Mouse extensor digitorum longus and soleus show distinctive ultrastructural changes induced by veratrine

We investigated whether veratrine (5 μl, 10 ng/kg) injected into the mouse extensor digitorum longus (EDL) (fast-twitch) and soleus (SOL) (slow-twitch) muscles provokes distinctive ultrastructural disturbances 15, 30 and 60 min later. The mitochondria in SOL were affected earlier (within 15 min) than in EDL. Swelling of the sarcoplasmic reticulum terminal cisternae was more marked in EDL than in SOL and caused distortion of sarcomeres so that fragmentation of myofilaments was more pronounced in EDL. Hypercontracted sarcomeres were seen mainly in SOL and veratrine caused infoldings of the sarcolemma only in this muscle. In both muscles, the T-tubules remained unaffected and by 60 min after veratrine most of the above alterations had reverted to normal. Pretreatment with tetrodotoxin prevented the alterations induced by veratrine. This suggests that most of the alterations resulted from the enhanced influx of Na+ into muscle fibers. These results emphasize the importance of considering the type of muscle when studying the action of myotoxic agents.

Comparison of xylazine and medotomidine as premedicants for cats being anaesthetised with propofol-sevoflurane

The effects of premedicating cats with saline, xylazine or medetomidine before anaesthetising them with propofol-sevoflurane were compared. Twenty-four cats were randomly assigned to three groups of eight to receive either 0.25 ml of saline, 0.50 mg/kg of xylazine or 0.02 mg/kg of medetomidine intravenously, and anaesthesia was induced with propofol and maintained with sevoflurane. Medetomidine produced a greater reduction in the induction dose of propofol and fewer adverse postoperative effects than saline or xylazine. Hypoxaemia was observed after induction with propofol in the cats premedicated with saline and xylazine, but not in the cats given medetomidine. The cats treated with medetomidine and xylazine developed profound bradycardia. The blood pressure of the cats premedicated with saline and xylazine decreased, but the blood pressure of the cats premedicated with medetomidine was maintained. The cats premedicated with saline took longer to recover from anaesthesia than the other two groups.

Preemptive dexamethasone and etoricoxib for pain and discomfort prevention after periodontal surgery: A double-masked, crossover, controlled clinical trial

Background: Several anti-inflammatory drugs have been used to reduce pain and discomfort after periodontal surgeries. This study evaluates the efficacy of using etoricoxib and dexamethasone for pain prevention after open-flap debridement surgery. Methods: For this prospective, double-masked, crossover, placebo-controlled, randomized clinical trial, open-flap debridement surgeries were performed on 15 patients (eight males and seven females, age range 20 to 56 years: mean age ± SD: 40 ± 9.7 years) who presented with chronic periodontitis after nonsurgical periodontal therapy at three quadrants. Each patient underwent three surgical procedures at intervals of 30 days and received one of the following premedication protocols 1-hour before surgery: group 1 = placebo, group 2 = 8 mg dexamethasone, and group 3 = 120 mg etoricoxib. Rescue medication (750 mg acetaminophen) was given to each patient who was instructed to take it when necessary. Pain intensity and discomfort were evaluated by a 101-point numeric rate scale and a four-point verbal rate scale, respectively, hourly for the first 8 hours after surgery and three times a day on the following 3 days. Results: The results demonstrate that groups 2 and 3 present reduced postoperative pain-intensity levels compared to group 1. There were statistically significant differences at the 4, 5, 6, 7, and 8 hour-periods after surgery (Friedman test; P<0.05). Furthermore, rescue-medication intake was significantly lower for groups 2 and 3 than for group 1 (analysis of variance; P<0.02). Conclusion: The adoption of a preemptive medication protocol using etoricoxib or dexamethasone may be considered effective for pain and discomfort prevention after open-flap debridement surgeries.

Participação da via alfa-2 adrenérgica no controle da secreção do hormônio do crescimento no período prépúbere em novilhas da raça Nelore

This study investigated GH secretion after clonidine (alpha-2 adrenergic agonist) treatment in pre-pubertal Nelore heifers. Clonidine (10 mg/kg, IV, 15 min samples for 4 h) was administrated in the same Nelore heifers at eight (n = 4), 12 (n = 5) and 15 (n = 4) months of age. The GH concentration was measured by radioimmunoassay (sensivity = 0.25 ng/mL, CV = 16%). At eight months, clonidine increased GH average concentration, total area of peaks, the total area of GH secretion and increased peak amplitude and reduced time to onset of peak (P < 0.05). At 15 months, the administration of clonidine increased the GH average concentration and at 12 months the increased occurred only in restricted intervals (P < 0.05). Clonidine injection stimulated GH secretion in prepubertal heifers and this effect was more evident in Nelore heifers at eight months compared to 12 and 15 months of age.

Analgésicos Tópicos

Background and objectives: Pain treatment involves the usage of common and opioid analgesics, nonsteroidal anti-inflammatory drugs (NSAIDs) and adjuvant analgesics. Traditionally, these drugs are administered systemically or into the neuraxis. However, when analgesics are applied through these pathways, they are associated with significant side effects, which can hinder its use. Topical administration of analgesics is an alternative. The objective of this paper is to discuss topical analgesics, the mechanisms of action and clinical efficacy. Content: This is a review paper addressing the usage of the topical local anesthetics: capsaicin, clonidine, tricyclic antidepressants, ketamine, opioids and cannabinoids, discussing mechanism of action and effectiveness. Conclusions: Topical analgesics are promising as a strategy for pain treatment, as they are associated with lower incidence of side effects. The benefit of local anesthetics, NSAID's and capsaicin is well established. However, the efficacy of clonidine, tricyclic antidepressants, ketamine, opioids and cannabinoids is still questionable. Studies have shown that the multimodal approach is an alternative, but studies are needed to confirm this hypothesis. © 2012 Elsevier Editora Ltda.

The value of intraocular pressure asymmetry in diagnosing glaucoma

PURPOSE

Effects of constant rate infusion of anesthetic or analgesic drugs on general anesthesia with isoflurane: A retrospective study in 200 dogs

Constant rate infusion (CRI) shows several advantages in balanced anesthesia, such as reduction of requirement for inhaled anesthetics and control of pain. The most commonly used drugs in these protocols are local anesthetics, dissociative, and opioids, which may be administered alone or in combinations. We evaluated the records of 200 dogs that underwent various surgical procedures with anesthetic or analgesic CRI in the perioperative period during 2011 and 2012 at the Veterinary Hospital of Franca University (Unifran), and identified possible complications during the transoperative period. Records evaluated included clinical state, laboratory tests, drugs used in premedication and induction, and CRI protocol. Acepromazine and morphine were the main drugs used in premedication. Propofol was used to induce anesthesia alone or in combination with other agents. We evaluated records of the 25 different CRI protocols. Fentanyl was the main drug employed in CRI, either alone or in combination. There were 128 episodes of anesthetic complications during CRI;the most common were hypotension, hypertension, and tachycardia, which occurred in 43 (32%), 35 (26.3%), and 19 (14.2%) dogs, respectively. Cardiac arrhythmia was reported in only 4 dogs. Signs of respiratory depression were present in dogs treated with 6 different CRI protocols. The consumption of isoflurane (vol %) reduced between 15.7% and 21.05% after 30minutes of the CRI in the fentanyl and fentanyl-lidocaine-ketamine CRI groups (p<0.05). In conclusion, CRI is a valid component of balanced anesthesia in dogs, safe, and has a low incidence of adverse effects. However, future studies are warranted to describe the results of the clinical use of CRI to better characterize and refine this technique.

Comparison of inflammatory cytokine profiles in plasma of patients undergoing otorhinological surgery with propofol or isoflurane anesthesia

Objective and design: The effects of anesthetics on cytokine release in patients without comorbidities who undergo minor surgery are not well defined. We compared inflammatory cytokine profiles in adult patients undergoing minimally invasive surgery who received isoflurane or propofol anesthesia. Methods: Thirty-four patients without comorbidities undergoing minor surgery were randomly assigned to receive an inhaled anesthetic (isoflurane; n = 16) or an intravenous anesthetic (propofol; n = 18). Blood samples were drawn before premedication and anesthesia (T1), 120 min after anesthesia induction (T2), and on the first post-operative day (T3). Plasma concentrations of interleukins (IL-) 1β, 6, 8, 10 and 12 and tumor necrosis factor (TNF)-α were measured using flow cytometry. Results: The pro-inflammatory cytokine IL-6 was increased in the isoflurane group at T2 and T3 compared to T1 (P < 0.01). In the propofol group, IL-6 and IL-8 were significantly increased at T3 compared to T1. However, there were no significant differences in cytokine concentrations between the isoflurane and propofol groups. Conclusion: An inflammatory response occurred earlier in patients who received an inhaled agent compared with an intravenous anesthetic, but no differences in plasma cytokine profiles were evident between isoflurane and propofol anesthesia in patients without comorbidities undergoing minimally invasive surgeries. © 2013 Springer Basel.

Avaliação algimétrica por estímulo nociceptivo térmico e pressórico em cães pré-tratados com levomepromazina, midazolam e quetamina, associados ou não ao butorfanol

Pós-graduação em Medicina Veterinária - FMVZ

Participação das vias alfa 2 - adrenérgica, dopaminérgica e gabaérgica no controle da secreção de GH no período pré-púbere de novilhas da raça nelore

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Efeitos da infusão contínua de lidocaína em bezerros anestesiados pelo isofluorano: Marcelo Augusto de Araújo. -

Pós-graduação em Ciência Animal - FMVA

Efeitos da administração peridural de neostigmina associada ou não a clonidina sobre a concentração alveolar mínima do isoflurano em cães

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)