Brain indole and catecholamines of turkeys during exposure to temperature stress

1976 ◽  
Vol 230 (1) ◽  
pp. 110-115 ◽  
Author(s):  
ME El Halawani ◽  
PE Waibel
Keyword(s):  
Temperature Stress ◽  
Chronic Exposure ◽  
Tryptophan Hydroxylase ◽  
Acute Stress ◽  
Acute Exposure ◽  
Continuous Exposure ◽  
Opposite Pattern ◽  
Stress Changes ◽  
Environmental Temperatures

Turnovers of dopamine (DA), norepinephrine (NE), epinephrine (E), and 5-hydroxytryptamine (5-HT) were determined in the brains of male turkeys during acute, chronic, and posttemperature stress. Changes induced in the depletion of endogenous monoamine levels 6 h after tyrosine hydroxylase or tryptophan hydroxylase inhibitions were regarded as changes in turnovers. High or low ambient temperature had no effect on brain DA turnover, whether the temperature stress was acute (6 h) or chronic (5 wk). Brain NE turnover increased upon acute exposure to either a cold (5 degrees C) or warm (32 degrees C) environment. Chronic exposure (5 wk) to such temperatures reduced significantly (P less than 0.001) the elevated NE turnover. The central E and 5-HT turnovers of birds kept at 32 degrees C for 6 h decreased and increased, respectively, whereas determination of E and 5-HT of birds kept at 5 degrees C showed an opposite pattern. Five weeks of continuous exposure to high and low environmental temperatures did not alter the changes in E and 5-HT turnovers from those observed during acute stress. Exposure of heat- or cold-reared turkeys to 24 degrees C reversed the changes in E and 5-HT turnovers. Thus the results indicated an increase in NE turnover only during acute exposure to thermal stress. However, the changes in E and 5-HT turnovers persisted during chronic exposure.

Association of Dyskalemias with Ischemic Stroke in Advanced Chronic Kidney Disease Patients Transitioning to Dialysis

2021 ◽  
pp. 1-9
Author(s):  
Ankur A. Dashputre ◽  
Keiichi Sumida ◽  
Fridtjof Thomas ◽  
Justin Gatwood ◽  
Oguz Akbilgic ◽  
...  
Keyword(s):  
Chronic Kidney Disease ◽  
Ischemic Stroke ◽  
Kidney Disease ◽  
Lower Risk ◽  
Chronic Exposure ◽  
Cox Regression ◽  
Acute Exposure ◽  
Continuous Exposure ◽  
Advanced Chronic Kidney Disease

<b><i>Introduction:</i></b> Hypo- and hyperkalemia are associated with a higher risk of ischemic stroke. However, this association has not been examined in an advanced chronic kidney disease (CKD) population. <b><i>Methods:</i></b> From among 102,477 US veterans transitioning to dialysis between 2007 and 2015, 21,357 patients with 2 pre-dialysis outpatient estimated glomerular filtration rates &#x3c;30 mL/min/1.73 m<sup>2</sup> 90–365 days apart and at least 1 potassium (K) each in the baseline and follow-up period were identified. We separately examined the association of both baseline time-averaged K (chronic exposure) and time-updated K (acute exposure) treated as categorized (hypokalemia [K &#x3c;3.5 mEq/L] and hyperkalemia [K &#x3e;5.5 mEq/L] vs. referent [3.5–5.5 mEq/L]) and continuous exposure with time to the first ischemic stroke event prior to dialysis initiation using multivariable-adjusted Cox regression models. <b><i>Results:</i></b> A total of 2,638 (12.4%) ischemic stroke events (crude event rate 41.9 per 1,000 patient years; 95% confidence interval [CI] 40.4–43.6) over a median (Q<sub>1</sub>–Q<sub>3</sub>) follow-up time of 2.56 (1.59–3.89) years were observed. The baseline time-averaged K category of hypokalemia (adjusted hazard ratio [aHR], 95% CI: 1.35, 1.01–1.81) was marginally associated with a significantly higher risk of ischemic stroke. However, time-updated hyperkalemia was associated with a significantly lower risk of ischemic stroke (aHR, 95% CI: 0.82, 0.68–0.98). The exposure-outcome relationship remained consistent when using continuous K levels for both the exposures. <b><i>Discussion/Conclusion:</i></b> In patients with advanced CKD, hypokalemia (chronic exposure) was associated with a higher risk of ischemic stroke, whereas hyperkalemia (acute exposure) was associated with a lower risk of ischemic stroke. Further studies in this population are needed to explore the mechanisms underlying these associations.

scholarly journals Investigation on amitraz, coumaphos and thymol concentrations in honey produced by Slovenian beekeepers in 2020

2021 ◽  
Vol 117 (2) ◽  
pp. 1
Author(s):  
Helena BAŠA ČESNIK ◽  
Veronika KMECL
Keyword(s):  
Chronic Exposure ◽  
Degradation Products ◽  
Daily Intake ◽  
Acute Exposure ◽  
Veterinary Drug ◽  
Acceptable Daily Intake ◽  
Gas Chromatograph ◽  
Conventional Production ◽  
Heptafluorobutyric Anhydride

A survey on concentrations of veterinary drug residues amitraz, coumaphos and thymol in honey, produced in year 2020 by Slovenian beekeepers, was conducted. 100 samples were analysed: 22 from organic and 78 from conventional production, with two analytical methods. In method for determination of coumaphos and thymol samples were extracted with acetone, petroleumether and dichlorometane. In method for determination of amitraz and its degradation products, samples were hydrolisated with HCl and NaOH, extractied with n-hexane and derivatisated with heptafluorobutyric anhydride. Determination in both methods was performed with gas chromatograph coupled with mass spectrometer. Measured concentrations of amitraz, coumaphos and thymol were in the range of 0.01-0.12 mg kg-1, 0.02-0.06 mg kg-1 and 0.08-0.17 mg kg-1, respectively. In 61 % of samples analysed no residues of amitraz, thymol and coumaphos were found. Data obtained were compared with the data from literature. Chronic and acute exposure were calculated for consumers. Maximum chronic exposure for amitraz and thymol was 0.1 % and 0.05 % of acceptable daily intake, respectively. Maximum acute exposure for amitraz and thymol was 4 % and 0.8 % of acute reference dose, respectively

scholarly journals Vasoactive Effects of Acute Ergot Exposure in Sheep

Toxins ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 291
Author(s):  
Rossalin Yonpiam ◽  
Jair Gobbet ◽  
Ashok Jadhav ◽  
Kaushik Desai ◽  
Barry Blakley ◽  
...  
Keyword(s):  
Single Dose ◽  
Chronic Exposure ◽  
Contractile Response ◽  
Ergot Alkaloids ◽  
Acute Exposure ◽  
Control Group ◽  
Vascular Effects ◽  
Adrenergic Antagonist ◽  
Vascular Sensitivity ◽  
Dose Dependent

Ergotism is a common and increasing problem in Saskatchewan’s livestock. Chronic exposure to low concentrations of ergot alkaloids is known to cause severe arterial vasoconstriction and gangrene through the activation of adrenergic and serotonergic receptors on vascular smooth muscles. The acute vascular effects of a single oral dose with high-level exposure to ergot alkaloids remain unknown and are examined in this study. This study had two main objectives; the first was to evaluate the role of α1-adrenergic receptors in mediating the acute vasocontractile response after single-dose exposure in sheep. The second was to examine whether terazosin (TE) could abolish the vascular contractile effects of ergot alkaloids. Twelve adult female sheep were randomly placed into control and exposure groups (n = 6/group). Ergot sclerotia were collected and finely ground. The concentrations of six ergot alkaloids (ergocornine, ergocristine, ergocryptine, ergometrine, ergosine, and ergotamine) were determined using HPLC/MS at Prairie Diagnostic Services Inc., (Saskatoon, SK, Canada). Each ewe within the treatment group received a single oral treatment of ground ergot sclerotia at a dose of 600 µg/kg BW (total ergot) while each ewe in the control group received water. Animals were euthanized 12 h after the treatment, and the pedal artery (dorsal metatarsal III artery) from the left hind limb from each animal was carefully dissected and mounted in an isolated tissue bath. The vascular contractile response to phenylephrine (PE) (α1-adrenergic agonist) was compared between the two groups before and after TE (α1-adrenergic antagonist) treatment. Acute exposure to ergot alkaloids resulted in a 38% increase in vascular sensitivity to PE compared to control (Ctl EC50 = 1.74 × 10−6 M; Exp EC50 = 1.079 × 10−6 M, p = 0.046). TE treatment resulted in a significant dose-dependent increase in EC50 in both exposure and control groups (p < 0.05 for all treatments). Surprisingly, TE effect was significantly more pronounced in the ergot exposed group compared to the control group at two of the three concentrations of TE (TE 30 nM, p = 0.36; TE 100 nM, p < 0.001; TE 300 nM, p < 0.001). Similar to chronic exposure, acute exposure to ergot alkaloids results in increased vascular sensitivity to PE. TE is a more potent dose-dependent antagonist for the PE contractile response in sheep exposed to ergot compared to the control group. This study may indicate that the dry gangrene seen in sheep, and likely other species, might be related to the activation of α1-adrenergic receptor. This effect may be reversed using TE, especially at early stages of the disease before cell death occurs. This study may also indicate that acute-single dose exposure scenario may be useful in the study of vascular effects of ergot alkaloids.

Determination of the temperature stress field in a plexiglas plate

1972 ◽  
Vol 3 (6) ◽  
pp. 743-744
Author(s):  
F. V. Dolinskii ◽  
V. A. Marakhovskii
Keyword(s):  
Stress Field ◽  
Temperature Stress ◽  
Plexiglas Plate

scholarly journals Genotoxic and Histopathological Effects of Chlorpyrifos on African Catfish, C. gariepinus and Ameliorative Potentials of Ackee Apple, blighia sapida Seed

2018 ◽  
Vol 6 (1) ◽  
pp. 1 ◽  
Author(s):  
Oluyinka Iyiolai ◽  
A. A. Adeagbo ◽  
W. S. Weliange ◽  
S. I. Abdulkareem ◽  
Anifowoshe T. Abass ◽  
...  
Keyword(s):  
Chronic Exposure ◽  
Clarias Gariepinus ◽  
Aquatic Organisms ◽  
Acute Exposure ◽  
Histopathological Analysis ◽  
African Catfish ◽  
Dependent Manner ◽  
Dose Dependent ◽  
Histopathological Effects ◽  
Positive Controls

Chlorpyrifos (CPF) is a very toxic pesticide commonly used for controlling agriculturally important pests. The present study investigates DNA damaging effects of CPF on Clarias gariepinus was assessed using genetic assays. Fish were exposed to varying concentrations of CPF (100ppm, 200ppm and 300ppm) at 96 hours (acute exposure). LC50 of the pesticide was found to be 120ppm and one-tenth of the LC50 (12ppm) was taken for the chronic exposure. Distilled water and colchicine were used as negative and positive controls respectively. After 28 days of chronic exposure, fish were fed with inclusion of B. sapida seed (powder) for 14 days. Liver and gills of the fish were removed following 96h exposure, days 7, 14 and 28 of the chronic exposure as well as after the period of amelioration (14 days) for CA assay and histopathological analysis. The results of CA assay showed statistically significant (p ˂ 0.05) increase in CA in a dose-dependent manner for all the exposed groups after acute exposure and time dependent after chronic exposure. Also, this study showed that CPF can potentially induce genotoxic and histopathological changes in fish and other aquatic organisms.

Determination of a Loading Pressure in the Metal Forming by the Given Movements

2013 ◽  
Vol 842 ◽  
pp. 494-499 ◽  
Author(s):  
Evgenii V. Murashkin ◽  
Marina V. Polonik
Keyword(s):  
Mathematical Model ◽  
Metal Forming ◽  
External Pressure ◽  
Stress Changes ◽  
The Given

We propose a mathematical model of large elastocreep deformations. As part of the constructed mathematical model the problem of deformation of the material in the vicinity of microdefect was solved. Integro-differential dependence of external pressure from irreversible deformations and displacements was obtained. The laws of loading material from vector displacements were calculated. We have shown that the monotonous laws of deformation can lead to non-monotonous stress changes.

scholarly journals The longer the worse: a combined proteomic and targeted study of the long-term versus short-term effects of silver nanoparticles on macrophages

2020 ◽  
Vol 7 (7) ◽  
pp. 2032-2046
Author(s):  
Bastien Dalzon ◽  
Catherine Aude-Garcia ◽  
Hélène Diemer ◽  
Joanna Bons ◽  
Caroline Marie-Desvergne ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Chronic Exposure ◽  
Acute Exposure ◽  
Short Term ◽  
Short Term Effects

At equal cumulated dose, a chronic exposure to silver nanoparticles produces more effects on macrophages than an acute exposure.

scholarly journals The effects of psychosocial stress on intergroup resource allocation

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Adam Schweda ◽  
Nadira Sophie Faber ◽  
Molly J. Crockett ◽  
Tobias Kalenscher
Keyword(s):  
Social Preferences ◽  
Social Dilemma ◽  
Opposite Pattern ◽  
Physiological Factors ◽  
Prosocial Motives ◽  
Tend And Befriend ◽  
Stress Changes ◽  
Effects Of Stress ◽  
Other Regarding ◽  
Fight Or Flight

AbstractStress changes our social behavior. Traditionally, stress has been associated with “fight-or-flight” – the tendency to attack an aggressor, or escape the stressor. But stress may also promote the opposite pattern, i.e., “tend-and-befriend” – increased prosociality toward others. It is currently unclear which situational or physiological factors promote one or the other. Here, we hypothesized that stress stimulates both tendencies, but that fight-or-flight is primarily directed against a potentially hostile outgroup, moderated by rapid-acting catecholamines, while tend-and-befriend is mainly shown towards a supportive ingroup, regulated by cortisol. To test this hypothesis, we measured stress-related neurohormonal modulators and sex hormones in male and female participants who were exposed to a psychosocial stressor, and subsequently played an intergroup social dilemma game in which they could reveal prosocial motives towards an ingroup (ingroup-love) and hostility towards an outgroup (outgroup-hate). We found no significant effects of stress on social preferences, but stress-related heart-rate increases predicted outgroup-hostile behavior. Furthermore, when controlling for testosterone, cortisol was associated with increased ingroup-love. Other-regarding behavior was overall higher in male than female participants. Our mixed results are of interest to scholars of the effects of stress on prosocial and aggressive behavior, but call for refinement in future replications.

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