anas

    2016-08-31

    Alert level frameworks advise agencies on a sequence of monitoring and management actions, and are implemented so as to reduce the risk of the public coming into contact with hazardous substances. Their effectiveness relies on the detection of the hazard, but with many systems not receiving any regular monitoring, pollution events often go undetected. We developed toxicological risk assessment models for acute and chronic exposure to pollutants that incorporate the probabilities that the public will come into contact with undetected pollution events, to identify the level of risk a system poses in regards to the pollutant. As a proof of concept, we successfully demonstrated that the models could be applied to determine probabilities of acute and chronic illness types related to recreational activities in waterbodies containing cyanotoxins. Using the acute model, we identified lakes that present a 'high' risk to develop Day Away From Work illness, and lakes that present a 'low' or 'medium' risk to develop First Aid Cases when used for swimming. The developed risk models succeeded in categorising lakes according to their risk level to the public in an objective way. Modelling by how much the probability of public exposure has to decrease to lower the risks to acceptable levels will enable authorities to identify suitable control measures and monitoring strategies. We suggest broadening the application of these models to other contaminants.

  15. Development of Toxicological Risk Assessment Models for Acute and Chronic Exposure to Pollutants

    PubMed Central

    Reichwaldt, Elke S.; Stone, Daniel; Barrington, Dani J.; Sinang, Som C.; Ghadouani, Anas

    2016-01-01

    Alert level frameworks advise agencies on a sequence of monitoring and management actions, and are implemented so as to reduce the risk of the public coming into contact with hazardous substances. Their effectiveness relies on the detection of the hazard, but with many systems not receiving any regular monitoring, pollution events often go undetected. We developed toxicological risk assessment models for acute and chronic exposure to pollutants that incorporate the probabilities that the public will come into contact with undetected pollution events, to identify the level of risk a system poses in regards to the pollutant. As a proof of concept, we successfully demonstrated that the models could be applied to determine probabilities of acute and chronic illness types related to recreational activities in waterbodies containing cyanotoxins. Using the acute model, we identified lakes that present a ‘high’ risk to develop Day Away From Work illness, and lakes that present a ‘low’ or ‘medium’ risk to develop First Aid Cases when used for swimming. The developed risk models succeeded in categorising lakes according to their risk level to the public in an objective way. Modelling by how much the probability of public exposure has to decrease to lower the risks to acceptable levels will enable authorities to identify suitable control measures and monitoring strategies. We suggest broadening the application of these models to other contaminants. PMID:27589798

  16. Hormetic Effects of Acute Methylmercury Exposure on Grp78 Expression in Rat Brain Cortex

    PubMed Central

    Zhang, Ye; Lu, Rongzhu; Liu, Wenshuai; Wu, Ying; Qian, Hai; Zhao, Xiaowu; Wang, Suhua; Xing, Guangwei; Yu, Feng; Aschner, Michael

    2013-01-01

    This study aims to explore the expression of GRP78, a marker of endoplasmic reticulum (ER) stress, in the cortex of rat brains acutely exposed to methylmercury (MeHg). Thirty Sprague-Dawley (SD) rats were randomly divided into six groups, and decapitated 6 hours (h) after intraperitoneal (i.p.) injection of MeHg (2, 4, 6, 8 or 10 mg/kg body weight) or normal saline. Protein and mRNA expression of Grp78 were detected by western blotting and real-time PCR, respectively. The results showed that a gradual increase in GRP78 protein expression was observed in the cortex of rats acutely exposed to MeHg (2, 4 or 6 mg/kg). Protein levels peaked in the 6 mg/kg group (p < 0.05 vs. controls), decreased in the 8 mg/kg group, and bottomed below the control level in the 10 mg/kg group. Parallel changes were noted for Grp78 mRNA expression. It may be implied that acute exposure to MeHg induced hormetic dose-dependent changes in Grp78 mRNA and protein expression, suggesting that activation of ER stress is involved in MeHg-induced neurotoxicity. Low level MeHg exposure may induce GRP78 protein expression to stimulate endogenous cytoprotective mechanisms. PMID:23549286

  17. Assessing the Effects of Acute Amyloid β Oligomer Exposure in the Rat

    PubMed Central

    Wong, Ryan S.; Cechetto, David F.; Whitehead, Shawn N.

    2016-01-01

    Alzheimer’s disease (AD) is the most common form of dementia, yet there are no therapeutic treatments that can either cure or delay its onset. Currently, the pathogenesis of AD is still uncertain, especially with respect to how the disease develops from a normal healthy brain. Amyloid β oligomers (AβO) are highly neurotoxic proteins and are considered potential initiators to the pathogenesis of AD. Rat brains were exposed to AβO via bilateral intracerebroventricular injections. Rats were then euthanized at either 1, 3, 7 or 21-days post surgery. Rat behavioural testing was performed using the Morris water maze and open field tests. Post-mortem brain tissue was immunolabelled for Aβ, microglia, and cholinergic neurons. Rats exposed to AβO showed deficits in spatial learning and anxiety-like behaviour. Acute positive staining for Aβ was only observed in the corpus callosum surrounding the lateral ventricles. AβO exposed rat brains also showed a delayed increase in activated microglia within the corpus callosum and a decreased number of cholinergic neurons within the basal forebrain. Acute exposure to AβO resulted in mild learning and memory impairments with co-concomitant white matter pathology within the corpus callosum and cholinergic cell loss within the basal forebrain. Results suggest that acute exposure to AβO in the rat may be a useful tool in assessing the early phases for the pathogenesis of AD. PMID:27563885

  18. Acute respiratory toxicity following inhalation exposure to soman in guinea pigs

    SciTech Connect

    Perkins, Michael W.; Pierre, Zdenka; Rezk, Peter; Sabnekar, Praveena; Sciuto, Alfred M.; Nambiar, Madhusoodana P.

    2010-06-01

    Respiratory toxicity and lung injury following inhalation exposure to chemical warfare nerve agent soman was examined in guinea pigs without therapeutics to improve survival. A microinstillation inhalation exposure technique that aerosolizes the agent in the trachea was used to administer soman to anesthetized age and weight matched male guinea pigs. Animals were exposed to 280, 561, 841, and 1121 mg/m{sup 3} concentrations of soman for 4 min. Survival data showed that all saline controls and animals exposed to 280 and 561 mg/m{sup 3} soman survived, while animals exposed to 841, and 1121 mg/m{sup 3} resulted in 38% and 13% survival, respectively. The microinstillation inhalation exposure LCt{sub 50} for soman determined by probit analysis was 827.2 mg/m{sup 3}. A majority of the animals that died at 1121 mg/m{sup 3} developed seizures and died within 15-30 min post-exposure. There was a dose-dependent decrease in pulse rate and blood oxygen saturation of animals exposed to soman at 5-6.5 min post-exposure. Body weight loss increased with the dose of soman exposure. Bronchoalveolar lavage (BAL) fluid and blood acetylcholinesterase and butyrylcholinesterase activity was inhibited dose-dependently in soman treated groups at 24 h. BAL cells showed a dose-dependent increase in cell death and total cell counts following soman exposure. Edema by wet/dry weight ratio of the accessory lung lobe and trachea was increased slightly in soman exposed animals. An increase in total bronchoalveolar lavage fluid protein was observed in soman exposed animals at all doses. Differential cell counts of BAL and blood showed an increase in total lymphocyte counts and percentage of neutrophils. These results indicate that microinstillation inhalation exposure to soman causes respiratory toxicity and acute lung injury in guinea pigs.

  19. Choosing optimal exposure times for XRF core-scanning: Suggestions based on the analysis of geological reference materials

    NASA Astrophysics Data System (ADS)

    Huang, Jyh-Jaan; Löwemark, Ludvig; Chang, Queenie; Lin, Tzu-Yu; Chen, Huei-Fen; Song, Sheng-Rong; Wei, Kuo-Yen

    2016-04-01

    X-ray fluorescence (XRF) core-scanning is a fast and nondestructive technique to assess elemental variations of unprocessed sediments. However, although the exposure time of XRF-scanning directly affects the scanning counts and total measurement time, only a few studies have considered the influence of exposure time during the scan. How to select an optimal exposure time to achieve reliable results and reduce the total measurement time is an important issue. To address this question, six geological reference materials from the Geological Survey of Japan (JLK-1, JMS-1, JMS-2, JSD-1, JSD-2, and JSD-3) were scanned by the Itrax-XRF core scanner using the Mo- and the Cr-tube with different exposure times to allow a comparison of scanning counts with absolute concentrations. The regression lines and correlation coefficients of elements that are generally used in paleoenvironmental studies were examined for the different exposure times and X-ray tubes. The results show that for those elements with relatively high concentrations or high detectability, the correlation coefficients are higher than 0.90 for all exposure times. In contrast, for the low detectability or low concentration elements, the correlation coefficients are relatively low, and improve little with increased exposure time. Therefore, we suggest that the influence of different exposure times is insignificant for the accuracy of the measurements. Thus, caution must be taken when interpreting the results of elements with low detectability, even when the exposure times are long and scanning counts are reasonably high.

  20. Acute pulmonary toxicity following inhalation exposure to aerosolized VX in anesthetized rats.

    PubMed

    Peng, Xinqi; Perkins, Michael W; Simons, Jannitt; Witriol, Alicia M; Rodriguez, Ashley M; Benjamin, Brittany M; Devorak, Jennifer; Sciuto, Alfred M

    2014-06-01

    This study evaluated acute toxicity and pulmonary injury in rats at 3, 6 and 24 h after an inhalation exposure to aerosolized O-ethyl S-[2-(diisopropylamino)ethyl] methylphosphonothioate (VX). Anesthetized male Sprague-Dawley rats (250-300 g) were incubated with a glass endotracheal tube and exposed to saline or VX (171, 343 and 514 mg×min/m³ or 0.2, 0.5 and 0.8 LCt₅₀, respectively) for 10 min. VX was delivered by a small animal ventilator at a volume of 2.5 ml × 70 breaths/minute. All VX-exposed animals experienced a significant loss in percentage body weight at 3, 6, and 24 h post-exposure. In comparison to controls, animals exposed to 514 mg×min/m³ of VX had significant increases in bronchoalveolar lavage (BAL) protein concentrations at 6 and 24 h post-exposure. Blood acetylcholinesterase (AChE) activity was inhibited dose dependently at each of the times points for all VX-exposed groups. AChE activity in lung homogenates was significantly inhibited in all VX-exposed groups at each time point. All VX-exposed animals assessed at 20 min and 3, 6 and 24 h post-exposure showed increases in lung resistance, which was prominent at 20 min and 3 h post-exposure. Histopathologic evaluation of lung tissue of the 514 mg×min/m³ VX-exposed animals at 3, 6 and 24 h indicated morphological changes, including perivascular inflammation, alveolar exudate and histiocytosis, alveolar septal inflammation and edema, alveolar epithelial necrosis, and bronchiolar inflammatory infiltrates, in comparison to controls. These results suggest that aerosolization of the highly toxic, persistent chemical warfare nerve agent VX results in acute pulmonary toxicity and lung injury in rats.

  1. Acute Infections and Environmental Exposure to Organochlorines in Inuit Infants from Nunavik

    PubMed Central

    Dallaire, Frédéric; Dewailly, Éric; Muckle, Gina; Vézina, Carole; Jacobson, Sandra W.; Jacobson, Joseph L.; Ayotte, Pierre

    2004-01-01

    The Inuit population of Nunavik (Canada) is exposed to immunotoxic organochlorines (OCs) mainly through the consumption of fish and marine mammal fat. We investigated the effect of perinatal exposure to polychlorinated biphenyls (PCBs) and dichlorodiphenyldichloroethylene (DDE) on the incidence of acute infections in Inuit infants. We reviewed the medical charts of a cohort of 199 Inuit infants during the first 12 months of life and evaluated the incidence rates of upper and lower respiratory tract infections (URTI and LRTIs, respectively), otitis media, and gastrointestinal (GI) infections. Maternal plasma during delivery and infant plasma at 7 months of age were sampled and assayed for PCBs and DDE. Compared to rates for infants in the first quartile of exposure to PCBs (least exposed), adjusted rate ratios for infants in higher quartiles ranged between 1.09 and 1.32 for URTIs, 0.99 and 1.39 for otitis, 1.52 and 1.89 for GI infections, and 1.16 and 1.68 for LRTIs during the first 6 months of follow-up. For all infections combined, the rate ratios ranged from 1.17 to 1.27. The effect size was similar for DDE exposure but was lower for the full 12-month follow-up. Globally, most rate ratios were > 1.0, but few were statistically significant (p < 0.05). No association was found when postnatal exposure was considered. These results show a possible association between prenatal exposure to OCs and acute infections early in life in this Inuit population. PMID:15471725

  2. Acute Exposure to Pacific Ciguatoxin Reduces Electroencephalogram Activity and Disrupts Neurotransmitter Metabolic Pathways in Motor Cortex.

    PubMed

    Kumar, Gajendra; Au, Ngan Pan Bennett; Lei, Elva Ngai Yu; Mak, Yim Ling; Chan, Leanne Lai Hang; Lam, Michael Hon Wah; Chan, Leo Lai; Lam, Paul Kwan Sing; Ma, Chi Him Eddie

    2016-09-10

    Ciguatera fish poisoning (CFP) is a common human food poisoning caused by consumption of ciguatoxin (CTX)-contaminated fish affecting over 50,000 people worldwide each year. CTXs are classified depending on their origin from the Pacific (P-CTXs), Indian Ocean (I-CTXs), and Caribbean (C-CTXs). P-CTX-1 is the most toxic CTX known and the major source of CFP causing an array of neurological symptoms. Neurological symptoms in some CFP patients last for several months or years; however, the underlying electrophysiological properties of acute exposure to CTXs remain unknown. Here, we used CTX purified from ciguatera fish sourced in the Pacific Ocean (P-CTX-1). Delta and theta electroencephalography (EEG) activity was reduced remarkably in 2 h and returned to normal in 6 h after a single exposure. However, second exposure to P-CTX-1 induced not only a further reduction in EEG activities but also a 2-week delay in returning to baseline EEG values. Ciguatoxicity was detected in the brain hours after the first and second exposure by mouse neuroblastoma assay. The spontaneous firing rate of single motor cortex neuron was reduced significantly measured by single-unit recording with high spatial resolution. Expression profile study of neurotransmitters using targeted profiling approach based on liquid chromatography-tandem mass spectrometry revealed an imbalance between excitatory and inhibitory neurotransmitters in the motor cortex. Our study provides a possible link between the brain oscillations and neurotransmitter release after acute exposure to P-CTX-1. Identification of EEG signatures and major metabolic pathways affected by P-CTX-1 provides new insight into potential biomarker development and therapeutic interventions.

  3. Acute and chronic cadmium exposure promotes E-cadherin degradation in MCF7 breast cancer cells.

    PubMed

    Ponce, Esmeralda; Louie, Maggie C; Sevigny, Mary B

    2015-10-01

    Cadmium is an environmental carcinogen that usually enters the body at minute concentrations through diet or cigarette smoke and bioaccumulates in soft tissues. In past studies, cadmium has been shown to contribute to the development of more aggressive cancer phenotypes including increased cell migration and invasion. This study aims to determine if cadmium exposure-both acute and chronic-contributes to breast cancer progression by interfering with the normal functional relationship between E-cadherin and β-catenin. An MCF7 breast cancer cell line (MCF7-Cd) chronically exposed to 10(-7)  M CdCl2 was previously developed and used as a model system to study chronic exposures, whereas parental MCF7 cells exposed to 10(-6)  M CdCl2 for short periods of time were used to study acute exposures. Cadmium exposure of MCF7 cells led to the degradation of the E-cadherin protein via the ubiquitination pathway. This resulted in fewer E-cadherin/β-catenin complexes and the relocation of active β-catenin to the nucleus, where it interacted with transcription factor TCF-4 to modulate gene expression. Interestingly, only cells chronically exposed to cadmium showed a significant decrease in the localization of β-catenin to the plasma membrane and an increased distance between cells. Our data suggest that cadmium exposure promotes breast cancer progression by (1) down-regulating E-cadherin, thus decreasing the number of E-cadherin/β-catenin adhesion complexes, and (2) enhancing the nuclear translocation of β-catenin to increase expression of cancer-promoting proteins (i.e., c-Jun and cyclin D1).

  4. Acute and subacute exposure to malathion impairs aversive but not non-associative memory in rats.

    PubMed

    Valvassori, Samira S; Fortunato, Jucélia J; Gomes, Karin M; Réus, Gislaine Z; Martins, Márcio R; Gavioli, Elaine C; Schetinger, Maria Rosa C; Dal-Pizzol, Felipe; Quevedo, João

    2007-07-01

    Malathion [S-(1,2-dicarbethoxy) ethyl-0,0-dimethyl-phosphorodithioate] is an organophosphorus compound that is widely used as pesticide especially in developing countries. This pesticide affects the central nervous system by inhibiting acetylcholinesterase, leading to an increase of acetylcholine in the synaptic cleft, and subsequent activation of cholinergic muscarinic and nicotinic receptors. In humans, intoxication with organophosphates causes a wide range of neurological symptoms, including memory deficits. The present study was aimed to investigate the effects of the acute (1 h prior the test) and subacute (once a day for 28 days) exposure to malathion at doses of 25, 50, 100 and 150 mg/kg in rats tested in the step-down inhibitory avoidance task, open-field habituation and elevated plus-maze tests. Interestingly, the acute and subacute treatment with malathion impaired aversive-memory in the step-down inhibitory avoidance task, but did not alter the animal performance in the elevated plus-maze and in the habituation to the open-field tests, and neither modified spontaneous locomotion. The activity of acetylcholinesterase enzyme was significantly reduced after subacute, but not acute, treatment with malathion (25, 100 and 150 mg/kg). Our results suggest that malathion impairs aversive-memory retention but not non-associative memory, without affecting anxiety-related behaviors. These findings support the view that the inhibition of acetylcholinesterase enzyme is not correlated with cognitive deficits observed in acute and subacute malathion-treated rats.

  5. Neurotoxicity of FireMaster 550® in zebrafish (Danio rerio): Chronic developmental and acute adolescent exposures

    PubMed Central

    Bailey, J.M.; Levin, E.D.

    2015-01-01

    BACKGROUND FireMaster® 550 (FM 550) is the second most commonly used flame retardant (FR) product in consumer goods and has been detected in household dust samples. However, neurobehavioral effects associated with exposure have not been characterized in detail. We investigated the behavioral effects of FM 550 in zebrafish to facilitate the integration of the cellular and molecular effects of FM 550 with its behavioral consequences. The effects of developmental FM 550 exposure on zebrafish larvae swimming shortly after the end of exposure as well as the persisting effects of this exposure on adolescent behavior were studied. In addition, the acute effects of FM 550 on behavior with exposure during adolescence in zebrafish were studied. METHODS Developmental exposure to 0, 0.01, 0.1 or 1 mg/L of FM 550 via immersion spanned 0–5 days post fertilization, with larval testing on day 6 and adolescent testing on days 40–45. Acute adolescent (45 dpf) exposure was to 0, 1.0 or 3.0 mg/L of FM 550 via immersion, for 24 hrs, with testing 2 hr or 1 week later. The vehicle condition was colony tank water with .0004% (developmental) or .0012% (adolescent) DMSO. Zebrafish behavior was characterized across several domains including learning, social affiliation, sensorimotor function, predator escape, and novel environment exploration. RESULTS Persisting effects of developmental FM 550 exposure included a significant (p < 0.01) reduction in social behavior among all dose groups. Acute FM550 exposure during adolescence caused hypoactivity and reduced social behavior (p’s < 0.05) when the fish were tested 2 hr after exposure. These effects were attenuated at the 1 week post exposure testing point. DISCUSSION Taken together, these data indicate that FM 550 may cause persisting neurobehavioral alterations to social behavior in the absence of perturbations along other behavioral domains and that developmental exposure is more costly to the organism than acute adolescent exposure

  6. Geographical distribution of acute symptoms after a train collision involving epichlorohydrin exposure.

    PubMed

    Radon, Katja; Rosenberger, Armin; Ehrenstein, Vera; Hoopmann, Michael; Basting, Imke; Tödt, Helga; Reichert, Jörg; Dressel, Holger; Schmid, Martina; Suchenwirth, Roland; Nowak, Dennis

    2006-09-01

    In September 2002, two freight trains collided in a northern German town. The inhabitants were potentially exposed to the probable human carcinogen epichlorohydrin. As no objective data on the level of exposure were available, we aimed to assess the geographical distribution of acute symptoms among local residents and subjects occupationally involved in the accident (e.g., firemen). A random sample of 932 adult local residents and 342 occupationally involved subjects were invited to answer a mail-in questionnaire. The main outcome measures were self-reported acute symptoms potentially associated with combustion products (e.g., irritation of the eyes, nose, or throat) and stress-related nonspecific symptoms. The main location during the first 26 h after the accident served as exposure proxy. For occupationally involved subjects, the time spent at the accident site was also used. The overall prevalence of symptoms potentially associated with combustion products was 9.8% for residents and 25.4% for occupationally involved subjects. After adjustment, subjects whose main location was close to the accident site had an increased risk for such symptoms. Among occupationally involved subjects the risk increased with duration at the accident site. Neither main location nor time at the accident site was significantly associated with non-specific symptoms. We could provide an example for designing and carrying out an epidemiologic study shortly after a local accident with potential public health impact. We could define parts of the population at increased risk for symptoms potentially specific for the exposure under study.

  7. Acute exposure to DE-71: effects on locomotor behavior and developmental neurotoxicity in zebrafish larvae.

    PubMed

    Chen, Lianguo; Huang, Changjiang; Hu, Chenyan; Yu, Ke; Yang, Lihua; Zhou, Bingsheng

    2012-10-01

    The aim of the present study was to investigate the acute developmental neurotoxicity of polybrominated diphenyl ethers (PBDEs) in zebrafish larvae. From 2 to 120 h postfertilization zebrafish embryos were exposed to DE-71 (0, 31.0, 68.7, and 227.6 µg/L). The authors studied the locomotor behavior of larvae, involvement of the cholinergic system, and selected gene and protein expressions in the central nervous system. The results showed that low DE-71 concentration caused hyperactivity, whereas higher concentrations decreased activity during the dark period. During the light period, larval activity was significantly reduced in a concentration-dependent manner. In the cholinergic system, acetylcholinesterase activity significantly increased (10.7 and 12.4%) in the 68.7 and 227.6 µg/L exposure groups, respectively, and acetylcholine concentration accordingly decreased (60.5%) in the 227.6 µg/L exposure group. The mRNA expressions of genes encoding myelin basic protein, neuron microtubule protein (α1-tubulin), and sonic hedgehog a were significantly downregulated. Western blotting assay demonstrated that the protein concentration of α1-tubulin was also decreased. Overall, the present study demonstrated that acute exposure to PBDEs can disrupt the neurobehavior of zebrafish larvae and affect cholinergic neurotransmission and neuron development.

  8. Dexamethasone exposure and asparaginase antibodies affect relapse risk in acute lymphoblastic leukemia.

    PubMed

    Kawedia, Jitesh D; Liu, Chengcheng; Pei, Deqing; Cheng, Cheng; Fernandez, Christian A; Howard, Scott C; Campana, Dario; Panetta, John C; Bowman, W Paul; Evans, William E; Pui, Ching-Hon; Relling, Mary V

    2012-02-16

    We have previously hypothesized that higher systemic exposure to asparaginase may cause increased exposure to dexamethasone, both critical chemotherapeutic agents for acute lymphoblastic leukemia. Whether interpatient pharmaco-kinetic differences in dexamethasone contribute to relapse risk has never been studied. The impact of plasma clearance of dexamethasone and anti-asparaginase antibody levels on risk of relapse was assessed in 410 children who were treated on a front-line clinical trial for acute lymphoblastic leukemia and were evaluable for all pharmacologic measures, using multivariate analyses, adjusting for standard clinical and biologic prognostic factors. Dexamethasone clearance (mean ± SD) was higher (P = 3 × 10(-8)) in patients whose sera was positive (17.7 ± 18.6 L/h per m(2)) versus nega-tive (10.6 ± 5.99 L/h per m(2)) for anti-asparaginase antibodies. In multivariate analyses, higher dexamethasone clearance was associated with a higher risk of any relapse (P = .01) and of central nervous system relapse (P = .014). Central nervous system relapse was also more common in patients with anti-asparaginase antibodies (P = .019). In conclusion, systemic clearance of dexamethasone is higher in patients with anti-asparaginase antibodies. Lower exposure to both drugs was associated with an increased risk of relapse.

  9. Acute toxicity effects of Prunus avium fruit extract and selection of optimum dose against radiation exposure.

    PubMed

    Sisodia, Rashmi; Sharma, K; Singh, Smita

    2009-01-01

    The objective of the study was to evaluate the acute toxicity of different doses of the methanolic extract of the fruit pulp of Prunus avium (family Rosaceae), which is used ethno-medicinally for the treatment of various diseases, and to find out the optimal dose of Prunus avium extract against 10 Gy gamma-radiation exposure. To test acute toxicity in mice, different doses of PAE (Prunus avium fruit extract) were given orally for 15 consecutive days, after which the animals were observed for another 15 days; the LD50/15 of the methanolic extract was calculated to be 4.947 gm/kg body weight (b.wt). In optimum dose selection against radiation exposure, oral administration of 450 mg/kg b.wt/d of PAE for 15 consecutive days before exposure to 10 Gy of gamma-radiation was found to afford maximum protection in terms of body weight and survivability of the mice in comparison to other doses.

  10. Acute pulmonary effects of nitrogen dioxide exposure during exercise in competitive athletes

    SciTech Connect

    Kim, S.U.; Koenig, J.Q.; Pierson, W.E.; Hanley, Q.S. )

    1991-04-01

    The acute pulmonary responses of athletes after short-term exposure to ambient concentrations of NO{sub 2} during heavy exercise have been examined. Intercollegiate male athletes were screened for history of cardiac disease, respiratory disease, allergic conditions and extensive exposure to pollutants. After completion of serum IgE level determination, exercise tolerance test and methacholine challenge test with normal results, nine healthy subjects 18 to 23 years of age were exposed to filtered air and to 0.18 and 0.30 ppm NO{sub 2} for 30 min on different days while exercising on a treadmill. Pulmonary function parameters were measured before and after each exposure. In this study, no statistically significant changes were observed in FEV1, RT PEFR, and Vmax50% after exposure to 0.18 and 0.30 ppm NO{sub 2}. For these selected healthy athletes, short-term exposure to ambient NO{sub 2} levels during heavy exercise does not affect adversely the pulmonary function.

  11. Temporal Changes in Rat Liver Gene Expression after Acute Cadmium and Chromium Exposure

    PubMed Central

    Madejczyk, Michael S.; Baer, Christine E.; Dennis, William E.; Minarchick, Valerie C.; Leonard, Stephen S.; Jackson, David A.; Stallings, Jonathan D.; Lewis, John A.

    2015-01-01

    U.S. Service Members and civilians are at risk of exposure to a variety of environmental health hazards throughout their normal duty activities and in industrial occupations. Metals are widely used in large quantities in a number of industrial processes and are a common environmental toxicant, which increases the possibility of being exposed at toxic levels. While metal toxicity has been widely studied, the exact mechanisms of toxicity remain unclear. In order to further elucidate these mechanisms and identify candidate biomarkers, rats were exposed via a single intraperitoneal injection to three concentrations of CdCl2 and Na2Cr2O7, with livers harvested at 1, 3, or 7 days after exposure. Cd and Cr accumulated in the liver at 1 day post exposure. Cd levels remained elevated over the length of the experiment, while Cr levels declined. Metal exposures induced ROS, including hydroxyl radical (•OH), resulting in DNA strand breaks and lipid peroxidation. Interestingly, ROS and cellular damage appeared to increase with time post-exposure in both metals, despite declines in Cr levels. Differentially expressed genes were identified via microarray analysis. Both metals perturbed gene expression in pathways related to oxidative stress, metabolism, DNA damage, cell cycle, and inflammatory response. This work provides insight into the temporal effects and mechanistic pathways involved in acute metal intoxication, leading to the identification of candidate biomarkers. PMID:25993096

  12. Effects of acute low-level microwaves on pentobarbital-induced hypothermia depend on exposure orientation

    SciTech Connect

    Lai, H.; Horita, A.; Chou, C.K.; Guy, A.W.

    1984-01-01

    Two series of experiments were performed to study the effects of acute exposure (45 min) to 2,450-MHz circularly polarized, pulsed microwaves (1 mW/cm2, 2-mus pulses, 500 pps, specific absorption rate (SAR) 0.6 W/kg) on the actions of pentobarbital in the rat. In the first experiment, rats were irradiated with microwaves and then immediately injected with pentobarbital. Microwave exposure did not significantly affect the extent of the pentobarbital-induced fall in colonic temperature. However, the rate of recovery from the hypothermia was significantly slower in the microwave-irradiated rats and they also took a significantly longer time to regain their righting reflex. In a second experiment, rats were first anesthetized with pentobarbital and then exposed to microwaves with their heads either pointing toward the source of microwaves (anterior exposure) or pointing away (posterior exposure). Microwave radiation significantly retarded the pentobarbital-induced fall in colonic temperature regardless of the orientation of exposure. However, the recovery from hypothermia was significantly faster in posterior-exposed animals compared to those of the anterior-exposed and sham-irradiated animals. Furthermore, the posterior-exposed rats took a significantly shorter time to regain their righting reflex than both the anterior-exposed and sham-irradiated animals.

  13. Indoor residential radon exposure and risk of childhood acute myeloid leukaemia

    PubMed Central

    Steinbuch, M; Weinberg, C R; Buckley, J D; Robison, L L; Sandler, D P

    1999-01-01

    Exposure to radon has been identified as a risk factor for lung cancer in uranium miners, but evidence of adverse health effects due to indoor radon exposure is inconsistent. Ecological studies have suggested a correlation between indoor radon levels and leukaemia incidence. We evaluated the risk associated with indoor residential radon exposure within a larger interview-based case–control study of risk factors for childhood acute myeloid leukaemia (AML). A total of 173 cases and 254 controls met the eligibility criteria, and information was collected through telephone interviews with parents and analysis of alpha-track radon detectors placed in the home for a period of 1 year. No association was observed between radon exposure and risk of AML, with adjusted odds ratios of 1.2 (95% confidence interval (CI) 0.7–1.8) for 37–100 Bq m–3 and 1.1 (95% CI 0.6–2.0) for > 100 Bq m–3 compared with < 37 Bq m–3. Although there was an inverse association between radon level and AML risk among children < 2 years at diagnosis, among children ≥2 years, AML risk was increased among those with higher radon exposure. The observed association after age 2 is most likely due to chance. Overall, there was no association between residential radon and risk of childhood AML. © 1999 Cancer Research Campaign PMID:10555766

  14. Acute Exposure to Crystalline Silica Reduces Macrophage Activation in Response to Bacterial Lipoproteins

    PubMed Central

    Beamer, Gillian L.; Seaver, Benjamin P.; Jessop, Forrest; Shepherd, David M.; Beamer, Celine A.

    2016-01-01

    Numerous studies have examined the relationship between alveolar macrophages (AMs) and crystalline silica (SiO2) using in vitro and in vivo immunotoxicity models; however, exactly how exposure to SiO2 alters the functionality of AM and the potential consequences for immunity to respiratory pathogens remains largely unknown. Because recognition and clearance of inhaled particulates and microbes are largely mediated by pattern recognition receptors (PRRs) on the surface of AM, we hypothesized that exposure to SiO2 limits the ability of AM to respond to bacterial challenge by altering PRR expression. Alveolar and bone marrow-derived macrophages downregulate TLR2 expression following acute SiO2 exposure (e.g., 4 h). Interestingly, these responses were dependent on interactions between SiO2 and the class A scavenger receptor CD204, but not MARCO. Furthermore, SiO2 exposure decreased uptake of fluorescently labeled Pam2CSK4 and Pam3CSK4, resulting in reduced secretion of IL-1β, but not IL-6. Collectively, our data suggest that SiO2 exposure alters AM phenotype, which in turn affects their ability to uptake and respond to bacterial lipoproteins. PMID:26913035

  15. Repeated exposure to modern volatile anaesthetics may cause chronic hepatitis as well as acute liver injury.

    PubMed

    Nicoll, Amanda; Moore, David; Njoku, Dolores; Hockey, Brad

    2012-11-06

    Volatile anaesthetic agents are known to cause acute hepatitis and fulminant hepatic failure in susceptible individuals. Four patients were identified with prolonged liver injury due to volatile anaesthetic-induced hepatitis. Three had liver biopsy confirmation and all gave blood for specific diagnostic tests (TFA and CYP 2E1 IgG4 antibodies). The Roussel Uclaf Causality Assessment Method (RUCAM) drug causality scale was used to determine the likelihood of volatile anaesthetics causing the chronic liver injury. We describe four cases of volatile anaesthetic hepatitis in which three evolved into chronic hepatitis. The fourth followed a more typical pattern of acute hepatitis; however, resolution took a few months. These cases all occurred with modern volatile anaesthetics, predominantly sevoflurane, and all cases were proven with specific antibody tests, liver histology and a drug causality scale. This is the first report of chronic liver injury due to volatile anaesthetic exposure.

  16. Repeated exposure to modern volatile anaesthetics may cause chronic hepatitis as well as acute liver injury

    PubMed Central

    Nicoll, Amanda; Moore, David; Njoku, Dolores; Hockey, Brad

    2012-01-01

    Volatile anaesthetic agents are known to cause acute hepatitis and fulminant hepatic failure in susceptible individuals. Four patients were identified with prolonged liver injury due to volatile anaesthetic-induced hepatitis. Three had liver biopsy confirmation and all gave blood for specific diagnostic tests (TFA and CYP 2E1 IgG4 antibodies). The Roussel Uclaf Causality Assessment Method (RUCAM) drug causality scale was used to determine the likelihood of volatile anaesthetics causing the chronic liver injury. We describe four cases of volatile anaesthetic hepatitis in which three evolved into chronic hepatitis. The fourth followed a more typical pattern of acute hepatitis; however, resolution took a few months. These cases all occurred with modern volatile anaesthetics, predominantly sevoflurane, and all cases were proven with specific antibody tests, liver histology and a drug causality scale. This is the first report of chronic liver injury due to volatile anaesthetic exposure. PMID:23131606

  17. Electrophysiologic and behavioral effects of perinatal and acute exposure of rats to lead and polychlorinated biphenyls.

    PubMed Central

    Carpenter, David O; Hussain, Rifat J; Berger, David F; Lombardo, John P; Park, Hye-Youn

    2002-01-01

    Lead and polychlorinated biphenyls (PCBs) both cause a reduction of intelligence quotient and behavioral abnormalities in exposed children that have features in common with attention deficit hyperactivity disorder. We have used rats as a model to study the effects of both perinatal and acute exposure to lead or PCBs in an effort to compare and understand the mechanisms of these nervous system decrements. Long-term potentiation (LTP) is an electrophysiologic measurement that correlates well with cognitive ability. We have determined the effects of chronic perinatal exposure to lead or PCB 153 as well as acute application of these substances to isolated brain slices, with recordings in two areas of the hippocampus, CA1 and CA3. Both substances, whether chronically or acutely applied, significantly reduced LTP in CA1 in animals at age 30 and 60 days. In CA3, they reduced LTP in 30-day animals but potentiated it in 60-day animals. Although neither lead nor PCB 153 alters baseline synaptic transmission at low stimulus strengths, at higher levels they induce changes in the same direction as those of LTP. These results show surprisingly similar actions of these quite different chemicals, and the similarity of effects on chronic and acute application indicates that effects are both pharmacologic and developmental. Behavioral studies of rats exposed to PCBs from contaminated fish show hyperactivity, impulsiveness, and increased frustration relative to unexposed controls. These results demonstrate that lead and PCBs have similar effects on synaptic plasticity and behavior and suggest that the compounds may act through a common mechanism. PMID:12060832

  18. Acute paraquat exposure impairs colonic motility by selectively attenuating nitrergic signalling in the mouse.

    PubMed

    Diss, Lucy; Dyball, Sarah; Ghela, Tina; Golding, Jonathan; Morris, Rachel; Robinson, Stephen; Tucker, Rosemary; Walter, Talia; Young, Paul; Allen, Marcus; Fidalgo, Sara; Gard, Paul; Mabley, Jon; Patel, Bhavik; Chatterjee, Prabal; Yeoman, Mark

    2016-02-01

    Paraquat, a common herbicide, is responsible for large numbers of deaths worldwide through both deliberate and accidental ingestion. Previous studies have eluded that the bioavailability of paraquat increases substantially with increasing dose and that these changes may in part be due to the effects that these high concentrations have on the gastrointestinal tract (GI tract). To date, the actions of acute, high concentrations (20mM for 60 min) of paraquat on the GI tract, particularly the colon which is a major site of paraquat absorption, are unknown. This study examined the effects of acute paraquat administration on colonic motility in the C57BL/6 mouse. Acute paraquat exposure decreased colonic motility and the amplitude of colonic migrating motor complexes (CMMCs), which are major motor patterns involved in faecal pellet propulsion. In isolated segments of distal colon, paraquat increased resting tension and markedly attenuated electrical field stimulation-evoked relaxations. Pharmacological dissection of paraquat's mechanism of action on both the CMMCs and field stimulated tissue using the nitric oxide synthase inhibitor NG-nitro-L-arginine and direct measurement of NO release from the myenteric plexus, demonstrated that paraquat selectively attenuates nitrergic signalling pathways. These changes did not appear to be due to alterations in colonic oxidative stress, inflammation or complex 1 activity, but were most likely caused by paraquat's ability to act as a redox couple. In summary, these data demonstrate that acute paraquat exposure attenuates colonic transit. These changes may facilitate the absorption of paraquat into the circulation and so facilitate its toxicity.

  19. Modeling Acute Health Effects of Astronauts from Exposure to Large Solar Particle Events

    NASA Technical Reports Server (NTRS)

    Hu, Shaowen; Kim, Myung-Hee Y.; Cucinotta, Francis A.

    2011-01-01

    In space exploration outside the Earth s geomagnetic field, radiation exposure from solar particle events (SPE) presents a health concern for astronauts, that could impair their performance and result in possible failure of the mission. Acute risks are of special concern during extra-vehicular activities because of the rapid onset of SPE. However, most SPEs will not lead to acute risks but can lead to mission disruption if accurate projection methods are not available. Acute Radiation Sickness (ARS) is a group of clinical syndromes developing acutely (within several seconds to 3 days) after high dose whole-body or significant partial-body ionizing radiation exposures. The manifestation of these syndromes reflects the disturbance of physiological processes of various cellular groups damaged by radiation. Hematopoietic cells, skin, epithelium, intestine, and vascular endothelium are among the most sensitive tissues of human body to ionizing radiation. Most ARS symptoms are directly related to these tissues and other systems (nervous, endocrine, and cardiovascular, etc.) with coupled regulations. Here we report the progress in bio-mathematical models to describe the dose and time-dependent early human responses to ionizing radiation. The responses include lymphocyte depression, granulocyte modulation, fatigue and weakness syndrome, and upper gastrointestinal distress. The modest dose and dose-rates of SPEs are predicted to lead to large sparing of ARS, however detailed experimental data on a range of proton dose-rates for organ doses from 0.5 to 2 Gy is needed to validate the models. We also report on the ARRBOD code that integrates the BRYNTRN and SUMDOSE codes, which are used to estimate the SPE organ doses for astronauts under various space travel scenarios, with our models of ARS. The more recent effort is to provide easy web access to space radiation risk assessment using the ARRBOD code.

  20. Acute vertigo in an anesthesia provider during exposure to a 3T MRI scanner.

    PubMed

    Gorlin, Andrew; Hoxworth, Joseph M; Pavlicek, William; Thunberg, Christopher A; Seamans, David

    2015-01-01

    Vertigo induced by exposure to the magnetic field of a magnetic resonance imaging (MRI) scanner is a well-known phenomenon within the radiology community but is not widely appreciated by other clinical specialists. Here, we describe a case of an anesthetist experiencing acute vertigo while providing sedation to a patient undergoing a 3 Tesla MRI scan. After discussing previous reports, and the evidence surrounding MRI-induced vertigo, we review potential etiologies that include the effects of both static and time-varying magnetic fields on the vestibular apparatus. We conclude our review by discussing the occupational standards that exist for MRI exposure and methods to minimize the risks of MRI-induced vertigo for clinicians working in the MRI environment.

  1. Acute effect of exposure of mollusk single neuron to 900-MHz mobile phone radiation.

    PubMed

    Partsvania, B; Sulaberidze, T; Shoshiashvili, L; Modebadze, Z

    2011-09-01

    The goal of the present work was to explore the influence of commercially available cell phone irradiation on the single neuron excitability and memory processes. A Transverse Electromagnetic Cell (TEM Cell) was used to expose single neurons of mollusk to the electromagnetic field. Finite-Difference Time-Domain (FDTD) method was used for modeling the TEM Cell and the electromagnetic field interactions with living nerve ganglion and neurons. Neuron electrophysiology was investigated using standard microelectrode technique. The specific absorption rate (SAR) deposited into the single neuron was calculated to be 0.63 W/kg with a temperature increment of 0.1°C. After acute exposure, average firing threshold of the action potentials was not changed. However, the average latent period was significantly decreased. This indicates that together with latent period the threshold and the time of habituation might be altered during exposure. However, these alterations are transient and only latent period remains on the changed level.

  2. Acute ethanol exposure affects spermatogonial stem cell homeostasis in pre-pubertal mice.

    PubMed

    Caires, Kyle C; Shima, Christina M; de Avila, Jeanene; McLean, Derek J

    2012-01-01

    Ethanol is a known modulator of neural stem cell development, but the consequences of ethanol toxicity on the cell fate decisions of spermatogonial stem cells (SSCs) is poorly understood. Using an in vivo treatment and stem cell transplantation approach, we investigated the effects of acute ethanol exposure on formation of the growing adult SSC population in neonatal and pre-pubertal mice. Treatment with a single dose of ethanol disrupted SSC homeostasis in vivo evidenced by a significant reduction (7-fold) of stem cell colonization efficiency in the testes of recipient mice following transplantation. Ethanol treatment also increased the rate of apoptosis in adult differentiating germ cells in situ. Gene expression analysis indicates that ethanol exposure has transient and long-term effects on the expression of GDNF and VEGF family molecules and supports the hypothesis that the niche microenvironment for SSCs is sensitive to ethanol toxicity during pre-pubertaland adult life.

  3. Caudate neuronal recording in freely behaving animals following acute and chronic dose response methylphenidate exposure.

    PubMed

    Claussen, Catherine M; Dafny, Nachum

    2015-09-01

    The misuse and abuse of the psychostimulant, methylphenidate (MPD) the drug of choice in the treatment of attention deficit hyperactivity disorder (ADHD) has seen a sharp uprising in recent years among both youth and adults for its cognitive enhancing effects and for recreational purposes. This uprise in illicit use has lead to many questions concerning the long-term consequences of MPD exposure. The objective of this study was to record animal behavior concomitantly with the caudate nucleus (CN) neuronal activity following acute and repetitive (chronic) dose response exposure to methylphenidate (MPD). A saline control and three MPD dose (0.6, 2.5, and 10.0mg/kg) groups were used. Behaviorally, the same MPD dose in some animals following chronic MPD exposure elicited behavioral sensitization and other animals elicited behavioral tolerance. Based on this finding, the CN neuronal population recorded from animals expressing behavioral sensitization was also evaluated separately from CN neurons recorded from animals expressing behavioral tolerance to chronic MPD exposure, respectively. Significant differences in CN neuronal population responses between the behaviorally sensitized and the behaviorally tolerant animals were observed for the 2.5 and 10.0mg/kg MPD exposed groups. For 2.5mg/kg MPD, behaviorally sensitized animals responded by decreasing their firing rates while behaviorally tolerant animals showed mainly an increase in their firing rates. The CN neuronal responses recorded from the behaviorally sensitized animals following 10.0mg/kg MPD responded by increasing their firing rates whereas the CN neuronal recordings from the behaviorally tolerant animals showed that approximately half decreased their firing rates in response to 10.0mg/kg MPD exposure. The comparison of percentage change in neuronal firing rates showed that the behaviorally tolerant animals trended to exhibit increases in their neuronal firing rates at ED1 following initial MPD exposure and

  4. Effect of Hypohydration and Altitude Exposure on Aerobic Exercise Performance and Acute Mountain Sickness

    DTIC Science & Technology

    2010-09-01

    Am. Physiol. Soc., 1996, sect. 4, vol. II, chapt. 55, p. 1277–1289. 23a.Institute of Medicine. Water. In: Dietary Reference Intakes for Water...expressed across time, was not different among the four trials. Total fluid intakes (ml) over the 8-h exposure were 893 242, 743 146, 853 418... Potassium , Sodium, Chloride, and sulfate. Washington, DC: Institute of Medicine 2005, p. 73–185. 24. Kanner AA, Marchi N, Fazio V, Mayberg MR, Koltz MT

  5. Acute exposure of Drosophila melanogaster to paraquat causes oxidative stress and mitochondrial dysfunction.

    PubMed

    Hosamani, Ravikumar

    2013-05-01

    Paraquat (PQ; 1, 1'-dimethyl-4-4'-bipyridinium), an herbicide and model neurotoxicant, is identified to be one of the prime risk factors in Parkinson's disease (PD). In the Drosophila system, PQ is commonly used to measure acquired resistance against oxidative stress (PQ resistance test). Despite this, under acute PQ exposure, data on the oxidative stress response and associated impact on mitochondria among flies is limited. Accordingly, in this study, we measured markers of oxidative stress and mitochondrial dysfunctions among adult male flies (8-10 days old) exposed to varying concentrations of PQ (10, 20, and 40 mM in 5% sucrose solution) employing a conventional filter disc method for 24 h. PQ exposure resulted in significant elevation in the levels of oxidative stress biomarkers (malondialdehyde: 43% increase: hydroperoxide: 32-39% increase), with concomitant enhancement in reduced glutathione and total thiol levels in cytosol. Higher activity of antioxidant enzymes were also evident along with increased free iron levels. Furthermore, PQ exposure caused a concentration-dependent increase in mitochondrial superoxide generation and activity of manganese-superoxide dismutase (Mn-SOD). The activity levels of complex I-III, complex II-III, and Mg+2 adinosine triphosphatase (ATPase) were also decreased significantly. A robust diminution in the activity of succinate dehydrogenase and moderate decline in the citrate synthase activity suggested a specific effect on citric acid cycle enzymes. Collectively, these data suggest that acute PQ exposure causes significant oxidative stress and mitochondrial dysfunction among flies in vivo. It is suggested that in various experimental settings, while conducting the "PQ resistance stress test" incorporation of selected biochemical end points is likely to enhance the quality of the data.

  6. Acute Inhalation Exposure to Vaporized Methamphetamine Causes Lung Injury in Mice

    PubMed Central

    Wells, Sandra M.; Buford, Mary C.; Braseth, Sarah N.; Hutchison, James D.; Holian, Andrij

    2009-01-01

    Methamphetamine (MA) is currently the most widespread illegally used stimulant in the United States. Use of MA by smoking is the fastest growing mode of administration, which increases concerns about potential pulmonary and other medical complications. A murine exposure system was developed to study the pulmonary affects of inhaled MA. Mice were exposed to 25–100 mg vaporized MA and assessments were made 3 h following initiation of exposure to model acute lung injury. Inhalation of MA vapor resulted in dose-dependent increases in MA plasma levels that were in the range of those experienced by MA users. At the highest MA dose, histological changes were observed in the lung and small but significant increases in lung wet weight to body weight ratios (5.656 ± 0.176 mg/g for the controls vs. 6.706± 0.135 mg/g for the 100 mg MA-exposed mice) were found. In addition, there was 53% increase in total protein in bronchoalveolar lavage (BAL) fluid, greater than 20% increase in albumin levels in the BAL fluid, greater than 2.5-fold increase in lactate dehydrogenase levels in the BAL fluid, and reduced total BAL cell numbers (approximately 77% of controls). Levels of the early response cytokines tumor necrosis factor (TNF)-α and interleukin (IL)-6 were dose-dependently increased in BAL fluid of MA-exposed mice. Exposure to 100 mg MA significantly increased free radical generation in the BAL cells to 107–146% of controls and to approximately 135% of the controls in lung tissue in situ. Together, these data show that acute inhalation exposure to relevant doses of volatilized MA is associated with elevated free radical formation and significant lung injury. PMID:18645723

  7. Analyses of differentially expressed genes after exposure to acute stress, acute ethanol, or a combination of both in mice.

    PubMed

    Baker, Jessica A; Li, Jingxin; Zhou, Diana; Yang, Ming; Cook, Melloni N; Jones, Byron C; Mulligan, Megan K; Hamre, Kristin M; Lu, Lu

    2017-02-01

    Alcohol abuse is a complex disorder, which is confounded by other factors, including stress. In the present study, we examined gene expression in the hippocampus of BXD recombinant inbred mice after exposure to ethanol (NOE), stress (RSS), and the combination of both (RSE). Mice were given an intraperitoneal (i.p.) injection of 1.8 g/kg ethanol or saline, and subsets of both groups were exposed to acute restraint stress for 15 min or controls. Gene expression in the hippocampus was examined using microarray analysis. Genes that were significantly (p < 0.05, q < 0.1) differentially expressed were further evaluated. Bioinformatic analyses were predominantly performed using tools available at GeneNetwork.org, and included gene ontology, presence of cis-regulation or polymorphisms, phenotype correlations, and principal component analyses. Comparisons of differential gene expression between groups showed little overlap. Gene Ontology demonstrated distinct biological processes in each group with the combined exposure (RSE) being unique from either the ethanol (NOE) or stress (RSS) group, suggesting that the interaction between these variables is mediated through diverse molecular pathways. This supports the hypothesis that exposure to stress alters ethanol-induced gene expression changes and that exposure to alcohol alters stress-induced gene expression changes. Behavior was profiled in all groups following treatment, and many of the differentially expressed genes are correlated with behavioral variation within experimental groups. Interestingly, in each group several genes were correlated with the same phenotype, suggesting that these genes are the potential origins of significant genetic networks. The distinct sets of differentially expressed genes within each group provide the basis for identifying molecular networks that may aid in understanding the complex interactions between stress and ethanol, and potentially provide relevant therapeutic targets. Using Ptp4

  8. Exposure to Discrimination and Heart Rate Variability Reactivity to Acute Stress among Women with Diabetes.

    PubMed

    Wagner, Julie; Lampert, Rachel; Tennen, Howard; Feinn, Richard

    2015-08-01

    Exposure to racial discrimination has been linked to physiological reactivity. This study investigated self-reported exposure to racial discrimination and parasympathetic [high-frequency heart rate variability (HF-HRV)] and sympathetic (norepinephrine and cortisol) activity at baseline and then again after acute laboratory stress. Lifetime exposure to racial discrimination was measured with the Schedule of Racist Events scale. Thirty-two women (16 Black and 16 White) with type 2 diabetes performed a public speaking stressor. Beat-to-beat intervals were recorded on electrocardiograph recorders, and HF-HRV was calculated using spectral analysis and natural log transformed. Norepinephrine and cortisol were measured in blood. Higher discrimination predicted lower stressor HF-HRV, even after controlling for baseline HF-HRV. When race, age, A1c and baseline systolic blood pressure were also controlled, racial discrimination remained a significant independent predictor of stressor HF-HRV. There was no association between lifetime discrimination and sympathetic markers. In conclusion, preliminary data suggest that among women with type 2 diabetes mellitus (T2DM), exposure to racial discrimination is adversely associated with parasympathetic, but not sympathetic, reactivity.

  9. Gene expression changes in female zebrafish (Danio rerio) brain in response to acute exposure to methylmercury

    USGS Publications Warehouse

    Richter, Catherine A.; Garcia-Reyero, Natàlia; Martyniuk, Chris; Knoebl, Iris; Pope, Marie; Wright-Osment, Maureen K.; Denslow, Nancy D.; Tillitt, Donald E.

    2011-01-01

    Methylmercury (MeHg) is a potent neurotoxicant and endocrine disruptor that accumulates in aquatic systems. Previous studies have shown suppression of hormone levels in both male and female fish, suggesting effects on gonadotropin regulation in the brain. The gene expression profile in adult female zebrafish whole brain induced by acute (96 h) MeHg exposure was investigated. Fish were exposed by injection to 0 or 0.5(mu or u)g MeHg/g. Gene expression changes in the brain were examined using a 22,000-feature zebrafish microarray. At a significance level of pexposure. Individual genes exhibiting altered expression in response to MeHg exposure implicate effects on glutathione metabolism in the mechanism of MeHg neurotoxicity. Gene ontology (GO) terms significantly enriched among altered genes included protein folding, cell redox homeostasis, and steroid biosynthetic process. The most affected biological functions were related to nervous system development and function, as well as lipid metabolism and molecular transport. These results support the involvement of oxidative stress and effects on protein structure in the mechanism of action of MeHg in the female brain. Future studies will compare the gene expression profile induced in response to MeHg with that induced by other toxicants and will investigate responsive genes as potential biomarkers of MeHg exposure.

  10. The desmosomal protein Desmoglein 1 aids recovery of epidermal differentiation after acute ultraviolet light exposure

    PubMed Central

    Johnson, Jodi L.; Koetsier, Jennifer L.; Sirico, Anna; Agidi, Ada T.; Antonini, Dario; Missero, Caterina; Green, Kathleen J.

    2014-01-01

    Epidermal structure is damaged by exposure to ultraviolet (UV) light but the molecular mechanisms governing structural repair are largely unknown. UVB (290-320 nm wavelengths) exposure prior to induction of differentiation reduced expression of differentiation-associated proteins, including Desmoglein 1 (Dsg1), Desmocollin 1 (Dsc1) and Keratins 1 and 10 (K1/K10) in a dose-dependent manner in normal human epidermal keratinocytes (NHEKs). The UVB- induced reduction in both Dsg1 transcript and protein was associated with reduced binding of the p63 transcription factor to previously unreported enhancer regulatory regions of the Dsg1 gene. Since Dsg1 promotes epidermal differentiation in addition to participating in cell-cell adhesion, the role of Dsg1 in aiding differentiation after UVB damage was tested. Compared to controls, depleting Dsg1 via shRNA resulted in further reduction of Dsc1 and K1/K10 expression in monolayer NHEK cultures and in abnormal epidermal architecture in organotypic skin models recovering from UVB exposure. Ectopic expression of Dsg1 in keratinocyte monolayers rescued the UVB-induced differentiation defect. Treatment of UVB-exposed monolayer or organotypic cultures with Trichostatin A, a histone deacetylase inhibitor, partially restored differentiation marker expression, suggesting a potential therapeutic strategy for reversing UV-induced impairment of epidermal differentiation after acute sun exposure. PMID:24594668

  11. The desmosomal protein desmoglein 1 aids recovery of epidermal differentiation after acute UV light exposure.

    PubMed

    Johnson, Jodi L; Koetsier, Jennifer L; Sirico, Anna; Agidi, Ada T; Antonini, Dario; Missero, Caterina; Green, Kathleen J

    2014-08-01

    Epidermal structure is damaged by exposure to UV light, but the molecular mechanisms governing structural repair are largely unknown. UVB (290-320 nm wavelengths) exposure before induction of differentiation reduced expression of differentiation-associated proteins, including desmoglein 1 (Dsg1), desmocollin 1 (Dsc1), and keratins 1 and 10 (K1/K10), in a dose-dependent manner in normal human epidermal keratinocytes (NHEKs). The UVB-induced reduction in both Dsg1 transcript and protein was associated with reduced binding of the p63 transcription factor to previously unreported enhancer regulatory regions of the Dsg1 gene. As Dsg1 promotes epidermal differentiation in addition to participating in cell-cell adhesion, the role of Dsg1 in aiding differentiation after UVB damage was tested. Compared with controls, depleting Dsg1 via short hairpin RNA resulted in further reduction of Dsc1 and K1/K10 expression in monolayer NHEK cultures and in abnormal epidermal architecture in organotypic skin models recovering from UVB exposure. Ectopic expression of Dsg1 in keratinocyte monolayers rescued the UVB-induced differentiation defect. Treatment of UVB-exposed monolayer or organotypic cultures with trichostatin A, a histone deacetylase inhibitor, partially restored differentiation marker expression, suggesting a potential therapeutic strategy for reversing UV-induced impairment of epidermal differentiation after acute sun exposure.

  12. Seasonal variations in the responses of glycolytic intermediates of human erythrocytes to acute cold exposure

    NASA Astrophysics Data System (ADS)

    Ohno, H.; Yahata, T.; Yamashita, K.; Kuroshima, A.

    1988-03-01

    Seven male students were studied to observe the effects of acute cold exposure (at 10°C for 60 min) on erythrocyte concentrations of glycolytic intermediates in summer and in winter. The subjects shivered slightly but frankly in both experiments. Significant decreases were observed in the concentrations of pyruvate and lactate during body cooling in summer, but not in winter. The lactate concentration remained significantly reduced 15 min after cold exposure. After 60 min of cold exposure in summer, a negative crossover point appeared to exist between phosphoenolpyruvate and pyruvate and erythrocyte pyruvate kinase activity showed a significant decrease. No seasonal difference was observed in the initial control values of the intermediates measured. From these results and the fact that glucose, pyruvate and lactate are evenly distributed between erythrocytes and plasma, it is likely that erythrocytes and skeletal muscles need less fuel substrate, glucose during cold exposure in winter than in summer, suggesting that an increased economy of energy for homeostasis is achieved.

  13. Acute exposure to ethanol on gestational day 15 affects social motivation of female offspring.

    PubMed

    Varlinskaya, Elena I; Mooney, Sandra M

    2014-03-15

    Alterations in social behavior are a hallmark of many neurodevelopmental disorders in humans. In rodents, social behavior is affected by prenatal insults. The outcomes are dependent on the timing of the insult as well as the sex and age of the animal tested. The limbic system is particularly important for social behavior, and a peak of neurogenesis within this system occurs on gestational day (G)15. Neurons appear particularly vulnerable to ethanol insult around the time they become post-mitotic. We tested the hypothesis that acute exposure to ethanol on G15 would result in significant social behavior deficits. Accordingly, Long Evans pregnant females were injected with ethanol (2.9 g/kg) or an equivalent volume of saline on G15. Offspring were assessed in a modified social interaction test on postnatal day (P) 28, P42, or P75, i.e., during early adolescence, late adolescence, or young adulthood. Prenatal ethanol exposure decreased social investigation in P28 females and transformed social preference into social avoidance in 75-day-old females. Contact behavior, play fighting, and locomotor activity differed as a function of age, but were not significantly affected by ethanol exposure. Males demonstrated significantly more contact behavior and play fighting at P42 than at P28 or P70, whereas there were no age-related changes in females. Adult females showed more locomotor activity than adult males. Overall, prenatal ethanol exposure on G15 enhanced social anxiety in females, with these effects seen in adulthood only.

  14. GENE EXPRESSION CHANGES IN FEMALE ZEBRAFISH (DANIO RERIO) BRAIN IN RESPONSE TO ACUTE EXPOSURE TO METHYLMERCURY

    PubMed Central

    Richter, Catherine A.; Garcia-Reyero, Natàlia; Martyniuk, Chris; Knoebl, Iris; Pope, Marie; Wright-Osment, Maureen K.; Denslow, Nancy D.; Tillitt, Donald E.

    2010-01-01

    Methylmercury (MeHg) is a potent neurotoxicant and endocrine disruptor that accumulates in aquatic systems. Previous studies have shown suppression of hormone levels in both male and female fish, suggesting effects on gonadotropin regulation in the brain. The gene expression profile in adult female zebrafish whole brain induced by acute (96 hr) MeHg exposure was investigated. Fish were exposed by injection to 0 or 0.5 μg MeHg/g. Gene expression changes in the brain were examined using a 22,000 feature zebrafish microarray. At a significance level of p<0.01, 79 genes were up-regulated and 76 genes were down-regulated in response to MeHg exposure. Individual genes exhibiting altered expression in response to MeHg exposure implicate effects on glutathione metabolism in the mechanism of MeHg neurotoxicity. Gene ontology (GO) terms significantly enriched among altered genes included protein folding, cell redox homeostasis, and steroid biosynthetic process. The most affected biological functions were related to the nervous system development and function, as well as lipid metabolism and molecular transport. These results support the involvement of oxidative stress and effects on protein structure in the mechanism of action of MeHg in the female brain. Future studies will compare the gene expression profile induced in response to MeHg with that induced by other toxicants and investigate responsive genes as potential biomarkers of MeHg exposure. PMID:21082716

  15. Acute health effects associated with exposure to volcanic air pollution (vog) from increased activity at Kilauea Volcano in 2008.

    PubMed

    Longo, Bernadette M; Yang, Wei; Green, Joshua B; Crosby, Frederick L; Crosby, Vickie L

    2010-01-01

    In 2008, the Kilauea Volcano on the island of Hawai'i increased eruption activity and emissions of sulfurous volcanic air pollution called vog. The purpose of this study was to promptly assess for a relative increase in cases of medically diagnosed acute illnesses in an exposed Hawaiian community. Using a within-clinic retrospective cohort design, comparisons were made for visits of acute illnesses during the 14 wk prior to the increased volcanic emissions (low exposure) to 14 wk of high vog exposure when ambient sulfur dioxide was threefold higher and averaged 75 parts per billion volume per day. Logistic regression analysis estimated effect measures between the low- and high-exposure cohorts for age, gender, race, and smoking status. There were statistically significant positive associations between high vog exposure and visits for medically diagnosed cough, headache, acute pharyngitis, and acute airway problems. More than a sixfold increase in odds was estimated for visits with acute airway problems, primarily experienced by young Pacific Islanders. These findings suggest that the elevated volcanic emissions in 2008 were associated with increased morbidity of acute illnesses in age and racial subgroups of the general Hawaiian population. Continued investigation is crucial to fully assess the health impact of this natural source of sulfurous air pollution. Culturally appropriate primary- and secondary-level health prevention initiatives are recommended for populations in Hawai'i and volcanically active areas worldwide.

  16. Mapping of radio frequency electromagnetic field exposure levels in outdoor environment and comparing with reference levels for general public health.

    PubMed

    Cansiz, Mustafa; Abbasov, Teymuraz; Kurt, M Bahattin; Celik, A Recai

    2016-11-02

    In this study, radio frequency electromagnetic field exposure levels were measured on the main streets in the city center of Diyarbakır, Turkey. Measured electric field levels were plotted on satellite imagery of Diyarbakır and were compared with exposure guidelines published by the International Commission on Non-Ionizing Radiation Protection (ICNIRP). Exposure measurements were performed in dense urban, urban and suburban areas each day for 7 consecutive days. The measurement system consisted of high precision and portable spectrum analyzer, three-axis electric field antenna, connection cable and a laptop which was used to record the measurement samples as a data logger. The highest exposure levels were detected for two places, which are called Diclekent and Batıkent. It was observed that the highest instantaneous electric field strength value for Batıkent was 7.18 V/m and for Diclekent was 5.81 V/m. It was statistically determined that the main contributor band to the total exposure levels was Universal Mobile Telecommunications System band. Finally, it was concluded that all measured exposure levels were lower than the reference levels recommended by ICNIRP for general public health.Journal of Exposure Science and Environmental Epidemiology advance online publication, 2 November 2016; doi:10.1038/jes.2016.64.

  17. Acute nonlymphocytic leukemia and residential exposure to power frequency magnetic fields

    SciTech Connect

    Severson, R.K.

    1986-01-01

    A population-based case-control study of adult acute nonlymphocytic leukemia (ANLL) and residential exposure to power frequency magnetic fields was conducted in King, Pierce and Snohomish Counties in Washington state. Of 164 cases who were diagnosed from January 1, 1981 through December 31, 1984, 114 were interviewed. Controls were selected from the study area on the basis of random digit dialing and frequency matched to the cases by age and sex. Analyses were undertaken to evaluate whether exposure to high levels of power frequency magnetic fields in the residence were associated with an increased risk of ANLL. Neither the directly measured magnetic fields nor the surrogate values based on the wiring configurations were associated with ANLL. Additional analyses suggested that persons with prior allergies were at decreased risk of acute myelocytic leukemia (AML). Also, persons with prior autoimmune diseases were at increased risk of AML. The increase in AML risk in rheumatoid arthritics was of borderline statistical significance. Finally, cigarette smoking was associated with an increased risk of AML. The risk of AML increased significantly with the number of years of cigarette smoking.

  18. Acute alcohol exposure markedly influences male fertility and fetal outcome in the male rat.

    PubMed

    Cicero, T J; Nock, B; O'Connor, L; Adams, M L; Sewing, B N; Meyer, E R

    1994-01-01

    Although it is recognized that drugs ingested by pregnant females produce marked cognitive and physiological deficits in their offspring, the possibility that paternal exposure to drugs prior to mating may have adverse effects on fertility and fetal outcome has not received much attention. The purpose of the present studies was to examine whether a single, acute exposure to alcohol influences the subsequent ability of adult male rats to mate and produce healthy and viable litters. Our results showed that a relatively large dose of alcohol 24 hours prior to breeding had little effect on the mating behavior of male rats, but there were markedly fewer pregnancies in females mated with alcohol-exposed male rats than in controls. Of equal importance, we found that, even when conception occurred and live births were produced, there were striking differences in fetal outcome. Alcohol-treated males sired many fewer pups than control males and there was a markedly enhanced mortality rate in their offspring. Collectively, these data suggest that acute paternal alcohol administration 24 hours prior to breeding does not affect mating behavior, but results in a greatly diminished fertility rate and fewer and less viable offspring. These studies suggest that paternal alcohol use may be as important as maternal alcohol abuse as a negative variable in pregnancy and fetal outcome.

  19. Evidence Report: Risk of Acute and Late Central Nervous System Effects from Radiation Exposure

    NASA Technical Reports Server (NTRS)

    Nelson, Gregory A.; Simonsen, Lisa; Huff, Janice L.

    2016-01-01

    Possible acute and late risks to the central nervous system (CNS) from galactic cosmic rays (GCR) and solar particle events (SPE) are concerns for human exploration of space. Acute CNS risks may include: altered cognitive function, reduced motor function, and behavioral changes, all of which may affect performance and human health. Late CNS risks may include neurological disorders such as Alzheimer's disease (AD), dementia and premature aging. Although detrimental CNS changes are observed in humans treated with high-dose radiation (e.g., gamma rays and 9 protons) for cancer and are supported by experimental evidence showing neurocognitive and behavioral effects in animal models, the significance of these results on the morbidity to astronauts has not been elucidated. There is a lack of human epidemiology data on which to base CNS risk estimates; therefore, risk projection based on scaling to human data, as done for cancer risk, is not possible for CNS risks. Research specific to the spaceflight environment using animal and cell models must be compiled to quantify the magnitude of CNS changes in order to estimate this risk and to establish validity of the current permissible exposure limits (PELs). In addition, the impact of radiation exposure in combination with individual sensitivity or other space flight factors, as well as assessment of the need for biological/pharmaceutical countermeasures, will be considered after further definition of CNS risk occurs.

  20. Acute exposure to apolipoprotein A1 inhibits macrophage chemotaxis in vitro and monocyte recruitment in vivo

    PubMed Central

    Iqbal, Asif J; Barrett, Tessa J; Taylor, Lewis; McNeill, Eileen; Manmadhan, Arun; Recio, Carlota; Carmineri, Alfredo; Brodermann, Maximillian H; White, Gemma E; Cooper, Dianne; DiDonato, Joseph A; Zamanian-Daryoush, Maryam; Hazen, Stanley L; Channon, Keith M

    2016-01-01

    Apolipoprotein A1 (apoA1) is the major protein component of high-density lipoprotein (HDL) and has well documented anti-inflammatory properties. To better understand the cellular and molecular basis of the anti-inflammatory actions of apoA1, we explored the effect of acute human apoA1 exposure on the migratory capacity of monocyte-derived cells in vitro and in vivo. Acute (20–60 min) apoA1 treatment induced a substantial (50–90%) reduction in macrophage chemotaxis to a range of chemoattractants. This acute treatment was anti-inflammatory in vivo as shown by pre-treatment of monocytes prior to adoptive transfer into an on-going murine peritonitis model. We find that apoA1 rapidly disrupts membrane lipid rafts, and as a consequence, dampens the PI3K/Akt signalling pathway that coordinates reorganization of the actin cytoskeleton and cell migration. Our data strengthen the evidence base for therapeutic apoA1 infusions in situations where reduced monocyte recruitment to sites of inflammation could have beneficial outcomes. DOI: http://dx.doi.org/10.7554/eLife.15190.001 PMID:27572261

  1. Acute kidney injury secondary to exposure to insecticides used for bedbug (Cimex lectularis) control.

    PubMed

    Bashir, Babar; Sharma, Shree G; Stein, Harold D; Sirota, Robert A; D'Agati, Vivette D

    2013-11-01

    Bedbug (Cimex lectularis) infestation is becoming a worldwide epidemic due to the emergence of insecticide-resistant strains. Pyrethroids are approved by the US Environmental Protection Agency for use against bedbugs and are considered minimally toxic to humans, with known respiratory, neurologic, and gastrointestinal effects. We present the first reported case of pyrethroid-induced toxic acute tubular necrosis (ATN). A 66-year-old healthy woman receiving no prior nephrotoxic medications presented with extreme weakness, decreased urine output, and acute kidney injury. She had administered multiple applications of a bedbug spray (permethrin) and a fogger (pyrethrin), exceeding the manufacturer's recommended amounts. She was found to have severe nonoliguric acute kidney injury associated with profound hypokalemia. Kidney biopsy revealed toxic ATN with extensive tubular degenerative changes and cytoplasmic vacuolization. With conservative management, serum creatinine level decreased from 13.0 mg/dL (estimated glomerular filtration rate, 3 mL/min/1.73 m(2)) to 1.67 mg/dL (estimated glomerular filtration rate, 37 mL/min/1.73 m(2)) within 6 weeks. Literature review uncovered no prior report of pyrethroid insecticide-induced ATN in humans, although there are reports of ATN with similar tubular vacuolization in rats exposed to this agent. Bedbug insecticides containing pyrethroids should be used with caution due to the potential development of toxic ATN after prolonged exposure.

  2. Acute radiation enteritis caused by dose-dependent radiation exposure in dogs: experimental research.

    PubMed

    Xu, Wenda; Chen, Jiang; Xu, Liu; Li, Hongyu; Guo, Xiaozhong

    2014-12-01

    Accidental or intended radiation exposure in mass casualty settings presents a serious and on-going threat. The development of mitigating and treating agents requires appropriate animal models. Unfortunately, the majority of research on radiation enteritis in animals has lacked specific assessments and targeted therapy. Our study showed beagle dogs, treated by intensity-modulated radiation therapy (IMRT) for abdominal irradiation, were administered single X-ray doses of 8-30 Gy. The degree of intestinal tract injury for all of the animals after radiation exposure was evaluated with regard to clinical syndrome, endoscopic findings, histological features, and intestinal function. The range of single doses (8 Gy, 10-14 Gy, and 16-30 Gy) represented the degree of injury (mild, moderate, and severe, respectively). Acute radiation enteritis included clinical syndrome with fever, vomiting, diarrhea, hemafecia, and weight loss; typical endoscopic findings included edema, bleeding, mucosal abrasions, and ulcers; and intestinal biopsy results revealed mucosal necrosis, erosion, and loss, inflammatory cell infiltration, hemorrhage, and congestion. Changes in serum diamine oxides (DAOs) and d-xylose represented intestinal barrier function and absorption function, respectively, and correlated with the extent of damage (P < 0.05 and P < 0.05, respectively). We successfully developed a dog model of acute radiation enteritis, thus obtaining a relatively objective evaluation of intestinal tract injury based on clinical performance and laboratory examination. The method of assessment of the degree of intestinal tract injury after abdominal irradiation could be beneficial in the development of novel and effective therapeutic strategies for acute radiation enteritis.

  3. Abundance of Plasma Antioxidant Proteins Confers Tolerance to Acute Hypobaric Hypoxia Exposure

    PubMed Central

    Padhy, Gayatri; Sethy, Niroj Kumar; Ganju, Lilly

    2013-01-01

    Abstract Padhy, Gayatri, Niroj Kumar Sethy, Lilly Ganju, and Kalpana Bhargava. Abundance of plasma antioxidant proteins confers tolerance to acute hypobaric hypoxia exposure. High Alt Med Biol 14:289–297, 2013—Systematic identification of molecular signatures for hypobaric hypoxia can aid in better understanding of human adaptation to high altitude. In an attempt to identify proteins promoting hypoxia tolerance during acute exposure to high altitude, we screened and identified hypoxia tolerant and susceptible rats based on hyperventilation time to a simulated altitude of 32,000 ft (9754 m). The hypoxia tolerance was further validated by estimating 8-isoprotane levels and protein carbonyls, which revealed that hypoxia tolerant rats possessed significant lower plasma levels as compared to susceptible rats. We used a comparative plasma proteome profiling approach using 2-dimensional gel electrophoresis (2-DGE) combined with MALDI TOF/TOF for both groups, along with an hypoxic control group. This resulted in the identification of 19 differentially expressed proteins. Seven proteins (TTR, GPx-3, PON1, Rab-3D, CLC11, CRP, and Hp) were upregulated in hypoxia tolerant rats, while apolipoprotein A-I (APOA1) was upregulated in hypoxia susceptible rats. We further confirmed the consistent higher expression levels of three antioxidant proteins (PON1, TTR, and GPx-3) in hypoxia-tolerant animals using ELISA and immunoblotting. Collectively, these proteomics-based results highlight the role of antioxidant enzymes in conferring hypoxia tolerance during acute hypobaric hypoxia. The expression of these antioxidant enzymes could be used as putative biomarkers for screening altitude adaptation as well as aiding in better management of altered oxygen pathophysiologies. PMID:24067188

  4. Work-Time Exposure and Acute Injuries in Inshore Lobstermen of the Northeast United States.

    PubMed

    Fulmer, Scott; Buchholz, Bryan; Jenkins, Paul; Scribani, Melissa

    2016-01-01

    The objective of this study was to inform efforts to reduce risk for musculoskeletal disorders among commercial lobstermen by characterizing and quantifying injuries that occur to people while harvesting lobsters commercially in the Northeast United States. This study aimed to estimate a denominator of exposure to lobstering in full-time equivalents (FTE), to estimate a fatality rate, and to calculate incidence rates for acute injuries within the sample population. Captains were randomly selected from those licensed to fish in Maine and Massachusetts. Data on work exposure and injuries with rapid onset that occurred on the boat ("acute injuries") were collected using a survey, which was administered quarterly via phone or face-to-face interview with the captain. The quarterly survey assessed the number of weeks worked during the quarter, average crew size, number of trips per week, and average trip length in hours. In addition, this survey captured relevant information (body segment affected, type of injury, and whether treatment was received) on all acute injuries occurring during the quarter. FTE were estimated using fishermen days and fishermen hours. The annual FTE estimated using days was 2,557 and using hours was 2,855. As expected, the summer months (3rd quarter) had the highest FTE and the winter (1st quarter) the lowest FTE. Fall (4th quarter) and spring (2nd quarter) ranked second and third, respectively. The incidence rates for all injuries (49.7/100 FTE) and injuries requiring treatment (15.0/100 FTE) were much higher than those reported in other studies of fishing that used Coast Guard data.

  5. Metabolic, Thermal and Cardiovascular Adjustments to Cold Exposure with Special Reference to Physical Work and Body Composition.

    DTIC Science & Technology

    1982-06-01

    frame of reference for the metabolic demands of the arm-leg work task, peak i021 on the cycle ergometer was determined on a separate day by means of a...andE identify by block numbr) Cold exposure; water exposure; temperature regulation; rectal temperature; lean, average and obese body fatness; body...at 36W (8.2 kcal.miLn- ) in air and water at,20, 24 and 280C. At rest, in all water conditions, the obese men (> 222 fat) maintained Tre at levels

  6. Induction of genomic instability after an acute whole-body exposure of mice to 56Fe ions

    NASA Astrophysics Data System (ADS)

    Rithidech, Kanokporn; Supanpaiboon, Wisa; Whorton, Elbert

    collected from CBA/CaJ and C57BL/6J mice at different times up to 3 months following an acute whole-body exposure to various doses of 1 GeV/amu 56 Fe ions (0, 0.1, 0.5 and 1.0 cGy) or 137 Cs gamma rays (0, 0.5, 1.0 and 3.0 cGy, as a reference radiation). These strains of mouse are known to be sensitive (CBA/CaJ) or resistant (C57BL/6J) to radiation-induced chromosomal damage and AML. At 2 days after the exposure, our data indicated that there was no increase in the frequency of MN-PCEs in CBA/CaJ mice exposed to 56 Fe ions while the frequency of MN-PCEs elevated as a function of dose in the C57BL/6J mice. At day 4, there was no dose related increase in either strain of mouse exposed to either 56 Fe ions or 137 Cs gamma rays. We also found that at the early sacrifice times (2 and 4 days) the 56 Fe ions were slightly more effective, per unit dose, in inducing MN-NCEs than 137 Cs gamma rays in both strains. Likewise, no increase in the frequency of MN-NCEs was found at late times after an acute exposure to either type of radiation. In contrast, both types of radiation induced increased MN-PCE frequencies in irradiated CBA/CaJ mice, but not C57BL/6J mice, at late times post-exposure. This finding indicates the potential induction of genomic instability in hematopoietic cells of CBA/CaJ mice by both types of radiation. The finding also demonstrates the influence of genetic background on radiation-induced genomic instability in vivo. Research funded by NASA Grant #NAG9- 1 52 .

  7. Sustained impairment of respiratory function and swim performance following acute oil exposure in a coastal marine fish.

    PubMed

    Johansen, J L; Esbaugh, A J

    2017-04-06

    Acute exposure to crude oil polycyclic aromatic hydrocarbons (PAH) can severely impair cardiorespiratory function and swim performance of larval fish; however, the effects of acute oil exposure on later life stages and the capacity for subsequent recovery is less clear. Red drum (Sciaenops ocellatus) is an economically important apex predator native to the Gulf of Mexico, which was directly exposed to the 2010 Deep Water Horizon (DWH) oil spill. Here we examine impact and recovery of young adult red drum from exposure to concentrations of 0, 4.1, and 12.1μgL(-1) ΣPAH50 naturally weathered oil-water accommodated fractions (geometric mean), which are well within the range of concentrations measured during the DWH incident. We focused on aerobic scope (ASc), burst- and critical swimming speeds (Uburst and Ucrit), cost of transport (COT), as well as the capacity to repay oxygen debt following exhaustive exercise (EPOC), which are critical parameters for success of all life stages of fishes. A 24h acute exposure to 4.1μgL(-1) ΣPAH caused a significant 9.7 and 12.6% reduction of Uburst and Ucrit respectively, but no change in ASc, COT or EPOC, highlighting a decoupled effect on the respiratory and swimming systems. A higher exposure concentration, 12.1μgL(-1) ΣPAH, caused an 8.6 and 8.4% impairment of Uburst and Ucrit, as well as an 18.4% reduction in ASc. These impairments persisted six weeks post-exposure, suggesting that recorded impacts are entrenched. Large predatory fishes are critically dependent on the cardiorespiratory and swimming systems for ecological fitness, and long-term impairment of performance due to acute oil exposure suggests that even acute exposure events may have long lasting impacts on the ecological fitness of affected populations.

  8. [The NSI (Noise Sensitivity Index)--a method for the demonstration of acute physical symptoms in noise exposure and combination exposure].

    PubMed

    Meister, A; Bening, Y; Brumm, L M

    1989-01-01

    The NSI (Noise Sensitive Index) is a method suitable for the single or repeated recording of acute, subjectively perceived bodily complaints caused by exposure against noise alone or combined with additional physical factors (e.g. physical load, high temperature) during the lapse of exposure. The paper describes the application of NSI in 6 experimental investigations. The results are indicative regarding their dependence on components of exposure and personality. If certain rules are taken into consideration, application, scoring and interpretation of NSI is easy, not very time consuming, and profitable.

  9. Decreasing incidence of acute appendicitis, with special reference to the consumption of dietary fiber.

    PubMed

    Arnbjörnsson, E; Asp, N G; Westin, S I

    1982-01-01

    The incidence of acute appendicitis and the total number of appendectomies performed in the adult population admitted to our medical center are both decreasing. The cause is not clear. Better nutrition and the wide-spread use of antibiotics are two possible factors which come to mind, but we know of no scientific evidence that these are responsible. There has been a slight decrease in the mean dietary fiber content in the Swedish diet during the last three decades. The decreased incidence of acute appendicitis cannot therefore be correlated with an increase in the mean dietary fiber intake.

  10. A study of acute muscle dysfunction with particular reference to dengue myopathy

    PubMed Central

    Verma, Rajesh; Holla, Vikram V.; Kumar, Vijay; Jain, Amita; Husain, Nuzhat; Malhotra, Kiran Preet; Garg, Ravindra Kumar; Malhotra, Hardeep Singh; Sharma, Praveen Kumar; Kumar, Neeraj

    2017-01-01

    Background: Acute myopathy is a common cause of acute motor quadriparesis which has various etiologies with different courses of illness and prognosis depending on the cause. Understanding this diversity helps us in proper approach toward diagnosis, predicting the prognosis, and possible complications and in improving the treatments that are being provided. This study was planned to study the clinical, electrophysiological, and etiological profile of patients presenting with acute myopathy. We also studied how dengue-related acute myopathy differs from other causes and also difference between myopathy due to myositis and hypokalemia in cases of dengue. Materials and Methods: This was a prospective, observational study involving all clinically suspected cases of acute myopathy of not more than 4 weeks duration with raised serum creatine kinase (CK) level. They were subjected to detailed clinical evaluation along with hematological, biochemical, microbiological, and electrophysiological studies and followed-up for outcome at 1 and 3 months. Muscle biopsy and histopathological examination were done in selected patients after taking informed consent. Statistical analysis was performed by appropriate methods using SPSS version 16.0 (Chicago, IL, USA). Results: We evaluated thirty patients of acute myopathy with raised CK level. Seventeen patients had fever, 11 had myalgia, and 5 had skin lesions. All presented with symmetric weakness, 17 (56.7%) patients having predominantly proximal weakness, neck or truncal weakness in 6 (20%), hyporeflexia in 12 (40%), with mean Medical Research Council (MRC) sum score of 46.67 ± 6.0. Eight (mean modified Barthel index [MBI] at presentation - 15 ± 3.7) patients had poor functional status according to MBI and 15 according to modified Rankin scale (MRS) (mean MRS score - 2.5 ± 1.2). Etiology was dengue viral infection in 14 patients; hypokalemia due to various causes other than dengue in 8; pyomyositis in 3; dermatomyositis

  11. 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

  12. Carryover Effects of Acute DEHP Exposure on Ovarian Function and Oocyte Developmental Competence in Lactating Cows

    PubMed Central

    Kalo, Dorit; Hadas, Ron; Furman, Ori; Ben-Ari, Julius; Maor, Yehoshua; Patterson, Donald G.; Tomey, Cynthia; Roth, Zvi

    2015-01-01

    We examined acute exposure of Holstein cows to di(2-ethylhexyl) phthalate (DEHP) and its carryover effects on ovarian function and oocyte developmental competence. Synchronized cows were tube-fed with water or 100 mg/kg DEHP per day for 3 days. Blood, urine and milk samples were collected before, during and after DEHP exposure to examine its clearance pattern. Ovarian follicular dynamics was monitored through an entire estrous cycle by ultrasonographic scanning. Follicular fluids were aspirated from the preovulatory follicles on days 0 and 29 of the experiment and analyzed for phthalate metabolites and estradiol concentration. The aspirated follicular fluid was used as maturation medium for in-vitro embryo production. Findings revealed that DEHP impairs the pattern of follicular development, with a prominent effect on dominant follicles. The diameter and growth rate of the first- and second-wave dominant follicles were lower (P < 0.05) in the DEHP-treated group. Estradiol concentration in the follicular fluid was lower in the DEHP-treated group than in controls, and associated with a higher number of follicular pathologies (follicle diameter >25 mm). The pattern of growth and regression of the corpus luteum differed between groups, with a lower volume in the DEHP-treated group (P < 0.05). The follicular fluid aspirated from the DEHP-treated group, but not the controls, contained 23 nM mono(2-ethylhexyl) phthalate. Culturing of cumulus oocyte complexes in the follicular fluid aspirated from DEHP-treated cows reduced the proportion of oocytes progressing to the MII stage, and the proportions of 2- to 4-cell-stage embryos (P < 0.04) and 7-day blastocysts (P < 0.06). The results describe the risk associated with acute exposure to DEHP and its deleterious carryover effects on ovarian function, nuclear maturation and oocyte developmental competence. PMID:26154164

  13. Impact of acute exposure to air pollution on the cardiorespiratory performance of military firemen.

    PubMed

    Oliveira, R S; Barros Neto, T L; Braga, A L F; Raso, V; Pereira, L A A; Morette, S R; Carneiro, R C

    2006-12-01

    The objective of the present study was to determine the impact of acute short-term exposure to air pollution on the cardiorespiratory performance of military firemen living and working in the city of Guarujá, São Paulo, Brazil. Twenty-five healthy non-smoking firemen aged 24 to 45 years had about 1 h of exposure to low and high levels of air pollution. The tests consisted of two phases: phase A, in Bertioga, a town with low levels of air pollution, and phase B, in Cubatão, a polluted town, with a 7-day interval between phases. The volunteers remained in the cities (Bertioga/Cubatão) only for the time required to perform the tests. Cumulative load 10 +/- 2 min-long exertion tests were performed on a treadmill, consisting of a 2-min stage at a load of 7 km/h, followed by increasing exertion of 1 km h-1 min-1 until the maximum individual limit. There were statistically significant differences (P < 0.05) in anaerobic threshold (AT) between Cubatão (35.04 +/- 4.91 mL kg-1 min-1) and Bertioga (36.98 +/- 5.62 mL kg-1 min-1; P = 0.01), in the heart rate at AT (AT HR; Cubatão 152.08 +/- 14.86 bpm, Bertioga 157.44 +/- 13.64 bpm; P = 0.001), and in percent maximal oxygen consumption at AT (AT%VO2max; Cubatão 64.56 +/- 6.55%, Bertioga 67.40 +/- 5.35%; P = 0.03). However, there were no differences in VO2max, maximal heart rate or velocity at AT (ATvel) observed in firemen between towns. The acute exposure to pollutants in Cubatão, SP, caused a significant reduction in the performance at submaximal levels of physical exertion.

  14. NEUROTOXICITY FOLLOWING ACUTE INHALATION EXPOSURE TO THE OIL DISPERSANT COREXIT EC9500A

    PubMed Central

    Sriram, Krishnan; Lin, Gary X.; Jefferson, Amy M.; Goldsmith, William T.; Jackson, Mark; McKinney, Walter; Frazer, David G.; Robinson, Victor A.; Castranova, Vincent

    2015-01-01

    Consequent to the 2010 Deepwater Horizon oil spill in the Gulf of Mexico, there is an emergent concern about the short- and long-term adverse health effects of exposure to crude oil, weathered-oil products, and oil dispersants among the workforce employed to contain and clean up the spill. Oil dispersants typically comprise of a mixture of solvents and surfactants that break down floating oil to micrometer-sized droplets within the water column, thus preventing it from reaching the shorelines. As dispersants are generally sprayed from the air, workers are at risk for exposure primarily via inhalation. Such inhaled fractions might potentially permeate or translocate to the brain via olfactory or systemic circulation, producing central nervous system (CNS) abnormalities. To determine whether oil dispersants pose a neurological risk, male Sprague-Dawley rats were exposed by whole-body inhalation exposure to a model oil dispersant, COREXIT EC9500A (CE; approximately 27 mg/m3 × 5 h/d × 1 d), and various molecular indices of neural dysfunction were evaluated in discrete brain areas, at 1 or 7 d postexposure. Exposure to CE produced partial loss of olfactory marker protein in the olfactory bulb. CE also reduced tyrosine hydroxylase protein content in the striatum. Further, CE altered the levels of various synaptic and neuronal intermediate filament proteins in specific brain areas. Reactive astrogliosis, as evidenced by increased expression of glial fibrillary acidic protein, was observed in the hippocampus and frontal cortex following exposure to CE. Collectively, these findings are suggestive of disruptions in olfactory signal transduction, axonal function, and synaptic vesicle fusion, events that potentially result in an imbalance in neurotransmitter signaling. Whether such acute molecular aberrations might persist and produce chronic neurological deficits remains to be ascertained. PMID:21916746

  15. Acute alcohol exposure during mouse gastrulation alters lipid metabolism in placental and heart development: Folate prevention

    PubMed Central

    Han, Mingda

    2016-01-01

    Background Embryonic acute exposure to ethanol (EtOH), lithium, and homocysteine (HCy) induces cardiac defects at the time of exposure; folic acid (FA) supplementation protects normal cardiogenesis (Han et al., 2009, 2012; Serrano et al., 2010). Our hypothesis is that EtOH exposure and FA protection relate to lipid and FA metabolism during mouse cardiogenesis and placentation. Methods On the morning of conception, pregnant C57BL/6J mice were placed on either of two FA‐containing diets: a 3.3 mg health maintenance diet or a high FA diet of 10.5 mg/kg. Mice were injected a binge level of EtOH, HCy, or saline on embryonic day (E) 6.75, targeting gastrulation. On E15.5, cardiac and umbilical blood flow were examined by ultrasound. Embryonic cardiac tissues were processed for gene expression of lipid and FA metabolism; the placenta and heart tissues for neutral lipid droplets, or for medium chain acyl‐dehydrogenase (MCAD) protein. Results EtOH exposure altered lipid‐related gene expression on E7.5 in comparison to control or FA‐supplemented groups and remained altered on E15.5 similarly to changes with HCy, signifying FA deficiency. In comparison to control tissues, the lipid‐related acyl CoA dehydrogenase medium length chain gene and its protein MCAD were altered with EtOH exposure, as were neutral lipid droplet localization in the heart and placenta. Conclusion EtOH altered gene expression associated with lipid and folate metabolism, as well as neutral lipids, in the E15.5 abnormally functioning heart and placenta. In comparison to controls, the high FA diet protected the embryo and placenta from these effects allowing normal development. Birth Defects Research (Part A) 106:749–760, 2016. © 2016 The Authors Birth Defects Research Part A: Clinical and Molecular Teratology Published by Wiley Periodicals, Inc. PMID:27296863

  16. Immune status influences fear and anxiety responses in mice after acute stress exposure.

    PubMed

    Clark, Sarah M; Sand, Joseph; Francis, T Chase; Nagaraju, Anitha; Michael, Kerry C; Keegan, Achsah D; Kusnecov, Alexander; Gould, Todd D; Tonelli, Leonardo H

    2014-05-01

    Significant evidence suggests that exposure to traumatic and/or acute stress in both mice and humans results in compromised immune function that in turn may affect associated brain processes. Additionally, recent studies in mouse models of immune deficiency have suggested that adaptive immunity may play a role during traumatic stress exposure and that impairments in lymphocyte function may contribute to increased susceptibility to various psychogenic stressors. However, rodent studies on the relationship between maladaptive stress responses and lymphocyte deficiency have been complicated by the fact that genetic manipulations in these models may also result in changes in CNS function due to the expression of targeted genes in tissues other than lymphocytes, including the brain. To address these issues we utilized mice with a deletion of recombination-activating gene 2 (Rag2), which has no confirmed expression in the CNS; thus, its loss should result in the absence of mature lymphocytes without altering CNS function directly. Stress responsiveness of immune deficient Rag2(-/-) mice on a BALB/c background was evaluated in three different paradigms: predator odor exposure (POE), fear conditioning (FC) and learned helplessness (LH). These models are often used to study different aspects of stress responsiveness after the exposure to an acute stressor. In addition, immunoblot analysis was used to assess hippocampal BDNF expression under both stressed and non-stressed conditions. Subsequent to POE, Rag2(-/-) mice exhibited a reduced acoustic startle response compared to BALB/c mice; no significant differences in behavior were observed in either FC or LH. Furthermore, analysis of hippocampal BDNF indicated that Rag2(-/-) mice have elevated levels of the mature form of BDNF compared to BALB/c mice. Results from our studies suggest that the absence of mature lymphocytes is associated with increased resilience to stress exposure in the POE and does not affect behavioral

  17. [Experiences with polychemotherapy of acute leukemias in adults with special reference to the COAP combination].

    PubMed

    Gürtler, R; Raderecht, C

    1975-01-01

    The authors give a report on their experiences with polychemotherapy in 77 acute leukaemias in adults. On this occasion the COAP combination was identified to be well effective and to be an enrichment of therapy because of its low side effects.

  18. ACUTE NEUROTOXIC EFFECTS OF INHALED PERCHLOROETHYLENE ON PATTERN VISUAL EVOKED POTENTIALS AS A FUNCTION OF EXPOSURE AND ESTIMATED BLOOD AND BRAIN CONCENTRATION.

    EPA Science Inventory

    Previous experiments have shown the effects of acute inhalation exposure to trichloroethylene (TCE) and toluene are related to the target tissue concentration at the time of testing. The current studies examined exposure to another volatile organic compound, perchloroethylene (P...

  19. Setting safe acute exposure limits for halon replacement chemicals using physiologically based pharmacokinetic modeling.

    PubMed

    Vinegar, A; Jepson, G W; Cisneros, M; Rubenstein, R; Brock, W J

    2000-08-01

    Most proposed replacements for Halon 1301 as a fire suppressant are halogenated hydrocarbons. The acute toxic endpoint of concern for these agents is cardiac sensitization. An approach is described that links the cardiac endpoint as assessed in dogs to a target arterial concentration in humans. Linkage was made using a physiologically based pharmacokinetic (PBPK) model. Monte Carlo simulations, which account for population variability, were used to establish safe exposure times at different exposure concentrations for Halon 1301 (bromotrifluoromethane), CF(3)I (trifluoroiodomethane), HFC-125 (pentafluoroethane), HFC-227ea (1,1,1,2,3,3,3-heptafluoropropane), and HFC-236fa (1,1,1,3,3,3-hexafluoropropane). Application of the modeling technique described here not only makes use of the conservative cardiac sensitization endpoint, but also uses an understanding of the pharmacokinetics of the chemical agents to better establish standards for safe exposure. The combined application of cardiac sensitization data and physiologically based modeling provides a quantitative approach, which can facilitate the selection and effective use of halon replacement candidates.

  20. Comparison of the responses of children and adults to acute ozone exposure

    SciTech Connect

    McDonnell, W.F.; Chapman, R.S.; Horstman, D.H.; Leigh, M.W.; Salaam, S.A.

    1986-07-01

    The purpose of the paper is to compare the results of two studies in which the respiratory responses of children and adults to acute ozone (O/sub 3/) exposure were measured. Forty-two 18-30 year old males were exposed for 2.5 hours in a controlled environmental chamber to either 0.0 or 0.12 ppm O3 while performing intermittent heavy exercise. Twenty-two 8-11 year old males were exposed in a similar manner to both air and 0.12 ppm O3. Measures of respiratory symptoms and function were made before and after exposure. Adults experienced an increase in the symptom cough and decrements in forced vital capacity and some measures of forced expiratory flow. Children experienced similar decrements in pulmonary function, but had no increase in symptoms. The authors concluded that as measured by pulmonary function children appear to be no more responsive to O3 exposure than are adults and may experience fewer symptoms.

  1. Oxidative Status and Acute Phase Reactants in Patients with Environmental Asbestos Exposure and Mesothelioma

    PubMed Central

    Sezgi, Cengizhan; Taylan, Mahsuk; Selimoglu Sen, Hadice; Evliyaoğlu, Osman; Kaya, Halide; Abakay, Ozlem; Abakay, Abdurrahman; Tanrıkulu, Abdullah Cetin; Senyiğit, Abdurrahman

    2014-01-01

    Background and Objectives. The aim of this study was to investigate inflammatory indicators and oxidative status in patients with asbestos exposure with and without mesothelioma and to compare results with data from healthy subjects. Methods. Eighty people with exposure to environmental asbestos and without any disease, 46 mesothelioma patients, and a control group of 50 people without exposure to environmental asbestos were enrolled in this prospective study. Serum total oxidant level (TOL), total antioxidant capacity (TAC), and oxidative stress index (OSI), CRP, transferrin, ceruloplasmin, α-1 antitrypsin, ferritin, and copper levels were measured. Results. Mesothelioma group exhibited higher TOL, OSI, α1-antitrypsin, ferritin and copper levels as compared to the other groups (P < 0.001, P = 0.007, P < 0.0001, P < 0.001, and P < 0.001, resp.). Transferrin was lower in the mesothelioma group than in the other two groups (P < 0.001). The asbestos group had higher TOL, TAC, α1-antitrypsin, and transferrin levels (P < 0.001, P < 0.001, P < 0.001, and P < 0.001, resp.), as well as lower OSI and ferritin levels as compared to the control group (P < 0.001 and P < 0.001). Conclusions. We believe that elevated acute phase reactants and oxidative stress markers (TOL and OSI) in the mesothelioma group can be used as predictive markers for the development of asbestos-related malignancy. PMID:24592197

  2. Acute effects of chlorinated resin acid exposure on juvenile rainbow trout, Oncorhynchus mykiss

    SciTech Connect

    Kennedy, C.J.; Sweeting, R.M.; Farrell, A.P.; McKeown, B.A.; Johansen, J.A.

    1995-06-01

    The effects of an acute exposure to either 14-monochlorodehydroabietic acid (MCDHAA) or 12,14-dichlorodehydroabietic acid (DCDHAA) were examined in juvenile rainbow trout, Oncorhynchus mykiss. The experimentally determined 96-h LC50 values (and their 95% confidence limits) were 1.03 (0.72, 1.48) and 0.91 (0.70, 1.21) mg/L, for MCDHAA and DCDHAA, respectively. To measure effects on several biochemical parameters, swimming performance, and disease resistance, juvenile trout were exposed for 24 h to sublethal concentrations of one or the other resin acid in an intermittent-flow respirometer. Hematocrit, plasma lactate, and liver protein were significantly affected by exposure to the highest dose (80% of the 96-h LC50 value) of either of the resin acids. Plasma cortisol levels were 14- and 3-fold higher than were controls. Resistance to infection by Aeromonas salmonicida was significantly reduced; the cumulative percent mortalities due to furunculosis in fish exposed to MCDHAA or DCDHAA reached 20 and 26%, respectively. Swimming performance, measured as critical swimming speed (mean values 6.32 {+-} 0.20 and 5.93 {+-} 0.15 body lengths per second for MCDHAA and DCDHAA, respectively), was not significantly affected by resin acid exposure.

  3. Carcinogenicity and other health effects of acrylonitrile with reference to occupational exposure limit.

    PubMed

    Sakurai, H

    2000-04-01

    The occupational exposure limit for acrylonitrile (AN) has been set by many organizations on the basis of its carcinogenicity. However, recent epidemiological studies do not afford evidence supporting the hypothesis that AN is carcinogenic to humans. Review of the 18 published cohort studies revealed that, although there is not adequate evidence in humans for carcinogenicity of AN, the possibility of a causal association between high exposure to AN and lung cancer in humans cannot be excluded. It was pointed out that carcinogenic potential of AN may be weak, if any, to humans, and the current occupational exposure limit (OEL) for AN of 2 ppm was evaluated as appropriate in view of AN exposure levels reported by epidemiological studies. Based also on review of the literature on health effects other than carcinogenicity, it was concluded that the current OEL for AN is a reasonable value and there is no need for a revision at present.

  4. ACUTE CHANGES IN PASSIVE GLENOHUMERAL ROTATION FOLLOWING TENNIS PLAY EXPOSURE IN ELITE FEMALE PLAYERS

    PubMed Central

    Kibler, W. Ben; Myers, Natalie L.; Smith, Belinda J.

    2016-01-01

    Background Alterations in glenohumeral (GH) rotation especially internal rotation and total range of motion have been associated with altered GH kinematics and susceptibility to injury. Researchers have evaluated long-term change in baseball and tennis players, and short-term changes in baseball players. However, acute (short-term) changes in GH rotation have not been evaluated in tennis players. Hypotheses/Purpose The purpose of this study was to quantify short-term glenohumeral rotational changes within a group of professional women's tennis players following competitive play. It was hypothesized that there would be acute alterations in passive glenohumeral internal rotation and total range of motion following episodes of tennis play. Study Design Cohort Study Methods Passive glenohumeral external rotation (GER), glenohumeral internal rotation (GIR), and total range of motion (TROM) were evaluated in a cohort of 79 professional adult female tennis players. Measurements were taken at three different time points (TP): baseline before match play (TP1), immediately after match play (TP2), and 24-hours after baseline (TP3). Results There was a statistically significant decrease in the mean GIR from TP1 (43 ± 11 °) to TP2 (39 ± 9 °) (p=0.002) and from TP1 to TP3 (38 ± 10 °) (p=0.001). All measures were at the level of minimal detectable change (MDC) (4 °) indicating clinical significance. There was a decrease in mean TROM from TP1 (146 ± 11 °) to TP2 (142 ± 12 °) (p=0.04), which was not above MDC (7 °). Subgroup analysis showed that 47% of the players demonstrated a decrease in GIR beyond MDC, and 37% demonstrated a decrease in TROM beyond MDC. GER remained unchanged across all time points (p>0.05). Conclusion Both GIR and TROM were reduced after acute exposure to tennis play. In a large subgroup of the cohort, the changes were clinically significant and approached values previously demonstrated to be associated with

  5. The body weight loss during acute exposure to high-altitude hypoxia in sea level residents.

    PubMed

    Ge, Ri-Li; Wood, Helen; Yang, Hui-Huang; Liu, Yi-Ning; Wang, Xiu-Juan; Babb, Tony

    2010-12-25

    Weight loss is frequently observed after acute exposure to high altitude. However, the magnitude and rate of weight loss during acute exposure to high altitude has not been clarified in a controlled prospective study. The present study was performed to evaluate weight loss at high altitude. A group of 120 male subjects [aged (32±6) years] who worked on the construction of the Golmud-Lhasa Railway at Kunlun Mountain (altitude of 4 678 m) served as volunteer subjects for this study. Eighty-five workers normally resided at sea level (sea level group) and 35 normally resided at an altitude of 2 200 m (moderate altitude group). Body weight, body mass index (BMI), and waist circumference were measured in all subjects after a 7-day stay at Golmud (altitude of 2 800 m, baseline measurements). Measurements were repeated after 33-day working on Kunlun Mountain. In order to examine the daily rate of weight loss at high altitude, body weight was measured in 20 subjects from the sea level group (sea level subset group) each morning before breakfast for 33 d at Kunlun Mountain. According to guidelines established by the Lake Louise acute mountain sickness (AMS) consensus report, each subject completed an AMS self-report questionnaire two days after arriving at Kunlun Mountain. After 33-day stay at an altitude of 4 678 m, the average weight loss for the sea level group was 10.4% (range 6.5% to 29%), while the average for the moderate altitude group was 2.2% (-2% to 9.1%). The degree of weight loss (Δ weight loss) after a 33-day stay at an altitude of 4 678 m was significantly correlated with baseline body weight in the sea level group (r=0.677, P<0.01), while the correlation was absent in the moderate altitude group (r=0.296, P>0.05). In the sea level subset group, a significant weight loss was observed within 20 d, but the weight remained stable thereafter. AMS-score at high altitude was significantly higher in the sea level group (4.69±2.48) than that in the moderate

  6. Acute effects and exposure to organic compounds in road maintenance workers exposed to asphalt.

    PubMed

    Norseth, T; Waage, J; Dale, I

    1991-01-01

    Subjective symptoms and exposure to organic compounds were recorded in road repair and construction workers. Abnormal fatigue, reduced appetite, laryngeal/pharyngeal irritation, and eye irritation were recorded more often in such workers handling asphalt than in a corresponding reference group without asphalt exposure. Mean daily exposure to volatile compounds was only occasionally above 1 ppm. Mean exposure to asphalt fume was 0.358 mg/m3. There was no correlation between symptoms and total amount of volatile compounds, but a significant positive correlation was demonstrated between symptoms and some substances. The highest correlation was found for 1, 2, 4 trimethyl benzene. Symptoms increased with increasing asphalt temperature and with increasing concentrations of asphalt fumes. Amine addition did not increase the sum of symptoms, but soft asphalt seems to result in fewer symptoms than the harder types. Symptoms were not related to external factors like weather, traffic density, or specific working operations. As preventive measures, asphalt temperature should be kept below 150 degrees C, fume concentrations below 0.40 mg/m3, and if possible, the use of harder asphalt types which also require high temperatures should be avoided.

  7. Graphical Arrays of Chemical-Specific Health Effect Reference Values for Inhalation Exposures (2009 Final Report)

    EPA Science Inventory

    This document provides graphical arrays and tables of key information on the derivation of human inhalation health effect reference values for specific chemicals, allowing comparisons across durations, populations, and intended use. A number of program offices within the Agency, ...

  8. Tobacco Smoke Exposure and the Risk of Childhood Acute Lymphoblastic and Myeloid Leukemias by Cytogenetic Subtype

    PubMed Central

    Metayer, Catherine; Zhang, Luoping; Wiemels, Joseph L.; Bartley, Karen; Schiffman, Joshua; Ma, Xiaomei; Aldrich, Melinda C.; Chang, Jeffrey S.; Selvin, Steve; Fu, Cecilia H.; Ducore, Jonathan; Smith, Martyn T.; Buffler, Patricia A.

    2013-01-01

    Background Tobacco smoke contains carcinogens known to damage somatic and germ cells. We investigated the effect tobacco smoke on the risk of childhood acute lymphoblastic leukemia (ALL) and myeloid leukemia (AML), especially subtypes of pre-natal origin like ALL with translocation t(12;21) or high-hyperdiploidy (51–67 chromosomes). Methods We collected information on exposures to tobacco smoking before conception, during pregnancy, and after birth in 767 ALL cases, 135 AML cases, and 1,139 controls (1996–2008). Among cases, chromosome translocations, deletions, or aneuploidy were identified by conventional karyotype and fluorescence in-situ hybridization. Results Multivariable regression analyses for ALL and AML overall showed no definite evidence of associations with self-reported (yes/no) parental prenatal active smoking and child's passive smoking. However, children with history of paternal prenatal smoking combined with postnatal passive smoking had a 1.5-fold increased risk of ALL (95% CI: 1.01–2.23), compared to those without smoking history (ORs for pre- or postnatal smoking only were close to one). This joint effect was seen for B-cell precursor ALL with t(12;21) (OR=2.08; 95% CI: 1.04–4.16), but not high hyperdiploid B-cell ALL. Similarly, child's passive smoking was associated with an elevated risk of AML with chromosome structural changes (OR=2.76; 95% CI: 1.01–7.58), but not aneuploidy. Conclusions our data suggest that exposure to tobacco smoking before were associated with increased risks of childhood ALL and AML; and risks varied by timing of exposure (before and/or after birth) and cytogenetic subtype, based on imprecise estimates. Impact Parents should limit exposures to tobacco smoke before and after the child's birth. PMID:23853208

  9. Acute Acrolein Exposure Induces Impairment of Vocal Fold Epithelial Barrier Function

    PubMed Central

    Zheng, Wei; Sivasankar, M. Preeti

    2016-01-01

    Acrolein is a ubiquitous pollutant abundant in cigarette smoke, mobile exhaust, and industrial waste. There is limited literature on the effects of acrolein on vocal fold tissue, although there are clinical reports of voice changes after pollutant exposures. Vocal folds are responsible for voice production. The overall objective of this study was to investigate the effects of acrolein exposure on viable, excised vocal fold epithelial tissue and to characterize the mechanism underlying acrolein toxicity. Vocal fold epithelia were studied because they form the outermost layer of the vocal folds and are a primary recipient of inhaled pollutants. Porcine vocal fold epithelia were exposed to 0, 50, 100, 500, 900 or 1300 μM of acrolein for 3 hours; the metabolic activity, epithelial resistance, epithelial permeability, tight junction protein (occludin and claudin 3) expression, cell membrane integrity and lipid peroxidation were investigated. The data demonstrated that acrolein exposure at 500 μM significantly reduced vocal fold epithelial metabolic activity by 27.2% (p≤0.001). Incubation with 100 μM acrolein caused a marked increase in epithelial permeability by 130.5% (p<0.05) and a reduction in transepithelial electrical resistance (TEER) by 180.0% (p<0.001). While the expression of tight junctional protein did not change in acrolein-treated samples, the cell membrane integrity was significantly damaged with a 45.6% increase of lipid peroxidation as compared to controls (p<0.05). Taken together, these data provide evidence that acute acrolein exposure impairs vocal fold epithelial barrier integrity. Lipid peroxidation-induced cell membrane damage may play an important role in reducing the barrier function of the epithelium. PMID:27643990

  10. Absence of acute ocular damage in humans after prolonged exposure to intense RF EMF

    NASA Astrophysics Data System (ADS)

    Adibzadeh, F.; van Rhoon, G. C.; Verduijn, G. M.; Naus-Postema, N. C.; Paulides, M. M.

    2016-01-01

    The eye is considered to be a critical organ when determining safety standards for radio frequency (RF) radiation. Experimental data obtained using animals showed that RF heating of the eye, particularly over a specific threshold, can induce cataracts. During the treatment of cancer in the head and neck by hyperthermia, the eyes receive a considerable dose of RF radiation due to stray radiation from the prolonged (60 min) and intense exposure at 434 MHz of this region. In the current study, we verified the exposure guidelines for humans by determining the association between the electromagnetic and thermal dose in the eyes with the reported ocular effects. We performed a simulation study to retrospectively assess the specific absorption rate (SAR) and temperature increase in the eyes of 16 selected patients (encompassing a total of 74 treatment sessions) whose treatment involved high power delivery as well as a minimal distance between the tumor site and the eye. Our results show that the basic restrictions on the peak 10 g spatial-averaged SAR (10 W kg-1) and peak tissue temperature increase (1 °C) are exceeded by up to 10.4 and 4.6 times, on average, and by at least 6.2 and 1.8 times when considering the lower limit of the 95% confidence interval. Evaluation of the acute effects according to patients’ feedback (all patients), the common toxicity criteria scores (all patients) and an ophthalmology investigation (one patient with the highest exposure) revealed no indication of any serious acute ocular effect, even though the eyes were exposed to high electromagnetic fields, leading to a high thermal dose. We also found that, although there is a strong correlation (R 2  =  0.88) between the predicted induced SAR and temperature in the eye, there are large uncertainties regarding the temperature-SAR relationship. Given this large uncertainty (129%) compared with the uncertainty of 3D temperature simulations (61%), we recommend using temperature

  11. Absence of acute ocular damage in humans after prolonged exposure to intense RF EMF.

    PubMed

    Adibzadeh, F; van Rhoon, G C; Verduijn, G M; Naus-Postema, N C; Paulides, M M

    2016-01-21

    The eye is considered to be a critical organ when determining safety standards for radio frequency (RF) radiation. Experimental data obtained using animals showed that RF heating of the eye, particularly over a specific threshold, can induce cataracts. During the treatment of cancer in the head and neck by hyperthermia, the eyes receive a considerable dose of RF radiation due to stray radiation from the prolonged (60 min) and intense exposure at 434 MHz of this region. In the current study, we verified the exposure guidelines for humans by determining the association between the electromagnetic and thermal dose in the eyes with the reported ocular effects. We performed a simulation study to retrospectively assess the specific absorption rate (SAR) and temperature increase in the eyes of 16 selected patients (encompassing a total of 74 treatment sessions) whose treatment involved high power delivery as well as a minimal distance between the tumor site and the eye. Our results show that the basic restrictions on the peak 10 g spatial-averaged SAR (10 W kg(-1)) and peak tissue temperature increase (1 °C) are exceeded by up to 10.4 and 4.6 times, on average, and by at least 6.2 and 1.8 times when considering the lower limit of the 95% confidence interval. Evaluation of the acute effects according to patients' feedback (all patients), the common toxicity criteria scores (all patients) and an ophthalmology investigation (one patient with the highest exposure) revealed no indication of any serious acute ocular effect, even though the eyes were exposed to high electromagnetic fields, leading to a high thermal dose. We also found that, although there is a strong correlation (R (2) =  0.88) between the predicted induced SAR and temperature in the eye, there are large uncertainties regarding the temperature-SAR relationship. Given this large uncertainty (129%) compared with the uncertainty of 3D temperature simulations (61%), we recommend using temperature simulations as a

  12. Acute retinal necrosis (ARN) in the context of neonatal HSV-2 exposure and subconjunctival dexamethasone: case report and literature review.

    PubMed

    McGrath, Lindsay; Woods, Marion; Lee, Lawrence; Conrad, Diana

    2013-01-01

    HSV-2 is an important cause of the acute retinal necrosis (ARN) syndrome in younger patients. We describe an atypical case of HSV-2 ARN in the context of neonatal exposure and subconjunctival steroid injection. Clinicians should be aware of the association of neonatal or congenital exposure to HSV-2 as a risk factor for this disease because early treatment may improve outcome and/or avoid involvement of both eyes.

  13. Oral exposure to Phytomonas serpens attenuates thrombocytopenia and leukopenia during acute infection with Trypanosoma cruzi.

    PubMed

    da Silva, Rosiane V; Malvezi, Aparecida D; Augusto, Leonardo da Silva; Kian, Danielle; Tatakihara, Vera Lúcia H; Yamauchi, Lucy M; Yamada-Ogatta, Sueli F; Rizzo, Luiz V; Schenkman, Sergio; Pinge-Filho, Phileno

    2013-01-01

    Mice infected with Trypanosoma cruzi, the agent of Chagas disease, rapidly develop anemia and thrombocytopenia. These effects are partially promoted by the parasite trans-sialidase (TS), which is shed in the blood and depletes sialic acid from the platelets, inducing accelerated platelet clearance and causing thrombocytopenia during the acute phase of disease. Here, we demonstrate that oral immunization of C57BL/6 mice with Phytomonas serpens, a phytoflagellate parasite that shares common antigens with T. cruzi but has no TS activity, reduces parasite burden and prevents thrombocytopenia and leukopenia. Immunization also reduces platelet loss after intraperitoneal injection of TS. In addition, passive transfer of immune sera raised in mice against P. serpens prevented platelet clearance. Thus, oral exposure to P. serpens attenuates the progression of thrombocytopenia induced by TS from T. cruzi. These findings are not only important for the understanding of the pathogenesis of T. cruzi infection but also for developing novel approaches of intervention in Chagas disease.

  14. [Experimental estimation of thermogenic levels of acute microwave exposure for different animal species].

    PubMed

    Kolganova, O I; Drozd, A I; Zhavoronkov, L P; Baranov, V D; Glushakova, V S; Panferova, T A

    2000-01-01

    In experiments on laboratory animals it was found the different patterns of reactions in response to acute thermogenic 7 GHz CW microwave exposures. The effects were related specifically to the intensity of the field. SAR equal 0.5-0.7 power of basal metabolism of different species did not result in increase of body temperature. At SARs over intensity of basal metabolism (up to 1.5-2.0 basal metabolism for the mice and for the rats and up to 1.5 for the rabbits) the "stepped" pattern of body heating with periods of rectal temperature stabilization was observed. This results may have implications for prognostic estimation of dose-temporal limits of endurable intensities of microwaves.

  15. [Decubitus lesions in patients referred to acute and post-acute home nursing care for the elderly in Genova].

    PubMed

    De Astis, V; Corbella, A; Bafico, F; Spinelli, E; Porcu, G; Bottari, L; Petrini, M; Madeddu, V

    1999-01-01

    The Elderly Services of USL 3 "Genovese" together with the team for Continuing Education designed and implemented a survey on the elderly clients referred to the home care and nursing home services. The aim of the study was to describe the frequency, distribution and severity of pressure ulcers. The data were collected during a period of seven months: from 1st November 1997 to 31st May 1998. One thousand seven hundred and twenty nine clients were observed; 705 (41%) had single or multiple pressure ulcers. Patients with multiple pressure ulcers accounted for 42% of the total. The sacrum was the most affected site (43% of the patients with a single ulcer and 33% with multiple ulcers). Patients with severe pressure ulcers (stages 3 degrees and 4 degrees NPUAP classification) accounted for 42% of the total. Pressure sores were observed in 15% of "at no risk" patients and in 40% of those at low risk (Norton Scale score). The study highlighted a lack of documentation (90% patients) on treatments performed in the hospital and prescribed at discharge for the pressure sores. These findings reflects possibly the fact that this aspect of care is unduly disregarded by nursing personnel, and that a goal-oriented retraining, underlining also the need of appropriate documentation, is warranted.

  16. Effect of Acute Exposure to Moderate Altitude on Muscle Power: Hypobaric Hypoxia vs. Normobaric Hypoxia

    PubMed Central

    Feriche, Belén; García-Ramos, Amador; Calderón-Soto, Carmen; Drobnic, Franchek; Bonitch- Góngora, Juan G.; Galilea, Pedro A.; Riera, Joan; Padial, Paulino

    2014-01-01

    When ascending to a higher altitude, changes in air density and oxygen levels affect the way in which explosive actions are executed. This study was designed to compare the effects of acute exposure to real or simulated moderate hypoxia on the dynamics of the force-velocity relationship observed in bench press exercise. Twenty-eight combat sports athletes were assigned to two groups and assessed on two separate occasions: G1 (n = 17) in conditions of normoxia (N1) and hypobaric hypoxia (HH) and G2 (n = 11) in conditions of normoxia (N2) and normobaric hypoxia (NH). Individual and complete force-velocity relationships in bench press were determined on each assessment day. For each exercise repetition, we obtained the mean and peak velocity and power shown by the athletes. Maximum power (Pmax) was recorded as the highest Pmean obtained across the complete force-velocity curve. Our findings indicate a significantly higher absolute load linked to Pmax (∼3%) and maximal strength (1RM) (∼6%) in G1 attributable to the climb to altitude (P<0.05). We also observed a stimulating effect of natural hypoxia on Pmean and Ppeak in the middle-high part of the curve (≥60 kg; P<0.01) and a 7.8% mean increase in barbell displacement velocity (P<0.001). No changes in any of the variables examined were observed in G2. According to these data, we can state that acute exposure to natural moderate altitude as opposed to simulated normobaric hypoxia leads to gains in 1RM, movement velocity and power during the execution of a force-velocity curve in bench press. PMID:25474104

  17. Effect of acute exposure to moderate altitude on muscle power: hypobaric hypoxia vs. normobaric hypoxia.

    PubMed

    Feriche, Belén; García-Ramos, Amador; Calderón-Soto, Carmen; Drobnic, Franchek; Bonitch-Góngora, Juan G; Galilea, Pedro A; Riera, Joan; Padial, Paulino

    2014-01-01

    When ascending to a higher altitude, changes in air density and oxygen levels affect the way in which explosive actions are executed. This study was designed to compare the effects of acute exposure to real or simulated moderate hypoxia on the dynamics of the force-velocity relationship observed in bench press exercise. Twenty-eight combat sports athletes were assigned to two groups and assessed on two separate occasions: G1 (n = 17) in conditions of normoxia (N1) and hypobaric hypoxia (HH) and G2 (n = 11) in conditions of normoxia (N2) and normobaric hypoxia (NH). Individual and complete force-velocity relationships in bench press were determined on each assessment day. For each exercise repetition, we obtained the mean and peak velocity and power shown by the athletes. Maximum power (Pmax) was recorded as the highest P(mean) obtained across the complete force-velocity curve. Our findings indicate a significantly higher absolute load linked to P(max) (∼ 3%) and maximal strength (1 RM) (∼ 6%) in G1 attributable to the climb to altitude (P<0.05). We also observed a stimulating effect of natural hypoxia on P(mean) and P(peak) in the middle-high part of the curve (≥ 60 kg; P<0.01) and a 7.8% mean increase in barbell displacement velocity (P<0.001). No changes in any of the variables examined were observed in G2. According to these data, we can state that acute exposure to natural moderate altitude as opposed to simulated normobaric hypoxia leads to gains in 1 RM, movement velocity and power during the execution of a force-velocity curve in bench press.

  18. Effects of Acutely Intermittent Hypoxic Exposure on Running Economy and Physical Performance in Basketball Players.

    PubMed

    Kilding, Andrew E; Dobson, Bryan P; Ikeda, Erika

    2016-07-01

    Kilding, AE, Dobson, BP, and Ikeda, E. Effects of acutely intermittent hypoxic exposure on running economy and physical performance in basketball players. J Strength Cond Res 30(7): 2033-2042, 2016-The aim of this study was to determine the effect of short duration intermittent hypoxic exposure (IHE) on physical performance in basketball players. Using a single-blind placebo-controlled group design, 14 trained basketball players were subjected to 15 days of passive short duration IHE (n = 7), or normoxic control (CON, n = 7), using a biofeedback nitrogen dilution device. A range of physiological, performance, and hematological variables were measured at baseline, and 10 days after IHE. After intervention, the IHE group, relative to the CON group, exhibited improvements in the Yo-Yo intermittent recovery level 1 (+4.8 ± 1.6%; effect size [ES]: 1.0 ± 0.4) and repeated high-intensity exercise test performance (-3.5 ± 1.6%; ES: -0.4 ± 0.2). Changes in hematological parameters were minimal, although soluble transferrin receptor increased after IHE (+9.2 ± 10.1%; ES: 0.3 ± 0.3). Running economy at 11 km·h (-9.0 ± 9.7%; ES: -0.7 ± 0.7) and 13 km·h was improved (-8.2 ± 6.9%; ES: -0.7 ± 0.5), but changes to V[Combining Dot Above]O2peak, HRpeak, and lactate were unclear. In summary, acutely IHE resulted in worthwhile changes in physical performance tests among competitive basketball players. However, physiological measures explaining the performance enhancement were in most part unclear.

  19. Acute effects of exposure to 1 mg/m(3) of vaporized 2-ethyl-1-hexanol in humans.

    PubMed

    Ernstgård, L; Norbäck, D; Nordquist, T; Wieslander, G; Wålinder, R; Johanson, G

    2010-04-01

    The objective was to assess acute effects from controlled exposure of volunteers to 2-ethyl-1-hexanol, a volatile organic compound that is often found in indoor air. Sixteen males and fourteen females were in random order exposed to 1 mg/m(3) of vapors of 2-ethyl-1-hexanol or to clean air (control exposure) in an exposure chamber during 2 h at rest. The subjects performed symptom ratings on Visual Analog Scales. During exposure to 2-ethyl-1-hexanol subjective ratings of smell and eye discomfort were minimally but significantly increased. Ratings of nasal irritation, throat irritation, headache, dyspnoea, fatigue, dizziness, nausea, and intoxication were not significantly affected. No exposure-related effects on measurement of blinking frequency by electromyography, measurement of the eye break-up time, vital staining of the eye, nasal lavage biomarkers, transfer tests, spirometric and rhinometric measures were seen. No differences in response were seen between sexes or between atopics and non-atopics. Practical Implications It is important to assess acute effects in volatile organic compounds like 2-ethyl-1-hexanol. 2-ethyl-1-hexanol is often found in indoor air generated by degradation of plastic building materials or in new buildings. There are associations between 2-ethyl-1-hexanol in indoor air and respiratory effects, eye irritation, headache, and blurred vision. A controlled chamber exposure study in acute effects was performed. In conclusion, this study showed weak subjective symptom of irritation in the eyes.

  20. Experimental exposure to propylene glycol mist in aviation emergency training: acute ocular and respiratory effects

    PubMed Central

    Wieslander, G; Norback, D; Lindgren, T

    2001-01-01

    OBJECTIVES—Propylene glycol (PG) (1-2 propanediol; CAS No 57-55-6) is a low toxicity compound widely used as a food additive, in pharmaceutical preparations, in cosmetics, and in the workplace—for example, water based paints, de-icing fluids, and cooling liquids. Exposure to PG mist may occur from smoke generators in discotheques, theatres, and aviation emergency training. Propylene glycol may cause contact allergy, but there is sparse information on health effects from occupational exposure to PG.
METHODS—Non-asthmatic volunteers (n=27) were exposed in an aircraft simulator to PG mist over 1 minute, during realistic training conditions. Geometric mean concentration of PG was 309 mg/m3 (range 176-851 mg/m3), with the highest concentrations in the afternoon. The medical investigation was performed both before and after the exposure (within 15 minutes). It included an estimate of tear film stability break up time, nasal patency by acoustic rhinometry, dynamic spirometry, and a doctor's administered questionnaire on symptoms.
RESULTS—After exposure to PG mist for 1 minute tear film stability decreased, ocular and throat symptoms increased, forced expiratory volume in 1 second/forced vital capacity (FEV1/FVC) was slightly reduced, and self rated severity of dyspnoea was slightly increased. No effect was found for nasal patency, vital capacity (VC), FVC, nasal symptoms, dermal symptoms, smell of solvent, or any systemic symptoms. Those exposed to the higher concentrations in the afternoon had a more pronounced increase of throat symptoms, and a more pronounced decrease of tear film stability. In four subjects who reported development of irritative cough during exposure to PG, FEV1 was decreased by 5%, but FEV1 was unchanged among those who did not develop a cough. Those who developed a cough also had an increased perception of mild dyspnoea.
CONCLUSION—Short exposure to PG mist from artificial smoke generators may cause acute ocular and upper airway

  1. Caffeine improves performance in double poling during acute exposure to 2,000-m altitude.

    PubMed

    Stadheim, H K; Nossum, E M; Olsen, R; Spencer, M; Jensen, J

    2015-12-15

    There is limited research on the physiological effects of caffeine (CAF) ingestion on exercise performance during acute hypoxia. The aim of the present study was therefore to test the effect of placebo (PLA) and CAF (4.5 mg/kg) on double poling (DP) performance during acute hypoxia. Thirteen male subelite cross-country skiers (V̇o2max 72.6 ± 5.68 ml·kg(-1)·min(-1)) were included. Performance was assessed as 1) an 8-km cross-country DP time-trial (C-PT), and 2) time until task failure at a set workload equal to ∼90% of DP V̇o2max. Testing was carried out in a hypobaric chamber, at 800 mbar (Pio2: ∼125 mmHg) corresponding to ∼2,000 m above sea level in a randomized double-blinded, placebo-controlled, cross-over design. CAF improved time to task failure from 6.10 ± 1.40 to 7.22 ± 1.30 min (P < 0.05) and velocity the first 4 km (P < 0.05) but not overall time usage for the 8-km C-PT. During submaximal exercise subjects reported lower pain in arms and rate of perceived exertion (RPE) following CAF ingestion. Throughout C-PTs similar RPE and pain was shown between treatments. However, higher heart rate was observed during the CAF 8 km (187 ± 7 vs. 185 ± 7; P < 0.05) and 90% C-PT (185 ± 7 vs. 181 ± 9) associated with increased ventilation, blood lactate, glucose, adrenaline, decreased pH, and bicarbonate. The present study demonstrates for the first time that CAF ingestion improves DP time to task failure although not consistently time trial performance during acute exposure to altitude. Mechanisms underpinning improvements seem related to reduced pain RPE and increased heart rate during CAF C-PTs.

  2. Acute and chronic effects of ferret odor exposure in Sprague-Dawley rats.

    PubMed

    Campeau, S; Nyhuis, T J; Sasse, S K; Day, H E W; Masini, C V

    2008-09-01

    This manuscript describes several behavioral and functional studies evaluating the capacity of ferret odors to elicit a number of acute and long-term responses in male Sprague-Dawley rats. Acute presentation elicits multiple responses, suggesting that ferret odor, likely from skin gland secretions, provides an anxiogenic-like stimulus in this strain of rats. Compared to cat odor, however, ferret odor did not produce rapid fear conditioning, a result perhaps attributable to methodological factors. Inactivation of the olfactory system and medial nucleus of the amygdala, combined with induction of the immediate-early gene c-fos, suggest the necessity of the accessory olfactory system in mediating the effects of ferret odor. Repeated exposures to ferret odor produce variable habituation of neuroendocrine and behavioral responses, perhaps indicative of the lack of control over the exact individual origin or concentration of ferret odor. Ferret odor induces rapid and long-term body weight regulation, thymic involution, adrenal hyperplasia and facilitation of the neuroendocrine response to additional challenges. It is argued that the use of such odors is exquisitely suited to investigate the brain regions coordinating anxiety-like responses and the long-term changes elicited by such stimuli.

  3. Biophysical model for assessment of risk of acute exposures in combination with low level chronic irradiation

    NASA Astrophysics Data System (ADS)

    Smirnova, O. A.

    A biophysical model is developed which describes the mortality dynamics in mammalian populations unexposed and exposed to radiation The model relates statistical biometric functions mortality rate life span probability density and life span probability with statistical characteristics and dynamics of a critical body system in individuals composing the population The model describing the dynamics of thrombocytopoiesis in nonirradiated and irradiated mammals is also developed this hematopoietic line being considered as the critical body system under exposures in question The mortality model constructed in the framework of the proposed approach was identified to reproduce the irradiation effects on populations of mice The most parameters of the thrombocytopoiesis model were determined from the data available in the literature on hematology and radiobiology the rest parameters were evaluated by fitting some experimental data on the dynamics of this system in acutely irradiated mice The successful verification of the thrombocytopoiesis model was fulfilled by the quantitative juxtaposition of the modeling predictions and experimental data on the dynamics of this system in mice exposed to either acute or chronic irradiation at wide ranges of doses and dose rates It is important that only experimental data on the mortality rate in nonirradiated population and the relevant statistical characteristics of the thrombocytopoiesis system in mice which are also available in the literature on radiobiology are needed for the final identification of

  4. Noninvasive Biomonitoring Approaches to Determine Dosimetry and Risk Following Acute Chemical Exposure: Analysis of Lead or Organophosphate Insecticide in Saliva

    SciTech Connect

    Timchalk, Chuck; Poet, Torka S.; Kousba, Ahmed A.; Campbell, James A.; Lin, Yuehe

    2004-04-01

    There is a need to develop approaches for assessing risk associated with acute exposures to a broad-range of chemical agents and to rapidly determine the potential implications to human health. Non-invasive biomonitoring approaches are being developed using reliable portable analytical systems to quantitate dosimetry utilizing readily obtainable body fluids, such as saliva. Saliva has been used to evaluate a broad range of biomarkers, drugs, and environmental contaminants including heavy metals and pesticides. To advance the application of non-invasive biomonitoring a microfluidic/ electrochemical device has also been developed for the analysis of lead (Pb), using square wave anodic stripping voltammetry. The system demonstrates a linear response over a broad concentration range (1 2000 ppb) and is capable of quantitating saliva Pb in rats orally administered acute doses of Pb-acetate. Appropriate pharmacokinetic analyses have been used to quantitate systemic dosimetry based on determination of saliva Pb concentrations. In addition, saliva has recently been used to quantitate dosimetry following exposure to the organophosphate insecticide chlorpyrifos in a rodent model system by measuring the major metabolite, trichloropyridinol, and saliva cholinesterase inhibition following acute exposures. These results suggest that technology developed for non-invasive biomonitoring can provide a sensitive, and portable analytical tool capable of assessing exposure and risk in real-time. By coupling these non-invasive technologies with pharmacokinetic modeling it is feasible to rapidly quantitate acute exposure to a broad range of chemical agents. In summary, it is envisioned that once fully developed, these monitoring and modeling approaches will be useful for accessing acute exposure and health risk.

  5. Determinants of active and environmental exposure to tobacco smoke and upper reference value of urinary cotinine in not exposed individuals.

    PubMed

    Campo, Laura; Polledri, Elisa; Bechtold, Petra; Gatti, Giulia; Ranzi, Andrea; Lauriola, Paolo; Goldoni, Carlo Alberto; Bertazzi, Pier Alberto; Fustinoni, Silvia

    2016-07-01

    The aims of this study were (1) to explore the behavioral and sociodemographic factors influencing urinary cotinine (COT-U) levels in active smokers and in environmental tobacco smoke (ETS)-exposed individuals, (2) to assess the specificity and sensitivity of the questionnaire for identifying active smokers and nonsmokers, and (3) to derive the upper reference value of COT-U in non-ETS exposed individuals. The COT-U levels of 495 adults (age range 18-69 years) who classified themselves as active smokers (29%) or as nonsmokers with (17%) or without (83%) ETS exposure were quantified by LC-MS-MS (quantification limit: 0.1µg/L, range of linearity: 0.1-4000µg/L). Median COT-U levels in these groups were 883, 1.38, and 0.39µg/L, respectively. Significant determinants of COT-U levels in active smokers were the number of cigarettes per day, type of smoking product, smoking environment, as well as time between the last cigarette and urine collection. Among ETS-exposed nonsmokers, significant determinants were living with smokers, being exposed to smoke at home, ETS exposure duration, as well as time between the last exposure and urine collection. When a 30-µg/L COT-U cut-off value was used to identify active daily smoking, the sensitivity and specificity of the questionnaire were 94% and 98%, respectively. For ETS exposure, the COT-U value of 1.78 (0.90 confidence interval 1.75-1.78) µg/L, corresponding to the 95th percentiles of the COT-U distribution in non-ETS-exposed participants, is proposed as upper reference value to identify environmental exposure.

  6. Large Variation in Brain Exposure of Reference CNS Drugs: a PET Study in Nonhuman Primates

    PubMed Central

    Varnäs, Katarina; Lundquist, Stefan; Nakao, Ryuji; Amini, Nahid; Takano, Akihiro; Finnema, Sjoerd J.; Halldin, Christer; Farde, Lars

    2015-01-01

    Background: Positron emission tomography microdosing of radiolabeled drugs allows for noninvasive studies of organ exposure in vivo. The aim of the present study was to examine and compare the brain exposure of 12 commercially available CNS drugs and one non-CNS drug. Methods: The drugs were radiolabeled with 11C (t 1/2 = 20.4 minutes) and examined using a high resolution research tomograph. In cynomolgus monkeys, each drug was examined twice. In rhesus monkeys, a first positron emission tomography microdosing measurement was repeated after preadministration with unlabeled drug to examine potential dose-dependent effects on brain exposure. Partition coefficients between brain and plasma (K P) were calculated by dividing the AUC0-90 min for brain with that for plasma or by a compartmental analysis (V T). Unbound K P (K P u,u) was obtained by correction for the free fraction in brain and plasma. Results: After intravenous injection, the maximum radioactivity concentration (C max, %ID) in brain ranged from 0.01% to 6.2%. For 10 of the 12 CNS drugs, C max, %ID was >2%, indicating a preferential distribution to brain. A lower C max, %ID was observed for morphine, sulpiride, and verapamil. K P ranged from 0.002 (sulpiride) to 68 (sertraline) and 7 of 13 drugs had K P u,u close to unity. For morphine, sulpiride, and verapamil, K P u,u was <0.3, indicating impaired diffusion and/or active efflux. Brain exposure at microdosing agreed with pharmacological dosing conditions for the investigated drugs. Conclusions: This study represents the largest positron emission tomography study on brain exposure of commercially available CNS drugs in nonhuman primates and may guide interpretation of positron emission tomography microdosing data for novel drug candidates. PMID:25813017

  7. [Effect of training on treadmill performance, aerobic capacity and body reactions to acute cold exposure].

    PubMed

    Iakushkin, A V; Akimov, E B; Andreev, R S; Kalenov, Iu N; Kozlov, A V; Kuznetsova, O V; Son'kin, V D

    2014-01-01

    An attempt was made to test the hypothesis that regular physical activity at the anaerobic threshold is able to stimulate an increase in the amount of body fat brown or beige, which can manifest itself in increasing lactate utilization during exercise and increase the reactivity in response to acute regional cooling. The methods used are: ramp test, regional acute cold exposure, measurement of gas exchange, lactate and glucose in the blood, heart rate, and heart rate variability, blood pressure and respiration variability at rest and during standard functional tests; infrared thermal imaging, statistical methods of results analysis. Workout 10 physically active volunteers (7 males and 3 females) on a treadmill at a speed corresponding to 75-80% of the persona VO2max for 30 minutes 3 times per week at a fixed ambient temperature 21-22°C for 6 weeks resulted in a significant (from 19 to 39%) increase in test work duration but VO2max on average changed little. The increase in power of anaerobic threshold was associated with a sharp slowdown in the accumulation of lactate in progress of ramp test. Lactate utilization rate during the recovery period, on the contrary, increased. In general, significantly increased work efficiency at a test load. Not revealed noticeable changes in the condition and response to a standard functional tests of autonomic systems, as judged by heart rate variability, blood pressure and respiration variability at rest and during orthostatic tests and imposed breathing rhythm. The functional response of the body to acute cold exposure (1 minute cooling of the feet in ice water) is not changed after a cycle of training--either in terms of metabolism (oxygen consumption, etc.), or the dynamics of the skin temperature in areas of most probable location of brown adipose tissue (BAT). These data do not confirm the previously expressed (2010) hypothesis about the function of BAT as a universal homeostatic instrument in the body. Probably, if under

  8. Male adolescent rats display blunted cytokine responses in the CNS after acute ethanol or lipopolysaccharide exposure.

    PubMed

    Doremus-Fitzwater, Tamara L; Gano, Anny; Paniccia, Jacqueline E; Deak, Terrence

    2015-09-01

    , no corresponding elevations were seen in adolescents after LPS; and (ii) neither adolescents nor adults demonstrated increases in plasma endotoxin concentrations following i.p. or i.g. ethanol administration. Analysis of BECs indicated that, for both routes of exposure, adolescents exhibited lower BECs than adults. Taken together, these data suggest that categorically different mechanisms are involved in the central cytokine response to antigen exposure versus ethanol administration. Furthermore, these findings confirm once again that acute ethanol intoxication is a potent activator of brain cytokines, and calls for future studies to identify the mechanisms underlying age-related differences in the cytokine response observed during ethanol intoxication.

  9. Gene expression-based dosimetry by dose and time in mice following acute radiation exposure.

    PubMed

    Tucker, James D; Divine, George W; Grever, William E; Thomas, Robert A; Joiner, Michael C; Smolinski, Joseph M; Auner, Gregory W

    2013-01-01

    Rapid and reliable methods for performing biological dosimetry are of paramount importance in the event of a large-scale nuclear event. Traditional dosimetry approaches lack the requisite rapid assessment capability, ease of use, portability and low cost, which are factors needed for triaging a large number of victims. Here we describe the results of experiments in which mice were acutely exposed to (60)Co gamma rays at doses of 0 (control) to 10 Gy. Blood was obtained from irradiated mice 0.5, 1, 2, 3, 5, and 7 days after exposure. mRNA expression levels of 106 selected genes were obtained by reverse-transcription real time PCR. Stepwise regression of dose received against individual gene transcript expression levels provided optimal dosimetry at each time point. The results indicate that only 4-7 different gene transcripts are needed to explain ≥ 0.69 of the variance (R(2)), and that receiver-operator characteristics, a measure of sensitivity and specificity, of ≥ 0.93 for these statistical models were achieved at each time point. These models provide an excellent description of the relationship between the actual and predicted doses up to 6 Gy. At doses of 8 and 10 Gy there appears to be saturation of the radiation-response signals with a corresponding diminution of accuracy. These results suggest that similar analyses in humans may be advantageous for use in a field-portable device designed to assess exposures in mass casualty situations.

  10. Gene Expression-Based Dosimetry by Dose and Time in Mice Following Acute Radiation Exposure

    PubMed Central

    Tucker, James D.; Divine, George W.; Grever, William E.; Thomas, Robert A.; Joiner, Michael C.; Smolinski, Joseph M.; Auner, Gregory W.

    2013-01-01

    Rapid and reliable methods for performing biological dosimetry are of paramount importance in the event of a large-scale nuclear event. Traditional dosimetry approaches lack the requisite rapid assessment capability, ease of use, portability and low cost, which are factors needed for triaging a large number of victims. Here we describe the results of experiments in which mice were acutely exposed to 60Co gamma rays at doses of 0 (control) to 10 Gy. Blood was obtained from irradiated mice 0.5, 1, 2, 3, 5, and 7 days after exposure. mRNA expression levels of 106 selected genes were obtained by reverse-transcription real time PCR. Stepwise regression of dose received against individual gene transcript expression levels provided optimal dosimetry at each time point. The results indicate that only 4–7 different gene transcripts are needed to explain ≥ 0.69 of the variance (R2), and that receiver-operator characteristics, a measure of sensitivity and specificity, of ≥ 0.93 for these statistical models were achieved at each time point. These models provide an excellent description of the relationship between the actual and predicted doses up to 6 Gy. At doses of 8 and 10 Gy there appears to be saturation of the radiation-response signals with a corresponding diminution of accuracy. These results suggest that similar analyses in humans may be advantageous for use in a field-portable device designed to assess exposures in mass casualty situations. PMID:24358280

  11. Acute exposure to 2G phase shifts the rat circadian timing system

    NASA Technical Reports Server (NTRS)

    Hoban-Higgins, T. M.; Murakami, D. M.; Tandon, T.; Fuller, C. A.

    1995-01-01

    The circadian timing system (CTS) provides internal and external temporal coordination of an animal's physiology and behavior. In mammals, the generation and coordination of these circadian rhythms is controlled by a neural pacemaker, the suprachiasmatic nucleus (SCN), located within the hypothalamus. The pacemaker is synchronized to the 24 hour day by time cures (zeitgebers) such as the light/dark cycle. When an animal is exposed to an environment without time cues, the circadian rhythms maintain internal temporal coordination, but exhibit a 'free-running' condition in which the period length is determined by the internal pacemaker. Maintenance of internal and external temporal coordination are critical for normal physiological and psychological function in human and non-human primates. Exposure to altered gravitational environments has been shown to affect the amplitude, mean, and timing of circadian rhythms in species ranging from unicellular organisms to man. However, it has not been determined whether altered gravitational fields have a direct effect on the neural pacemaker, or affect peripheral parameters. In previous studies, the ability of a stimulus to phase shift circadian rhythms was used to determine whether a stimulus has a direct effect on the neural pacemaker. The present experiment was performed in order to determine whether acute exposure to a hyperdynamic field could phase shift circadian rhythms.

  12. EFFECTS OF ACUTE EXPOSURE TO CONCENTRATED AMBIENT PARTICULATES ON CARDIOPULMONARY, THERMOREGULATORY, AND BIOCHEMICAL PARAMETERS IN OLD SPONTANEOUSLY HYPERTENSIVE RATS

    EPA Science Inventory


    EFFECTS OF ACUTE EXPOSURE TO CONCENTRATED AMBIENT PARTICULATES ON CARDIOPULMONARY, THERMOREGULATORY, AND BIOCHEMICAL PARAMETERS IN OLD SPONTANEOUSLY HYPERTENSIVE RATS. JP Nolan1, LB Wichers2, DW Winsett1, UP Kodavanti1, MCJ Schladweiler1, DL Costa1, and WP Watkinson1. 1US E...

  13. Acute Exposure to Stress Improves Performance in Trace Eyeblink Conditioning and Spatial Learning Tasks in Healthy Men

    ERIC Educational Resources Information Center

    Duncko, Roman; Cornwell, Brian; Cui, Lihong; Merikangas, Kathleen R.; Grillon, Christian

    2007-01-01

    The present study investigated the effects of acute stress exposure on learning performance in humans using analogs of two paradigms frequently used in animals. Healthy male participants were exposed to the cold pressor test (CPT) procedure, i.e., insertion of the dominant hand into ice water for 60 sec. Following the CPT or the control procedure,…

  14. Vasopressin Regulation and Renal Fluid and Electrolyte Handling in Rat Models of Acute and Chronic alcohol Exposure

    DTIC Science & Technology

    2004-10-01

    evaluating fluid and electrolyte regulating ability in models of acute and chronic alcohol exposure and alcohol withdrawal, and 2) uncovering mechanisms ...be used to define mechanisms behind alcohol effects better than study of humans because conditions of alcohol dosing, hydration status, and fluid...vasopressin receptor regulation, and have determined that altered renal responsiveness to vasopressin is the main mechanism behind fluid balance perturbations

  15. Bovine laminitis: clinical aspects, pathology and pathogenesis with reference to acute equine laminitis.

    PubMed

    Boosman, R; Németh, F; Gruys, E

    1991-07-01

    This review deals with the features of clinical and subclinical laminitis in cattle. Prominent clinical signs of acute laminitis are a tender gait and arched back. The sole horn reveals red and yellowish discolourations within five days. In subacute and chronic cases clinical signs are less severe. In chronic laminitis the shape of the claws is altered. Laminitis is frequently followed by sole ulceration and white zone lesions. Blood tests showed no significant changes for laminitic animals. Arteriographic studies of claws affected by laminitis indicated that blood vessels had narrowed lumens. Gross pathology revealed congestion of the corium and rotation of the distal phalanx. Histopathologic studies indicate that laminitis is associated with changes of the vasculature. Peripartum management and nutrition are important factors in its aetiology. It is hypothesised that laminitis is evoked by disturbed digital circulation. In the pathogenesis of acute laminitis three factors are considered important: the occurrence of thrombosis, haemodynamic aspects of the corium, and endotoxins which trigger these pathologic events.

  16. Effects of Acute Exposure to Moderate Altitude on Vascular Function, Metabolism and Systemic Inflammation

    PubMed Central

    Stöwhas, Anne-Christin; Latshang, Tsogyal D.; Lo Cascio, Christian M.; Lautwein, Sina; Stadelmann, Katrin; Tesler, Noemi; Ayers, Lisa; Berneis, Kaspar; Gerber, Philipp A.; Huber, Reto; Achermann, Peter; Bloch, Konrad E.; Kohler, Malcolm

    2013-01-01

    Background Travel to mountain areas is popular. However, the effects of acute exposure to moderate altitude on the cardiovascular system and metabolism are largely unknown. Objectives To investigate the effects of acute exposure to moderate altitude on vascular function, metabolism and systemic inflammation. Methods In 51 healthy male subjects with a mean (SD) age of 26.9 (9.3) years, oxygen saturation, blood pressure, heart rate, arterial stiffness, lipid profiles, low density lipoprotein (LDL) particle size, insulin resistance (HOMA-index), highly-sensitive C-reactive protein and pro-inflammatory cytokines were measured at 490 m (Zurich) and during two days at 2590 m, (Davos Jakobshorn, Switzerland) in randomized order. The largest differences in outcomes between the two altitudes are reported. Results Mean (SD) oxygen saturation was significantly lower at 2590 m, 91.0 (2.0)%, compared to 490 m, 96.0 (1.0)%, p<0.001. Mean blood pressure (mean difference +4.8 mmHg, p<0.001) and heart rate (mean difference +3.3 bpm, p<0.001) were significantly higher at 2590 m, compared to 490 m, but this was not associated with increased arterial stiffness. At 2590 m, lipid profiles improved (median difference triglycerides −0.14 mmol/l, p = 0.012, HDL +0.08 mmol/l, p<0.001, total cholesterol/HDL-ratio −0.25, p = 0.001), LDL particle size increased (median difference +0.45 nm, p = 0.048) and hsCRP decreased (median difference −0.18 mg/l, p = 0.024) compared to 490 m. No significant change in pro-inflammatory cytokines or insulin resistance was observed upon ascent to 2590 m. Conclusions Short-term stay at moderate altitude is associated with increased blood pressure and heart rate likely due to augmented sympathetic activity. Exposure to moderate altitude improves the lipid profile and systemic inflammation, but seems to have no significant effect on glucose metabolism. Trial Registration ClinicalTrials.gov NCT01130948 PMID:23936377

  17. Acute lung injury following inhalation exposure to nerve agent VX in guinea pigs.

    PubMed

    Wright, Benjamin S; Rezk, Peter E; Graham, Jacob R; Steele, Keith E; Gordon, Richard K; Sciuto, Alfred M; Nambiar, Madhusoodana P

    2006-05-01

    A microinstillation technique of inhalation exposure was utilized to assess lung injury following chemical warfare nerve agent VX [methylphosphonothioic acid S-(2-[bis(1-methylethyl)amino]ethyl) O-ethyl ester] exposure in guinea pigs. Animals were anesthetized using Telazol-meditomidine, gently intubated, and VX was aerosolized using a microcatheter placed 2 cm above the bifurcation of the trachea. Different doses (50.4 microg/m3, 70.4 micro g/m(m3), 90.4 microg/m(m3)) of VX were administered at 40 pulses/min for 5 min. Dosing of VX was calculated by the volume of aerosol produced per 200 pulses and diluting the agent accordingly. Although the survival rate of animals exposed to different doses of VX was similar to the controls, nearly a 20% weight reduction was observed in exposed animals. After 24 h of recovery, the animals were euthanized and bronchoalveolar lavage (BAL) was performed with oxygen free saline. BAL was centrifuged and separated into BAL fluid (BALF) and BAL cells (BALC) and analyzed for indication of lung injury. The edema by dry/wet weight ratio of the accessory lobe increased 11% in VX-treated animals. BAL cell number was increased in VX-treated animals compared to controls, independent of dosage. Trypan blue viability assay indicated an increase in BAL cell death in 70.4 microg/m(m3) and 90.4 microg/m(m3) VX-exposed animals. Differential cell counting of BALC indicated a decrease in macrophage/monocytes in VX-exposed animals. The total amount of BAL protein increased gradually with the exposed dose of VX and was highest in animals exposed to 90.4 microg/m(m3), indicating that this dose of VX caused lung injury that persisted at 24 h. In addition, histopathology results also suggest that inhalation exposure to VX induces acute lung injury.

  18. Clinical and pathological manifestations of cardiovascular disease in rat models: the influence of acute ozone exposure.

    PubMed

    Ramot, Yuval; Kodavanti, Urmila P; Kissling, Grace E; Ledbetter, Allen D; Nyska, Abraham

    2015-01-01

    Rodent models of cardiovascular diseases (CVD) and metabolic disorders are used for examining susceptibility variations to environmental exposures. However, cross-model organ pathologies and clinical manifestations are often not compared. We hypothesized that genetic CVD rat models will exhibit baseline pathologies and will thus express varied lung response to acute ozone exposure. Male 12-14-week-old healthy Wistar Kyoto (WKY), Wistar (WIS), and Sprague-Dawley (SD) rats and CVD-compromised spontaneously hypertensive (SH), fawn-hooded hypertensive (FHH), stroke-prone SH (SHSP), obese SH heart-failure (SHHF), obese diabetic JCR (JCR) rats were exposed to 0.0, 0.25, 0.5, or 1.0 ppm ozone for 4 h and clinical biomarkers, and lung, heart and kidney pathologies were compared immediately following (0-h) or 20-h later. Strain differences were observed between air-exposed CVD-prone and WKY rats in clinical biomarkers and in kidney and heart pathology. Serum cholesterol was higher in air-exposed obese SHHF and JCR compared to other air-exposed strains. Ozone did not produce lesions in the heart or kidney. CVD-prone and SD rats demonstrated glomerulopathy and kidney inflammation (WKY = WIS = SH < SD = SHSP < SHHF < JCR = FHH) regardless of ozone. Cardiac myofiber degeneration was evident in SH, SHHF, and JCR, while only JCR tends to have inflammation in coronaries. Lung pathology in air-exposed rats was minimal in all strains except JCR. Ozone induced variable alveolar histiocytosis and bronchiolar inflammation; JCR and SHHF were less affected. This study provides a comparative account of the clinical manifestations of disease and early-life organ pathologies in several rat models of CVD and their differential susceptibility to lung injury from air pollutant exposure.

  19. Evaluating the acute effects of oral, non-combustible potential reduced exposure products marketed to smokers

    PubMed Central

    Cobb, CO; Weaver, MF; Eissenberg, T

    2011-01-01

    Background Non-combustible potential reduced exposure products (PREPs; eg, Star Scientific’s Ariva; a variety of other smokeless tobacco products) are marketed to reduce the harm associated with smoking. This marketing occurs despite an absence of objective data concerning the toxicant exposure and effects of these PREPs. Methods used to examine combustible PREPs were adapted to assess the acute effects of non-combustible PREPs for smokers. Methods 28 overnight abstinent cigarette smokers (17 men, 14 non-white) each completed seven, Latin-squared ordered, approximately 2.5 h laboratory sessions that differed by product administered: Ariva, Marlboro Snus (Philip Morris, USA), Camel Snus (RJ Reynolds, Winston-Salem, North Carolina, USA), Commit nicotine lozenge (GlaxoSmithKline; 2 mg), own brand cigarettes, Quest cigarettes (Vector Tobacco; delivers very low levels of nicotine) and sham smoking (ie, puffing on an unlit cigarette). In each session, the product was administered twice (separated by 60 min), and plasma nicotine levels, expired air CO and subjective effects were assessed regularly. Results Non-combustible products delivered less nicotine than own brand cigarettes, did not expose smokers to CO and failed to suppress tobacco abstinence symptoms as effectively as combustible products. Conclusions While decreased toxicant exposure is a potential indicator of harm reduction potential, a failure to suppress abstinence symptoms suggests that currently marketed non-combustible PREPs may not be a viable harm reduction strategy for US smokers. This study demonstrates how clinical laboratory methods can be used to evaluate the short-term effects of non-combustible PREPs for smokers. PMID:19346218

  20. Modeling the acute health effects of astronauts from exposure to large solar particle events.

    PubMed

    Hu, Shaowen; Kim, Myung-Hee Y; McClellan, Gene E; Cucinotta, Francis A

    2009-04-01

    Radiation exposure from Solar Particle Events (SPE) presents a significant health concern for astronauts for exploration missions outside the protection of the Earth's magnetic field, which could impair their performance and result in the possibility of failure of the mission. Assessing the potential for early radiation effects under such adverse conditions is of prime importance. Here we apply a biologically based mathematical model that describes the dose- and time-dependent early human responses that constitute the prodromal syndromes to consider acute risks from SPEs. We examine the possible early effects on crews from exposure to some historically large solar events on lunar and/or Mars missions. The doses and dose rates of specific organs were calculated using the Baryon radiation transport (BRYNTRN) code and a computerized anatomical man model, while the hazard of the early radiation effects and performance reduction were calculated using the Radiation-Induced Performance Decrement (RIPD) code. Based on model assumptions we show that exposure to these historical events would cause moderate early health effects to crew members inside a typical spacecraft or during extra-vehicular activities, if effective shielding and medical countermeasure tactics were not provided. We also calculate possible even worse cases (double intensity, multiple occurrences in a short period of time, etc.) to estimate the severity, onset and duration of various types of early illness. Uncertainties in the calculation due to limited data on relative biological effectiveness and dose-rate modifying factors for protons and secondary radiation, and the identification of sensitive sites in critical organs are discussed.

  1. Household pesticide exposure and the risk of childhood acute leukemia in Shanghai, China.

    PubMed

    Zhang, Yan; Gao, Yu; Shi, Rong; Chen, Didi; Wang, Xiaojin; Kamijima, Michihiro; Sakai, Kiyoshi; Nakajima, Tamie; Khalequzzaman, Md; Zhou, Yijun; Zheng, Ying; Bao, Pingping; Tian, Ying

    2015-08-01

    Childhood acute leukemia (AL) is the most common malignant tumor in children, but its etiology remains largely unknown. We investigated the relationship between household exposure to pesticides and childhood AL. Between 2009 and 2010 in Shanghai, a total of 248 newly diagnosed cases of AL and 111 gender-, age-, and hospital-matched controls were included. Five nonspecific dialkyl phosphate (DAP) metabolites of organophosphate pesticides (OPPs) [including dimethyl phosphate (DMP), diethyl phosphate (DEP), dimethyl thiophosphate (DMTP), diethyl thiophosphate (DETP), and diethyl dithiophosphate (DEDTP)] in the urine were analyzed by gas chromatography. The results showed that the median DMP, DEP, DMTP, DETP, and DEDEP levels adjusted for creatinine (Cr) in cases (13.2, 10.0, 31.3, 8.5, and 6.1 μg g(-1), respectively) were all significantly elevated compared with those in controls (3.6, 3.6, 13.3, 2.7, and 1.7 μg g(-1), respectively) (P < 0.05). The household use of mosquito repellent was significantly associated with an increased risk of childhood AL (odds ratio (OR) = 1.9; 95% confidence interval (CI) 1.2-3.1). Moreover, higher exposures were significantly associated with an elevated risk of childhood AL for DMs, DEs, and DAPs. Our findings support the notion that the household use of pesticides may play a role in the etiology of childhood AL and provide some evidence to warrant further investigation of the link between household pesticide exposures and childhood AL in Shanghai.

  2. Community exposure in California to coastal flooding hazards enhanced by climate change, reference year 2010

    USGS Publications Warehouse

    Jones, Jeanne M.; Wood, Nathan J.; Ng, Peter; Henry, Kevin; Jones, J.L.; Peters, Jeff; Jamieson, Matthew

    2016-01-01

    The data set contains information on potential population, economic, land cover, and infrastructure flooding exposure for San Francisco Bay and coastal communities of the state of California, USA. The type of information includes U.S. Census data on the number and types of residents, InfoGroup data on numbers and types of employees, county parcel values, HAZUS building replacement values, NLCD land cover estimates, and infrastructure data on roads, rail, and critical facilities from a variety of sources.

  3. Studies of adaptive response and mutation induction in MCF-10A cells following exposure to chronic or acute ionizing radiation.

    PubMed

    Manesh, Sara Shakeri; Sangsuwan, Traimate; Wojcik, Andrzej; Haghdoost, Siamak

    2015-10-01

    A phenomenon in which exposure to a low adapting dose of radiation makes cells more resistant to the effects of a subsequent high dose exposure is termed radio-adaptive response. Adaptive response could hypothetically reduce the risk of late adverse effects of chronic or acute radiation exposures in humans. Understanding the underlying mechanisms of such responses is of relevance for radiation protection as well as for the clinical applications of radiation in medicine. However, due to the variability of responses depending on the model system and radiation condition, there is a need to further study under what conditions adaptive response can be induced. In this study, we analyzed if there is a dose rate dependence for the adapting dose, assuming that the adapting dose induces DNA response/repair pathways that are dose rate dependent. MCF-10A cells were exposed to a 50mGy adapting dose administered acutely (0.40Gy/min) or chronically (1.4mGy/h or 4.1mGy/h) and then irradiated by high acute challenging doses. The endpoints of study include clonogenic cell survival and mutation frequency at X-linked hprt locus. In another series of experiment, cells were exposed to 100mGy and 1Gy at different dose rates (acutely and chronically) and then the mutation frequencies were studied. Adaptive response was absent at the level of clonogenic survival. The mutation frequencies were significantly decreased in the cells pre-exposed to 50mGy at 1.4mGy/h followed by 1Gy acute exposure as challenging dose. Importantly, at single dose exposures (1 Gy or 100mGy), no differences at the level of mutation were found comparing different dose rates.

  4. Acute and chronic ethanol exposure differentially regulate CB1 receptor function at glutamatergic synapses in the rat basolateral amygdala.

    PubMed

    Robinson, Stacey L; Alexander, Nancy J; Bluett, Rebecca J; Patel, Sachin; McCool, Brian A

    2016-09-01

    The endogenous cannabinoid (eCB) system has been suggested to play a key role in ethanol preference and intake, the acute effects of ethanol, and in the development of withdrawal symptoms following ethanol dependence. Ethanol-dependent alterations in glutamatergic signaling within the lateral/basolateral nucleus of the amygdala (BLA) are critical for the development and expression of withdrawal-induced anxiety. Notably, the eCB system significantly regulates both glutamatergic and GABAergic synaptic activity within the BLA. Chronic ethanol exposure significantly alters eCB system expression within regions critical to the expression of emotionality and anxiety-related behavior, including the BLA. Here, we investigated specific interactions between the BLA eCB system and its functional regulation of synaptic activity during acute and chronic ethanol exposure. In tissue from ethanol naïve-rats, a prolonged acute ethanol exposure caused a dose dependent inhibition of glutamatergic synaptic activity via a presynaptic mechanism that was occluded by CB1 antagonist/inverse agonists SR141716a and AM251. Importantly, this acute ethanol inhibition was attenuated following 10 day chronic intermittent ethanol vapor exposure (CIE). CIE exposure also significantly down-regulated CB1-mediated presynaptic inhibition at glutamatergic afferent terminals but spared CB1-inhibition of GABAergic synapses arising from local inhibitory-interneurons. CIE also significantly elevated BLA N-arachidonoylethanolamine (AEA or anandamide) levels and decreased CB1 receptor protein levels. Collectively, these data suggest a dynamic regulation of the BLA eCB system by acute and chronic ethanol.

  5. Effects of acute exposure to WIFI signals (2.45GHz) on heart variability and blood pressure in Albinos rabbit.

    PubMed

    Saili, Linda; Hanini, Amel; Smirani, Chiraz; Azzouz, Ines; Azzouz, Amina; Sakly, Mohsen; Abdelmelek, Hafedh; Bouslama, Zihad

    2015-09-01

    Electrocardiogram and arterial pressure measurements were studied under acute exposures to WIFI (2.45GHz) during one hour in adult male rabbits. Antennas of WIFI were placed at 25cm at the right side near the heart. Acute exposure of rabbits to WIFI increased heart frequency (+22%) and arterial blood pressure (+14%). Moreover, analysis of ECG revealed that WIFI induced a combined increase of PR and QT intervals. By contrast, the same exposure failed to alter maximum amplitude and P waves. After intravenously injection of dopamine (0.50ml/kg) and epinephrine (0.50ml/kg) under acute exposure to RF we found that, WIFI alter catecholamines (dopamine, epinephrine) action on heart variability and blood pressure compared to control. These results suggest for the first time, as far as we know, that exposure to WIFI affect heart rhythm, blood pressure, and catecholamines efficacy on cardiovascular system; indicating that radiofrequency can act directly and/or indirectly on cardiovascular system.

  6. Upregulation of uncoupling protein Ucp2 through acute cold exposure increases post-thaw sperm quality in zebrafish.

    PubMed

    Wang, Gongfa; Kang, Ning; Gong, Hongmei; Luo, Yan; Bai, Chenglian; Chen, Yuanhong; Ji, Xiaoping; Huang, Changjiang; Dong, Qiaoxiang

    2015-12-01

    Oxidative stress plays an important role in sperm damage during cryopreservation. Mild mitochondrial uncoupling has been shown to reduce excessive reactive oxygen species (ROS) and thus mitigate oxidative stress. Uncoupling protein (Ucp2) regulates mitochondrial uncoupling and can be induced by temperature fluctuation. In the present study, we explored a novel approach of acute cold exposure on Ucp2 activation and its association with oxidative damage and post-thaw sperm quality in zebrafish. Our study revealed that acute cold exposure of zebrafish at 18 °C for 24 h led to significant increase of ucp2 mRNA and Ucp2 protein in zebrafish fresh sperm as well as thawed sperm after cryopreservation. Although cold exposure had no effect on fresh sperm quality except for decreasing lipid peroxidation, sperm collected from cold-exposed zebrafish exhibited higher resistance to cryodamage, which was demonstrated by increased post-thaw motility, decreased lipid peroxidation, increased ATP production, and ultimately increased fertilization success. However, except for reduced lipid peroxidation, we did not observe any significant ROS reduction associated with increased Ucp2 activation in cold-exposed group, suggesting mechanisms other than mitochondrial uncoupling could have contributed to cold exposure associated benefits in post-thaw sperm survival. Nevertheless, our findings indicate that acute cold exposure prior to sperm cryopreservation is beneficial for post-thaw sperm survival in zebrafish, and this novel approach may be used to improve post-thaw sperm quality for other aquatic species.

  7. Persistence of Breakage in Specific Chromosome Bands 6 Years after Acute Exposure to Oil

    PubMed Central

    Francés, Alexandra; Hildur, Kristin; Barberà, Joan Albert; Rodríguez-Trigo, Gema; Zock, Jan-Paul; Giraldo, Jesús; Monyarch, Gemma; Rodriguez-Rodriguez, Emma; de Castro Reis, Fernanda; Souto, Ana; Gómez, Federico P.; Pozo-Rodríguez, Francisco; Templado, Cristina; Fuster, Carme

    2016-01-01

    analyses were performed in 47 exposed individuals. A total of 251 breakpoints in exposed individuals) were identified, showing a non-uniform distribution in the human ideogram. Ten chromosome bands were found to be especially prone to breakage through both statistical methods. By comparing these bands with those observed in certain exposed individuals who had already participated the previous study, it was found in both studies that four bands (2q21, 3q27, 5q31 and 17p11.2) are particularly sensitive to breakage. Additionally, the dysfunction in DNA repair mechanisms was not significantly higher in oil-exposed individuals than in non-exposed individuals. Limitations The sample size and the possibility of some kind of selection bias should be considered. Genotoxic results cannot be extrapolated to the high number of individuals who participated occasionally in clean-up tasks. Conclusion Our findings show the existence of at least four target bands (2q21, 3q27, 5q31 and 17p11.2) with a greater propensity to break over time after an acute exposure to oil. The breaks in these bands, which are commonly involved in hematological cancer, may explain the increase of cancer risk reported in chronically benzene-exposed individuals. In addition, a more efficiency of the DNA repair mechanisms has been detected six years after in fishermen who were highly exposed to the oil spill. To date, only this study, performed by our group on the previous and present genotoxic effects, has analyzed the chromosomal regions affected by breakage after an acute oil exposure. PMID:27479010

  8. Occupational exposure in small and medium scale industry with specific reference to heat and noise.

    PubMed

    Singh, Lakhwinder Pal; Bhardwaj, Arvind; Deepak, Kishore Kumar

    2010-01-01

    This study was undertaken to assess heat and noise exposure and occupational safety practices in small and medium scale casting and forging units (SMEs) of Northern India. We conducted personal interviews of 350 male workers of these units through a comprehensive questionnaire and collected information on heat and noise exposure, use of protective equipment, sweat loss and water intake, working hour. The ambient wet bulb globe temperature (WBGT index) was measured using quest temp 34/36o area heat stress monitor. A-weighted Leq ambient noise was measured using a quest sound level meter "ANSI SI. 43-1997 (R 2002) type-1 model SOUNDPRO SE/DL". We also incorporated OSHA norms for hearing conservation which include - an exchange rate of 5dB(A), criterion level at 90dB(A), criterion time of eight hours, threshold level is equal to 80dB(A), upper limit is equal to 140dB(A) and with F/S response rate. Results of the study revealed that occupational heat exposure in melting, casting, forging and punching sections is high compared to ACGIH/NIOSH norms. Ambience noise in various sections like casting / molding, drop forging, cutting presses, punching, grinding and barreling process was found to be more than 90dB(A). About 95% of the workers suffered speech interference where as high noise annoyance was reported by only 20%. Overall, 68% workers were not using any personal protective equipment (PPE). The study concluded that the proportion of SME workers exposed to high level heat stress and noise (60 - 72 hrs/week) is high. The workers engaged in forging and grinding sections are more prone to noise induced hearing loss (NIHL) at higher frequencies as compared to workers of other sections. It is recommended that there is a strong need to implement the standard of working hours as well as heat stress and noise control measures.

  9. Biological monitoring of mercury exposure in individuals referred to a toxicological center in Venezuela.

    PubMed

    Rojas, Maritza; Seijas, David; Agreda, Olga; Rodríguez, Maritza

    2006-02-01

    People in developing countries are often considered at greater risk of mercury (Hg) poisoning due to a variety of factors including a lack of awareness regarding their occupational risks. Individuals requiring urine mercury (U-Hg) analysis at the Center for Toxicological Investigations of the University of Carabobo (CITUC), between 1998 and 2002 were studied to identify demographic characteristics associated to U-Hg levels. The studied population included individuals with a history of exposure (or related exposures) to Hg processes, and was comprised of 1159 individuals (65 children, 1094 adults) ages 0.58-79 years old, mean 36.63+/-12.4. Children's geometric mean U-Hg levels were 2.73 microg/g Creatinine (Ct) and in adults 2.55 microg/g Ct. The highest frequency of adults' occupations were shipyard workers (35.47%), dentists (23.5%), lab technicians (11.43%), dental employees 10.42% and miners (10.2%). Chemical laboratory technicians had the highest mean U-Hg (4.46 microg/g Ct). Mean U-Hg levels in female adults (3.45 microg/g Ct) were statistically superior to levels in male adults (2.15 microg/g Ct). Two of the 172 women in reproductive age, had U-Hg levels higher than 78 microg/g Ct. Individuals from Falcon State were found to have the highest mean U-Hg (4.53 microg/g Ct). U-Hg levels higher than permissible limits were found in only 2 states (Carabobo and Bolivar) with a total of 24 cases. Although the results of this investigation were highly variable, the findings can be used to examine circumstances which influence mercury toxicity trends, and possibly used in future studies working to identify Hg exposures.

  10. Toxicology of microcystins with reference to cases of human intoxications and epidemiological investigations of exposures to cyanobacteria and cyanotoxins.

    PubMed

    Svirčev, Zorica; Drobac, Damjana; Tokodi, Nada; Mijović, Biljana; Codd, Geoffrey A; Meriluoto, Jussi

    2017-02-01

    Blooms of cyanobacteria have been documented throughout history, all over the world. Mass populations of these organisms typically present hazards to human health and are known for the production of a wide range of highly toxic metabolites-cyanotoxins, of which among the most common and most investigated are the microcystins. The toxicity of the family of microcystin congeners to animal and cell models has received much attention; however, less is known about their negative effects on human health, whether via acute or chronic exposure. Useful information may be acquired through epidemiological studies since they can contribute to knowledge of the relationships between cyanotoxins and human health in environmental settings. The aim of this review is to compile and evaluate the available published reports and epidemiological investigations of human health incidents associated with exposure to mass populations of cyanobacteria from throughout the world and to identify the occurrence and likely role of microcystins in these events. After an initial screening of 134 publications, 42 publications (25 on the chronic and 17 on the acute effects of cyanotoxins) describing 33 cases of poisonings by cyanobacterial toxins in 11 countries were reviewed. The countries were Australia, China, Sri Lanka, Namibia, Serbia, Sweden, UK, Portugal, Brazil, USA, and Canada. At least 36 publications link cyanobacteria/cyanotoxins including microcystins to adverse human health effects. The studies were published between 1960 and 2016. Although the scattered epidemiological evidence does not provide a definitive conclusion, it can serve as additional information for the medical assessment of the role of microcystins in cancer development and other human health problems. This paper discusses the major cases of cyanotoxin poisonings as well as the strengths, weaknesses, and importance of the performed epidemiological research. This study also proposes some recommendations for future

  11. Sensitivity of ecological soil-screening levels for metals to exposure model parameterization and toxicity reference values.

    PubMed

    Sample, Bradley E; Fairbrother, Anne; Kaiser, Ashley; Law, Sheryl; Adams, Bill

    2014-10-01

    Ecological soil-screening levels (Eco-SSLs) were developed by the United States Environmental Protection Agency (USEPA) for the purposes of setting conservative soil screening values that can be used to eliminate the need for further ecological assessment for specific analytes at a given site. Ecological soil-screening levels for wildlife represent a simplified dietary exposure model solved in terms of soil concentrations to produce exposure equal to a no-observed-adverse-effect toxicity reference value (TRV). Sensitivity analyses were performed for 6 avian and mammalian model species, and 16 metals/metalloids for which Eco-SSLs have been developed. The relative influence of model parameters was expressed as the absolute value of the range of variation observed in the resulting soil concentration when exposure is equal to the TRV. Rank analysis of variance was used to identify parameters with greatest influence on model output. For both birds and mammals, soil ingestion displayed the broadest overall range (variability), although TRVs consistently had the greatest influence on calculated soil concentrations; bioavailability in food was consistently the least influential parameter, although an important site-specific variable. Relative importance of parameters differed by trophic group. Soil ingestion ranked 2nd for carnivores and herbivores, but was 4th for invertivores. Different patterns were exhibited, depending on which parameter, trophic group, and analyte combination was considered. The approach for TRV selection was also examined in detail, with Cu as the representative analyte. The underlying assumption that generic body-weight-normalized TRVs can be used to derive protective levels for any species is not supported by the data. Whereas the use of site-, species-, and analyte-specific exposure parameters is recommended to reduce variation in exposure estimates (soil protection level), improvement of TRVs is more problematic.

  12. Sensitivity of ecological soil-screening levels for metals to exposure model parameterization and toxicity reference values

    PubMed Central

    Sample, Bradley E; Fairbrother, Anne; Kaiser, Ashley; Law, Sheryl; Adams, Bill

    2014-01-01

    Ecological soil-screening levels (Eco-SSLs) were developed by the United States Environmental Protection Agency (USEPA) for the purposes of setting conservative soil screening values that can be used to eliminate the need for further ecological assessment for specific analytes at a given site. Ecological soil-screening levels for wildlife represent a simplified dietary exposure model solved in terms of soil concentrations to produce exposure equal to a no-observed-adverse-effect toxicity reference value (TRV). Sensitivity analyses were performed for 6 avian and mammalian model species, and 16 metals/metalloids for which Eco-SSLs have been developed. The relative influence of model parameters was expressed as the absolute value of the range of variation observed in the resulting soil concentration when exposure is equal to the TRV. Rank analysis of variance was used to identify parameters with greatest influence on model output. For both birds and mammals, soil ingestion displayed the broadest overall range (variability), although TRVs consistently had the greatest influence on calculated soil concentrations; bioavailability in food was consistently the least influential parameter, although an important site-specific variable. Relative importance of parameters differed by trophic group. Soil ingestion ranked 2nd for carnivores and herbivores, but was 4th for invertivores. Different patterns were exhibited, depending on which parameter, trophic group, and analyte combination was considered. The approach for TRV selection was also examined in detail, with Cu as the representative analyte. The underlying assumption that generic body-weight–normalized TRVs can be used to derive protective levels for any species is not supported by the data. Whereas the use of site-, species-, and analyte-specific exposure parameters is recommended to reduce variation in exposure estimates (soil protection level), improvement of TRVs is more problematic. Environ Toxicol Chem 2014

  13. Effects of acute chlorpyrifos exposure on in vivo acetylcholine accumulation in rat striatum

    SciTech Connect

    Karanth, Subramanya; Liu, Jing; Mirajkar, Nikita; Pope, Carey . E-mail: carey.pope@okstate.edu

    2006-10-01

    This study examined the acute effects of chlorpyrifos (CPF) on cholinesterase inhibition and acetylcholine levels in the striatum of freely moving rats using in vivo microdialysis. Adult, male Sprague-Dawley rats were treated with vehicle (peanut oil, 2 ml/kg) or CPF (84, 156 or 279 mg/kg, sc) and functional signs of toxicity, body weight and motor activity recorded. Microdialysis was conducted at 1, 4 and 7 days after CPF exposure for measurement of acetylcholine levels in striatum. Rats were then sacrificed and the contralateral striatum and diaphragm were collected for biochemical measurements. Few overt signs of cholinergic toxicity were noted in any rats. Body weight gain was significantly affected in the high-dose (279 mg/kg) group only, while motor activity (nocturnal rearing) was significantly reduced in all CPF-treated groups at one day (84 mg/kg) or from 1-4 days (156 and 279 mg/kg) after dosing. Cholinesterase activities in both diaphragm and striatum were markedly inhibited (50-92%) in a time-dependent manner, but there were relatively minimal dose-related changes. In contrast, time- and dose-dependent changes in striatal acetylcholine levels were noted, with significantly higher levels noted in the high-dose group compared to other groups. Maximal increases in striatal acetylcholine levels were observed at 4-7 days after dosing (84 mg/kg, 7-9-fold; 156 mg/kg, 10-13-fold; 279 mg/kg, 35-57-fold). Substantially higher acetylcholine levels were noted when an exogenous cholinesterase inhibitor was included in the perfusion buffer, but CPF treatment-related differences were substantially lower in magnitude under those conditions. The results suggest that marked differences in acetylcholine accumulation can occur with dosages of CPF eliciting relatively similar degrees of cholinesterase inhibition. Furthermore, the minimal expression of classic signs of cholinergic toxicity in the presence of extensive brain acetylcholine accumulation suggests that some

  14. Direct and indirect tasks on assessment of dose and time distributions and thresholds of acute radiation exposure.

    PubMed

    Osovets, S V; Azizova, T V; Day, R D; Wald, N; Moseeva, M B

    2012-02-01

    Mathematical methods were developed to construct dose and time distributions and their associated risks and threshold values for lethal and non-lethal effects of acute radiation exposure to include mortality and incidence, prodromal vomiting, and agranulocytosis. A new distribution (T-model) was obtained to describe time parameters of acute radiation syndrome such as the latency period, time to onset of vomiting, and time to initiation of agranulocytosis. Based on the dose and time distributions, the parameter translation method was defined using an orthogonal regression, which allows one to solve for these distributions in the case of acute radiation exposure. The assessment of threshold doses was performed for some effects of acute radiation syndrome: for the latency period, ∼6-8 Gy absorbed dose and ∼0.7-0.9 h time to onset of vomiting; and for incidence (agranulocytosis), ∼2-3 Gy absorbed dose and ∼2-3 h time to onset of vomiting. The obtained new formula for assessment of radiation risk is applicable to the time parameters of acute radiation syndrome.

  15. The effects of acetazolamide and spironolactone on the body water distribution of rabbits during acute exposure to simulated altitude

    NASA Astrophysics Data System (ADS)

    Jain, S. C.; Singh, M. V.; Rawal, S. B.

    1984-06-01

    The role of body water metabolism on acute altitude exposure was studied. The studies were carried out in rabbits divided into four groups, namely, (i) control, (ii) exposed to acute hypoxia, (iii) exposed to acute hypoxia after treatment with 250 mg acetazolamide and (iv) exposed to acute hypoxia after treatment with 25 mg spironolactone. Total body water, extracellular water, intracellular water and blood volume decreased by an insignificant amount on exposure to hypoxia and plasma volume decreased by 5.7% (P<0.025). Treatment with either acetazolamide or spironolactone resulted in further marginal decrease in total body water. In the case of acetazolamide, the loss occurs from both intracellular and extracellular compartments, while treatment with spironolactone resulted in significant loss only from extracellular compartment. Treatment with both the drugs resulted in a small rise in pO2 and pCO2 with a slight decrease in pH. Our data suggested spironolactone to be a better prophylactic agent for use on acute high altitude induction.

  16. Acute exposure to 17α-ethinylestradiol disrupts audience effect on male-female interactions in Betta splendens.

    PubMed

    Forette, Lindsay M; Mannion, Krystal L; Dzieweczynski, Teresa L

    2015-04-01

    Endocrine disrupting chemicals can negatively impact the morphology and behavior of organisms inhabiting polluted waters. Male-typical behaviors are often reduced after exposure, suggesting that exposure may have population-level effects. One way in which exposure may exert population-level effects is by interfering with communication within a network of individuals. Acute exposure to the estrogen mimic 17α-ethinylestradiol (EE2) disrupts the ability of male Siamese fighting fish, Betta splendens, to modify their behavior during male-male interactions when an audience is present. However, it is unknown whether audience effects during male-female interactions may be similarly altered. To examine this, male-female pairs that were given an acute exposure to EE2 or remained unexposed interacted in the presence of a female, male, or no audience. Sex differences were found between unexposed males and females. More interactant-directed gill flaring was displayed by control males when a male audience was present while control females performed this behavior more in the presence of an audience, regardless of sex. Both males and females in the control group performed more interactant-directed tail beats in the presence of a female audience. EE2 exposure made all audience effects disappear as treated males and females did not differ in their responses between audience types. These results demonstrate that acute exposure to EE2 may disrupt behavioral adjustments to audience type within a social network. This disruption may, in turn, influence population dynamics in this species as both males and females use information obtained from observing interactions in later encounters with the observed individuals.

  17. Whole adult organism transcriptional profiling of acute metal exposures in male Zebrafish

    PubMed Central

    2014-01-01

    Background A convergence of technological breakthroughs in the past decade has facilitated the development of rapid screening tools for biomarkers of toxicant exposure and effect. Platforms using the whole adult organism to evaluate the genome-wide response to toxicants are especially attractive. Recent work demonstrates the feasibility of this approach in vertebrates using the experimentally robust zebrafish model. In the present study, we evaluated gene expression changes in whole adult male zebrafish following an acute 24 hr high dose exposure to three metals with known human health risks. Male adult zebrafish were exposed to nickel chloride, cobalt chloride or sodium dichromate concentrations corresponding to their respective 96 hr LC20, LC40 and LC60. Histopathology was performed on a subset of metal-exposed zebrafish to phenotypically anchor transcriptional changes associated with each metal. Results Comparative analysis identified subsets of differentially expressed transcripts both overlapping and unique to each metal. Application of gene ontology (GO) and transcription factor (TF) enrichment algorithms revealed a number of key biological processes perturbed by metal poisonings and the master transcriptional regulators mediating gene expression changes. Metal poisoning differentially activated biological processes associated with ribosome biogenesis, proteosomal degradation, and p53 signaling cascades, while repressing oxygen-generating pathways associated with amino acid and lipid metabolism. Despite appreciable effects on gene regulation, nickel poisoning did not induce any morphological alterations in male zebrafish organs and tissues. Histopathological effects of cobalt remained confined to the olfactory system, while chromium targeted the gills, pharynx, and intestinal mucosa. A number of enriched transcription factors mediated the observed gene response to metal poisoning, including known targets such as p53, HIF1α, and the myc oncogene, and novel

  18. Hematological Alterations on Sub-acute Exposure to Flubendiamide in Sprague Dawley Rats

    PubMed Central

    Vemu, Bhaskar; Dumka, Vinod Kumar

    2014-01-01

    Background: Pesticide poisoning is a common occurrence around the world. Pesticides can act on various body systems resulting in toxicity. Flubendiamide is a new generation pesticide, reported to have better activity against Lepidopteran insects. The present study was carried out with an objective to analyze the effects of flubendiamide sub-acute exposure on hematology of rats. Materials and Methods: Male and female Sprague Dawley (SD) rats (9–11 weeks) were divided into five groups with six animals in each group. First group served as control, while the rest were exposed to ascending oral doses of flubendiamide (125, 250, 500 and 1000 mg/kg) for 28 days. After the trial period, blood was collected in heparinized vials and analyzed using Siemens ADVIA 2120® autoanalyzer. Various erythrocytic, platelet and leukocyte parameters were measured and analyzed using statistical tests by one-way analysis of variance (ANOVA) and t-test using Statistical Package for Social Sciences (SPSS)® 20 software. Results: After processing the data through statistical analysis, it was observed that the effect of flubendiamide exposure on female rats was negligible. The only significant change observed in the female rats was that in total erythrocytic count, while rest of the parameters showed non-significant bidirectional changes. In males, many parameters viz., total leukocyte count (TLC), total erythrocyte count (TEC), packed cell volume (PCV), mean corpuscular volume (MCV), platelet count (PC), mean platelet volume (MPV), platelet distribution width (PDW), hemoglobin distribution width (HDW), large platelets (LPT) and plateletcrit (PCT) expressed significant difference when compared to control. Conclusion: Many of the changes were dose independent, but sex specific. This lead to the hypothesis that saturation toxicokinetics might be one of the reasons for this varied response, which can only be evaluated after further testing. PMID:25948968

  19. Acute exposure to acid fog: influence of breathing pattern on effective dose.

    PubMed

    Bowes, S M; Francis, M; Laube, B L; Frank, R

    1995-02-01

    Concern about the possible adverse health effects of acid fog has been fed by two observations: air pollution disasters earlier in this century were typically associated with fog, and current samples of fog water can be strongly acid. To study the acute effects of acid fog on the lung, the authors generated a monodisperse 10 microM MMAD aerosol of H2SO4 with a pH of 2.0 and a nominal concentration of 500 micrograms/m3. They exposed seven healthy young men on alternate days to acid or control equiosmolar NaCl aerosol during 40 min of resting ventilation and 20 min of exercise; the latter was sufficiently intense to induce oronasal breathing. Exposure was by means of a head dome, a head-only exposure device that permitted continuous measurement (unfettered breathing) of Vr, f, VE, and the onset and persistence of oronasal breathing. In this article the authors compare the relative importance of parameters contributing to the between-subject variability in estimated hydrogen ion dose to the lower airways (H+LAW), based on analysis of variance. Physiologic parameters accounted for 70% of the variability, of which 34% was due to differences in duration of oronasal breathing (tON) and 36% to differences in ventilation rate during oronasal breathing (VE(ON)); inhaled hydrogen ion concentration [H+], the environmental parameter, contributed only 30%. Minute ventilation at the time of transition from nasal to oronasal breathing varied significantly among subjects even if normalized to FVC, an index of lung size.

  20. Effects of Acute and Chronic Heavy Metal (Cu, Cd, and Zn) Exposure on Sea Cucumbers (Apostichopus japonicus)

    PubMed Central

    Li, Li; Tian, Xiangli; Yu, Xiao; Dong, Shuanglin

    2016-01-01

    Acute and chronic toxicity tests were conducted with sea cucumber (Apostichopus japonicus) exposed to heavy metals. Acute toxicity values (96 h LC50) were 2.697, 0.133, and 1.574 mg L−1 for Zn, Cu, and Cd, respectively, and were ranked in order of toxicity: Cu > Cd > Zn. Under chronic metal exposure the specific growth rates of sea cucumbers decreased with the increase of metal concentration for all the three metals. After acute metal exposure, the oxygen consumption rate (OCR) decreased. The OCRs in all groups were significantly different than control (P < 0.05) except in the group treated with 1.00 mg L−1 Zn (P < 0.05), where the increase of OCR was observed. The OCRs in groups chronically exposed to metals were significantly lower than that in the control group (P < 0.05). The activity of both pyruvate kinase (PK) and hexokinase (HK) in sea cucumbers followed: respiratory tree > muscle > intestine in natural sea water. After chronic Zn, Cu, and Cd exposure, the change pattern of HK and PK in respiratory tree, muscle, and intestine varied slightly. However, the activity of the enzyme showed a general trend of increase and then decrease and the higher the exposure concentration was, the earlier the highest point of enzyme activity was obtained. PMID:27382568

  1. Case Study: Three Acute 241Am Inhalation Exposures with DTPA Therapy

    SciTech Connect

    Carbaugh, Eugene H.; Lynch, Timothy P.; Cannon, Curt; Lewis, Loren L.

    2010-10-01

    Three workers incurred inhalation exposures to 241Am oxide as a result of waste sorting and compaction activities. The magnitudes of the exposures were not fully recognized until the following day when an in vivo chest count identified a significant lung deposition of 241Am in a male worker, and DTPA chelation therapy was initiated. Two additional workers (one female and one male) were then identified as sufficiently exposed to also warrant therapy. In vivo bioassay measurements were performed over the ensuing 6 months to quantify the 241Am activity in the lungs, liver, and skeleton. Urine and fecal samples were collected and showed readily detectable 241Am. Clinical lab tests and medical evaluations all showed normal results. There were no significant adverse clinical health effects from the therapy. The estimated 241Am inhalation intakes for the three workers were 1800 Bq, 630 Bq, and 150 Bq. Lung retention showed somewhat longer pulmonary clearance half-times than standard inhalation class W or absorption Type M assumptions. The three underwent slightly different therapy regimes, with therapy effectiveness factors (defined as the ratio of the reference doses without therapy relative to the final assessed doses) of 4.65, 1.93, and 1.67, respectively.

  2. Health advisory values for drinking water contaminants and the methodology for determining acute exposure values.

    PubMed

    Donohue, Joyce Morrissey; Lipscomb, John C

    2002-04-08

    The Health Advisory (HA) Program of the Office of Water provides informal technical guidance to Federal, State and local officials responsible for protecting health when emergency spills or contamination situations occur. Under this program, first initiated in 1985, HA values are developed for 1-day, 10-day, longer-term (approx. 7 years) and lifetime exposures based on data describing non- cancer endpoints of toxicity. For substances that are known or probable human carcinogens, lifetime HAs are not recommended. In these situations, the HA document provides an estimate of the drinking water concentration that is equivalent to a l0(-4) 10(-6) cancer risk. US EPA has HA documents for over 175 chemicals dating from 1987 to 1998. A tabular summary of HA values can be accessed through the EPA Office of Science and Technology (OST) web page. The HA support documents provide a concise technical summary of and references for information on chemical, physical and toxicological properties, analytical methods, and treatment technologies. Some of the lifetime HA and cancer values in the HA documents may no longer agree with the most recent Agency assessment for Reference Dose (RfD) and cancer effects. However, the lifetime HA and cancer values presented in the HA tables have been updated to correspond with agency consensus values as presented in the Integrated Risk Information System (IRIS) database.

  3. Loblolly pine and slash pine responses to acute aluminum and acid exposures.

    PubMed

    Nowak, Jaroslaw; Friend, Alexander L

    2006-09-01

    In response to concerns about aluminum and HCl exposure associated with rocket motor testing and launches, survival and growth of full-sib families of loblolly pine (Pinus taeda L.) and slash pine (Pinus elliottii Engelm.) were evaluated in a nursery bed experiment. Each species was exposed to a single soil application of aluminum chloride (0.33 M AlCl(3), pH 2.5), hydrochloric acid (0.39 M HCl, pH 0.6) or water, with or without mycorrhizal inoculation with Pisolithus tinctorius (Coker and Couch). After 20 weeks without inoculation, survival in AlCl(3) and HCl treatments averaged 52% for loblolly pine and 72% for slash pine. Inoculation improved survival of loblolly pine, receiving HCl from 49 to 73%, and of those receiving AlCl3, from 55 to 90%. Inoculation also resulted in improved survival and growth of individual families in AlCl(3), but not in HCl treatments. Results illustrate the relative resistance of both pine species to the acute treatments supplied, the improvement in resistance associated with mycorrhizal inoculation and the importance of field testing, following hydroponic screening, to verify the resistance to soil-supplied stresses.

  4. Acute Oral Ethanol Exposure Triggers Asthma In Cockroach Allergen–Sensitized Mice

    PubMed Central

    Bouchard, Jacqueline C.; Kim, Jiyoun; Beal, Dominic R.; Vaickus, Louis J.; Craciun, Florin L.; Remick, Daniel G.

    2013-01-01

    Asthma may be triggered by multiple mediators, including allergen-IgE cross-linking and non-IgE mechanisms. Several clinical studies have shown acute ethanol consumption exacerbates asthma, yet no animal model exists to study this process. We developed a model of ethanol-triggered asthma in allergen-sensitized mice to evaluate the mechanisms of ethanol inducing asthma-like responses. Outbred mice were exposed to cockroach allergens on Days 0 and 14; and on Day 21, mice received ethanol by oral gavage. Tracer studies confirmed alcohol aspiration did not occur. Within 30 minutes, alcohol induced degranulation of over 74% of mast cells, and multiple parameters of asthma-like pulmonary inflammation were triggered. Ethanol-gavaged mice had a fivefold increased production of eotaxin-2 (534 pg/mL) and a sevenfold increase in bronchoalveolar eosinophils (70,080 cells). Ethanol induced a 10-fold increase in IL-13, from 84 pg/mL in sensitized mice to 845 pg/mL in ethanol-gavaged sensitized mice. In cockroach allergen–sensitized mice, ethanol triggered asthma-like changes in respiratory physiology and a significant fivefold increase in airway mucin production. Importantly, none of these asthmatic exacerbations were observed in normal mice gavaged with ethanol. Cromolyn sodium effectively stabilized mast cells, yet increased mucin production and bronchoalveolar eosinophil recruitment. Together, these data show a single oral alcohol exposure will trigger asthma-like pulmonary inflammation in allergen-sensitized mice, providing a novel asthma model. PMID:22796441

  5. Acute, whole-body microwave exposure and testicular function of rats

    SciTech Connect

    Lebovitz, R.M.; Johnson, L.

    1987-01-01

    Male Sprague-Dawley rats were exposed for 8 h to continuous-wave microwave radiation (MWR, 1.3 Ghz) at a mean specific absorbed dose rate of 9 mW/g. MWR exposure and sham-irradiation took place in unidirectionally energized cylindrical waveguide sections, within which the animals were essentially unrestrained. The MWR treatment in this setting was determined to yield an elevation of deep rectal temperature to 4.5 degrees C. The animals were taken for analysis at 6.5, 13, 26, and 52 days following treatment, which corresponded to .5, 1, 2, and 4 cycles of the seminiferous epithelium. Net mass of testes, epididymides, and seminal vesicles; daily sperm production (DSP) per testis and per gram of testis; and the number of epididymal sperm were determined. The levels of circulating follicle-stimulating hormone (FSH) and leutinizing hormone (LH) were derived via radioimmunoassay of plasma samples taken at the time of sacrifice. Despite the evident acute thermogenesis of the MWR at 9 mW/g, no substantial decrement in testicular function was found. We conclude that, in the unrestrained rat, whole body irradiation at 9 mW/g, while sufficient to induce evident hyperthermia, is not a sufficient condition for disruption of any of these key measures of testicular function.

  6. Adolescent and adult rat cortical protein kinase A display divergent responses to acute ethanol exposure

    PubMed Central

    Gigante, Eduardo D.; Santerre, Jessica L.; Carter, Jenna M.; Werner, David F.

    2014-01-01

    Adolescent rats display reduced sensitivity to many dysphoria-related effects of alcohol (ethanol) including motor ataxia and sedative hypnosis, but the underlying neurobiological factors that contribute to these differences remain unknown. The cyclic adenosine monophosphate (cAMP)-dependent protein kinase A (PKA) pathway, particularly the type II regulatory subunit (RII), has been implicated in ethanol-induced molecular and behavioral responses in adults. Therefore, the current study examined cerebral cortical PKA in adolescent and adult ethanol responses. With the exception of early adolescence, PKA RIIα and RIIβ subunit levels largely did not differ from adult levels in either whole cell lysate or P2 synaptosomal expression. However, following acute ethanol exposure, PKA RIIβ P2 synaptosomal expression and activity were increased in adults, but not in adolescents. Behaviorally, intracerebroventricular administration of the PKA activator Sp-cAMP and inhibitor Rp-cAMP prior to ethanol administration increased adolescent sensitivity to the sedative-hypnotic effects of ethanol compared to controls. Sp-cAMP was ineffective in adults whereas Rp-cAMP suggestively reduced loss of righting reflex (LORR) with paralleled increases in blood ethanol concentrations. Overall, these data suggest that PKA activity modulates the sedative/hypnotic effects of ethanol and may potentially play a wider role in the differential ethanol responses observed between adolescents and adults. PMID:24874150

  7. Adolescent and adult rat cortical protein kinase A display divergent responses to acute ethanol exposure.

    PubMed

    Gigante, Eduardo D; Santerre, Jessica L; Carter, Jenna M; Werner, David F

    2014-08-01

    Adolescent rats display reduced sensitivity to many dysphoria-related effects of alcohol (ethanol) including motor ataxia and sedative hypnosis, but the underlying neurobiological factors that contribute to these differences remain unknown. The cyclic adenosine monophosphate (cAMP)-dependent protein kinase A (PKA) pathway, particularly the type II regulatory subunit (RII), has been implicated in ethanol-induced molecular and behavioral responses in adults. Therefore, the current study examined cerebral cortical PKA in adolescent and adult ethanol responses. With the exception of early adolescence, PKA RIIα and RIIβ subunit levels largely did not differ from adult levels in either whole cell lysate or P2 synaptosomal expression. However, following acute ethanol exposure, PKA RIIβ P2 synaptosomal expression and activity were increased in adults, but not in adolescents. Behaviorally, intracerebroventricular administration of the PKA activator Sp-cAMP and inhibitor Rp-cAMP prior to ethanol administration increased adolescent sensitivity to the sedative-hypnotic effects of ethanol compared to controls. Sp-cAMP was ineffective in adults whereas Rp-cAMP suggestively reduced loss of righting reflex (LORR) with paralleled increases in blood ethanol concentrations. Overall, these data suggest that PKA activity modulates the sedative/hypnotic effects of ethanol and may potentially play a wider role in the differential ethanol responses observed between adolescents and adults.

  8. Immunologic biomarkers associated with an acute exposure to exothermic byproducts of a ureaformaldehyde spill.

    PubMed Central

    Madison, R E; Broughton, A; Thrasher, J D

    1991-01-01

    A community was exposed for several days to formaldehyde (HCHO), hexamethylenetetramine, trimethylamine, and paraformaldehyde emitted from an overheated tanker car containing ureaformaldehyde resin. Residents experienced acute HCHO symptoms at the time of the accident. Many developed chronic, multiple organ health complaints. Three years following the accident, exposed subjects were compared to residents of a nearby unexposed community for the following immunological parameters: white blood cell count, total lymphocyte count, percent and total lymphocyte subsets (CD5, CD4, CD8, CD19, CD25, and CD26 cells), prevalence of autoantibodies, and antibodies to HCHO-human serum albumin (HCHO-HSA) conjugate. The data were adjusted for gender, age, history of smoking, mobile home residency, and use of wood stoves. There was a statistically significant difference for the following: elevated percent and absolute numbers of CD26 cells (p less than 0.0001); autoantibodies (p less than 0.004), and greater titers of isotypes IgG (p less than 0.0005) and IgM (p less than 0.005) to HCHO-HSA. It is concluded that the exposed subjects had an activated immune system in addition to the elevated autoantibodies. Also, isotypes to HCHO-HSA resulted from the exposure and no other sources, such as smoking, mobile home residency, and use of wood stoves. PMID:1683282

  9. DEVELOPMENT OF ACUTE RFC METHODOLOGY; CONSIDERATIONS IN PROCEDURES RELATING TO DOSIMETRY UNDER CHRONIC VERSUS ACUTE EXPOSURE SCENARIOS

    EPA Science Inventory

    The project considers and examines in detail relationships between critical variables such as exposure time to steady-state as well as physiological determinants related to exposure to predict the nature of the dosimetric adjustment. Overall, this project advances the science t...

  10. Effects of acute exposure to heavy fuel oil from the Prestige spill on a seabird.

    PubMed

    Alonso-Alvarez, Carlos; Pérez, Cristobal; Velando, Alberto

    2007-08-15

    Large quantities of petroleum products are released into the marine environment as result of tanker wrecks. Such catastrophic events have a dramatic impact on marine ecosystems, affecting a broad range of species. Seabirds are placed at the uppermost trophic level of the marine food chain. Therefore, important toxic effects are expected in these organisms. The recent Prestige oil spill gave the opportunity to test this. A previous study reported that yellow-legged gulls (Larus michahellis) breeding in the oiled area (17 months after the spill) showed differences both in plasma biochemistry and in the total circulating levels of polycyclic aromatic hydrocarbons (TPAHs) in blood regard to gulls sampled in clean areas. In the present study, wild yellow-legged gulls were fed with heavy fuel oil from the Prestige oil spill (P-gulls) and compared with control gulls (C-gulls) fed only with the vehicle (vegetable oil). Consistent with the cited previous findings, gulls fed with fuel oil showed reduced glucose and inorganic phosphorus levels in plasma, as well as a trend to significantly reduced creatinine values. In addition, glucose concentration was negatively related to TPAH levels. Males but not females fed with fuel oil showed higher plasma activity of asparatate aminotransferase (AST) than controls. With regard to plasma activity of gamma-glutamyl transferase (GGT), the results were opposite to the previous study. The GGT activity increased in C-females, apparently to meet with increased liver metabolism due to egg laying demands, but not in P-females. Differences to the previous study possibly reflect different adaptive responses of these enzymes to an acute short-term exposure to heavy fuel oil. Since the yellow-legged gull belongs to a complex of species widely distributed throughout the Northern hemisphere, the results as a whole might provide a tool for future evaluations of short- and long-term effects of oil spills on seabirds. Decreased glucose and inorganic

  11. Effect of acute cold exposure and insulin hypoglycemia on plasma thyrotropin levels by IRMA in healthy young males.

    PubMed

    Vigas, M; Martino, E; Bukovská, M; Langer, P

    1988-12-01

    Thyrotropin (TSH) levels in plasma were estimated with the aid of immunoradiometric assay in two groups of healthy male subjects aged 21-22 years in two experiments: 1. acute (30 min) exposure to 4 degrees C in a cold room; 2. insulin (0.01 U per kg i.v.) hypoglycemia at room temperature and at 55 degrees C. Immediately after cold exposure a decrease of TSH level was found (P less than 0.01), while no changes were observed during 30 min exposure. After insulin injection a significant decrease (P less than 0.05 to less than 0.001) of TSH level was found at 45 to 120 min irrespectively of the ambient temperature. In addition, increased levels of noradrenaline and decreased levels of growth hormone after cold exposure are presented.

  12. Evaluation ecological risks using receptor-specific toxicity reference values and USEPA`s wildlife exposure factors handbook

    SciTech Connect

    Gordon, E.K.; Brenzikofer, A.M.; Schmeising, L.M.

    1995-12-31

    An ecological risk assessment was performed for a site at a closing US Air Force Base in Colorado; contaminated abiotic media included shallow soil, surface water, and sediment. To evaluate the potential for impacts on wildlife species exposed to contaminants in these media, a two-phased approach was used. First, dietary Toxicity Reference Values (TRVs) were developed to represent No Observed Adverse Effect Levels (NOAELs) for each chemical of potential concern for the selected wildlife indicator species, red fox (Vulpes vulpes), deer mouse (Peromyscus maniculatus), and mallard (Anasplatyrhynchos). TRVs were determined by applying a series of Uncertainty Factors (UFs) to dietary toxic effects data obtained from the literature for each chemical. UFs were assigned for three uncertainty categories (intertaxon, study duration, and study endpoint). Dietary TRVs were then compared to the site exposure-point concentrations for contaminants in each medium. If a TRV exceeded the site concentration for a given chemical, then that chemical was retained for the second phase of the evaluation, the exposure assessment. Exposure was evaluated for each species using predictive models for ingestion of soil/sediment, and water, as provided in the USEPA Wildlife Exposure Factors Handbook (1993). These models estimate the potential Average Daily Dose (ADD{sub pot}) received by wildlife species exposed to contaminants in abiotic media. The ADD{sub pot}s were then compared to the TRVs on a dose basis. If an ADD{sub pot} exceeded the dose-based TRV for a given chemical, it was assumed that the predicted amount of contaminant ingested was potentially capable of causing adverse effects to the wildlife indicator species. ADD{sub pot}s for each ingestion route were summed for species exposed to contaminants in multiple media to determine the total average daily dose received via all direct routes.

  13. Acute Chlorine Gas Exposure Produces Transient Inflammation and a Progressive Alteration in Surfactant Composition with Accompanying Mechanical Dysfunction

    PubMed Central

    Massa, Christopher B; Scott, Pamela; Abramova, Elena; Gardner, Carol; Laskin, Debra L; Gow, Andrew J

    2014-01-01

    Acute Cl2 exposure following industrial accidents or military/terrorist activity causes pulmonary injury and severe acute respiratory distress. Prior studies suggest that antioxidant depletion is important in producing dysfunction, however a pathophysiologic mechanism has not been elucidated. We propose that acute Cl2 inhalation leads to oxidative modification of lung lining fluid, producing surfactant inactivation, inflammation and mechanical respiratory dysfunction at the organ level. C57BL/6J mice underwent whole-body exposure to an effective 60 ppm-hour Cl2 dose, and were sacrificed 3, 24 and 48 hours later. Whereas pulmonary architecture and endothelial barrier function were preserved, transient neutrophilia, peaking at 24 hours, was noted. Increased expression of ARG1, CCL2, RETLNA, IL-1b, and PTGS2 genes was observed in bronchoalveolar lavage (BAL) cells with peak change in all genes at 24 hours. Cl2 exposure had no effect on NOS2 mRNA or iNOS protein expression, nor on BAL NO3− or NO2−. Expression of the alternative macrophage activation markers, Relm-α and mannose receptor was increased in alveolar macrophages and pulmonary epithelium. Capillary surfactometry demonstrated impaired surfactant function, and altered BAL phospholipid and surfactant protein content following exposure. Organ level respiratory function was assessed by forced oscillation technique at 5 end expiratory pressures. Cl2 exposure had no significant effect on either airway or tissue resistance. Pulmonary elastance was elevated with time following exposure and demonstrated PEEP refractory derecruitment at 48 hours, despite waning inflammation. These data support a role for surfactant inactivation as a physiologic mechanism underlying respiratory dysfunction following Cl2 inhalation. PMID:24582687

  14. An assessment of reference exposure in analogic and digital mammographic units

    NASA Astrophysics Data System (ADS)

    Tilly, J. G.; Miguel, C.; Schelin, H. R.; Porto, L. E.; Paschuk, S.; Denyak, V.; Kmiecik, C.

    2014-11-01

    In this study, the incident air kerma (Ki,a), half-value layer (HVL), output and voltage accuracy for 28 mammography services were evaluated. All mammographs had high frequency rectification, a focus-film distance greater than 60 cm, automatic exposure control, a Mo-Mo anode-filter combination, and compression system. Twenty-three evaluations were made of analogic imaging systems and 21 of digital imaging systems, two of which were full field digital mammography units. The Ki,a was measured in the beam radiation with a 6 cm3 ionization chamber, calibrated for a mammography range of energy. A standard American College of Radiology mammographic phantom simulated a skull caudal incidence. The average, minimum, and maximum Ki,a values were 10.13 mGy, 3.92 mGy, and 30.41 mGy, respectively. However, when the analogic and digital systems are analyzed separately in two subsets, the values were 8.13 mGy, 3.92 mGy, and 11.78 mGy for the analogic systems and 12.33 mGy, 5.21 mGy, and 30.41 mGy for the digital systems, respectively. The results show that the Ki,a values found in digital systems were higher than those in analogic systems, highlighting the differences between these acquisition systems. All HVL values, measured in the primary beam at 28 kV were found between 0.33 mm Al and 0.43 mm Al. Although the manufacture time of the equipment was approximately 146 months (~12 years) prior, the variation in output was between 0.071 mGy/mAs and 0.164 mGy/mAs for the entire sample.

  15. Effect of Prenatal Exposure to Polychlorinated Biphenyls on Incidence of Acute Respiratory Infections in Preschool Inuit Children

    PubMed Central

    Dallaire, Frédéric; Dewailly, Éric; Vézina, Carole; Muckle, Gina; Weber, Jean-Philippe; Bruneau, Suzanne; Ayotte, Pierre

    2006-01-01

    Objective We set out to assess whether environmental prenatal exposure to polychlorinated biphenyls (PCBs) is associated with incidence of acute respiratory infections in preschool Inuit children. Study design We reviewed the medical charts of 343 children from 0 to 5 years of age and evaluated the associations between PCB-153 concentration in umbilical cord plasma and the incidence rates of acute otitis media (AOM) and of upper and lower respiratory tract infections (URTIs and LRTIs, respectively). Results The incidence rates of AOM and LRTIs were positively associated with prenatal exposure to PCBs. Compared with children in the first quartile of exposure (least exposed), children in fourth quartile (most exposed) had rate ratios of 1.25 (p < 0.001) and 1.40 (p < 0.001) for AOM and LRTIs, respectively. There was no association between prenatal PCB exposure and incidence rate of URTIs or hospitalization. Conclusion Prenatal exposure to PCBs could be responsible for a significant portion of respiratory infections in children of this population. PMID:16882544

  16. Acute nonhypothermic exposure to cold impedes motor skill performance in video gaming compared to thermo-neutral and hot conditions.

    PubMed

    Edwards, Andrew M; Crowther, Robert G; Morton, R Hugh; Polman, Remco C

    2011-02-01

    The study examined whether or not acute exposure to unfamiliar hot or cold conditions impairs performance of highly skilled coordinative activities and whether prior physical self-efficacy beliefs were associated with task completion. Nineteen volunteers completed both Guitar Hero and Archery activities as a test battery using the Nintendo Wii console in cold (2 degrees C), neutral (20 degrees C), and hot (38 degrees C) conditions. Participants all completed physical self-efficacy questionnaires following experimental familiarization. Performances of both Guitar Hero and Archery significantly decreased in the cold compared with the neutral condition. The cold trial was also perceived as the condition requiring both greater concentration and effort. There was no association between performance and physical self-efficacy. Performance of these coordinative tasks was compromised by acute (nonhypothermic) exposure to cold; the most likely explanation is that the cold condition presented a greater challenge to attentional processes as a form of environmental distraction.

  17. Genome-Wide Expression Analysis Reveals Diverse Effects of Acute Nicotine Exposure on Neuronal Function-Related Genes and Pathways

    PubMed Central

    Wang, Ju; Cui, Wenyan; Wei, Jinxue; Sun, Dongxiao; Gutala, Ramana; Gu, Jun; Li, Ming D.

    2011-01-01

    Previous human and animal studies demonstrate that acute nicotine exposure has complicated influences on the function of the nervous system, which may lead to long-lasting effects on the behavior and physiology of the subject. To determine the genes and pathways that might account for long-term changes after acute nicotine exposure, a pathway-focused oligoarray specifically designed for drug addiction research was used to assess acute nicotine effect on gene expression in the neuron-like SH-SY5Y cells. Our results showed that 295 genes involved in various biological functions were differentially regulated by 1 h of nicotine treatment. Among these genes, the expression changes of 221 were blocked by mecamylamine, indicating that the majority of nicotine-modulated genes were altered through the nicotinic acetylcholine receptors (nAChRs)-mediated signaling process. We further identified 14 biochemical pathways enriched among the nicotine-modulated genes, among which were those involved in neural development/synaptic plasticity, neuronal survival/death, immune response, or cellular metabolism. In the genes significantly regulated by nicotine but blocked by mecamylamine, 13 enriched pathways were detected. Nine of these pathways were shared with those enriched in the genes regulated by nicotine, including neuronal function-related pathways such as glucocorticoid receptor signaling, p38 MAPK signaling, PI3K/AKT signaling, and PTEN signaling, implying that nAChRs play important roles in the regulation of these biological processes. Together, our results not only provide insights into the mechanism underlying the acute response of neuronal cells to nicotine but also provide clues to how acute nicotine exposure exerts long-term effects on the nervous system. PMID:21556275

  18. Response of rat alveolar macrophages to ozone: quantitative assessment of population size, morphology, and proliferation following acute exposure

    SciTech Connect

    Hotchkiss, J.A.; Harkema, J.R.; Kirkpatrick, D.T.; Henderson, R.F.

    1989-01-01

    The purpose of this study was to evaluate the in vivo effects of an acute exposure to low levels of ozone on rat pulmonary alveolar macrophages (PAM). Fisher 344 rats exposed to 0.0, 0.12, 0.8, or 1.5 ppm O3 for 6 h were killed immediately after and 3, 18, 42, or 66 h after ozone exposure and their lungs were lavaged. Compared to sham-exposed (control) rats, exposure to 0.12 ppm O3 had no measurable effect on the total number, labeling index (LI), mitotic index (MI), or morphology of rat alveolar macrophages. The number of neutrophils was significantly (p less than or equal to 0.001) greater than in controls at 3, 18, and 42 h after exposure to 1.5 ppm O3 and 42 h after exposure to 0.8 ppm O3. The number of PAM was approximately twice that of controls 42 and 66 h after exposure to 0.8 and 1.5 ppm O3. There was a significant (p less than or equal to 0.001) increase in PAM MI 42 and 66 h after exposure to 1.5 ppm O3 and 42 h after 0.8 ppm O3. The increase in the number of PAM in mitosis was preceded by an increase in PAM LI. The PAM LI was significantly (p less than or equal to 0.001) greater than controls 18 and 42 h after exposure but returned to near normal levels by 66 h after exposure. There was a transient decrease in the mean nuclear/cytoplasmic ratio of PAM from rats exposed to 1.5 ppm O3 18 and 42 h after exposure due to an increase in the mean PAM cytoplasmic area. Comparison of the PAM population doubling time (Dt) and cell cycle time (Ct) suggest that PAM proliferation played a significant role in the observed increase in PAM following exposure to 0.8 and 1.5 ppm O3. These results highlight the dynamic response of PAM to an acute exposure to ozone and suggest that the proliferative response of pulmonary alveolar macrophages may be a useful indicator of pulmonary damage following inhalation of an irritant oxidant.

  19. Mimicking acute and chronic stress exposure in naive beef steers alters the acute phase response (APR) associated with vaccination

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was designed to determine the effect of an acute versus chronic stress model on the APR associated with vaccination in naïve beef steers. Steers (n=32; 209 +/- 8 kg) were blocked by body weight and assigned to 1 of 3 treatments: 1) Chronic stress (CHR), 0.5 mg/kg body weight dexamethasone...

  20. Exposure Medium: Key in Identifying Free Ag+ as the Exclusive Species of Silver Nanoparticles with Acute Toxicity to Daphnia magna

    PubMed Central

    Shen, Mo-Hai; Zhou, Xiao-Xia; Yang, Xiao-Ya; Chao, Jing-Bo; Liu, Rui; Liu, Jing-Fu

    2015-01-01

    It is still not very clear what roles the various Ag species play in the toxicity of silver nanoparticles (AgNPs). In this study, we found that traditional exposure media result in uncontrollable but consistent physicochemical transformation of AgNPs, causing artifacts in determination of median lethal concentration (LC50) and hindering the identification of Ag species responsible for the acute toxicity of AgNPs to Daphnia magna. This obstacle was overcome by using 8 h exposure in 0.1 mmol L−1 NaNO3 medium, in which we measured the 8-h LC50 of seven AgNPs with different sizes and coatings, and determined the concentrations of various Ag species. The LC50 as free Ag+ of the seven AgNPs (0.37–0.44 μg L−1) agreed very well with that of AgNO3 (0.40 μg L−1), and showed the lowest value compared to that as total Ag, total Ag+, and dissolved Ag, demonstrating free Ag+ is exclusively responsible for the acute toxicity of AgNPs to D. magna, while other Ag species in AgNPs have no contribution to the acute toxicity. Our results demonstrated the great importance of developing appropriate exposure media for evaluating risk of nanomaterials. PMID:25858866

  1. Exposure Medium: Key in Identifying Free Ag+ as the Exclusive Species of Silver Nanoparticles with Acute Toxicity to Daphnia magna

    NASA Astrophysics Data System (ADS)

    Shen, Mo-Hai; Zhou, Xiao-Xia; Yang, Xiao-Ya; Chao, Jing-Bo; Liu, Rui; Liu, Jing-Fu

    2015-04-01

    It is still not very clear what roles the various Ag species play in the toxicity of silver nanoparticles (AgNPs). In this study, we found that traditional exposure media result in uncontrollable but consistent physicochemical transformation of AgNPs, causing artifacts in determination of median lethal concentration (LC50) and hindering the identification of Ag species responsible for the acute toxicity of AgNPs to Daphnia magna. This obstacle was overcome by using 8 h exposure in 0.1 mmol L-1 NaNO3 medium, in which we measured the 8-h LC50 of seven AgNPs with different sizes and coatings, and determined the concentrations of various Ag species. The LC50 as free Ag+ of the seven AgNPs (0.37-0.44 μg L-1) agreed very well with that of AgNO3 (0.40 μg L-1), and showed the lowest value compared to that as total Ag, total Ag+, and dissolved Ag, demonstrating free Ag+ is exclusively responsible for the acute toxicity of AgNPs to D. magna, while other Ag species in AgNPs have no contribution to the acute toxicity. Our results demonstrated the great importance of developing appropriate exposure media for evaluating risk of nanomaterials.

  2. Father's occupational exposure to carcinogenic agents and childhood acute leukemia: a new method to assess exposure (a case-control study)

    PubMed Central

    Perez-Saldivar, Maria Luisa; Ortega-Alvarez, Manuel Carlos; Fajardo-Gutierrez, Arturo; Bernaldez-Rios, Roberto; del Campo-Martinez, Maria de los Angeles; Medina-Sanson, Aurora; Palomo-Colli, Miguel Angel; Paredes-Aguilera, Rogelio; Martínez-Avalos, Armando; Borja-Aburto, Victor Hugo; Rodriguez-Rivera, Maria de Jesus; Vargas-Garcia, Victor Manuel; Zarco-Contreras, Jesus; Flores-Lujano, Janet; Mejia-Arangure, Juan Manuel

    2008-01-01

    Background Medical research has not been able to establish whether a father's occupational exposures are associated with the development of acute leukemia (AL) in their offspring. The studies conducted have weaknesses that have generated a misclassification of such exposure. Occupations and exposures to substances associated with childhood cancer are not very frequently encountered in the general population; thus, the reported risks are both inconsistent and inaccurate. In this study, to assess exposure we used a new method, an exposure index, which took into consideration the industrial branch, specific position, use of protective equipment, substances at work, degree of contact with such substances, and time of exposure. This index allowed us to obtain a grade, which permitted the identification of individuals according to their level of exposure to known or potentially carcinogenic agents that are not necessarily specifically identified as risk factors for leukemia. The aim of this study was to determine the association between a father's occupational exposure to carcinogenic agents and the presence of AL in their offspring. Methods From 1999 to 2000, a case-control study was performed with 193 children who reside in Mexico City and had been diagnosed with AL. The initial sample-size calculation was 150 children per group, assessed with an expected odds ratio (OR) of three and a minimum exposure frequency of 15.8%. These children were matched by age, sex, and institution with 193 pediatric surgical patients at secondary-care hospitals. A questionnaire was used to determine each child's background and the characteristics of the father's occupation(s). In order to determine the level of exposure to carcinogenic agents, a previously validated exposure index (occupational exposure index, OEI) was used. The consistency and validity of the index were assessed by a questionnaire comparison, the sensory recognition of the work area, and an expert's opinion. Results The

  3. Time course of systemic oxidative stress and inflammatory response induced by an acute exposure to Residual Oil Fly Ash

    SciTech Connect

    Marchini, T.; Magnani, N.D.; Paz, M.L.; Vanasco, V.; Tasat, D.; González Maglio, D.H.; and others

    2014-01-15

    It is suggested that systemic oxidative stress and inflammation play a central role in the onset and progression of cardiovascular diseases associated with the exposure to particulate matter (PM). The aim of this work was to evaluate the time changes of systemic markers of oxidative stress and inflammation, after an acute exposure to Residual Oil Fly Ash (ROFA). Female Swiss mice were intranasally instilled with a ROFA suspension (1.0 mg/kg body weight) or saline solution, and plasma levels of oxidative damage markers [thiobarbituric acid reactive substances (TBARSs) and protein carbonyls], antioxidant status [reduced (GSH) and oxidized (GSSG) glutathione, ascorbic acid levels, and superoxide dismutase (SOD) activity], cytokines levels, and intravascular leukocyte activation were evaluated after 1, 3 or 5 h of exposure. Oxidative damage to lipids and decreased GSH/GSSG ratio were observed in ROFA-exposed mice as early as 1 h. Afterwards, increased protein oxidation, decreased ascorbic acid content and SOD activity were found in this group at 3 h. The onset of an adaptive response was observed at 5 h after the ROFA exposure, as indicated by decreased TBARS plasma content and increased SOD activity. The observed increase in oxidative damage to plasma macromolecules, together with systemic antioxidants depletion, may be a consequence of a systemic inflammatory response triggered by the ROFA exposure, since increased TNF-α and IL-6 plasma levels and polymorphonuclear leukocytes activation was found at every evaluated time point. These findings contribute to the understanding of the increase in cardiovascular morbidity and mortality, in association with environmental PM inhalation. - Highlights: • An acute exposure to ROFA triggers the occurrence of systemic oxidative stress. • Changes in plasmatic oxidative stress markers appear as early as 1 h after exposure. • ROFA induces proinflammatory cytokines release and intravascular leukocyte activation. • PMN

  4. Pathology of acute inhalation exposure to 3-methylfuran in the rat and hamster

    SciTech Connect

    Haschek, W.M.; Morse, C.C.; Boyd, M.R.; Hakkinen, P.J.; Witschi, H.P.

    1983-01-01

    The acute inhalation toxicity of 3-methylfuran (3MF) was investigated in SPF Fischer-derived and CD/CR rats, and golden Syrian hamsters by determination of the 2-week LC/sub 50/, and by histologic examination of animals killed 1, 3, and 14 days following a 1-hr exposure to 148 and 322 ..mu..mole 3MF/liter for CD/CR rats and hamsters, respectively. The Fischer-derived rat was more sensitive to 3MF-induced lethality than the CD/CR rat with an LC/sub 50/ in the male rat of 81 ..mu..mole/liter-1 hr as compared to 222 ..mu..mole/liter-1hr. No sex difference was found. The hamster was relatively resistant with no lethality at 322 ..mu..mole 3MF/liter-2 hr. Pulmonary damage was present in both species. In the hamster, selective necrosis of nonciliated bronchiolar epithelial (Clara) cells was seen at 1 day with virtually complete regeneration by 14 days whereas in the rat the bronchiolar epithelial damage was more extensive and was followed by scattered peribronchiolar fibrosis and epithelial mucous metaplasia suggestive of ''small airway disease'' of man. Relatively selective 3MF-induced necrosis of olfactory epithelium occurred in the nasal mucosa of both species. Resolution of this lesion was seen by 14 days in the hamster. In the rat, however, the necrosis was much more extensive and was followed by partially occlusive fibrosis of the nasal cavity as seen at 14 days. 3MF also induced centrilobular hepatic necrosis in both species. In the rat, lymphocyte necrosis in the thymus and spleen, and esophageal necrosis was also seen.

  5. Pathology of acute inhalation exposure to 3-methylfuran in the rat and hamster

    SciTech Connect

    Haschek, W.M.; Morse, C.C.; Boyd, M.R.; Hakkinen, P.J.; Witschi, H.P.

    1983-12-01

    The acute inhalation toxicity of 3-methylfuran (3MF) was investigated in SPF Fischer-derived and CD/CR rats, and golden Syrian hamsters by determination of the 2-week LC50, and by histologic examination of animals killed 1, 3, and 14 days following a 1-hr exposure to 148 and 322 mumole 3MF/liter for CD/CR rats and hamsters, respectively. The Fischer-derived rat was more sensitive to 3MF-induced lethality than the CD/CR rat with an LC50 in the male rat of 81 mumole/liter-1 hr as compared to 222 mumole/liter-1 hr. No sex difference was found. The hamster was relatively resistant with no lethality at 322 mumole 3MF/liter-2 hr. Pulmonary damage was present in both species. In the hamster, selective necrosis of nonciliated bronchiolar epithelial (Clara) cells was seen at 1 day with virtually complete regeneration by 14 days whereas in the rat the bronchiolar epithelial damage was more extensive and was followed by scattered peribronchiolar fibrosis and epithelial mucous metaplasia suggestive of ''small airway disease'' of man. Relatively selective 3MF-induced necrosis of olfactory epithelium occurred in the nasal mucosa of both species. Resolution of this lesion was seen by 14 days in the hamster. In the rat, however, the necrosis was much more extensive and was followed by partially occlusive fibrosis of the nasal cavity as seen at 14 days. 3MF also induced centrilobular hepatic necrosis in both species. In the rat, lymphocyte necrosis in the thymus and spleen, and esophageal necrosis was also seen.

  6. High Resolution ECG for Evaluation of QT Interval Variability during Exposure to Acute Hypoxia

    NASA Technical Reports Server (NTRS)

    Zupet, P.; Finderle, Z.; Schlegel, Todd T.; Starc, V.

    2010-01-01

    Ventricular repolarization instability as quantified by the index of QT interval variability (QTVI) is one of the best predictors for risk of malignant ventricular arrhythmias and sudden cardiac death. Because it is difficult to appropriately monitor early signs of organ dysfunction at high altitude, we investigated whether high resolution advanced ECG (HR-ECG) analysis might be helpful as a non-invasive and easy-to-use tool for evaluating the risk of cardiac arrhythmias during exposure to acute hypoxia. 19 non-acclimatized healthy trained alpinists (age 37, 8 plus or minus 4,7 years) participated in the study. Five-minute high-resolution 12-lead electrocardiograms (ECGs) were recorded (Cardiosoft) in each subject at rest in the supine position breathing room air and then after breathing 12.5% oxygen for 30 min. For beat-to-beat RR and QT variability, the program of Starc was utilized to derive standard time domain measures such as root mean square of the successive interval difference (rMSSD) of RRV and QTV, the corrected QT interval (QTc) and the QTVI in lead II. Changes were evaluated with paired-samples t-test with p-values less than 0.05 considered statistically significant. As expected, the RR interval and its variability both decreased with increasing altitude, with p = 0.000 and p = 0.005, respectively. Significant increases were found in both the rMSSDQT and the QTVI in lead II, with p = 0.002 and p = 0.003, respectively. There was no change in QTc interval length (p = non significant). QT variability parameters may be useful for evaluating changes in ventricular repolarization caused by hypoxia. These changes might be driven by increases in sympathetic nervous system activity at ventricular level.

  7. Acute exposure of rabbit jejunum to ethanol. In vitro uptake of hexoses

    SciTech Connect

    Thomson, A.B.

    1984-03-01

    The effect of acute exposure of rabbit jejunum to ethanol on the uptake of three hexoses was examined in vitro. With ethanol present in the preincubation medium for 30 min, or directly in the incubation medium for 6 min, glucose uptake was reduced. Kinetic analysis demonstrated that ethanol in the preincubation medium was associated with a rise in the value of the apparent Michaelis constant (Km*), whereas the inhibition of glucose uptake observed with ethanol present directly in the incubation medium was associated with a reduction in the apparent passive permeability coefficient (Pd*), a reduction in the maximal transport rate (Jdm), and an increase in Km*. When increasing concentrations of ethanol were added to the preincubation or to the incubation medium, there was a reduction in the uptake of both 1 mM and 40 mM glucose, galactose, and 3-O-methyl glucose. The addition of 40 mM galactose or 1 mM phloridzin to 40 mM glucose was associated with a 50% reduction in glucose uptake, but this uptake was not further inhibited by the addition of 6% ethanol (v/v). Similarly, the uptake of 3-O-methyl glucose was inhibited by the addition of 40 mM glucose or galactose but no further reduction in uptake was achieved by adding ethanol. Finally, galactose uptake was inhibited by adding 40 mM glucose or 40 mM 3-O-MG, but the addition of 6% ethanol was associated with no further decline in the uptake of galactose.(ABSTRACT TRUNCATED AT 250 WORDS)

  8. Carcinogenesis and low-level ionizing radiation with special reference to lung cancer and exposure to radon daughters

    SciTech Connect

    Fabrikant, J.I.

    1982-04-01

    Of the important health effects of ionizing radiation, three important late effects - carcinogenesis, teratogenesis and mutagenesis are of greatest concern. This is because any exposure, even at low levels, carries some risk of such deleterious effects. As the dose of radiation increases above very low levels, the risk of health effects increases. Cancer-induction is the most important late somatic effect of low-dose ionizing radiation. Solid cancers, rather than leukemia, are principal late effects in exposed individuals. Tissues vary greatly in their susceptibility to radiation carcinogenesis. The most frequently occurring radiation-induced cancers in man include, in decreasing order of susceptibility: the female breast, the thyroid gland, the blood-forming tissues, the lung, certain organs of the gastrointestinal tract, and the bones. A number of biological and physical factors affect the cancer risk, such as age, sex, life-style, LET, and RBE. Despite uncertainty about low-level radiation risks, regulatory and advisory bodies must set standards for exposure, and individuals need information to be able to make informed judgments for themselves. From the point of view of the policy maker, the overriding concern is the fact that small doses of radiation can cause people to have more cancers than would otherwise be expected. While concern for all radiation effects exists, our human experience is limited to cancer-induction in exposed populations. This discussion is limited to cancer risk estimation and decision-making in relation to the health effects on populations of exposure to low levels of ionizing radiation. Here, low-level radiation will refer to yearly whole-body doses up to 5 rems or 0.05 Sv, or to cumulative doses up to 50 rems or 0.5 Sv from low-LET radiation and from high-LET radiation. (ERB)

  9. Effects of acute fresh water exposure on water flux rates and osmotic responses in Kemp's ridley sea turtles (Lepidochelys kempi).

    PubMed

    Ortiz, R M; Patterson, R M; Wade, C E; Byers, F M

    2000-09-01

    Water flux rates and osmotic responses of Kemp's Ridley sea turtles (Lepidochelys kempi) acutely exposed to fresh water were quantified. Salt-water adapted turtles were exposed to fresh water for 4 d before being returned to salt water. During the initial salt water phase, absolute and relative water flux rates were 1.2+/-0.1 l d(-1) and 123.0+/-6.8 ml kg(-1) d(-1), respectively. When turtles were exposed to fresh water, rates increased by approximately 30%. Upon return to salt water, rates decreased to original levels. Plasma osmolality, Na(+), K(+), and Cl(-) decreased during exposure to fresh water, and subsequently increased during the return to salt water. The Na(+):K(+) ratio was elevated during the fresh water phase and subsequently decreased upon return to salt water. Aldosterone and corticosterone were not altered during exposure to fresh water. Elevated water flux rates during fresh water exposure reflected an increase in water consumption, resulting in a decrease in ionic and osmotic concentrations. The lack of a change in adrenocorticoids to acute fresh water exposure suggests that adrenal responsiveness to an hypo-osmotic environment may be delayed in marine turtles when compared to marine mammals.

  10. Effects of acute fresh water exposure on water flux rates and osmotic responses in Kemp's ridley sea turtles (Lepidochelys kempi)

    NASA Technical Reports Server (NTRS)

    Ortiz, R. M.; Patterson, R. M.; Wade, C. E.; Byers, F. M.

    2000-01-01

    Water flux rates and osmotic responses of Kemp's Ridley sea turtles (Lepidochelys kempi) acutely exposed to fresh water were quantified. Salt-water adapted turtles were exposed to fresh water for 4 d before being returned to salt water. During the initial salt water phase, absolute and relative water flux rates were 1.2+/-0.1 l d(-1) and 123.0+/-6.8 ml kg(-1) d(-1), respectively. When turtles were exposed to fresh water, rates increased by approximately 30%. Upon return to salt water, rates decreased to original levels. Plasma osmolality, Na(+), K(+), and Cl(-) decreased during exposure to fresh water, and subsequently increased during the return to salt water. The Na(+):K(+) ratio was elevated during the fresh water phase and subsequently decreased upon return to salt water. Aldosterone and corticosterone were not altered during exposure to fresh water. Elevated water flux rates during fresh water exposure reflected an increase in water consumption, resulting in a decrease in ionic and osmotic concentrations. The lack of a change in adrenocorticoids to acute fresh water exposure suggests that adrenal responsiveness to an hypo-osmotic environment may be delayed in marine turtles when compared to marine mammals.

  11. Development and Application of Acute Exposure Guideline Levels (AEGLs) for Chemical Warfare Nerve and Sulfur Mustard Agents.

    SciTech Connect

    Watson, Annetta Paule; Opresko, Dennis M; Young, Robert A; Hauschild, Veronique

    2006-01-01

    Acute exposure guideline levels (AEGLs) have been developed for the chemical warfare agents GB, GA, GD, GF, VX, and sulfur mustard. These AEGLs were approved by the National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances after Federal Register publication and comment, and judged as scientifically valid by the National Research Council Committee on Toxicology Subcommittee on AEGLs. AEGLs represent general public exposure limits for durations ranging from 10 min to 8 h, and for three levels of severity (AEGL-1, AEGL-2, AEGL-3). Mild effects are possible at concentrations greater than AEGL-1, while life-threatening effects are expected at concentrations greater than AEGL-3. AEGLs can be applied to various civilian and national defense purposes, including evacuation and shelter-in-place protocols, reentry levels, protective clothing specifications, and analytical monitoring requirements. This report documents development and derivation of AEGL values for six key chemical warfare agents, and makes recommendations for their application to various potential exposure scenarios.

  12. Genotype and toxicity relationships among Hyalella azteca: I. Acute exposure to metals or low pH

    SciTech Connect

    Duan, Y.; Guttman, S.I.; Oris, J.T.; Bailer, A.J.

    2000-05-01

    Comparative genotype and toxin interactions at three polymorphic enzyme loci were examined in a laboratory population of amphipods (Hyalella azteca) during acute exposure to cadmium, zinc, copper, lead, or low pH. Significant toxin-genotype interactions were observed using logistic regression to model mortality in ten of 15 analyses. Both stressor-specific and nonspecific modes of selection were observed. In general, low pH selected for different genotypes than those selected by metals, especially zinc. Different modes of selection were also observed when amphipods were exposed to different metals. These results suggest that exposure to low pH would significantly reduce the ability of H. azteca to survive subsequent contamination by metals; exposure to stressors in the reverse order would also compromise a population's chance of survival. A genetic distance analysis showed that the magnitude of genetic differentiation consistently increased among survivors compared with that of the initial populations. These increases in genetic divergence estimates suggest that acute exposure to metals or low pH may have an evolutionarily significant impact on the species. They also suggest that both genotype frequency and genetic distance measures (based on allozyme data) may be used as bioindicators for environmental monitoring programs. Validation of such bioindicators requires an understanding of the population's genetic background, genetic structure, and history.

  13. Respiratory symptoms and functional impairment from acute (cross-shift) exposure to welding gases and fumes

    SciTech Connect

    Kilburn, K.H.; Warshaw, R.H.; Boylen, C.T.; Thornton, J.C. )

    1989-11-01

    One hundred forty-five male welders from a West Coast shipyard were studied cross-sectionally and across a Monday work shift by pulmonary function tests and a questionnaire. Ten years of welding was associated with chronic bronchitis in 23.3% of nonsmokers compared to 3.3% in male controls, shortness of breath in 31.5% of nonsmokers compared to 1.5% in controls, and chest pain or heaviness in 38.4% compared to 4.4% in controls. Men who welded aluminum but had never smoked had more frequent wheezing, chest tightness, phlegm, feverishness and fatigue than those welding mild (black) or stainless steel. There were no significant cross-shift effects from welding exposure on measurements of pulmonary function. Although baseline expiratory flows were reduced slightly when compared to Caucasian-predicted values, ethnic specific comparisons for the largest subgroup showed only that FEF25-75 was reduced to 92.9 percentage of predicted values. Diffusing capacities for carbon monoxide were significantly reduced as compared to referents. The pulmonary function values of 25 current smokers were indistinguishable from the 41 who had never smoked, which probably reflects their low consumption of cigarettes.

  14. No acute toxicity to Uca pugnax, the mud fiddler crab, following a 96-h exposure to sediment-bound permethrin.

    PubMed

    Stueckle, Todd A; Griffin, Kristin; Foran, Christy M

    2008-08-01

    In coastal areas, the application of pyrethroid insecticides and the resulting sediment residues pose a potential threat to marine benthic ecosystems. Pyrethroids cause acute toxicity and exhibit a wide range of sublethal effects on fish and crustaceans when exposure is aqueous. Fiddler crabs that inhabit salt marsh sediment are sensitive to sediment-associated pollutants and serve as a sentinel species for xenobiotic exposure. We exposed adult U. pugnax to salt marsh sediment spiked with different 60% trans/40% cis permethrin concentrations for 96 h, and evaluated changes in oxygen consumption rate, hemolymph osmolarity, and glutathione S-transferase activity (GST) following exposure. Marsh sediment was not lethal to U. pugnax at permethrin concentrations of 100-10,000 microg/kg. Sediment-bound permethrin had no significant effect on respiration and osmoregulation. Exposure caused an induction of hepatopancreas GST in a dose-dependent manner. Gill and midgut tissues showed induction at permethrin concentrations at 10,000 microg/kg. We conclude that short term exposure to permethrin-contaminated sediment does not pose a significant threat to this species or impact respiration and osmoregulation. Furthermore, increased GST activity allows us to evaluate this enzyme's induction as a generalist biomarker for sediment-bound pyrethroid exposures.

  15. Survival time analysis of least killifish (Heterandria formosa) and mosquitofish (Gambusia affinis) in acute exposures to endosulfan sulfate.

    PubMed

    Carriger, John F; Hoang, Tham C; Rand, Gary M

    2010-05-01

    Single-species flow-through toxicity tests were conducted to determine the times-to-death of two indigenous fish to South Florida--least killifish (Heterandria formosa) and mosquitofish (Gambusia affinis)--from acute exposure to endosulfan sulfate. Mortalities were recorded within 8-h periods from test initiation to termination at 96 h. The 96-h LC(50)s for least killifish and mosquitofish estimated using the trimmed-Spearman-Karber method were 2.0 and 2.3 microg/l, respectively. An accelerated failure time model was used to estimate times to death at selected concentrations. Data were fit to log-normal, log-logistic, and Weibull distributions. Acute toxicity data fit to the Weibull distribution produced a better relative fit than log-normal or log-logistic distributions for both toxicity tests. The survival-time profiles and associated statistics illustrate the benefit of considering exposure duration as well as concentration when predicting acute risk to species' populations. Both toxicity tests had similar outcomes from exposure to endosulfan sulfate, with least killifish being slightly more likely to die at lower concentrations and shorter time periods than mosquitofish. From the models generated by the toxicity tests, times-to-death for least killifish and mosquitofish were estimated for environmentally relevant concentrations of total endosulfan at a site of concern in South Florida. When the results from the current toxicity tests were compared to environmental concentrations from previous screening-level ecological risk assessments, the durations necessary to potentially kill 10% or more of the populations of the two native south Florida fish species were estimated to be 77 and 96 h for least killifish and mosquitofish, respectively. However, the exposure values included the alpha and beta isomers as well as endosulfan sulfate; therefore, an understanding of their toxicity might be important in understanding the survival dynamics of fish species in

  16. WHY DO THE ACUTE BEHAVIORAL EFFECTS OT TOLUENE IN RATS DEPEND ON THE ROUTE OF EXPOSURE?

    EPA Science Inventory

    Despite evidence suggesting that the acute effects of organic solvents are related to their concentration in the brain, we have observed route-dependent differences in the acute behavioral effects of toluene. Whereas inhaled toluene disrupts the performance of rats on a visual si...

  17. Acute Toxicity Estimation and Operational Risk Management of Chemical Warfare Agent Exposures

    DTIC Science & Technology

    2004-05-01

    December 2001 Deputy Assistant to The Secretary of Defense Chemical and Biological (Warfare Agent) Defense ((DATSD- CBD ) interim-certified acute...avoidance (detection), protection, decontamination, and medical intervention. d. Compares the DATSD- CBD interim-certified acute toxicity values...defense. 2. CONCLUSIONS AND RECOMMENDATIONS. a. Translating Toxicity Information into ORM Terminology. The 2001 DATSD- CBD toxicity

  18. Acute Toluene Exposure alters expression of genes associated with synaptic structure and function

    EPA Science Inventory

    Toluene (TOL), a volatile organic compound, is a ubiquitous air pollutant of interest to EPA regulatory programs. Whereas its acute functional effects are well described, several potential modes of action in the CNS have been proposed. Therefore, the genomic response to acute TOL...

  19. SYSTEMIC IMBALANCE OF ESSENTIAL METALS AND CARDIAC GENE EXPRESSION IN RATS FOLLOWING ACUTE PULMONARY ZINC EXPOSURE

    EPA Science Inventory

    We have recently demonstrated that PM containing water-soluble zinc may cause cardiac injury following pulmonary exposure. To investigate if pulmonary zinc exposure causes systemic metal imbalance and direct cardiac effects, we intratracheally (IT) instilled male Wistar Kyoto (WK...

  20. Multi-walled carbon nanotube-physicochemical properties predict the systemic acute phase response following pulmonary exposure in mice.

    PubMed

    Poulsen, Sarah S; Knudsen, Kristina B; Jackson, Petra; Weydahl, Ingrid E K; Saber, Anne T; Wallin, Håkan; Vogel, Ulla

    2017-01-01

    Pulmonary exposure to multi-walled carbon nanotubes (MWCNTs) has been linked to an increased risk of developing cardiovascular disease in addition to the well-documented physicochemical-dependent adverse lung effects. A proposed mechanism is through a strong and sustained pulmonary secretion of acute phase proteins to the blood. We identified physicochemical determinants of MWCNT-induced systemic acute phase response by analyzing effects of pulmonary exposure to 14 commercial, well-characterized MWCNTs in female C57BL/6J mice pulmonary exposed to 0, 6, 18 or 54 μg MWCNT/mouse. Plasma levels of acute phase response proteins serum amyloid A1/2 (SAA1/2) and SAA3 were determined on day 1, 28 or 92. Expression levels of hepatic Saa1 and pulmonary Saa3 mRNA levels were assessed to determine the origin of the acute phase response proteins. Pulmonary Saa3 mRNA expression levels were greater and lasted longer than hepatic Saa1 mRNA expression. Plasma SAA1/2 and SAA3 protein levels were related to time and physicochemical properties using adjusted, multiple regression analyses. SAA3 and SAA1/2 plasma protein levels were increased after exposure to almost all of the MWCNTs on day 1, whereas limited changes were observed on day 28 and 92. SAA1/2 and SAA3 protein levels did not correlate and only SAA3 protein levels correlated with neutrophil influx. The multiple regression analyses revealed a protective effect of MWCNT length on SAA1/2 protein level on day 1, such that a longer length resulted in lowered SAA1/2 plasma levels. Increased SAA3 protein levels were positively related to dose and content of Mn, Mg and Co on day 1, whereas oxidation and diameter of the MWCNTs were protective on day 28 and 92, respectively. The results of this study reveal very differently controlled pulmonary and hepatic acute phase responses after MWCNT exposure. As the responses were influenced by the physicochemical properties of the MWCNTs, this study provides the first step towards designing

  1. Acute invasive pulmonary aspergillosis, shortly after occupational exposure to polluted muddy water, in a previously healthy subject

    PubMed Central

    Pilaniya, Vikas; Gera, Kamal; Gothi, Rajesh; Shah, Ashok

    2015-01-01

    Invasive pulmonary aspergillosis (IPA) predominantly occurs in severely neutropenic immunocompromised subjects. The occurrence of acute IPA after brief but massive exposure to Aspergillus conidia in previously healthy subjects has been documented, although only six such cases have been reported. The diagnosis was delayed in all six of the affected patients, five of whom died. We report the case of a 50-year-old HIV-negative male, a water pipeline maintenance worker, who presented with acute-onset dyspnea and fever one day after working for 2 h in a deep pit containing polluted, muddy water. Over a one-month period, his general condition deteriorated markedly, despite antibiotic therapy. Imaging showed bilateral diffuse nodules with cavitation, some of which were surrounded by ground-glass opacity suggestive of a halo sign (a hallmark of IPA). Cultures (of sputum/bronchial aspirate samples) and serology were positive for Aspergillus fumigatus. After being started on itraconazole, the patient improved. We conclude that massive exposure to Aspergillus conidia can lead to acute IPA in immunocompetent subjects. PMID:26578140

  2. Is hair analysis for dialkyl phosphate metabolites a suitable biomarker for assessing past acute exposure to organophosphate pesticides?

    PubMed

    Tsatsakis, A M; Tutudaki, M; Tzatzarakis, M N; Dawson, A; Mohamed, F; Christaki, M; Alegakis, A K

    2012-03-01

    In the present paper, the possibility to use dialkyl phosphate metabolites (DAPs) hair segmental analysis as a biomarker of past acute exposure to organophosphates is examined. Hair samples of four acute poisoning survivors were collected and segmental hair analysis was performed. The total hair samples were divided to 1 cm segments and analysed by gas chromatography-mass spectrometry (GC-MS) for the presence of four DAP metabolites, dimethyl phosphate (DMP), diethyl phosphate (DEP), diethyl thiophosphate (DETP) and diethyl dithiophosphate (DEDTP). Results were examined under the light of pesticide type and time of hair sample collection. Although DAPs were detected all along the hair shaft, higher concentrations (peaks) were detected in the segments proximate to the suicide period. It was also observed that the elevated concentrations of the present metabolites corresponded to the ones produced by the ingested parent compound. Conclusively, measurements of DAPs in the appropriate hair segments of OP-poisoned patients can be used for assessing past acute exposure to organophosphates in certain cases.

  3. The effects of acute alcohol exposure on the response properties of neurons in visual cortex area 17 of cats

    SciTech Connect

    Chen Bo; Xia Jing; Li Guangxing; Zhou Yifeng

    2010-03-15

    Physiological and behavioral studies have demonstrated that a number of visual functions such as visual acuity, contrast sensitivity, and motion perception can be impaired by acute alcohol exposure. The orientation- and direction-selective responses of cells in primary visual cortex are thought to participate in the perception of form and motion. To investigate how orientation selectivity and direction selectivity of neurons are influenced by acute alcohol exposure in vivo, we used the extracellular single-unit recording technique to examine the response properties of neurons in primary visual cortex (A17) of adult cats. We found that alcohol reduces spontaneous activity, visual evoked unit responses, the signal-to-noise ratio, and orientation selectivity of A17 cells. In addition, small but detectable changes in both the preferred orientation/direction and the bandwidth of the orientation tuning curve of strongly orientation-biased A17 cells were observed after acute alcohol administration. Our findings may provide physiological evidence for some alcohol-related deficits in visual function observed in behavioral studies.

  4. Home paint exposures and risk of childhood acute lymphoblastic leukemia: Findings from the Childhood Leukemia International Consortium

    PubMed Central

    Bailey, Helen D; Metayer, Catherine; Milne, Elizabeth; Petridou, Eleni; Infante-Rivard, Claire; Spector, Logan G; Clavel, Jacqueline; Dockerty, John D; Zhang, Luoping; Armstrong, Bruce K; Rudant, Jérémie; Fritschi, Lin; Amigou, Alicia; Hatzipantelis, Emmanouel; Kang, Alice Y; Stiakaki, Eftychia; Schüz, Joachim

    2017-01-01

    Purpose It has been suggested that home paint exposure increases the risk of childhood acute lymphoblastic leukemia (ALL). Methods We obtained individual level data from eight case-control studies participating in the Childhood Leukemia International Consortium. All studies had home paint exposure data (sometimes including lacquers and varnishes) for the pregnancy period with additional data for the 1–3 month period before conception in five, the year before conception in two, and the period after birth in four studies respectively. Cytogenetic subtype data were available for some studies. Data were harmonized to a compatible format. Pooled analyses of individual data were undertaken using unconditional logistic regression. Results Based on 3,002 cases and 3,836 controls, the pooled odds ratio (OR) for home paint exposure in the 1–3 months before conception and risk of ALL was 1.54 (95% confidence interval (CI) 1.28, 1.85), while based on 1160 cases and 1641 controls for exposure in the year before conception it was 1.00 (95% CI 0.86, 1.17). For exposure during pregnancy, using 4,382 cases and 5,747 controls, the pooled OR was 1.14 (95% CI 1.04, 1.25) and for exposure after birth, the OR was 1.22 (95% CI 1.07, 1.39), based on data from 1,962 cases and 2,973 controls. The risk was greater for certain cytogenetic subtypes and if someone other than the parents did the painting. Conclusions Home paint exposure shortly before conception, during pregnancy and/or after birth appeared to increase the risk of childhood ALL. It may be prudent to limit exposure during these periods. PMID:26134047

  5. Impacts of stage-specific acute pesticide exposure on predicted population structure of the soft-shell clam, Mya arenaria

    PubMed Central

    Lindsay, S.; Chasse, J.; Butler, R.A.; Morrill, W.; Van Beneden, R.J.

    2010-01-01

    A combined laboratory and modeling approach was used to assess the impact of selected pesticides on early life stages of the soft-shell clam, Mya arenaria. Clams were exposed for 24 h as veligers or pediveligers to the broad-spectrum herbicide hexazinone [3-cyclohexyl-6-(dimethylamino)-1-methyl-1,3,5-triazine-2,4 (1h,3h)-dione; (Velpar®)], the phenoxyacetic acid herbicide, 2,4-D (2,4- dichlorophenoxyacetic acid; Agway® Super BK 32), or phosmet (Imidan®). In addition, juvenile clams were exposed for 24 h to 2,4-D and their growth monitored for 21 months. Laboratory experiments indicated veligers were more sensitive to acute pesticide exposure than pediveligers, with 2,4-D exposed veligers exhibiting the lowest survival among all treatments. Relative to controls, juvenile clams exposed to 0.5 ppm 2,4-D had enhanced survival following the initial 3 months of grow out. Juveniles exposed to 0.5 ppm, 5 ppm and 10 ppm 2,4-D showed an initial growth delay relative to control clams, but at 21 months post exposure these clams were significantly larger than control clams. Data from the larval and juvenile exposures were used to generate a stage-specific matrix model to predict the effect of pesticide exposure on clam populations. Impacts on simulated clam populations varied with the pesticide and stage exposed. For example, 2,4-D exposure of veligers and pediveligers significantly reduced predicted recruitment as well as population growth rate compared to controls, but juvenile exposure to 2,4-D did not significantly reduce population growth rate. With the exception of veligers exposed to 10 ppm, hexazinone exposure at the both veliger and pediveliger stages significantly reduced predicted recruitment success compared to 0 ppm controls. Hexazinone exposure also reduced modeled population growth rates, but these reductions were only slight in the pediveliger exposure simulations. Veliger and pediveliger exposure to phosmet reduced modeled population growth rate in a dose

  6. Genotoxicity assessment of cerium oxide nanoparticles in female Wistar rats after acute oral exposure.

    PubMed

    Kumari, Monika; Kumari, Srinivas Indu; Kamal, Sarika Srinivas Kalyan; Grover, Paramjit

    2014-12-01

    Cerium oxide nanoparticles (CeO2 NPs; nanoceria) have demonstrated excellent potential for commercial use in various arenas, such as in biomedical industry in cosmetics and as a fuel additive. However, limited knowledge exists regarding their potential toxicity. In this study, acute oral toxicity of CeO2 NPs and their microparticles (MPs; bulk) was carried out in female albino Wistar rats. The CeO2 NPs and CeO2 MPs were characterized utilizing transmission electron microscopy (TEM), dynamic light scattering (DLS) and laser Doppler velocimetry (LDV) for the size, distribution and surface charge respectively. The genotoxicity studies were conducted using micronucleus test (MNT), comet and chromosomal aberration (CA) assays. Results revealed that at high dose (1000mg/kg bw) CeO2 NPs induced significant DNA damage in peripheral blood leukocytes (PBL) and liver cells, micronucleus formation in bone marrow and blood cells and total cytogenetic changes in bone marrow. However, significant genotoxicity was not observed at 500 and 100mg/kg bw of CeO2 NPs. The findings from biochemical assays depicted significant alterations in ALP and LDH activity in serum and GSH content in liver, kidneys and brain only at the high dose of CeO2 NPs. Tissue biodistribution of both particles was analyzed by inductively coupled plasma optical emission spectrometer (ICP-OES). Bioaccumulation of nanoceria in all tissues was significant and dose-, time- and organ-dependent. Moreover, CeO2 NPs exhibited higher tissue distribution along with greater clearance in large fractions through urine and feces than CeO2 bulk, whereas, maximum amount of micro-sized CeO2 got excreted in feces. The histopathological examination documented alterations in the liver due to exposure with CeO2 NPs only. Hence, the results suggest that bioaccumulation of CeO2 NPs may induce genotoxic effects. However, further research on long term fate and adverse effects of CeO2 NPs is warranted.

  7. Acute Free-Iron Exposure Does Not Explain the Impaired Haemorheology Associated with Haemochromatosis

    PubMed Central

    McNamee, Antony P.; Sabapathy, Surendran; Singh, Indu; Horobin, Jarod; Guerrero, Janelle; Simmonds, Michael J.

    2016-01-01

    . Acute exposure to elevated iron levels does not appear (in isolation) to account for these differences. Further consideration is required prior to utilising routine venesection blood for harvesting RBC concentrates due to the potential risk of microvascular disorders arising from impaired haemorheology. PMID:26741993

  8. Acute exposure to gas-supersaturated water does not affect reproductive success of female adult chinook salmon late in maturation

    USGS Publications Warehouse

    Gale, William L.; Maule, A.G.; Postera, A.; Peters, M.H.

    2004-01-01

    At times, total dissolved gas concentrations in the Columbia and Snake rivers have been elevated due to involuntary spill from high spring runoff and voluntary spill used as a method to pass juvenile salmonids over dams. The goal of this project was to determine if acute exposure to total dissolved gas supersaturation (TDGS) affects the reproductive performance of female chinook salmon late in their maturation. During this study, adult female spring chinook salmon were exposed to mean TDGS levels of 114.1 % to 125.5%. We ended exposures at first mortality, or at the appearance of impending death. Based on this criterion, exposures lasted from 10 to 68 h and were inversely related to TDGS. There was no effect of TDGS on pre-spawning mortality or fecundity when comparing treatment fish to experimental controls or the general hatchery population four to six weeks after exposures. Egg quality, based on egg weight and egg diameter, did not differ between treatment and control fish. Fertilization rate and survival to eyed-stage was high (>94%) for all groups. With the exception of Renibacterium salmoninarum (the causative agent of bacterial kidney disease; BKD), no viral or bacterial fish pathogens were isolated from experimental fish. The prevalence (about 45%) and severity of R. salmoninarum did not differ among the groups or the general hatchery population. We conclude that these acute exposures to moderate levels of gas-supersaturated water-perhaps similar to that experienced by immigrating adult salmon as they approach and pass a hydropower dam on the Columbia River-did not affect reproductive success of female chinook salmon late in their maturation. These results are most applicable to summer and fall chinook salmon, which migrate in the summer/fall and spawn shortly after reaching their natal streams. Published in 2004 by John Wiley and Sons, Ltd.

  9. Quantifying Fish Swimming Behavior in Response to Acute Exposure of Aqueous Copper Using Computer Assisted Video and Digital Image Analysis

    PubMed Central

    Calfee, Robin D.; Puglis, Holly J.; Little, Edward E.; Brumbaugh, William G.; Mebane, Christopher A.

    2016-01-01

    Behavioral responses of aquatic organisms to environmental contaminants can be precursors of other effects such as survival, growth, or reproduction. However, these responses may be subtle, and measurement can be challenging. Using juvenile white sturgeon (Acipenser transmontanus) with copper exposures, this paper illustrates techniques used for quantifying behavioral responses using computer assisted video and digital image analysis. In previous studies severe impairments in swimming behavior were observed among early life stage white sturgeon during acute and chronic exposures to copper. Sturgeon behavior was rapidly impaired and to the extent that survival in the field would be jeopardized, as fish would be swept downstream, or readily captured by predators. The objectives of this investigation were to illustrate protocols to quantify swimming activity during a series of acute copper exposures to determine time to effect during early lifestage development, and to understand the significance of these responses relative to survival of these vulnerable early lifestage fish. With mortality being on a time continuum, determining when copper first affects swimming ability helps us to understand the implications for population level effects. The techniques used are readily adaptable to experimental designs with other organisms and stressors. PMID:26967350

  10. Quantifying fish swimming behavior in response to acute exposure of aqueous copper using computer assisted video and digital image analysis

    USGS Publications Warehouse

    Calfee, Robin D.; Puglis, Holly J.; Little, Edward E.; Brumbaugh, William G.; Mebane, Christopher A.

    2016-01-01

    Behavioral responses of aquatic organisms to environmental contaminants can be precursors of other effects such as survival, growth, or reproduction. However, these responses may be subtle, and measurement can be challenging. Using juvenile white sturgeon (Acipenser transmontanus) with copper exposures, this paper illustrates techniques used for quantifying behavioral responses using computer assisted video and digital image analysis. In previous studies severe impairments in swimming behavior were observed among early life stage white sturgeon during acute and chronic exposures to copper. Sturgeon behavior was rapidly impaired and to the extent that survival in the field would be jeopardized, as fish would be swept downstream, or readily captured by predators. The objectives of this investigation were to illustrate protocols to quantify swimming activity during a series of acute copper exposures to determine time to effect during early lifestage development, and to understand the significance of these responses relative to survival of these vulnerable early lifestage fish. With mortality being on a time continuum, determining when copper first affects swimming ability helps us to understand the implications for population level effects. The techniques used are readily adaptable to experimental designs with other organisms and stressors.

  11. Eruptive cherry angiomas and irritant symptoms after one acute exposure to the glycol ether solvent 2-butoxyethanol.

    PubMed

    Raymond, L W; Williford, L S; Burke, W A

    1998-12-01

    Seven clerical workers were evaluated in 1993, 8 months after exposure to vaporized 2-butoxyethanol (2-BE; also called butyl cellosolve or ethylene glycol monobutyl ether [EGMBE or EGBE]), which had been applied overnight to strip the floor of their file room. At the time of exposure, they had noted intense eye and respiratory irritation, marked dyspnea, nausea, and faintness, suggesting a concentration of 2-BE in the air of 200-300 parts per million (ppm). All seven workers later experienced recurrent eye and respiratory irritation, dry cough, and headache. Four months after the exposure, cherry angiomas began to appear on the arms, trunk, and thighs of six workers, who voiced concerns about the possibility of cancer. Our evaluation found no evidence of hematologic, liver, lung, or renal toxicity, but elevations in the erythrocyte sedimentation rate and blood pressure of each subject were found. Workplace air sampling found no detectable 2-BE, but traces (0.1-0.2 ppm) of formaldehyde were identified. Irritant symptoms abated after the group was moved to a room with better ventilation, and the mild hypertension gradually cleared, but new cherry angiomas have continued to appear 5 years after the acute exposure, as the initial ones persisted. These angiomas occur in healthy persons as they age but in this instance appear to have resulted from a single overexposure to 2-BE. We felt confident in reassuring the workers that they would suffer no serious consequences from this exposure.

  12. The Effects of Acute Waterborne Exposure to Sublethal Concentrations of Molybdenum on the Stress Response in Rainbow Trout, Oncorhynchus mykiss

    PubMed Central

    Ricketts, Chelsea D.; Bates, William R.; Reid, Scott D.

    2015-01-01

    To determine if molybdenum (Mo) is a chemical stressor, fingerling and juvenile rainbow trout (Oncorhynchus mykiss) were exposed to waterborne sodium molybdate (0, 2, 20, or 1,000 mg l-1 of Mo) and components of the physiological (plasma cortisol, blood glucose, and hematocrit) and cellular (heat shock protein [hsp] 72, hsp73, and hsp90 in the liver, gills, heart, and erythrocytes and metallothionein [MT] in the liver and gills) stress responses were measured prior to initiation of exposure and at 8, 24, and 96 h. During the acute exposure, plasma cortisol, blood glucose, and hematocrit levels remained unchanged in all treatments. Heat shock protein 72 was not induced as a result of exposure and there were no detectable changes in total hsp70 (72 and 73), hsp90, and MT levels in any of the tissues relative to controls. Both fingerling and juvenile fish responded with similar lack of apparent sensitivity to Mo exposure. These experiments demonstrate that exposure to waterborne Mo of up to 1,000 mg l-1 did not activate a physiological or cellular stress response in fish. Information from this study suggests that Mo water quality guidelines for the protection of aquatic life are highly protective of freshwater fish, namely rainbow trout. PMID:25629693

  13. Imaging of nontraumatic acute hip pain in children: multimodality approach with attention to the reduction of medical radiation exposure.

    PubMed

    Sarwar, Zahir U; DeFlorio, Robert; Catanzano, Tara M

    2014-08-01

    Nontraumatic acute hip pain in children is common. However, the presentation and etiology is variable, including difficulty with weight bearing and abnormal gait. Barriers in communication, multiple possible etiologies, and age-specific anatomical variations of the pediatric hip make the evaluation of hip pain in children a difficult clinical diagnosis. Multimodality radiologic approach plays an important role for the evaluation of these children. However, owing to the complexity of pediatric hip disease, children sometimes undergo multiple radiologic examinations, resulting in delay in diagnosis and increased radiation dose. This article focuses on the illustration and discussion of common causes of acute hip pain or limp in children. Current recommendations for the imaging of these patients with specific attention to the ALARA (as low radiation as reasonably achievable) principle of radiation exposure are considered. Examples of the entities discussed are provided.

  14. Slow and stepped re-warming after acute low temperature exposure do not improve survival of Drosophila melanogaster larvae.

    PubMed

    Sinclair, Brent J; Rajamohan, Arun

    2008-01-01

    We tested that hypothesis that slow re-warming rates would improve the ability of Drosophila melanogaster Meigen larvae to survive acute low temperature exposure. Four larval stages (1(st), 2(nd), 3(rd) instars and wandering stage 3(rd) instars) of four wild-type strains were exposed to -7 degrees C for periods of time expected to result in 90 % mortality. Larvae were then either directly transferred to their rearing temperature (21 degrees C), or returned to this temperature in a stepwise fashion (pausing at 0 and 15 degrees C) or by slow warming at 1 or 0.1 degrees C/min. We observed a reduced rapid cold-hardening effect and no general increase in survival of acute chilling in larvae re-warmed in a stepwise or slow fashion, and hypothesise that slow re-warming may result in accumulation of further chill injuries.

  15. Acute chlorine gas exposure produces transient inflammation and a progressive alteration in surfactant composition with accompanying mechanical dysfunction

    SciTech Connect

    Massa, Christopher B.; Scott, Pamela; Abramova, Elena; Gardner, Carol; Laskin, Debra L.; Gow, Andrew J.

    2014-07-01

    Acute Cl{sub 2} exposure following industrial accidents or military/terrorist activity causes pulmonary injury and severe acute respiratory distress. Prior studies suggest that antioxidant depletion is important in producing dysfunction, however a pathophysiologic mechanism has not been elucidated. We propose that acute Cl{sub 2} inhalation leads to oxidative modification of lung lining fluid, producing surfactant inactivation, inflammation and mechanical respiratory dysfunction at the organ level. C57BL/6J mice underwent whole-body exposure to an effective 60 ppm-hour Cl{sub 2} dose, and were euthanized 3, 24 and 48 h later. Whereas pulmonary architecture and endothelial barrier function were preserved, transient neutrophilia, peaking at 24 h, was noted. Increased expression of ARG1, CCL2, RETLNA, IL-1b, and PTGS2 genes was observed in bronchoalveolar lavage (BAL) cells with peak change in all genes at 24 h. Cl{sub 2} exposure had no effect on NOS2 mRNA or iNOS protein expression, nor on BAL NO{sub 3}{sup −} or NO{sub 2}{sup −}. Expression of the alternative macrophage activation markers, Relm-α and mannose receptor was increased in alveolar macrophages and pulmonary epithelium. Capillary surfactometry demonstrated impaired surfactant function, and altered BAL phospholipid and surfactant protein content following exposure. Organ level respiratory function was assessed by forced oscillation technique at 5 end expiratory pressures. Cl{sub 2} exposure had no significant effect on either airway or tissue resistance. Pulmonary elastance was elevated with time following exposure and demonstrated PEEP refractory derecruitment at 48 h, despite waning inflammation. These data support a role for surfactant inactivation as a physiologic mechanism underlying respiratory dysfunction following Cl{sub 2} inhalation. - Highlights: • Effect of 60 ppm*hr Cl{sub 2} gas on lung inflammation and mechanical function examined. • Pulmonary inflammation is transient and minor.

  16. Evaluation of Pulmonary and Systemic Toxicity of Oil Dispersant (COREXIT EC9500A®) Following Acute Repeated Inhalation Exposure

    PubMed Central

    Roberts, Jenny R; Anderson, Stacey E; Kan, Hong; Krajnak, Kristine; Thompson, Janet A; Kenyon, Allison; Goldsmith, William T; McKinney, Walter; Frazer, David G; Jackson, Mark; Fedan, Jeffrey S

    2014-01-01

    INTRODUCTION Oil spill cleanup workers come into contact with numerous potentially hazardous chemicals derived from the oil spills, as well as chemicals applied for mitigation of the spill, including oil dispersants. In response to the Deepwater Horizon Macondo well oil spill in the Gulf of Mexico in 2010, a record volume of the oil dispersant, COREXIT EC9500A, was delivered via aerial applications, raising concern regarding potential health effects that may result from pulmonary exposure to the dispersant. METHODS The current study examined the effects on pulmonary functions, cardiovascular functions, and systemic immune responses in rats to acute repeated inhalation exposure of COREXIT EC9500A at 25 mg/m3, five hours per day, over nine work days, or filtered air (control). At one and seven days following the last exposure, a battery of parameters was measured to evaluate lung function, injury, and inflammation; cardiovascular function; peripheral vascular responses; and systemic immune responses. RESULTS No significant alterations in airway reactivity were observed at one or seven days after exposure either in baseline values or following methacholine (MCh) inhalation challenge. Although there was a trend for an increase in lung neutrophils and phagocyte oxidant production at one-day post exposure, there were no significant differences in parameters of lung inflammation. In addition, increased blood monocytes and neutrophils, and decreased lymphocyte numbers at one-day post exposure also did not differ significantly from air controls, and no alterations in splenocyte populations, or serum or spleen immunoglobulin M (IgM) to antigen were observed. There were no significant differences in peripheral vascular responsiveness to vasoconstrictor and vasodilator agonists or in blood pressure (BP) responses to these agents; however, the baseline heart rate (HR) and HR responses to isoproterenol (ISO) were significantly elevated at one-day post exposure, with resolution

  17. Formaldehyde Exposure and Mortality Risks From Acute Myeloid Leukemia and Other Lymphohematopoietic Malignancies in the US National Cancer Institute Cohort Study of Workers in Formaldehyde Industries

    PubMed Central

    Dell, Linda D.; Boffetta, Paolo; Gallagher, Alexa E.; Crawford, Lori; Lees, Peter SJ.; Mundt, Kenneth A.

    2015-01-01

    Objectives: To evaluate associations between cumulative and peak formaldehyde exposure and mortality from acute myeloid leukemia (AML) and other lymphohematopoietic malignancies. Methods: Cox proportional hazards analyses. Results: Acute myeloid leukemia was unrelated to cumulative exposure. Hodgkin lymphoma relative risk estimates in the highest exposure categories of cumulative and peak exposures were, respectively, 3.76 (Ptrend = 0.05) and 5.13 (Ptrend = 0.003). There were suggestive associations with peak exposure observed for chronic myeloid leukemia, albeit based on very small numbers. No other lymphohematopoietic malignancy was associated with either chronic or peak exposure. Conclusions: Insofar as there is no prior epidemiologic evidence supporting associations between formaldehyde and either Hodgkin leukemia or chronic myeloid leukemia, any causal interpretations of the observed risk patterns are at most tentative. Findings from this re-analysis do not support the hypothesis that formaldehyde is a cause of AML. PMID:26147546

  18. Short-term exposure to ambient particulate matter and emergency ambulance dispatch for acute illness in Japan.

    PubMed

    Tasmin, Saira; Ueda, Kayo; Stickley, Andrew; Yasumoto, Shinya; Phung, Vera Ling Hui; Oishi, Mizuki; Yasukouchi, Shusuke; Uehara, Yamato; Michikawa, Takehiro; Nitta, Hiroshi

    2016-10-01

    Short-term exposure to air pollution may be linked to negative health outcomes that require an emergency medical response. However, few studies have been undertaken on this phenomenon to date. The aim of this study therefore was to examine the association between short-term exposure to ambient suspended particulate matter (SPM) and emergency ambulance dispatches (EADs) for acute illness in Japan. Daily EAD data, daily mean SPM and meteorological data were obtained for four prefectures in the Kanto region of Japan for the period from 2007 to 2011. The area-specific association between daily EAD for acute illness and SPM was explored using generalized linear models while controlling for ambient temperature, relative humidity, seasonality, long-term trends, day of the week and public holidays. Stratified analyses were conducted to evaluate the modifying effects of age, sex and medical conditions. Area-specific estimates were combined using meta-analyses. For the total study period the mean level of SPM was 23.7μg/m(3). In general, higher SPM was associated with a significant increase in EAD for acute illness [estimated pooled relative risk (RR): 1.008, 95% CI: 1.007 to 1.010 per 10μg/m(3) increase in SPM at lag 0-1]. The effects of SPM on EAD for acute illness were significantly greater for moderate/mild medical conditions (e.g. cases that resulted in <3weeks hospitalization or no hospitalization) when compared to severe medical conditions (e.g. critical cases, and cases that led to >3weeks hospitalization or which resulted in death). Using EAD data, this study has shown the adverse health effects of ambient air pollution. This highlights the importance of reducing the level of air pollution in order to maintain population health and well-being.

  19. [Age, gender and individually-typological characteristics of reaction to acute hypoxic exposure].

    PubMed

    Krivoshchekov, S G; Balioz, N V; Nekipelova, N V; Kapilevich, L V

    2014-01-01

    Individual pequliarities of hypoxic resistance, assessed by the response of cardiorespiratory system to acute normobaric hypoxia (10% O2), were studied in healthy subjects. Age changes in dynamics of blood oxygen saturation after the acute hypoxia are shown at level of separate sites curve SpO2 (phases of a delay, decrease and lifting). It is established, that at children sensitivity to acute hypoxia above, than at teenagers, and at teenagers above, than at adults. Higher lability of mental processes, sympathetic activity, and personal anxiety are associated with choleric temperament. Cholerics are characterized by slower restoration of blood oxygen saturation after the acute hypoxia compared with sanguine persons that we consider an indication of less hypoxic tolerance of the first group. We have developed the complex algorithm, dynamics describing dependence oxygen saturation in various phases of the hypoxic test, which can be used as a universal method of an estimation hypoxic stability at different groups of the population.

  20. Quantitative Structure--Activity Relationship Modeling of Rat Acute Toxicity by Oral Exposure

    EPA Science Inventory

    Background: Few Quantitative Structure-Activity Relationship (QSAR) studies have successfully modeled large, diverse rodent toxicity endpoints. Objective: In this study, a combinatorial QSAR approach has been employed for the creation of robust and predictive models of acute toxi...

  1. Relation of structure to function for the US reference standard endotoxin after exposure to /sup 60/Co radiation

    SciTech Connect

    Csako, G.; Suba, E.A.; Ahlgren, A.; Tsai, C.M.; Elin, R.J.

    1986-01-01

    The structure and function of the highly purified US reference standard endotoxin (RSE) were studied after exposure to ionizing radiation from a /sup 60/Co source. With increasing doses of radiation, the trilaminar ribbon-like structure of untreated endotoxin exhibited focal swelling, after which only spherical particles were seen by electron microscopy. These morphological changes were paralleled by the respective loss of O-side chain repeating units and pieces of the R-core from the lipopolysaccharide molecules, as demonstrated by electrophoresis. The biologic function of the irradiated endotoxin was assessed with a variety of tests. At higher doses of radiation, a direct relation was observed between the degradation of the molecular and supramolecular structure and the loss of biologic function. At lower doses of radiation, however, there was variability among the functional assays in their rate of change with progressive irradiation of the RSE. The results suggest that the carbohydrate moiety plays an important role both in determining the supramolecular structure and in modulating certain biologic activities of bacterial endotoxins.

  2. Effects of Acute Oral 5-aminotetrazole (5-AT) Exposure to Rats (Rattus norvegicus)

    DTIC Science & Technology

    2015-02-12

    Micronucleus Assay (MNA) Male rats from the 5-AT study (three highest dose groups and the vehicle control) were tested for DNA damage in their peripheral...Dose Test (Sub-acute Study) - Sperm Collection and Analysis 09/25/2013 10/07/2013 14-Day Repeated Dose Test (Sub-acute Study) - Micronucleus Assay...2015 Prepared by: Valerie H Adams, Ph.D. Approved for public release; distribution unlimited. Specialty: 500C Toxicity Test Toxicity Report No. S

  3. Acute respiratory distress syndrome and chemical burns after exposure to chlorine-containing bleach: a case report.

    PubMed

    Shin, Hong-Joon; Chang, Jin-Sun; Ahn, Seong; Kim, Tae-Ok; Park, Cheol-Kyu; Lim, Jung-Hwan; Oh, In-Jae; Kim, Yu-Il; Lim, Sung-Chul; Kim, Young-Chul; Kwon, Yong-Soo

    2017-01-01

    Chlorine-containing bleach can cause acute respiratory distress syndrome (ARDS) and chemical burns. However, simultaneous occurrence of the two conditions caused by this agent is very rare. We describe the case of a 74-year-old female who presented with shortness of breath and hemoptysis following accidental exposure to chlorine-containing bleach. She had second- to third-degree chemical burns on both buttocks and thighs, and received mechanical ventilation because of the development of ARDS. Mechanical ventilation was discontinued on day 6 of hospitalization because of the rapid improvement of hypoxemia, and the patient was transferred to another hospital for further management of the chemical burns on day 18.

  4. Adolescent mice are less sensitive to the effects of acute nicotine on context pre-exposure than adults.

    PubMed

    Kutlu, Munir Gunes; Braak, David C; Tumolo, Jessica M; Gould, Thomas J

    2016-07-01

    Adolescence is a critical developmental period associated with both increased vulnerability to substance abuse and maturation of certain brain regions important for learning and memory such as the hippocampus. In this study, we employed a hippocampus-dependent learning context pre-exposure facilitation effect (CPFE) paradigm in order to test the effects of acute nicotine on contextual processing during adolescence (post-natal day (PND) 38) and adulthood (PND 53). In Experiment 1, adolescent or adult C57BL6/J mice received either saline or one of three nicotine doses (0.09, 0.18, and 0.36mg/kg) prior to contextual pre-exposure and testing. Our results demonstrated that both adolescent and adult mice showed CPFE in the saline groups. However, adolescent mice only showed acute nicotine enhancement of CPFE with the highest nicotine dose whereas adult mice showed the enhancing effects of acute nicotine with all three doses. In Experiment 2, to determine if the lack of nicotine's effects on CPFE shown by adolescent mice is specific to the age when they are tested, mice were either given contextual pre-exposure during adolescence or adulthood and received immediate shock and testing during adulthood after a 15day delay. We found that both adolescent and adult mice showed CPFE in the saline groups when tested during adulthood. However, like Experiment 1, mice that received contextual pre-exposure during adolescence did not show acute nicotine enhancement except at the highest dose (0.36mg/kg) whereas both low (0.09mg/kg) and high (0.36mg/kg) doses enhanced CPFE in adult mice. Finally, we showed that the enhanced freezing response found with 0.36mg/kg nicotine in the 15-day experiment may be a result of decreased locomotor activity as mice that received this dose of nicotine traveled shorter distances in an open field paradigm. Overall, our results indicate that while adolescent mice showed normal contextual processing when tested both during adolescence and adulthood, they

  5. Histopathological changes in gills of the estuarine crab Chasmagnathus granulata (Crustacea-Decapoda) following acute exposure to ammonia.

    PubMed

    de Freitas Rebelo, M; Rodriguez, E M; Santos, E A; Ansaldo, M

    2000-02-01

    Histopathological effects of ammonia on the gills of the estuarine crab Chasmagnathus granulata (Dana, 1851) were evaluated after acute exposure to ammonia concentrations around LC(50) value (17.85 Mm). Disruption of pilaster cells and a subsequent collapse of gill lamellae were the main effects observed. Epithelial necrosis and hyperplasia were also detected. Significant (P<0.05) increases in pCO(2) and lactate, and significant decreases of pO(2) were detected in the haemolymph of ammonia-exposed crabs. These changes suggest that the observed histopathological damage affected gas exchange, possibly leading to death.

  6. Interaction of exposure concentration and duration in determining acute toxic effects of sarin vapor in rats.

    PubMed

    Mioduszewski, R; Manthei, J; Way, R; Burnett, D; Gaviola, B; Muse, W; Thomson, S; Sommerville, D; Crosier, R

    2002-04-01

    Sarin (GB) vapor exposure is associated with both systemic and local toxic effects occurring primarily via the inhalation and ocular routes. The objective of these studies was to develop models for predicting dose-response effects of GB vapor concentrations as a function of exposure duration. Thus, the probability of GB vapor-induced lethality was estimated in rats exposed to various combinations of exposure concentration and duration. Groups of male and female Sprague-Dawley rats were exposed to one of a series of GB vapor concentrations for a single duration (5-360 min) in a whole-body dynamic chamber. The onset of clinical signs and changes in blood cholinesterase activity were measured with each exposure. Separate effective concentrations for lethality in 50% of the exposed population (LC50) and corresponding dose-response slopes were determined for each exposure duration by the Bliss probit method. Contrary to that predicted by Haber's rule, the interaction of LC50 x time (LCT50) values increased with exposure duration (i.e., the CT for 50% lethality in the exposed population and corresponding dose-response slope was not constant over time). A plot of log (LCT50) versus log (exposure time) showed significant curvature. Predictive models derived from multifactor probit analysis of results describing the relationship between exposure conditions and probability of lethality in the rat are discussed. Overall, female rats were more sensitive to GB vapor toxicity than male rats over the range of exposure concentration and duration studied. Miosis was the initial clinical sign noted after the start of GB vapor exposure. Although blood cholinesterase activity was significantly inhibited by GB vapor exposure, poor correlation between cholinesterase inhibition and exposure conditions or cholinesterase inhibition and severity of clinical signs was noted.

  7. Effects of acute and chronic exposure to lead on the behavior of the pond snail Helisoma trivolvis

    SciTech Connect

    Bennett, V.T.; Copeland, J.

    1997-09-01

    The behavior of aquatic invertebrates may be useful as an indicator for the presence of toxicants in both freshwater and marine environments. The pond snail Helisoma trivolvis, the red ram`s horn, was exposed to low levels of lead (0.05 ppm). Chronic exposure significantly reduced the number of head movements but had no affect on radula movement or antenna twitches. Acute exposure resulted in curling of the foot that lasted 0.5 to 14.0 minutes. Electrochemical analysis of lead levels within treated snails indicated a higher concentration of lead in the tissue than that in the treated environment. Organ analysis of the digestive gland, 1 salivary gland, reproductive organs and the cerebral ganglion is currently being studied.

  8. Assessing chronic fish health: An application to a case of an acute exposure to chemically treated crude oil.

    PubMed

    Mauduit, F; Domenici, P; Farrell, A P; Lacroix, C; Le Floch, S; Lemaire, P; Nicolas-Kopec, A; Whittington, M; Zambonino-Infante, J L; Claireaux, G

    2016-09-01

    Human alteration of marine ecosystems is substantial and growing. Yet, no adequate methodology exists that provides reliable predictions of how environmental degradation will affect these ecosystems at a relevant level of biological organization. The primary objective of this study was to develop a methodology to evaluate a fish's capacity to face a well-established environmental challenge, an exposure to chemically dispersed oil, and characterize the long-term consequences. Therefore, we applied high-throughput, non-lethal challenge tests to assess hypoxia tolerance, temperature susceptibility and maximal swimming speed as proxies for a fish's functional integrity. These whole animal challenge tests were implemented before (1 month) and after (1 month) juvenile European sea bass (Dicentrarchus labrax) had been acutely exposed (48h) to a mixture containing 0.08gL(-1) of weathered Arabian light crude oil plus 4% dispersant (Corexit© EC9500A), a realistic exposure concentration during an oil spill. In addition, experimental populations were then transferred into semi-natural tidal mesocosm ponds and correlates of Darwinian fitness (growth and survival) were monitored over a period of 4 months. Our results revealed that fish acutely exposed to chemically dispersed oil remained impaired in terms of their hypoxia tolerance and swimming performance, but not in temperature susceptibility for 1 month post-exposure. Nevertheless, these functional impairments had no subsequent ecological consequences under mildly selective environmental conditions since growth and survival were not impacted during the mesocosm pond study. Furthermore, the earlier effects on fish performance were presumably temporary because re-testing the fish 10 months post-exposure revealed no significant residual effects on hypoxia tolerance, temperature susceptibility and maximal swimming speed. We propose that the functional proxies and correlates of Darwinian fitness used here provide a useful

  9. Probabilistic acute risk assessment of cumulative exposure to organophosphorus and carbamate pesticides from dietary vegetables and fruits in Shanghai populations.

    PubMed

    Li, Fan; Yuan, Yaqun; Meng, Pai; Wu, Min; Li, Shuguang; Chen, Bo

    2017-02-03

    Organophosphorus pesticides (OPs) and carbamate pesticides (CPs) are among the most widely used pesticides in China, playing a major role in protecting agricultural commodities. In this study, we determined the cumulative acute exposure to OPs and CPs of Shanghai residents from vegetables and fruits (VFs). The food consumption data were obtained from the Shanghai Food Consumption Survey (SHFCS) of 2012-14 including a total of 1973 participants aged 2-90 years. The pesticide residue data were obtained from the Shanghai monitoring programme during 2008-11 with 34 organophosphates and 11 carbamates analysed in a total of 5335 samples of VFs. A probabilistic approach was performed as recommended by the EFSA, using the optimistic model with non-detects set as zero and with processing factors (PFs) being used and the pessimistic model with non-detects replaced by limit of detection (LOD) and without PFs. We used the relative potency factor (RPF) method to normalise the various pesticides to the index compound (IC) of methamidophos and chlorpyrifos separately. Only in the pessimistic model using methamidophos as the IC was there was small risk of exposure exceeding the ARfD (3 µg kg(-)(1) bw day(-)(1)) in the populations of preschool children (0.029%), school-age children (0.022%) and adults (0.002%). There were no risk of exposure exceeding the ARfD of methamidophos in the optimistic model and of chlorpyrifos (100 µg kg(-)(1) bw day(-)(1)) in both optimistic and pessimistic models in all three populations. Considering the Chinese habits of overwhelmingly eating processed food (vegetables being cooked, and fruits being washed or peeled), we conclude that little acute risk was found for the exposure to VF-sourced OPs and CPs in Shanghai.

  10. DEVELOPMENT OF EXPOSURE-RESPONSE MODELS FOR THE ACUTE RESPIRATORY EFFECTS OF INHALED IRRITANTS IN HUMANS

    EPA Science Inventory

    In order to conduct quantitative risk assessment with minimal uncertainty for short-term exposure to ozone and other respiratory irritants, one must identify exposure-response (E-R) models which accurately predict the distribution of the magnitudes of response (or the proportion ...

  11. Acute microinstillation inhalation exposure to sarin induces changes in respiratory dynamics and functions in guinea pigs.

    PubMed

    Conti, Michele L; Che, Magnus M; Boylan, Megan; Sciuto, Alfred M; Gordon, Richard K; Nambiar, Madhusoodana P

    2009-01-01

    This study investigates the toxic effects of sarin on respiratory dynamics following microinstillation inhalation exposure in guinea pigs. Animals are exposed to sarin for 4 minutes, and respiratory functions are monitored at 4 hours and 24 hours by whole-body barometric plethysmography. Data show significant changes in respiratory dynamics and function following sarin exposure. An increase in respiratory frequency is observed at 4 hours post exposure compared with saline controls. Tidal volume and minute volume are also increased in sarin-exposed animals 4 hours after exposure. Peak inspiratory flow increases, whereas peak expiratory flow increases at 4 hours and is erratic following sarin exposure. Animals exposed to sarin show a significant decrease in expiratory time and inspiratory time. End-inspiratory pause is unchanged whereas end-expiratory pause is slightly decreased 24 hours after sarin exposure. These results indicate that inhalation exposure to sarin alters respiratory dynamics and function at 4 hours, with return to normal levels at 24 hours post exposure.

  12. Acute effects of 50 Hz magnetic field exposure on human visual task and cardiovascular performance

    SciTech Connect

    Whittington, C.J.; Podd, J.V.; Rapley, B.R.

    1996-05-01

    One hundred subjects, males and females with ages ranging between 18 and 48 years, were studied under both field-exposed and sham-exposed conditions. A 50 Hz, 100 {micro}T magnetic field (MF) was used. To examine the effect of field exposure on performance, a two-alternative, forced-choice, duration-discrimination task with three levels of difficulty was used. The subject`s task was to decide which of two sequentially presented light flashes had the longer duration. The standard duration was 50 ms, and the alternative durations were 65, 100, or 125 ms. Both reaction time and percentage of correct responses were recorded for each subject. MF and sham exposure were for 9 min each. Blood pressure and heart rate were also measured before and following MF exposure and sham-exposure trials. The study was performed double blind, with the exposure order counterbalanced. Compared to sham exposure, MF exposure significantly decreased reaction time on the hardest level of the performance task. MF exposure did not reliably affect percentage correct or cardiovascular performance. It was demonstrated that a relatively high level of statistical power was the basis for the observed MF effect, and the need to pay closer attention to power levels in future research is discussed.

  13. Oxidative stress related to chlorpyrifos exposure in rainbow trout: Acute and medium term effects on genetic biomarkers.

    PubMed

    Benedetto, A; Brizio, P; Squadrone, S; Scanzio, T; Righetti, M; Gasco, L; Prearo, M; Abete, M C

    2016-05-01

    Organophosphates (OPs) are derivatives of phosphoric acid widely used in agriculture as pesticides. Chlorpyrifos (CPF) is an OP that is extremely toxic to aquatic organisms. Rainbow trout (Oncorhynchus mykiss) is considered as a sentinel model species for ecotoxicology assessment in freshwater ecosystems. An exposure study was carried out on rainbow trout to investigate genetic responses to CPF-induced oxidative stress by Real-Time PCR, and to determine the accumulation dynamics of CPF and toxic metabolite chlorpyrifos-oxon (CPF-ox) in edible parts, by HPLC-MS/MS. Among the genes considered to be related to oxidative stress, a significant increase in HSP70 mRNA levels was observed in liver samples up to 14 days after CPF exposure (0.05 mg/L). CPF concentrations in muscle samples reach mean values of 285.25 ng/g within 96 hours of exposure, while CPF-ox concentrations were always under the limit of quantification (LOQ) of the applied method. Our findings lead us to consider HSP70 as a suitable genetic marker in rainbow trout for acute and medium-term monitoring of CPF exposure, complementary to analytical determinations.

  14. Lipid peroxidation and antioxidative protection mechanism in rat lungs upon acute and chronic exposure to nitrogen dioxide.

    PubMed Central

    Sagai, M; Ichinose, T

    1987-01-01

    This work was done to clarify the relation between the changes of lipid peroxidation and the activities of antioxidative protective enzymes in lungs of rats exposed acutely, subacutely, and chronically to nitrogen dioxide. It was confirmed that the activities of the antioxidative enzymes to protect cells from oxidative stress increased in an early phase, and then the activities decreased gradually. Lipid peroxides increased once in an early phase and then returned to the control level; thereafter, lipid peroxides increased gradually again. Lipid peroxidation as measured by ethane exhalation increased significantly with 0.04, 0.4, and 4 ppm nitrogen dioxide exposure for 9, 18, and 27 months, and a dose-response relationship was clearly observed. The temporal changes of lipid peroxidation varied inversely with that of the activities of antioxidative protective enzymes. From these results, it was suggested that the increments of antioxidative protective enzyme activities in an early phase were complementary effects to protect cells from damage by lipid peroxides which were increased by nitrogen dioxide exposure, and that the complementary effects are lost in later phases of life-span exposure. Finally, loss of such protective complementary effects might relate to some chronic diseases in lungs. Therefore, the temporal changes described above are important characteristics in chronic exposure of air pollutants. PMID:3665862

  15. Moderate (2%, v/v) Ethanol Feeding Alters Hepatic Wound Healing after Acute Carbon Tetrachloride Exposure in Mice

    PubMed Central

    Deshpande, Krutika T.; Liu, Shinlan; McCracken, Jennifer M.; Jiang, Lu; Gaw, Ta Ehpaw; Kaydo, Lindsey N.; Richard, Zachary C.; O’Neil, Maura F.; Pritchard, Michele T.

    2016-01-01

    Wound healing consists of three overlapping phases: inflammation, proliferation, and matrix synthesis and remodeling. Prolonged alcohol abuse can cause liver fibrosis due to deregulated matrix remodeling. Previous studies demonstrated that moderate ethanol feeding enhances liver fibrogenic markers and frank fibrosis independent of differences in CCl4-induced liver injury. Our objective was to determine whether or not other phases of the hepatic wound healing response were affected by moderate ethanol after CCl4 exposure. Mice were fed moderate ethanol (2% v/v) for two days and then were exposed to CCl4 and euthanized 24–96 h later. Liver injury was not different between pair- and ethanol-fed mice; however, removal of necrotic tissue was delayed after CCl4-induced liver injury in ethanol-fed mice. Inflammation, measured by TNFα mRNA and protein and hepatic Ly6c transcript accumulation, was reduced and associated with enhanced hepatocyte apoptosis after ethanol feeding. Hepatocytes entered the cell cycle equivalently in pair- and ethanol-fed mice after CCl4 exposure, but hepatocyte proliferation was prolonged in livers from ethanol-fed mice. CCl4-induced hepatic stellate cell activation was increased and matrix remodeling was prolonged in ethanol-fed mice compared to controls. Taken together, moderate ethanol affected each phase of the wound healing response to CCl4. These data highlight previously unknown effects of moderate ethanol exposure on hepatic wound healing after acute hepatotoxicant exposure. PMID:26751492

  16. Moderate (2%, v/v) Ethanol Feeding Alters Hepatic Wound Healing after Acute Carbon Tetrachloride Exposure in Mice.

    PubMed

    Deshpande, Krutika T; Liu, Shinlan; McCracken, Jennifer M; Jiang, Lu; Gaw, Ta Ehpaw; Kaydo, Lindsey N; Richard, Zachary C; O'Neil, Maura F; Pritchard, Michele T

    2016-01-06

    Wound healing consists of three overlapping phases: inflammation, proliferation, and matrix synthesis and remodeling. Prolonged alcohol abuse can cause liver fibrosis due to deregulated matrix remodeling. Previous studies demonstrated that moderate ethanol feeding enhances liver fibrogenic markers and frank fibrosis independent of differences in CCl₄-induced liver injury. Our objective was to determine whether or not other phases of the hepatic wound healing response were affected by moderate ethanol after CCl₄ exposure. Mice were fed moderate ethanol (2% v/v) for two days and then were exposed to CCl₄ and euthanized 24-96 h later. Liver injury was not different between pair- and ethanol-fed mice; however, removal of necrotic tissue was delayed after CCl₄-induced liver injury in ethanol-fed mice. Inflammation, measured by TNFα mRNA and protein and hepatic Ly6c transcript accumulation, was reduced and associated with enhanced hepatocyte apoptosis after ethanol feeding. Hepatocytes entered the cell cycle equivalently in pair- and ethanol-fed mice after CCl₄ exposure, but hepatocyte proliferation was prolonged in livers from ethanol-fed mice. CCl₄-induced hepatic stellate cell activation was increased and matrix remodeling was prolonged in ethanol-fed mice compared to controls. Taken together, moderate ethanol affected each phase of the wound healing response to CCl₄. These data highlight previously unknown effects of moderate ethanol exposure on hepatic wound healing after acute hepatotoxicant exposure.

  17. Probabilistic acute dietary exposure assessments to captan and tolylfluanid using several European food consumption and pesticide concentration databases.

    PubMed

    Boon, Polly E; Svensson, Kettil; Moussavian, Shahnaz; van der Voet, Hilko; Petersen, Annette; Ruprich, Jiri; Debegnach, Francesca; de Boer, Waldo J; van Donkersgoed, Gerda; Brera, Carlo; van Klaveren, Jacob D; Busk, Leif

    2009-12-01

    Probabilistic dietary acute exposure assessments of captan and tolylfluanid were performed for the populations of the Czech Republic, Denmark, Italy, the Netherlands and Sweden. The basis for these assessments was national databases for food consumption and pesticide concentration data harmonised at the level of raw agricultural commodity. Data were obtained from national food consumption surveys and national monitoring programmes and organised in an electronic platform of databases connected to probabilistic software. The exposure assessments were conducted by linking national food consumption data either (1) to national pesticide concentration data or (2) to a pooled database containing all national pesticide concentration data. We show that with this tool national exposure assessments can be performed in a harmonised way and that pesticide concentrations of other countries can be linked to national food consumption surveys. In this way it is possible to exchange or merge concentration data between countries in situations of data scarcity. This electronic platform in connection with probabilistic software can be seen as a prototype of a data warehouse, including a harmonised approach for dietary exposure modelling.

  18. Estimated personal soot exposure is associated with acute myocardial infarction onset in a case-crossover study.

    PubMed

    von Klot, Stephanie; Cyrys, Josef; Hoek, Gerard; Kühnel, Brigitte; Pitz, Mike; Kuhn, Ulrike; Kuch, Bernhard; Meisinger, Christa; Hörmann, Allmut; Wichmann, H-Erich; Peters, Annette

    2011-01-01

    The current study investigates the association of estimated personal exposure to traffic-related air pollution and acute myocardial infarction (AMI). Cases of AMI were interviewed in the Augsburg KORA Myocardial Infarction Registry from February 1999 through December 2003, and 960 AMI survivors were included in the analyses. The time-varying component of daily personal soot exposure (the temporally variable contribution due to the daily area level of exposure and daily personal activities) was estimated using a linear combination of estimated mean ambient soot concentration, time spent outdoors, and time spent in traffic. The association of soot exposure with AMI onset was estimated in a case-crossover analysis controlling for temperature and day of the week using conditional logistic regression analyses. Estimated personal soot exposure was associated with AMI (relative risk, 1.30 per 1.1 m(-1) × 10(-5) [95% confidence interval, 1.09-1.55]). Estimated ambient soot and measured ambient PM(2.5) particulate matter 2.5 µm and smaller in aerodynamic diameter were not significantly associated with AMI onset. Our results suggest that an increase in risk of AMI in association with personal soot exposure may be in great part due to the contribution of personal soot from individual times spent in traffic and individual times spent outdoors. As a consequence, estimates calculated based on measurements at urban background stations may be underestimations. Health effects of traffic-related air pollution may need to be updated, taking into account individual time spent in traffic and outdoors, to adequately protect the public.

  19. Exposure and measurement contributions to estimates of acute air pollution effects.

    PubMed

    Sheppard, Lianne; Slaughter, James C; Schildcrout, Jonathan; Liu, L-J Sally; Lumley, Thomas

    2005-07-01

    Air pollution health effect studies are intended to estimate the effect of a pollutant on a health outcome. The definition of this effect depends upon the study design, disease model parameterization, and the type of analysis. Further limitations are imposed by the nature of exposure and our ability to measure it. We define a plausible exposure model for air pollutants that are relatively nonreactive and discuss how exposure varies. We discuss plausible disease models and show how their parameterizations are affected by different exposure partitions and by different study designs. We then discuss a measurement model conditional on ambient concentrations and incorporate this into the disease model. We use simulation studies to show the impact of a range of exposure model assumptions on estimation of the health effect in the ecologic time series design. This design only uses information from the time-varying ambient source exposure. When ambient and nonambient sources are independent, exposure variation due to nonambient source exposures behaves like Berkson measurement error and does not bias the effect estimates. Variation in the population attenuation of ambient concentrations over time does bias the estimates with the bias being either positive or negative depending upon the association of this parameter with ambient pollution. It is not realistic to substitute measured average personal exposures into time series studies because so much of the variation in personal exposures comes from nonambient sources that do not contribute information in the time series design. We conclude that general statements about the implications of measurement error need to be conditioned on the health effect study design and the health effect parameter to be estimated.

  20. The contribution of temperature, exposure intensity and visible light to the inhibitory effect of irradiation on acute chlamydial infection.

    PubMed

    Marti, Hanna; Blenn, Christian; Borel, Nicole

    2015-12-01

    Water-filtered infrared A (wIRA) is radiation with a spectrum ranging from 780 to 1400 nm. Chlamydiaceae are obligate intracellular bacteria associated with various diseases in both animals and humans. A recent in vitro study demonstrated that wIRA combined with visible light (wIRA/VIS) has potential as a non-chemical method for the treatment of chlamydial infections without adversely affecting the cell viability. The aim of this study was to investigate the influence of various factors on the effect of wIRA/VIS on acute chlamydial infection, namely the impact of temperature, exposure intensity and infectious dose (multiplicity of infection) as well as the efficacy of the visible light component.We demonstrate that non-thermal effects contribute to the inhibition of acute chlamydial infection. Visible light enhances the inhibitory effect of wIRA on extracellular bacteria (elementary bodies or EBs).Moreover, the inhibitory effect of wIRA/VIS following treatment of EBs prior to infection correlated with increased irradiation intensity. The infectivity of mature chlamydial inclusions was significantly reduced upon wIRA/VIS exposure at all irradiation intensities investigated, suggesting the contribution of host cell factors to the anti-chlamydial effect of wIRA/VIS in the late stage of the developmental cycle. The effect of irradiation was not influenced by the infectious dose.

  1. Cellular distribution of uranium after acute exposure of renal epithelial cells: SEM, TEM and nuclear microscopy analysis

    NASA Astrophysics Data System (ADS)

    Carrière, Marie; Gouget, Barbara; Gallien, Jean-Paul; Avoscan, Laure; Gobin, Renée; Verbavatz, Jean-Marc; Khodja, Hicham

    2005-04-01

    The major health effect of uranium exposure has been reported to be chemical kidney toxicity, functional and histological damages being mainly observed in proximal tubule cells. Uranium enters the proximal tubule as uranyl-bicarbonate or uranyl-citrate complexes. The aim of our research is to investigate the mechanisms of uranium toxicity, intracellular accumulation and repartition after acute intoxication of rat renal proximal tubule epithelial cells, as a function of its chemical form. Microscopic observations of renal epithelial cells after acute exposure to uranyl-bicarbonate showing the presence of intracellular precipitates as thin needles of uranyl-phosphate localized in cell lysosomes have been published. However the initial site of precipitates formation has not been identified yet: they could either be formed outside the cells before internalization, or directly inside the cells. Uranium solubility as a function and initial concentration was specified by ICP-MS analysis of culture media. In parallel, uranium uptake and distribution in cell monolayers exposed to U-bicarbonate was investigated by nuclear microprobe analyses. Finally, the presence of uranium precipitates was tested out by scanning electron microscopic observations (SEM), while extracellular and/or intracellular precipitates were observed on thin sections of cells by transmission electron microscopy (TEM).

  2. Acute exposure to cold rapidly increases the number of nucleotide binding sites, but not proton conductance, in BAT mitochondria

    SciTech Connect

    Swick, A.G.; Swick, R.W.

    1986-03-01

    Studies on the effect of acute cold exposure of rats on brown adipose tissue (BAT) thermogenic activity have produced equivocal results. Therefore, the authors have reexamined the response of BAT mitochondria to abrupt changes in environmental temperature. /sup 3/H-GDP binding to BAT mitochondria increased more than 2-fold in 20 min when rats were moved from 27/sup 0/C to 4/sup 0/C. When rats housed at 4/sup 0/C for 2 h were returned to 27/sup 0/C, GDP binding decreased sharply in 20 min and returned to control levels in 2 h. On the other hand, GDP-inhibitable proton conductance, as measured by passive swelling in isotonic K-acetate of KCl buffers, was unaffected by brief cold exposure but more than doubled in rats kept at 4/sup 0/C for 10 days. The authors conclude that GDP-inhibitable swelling may be more indicative of uncoupling protein concentration whereas thermogenic activity is more appropriately indicated by GDP binding. GDP binding to BAT mitochondria from warm and acutely cold treated rats was not altered by prior swelling of the mitochondria nor by freeze-thawing the mitochondria before assay. Therefore, alterations of the number of GDP binding sites may not be a result of conformational changes of the mitochondril membrane.

  3. Effect of acute hexavalent chromium exposure on pituitary-thyroid axis of a freshwater fish, Channa punctatus (Bloch).

    PubMed

    Mishra, Ashish K; Mohanty, Banalata

    2015-01-01

    Acute exposure to hexavalent chromium (10 mg L(-1) , 20 mg L(-1) , and 40 mg L(-1) potassium dichromate for 96 h) dose-dependently affected the pituitary-thyroid axis of teleost, Channa punctatus. Significant hypertrophy of the thyroid follicle was observed in 20 mg L(-1) and 40 mg L(-1) groups; the follicular epithelium was however hypertrophied only in 40 mg L(-1) group. The colloid depletion in the lumen of thyroid follicle was evident in 20 mg L(-1) and 40 mg L(-1) groups. Serum thyroid hormones (thyroxine/T4 and triiodothyronine/T3) level increased significantly at both the higher doses. Increased immunointensity and significant hypertrophy of the pituitary thyrotrophs (anti TSHβ-immunoreactive cells) was observed in both 20 mg L(-1) and 40 mg L(-1) chromium-exposed fish. The increased thyroid hormones secretion observed in this study might be an adaptive response of the pituitary-thyroid axis under acute chromium-induced stress condition to maintain homeostasis. The long-term Cr(VI) exposures, however, may lead to attenuation/exhaustion of the pituitary-thyroid axis and pose serious threat to fish health and affect their population.

  4. Acute stress, depression, and anxiety symptoms among English and Spanish speaking children with recent trauma exposure.

    PubMed

    Barber, Beth A; Kohl, Krista L; Kassam-Adams, Nancy; Gold, Jeffrey I

    2014-03-01

    A growing literature suggests the clinical importance of acute stress disorder symptoms in youth following potentially traumatic events. A multisite sample of English and Spanish speaking children and adolescents (N = 479) between the ages of 8-17, along with their caregivers completed interviews and self-report questionnaires between 2 days and 1 month following the event. The results indicate that children with greater total acute stress symptoms reported greater depressive (r = .41, p < .01) and anxiety symptoms (r = .53, p < .01). Examining specific acute stress subscales, reexperiencing was correlated with anxiety (r = .47, p < .01) and arousal was correlated with depression (r = .50, p < .01) and anxiety (r = .55, p < .01). Age was inversely associated with total acute stress symptoms (r = -.24, p < .01), reexperiencing (r = -.17, p < .01), avoidance (r = -.27, p < .01), and arousal (r = -.19, p < .01) and gender was related to total anxiety symptoms (Spearman's ρ = .17, p < .01). The current study supports the importance of screening acute stress symptoms and other mental health outcomes following a potentially traumatic event in children and adolescents. Early screening may enable clinicians to identify and acutely intervene to support children's psychological and physical recovery.

  5. Combining near- and far-field exposure for an organ-specific and whole-body RF-EMF proxy for epidemiological research: a reference case.

    PubMed

    Lauer, Oliver; Frei, Patrizia; Gosselin, Marie-Christine; Joseph, Wout; Röösli, Martin; Fröhlich, Jürg

    2013-07-01

    A framework for the combination of near-field (NF) and far-field (FF) radio frequency electromagnetic exposure sources to the average organ and whole-body specific absorption rates (SARs) is presented. As a reference case, values based on numerically derived SARs for whole-body and individual organs and tissues are combined with realistic exposure data, which have been collected using personal exposure meters during the Swiss Qualifex study. The framework presented can be applied to any study region where exposure data is collected by appropriate measurement equipment. Based on results derived from the data for the region of Basel, Switzerland, the relative importance of NF and FF sources to the personal exposure is examined for three different study groups. The results show that a 24-h whole-body averaged exposure of a typical mobile phone user is dominated by the use of his or her own mobile phone when a Global System for Mobile Communications (GSM) 900 or GSM 1800 phone is used. If only Universal Mobile Telecommunications System (UMTS) phones are used, the user would experience a lower exposure level on average caused by the lower average output power of UMTS phones. Data presented clearly indicate the necessity of collecting band-selective exposure data in epidemiological studies related to electromagnetic fields.

  6. Rapid communication: acute exposure to mercury from dental amalgam does not affect the levels of C-reactive protein or interleukin-6 in peripheral blood.

    PubMed

    Sandborgh-Englund, Gunilla; af Geijersstam, Eric; Loftenius, Annika

    2003-03-28

    In a previous study, a significant increase in serum interleukin-6 (IL-6) was apparent after an acute low-level mercury (Hg) exposure, achieved by removal of amalgam fillings (Loftenius et al., 1998). In the present study, 11 healthy volunteers were exposed to an oral dose of 1 g of pulverized amalgam powder. Hg, IL-6, and C-reactive protein (CRP) levels in plasma were followed before and up to 72 h after exposure. The Hg levels were low and stable prior to exposure and increased rapidly after exposure. The median Hg increase was 12.9 nmol/L, which is considerably higher than in the previous study. No significant change over time was observed for IL-6 and CRP levels. Therefore, it cannot be ruled out that our previous finding of increasing IL-6 levels detected after acute low-level Hg exposure through removal of amalgam fillings was due to the dental treatment per se.

  7. Renal excretion in coho salmon (Oncorhynchus kisutch) after acute exposure to 3-trifluoromethyl-4-nitrophenol

    USGS Publications Warehouse

    Hunn, J.B.; Allen, J.L.

    1975-01-01

    COHO SALMON (ONCORHYNCHUS KISUTCH) EXPOSED TO AN ACUTE, SUBLETHAL CONCENTRATION OF 3-TRIFLUOROMETHLY 1-4 NITROPHENOL (TFM) EXHIBITED AN INCREASED OUTPUT OF URINE WHEN COMPARED WITH CONTROLS, BUT THE URINARY EXCRETION OF NA, K, CA, MG AND C1 WAS NOT AFFECTED. ABOUT 35 TIMES MORE CONJUGATED TFM THAN FREE TFM WAS EXCRETED DURING THE 24-HOUR STUDY PERIOD.

  8. NEUROCHEMICAL EFFECTS OF CHRONIC DIETARY AND REPEATED HIGH-LEVEL ACUTE EXPOSURE TO CHLORPYRIFOS IN RATS.

    EPA Science Inventory

    Lots of information is available surrounding the acute toxicity of anticholinesterase pesticides, but these have been very few detailed studies on the chronic effects of these pesticides. Humans are exposed on a chronic basis and some humans believe that have been affected advers...

  9. Acute renal failure in 2 adult llamas after exposure to Oak trees (Quercus spp.)

    PubMed Central

    Chamorro, Manuel F.; Passler, Thomas; Joiner, Kellye; Poppenga, Robert H.; Bayne, Jenna; Walz, Paul H.

    2013-01-01

    Two adult llamas (Lama glama) previously exposed to oak trees (Quercus spp.) were presented with a history of depression and anorexia. Clinicopathological abnormalities included severe gastroenteritis, acute renal failure, and increased liver enzymes. This is believed to be the first report of oak toxicosis in South American camelids. PMID:23814303

  10. Acute renal failure in 2 adult llamas after exposure to Oak trees (Quercus spp.).

    PubMed

    Chamorro, Manuel F; Passler, Thomas; Joiner, Kellye; Poppenga, Robert H; Bayne, Jenna; Walz, Paul H

    2013-01-01

    Two adult llamas (Lama glama) previously exposed to oak trees (Quercus spp.) were presented with a history of depression and anorexia. Clinicopathological abnormalities included severe gastroenteritis, acute renal failure, and increased liver enzymes. This is believed to be the first report of oak toxicosis in South American camelids.

  11. Clinical and pathological manifestations of cardiovascular disease in rat models: the influence of acute ozone exposure

    EPA Science Inventory

    This paper shows that rat models of cardiovascular diseases have differential degrees of underlying pathologies at a young age. Rodent models of cardiovascular diseases (CVD) and metabolic disorders are used for examining susceptibility variations to environmental exposures. How...

  12. ACUTE EXPOSURE TO PARTICULATE MATTER IN A RAT MODEL OF HEART FAILURE

    EPA Science Inventory

    Human exposure to ambient particulate matter (PM) has been linked to cardiovascular morbidity and mortality. This association strengthens in people with preexisting cardiopulmonary diseases—especially heart failure (HF). To better characterize the cardiovascular effects of PM, we...

  13. The Effects of In Vivo Acute Exposure to Polychlorinatedbiphenyls on Free and Total Thyroxine in Rats

    EPA Science Inventory

    Hypothyroxinemia in rats has been well documented as a result of either developmental or adult exposure to polychlorinated biphenyls (PCBs). Hypothetical mechanisms for this include induction of hepatic catabolic enzymes and cellular hormone transporters, and/or interference wit...

  14. Acute Phase Response and Metabolic Syndrome Biomarkers of Libby Asbestos Exposure

    EPA Science Inventory

    Identification of biomarkers assists in the disease diagnosis and environmental health risk assessment. Exposure to Libby amphibole (LA) has been associated with increased cardiovascular mortality. We hypothesized that rats exposed to LA would present a unique serum proteomic pro...

  15. Acute Phase Response, Inflammation and Metabolic Syndrome Biomarkers of Libby Asbestos Exposure

    EPA Science Inventory

    Background: Identification of biomarkers assists in the diagnosis of disease and the assessment of health risks from environmental exposures. Objective: We hypothesized that rats exposed to Libby amphibole (LA) would present with a unique serum proteomic profile which could help ...

  16. Exploring Uncoupling Proteins and Antioxidant Mechanisms under Acute Cold Exposure in Brains of Fish

    PubMed Central

    Lucassen, Magnus; Schmidt, Maike M.; Dringen, Ralf; Abele, Doris; Hwang, Pung-Pung

    2011-01-01

    Exposure to fluctuating temperatures accelerates the mitochondrial respiration and increases the formation of mitochondrial reactive oxygen species (ROS) in ectothermic vertebrates including fish. To date, little is known on potential oxidative damage and on protective antioxidative defense mechanisms in the brain of fish under cold shock. In this study, the concentration of cellular protein carbonyls in brain was significantly increased by 38% within 1 h after cold exposure (from 28°C to 18°C) of zebrafish (Danio rerio). In addition, the specific activity of superoxide dismutase (SOD) and the mRNA level of catalase (CAT) were increased after cold exposure by about 60% (6 h) and by 60%–90% (1 and 24 h), respectively, while the specific glutathione content as well as the ratio of glutathione disulfide to glutathione remained constant and at a very low level. In addition, cold exposure increased the protein level of hypoxia-inducible factor (HIF) by about 50% and the mRNA level of the glucose transporter zglut3 in brain by 50%–100%. To test for an involvement of uncoupling proteins (UCPs) in the cold adaptation of zebrafish, five UCP members were annotated and identified (zucp1-5). With the exception of zucp1, the mRNA levels of the other four zucps were significantly increased after cold exposure. In addition, the mRNA levels of four of the fish homologs (zppar) of the peroxisome proliferator-activated receptor (PPAR) were increased after cold exposure. These data suggest that PPARs and UCPs are involved in the alterations observed in zebrafish brain after exposure to 18°C. The observed stimulation of the PPAR-UCP axis may help to prevent oxidative damage and to maintain metabolic balance and cellular homeostasis in the brains of ectothermic zebrafish upon cold exposure. PMID:21464954

  17. Exploring uncoupling proteins and antioxidant mechanisms under acute cold exposure in brains of fish.

    PubMed

    Tseng, Yung-Che; Chen, Ruo-Dong; Lucassen, Magnus; Schmidt, Maike M; Dringen, Ralf; Abele, Doris; Hwang, Pung-Pung

    2011-03-25

    Exposure to fluctuating temperatures accelerates the mitochondrial respiration and increases the formation of mitochondrial reactive oxygen species (ROS) in ectothermic vertebrates including fish. To date, little is known on potential oxidative damage and on protective antioxidative defense mechanisms in the brain of fish under cold shock. In this study, the concentration of cellular protein carbonyls in brain was significantly increased by 38% within 1 h after cold exposure (from 28 °C to 18 °C) of zebrafish (Danio rerio). In addition, the specific activity of superoxide dismutase (SOD) and the mRNA level of catalase (CAT) were increased after cold exposure by about 60% (6 h) and by 60%-90% (1 and 24 h), respectively, while the specific glutathione content as well as the ratio of glutathione disulfide to glutathione remained constant and at a very low level. In addition, cold exposure increased the protein level of hypoxia-inducible factor (HIF) by about 50% and the mRNA level of the glucose transporter zglut3 in brain by 50%-100%. To test for an involvement of uncoupling proteins (UCPs) in the cold adaptation of zebrafish, five UCP members were annotated and identified (zucp1-5). With the exception of zucp1, the mRNA levels of the other four zucps were significantly increased after cold exposure. In addition, the mRNA levels of four of the fish homologs (zppar) of the peroxisome proliferator-activated receptor (PPAR) were increased after cold exposure. These data suggest that PPARs and UCPs are involved in the alterations observed in zebrafish brain after exposure to 18°C. The observed stimulation of the PPAR-UCP axis may help to prevent oxidative damage and to maintain metabolic balance and cellular homeostasis in the brains of ectothermic zebrafish upon cold exposure.

  18. Interaction of Exposure Concentration and Duration in Determining Acute Toxic Effects of Sarin Vapor in Rats

    DTIC Science & Technology

    2002-01-01

    effects occur in the rat and 2) develop models for predicting dose - response effects of low CW agent concentrations as a function of exposure duration. Sarin...effective concentrations for lethality (LC50) and miosis (EC50) in 50% of the exposed population and corresponding dose - response slopes were determined for...exposure duration (i.e., the CT for 50% lethality exposed population and corresponding dose - response slope was not constant over time). A plot of Log (LCt50

  19. Acute exposure to high environmental ammonia (HEA) triggers the emersion response in the green shore crab.

    PubMed

    Zimmer, Alex M; Wood, Chris M

    2017-02-01

    The physiological effects of high environmental ammonia (HEA) exposure have been well documented in many aquatic species. In particular, it has recently been demonstrated that exposure to ammonia in fish leads to a similar hyperventilatory response as observed during exposure to hypoxia. In littoral crabs, such as the green crab (Carcinus maenas), exposure to severe hypoxia triggers an emersion response whereby crabs escape hypoxia to breathe air. We hypothesized that exposure to HEA in green crabs would lead to a similar behavioural response which is specific to ammonia. Using an experimental arena containing a rock bed onto which crabs could emerse, we established that exposure to HEA (4mmol/l NH4HCO3) for 15min triggers emersion in crabs. In experiments utilizing NaHCO3 controls and NH4HCO3 injections, we further determined that emersion was triggered specifically by external ammonia and was independent of secondary acid-base or respiratory disturbances caused by HEA. We then hypothesized that emersion from HEA provides a physiological benefit, similar to emersion from hypoxia. Exposure to 15min of HEA without emersion (no rock bed present) caused significant increases in arterial haemolymph total ammonia (Tamm), pH, and [HCO3(-)]. When emersion was allowed, arterial haemolymph Tamm and [HCO3(-)] increased, but no alkalosis developed. Moreover, emersion decreased haemolymph partial pressure of NH3 relative to crabs which could not emerse. Overall, we demonstrate a novel behavioural response to HEA exposure in crabs which we propose may share similar mechanistic pathways with the emersion response triggered by hypoxia.

  20. Transient activation of microglia following acute alcohol exposure in developing mouse neocortex is primarily driven by BAX-dependent neurodegeneration.

    PubMed

    Ahlers, Katelin E; Karaçay, Bahri; Fuller, Leah; Bonthius, Daniel J; Dailey, Michael E

    2015-10-01

    Fetal alcohol exposure is the most common known cause of preventable mental retardation, yet we know little about how microglia respond to, or are affected by, alcohol in the developing brain in vivo. Using an acute (single day) model of moderate (3 g/kg) to severe (5 g/kg) alcohol exposure in postnatal day (P) 7 or P8 mice, we found that alcohol-induced neuroapoptosis in the neocortex is closely correlated in space and time with the appearance of activated microglia near dead cells. The timing and molecular pattern of microglial activation varied with the level of cell death. Although microglia rapidly mobilized to contact and engulf late-stage apoptotic neurons, apoptotic bodies temporarily accumulated in neocortex, suggesting that in severe cases of alcohol toxicity the neurodegeneration rate exceeds the clearance capacity of endogenous microglia. Nevertheless, most dead cells were cleared and microglia began to deactivate within 1-2 days of the initial insult. Coincident with microglial activation and deactivation, there was a transient increase in expression of pro-inflammatory factors, TNFα and IL-1β, after severe (5 g/kg) but not moderate (3 g/kg) EtOH levels. Alcohol-induced microglial activation and pro-inflammatory factor expression were largely abolished in BAX null mice lacking neuroapoptosis, indicating that microglial activation is primarily triggered by apoptosis rather than the alcohol. Therefore, acute alcohol exposure in the developing neocortex causes transient microglial activation and mobilization, promoting clearance of dead cells and tissue recovery. Moreover, cortical microglia show a remarkable capacity to rapidly deactivate following even severe neurodegenerative insults in the developing brain.

  1. Effect of Acute Noise Exposure on Salivary Cortisol: A Randomized Controlled Trial.

    PubMed

    Pouryaghoub, Gholamreza; Mehrdad, Ramin; Valipouri, Alireza

    2016-10-01

    Cardiovascular adverse effects are interesting aspects of occupational noise exposure. One possible mechanism of these effects is an alternation in hypothalamic-pituitary-adrenal axis. Our aim was to measure salivary cortisol response to relatively high-intensity noise exposure in a controlled randomized trial study. We exposed 50 male volunteers to 90 dBA noise for 20 minutes and compared their level of salivary cortisol with 50 non-exposed controls. Salivary samples obtained before and after exposure. Before intervention means (SD) salivary cortisol level were 3.24 (0.47)ng/ml and 3.25 (0.41)ng/ml for exposed and non-exposed groups respectively. Mean salivary cortisol level increased to 4.17 ng/mlafter intervention in exposure group. This increment was statistically significant (P=0.00). Mean salivary cortisol level of the non-exposed group had statistically non-significant decrement after this period (0.2 ng/ml). The difference between salivary cortisol level of non-exposed and exposed groups after the intervention was statistically significant. Noise exposure may affect the hypothalamic-pituitary-adrenal axis activity, and this may be one of the mechanisms of noise exposure cardiovascular effects.

  2. Evaluation of the respiratory tract after acute exposure to a pyrotechnically generated aerosol fire suppressant.

    PubMed

    Smith, E A; Kimmel, E C; English, J H; Bowen, L E; Reboulet, J E; Carpenter, R L

    1997-01-01

    Fischer 344 rats (250-300 g) were exposed to the resulting aerosols from the pyrolysis of Spectrex Fire Extinguishant (SFE) Formulation A, a pyrotechnically generated aerosol fire suppressant, at a loading equivalent of 50 or 80 g m(-3) air for 15 or 60 min. Exposures were conducted in a 700-1 whole-body inhalation chamber under static conditions. The chamber atmosphere was analyzed for mass aerosol concentration and size distribution. Clinical observations were taken throughout the exposure. Animals were euthanized at 1 h, 6 h, 24 h, 7 days or 14 days post-exposure and underwent histopathological examination, enzyme analyses and wet/dry lung weight determination. No deaths occurred during the study. Animals exhibited signs of dyspnea, coughing, lack of coordination and lethargy during each exposure. These signs became more pronounced as the load and exposure length increased. No lesions were noted in the trachea, lung, heart or abdominal organs upon gross examination. A reversible pulmonary edema and olfactory necrosis were observed only in those animals exposed to an SFE loading equivalent to 80 g m(-3) for 60 min. Protein concentrations increased in the bronchoalveolar lavage but no changes in enzyme levels were observed. There was no significant difference between the control groups and the exposure groups for wet/dry lung weight determination.

  3. Effect of acute cadmium exposure on metal accumulation and oxidative stress biomarkers of Sparus aurata.

    PubMed

    Souid, Ghada; Souayed, Nouha; Yaktiti, Fatma; Maaroufi, Khira

    2013-03-01

    Cadmium (Cd) is a non-essential metal which could be toxic in traces for aquatic species. Increasing Cd concentrations in sea water is mainly related to waste waters provided from growing industrial and agricultural activities. The present study investigated the accumulation of Cd (0.5mg/L) in different tissues of Sparus aurata under a short term exposure (2, 4 and 24h) using the atomic absorption. This work investigated also the impact of the metal on oxidative stress biomarkers and acetyl cholinesterase activity (AchE). Our results showed that Cd accumulation in different tissues depends largely on the length of the exposure period to the metal. Indeed, the highest concentrations were obtained after 24h. Cd accumulation in tissues was in the following order: intestines > liver > gills > dorsal muscle. Cadmium administration increased significantly catalase activity (CAT), glutathione level (GSH) and malondialdehyde production (MDA) after 24h of exposure. In contrast, AchE activity was decreased after the same period of exposure to the metal. There were no significant changes in oxidative stress biomarkers after 2 and 4h of exposure, except for superoxide dismutase (SOD) activity which attained the highest level after 4h. These results suggest that short-term exposure of Sparus aurata to Cd (0.5mg/L) induced an important metal accumulation in intestine and a notable oxidative stress response.

  4. Mimicking exposures to acute and lifetime concentrations of inhaled silver nanoparticles by two different in vitro approaches

    PubMed Central

    Herzog, Fabian; Loza, Kateryna; Balog, Sandor; Clift, Martin J D; Epple, Matthias; Gehr, Peter; Petri-Fink, Alke

    2014-01-01

    Summary In the emerging market of nano-sized products, silver nanoparticles (Ag NPs) are widely used due to their antimicrobial properties. Human interaction with Ag NPs can occur through the lung, skin, gastrointestinal tract, and bloodstream. However, the inhalation of Ag NP aerosols is a primary concern. To study the possible effects of inhaled Ag NPs, an in vitro triple cell co-culture model of the human alveolar/airway barrier (A549 epithelial cells, human peripheral blood monocyte derived dendritic and macrophage cells) together with an air–liquid interface cell exposure (ALICE) system was used in order to reflect a real-life exposure scenario. Cells were exposed at the air–liquid interface (ALI) to 0.03, 0.3, and 3 µg Ag/cm2 of Ag NPs (diameter 100 nm; coated with polyvinylpyrrolidone: PVP). Ag NPs were found to be highly aggregated within ALI exposed cells with no impairment of cell morphology. Furthermore, a significant increase in release of cytotoxic (LDH), oxidative stress (SOD-1, HMOX-1) or pro-inflammatory markers (TNF-α, IL-8) was absent. As a comparison, cells were exposed to Ag NPs in submerged conditions to 10, 20, and 30 µg Ag/mL. The deposited dose per surface area was estimated by using a dosimetry model (ISDD) to directly compare submerged vs ALI exposure concentrations after 4 and 24 h. Unlike ALI exposures, the two highest concentrations under submerged conditions promoted a cytotoxic and pro-inflammatory response after 24 h. Interestingly, when cell cultures were co-incubated with lipopolysaccharide (LPS), no synergistic inflammatory effects were observed. By using two different exposure scenarios it has been shown that the ALI as well as the suspension conditions for the lower concentrations after 4 h, reflecting real-life concentrations of an acute 24 h exposure, did not induce any adverse effects in a complex 3D model mimicking the human alveolar/airway barrier. However, the highest concentrations used in the ALI setup, as well as

  5. Acute exposure to selenium disrupts associative conditioning and long-term memory recall in honey bees (Apis mellifera).

    PubMed

    Burden, Christina M; Elmore, Christopher; Hladun, Kristen R; Trumble, John T; Smith, Brian H

    2016-05-01

    A plethora of toxic compounds - including pesticides, heavy metals, and metalloids - have been detected in honey bees (Apis mellifera) and their colonies. One such compound is selenium, which bees are exposed to by consuming nectar and pollen from flowers grown in contaminated areas. Though selenium is lethal at high concentrations, sublethal exposure may also impair honey bees' ability to function normally. Examining the effect of selenium exposure on learning and memory provides a sensitive assay with which to identify sublethal effects on honey bee health and behavior. To determine whether sublethal selenium exposure causes learning and memory deficits, we used proboscis extension reflex conditioning coupled with recall tests 30min and 24h post-conditioning. We exposed forager honey bees to a single sublethal dose of selenium, and 3h later we used an olfactory conditioning assay to train the bees to discriminate between one odor associated with sucrose-reinforcement and a second unreinforced odor. Following conditioning we tested short- and long-term recall of the task. Acute exposure to as little as 1.8ng of an inorganic form of selenium (sodium selenate) before conditioning caused a reduction in behavioral performance during conditioning. And, exposure to 18ng of either an inorganic form (sodium selenate) or an organic form (methylseleno-l-cysteine) of selenium caused a reduction in the bees' performance during the long-term recall test. These concentrations of selenium are lower than those found in the nectar of plants grown in selenium-contaminated soil, indicating that even low-grade selenium toxicity produces significant learning and memory impairments. This may reduce foragers' ability to effectively gather resources for the colony or nurse bees' ability to care for and maintain a healthy colony.

  6. Time course of systemic oxidative stress and inflammatory response induced by an acute exposure to Residual Oil Fly Ash.

    PubMed

    Marchini, T; Magnani, N D; Paz, M L; Vanasco, V; Tasat, D; González Maglio, D H; Alvarez, S; Evelson, P A

    2014-01-15

    It is suggested that systemic oxidative stress and inflammation play a central role in the onset and progression of cardiovascular diseases associated with the exposure to particulate matter (PM). The aim of this work was to evaluate the time changes of systemic markers of oxidative stress and inflammation, after an acute exposure to Residual Oil Fly Ash (ROFA). Female Swiss mice were intranasally instilled with a ROFA suspension (1.0mg/kg body weight) or saline solution, and plasma levels of oxidative damage markers [thiobarbituric acid reactive substances (TBARSs) and protein carbonyls], antioxidant status [reduced (GSH) and oxidized (GSSG) glutathione, ascorbic acid levels, and superoxide dismutase (SOD) activity], cytokines levels, and intravascular leukocyte activation were evaluated after 1, 3 or 5h of exposure. Oxidative damage to lipids and decreased GSH/GSSG ratio were observed in ROFA-exposed mice as early as 1h. Afterwards, increased protein oxidation, decreased ascorbic acid content and SOD activity were found in this group at 3h. The onset of an adaptive response was observed at 5h after the ROFA exposure, as indicated by decreased TBARS plasma content and increased SOD activity. The observed increase in oxidative damage to plasma macromolecules, together with systemic antioxidants depletion, may be a consequence of a systemic inflammatory response triggered by the ROFA exposure, since increased TNF-α and IL-6 plasma levels and polymorphonuclear leukocytes activation was found at every evaluated time point. These findings contribute to the understanding of the increase in cardiovascular morbidity and mortality, in association with environmental PM inhalation.

  7. Maternal Benzene Exposure during Pregnancy and Risk of Childhood Acute Lymphoblastic Leukemia: A Meta-Analysis of Epidemiologic Studies

    PubMed Central

    Li, Zhen; Zhu, Jie; Bi, Yongyi; Bai, YuE; Wang, Hong

    2014-01-01

    Background The prevalence of childhood leukemia is increasing rapidly all over the world. However, studies on maternal benzene exposure during pregnancy and childhood acute lymphoblastic leukemia (ALL) have not been systematically assessed. Therefore, we performed a meta-analysis to investigate the association between maternal solvent, paint, petroleum exposure, and smoking during pregnancy and risk of childhood ALL. Methods Relevant studies up to September 1st, 2013 were identified by searching the PubMed, EMBASE, Cochrane library and the Web of Science databases. The effects were pooled using either fixed or random effect models based on the heterogeneity of the studies. Results Twenty-eight case-control studies and one cohort study were included for analysis, with a total of 16,695 cases and 1,472,786 controls involved. Pooled odds ratio (OR) with 95% confidence interval (CI) for ALL was 1.25 (1.09, 1.45) for solvent, 1.23 (1.02, 1.47) for paint, 1.42 (1.10, 1.84) for petroleum exposure, and 0.99 (0.93, 1.06) for maternal smoking during pregnancy. No publication bias was found in this meta-analysis and consistent results were observed for subgroup and sensitivity analyses. Conclusions Childhood ALL was associated with maternal solvent, paint, and petroleum exposure during pregnancy. No association was found between ALL and maternal smoking during pregnancy. Avoidance of maternal occupational and environmental benzene exposure during pregnancy could contribute to a decrease in the risk of childhood ALL. PMID:25333868

  8. Oxidative DNA damage after acute exposure to arsenite and monomethylarsonous acid in biomethylation-deficient human cells.

    PubMed

    Orihuela, Ruben; Kojima, Chikara; Tokar, Erik J; Person, Rachel J; Xu, Yuanyuan; Qu, Wei; Waalkes, Michael P

    2013-07-01

    The carcinogen inorganic arsenic (iAs) undergoes biomethylation (BMT) in some cells. The methylated metabolite, monomethylarsonous (MMA(3+)), may cause oxidative DNA damage (ODD). With chronic iAs exposure, BMT-competent cells show ODD while BMT-deficient do not. To further define these events, we studied ODD produced by acute iAs or MMA(3+) in the BMT-deficient human prostate cell line, RWPE-1. ODD, measured by the immuno-spin trapping method, was assessed after exposure to iAs or MMA(3+) alone, with the arsenic BMT inhibitor selenite or after glutathione (GSH) depletion. The expression of oxidative stress-related genes (HO-1, SOD-1, SOD-2, Nrf2 and Keap-1) was also assessed. Exposure to iAs at 24 h (0-20 µM), stimulated ODD only at levels above the LC50 of a 48 h exposure (17 µM). If iAs induced ODD, it also activated oxidative stress-related genes. Selenium did not alter iAs-induced ODD. MMA(3+) at 24 h (0-0.5 µM) caused ODD at levels below the LC50 of a 48 h exposure (1.5 µM), which were greatly increased by GSH depletion but not selenite. MMA(3+) induced ODD at levels not activating oxidant stress response genes. Overall, iAs induced ODD in BMT-deficient cells only at toxic levels. MMA(3+) caused ODD at non-toxic levels, independently of cellular BMT capacity and in a fashion not requiring further BMT.

  9. 2013 Space Radiation Standing Review Panel Status Review for: The Risk of Acute and Late Central Nervous System Effects from Radiation Exposure, The Risk of Acute Radiation Syndromes Due to Solar Particle Events (SPEs), The Risk Of Degenerative Tissue Or Other Health Effects From Radiation Exposure, and The Risk of Radiation Carcinogenesis

    NASA Technical Reports Server (NTRS)

    2014-01-01

    The Space Radiation Standing Review Panel (from here on referred to as the SRP) was impressed with the strong research program presented by the scientists and staff associated with NASA's Space Radiation Program Element and National Space Biomedical Research Institute (NSBRI). The presentations given on-site and the reports of ongoing research that were provided in advance indicated the potential Risk of Acute and Late Central Nervous System Effects from Radiation Exposure (CNS) and were extensively discussed by the SRP. This new data leads the SRP to recommend that a higher priority should be placed on research designed to identify and understand these risks at the mechanistic level. To support this effort the SRP feels that a shift of emphasis from Acute Radiation Syndromes (ARS) and carcinogenesis to CNS-related endpoints is justified at this point. However, these research efforts need to focus on mechanisms, should follow pace with advances in the field of CNS in general and should consider the specific comments and suggestions made by the SRP as outlined below. The SRP further recommends that the Space Radiation Program Element continue with its efforts to fill the vacant positions (Element Scientist, CNS Risk Discipline Lead) as soon as possible. The SRP also strongly recommends that NASA should continue the NASA Space Radiation Summer School. In addition to these broad recommendations, there are specific comments/recommendations noted for each risk, described in detail below.

  10. The influence of acute and 23 days of intermittent hypoxic exposures on the exercise-induced forehead sweating response.

    PubMed

    Kacin, Alan; Golja, Petra; Eiken, Ola; Tipton, Michael J; Mekjavic, Igor B

    2007-03-01

    The effect of acute and 23 days of intermittent exposures to normobaric hypoxia on the forehead sweating response during steady-state exercise was investigated. Eight endurance athletes slept in a normobaric hypoxic room for a minimum of 8 h per day at a simulated altitude equivalent to 2,700 m for 23 days (sleep high-train low regimen). Peak oxygen uptake (VO2(peak)) and peak work rate (WR(peak)) were determined under normoxic (20.9%O(2)) and hypoxic (13.5%O(2)) conditions prior to (pre-IHE), and immediately after (post-IHE) the intermittent hypoxic exposures (IHE). Also, each subject performed three 30-min cycle-ergometry bouts: (1) normoxic exercise at 50% WR(peak) attained in normoxia (control trial; CT); (2) hypoxic exercise at 50% WR(peak) attained in hypoxia (hypoxic relative trial; HRT) and (3) hypoxic exercise at the same absolute work rate as in CT (hypoxic absolute trial; HAT). Exposure to hypoxia induced a 33 and 37% decrease (P < 0.001) in (VO2(peak)) pre-IHE and post-IHE, respectively. Despite similar relative oxygen uptake during HAT pre-IHE and post-IHE, the ratings of perceived whole-body exertion decreased substantially (P < 0.05) post-IHE. Pre-IHE the sweat secretion on the forehead (m(sw)f) was greater (P < 0.01) in the HAT (2.60 (0.80) mg cm(-2) min(-1)) compared to the other two trials (CT = 1.87 (1.09) mg cm(-2) min(-1); HRT = 1.57 (0.82) mg cm(-2) min(-1)) despite a similar exercise-induced elevation in body temperatures, resulting in an augmented (P < 0.01) gain of the sweating response (m(sw)f/Delta T(re)). The augmented (m(sw)f) and m(sw)f/Delta T(re) during the HAT were no longer evident post-IHE. Thus, it appears that exercise sweating on the forehead is potentiated by acute exposure to hypoxia, an effect which can be abolished by 23 days of intermittent hypoxic exposures.

  11. Cardiac and mitochondrial dysfunction following acute pulmonary exposure to mountaintop removal mining particulate matter

    PubMed Central

    Nichols, Cody E.; Shepherd, Danielle L.; Knuckles, Travis L.; Thapa, Dharendra; Stricker, Janelle C.; Stapleton, Phoebe A.; Minarchick, Valerie C.; Erdely, Aaron; Zeidler-Erdely, Patti C.; Alway, Stephen E.; Nurkiewicz, Timothy R.

    2015-01-01

    Throughout the United States, air pollution correlates with adverse health outcomes, and cardiovascular disease incidence is commonly increased following environmental exposure. In areas surrounding active mountaintop removal mines (MTM), a further increase in cardiovascular morbidity is observed and may be attributed in part to particulate matter (PM) released from the mine. The mitochondrion has been shown to be central in the etiology of many cardiovascular diseases, yet its roles in PM-related cardiovascular effects are not realized. In this study, we sought to elucidate the cardiac processes that are disrupted following exposure to mountaintop removal mining particulate matter (PMMTM). To address this question, we exposed male Sprague-Dawley rats to PMMTM, collected within one mile of an active MTM site, using intratracheal instillation. Twenty-four hours following exposure, we evaluated cardiac function, apoptotic indices, and mitochondrial function. PMMTM exposure elicited a significant decrease in ejection fraction and fractional shortening compared with controls. Investigation into the cellular impacts of PMMTM exposure identified a significant increase in mitochondrial-induced apoptotic signaling, as reflected by an increase in TUNEL-positive nuclei and increased caspase-3 and -9 activities. Finally, a significant increase in mitochondrial transition pore opening leading to decreased mitochondrial function was identified following exposure. In conclusion, our data suggest that pulmonary exposure to PMMTM increases cardiac mitochondrial-associated apoptotic signaling and decreases mitochondrial function concomitant with decreased cardiac function. These results suggest that increased cardiovascular disease incidence in populations surrounding MTM mines may be associated with increased cardiac cell apoptotic signaling and decreased mitochondrial function. PMID:26497962

  12. Effect of acute pesticide exposure on bee spatial working memory using an analogue of the radial-arm maze

    NASA Astrophysics Data System (ADS)

    Samuelson, Elizabeth E. W.; Chen-Wishart, Zachary P.; Gill, Richard J.; Leadbeater, Ellouise

    2016-12-01

    Pesticides, including neonicotinoids, typically target pest insects by being neurotoxic. Inadvertent exposure to foraging insect pollinators is usually sub-lethal, but may affect cognition. One cognitive trait, spatial working memory, may be important in avoiding previously-visited flowers and other spatial tasks such as navigation. To test this, we investigated the effect of acute thiamethoxam exposure on spatial working memory in the bumblebee Bombus terrestris, using an adaptation of the radial-arm maze (RAM). We first demonstrated that bumblebees use spatial working memory to solve the RAM by showing that untreated bees performed significantly better than would be expected if choices were random or governed by stereotyped visitation rules. We then exposed bees to either a high sub-lethal positive control thiamethoxam dose (2.5 ng‑1 bee), or one of two low doses (0.377 or 0.091 ng‑1) based on estimated field-realistic exposure. The high dose caused bees to make more and earlier spatial memory errors and take longer to complete the task than unexposed bees. For the low doses, the negative effects were smaller but statistically significant, and dependent on bee size. The spatial working memory impairment shown here has the potential to harm bees exposed to thiamethoxam, through possible impacts on foraging efficiency or homing.

  13. Acute exposure to GSM 900-MHz electromagnetic fields induces glial reactivity and biochemical modifications in the rat brain.

    PubMed

    Mausset-Bonnefont, Anne-Laure; Hirbec, Hélène; Bonnefont, Xavier; Privat, Alain; Vignon, Jacques; de Sèze, René

    2004-12-01

    The worldwide proliferation of mobile phones raises the question of the effects of 900-MHz electromagnetic fields (EMF) on the brain. Using a head-only exposure device in the rat, we showed that a 15-min exposure to 900-MHz pulsed microwaves at a high brain-averaged power of 6 W/kg induced a strong glial reaction in the brain. This effect, which suggests neuronal damage, was particularly pronounced in the striatum. Moreover, we observed significant and immediate effects on the Kd and Bmax values of N-methyl-D-aspartate (NMDA) and GABA(A) receptors as well as on dopamine transporters. Decrease of the amount of NMDA receptors at the postsynaptic membrane is also reported. Although we showed that the rat general locomotor behavior was not significantly altered on the short term, our results provide the first evidence for rapid cellular and molecular alterations in the rat brain after an acute exposure to high power GSM (Global System for Mobile communication) 900-MHz microwaves.

  14. Single- and double-strand DNA breaks in rat brain cells after acute exposure to radiofrequency electromagnetic radiation.

    PubMed

    Lai, H; Singh, N P

    1996-04-01

    We investigated the effects of acute (2-h) exposure to pulsed (2-micros pulse width, 500 pulses s(-1)) and continuous wave 2450-MHz radiofrequency electromagnetic radiation on DNA strand breaks in brain cells of rat. The spatial averaged power density of the radiation was 2mW/cm2, which produced a whole-body average-specific absorption rate of 1.2W/kg. Single- and double-strand DNA breaks in individual brain cells were measured at 4h post-exposure using a microgel electrophoresis assay. An increase in both types of DNA strand breaks was observed after exposure to either the pulsed or continuous-wave radiation, No significant difference was observed between the effects of the two forms of radiation. We speculate that these effects could result from a direct effect of radiofrequency electromagnetic energy on DNA molecules and/or impairment of DNA-damage repair mechanisms in brain cells. Our data further support the results of earlier in vitro and in vivo studies showing effects of radiofrequency electromagnetic radiation on DNA.

  15. Effect of acute pesticide exposure on bee spatial working memory using an analogue of the radial-arm maze

    PubMed Central

    Samuelson, Elizabeth E. W.; Chen-Wishart, Zachary P.; Gill, Richard J.; Leadbeater, Ellouise

    2016-01-01

    Pesticides, including neonicotinoids, typically target pest insects by being neurotoxic. Inadvertent exposure to foraging insect pollinators is usually sub-lethal, but may affect cognition. One cognitive trait, spatial working memory, may be important in avoiding previously-visited flowers and other spatial tasks such as navigation. To test this, we investigated the effect of acute thiamethoxam exposure on spatial working memory in the bumblebee Bombus terrestris, using an adaptation of the radial-arm maze (RAM). We first demonstrated that bumblebees use spatial working memory to solve the RAM by showing that untreated bees performed significantly better than would be expected if choices were random or governed by stereotyped visitation rules. We then exposed bees to either a high sub-lethal positive control thiamethoxam dose (2.5 ng−1 bee), or one of two low doses (0.377 or 0.091 ng−1) based on estimated field-realistic exposure. The high dose caused bees to make more and earlier spatial memory errors and take longer to complete the task than unexposed bees. For the low doses, the negative effects were smaller but statistically significant, and dependent on bee size. The spatial working memory impairment shown here has the potential to harm bees exposed to thiamethoxam, through possible impacts on foraging efficiency or homing. PMID:27958350

  16. Effect of acute pesticide exposure on bee spatial working memory using an analogue of the radial-arm maze.

    PubMed

    Samuelson, Elizabeth E W; Chen-Wishart, Zachary P; Gill, Richard J; Leadbeater, Ellouise

    2016-12-13

    Pesticides, including neonicotinoids, typically target pest insects by being neurotoxic. Inadvertent exposure to foraging insect pollinators is usually sub-lethal, but may affect cognition. One cognitive trait, spatial working memory, may be important in avoiding previously-visited flowers and other spatial tasks such as navigation. To test this, we investigated the effect of acute thiamethoxam exposure on spatial working memory in the bumblebee Bombus terrestris, using an adaptation of the radial-arm maze (RAM). We first demonstrated that bumblebees use spatial working memory to solve the RAM by showing that untreated bees performed significantly better than would be expected if choices were random or governed by stereotyped visitation rules. We then exposed bees to either a high sub-lethal positive control thiamethoxam dose (2.5 ng(-1) bee), or one of two low doses (0.377 or 0.091 ng(-1)) based on estimated field-realistic exposure. The high dose caused bees to make more and earlier spatial memory errors and take longer to complete the task than unexposed bees. For the low doses, the negative effects were smaller but statistically significant, and dependent on bee size. The spatial working memory impairment shown here has the potential to harm bees exposed to thiamethoxam, through possible impacts on foraging efficiency or homing.

  17. Effect of acute exposure to ozone on heart rate and blood pressure of the conscious rat

    SciTech Connect

    Uchiyama, I.; Simomura, Y.; Yokoyama, E.

    1985-12-01

    Electrocardiogram and arterial blood pressure in conscious and unrestrained rats of various ages were recorded during a 3-hr exposure to filtered air or 1 ppm ozone (O/sub 3/). In general, heart rate and mean arterial blood pressure of rats significantly decreased during exposure to O/sub 3/, whereas these functional parameters remained almost stable during exposure to filtered air. Heart rate usually reached a plateau during the exposure to O/sub 3/. Additionally, PR interval and QRS complex significantly increased and premature atrial contraction and incomplete A-V block were frequently observed during the exposure to O/sub 3/. These circulatory effects of O/sub 3/ were more markedly manifested by rats 11 weeks old than either those 8 or 4 weeks old. On the other hand, no significant difference in the circulatory responses was observed between male and female rats. These circulatory effects of O/sub 3/ may be significant from the viewpoint of health effects, although its mechanisms remain unsolved.

  18. Probabilistic acute dietary exposure assessment of the Chinese population to cypermethrin residues.

    PubMed

    Sun, J-F; Liu, P; Li, C-Y; Li, J-X; Wang, C-N; Min, J; Hu, D; Wu, Y-N

    2011-01-01

    A probabilistic estimation of dietary exposure to cypermethrin residues for the Chinese population was performed. Cypermethrin residue data were obtained from the national food contamination monitoring program for 2001-2006, encompassing 14,096 samples from 36 commodities with a detection rate of 10.4%. Food consumption data were gathered from the national nutrition and health survey conducted in 2002, comprising 65,915 consumers aged 2-100 years and 3701 children of 2-6 years old. The whole country was roughly divided into six regions and the ranges of the median and of P99.9 exposure estimated for these regions were 0.018-0.026 and 3.131-7.095 µg kg(-1 )bw day(-1), respectively. Pak-choi and Chinese cabbage contributed 33.9 and 13.2%, respectively, to the cypermethrin intake for the general population, while pak-choi and citrus covered 30.7 and 22.5% of the total intake for children, respectively. The exposure of the rural population was higher than urban populations. Rural areas mainly located in the plains of central China had among the highest exposure of the six regions, accounting for 17.7% of the ARfD at P99.9, while the 99.99th percentile of exposure for children, especially rural children, far exceeded the ARfD, which is a cause for concern.

  19. Postnatal acute renal failure after fetal exposure to angiotensin receptor blockers.

    PubMed

    Marchetto, Luca; Sordino, Desiree; De Bernardo, Giuseppe; Trevisanuto, Daniele

    2015-07-02

    Maternal hypertensive treatment with angiotensin receptor blockers (ARBs) during the second and third trimester of pregnancy is associated with several fetal and neonatal complications, and potential adverse outcomes. We report a neonate presenting with transient renal acute failure during the first days of life after maternal treatment with ARBs. Women who became pregnant while taking one of these drugs must modify antihypertensive therapy with a different class drug as soon as pregnancy is recognised.

  20. Defining suitable reference genes for RT-qPCR analysis on human sertoli cells after 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposure.

    PubMed

    Ribeiro, Mariana Antunes; dos Reis, Mariana Bisarro; de Moraes, Leonardo Nazário; Briton-Jones, Christine; Rainho, Cláudia Aparecida; Scarano, Wellerson Rodrigo

    2014-11-01

    Quantitative real-time RT-PCR (qPCR) has proven to be a valuable molecular technique to quantify gene expression. There are few studies in the literature that describe suitable reference genes to normalize gene expression data. Studies of transcriptionally disruptive toxins, like tetrachlorodibenzo-p-dioxin (TCDD), require careful consideration of reference genes. The present study was designed to validate potential reference genes in human Sertoli cells after exposure to TCDD. 32 candidate reference genes were analyzed to determine their applicability. geNorm and NormFinder softwares were used to obtain an estimation of the expression stability of the 32 genes and to identify the most suitable genes for qPCR data normalization.

  1. Effects of acute versus repeated cocaine exposure on the expression of endocannabinoid signaling-related proteins in the mouse cerebellum

    PubMed Central

    Palomino, Ana; Pavón, Francisco-Javier; Blanco-Calvo, Eduardo; Serrano, Antonia; Arrabal, Sergio; Rivera, Patricia; Alén, Francisco; Vargas, Antonio; Bilbao, Ainhoa; Rubio, Leticia; Rodríguez de Fonseca, Fernando; Suárez, Juan

    2014-01-01

    Growing awareness of cerebellar involvement in addiction is based on the cerebellum’s intermediary position between motor and reward, potentially acting as an interface between motivational and cognitive functions. Here, we examined the impact of acute and repeated cocaine exposure on the two main signaling systems in the mouse cerebellum: the endocannabinoid (eCB) and glutamate systems. To this end, we investigated whether eCB signaling-related gene and protein expression {cannabinoid receptor type 1 receptors and enzymes that produce [diacylglycerol lipase alpha/beta (DAGLα/β) and N-acyl phosphatidylethanolamine phospholipase D (NAPE-PLD)] and degrade [monoacylglycerol lipase (MAGL) and fatty acid amino hydrolase (FAAH)] eCB} were altered. In addition, we analyzed the gene expression of relevant components of the glutamate signaling system [glutamate synthesizing enzymes liver-type glutaminase isoform (LGA) and kidney-type glutaminase isoform (KGA), metabotropic glutamatergic receptor (mGluR3/5), NMDA-ionotropic glutamatergic receptor (NR1/2A/2B/2C) and AMPA-ionotropic receptor subunits (GluR1/2/3/4)] and the gene expression of tyrosine hydroxylase (TH), the rate-limiting enzyme in catecholamine biosynthesis, because noradrenergic terminals innervate the cerebellar cortex. Results indicated that acute cocaine exposure decreased DAGLα expression, suggesting a down-regulation of 2-arachidonylglycerol (2-AG) production, as well as gene expression of TH, KGA, mGluR3 and all ionotropic receptor subunits analyzed in the cerebellum. The acquisition of conditioned locomotion and sensitization after repeated cocaine exposure were associated with an increased NAPE-PLD/FAAH ratio, suggesting enhanced anandamide production, and a decreased DAGLβ/MAGL ratio, suggesting decreased 2-AG generation. Repeated cocaine also increased LGA gene expression but had no effect on glutamate receptors. These findings indicate that acute cocaine modulates the expression of the eCB and

  2. Effects of acute versus repeated cocaine exposure on the expression of endocannabinoid signaling-related proteins in the mouse cerebellum.

    PubMed

    Palomino, Ana; Pavón, Francisco-Javier; Blanco-Calvo, Eduardo; Serrano, Antonia; Arrabal, Sergio; Rivera, Patricia; Alén, Francisco; Vargas, Antonio; Bilbao, Ainhoa; Rubio, Leticia; Rodríguez de Fonseca, Fernando; Suárez, Juan

    2014-01-01

    Growing awareness of cerebellar involvement in addiction is based on the cerebellum's intermediary position between motor and reward, potentially acting as an interface between motivational and cognitive functions. Here, we examined the impact of acute and repeated cocaine exposure on the two main signaling systems in the mouse cerebellum: the endocannabinoid (eCB) and glutamate systems. To this end, we investigated whether eCB signaling-related gene and protein expression {cannabinoid receptor type 1 receptors and enzymes that produce [diacylglycerol lipase alpha/beta (DAGLα/β) and N-acyl phosphatidylethanolamine phospholipase D (NAPE-PLD)] and degrade [monoacylglycerol lipase (MAGL) and fatty acid amino hydrolase (FAAH)] eCB} were altered. In addition, we analyzed the gene expression of relevant components of the glutamate signaling system [glutamate synthesizing enzymes liver-type glutaminase isoform (LGA) and kidney-type glutaminase isoform (KGA), metabotropic glutamatergic receptor (mGluR3/5), NMDA-ionotropic glutamatergic receptor (NR1/2A/2B/2C) and AMPA-ionotropic receptor subunits (GluR1/2/3/4)] and the gene expression of tyrosine hydroxylase (TH), the rate-limiting enzyme in catecholamine biosynthesis, because noradrenergic terminals innervate the cerebellar cortex. Results indicated that acute cocaine exposure decreased DAGLα expression, suggesting a down-regulation of 2-arachidonylglycerol (2-AG) production, as well as gene expression of TH, KGA, mGluR3 and all ionotropic receptor subunits analyzed in the cerebellum. The acquisition of conditioned locomotion and sensitization after repeated cocaine exposure were associated with an increased NAPE-PLD/FAAH ratio, suggesting enhanced anandamide production, and a decreased DAGLβ/MAGL ratio, suggesting decreased 2-AG generation. Repeated cocaine also increased LGA gene expression but had no effect on glutamate receptors. These findings indicate that acute cocaine modulates the expression of the eCB and

  3. Dose-related gene expression changes in forebrain following acute, low-level chlorpyrifos exposure in neonatal rats

    SciTech Connect

    Ray, Anamika; Liu Jing; Ayoubi, Patricia; Pope, Carey

    2010-10-15

    Chlorpyrifos (CPF) is a widely used organophosphorus insecticide (OP) and putative developmental neurotoxicant in humans. The acute toxicity of CPF is elicited by acetylcholinesterase (AChE) inhibition. We characterized dose-related (0.1, 0.5, 1 and 2 mg/kg) gene expression profiles and changes in cell signaling pathways 24 h following acute CPF exposure in 7-day-old rats. Microarray experiments indicated that approximately 9% of the 44,000 genes were differentially expressed following either one of the four CPF dosages studied (546, 505, 522, and 3,066 genes with 0.1, 0.5, 1.0 and 2.0 mg/kg CPF). Genes were grouped according to dose-related expression patterns using K-means clustering while gene networks and canonical pathways were evaluated using Ingenuity Pathway Analysis (registered) . Twenty clusters were identified and differential expression of selected genes was verified by RT-PCR. The four largest clusters (each containing from 276 to 905 genes) constituted over 50% of all differentially expressed genes and exhibited up-regulation following exposure to the highest dosage (2 mg/kg CPF). The total number of gene networks affected by CPF also rose sharply with the highest dosage of CPF (18, 16, 18 and 50 with 0.1, 0.5, 1 and 2 mg/kg CPF). Forebrain cholinesterase (ChE) activity was significantly reduced (26%) only in the highest dosage group. Based on magnitude of dose-related changes in differentially expressed genes, relative numbers of gene clusters and signaling networks affected, and forebrain ChE inhibition only at 2 mg/kg CPF, we focused subsequent analyses on this treatment group. Six canonical pathways were identified that were significantly affected by 2 mg/kg CPF (MAPK, oxidative stress, NF{Kappa}B, mitochondrial dysfunction, arylhydrocarbon receptor and adrenergic receptor signaling). Evaluation of different cellular functions of the differentially expressed genes suggested changes related to olfactory receptors, cell adhesion/migration, synapse

  4. Repeated acute exposures to hypergravity during early development subtly affect CD-1 mouse neurobehavioural profile.

    PubMed

    Francia, Nadia; Simeoni, Michelle; Petruzzi, Simona; Santucci, Daniela; Aloe, Luigi; Alleva, Enrico

    2006-05-15

    Exposure to altered gravitational environment, especially during critical ontogenetic phases, may induce persistent nervous system modifications and behavioural anomalies. This study evaluated the effects of hypergravity exposure on the development of the nervous system and assessed the relevance of parity in the mother's responses to altered gravitational stimuli. CD-1 mouse pups of both sexes delivered by primiparous and biparous dams were exposed to 1h of 2 G rotationally induced hypergravity from PND2 to PND9. Sensorimotor responses and somatic growth were daily measured (PND2-PND15), ultrasonic vocalisations recorded on PNDs 2, 5 and 9, and homing behaviour evaluated on PND12. In addition, spatial orientation ability was assessed in a T-maze on PND18, while mice exploratory behaviour and locomotor activity were evaluated in an open-field test (PND21). Long-term effects of hypergravity exposure on both spatial learning (Morris water-maze test) and brain levels of NGF and BDNF were also investigated at adulthood. Rotation per se induced a delay in somatic growth, sensorimotor responses and ultrasonic vocalisation profile, while hypergravity highlighted sex differences in open-field behaviour. Strategies to solve a spatial learning task, rather than learning per se, were affected by early exposure to rotation, while hypergravity selectively altered behavioural profile in the reversal phase of the test. Early exposure to rotation per se also decreased hypothalamic BDNF levels, while hypergravity reduced NGF levels in the frontal cortex. Previous maternal experience did not interact with hypergravity exposure, while differences between offspring of primiparous and biparous dams were observed in sensorimotor development and exploratory behaviour.

  5. Effect of acute ozone exposure on the proteinase-antiproteinase balance in the rat lung

    SciTech Connect

    Pickrell, J.A.; Gregory, R.E.; Cole, D.J.; Hahn, F.F.; Henderson, R.F.

    1987-04-01

    Lung disease may result from a persisting proteinase excess or a depletion of antiproteinase in pulmonary parenchyma. We investigated the in vivo effect of a 48-hr exposure to ozone at 0.5, 1.0, or 1.5 ppm on proteinase and antiproteinase activity of rat lungs. Elastase inhibitory capacities of serum, lung tissue, and airway washings were measured as indicators of antielastase activity. Trypsin inhibitory capacity was measured using an esterolytic procedure. Proteinase was measured as radioactive release from a /sup 14/C-globin substrate. The 48-hr exposures to O/sub 3/ at levels up to 1 ppm produced concentration-dependent decreases of 35-80% of antiproteinase activities in serum and in lung tissue. However, exposure to 1.5 ppm O/sub 3/ resulted in no decrease in antiproteinase activities. Acid proteinase activities (pH 4.2) were increased 65-120% by exposure to 1 or 1.5 ppm O/sub 3/, which correlated with inflammatory cells noted histologically. At 1.5 ppm O/sub 3/, pulmonary edema and hemorrhage were noted in histologic sections. These changes led to a flooding of the alveoli with up to 40 times normal protein levels and a greater than fivefold increase in airway antiproteinase. These data suggest that serum and soluble lung tissue antiproteinase activity decreased upon exposure to low levels of ozone. However, if O/sub 3/ exposure is high enough to produce pulmonary hemorrhage, antiproteinase may increase following serum exudation. These changes may be important in the development of ozone-induced lung diseases, especially emphysema.

  6. Urinary metabolic signatures and early triage of acute radiation exposure in rat model.

    PubMed

    Zhao, Mingxiao; Lau, Kim Kt; Zhou, Xian; Wu, Jianfang; Yang, Jun; Wang, Chang

    2017-03-28

    After a large-scale radiological accident, early-response biomarkers to assess radiation exposure over a broad dose range are not only the basis of rapid radiation triage, but are also the key to the rational use of limited medical resources and to the improvement of treatment efficiency. Because of its high throughput, rapid assays and minimally invasive sample collection, metabolomics has been applied to research into radiation exposure biomarkers in recent years. Due to the complexity of radiobiological effects, most of the potential biomarkers are both dose-dependent and time-dependent. In reality, it is very difficult to find a single biomarker that is both sensitive and specific in a given radiation exposure scenario. Therefore, a multi-parameters approach for radiation exposure assessment is more realistic in real nuclear accidents. In this study, untargeted metabolomic profiling based on gas chromatography-mass spectrometry (GC-MS) and targeted amino acid profiling based on LC-MS/MS were combined to investigate early urinary metabolite responses within 48 h post-exposure in a rat model. A few of the key early-response metabolites for radiation exposure were identified, which revealed the most relevant metabolic pathways. Furthermore, a panel of potential urinary biomarkers was selected through a multi-criteria approach and applied to early triage following irradiation. Our study suggests that it is feasible to use a multi-parameters approach to triage radiation damage, and the urinary excretion levels of the relevant metabolites provide insights into radiation damage and repair.

  7. Associations between chronic community noise exposure and blood pressure at rest and during acute noise and non-noise stressors among urban school children in India.

    PubMed

    Lepore, Stephen J; Shejwal, Bhaskar; Kim, Bang Hyun; Evans, Gary W

    2010-09-01

    The present study builds on prior research that has examined the association between children's chronic exposure to community noise and resting blood pressure and blood pressure dysregulation during exposure to acute stressors. A novel contribution of the study is that it examines how chronic noise exposure relates to blood pressure responses during exposure to both noise and non-noise acute stressors. The acute noise stressor was recorded street noise and the non-noise stressor was mental arithmetic. The sample consisted of 189 3rd and 6th grade children (51.9% percent boys; 52.9% 3rd graders) from a noisy (n = 95) or relatively quiet (n = 94) public school in the city of Pune, India. There were no statistically significant differences between chronic noise levels and resting blood pressure levels. However, relative to quiet-school children, noisy-school children had significantly lower increases in blood pressure when exposed to either an acute noise or non-noise stressor. This finding suggests that chronic noise exposure may result in hypo-reactivity to a variety of stressors and not just habituation to noise stressors.

  8. Acute exposure of the aquatic macrophyte Callitriche obtusangula to the herbicide oxadiazon: the protective role of N-acetylcysteine.

    PubMed

    Iriti, Marcello; Castorina, Giulia; Picchi, Valentina; Faoro, Franco; Gomarasca, Stefano

    2009-03-01

    In this study we investigated the acute exposure of the aquatic macrophyte Callitriche obtusangula to the herbicide oxadiazon (Ronstar). The toxic effects on C. obtusangula were evaluated, 24h after exposure, by assessing visible necrotic leaf lesions and, 12 h after exposure, via analyses of dead cells and hydrogen peroxide (H2O2) deposits localized by histocytochemical analysis with Trypan blue and 3,3'-diaminobenzidine (DAB), respectively. As a result, we found that 0.1275 microg L(-1) a.i. (active ingredient) oxadiazon was the maximum concentration that produced no observable adverse effects (NOAEC) both at leaf and tissue levels, at any considered exposure time. Additionally, we assayed the protective effect of pre-treatment with 0.25 mM N-acetylcysteine (NAC), a cysteine donor, on the damage caused by the toxic herbicidal dose of 6.37 microg L(-1) a.i to C. obtusangula, correlating the NAC observed protection to the direct H2O2-scavenging and to the enhancement of glutathione parameters. NAC-treated plants showed a fourfold increase in the GSH (reduced glutathione)+GSSG (oxidised glutathione) content (149.2 nmol g(-1) FW) compared to controls (36.1 nmol g(-1) FW); in the NAC+oxadiazon treatments, the GSH+GSSG content was more than fivefold higher (202.1 nmol g(-1) FW). GSH showed a similar trend in NAC and NAC+oxadiazon treatments, being six- (130.0 nmol g(-1) FW) and eightfold (185.0 nmol g(-1) FW) higher, respectively, compared to controls (20.7 nmol g(-1) FW). Accordingly, the GSH/GSSG ratio in NAC- and NAC+oxadiazon-treated plants was significantly increased compared to controls, indicating alleviation of oxidative stress.

  9. Electrocardiographic and autonomic effects of acute particulate matter (PM) exposure in a rat model of cardiomyopathy

    EPA Science Inventory

    Human exposure to ambient PM from fossil-fuel emissions is linked to cardiovascular disease and death. This association strengthens in people with preexisting cardiac disease--especially heart failure (HF). Cardiomyopathy is the most common cause of heart failure. The mechanisms ...

  10. Acute effects of exposure to space radiation on CNS function and cognitive performance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    On exploratory class missions, such as a mission to Mars, astronauts will be exposed to types and doses of radiation (cosmic rays) that are not experienced in low earth orbit where the Space Shuttle and International Space Station operate. Exposure to cosmic rays produces changes in neuronal functi...

  11. KIDNEY TOXICOGENOMICS OF ACUTE SODIUM AND POTASSIUM BROMATE EXPOSURE IN F344 MALE RAT

    EPA Science Inventory

    Bromate, used in both the food and cosmetics industry, is a drinking water disinfection by-product that is nephrotoxic and carcinogenic to rodents. To gain insight into the carcinogenic mechanism of action, identify possible biomarkers of exposure, and determine if the cation, po...

  12. Altered Hippocampal Lipid Profile Following Acute Postnatal Exposure to Di(2-Ethylhexyl) Phthalate in Rats

    PubMed Central

    Smith, Catherine A.; Farmer, Kyle; Lee, Hyunmin; Holahan, Matthew R.; Smith, Jeffrey C.

    2015-01-01

    Slight changes in the abundance of certain lipid species in the brain may drastically alter normal neurodevelopment via membrane stability, cell signalling, and cell survival. Previous findings have demonstrated that postnatal exposure to di (2-ethylhexyl) phthalate (DEHP) disrupts normal axonal and neural development in the hippocampus. The goal of the current study was to determine whether postnatal exposure to DEHP alters the lipid profile in the hippocampus during postnatal development. Systemic treatment with 10 mg/kg DEHP during postnatal development led to elevated levels of phosphatidylcholine and sphingomyelin in the hippocampus of female rats. There was no effect of DEHP exposure on the overall abundance of phosphatidylcholine or sphingomyelin in male rats or of lysophosphatidylcholine in male or female rats. Individual analyses of each identified lipid species revealed 10 phosphatidylcholine and six sphingomyelin lipids in DEHP-treated females and a single lysophosphatidylcholine in DEHP-treated males with a two-fold or higher increase in relative abundance. Our results are congruent with previous work that found that postnatal exposure to DEHP had a near-selective detrimental effect on hippocampal development in males but not females. Together, results suggest a neuroprotective effect of these elevated lipid species in females. PMID:26516880

  13. Renal responses to acute lead waterborne exposure in the freshwater rainbow trout (Oncorhynchus mykiss).

    PubMed

    Patel, Monika; Rogers, Joseph T; Pane, Eric F; Wood, Chris M

    2006-12-30

    The possible nephrotoxic effects of waterborne lead exposure (as Pb(NO3)2) were investigated in the freshwater rainbow trout (Oncorhynchus mykiss). Kidney lead accumulation was time-dependent, increasing upon exposure to 0.57+/-0.01 mg dissolved Pb L(-1) for up to 96 h with a significantly higher burden occurring in the posterior kidney compared to the anterior segment. Urine analyses in trout exposed to 1.20+/-0.09 mg dissolved Pb L(-1) revealed a significant increase in urinary lead excretion rate throughout 96 h of exposure. Urine flow rate and glomerular filtration rate (GFR) were not impacted with the exception of a significant decrease in GFR from 84 to 96 h in lead-exposed trout. Urine pH decreased significantly over time in lead-exposed fish. Correspondingly, urine ammonia excretion rate showed a marked increase from 48 h onwards. In experimental fish, urine glucose excretion was significantly greater by 96 h while urine lactate, urea and protein excretion were not significantly altered by lead exposure. The urine excretion rate of Ca2+ increased significantly by approximately 43% after only 24 h of lead exposure, and was maintained at a higher rate than controls for up to 96 h. Magnesium excretion increased in a time-dependent fashion, reaching a two- to three-fold rise by 96 h. In contrast, rates of Na+ and Cl- excretion were decreased in experimental fish by approximately 30% by 48 h, this trend continuing for the duration of lead-exposure. There were no changes in any of these parameters in similarly treated control fish. Clearance ratio analyses indicated progressive decreases in the net reabsorption efficiencies of the renal system for Ca2+, Mg2+, Pb, and glucose, suggesting that the active tubular transport mechanisms for these substances were inhibited by lead exposure, while Na+, K+, Cl-, lactate, and protein reabsorptions were unaffected. Net ammonia secretion increased. We conclude that changes in renal function both reflect and help to minimize

  14. Acute exposure to 17α-ethinylestradiol alters boldness behavioral syndrome in female Siamese fighting fish.

    PubMed

    Dzieweczynski, Teresa L; Campbell, Brennah A; Marks, Jodi M; Logan, Brittney

    2014-09-01

    The role of anthropogenic sources in generating, maintaining, and influencing behavioral syndromes has recently been identified as an important area of future research. Endocrine disrupting chemicals are prevalent and persistent in aquatic ecosystems worldwide. These chemicals are known to have marked effects on the morphology and behavior of exposed individuals and, as such, may serve as a potential influence on behavioral syndromes. However, both the effects of exposure on behaviors beyond courtship and aggression and how exposure might affect behavioral variation at the individual level are understudied. To address this question, we examined boldness behavior in female Siamese fighting fish in three different assays (Novel Environment, Empty Tank, Shoaling) both before and after they were exposed to the estrogen mimic, 17α-ethinylestradiol (EE2). EE2 influences courtship, aggression, and boldness in males of this species but its effects have not been examined in females, to our knowledge. Females were tested multiple times in each assay before and after exposure so that behavioral consistency could be examined. A behavioral syndrome for boldness and activity level occurred across the three assays. The reductions in boldness and loss of the behavioral syndrome that resulted from EE2 exposure were surprising and suggest that the effects of EE2 exposure on female behavior and physiology should be examined more frequently. This study is one of the first to examine the effects of EE2 in females as well as on correlated behaviors and emphasizes the importance of examining the effects of endocrine disrupting chemicals on individual behavioral variation and consistency.

  15. Acute Atrazine Exposure has Lasting Effects on Chemosensory Responses to Food Odors in Crayfish (Orconectes virilis).

    PubMed

    Belanger, Rachelle M; Mooney, Lauren N; Nguyen, Hung M; Abraham, Noor K; Peters, Tyler J; Kana, Maria A; May, Lauren A

    2016-02-01

    The herbicide atrazine is known to impact negatively olfactory-mediated behaviors in aquatic animals. We have shown that atrazine exposure has deleterious effects on olfactory-mediated behavioral responses to food odors in crayfish; however, recovery of chemosensory abilities post-atrazine exposure has not been investigated. We examined whether crayfish (Orconectes virilis) recovered chemosensory abilities after a 96-h exposure to sublethal, environmentally relevant concentrations of 80 ppb (µg/L) atrazine. Following treatment, we analyzed the ability of the crayfish to locate a food source using a Y-maze with one arm containing fish-flavored gelatin and the other containing unflavored gelatin. We compared the time spent in the food arm of the Y-maze, near the food source, as well as moving and walking speed of control and atrazine-treated crayfish. We also compared the number of crayfish that handled the food source and the amount of food consumed. Following 24-, 48-, and 72-h recovery periods in fresh water, behavioral trials were repeated to determine if there was any observable recovery of chemosensory-mediated behaviors. Atrazine-treated crayfish spent less time in the food arm, at the odor source, and were less successful at finding the food odor source than control crayfish for all times tested. Additionally, atrazine-treated crayfish consumed less fish-flavored than control crayfish; however, treatment did not affect locomotion. Overall, we found that crayfish are not able to recover chemosensory abilities 72 h post-atrazine exposure. Because crayfish rely heavily on their chemosensory abilities to acquire food, the negative impacts of atrazine exposure could affect population size in areas where atrazine is heavily applied.

  16. Acute exposure of mercury chloride stimulates the tissue regeneration program and reactive oxygen species production in the Drosophila midgut.

    PubMed

    Chen, Zhi; Wu, Xiaochun; Luo, Hongjie; Zhao, Lingling; Ji, Xin; Qiao, Xianfeng; Jin, Yaping; Liu, Wei

    2016-01-01

    We used Drosophila as an animal model to study the digestive tract in response to the exposure of inorganic mercury (HgCl2). We found that after oral administration, mercury was mainly sequestered within the midgut. This resulted in increased cell death, which in turn stimulated the tissue regeneration program, including accelerated proliferation and differentiation of the intestinal stem cells (ISCs). We further demonstrated that these injuries correlate closely with the excessive production of the reactive oxygen species (ROS), as vitamin E, an antioxidant reagent, efficiently suppressed the HgCl2-induced phenotypes of midgut and improved the viability. We propose that the Drosophila midgut could serve as a suitable model to study the treatment of acute hydrargyrism on the digestive systems.

  17. Acute respiratory distress syndrome and chemical burns after exposure to chlorine-containing bleach: a case report

    PubMed Central

    Shin, Hong-Joon; Chang, Jin-Sun; Ahn, Seong; Kim, Tae-Ok; Park, Cheol-Kyu; Lim, Jung-Hwan; Oh, In-Jae; Kim, Yu-Il; Lim, Sung-Chul; Kim, Young-Chul

    2017-01-01

    Chlorine-containing bleach can cause acute respiratory distress syndrome (ARDS) and chemical burns. However, simultaneous occurrence of the two conditions caused by this agent is very rare. We describe the case of a 74-year-old female who presented with shortness of breath and hemoptysis following accidental exposure to chlorine-containing bleach. She had second- to third-degree chemical burns on both buttocks and thighs, and received mechanical ventilation because of the development of ARDS. Mechanical ventilation was discontinued on day 6 of hospitalization because of the rapid improvement of hypoxemia, and the patient was transferred to another hospital for further management of the chemical burns on day 18. PMID:28203432

  18. Toxicological responses to acute mercury exposure for three species of Manila clam Ruditapes philippinarum by NMR-based metabolomics.

    PubMed

    Liu, Xiaoli; Zhang, Linbao; You, Liping; Cong, Ming; Zhao, Jianmin; Wu, Huifeng; Li, Chenghua; Liu, Dongyan; Yu, Junbao

    2011-03-01

    The Manila clam (Ruditapes philippinarum) has been considered a good sentinel species for metal pollution monitoring in estuarine tidal flats. Along the Bohai coast of China, there are dominantly distributed three species of clams (White, Liangdao Red and Zebra in Yantai population) endowed with distinct tolerances to environmental stressors. In this study, adductor muscle samples were collected from both control and acute mercury exposed White, Liangdao Red and Zebra clams, and the extracts were analyzed by NMR-based metabolomics to compare the metabolic profiles and responses to the acute mercury exposure to determine the most sensitive clam species capable of acting as abioindicator for heavy metal pollution monitoring. The major abundant metabolites in the White clam sample were branched-chain amino acids (leucine, isoleucine and valine), lactate, arginine, aspartate, acetylcholine, homarine and ATP/ADP, while the metabolite profile of Zebra clam sample comprised high levels of glutamine, acetoacetate, betaine, taurine and one unidentified metabolite. For the Liangdao Red clam sample, the metabolite profile relatively exhibited high amount of branched-chain amino acids, arginine, glutamate, succinate, acetylcholine, homarine and two unassigned metabolites. After 48h exposure of 20μgL(-1) Hg(2+), the metabolic profiles showed significant differences between three clam species, which included increased lactate, succinate, taurine, acetylcholine, betaine and homarine and decreased alanine, arginine, glutamine, glutamate, acetoacetate, glycine and ATP/ADP in White clam samples, and elevated succinate, taurine and acetylcholine, and declined glutamine, glycine, and aspartate in Liangdao Red clam samples, while the increased branched-chain amino acids, lactate, succinate, acetylcholine and homarine, and reduced alanine, acetoacetate, glycine and taurine were observed in the Zebra clam samples. Overall, our findings showed that White clams could be a preferable

  19. Combined exposure to simulated microgravity and acute or chronic radiation reduces neuronal network integrity and cell survival

    NASA Astrophysics Data System (ADS)

    Benotmane, Rafi

    During orbital or interplanetary space flights, astronauts are exposed to cosmic radiations and microgravity. This study aimed at assessing the effect of these combined conditions on neuronal network density, cell morphology and survival, using well-connected mouse cortical neuron cultures. To this end, neurons were exposed to acute low and high doses of low LET (X-rays) radiation or to chronic low dose-rate of high LET neutron irradiation (Californium-252), under the simulated microgravity generated by the Random Positioning Machine (RPM, Dutch space). High content image analysis of cortical neurons positive for the neuronal marker βIII-tubulin unveiled a reduced neuronal network integrity and connectivity, and an altered cell morphology after exposure to acute/chronic radiation or to simulated microgravity. Additionally, in both conditions, a defect in DNA-repair efficiency was revealed by an increased number of γH2AX-positive foci, as well as an increased number of Annexin V-positive apoptotic neurons. Of interest, when combining both simulated space conditions, we noted a synergistic effect on neuronal network density, neuronal morphology, cell survival and DNA repair. Furthermore, these observations are in agreement with preliminary gene expression data, revealing modulations in cytoskeletal and apoptosis-related genes after exposure to simulated microgravity. In conclusion, the observed in vitro changes in neuronal network integrity and cell survival induced by space simulated conditions provide us with mechanistic understanding to evaluate health risks and the development of countermeasures to prevent neurological disorders in astronauts over long-term space travels. Acknowledgements: This work is supported partly by the EU-FP7 projects CEREBRAD (n° 295552)

  20. Acute inferior myocardial infarction after electrical weapon exposure: case report and review of the literature.

    PubMed

    Belen, Erdal; Tipi, Fatih Fahri; Bayyiğit, Akif; Helvacı, Ayşen Şerife

    2015-03-01

    The use of conducted electrical weapons (CEWs) by legal security forces and in civil society is rapidly increasing. While they are generally considered safe devices, and fatal complications are rare, it is possible to see a small number of complications. In the present case, we describe the detection of acute inferior myocardial infarction in a patient who experienced chest pain after being exposed to a CEW. In such cases, multiple factors should be considered, and the choice of treatment and follow-up should be decided accordingly.

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

    SciTech Connect

    Winkler, J.D.

    1987-01-01

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

  2. Flaxseed Mitigates Acute Oxidative Lung Damage in a Mouse Model of Repeated Radiation and Hyperoxia Exposure Associated with Space Exploration

    PubMed Central

    Pietrofesa, Ralph A.; Solomides, Charalambos C.; Christofidou-Solomidou, Melpo

    2015-01-01

    Background Spaceflight missions may require crewmembers to conduct extravehicular activities (EVA). Pre-breathe protocols in preparation for an EVA entail 100% hyperoxia exposure that may last for a few hours and be repeated 2-3 times weekly. Each EVA is associated with additional challenges such as low levels of total body cosmic/galactic radiation exposure that may present a threat to crewmember health. We have developed a mouse model of total body radiation and hyperoxia exposure and identified acute damage of lung tissues. In the current study we evaluated the usefulness of dietary flaxseed (FS) as a countermeasure agent for such double-hit exposures. Methods We evaluated lung tissue changes 2 weeks post-initiation of exposure challenges. Mouse cohorts (n=5/group) were pre-fed diets containing either 0% FS or 10% FS for 3 weeks and exposed to: a) normoxia (Untreated); b) >95% O2 (O2); c) 0.25Gy single fraction gamma radiation (IR); or d) a combination of O2 and IR (O2+IR) 3 times per week for 2 consecutive weeks, where 8-hour hyperoxia treatments were spanned by normoxic intervals. Results At 2 weeks post challenge, while control-diet fed mice developed significant lung injury and inflammation across all challenges, FS protected lung tissues by decreasing bronchoalveolar lavage fluid (BALF) neutrophils (p<0.003) and protein levels, oxidative tissue damage, as determined by levels of malondialdehyde (MDA) (p<0.008) and nitrosative stress as determined by nitrite levels. Lung hydroxyproline levels, a measure of lung fibrosis, were significantly elevated in mice fed 0% FS (p<0.01) and exposed to hyperoxia/radiation or the combination treatment, but not in FS-fed mice. FS also decreased levels of a pro-inflammatory, pro-fibrogenic cytokine (TGF-β1) gene expression levels in lung. Conclusion Flaxseed mitigated adverse effects in lung of repeat exposures to radiation/hyperoxia. This data will provide useful information in the design of countermeasures to early

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

    PubMed

    Barimo, John F; Walsh, Patrick J

    2005-11-10

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

  4. Cellular metabolic, stress, and histological response on exposure to acute toxicity of endosulfan in tilapia (Oreochromis mossambicus).

    PubMed

    Kumar, Neeraj; Sharma, Rupam; Tripathi, Gayatri; Kumar, Kundan; Dalvi, Rishikesh S; Krishna, Gopal

    2016-01-01

    Endosulfan is one of the most hazardous organochlorines pesticides responsible for environmental pollution, as it is very persistent and shows bio-magnification. This study evaluated the impact of acute endosulfan toxicity on metabolic enzymes, lysozyme activities, heat shock protein (Hsp) 70 expression, and histopathology in Tilapia (Oreochromis mossambicus). Among the indicators that were induced in dose dependent manner were the enzymes of amino acid metabolism (serum alanine aminotransferase and aspartate aminotransferase), carbohydrate metabolism (serum lactate dehydrogenase), pentose phosphate pathway (Glucose-6-phosphate dehydrogenase) as well as lysozyme and Hsp70 in liver and gill, while liver and gill Isocitrate dehydrogenase (TCA cycle enzyme) and marker of general energetics (Total adenosine triphosphatase) were inhibited. Histopathological alterations in gill were clubbing of secondary gill lamellae, marked hyperplasia, complete loss of secondary lamellae and atrophy of primary gill filaments. Whereas in liver, swollen hepatocyte, and degeneration with loss of cellular boundaries were distinctly noticed. Overall results clearly demonstrated the unbalanced metabolism and damage of the vital organs like liver and gill in Tilapia due to acute endosulfan exposure.

  5. Pulmonary Inflammatory Responses To Acute Meteorite Dust Exposures - Implications For Human Space Exploration

    NASA Technical Reports Server (NTRS)

    Harrington, A. D.; McCubbin, F. M.; Kaur, J.; Smirnov, A.; Galdanes, K.; Schoonen, M. A. A.; Chen, L. C.; Tsirka, S. E.; Gordon, T.

    2017-01-01

    The previous manned missions to the Moon represent milestones of human ingenuity, perseverance, and intellectual curiosity. However, one of the major ongoing concerns is the array of hazards associated with lunar surface dust. Not only did the dust cause mechanical and structural integrity issues with the suits, the dust 'storm' generated upon reentrance into the crew cabin caused "lunar hay fever" and "almost blindness" (Figure 1). It was further reported that the allergic response to the dust worsened with each exposure. The lack of gravity exacerbated the exposure, requiring the astronauts to wear their helmet within the module in order to avoid breathing the irritating particles. Due to the prevalence of these high exposures, the Human Research Roadmap developed by NASA identifies the Risk of Adverse Health and Performance Effects of Celestial Dust Exposure as an area of concern. Extended human exploration will further increase the probability of inadvertent and repeated exposures to celestial dusts. Going forward, hazard assessments of celestial dusts will be determined through sample return efforts prior to astronaut deployment. Studies on the lunar highland regolith indicate that the dust is not only respirable but also reactive, and previous studies concluded that it is moderately toxic; generating a greater response than titanium oxide but a lower response than quartz. The presence of reactive oxygen species (ROS) on the surface of the dust has been implicated. However, there is actually little data related to physicochemical characteristics of particulates and pulmonary toxicity, especially as it relates to celestial dust exposure. As a direct response to this deficit, the present study evaluates the role of a particulate's innate geochemical features (e.g., bulk chemistry, internal composition, morphology, size, and reactivity) in generating adverse toxicological responses in vitro and in vivo. This highly interdisciplinary study evaluates the relative

  6. Acute Exposure to Di(2-Ethylhexyl) Phthalate in Adulthood Causes Adverse Reproductive Outcomes Later in Life and Accelerates Reproductive Aging in Female Mice

    PubMed Central

    Hannon, Patrick R.; Niermann, Sarah; Flaws, Jodi A.

    2016-01-01

    Humans are ubiquitously exposed to di(2-ethylhexyl) phthalate (DEHP), which is an environmental toxicant incorporated in consumer products. Studies have shown that DEHP targets the ovary to disrupt essential processes required for reproductive and nonreproductive health. Specifically, 10-day exposure to DEHP accelerates primordial follicle recruitment and disrupts estrous cyclicity in adult mice. However, it is unknown if these effects on folliculogenesis and cyclicity following acute DEHP exposure can have permanent effects on reproductive outcomes. Further, the premature depletion of primordial follicles can cause early reproductive senescence, and it is unknown if acute DEHP exposure accelerates reproductive aging. This study tested the hypothesis that acute DEHP exposure causes infertility, disrupts estrous cyclicity, alters hormone levels, and depletes follicle numbers by inducing atresia later in life, leading to accelerated reproductive aging. Adult CD-1 mice were orally dosed with vehicle or DEHP (20 μg/kg/day–500 mg/kg/day) daily for 10 days, and reproductive outcomes were assessed at 6 and 9 months postdosing. Acute DEHP exposure significantly altered estrous cyclicity compared to controls at 6 and 9 months postdosing by increasing the percentage of days the mice were in estrus and metestrus/diestrus, respectively. DEHP also significantly decreased inhibin B levels compared to controls at 9 months postdosing. Further, DEHP significantly increased the BAX/BCL2 ratio in primordial follicles leading to a significant decrease in primordial and total follicle numbers compared to controls at 9 months postdosing. Collectively, the adverse effects present following acute DEHP exposure persist later in life and are consistent with accelerated reproductive aging. PMID:26678702

  7. Epidemiological studies on radiation carcinogenesis in human populations following acute exposure: nuclear explosions and medical radiation

    SciTech Connect

    Fabrikant, J.I.

    1981-05-01

    The current knowledge of the carcinogenic effect of radiation in man is considered. The discussion is restricted to dose-incidence data in humans, particularly to certain of those epidemiological studies of human populations that are used most frequently for risk estimation for low-dose radiation carcinogenesis in man. Emphasis is placed solely on those surveys concerned with nuclear explosions and medical exposures. (ACR)

  8. Genome-wide Gene Expression Profiling of Acute Metal Exposures in Male Zebrafish

    DTIC Science & Technology

    2014-10-23

    Zebrafish Whole organism Nickel Chromium Cobalt Toxicogenomics To capture global responses to metal poisoning and mechanistic insights into metal...nickel, chromium , cobalt, toxicogenomics 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT Same as Report (SAR) 18. NUMBER OF PAGES 3 19a...fold changedata stood as is. Exposure to chromium , cobalt, or nickel significantly altered the expression of 696, 461, and 287 genes respectively (Fig. 2

  9. CHOLINE AMELIORATES DEFICITS IN BALANCE CAUSED BY ACUTE NEONATAL ETHANOL EXPOSURE

    PubMed Central

    Bearer, Cynthia F.; Wellmann, Kristen A.; Tang, Ningfeng; He, Min; Mooney, Sandra M.

    2015-01-01

    Fetal alcohol spectrum disorder (FASD) is estimated to occur in 1% of all live births. The developing cerebellum is vulnerable to the toxic effects of alcohol. People with FASD have cerebellar hypoplasia and developmental deficits associated with cerebellar injury. Choline is an essential nutrient but many diets in the USA are choline deficient. In rats, choline given with or following alcohol exposure reduces many alcohol-induced neurobehavioral deficits, but not those associated with cerebellar function. Our objective was to determine if choline supplementation prior to alcohol exposure would ameliorate the impact of ethanol on a cerebellar-associated behavioral test in mice. Pregnant C57Bl6/J mice were maintained on a choline deficient diet from embryonic day 4.5. On postnatal day 1 (P1), pups were assigned to one of 8 treatment groups: choline (C) or saline (S) pre-treatment from P1-5, ethanol (6 g/kg) or Intralipid® on P5, C or S post-treatment from P6-20. On P30, balance and coordination were tested using the dowel crossing test. Overall, there was a significant effect of treatment and females crossed longer distances than males. Ethanol exposure significantly reduced the total distance crossed. Choline pre-treatment increased the distance crossed by males, and both pre- and post-treatment with choline significantly increased total distance crossed for females and males. There was no effect of choline on Intralipid®-exposed animals. This is the first study to show that choline ameliorates ethanol-induced effects on balance and coordination when given before ethanol exposure. Choline fortification of common foodstuffs may reduce the effects of alcohol. PMID:26085462

  10. The Acute Effects of Single Exposures to White Phosphorus Smoke in Rats and Guinea Pigs

    DTIC Science & Technology

    1980-09-01

    appear fully recovered 2 weeks after exposure, based on - appearance, blood chemistries, lung function tests, and pathology. DOR u 47 EDITION OF INOV 65 IS...water. Five grams of dry food and 15 ml of the test solution was placed in plastic culture vials. Wild- type Oregon-K strain Drosophila Melanogaster red...eyed males (age I to 2 days) were put in the vials which were placed in a controlled light, temperature, and humidity incubator. The food mixture was

  11. Exposure to and acute effects of medium-density fiber board dust.

    PubMed

    Priha, Eero; Pennanen, Sirpa; Rantio, Tiina; Uitti, Jukka; Liesivuori, Jyrki

    2004-11-01

    The goals of this study were (1) to investigate workers' exposure to medium-density fiber (MDF) dust (inhalable dust, particle size),formaldehyde, and volatile organic compounds; (2) to study the possible inflammatory nasal reactions caused by exposure to MDF board dust; and (3) to determine the occurrence of irritative symptoms among exposed workers. Nasal lavage fluid was analyzed for cytokines and nitric oxide/nitrite. and inflammatory cells were counted. The time-weighted average of MDF dust was 1.4 mg/m3 in the workers' breathing zones. MDF board dust was composed mainly of particles exceeding 10 microm in diameter. The MDF board dust released formaldehyde in concentration of about 1000 microg/g when extracted with water for 6 hours at 37 degrees C. The cell counts and cytokine levels of the nasal lavage fluid samples did not show statistically significant differences between the workers exposed to MDF board dust and those exposed to other wood dusts. Nevertheless, two MDF-exposed workers had a considerable increase in the proportion of eosinophils and cytokine levels. Several workers exposed to MDF and wood dusts experienced nasal, eye, and skin symptoms at the end of a work shift. Both exposed groups had significantly more nasal symptoms, although the median dust level was only 1.2 mg/m3, considerably less than the occupational exposure limit for wood dust in Finland. Nasal symptoms were more frequent among workers exposed to MDF board dust and did not correlate with smoking. Our results suggest that the occupational exposure limit of 5 mg/m3 is probably too high for MDF board dust.

  12. Use of ammonium chloride and sodium bicarbonate in acute heat exposure of broilers.

    PubMed

    Branton, S L; Reece, F N; Deaton, J W

    1986-09-01

    Ammonium chloride (NH4Cl) and sodium bicarbonate (NaHCO3) were added separately to the drinking water of 42- to 52-day-old broilers. Birds were given access to the water ad libitum for a total of 42.5 hr consisting of 18.5 hr prior to an 8-hr interval of severe heat exposure and a further 16 hr-post exposure. Water and feed intake during the treatment period were unaffected by either NH4Cl at 6.25 g/liter (.63%) of distilled water (DW) or NaHCO3 at 3.15 g/liter (.32%) DW. Water intake was increased by approximately 20% in birds given water containing 6.25 g of NaHCO3/liter (.63%) DW, while both feed and water intake were severely limited by NH4Cl at 31 g/liter (3.1%) DW. Blood pH of birds was substantially lowered by consumption of NH4Cl, while consumption of NaHCO3 did not significantly affect blood pH. Blood pH of all treatments increased during the heat exposure period and declined afterward; however, blood pH change appeared to be more pronounced for birds receiving the NH4CL. A correlation coefficient (r = -.31) existed between blood pH and mortality, while a correlation (r = -.72) was demonstrated between water consumption and mortality.

  13. Acute cigarette smoke exposure causes lung injury in rabbits treated with ibuprofen

    SciTech Connect

    Witten, M.L.; Lemen, R.J.; Quan, S.F.; Sobonya, R.E.; Magarelli, J.L.; Bruck, D.C.

    1987-01-01

    We studied lung clearance of aerosolized technetium-labeled diethylenetriamine pentaacetic acid (/sup 99m/TcDTPA), plasma concentrations of 6-keto-PGF1 alpha and thromboxane B2, and pulmonary edema as indices of lung injury in rabbits exposed to cigarette smoke (CSE). Forty-six rabbits were randomly assigned to 4 groups: control sham smoke exposure (SS, N = 9), sham smoke exposure ibuprofen-pretreated (SS-I, N = 10), CSE (N = 9), sham smoke exposure ibuprofen-pretreated (SS-I, N = 10), CSE (N = 9), and CSE ibuprofen-pretreated (CSE-I, N = 19). Ibuprofen (cyclooxygenase eicosanoid inhibitor) was administered as a single daily intramuscular injection (25 mg/kg) for 7 days before the experiment. Cigarette or sham smoke was delivered by syringe in a series of 5, 10, 20, and 30 tidal volume breaths with a 15-min counting period between each subset of breaths to determine /sup 99m/TcDTPA biological half-life (T1/2). In the ibuprofen pretreated group, CSE caused significant decreases in /sup 99m/TcDTPA T1/2 and dynamic lung compliance. Furthermore, these changes in lung function were accompanied by severe injury to type I alveolar cell epithelium, pulmonary edema, and frequently death of the rabbits. These findings suggest that inhibition of the cyclooxygenase pathway before CSE exacerbates lung injury in rabbits.

  14. Estimating the acute health effects of coarse particulate matter accounting for exposure measurement error.

    PubMed

    Chang, Howard H; Peng, Roger D; Dominici, Francesca

    2011-10-01

    In air pollution epidemiology, there is a growing interest in estimating the health effects of coarse particulate matter (PM) with aerodynamic diameter between 2.5 and 10 μm. Coarse PM concentrations can exhibit considerable spatial heterogeneity because the particles travel shorter distances and do not remain suspended in the atmosphere for an extended period of time. In this paper, we develop a modeling approach for estimating the short-term effects of air pollution in time series analysis when the ambient concentrations vary spatially within the study region. Specifically, our approach quantifies the error in the exposure variable by characterizing, on any given day, the disagreement in ambient concentrations measured across monitoring stations. This is accomplished by viewing monitor-level measurements as error-prone repeated measurements of the unobserved population average exposure. Inference is carried out in a Bayesian framework to fully account for uncertainty in the estimation of model parameters. Finally, by using different exposure indicators, we investigate the sensitivity of the association between coarse PM and daily hospital admissions based on a recent national multisite time series analysis. Among Medicare enrollees from 59 US counties between the period 1999 and 2005, we find a consistent positive association between coarse PM and same-day admission for cardiovascular diseases.

  15. Acute exposure to hair bleach causes airway hyperresponsiveness in a rabbit model.

    PubMed

    Mensing, T; Marek, W; Raulf-Heimsoth, M; Baur, X

    1998-12-01

    Ammonium persulphate (APS) and hydrogen peroxide (H2O2) are used as oxidants in many industrial processes and are the main constituents of standard hair bleaching products. In a previous study, it was demonstrated that aerosols of APS induce alterations in airway responsiveness. The present study examined whether exposure for 4 h to a hair bleach composition (containing APS, potassium persulphate and H2O2) or H2O2 could induce airway hyperresponsiveness and/or an obstructive ventilation pattern in a rabbit model. Exposure to the aerosols altered neither baseline airway resistance, dynamic elastance, slope of inspiratory pressure generation nor arterial blood pressure and blood gas measurements. Similarly to APS, hair bleach aerosols containing > or =10.9 mg x m(-3) persulphate (ammonium and potassium salt) in air and > or =1.36 mg x m(-3) H2O2 in air caused airway hyperresponsiveness to acetylcholine after 4 h of exposure. Aerosolized H2O2 (> or =37 mg x m(-3) in air) did not influence airway responsiveness to acetylcholine. The results demonstrate that hair bleaching products containing persulphates dissolved in H2O2 cause airway hyperresponsiveness to acetylcholine in rabbits.

  16. Acute High-Dose and Chronic Lifetime Exposure to Alcohol Consumption and Differentiated Thyroid Cancer: T-CALOS Korea

    PubMed Central

    Hwang, Yunji; Lee, Kyu Eun; Weiderpass, Elisabete; Park, Young Joo; Chai, Young Jun; Kwon, Hyungju; Park, Do Joon; Cho, BeLong; Choi, Ho-Chun; Kang, Daehee; Park, Sue K.

    2016-01-01

    Background This study evaluated the effects of acute high-dose and chronic lifetime exposure to alcohol and exposure patterns on the development of differentiated thyroid cancer (DTC). Methods The Thyroid Cancer Longitudinal Study (T-CALOS) included 2,258 DTC patients (449 men and 1,809 women) and 22,580 healthy participants (4,490 men and 18,090 women) who were individually matched by age, gender, and enrollment year. In-person interviews were conducted with a structured questionnaire to obtain epidemiologic data. Clinicopathologic features of the patients were obtained by chart reviews. Odds ratios (ORs) and 95% confidence intervals (95%CI) were estimated using conditional regression models. Results While light or moderate drinking behavior was related to a reduced risk of DTC, acute heavy alcohol consumption (151 g or more per event or on a single occasion) was associated with increased risks in men (OR = 2.22, 95%CI = 1.27–3.87) and women (OR = 3.61, 95%CI = 1.52–8.58) compared with never-drinkers. The consumption of alcohol for 31 or more years was a significant risk factor for DTC for both men (31–40 years: OR = 1.58, 95%CI = 1.10–2.28; 41+ years: OR = 3.46, 95%CI = 2.06–5.80) and women (31–40 years: OR = 2.18, 95%CI = 1.62–2.92; 41+ years: OR = 2.71, 95%CI = 1.36–5.05) compared with never-drinkers. The consumption of a large amount of alcohol on a single occasion was also a significant risk factor, even after restricting DTC outcomes to tumor size, lymph node metastasis, extrathyroidal extension and TNM stage. Conclusion The findings of this study suggest that the threshold effects of acute high-dose alcohol consumption and long-term alcohol consumption are linked to an increased risk of DTC. PMID:26985827

  17. Impact of acute exposure to WTC dust on ciliated and goblet cells in lungs of rats.

    PubMed

    Cohen, Mitchell D; Vaughan, Joshua M; Garrett, Brittany; Prophete, Colette; Horton, Lori; Sisco, Maureen; Ghio, Andrew; Zelikoff, Judith; Lung-chi, Chen

    2015-01-01

    Clinical studies and the World Trade Center (WTC) Health Registry have revealed increases in the incidence of chronic (non-cancer) lung disorders among first responders (FR) who were at Ground Zero during the initial 72 h after the collapse. Our previous analyses of rats exposed to building-derived WTC dusts using exposure scenarios/levels that mimicked FR mouth-breathing showed that a single WTC dust exposure led to changes in expression of genes whose products could be involved in the lung ailments, but few other significant pathologies. We concluded that rather than acting as direct inducers of many of the FR health effects, it was more likely inhaled WTC dusts instead may have impacted on toxicities induced by other rescue-related co-pollutants present in Ground Zero air. To allow for such effects to occur, we hypothesized that the alkaline WTC dusts induced damage to the normal ability of the lungs to clear inhaled particles. To validate this, rats were exposed on two consecutive days (2 h/d, by intratracheal inhalation) to WTC dust (collected 12-13 September 2001) and examined over a 1-yr period thereafter for changes in the presence of ciliated cells in the airways and hyperplastic goblet cells in the lungs. WTC dust levels in the lungs were assessed in parallel to verify that any changes in levels of these cells corresponded with decreases in host ability to clear the particles themselves. Image analyses of the rat lungs revealed a significant decrease in ciliated cells and increase in hyperplastic goblet cells due to the single series of WTC dust exposures. The study also showed there was only a nominal non-significant decrease (6-11%) in WTC dust burden over a 1-yr period after the final exposure. These results provide support for our current hypothesis that exposure to WTC dusts caused changes in airway morphology/cell composition; such changes could, in turn, have led to potential alterations in the clearance/toxicities of other pollutants inhaled

  18. Impact of acute exposure to WTC dust on ciliated and goblet cells in lungs of rats

    PubMed Central

    Cohen, Mitchell D.; Vaughan, Joshua M.; Garrett, Brittany; Prophete, Colette; Horton, Lori; Sisco, Maureen; Ghio, Andrew; Zelikoff, Judith; Lung-chi, Chen

    2015-01-01

    Clinical studies and the World Trade Center (WTC) Health Registry have revealed increases in the incidence of chronic (non-cancer) lung disorders among first responders (FR) who were at Ground Zero during the initial 72 h after the collapse. Our previous analyses of rats exposed to building-derived WTC dusts using exposure scenarios/levels that mimicked FR mouth-breathing showed that a single WTC dust exposure led to changes in expression of genes whose products could be involved in the lung ailments, but few other significant pathologies. We concluded that rather than acting as direct inducers of many of the FR health effects, it was more likely inhaled WTC dusts instead may have impacted on toxicities induced by other rescue-related co-pollutants present in Ground Zero air. To allow for such effects to occur, we hypothesized that the alkaline WTC dusts induced damage to the normal ability of the lungs to clear inhaled particles. To validate this, rats were exposed on two consecutive days (2 h/d, by intratracheal inhalation) to WTC dust (collected 12–13 September 2001) and examined over a 1-yr period thereafter for changes in the presence of ciliated cells in the airways and hyperplastic goblet cells in the lungs. WTC dust levels in the lungs were assessed in parallel to verify that any changes in levels of these cells corresponded with decreases in host ability to clear the particles themselves. Image analyses of the rat lungs revealed a significant decrease in ciliated cells and increase in hyperplastic goblet cells due to the single series of WTC dust exposures. The study also showed there was only a nominal non-significant decrease (6–11%) in WTC dust burden over a 1-yr period after the final exposure. These results provide support for our current hypothesis that exposure to WTC dusts caused changes in airway morphology/cell composition; such changes could, in turn, have led to potential alterations in the clearance/toxicities of other pollutants inhaled

  19. [Case report of acute death on the 7th day due to exposure to the vapor of the insecticide chlorfenapyr].

    PubMed

    Hoshiko, Michiko; Naito, Shinji; Koga, Mitsuaki; Mori, Mihoko; Hara, Kunio; Ishitake, Tatsuya

    2007-04-01

    We present the case of a 55-year-old male agricultural worker who complained of severe general fatigue and hyperperspiration after exposure to an insecticide vapor. He worked in a tea plantation and used chlorfenapyr, a broad spectrum for harmful insects, without any protective mask or clothes. After one day of insecticide spray work, he gradually began to complain of general fatigue, hyperperspiration, nausea and vomiting. At first, he was diagnosed as being dehydrated and was treated with fluid replacement therapy. Although he received this conservative therapy, there was no effect on the above mentioned symptoms. On the 7th day of the onset of his symptoms, his consciousness level deteriorated rapidly and body temperature exceeded 40 degrees C. No cerebral vascular disease or meningitis was observed. Finally, he died despite intensive care. The findings of the clinical course and laboratory data suggest a clinical diagnosis of acute pesticide poisoning due to exposure to chlorfenapyr vapor. We suggest that agricultural workers should use this insecticide with caution and sufficient protective gear.

  20. Acute and sub-lethal exposure to copper oxide nanoparticles causes oxidative stress and teratogenicity in zebrafish embryos.

    PubMed

    Ganesan, Santhanamari; Anaimalai Thirumurthi, Naveenkumar; Raghunath, Azhwar; Vijayakumar, Savitha; Perumal, Ekambaram

    2016-04-01

    Nano-copper oxides are a versatile inorganic material. As a result of their versatility, the immense applications and usage end up in the environment causing a concern for the lifespan of various beings. The ambiguities surround globally on the toxic effects of copper oxide nanoparticles (CuO-NPs). Hence, the present study endeavored to study the sub-lethal acute exposure effects on the developing zebrafish embryos. The 48 hpf LC50 value was about 64 ppm. Therefore, we have chosen the sub-lethal dose of 40 and 60 ppm for the study. Accumulation of CuO-NPs was evidenced from the SEM-EDS and AAS analyzes. The alterations in the AChE and Na(+)/K(+)-ATPase activities disrupted the development process. An increment in the levels of oxidants with a concomitant decrease in the antioxidant enzymes confirmed the induction of oxidative stress. Oxidative stress triggered apoptosis in the exposed embryos. Developmental anomalies were observed with CuO-NPs exposure in addition to oxidative stress in the developing embryos. Decreased heart rate and hatching delay hindered the normal developmental processes. Our work has offered valuable data on the connection between oxidative stress and teratogenicity leading to lethality caused by CuO-NPs. A further molecular mechanism unraveling the uncharted connection between oxidative stress and teratogenicity will aid in the safe use of CuO-NPs.

  1. Early changes in gene expression induced by acute UV exposure in leaves of Psychotria brachyceras, a bioactive alkaloid accumulating plant.

    PubMed

    do Nascimento, Naíla Cannes; Menguer, Paloma Koprovski; Sperotto, Raul Antonio; de Almeida, Márcia Rodrigues; Fett-Neto, Arthur Germano

    2013-05-01

    UV-B radiation can damage biomolecules, such as DNA, RNA, and proteins, halting essential cellular processes; this damage is partly due to ROS generation. Plant secondary metabolites may protect against UV-B. Psychotria brachyceras Müll. Arg. (Rubiaceae), a subtropical shrub, produces brachycerine, a monoterpene indole alkaloid mainly accumulated in leaf tissues, which displays antioxidant and antimutagenic activities. Exposure of P. brachyceras cuttings to UV-B radiation significantly increases leaf brachycerine concentration. It has been suggested that this alkaloid might contribute to protection against UV-B damage both through its quenching activity on ROS and as UV shield. To identify differentially expressed genes of P. brachyceras in response to UV-B and investigate a possible influence of this stimulus on putative brachycerine-related genes, suppressive subtractive hybridization was applied. Complementary DNA from UV-B-treated leaves for 24 h was used as tester, and cDNA from untreated leaves, as driver. After BLASTX alignments, 134 sequences matched plant genes. Using quantitative RT-PCR, selected genes potentially related to brachycerine showed significant increases in transcription after UV-B exposure: tryptophan decarboxylase, ACC oxidase, UDP-glucose glucosyltransferase, lipase, and serine/threonine kinase. Results suggest a possible involvement of brachycerine in acute UV-B responses and show that alkaloid accumulation seems at least partly regulated at transcriptional level.

  2. Acute ethanol exposure suppresses the repair of O6-methylguanine DNA lesions in castrated adult male rats.

    PubMed

    Wilson, D M; Tentler, J J; Carney, J P; Wilson, T M; Kelley, M R

    1994-10-01

    Alcohol has clearly been associated with an increase of cancers in numerous tissue, including the respiratory tract, colon, rectum, liver, but especially the esophagus, larynx, pharynx, and mouth. Alcohol alone has not been shown to be a mutagen until it is converted to acetaldehyde and, therefore, alcohol presumably acts as a cocarcinogen. Previous data has shown that alcohol concentrations of 2% or greater inhibits DNA repair, and in light of the widespread consumption of alcoholic beverages with alcohol contents ranging from 4 to 5% (beer and wine coolers) to 50% (whiskey), interest in determining the mechanism(s) responsible for alcohol-induced carcinogenesis has heightened. Although previous studies, in intact rats, have investigated the effects of chronic alcohol exposure on some aspects of DNA repair, we have begun to address the effects of acute or "binge" alcohol exposure on mammalian DNA repair. Toward this end, we report the inhibition of O6-methylguanine-DNA methyltransferase (MGMT) by a single intraperitoneal injection of 30% ethanol in adult male castrated rats. This inhibition lasted for at least 24 hr. We also observed a dose-response effect of ethanol on MGMT activity, again only in the castrated rats. The finding of ethanol's effect on MGMT activity in castrated and not intact rats implies a hormonal component of MGMT DNA repair response, which has only been alluded to in past research.

  3. Rainbow trout (Oncorhynchus mykiss) pro-oxidant and genotoxic responses following acute and chronic exposure to the antibiotic oxytetracycline.

    PubMed

    Rodrigues, Sara; Antunes, Sara C; Correia, Alberto T; Nunes, Bruno

    2017-01-01

    Oxytetracycline (OTC), an antibacterial agent, is extensively used in aquaculture practices all over the world, but also in human and veterinary medicines. Because of its intensive use, low rates of absorption by treated animals, inadequate disposal, and low efficiency of removal in wastewater treatment plants, the potential harmful effects on aquatic organisms are of great concern. This work aimed to assess the effects of this antibiotic in rainbow trout, following both acute and chronic exposures. Catalase (CAT), total glutathione peroxidase (GPx), glutathione reductase (GRed) activities and lipid peroxidation (TBARS levels) were quantified as oxidative stress biomarkers, in gills and liver. Genotoxic endpoints, reflecting different types of genetic damage in blood cells, were also determined, by analysis of genetic damage (determination of the genetic damage index, GDI, measured by comet assay) and erythrocytic nuclear abnormalities (ENAs). The obtained results showed a mild pattern of antioxidant response, with modifications in CAT and GPx activities in gills, and lipid peroxidation in liver. These results suggest that despite the occurrence of oxidative effects, a full scenario of oxidative stress is not likely. However, exposure to OTC resulted in the establishment of genotoxic alterations with the induction of DNA strand breaks in blood cells (increase of GDI), and of chromosome breakage and/or segregational abnormalities (increase of ENAs). Considering that the oxidative response was not totally devisable, other mechanisms may be involved in the genotoxic effects reported.

  4. EFFECTS OF ACUTE EXPOSURE TO CONCENTRATED AMBIENT PARTICULATES ON CARDIOPULMONARY, THERMOREGULATORY, AND BIOCHEMICAL PARAMETERS HEALTHY AND MONOCROTALINE-TREATED SPRAGUE-DAWLEY RATS

    EPA Science Inventory


    EFFECTS OF ACUTE EXPOSURE TO CONCENTRATED AMBIENT PARTICULATES ON CARDIOPULMONARY, THERMOREGULATORY, AND BIOCHEMICAL PARAMETERS IN HEALTHY AND MONOCROTALINE-TREATED SPRAGUE-DAWLEY RATS. LB Wichers1, JP Nolan2, DW Winsett2, UP Kodavanti2, MCJ Schladweiler2, DL Costa2, and WP ...

  5. USE OF THE FUNGICIDE CARBENDAZIM AS A MODEL COMPOUND TO DETERMINE THE IMPACT OF ACUTE CHEMICAL EXPOSURE DURING OOCYTE MATURATION AND FERTILIZATION ON PREGNANCY OUTCOME IN THE HAMSTER

    EPA Science Inventory

    Here we use a hamster animal model to identify early pregnancy loss due to an acute chemical exposure to the female during the perifertilization interval. The fungicide carbendazim (methyl 1H-benzimidazole-2-carbamate), a microtubule poison with antimitotic activity, was selected...

  6. Use of a custom RT-PCR array to analyze toxicity pathways at different life stages in Brown Norway Rat Brain following acute Toluene exposure.

    EPA Science Inventory

    To investigate the contribution of different life stages on response to toxicants, we utilized a custom designed RT-PCR array to examine the effects of acute exposure by oral gavage of the volatile organic solvent toluene (0.00, 0.65 or 1.0 glkg) in the brains of ma1e Brown Norwa...

  7. OXIDATIVE STRESS PARTICIPATES IN ACUTE LUNG INJURY AND ACTIVATION OF MITOGEN ACTIVATED PROTEIN KINASES (MAPK) FOLLOWING AIR POLLUTION PARTICLE EXPOSURE (PM)

    EPA Science Inventory

    OXIDATIVE STRESS PARTICIPATES IN ACUTE LUNG INJURY AND ACTIVATION OF MITOGEN ACTIVATED PROTEIN KINASES (MAPK) FOLLOWING AIR POLLUTION PARTICLE EXPOSURE (PM). E S Roberts1, R Jaskot2, J Richards2, and K L Dreher2. 1College of Veterinary Medicine, NC State University, Raleigh, NC a...

  8. Influence of dissolved organic carbon on toxicity of copper to a unionid mussel (Villosa iris) and a cladoceran (Ceriodaphnia dubia) in acute and chronic water exposures

    USGS Publications Warehouse

    Wang, Ning; Mebane, Christopher A.; Kunz, James L.; Ingersoll, Christopher G.; Brumbaugh, William G.; Santore, Robert C.; Gorsuch, Joseph W.; Arnold, W. Ray

    2011-01-01

    Acute and chronic toxicity of copper (Cu) to a unionid mussel (Villosa iris) and a cladoceran (Ceriodaphnia dubia) were determined in water exposures at four concentrations of dissolved organic carbon (DOC; nominally 0.5, 2.5, 5, and 10 mg/L as carbon [C]). Test waters with DOC concentrations of 2.5 to 10 mg C/L were prepared by mixing a concentrate of natural organic matter (Suwannee River, GA, USA) in diluted well water (hardness 100 mg/L as CaCO3, pH 8.3, DOC 0.5 mg C/L). Acute median effect concentrations (EC50s) for dissolved Cu increased approximately fivefold (15–72 μg Cu/L) for mussel survival in 4-d exposures and increased about 11-fold (25–267 μg Cu/L) for cladoceran survival in 2-d exposures across DOC concentrations from 0.5 to 10 mg C/L. Similarly, chronic 20% effect concentrations (EC20s) for the mussel in 28-d exposures increased about fivefold (13–61 μg Cu/L for survival; 8.8–38 μg Cu/L for biomass), and the EC20s for the cladoceran in 7-d exposures increased approximately 17-fold (13–215 μg Cu/L) for survival or approximately fourfold (12–42 μg Cu/L) for reproduction across DOC concentrations from 0.5 to 10 mg C/L. The acute and chronic values for the mussel were less than or approximately equal to the values for the cladoceran. Predictions from the biotic ligand model (BLM) used to derive the U.S. Environmental Protection Agency's ambient water quality criteria (AWQC) for Cu explained more than 90% of the variation in the acute and chronic endpoints for the two species, with the exception of the EC20 for cladoceran reproduction (only 46% of variation explained). The BLM-normalized acute EC50s and chronic EC20s for the mussel and BLM-normalized chronic EC20s for the cladoceran in waters with DOC concentrations of 2.5 to 10 mg C/L were equal to or less than the final acute value and final chronic value in the BLM-based AWQC for Cu, respectively, indicating that the Cu AWQC might not adequately protect the mussel from acute and

  9. Influence of dissolved organic carbon on toxicity of copper to a unionid mussel (Villosa iris) and a cladoceran (Ceriodaphnia dubia) in acute and chronic water exposures.

    PubMed

    Wang, Ning; Mebane, Christopher A; Kunz, James L; Ingersoll, Christopher G; Brumbaugh, William G; Santore, Robert C; Gorsuch, Joseph W; Arnold, W Ray

    2011-09-01

    Acute and chronic toxicity of copper (Cu) to a unionid mussel (Villosa iris) and a cladoceran (Ceriodaphnia dubia) were determined in water exposures at four concentrations of dissolved organic carbon (DOC; nominally 0.5, 2.5, 5, and 10 mg/L as carbon [C]). Test waters with DOC concentrations of 2.5 to 10 mg C/L were prepared by mixing a concentrate of natural organic matter (Suwannee River, GA, USA) in diluted well water (hardness 100 mg/L as CaCO(3) , pH 8.3, DOC 0.5 mg C/L). Acute median effect concentrations (EC50s) for dissolved Cu increased approximately fivefold (15-72 µg Cu/L) for mussel survival in 4-d exposures and increased about 11-fold (25-267 µg Cu/L) for cladoceran survival in 2-d exposures across DOC concentrations from 0.5 to 10 mg C/L. Similarly, chronic 20% effect concentrations (EC20s) for the mussel in 28-d exposures increased about fivefold (13-61 µg Cu/L for survival; 8.8-38 µg Cu/L for biomass), and the EC20s for the cladoceran in 7-d exposures increased approximately 17-fold (13-215 µg Cu/L) for survival or approximately fourfold (12-42 µg Cu/L) for reproduction across DOC concentrations from 0.5 to 10 mg C/L. The acute and chronic values for the mussel were less than or approximately equal to the values for the cladoceran. Predictions from the biotic ligand model (BLM) used to derive the U.S. Environmental Protection Agency's ambient water quality criteria (AWQC) for Cu explained more than 90% of the variation in the acute and chronic endpoints for the two species, with the exception of the EC20 for cladoceran reproduction (only 46% of variation explained). The BLM-normalized acute EC50s and chronic EC20s for the mussel and BLM-normalized chronic EC20s for the cladoceran in waters with DOC concentrations of 2.5 to 10 mg C/L were equal to or less than the final acute value and final chronic value in the BLM-based AWQC for Cu, respectively, indicating that the Cu AWQC might not adequately protect the mussel from acute and

  10. Influence of dissolved organic carbon on toxicity of copper to a unionid mussel (Villosa iris) and a cladoceran (Ceriodaphnia dubia) in acute and chronic water exposures

    USGS Publications Warehouse

    Wang, N.; Mebane, C.A.; Kunz, J.L.; Ingersoll, C.G.; Brumbaugh, W.G.; Santore, R.C.; Gorsuch, J.W.; Arnold, W.R.

    2011-01-01

    Acute and chronic toxicity of copper (Cu) to a unionid mussel (Villosa iris) and a cladoceran (Ceriodaphnia dubia) were determined in water exposures at four concentrations of dissolved organic carbon (DOC; nominally 0.5, 2.5, 5, and 10mg/L as carbon [C]). Test waters with DOC concentrations of 2.5 to 10mgC/L were prepared by mixing a concentrate of natural organic matter (Suwannee River, GA, USA) in diluted well water (hardness 100mg/L as CaCO3, pH 8.3, DOC 0.5mgC/L). Acute median effect concentrations (EC50s) for dissolved Cu increased approximately fivefold (15-72??gCu/L) for mussel survival in 4-d exposures and increased about 11-fold (25-267??gCu/L) for cladoceran survival in 2-d exposures across DOC concentrations from 0.5 to 10mgC/L. Similarly, chronic 20% effect concentrations (EC20s) for the mussel in 28-d exposures increased about fivefold (13-61??gCu/L for survival; 8.8-38??gCu/L for biomass), and the EC20s for the cladoceran in 7-d exposures increased approximately 17-fold (13-215??gCu/L) for survival or approximately fourfold (12-42??gCu/L) for reproduction across DOC concentrations from 0.5 to 10mgC/L. The acute and chronic values for the mussel were less than or approximately equal to the values for the cladoceran. Predictions from the biotic ligand model (BLM) used to derive the U.S. Environmental Protection Agency's ambient water quality criteria (AWQC) for Cu explained more than 90% of the variation in the acute and chronic endpoints for the two species, with the exception of the EC20 for cladoceran reproduction (only 46% of variation explained). The BLM-normalized acute EC50s and chronic EC20s for the mussel and BLM-normalized chronic EC20s for the cladoceran in waters with DOC concentrations of 2.5 to 10mgC/L were equal to or less than the final acute value and final chronic value in the BLM-based AWQC for Cu, respectively, indicating that the Cu AWQC might not adequately protect the mussel from acute and chronic exposure, and the cladoceran

  11. Effect of chromium (VI) exposure on antioxidant defense status and trace element homeostasis in acute experiment in rat.

    PubMed

    Kotyzová, Dana; Hodková, Anna; Bludovská, Monika; Eybl, Vladislav

    2015-11-01

    Occupational exposure to hexavalent chromium (Cr(VI)) compounds is of concern in many Cr-related industries and their surrounding environment. Cr(VI) is a proven toxin and carcinogen. The Cr(VI) compounds are easily absorbed, can diffuse across cell membranes, and have strong oxidative potential. Despite intensive studies of Cr(VI) pro-oxidative effects, limited data exist on the influence of Cr(VI) on selenoenzymes thioredoxin reductase (TrxR) and glutathione peroxidase (GPx)-important components of antioxidant defense system. This study investigates the effect of Cr(VI) exposure on antioxidant defense status, with focus on these selenoenzymes, and on trace element homeostasis in an acute experiment in rat. Male Wistar rats (130-140g) were assigned to two groups of 8 animals: I. control; and II. Cr(VI) treated. The animals in Cr(VI) group were administered a single dose of K2Cr2O7 (20 mg /kg, intraperitoneally (ip)). The control group received saline solution. After 24 h, the animals were sacrificed and the liver and kidneys were examined for lipid peroxidation (LP; thiobarbituric acid reactive substances (TBARS) concentration), the level of reduced glutathione (GSH) and the activities of GPx-1, TrxR-1, and glutathione reductase (GR). Samples of tissues were also used to estimate Cr accumulation and alterations in zinc, copper, and iron levels. The acute Cr(VI) exposure caused an increase in both hepatic and renal LP (by 70%, p < 0.01 and by 15%, p < 0.05, respectively), increased hepatic GSH level and GPx-1 activity, and decreased renal GPx-1 activity. The activity of GR was not changed. A significant inhibitory effect of Cr(VI) was found on TrxR-1 activity in both the liver and the kidneys. The ability of Cr(VI) to cause TrxR inhibition could contribute to its cytotoxic effects. Further investigation of oxidative responses in different in vivo models may enable the development of strategies to protect against Cr(VI) oxidative damage.

  12. Transcriptional response of rat frontal cortex following acute In Vivo exposure to the pyrethroid insecticides permethrin and deltamethrin

    PubMed Central

    Harrill, Joshua A; Li, Zhen; Wright, Fred A; Radio, Nicholas M; Mundy, William R; Tornero-Velez, Rogelio; Crofton, Kevin M

    2008-01-01

    Background Pyrethroids are neurotoxic pesticides that interact with membrane bound ion channels in neurons and disrupt nerve function. The purpose of this study was to characterize and explore changes in gene expression that occur in the rat frontal cortex, an area of CNS affected by pyrethroids, following an acute low-dose exposure. Results Rats were acutely exposed to either deltamethrin (0.3 – 3 mg/kg) or permethrin (1 – 100 mg/kg) followed by collection of cortical tissue at 6 hours. The doses used range from those that cause minimal signs of intoxication at the behavioral level to doses well below apparent no effect levels in the whole animal. A statistical framework based on parallel linear (SAM) and isotonic regression (PIR) methods identified 95 and 53 probe sets as dose-responsive. The PIR analysis was most sensitive for detecting transcripts with changes in expression at the NOAEL dose. A sub-set of genes (Camk1g, Ddc, Gpd3, c-fos and Egr1) was then confirmed by qRT-PCR and examined in a time course study. Changes in mRNA levels were typically less than 3-fold in magnitude across all components of the study. The responses observed are consistent with pyrethroids producing increased neuronal excitation in the cortex following a low-dose in vivo exposure. In addition, Significance Analysis of Function and Expression (SAFE) identified significantly enriched gene categories common for both pyrethroids, including some relating to branching morphogenesis. Exposure of primary cortical cell cultures to both compounds resulted in an increase (~25%) in the number of neurite branch points, supporting the results of the SAFE analysis. Conclusion In the present study, pyrethroids induced changes in gene expression in the frontal cortex near the threshold for decreases in ambulatory motor activity in vivo. The penalized regression methods performed similarly in detecting dose-dependent changes in gene transcription. Finally, SAFE analysis of gene expression data

  13. Acute fluoxetine exposure alters crab anxiety-like behaviour, but not aggressiveness

    PubMed Central

    Hamilton, Trevor James; Kwan, Garfield T.; Gallup, Joshua; Tresguerres, Martin

    2016-01-01

    Aggression and responsiveness to noxious stimuli are adaptable traits that are ubiquitous throughout the animal kingdom. Like vertebrate animals, some invertebrates have been shown to exhibit anxiety-like behaviour and altered levels of aggression that are modulated by the neurotransmitter serotonin. To investigate whether this influence of serotonin is conserved in crabs and whether these behaviours are sensitive to human antidepressant drugs; the striped shore crab, Pachygrapsus crassipes, was studied using anxiety (light/dark test) and aggression (mirror test) paradigms. Crabs were individually exposed to acute doses of the selective serotonin reuptake inhibitor, fluoxetine (5 or 25 mg/L), commonly known as Prozac®, followed by behavioural testing. The high dose of fluoxetine significantly decreased anxiety-like behaviour but had no impact on mobility or aggression. These results suggest that anxiety-like behaviour is more sensitive to modulation of serotonin than is aggressiveness in the shore crab. PMID:26806870

  14. Acute fluoxetine exposure alters crab anxiety-like behaviour, but not aggressiveness.

    PubMed

    Hamilton, Trevor James; Kwan, Garfield T; Gallup, Joshua; Tresguerres, Martin

    2016-01-25

    Aggression and responsiveness to noxious stimuli are adaptable traits that are ubiquitous throughout the animal kingdom. Like vertebrate animals, some invertebrates have been shown to exhibit anxiety-like behaviour and altered levels of aggression that are modulated by the neurotransmitter serotonin. To investigate whether this influence of serotonin is conserved in crabs and whether these behaviours are sensitive to human antidepressant drugs; the striped shore crab, Pachygrapsus crassipes, was studied using anxiety (light/dark test) and aggression (mirror test) paradigms. Crabs were individually exposed to acute doses of the selective serotonin reuptake inhibitor, fluoxetine (5 or 25 mg/L), commonly known as Prozac®, followed by behavioural testing. The high dose of fluoxetine significantly decreased anxiety-like behaviour but had no impact on mobility or aggression. These results suggest that anxiety-like behaviour is more sensitive to modulation of serotonin than is aggressiveness in the shore crab.

  15. (Acute radiation syndrome within the high-exposure group of Chernobyl)

    SciTech Connect

    Eckerman, K.F.

    1990-11-05

    Dr. K. F. Eckerman participated as a member of an American scientific team in meetings with Soviet scientists at the Institute of Biophysics in Moscow on October 18 and 19, 1990. The meetings were part of an agreement between the two countries under the Joint USSR-USA Coordinating Committee on Civil Nuclear Reactor Safety (JCCCNRS). The meetings were part of the efforts of Working Group 7.2 on Health Effects. These discussions were limited to the acute radiation syndrome (ARS) within the highly exposed Chernobyl patients. The specific objective of this meeting was to review the clinical and laboratory data on the Chernobyl ARS patients and to see what might be done to make these data available to improve our understanding of the syndrome.

  16. Different uranium distribution patterns in cytosolic protein pool of zebrafish gills after chronic and acute waterborne exposures.

    PubMed

    Bucher, Guillaume; Mounicou, Sandra; Simon, Olivier; Floriani, Magali; Lobinski, Ryszard; Frelon, Sandrine

    2014-09-01

    The toxicity of uranium (U) to aquatic organisms depends notably on its compartmentalization in organs, tissues, cells as well as on its distribution among biomolecules. In order to contribute to the understanding of U accumulation and associated toxicity mechanisms in case of waterborne exposure, this study focused on U fate in the gills epithelia, uptake pathway, of the fish model Danio rerio (zebrafish). U distribution among cytosolic biomolecules was investigated after no addition (0μgL(-)(1) (c0) for 3 and 30d), chronic (20μgL(-)(1) (c20) for 30d) and acute (20μgL(-)(1) (c20) and 250μgL(-)(1) (c250) for 3d) exposures to depleted U. Cytosolic U accounted for an average of 24-32% of gills burden for c20 and c250, respectively. Size Exclusion Chromatography (SEC) coupled with Inductively Coupled Plasma-Sector Field Mass Spectrometry (ICP-SFMS) allowed identification of ecotoxicologically relevant U-containing fractions among cytosolic biomolecules as a function of exposure conditions. In c0 and c20 samples, most U (ca.80%) was found in the Low Molecular Weight fraction (LMW, <18kDa), often considered as a detoxifying fraction. In c250 exposed fish, U was equally distributed between LMW (40%) and High Molecular Weight (HMW, 150-670kDa; 40%) fractions, the latter including sensitive metalloproteins. Uranium-biomolecules were co-eluted with endogenous essential metal (Fe, Cu and Zn) species, however, no major influence on their cytosolic concentration and distribution pattern among cytosolic proteins was found.

  17. The Protective Effects of Melatonin Against Oxidative Stress and Inflammation Induced by Acute Cadmium Exposure in Mice Testis.

    PubMed

    Li, Renyan; Luo, Xue; Li, Lianbing; Peng, Qiang; Yang, Yuyou; Zhao, Letian; Ma, Mingfu; Hou, Zhiwei

    2016-03-01

    Cadmium (Cd) is widely used in daily life and was recently recognized as a possible source of human toxicity due to its ability to accumulate in organs. Previous studies have shown that Cd exposure may cause testicular toxicity through oxidative stress and an inflammatory effect. Melatonin has been demonstrated to be an effective anti-oxidant and has an anti-inflammatory effect. The aim of the present study was to investigate the toxicological effects of Cd on reproduction in male mice and the potential protective action of melatonin against these adverse effects. Adult male mice were injected intraperitoneally with Cd at a dose of 2 mg/kg body weight per day for seven consecutive days with or without melatonin pretreatment. Sex organ weight, sperm parameters including sperm quality, apoptosis, acrosome integrity, mitochondrial membrane potential, testicular morphology, serum sex hormone, inflammatory status, and oxidative stress were evaluated. The results showed that significant adverse effects were observed in the male reproductive system after Cd exposure, including alterations in sperm parameters, increased DNA damage, and sex hormone disturbance. Acute Cd exposure also significantly increased malondialdehyde (MDA) contents, decreased glutathione (GSH) and superoxide dismutase (SOD) activities, and upregulated levels of the pro-inflammatory cytokines, tumor necrosis factor-alpha (TNF-α), and interleukin-1beta (IL-1β), in the testis. In contrast, melatonin pretreatment significantly alleviated these toxic effects, and its mechanism may involve inhibiting MDA level, restoring GSH and SOD activities, and reducing the upregulation of TNF-α and IL-1β. Our data suggest that oxidative stress and inflammation are involved in Cd-induced toxicity in the male reproductive system and that co-administration of melatonin exerts a protective effect against Cd-induced male reproductive toxicity.

  18. Efficacy of multiple exposure with low level He-Ne laser dose on acute wound healing: a pre-clinical study

    NASA Astrophysics Data System (ADS)

    Prabhu, Vijendra; Rao, Bola Sadashiva S.; Mahato, Krishna Kishore

    2014-02-01

    Investigations on the use of Low Level Laser Therapy (LLLT) for wound healing especially with the red laser light have demonstrated its pro-healing potential on a variety of pre-clinical and surgical wounds. However, until now, in LLLT the effect of multiple exposure of low dose laser irradiation on acute wound healing on well-designed pre-clinical model is not much explored. The present study aimed to investigate the effect of multiple exposure of low dose Helium Neon laser on healing progression of full thickness excision wounds in Swiss albino mice. Further, the efficacy of the multiple exposure of low dose laser irradiation was compared with the single exposure of optimum dose. Full thickness excision wounds (circular) of 15 mm diameter were created, and subsequently illuminated with the multiple exposures (1, 2, 3, 4 and 5 exposure/ week until healing) of He-Ne (632.8 nm, 4.02 mWcm-2) laser at 0.5 Jcm-2 along with single exposure of optimum laser dose (2 J/cm-2) and un-illuminated controls. Classical biophysical parameters such as contraction kinetics, area under the curve and the mean healing time were documented as the assessment parameters to examine the efficacy of multiple exposures with low level laser dose. Experimental findings substantiated that either single or multiple exposures of 0.5 J/cm2 failed to produce any detectable alterations on wound contraction, area under the curve and mean healing time compared to single exposure of optimum dose (2 Jcm-2) and un-illuminated controls. Single exposure of optimum, laser dose was found to be ideal for acute wound healing.

  19. Acute exposure to vibration is an apoptosis-inducing stimulus in the vocal fold epithelium.

    PubMed

    Novaleski, Carolyn K; Kimball, Emily E; Mizuta, Masanobu; Rousseau, Bernard

    2016-10-01

    Clinical voice disorders pose significant communication-related challenges to patients. The purpose of this study was to quantify the rate of apoptosis and tumor necrosis factor-alpha (TNF-α) signaling in vocal fold epithelial cells in response to increasing time-doses and cycle-doses of vibration. 20 New Zealand white breeder rabbits were randomized to three groups of time-doses of vibration exposure (30, 60, 120min) or a control group (120min of vocal fold adduction and abduction). Estimated cycle-doses of vocal fold vibration were extrapolated based on mean fundamental frequency. Laryngeal tissue specimens were evaluated for apoptosis and gene transcript and protein levels of TNF-α. Results revealed that terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining was significantly higher after 120min of vibration compared to the control. Transmission electron microscopy (TEM) revealed no significant effect of time-dose on the mean area of epithelial cell nuclei. Extrapolated cycle-doses of vibration exposure were closely related to experimental time-dose conditions, although no significant correlations were observed with TUNEL staining or mean area of epithelial cell nuclei. TUNEL staining was positively correlated with TNF-α protein expression. Our findings suggest that apoptosis can be induced in the vocal fold epithelium after 120min of modal intensity phonation. In contrast, shorter durations of vibration exposure do not result in apoptosis signaling. However, morphological features of apoptosis are not observed using TEM. Future studies are necessary to examine the contribution of abnormal apoptosis to vocal fold diseases.

  20. Pro-inflammatory responses of human bronchial epithelial cells to acute nitrogen dioxide exposure.

    PubMed

    Ayyagari, Vijayalakshmi N; Januszkiewicz, Adolph; Nath, Jayasree

    2004-04-15

    Nitrogen dioxide (NO2) is an environmental oxidant, known to be associated with lung epithelial injury. In the present study, cellular pro-inflammatory responses following exposure to a brief high concentration of NO2 (45 ppm) were assessed, using normal human bronchial epithelial (NHBE) cells as an in vitro model of inhalation injury. Generation and release of pro-inflammatory mediators such as nitric oxide (NO), IL-8, TNF-alpha, IFN-gamma and IL-1beta were assessed at different time intervals following NO2 exposure. Effects of a pre-existing inflammatory condition was tested by treating the NHBE cells with different inflammatory cytokines such as IFN-gamma, IL-8, TNF-alpha, IL-1beta, either alone or in combination, before exposing them to NO2. Immunofluorescence studies confirmed oxidant-induced formation of 3-nitrotyrosine in the NO2-exposed cells. A marked increase in the levels of nitrite (as an index of NO) and IL-8 were observed in the NO2-exposed cells, which were further enhanced in the presence of the cytokines. Effects of various NO inhibitors combined, with immunofluorescence and Western blotting data, indicated partial contribution of the nitric oxide synthases (NOSs) toward the observed increase in nitrite levels. Furthermore, a significant increase in IL-1beta and TNF-alpha generation was observed in the NO2-exposed cells. Although NO2 exposure alone did induce slight cytotoxicity (<12%), but presence of inflammatory cytokines such as TNF-alpha and IFN-gamma resulted in an increased cell death (28-36%). These results suggest a synergistic role of inflammatory mediators, particularly of NO and IL-8, in NO2-mediated early cellular changes. Our results also demonstrate an increased sensitivity of the cytokine-treated NHBE cells toward NO2, which may have significant functional implications in vivo.

  1. Oxidative stress in toadfish (Halobactrachus didactylus) cardiac muscle. Acute exposure to vanadate oligomers.

    PubMed

    Aureliano, M; Joaquim, N; Sousa, A; Martins, H; Coucelo, J M

    2002-06-07

    Vanadate solutions as "metavanadate" (containing ortho and metavanadate species) and "decavanadate" (containing mainly decameric species) (5 mM; 1 mg/kg) were injected intraperitoneously in Halobatrachus didactylus (toadfish), in order to evaluate the contribution of decameric vanadate species to vanadium (V) intoxication on the cardiac tissue. Following short-term exposure (1 and 7 days), different changes on antioxidant enzyme activities-superoxide dismutase (SOD), catalase (CAT), selenium-glutathione peroxidase (Se-GPx), total glutathione peroxidase (GPx), lipid peroxidation and subcellular vanadium distribution were observed in mitochondrial and cytosolic fractions of heart ventricle toadfish. After 1 day of vanadium intoxication, SOD, CAT and Se-GPx activities were decreased up to 25%, by both vanadate solutions, except mitochondrial CAT activity that increased (+23%) upon decavanadate administration. After 7 days of exposure, decavanadate versus metavanadate solutions promoted different effects mainly on cytosolic CAT activity (-56% versus -5%), mitochondrial CAT activity (-10% versus +10%) and total GPx activity (+1% versus -35%), whereas lipid peroxidation products were significantly increased (+82%) upon 500 microM decavanadate intoxication. Accumulation of vanadium in total (0.137+/-0.011 microg/g) and mitochondrial (0.022+/-0.001 microg/g) fractions was observed upon 7 days of metavanadate exposure, whereas for decavanadate, the concentration of vanadium increased in cytosolic (0.020+/-0.005 microg/g) and mitochondrial (0.021+/-0.009 microg/g) fractions. It is concluded that decameric vanadate species are responsible for a strong increase on lipid peroxidation and a decrease in cytosolic catalase activity thus contributing to oxidative stress responses upon vanadate intoxication, in the toadfish heart.

  2. Impaired regulation of divalent cations with acute copper exposure in the marine clam Mesodesma mactroides.

    PubMed

    Jorge, Marianna Basso; Lauer, Mariana Machado; Martins, Camila De Martinez Gaspar; Bianchini, Adalto

    2016-01-01

    The mechanism of copper (Cu) toxicity in marine invertebrates remains unclear. Therefore, marine clams (Mesodesma mactroides) were exposed (96h) to a concentration of dissolved Cu (1.6μmolL(-1)) inducing 10% mortality in sea water (30ppt). After in vivo exposure, tissue Cu accumulation (hemolymph, gill and digestive gland); hemolymph ionic (Na(+), K(+), Mg(2+) and Ca(2+)) and osmotic concentrations; tissue (gill and digestive gland) ionic concentration, enzyme (Na(+),K(+)-ATPase and carbonic anhydrase) activity, and oxygen consumption; and whole-body oxygen consumption were analyzed. Succinate dehydrogenase activity was evaluated in mitochondria isolated from gills and digestive gland and exposed (1h) in vitro to different concentrations of dissolved Cu (0.8, 7.7 and 78.7μmolL(-1)). In vivo exposure induced Cu accumulation in hemolymph, gills and digestive gland; increased Mg(2+) and decreased Ca(2+) concentration in hemolymph; decreased Mg(2+) concentration, increased Na(+),K(+)-ATPase activity and reduced carbonic anhydrase activity in gills; decreased Mg(2+) concentration, increased Ca(2+) concentration and increased Na(+),K(+)-ATPase activity in digestive gland; and reduced gill, digestive gland and whole-body oxygen consumption. Succinate dehydrogenase activity was inhibited after in vitro exposure to 78.7μmolL(-1) Cu. These findings indicate that Cu is an ionoregulatory toxicant in the marine clam M. mactroides. However, toxicity is related to disturbances in regulation of divalent cations (Mg(2+) and Ca(2+)) without effect on regulation of major monovalent cations (Na(+) and K(+)), as opposed to that observed in osmoregulating invertebrates exposed to Cu. However, other mechanism(s) of toxicity cannot be ruled out. Future studies must be performed to evaluate the consequence of the Cu-induced respiratory disturbances observed in M. mactroides.

  3. Progression of micronutrient alteration and hepatotoxicity following acute PCB126 exposure.

    PubMed

    Klaren, W D; Gadupudi, G S; Wels, B; Simmons, D L; Olivier, A K; Robertson, L W

    2015-12-02

    Polychlorinated Biphenyls (PCBs) are industrial chemicals that have become a persistent threat to human health due to ongoing exposure. A subset of PCBs, known as dioxin-like PCBs, pose a special threat given their potent hepatic effects. Micronutrients, especially Cu, Zn and Se, homeostatic dysfunction is commonly seen after exposure to dioxin-like PCBs. This study investigates whether micronutrient alteration is the byproduct of the ongoing hepatotoxicity, marked by lipid accumulation, or a concurrent, yet independent event of hepatic damage. A time course study was carried out using male Sprague-Dawley rats with treatments of PCB126, the prototypical dioxin-like PCB, resulting in 6 different time points. Animals were fed a purified diet, based on AIN-93G, for three weeks to ensure micronutrient equilibration. A single IP injection of either tocopherol-stripped soy oil vehicle (5 mL/kg) or 5 μmol/kg PCB126 dose in vehicle was given at various time points resulting in exposures of 9h, 18 h, 36 h, 3 days, 6 days, and 12 days. Mild hepatic vacuolar change was seen as early as 36 h with drastic changes at the later time points, 6 and 12 days. Micronutrient alterations, specifically Cu, Zn, and Se, were not seen until after day 3 and only observed in the liver. No alterations were seen in the duodenum, suggesting that absorption and excretion may not be involved. Micronutrient alterations occur with ROS formation, lipid accumulation, and hepatomegaly. To probe the mechanistic underpinnings, alteration of gene expression of several copper chaperones was investigated; only metallothionein appeared elevated. These data suggest that the disruption in micronutrient status is a result of the hepatic injury elicited by PCB126 and is mediated in part by metallothionein.

  4. Chemical exposures of women workers in the plastics industry with particular reference to breast cancer and reproductive hazards.

    PubMed

    DeMatteo, Robert; Keith, Margaret M; Brophy, James T; Wordsworth, Anne; Watterson, Andrew E; Beck, Matthias; Ford, Anne Rochon; Gilbertson, Michael; Pharityal, Jyoti; Rootham, Magali; Scott, Dayna Nadine

    2012-01-01

    Despite concern about the harmful effects of substances contained in various plastic consumer products, little attention has focused on the more heavily exposed women working in the plastics industry. Through a review of the toxicology, industrial hygiene, and epidemiology literatures in conjunction with qualitative research, this article explores occupational exposures in producing plastics and health risks to workers, particularly women, who make up a large part of the workforce. The review demonstrates that workers are exposed to chemicals that have been identified as mammary carcinogens and endocrine disrupting chemicals, and that the work environment is heavily contaminated with dust and fumes. Consequently, plastics workers have a body burden that far exceeds that found in the general public. The nature of these exposures in the plastics industry places women at disproportionate risk, underlining the importance of gender. Measures for eliminating these exposures and the need for regulatory action are discussed.

  5. Chromium and disease: Review of epidemiologic studies with particular reference to etiologic information provided by measures of exposure

    SciTech Connect

    Lees, P.S.J. )

    1991-05-01

    Dozens of epidemiologic studies have been conducted since the late 1940s in an attempt to elucidate the relationship between exposure to chromium compounds and increased rates of certain cancers observed in several industries. The relationship between employment in industries producing chromium compounds from chromite ore and lung cancer has been well established in numerous studies. The relationship between exposure to certain chromium-based pigments and chromic acid and lung cancer, although not as strong, is fairly well accepted. The data concerning emissions from stainless-steel manufacturing and disease are contradictory. Hypotheses about the carcinogenicity of specific chromium compounds generally relate to their solubility in body fluids. These hypotheses, however, have generally been produced as a result of toxicologic, not epidemiologic, investigation. Well-designed epidemiologic studies incorporating detailed assessments of worker exposures have the potential to help elucidate causality, identify specific carcinogenic compounds, and quantify risk in humans, eliminating the need to extrapolate from animal data.

  6. Mental- and physical-health effects of acute exposure to media images of the September 11, 2001, attacks and the Iraq War.

    PubMed

    Silver, Roxane Cohen; Holman, E Alison; Andersen, Judith Pizarro; Poulin, Michael; McIntosh, Daniel N; Gil-Rivas, Virginia

    2013-09-01

    Millions of people witnessed early, repeated television coverage of the September 11 (9/11), 2001, terrorist attacks and were subsequently exposed to graphic media images of the Iraq War. In the present study, we examined psychological- and physical-health impacts of exposure to these collective traumas. A U.S. national sample (N = 2,189) completed Web-based surveys 1 to 3 weeks after 9/11; a subsample (n = 1,322) also completed surveys at the initiation of the Iraq War. These surveys measured media exposure and acute stress responses. Posttraumatic stress symptoms related to 9/11 and physician-diagnosed health ailments were assessed annually for 3 years. Early 9/11- and Iraq War-related television exposure and frequency of exposure to war images predicted increased posttraumatic stress symptoms 2 to 3 years after 9/11. Exposure to 4 or more hr daily of early 9/11-related television and cumulative acute stress predicted increased incidence of health ailments 2 to 3 years later. These findings suggest that exposure to graphic media images may result in physical and psychological effects previously assumed to require direct trauma exposure.

  7. A retrospective study on acute health effects due to volcanic ash exposure during the eruption of Mount Etna (Sicily) in 2002

    PubMed Central

    2013-01-01

    Background Mount Etna, located in the eastern part of Sicily (Italy), is the highest and most active volcano in Europe. During the sustained eruption that occurred in October-November 2002 huge amounts of volcanic ash fell on a densely populated area south-east of Mount Etna in Catania province. The volcanic ash fall caused extensive damage to infrastructure utilities and distress in the exposed population. This retrospective study evaluates whether or not there was an association between ash fall and acute health effects in exposed local communities. Methods We collected the number and type of visits to the emergency department (ED) for diseases that could be related to volcanic ash exposure in public hospitals of the Province of Catania between October 20 and November 7, 2002. We compared the magnitude of differences in ED visits between the ash exposure period in 2002 and the same period of the previous year 2001. Results We observed a significant increase of ED visits for acute respiratory and cardiovascular diseases, and ocular disturbances during the ash exposure time period. Conclusions There was a positive association between exposure to volcanic ash from the 2002 eruption of Mount Etna and acute health effects in the Catania residents. This study documents the need for public health preparedness and response initiatives to protect nearby populations from exposure to ash fall from future eruptions of Mount Etna. PMID:23924394

  8. Postmortem tissue contents of {sup 241}Am in a person with a massive acute exposure

    SciTech Connect

    McInroy, J.F.; Kathren, R.L.; Toohey, R.E. |

    1995-09-01

    {sup 241}Am was determined radiochemically in the tissues of USTUR Case 246, a 76-y-old man who died of cardiovascular disease 11 y after massive percutaneous exposure following a chemical explosion in a glove box. This worker was treated extensively with a chelation drug, DTPA, for over 4 y after exposure. The estimate {sup 241}Am deposition at the time of death was 540 kBq, of which 90% was in the skeleton, 5.1% in the liver, and 3.5% in muscle and fat. Among the soft tissues, the highest concentrations were observed in liver (22 Bq g{sup -1}), certain cartilaginous structures such as the larynx (15 Bq g{sup -1}) and the red marrow (9.7 Bq g{sup -1}), as compared with the mean soft tissue concentration of approximately 1 Bq g{sup -1}. Concentration in muscle was approximately that of the soft tissue average, while concentrations in the pancreas, a hilar lymph node and fat were less than the average. Concentrations in bone ash were inversely related to the ratio of ash weight to wet weight a surrogate for bone volume-to-surface ratio. the distribution of activity in this case is reasonable consistent with that observed in another human case, when allowance is made for chelation therapy, and also tends to support more recent models of {sup 241}Am metabolism. 26 refs., 2 figs., 4 tabs.

  9. Acute leptin exposure reduces megalin expression and upregulates TGFβ1 in cultured renal proximal tubule cells.

    PubMed

    Briffa, Jessica F; Grinfeld, Esther; Mathai, Michael L; Poronnik, Phillip; McAinch, Andrew J; Hryciw, Deanne H

    2015-02-05

    Increased leptin concentrations observed in obesity can lead to proteinuria, suggesting that leptin may play a role in obesity-related kidney disease. Obesity reduces activation of AMP-activated protein kinase (AMPK) and increases transforming growth factor-β1 (TGF-β1) expression in the kidney, leading to albuminuria. Thus we investigated if elevated leptin altered AMPK and TGF-β1 signaling in proximal tubule cells (PTCs). In opossum kidney (OK) PTCs Western blot analysis demonstrated that leptin upregulates TGF-β1 secretion (0.50 µg/ml) and phosphorylated AMPKα (at 0.25, and 0.50 µg/ml), and downregulates megalin expression at all concentrations (0.05-0.50 µg/ml). Using the AMPK inhibitor, Compound C, leptin exposure regulated TGF-β1 expression and secretion in PTCs via an AMPK mediated pathway. In addition, elevated leptin exposure (0.50 µg/ml) reduced albumin handling in OK cells independently of megalin expression. This study demonstrates that leptin upregulates TGF-β1, reduces megalin, and reduces albumin handling in PTCs by an AMPK mediated pathway.

  10. Acute high-intensity sound exposure alters responses of place cells in hippocampus.

    PubMed

    Goble, T J; Møller, A R; Thompson, L T

    2009-07-01

    Overstimulation is known to activate neural plasticity in the auditory nervous system causing changes in function and re-organization. It has been shown earlier that overstimulation using high-intensity noise or tones can induce signs of tinnitus. Here we show in studies in rats that overstimulation causes changes in the way place cells of the hippocampus respond as rats search for rewards in a spatial maze. In familiar environments, a subset of hippocampal pyramidal neurons, known as place cells, respond when the animal moves through specific locations but are relatively silent in others. This place-field activity (i.e. location-specific firing) is stable in a fixed environment. The present study shows that activation of neural plasticity through overstimulation by sound can alter the response of these place cells. Rats implanted with chronic drivable dorsal hippocampal tetrodes (four microelectrodes) were assessed for stable single-unit place-field responses that were extracted from multiunit responses using NeuroExplorer computer spike-sorting software. Rats then underwent either 30 min exposure to a 4 kHz tone at 104 dB SPL or a control period in the same sound chamber. The place-field activity was significantly altered after sound exposure showing that plastic changes induced by overstimulation are not limited to the auditory nervous system but extend to other parts of the CNS, in this case to the hippocampus, a brain region often studied in the context of plasticity.

  11. Use of a 15 k gene microarray to determine gene expression changes in response to acute and chronic methylmercury exposure in the fathead minnow Pimephales promelas Rafinesque

    USGS Publications Warehouse

    Klaper, R.; Carter, Barbara J.; Richter, C.A.; Drevnick, P.E.; Sandheinrich, M.B.; Tillitt, D.E.

    2008-01-01

    This study describes the use of a 15 000 gene microarray developed for the toxicological model species, Pimephales promelas, in investigating the impact of acute and chronic methylmercury exposures in male gonad and liver tissues. The results show significant differences in the individual genes that were differentially expressed in response to each treatment. In liver, a total of 650 genes exhibited significantly (P < 0.05) altered expression with greater than two-fold differences from the controls in response to acute exposure and a total of 267 genes were differentially expressed in response to chronic exposure. A majority of these genes were downregulated rather than upregulated. Fewer genes were altered in gonad than in liver at both timepoints. A total of 212 genes were differentially expressed in response to acute exposure and 155 genes were altered in response to chronic exposure. Despite the differences in individual genes expressed across treatments, the functional categories that altered genes were associated with showed some similarities. Of interest in light of other studies involving the effects of methylmercury on fish, several genes associated with apoptosis were upregulated in response to both acute and chronic exposures. Induction of apoptosis has been associated with effects on reproduction seen in the previous studies. This study demonstrates the utility of microarray analysis for investigations of the physiological effects of toxicants as well as the time-course of effects that may take place. In addition, it is the first publication to demonstrate the use of this new 15 000 gene microarray for fish biology and toxicology. ?? 2008 The Authors.

  12. Histopathological findings in rabbits after experimental acute exposure to the Loxosceles intermedia (brown spider) venom