Search results for "Cold Temperature"
showing 10 items of 166 documents
The effects of cold and glucagon on lipolysis, glycogenolysis and oxygen consumption in young chicks.
1973
Abstract 1. 1. To study the possible role of glucagon in avian thermoregulation the effects of cold exposure and glucagon on lipolysis, glycogenolysis and oxygen consumption were measured in young chicks. 2. 2. Cold exposure (+10°C) and glucagon injection (0·3 mg/kg, i.p. at +30°C) both caused a marked increase in the plasma FFA and a decrease in the liver glycogen content. 3. 3. It is suggested that glucagon possibly acts in the avian thermoregulation by producing at least lipolysis and glycogenolysis during cold exposure.
Measurement of brain tissue pressure in cold induced cerebral oedema.
1973
Experiments were performed in order to evaluate the concept that brain oedema is associated with an increase in local interstitial fluid pressure. Assuming that the pressure measured by the cotton wick technique represents the hydrostatic interstitial fluid pressure, the tissue pressure was recorded with pressure transducers in the white matter adjacent and remote to a local cold injury, in the opposite hemisphere, and in the cisterna magna. In 9 cats during steady-state conditions mean tissue pressures between 1.20±0.30 mm Hg and 2.33±0.80 mm Hg were found, as compared to a mean CSF pressure of 5.17±0.82 mm Hg. The tissue pressure was found to increase significantly adjacent to the lesion …
Inducing Cold-Sensitivity in the Frigophilic Fly Drosophila montana by RNAi.
2016
Cold acclimation is a critical physiological adaptation for coping with seasonal cold. By increasing their cold tolerance individuals can remain active for longer at the onset of winter and can recover more quickly from a cold shock. In insects, despite many physiological studies, little is known about the genetic basis of cold acclimation. Recently, transcriptomic analyses in Drosophila virilis and D. montana revealed candidate genes for cold acclimation by identifying genes upregulated during exposure to cold. Here, we test the role of myo-inositol-1-phosphate synthase (Inos), in cold tolerance in D. montana using an RNAi approach. D. montana has a circumpolar distribution and overwinters…
Improved yield and functionality of parathyroid cells separated by using collagenase-digestion with cold pre-incubation.
2001
Preparation of cells from solid organs often induces a functional impairment due to the proteolytic cell damage by the applied digestive enzyme like collagenase, trypsin or dispase. To preserve the tissue and to enhance the yield of cells, Laue et al. reported an islet cell isolation with pre-incubation at 4 C permitting the enzyme to diffuse into the tissue and explicite activity equally throughout the whole particle. The aim of this study was to investigate whether this procedure can be applied to parathyroid glands. Therefore porcine parathyroid glands were dissected into 1 mm3 pieces. Subsequently one group of these pieces was incubated 22 h at 4 C in 2 mg/ml collagenase before activati…
Spontaneous lymphokine synthesis by human blood mononuclear cells
1975
LYMPHOCYTES, after antigenic stimulation, may synthesise and release biologically active soluble factors other than antibodies. These mediators were termed lymphokines by Dumonde1, and the most extensively studied and best characterised are migration inhibitory factors which can inhibit the migration of macrophages or leukocytes: this is the property used for their in vitro bioassay. Apart from antigens, various other stimuli may trigger lymphokine synthesis by lymphocytes, for example, polyclonal mitogens2, anti-immunoglobulin or membrane Fc or C3-receptor reactions3,4. Furthermore, migration inhibitory activity has been found in the long term culture supernatants of some established lymph…
The Impact of Environmental Conditions on Efficiency of Host Plant DNA Barcoding for Polyphagous Beetles.
2015
Recently, several papers were published dealing with host plant identification for selected species of insects, including beetles. These studies took advantage of the DNA barcoding approach and generally showed that it is possible to identify diet composition from plant DNA present in insect guts. However, none of these studies considered how the impact of environmental conditions affected the likelihood of insect feeding and, therefore, the presence of host plant DNA that could be amplified and sequenced. In the present study, individuals of the polyphagous weevil Centricnemus leucogrammus (Germar, 1824) (Curculionidae: Entiminae) were used to test the hypothesis that harsh environmental c…
Interpositus nucleus inactivation reduces unconditioned response amplitude after paired but not explicitly unpaired treatment in rabbit eyeblink cond…
2001
The amplitude of unconditioned responses (URs) in unconditioned stimulus (US) alone presentations were measured in six rabbits during explicitly unpaired and classical conditioning treatments. After both phases of the experiment, the interpositus nucleus (IPN) was reversibly inactivated by a cold probe. URs after unpaired treatment were unaffected by inactivation but after acquisition of a robust level of conditioned responses (CRs), URs in US-alone test trials were reduced in amplitude compared with URs immediately before and after inactivation. The results suggest that the IPN has a role in CR-related reflex modification.
Cortical Temperature Change: A Tool for Modulating Brain States?12
2016
Reduction in temperature depolarizes neurons by a partial closure of potassium channels but decreases the vesicle release probability within synapses. Compared with cooling, neuromodulators produce qualitatively similar effects on intrinsic neuronal properties and synapses in the cortex. We used this similarity of neuronal action in ketamine-xylazine-anesthetized mice and non-anesthetized mice to manipulate the thalamocortical activity. We recorded cortical electroencephalogram/local field potential (LFP) activity and intracellular activities from the somatosensory thalamus in control conditions, during cortical cooling and on rewarming. In the deeply anesthetized mice, moderate cortical co…
How consistent are the transcriptome changes associated with cold acclimation in two species of the Drosophila virilis group?
2015
This work was financially support by a Marie Curie Initial Training Network grant, “Understanding the evolutionary origin of biological diversity” (ITN-2008–213780 SPECIATION), grants from the Academy of Finland to A.H. (project 132619) and M.K. (projects 268214 and 272927), a grant from NERC, UK to M.G.R. (grant NE/J020818/1), and NERC, UK PhD studentship to D.J.P. (NE/I528634/1). For many organisms the ability to cold acclimate with the onset of seasonal cold has major implications for their fitness. In insects, where this ability is widespread, the physiological changes associated with increased cold tolerance have been well studied. Despite this, little work has been done to trace chang…
Identifying conserved genes involved in crop tolerance to cold stress
2022
Low temperature is a limiting factor for crop productivity in tropical and subtropical climates. Cold stress response in plants involves perceiving and relaying the signal through a transcriptional cascade composed of different transduction components, resulting in altered gene activity. We performed a meta-analysis of four previously published datasets of cold-tolerant and cold-sensitive crops to better understand the gene regulatory networks and identify key genes involved in cold stress tolerance conserved across phylogenetically distant species. Re-analysing the raw data with the same bioinformatics pipeline, we identified common cold tolerance-related genes. We found 236 and 242 common…