Depresión: una mirada integrativa / Depression: an integrative view

En este trabajo se revisan las contribuciones de la literatura psicoanalítica al tema de la depresión, en particular los trabajos de Freud, Klein y Bibring y se plantean algunos subtipos de ella. Asimismo, siguiendo el concepto de las series complementarias de Freud, se sugiere una mirada amplia para evaluar los factores etiológicos del paciente depresivo. Se propone el tratamiento integral de la depresión que integre los aportes del psicoanálisis con la farmacoterapia

Overview of molecular mechanisms in chagasic cardioneuromyopathy and achalasia

Evidence accumulated by our investigations over the years give adequate proof for the existence of circulating antibodies in Chagas disease which bind to beta adrenergic and muscarinc cholinergic receptor of myocardium. The interaction of agonist-like antibodies with neurotransmitter receptors, triggers in the cells intracellular signal transductions that alter the physiological behaviour of the target organs. These events convert the normal cells into pathologically active cells. The interaction of antibodies with heart beta adrenergic and cholinergic receptors triggers physiologic, morphologic, enzymatic and molecular alterations, leading to tissue damage. The analysis of the prevalence and distribution of these antibodies reveals a strong association with cardiac and esophageal autonomic dysfunction in seropositive patients in comparison with those without alteration of the heart and esophagus autonomic disorders: therefore, the presence of these antibodies may partially explain the cardiomyoneurophathy and achalasia of Chagas disease, in which the sympathetic and parasympathetic systems are affected. The deposit of autoantibodies behaving like an agonist on neurotransmitter receptors, induceds desensitization and/or down regulation of the receptors. This is turn, could lead to a progressive blockade of neurotransmitter receptors, with sympathetic and parasympathetic dennervation, a phenomenon that has been described during the course of Chagas cardioneuropathy and achalasia. The clinical relevance of these findings is the demonstration, using biomolecules, of a strong association between the existence of circulating autoantibodies against peptides corresponding to the second extracellular loop of the human heart beta, adrenoceptor and M2 cholinoceptor in chagasic patients, and the presence of dysautonomic symptoms, making these autoantibodies a proper early marker of heart and digestive autonomic dysfunction.

Characterization of the receptors responsible for the diphasic effect of bradykinin in rat duodenum

The response of the rat duodenum to bradykinin (BK) consists of relaxant and contractile components, which have been atributed to different receptor types. To characterize the receptor responsible for this diphasic response we studied the effects of BK analogues known to act on B1 or B2 receptors in other systems. DesArg**9-Leu**8-BK and Thi**5,**8DPhe**7-BK presented only relaxant and only contractile effects, respectively, whereas DArgOHyp883Thi**5,**8DPhe**7-BK was a potent antagonist of the relaxation (but not of the contraction) induced by BK. Our results show that the relaxant and contractile components of the rat duodenum's response to BK are due to B2 and B1 receptor subtypes, respectively

Teorias aminérgicas da depressäo

Revisa-se os conceitos mais recentes em relaçäo às teorias aminérgicas da depressäo. Verifica-se que as teorias propostas no início da década de 60 sofreram certas modificaçöes contextuais. Em primeiro lugar, deixou de se dar ênfase a uma alteraçäo isolada como causa dos sintomas depressivos, pela constataçäo de que, in vivo, a variaç äo na disponibilidade de um neurotransmissor também influi na disstribuiçäo e metabolismo dos demais. Em segundo, passou-se a valorizar a contribuiçäo dos receptores pré e pós-sinápticos das aminas cerebrais, responsabilizando-os pelo prazo de latência necessários aos efeitos terapêuticos dos antidepressores em geral. As alteraç öes na sensibilidade e número desses receptores têm sido amplamente estudadas, porém resultados controversos näo permitiram correlaç äo clínica até o presente

The role of sulfhydryl and disulfide groups of membrane proteins in electrical conduction and chemical transmission

Se discuten en este trabajo las reacciones químicas de los grupos sulfidrilo y bisulfuro y se revisa el uso de reactivos específicos para estos grupos como una herramienta en electrofisiología. Los cambios drásticos y específicos que se observan cuandos e aplican estos reactivos demuestran el papel crítico que juegan los grupos sulfidrilo y bisulfuro en los procesos de excitabilidad eléctrica, transmisión sináptica y, particularmente, en la función de los receptores post-sinápticos. Se ha demostrado que lso grupos sulfidrilo intervienen en el proceso de inactivación lenta de los canales de sodio dependientes de voltaje, en la activación de canales de calcio dependientes de voltaje y determinan la conductancia de los canales de sodio. Tanto los grupos sulfidrilo como los bisulfuro juegan un papel en la función de los receptores colinergicos nicotínicos de la sinapsis neuromuscular de los vertebrados y en la de los receptores glutaminérgicos de los invertebrados. La secreción de neurotransmisor por las terminaciones nerviosas presinápticas en estas uniones neuromusculares es también afectada por la modificación química de los grupos sulfidrilo y bisulfuro. Aunque en la mayoría de los casos no se ha esclarecido aun el sitio de acción de estos reactivos, los resultados de su utilización permiten una visión mas clara de las relaciones entre la estructura y la función de los canales y receptores existentes en las membranas excitables