Short-term exposure to tricyclic antidepressants delays righting time in marine and freshwater snails with evidence for low-dose stimulation of righting speed by imipramine

2019 ◽  
Vol 26 (8) ◽  
pp. 7840-7846 ◽  
Author(s):  
Peter P. Fong ◽  
Kelsey E. DiPenta ◽  
Sarahrose M. Jonik ◽  
Courtney D. Ward
Keyword(s):  
Tricyclic Antidepressants ◽  
Low Dose ◽  
Freshwater Snails ◽  
Short Term ◽  
Short Term Exposure ◽  
Stimulation Of

Cold acclimation inhibits CO2-dependent stimulation of photosynthesis in spring wheat and spring rye

Botany ◽  
2012 ◽  
Vol 90 (6) ◽  
pp. 433-444 ◽  
Author(s):  
Keshav Dahal ◽  
Khalil Kane ◽  
Fathey Sarhan ◽  
Bernard Grodzinski ◽  
Norman P.A. Hüner
Keyword(s):  
Triticum Aestivum ◽  
Cold Acclimation ◽  
Temperature Sensitivity ◽  
Spring Wheat ◽  
Secale Cereale ◽  
Triticum Aestivum L ◽  
Short Term ◽  
Short Term Exposure ◽  
Secale Cereale L ◽  
Stimulation Of

We assessed the effects of short-term elevated CO2 on the light-saturated rates of photosynthesis (Asat) of spring (‘SR4A’, ‘Katepwa’) and winter (‘Musketeer’, ‘Norstar’) wheat ( Triticum aestivum L.) and rye ( Secale cereale L.) cultivars grown at ambient CO2 (380 µmol C·mol–1) at either 20/16 °C (nonacclimated, NA) or 5/5 °C (cold acclimated, CA). In spring wheat–rye, cold acclimation decreased CO2-stimulation of Asat by 45%–60% relative to NA controls following a short-term (80 h) shift of plants from ambient to elevated CO2 (700 µmol C·mol–1). In contrast, in winter wheat–rye, cold acclimation enhanced CO2-stimulation of Asat by 15%–35% relative to NA controls upon a shift to elevated CO2. The stimulation observed for CA spring cultivars was about 60% less than that of CA winter cultivars. We conclude that a short-term exposure of spring cultivars to elevated CO2 cannot compensate for the cold acclimation-induced inhibition of Asat. Cold acclimation of spring cultivars appeared to exacerbate Rubisco CO2 substrate limitations present under ambient CO2. Furthermore, CA spring cultivars were unable to adjust their short-term temperature sensitivity of Asat under elevated CO2 compared with the winter cultivars.

To the Question About Pharmacological Protection During Irradiation in Non-infecting Doses: Maybe, Necessary? Part 1. General Overview of Medical-tactical and Phenomenological Aspects

2021 ◽  
Vol 66 (4) ◽  
pp. 89-100
Author(s):  
A. Ivanchenko ◽  
V. Basharin ◽  
I. Drachev ◽  
A. Seleznev ◽  
A. Bushmanov
Keyword(s):  
Radiation Effects ◽  
Low Dose ◽  
Dose Range ◽  
Living Organism ◽  
Short Term ◽  
Final State ◽  
Stochastic Effects ◽  
Low Dose Rate ◽  
Dose Limits ◽  
Stimulation Of

Purpose: Review of modern concepts of the biological effect of ionizing radiation in medium doses on a living organism and the consequences of radiation in order to assess the need for the use of drugs suitable for the purpose of modifying the effects; stimulation of discussion on the issue under consideration. Results: The conditions of origin and the list of possible radiation effects from irradiation at medium doses of the 0.1–1 Gy range were assessed, the scale and phenomenology of the consequences were assessed as a subject of modification by antiradiation agents. Conclusions: Pharmacological support (use of PLC) under conditions of short-term and prolonged irradiation with a low dose rate and in the dose range of 0.2–1 Gy seems to be necessary due to the reality of deterministic effects when the dose limits are exceeded (partly at the premorbid or preclinical level, with pronounced psychogenic reactions – components of the final state), as well as with the possibility of stochastic effects in excess of spontaneous ones, although, according to approximate estimates, with an insignificant frequency.

scholarly journals Preliminary results of toxicity studies in rats following low-dose and short-term exposure to methyl mercaptan

2019 ◽  
Vol 6 ◽  
pp. 431-438 ◽  
Author(s):  
Jingjing Fang ◽  
Xinhong Xu ◽  
Lu Jiang ◽  
Jiangbo Qiao ◽  
Hongyuan Zhou ◽  
...  
Keyword(s):  
Low Dose ◽  
Methyl Mercaptan ◽  
Short Term ◽  
Preliminary Results ◽  
Toxicity Studies ◽  
Short Term Exposure

Neuroimmunological Effects of Exposure to Methylmercury Forms in the Sprague-Dawley Rats. Activation of the Hypothalamic-Pituitary-Adrenal Axis and Lymphocyte Responsiveness

1997 ◽  
Vol 13 (1) ◽  
pp. 57-66 ◽  
Author(s):  
Hector G. Ortega ◽  
Manuel Lopez ◽  
Atsushi Takaki ◽  
Qin-Heng Huang ◽  
Akira Arimura ◽  
...  
Keyword(s):  
Hpa Axis ◽  
Low Dose ◽  
Fold Increase ◽  
Exposed Group ◽  
Blood Levels ◽  
High Dose ◽  
Sprague Dawley ◽  
Short Term ◽  
Hypothalamic Pituitary Adrenal ◽  
Short Term Exposure

The effects of different methylmercury (MeHg) forms on the immune system and the hypothalamic pituitary adrenal (HPA) axis were assessed. The lymphocyte response to Concanavalin A (Con A) stimulation, blood levels of interleukin-6 (IL-6), adrenocorticotrophin hormone (ACTH), and corticosterone in the presence of different MeHg compounds was measured. Rats were exposed to methylmercury sulfide [(MeHg)2S] and methylmercury chloride (MeHgCl) at concentrations of 5 and 500 μg per liter in the drinking water for 8 or 16 weeks. Short-term exposure (8 weeks) at both, low- and high-doses of (MeHg)2S significantly enhanced lymphocyte responsiveness. MeHgCl only induced increased lymphocyte responsiveness at the low-dose exposure. Circulating levels of IL-6 after short-term exposure were increased in the MeHgCl-exposed group. The HPA axis activation was demonstrated by increased levels of ACTH and corticosterone levels. This response was predominant in low-dose exposed animals. Long-term (16 weeks) exposure resulted in a reduction in lymphocyte proliferation after both low- and high-dose MeHgCl exposures. The (MeHg)2S exposure resulted in a 3-fold increase in the proliferative response. Levels of ACTH were elevated 3-fold in the (MeHg)2S-exposed group, and no increase of corticosterone was observed in the high-dose exposed group at 8 weeks, no effect of(MeHg)2S was observed at 16 weeks. The MeHgCl exposed group showed an increase in ACTH and corticosterone levels at 8 weeks; this response was not observed at 16 weeks. These data indicate that exposure to MeHg compounds enhances T-cell proliferation in most of the cases, in a dose- and time-dependent fashion. Release of IL-6 also depends on the length of exposure. Early increases in circulating ACTH at 8 weeks also suggest activation of the HPA axis. This may contribute to the production of IL-6 and surveillance of regulatory homeostatic responses against environmental agents that mimic stress-like responses.

scholarly journals Hormone-Like Effects of 4-Vinylcyclohexene Diepoxide on Follicular Development

2020 ◽  
Vol 8 ◽  
Author(s):  
Lian Bao Cao ◽  
Hong Bin Liu ◽  
Gang Lu ◽  
Yue Lv ◽  
Chi Kwan Leung ◽  
...  
Keyword(s):  
Ovarian Reserve ◽  
Low Dose ◽  
Follicular Development ◽  
Primordial Follicle ◽  
High Dose ◽  
Short Term ◽  
Primary Follicle ◽  
Vinylcyclohexene Diepoxide ◽  
Short Term Exposure

Background4-vinylcyclohexene diepoxide (VCD) has long been considered a hazardous occupational chemical that promotes ovarian failure. However, VCD is also used as a research compound to chemically induce animal models of premature ovarian insufficiency (POI), and in related work we unexpectedly found that VCD apparently exhibits both dose- and duration-dependent opposing, hormone-like effects on the maintenance of the primordial follicle pool, follicle development, and ovulation induction.ResultsWe conducted experiments with cultured murine ovaries and performed transplantation experiments using postnatal day (PD) 2 and PD12 mice and found that low-dose, short-term exposure to VCD (VCDlow) actually protects the primordial/primary follicle pool and improves the functional ovarian reserve (FOR) by disrupting follicular atresia. VCDlow inhibits follicular apoptosis and regulates the Pten-PI3K-Foxo3a pathway. Short-term VCD exposure in vivo (80 mg/kg, 5 days) significantly increases the number of superovulated metaphase II oocytes, preovulatory follicles, and corpus luteum in middle-aged mice with diminished ovarian reserve (DOR). We demonstrate that low-dose but not high-dose VCD promotes aromatase levels in granulosa cells (GCs), thereby enhancing the levels of estradiol secretion.ConclusionOur study illustrates a previously unappreciated, hormone-like action for the occupational “ovotoxin” molecule VCD and strongly suggests that VCDlow should be explored for its potential utility for treating human ovarian follicular development disorders, including subfertility in perimenopausal women.

scholarly journals Deoxynivalenol Impairs Weight Gain and Affects Markers of Gut Health after Low-Dose, Short-Term Exposure of Growing Pigs

Toxins ◽  
2015 ◽  
Vol 7 (6) ◽  
pp. 2071-2095 ◽  
Author(s):  
Arash Alizadeh ◽  
Saskia Braber ◽  
Peyman Akbari ◽  
Johan Garssen ◽  
Johanna Fink-Gremmels
Keyword(s):  
Weight Gain ◽  
Low Dose ◽  
Growing Pigs ◽  
Gut Health ◽  
Short Term ◽  
Short Term Exposure

scholarly journals Limits to the early increase in free cytoplasmic calcium concentration during the mitogenic stimulation of lymphocytes

1983 ◽  
Vol 212 (3) ◽  
pp. 685-690 ◽  
Author(s):  
T R Hesketh ◽  
T Pozzan ◽  
G A Smith ◽  
J C Metcalfe
Keyword(s):  
Cell Cycle ◽  
Calcium Concentration ◽  
Critical Concentration ◽  
Ionophore A23187 ◽  
Cytoplasmic Calcium ◽  
Short Term ◽  
Mitogenic Stimulation ◽  
Short Term Exposure ◽  
Early Increase ◽  
Stimulation Of

Three aspects of the calcium hypothesis we have proposed previously [Metcalfe, Pozzan, Smith & Hesketh (1980) Biochem. Soc. Symp. 45, 1-26] for the control of mitogenic stimulation of lymphocytes are examined in studies on the mitogenic action of the Ca2+ ionophore A23187 and its effect on cap formation. (1) Pig lymphocytes that were mitogenically stimulated by continuous incubation with 3H-labelled A23187 for 48 h contained between 3 and 15 amol of ionophore per cell. Lymphocytes exposed to 3H-labelled A23187 for 2h before washing the cells and resuspending them in ionophore-free medium were only stimulated mitogenically at 48h if the residual ionophore associated with the cells after washing was in the concentration range 3-15 amol per cell. When the cells were washed repeatedly after 2h incubation with ionophore to reduce the cell-associated ionophore below the critical concentration range, no mitogenic stimulation occurred as a result of short-term exposure to any ionophore concentration. Re-addition of ionophore to within the indicated range of cell-associated concentrations restored mitogenic stimulation at 48h. We conclude that large, short-term Ca2+ fluxes into the cells induced by the ionophore cannot generate a mitogenic signal that commits the cells to enter the cell cycle. (2) Further experiments with the ionophore showed that detectable mitogenic stimulation at 48h required a minimum of 3h exposure to optimal ionophore concentrations, and that maximal stimulation required at least 20h exposure. This is consistent with the view that a prolonged increase in the free cytoplasmic calcium concentration is required to stimulate the maximum proportion of the cells into the cell cycle. (3) Mouse splenic lymphocytes treated for short periods with very high ionophore concentrations (30 microM) in the presence of various external Ca2+ concentrations showed significant inhibition of cap formation of surface immunoglobulin receptors in the range 1-10 microM-Ca2+ in normal or depolarizing medium. We conclude that mitogens at optimal concentrations for the stimulation of lymphocytes do not cause any early increase in the free cytoplasmic Ca2+ concentration above 10 microM.

Short-Term Exposure to Low-Dose Ritonavir Impairs Clearance and Enhances Adverse Effects of Trazodone

2003 ◽  
Vol 43 (4) ◽  
pp. 414-422 ◽  
Author(s):  
David J. Greenblatt ◽  
Lisa L. von Moltke ◽  
Jerold S. Harmatz ◽  
Steven M. Fogelman ◽  
Gengsheng Chen ◽  
...  
Keyword(s):  
Adverse Effects ◽  
Low Dose ◽  
Short Term ◽  
Short Term Exposure

The Effect of Dimethyl Sulfoxide on In Vitro Platelet Function

1976 ◽  
Vol 36 (01) ◽  
pp. 221-229 ◽  
Author(s):  
Charles A. Schiffer ◽  
Caroline L. Whitaker ◽  
Morton Schmukler ◽  
Joseph Aisner ◽  
Steven L. Hilbert
Keyword(s):  
Platelet Count ◽  
Platelet Aggregation ◽  
Dimethyl Sulfoxide ◽  
Platelet Function ◽  
Platelet Volume ◽  
Short Term ◽  
Platelet Factor ◽  
Short Term Exposure ◽  
Structural Abnormalities

SummaryAlthough dimethyl sulfoxide (DMSO) has been used extensively as a cryopreservative for platelets there are few studies dealing with the effect of DMSO on platelet function. Using techniques similar to those employed in platelet cryopreservation platelets were incubated with final concentrations of 2-10% DMSO at 25° C. After exposure to 5 and 10% DMSO platelets remained discoid and electron micrographs revealed no structural abnormalities. There was no significant change in platelet count. In terms of injury to platelet membranes, there was no increased availability of platelet factor-3 or leakage of nucleotides, 5 hydroxytryptamine (5HT) or glycosidases with final DMSO concentrations of 2.5, 5 and 10% DMSO. Thrombin stimulated nucleotide and 5HT release was reduced by 10% DMSO. Impairment of thrombin induced glycosidase release was noted at lower DMSO concentrations and was dose related. Similarly, aggregation to ADP was progressively impaired at DMSO concentrations from 1-5% and was dose related. After the platelets exposed to DMSO were washed, however, aggregation and release returned to control values. Platelet aggregation by epinephrine was also inhibited by DMSO and this could not be corrected by washing the platelets. DMSO-plasma solutions are hypertonic but only minimal increases in platelet volume (at 10% DMSO) could be detected. Shrinkage of platelets was seen with hypertonic solutions of sodium chloride or sucrose suggesting that the rapid transmembrane passage of DMSO prevented significant shifts of water. These studies demonstrate that there are minimal irreversible alterations in in vitro platelet function after short-term exposure to DMSO.

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