D-Dimer elevation and adverse outcomes.

D-Dimer is a biomarker of fibrin formation and degradation. While a D-dimer within normal limits is used to rule out the diagnosis of deep venous thrombosis and pulmonary embolism among patients with a low clinical probability of venous thromboembolism (VTE), the prognostic association of an elevated D-dimer with adverse outcomes has received far less emphasis. An elevated D-dimer is independently associated with an increased risk for incident VTE, recurrent VTE, and mortality. An elevated D-dimer is an independent correlate of increased mortality and subsequent VTE across a broad variety of disease states. Therefore, medically ill subjects in whom the D-dimer is elevated constitute a high risk subgroup in which the prospective evaluation of the efficacy and safety of antithrombotic therapy is warranted.

Whole spectrum analysis of ligand efficacy at constitutively active human wild-type and S267K 5-HT6 receptors in HEK-293F cells.

INTRODUCTION: Modulation of constitutive activity by the recombinant wild-type human 5-HT6 receptor was investigated with a series of 5-HT6 receptor ligands by monitoring the cAMP signalling pathway. The impact of the mutation S267K near the B(261)BXXB(265) CIII-loop motif was analyzed on the magnitude of constitutive receptor activity as previously conflicting results have been reported. METHODS: The wild-type 5-HT6 receptor plasmid was obtained by PCR and the mutant S267K5-HT6 receptor was constructed by site-directed mutagenesis and stably transfected in HEK-293F cells by electroporation. The cAMP signalling pathway was monitored as a functional read-out to investigate ligands' responses using homogeneous time resolved fluorescence. RESULTS: Constitutive activity was present both at wild-type and mutant S267K 5-HT6 receptors. Negative efficacy (E(max), % versus basal) as observed at nanomolar concentrations with SB-271046 was larger for mutant (-92+/-1%) than wild-type 5-HT6 receptor (-45+/-1%). Ro 04-6790 also demonstrated negative efficacy at the wild-type 5-HT6 receptor with a magnitude similar to SB-271046 but with a 36-fold lower potency. MS-245 demonstrated at nanomolar concentrations intermediate negative efficacy; -48+/-3% and -16+/-2% at mutant and wild-type 5-HT6 receptor, respectively. The 5-HT-mediated cAMP response was blocked by SB-271046, MS-245 and Ro 04-6790 to their respective level of negative efficacy with pKB values fitting with their binding pK(i) values. E-6801 was a highly potent (pEC50: 10.17 to 10.19) and efficacious agonist (+98 to +102% versus 5-HT) at both wild-type and mutant 5-HT6 receptors. DISCUSSION: The recombinant wild-type human 5-HT6 receptor is constitutively active in HEK-293F cells and displays a high resolution to monitor efficacy properties of 5-HT6 receptor ligands. The resolution capacity to differentiate between efficacy properties of 5-HT6 receptor ligands, in particular for negative efficacy, can be further enhanced by monitoring the mutant S267K 5-HT6 receptor.

Efficacy of selective 5-HT6 receptor ligands determined by monitoring 5-HT6 receptor-mediated cAMP signaling pathways.

1. Two novel selective 5-HT6 receptor ligands E-6801 (6-chloro-N-(3-(2-(dimethylamino)ethyl)-1H-indol-5-yl)imidazo[2,1-b]thiazole-5-sulfonamide) and E-6837 (5-chloro-N-(3-(2-(dimethylamino)ethyl)-1H-indol-5-yl)naphthalene-2-sulfonamide) were investigated and compared to the putative 5-HT6 receptor antagonists SB-271046 (5-chloro-N-(4-methoxy-3-(piperazin-1-yl)phenyl)-3-methylbenzo[b]thiophene-2-sulfonamide) and Ro 04-06790 (N-(2,6-bis(methylamino)pyrimidin-4-yl)-4-aminobenzenesulfonamide) using a cAMP-mediated pathway. 2. Forskolin stimulation, to increase the magnitude of agonist cAMP responses, and site-directed mutagenesis of the 5-HT6 receptor, in order to yield constitutively active receptor, were applied. 3. 5-HT (E(max), % over basal: 200), E-6801 (120) and E-6837 (23) induced cAMP formation at the rat 5-HT6 receptor. In the copresence of forskolin, cAMP responses were more potent and enhanced to 294 (5-HT, % over forskolin), 250 (E-6801) and 207 (E-6837), respectively. 5-HT-mediated cAMP formation was dose-dependently blocked by SB-271046 (pA(2): 8.76+/-0.22) and Ro 04-6790 (pA(2): 7.89+/-0.10) and not affected by the copresence of forskolin. Both E-6801 and E-6837 yielded partial antagonism of the 5-HT response in the absence of forskolin, whereas antagonism was either completely absent (E-6801) or attenuated (E-6837) in the copresence of forskolin. Intrinsic activity of these 5-HT6 receptor ligands at a constitutively active human S267K 5-HT6 receptor in Cos-7 cells indicated similar efficacy (E(max), % over basal) for 5-HT (97), E-6801 (91) and E-6837 (100), while Ro 04-6790 (-33) and SB-271046 (-39) were equi-efficacious inverse agonists. 4. The use of either forskolin or a constitutively active S267K 5-HT6 receptor enhances the resolution for monitoring the efficacy of 5-HT6 receptor ligands. E-6801 and E-6837 are potent partial agonists at the 5-HT6 receptor. Ro 04-6790 and SB-271046 appear to act as inverse agonists/antagonists.

Chronic 5-HT6 receptor modulation by E-6837 induces hypophagia and sustained weight loss in diet-induced obese rats.

E-6837 is a novel, selective and high-affinity 5-HT(6) receptor ligand (pK(i): 9.13) which in vitro demonstrates partial agonism at a presumably silent rat 5-HT(6) receptor and full agonism at a constitutively active human 5-HT(6) receptor by monitoring the cAMP signaling pathway.The effects of chronic treatment with E-6837 were determined in diet-induced obese (DIO)-rats on changes in body weight, food and water intake, plasma indices of comorbid risk factors, and weight regain on compound withdrawal. The centrally acting antiobesity drug, sibutramine, was used as the reference comparator. Sustained body weight loss and decreased cumulative food intake of DIO-rats was observed with E-6837 (30 mg kg(-1), p.o., twice a day) during the 4-week treatment period. The onset of the E-6837 effect on body weight was slower than that of sibutramine (5 mg kg(-1), p.o.), while its maximal effect was greater, that is -15.7 versus -11.0%.E-6837-induced weight loss was exclusively mediated by a decrease (31.7%) in fat mass, with a concomitant reduction (49.6%) in plasma leptin. Reduced obesity was also reflected in improved glycemic control. Although weight regain occurred after withdrawal from either compound, the body weights after E-6837 (-6.6%) remained lower than after sibutramine (-3.8%) indicating that the greater efficacy of the former did not result in profound rebound hyperphagia/weight gain. These results show that the 5-HT(6) receptor partial agonist, E-6837, is a promising new approach to the management of obesity with the potential to produce greater sustained weight loss than sibutramine.

Reanalysis of constitutively active rat and human 5-HT7(a) receptors in HEK-293F cells demonstrates lack of silent properties for reported neutral antagonists.

The present study reinvestigated a series of 5-HT receptor antagonists at both constitutively active rat and human 5-HT7(a) receptors in HEK-293F cells using the cAMP signalling pathway as a functional read-out. Both rat and human 5-HT7(a) receptors were expressed in similar amounts ([3H]-LSD binding: 1.0 to 1.1 pmol/mg protein). Attenuation of basal cAMP formation by the inverse agonist SB-691673 (1 microM) was slightly larger by the human 5-HT7(a) (-73+/-3 %) than rat 5-HT7(a) receptor (-62+/-3 %). The 5-HT receptor antagonists investigated here displayed systematically inverse agonism. While methiothepin and SB-269970 displayed similar negative intrinsic activity to SB-691673 at the rat 5-HT7(a) receptor, the compounds SB-258719, mesulergine and metergoline displayed some lower negative intrinsic activity (between -38 and -49%). Inverse agonist properties were observed with potencies fitting with their respective binding pIC50 values and pKB values as estimated from antagonist studies with 5-HT. With the exception of SB-258719 and mesulergine, which remained a partial inverse agonist at the human 5-HT7(a) receptor, the other compounds behaved with a similar Emax value to the full inverse agonist SB-691673. In conclusion, none of the 5-HT receptor antagonists investigated displayed silent properties at the rat or human 5-HT7(a) receptor, when these are expressed in a system allowing detection of constitutive activity. They appear to be partial to full inverse agonists, further illustrating that an antagonist is preferentially an inverse agonist when investigated under constitutively active receptor conditions.

Endorectal multiparametric MRI of the prostate: incremental effect of perfusion imaging on biopsy target identification.

PURPOSE: To evaluate the incremental effect of perfusion imaging on biopsy target identification at endorectal multiparametric prostate magnetic resonance imaging (MRI). MATERIALS AND METHODS: We retrospectively 52 patients who underwent endorectal multiparametric prostate MRI for suspected or untreated prostate cancer. Two readers independently identified biopsy targets without and with perfusion images. RESULTS: Reader 1 identified 36 targets without and 39 targets with perfusion imaging (P>.05). The corresponding numbers for reader 2 were 38 and 38, respectively (P=.5). CONCLUSION: Perfusion imaging does not significantly increase the number of biopsy targets identified at endorectal multiparametric prostate MRI.

Synthesis of new benzoxazinone derivatives as neuropeptide Y5 antagonists for the treatment of obesity.

Screening of our internal chemical collection against the neuropeptide Y5 (NPY Y5) receptor allowed the identification of a benzoxazine derivative 5f as a hit that showed moderate affinity (IC(50) = 300 nM). With the aim of improving the in vitro potency, a series of 2-benzoxazinone derivatives have been synthesized and tested for NPY Y5 activity. Most of the compounds were found to be potent and selective NPY Y5 antagonists having nanomolar binding affinities for the NPY Y5 receptor and showing functional antagonism in the forskolin-induced cyclic AMP test. Prelimminary studies in order to understand the structure-activity relationship were undertaken. Selected compounds were further evaluated for in vivo efficacy, affording the lead compound 2-[4-(8-methyl-2-oxo-4H-benzo[d][1,3]oxazin-1-yl)piperidin-1-yl]-N-(9-oxo-9H-fluoren-3-yl)acetamide 5p, which displayed in vivo activity reducing food intake in rodents.

Medicinal chemistry driven approaches toward novel and selective serotonin 5-HT6 receptor ligands.

Based on a medicinal chemistry guided hypothetical pharmacophore model, novel series of indolyl sulfonamides have been designed and prepared as selective and high-affinity serotonin 5-HT(6) receptor ligands. Furthermore, based on a screening approach of a discovery library, a series of benzoxazinepiperidinyl sulfonamides were identified as selective 5-HT(6) ligands. Many of the compounds described in this paper possess excellent affinities, displaying pK(i) values greater than 8 (some even >9) and high selectivities against a wide range (>50) of other CNS relevant receptors. First, structure-affinity relationships of these ligands are discussed. In terms of functionality, high-affinity antagonists, as well as agonists and even partial agonists, were prepared. Compounds 19c and 19g represent the highest-affinity 5-HT(6) agonists ever reported in the literature. These valuable tool compounds should allow for the detailed study of the role of the 5-HT(6) receptor in relevant animal models of disorders such as cognition deficits, depression, anxiety, or obesity.

Oclusión intencional de la arteria subclavia izquierda durante el tratamiento endovascular de la aorta torácica descendente / Intentional Occlusion of the Left Subclavian Artery during Endovascular Repair of the Descending Thoracic Aorta

Introducción La seguridad y la eficacia del tratamiento endovascular de la aorta torácica descendente dependen de ciertas condiciones anatómicas, en particular de la presencia de un segmento sano de aorta (cuello proximal). En una proporción importante de pacientes, este cuello proximal es insuficiente o inexistente. Un bypass o transposición de la arteria subclavia izquierda permitiría mantener una perfusión adecuada del brazo izquierdo luego del implante de la endoprótesis. Sin embargo, este abordaje quirúrgico no siempre es factible en pacientes inestables, tratados de forma urgente o que presentan múltiples comorbilidades. Objetivo Evaluar las consecuencias clínicas y neurológicas de la oclusión intencional de la arteria subclavia izquierda durante el tratamiento endovascular de la aorta torácica descendente. Material y métodos Entre agosto de 1999 y febrero de 2010, 136 pacientes fueron tratados consecutivamente con implante de endoprótesis autoexpandibles. En 29 pacientes (21%) con ausencia de un cuello proximal adecuado (sector sano de aorta ≥ 15 mm de longitud) se debió cubrir intencionalmente el origen de la arteria subclavia izquierda. En todos los casos, previo al tratamiento se realizó una angiografía selectiva de la arteria vertebral derecha con el objetivo de confirmar la permeabilidad de ésta y la conformación de la circulación vertebrobasilar. Resultados Se trataron 20 hombres y 9 mujeres, cuya edad media fue de 62 (49-72) años. La patología de base fue disección aórtica tipo B aguda (n = 4), disección aórtica tipo B crónica (n = 14), hematoma intramural (n = 1), aneurisma verdadero (n = 7), úlcera aórtica (n = 1) y seudoaneurisma traumático (n = 2). El implante del dispositivo fue exitoso en todos los pacientes. No se registraron complicaciones clínicas ni neurológicas a 29 (13-50) meses de seguimiento medio. Conclusiones La utilización de criterios de selección estrictos permite la oclusión intencional de la arteria subclavia izquierda durante el tratamiento endovascular de la aorta torácica descendente, sin aumentar la incidencia de complicaciones mayores. Así, la revascularización quirúrgica queda reservada para pacientes con síntomas graves de isquemia durante el seguimiento.

Background Safety and efficacy of endovascular repair of the descending thoracic aorta depends on certain anatomic conditions, especially on the presence of a suitable proximal neck. This proximal neck is insufficient or absent in many patients. The use of left subclavian-carotid transposition or left carotid-tosubclavian artery bypass might allow an adequate perfusion of the left arm after the implantation of the stent-graft. However, this surgical approach is not feasible in unstable patients undergoing emergency surgery or with multiple comorbidities. Objective To evaluate the clinical and neurological outcomes of the intentional occlusion of the left subclavian artery during endovascular repair of the descending thoracic aorta. Material and Methods Between August 1999 and February 2010, 136 patients consecutively underwent implantation of self-expandable stent-grafts. The origin of the left subclavian artery was intentionally covered in 29 patients (21%) with absence of adequate proximal neck (normal aortic segment ≥15 mm long). Before the procedure, all patients underwent selective angiography of the right vertebral artery to exclude stenosis and to evaluate vertebrobasilar circulation. Results A total of 20 men and 9 women were treated; mean age was 62 (49-72) years. Stent-graft implantation was indicated due to acute type B aortic dissection (n=4), chronic type B aortic dissection (n=14), intramural hematoma (n=1), true aneurysm (n=7), aortic ulcer (n=1), and traumatic pseudoaneurysm (n=2). The device was successfully implanted in all patients. No clinical or neurological complications were reported after a mean follow-up of 29 months (13-50). Conclusions The use of strict selection criteria allows intentional occlusion of the left subclavian artery during stent-graft implantation of the descending thoracic aorta without increasing the incidence of major complications. Thus, surgical revascularization is reserved for patients with severe symptoms of ischemia during follow-up.

Stents liberadores de droga en el tratamiento de la reestenosis intrastent difusa: predictores clínicos y angiográficos de eventos / Drug Eluting Stents for the Treatment of Diffuse In-Stent Stenosis: Clinical and Angiographic Predictors of Events

Introducción El tratamiento de la reestenosis intrastent (RIS) difusa con balón, stent o aterectomía tiene una tasa alta de recurrencia (~35-80%). Por ello, los stents liberadores de droga (SLD) constituyen la primera elección para su tratamiento. Sin embargo, hay escasa información sobre predictores de eventos a largo plazo. Objetivo Evaluar la relación entre las variables clínicas y angiográficas con la ocurrencia de eventos alejados en el tratamiento de las RIS difusas con SLD en una población no seleccionada. Material y métodos Entre enero de 2004 y julio de 2008, 110 pacientes consecutivos con 125 lesiones por RIS difusa recibieron el implante de 137 SLD. Se utilizaron solamente SLD disponibles en el mercado (Cypher® 40,0%, Taxus® 51,8% y Endeavor® 9,1%). Durante el seguimiento se evaluó la incidencia de muerte, infarto agudo de miocardio o reintervención. La influencia de las variables clínicas, angiográficas y del procedimiento sobre dichos eventos se analizó en un modelo de regresión logística. Resultados Se logró tratar con éxito todas las lesiones. La incidencia de eventos al mes fue del 3,6% (IC 95% 1,2-8,5%). Hubo una muerte y cuatro pacientes requirieron reintervención, dos de ellos por trombosis del stent. El seguimiento medio fue de 18 meses. No hubo casos de trombosis definida del stent. Tres pacientes fallecieron (dos luego de una cirugía de revascularización miocárdica y otro de muerte súbita). Diez pacientes requirieron reintervención de la lesión responsable (9,1%), cinco de los cuales fueron tratados en forma percutánea. La incidencia global de eventos clínicos adversos fue del 13,6% (IC 95% 8,1-21,0%). En el análisis multivariado, la diabetes insulinodependiente (OR 6,44, p = 0,02), la enfermedad de múltiples vasos (OR 5,78, p = 0,02) y el tipo de RIS según Mehran (OR 2,74, p = 0,04) fueron predictores independientes de eventos. La insuficiencia renal crónica y el tratamiento de obstrucciones en puentes venosos mostraron una tendencia no significativa. El área bajo la curva ROC fue de 0,80 (IC 95% 0,65-0,94). Conclusiones Los SLD son seguros y efectivos en el tratamiento de la RIS difusa en pacientes no seleccionados. La evolución en el seguimiento puede predecirse sobre la base de variables clínicas y angiográficas.

Background The use of balloon angioplasty, stent implant or atherectomy for the treatment of in-stent restenosis (ISR) has high recurrence rates (~35-80%). For this reason, drug eluting stents (DESs) are the treatment of choice of this condition. However, there is little information regarding predictors of long-term events. Objective To evaluate the relation between clinical and angiographic variables with the occurrence of long-term events in an unselected population with diffuse ISR treated with DESs. Material and Methods Between January 2004 and July 2008, 137 DESs were implanted in 125 coronary artery lesions from 110 patients with ISR. We only used the currently devices available (Cypher® 40.0%, Taxus® 51.8% and Endeavor® 9.1%). The incidence of mortality, acute myocardial infarction or reintervention was evaluated during follow-up. A logistic regression model was used to analyze the influence of clinical and angiographic variables and of the procedure on the presence of events. Results All lesions were successfully treated. The incidence of events after one month was 3.6% (95% CI: 1.2-8.5%). One patient died and four patients underwent reintervention, two of them due to in-stent thrombosis. Mean follow-up was 18 months. There were no cases of defined in-stent thrombosis. Three patients died (two after coronary artery bypass graft surgery and one due to sudden death). Ten patients required reintervention of the culprit vessel (9.1%); five of them underwent percutaneous revascularization. The global incidence of adverse clinical events was 13.6% (95% CI: 8.1-21.0%). Multivariate analysis identified insulin-dependent diabetes mellitus (OR 6.44, p=0.02), multivessel disease (OR 5.78, p=0.02) and ISR Mehran type (OR 2.74, p=0.04) as independent predictors of events. Renal chronic failure and treatment of venous graft obstructions showed a non significant trend. The area under the ROC curve was 0.80 (95% CI: 0.65-0.94). Conclusions Drug eluting stents are safe and effective for the treatment of ISR in unselected patients. Long-term outcomes may be predicted based on clinical and angiographic variables.

Detección de Porphyromonas endodontalis en saliva total por PCR / Detection of Porphyromonas endodontalis in whole saliva by PCR

P. endodontalis es un anaerobio frecuentemente asociado con periodontitis periapicales. Buscando establecer metodologías, en el presente trabajo se adaptó un procedimiento en la técnica de PCR como una alternativa para la detección de P. endodontalis. Se normalizó la técnica hasta lograr una sensibilidad de 12 bacterias por muestra, en diluciones de saliva total. Se realizó un estudio piloto de pruebas diagnósticas comparativas: ensayo microbiológico contra PCR (reacción en cadena de polimerasa) para detección de Porphyromonas endodontalis en saliva y fluido crevicular. Se estudiaron 40 muestras, 20 procedentes de 10 individuos con enfermedad periodontal y 10 sanos. La técnica de PCR fue igual de sensible al cultivo microbiológico en muestra de saliva, mostrando una gran ventja de aplicación debido a la rapidez con que se pueden obtener resultados