Garlic prevents the oxidizing and inflammatory effects of sepsis induced by bacterial lipopolysaccharide at the systemic and aortic level in the rat. Role of trpv1.

Garlic (Allium sativum) possesses healing properties for diseases like systemic arterial hypertension, cancer and diabetes, among others. Its main component, allicin, binds to the Transient Receptor Potential Vanilloid Type 1 (TRPV1). In this study, we investigated TRPV1's involvement in the regulation of various molecules at the systemic and aortic levels in Wistar rats treated with bacterial lipopolysaccharide (LPS) and garlic to activate the receptor. The experimental groups were as follows: 1) Control, 2) LPS, 3) Garlic, and 4) LPS + Garlic. Using Uv-visible spectrophotometry and capillary zone electrophoresis, we measured the levels of nitric oxide (NO), biopterins BH2 and BH4, total antioxidant capacity (TAC) and oxidizing capacity (OXCA). We also analyzed molecules related to vascular homeostasis such as angiotensin Ang 1-7 and Ang II, as well as endothelin ET-1. In addition, we assessed the inflammatory response by determining the levels of interleukin-6 (IL-6), tumor necrosis factor alpha (TNFα), and galectin-3 (GTN-3). For cell damage assessment, we measured levels of malondialdehyde (MDA), malonate (MTO) and 8-hydroxy-2-deoxyguanosine (8HO2dG). The results showed that LPS influenced the NO pathway at both systemic and aortic levels by increasing OXCA and reducing TAC. It also disrupted vascular homeostasis by increasing Ang-II and ET-1, while decreasing Ang1-7 levels. IL-6, TNFα, GTN-3, as well as MDA, MTO, and 8HO2dG were significantly elevated compared to the control group. The expression of iNOS was increased, but TRPV1 remained unaffected by LPS. However, garlic treatment effectively mitigated the effects of LPS and significantly increased TRPV1 expression. Furthermore, LPS caused a significant decrease in calcitonin gene-related peptide (CGRP) in the aorta, which was counteracted by garlic treatment. Overall, TRPV1 appears to play a crucial role in regulating oxidative stress and the molecules involved in damage and inflammation induced by LPS. Thus, studying TRPV1, CGRP, and allicin may offer a potential strategy for mitigating inflammatory and oxidative stress in sepsis.

Deodorized Garlic Decreases Oxidative Stress Caused by Lipopolysaccharide in Rat Heart through Hydrogen Sulfide: Preliminary Findings.

Deodorized garlic (DG) may favor the activity of the antioxidant enzymes and promote the synthesis of hydrogen sulfide (H2S). The objective was to test if DG favors an increase in H2S and if it decreases the oxidative stress caused by lipopolysaccharide (LPS) in rat hearts. A total of 24 rats were divided into 4 groups: Group 1 control (C), Group 2 LPS, Group 3 DG, and Group 4 LPS plus DG. The cardiac mechanical performance (CMP), coronary vascular resistance (CVR), and oxidative stress markers, such as total antioxidant capacity (TAC), glutathione (GSH), selenium (Se), lipid peroxidation (LPO), thiols, hydrogen sulfide (H2S), and the activities and expressions of thioredoxin reductase (TrxR), glutathione peroxidase (GPx), and glutathione-S-transferase (GST), cystathionine synthetase (CBS), cystathionine γ-lyase (CTH), iNOS, and eNOS-p, were analyzed in the heart. Infarct zones in the cardiac tissue were present (p = 0.01). The CMP and CVR decreased and increased (p ≤ 0.05), TAC, GSH, H2S, NO, thiols, and GST activity (p ≤ 0.01) decreased, and LPO and iNOS increased (p ≤ 0.05). The activities and expressions of TrxR, GPx, eNOS-p, CTH, and CBS (p ≤ 0.05) decreased with the LPS treatment; however, DG normalized this effect. DG treatment decreases heart damage caused by LPS through the cross-talk between the H2S and NO systems.

Caso Clínico: Neurofibromatosis Tipo 1, resolución quirúrgica / Case Report: Neurofibromatos Type 1, Surgical Management

INTRODUCCIÓN: La neurofibromatosis tipo 1(NF1) descrita por primera vez por von Recklinghausen en 1884, es una enfermedad de transmisión genética autosómica dominante, causada por un espectro de mutaciones en el gen NF-1, de evolución impredecible, que afecta múltiples órganos y sistemas, como la piel y el sistema nervioso, afectando también el desarrollo infantil y al estado neurocognitivo. Representa para el médico la toma de decisiones de manejo a menudo complejas, que requieren un enfoque multidisciplinario. CASO CLÍNICO: Paciente femenino de 9 años de edad, con antecedente de neurofibromatosis tipo 1. Presenta masa en región cervical anterior, que ocupa además el hemitórax izquierdo, comprimiendo el mediastino anterior, la tráquea del lado izquierdo, el corazón, el pulmón izquierdo; la masa produce sintomatología: disnea, disfagia y dolor, por lo que se programa intervención quirúrgica para exéresis del tumor. Se realizó cervico-esternotomía- toracotomía izquierda, se extirpó masa de 12 x 7 cm, ubicada a nivel de cayado aórtico, íntimamente adherida a la columna vertebral cervico-torácica. EVOLUCIÓN: Durante el acto quirúrgico la paciente tuvo un sangrado cuantioso, proveniente de arteria colateral de carótida común izquierda, por lo que se decidió empaquetar para resolución posterior, 24 horas después se desempaquetó, logrando control del sangrado tras el procedimiento. Los resultados de anatomía patología establecieron que la masa fue un neurofibroma. El seguimiento posterior determinó mejoría de la sintomatología, sin complicaciones quirúrgicas tardías. CONCLUSIÓN: La Neurofibromatosis es una patología congénita, poco frecuente y de complejo manejo. Aunque no existe tratamiento definitivo para la neurofibromatosis tipo 1, se puede realizar un manejo integral para mejorar la calidad de vida del paciente. Los tumores pueden extirparse mediante cirugía, aunque a menudo vuelven a crecer.(au)

BACKGROUND: Neurofibromatosis type 1, first described by von Recklinghausen in 1884, is an autosomal dominant genetically transmitted disease, caused by a spectrum of mutations in the NF-1 gen, with unpredictable evolution, that affects multiple organs and systems, such as the skin and the nervous system, also affecting child development and neurocognitive functions. It often requires complex management decisions from the physician that involve a multidisciplinary approach. CASE REPORTS: 9 year old female patient with a history of type 1 neurofibromatosis. She presented with a mass located in the anterior cervical region, occupying also the left hemithorax, compressing the anterior mediastinum, the trachea from its left side, the heart, and the left lung; the mass produced symptoms: dyspnea, dysphagia and pain, so surgical excision of the mass was scheduled. A left cervical-sternotomy-thoracotomy was performed, a 12 x 7cm mass, located at aortic arch level, closely adhered to the cervical-thoracic spine, was excised. EVOLUTION: During the surgical procedure, the patient had profuse bleeding, coming form the left common carotid colateral artery, so abdominal packing was performed, for later resolution. 24 hours later, bleeding control was achieved after the surgical re-intervention. The pathology lab results established that the mass was in fact a neurofibroma. Subsequent follow-up determined symptoms improvement, without late surgical complications. CONCLUSIONS: Neurofibromatosis is a congenital infrequent, disease, with a complex treatment. Although there is no definitive treatment for type 1 neurofibromatosis, comprehensive management can be achieved to improve the patient's quality of life. Tumors can be surgically removed, although they often grow back.(au)

The Role of the Activation of the TRPV1 Receptor and of Nitric Oxide in Changes in Endothelial and Cardiac Function and Biomarker Levels in Hypertensive Rats.

The purpose of the present study was to analyze the actions of transient receptor potential vanilloid type 1 (TRPV1) agonist capsaicin (CS) and of its antagonist capsazepine (CZ), on cardiac function as well as endothelial biomarkers and some parameters related with nitric oxide (NO) release in L-NG-nitroarginine methyl ester (L-NAME)-induced hypertensive rats. NO has been implicated in the pathophysiology of systemic arterial hypertension (SAHT). We analyzed the levels of nitric oxide (NO), tetrahydrobiopterin (BH4), malondialdehyde (MDA), total antioxidant capacity (TAC), cyclic guanosin monophosphate (cGMP), phosphodiesterase-3 (PDE-3), and the expression of endothelial nitric oxide synthase (eNOS), guanosine triphosphate cyclohydrolase 1 (GTPCH-1), protein kinase B (AKT), and TRPV1 in serum and cardiac tissue of normotensive (118±3 mmHg) and hypertensive (H) rats (165 ± 4 mmHg). Cardiac mechanical performance (CMP) was calculated and NO was quantified in the coronary effluent in the Langendorff isolated heart model. In hypertensive rats capsaicin increased the levels of NO, BH4, cGMP, and TAC, and reduced PDE-3 and MDA. Expressions of eNOS, GTPCH-1, and TRPV1 were increased, while AKT was decreased. Capsazepine diminished these effects. In the hypertensive heart, CMP improved with the CS treatment. In conclusion, the activation of TRPV1 in H rats may be an alternative mechanism for the improvement of cardiac function and systemic levels of biomarkers related to the bioavailability of NO.

Extracts of Crataegus oxyacantha and Rosmarinus officinalis Attenuate Ischemic Myocardial Damage by Decreasing Oxidative Stress and Regulating the Production of Cardiac Vasoactive Agents.

Numerous studies have supported a role for oxidative stress in the development of ischemic damage and endothelial dysfunction. Crataegus oxyacantha (Co) and Rosmarinus officinalis (Ro) extracts are polyphenolic-rich compounds that have proven to be efficient in the treatment of cardiovascular diseases. We studied the effect of extracts from Co and Ro on the myocardial damage associated with the oxidative status and to the production of different vasoactive agents. Rats were assigned to the following groups: (a) sham; (b) vehicle-treated myocardial infarction (MI) (MI-V); (c) Ro extract-treated myocardial infarction (MI-Ro); (d) Co extract-treated myocardial infarction (MI-Co); or (e) Ro+Co-treated myocardial infarction (MI-Ro+Co). Ro and Co treatments increased total antioxidant capacity, the expression of superoxide dismutase (SOD)-Cu2+/Zn2+, SOD-Mn2+, and catalase, with the subsequent decline of malondialdehyde and 8-hydroxy-2'-deoxyguanosine levels. The extracts diminished vasoconstrictor peptide levels (angiotensin II and endothelin-1), increased vasodilators agents (angiotensin 1-7 and bradikinin) and improved nitric oxide metabolism. Polyphenol treatment restored the left intraventricular pressure and cardiac mechanical work. We conclude that Ro and Co treatment attenuate morphological and functional ischemic-related changes by both an oxidant load reduction and improvement of the balance between vasoconstrictors and vasodilators.

Reynolds syndrome: a rare rheumatologic disease that internists should have in mind. case report

ABSTRACT Introduction: Reynolds syndrome (RS) is an autoimmune disorder characterized by overlapping primary biliary cirrhosis (PBC) and limited cutaneous systemic sclerosis (lcSSc). Some published cases do not report pulmonary arterial hypertension (PAH), and diagnoses are usually based on clinical, immunological and histological findings, mainly focused on dermatologic features, on those associated with Sjogren's syndrome, or on an interesting presentation of malignant thymoma; only one case of reported PAH was found, but it was an image report. Case Presentation: This paper reports the case of a 75-year-old woman who presented with some of the features mentioned above, severe PAH, dyspnea for one month and two weeks of purulent expectoration, as well as generalized pruritus, nasal telangiectasias, Raynaud phenomenon, sclerodactyly, and high levels of alkaline phosphatase and transaminases. Pulmonary arterial hypertension was documented through a transthoracic echocardiogram, and inmunoflorecence reported mitochondrial and centromere patterns of antinuclear-antibodies. Consequently, RS was diagnosed and phosphodiesterase type-5 inhibitors were started for PAH treatment resulting in the improvement of dyspnea. Conclusion: Dyspnea could be caused by many conditions, but in the presence of clinical and physical findings, it suggests an autoimmune disorder. Scleroderma should be considered and, additionally, PAH should be investigated since it is present in up to 10% of patients, conferring a worse prognosis. Internists should keep in mind that these disorders may be associated with other autoimmune diseases.

In female rat heart mitochondria, oophorectomy results in loss of oxidative phosphorylation.

Oophorectomy in adult rats affected cardiac mitochondrial function. Progression of mitochondrial alterations was assessed at one, two and three months after surgery: at one month, very slight changes were observed, which increased at two and three months. Gradual effects included decrease in the rates of oxygen consumption and in respiratory uncoupling in the presence of complex I substrates, as well as compromised Ca2+ buffering ability. Malondialdehyde concentration increased, whereas the ROS-detoxifying enzyme Mn2+ superoxide dismutase (MnSOD) and aconitase lost activity. In the mitochondrial respiratory chain, the concentration and activity of complex I and complex IV decreased. Among other mitochondrial enzymes and transporters, adenine nucleotide carrier and glutaminase decreased. 2-Oxoglutarate dehydrogenase and pyruvate dehydrogenase also decreased. Data strongly suggest that in the female rat heart, estrogen depletion leads to progressive, severe mitochondrial dysfunction.

Association of burnout with stress, coping strategies and vocational satisfaction in chilean clinical dental students / Asociación de burnout con estrés, estrategias de afrontamiento y satisfacción vocacional en estudiantes chilenos de odontología en etapa clínica

Abstract: Objective: dental students are particularly affected by stress, which can lead to ‘burnout syndrome’ by association with other psychological factors. The aim of this study was to analyse the effect of perceived stress, coping strategies, and vocational satisfaction on the severity of burnout in Chilean dental students in the clinical years. Method: The study population was comprised of clinical dental students of five Chilean dental schools. The following variables were considered: age, gender, year of study, burnout, coping strategies, perceived stress, and vocational satisfaction. Statistical analysis included descriptive measures, correlation tests, and stepwise multiple regression analysis. Results: The final sample included 244 students. Three (1.23 percent) students did not have burnout in any of its factors and 38 (15.57 percent) had severe levels in all three factors. There was a statistically significant greater ‘emotional exhaustion’ in 4th year students. There was a statistically significant correlation of the three factors of burnout with ‘social withdrawal’ coping strategy, high levels of perceived stress, and low levels of present and future vocational satisfaction. Conclusion: Most students presented moderate and high levels of burnout. This situation is associated with dysfunctional coping strategies, high levels of perceived stress, and low levels of present and future vocational satisfaction.

Resumen: Objetivo: los estudiantes de odontología se ven particularmente afectados por el estrés, que puede conducir al síndrome de burnout por asociación con otros factores psicológicos. El objetivo de este estudio fue analizar el efecto del estrés percibido, las estrategias de afrontamiento y la satisfacción vocacional en la severidad del burnout en los estudiantes de odontología chilenos en los años clínicos. Método: La población estudiada estaba compuesta por estudiantes de odontología en etapa clínica de cinco escuelas dentales chilenas. Se consideraron las siguientes variables: edad, sexo, año de estudio, burnout, estrategias de afrontamiento, estrés percibido y satisfacción vocacional. El análisis estadístico incluyó estadísticas descriptivas, pruebas de correlación y análisis de regresión múltiple. Resultados: La muestra final incluyó a 244 estudiantes. Tres (1.23 por ciento) estudiantes no presentaron burnout en ninguno de sus factores y 38 (15.57 por ciento) tuvieron niveles severos en los tres factores. Hubo un mayor "agotamiento emocional" estadísticamente significativo en los estudiantes de cuarto año. Hubo una correlación estadísticamente significativa de los tres factores de burnout con la estrategia de "retirada social", altos niveles de percepción de estrés y bajos niveles de satisfacción vocacional presente y futura. Conclusión: La mayoría de los estudiantes presentaron niveles moderados y altos de burnout. Esta situación se asocia con estrategias de afrontamiento disfuncionales, altos niveles de estrés percibido y bajos niveles de satisfacción vocacional presente y futura.

Peroxisome proliferator-activated receptor-α stimulation by clofibrate favors an antioxidant and vasodilator environment in a stressed left ventricle.

BACKGROUND: Arterial high blood pressure is a risk factor for target organ damage; the most susceptible organs are the arteries, brain, kidneys, and heart. The damage mechanisms include oxidative stress and renin-angiotensin system (RAS) overactivity. Therefore, our aim was to study whether clofibrate-induced peroxisome proliferator-activated receptor-alpha (PPAR-α) stimulation is able to prevent alterations in cardiac functioning derived from RAS overstimulation in the left ventricle of rats with hypertension secondary to aortic coarctation and to improve antioxidant defenses. METHODS: Male Wistar rats were assigned to Control (Sham)- or aortic coarctation-surgery and further divided to receive (1 or 21 days) vehicle, clofibrate (100mg/kg), captopril (20mg/kg), or clofibrate+captopril. The left ventricle was obtained to measure: angiotensin II and -(1-7), AT1 and AT2 receptors, angiotensin converting enzyme (ACE)-1 and -2, and MAS receptor; the activity and expression of superoxide dismutase, catalase, endothelial nitric oxide synthase, the production of reactive oxygen species (ROS) and peroxidated lipids; as well as ex vivo cardiac functioning. RESULTS: Clofibrate decreased angiotensin II, AT1 receptor and ACE expression, and raised angiotensin-(1-7), AT2 receptor, ACE-2 expression, superoxide dismutase and endothelial nitric oxide synthase participation. These effects promoted lower coronary vascular resistance and improved mechanical work compared to aortic coarctated vehicle-treated rats. CONCLUSIONS: Clofibrate-induced PPAR-α stimulation changes the angiotensin II receptor profile, favors the ACE2/angiotensin-(1-7)/AT2 receptor axis decreasing the vasoconstrictor environment, activates the antioxidant defense, and facilitates endothelial nitric oxide synthase activity favoring vasodilation. This may represent a protection for the stressed heart.

PPARα Stimulation Modulates Myocardial Ischemia-induced Activation of Renin-Angiotensin System.

We have recently demonstrated that peroxisome proliferator-activated receptor alpha (PPARα) stimulation lowers the production of angiotensin II while increasing the production of Ang-(1-7), both in cardiac and plasmatic level. This stimulation improves nitric oxide bioavailability, preserving cardiac histologic features and functioning. Based on these results, we decided to study the effect of PPARα stimulation on renin-angiotensin system components of ischemic myocardium. Male Wistar rats (weighing 300-350 g) were assigned to the following groups: (1) sham, (2) myocardial ischemia vehicle-treated (MI-V), and (3) myocardial ischemia clofibrate-treated. Expression of the angiotensin-converting enzyme increased during ischemia, whereas clofibrate-treated group remained comparable to control. Activation of the PPARα receptor stimulated the expression of angiotensin-converting enzyme-2; while the activity of this enzyme was increased in MI-V, clofibrate inhibited any change. The concentration of bradykinin and phospho-Akt(SER473) in homogenate increased in the animals treated with the drug. Mas receptor expression increased in MI-V rats. In conclusion, stimulation of PPARα by clofibrate prevents an increase in the activity of renin-angiotensin system and promotes the production of vasodilator substances.

Utilization of therapies for stress management in chilean clinical dental students / Utilización de terapias para manejar el estrés en estudiantes de odontología chilenos en etapa clínica

Abstract: dental students suffer greater stress than the rest of the university population. In general, most health students seek little assistance to help them cope with stress. The aim of this study is to evaluate the use of therapies to manage stress in Chilean clinical dental students. A cross-sectional study was conducted nationwide; this report is a secondary data analysis. The study population was dental students in clinical years (4th and 5th) of 5 Chilean dental schools: Antofagasta, Valparaíso, Viña del Mar, Concepción, and La Frontera. This paper reports the use of therapies for stress management during the past six months considering four options: medical/psychiatric, psychological, self-medication and alternative. Tabulation and analysis were done in STATA 10/SE. Three hundred thirty-seven students were surveyed, 54.01 percent were men and 64.99 percent were in fourth year, with an average age of 22.94 more less 2.04. The 48.07 percent of students have used any of the four types of therapies; women and fourth-year students use more any form of therapy with 53.30 percent (p=.037) and 48.86 percent (p=.694), respectively, than men and fifth year students. About half of the students have used some form of therapy to manage stress in the last six months; of the students that received therapy, the percentage of women was significantly higher.

Resumen: los estudiantes de odontología sufren mayor estrés que el resto de la población universitaria. En general los estudiantes del área de la salud recurren escasamente a ayuda para enfrentar el estrés. El objetivo de este trabajo es evaluar la utilización de terapias para manejar el estrés en estudiantes chilenos de odontología en etapa clínica. Se realizó un estudio de corte transversal con alcance nacional, este corresponde a un análisis secundario de datos. La población en estudio fueron estudiantes de odontología en período de clínica (4to y 5to año), de 5 Universidades: de Antofagasta, de Valparaíso, de Viña del Mar, de Concepción y de La Frontera. Para el presente estudio se reportan la utilización de terapias para manejar el estrés durante los últimos seis meses considerando cuatro opciones: médico/psiquiátrico, psicológico, automedicación y alternativo. La tabulación y análisis se hizo en STATA 10/SE. Se encuestaron 337 alumnos, 54.01 percent correspondió a hombres y el 64.99 percent a cuarto año, con una edad promedio 22.94 más menos 2.04. Un 48.07 percent ha utilizado alguno de los cuatro tipos de terapia consultadas, las mujeres utilizan en mayor proporción alguna forma de terapia con el 53.30 percent (p=.037), así como los alumnos de cuarto año con un 48.86 percent (p=.694), en comparación a los hombres y alumnos de quinto año respectivamente. Aproximadamente la mitad de los estudiantes han utilizado alguna forma de terapia para manejar el estrés en los últimos seis meses, siendo significativamente superior en mujeres.

Afrontamiento familiar frente a las secuelas generadas en pacientes que sufrieron Trauma Craneoencefálico (TCE) / Family coping face to after-effects generated in patients who suffered Traumatic Brain Injury (TBI)

La presente investigación buscó conocer las diferentes estrategias de afrontamiento empleadas por las familias frente a las secuelas generadas en los pacientes que sufrieron Trauma Craneoencefálico (TCE) en el segundo semestre de 2010; para esto se realizó un estudio cualitativo con enfoque fenomenológico, aplicado a una muestra de 15 cuidadores principales de pacientes que sufrieron Trauma Craneoencefálico (TCE). El método utilizado para la recolección de la información fue la entrevista a profundidad, manejando como instrumento de ayuda la grabadora de voz y las notas de campo. El análisis utilizado fue de contenido tomando como referencia las etapas de afrontamiento familiar desorganización, recuperación, reorganización. La familia es el agente principal de la recuperación prolongada de la persona lesionada y las adaptaciones a la discapacidad. La relación de consanguinidad encontrada en la mayor parte de los cuidadores fue (madre - hijo). Las estrategias más utilizadas por los cuidadores fueron: aceptación de la responsabilidad, independencia y vida personal, tensión emocional familiar, autocontrol y reevaluación positiva.

This study aimed to know the different coping strategies used by families from the after-effects in patients who suffered traumatic brain injury (TBI) in the second half of 2010, It was conducted a qualitative study with a phenomenological approach applied a sample of fifteen primary caregivers of patients who suffered Traumatic Brain Injury (TBI). The method used for data collection was the depth interview as an aid handling voice recorder and field notes. The content analysis was used with reference to the stages of family coping Disorganization, Recovery, Reorganization. The family is the principal agent of the long term recovery of the injured person and adaptations to disability. The relationship of consanguinity found in most of the caregivers was (mother - child). The most used strategies used by caregivers were: Acceptance of Responsibility, Independence and Personal Life, Family Emotional Stress, Selfcontrol and positive reappraisal.

Escarabajos coprófagos (Coleoptera: Scarabaeinae) de la vertiente voroccidental, Sierra Nevada de Santa Marta, Colombia / Dung beetles (Coleoptera: Scarabaeinae) of the northwestern slope of the Sierra Nevada of Santa Marta, Colombia

The community structure of dung beetles in the middle and lower river basin of the Gaira river, Sierra Nevada de Santa Marta, Colombia, is described. Four sites were selected along an altitudinal gradient of 50-940 m for sampling from June to October, 2004. Dung beetles were captured using modified pitfall traps and manual recollections. We captured 7,872 individuals belonging to 29 species, distributed in 15 genera and five tribes of Scarabaeinae. Canthon and Onthophagus were the most diverse genera, each represented by six species. The sampled sites shared the following species: Onthophagus acuminatus Harold, O. clypeatus Blanchard, O. marginicollis Harold. Bocatoma was the most diverse site with 23 species; whereas Port Mosquito presented the highest abundance, with 3,262 individuals. Seven species represented 89 percent of all captures: Canthidium sp., Dichotomius sp., Uroxys sp. 1, Uroxys sp. 2, O. marginicollis, O. clypeatus and O. acuminatus. Of the 29 captured species, 17 belonged to the functional group of diggers and 10 were ball-rollers. We did not observe significant among-site differences in community structure. Abiotic factors such as altitude, temperature and humidity cannot explain observed variation in community structure across sites, indicating other variables such as vegetation cover, density of the vegetation and soil type may play a role in the community structure of these insects.

Se describe la estructura de la comunidad de escarabajos coprófagos en la cuenca media y baja del río Gaira, Sierra Nevada de Santa Marta, Colombia. Se seleccionaron cuatro sitios de muestreo a lo largo de un gradiente altitudinal de 50-940 m, realizándose muestreos desde junio hasta octubre, 2004. La captura de los escarabajos se realizó con trampas pitfall modificadas y colecta manual. Se capturaron 7,872 individuos pertenecientes a 29 especies, repartidos en 15 géneros y 5 tribus de Scarabaeinae. Canthon y Onthophagus fueron los géneros más diversos con seis especies cada uno. Las cuatro estaciones comparten tres especies: Onthophagus acuminatus Harold, O. clypeatus Blanchard, O. marginicollis Harold. Bocatoma tuvo el mayor número de especies, 23; mientras que Puerto Mosquito con 3.262 individuos presentó la mayor abundancia. Las especies Canthidium sp., Dichotomius sp, Uroxys sp.1, Uroxys sp.2, O. marginicollis, O. clypeatus y O. acuminatus representaron el 89 por ciento de la abundancia en el área de estudio. Entre las 29 especies capturadas; 17 pertenecen a los cavadores, 10 a los rodadores y dos residentes. No se registraron diferencias significativas entre las cuatro estaciones con respecto estructura de la comunidad. Tampoco se observó correlación entre los factores abióticos y la estructura de la comunidad. La altitud, temperatura y humedad no explican las diferencias en la distribución de la comunidad, indicando que otras variables, como la cobertura vegetal, la densidad de la vegetación y el tipo de suelo pueden jugar un papel en la estructura de la comunidad de estos insectos.

El extracto acuoso de viscum album induce la expresión de las sintasas de oxido nítrico inducible y endotelial en corazón aislado y perfundido de cobayo. Evidencia del mecanismo de vasodilatación coronaria / Viscum album aqueous extract induces inducible and endothelial nitric oxide synthases expression in isolated and perfused guinea pig heart. Evidence of the coronary vasodilation mechanism

The pharmacological effect of a Viscum album aqueous extract was evaluated on the Langendorff isolated and perfused heart model in normotense male guinea pig hearts. Coronary vascular resistance, left intraventricular pressure, nitric oxide release in the perfusion liquid, cyclic guanosine monophosphate production, and analysis of inducible and endothelial nitric oxide synthases expression by Western Blot in ventricular tissue were recorded in absence and presence of blockers and inhibitors, such as 3 microM gadolinium chloride, 100 microM N(omega)-nitro-L-arginine methyl ester and 10 microM 1H-[1,2,4]oxadiazolo[4,2-a]quinoxalin-1-one. V. album aqueous extract exerts a significant decrease in the coronary vascular resistance, which courses with significant increases in nitric oxide and cyclic guanosine monophosphate production. Analysis of the expression of both nitric oxide synthases revealed that this extract significantly induces the expression of both isoforms in guinea pig hearts. These effects were inhibited by the presence of blockers and inhibitors. The coronary vasodilation induced by the extract is mediated by the nitric oxide/soluble guanylyl cyclase pathway. In addition, this extract shows a positive inotropic effect which that is tyramine-mediated by means of beta1-adrenergic stimulation.

Estudio de los extractos de Magnolia grandiflora sobre el músculo cardíaco de cobayo / Study of Magnolia Grandiflora extracts in guinea pigs cardiac muscle

Se evaluó farmacológicamente los extractos de diversas variedades de Magnolia grandiflora sobre el músculo cardíaco. Se recolectó en el período de marzo a julio hojas y flores de Magnolia grandiflora nativa del Instituto Nacional de Cardiología "Ignacio Chávez", de la zona norte, poniente y oriente del Distrito Federal, de los estados de Puebla, Colima y Chiapas. Éstas se procesaron por separado y los extractos se obtuvieron por maceración con una mezcla de etanol-agua (1:3 v/v) a 4°C durante dos semanas. El análisis cualitativo se realizó por cromatografía en capa fina, columna y de líquidos de alta resolución (CLAR). El análisis funcional y molecular se efectuó por reactividad química específica y resonancia magnética protónica (RMN ¹H). La evaluación farmacológica se realizó en corazones aislados de cobayo macho. Los extractos, fracciones y compuestos se administraron en bolos seriados bajo un estudio de curvas dosis-respuesta gradual en donde se midió la presión intraventricular izquierda y la presión de perfusión coronaria, evaluando así el efecto inotrópico positivo y vasodilatador de los extractos de Magnolia grandiflora. Se identificó y aisló vulgarenol y 2-p-hidroxifenil-2-OH-etilamina, por lo que los resultados sugieren que su efecto vasodilatador e inotrópico positivo, se deben a la presencia de estas sustancias, las cuales se complementan con magnograndiólido y tiramina.

Several extracts from diverse Magnolia grandiflora varieties were pharmacological evaluated in the cardiac muscle. From March to July, flowers and leaves from Magnolia grandiflora, native from the National Institute of Cardiology "Ignacio Chávez", from north, west, and orient zones from Mexico City, and from Puebla, Colima and Chiapas states were collected. They were separately processed and the extracts were obtained by maceration with ethanol-water (1:3 v/v) at 4°C during two weeks. Qualitative analysis was accomplished with thin-layer, column and high-performance liquid chromatographies (HPLC). Functional and molecular analysis was made by specific chemical reactivity and by protonic magnetic resonance (RMN ¹H). Pharmacological evaluation was completed in isolated and perfused male guinea pigs hearts. Extracts, fractions, and compounds were administrated by serial bolus in a gradual dose-response curves study in which left intraventricular pressure and coronary perfusion pressure were recorded, evaluating by such the positive inotropic and vasodilator effects of Magnolia grandifloraextracts. Vulgarenol and 2-p-hydroxyphenyl-2-hydroxy-ethylamine were isolated and identified, and the obtained results suggest that its positive inotropic and vasodilator effects are owed to these substances, being complemented by magnograndiolide and tyramine.

Estudio de la relación entre las características electromoleculares de los digitálicos y su acción farmacológica / Relationship between the electromolecular properties of digitalis compounds and their pharmacological properties

Pese a su reducido margen de seguridad, los digitálicos siguen utilizándose en el tratamiento de la insuficiencia cardiaca congestiva y la fibrilación auricular crónica. Con el descubrimiento de su estructura, se han realizado remodelaciones para disminuir su toxicidad. Investigaciones recientes reportan que la eficacia digitálica radica en la electronegatividad del anillo "D" esteroideo, generada por la lactona e hidroxilo que poseen estos compuestos. En el presente trabajo, damos cuenta de la importancia que tiene esta propiedad molecular, que aunada a la conformación estructural, dan lugar a cambios significativos en las propiedades farmacológicas como el inotropismo y el margen de seguridad. Así, evaluamos una serie de once compuestos derivados de digitoxigenina, con grupos que sustituyen sobre el anillo "D" al hidroxilo y/o la lactona, los cuales denominamos -OH, -Lac, D-01, D-02, D-03, D-07, D-14, D-15, D-20, D-21 y D-22. La electronegatividad y la energía conformacional de cada compuesto se determinaron por el método Duhamm. El estudio farmacológico se realizó en corazones aislados de cobayo con base en el modelo de Langendorff y, en corazón de perro conforme al modelo cardiopulmonar de Starling. Los resultados permiten observar que la modulación de la acción digitálica está centrada, estructuralmente, en los sustituyentes de la fracción "D". El efecto inotrópico positivo y el margen de seguridad, medido como el cociente de la dosis tóxica sobre la dosis inotrópica, están relacionados con el aumento de electronegatividad y con una disminución de las energías rotacional y translacional que definen la conformación molecular; en consecuencia, estas propiedades son imprescindibles en la eficacia digitálica.

In spite their reduced therapeutic index, digitalis-type drugs continue being used for treating diseases such as congestive heart failure and chronic atrial fibrillation. Thanks to the development of several methods, their structural determination has been feasible, so, structural modifications have been worked out to modulate their toxicity. Several reports realizes that efficacy for these digitalis-type drugs lies on the electronegativity centered on the steroidal moiety (D-ring) generated by either lactone and hydroxyl sub-stituents attached to the steroidal moiety. In this work, we report how electronegativity, and so structural conformation, does modify their pharmacological properties, e.g., inotropism and safety margin. Thus, we evaluated a series of eleven drugs derived from digitoxigenin, named -OH, -Lac, D-01, D-02, D-03, D-07, D-14, D-15, D-20, D-21 and D-22, with groups that substitute both lactone and hydroxyl groups on the steroidal D-ring. Electronegativity and conformational energy were determined by Duhamm's method. The pharmacological evaluation for these drugs was accomplished in guinea pigs isolated hearts (according to the model proposed by Langendorff) and dog's isolated heart (as established by Starling's in vivo model). The results may suggest that digitalis-like action lies on the substituents attached to the D-ring. Positive inotropic effect and therapeutic index are related with increases in electronegativity as well with decreases in rotational and traslational energies; therefore, these molecular properties have such importance for the digitalis efficacy. (Arch Cardiol Mex 2003; 73:11-17).