Interrelación del equilibrio tromboxano A2-prostaciclina y su modificación cuando se ingiere aspirina / Interrelation of the balance tromboxano A2-prostaciclina and its modification when aspirin is ingested

Introducción: la aspirina, es usada por su acción antiinflamatoria, analgésica, antipirética y antiagregante plaquetaria. El conocimiento del metabolismo del ácido araquidónico es fundamental para el estomatólogo que basa su trabajo en diagnosticar y tratar procesos inflamatorios en tejidos bucodentales, también por su condición de cirujano debe estar alerta en no realizar intervenciones quirúrgicas en pacientes que estén tomando aspirina, por interrumpir este medicamento la agregación plaquetaria, importante paso de la hemostasia normal. Objetivo: interpretar la interrelación hemostática del tromboxano A2 y la prostaciclina en condiciones fisiológicas, y el resultado de su modificación cuando se ingiere aspirina. Método: PubMed fue empleada como fundamental fuente de búsqueda, que incluyó el conocimiento sobre el fármaco aspirina, la interacción del tromboxano y la prostaclina, y la acción que sobre el equilibrio de estos productos ejerce la aspirina; también se revisaron HINARI, LILACS y Medline. Desarrollo: el ácido araquidónico es un ácido graso poliinsaturado de 20 átomos de carbono (ácido 5, 8, 11, 14-eicosatetraenoico) que procede directamente de la dieta. La relación recíproca entre PG-I2 y el TxA2 constituye un mecanismo finamente equilibrado que sirve para regular la función plaquetaria del ser humano. La utilidad de la aspirina en los pacientes expuestos a trombogénesis se debe, en gran parte, a su capacidad para inhibir la síntesis del TxA2, agente derivado del ácido araquidónico, elemento que se encuentra esterificado a los fosfolípidos de la membrana plaquetaria. El óxido nítrico, igual que la PG-I2, actúa también como vasodilatador e inhibidor de la agregación plaquetaria. Conclusiones: los pacientes que acuden al estomatólogo y por prescripción facultativa están tomando aspirina, tienen su sistema plaquetario inhibido y no pueden sintetizar tromboxano. El proceder quirúrgico por parte del estomatólogo en un paciente que esté ingiriendo aspirina lo expone al desarrollo de hemorragia de causa iatrogénica(AU)

Introduction: aspirin is used by its arachidonic acid is fundamental for the dentist that bases its work on diagnosis and treatment of inflammatory processes, also for its surgeon condition he should be alert to do not carry out surgical interventions in patients that are taking aspirin, because this drug interrupts platelet aggregation, important step of the normal hemostasis. Objective: to interpret the hemostatic interrelation of the tromboxano A2 and the prostaciclina in physiologic conditions and the result of their modification when aspirin is ingested. Method: it was employee as fundamental search source the PubMed, other databases also revised they were HINARI, LILACS, Medline. Was carried out a search that included the knowledge on the drug aspirin, the interaction of the tromboxano and the prostaclina, and the action that it has more than enough the balance of these products it exercises the aspirin. Development: the arachidonic acid is a polyunsaturated fatty acid of 20 atoms of carbon (5, 8, 11, 14-eicosatetraenoic acid) that proceeds directly from diet. The reciprocal relationship between PG-I2 and TxA2 constitutes a finely balanced mechanism that is good to regulate the human being's platelet function. The utility of aspirin in patients exposed to thrombogenesis is largely due to its capacity to inhibit the synthesis of the TxA2, agent derived from arachidonic acid, which is esterified to the phospholipids of the platelet membrane. Nitric oxide, the same as the PG-I 2, also acts as vasodilator and inhibitor of the platelet aggregation. Conclusions: the patients that go to the dentist and for medical prescription are taking aspirin, have their platelet system inhibited and cannot synthesize tromboxane. Surgical processes performed by the dentist in a patient that is ingesting aspirin exposes him to the development of hemorrhage of yatrogenic cause(AU)

Effect of mild irritant on gastric mucosal offensive and defensive factors.

The effect of hypotonic medium (Distilled water: DW) and hypertonic saline (HS: 5% NaCl) compared to control normal saline (NS) was studied on gastric ulcer induced by aspirin, 6 h cold restraint stress, ethanol, and pylorus ligation in rats. DW did not afford any protection while HS showed significant ulcer protective effects in all gastric ulcer models studied. The cytoprotective effect of HS seemed to be not only due to its effect on gastric acid secretion but also its effect on mucosal defensive factors like enhanced mucin secretion and decreased cell shedding. As determined by radioimmunoassay, DW did not produce any change in the accumulation of PGE and PGI2, while HS increased them significantly in the human gastric mucosal incubates compared to NS. However, in the incubates of human colonic mucosa, both DW and HS showed a significant increase in PGE with a tendency to increase in PGI2 accumulation.

Reatividade vascular da artéria mamária interna: estudos farmacológicos comparativos entre artérias caninas direita e esquerda / Vascular reactivity of the internal mammary artery: comparative pharmacological studies between canine right and left arteries

Para estudos comparativos da reatividade vascular entre artéria mamária interna (AMI) canina direita e esquerda, realizaram-se experimentos "in vitro" utilizando-se banhos orgânicos ("organ chambers") e ensaios biológicos: 1) os produtos plaquetários ADP e 5-HT induziram, respectivamente, vasodilatação dependente e independente do endotélio; 2) os autacóides, bradicinina e histamina, também induziram vasodilatação, respectivamente, dependente e independente do endotélio; 3) o A23187, vasodilatador independente de receptor, induziu relaxamentos dependentes do endotélio; 4) dopamina, dobutamina, papaverina e a poli-L-arginina induziram vasodilatações independentes do endotélio; 5) a NOR induziu intensa vasoconstrição comparável à causada pelo KCI e pela endotelina; 6) em 83 porcento de 24 ensaios, a liberação basal de NO foi maior na AMI esquerda, em comparação com a AMI direita; 7) ensaios biológicos de AMIs demonstraram a importância da PGI2 nas condições de hipóxia, uma vez que a indometacina aboliu vasodilatação adicional em resposta à hipóxia em condições de vasodilatação induzida pela liberação basal de NO; 8) não ocorreram diferenças significantes de resposta, comparando-se estudos realizados em AMIs direita e esquerda

Human centrifugation: new approach in the treatment of diabetic background retinopathy; preliminary communication

En trabajos previos reportamos que el Tratamiento por Centrifugación Humana (TCH) provocaba liberación endógena de prostaglandinas por un estímulo mecánico sobre la pared de los vasos. Hasta el momento actual, la importancia de la Prostaciclina (PGI) y el TCH en el tratamiento de la retinopatía diabética no ha sido investigado. Hemos evaluado la evolución de la agudeza visual y el fundus ocular al mes, a los 3 meses, a los 6 meses y al año despues del TCH en veintecinco paciente. Los niveles de PGI2 fueron determinados pre y post TCH en siete pacientes y cuatro voluntarios normales. El TCH realizado en una centrífuga Modelo Isasi. Los pacientes fueron expuestos diariamente a perfiles de aceleración de la cabeza a los pies -por una hora durante un mes. Esta comunicación preleminar demostró que: a) El RCH provoca liberación de PGI2 (p < 0.001). b) El TCH substancialmente visual (p < 0.001). c) El TCH tiene efectos beneficiosos a largo prazo

El endotelio y la circulación coronaria / The endothelium and the coronary circulation

In the last few years, so many different substances produced by the endothelium have been discovered that this structure is considered today a parafcrine organ. Among these substances, there are at least three with marked vascular effects: prostacyclin (PGI-2) and the endothelium-derived relaxing factor (EDRF) are vasodilators, platelet stabilizers and anti-atherogenic. On the other hand, endothelin-1 (ET-1) is a potent vasoconstrictor and probably pro-atherogenic. There are many agents that stimulate the liberation of these substances by the endothelium and most of then stimulate simultaneously the production of the three substances. even thought it is not possible yet to define the exact participation of the endothelium in the normal regulation of coronary blood flow it is highly probably that a disfunction of this structure secondary to hypercolesterolemia, hypertension, atheromatosis, diabetes and smoking may decrease the coronary reserve, induce coronary spasm and facilitates the development of atheroma

Deficient release of prostacyclin-like activity by rat stomach under stress

O modelo de imobilizaçäo tem sido utilizado para promover a ulceraçäo da mucosa gástrica de ratos. Procedeu-se à determinaçäo da atividade de prostaciclina-simile em fragmentos de estômago de ratos submetidos à estresse de confinamento e em controles. Nossos achados apoiam a idéia de que fatores psicológicos sejam responsáveis pela inflamaçäo da mucosa gástrica mediada por alteraçöes no fluxo sangüíneo da mucosa gástrica, que estäo relacionados com a atividade da prostaciclina

Increased release of prostacyclin-like activity from rat aorta by plasma from patients with hepatic or renal failure

Cortes de aorta "exaurida" de ratos, foram incubados por 20 min. em temperatura ambiente, com plasma de seis pacientes urêmicos em hemodiálise de manutençäo, com plasma de 23 hepatopatas e com plasma de voluntários sadios. Observou-se que plasma de pacientes urêmicos e de hepatopatas, estimularam a liberaçäo de prostaciclina em grau maior do que o plasma dos normais. A liberaçäo aumentada de prostaciclina pode ter um papel na patogênese da diátese hemorrágica dos pacientes com insuficiência renal ou hepática

Wilms' tumor: analysis of thirty cases.

Thirty cases of Wilms' tumor who had been treated at the Ramathibodi Hospital from January 1970 to December 1982 were analysed retrospectively. There were 14 boys and 16 girls, aged 6 months to 7 years (mean age was 2 years). The right kidney was involved in 12 cases, the left side involvement in 18 cases. Other than the abdominal mass, the common signs and symptoms were hematuria (30%) and hypertension (13.3%). The congenital anomalies were found in 2 cases. There was an increase in VMA in three of the six cases determined for VMA:creatine ratio and VMA in 24 hours urine. Seven cases (23.3%) had nephrectomy done in other hospitals. Ninety percent of the patients came in with the stage II-IV, only 10% had stage I. The treatment consisted of surgery, radiation therapy, actinomycin-D, vincristine and adriamycin. Eight patients (26.6%) were lost to follow-up. The cure rate in stage II, III and IV were 71.4%, 50% and 29% respectively. The serious surgical complications include a case of shock due to excessive bleeding and another case of sudden death during the operation due to the tumor emboli from the inferior vena cava to the main pulmonary and both bronchial arteries.