Effect of short exposure to cold on plasma thyroxine in Coturnix quail: Role of the infundibular complex and its neural afferents

1984 ◽  
Vol 56 (1) ◽  
pp. 1-8 ◽  
Author(s):  
S. Herbuté ◽  
R. Pintat ◽  
F. Ramade ◽  
J.D. Baylé
Keyword(s):  
Short Exposure ◽  
Exposure To Cold ◽  
Coturnix Quail

Thyroid hormone-catecholamine interrelationships during exposure to cold

1981 ◽  
Vol 97 (1) ◽  
pp. 91-97 ◽  
Author(s):  
H. Storm ◽  
C. van Hardeveld ◽  
A. A. H. Kassenaar
Keyword(s):  
Nervous System ◽  
Plasma Concentration ◽  
Thyroid Hormone ◽  
Sympathetic Nervous System ◽  
Plasma Levels ◽  
Surgical Procedure ◽  
Exposure To Cold ◽  
Basal Plasma ◽  
Sympathetic Nervous

Abstract. Basal plasma levels for adrenalin (A), noradrenalin (NA), l-triiodothyronine (T3), and l-thyroxine (T4) were determined in rats with a chronically inserted catheter. The experiments described in this report were started 3 days after the surgical procedure when T3 and T4 levels had returned to normal. Basal levels for the catecholamines were reached already 4 h after the operation. The T3/T4 ratio in plasma was significantly increased after 3, 7, and 14 days in rats kept at 4°C and the same holds for the iodide in the 24-h urine after 7 and 14 days at 4°C. The venous NA plasma concentration was increased 6- to 12-fold during the same period of exposure to cold, whereas the A concentration remained at the basal level. During infusion of NA at 23°C the T3/T4 ratio in plasma was significantly increased after 7 days compared to pair-fed controls, and the same holds for the iodide excretion in the 24-h urine. This paper presents further evidence for a role of the sympathetic nervous system on T4 metabolism in rats at resting conditions.

scholarly journals A ROLE OF VIRECHANA IN SHEETAPITTA- A CASE STUDY

2018 ◽  
Vol 6 (07) ◽  
Author(s):  
Kavya Ramrao Kadapi ◽  
Devashis Biswas
Keyword(s):  
Burning Sensation ◽  
Cold Climate ◽  
Urticaria Pigmentosa ◽  
Exposure To Cold

A 45-years old female, presented with complaints of Reddish lesions in the both the limbs on and off since 1 moth associated with Burning sensation, pain ,itching aggravating more during evening hours and on exposure to cold climate . Diagnosed as Sheeta-Pittavis-à-vis Urticaria Pigmentosa. Its management was successfully done by following the principle of Shodhana The purpose of this paper was to justify how a clinical hypothesis based on appropriate diagnosis  of Dosha – Dushya along with scrutinizing magnitude of the shodhana therapy alone would help in curing the condition by using the principle of purificatory treatment.

Unexpected Evidence That Dimethylsulphoxide (DMSO) Upregulates Expression of CXCR4 on Hematopoietic Stem/Progenitor Cells (HSPC), Increases Their Responsiveness to an SDF-1 Gradient and Enhances Homing to Bone Marrow.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 1973-1973
Author(s):  
Marcin Majka ◽  
Danuta Jarocha ◽  
Marcin Wysoczynski ◽  
Duygu Sag ◽  
Ewa Zuba-Surma ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Progenitor Cells ◽  
Mononuclear Cells ◽  
Short Exposure ◽  
Hematopoietic Stem ◽  
Akt Phosphorylation ◽  
Human Cd34 ◽  
New Strategy ◽  
First Time

Abstract Cryopreservation of bone marrow (BM), mobilized peripheral blood (mPB) and cord blood (CB) cells is a routine procedure to store hematopoietic stem/progenitor cells (HSPC) for transplantation. Dimethylsulphoxide (DMSO), the most commonly used cryoprotectant, is toxic to cells at higher concentrations (>10%); moreover, the freezing-thawing procedure itself is inevitably connected with the loss of HSPC. However, by chance we observed that short exposure of HSPC to DMSO enhances the responsiveness of these cells to an SDF-1 gradient and since SDF-1 is a major chemoattractant that navigates homing of HSPC to BM we became interested in elucidating this phenomenon. We found that short incubation (5–10 min) of human CB mononuclear cells (MNC) with DMSO at concentrations employed for cryopreservation (5–10%) significantly upregulates the expression of both CXCR4 (x 2–3) and CD34 (x 1.5) on CB MNC (as measured by FACS). Furthermore, DMSO significantly increased the chemotactic responsiveness (x 2–4) of CB MNC, BM MNC and selected CXCR4+ human hematopoietic cell lines (Jurkat, THP-1 cells) when the cells were exposed to 5–10% DMSO before chemotaxis assay. These responses to an SDF-1 gradient correlated with enhanced chemotaxis also of human CD34+, CD34+ CD38+, CD34+ CD38−, and CD34+ CXCR4+ clonogeneic progenitor cells, suggesting that DMSO directly enhances the responsiveness of human early progenitors (p<0.0001). At the molecular level, 5–10% DMSO strongly stimulated and prolonged SDF-1-dependent AKT phosphorylation. However, at the same time DMSO inhibited phosphorylation of MAPKp42/44. Similar observations were made for Sca-1+ BM-derived murine cells. In parallel experiments we found that murine Sca-1+ cells when preincubated with DMSO formed more 12 day-CFU-S colonies in spleens after transplantation into irradiated syngeneic recipients. Accordingly, x 2 more CFU-S were formed when Sca-1+ cells were exposed before transplantation to 5% DMSO and about x 4 more after exposure to 10% DMSO. Finally we employed a Ly5.1/Ly5.2 congeneic transplant model and showed that transplantation of Ly5.1 Sca-1+ cells exposed to 10% DMSO before transplantation resulted in higher chimerism in transplanted Ly5.2 mice as compared to untreated cells (control) (p<0.0001). In conclusion, we show for the first time an unexpected beneficial role of DMSO (5–10%) in regulation of homing of HSPC after transplantation and suggest that a short priming of HSPC with DMSO, even of non-cryopreserved cells, before transplantation may become a new strategy to enhance engraftment

Role of light and temperature in the regulation of reproduction in the red-sided garter snake, Thamnophis sirtalis parietalis

1987 ◽  
Vol 65 (8) ◽  
pp. 2090-2096 ◽  
Author(s):  
Joan M. Whittier ◽  
Robert T. Mason ◽  
David Crews ◽  
Paul Licht
Keyword(s):  
Sexual Behavior ◽  
Courtship Behavior ◽  
Cold Temperature ◽  
Thamnophis Sirtalis ◽  
Garter Snakes ◽  
Thamnophis Sirtalis Parietalis ◽  
Long Day ◽  
Exposure To Cold ◽  
Ovarian Activation

The influence of photoperiodic manipulation on sexual behavior and ovarian recrudescence of male and female red-sided garter snakes (Thamnophis sirtalis parietalis) was examined over a 4-year period. Snakes were exposed to photoperiodic manipulations before, during, and after a 17-week cold temperature dormancy; sexual behavior of males and females and ovarian recrudescence were observed after emergence from cold temperature dormancy. In the 1st year (1982), males were exposed to two conditions representing minimum and maximum exposure to daylight: (i) 6 weeks of a short-day prehibernation period (10L:14D, 28:18 °C), followed by 17 weeks of hibernation in complete darkness (0L:24D, 4 °C) and emergence into warm dark conditions (0L:24D, 28:18 °C); and (ii) 6 weeks of a long-day prehibernation period (14L:10D, 28:18 °C), followed by 17 weeks of hibernation with exposure to light (12L:12D, 4 °C) and emergence into warm, long days (14L:10D, 28:18 °C). Males in both conditions exhibited intense courtship behavior on emergence from hibernation. Females in 1982 were significantly influenced only by long-day prehibernation conditions (14L:10D, 28:18 °C); under these conditions, ovarian recrudescence on emergence was inhibited. Long prehibernation photoperiod did not significantly influence female receptive behavior on emergence, indicating that neuroendocrine control of ovarian activation and sexual behavior may be separate in this species. In three subsequent years (1983, 1984, 1985) none of the photoperiodic conditions significantly influenced male or female sexual behavior or ovarian recrudescence. Slight differences in experimental protocol in these subsequent years that may account for differences in results from 1982 are discussed. Finally, ovarian development was found to be clearly tied to the duration of cold temperature dormancy in this species. Females receiving 7 or 17 weeks of exposure to cold (4 °C) underwent vitellogenesis at similar frequencies. Most females receiving 0 or only 4 weeks of exposure to cold (4 °C) did not become vitellogenic. Mating on emergence was not a requirement for the initiation of vitellogenesis in this study.

scholarly journals INVESTIGATING THE ROLE OF AHR IN MEDIATING SEX DIFFERENCES OF AGING MACROPHAGES

2019 ◽  
Vol 3 (Supplement_1) ◽  
pp. S836-S836
Author(s):  
Evelyn Navar ◽  
Bérénice A Benayoun ◽  
Nirmal Sampathkumar ◽  
Jisoo Chae
Keyword(s):  
Short Exposure ◽  
Low Grade ◽  
Rna Seq ◽  
Phagocytosis Assay ◽  
Short Exposure Time ◽  
Aryl Hydrocarbon ◽  
Age Related ◽  
Low Grade Inflammation ◽  
Phagocytosis Activity

Abstract “Inflamm-aging” describes a state of chronic low-grade inflammation which occurs with age in the absence of infection. This process is related to many chronic age-related diseases. Aryl hydrocarbon receptor (Ahr), is a transcription factor that is thought to decrease inflammation, and decrease of Ahr with aging only in females was previously observed in a macrophage RNA-seq with aging. Based on this, I hypothesized that 1) Ahr expression will decrease with age in female cells; and 2) phagocytic activity and Ahr expression in macrophages will increase when exposed to estrogens (E2). To test these hypotheses, Ahr signaling was quantified by RT-qPCR in aging male and female mice BMDMs, and in macrophages that were treated with E2. I also performed a phagocytosis assay on macrophages treated with E2. I found a significant downregulation of Ahr in old female BMDMs. Ahrr (Ahr Repressor) was significantly downregulated in both old female and males with aging. Arnt (Ahr Nuclear Translocator) did not significantly change with aging. The qPCR performed on the E2 treated cells showed no significant trend for Ahr regulation. Finally, the phagocytosis assay revealed an overall increase in phagocytosis activity in cells treated with estrogen. Our hypotheses were supported by data showing a decrease in Ahr expression with age and increase in phagocytosis activity in estrogen treated cells. The RT-qPCR results for the E2 treated cells did not support our hypothesis, but could stem from a relatively short exposure time for estrogen.

Role of the Thyroid in Metabolic Response to Low Temperature

1956 ◽  
Vol 188 (1) ◽  
pp. 40-44 ◽  
Author(s):  
A. C. L. Hsieh ◽  
L. D. Carlson
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Low Temperature ◽  
Metabolic Response ◽  
Muscular Activity ◽  
Half Time ◽  
High Metabolic Rate ◽  
Cold Adapted ◽  
Exposure To Cold

Cold-adapted rats, kept at 5°C, and warm-adapted rats, kept at 28°C, were curarized and oxygen consumption; heart rate; muscular activity; rectal, foot and room temperatures recorded during a period at 30°C and during exposure to cold. The experiments were performed before and at varying intervals after thyroidectomy. Oxygen consumption measured at 30°C reached a minimum 8 days after thyroidectomy in the rats kept at 5°C and 12 days after thyroidectomy in the rats kept at 28°C. The half-time for the decline was twice as long for the rats kept at 28°C, indicating that thyroxin stores were being utilized twice as fast by the rats kept at 5°C. Upon exposure to cold the rats responded by an increase in oxygen consumption. Since the response persisted after thyroxin stores had been depleted it is concluded that the metabolic response to cold is not directly dependent upon the amount of circulating thyroxin. Rats kept at 5°C reduced their food intake and lost weight following thyroidectomy, but maintained a high metabolic rate. The significance of these findings are discussed.

The Role of Transparency in Perceptual Grouping and Pattern Recognition

Perception ◽  
1992 ◽  
Vol 21 (1) ◽  
pp. 133-139 ◽  
Author(s):  
Takeo Watanabe ◽  
Patrick Cavanagh
Keyword(s):  
Pattern Recognition ◽  
Perceptual Grouping ◽  
Exposure Duration ◽  
The Other ◽  
Short Exposure ◽  
Stimulus Exposure ◽  
Digit Recognition ◽  
Invalid Condition ◽  
Luminance Condition

The shortest stimulus exposure time for which transparency can be seen was examined. In the first experiment, overlapping digits were presented for 120 ms and the luminance in the overlapping regions was varied. Subjects reported, in separate blocks of trials, either the apparent transparency of the digits or the identity of the digits. When the luminance was set so that one set of digits appeared to be seen through the other, recognition of the digits was high. When the luminance in the overlapping regions did not produce impressions of transparency, digit recognition was low. In the second experiment, digit identification at several stimulus durations was compared between stimuli that had luminance that was valid for transparency and stimuli that had invalid luminance. Performance was found to be higher in the valid luminance condition than in the invalid condition after as little as 60 ms exposure duration. This result suggests that the impression of transparency requires only relatively short exposure durations.

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