Ketamina epidural en cirugía de hemiabdomen inferior / Epidural ketamine in low abdominal surgery

Introducción: La ketamina de uso corriente es una droga utilizada principalmente para la inducción y el mantenimiento de la anestesia, compuesta por una mezcla racémica de enantiómeros R (-) y S (+). En la década de los años 80 comienza la administración humana de la ketamina por vía epidural. A partir de entonces se han presentado disímiles investigaciones para justificar su acción analgésica en este espacio con varias hipótesis: 1 supresión específica laminar de las astas dorsales, 2 mediación por el sistema opioide endógeno y sustancia gris periacueductal, y 3 bloqueo de los canales del calcio por antagonismo no competitivo de los receptores N-metil-d-aspartato. Objetivo: Demostrar la eficacia de la ketamina por vía epidural como analgésico postoperatorio en la cirugía de hemiabdomen inferior. Material y Método: Se realizó un ensayo clínico aleatorizado y prospectivo en una muestra de 50 pacientes operados de hernia inguinal electiva. Los pacientes fueron divididos en dos grupos, un grupo tratado con 50 mg de ketamina y otro grupo al que se le administró una dosis de 2 mg de morfina liofilizada. Resultados: la ketamina por vía epidural en una dosis de 50 mg proporciona una analgesia adecuada por un período de al menos de 6 horas. La morfina brinda una analgesia por encima de las 18 horas. Conclusión: La ketamina por vía epidural es menos efectiva que la morfina desde el punto de vista analgésico, pero es una alternativa importante pues permite disminuir la dosis de morfina si se combinan ambos fármacos o se asocia a anestésicos locales (AU)

Introduction: Ketamine is a drug used for induction and maintenance of anesthesia, exists as a racemic mixture of R- and S+-enantiomers. Epidural ketamine starts to human administration about 80’ years. After that, various studies have been published about the mechanism of analgesic action of ketamine: lamina-specific suppression of dorsal-horn unit activity (1), opiate agonist at the spinal level in the same way as opioids (2) and non-competitive N-methyl-D-aspar-tate NMDA receptor antagonist (3). Purpose: To evaluate the efficacy of epidural ketamine for postoperative pain relief in lower abdominal procedures. Materials and Methods: 50 patients undergoing inguinal herniotomy were studied in a comparative propective trial. They were divided into two groups to receive epidural ketamine 50 mg or epidural morphine 2 mg. Results: Epidural ketamine in doses to 50 mg provide adequate analgesia during 6 hours. Morphine administered epidurally obtained analgesia more than 18 hours. Conclusion: Epidurally administered ketamine is less effective than epidural morphine for postoperative analgesia, but it playes an important role in morphine-induced analgesia and during the combination with local anaesthetic (AU)

1-[(Benzofuran-2-yl)phenylmethyl]-triazoles and -tetrazoles - potent competitive inhibitors of aromatase.

The synthesis of a series of novel 1-[(benzofuran-2-yl)phenylmethyl]-triazoles and -tetrazoles is described. The compounds were tested for human placental aromatase inhibition in vitro, using [1beta-3H]-androstenedione as the substrate for the aromatase enzyme, the percentage inhibition and IC50 data is included.

Effect of shape, size, and valency of multivalent mannosides on their binding properties to phytohemagglutinins.

Clusters of di-, tri-, and tetra-antennary alpha-D-mannopyranosides were synthesized in good yields based on the coupling of amine-bearing mono- or trisaccharide [Man alpha(1 --> 6)[Man alpha(1 --> 3)]Man] haptens to poly-isocyanate or -isothiocyanate tethering cores. The relative binding properties of the resulting multivalent ligands were determined by turbidimetric and solid phase enzyme-linked lectin assays (ELLA) using plant lectins (phytohemagglutinins) Concanavalin A (Con A) and Pisum sativum (pea lectin) having four and two carbohydrate binding sites, respectively. Rapid and efficient cross-linking between tetravalent Con A and mannopyranosylated clusters were measured by a microtiter plate version of turbidimetric analyses. In inhibition of binding of the lectins to yeast mannan, the best tetravalent monosaccharide (30) and trisaccharide (31) inhibitors were shown to be 140 and 1155 times more potent inhibitors than monomeric methyl alpha-D-mannopyranoside against pea lectin and Con A, respectively. Compounds 30 and 31 were thus 35- and 289-fold more potent than the reference monosaccharide based on their hapten contents. As a general observation, the ligands bearing the Man alpha(1 --> 6)[Man alpha(1 --> 3)]Man trimannoside structures were found to be more potent inhibitors for Con A than the ligands having single mannoside residues, whereas pea lectin could not discriminate between the two types of ligands.