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Effect of electromagnetic field exposure on mouse brain morphological and histopathological profiling
2020
Zymantiene, Judita | Juozaitiene, Vida | Zelvyte, Rasa | Oberauskas, Vaidas | Spancerniene, Ugne | Sederevicius, Antanas | Aniuliene, Albina
Mobile phones (MP) and other electronic and communication devices that are used daily expose users to electromagnetic fields (EMF) and contribute to an increasing incidence of neurological disorders. Brain tissue is the closest organ to the MP as it operates, thus the influence of MP radiation on brain tissue is of particular concern, although research is still inconclusive. The present study investigated the possible effect of an EMF (1,350–1,375 megahertz (MHz)) from an MP on morphological and histopathological profiles in the mouse brain. Healthy BALB/c mice were assigned to three equal groups (a control and two experimental groups, n = 10 each). Experimental mice were exposed to EMFs continuously for 72 h, those of experimental group I to a 1,350 MHz field at a specific absorption rate (SAR) of 4.0 W/kg, and group II to a 1,375 MHz field EMF at an SAR of 4.0 W/kg. Brain segmentation and histopathological analysis were applied to detect changes in the morphometric parameters of the brain lobes and identify pathological lesions, respectively. Histopathology results revealed shrinkage of pyramidal neurons, presence of mild perivascular and perineural oedema, and some vacuolation of neurons and glial cells derived from mouse great hemispheres. The lesions also included reduction of Purkinje cells, vacuolisation of neurons and glial cells, and interstitial oedema in the cerebellum. MP distance of 3 cm from the cage may induce appreciable morphological changes in mouse brain structures; therefore, more comprehensive research is essential for assessment of safe distance. These pronounced effects may interfere with the results of laboratory tests on murine experimental models in veterinary or biomedical research.
Показать больше [+] Меньше [-]Pre-warming following premedication limits hypothermia before and during anesthesia in Sprague-Dawley rats (Rattus norvegicus)
2021
Rufiange, Maxime | Leung, Vivian S. Y. | Simpson, Keith | Pang, Daniel S. J.
In humans and other mammals, general anesthesia impairs thermoregulation, leading to warm core blood redistributing to the periphery. This redistribution is an important contributor to hypothermia that can be reduced with pre-warming before anesthesia. Additionally, sedation following premedication has been associated with hypothermia in dogs. In a prospective, randomized, cross-over study, 8 adult male and female rats (weighing 388 to 755 g) were sedated with intramuscular ketamine-midazolam-hydromorphone, then placed in an unwarmed cage or warmed box for 14 minutes, followed by 30 minutes of isoflurane anesthesia with active warming. Core body temperature was monitored throughout. After sedation, warmed rats gained 0.28°C ± 0.13°C and unwarmed rats lost 0.19°C ± 0.43°C, a significant difference between groups (P = 0.004). After anesthesia, warmed rats maintained higher core temperatures (P < 0.0001) with 2/8 and 6/8 of warmed and unwarmed rats becoming hypothermic, respectively. Pre-warming during sedation and active warming during general anesthesia is effective in minimizing hypothermia.
Показать больше [+] Меньше [-]Evaluation of the effects of a 4.7-mg deslorelin acetate implant on egg laying in cockatiels (Nymphicus hollandicus)
2017
Summa, Noemie M. | Sanchez-Migallon Guzman, David | Wils-Plotz, Emma L. | Riedl, Nerisa E. | Kass, Philip H. | Hawkins, Michelle G.
OBJECTIVE To evaluate effects of administration of a 4.7-mg deslorelin acetate implant on egg laying in healthy cockatiels (Nymphicus hollandicus). ANIMALS 52 cockatiels. PROCEDURES 26 breeding pairs (a female and its respective male in each pair) were selected on the basis of their history of egg laying. Female birds were sedated and received a 4.7-mg deslorelin acetate implant (n = 13) or placebo implant (13) in the subcutaneous tissues between the scapulae. Male and female birds of each breeding pair were placed in separate but adjacent cages. Birds were exposed to 16 hours of light and 8 hours of darkness. A nest box was placed in cages of female birds to stimulate reproductive activity. Egg production and quality were monitored daily for 365 days. RESULTS Deslorelin acetate implants significantly suppressed egg laying in cockatiels, compared with effects for the placebo implants. Eleven of 13 placeboimplanted birds laid eggs between 12 and 42 days after implantation. None of the deslorelin-implanted birds laid eggs within 180 days after implantation, and only 5 of 13 deslorelin-implanted birds laid an egg during the study period (first egg laid between 192 and 230 days after implantation). No differences in egg quality or number of eggs per clutch were observed between the 2 groups. CONCLUSIONS AND CLINICAL RELEVANCE Insertion of a 4.7-mg deslorelin acetate implant suppressed egg laying in healthy cockatiels for at least 180 days. Studies are necessary to evaluate effects of a deslorelin acetate implant in other avian species or in association with reproductive disorders.
Показать больше [+] Меньше [-]Porcine salivary analysis by 2-dimensional gel electrophoresis in 3 models of acute stress: A pilot study
2014
Fuentes-Rubio, Maria | Ceron, Jose J. | Torre, Carlos de | Escribano, Damian | Gutierrez, Ana M. | Tecles, Fernando
The purpose of this research was to study changes in the salivary proteome of healthy pigs in stressful situations to identify any potential new salivary biomarker of stress. Three groups of animals were subjected to 3 stress models: snaring restraint followed by simulated sampling of vena cava blood; brief transport by road; and restriction of movement in a digestibility cage. Saliva was obtained from each animal before and 15 and 30 min after the induction of stress. The samples from the animals that showed the greatest increase in salivary cortisol concentration were pooled and run on 2-dimensional gels. Coomassie Brilliant Blue R-250 was used for spot detection and mass spectrometry for spot identification. Statistical analyses showed that 2 proteins had significant differences in expression before and after the induction of stress. These proteins were identified as odorant-binding protein and fragments of albumin. Further studies will be necessary to confirm the value of using these proteins as salivary biomarkers of stress in pigs.
Показать больше [+] Меньше [-]Welfare assessment of two hybrids of laying hens housed in conventional cages
2018
H.D.H. Mahboub | I.M. Fares | R.A. Darwish
The aims of this study were twofold: to assess the welfare of two hybrids of laying hens in conventional cages and to investigate the effects of tier’s level on the integument condition and fearfulness. Two commercial hybrids, white Lohmann Selected Leghorn (LSL) and brown Lohmann Traditional (LT) at about 18 weeks of age were used in the current study and were housed at three hens / cage. No birds were beak-trimmed. External appearance of the body (scoring of plumage condition and skin injuries at body parts and comb), heterophil-lymphocyte (H-L) ratios and duration of tonic immobility (TI) were used as indicators of well-being. LSL birds showed better plumage condition and low H-L ratios than LT birds while no significant difference was recorded in TI test between the two hybrids. Hens housed in the top tier showed worse feather condition and more wounds than birds in middle and bottom tiers whereas for fear levels, no significant difference was revealed for hens from different tiers of cages. These results suggest that the welfare of LSL birds was relatively good compared to LT. Therefore, conventional cages can be used by the hens to a large extent if birds are properly selected to be specifically adapted to cages.
Показать больше [+] Меньше [-]Effects of ultraviolet radiation produced from artificial lights on serum 25-hydroxyvitamin D concentration in captive domestic rabbits (Oryctolagus cuniculi)
2014
Emerson, Jessica A. | Whittington, Julia K. | Allender, Matthew C. | Mitchell, Mark A.
Objective—To determine the effects of UVB radiation produced by artificial lights on serum 25-hydroxyvitamin D concentrations in domestic rabbits (Oryctolagus cuniculi) Animals—9 juvenile domestic rabbits. Procedures—After an acclimation period, rabbits were anesthetized with isoflurane, and an initial blood sample was collected for determination of serum 25-hydroxyvitamin D concentration. Rabbits were randomly assigned to receive 12-hour exposure to UVB radiation produced by 2 compact fluorescent lights daily (n = 5) or no UVB supplementation (4) commencing on day 1. The UVB radiation emitted into the cage was measured at 9 points approximately 34 cm from the surface of the UVB light sources (representing the position of the rabbits in the cage) after 10 hours of exposure on days 1, 8, and 14. On day 14, another blood sample was collected from anesthetized rabbits for determination of serum 25-hydroxyvitamin D concentration. Results—The UVB radiation level was 8.3 to 58.1 μW/cm2 for the exposed rabbits and consistently < 0.001 μW/cm2 for the control rabbits. Mean ± SD serum 25-hydroxyvitamin D concentrations in the rabbits that were or were not provided supplemental UVB radiation for 14 days differed significantly (66.4 ± 14.3 nmol/L and 31.7 ± 9.9 nmol/L, respectively). Conclusions and Clinical Relevance—Exposure to UVB radiation produced by artificial light significantly increased serum 25-hydroxyvitamin D concentration in juvenile rabbits. Because vitamin D is an essential hormone in vertebrates, these findings suggested that the provision of supplemental UVB radiation to captive rabbits may be important.
Показать больше [+] Меньше [-]Rearing and breeding of germ-free mice for over 1 year in a sealed positive pressure cage system
2019
Niimi, K. ((RIKEN Center for Brain Science, Wako-shi, Saitama (Japan). Research Resources Division), (RIKEN Brain Science Institute, Wako-shi, Saitama (Japan). Research Resources Center)) | Hardy, P. | Bilecki, B. | Takahashi, E.