Invasive electrochemical impedance spectroscopy with phase delay for experimental atherosclerosis phenotyping.

Distinguishing quiescent from rupture-prone atherosclerotic lesions has significant translational and clinical implications. Electrochemical impedance spectroscopy (EIS) characterizes biological tissues by assessing impedance and phase delay responses to alternating current at multiple frequencies. We evaluated invasive 6-point stretchable EIS sensors over a spectrum of experimental atherosclerosis and compared results with intravascular ultrasound (IVUS), molecular positron emission tomography (PET) imaging, and histology. Male New Zealand White rabbits (n = 16) were placed on a high-fat diet, with or without endothelial denudation via balloon injury of the infrarenal abdominal aorta. Rabbits underwent in vivo micro-PET imaging of the abdominal aorta with 68Ga-DOTATATE, 18F-NaF, and 18F-FDG, followed by invasive interrogation via IVUS and EIS. Background signal-corrected values of impedance and phase delay were determined. Abdominal aortic samples were collected for histology. Analyses were performed blindly. EIS impedance was associated with markers of plaque activity including macrophage infiltration (r = .813, p = .008) and macrophage/smooth muscle cell (SMC) ratio (r = .813, p = .026). Moreover, EIS phase delay correlated with anatomic markers of plaque burden, namely intima/media ratio (r = .883, p = .004) and %stenosis (r = .901, p = .002), similar to IVUS. 68Ga-DOTATATE correlated with intimal macrophage infiltration (r = .861, p = .003) and macrophage/SMC ratio (r = .831, p = .021), 18F-NaF with SMC infiltration (r = -.842, p = .018), and 18F-FDG correlated with macrophage/SMC ratio (r = .787, p = .036). EIS with phase delay integrates key atherosclerosis features that otherwise require multiple complementary invasive and non-invasive imaging approaches to capture. These findings indicate the potential of invasive EIS to comprehensively evaluate human coronary artery disease.

Flexible 3-D Electrochemical Impedance Spectroscopy Sensors Incorporating Phase Delay for Comprehensive Characterization of Atherosclerosis.

Background: Distinguishing quiescent from rupture-prone atherosclerotic lesions has significant translational and clinical implications. Electrochemical impedance spectroscopy (EIS) characterizes biological tissues by assessing impedance and phase delay responses to alternating current at multiple frequencies.We evaluated invasive 6-point stretchable EIS sensors over a spectrum of experimental atherosclerosis and compared results with intravascular ultrasound (IVUS), molecular positron emission tomography (PET) imaging, and histology. Methods: Male New Zealand White rabbits (n=16) were placed on a high-fat diet for 4 or 8 weeks, with or without endothelial denudation via balloon injury of the infrarenal abdominal aorta. Rabbits underwent in vivo micro-PET imaging of the abdominal aorta with 68 Ga-DOTATATE, 18 F-NaF, and 18 F-FDG, followed by invasive interrogation via IVUS and EIS. Background signal corrected values of impedance and phase delay were determined. Abdominal aortic samples were collected for histological analyses. Analyses were performed blindly. Results: Phase delay correlated with anatomic markers of plaque burden, namely intima/media ratio (r=0.883 at 1 kHz, P =0.004) and %stenosis (r=0.901 at 0.25 kHz, P =0.002), similar to IVUS. Moreover, impedance was associated with markers of plaque activity including macrophage infiltration (r=0.813 at 10 kHz, P =0.008) and macrophage/smooth muscle cell (SMC) ratio (r=0.813 at 25 kHz, P =0.026). 68 Ga-DOTATATE correlated with intimal macrophage infiltration (r=0.861, P =0.003) and macrophage/SMC ratio (r=0.831, P =0.021), 18 F-NaF with SMC infiltration (r=-0.842, P =0.018), and 18 F-FDG correlated with macrophage/SMC ratio (r=0.787, P =0.036). Conclusions: EIS with phase delay integrates key atherosclerosis features that otherwise require multiple complementary invasive and non-invasive imaging approaches to capture. These findings indicate the potential of invasive EIS as a comprehensive modality for evaluation of human coronary artery disease. HIGHLIGHTS: Electrochemical impedance spectroscopy (EIS) characterizes both anatomic features - via phase delay; and inflammatory activity - via impedance profiles, of underlying atherosclerosis.EIS can serve as an integrated, comprehensive metric for atherosclerosis evaluation by capturing morphological and compositional plaque characteristics that otherwise require multiple imaging modalities to obtain.Translation of these findings from animal models to human coronary artery disease may provide an additional strategy to help guide clinical management.

A self-assembled implantable microtubular pacemaker for wireless cardiac electrotherapy.

The current cardiac pacemakers are battery dependent, and the pacing leads are prone to introduce valve damage and infection, plus a complete pacemaker retrieval is needed for battery replacement. Despite the reported wireless bioelectronics to pace the epicardium, open-chest surgery (thoracotomy) is required to implant the device, and the procedure is invasive, requiring prolonged wound healing and health care burden. We hereby demonstrate a fully biocompatible wireless microelectronics with a self-assembled design that can be rolled into a lightweight microtubular pacemaker for intravascular implantation and pacing. The radio frequency was used to transfer energy to the microtubular pacemaker for electrical stimulation. We show that this pacemaker provides effective pacing to restore cardiac contraction from a nonbeating heart and have the capacity to perform overdrive pacing to augment blood circulation in an anesthetized pig model. Thus, this microtubular pacemaker paves the way for the minimally invasive implantation of leadless and battery-free microelectronics.

Photobiomodulation effects on active brain networks during a spatial memory task.

Photobiomodulation (PBM) or the use of red to near-infrared irradiation spectrum, is a non-invasive intervention that produces neurostimulatory effects and reaches benefits in several pathologies as well as in healthy subjects. The main objective of this study was to evaluate and compare the effects of PBM in a rat brain network on basal state and functional activity during the execution of a reversal task. Twenty-eight rats were divided into four groups: control group (n = 7), control photobiomodulation group (n = 8), behavioural group (n = 6) and behavioural photobiomodulation group (n = 7). Reversal memory was assessed using a Morris water maze and cytochrome c oxidase (CCO) was used as a brain metabolic activity marker. After five days of PBM, the control photobiomodulation group showed a decrease of CCO levels in the striatum, medial septum, entorhinal, hippocampus, amygdala, thalamus, mammillary nuclei and VTA. Both behavioural groups performed the task correctly, however, the behavioural photobiomodulation group displayed CCO reduction in some regions involved in the execution of the reversal task: septum, entorhinal, CA1, CA3, central amygdala and supramammilar, along with higher levels in accumbens. These results could show the effect of PBM on active brain networks. Further studies will be necessary to elucidate its effects in different brain networks that are involved in the execution of other memory tasks.

Photobiomodulation rescues cognitive flexibility in early stressed subjects.

Neglectful parenting is one of the most prevalent forms of child mistreatment. This early life stress leads to long-term alterations in all the psychological domains, as well as brain alterations. Animal models have been developed to emulate and further study this early life stress, and one of most widely used models is maternal separation. In both human and animal models, cognitive flexibility has been found to be altered. In this study, we performed maternal separation (10 days, 4 h per day) in rats, and in adulthood, we tested their spatial navigation and cognitive flexibility. In addition, we delivered photobiomodulation treatment (Low-level light therapy: 1064 nm, 30 mW, 60 cycles) on the rats' brains, and we tested energy oxidative metabolism using cytochrome c oxidase histochemistry. Early life stress delivered in the form of maternal separation on the first 10 postnatal days leads to cognitive flexibility impairment and a general increase in energy metabolism in adulthood. Low-level light therapy seems to be useful for treating these unwanted outcomes, because it rescued cognitive flexibility and returned the oxidative energy metabolism to balanced scores, without harming controls' brains or behavior. Photobiomodulation is a promising tool in the treatment of chronic stress-related consequences because it rescued cognitive flexibility.

Factores de riesgo cardiovascular en adolescentes de una ciudad del Paraguay / Cardiovascular risk factors in adolescents in a city of Paraguay

Resumen Introducción: los factores de riesgo cardiovascular aparecen tempranamente en la niñez y adolescencia. Los principales son: hipertensión arterial, obesidad, la dieta inadecuada, el sedentarismo, el alcoholismo y el tabaquismo. Objetivo: determinar la prevalencia de factores de riesgo cardiovascular en adolescentes del Colegio Nacional de Enseñanza Media Diversificada de Itá (Paraguay) que asistieron al control clínico en meses de marzo y abril del 2015. Metodología: estudio observacional, descriptivo, prospectivo, de corte transversal que incluyó a 132 adolescentes de ambos sexos. Resultados: las prevalencias fueron: hipertensión arterial sistólica 1.5%, sobrepeso 8.3%, obesidad 2.7%, sedentarismo 58.3%, tabaquismo 6.8% y han tomado alcohol ocasionalmente 47.7%. El sobrepeso y la obesidad no mostraron relación estadísticamente significativa con las cifras elevadas de presión arterial. Conclusiones: la prevalencia de hipertensión arterial y exceso de peso encontradas fueron bajas. Llama la atención la alta frecuencia de bajo peso y la tendencia al sedentarismo. Entre los tabaquistas, dos tercios corresponden al sexo femenino.

Abstract Introduction: cardiovascular risk factors appear early in childhood and adolescence. The main ones are: arterial hypertension, obesity, inadequate diet, sedentary lifestyle, alcoholism and smoking. Objective: to determine the prevalence of cardiovascular risk factors in adolescents of the National School of Diversified Middle Education of Itá (Paraguay) who attended clinical control in March and April 2.015. Methodology: observational, descriptive, prospective, cross-sectional study that included 132 adolescents of both sexes. Results: prevalences were: systolic arterial hypertension 1.5%, overweight 8.3%, obesity 2.7%, sedentary lifestyle 58.3%, smoking 6.8% and occasional alcohol consumption 47.7%. Overweight and obesity did not show a statistically significant relationship with high blood pressure. Conclusions: the prevalence of arterial hypertension and excess weight found were low. Draws attention the high frequency of low weight and the tendency to sedentarism. Among smokers, twothirds correspond to women.

Sustained-release Formulation of Mitomycin C to the Upper Urinary Tract Using a Thermosensitive Polymer: A Preclinical Study.

OBJECTIVE: To evaluate the safety and feasibility of single and serial instillations of MitoGel into the upper urinary tract using a preclinical swine animal model. MitoGel is a novel sustained release formulation of mitomycin C (MMC) based on RTGel, a proprietary thermosensitive hydrogel technology. MitoGel is liquid at cold temperatures and solidifies to gel state at body temperature. It is intended as a treatment for upper tract urothelial carcinoma, given its ability to provide sustained release of MMC in the upper urinary tract. MATERIALS AND METHODS: We utilized 23 pigs in a 3-phase design. All animals underwent bilateral nephrostomy tube placement. During phase 1, 3 animals underwent antegrade RTGel instillation, imaging, and euthanasia within 12 hours. In phase 2, 10 pigs underwent single antegrade instillation, unilateral nephrectomy 3 days following instillation, and contralateral nephrectomy and euthanasia 30 days following instillation. During phase 3, 10 animals underwent 6 instillations over 3 weeks, followed by bilateral nephrectomy and necropsy 30 days postinstillation. MitoGel (2 mg/mL and 4 mg/mL), aqueous MMC (2 mg/mL and 4 mg/mL), and RTGel alone were evaluated. RESULTS: MitoGel remained visible within the pelvicalyceal system on fluoroscopic and computed tomography imaging for 4-6 hours. MMC plasma levels were well within acceptable safety thresholds. There was no evidence of urinary obstruction, acute kidney injury, sepsis, or myelosuppression. Histologic changes in the urinary system were mild and transient. CONCLUSION: Antegrade MitoGel delivery to the pelvicalyceal system of Yorkshire swine is feasible and safe. Further evaluation of MitoGel in human clinical trials is warranted.

Grupo psicoeducativo en cuidados paliativos para el paciente cardiópata y su familia / Psychoeducational group in palliative care for cardiac patient and his family

El presente artículo tiene la finalidad de compartir la experiencia que ha tenido la Unidad de Cuidados Integrales Avanzados (UCIA) con la conformación de grupos a los que se les brinda atención psicoeducativa, como parte de los cuidados paliativos ofrecidos por el Instituto Nacional de Cardiología Ignacio Chávez. En la atención directa con los pacientes en situación de terminalidad y su familia se identificaron situaciones que afectan directamente su calidad de vida, razón por la cual se diseñó un programa para realizar intervención psicoeducativa con enfoque biopsicosocial a través de un equipo de salud transdisciplinar con el objetivo principal de ampliar el repertorio de afrontamiento del paciente y del cuidador principal a través de la orientación respecto a la enfermedad, síntomas y cuidados paliativos específicos que puede realizar en el hogar. Dicho programa cuenta con las políticas, normas y lineamientos de operación que considera el contexto actual de los pacientes en situación de terminalidad y de su familia. Se destacan aspectos importantes observados posterior a la psicoeducación tales como: identificación de conductas adaptativas, ampliación del repertorio de afrontamiento, disminución de las consultas en los servicios de urgencias y del número de hospitalizaciones.

This article aims to share the experience of the Comprehensive Care Unit (CCU) with the formation of groups that are given psychoeducational care, as part of the palliative care offered by the National Institute of Cardiology Ignacio Chavez. In direct care with terminally ill patients and their families, situations that directly affect their quality of life were identified, that is why a program was designed to carry out a psychoeducational intervention with a bio-psycho-social approach through a team of transdisciplinary health, with the main objective of expanding the repertoire for coping with the patient and the main caregiver through orientation regarding the illness, symptoms and specific palliative care that can be done at home. This program has the policies, rules and guidelines of operation that considers the current context of terminally ill patients and their family. Important aspects observed after psychoeducation are highlighted such as identification of adaptive behaviors, expansion of coping repertoire, reduction of visits to the emergency services and number of hospitalizations.

Prevalência de tuberculose pulmonar e sintomáticos respiratórios em um hospital psiquiátrico de referência em Alagoas / Prevalence of pulmonary tuberculosis and respiratory symptomatic subjects in a referral psychiatric hospital in Alagoas State / Prevalencia de tuberculosis pulmonar y sintomáticos respiratorios de un hospital psiquiátrico de referencia de Alagoas

Objetivo: Avaliar a prevalência de tuberculose pulmonar (TBP) bacilífera e sintomáticos respiratórios (SR) em um hospital psiquiátrico público de referência em Alagoas, Brasil. Métodos: Pesquisa transversal quantitativa conduzida nas alas de internação do Hospital Escola Portugal Ramalho por meio de questionários contendo dados demográficos, epidemiológicos e sociais, de março a abril de 2013. Grupos estabelecidos: SR, submetidos às coletas para baciloscopia, e assintomáticos (AR). Resultados: Participaram do estudo 143 pacientes, sendo 61,5% (n=88) homens, 51,7% (n=74) adultos jovens, 30,8% (n=44) analfabetos e 41,3% (n=59) com alguma condição debilitante associada. A prevalência de TBP bacilífera encontrada foi de 0,69% (n=1). Os SR representaram 14,7% (n=21) da amostra e foram associados ao grupo de pacientes internados há mais de dois anos e sem perspectiva de alta (p=0,01), e ao hábito de fumar (p=0,02). Conclusão: Encontrou-se nesse grupo uma alta prevalência de TBP bacilífera, se comparada à da população brasileira, sendo os SR associados ao maior tempo de internação hospitalar e ao hábito de fumar.

Objective: To evaluate the prevalence of bacilliferous pulmonary tuberculosis (PTB) and respiratory symptomatic (RS) subjects in a referral public psychiatric hospital in Alagoas, Brazil. Methods: Quantitative cross-sectional research conducted in the hospital wards of Portugal Ramalho Hospital School by means of questionnaire forms addressing demographic, epidemiological and social data, from March to April 2013. Groups established: RS, which underwent sputum collections for bacilloscopy, and asymptomatic subjects (RA). Results: The study included 143 participants, with 61.5% (n=88) males, 51.7% (n=74) young adults, 30.8% (n=44) illiterate and 41.3% (n=59) presenting some debilitating comorbid condition. The prevalence of bacilliferous PTB was found at 0.69% (n=1). RS represented 14.7% (n=21) of the sample and were associated with the group of patients hospitalized for over two years and without prospect of discharge (p=0.01), and to smoking (p=0.02). Conclusion: A high prevalence of bacilliferous PTB was found in this group, compared to that found in the Brazilian population, and RS subjects were associated with longer hospitalization length and smoking.

Objetivo: Evaluar la prevalencia de la tuberculosis pulmonar (TBP) bacilífera y de los sintomáticos respiratorios de un hospital público psiquiátrico de referencia en Alagoas, Brasil. Métodos: Investigación transversal cuantitativa realizada en las alas de internación del Hospital Escuela Portugal Ramalho a través de cuestionarios con datos demográficos, epidemiológicos y sociales entre marzo y abril de 2013. Grupos establecidos: los Sintomáticos Respiratorios (SR), conducidos a realizar la baciloscopia y los asintomáticos respiratorios (AR). Resultados: Participaron del estudio 143 pacientes, el 61,5% (n=88) hombres, el 51,7% (n=74) adultos jóvenes, el 30,8% (n=44) analfabetos y el 41,3% (n=59) con alguna debilidad asociada. La prevalencia de TBP bacilífera encontrada fue del 0,69% (n=1). Los SR representaron el 14,7% (n=21) de la muestra y estuvieron asociados al grupo de pacientes ingresados hacía más de dos años y sin perspectiva de alta hospitalaria (p=0,01) y el hábito de fumar (p=0,02). Conclusión: En este grupo se encontró elevada prevalencia de TBP bacilífera al comparar a la población brasileña y los SR estuvieron asociados al mayor tiempo de ingreso hospitalario y el habito de fumar.

Biomarcadores de la falla cardiaca en pequeños animales / Heart failure biomarkers in small animals

Tradicionalmente, la evaluación de la función cardiaca se realiza mediante el electrocardiografía, radiografía y ecocardiografía para la evaluación de los pacientes con insuficiencia cardiaca, la cual no solo resulta de una sobrecarga de volumen o presión, o de lesiones estructurales, sino también de una compleja interacción entre genética, inflamación, factores neurohormonales y bioquímicos que actúan en los miocitos cardiacos, el intersticio cardiaco o ambos. Un aumento del número de enzimas, hormonas, sustancias biológicas y otros marcadores de esfuerzo cardiaco y mal funcionamiento, así como lesiones de los miocitos pueden ser medidos en sangre y son denominados colectivamente como biomarcadores, los cuales son de importancia clínica. Esta revisión se centra en los biomarcadores derivados de la sangre o la orina que no sean los niveles séricos de hemoglobina, electrolitos, enzimas hepáticas y creatinina, que se determinarán como parte rutinaria de la atención clínica para el diagnóstico de las enfermedades cardiacas en pequeños animales...

Traditionally, the evaluation of cardiac function is performed by electrocardiography, radiographyand echocardiography for the assessment of patients with heart failure, which resultsnot only from a volume or pressure overload, or from structural damage, but also from a complexinteraction between genetics, inflammation, neurohormonal and biochemical factorsacting on cardiac myocytes, cardiac interstitium or both. An increased number of enzymes,hormones, biological substances and other cardiac stress and malfunction markers, as wellas myocyte damage can be measured in blood and are collectively referred to as biomarkers,which are clinically important. This review focused on biomarkers derived from blood orurine that are not the serum levels of hemoglobin, electrolytes, liver enzymes and creatinine,to be established as a routine part of clinical care for the diagnosis of heart diseases in smallanimals...

Tradicionalmente, a avaliação da função cardíaca é realizada mediante a electrocardiografia,radiografia e eco-cardiografia para a avaliação dos pacientes com insuficiência cardíaca,quando não é apenas o resultado de uma sobrecarga de volume ou pressão, ou de lesõesestruturais, mas também de uma complexa interação entre genética, inflamação, fatoresneuro-hormonais e bioquímicos que atuam nos miócitos cardíacos, o interstício cardíacoou ambos. Um aumento do número de enzimas, hormônios, substâncias biológicas e outrosmarcadores de esforço cardíaco e mal-funcionamento, bem como lesões dos miócitos podemser medidos no sangue e são denominados coletivamente como biomarcadores, os quais sãode importância clínica. Esta revisão se centra nos biomarcadores derivados do sangue ou daurina que não sejam os níveis séricos de hemoglobina, eletrólitos, enzimas hepáticas e creatina,que se determinarão como parte rotineira do atendimento clínica para o diagnóstico dasdoenças cardíacas em animais pequenos...

Why are men more likely to support group-based dominance than women? The mediating role of gender identification.

Arguing from a sociobiological perspective, Sidanius and Pratto (1999) have shown that the male/female difference in social dominance orientation (SDO) is largely invariant across cultural, situational and contextual boundaries. The main objective of this study was to test the validity of Social Dominance Theory (SDT) by contrasting it with a model derived from Social Identity Theory (SIT). More specifically, while SIT predicts that gender identification mediates the effect of gender on SDO, SDT predicts the reverse. According to SDT, the degree to which men and women endorse status legitimizing ideology should determine to what extent they identify with their gender group. Using structural equation modelling, the results provide strong support for the SIT model and no support for SDT predictions. Implications of these results for social dominance theory and its sociobiologically based invariance hypothesis are discussed.

Avaliação clínica da tolerância ao exercício e das trocas gasosas pulmonares nas denças intersticiais fibrosantes / Gas exchange and cardiopulmonary responses to a 6 minute step test in patients with pulmonary fibrosis: comparison with cycle ergometry in isometric conditions

As doenças pulmonares intersticiais (DPIj constituem grupo heterogéneo de condições, classificadas pelas características clínicas, radiológicas, histopatológicas e prognósticas distintas. As alterações funcionais são caracterizadas por distúrbio ventilatório restritivo, com redução dos volumes pulmonares associados à baixa complacência pulmonar, queda da capacidade de difusão pulmonar ao monóxido de carbono e hipoxemia arterial no exercício. O teste do degrau é usado para avaliar a capacidade funcional de pacientes em diferentes doenças. Entretanto, pouco se conhece sobre a demanda cardiorrespiratória e de trocas gasosas quando comparados os teste do degrau e cicloergômetro em pacientes com DPI. OBJETIVO: Avaliar, em condições isometabólicas, as variáveis ventilatórias, de trocas gasosas e cardiovasculares obtidas no teste do degrau de 6 minutos e no teste submáximo em cicloergômetro, em pacientes com DPI. MÉTODO: Estudo prospectivo com 31 pacientes com fibrose pulmonar idiopática e pneumonite por hipersensibilidade crõnica, que realizaram avaliação de um índice de dispnéia, volumes pulmonares estáticos, capacidade de difusão, teste de exercício cardiorrespiratório(TECR), testes do degrau de 6 minutos(TD6), TEOR com carga fixa em cicloergômetro(cicio) e gasometria arterial de repouso exercício subrnáximo no cicloergômetro. RESULTADOS: De um grupo de 30 pacientes que realizou a avaliação da capacidade de difusão pulmonar para o monóxido de carbono (Dco), 27 (90 por cento) apresentaram valores abaixo do limite inferior da normalidade e 17 (57 por cento) tiveram Dco < 50 por cento do previsto brasileiro. As variáveis metabólicas VCO2 e R foram mais elevadas no cicloergômetro em relação ao degrau (p < 0,05), com resposta ventilatória também mais elevada (VE e VE/VC02). Desta forma, a maior resposta ventilatória no cicloergômetro deveu-se não somente a um VC02 mais elevado, mas também a um excesso ventilatório em relação à liberação pulmonar de C02 (maior VE/VC02)...

Does social dominance generate prejudice? Integrating individual and contextual determinants of intergroup cognitions.

Social dominance orientation (SDO) has been proposed as an important variable in the explanation of prejudice. We distinguish between three conceptualizations of SDO: SDO as a personality trait (personality model), SDO as a moderator of the effects of situational variables (Person x Situation model), and SDO as a mediator of the effect of social position on prejudice (group socialization model [GSM]). Four studies (N = 1.657) looking at the relations between social positions, SDO, and prejudice in a natural setting and in a laboratory setting provide strong support for the GSM. In contrast to previous correlational findings, there is evidence of a cause (dominant social position), an effect (prejudice increases), and a mediator (SDO). These results suggest new perspectives on the integration of individual and contextual determinants of prejudice.

Infantile osteopetrosis: a case report with osteomyelitis of the maxilla.

A case of a pediatric patient diagnosed with osteopetrosis complicated by osteomyelitis in the maxilla is presented. The combined medical-surgical treatment for this type of patient is discussed.

Hiponatremia grave por tiazidas: comunicación de un caso / Severe hyponatremia due to tiazidas

La hiponatremia es un disturbio hidroelectrolítico frecuente entre pacientes internados; y su presencia está asociada a un incremento en la mortalidad. Las tiazidas, que son drogas ampliamente usadas en el tratamiento de la hipertensión arterial, son una causa infrecuente de hiponatremia severa. El caso presentado ejemplifica una hiponatremia euvolémica grave, donde se establecen llaves diagnosticas para dilucidar la causa del estado hiponatrémico