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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.
Afficher plus [+] Moins [-]Changes in CO-oximetry values and pulse oximetry in isoflurane-anesthetized dogs with and without nitrous oxide
2020
Jones, Teela | Feng, Cindy | Duke-Novakovski, Tanya
Concentrations of 64% to 70% nitrous oxide (N(2)O) provide intra-operative analgesia. Clinically, pulse oximeter estimation (SpO(2)) of oxygen (O(2)) hemoglobin saturation (SaO(2)) was observed to decrease with N2O. Absorption atelectasis from breathing O2 was thought to decrease arterial partial pressure of O2 (PaO(2)) below 70 mmHg and reduce SaO(2) and SpO(2) when N(2)O was used. Administering N(2)O from the beginning of the anesthesia might prevent atelectasis development and low PaO(2).The study was done in 2 parts (P, 0.05). In Part 1, isoflurane-anesthetized dogs undergoing ovariohysterectomy (n = 15 each group) breathed N(2)O from anesthesia start (N(2)O early) or 1 hour later (N2Olate). SpO(2), CO-oximetry values, and PaO(2) were compared to dogs breathing O(2) throughout anesthesia (control). Timing of N(2)O introduction did not affect PaO(2) (lowest = 94 mmHg), SaO(2), or SpO(2). With N(2)O, the lowest SpO(2) value was 91% and corresponded to a PaO2 of 151 mmHg. Carboxyhemoglobin increased (highest = 2.7%) and SaO(2) decreased with N2O (lowest = 96.7%). In Part 2, to replicate findings, 10 isoflurane-anesthetized dogs breathed N(2)O, then O(2). With N2O, SaO2 did not decrease, but carboxyhemoglobin increased and returned to baseline once N2O was discontinued. The dog with the highest carboxyhemoglobin (2%) had an SaO(2) of 96.8% (PaO(2) = 93 mmHg). Carboxyhemoglobin and SaO(2) changes were not clinically significant. Pulse oximetry did not reliably estimate SaO(2) but N(2)O was not always a factor.
Afficher plus [+] Moins [-]Pharmacokinetics of danofloxacin following intramuscular administration of a single dose in koi (Cyprinus carpio)
2020
Parker-Graham, Christine A. | Siniard, Wesley C. | Byrne, Barbara A. | Knych, Heather K. | Soto, Esteban
OBJECTIVE To determine the pharmacokinetics of danofloxacin following IM administration of a single dose (10 mg/kg) in koi (Cyprinus carpio). ANIMALS 69 healthy adult koi housed in a 980-L flow-through-system tank. PROCEDURES 3 fish were kept as untreated controls, and the remaining 66 fish were assigned to 11 treatment groups with 6 fish/group. Fish in the treatment groups were given a single dose of danofloxacin (10 mg/kg) IM in the left epaxial musculature. Fifteen, 30, and 45 minutes and 1, 4, 12, 24, 72, 96, 120, and 144 hours after administration of danofloxacin, fish in each treatment group were euthanized, and blood samples and samples of liver, spleen, gill, anterior kidney, posterior kidney, skin and muscle, and scales were collected. Plasma and tissue drug concentrations were determined by liquid chromatography–tandem mass spectrometry, and noncompartmental pharmacokinetic analyses were performed. Tissues from the untreated control fish and fish euthanized 144 hours after danofloxacin administration were examined histologically. RESULTS Maximum plasma concentration (mean, 8,315.7 ng/mL) was reached approximately 45 minutes after danofloxacin administration; plasma elimination half-life was 15 hours. Danofloxacin was detected in all examined tissues from all 6 fish euthanized 15 minutes after drug administration and was detected in some tissues from 3 of the 6 fish euthanized 144 hours after drug administration. For all tissues, results of histologic examination were unremarkable. CONCLUSIONS AND CLINICAL RELEVANCE IM administration of a single dose (10 mg/kg) of danofloxacin in koi resulted in rapid absorption, with maximum plasma concentration reached approximately 45 minutes after drug administration; the drug could still be detected in some tissues 144 hours after administration.
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