P2X7 Receptor in Dendritic Cells and Macrophages: Implications in Antigen Presentation and T Lymphocyte Activation.

The P2X7 receptor, a member of the P2X purinergic receptor family, is a non-selective ion channel. Over the years, it has been associated with various biological functions, from modulating to regulating inflammation. However, its emerging role in antigen presentation has captured the scientific community's attention. This function is essential for the immune system to identify and respond to external threats, such as pathogens and tumor cells, through T lymphocytes. New studies show that the P2X7 receptor is crucial for controlling how antigens are presented and how T cells are activated. These studies focus on antigen-presenting cells, like dendritic cells and macrophages. This review examines how the P2X7 receptor interferes with effective antigen presentation and activates T cells and discusses the fundamental mechanisms that can affect the immune response. Understanding these P2X7-mediated processes in great detail opens up exciting opportunities to create new immunological therapies.

Natural pentacyclic triterpenoid as allosteric modulators of human 5-lipoxygenase with potential anti-inflammatory activity.

This study explored new methods to inhibit human 5-lipoxygenase (5-hLOX) by analyzing natural terpenes that share structural similarities with acetoxyboswellic acid (AKBA). Enzymatic assays were used to evaluate the terpene's ability to inhibit the enzyme, potentially providing anti-inflammatory benefits. Our research focused on how certain types of triterpenes can inhibit 5-hLOX allosterically via a newly discovered allosteric site identified by enzyme crystallization. To determine whether natural boswellic acid analogs mimicked the allosteric known inhibitor AKBA, we combined 5-hLOX inhibition with in silico modeling. Our research has discovered that certain amino acids, specifically Arg 138, Arg 101, Arg 68, and Gln129, located in the allosteric 5-hLOX pocket, play a critical role in stabilizing glycyrrhetinic isomers. These amino acids form hydrogen bonds and hydrophobic interactions that contribute to the inhibitory potency of boswellic acid derivatives. We have found that α and ß glycyrrhetinic acid isomers, carbenoxolone, and to a minor extent, prednisolone, have a potent inhibitory effect against 5-hLOX with IC50 values of 8.64, 3.94, 52.98, and 291.20 µM, respectively. These values are in line with our calculated in silico allosteric site binding energy estimations. In contrast, other steroidal or non-steroidal anti-inflammatory agents exhibited inhibitory potencies larger than 500 µM. However, the specific pharmacodynamic mechanisms are currently unknown. We propose that AKBA analogs may lead to the future development of novel anti-inflammatory agents.Communicated by Ramaswamy H. Sarma.

Changes in brain activity of trainees during laparoscopic surgical virtual training assessed with electroencephalography.

OBJECTIVE: Evaluate changes in brain activity of trainees during laparoscopic surgical training from electroencephalographic (EEG) signals in an ecological scenario with few restrictions for the user. DESIGN: Longitudinal study with two follow-up measurements in the first and last session of a 4-week training with LapSim laparoscopic surgery simulator. Variables analyzed include EEG neuronal activations in theta and alpha bands, tasks performance measures, and subjective measures such as perception of mental workload. SETTING: Medical School, Universidad de Antioquia, Medellin, Colombia. PARTICIPANTS: First-year surgical residents (n = 16, age = 28.0 ± 2.6 years old, right-handed, 9 females) RESULTS: Significant improvements in tasks performance were found together with changes in neuronal activity over frontal and parietal cortex. These changes were also correlated with task performance through training sessions. CONCLUSIONS: The use of neurophysiological measures such as electroencephalography combined with source separation techniques allows evaluating neural changes associated with motor training. The experiment proposed in this work establishes less controlled recording conditions leading to a more realistic analysis scenario to cognitive assessment in residents training.

P2X7 receptor is essential for cross-dressing of bone marrow-derived dendritic cells.

T cell activation requires the processing and presentation of antigenic peptides in the context of a major histocompatibility complex (MHC complex). Cross-dressing is a non-conventional antigen presentation mechanism, involving the transfer of preformed peptide/MHC complexes from whole cells, such as apoptotic cells (ACs) to the cell membrane of professional antigen-presenting cells (APCs), such as dendritic cells (DCs). This is an essential mechanism for the induction of immune response against viral antigens, tumors, and graft rejection, which until now has not been clarified. Here we show for first time that the P2X7 receptor (P2X7R) is crucial to induce cross-dressing between ACs and Bone-Marrow DCs (BMDCs). In controlled ex vivo assays, we found that the P2X7R in both ACs and BMDCs is required to induce membrane and fully functional peptide/MHC complex transfer to BMDCs. These findings show that acquisition of ACs-derived preformed antigen/MHC-I complexes by BMDCs requires P2X7R expression.

Chitosan-Based Delivery of Avian Reovirus Fusogenic Protein p10 Gene: In Vitro and In Vivo Studies towards a New Vaccine against Melanoma.

Reovirus is known to have an anticancer effect in both the preclinical and clinical assays. Current evidence suggests that the reovirus-mediated impact on tumor growth depends on the activation of specific antitumor immune responses. A feasible explanation for the oncolytic effects and immune system activation is through the expression of the fusogenic reovirus protein. In this work, we evaluated the in vivo antitumor effects of the expression of fusogenic protein p10 of avian reovirus (ARV-p10). We used chitosan nanoparticles (CH-NPs) as a vehicle for the ARV-p10 DNA in murine B16 melanoma models both in vitro and in vivo. We confirmed that ARV-p10 delivery through a chitosan-based formulation (ARV-p10 CH-NPs) was capable of inducing cell fusion in cultured melanoma cells, showing a mild cytotoxic effect. Interestingly, intratumor injection of ARV-p10 CH-NPs delayed tumor growth, without changing lymphoid populations in the tumor tissue and spleen. The injection of chitosan nanoparticles (CH-NPs) also delayed tumor growth, suggesting the nanoparticle itself would attack tumor cells. In conclusion, we proved that in vitro ARV-p10 protein expression using CH-NPs in murine melanoma cells induces a cytotoxic effect associated with its cell fusion. Further studies are necessary for establishing a protocol for efficient in vivo DNA delivery of fusion proteins to produce an antitumoral effect.

Chitosan-Based Nanoparticles for Intracellular Delivery of ISAV Fusion Protein cDNA into Melanoma Cells: A Path to Develop Oncolytic Anticancer Therapies.

Oncolytic virus therapy has been tested against cancer in preclinical models and clinical assays. Current evidence shows that viruses induce cytopathic effects associated with fusogenic protein-mediated syncytium formation and immunogenic cell death of eukaryotic cells. We have previously demonstrated that tumor cell bodies generated from cells expressing the fusogenic protein of the infectious salmon anemia virus (ISAV-F) enhance crosspriming and display prophylactic antitumor activity against melanoma tumors. In this work, we evaluated the effects of the expression of ISAV-F on the B16 melanoma model, both in vitro and in vivo, using chitosan nanoparticles as transfection vehicle. We confirmed that the transfection of B16 tumor cells with chitosan nanoparticles (NP-ISAV) allows the expression of a fusogenically active ISAV-F protein and decreases cell viability because of syncytium formation in vitro. However, the in vivo transfection induces a delay in tumor growth, without inducing changes on the lymphoid populations in the tumor and the spleen. Altogether, our observations show that expression of ISAV fusion protein using chitosan nanoparticles induces cell fusion in melanoma cells and slight antitumor response.

Adrenal paracoccidioidomycosis / [Paracoccidiodomicosis suprarrenal].

Primary adrenal insufficiency is a defect in glucocorticoid, mineralocorticoid and sexual androgens production. Patients with this disorder have low cortisol levels and aldosterone deficiency with concomitant hyponatremia and hyperkalemia. The most common etiology of this disease is the production of antibodies against the enzyme 21 hydroxylase. Another common cause, particularly in low income countries, are infectious diseases. Several micro-organisms have been reported as a causal agent in adrenal insufficiency including Mycobacterium tuberculosis, Mycobacterium avium complex, Neisseria meningitidis, Pseudomonas aeruginosa, Haemophilus influenzae, cytomegalovirus, Pneumocystis jirovecii, Histoplasma capsulatum, Blastomyces dermatiditis, Cryptococcus neoformans, Cocciodiodes immitis, Nocardia spp. and Paracoccidioides brasiliensis. In this article, we present the computerized tomography and the adrenal biopsy of a patient with adrenal insufficiency. The final diagnosis was paracoccidioidomycosis.

La insuficiencia suprarrenal primaria es un defecto en la producción de glucocorticoides, mineralocorticoides y andrógenos sexuales. Los pacientes afectados por esta condición se caracterizan por concentraciones bajas de cortisol y deficiencia de aldosterona con hiponatremia e hiperpotasemia concomitantes. La etiología más común es el desarrollo de anticuerpos contra la enzima 21 hidroxilasa. Otra causa importante de la insuficiencia suprarrenal primaria son las enfermedades infecciosas, en especial en los países de bajos ingresos. Entre las causas infecciosas que se han descrito se encuentran: Mycobacterium tuberculosis, el complejo de Mycobacterium avium, Neisseria meningitidis, Pseudomonas aeruginosa, Haemophilus influenzae, citomegalovirus, Pneumocystis jirovecii, Histoplasma capsulatum, Blastomyces dermatiditis, Cryptococcus neoformans, Cocciodiodes immitis, Nocardia spp. y Paracoccidioides brasiliensis. En este artículo se presenta la imagen de la tomografía de un paciente que presentó falla suprarrenal, con masas en las glándulas suprarrenales, cuya biopsia permitió establecer el diagnóstico final de paracoccidioidomicosis.

Paracoccidiodomicosis suprarrenal / Adrenal paracoccidioidomycosis

La insuficiencia suprarrenal primaria es un defecto en la producción de glucocorticoides, mineralocorticoides y andrógenos sexuales. Los pacientes afectados por esta condición se caracterizan por concentraciones bajas de cortisol y deficiencia de aldosterona con hiponatremia e hiperpotasemia concomitantes. La etiología más común es el desarrollo de anticuerpos contra la enzima 21 hidroxilasa. Otra causa importante de la insuficiencia suprarrenal primaria son las enfermedades infecciosas, en especial en los países de bajos ingresos. Entre las causas infecciosas que se han descrito se encuentran: Mycobacterium tuberculosis, el complejo de Mycobacterium avium, Neisseria meningitidis, Pseudomonas aeruginosa, Haemophilus influenzae, citomegalovirus, Pneumocystis jirovecii, Histoplasma capsulatum, Blastomyces dermatiditis, Cryptococcus neoformans, Cocciodiodes immitis, Nocardia spp. y Paracoccidioides brasiliensis. En este artículo se presenta la imagen de la tomografía de un paciente que presentó falla suprarrenal, con masas en las glándulas suprarrenales, cuya biopsia permitió establecer el diagnóstico final de paracoccidioidomicosis.

Primary adrenal insufficiency is a defect in glucocorticoid, mineralocorticoid and sexual androgens production. Patients with this disorder have low cortisol levels and aldosterone deficiency with concomitant hyponatremia and hyperkalemia. The most common etiology of this disease is the production of antibodies against the enzyme 21 hydroxylase. Another common cause, particularly in low income countries, are infectious diseases. Several micro-organisms have been reported as a causal agent in adrenal insufficiency including Mycobacterium tuberculosis, Mycobacterium avium complex, Neisseria meningitidis, Pseudomonas aeruginosa, Haemophilus influenzae, cytomegalovirus, Pneumocystis jirovecii, Histoplasma capsulatum, Blastomyces dermatiditis, Cryptococcus neoformans, Cocciodiodes immitis, Nocardia spp. and Paracoccidioides brasiliensis. In this article, we present the computerized tomography and the adrenal biopsy of a patient with adrenal insufficiency. The final diagnosis was paracoccidioidomycosis.

Potent Vasodilator and Cellular Antioxidant Activity of Endemic Patagonian Calafate Berries (Berberis microphylla) with Nutraceutical Potential.

Hydroalcoholic extracts of Patagonian Calafate berry (Berberis microphylla) contain mono or disaccharide conjugated anthocyanins and flavonols. The Liquid Chromatography-Mass Spectrometry (LC-MS) chemical extract profile identified glycosylated anthocyanidins such as delphinidin-, petunidin- and malvidin-3-glucoside as the major constituents. The predominant flavonols were 3-O substituents quercetin-rutinoside or -rhamnoside. Anthocyanins doubled flavonols in mass (13.1 vs. 6 mg/g extract). Polyphenols vascular actions were examined in the rat arterial mesenteric bed bioassay; extract perfusion elicited concentration-dependent vasodilatation mimicked by conjugated anthocyanins standards. Vascular responses of main glycosylated anthocyanins were endothelium-dependent (p < 0.001) and mediated by NO production (p < 0.05). The anthocyanins antioxidant activity determined in isolated endothelial cells (CAA) showed a reduced redox potential as compared to the extract or quercetin. While in the 2,2-Diphenyl-1-picrylhydrazyl (DPPH) assay, the anthocyanins showed an equivalent quercetin potency, the extract was 15-fold less active, proposing that the anthocyanin-induced vasodilation is not due to an antioxidant mechanism. The extract shows promising commercial nutraceutical potential.

ATP-loaded biomimetic nanoparticles as controlled release system for extracellular drugs in cancer applications.

PURPOSE: The antitumoral effect of ATP requires its accumulation in the extracellular space to interact with membrane receptors in target cells. We propose the use of albumin nanoparticles (ANPs) coated with erythrocyte membranes (EMs) to load, deliver, release, and enhance the extracellular anticancer activity of ATP. MATERIALS AND METHODS: ANPs were synthesized by desolvation method and optimal values of pH, albumin concentration, and ethanol volume were determined. EMs were derived from erythrocyte lysates and were coated on to ANPs using an extruder. Size was determined by transmission electron microscopy (TEM) and hydrodynamic size and zeta potential were determined by dynamic light scattering. Coating of the ANPs with the EMs was verified by TEM and confocal microscopy. Nanoparticle cell uptake was analyzed by confocal microscopy using HeLa and HEK-293 cell cultures treated with nanoparticles stained with 1,1'-diocta-decyl-3,3,3',3'-tetramethylindodicarbocyanine, 4-chlorobenzenesulfonate salt (DiD) for EM-ANPs and Alexa 488 for ANPs. Cell viability was analyzed by [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt (MTS) and Annexin V/propidium iodide assays. RESULTS: Optimal values of ANP preparation were as follows: pH=9, 10 mg/mL albumin concentration, and 2.33±0.04 mL ethanol volume. Size distributions as analyzed by TEM were as follows: ANPs =91.9±4.3 nm and EM-ANPs =98.3±5.1 nm; hydrodynamic sizes: ANPs =180.5±6.8 nm and EM-ANPs =197.8±3.2 nm; and zeta potentials: ANPs =17.8±3.5 mV, ANPs+ATP =-13.60±0.48 and EM-ANPs =-13.7±2.9 mV. The EMs coating the ANPs were observed by TEM and confocal microscopy. A fewer number of internalized EM-ANPs+ATP compared to non-coated ANPs+ATP was observed in HeLa and HEK-293 cells. Cell viability decreased up to 48.6%±2.0% with a concentration of 400 µM ATP after 72 hours of treatment and cell death is caused mainly via apoptosis. CONCLUSION: Our current results show that it is possible to obtain nanoparticles from highly biocompatible, biodegradable materials and that their coating with EMs allows the regulation of the internalization process in order to promote extracellular activity of ATP.

Incidencia de lesión de vías biliares en un hospital universitario: análisis de más de 1600 colecistectomías laparoscópicas / Incidence of bile duct lesion at a university hospital: analysis of more than 1600 laparoscopic cholecystectomies

Introducción. La colecistectomía laparoscópica es el procedimiento laparoscópico más comúnmente realizado por el cirujano general. La lesión de la vía biliar es la complicación más temida debido a sus implicaciones clínicas y económicas. El objetivo de esta investigación fue determinar la incidencia de la lesión de la vía biliar en un centro de formación académica e identificar los posibles factores de riesgo asociados a su presentación. Materiales y métodos. Se llevó a cabo un estudio observacional retrospectivo en pacientes a quienes se les practicó una colecistectomía laparoscópica en el Hospital Universitario San Vicente Fundación de Medellín entre marzo de 2011 y septiembre 2016. Se realizó un análisis univariado y bivariado para explorar la asociación de algunas variables preoperatorias e intraoperatorias con la lesión de la vía biliar. Se utilizó el programa estadístico Stata 2014™. Resultados. Se incluyeron 1.601 pacientes. La incidencia de lesión de la vía biliar fue de 0,8 % (14 pacientes), con una mortalidad global de 0,4 %. La mayoría de estas lesiones fueron tipo A de Strasberg; solo dos pacientes requirieron una reconstrucción compleja de la vía biliar. Se encontró relación estadísticamente significativa con mayor tiempo operatorio (p<0,05) y mayor sangrado intraoperatorio (p<0,05) con la presentación de lesión de la vía biliar. Conclusión. La colecistectomía laparoscópica es un procedimiento seguro en el Hospital Universitario San Vicente Fundación, centro de formación de residentes quirúrgicos. La tasa de lesión de la vía biliar es similar a la reportada en la literatura

Introduction. Laparoscopic cholecystectomy is the most common laparoscopic procedure performed by the general surgeon. Bile duct injury (BDI) is the most feared complication due to its clinical and economic implications. The goal of this study was to determine the incidence of BDI at a teaching hospital and to identify possible related risk factors. Methods. This is an observational retrospective study that included patients who underwent laparoscopic cholecystectomy at San Vicente Foundation University Hospital (HUSVF) in Medellin, Colombia, in the period 2011 to September 2016. Univariate and bivariate analyses were performed to explore possible association of some perioperative variables with BDI. Statistic software STATA 2014 was used. Results. A total of 1,601 patients were included. BDI incidence was 0.8% (14 patients), global mortality was 0.4%. Most of BDIs were type A of the Strasberg classification and only two patients required complex reconstructions of the bile ducts. Longer operative time (p>0.05) and higher intraoperative blood loss (p<0.05) were related with BDI. Conclusion. Laparoscopic cholecystectomy is a safe procedure at HUSVF, a training center for surgical residents. Bile duct injury rate at this hospital is similar to that reported in the literature

Copper-induced increased expression of genes involved in photosynthesis, carotenoid synthesis and C assimilation in the marine alga Ulva compressa.

BACKGROUND: The marine alga Ulva compressa is the dominant species in coastal areas receiving effluents from copper mines. The alga can accumulate high amounts of copper and possesses a strong antioxidant system. Here, we performed short-term transcriptomic analyses using total RNA of the alga cultivated with 10 µM of copper for 0, 3, 6, 12 and 24 h by RNA-seq. RESULTS: De novo transcriptomes were assembled using the Trinity software, putative proteins were annotated and classified using Blast2GO. Differentially expressed transcripts were identified using edgeR. Transcript levels were compared by paired times 0 vs 3, 0 vs 6, 0 vs 12 and 0 vs 24 h at an FDR < 0.01 and Log2 Fold Change > 2. Up-regulated transcripts encode proteins belonging to photosystem II (PSII), Light Harvesting II Complex (LHCII), PSI and LHCI, proteins involved in assembly and repair of PSII, and assembly and protection of PSI. In addition, transcripts encoding enzymes leading to ß-carotene synthesis and enzymes belonging to the Calvin-Benson cycle were also increased. We further analyzed photosynthesis and carotenoid levels in the alga cultivated with 10 µM of copper for 0 to 24 h. Photosynthesis was increased from 3 to 24 h as well as the level of total carotenoids. The increase in transcripts encoding enzymes of the Calvin-Benson cycle suggests that C assimilation may also be increased. CONCLUSIONS: Thus, U. compressa displays a short-term response to copper stress enhancing the expression of genes encoding proteins involved in photosynthesis, enzymes involved carotenoids synthesis, as well as those belonging to the Calvin-Benson cycle, which may result in an increase in C assimilation.

Nesidioblastosis del adulto tras derivación gástrica / Nesidioblastosis in the adult following gastric bypass

La hipoglucemia por hiperinsulinismo endógeno ha sido descrita como una complicación de la cirugía bariátrica. Se presenta el caso de un hombre de 34 años con tríada de Whipple que se manifestó ocho años después de someterse a derivación (bypass) gástrica. La hipoglucemia se asociaba con niveles elevados de insulina y péptido C, pero la localización del hiperinsulinismo endógeno solo se pudo precisar mediante cateterismo de arterias pancreáticas con estimulación intraarterial selectiva con calcio. Se decidió practicar una pancreatectomía subtotal laparoscópica, después de la cual el paciente presentó una excelente evolución posoperatoria y mejoró significativamente su sintomatología. Mediante la evaluación histopatológica e inmunohistoquímica, se confirmó una nesidioblastosis del adulto. Es importante reconocer esta enfermedad como una complicación de la cirugía bariátrica, más aún cuando estos procedimientos son tan frecuentes en la actualidad debido a la epidemia de obesidad. Los síntomas se pueden confundir con los de un síndrome de evacuación gástrica rápida (dumping), el cual no tiene repercusiones tan graves sobre la salud del paciente, como sí la tiene la nesidioblastosis

Hypoglycemia due to endogenous hyperinsulinism has been described as a complication of bariatric surgery. We present the case of a 34-year-old man who developed a Whipple's triad eight years after undergoing gastric bypass. Hypoglycemia was associated with high serum levels of insulin and C peptide; anatomic localization of endogenous hyperinsulinism was finally demonstrated with a selective intra-arterial calcium-stimulation test. Patient was offered a laparoscopic subtotal pancreatectomy, which resulted in an excellent postoperative course and significant symptoms resolution. Pathology report and inmunohistochemical analysis confirmed the diagnosis of adult nesidioblastosis. We believe it is important to recognize this condition as a complication of bariatric surgery, a procedure performed more frequently nowadays due to the obesity epidemic. Symptoms might be confused with those of dumping syndrome which does not have severe consequences in the patient´s health as nesidioblastosis does

Superioridad clínica de la apendicectomía laparoscópica sobre la técnica abierta: ¿adopción lenta de un nuevo estándar de tratamiento? / Clinical superiority of laparoscopic appendectomy over the open technique: sluggish adoption of a new standard of treatment?

Introducción. La apendicectomía es uno de los procedimientos que más practican los cirujanos generales. La tendencia actual es hacia un mayor uso de la técnica laparoscópica, sin embargo, su aplicación rutinaria es aún controvertida. Objetivo. Comparar los resultados clínicos de las técnicas de apendicectomía laparoscópica y abierta en un centro de atención de tercer nivel. Materiales y métodos. Se llevó a cabo un estudio de cohorte en pacientes sometidos a apendicectomía en un periodo de cuatro años. Se compararon variables perioperatorias y posoperatorias. Se hizo un análisis multivariado para determinar los factores asociados a la infección del sitio operatorio. Resultados. Se incluyeron 600 pacientes: 389 apendicectomías abiertas y 211 por laparoscopia. Las características demográficas fueron similares en ambos grupos. El tiempo operatorio promedio fue mayor en las apendicectomías laparoscópicas, 30,3 minutos Vs. 24,4 minutos (p<0,01), y no se presentó ningún caso de conversión. Fue mayor el número de complicaciones de la apendicectomía abierta en comparación con la laparoscópica (15,1 % Vs. 3,7 %, respectivamente), además de tener una tendencia a mayor estancia hospitalaria y reintervención. Los pacientes de apendicectomía abierta tuvieron mayor infección en la incisión del sitio operatorio (8,7 % Vs. 2,8 %; p=0,01). La apendicectomía laparoscópica no aumentó la incidencia de infección del sitio operatorio (órgano o espacio, RR=0,98 (0,97-1,00). La obesidad, la apendicitis complicada y la técnica abierta se asociaron con la presentación de infección del sitio operatorio (p<0,01). Conclusión. En pacientes adultos, la apendicectomía laparoscópica es superior en resultados clínicos comparada con la técnica abierta, sobre todo en la disminución de la incidencia de infección del sitio operatorio (en la incisión y órgano o espacio), por lo cual se recomienda su uso generalizado en nuestro país

Introduction: Appendectomy is one of the most commonly performed procedures by general surgeons. Current tendency is towards an increasing use of laparoscopic technique; however, its routine implementation is still controversial. Aim: To compare clinical outcomes of the open (OA) and laparoscopic (LA) appendectomy techniques at a single tertiary level of care institution. Methods: Cohort study in patients that underwent appendectomy during a four-year period. Perioperative and postoperative variables were compared. Factors related to surgical site infection (SSI) were determined by multivariate analysis. Results: 600 patients were included: 389 OA and 211 LA. Demographic characteristics were similar in both groups. Mean operative time was longer in LA, 30.3min vs 24.4min (p<0.01), there were no conversions to the open technique. There were more complications in OA compared to LA (15.1% vs 3.7% respectively), furthermore OA had a tendency towards longer hospital stay and reoperation. OA patients had higher incidence of incisional SSI (8.7% vs 2.8%, p=0.01). LA was not related to higher incidence of organ/space SSI (RR 0.98, CI 0.97-1.00). Obesity, complicated appendicitis, and open surgical technique, were related to the development of SSI (p<0.01). Conclusion: Laparoscopic appendectomy is superior in clinical outcomes as compared to the open technique. This is especially true because LA decreases the incidence of incisional and organ/space SS. In consequence, we recommend its routine implementation in our country.

Factores facilitadores de la violencia laboral: una revisión de la evidencia científica en América Latina / Enabling factors of workplace violence: a review of the scientific evidence in Latin America

En el presente artículo se dan a conocer los resultados de una revisión sistemática de la literatura que reporta investigaciones en poblaciones latinoamericanas en torno a factores facilitadores de la violencia laboral. Para esto se realizó una búsqueda en las bases de Academic Search Complete (EBSCOhost), Fuente Académica Premier, PSICODOC, Scielo.org, JSTOR y SCOPUS. Se contemplaron estudios empíricos e indexados entre los años 2009 y 2014. Se trabajó con una selección de 17 artículos y se generaron cuatro categorías de análisis cualitativo: 1. Aproximación metodológica de los estudios. 2. Factores determinantes individuales. 3. Factores determinantes sociales-interpersonales. 4. Factores determinantes organizacionales. A partir del análisis se concluye que la violencia en el trabajo tiene un carácter multideterminado, transversal y multicausal, por lo cual debe existir una perspectiva sistémica para su abordaje, con el fin de abarcar toda su complejidad y profundidad.

This article discloses the results of a systematic review of the literature reporting research in Latin American populations around facilitating factors of workplace violence. For this, a search was conducted on the bases of Academic Search Complete (EBSCOhost) Academic Source Premier, PSICODOC, Scielo.org, JSTOR and Scopus. Empirical studies were contemplated and indexed between 2009 and 2014. We worked with a selection of 17 articles, and four categories of qualitative analysis were generated: 1. Methodological approach of the studies. 2. Individual determinants. 3. social-interpersonal determinants. 4. organizational determinants. The analysis concluded that violence at work has a multi-determined, transversal and multi-causal character, so there must be a systemic perspective to address them, in order to cover all its complexity and depth.

Zinc as Allosteric Ion Channel Modulator: Ionotropic Receptors as Metalloproteins.

Zinc is an essential metal to life. This transition metal is a structural component of many proteins and is actively involved in the catalytic activity of cell enzymes. In either case, these zinc-containing proteins are metalloproteins. However, the amino acid residues that serve as ligands for metal coordination are not necessarily the same in structural proteins compared to enzymes. While crystals of structural proteins that bind zinc reveal a higher preference for cysteine sulfhydryls rather than histidine imidazole rings, catalytic enzymes reveal the opposite, i.e., a greater preference for the histidines over cysteines for catalysis, plus the influence of carboxylic acids. Based on this paradigm, we reviewed the putative ligands of zinc in ionotropic receptors, where zinc has been described as an allosteric modulator of channel receptors. Although these receptors do not strictly qualify as metalloproteins since they do not normally bind zinc in structural domains, they do transitorily bind zinc at allosteric sites, modifying transiently the receptor channel's ion permeability. The present contribution summarizes current information showing that zinc allosteric modulation of receptor channels occurs by the preferential metal coordination to imidazole rings as well as to the sulfhydryl groups of cysteine in addition to the carboxyl group of acid residues, as with enzymes and catalysis. It is remarkable that most channels, either voltage-sensitive or transmitter-gated receptor channels, are susceptible to zinc modulation either as positive or negative regulators.

Relación entre gastrectomía de tipo manga y reflujo gastroesofágico / Relationship between sleeve gastrectomy and gastroesophageal reflux

La enfermedad por reflujo gastroesofágico es una entidad muy frecuente en la población general, con secuelas significativas, como esofagitis péptica, esófago de Barrett y carcinoma de esófago. La obesidad, por su parte, es una condición que se ha incrementado en el mundo en las últimas tres décadas y es uno de los principales factores de riesgo para reflujo gastroesofágico y esófago de Barrett. En los últimos años, la cirugía bariátrica se ha convertido en el mejor tratamiento para la obesidad mórbida y algunas de sus técnicas son reconocidas por ser procedimientos esencialmente antirreflujo como, por ejemplo, la derivación gástrica laparoscópica en Y de Roux. Sin embargo, la relación entre la manga gástrica por laparoscopia y el reflujo gastroesofágico, sigue siendo un tema controvertido. El propósito de esta revisión es presentar la información disponible sobre los mecanismos fisiopatológicos asociados a la presentación de reflujo gastroesofágico después de manga gástrica por laparoscopia y la influencia de la técnica quirúrgica en la prevención de esta complicación.

Gastroesophageal reflux disease (GERD) is a very common disease in the general population with significant consequences like peptic esophagitis, Barrett's esophagus (BE), and esophageal carcinoma. On the other hand, obesity is a condition that has increased in the world in the last three decades and is one of the major risk factors for GERD and BE. In recent years, bariatric surgery has become the best treatment option for morbid obesity and some of these techniques are recognized as being essentially anti-reflux procedures like laparoscopic Roux-en-Y gastric bypass (LRYGB). However, the relationship between laparoscopic sleeve gastrectomy (LSG) and GERD remains controversial. The purpose of this review is to present the available evidence about the pathophysiological mechanisms associated with the presentation of GERD after LSG and the influence of surgical technique in preventing this complication.

Capacidad buffer de la saliva en presencia de bebidas energéticas comercializadas en Chile, estudio in vitro / In vitro study of the buffering capacity of saliva in the presence of energy drinks sold in Chile

OBJETIVO Determinar la capacidad buffer de la saliva al ser añadida a distintas bebidas energéticas comercializadas en Chile, mediante mediciones de pH in vitro. MÉTODOS Fue requerida la participación de 3 pacientes jóvenes sistémicamente sanos, sin enfermedad de las glándulas salivales. Las muestras de saliva estimulada fueron obtenidas de cada paciente, las cuales fueron mezcladas y almacenadas en una sola muestra. Se seleccionaron 13 bebidas energéticas comercializadas a nivel nacional. Un total de 5 mL de cada bebida energética se distribuyó en 4 tubos Falcon. Se midió el pH de cada una de las bebidas energéticas, de la saliva y del agua potable. Se añadió 1 mL de agua potable al tubo Falcon número 1 y 1 mL de saliva a los 3 tubos restantes, cada 3 min hasta completar 13 mL de solución en cada uno (38% vol./vol.). Las mediciones de pH fueron realizadas en cada 1 mL añadido (saliva/agua), para permitir al ph-metro registrar de manera correcta. RESULTADOS Los rangos de pH para las bebidas energéticas van desde pH 2,42 ± 0,008 (Battery Gingered®), hasta pH 3,44 ± 0,005 (Battery Sugar Free®). La saliva en promedio tuvo un valor de pH 7,99 y el agua potable de 7,05. La bebida que más logró aumentar el pH, luego de agregar la saliva, fue la bebida Speed® que llegó a un valor de pH 4,38, mientras la que logró menos fue la bebida Quick Energy®, con un valor de pH 3,37. CONCLUSIÓN La capacidad buffer de la saliva logró aumentar entre 17 y 54% el pH de las bebidas energéticas analizadas en este estudio. Sin embargo, no pudo neutralizar los bajos niveles de pH de estas bebidas más allá de un pH final de 4,38, que es crítico para la estructura dentaria.

OBJECTIVE To determine, using in vitro pH measurements, the buffering capacity of saliva when added to different energy drinks sold in Chile. METHOD The participation of 3 young and systemically healthy patients, with no diseases of the saliva glands, was obtained. Samples of stimulated saliva where obtained from each patient and then mixed and stored as one sample. The study used 13 energy drinks sold nationwide, with 5 mL of each one being distributed into 4 Falcon tubes. The pH of each of the energy drinks, the saliva sample, and drinking water was measured. 1 mL of drinking water was added into Falcon tube number 1, and 1 mL of saliva into the 3 remaining every 3 min until completing 13 mL of solution in each one (38% vol./vol.). The pH measurements where performed upon adding each 1 mL (saliva/water) to allow the pH meter to correctly register the data. RESULTS The pH levels for energy drinks range between pH 2.42 ± 0.008 (Battery Gingered®), to pH 3.44 ± 0.005 (Battery Sugar Free®). The saliva had a mean pH value of 7.99, and 7.05 for drinkable water. The energy drink that achieved a higher increase in pH level was Speed®, reaching a value of pH 4.38, while the energy drink that increased the pH level the least was Quick Energy®, only reaching a pH of 3.37. CONCLUSION The buffering capacity of saliva managed to increase the pH level of energy drinks analyzed in this study between 17 and 54%. However, saliva was unable to neutralize further than 4.38 the low levels of pH in these drinks, thus being critical to dental structure.

Trauma esplénico cerrado: predictores de la falla del manejo no operatorio / Blunt splenic trauma: predictors of failure of nonoperative management

Introducción. El manejo no operatorio del trauma esplénico cerrado es el método preferencial para la preservación esplénica; sin embargo, los criterios para decidir qué pacientes pueden ser manejados sin cirugía sigue siendo materia de debate. El objetivo de este estudio fue describir las características generales de estos pacientes, los resultados del manejo no operatorio y explorar los factores asociados a su falla. Métodos. Es un estudio descriptivo de los pacientes con diagnóstico de trauma esplénico cerrado, admitidos a un centro de atención de alta complejidad, durante el periodo comprendido entre enero de 2003 y marzo de 2009. Los pacientes se clasificaron en dos grupos: manejo operatorio y manejo no operatorio; en el último se analizaron los pacientes en los que falló dicho manejo. Un valor de p menor de 0,05 se consideró de significancia estadística. Resultados. Se incluyeron 82 pacientes. Después de la evaluación primaria o secundaria, el 25,6 % recibió manejo operatorio y, el 74,4 %, manejo no operatorio; el tratamiento no quirúrgico falló en el 22,9 %. Esta falla se asoció con un puntaje Injury Severity Score (ISS) mayor o igual a 20 (RR=6,4; IC95% 2,34-17,86), presencia de hemoperitoneo en la tomografía axial de ingreso (p=0,02) y el grado de lesión esplénica (p<0,001). Las complicaciones ocurrieron en el 31,7 % y las infecciones fueron la causa más frecuente en ambos grupos. La mortalidad global fue 7,3 % (3 pacientes en el grupo de manejo no operatorio y 3 en el de manejo operatorio), debida a las lesiones asociadas en la mayoría de los pacientes. Conclusiones. La mayoría de pacientes con trauma cerrado de bazo puede recibir manejo no operatorio, siendo este un método seguro y efectivo para la preservación esplénica, si se mantiene una vigilancia clínica continua, especialmente en casos de trauma grave.

Background: Nonoperative Management (NOM) of blunt splenic injuries is the preferred method of management for splenic preservation; however, the criteria for deciding what group of patients can be managed non-operatively remain controversial. The aim of this study was to describe the general features of this group of patients as well as to explore the results and factors related to failure of NOM. Methods: We described patients who were admitted to a first level trauma center with a diagnosis of blunt splenic injury between January 2003 and March 2009. The patients were classified in two groups: operative management and NOM; in the last group we analyzed the factors associated with failure. Results: A total of 82 patients were included in the study. Operative Management during the primary or secondary survey was performed on 25.6 % of patients, while 74.4% under went NOM. Of those who underwent NOM, 22.9% failed treatment. An Injury Severity Score (ISS) ≥20 (RR: 6.4 – CI 95%: 2.34-17.86), hemoperitoneum on the initial computed tomography (CT) scan (p=0.02), and splenic injury grade were factors associated with failed NOM (FNOM). The overall mortality rate was 7.3%; 14.3% for OM and 4.9% for NOM groups, respectively. Conclusions: The majority of blunt splenic trauma patients are candidates for NOM, as it is a safe and effective technique for splenic preservation if continuous medical surveillance is maintained.

Salud mental y naturaleza del trabajo: cuando las demandas emocionales resultan inevitables / Mental health and nature of work: when the emotional demands becomes inevitable

ANTECEDENTES: el trabajo en servicios y particularmente el trabajo que involucra asistencia a personas se caracteriza por altas demandas emocionales. OBJETIVO: describir las demandas emocionales y efectos en la salud mental de trabajadores de una institución pública en Chile cuyo trabajo es particularmente demandante en el uso de las emociones. MÉTODO: con un diseño transversal, se aplicó una encuesta al 77% de los funcionarios para analizar las demandas emocionales del trabajo y un screening de distrés y síntomas depresivos. Se describen las prevalencias y las diferencias de éstas en función de algunas dimensiones sociodemográficas y laborales. Posteriormente se analiza la asociación entre la exposición a las demandas emocionales y la chance de presentar síntomas depresivos o distrés elevado. RESULTADOS: las prevalencias encontradas son mayores a las de la población general tanto en el reporte de demandas emocionales del trabajo como en los resultados de salud mental. CONCLUSIÓN: se comprueba la hipótesis de que la índole de la tarea que expone a altas demandas emocionales tiene efectos negativos en la salud mental. Dado lo anterior, la preocupación por la salud mental de personas que se desempeñan en trabajos de esta naturaleza debe ser un tema prioritario y, en consecuencia, se requieren medidas diligentes para prevenir la aparición de problemas de salud mental.(AU)

BACKGROUND: work in services and particularly work that involves assisting persons is characterized by high emotional demands. OBJECTIVE: To describe the emotional demands and effects on the mental health of workers at a public institution in Chile whose work is particularly demanding in the use of emotions. METHOD: In a cross-sectional design, a survey was applied to 77% of the institution's staff. The survey included an emotional demands scale and a screening of distress and depressive symptoms. Prevalences and differences based on several demographic and work-related dimensions were described. The association between exposure to emotional demands and the likelihood of having depressive symptoms or high distress were reported. RESULTS: Higher prevalences were found than those reported in the general population for both the emotional demands of the work and the mental health outcomes reported. CONCLUSION: the hypothesis that the nature of the work that presents high emotional demands has negative effects on mental health. Hence, concerns about the mental health of people who work in these types of jobs should be a priority, and therefore, diligent measures are necessary to prevent the onset of mental health problems in these settings.(AU)

ANTECEDENTES: o trabalho em serviços e especialmente o trabalho que envolve assistência a pessoas caracteriza-se pelas altas demandas emocionais. OBJETIVO: descrever as demandas emocionais e seus efeitos na saúde mental de trabalhadores de uma instituição pública no Chile, cujo trabalho é particularmente intenso no que diz respeito ao emprego das emoções. MÉTODO: com desenho de corte transversal, aplicou-se um questionário a 77% dos funcionários da empresa, visando analisar as demandas emocionais do trabalho, assim como um screening de distress e sintomas depressivos. Descrevem-se as prevalências e as diferenças observadas em função de algumas dimensões sociodemográficas e funcionais. Posteriormente, se analisa a associação entre a exposição às demandas emocionais e a possibilidade de apresentar sintomas depressivos ou distress elevado. RESULTADOS: as prevalências encontradas são mais acentuadas que na população em geral, tanto no que diz respeito às demandas emocionais do trabalho como nos resultados relativos a saúde mental. CONCLUSÃO: corrobora-se a hipótese de que a natureza da tarefa que expõe a elevadas demandas emocionais tem efeitos negativos na saúde mental. Assim, a preocupação pela saúde mental de pessoas que desenvolvem trabalhos dessa natureza deve ser um tema prioritário e, como consequência, requerem-se medidas urgentes para prevenir o surgimento de problemas de saúde mental.(AU)