Local orchestration of distributed functional patterns supporting loss and restoration of consciousness in the primate brain.

A central challenge of neuroscience is to elucidate how brain function supports consciousness. Here, we combine the specificity of focal deep brain stimulation with fMRI coverage of the entire cortex, in awake and anaesthetised non-human primates. During propofol, sevoflurane, or ketamine anaesthesia, and subsequent restoration of responsiveness by electrical stimulation of the central thalamus, we investigate how loss of consciousness impacts distributed patterns of structure-function organisation across scales. We report that distributed brain activity under anaesthesia is increasingly constrained by brain structure across scales, coinciding with anaesthetic-induced collapse of multiple dimensions of hierarchical cortical organisation. These distributed signatures are observed across different anaesthetics, and they are reversed by electrical stimulation of the central thalamus, coinciding with recovery of behavioural markers of arousal. No such effects were observed upon stimulating the ventral lateral thalamus, demonstrating specificity. Overall, we identify consistent distributed signatures of consciousness that are orchestrated by specific thalamic nuclei.

Topical application of L-Menthol - Physiological and genetic considerations to assist in developing female athlete research: A narrative review.

L-menthol is a cyclic monoterpene derived from aromatic plants, which gives a cooling sensation upon application. With this in mind, L-menthol is beginning to be considered as a potential ergogenic aid for exercise and sporting competitions, particularly in hot environments, however female-specific research is lacking. The aim of this narrative review is to summarize available literature relating to topical application of L-menthol and provide commentary on avenues of consideration relating to future research developments of topical L-menthol in female athletes. From available studies in male participants, L-menthol topical application results in no endurance exercise performance improvements, however decreases in thermal sensation are observed. Mixed results are observed within strength performance parameters. Several genetic variations and single nucleotide polymorphisms have been identified in relation to sweat production, fluid loss and body mass changes - factors which may influence topical application of L-menthol. More specifically to female athletes, genetic variations relating to sweat responses and skin thickness, phases of the menstrual cycle, and body composition indices may affect the ergogenic effects of L-menthol topical application, via alterations in thermogenic responses, along with differing tissue distribution compared to their male counterparts. This narrative review concludes that further development of female athlete research and protocols for topical application of L-menthol is warranted due to physiological and genetic variations. Such developments would benefit research and practitioners alike with further personalized sport science strategies around phases of the menstrual cycle and body composition indices, with a view to optimize ergogenic effects of L-menthol.

Effects of Anesthetic Administration on Rat Hypothalamus and Cerebral Cortex Peptidome.

Prohormone-derived neuropeptides act as cell-cell signaling molecules to mediate a wide variety of biological processes in the animal brain. Mass spectrometry-based peptidomic experiments are valuable approaches to gain insight into the dynamics of individual peptides under different physiological conditions or experimental treatments. However, the use of anesthetics during animal procedures may confound experimental peptide measurements, especially in the brain, where anesthetics act. Here, we investigated the effects of the commonly used anesthetics isoflurane and sodium pentobarbital on the peptide profile in the rodent hypothalamus and cerebral cortex, as assessed by label-free quantitative peptidomics. Our results showed that neither anesthetic dramatically alters peptide levels, although extended isoflurane exposure did cause changes in a small number of prohormone-derived peptides in the cerebral cortex. Overall, our results demonstrate that acute anesthetic administration can be utilized in peptidomic experiments of the hypothalamus and cerebral cortex without greatly affecting the measured peptide profiles.

Putting the Pacific fat sleeper Dormitator latifrons (Pisces: Eleotridae) to sleep: effects of clove oil and lidocaine anesthetic.

Among the different handling techniques in aquaculture, the use of anesthetics has had a growing interest focused on guaranteeing animal welfare, and reducing possible stress situations during general handling. The aim of this study was to present the use of eugenol and lidocaine with non-invasive anesthesia procedures in Dormitator latifrons, in which the different stages of anesthesia (induction and recovery) were determined. One hundred and twenty healthy fish of average weight of 73.59 ± 13.53 g and standard length of 17 ± 1.36 cm were used. The experimental fish were subjected to fasting for 24 h prior to the tests. Five fish were subjected to eugenol (25, 50, 100, and 200 µL/L), and lidocaine (100, 200, 300, and 400 mg/L), in triplicate. The time to reach deep and recovery anesthesia were recorded and the data analyzed using ANOVA (α= 0.05). Organisms exposed to anesthetics evidenced early episodes of fast, short-distance swimming (initial hyperactivity) for short periods of time. Survival was 100% with both compounds and concentrations. Fish exposed to a eugenol concentration of 200 µL/L had longer anesthesia times and took longer time to recover (P<0.05). The most effective concentrations for eugenol and lidocaine were of 200 µL/L and 400 µL/L in juvenile fish, promoting rapid inductions, without compromising the conditions for the recovery of the fish. This work provides practical information for handling and transportation D. latiforns with the least possible stress and ensuring animal welfare.

Physiological Response of Atlantic Salmon (Salmo salar) to Long-Term Exposure to an Anesthetic Obtained from Heterosigma akashiwo.

Despite the invaluable role of anesthetics as a tool for ensuring animal welfare in stressful situations, there is currently a lack of anesthetic drugs that meet the requirements of intensive aquaculture. In response to the growing interest in anesthetic substances of natural origin, this study evaluated the physiological and health impact of an anesthetic based on an extract of the microalga Heterosigma akashiwo on juvenile salmon (Salmo salar) exposed for a period of 72 h. To simulate a condition closer to reality where fish are subjected to stimuli (e.g., transport), the animals were exposed to 50 mg L-1 of algal extract and to physical stress. Functional, physiological, and histological parameters were evaluated in blood and tissues at different sampling periods (0, 24, and 72 h). There was no mortality and the induction and recovery times observed were within the established criteria for anesthetic efficacy. The anesthetic extract did not induce any side effects, such as stress or metabolic damage, indicating that this extract is a viable option for supporting fish welfare during deleterious events. This study provides information to support that the anesthetic extract tested, derived from H. akashiwo, is a promising candidate drug for operations requiring sedation (e.g., Salmonid transport).

Anesthetic Pharmacology of the Mint Extracts L-Carvone and Methyl Salicylate.

INTRODUCTION: Hydrocarbons with sufficient water solubility allosterically modulate anesthetic-sensitive ion channels. Mint extracts L-carvone and methyl salicylate water solubility exceeds modulation cutoff values for γ-amino butyric acid type A (GABAA) receptors, N-methyl-D-aspartate (NMDA) receptors, and type-2 voltage-gated sodium (Nav1.2) channels. We hypothesized that mint extracts modulate these channels at concentrations that anesthetize rats. METHODS: Channels were expressed separately in frog oocytes and studied using 2-electrode voltage clamp techniques at drug concentrations up to 10 mM. Normalized current effects were fit to Hill equations. Mint compounds were formulated in a lipid emulsion and administered IV to rats. When unresponsive to the tail clamp, rats were exsanguinated, and plasma drug concentrations were measured. RESULTS: Both mint compounds caused concentration-dependent inhibition of all channels except for methyl salicylate which inhibited GABAA receptors at low concentrations and potentiated at high concentrations. Plasma drug concentrations in anesthetized rats were 7.9 mM for L-carvone and 2.7 mM for methyl salicylate. This corresponded to ≥53% NMDA receptor inhibition and ≥78% Nav1.2 channel inhibition by both compounds and 30% potentiation of GABAA receptors by methyl salicylate. CONCLUSION: L-Carvone and methyl salicylate allosterically modulate cell receptor targets important to molecular actions of conventional anesthetics at concentrations that also induce general anesthesia in rats.

Acupoint Injection Decreases Anesthetic Cosumption during Combined Spinal-Epidural and Patient-Controlled Epidural Labor Analgesia.

OBJECTIVE: To explore if acupoint injection can improve analgesic effects or delivery outcomes in parturients who received combined spinal-epidural analgesia (CSEA) and patient-controlled epidural analgesia (PCEA) for labor analgesia. METHODS: A total of 307 participants were prospectively collected from July 2017 to December 2019. The participants were randomized into the combined acupoint injection with CSEA plus PCEA group (AICP group, n=168) and CSEA plus PCEA group (CP group, n=139) for labor analgesia using a random number table. Both groups received CSEA plus PCEA at cervical dilation 3 cm during labor process, and parturients of the AICP group were implemented acupoint injection for which bilateral acupoint of Zusanli (ST 36) and Sanyinjiao (SP 6) were selected in addition. The primary outcome was Visual Analogue Scale (VAS) score, and the secondary outcomes were obstetric outcomes and requirement of anesthetics doses. Safety evaluations were performed after intervention. RESULTS: The VAS scores were significantly lower in the AICP group than in the CP group at 10, 30, 60, and 120 min after labor analgesia (all P<0.05). The latent phase of the AICP group was shorter than that of the CP group (P<0.05). There were less additional anesthetics consumption, lower incidences of uterine atony, fever, pruritus and urinary retention in the AICP group than those in the CP group (all P<0.05). CONCLUSION: Acupoint injection combined CSEA plus PCEA for labor analgesia can decrease the anesthetic consumption, improve analgesic quality, and reduce adverse reactions in the parturients. (Registration No. ChiMCTR-2000003120).

Acupoint Injection Decreases Anesthetic Cosumption during Combined Spinal-Epidural and Patient-Controlled Epidural Labor Analgesia / 中国结合医学杂志

OBJECTIVE@#To explore if acupoint injection can improve analgesic effects or delivery outcomes in parturients who received combined spinal-epidural analgesia (CSEA) and patient-controlled epidural analgesia (PCEA) for labor analgesia.@*METHODS@#A total of 307 participants were prospectively collected from July 2017 to December 2019. The participants were randomized into the combined acupoint injection with CSEA plus PCEA group (AICP group, n=168) and CSEA plus PCEA group (CP group, n=139) for labor analgesia using a random number table. Both groups received CSEA plus PCEA at cervical dilation 3 cm during labor process, and parturients of the AICP group were implemented acupoint injection for which bilateral acupoint of Zusanli (ST 36) and Sanyinjiao (SP 6) were selected in addition. The primary outcome was Visual Analogue Scale (VAS) score, and the secondary outcomes were obstetric outcomes and requirement of anesthetics doses. Safety evaluations were performed after intervention.@*RESULTS@#The VAS scores were significantly lower in the AICP group than in the CP group at 10, 30, 60, and 120 min after labor analgesia (all P<0.05). The latent phase of the AICP group was shorter than that of the CP group (P<0.05). There were less additional anesthetics consumption, lower incidences of uterine atony, fever, pruritus and urinary retention in the AICP group than those in the CP group (all P<0.05).@*CONCLUSION@#Acupoint injection combined CSEA plus PCEA for labor analgesia can decrease the anesthetic consumption, improve analgesic quality, and reduce adverse reactions in the parturients. (Registration No. ChiMCTR-2000003120).

USE OF TRICAINE METHANESULFONATE, CLOVE OIL AND 2-PHENOXYETHANOL FOR IMMERSION EUTHANASIA OF UNGA CICHLIDS (SAROTHERODON LINELLII).

Fish may warrant euthanasia for a variety of reasons, but euthanasia may be difficult to accomplish or confirm because fish can recover from deep anesthesia even after cardiac and respiratory arrest. The efficacies of three types of anesthetics were evaluated to compare their suitability for euthanasia of Unga cichlids (Sarotherodon linellii). Thirty cichlids were randomly assigned to be immersed in one of the three anesthetic solutions: tricaine methanesulfonate (MS-222), 2-phenoxyethanol (2-PE), and clove oil (CO) at doses of 1,000 mg/L, 2 mL/L, and 500 mg/L respectively. The opercular rates and caudal fin stroke rates were quantified, and the time to cessation of physiological measures (CPM) including caudal fin strokes, the reaction to external stimuli, the righting reflex, swimming, and operculation were recorded. Varying anesthetic induction times were observed with all three euthanasia solutions; the time to CPM in the 2-PE group occurred at a significantly slower rate than in the MS-222 group (P < 0.01). No significant differences were identified for the time to CPM when comparing the standard length or weight of the cichlids in all euthanasia solutions (P > 0.05). The cost of euthanasia per cichlid was calculated, with the most economically viable option being 2-PE; at more than seven times the price of 2-PE, MS-222 was the most expensive. After a 60-min immersion in the euthanasia solution, the presence of an audible heartbeat was identified in 100% of the cichlids immersed in 2-PE, 100% immersed in CO, and 90% in MS-222, indicating that they were not reliably euthanized. Therefore, a two-step protocol is recommended in cichlids for euthanasia: heavy anesthesia via immersion followed by an intravenous or intracardiac injection of euthanasia solution, or other secondary method of euthanasia.

Effect of Cymbopogon citratus Essential Oil (EO) on Handling Stress in Giant Freshwater Prawn (Macrobrachium rosenbergii).

BACKGROUND AND OBJECTIVE: Effects of Cymbopogon citratus essential oil (EO) was tested on minimizing handling stress in Macrobrachium rosenbergii through the evaluation of their metabolite responses [glucose, lactate, glycogen, protein, Lactate Dehydrogenase (LDH), Malate Dehydrogenase (MDH), Acetylcholinesterase (AChE) and Alanine Aminotransferase (ALT)]. This study aimed to investigate the efficacy of C. citratus extract in the anaesthetization of M. rosenbergii. MATERIALS AND METHODS: Three treatments including control, prawn exposed to stress alone (T1) and prawn exposed to stress in the presence of C. citratus EO (T2) were tested. A C. citratus EO at 500 µL L-1 had been determined in a previous study and was selected as the critical dose to be applied as an anesthetic agent. Handling stress was induced into prawns by netting, at 2 min interval for 30 min and their hemolymph were collected to determine the metabolite responses. RESULTS: The increase of glucose, lactate and LDH of M. rosenbergii when exposed to handling stress alone (T1) in comparison to T2 (stress with anesthetic C. citratus EO) were identified. Further, a low glycogen level in parallel with low AChE activity was observed which indicates the involvement of secondary metabolites to cope with the energy demand in T1 over T2. CONCLUSION: This study indicates the efficiency of C. citratus EO to reduce stress during handling in M. rosenbergii.

Effects of cranial electrotherapy stimulation on preoperative anxiety and blood pressure during anesthetic induction in patients with essential hypertension.

OBJECTIVE: Cranial electrotherapy stimulation (CES) is a non-invasive treatment that improves symptoms such as anxiety and pain. The purpose of this study was to analyze the effect of CES pretreatment on levels of preoperative anxiety, pain, and hemodynamic responses-especially changes in blood pressure-during anesthetic induction in patients with essential hypertension. METHODS: Eighty patients undergoing general anesthesia were randomly assigned to receive either no pretreatment (control group, n = 40) or CES pretreatment (CES group, n = 40). Anxiety scores, systolic and diastolic blood pressures, mean arterial pressure, and heart rate were measured in the general ward the evening before surgery, as well as in the preoperative holding area, operating room, and after intubation. Withdrawal responses to rocuronium injection were also measured. RESULTS: Anxiety scores in the operating room were significantly lower in the CES group. Withdrawal responses to rocuronium injection were also significantly lower in the CES group. There were no significant differences in hemodynamic values between the two groups. CONCLUSIONS: CES pretreatment reduces both preoperative anxiety levels and withdrawal responses to rocuronium injection. However, it does not have a significant effect on hemodynamic responses.

Anesthetic pretreatment confers thermotolerance on Saccharomyces cerevisiae yeast.

Saccharomyces cerevisiae yeast, when pretreated with elevated temperatures, undergo adaptive changes that promote survival after an otherwise lethal heat stress. The heat shock response, a cellular stress response variant, mediates these adaptive changes. Ethanol, a low-potency anesthetic, promotes thermotolerance possibly through heat shock response activation. Therefore, we hypothesized other anesthetic compounds, like ethanol, may invoke the heat shock response to promote thermotolerance. To test this hypothesis, we pretreated yeast with a series of non-volatile anesthetic and anesthetic-related compounds and quantified survival following lethal heat shock (52 °C for 5 min). Most compounds invoked thermoprotection and promoted survival with a potency proportional to hydrophobicity: tribromoethanol (5.6 mM, peak survival response), trichloroethanol (17.8 mM), dichloroethanol (100 mM), monochloroethanol (316 mM), trifluoroethanol (177.8 mM), ethanol (1 M), isopropanol (1 M), propofol (316 µM), and carbon tetrabromide (32 µM). Thermoprotection conferred by pretreatment with elevated temperatures was "left shifted" by anesthetic co-treatment from (in °C) 35.3 ± 0.1 to 32.2 ± 0.1 with trifluoroethanol (177.8 mM), to 31.2 ± 0.1 with trichloroethanol (17.8 mM), and to 29.1 ± 0.3 with tribromoethanol (5.6 mM). Yeast in postdiauxic shift growth phase, relative to mid-log, responded with greater heat shock survival; and media supplementation with tryptophan and leucine blocked thermoprotection, perhaps by reversing the amino acid starvation response. Our results suggest S. cerevisase may serve as a model organism for understanding anesthetic toxicity and anesthetic preconditioning, a process by which anesthetics promote tissue survival after hypoxic insult.

The effects of commonly used anaesthetics on colour measurements across body regions in the poeciliid fish, Girardinus metallicus.

The effects of common anaesthetics on the hue, saturation and brightness measurements of the poeciliid fish Girardinus metallicus were investigated in two experiments. For both experiments the coloration of four body regions was measured from digital images of the same males obtained under three conditions: (1) control (in a water-filled chamber); (2) anaesthetised with MS-222; and (3) anaesthetised with eugenol (clove oil). In experiment 1 anaesthetised fish were photographed out of water. In experiment 2 all photographs were taken in a water-filled chamber. Anaesthetics altered coloration in both experiments. In the more methodologically consistent experiment 2 we found significantly different hue, increased saturation and decreased brightness in anaesthetic v. control conditions, consistent with darkening caused by the anaesthetics. The body regions differed in coloration consistent with countershading but did not differentially change in response to anaesthesia. These findings suggest that photographing fish in a water-filled chamber without anaesthetic is preferable for obtaining digital images for colour analysis and that multiple body regions of fish should be measured when assessing coloration patterns meaningful in behavioural contexts, to account for the gradients caused by countershading. We are encouraged that some researchers employ such methods already and caution against using anaesthetics except when absolutely necessary for immobilisation.

Anesthetic Efficiency of Three Medicinal Plant Oils for Aquatic Species: Coriander Coriandrum sativum, Linaloe Tree Bursera delpechiana, and Lavender Lavandula hybrida.

This study evaluated the potential of three essential oils (EOs) that were obtained from coriander Coriandrum sativum (CEO), linaloe tree Bursera delpechiana (BEO), and lavender Lavandula hybrida (LEO) as anesthetic agents. Convict Cichlids Amatitlania nigrofasciata (Günther 1867) were exposed to eight concentrations of anesthetic (50, 75, 100, 125, 150, 200, 250, and 300 µL/L). After exposure to the anesthetic, the fish were transferred to clean water to recover. All of the EOs produced an anesthetic effect after exposure to the compounds for 30 min at the minimal effective concentration (MEC), which was identified according to deep anesthesia (A5  < 3 min) and full recovery (R3  < 5 min) times. At 50 and 75 µL/L, the total loss of equilibrium was not observed for all tested EOs. The total loss of reflex was induced at a faster rate with higher concentrations of anesthetic in all groups. The recovery time generally increased as the concentration of the anesthetic increased. These findings suggest that CEO, BEO, and LEO are all novel potential anesthetics for aquaculture, and the optimal concentrations were identified as 150 µL/L (A5 ; 156 ± 1.7 s and R3 ; 165 ± 2.9 s), 125 µL/L (A5 ; 176 ± 3.5 s; R3 ; 125 ± 2.0 s), and 200 µL/L (A5 ; 20.1 ± 2.4 s and R3 ; 162 ± 3.4 s), respectively. When considering the active ingredients of EOs, this study also demonstrated that future studies should be focused on the major components such as linalyl acetate, 1.8-cineole, α-pinene, geraniol, and linalool. Their synergistic effects should be examined in herbal anesthetic treatments, since new commercial anesthetics will likely contain them.

A newly developed anesthetic based on a unique chemical core.

Intravenous anesthetic agents are associated with cardiovascular instability and poorly tolerated in patients with cardiovascular disease, trauma, or acute systemic illness. We hypothesized that a new class of intravenous (IV) anesthetic molecules that is highly selective for the slow type of γ-aminobutyric acid type A receptor (GABAAR) could have potent anesthetic efficacy with limited cardiovascular effects. Through in silico screening using our GABAAR model, we identified a class of lead compounds that are N-arylpyrrole derivatives. Electrophysiological analyses using both an in vitro expression system and intact rodent hippocampal brain slice recordings demonstrate a GABAAR-mediated mechanism. In vivo experiments also demonstrate overt anesthetic activity in both tadpoles and rats with a potency slightly greater than that of propofol. Unlike the clinically approved GABAergic anesthetic etomidate, the chemical structure of our N-arylpyrrole derivative is devoid of the chemical moieties producing adrenal suppression. Our class of compounds also shows minimal to no suppression of blood pressure, in marked contrast to the hemodynamic effects of propofol. These compounds are derived from chemical structures not previously associated with anesthesia and demonstrate that selective targeting of GABAAR-slow subtypes may eliminate the hemodynamic side effects associated with conventional IV anesthetics.

Clove Oil and AQUI-S Efficacy for Zebrafish Embryo, Larva, and Adult Anesthesia.

Since the use of the zebrafish Danio rerio genetic model organism within the scientific research community continues to grow rapidly, continued procedural refinement to support high-quality, reproducible research and improve animal welfare remains an important focus. As such, anesthesia remains one of the most frequent procedures conducted. Here, we compared the effectiveness of clove oil (active ingredient eugenol) and AQUI-S (active ingredient iso-eugenol) with the currently most commonly used tricaine/MS-222 (ethyl 3-aminobenzoate methanesulfonate) and benzocaine anesthesia. We focused on embryos (1 day postfertilization), larvae (5 days postfertilization), and adults (9-11 months) and for the first time used exposure times that are the most relevant in research settings by using zebrafish as a genetic model system. For each age, tricaine and benzocaine achieved the most reproducible, robust anesthesia with the quickest induction and recovery. For some experimental procedures, specific clove oil concentrations in embryos and larvae may represent suitable alternatives. Although different aquatic species at specific ages respond differentially to these agents, the systematic study of comparable effective dosages for procedures most commonly employed represent an important step toward refinement.

Involvement of HPI-axis in anesthesia with Lippia alba essential oil citral and linalool chemotypes: gene expression in the secondary responses in silver catfish.

In teleost fish, stress initiates a hormone cascade along the hypothalamus-pituitary-interrenal (HPI) axis to provoke several physiological reactions in order to maintain homeostasis. In aquaculture, a number of factors induce stress in fish, such as handling and transport, and in order to reduce the consequences of this, the use of anesthetics has been an interesting alternative. Essential oil (EO) of Lippia alba is considered to be a good anesthetic; however, its distinct chemotypes have different side effects. Therefore, the present study aimed to investigate, in detail, the expression of genes involved with the HPI axis and the effects of anesthesia with the EOs of two chemotypes of L. alba (citral EO-C and linalool EO-L) on this expression in silver catfish, Rhamdia quelen. Anesthesia with the EO-C is stressful for silver catfish because there was an upregulation of the genes directly related to stress: slc6a2, crh, hsd20b, hspa12a, and hsp90. In this study, it was also possible to observe the importance of the hsd11b2 gene in the response to stress by handling. The use of EO-C as anesthetics for fish is not recommended, but, the use of OE-L is indicated for silver catfish as it does not cause major changes in the HPI axis.

Basil, tea tree and clove essential oils as analgesics and anaesthetics in Amphiprion clarkii (Bennett, 1830) / Óleos essenciais de manjericão, melaleuca e cravo como anestésicos e analgésicos em Amphiprion clarkii (Bennett, 1830)

Abstract In this study were evaluated the anaesthesia and analgesic effects of clove Eugenia caryophyllata, tea tree Melaleuca alternifolia and basil Ocimum basilicum essential oils (EO) during handling of yellowtail clownfish Amphiprion clarkii. Juveniles (3.70 ± 0.75 cm and 1.03 ± 0.50 g; mean ± standard deviation) were submitted to concentrations of 40, 50, 60, 70 and 80 µl L-1 of clove, 150, 200, 250, 300 and 350 µl L-1 of basil and 200, 300, 400, 500 and 600 µl L-1 of tea tree oils (n=10/concentration), previously defined in pilot tests. Individually and only once, fish from each treatment were placed in a glass recipient containing 1 L of seawater at a temperature of 25 °C, salinity of 35 g L-1 and the specific concentration of diluted EO (stock solution). Control (only seawater) and blank (seawater and ethanol at the highest concentration used to dilute the oils) treatments were also conducted. After reaching the stage of surgical anaesthesia, fish were submitted to biometry and a sensibility test. After that, they were transferred to clean seawater for anaesthesia recovery. The times of induction needed to reach each anaesthesia stage and anaesthesia recovery were recorded. Animals were observed for 72 hours after the procedures. All the EO provoked anaesthesia and analgesic effects in A. clarkii, but basil oil is not recommended because it caused involuntary muscle contractions and mortality in 100% and 12% of fish, respectively. The lower concentrations that promote suitable induction and recovery times are 50 µl L-1 of clove oil and 500 µl L-1 of tea tree oil. However, due to its complementary high analgesic efficiency, clove oil is recommended as the ideal anaesthetic for A. clarkii.

Resumo Neste estudo foram avaliados os efeitos anestésicos e analgésicos dos óleos essenciais (OE) de cravo Eugenia caryophyllata, melaleuca Melaleuca alternifolia e manjericão Ocimum basilicum durante manejo de peixes-palhaços Amphiprion clarkii. Juvenis (3.70 ± 0.75 cm e 1.03 ± 0.50 g; média ± desvio padrão) foram submetidos às concentrações de 40, 50, 60, 70 e 80 µl L-1 de cravo, 150, 200, 250, 300 e 350 µl L-1 de manjericão e 200, 300, 400, 500 e 600 µl L-1 de melaleuca (n=10/concentração), previamente definidas em testes pilotos. Individualmente e somente uma vez, os peixes de cada tratamento foram colocados em recipiente de vidro contendo 1 L de água salgada, em temperatura de 25 °C, salinidade de 35 g L-1 e a concentração específica de OE diluída (solução estoque). Tratamentos controle (apenas água marinha) e branco (água marinha e a maior concentração de etanol utilizada para diluição dos óleos) também foram conduzidos. Após atingirem o estágio de anestesia cirúrgica, os peixes foram submetidos à biometria e teste de sensibilidade. Em seguida, foram transferidos para água marinha limpa. Os tempos necessários para atingir cada estágio anestésico e recuperação foram registrados. Os animais foram observados por 72 horas após os procedimentos. Todos os OE provocaram anestesia e analgesia em A. clarkii, porém o óleo de manjericão não é recomendado, pois causou contrações musculares involuntárias e mortalidade em 100% e 12% dos animais, respectivamente. As menores concentrações que promovem indução anestésica e recuperação em tempos adequados são 50 µl L-1 de óleo de cravo e 500 µl L-1 de óleo de melaleuca. Entretanto, devido à sua alta eficiência analgésica complementar, o óleo de cravo é recomendado como o anestésico ideal para A. clarkii.

Cardiocerebral protective effects of dexmedetomidine as anesthetic in colorectal cancer surgery.

OBJECTIVE: To explore the cardiocerebral protective effect of dexmedetomidine as an anesthetic in colorectal cancer surgery. PATIENTS AND METHODS: A total of 246 colorectal cancer patients were enrolled in this retrospective analysis. Those patients were admitted to the Affiliated Hospital of Qingdao University and underwent surgery from July 2014 to July 2016. The patients were divided into observation group and control group according to the anesthetic used in surgery. The conventional anesthetic was administered to patients in control group, whereas conventional anesthetic supplemented with dexmedetomidine was administered to patients in the observation group. The heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), jugular venous oxygen saturation (Sj-vO2), cerebral oxygen extraction ratio (ERO2), and cerebral arterial partial pressure of oxygen (PaO2) were recorded before dexmedetomidine administration (T0), 30 min after start of surgery (T1), and 2 h after surgery (T2). Central venous blood (4 ml) was withdrawn 6 hours and 24 hours after surgery. Following centrifugation, the serum was collected and stored at -70°C. After collection of all the blood samples, concentrations of creatine kinase (CK-MB), troponin I (cTnI), TNF-α and S100ß in serum were measured using ELISA, and differences between the two groups were compared. RESULTS: Differences of the parameters measured at T0 were not statistically significant between observation group and control group (p>0.05), whereas the parameters measured at T1 and T2 were significantly better in the observation group than those in the control group (p<0.05). The post-surgery blood test showed that indicators of cardiocerebral hemodynamics were better in the observation group than those in the control group (p<0.05). CONCLUSIONS: Administration of dexmedetomidine in colorectal cancer surgery can provide effective cardiocerebral protection and it is worth popularizing in clinical practice.

Modulation of rainbow trout (Oncorhynchus mykiss) cutaneous mucosal immune responses following anesthesia: A comparative study on different anesthetic agents.

The present study investigated the possible effects of different anesthetic agents including MS222 (50 ppm), 2-Phenoxyethanol (2-PE) (0.2 mL L-1) and clove oil (25 ppm), on cutaneous mucosal immune parameters in rainbow trout (Oncorhynchus mykiss). The induction and recovery times for each anesthetic agent were assessed. Also, the immune parameters were measured in skin mucus, 1 and 24 h post anesthesia. No significant difference was observed among treatments at 1 h post-anesthesia except for bactericidal and alkaline phosphatase (ALP) activities which was significantly enhanced in fish exposed to 2-PE compared to other anesthetics. At 24 h post-anesthesia, most of the skin mucosal immune parameters were increased upon exposure to clove oil but decreased following exposure to 2-PE. However, no significant change was noticed after MS222 exposure. These results demonstrated that the anesthetics type should be considered to avoid possible immunosuppression in farmed fish. Furthermore, the present results could be useful for better understanding of alterations in cutaneous mucosal immunity in response to chemical stressors such as anesthetic agents.