Effect of constant light and immobilization stress on rat submandibular saliva secretory response induced by cholinergic and peptidergic agonists

The aim of this work was to analyse the parasympathetic control of submandibular saliva secretory response to cholinergic and peptidergic agonists in rats chronically exposed to constant light or repeated immobilization. Thirty two adult male Wistar rats were used: LL (8 rats exposed to constant light for 20 days), IMO (8 rats submitted to 14:10 h light: dark cycle and immobilized 2 hours daily for 7 days), and control (16 rats not exposed to stress and submitted to 14:10 hours light:dark cycle). Saliva was collected under anesthesia from the salivary ducts of submandibular glands under increasing doses of methacholine and substance P. Secretory responses (µg/saliva/mg dry weight gland) to methacholine were significantly higher in LL and IMO groups compared to control for the following doses (µg/kg body weight): 3 (153±9 versus 46±3, p<0.001 and 76±3 versus 40±3, p<0.001), 10 (379±23 versus 277±8, p<0.001 and 275±19 versus 250±10, p<0.01) and 30 (729±25 versus 695±19, p<0.05 and 1008±39 versus 640±20, p<0.001). Also, responses to substance P were significantly increased in LL and IMO groups compared to control for the following doses: 0.2 (80±3 versus 30±3, p<0.01 and 94±16 versus 31±3, p<0.001), 0.5 (328±20 versus 231±16, p<0.01 and 531±31 versus 219±25,p<0.001), 1 (681±35 versus 547±30, p<0.01 and 1031±63 versus 563±53, p<0.001), and 5 (2222±88 versus 1868±59, p<0.01 and 3230±145 versus 1921±218, p<0.001). In conclusion, supersensitivity of secretory response to both agonists suggests that chronic exposure of rats to stressors capable of activating the sympathetic adrenal system promotes inhibition of the parasympathetic control of salivary secretion.

Diagnosis and treatment of anaphylaxis: there is an urgent needs to implement the use of guidelines / Diagnóstico e tratamento da anafilaxia: há necessidade urgente de implementar o uso das diretrizes

ABSTRACT Anaphylaxis is a severe, life-threatening generalized or systemic hypersensitivity reaction that requires rapid and adequate care. This study aimed to obtain an integrated view of the level of physicians' knowledge related with treatment of anaphylaxis in studies published within the last 5 years. Sixteen studies were found and four points were identified as of the great interest to the authors: (1) emergency pharmacological treatment, (2) epinephrine auto-injectors prescription, (3) knowledge of the main signs of anaphylaxis, and (4) admission of the patient to verify biphasic reactions. Concern about the use of intramuscular adrenaline as the first choice in relation with anaphylaxis was evident in most studies, rather than its use in the comparison dial, and especially low in a study that included data from Brazil, in which the frequency of its use was 23.8%. An adrenaline autoinjector is highly recommended among specialists for patients at risk of anaphylaxis, however, its use is still infrequent among non-specialists and in countries that this agent is not available. Intervention studies have shown improved medical knowledge of anaphylaxis following disclosure of the information contained in the international guidelines. The analysis of these studies reinforces the need to disseminate international guidelines for diagnosis and treatment of anaphylaxis, as well as providing an adrenaline autoinjector, to improve management and to prevent a fatal outcome.

RESUMO Anafilaxia é uma reação de hipersensibilidade generalizada ou sistêmica grave, com risco de morte, que exige atendimento rápido e correto. Este estudo teve como objetivo obter uma visão integrada do nível de conhecimento dos médicos no atendimento da anafilaxia à luz dos estudos publicados internacionalmente nos últimos 5 anos. Foram encontrados 16 estudos, com quatro pontos identificados como de maior interesse dos autores: (1) tratamento farmacológico de emergência, (2) prescrição de autoinjetores de adrenalina, (3) conhecimento dos principais indícios da anafilaxia e (4) observação do paciente para verificar reações bifásicas. A preocupação com o uso da adrenalina intramuscular como primeira escolha frente à anafilaxia foi evidente na maioria dos estudos, mas o conhecimento sobre seu uso se mostrou desigual e especialmente baixo em estudo que incluiu dados do Brasil, onde a frequência de seu uso foi de 23,8%. A adrenalina autoinjetável é altamente recomendada entre especialistas para pacientes em risco de anafilaxia, mas seu uso ainda é pouco frequente entre não especialistas e em países que não dispõem dela em seus mercados internos. Estudos de intervenção comprovaram a melhora no entendimento dos médicos sobre anafilaxia após a divulgação das informações contidas nas diretrizes internacionais. A análise dos estudos reforça a necessidade de disseminar as diretrizes internacionais no manejo da anafilaxia, bem como de disponibilizar a adrenalina autoinjetável, a fim de melhorar o atendimento e evitar um desfecho fatal.

Cardiopulmonary resuscitation in an average brazilian intensive care unit: should we perform less or better?

Abstract Introduction: Few data can be found about cardiac arrest in the intensive care unit outside reference centers in third world countries. Objective: To study epidemiology and prognostic factors associated with cardiac arrest in the intensive care unit (ICU) in an average Brazilian center. Methods: Between June 2011 and July 2014, 302 cases of cardiac arrest in the intensive care unit were prospectively evaluated in 273 patients (age: 68.9 ± 15 years) admitted in three mixed units. Data regarding cardiac arrest and cardiopulmonary resuscitation were collected in an "Utstein style" form and epidemiologic data was prospectively obtained. Factors associated with do not resuscitate orders, return of spontaneous circulation and survival were studied using binary logistic regression. Statistical package software used was SPSS 19.0 (IBM Inc., USA). Results: Among 302 cardiac arrests, 230 (76.3%) had their initial rhythm recorded and 141 (61.3%) was in asystole, 62 (27%) in pulseless electric activity (PEA) and 27 had a shockable rhythm (11.7%). In 109 (36.1%) cases, cardiac arrest had a suspected reversible cause. Most frequent suspected cardiac arrest causes were hypotension (n=98; 32.5%), multiple (19.2%) and hypoxemia (17.5%). Sixty (19.9%) cardiac arrests had do not resuscitate orders. Prior left ventricle dysfunction was the only predictor of do not resuscitate order (OR: 3.1 [CI=1.03-9.4]; P=0.04). Among patients that received cardiopulmonary resuscitation, 59 (24.4%) achieved return of spontaneous circulation and 12 survived to discharge (5.6%). Initial shockable rhythm was the only return of spontaneous circulation predictor (OR: 24.9 (2.4-257); P=0.007) and survival (OR: 4.6 (1.4-15); P=0.01). Conclusion: Cardiopulmonary resuscitation rate was high considering ICU patients, so was mortality. Prior left ventricular dysfunction was a predictor of do not resuscitate order. Initial shockable rhythm was a predictor of return of spontaneous circulation and survival.

Effect of Tetrahydrozoline on the Permeability of Trabecular Meshwork Cell Monolayer

PURPOSE: To investigate the effects of tetrahydrozoline (THZ) on the survival of cultured human trabecular meshwork cells (HTMC) and the permeability of HTMC monolayer. METHODS: Primary cultured HTMC were exposed to an adrenergic agonist (0.01, 0.1, 1.0 or 10 µM THZ) for 1 day and 3 days. Carboxyfluorescein permeability through the HTMC monolayer was measured using Transwell. Cellular viability and nitric oxide (NO) production were assessed using MTT and Griess assays, respectively. RESULTS: THZ did not affect the cellular survival (p > 0.05) or NO production (p > 0.05). THZ significantly increased the carboxyfluorescein permeability through the HTMC monolayer in a dose-dependent manner compared with non-exposed control (p < 0.05) after exposure for 1 and 3 days. CONCLUSIONS: THZ does not affect the survival of HTMC but decreases the permeability of HTMC monolayer in a dose-dependent manner. Thus, THZ may possibly decrease trabecular outflow.

Effects of preanesthetic dexmedetomidine on hemodynamic responses to endotracheal intubation in elderly patients undergoing treatment for hypertension: a randomized, double-blinded trial / 대한마취과학회지

BACKGROUND: Dexmedetomidine is an alpha-2 adrenergic agonist with sedative, anxiolytic, and analgesic properties. This study was designed to evaluate the inhibitory effects of preoperative administration of 0.5 µg/kg dexmedetomidine on hemodynamic responses caused by endotracheal intubation in elderly patients undergoing treatment for hypertension. METHODS: Forty elderly (≥ 65 years old) patients who had been receiving hypertension treatment, had American Society of Anesthesiologists physical status II, and were scheduled to undergo elective noncardiac surgery were randomly selected and assigned to 2 groups. Group C received normal saline and group D received 0.5 µg/kg dexmedetomidine intravenously over 10 min just before endotracheal intubation. Systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), and heart rate (HR) were recorded preoperatively in the ward, immediately after study drug administration, and at 1, 3, and 5 min after endotracheal intubation. RESULTS: Compared to group C, group D showed significantly lower SBP and MAP at 1, 3, and 5 min as well as significantly lower DBP and HR at 3 and 5 min after endotracheal intubation. CONCLUSIONS: In elderly patients receiving hypertension treatment, a single preanesthetic dose of dexmedetomidine (0.5 µg/kg) effectively suppressed the hemodynamic responses to endotracheal intubation.

β3-adrenoceptor impacts apoptosis in cultured cardiomyocytes via activation of PI3K/Akt and p38MAPK / 华中科技大学学报（医学）（英德文版）

β3-adrenoceptor (β3-AR) has been shown to promote myocardial apoptosis. However, the exact physiological role and importance of this receptor in the human myocardium, and its underlying mode of action, have not been fully elucidated. The present study aimed to determine the effects of β3-AR on the promotion of myocardial apoptosis and on norepinephrine (NE) injury. We analyzed NE-induced cardiomyocyte (CM) apoptosis by using a TUNEL and an annexin V/propidium iodide apoptosis assay. Furthermore, we investigated the NE-induced expression of the apoptosis marker genes Akt and p38MAPK, their phosphorylated counterparts p-Akt and p-p38MAPK, caspase-3, Bcl-2, and Bax. In addition, we determined the effect of a 48-h treatment with a β3-AR agonist and antagonist on expression of these marker genes. β3-AR overexpression was found to increase CM apoptosis, accompanied by an increased expression of caspase-3, bax/bcl-2, and p-p38MAPK. In contrast, the β3-blocker reduced apoptosis of CMs and the associated elevated Akt expression. We identified a novel and potent anti-apoptosis mechanism via the PI3K/Akt pathway and a pro-apoptosis pathway mediated by p38MAPK.

Updated roles of adrenergic receptors in prostate cancer / 中华男科学杂志

Adrenergic receptors are members of the G-protein coupled receptor superfamily. Recent studies revealed that these adrenergic receptors are playing an important role in the growth and metastasis of prostate cancer cells. The expression of adrenergic receptors rises significantly in prostate cancer cells and tissues. Agonists of these receptors promote the growth and mobility of prostate cancer cells, while antagonists may suppress their proliferation, trigger their apoptosis, and inhibit their metastasis. Clinically, receptor antagonists can significantly reduce the risk of prostate cancer and improve its prognosis after androgen depravation therapy. This article presents an overview on the roles of adrenergic receptors in prostate cancer.

effect of high-fructose intake on the vasopressor response to angiotensin ii and adrenergic agonists in Sprague-Dawley rats

Effect of losartan was assessed on systemic haemodynamic responses to angiotensin II [Ang II] and adrenergic agonists in the model of high-fructose-fed rat. Twenty-four Sprague-Dawley [SD] rats were fed for 8 weeks either 20% fructose solution [FFR] or tap water [C] ad libitum. FFR or C group received losartan [10mg/kg/day p.o.] for 1 week at the end of feeding period [FFR-L and L] respectively, then the vasopressor responses to Ang II, noradrenaline [NA], phenylephrine [PE] and methoxamine [ME] were determined. The responses [%] to NA, PE, ME and Ang II in FFR were lower [p<0.05] than C [FFR vs. C; 22 +/- 2 vs. 32 +/- 2, 30 +/- 3 vs. 40 +/- 3, 9 +/- 1 vs. 13 +/- 1, 10 +/- 1 vs. 17 +/- 1] respectively. L group had blunted [p<0.05] responses to NA, PE, ME and Ang II compared to C [L vs. C; 26 +/- 2 vs. 32 +/- 2, 30 +/- 3 vs. 40 +/- 3, 7 +/- 0.7 vs. 13 +/- 1, 5 +/- 0.4 vs. 17 +/- 1] respectively. FFR-L group had aggravated [p<0.05] response to NA and ME, but blunted response to Ang II compared to FFR [FFR-L vs. FFR; 39 +/- 3 vs. 22 +/- 2, 11 +/- 1 vs. 9 +/- 1, 3 +/- 0.4 vs. 10 +/- 1] respectively. Fructose intake for 8 weeks results in smaller vasopressor response to adrenergic agonists and Ang II. Data also demonstrated an important role played by Ang II in the control of systemic haemodynamics in FFR and point to its interaction with adrenergic neurotransmission

Transient Distal Penile Corporoglanular Shunt as an Adjunct to Aspiration and Irrigation Procedures in the Treatment of Early Ischemic Priapism

PURPOSE: Ischemic priapism, a compartment syndrome, requires urgent treatment in order to nourish the corpora cavernosa. As the first step, aspiration of blood and irrigation of the cavernosal bodies is performed to prevent fibrotic activity and secure erectile capability. During aspiration, there are risks of cardiovascular side effects of adrenergic agonists. We aimed to evaluate a transient distal penile corporoglanular shunt technique in place of aspiration and irrigation techniques for treatment of early ischemic priapism. MATERIALS AND METHODS: A transient distal penile shunt was applied to 15 patients with early ischemic priapism between January 2011 and May 2012. Priapism duration, history, causes, pain, and any prior management of priapism were assessed in all patients. A complete blood count and penile Doppler ultrasonography were performed, which showed attenuated blood flow in the cavernosal artery. A sterile closed system blood collection set, which has two needles and tubing, was used for the transient distal penile shunt. RESULTS: Ten of 15 patients with early ischemic priapism were successfully treated with this transient shunt technique. No additional procedures were needed after the resolution of rigidity in the 10 successfully treated patients. CONCLUSIONS: The transient nature of this technique is an advantage over aspiration and irrigation in the treatment of early ischemic priapism. Our results indicate that the technique can be offered for patients with an ischemic priapism episode of no more than 7 hours.

Antihyperalgesic effects of dexmedetomidine on high-dose remifentanil-induced hyperalgesia / 대한마취과학회지

BACKGROUND: Dexmedetomidine is a highly selective alpha2 adrenergic agonist that has been shown to decrease the intensity of opioid-induced hyperalgesia (OIH). We aimed to investigate the antihyperalgesic effects of dexmedetomidine on high-dose remifentanil-induced hyperalgesia. METHODS: Ninety American Society of Anesthesiologists physical status I-II patients undergoing laparoscopically assisted vaginal hysterectomy (LAVH) were randomly assigned to one of the following three groups, each of which received either dexmedetomidine (an initial dose of 1.0 microg/kg for 10 min, followed by a continuous infusion of 0.7 microg/kg/hr) or placebo saline 15 min before the induction of anesthesia and intraoperative remifentanil infusion: group C received a placebo and 0.05 microg/kg/min remifentanil; group RH received a placebo and 0.3 microg/kg/min remifentanil; and group DRH received dexmedetomidine and 0.3 microg/kg/min remifentanil. RESULTS: The mechanical hyperalgesia threshold 24 hr after surgery was significantly lower in group RH than in the other two groups. Postoperative pain intensity using visual analog scale (VAS) and cumulative volume of a patient-controlled analgesia (PCA) containing morphine over 24 hr were significantly greater in group RH than in group DRH. The time to the first postoperative analgesic requirement was significantly shorter in group RH than in the other two groups. The desflurane requirement was significantly greater in group C than in the other groups. The frequency of hypotension and bradycardia was significantly higher, but shivering and postoperative nausea and vomiting were significantly lower in group DRH than in the other two groups. CONCLUSIONS: High-doses of remifentanil induced hyperalgesia, which presented a decreased mechanical hyperalgesia threshold, enhanced pain intensity, a shorter time to first postoperative analgesic requirement, and greater morphine consumption, but dexmedetomidine efficiently alleviated those symptoms. Dexmedetomidine may be a novel and effective treatment option for preventing or attenuating OIH.

Farmacovigilancia intensiva de agonistas adrenérgicos empleados en la atención al paciente grave / Intensive pharmacovigilance of adrenergic agonists used in the severe patient care

La farmacovigilancia es una rama de la Farmacología de reciente evolución. Surge por acontecimientos desencadenados con la explosión farmacológica después de la II Guerra Mundial, que permitieron grandes avances en el tratamiento de enfermedades que antes conducían rápida e inexorablemente a la muerte o a una grave incapacidad. Objetivo: monitorear los tratamientos administrados con agonistas adrenérgicos empleados en el paciente grave. Método: se realizó un estudio de tipo observacional prospectivo en pacientes que recibieron tratamiento con agonistas adrenérgicos en la unidad de cuidados intermedios del Hospital Municipal Manuel Piti Fajardo de Florida, Camagüey; desde enero a julio de 2010. La muestra quedó constituida por 71 pacientes. Para el estudio se tuvieron en cuenta variables sociodemográficas, epidemiológicas, tipo y grado de severidad, causalidad, mecanismos de producción de las reacciones adversas medicamentosas, así como el desenlace final de las mismas. Resultados: se obtuvo más de un cincuenta por ciento de pacientes con sospechas de reacción adversa medicamentosa a predominio de aquellos en que se detectaron manifestaciones como taquicardia, palidez e hipertensión arterial entre los signos y síntomas, según el agonista adrenérgico administrado se observóefectos de (tipo A) en aquellos que adquirieron un grado de severidad moderado, clasificadas como probadas, donde el mayor por ciento de la muestra necesitó tratamiento para la resolución de los síntomas

Pharmacovigilance is a branch of Pharmacology of recent development. It arises by events triggered with the pharmacological explosion after the Second World War, which allowed great advances in the treatment of diseases which before lead to a rapid and inexorably death or a severe disability.Objective: to observe treatments administered with adrenergic agonists used in the severe patient. Methods: a prospective observational study was performed on patients who were treated with adrenergic agonists in the intermediate care unit at the Municipal Hospital Manuel "Piti" Fajardo, Florida, Camagüey; from January to July 2010. The sample was constituted by 71 patients. The study took into account sociodemographic and epidemiological variables, type and degree of severity, causation, mechanisms of production of drug adverse reactions, as well as their final outcome. Results: more than fifty percent of patients with suspicion of adverse drug reaction was obtained to predominance of those in which were detected manifestations such as tachycardia, pallor and hypertension between signs and symptoms,according to adrenergic agonist was observed (type A) effects in those who acquired a moderate degree of severity, classified as proven, where the greatest percent of the sample needed treatment to the resolutionof symptoms

Uso de dexmedetomidina en anestesia total intravenosa (TIVA): [revisión] / Use of dexmedetomidine in total intravenous anesthesia (TIVA): [review]

La dexmedetomidina se usó para sedación inicialmente en unidades de cuidados intensivos. Sin embargo, sus efectos sedantes, analgésicos y ansiolíticos sin alteración de la función ventilatoria, permiten ampliar su uso en cirugía como anestésico intravenoso. La literatura reporta su utilidad en poblaciones quirúrgicas definidas, pero aún faltan estudios que respalden su utilización en todos los escenarios de la anestesia total intravenosa (TIVA). El propósito de la actual revisión es describir el papel de la exmedetomidina en la misma. Materiales y métodos. Se realizó la búsqueda de literatura en las bases de datos referenciales de PubMed, Medline, EMBASE, Cochrane y LILACS. Fue ampliada según la bibliografía encontrada en los artículos inicialmente revisados y analizados por los autores; la búsqueda fue hecha bajo los términos MeSH incluidos en las palabras claves.

Dexmedetomidine was used initially for sedation in intensive care units. However, because of its sedative, analgesic and anti-anxiety effects and the fact that it does not alter ventilatory function, its use may be expanded as an intravenous agent in surgery. There are reports in the literature about its effective use in specific surgical populations, although further studies are required in order to support its use in all situations where total intravenous anesthesia (TIVA) is applied. The purpose of this review is to describe the role of dexmedetomidine in this form of anesthesia.Materials y methods. A literature search was conducted in PubMed, Medline, EMBASE, Cochrane and LILACS. The search was expanded based on the references found in the articles reviewed initially and analyzed by the authors; the search was conducted under the MeSH included as key words below.

Effects of anti-glaucoma drugs on resistive index of the medial long posterior ciliary artery using color Doppler imaging in Beagle dogs

Color Doppler imaging (CDI) was carried out to evaluate the effects of anti-glaucoma drugs on ophthalmic circulation using CDI-derived resistive index (RI) values. CDI was performed on nine Beagle dogs, and RI values were calculated for the medial long posterior ciliary artery before and after the administration of anti-glaucoma drugs. A significant increase in RI values was found after topical administration of levobunolol (p < 0.05) or dipivefrin (p < 0.05). Pilocarpine showed no effects on RI values after topical administration. The results suggest that some anti-glaucoma drugs could affect ophthalmic blood flow.

Tratamento clínico do glaucoma: pressão-alvo X terapia clínica máxima X terapia clínica mínima / Clinical treatment of glaucoma: target pressure X maximum clinical therapy X minimum clinical therapy / maximum clinical therapy X minimum clinical therapy

Os fundamentos do tratamento clínico do glaucoma, em especial o conceito de pressão-alvo, são apresentados, bem como os principais grupos de drogas atualmente utilizadas e os conceitos de terapia clínica máxima e mínima.

The fundamentals of the clinical treatment of glaucoma, especially the concept of target pressure, are presented, as well as the main groups of drugs currently used and the concepts of minimum and maximum medical therapy.

Effects in Lumen Width of Nasolacrimal Drainage System After Adrenergic Drug Irrigation

PURPOSE: The lacrimal sac and nasolacrimal duct are surrounded by a wide cavernous system of veins and arteries, and the blood vessels of the cavernous body are innnervated by the autonomic nervous system. The purpose of this study was to determine the effect of an adrenergic agonist on the lumen width of the nasolacrimal drainage system. METHODS: Dacryocystography was performed on 35 patients with only epiphora and not nasolacrimal duct obstruction. The anteroposterior (AP) diameters and the oblque diameters of the nasolacrimal ducts were measured. Next, 18 patients were infused with 0.5 ml Alphagan-P(R) (alpha-2 adrenergic receptor agonist), 17 patients were infused with 0.5 ml DL methylephedrine hydrochloride (alpha-1 and alpha-2 adrenergic receptor agonist), and dacryocystography was performed again to determine the change in the lumen width of the nasolacrimal drainage system. RESULTS: The alpha-adrenergics caused a significant increase in the lumen width of the nasolacrimal drainage system, and the changes were more pronounced in the nasolacrimal duct than in the lacrimal sac. Although the nasolacrimal duct widening was more notable in the Alphagan-P(R) infusion group than the DL methylephedrine hydrochloride infusion group, there was no significant statistical difference. Patients' subjective symptoms improved in both groups. CONCLUSIONS: The alpha-adrenergics constrict the blood vessels of the cavernous body, leading to the increase in the lumen width of the nasolacrimal drainage system. This effect was more significant in the Alphagan-P(R) infusion group. In conclusion, infusion of alpha-adrenergics in patients with functional nasolacrimal duct obstruction can be considered as an alternative to surgical management.

Rocuronium-induced neuromuscular block after long pretreatment of clonidine in rabbits / 대한마취과학회지

BACKGROUND: Clonidine, an alpha-2 adrenergic agonist, is used in the perioperative period and in intensive care for the management of hypertension. The in vivo and in vitro effects of clonidine on the actions of nondepolarizing neuromuscular blocking drugs are conflicting. We evaluated the potency and time course of rocuronium-induced neuromuscular block after prolonged pretreatment with clonidine in rabbits. METHODS: Sixty rabbits were randomly assigned to three groups; control (C) group: normal saline 0.1 ml/kg daily subcutaneous for 6 weeks; S3 group: clonidine 4 microgram/kg daily subcutaneous for 3 weeks; S6 group: clonidine 4 microgram/kg daily subcutaneous for 6 weeks. The dose-response relations of rocuronium were tested in 30 rabbits (10 from each of the three groups) during ketamine-thiopental anesthesia, while the time course of rocuronium 0.6 mg/kg was examined in 10 rabbits each from the three groups. RESULTS: There was no difference in mean arterial pressure and pulse rate among the experimental groups. The calculated ED(50) for rocuronium decreased significantly from 64.1 microgram/kg (C group) to 50.3 microgram/kg (S3 group) and 47.8microgram/kg (S6 group) (P < 0.001). There was no difference in the onset and the recovery times after rocuronium. CONCLUSIONS: Rocuronium after pretreatment with clonidine for three or six weeks may have an increased effect, but no difference in the duration of action compared with control group.

Intoxicación por amitraz / Amitraz poisoning

En nuestro medio, la intoxicación por amitraz y su solvente xileno es una patología poco frecuente, pero puede observarse un aumento en zonas rurales, donde se lo emplea como insecticida-ectoparasiticida. Por tal razón, se cuenta con escasa bibliografía que oriente su manejo en niños. Presentamos el caso de un paciente de 2 años de edad, con ingestión accidental de amitraz, internado en nuestra Unidad de Cuidados Intensivos Pediátricos y que requirió ventilación mecánica. Creemos que comunicar este caso puede ser útil para alertar sobre esta intoxicación, poco frecuente en nuestro medio.

Poisoning due to amitraz together with its solvent xilene, is an unusual condition although may be increasing in rural areas where it is used as insecticide-ectoparasiticide. At present, there is scare references to orient physicians concerning its handlingin childhood. We present the case of a 2-year-old boy who suffered an accidental intake of amitraz and was admitted into our Pediatric Intensive Care Unit requiring mechanical ventilation. We consider the usefulness of informing the medical community about this case so as to be aware of this rare kind of poisoning in our community.

Regulation of resting intracellular Ca(2+) concentration of ventricular myocytes by beta(3)-adrenoceptor and its signaling pathway in rats with experimental heart failure / 南方医科大学学报

<p><b>OBJECTIVE</b>To observe the effect of beta(3)-adrenoceptor (AR) in regulating resting intracellular Ca(2+) concentration of the ventricular myocytes and investigate the signaling pathway in rats with experimental heart failure.</p><p><b>METHODS</b>Rat models of experimental heart failure were established by ligation of the anterior descending artery, and the myocytes were isolated by enzymatic digestion. The resting intracellular Ca(2+) concentration was determined using laser scanning confocal microscopy (LSCM) in the cells stimulated with 1 micromol/L BRL37344 (a selective beta(3)-AR agonist) alone or in combination with PTX, L-NAME, or methylene blue.</p><p><b>RESULTS</b>In the ventricular myocytes from normal control rats, BRL373444 reduced the resting intracellular Ca(2+) concentration of by 45.5%, while the reduction increased to 59.4% in the cells from rats with heart failure. In combination with L-NAME (10 micromol/L), methylene blue (10 micromol/L), and PTX (2 microg/ml), BRL373444 caused a reduction in resting intracellular Ca(2+) concentration of the ventricle myocytes from normal control rats by 10.1%, 16.9%, and 15.4%, respectively in control group, while the rate was 16.9%, 19.3%, and 11.7% in the heart failure group.</p><p><b>CONCLUSIONS</b>Beta(3)-AR agonist can decrease the resting intracellular Ca(2+) concentration of the ventricular myocytes, but the reduction is smaller in cells from rats with heart failure than in cells of normal rats. This effect is mediated through the PTX-NOS-NO pathway.</p>