Comparison of Sedative Effects of Alfaxalone-Ketamine and Alfaxalone-Midazolam Administered Intramuscularly in Chickens.

The objective of this study was to compare the sedative effects of intramuscular alfaxalone combined with either ketamine or midazolam in chickens (Gallus gallus domesticus). A prospective, randomized blinded crossover study design with a 7-day washout period was used. Nine adult layer hens received alfaxalone 15 mg/kg with ketamine 5 mg/kg IM (treatment AK) or alfaxalone 15 mg/kg with midazolam 1 mg/kg IM (treatment AM). Time to lateral recumbency, time to loss of righting reflex, induction quality, duration of loss of righting reflex, time to sternal recumbency or vigorous response to stimulation, and time to standing were recorded. Muscle tone, response to noxious stimulation, heart rate, respiratory rate, and oxygen saturation were monitored once the righting reflex was absent. Induction and recovery times were not different between treatments. Lateral recumbency was induced in 8 of 9 birds receiving AK compared to 6 of 9 birds receiving AM. Righting reflex was absent in 7 of 9 and 5 of 9 chickens administered AK and AM, respectively. Median time to loss of righting reflex for AK and AM were 5.5 (4.3-9.3) minutes and 9.1 (4.8-15.0) minutes, respectively (P = .88). Median duration of loss of righting reflex was 21.6 (16.0-36.9) minutes for AK and 21.1 (11.9-26.4) minutes for AM (P = .38). Alfaxalone-ketamine resulted in moderate excitation during induction. Further investigations are warranted to investigate the effects of alfaxalone and midazolam or ketamine at different doses.

Effect of preoxygenation before isoflurane induction and rocuronium-induced apnea on time until hemoglobin desaturation in domestic chickens (Gallus gallus domesticus).

OBJECTIVE: To evaluate the time to hemoglobin oxygen desaturation in chickens (Gallus gallus domesticus) with and without preoxygenation before isoflurane induction of anesthesia and rocuronium-induced apnea. STUDY DESIGN: Prospective, randomized crossover study. ANIMALS: A total of 10 healthy adult Lohmann Brown-Lite hens. METHODS: Hens were anesthetized with isoflurane for intravenous (IV) and intraarterial catheter placement and allowed to fully recover from anesthesia. Hens in the preoxygenation treatment were administered oxygen (2 L minute-1) via a facemask for 3 minutes prior to induction of anesthesia with 3% isoflurane in oxygen. In the alternative treatment, hens were not preoxygenated prior to induction of anesthesia with isoflurane in oxygen. Apnea was then induced with rocuronium bromide (1.0 mg kg-1) administered IV, and anesthesia was maintained with IV propofol infusion. A cloacal pulse oximeter measured hemoglobin oxygen saturation (SpO2). Time was recorded from the start of apnea until SpO2 was 90% (desaturation). The trachea was intubated, and anesthesia was maintained with isoflurane in oxygen with manual ventilation until spontaneous breathing returned and SpO2 ≥ 99%. PaO2 was measured before each treatment, after preoxygenation, postinduction and at desaturation. Data were analyzed between treatments using Wilcoxon matched-pairs signed rank tests with Holm-Sidák multiple comparison test, and within treatments using Friedman test with Dunn's multiple comparison test (p < 0.05). Data are reported as median (range). RESULTS: Time from start of apnea until hemoglobin desaturation was not significantly different between preoxygenated and nonpreoxygenated hens [26.5 (16-50) seconds and 24.0 (5-57) seconds, respectively; p = 0.25]. No differences in PaO2 between treatments were observed at any time point. CONCLUSIONS AND CLINICAL RELEVANCE: Preoxygenation for 3 minutes before isoflurane mask induction of anesthesia and apnea does not significantly increase time until desaturation in hens.

Insulinotropic nucleobindin-2/nesfatin-1 is dynamically expressed in the haemochorial mouse and human placenta.

The placenta is the physiological bridge between mother and fetus and has life-sustaining functions during pregnancy, including metabolic regulation, fetal protection and hormone secretion. Nucleobindin-2 (NUCB2) is a calcium- and DNA-binding protein and precursor of nesfatin-1, a signalling peptide with multiple functions, including regulation of energy homeostasis and glucose transport. These are also key functions of the placenta, yet NUCB2/nesfatin-1 expression has never been comprehensively studied in this organ. In the present study, mouse placental samples from Embryonic Day (E) 7.5 to E17.5 and human chorionic villi from the first and second trimester, as well as term pregnancy, were analysed for NUCB2/nesfatin-1 expression by immunohistochemistry with an antiserum that recognised both NUCB2 and nesfatin-1. From E7.5 to E9.5, NUCB2/nesfatin-1 was expressed in the ectoplacental cone, then parietal trophoblast giant cells and early spongiotrophoblast. At E10.5-12.5, NUCB2/nesfatin-1 expression became detectable in the developing labyrinth. From E12.5 and onwards, NUCB2/nesfatin-1 was expressed in the glycogen trophoblast cells, as well as highly expressed in syncytiotrophoblast, sinusoidal trophoblast giant cells and fetal capillary endothelial cells of the labyrinth. In all trimesters of human pregnancy, NUCB2/nesfatin-1 was highly expressed in syncytiotrophoblast. In addition, there was a significant increase in NUCB2 expression in human primary trophoblast cells induced to syncytialise. Thus, the haemochorial mammalian placenta is a novel source of NUCB2/nesfatin-1 and likely a site of its action, with potential roles in glucose homeostasis and/or nutrient sensing.