An orally available Cav2.2 calcium channel inhibitor for the treatment of neuropathic pain.

BACKGROUND AND PURPOSE: Neuropathic pain affects up to 10% of the global population and is caused by an injury or a disease affecting the somatosensory, peripheral, or central nervous system. NP is characterized by chronic, severe and opioid-resistant properties. Therefore, its clinical management remains very challenging. The N-type voltage-gated calcium channel, Cav2.2, is a validated target for therapeutic intervention in chronic and neuropathic pain. The conotoxin ziconotide (Prialt®) is an FDA-approved drug that blocks Cav2.2 channel but needs to be administered intrathecally. Thus, although being principally efficient, the required application route is very much in disfavour. EXPERIMENTAL APPROACH AND KEY RESULTS: Here, we describe an orally available drug candidate, RD2, which competes with ziconotide binding to Cav2.2 at nanomolar concentrations and inhibits Cav2.2 almost completely reversible. Other voltage-gated calcium channel subtypes, like Cav1.2 and Cav3.2, were affected by RD2 only at concentrations higher than 10 µM. Data from sciatic inflammatory neuritis rat model demonstrated the in vivo proof of concept, as low-dose RD2 (5 mg·kg-1) administered orally alleviated neuropathic pain compared with vehicle controls. High-dose RD2 (50 mg·kg-1) was necessary to reduce pain sensation in acute thermal response assessed by the tail flick test. CONCLUSIONS AND IMPLICATIONS: Taken together, these results demonstrate that RD2 has antiallodynic properties. RD2 is orally available, which is the most convenient application form for patients and caregivers. The surprising and novel result from standard receptor screens opens the room for further optimization into new promising drug candidates, which address an unmet medical need.

CLC Anion/Proton Exchangers Regulate Secretory Vesicle Filling and Granule Exocytosis in Chromaffin Cells.

ClC-3, ClC-4, and ClC-5 are electrogenic chloride/proton exchangers that can be found in endosomal compartments of mammalian cells. Although the association with genetic diseases and the severe phenotype of knock-out animals illustrate their physiological importance, the cellular functions of these proteins have remained insufficiently understood. We here study the role of two Clcn3 splice variants, ClC-3b and ClC-3c, in granular exocytosis and catecholamine accumulation of adrenal chromaffin cells using a combination of high-resolution capacitance measurements, amperometry, protein expression/gene knock out/down, rescue experiments, and confocal microscopy. We demonstrate that ClC-3c resides in immature as well as in mature secretory granules, where it regulates catecholamine accumulation and contributes to the establishment of the readily releasable pool of secretory vesicles. The lysosomal splice variant ClC-3b contributes to vesicle priming only with low efficiency and leaves the vesicular catecholamine content unaltered. The related Cl-/H+ antiporter ClC-5 undergoes age-dependent downregulation in wild-type conditions. Its upregulation in Clcn3-/- cells partially rescues the exocytotic mutant defect. Our study demonstrates how different CLC transporters with similar transport functions, but distinct localizations can contribute to vesicle functions in the regulated secretory pathway of granule secretion in chromaffin cells.SIGNIFICANCE STATEMENT Cl-/H+ exchangers are expressed along the endosomal/lysosomal system of mammalian cells; however, their exact subcellular functions have remained insufficiently understood. We used chromaffin cells, a system extensively used to understand presynaptic mechanisms of synaptic transmission, to define the role of CLC exchangers in neurosecretion. Disruption of ClC-3 impairs catecholamine accumulation and secretory vesicle priming. There are multiple ClC-3 splice variants, and only expression of one, ClC-3c, in double Cl-/H+ exchanger-deficient cells fully rescues the WT phenotype. Another splice variant, ClC-3b, is present in lysosomes and is not necessary for catecholamine secretion. The distinct functions of ClC-3c and ClC-3b illustrate the impact of expressing multiple CLC transporters with similar transport functions and separate localizations in different endosomal compartments.

CaV ß controls the endocytic turnover of CaV 1.2 L-type calcium channel.

Membrane depolarization activates the multisubunit CaV 1.2 L-type calcium channel initiating various excitation coupling responses. Intracellular trafficking into and out of the plasma membrane regulates the channel's surface expression and stability, and thus, the strength of CaV 1.2-mediated Ca2+ signals. The mechanisms regulating the residency time of the channel at the cell membrane are unclear. Here, we coexpressed the channel core complex CaV 1.2α1 pore-forming and auxiliary CaV ß subunits and analyzed their trafficking dynamics from single-particle-tracking trajectories. Speed histograms obtained for each subunit were best fitted to a sum of diffusive and directed motion terms. The same mean speed for the highest-mobility state underlying directed motion was found for all subunits. The frequency of this component increased by covalent linkage of CaV ß to CaV 1.2α1 suggesting that high-speed transport occurs in association with CaV ß. Selective tracking of CaV 1.2α1 along the postendocytic pathway failed to show the highly mobile state, implying CaV ß-independent retrograde transport. Retrograde speeds of CaV 1.2α1 are compatible with myosin VI-mediated backward transport. Moreover, residency time at the cell surface was significantly prolonged when CaV 1.2α1 was covalently linked to CaV ß. Thus, CaV ß promotes fast transport speed along anterograde trafficking and acts as a molecular switch controlling the endocytic turnover of L-type calcium channels.

High Incidence of Sleep-Related Breathing Disorders in Children with Down Syndrome Referred to a High-Altitude Sleep Laboratory.

Aims: The aim of the study was to assess the incidence of sleep-related breathing disorders (SRBD) in children with Down Syndrome (DS) living at high altitude. Methods: A retrospective descriptive study was conducted on 53 children with DS who underwent polysomnography (PSG) at San Ignacio University Hospital (2640 m/8660 ft above sea level) from 2009 to 2016. Data were extracted from official PSG reports and analyzed using measures of central tendency and dispersion, frequency calculation, ranges, and confidence intervals. Associations were examined using t-test, chi-square test, and analysis of variance test. Results: Obstructive sleep apnea (OSA) was present in 90.5% of children. Central sleep apnea was evident in 11.3%. Periodic breathing was seen in 15.1% of patients. Snoring was able to predict OSA with a sensitivity of 61.7%, a specificity of 100%, and negative predictive value of 25%. Conclusion: Children with DS who live at high altitude have a high incidence of SRBD. Our findings show a higher incidence of SRBD than previously reported in the population with DS. Furthermore, snoring was not sensitive enough to predict OSA. This high risk of SRBD may increase the risk of other comorbid conditions seen in the population with DS. Our results support the need for routine PSG screening independent of symptoms such as snoring status.

A Tripartite Interaction Among the Calcium Channel α1- and ß-Subunits and F-Actin Increases the Readily Releasable Pool of Vesicles and Its Recovery After Depletion.

Neurotransmitter release is initiated by the influx of Ca2+ via voltage-gated calcium channels. The accessory ß-subunit (CaVß) of these channels shapes synaptic transmission by associating with the pore-forming subunit (CaVα1) and up-regulating presynaptic calcium currents. Besides CaVα1, CaVß interacts with several partners including actin filaments (F-actin). These filaments are known to associate with synaptic vesicles (SVs) at the presynaptic terminals and support their translocation within different pools, but the role of CaVß/F-actin association on synaptic transmission has not yet been explored. We here study how CaVß4, the major calcium channel ß isoform in mamalian brain, modifies synaptic transmission in concert with F-actin in cultured hippocampal neurons. We analyzed the effect of exogenous CaVß4 before and after pharmacological disruption of the actin cytoskeleton and dissected calcium channel-dependent and -independent functions by comparing the effects of the wild-type subunit with the one bearing a double mutation that impairs binding to CaVα1. We found that exogenously expressed wild-type CaVß4 enhances spontaneous and depolarization-evoked excitatory postsynaptic currents (EPSCs) without altering synaptogenesis. CaVß4 increases the size of the readily releasable pool (RRP) of SVs at resting conditions and accelerates their recovery after depletion. The enhanced neurotransmitter release induced by CaVß4 is abolished upon disruption of the actin cytoskeleton. The CaVα1 association-deficient CaVß4 mutant associates with actin filaments, but neither alters postsynaptic responses nor the time course of the RRP recovery. Furthermore, this mutant protein preserves the ability to increase the RRP size. These results indicate that the interplay between CaVß4 and F-actin also support the recruitment of SVs to the RRP in a CaVα1-independent manner. Our studies show an emerging role of CaVß in determining SV maturation toward the priming state and its replenishment after release. We envision that this subunit plays a role in coupling exocytosis to endocytosis during the vesicle cycle.

Rapid Turnover of the Cardiac L-Type CaV1.2 Channel by Endocytic Recycling Regulates Its Cell Surface Availability.

Calcium entry through CaV1.2 L-type calcium channels regulates cardiac contractility. Here, we study the impact of exocytic and post-endocytic trafficking on cell surface channel abundance in cardiomyocytes. Single-molecule localization and confocal microscopy reveal an intracellular CaV1.2 pool tightly associated with microtubules from the perinuclear region to the cell periphery, and with actin filaments at the cell cortex. Channels newly inserted into the plasma membrane become internalized with an average time constant of 7.5 min and are sorted out to the Rab11a-recycling compartment. CaV1.2 recycling suffices for maintaining stable L-type current amplitudes over 20 hr independent of de novo channel transport along microtubules. Disruption of the actin cytoskeleton re-routes CaV1.2 from recycling toward lysosomal degradation. We identify endocytic recycling as essential for the homeostatic regulation of voltage-dependent calcium influx into cardiomyocytes. This mechanism provides the basis for a dynamic adjustment of the channel's surface availability and thus, of heart's contraction.

Human platelet interaction with E. coli O111 promotes tissue-factor-dependent procoagulant activity, involving Toll like receptor 4.

Platelets have a major role in clotting activation and contribute to the innate immune response during systemic infections. Human platelets contain tissue factor (TF) and express functional Toll-like receptor 4 (TLR4). However, the role of TLR4 in triggering the procoagulant properties of platelets, upon challenge with bacteria, is yet unknown. Our hypothesis is that E. coli O111-TLR4 interaction activates platelets and elicits their procoagulant activity. We demonstrated that the strain, but not ultrapure LPS, increased surface P-selectin expression, platelet dependent TF procoagulant activity (TF-PCA) and prompted a faster thrombin generation (TG). Blockade of TLR4 resulted in decreased platelet activation, TF-PCA and TG, revealing the participation of this immune receptor on the procoagulant response of platelets. Our results provide a novel mechanism by which individuals with bacterial infections would have an increased incidence of blood clots. Furthermore, the identification of platelet TF and TLR4 as regulators of the effect of E. coli O111 might represent a novel therapeutic target to reduce the devastating consequences of the hemostatic disorder during sepsis.

The S4---S5 linker - gearbox of TRP channel gating.

Transient receptor potential (TRP) channels are cation channels which participate in a wide variety of physiological processes in organisms ranging from fungi to humans. They fulfill roles in body homeostasis, are sensors for noxious chemicals and temperature in the mammalian somatosensory system and are activated by light stimulated phospholipase C activity in Drosophila or by hypertonicity in yeast. The transmembrane topology of TRP channels is similar to that of voltage-gated cation channels. TRP proteins assemble as tetramers with each subunit containing six transmembrane helices (S1-S6) and intracellular N- and C-termini. Here we focus on the emerging functions of the cytosolic S4-S5 linker on TRP channel gating. Most of this knowledge comes from pathogenic mutations within the S4-S5 linker that alter TRP channel activities. This knowledge has stimulated forward genetic approaches to identify additional residues around this region which are essential for channel gating and is supported, in part, by recent structures obtained for TRPV1, TRPV2, TRPV6, TRPA1, and TRPP2.

Platelet tissue factor activity and membrane cholesterol are increased in hypercholesterolemia and normalized by rosuvastatin, but not by atorvastatin.

BACKGROUND AND AIMS: High plasma LDL-cholesterol (LDL-C) and platelet responses have major pathogenic roles in atherothrombosis. Thus, statins and anti-platelet drugs constitute mainstays in cardiovascular prevention/treatment. However, the role of platelet tissue factor-dependent procoagulant activity (TF-PCA) has remained unexplored in hypercholesterolemia. We aimed to study platelet TF-PCA and its relationship with membrane cholesterol in vitro and in 45 hypercholesterolemic patients (HC-patients) (LDL-C >3.37 mmol/L, 130 mg/dL) and 37 control subjects (LDL-C <3.37 mmol/L). The effect of 1-month administration of 80 mg/day atorvastatin (n = 21) and 20 mg/day rosuvastatin (n = 24) was compared. METHODS: Platelet TF-PCA was induced by GPIbα activation with VWF-ristocetin. RESULTS: Cholesterol-enriched platelets in vitro had augmented aggregation/secretion and platelet FXa generation (1.65-fold increase, p = 0.01). HC-patients had 1.5-, 2.3- and 2.5-fold increases in platelet cholesterol, TF protein and activity, respectively; their platelets had neither hyper-aggregation nor endogenous thrombin generation (ETP). Rosuvastatin, but not atorvastatin, normalized platelet cholesterol, TF protein and FXa generation. It also increased slightly the plasma HDL-C levels, which correlated negatively with TF-PCA. CONCLUSIONS: Platelets from HC-patients were not hyper-responsive to low concentrations of classical agonists and had normal PRP-ETP, before and after statin administration. However, washed platelets from HC-patients had increased membrane cholesterol, TF protein and TF-PCA. The platelet TF-dependent PCA was specifically expressed after VWF-induced GPIbα activation. Rosuvastatin, but not atorvastatin treatment, normalized the membrane cholesterol, TF protein and TF-PCA in HC-patients, possibly unveiling a new pleiotropic effect of rosuvastatin. Modulation of platelet TF-PCA may become a novel target to prevent/treat atherothrombosis without increasing bleeding risks.

Association of Cardiovascular Disease and Sleep Apnea at Different Altitudes.

Otero, Liliana, Patricia Hidalgo, Rafael González, and Carlos A. Morillo. Association of cardiovascular disease and sleep apnea at different altitudes. High Alt Med Biol. 17:336-341, 2016.-We evaluated the prevalence of sleep apnea (SA) in patients with cardiovascular disease (CVD) at different altitudes. A total of 398 subjects with coronary artery disease (CAD), 144 subjects with atrial fibrillation (AF), and 292 controls (without CVD) were recruited in three cities at sea level, moderate altitude, and high altitude. All participants underwent polysomnography. Multinomial logistic regression, X2, and Hosmer and Lemeshow tests were used to determine interactions among CVD, SA, and altitude. Men and women with CVD at high altitude had a higher risk for SA than men and women living at lower altitudes. The highest risk of SA was observed in men with AF and men with CAD living at high altitude. Obstructive SA (OSA) prevalence was significantly increased in CVD subjects living at high altitude (OR: 5.52; p < 0.0001). Central SA (CSA) was more frequent in subjects with CVD than control group (OR: 2.44; p < 0.021). OSA was the most frequent type of SA in subjects with CVD and overweight subjects, and in control individuals with obesity or being overweight. Significant differences in the prevalence of SA associated with altitude and gender were noted in subjects with CAD and AF.

Análisis de costo-efectividad de pramipexol comparado con levodopa y cabergolina para pacientes con síndrome de piernas inquietas en Colombia / Análise de custo-eficácia do pramipexol e cabergolina comparação com levodopa para pacientes com síndrome das pernas inquietas na Colômbia

Problema de investigación: Describir los costos y la efectividad del pramipexol comparado con levodopa y cabergolina para el tratamiento de pacientes con síndrome de piernas inquietas.Tipo de evaluación económica\r\nAnálisis de costo-utilidad. Población objetivo: Población adulta con diagnóstico de síndrome de piernas inquietas. Intervención y comparadores: Intervención: Pramipexol, Comparadores: Levodopa y cabergolina. Horizonte temporal: 16 semanas. Perspectiva Sistema: General de Seguridad Social en Salud (SGSSS). Tasa de descuento: No aplica. Estructura del modelo: Modelo de Markov. Fuentes de datos de efectividad y \r\nseguridad: Reporte de efectividad y seguridad elaborado en diciembre de 2014 en el IETS, Ensayos clínicos aleatorizados. Desenlaces y valoración: Años de vida ajustados por calidad (AVAC). Costos incluidos: Costos de medicamentos, Costos de procedimientos. Fuentes de datos de costos:SISMED, Manual tarifario ISS 2001. Resultados del caso base: En el escenario del caso base, pramipexol es una estrategia costo-efectiva con respecto a levodopa. El costo por AVAC ganado con pramipexol es de $7.480 comparado con levodopa. Análisis de sensibilidad: El análisis de sensibilidad determinístico y el diagrama de tornado mostraron que la variable con mayor impacto sobre las estimaciones de costo-efectividad es el precio de levodopa. No se realizó análisis de sensibilidad probabilístico. Conclusiones y discusión: Pramipexol ofrece una mejor relación entre costos y efectividad respecto a levodopa y cabergolina. De acuerdo con el criterio de los expertos clínicos la cabergolina no hace parte de la práctica clínica habitual para este trastorno y la \r\nlevodopa tiene un uso que requiere de supervisión por el efecto que agudiza las manifestaciones clínicas. La principal limitación de este estudio está relacionada con la poca información proveniente de estudios de investigación clínica y evaluaciones económicas.(AU)

Análisis de impacto presupuestal de pramipexol comparado con levodopa como terapia de primera línea para pacientes con síndrome de piernas inquietas en Colombia / Budget impact analysis of pramipexole compared to levodopa as first-line therapy for patients with restless legs syndrome in Colombia

Tecnologías evaluadas: Nuevas: pramipexol y cabergolina; Actuales: levodopa (en combinación con carbidopa). Población: Pacientes mayores de 18 años con síndrome de piernas inquietas. Perspectiva: La perspectiva del presente AIP corresponde al tercero pagador, que en este caso es el Sistema General de Seguridad Social en Salud (SGSSS) en Colombia. Horizonte temporal: El horizonte temporal de este AIP en el caso base corresponde a un año. Adicionalmente se reportan las estimaciones del impacto presupuestal para los años 2 y 3, bajo el supuesto de la inclusión en el POS en el año 1. Costos incluidos: Costo por mg de los medicamentos. Fuente de costos: Sistema de información de Precios de Medicamentos y Dispositivos Médicos - SISMED. Escenarios: En la construcción de escenarios se consideró una participación de\r\nmercado más alta para pramipexol en comparación con levodopa. Lo anterior a partir de las recomendaciones resultado de la consulta con expertos y la participación de mercado de los medicamentos en el SISMED. \r\nResultados: Para la inclusión en el POS de pramipexol y cabergolina como terapia de primera línea para pacientes con síndrome de piernas inquietas en Colombia, se requeriría una inversión de $21.708.230.419 en el año 1 y de $53.499.840.477 en el año 3. En el caso que los medicamentos del escenario nuevo sean incluidos con un precio común basado en las metodologías de grupos terapéuticos del Ministerio de Salud y protección Social, el impacto presupuestal sería el mismo con una inversión de $21.708.230.419 en el año 1 y $53.499.840.477, en el año 3.(AU)

Impacto en la calidad de vida por la asociación entre trastornos de sueño y síndrome de intestino irritable / Impact on the Quality of Life of the Association between Sleep Disorders and Irritable Bowel Syndrome

Objetivos: determinar si la presencia de alteraciones del sueño se asocia con el deterioro en la calidad de vida, medida a través del cuestionario SF-36, en pacientes con síndrome de intestino irritable (SII). Métodos: se diseñó un estudio de corte transversal en el que se incluyeron individuos con SII seleccionados con los criterios de Roma III, a los que se les aplicó la escala de Epworth, el cuestionario de Pittsburgh y los criterios para síndrome de piernas inquietas (SPI); de manera simultánea, se les realizó la evaluación de calidad de vida usando la escala SF-36. Resultados: se incluyeron 80 pacientes con SII, la mayoría mujeres; el 81% presentó algún tipo de trastorno del sueño determinado por la alteración en 1 o más escalas. Al estratificar los pacientes con y sin trastornos del sueño, se observó que el subgrupo con trastorno del sueño se asoció con mayores alteraciones en la calidad de vida, con OR 4,8125, IC 95%: 1,17-19,02, p < 0,0076, diferencia estadísticamente significativa. Conclusiones: en este estudio se encontró que hasta un 81% de los pacientes con SII presentan trastornos de sueño, y que las alteraciones del sueño en pacientes con SII se asocian con un mayor compromiso de la calidad de vida según la escala SF-36.

Objectives: The objectives of this study were to determine if sleep disorders in patients with irritable bowel syndrome (IBS) were associated with impaired quality of life as measured by the SF36 questionnaire. Methods: This is cross-sectional study in which individuals with IBS according to the Rome III criteria were evaluated for sleep disorders with the Epworth Sleepiness Scale questionnaire and the Pittsburgh Sleep Quality Index (PSQI) questionnaire. They were also evaluated for restless legs syndrome (RLS) and, simultaneously, the Short Form (36) Health Survey was used to evaluate participants’ quality of life. Results: Eighty patients with IBS, mostly women, were included in this study. 81% had some type of specific sleep disorder as measured by at least one of the questionnaires. Patients were groups into those who had sleep disorders, and those who did not. The group which had sleep disorders had statistically significantly more alterations in quality of life (OR 4.8125, 95% CI: 1.17 to 19.02, p <0.0076). Conclusions: This study found that up to 81% of IBS patients have sleep disorders and that sleep disturbances in patients with IBS are associated with decreased quality of life according to the SF36 scale.

[Phenotypic and genotypic diagnosis of bone and miliary tuberculosis in an HIV+ patient in Bogotá, Colombia]. / Diagnóstico genotípico y fenotípico de tuberculosis ósea y miliar en un paciente positivo para HIV en Bogotá, Colombia.

Tuberculosis is the single most frequent cause of death by an infectious agent worldwide. Diagnosis of extra-pulmonary tuberculosis is not always possible through conventional methods, due to the long time required for cultures and the paucibacillary nature of samples; hence the need of rapid molecular methods. HIV infection increases the risk of tuberculosis, and HIV/tuberculosis coinfection is associated with higher mortality. We describe the case of a 56-year old mestizo male patient suspected of having tuberculosis who consulted the San Ignacio Hospital in Bogotá with a two-month history of a painful ulcerated lesion over the distal third area of the right forearm and in whom HIV coinfection was confirmed. Bone and pulmonary histological examination evidenced multiple granulomas, giant cells and fibrosis. Cultures and IS6110-PCR from lung and bone tissues were positive for Mycobacterium tuberculosis complex. Mycobacterium tuberculosis isolates were sensitive to first line drugs.

Platelets enhance tissue factor protein and metastasis initiating cell markers, and act as chemoattractants increasing the migration of ovarian cancer cells.

BACKGROUND: An increase in circulating platelets, or thrombocytosis, is recognized as an independent risk factor of bad prognosis and metastasis in patients with ovarian cancer; however the complex role of platelets in tumor progression has not been fully elucidated. Platelet activation has been associated with an epithelial to mesenchymal transition (EMT), while Tissue Factor (TF) protein expression by cancer cells has been shown to correlate with hypercoagulable state and metastasis. The aim of this work was to determine the effect of platelet-cancer cell interaction on TF and "Metastasis Initiating Cell (MIC)" marker levels and migration in ovarian cancer cell lines and cancer cells isolated from the ascetic fluid of ovarian cancer patients. METHODS: With informed patient consent, ascitic fluid isolated ovarian cancer cells, cell lines and ovarian cancer spheres were co-cultivated with human platelets. TF, EMT and stem cell marker levels were determined by Western blotting, flow cytometry and RT-PCR. Cancer cell migration was determined by Boyden chambers and the scratch assay. RESULTS: The co-culture of patient-derived ovarian cancer cells with platelets causes: 1) a phenotypic change in cancer cells, 2) chemoattraction and cancer cell migration, 3) induced MIC markers (EMT/stemness), 3) increased sphere formation and 4) increased TF protein levels and activity. CONCLUSIONS: We present the first evidence that platelets act as chemoattractants to cancer cells. Furthermore, platelets promote the formation of ovarian cancer spheres that express MIC markers and the metastatic protein TF. Our results suggest that platelet-cancer cell interaction plays a role in the formation of metastatic foci.

Síndrome de apnea/hipopnea obstructiva del sueño y su asociación con las enfermedades cardiovasculares / Obstructive Sleep Apnea Hypopnea Syndrome and its association with cardiovascular disease

Introducción:El síndrome de apnea/hipopnea obstructiva del sueño, es una entidad que ha cobrado importancia en los últimos años, con una prevalencia estimada en adultos de edad media cercana al 4 y al 2% en hombres y mujeres, respectivamente, y que por su frecuencia constituye un problema de salud pública. Objetivo:Exponer, tras un análisis exhaustivo de la literatura disponible, la asociación entre el síndrome de apnea/hipopnea obstructiva del sueño y las enfermedades cardiovasculares. Método: Se hizo una revisión narrativa a partir de la literatura encontrada en las bases de datos más reconocidas. Se incluyeron 59 estudios publicados en los últimos treinta años y se excluyeron reportes y series de casos. Conclusiones: El síndrome de apnea/hipopnea obstructiva del sueño se reconoce hoy en día como un problema de salud pública mundial. En Latinoamérica, más específicamente en Colombia, se requieren estudios prospectivos de cohorte que sirvan de pauta para la población del continente e indiquen posibles diferencias respecto a la comunidad internacional en cuanto a su tratamiento y diagnóstico oportunos, así como acerca del impacto de estos en lo concerniente a los desenlaces cardiovasculares de los pacientes.

Introduction: The Obstructive Sleep Apnea Hypopnea Syndrome has gained importance has gained importance in recent years, with an estimated prevalence in population of middle-aged adults around 4 and 2% in men and women respectively, and that given its frequency constitutes a public health problem. Objective: To show, after a thorough analysis of the available literature, the association between the Obstructive Sleep Apnea Hypopnea Syndrome and cardiovascular diseases. Method: A narrative review was made from the literature found at the most recognized databases. Fifty nine studies published in the last thirty years were included and reports and case series were excluded. Conclusions: The Obstructive Sleep Apnea Hypopnea Syndrome is recognized today as a global public health problem. Latin America, specifically Colombia, requires prospective cohort studies that serve as a guideline for the continent's population and that could indicate possible differences compared to the international community regarding early diagnosis and treatment, and its impact in cardiovascular outcomes of these patients.

Diagnóstico genotípico y fenotípico de tuberculosis ósea y miliar en un paciente positivo para HIV en Bogotá, Colombia / Phenotypic and genotypic diagnosis of bone and miliary tuberculosis in an HIV+ patient in Bogotá, Colombia

La tuberculosis se considera la causa más frecuente de muerte producida por un solo agente infeccioso. El diagnóstico de la tuberculosis extrapulmonar no siempre es posible mediante los métodos convencionales debido al lento crecimiento del bacilo y a la naturaleza paucibacilar de las muestras, por lo que es necesario recurrir a las técnicas moleculares. El riesgo de tuberculosis, así como la mortalidad, aumenta en los pacientes con infección por HIV, en quienes el compromiso extrapulmonar es más frecuente. Se describe el caso de un hombre mestizo de 56 años de edad con sospecha de padecer tuberculosis, que asistió a consulta en el Hospital San Ignacio de Bogotá y relató haber tenido dolor en una lesión ulcerada localizada en el tercio distal del antebrazo derecho durante los dos meses anteriores y en quien se confirmó la infección por HIV. El examen histológico de los tejidos óseo y pulmonar demostró la presencia de granulomas múltiples, células gigantes y fibrosis. Tanto los cultivos como la reacción en cadena de la polimerasa en la secuencia de inserción 6110 ( insertion sequence , IS6110) fueron positivos. Los aislamientos de Mycobacterium tuberculosis recuperados fueron sensibles a los medicamentos antituberculosos de primera línea.

Tuberculosis is the single most frequent cause of death by an infectious agent worldwide. Diagnosis of extra-pulmonary tuberculosis is not always possible through conventional methods, due to the long time required for cultures and the paucibacillary nature of samples; hence the need of rapid molecular methods. HIV infection increases the risk of tuberculosis, and HIV/tuberculosis coinfection is associated with higher mortality. We describe the case of a 56-year old mestizo male patient suspected of having tuberculosis who consulted the San Ignacio Hospital in Bogotá with a two-month history of a painful ulcerated lesion over the distal third area of the right forearm and in whom HIV coinfection was confirmed. Bone and pulmonary histological examination evidenced multiple granulomas, giant cells and fibrosis. Cultures and IS6110-PCR from lung and bone tissues were positive for Mycobacterium tuberculosis complex. Mycobacterium tuberculosis isolates were sensitive to first line drugs.

Direct interaction of CaVß with actin up-regulates L-type calcium currents in HL-1 cardiomyocytes.

Expression of the ß-subunit (CaVß) is required for normal function of cardiac L-type calcium channels, and its up-regulation is associated with heart failure. CaVß binds to the α1 pore-forming subunit of L-type channels and augments calcium current density by facilitating channel opening and increasing the number of channels in the plasma membrane, by a poorly understood mechanism. Actin, a key component of the intracellular trafficking machinery, interacts with Src homology 3 domains in different proteins. Although CaVß encompasses a highly conserved Src homology 3 domain, association with actin has not yet been explored. Here, using co-sedimentation assays and FRET experiments, we uncover a direct interaction between CaVß and actin filaments. Consistently, single-molecule localization analysis reveals streaklike structures composed by CaVß2 that distribute over several micrometers along actin filaments in HL-1 cardiomyocytes. Overexpression of CaVß2-N3 in HL-1 cells induces an increase in L-type current without altering voltage-dependent activation, thus reflecting an increased number of channels in the plasma membrane. CaVß mediated L-type up-regulation, and CaVß-actin association is prevented by disruption of the actin cytoskeleton with cytochalasin D. Our study reveals for the first time an interacting partner of CaVß that is directly involved in vesicular trafficking. We propose a model in which CaVß promotes anterograde trafficking of the L-type channels by anchoring them to actin filaments in their itinerary to the plasma membrane.

Atorvastatin reduces the proadhesive and prothrombotic endothelial cell phenotype induced by cocaine and plasma from cocaine consumers in vitro.

OBJECTIVE: Cocaine consumption is a risk factor for vascular ischemic complications. Although endothelial dysfunction and accelerated atherosclerosis have been observed in cocaine consumers, the mechanisms underlying their pathogenesis are not fully understood. This study aimed at identifying the effects of atorvastatin in relation to a proadhesive and prothrombotic phenotype induced by cocaine and plasma from chronic cocaine users on endothelial cells. APPROACH AND RESULTS: Human umbilical vein endothelial cells were exposed to either cocaine or platelet-free plasma (PFP) from chronic cocaine consumers in the presence or absence of 10 µmol/L of atorvastatin. Atorvastatin significantly reduced the enhanced platelet adhesion that was induced by cocaine and PFP from chronic cocaine consumers, as well as the release of the von Willebrand factor. Atorvastatin also avoided striking alterations on cell monolayer structure triggered by both stimuli and enhanced NO reduction because of cocaine stimulation through disrupting interactions between endothelial nitric oxide synthase (eNOS) and caveolin-1, thus increasing eNOS bioavailability. Cocaine-increased tissue factor-dependent procoagulant activity and reactive oxygen species generation were not counteracted by atorvastatin. Although monocyte chemoattractant protein-1 levels were not significantly higher than controls either under cocaine or PFP stimulation, atorvastatin completely avoided monocyte chemoattractant protein-1 release in both conditions. Platelets stimulated with cocaine or PFP did not express P-selectin, glycoprotein IIb/IIIa, or CD40L and failed to adhere to resting human umbilical vein endothelial cell. CONCLUSIONS: Cocaine and patient plasma equally induced a proadhesive and prothrombotic phenotype in endothelial cells, except for von Willebrand Factor release, which was only induced by PFP from chronic cocaine consumers. Atorvastatin improved endothelial cell function by reducing cocaine-induced and PFP from chronic cocaine consumer-induced effects on platelet adhesion, cell architecture, and NO production.

Structure-function of proteins interacting with the α1 pore-forming subunit of high-voltage-activated calcium channels.

Openings of high-voltage-activated (HVA) calcium channels lead to a transient increase in calcium concentration that in turn activate a plethora of cellular functions, including muscle contraction, secretion and gene transcription. To coordinate all these responses calcium channels form supramolecular assemblies containing effectors and regulatory proteins that couple calcium influx to the downstream signal cascades and to feedback elements. According to the original biochemical characterization of skeletal muscle Dihydropyridine receptors, HVA calcium channels are multi-subunit protein complexes consisting of a pore-forming subunit (α1) associated with four additional polypeptide chains ß, α2, δ, and γ, often referred to as accessory subunits. Twenty-five years after the first purification of a high-voltage calcium channel, the concept of a flexible stoichiometry to expand the repertoire of mechanisms that regulate calcium channel influx has emerged. Several other proteins have been identified that associate directly with the α1-subunit, including calmodulin and multiple members of the small and large GTPase family. Some of these proteins only interact with a subset of α1-subunits and during specific stages of biogenesis. More strikingly, most of the α1-subunit interacting proteins, such as the ß-subunit and small GTPases, regulate both gating and trafficking through a variety of mechanisms. Modulation of channel activity covers almost all biophysical properties of the channel. Likewise, regulation of the number of channels in the plasma membrane is performed by altering the release of the α1-subunit from the endoplasmic reticulum, by reducing its degradation or enhancing its recycling back to the cell surface. In this review, we discuss the structural basis, interplay and functional role of selected proteins that interact with the central pore-forming subunit of HVA calcium channels.