Manganese-rhodium nanoparticles: Adsorption on titanium oxide surfaces and catalyst for syngas reactions.

Manganese-rhodium (Mn-Rh) nanoparticles have emerged as a promising candidate for catalytic applications in the production of syngas, a critical precursor for a wide range of industrial processes. This study employs a comprehensive, theoretical, and computational approach to investigate the structural and electronic properties of Mn-Rh nanoparticles, with a specific focus on their interaction with titanium oxide (TiO2) surfaces and their potential as catalysts for syngas reactions. The density functional theory calculations are employed to explore the adsorption behavior of Mn-Rh nanoparticles on TiO2 surfaces. By analyzing the adsorption energies, geometries, and electronic structure at the nanoscale interface, we provide valuable insights into the stability and reactivity of Mn-Rh nanoparticles when immobilized on TiO2 supports. Furthermore, the catalytic performance of Mn-Rh nanoparticles in syngas production is thoroughly examined. Through detailed reaction mechanism studies and kinetic analysis, we elucidate the role of Mn and Rh in promoting syngas generation via carbon dioxide reforming and partial oxidation reactions. The findings demonstrate the potential of Mn-Rh nanoparticles as efficient catalysts for these crucial syngas reactions. This research work not only enhances our understanding of the fundamental properties of Mn-Rh nanoparticles but also highlights their application as catalysts for sustainable and industrially significant syngas production.

Radiological environmental monitoring of groundwater around NPP: A proposal for its assessment.

Whether a nuclear installation has radiological impact and, in that case, its extension, are the questions behind any environmental analysis of the installation along its operational life. This analysis is based on the detailed establishment of the radiological background of the area. Accordingly, the dismantling and decommissioning process (D&D) of a nuclear power plant starts with a radiological monitoring plan, which includes the radiological characterization of the area and of its surroundings. At the completion of the D&D, unrestricted use for the site will be permitted strictly in accordance with results of the radiological survey within the limits established by the local authorities. Groundwater quality is typically included in any radiological analysis since, among other reasons, a significant part of it is highly likely to end up being extracted for domestic use and hence, human consumption. While there is no regulation containing maximum activity concentration or radionuclide guidance values for water that may be destined for uses other than public consumption, if groundwater is considered a "part" of the land, dose criteria for site release can be applied. Therefore, together with the guidance levels to be established for the different radionuclides expected in the groundwater, the detection limits to be employed when performing routine radio analytical characterization procedures in the laboratory should also be provided. In this paper, we first propose a relation of the potential radionuclides to be analyzed in groundwater, together with their detection limits to be achieved when the determinations are performed in a laboratory, and subsequently, we discuss the most suitable analytical methodologies and resources that would be necessary to undertake radiological characterization plans from a practical point of view.

Análisis de factores de riesgo cardiometabólicos y nutricionales en pacientes diabéticos tipo 2 e hipertensos esenciales usuarios de atención privada y pública / Analysis of cardiometabolic and nutritional risk factors in patients with diabetes type 2 and essential hypertension users of private and public care

La enfermedad cardiovascular es una de las principales causas de morbimortalidad en Chile, según resultados entregados por la Encuesta Nacional de Salud 2017 un 3,3% de la población ha presentado un infarto agudo al miocardio, un 2,6% reporta haber sufrido un ataque cerebrovascular, el 74% de los chilenos presenta obesidad y un 87% sedentarismo, siendo la diabetes mellitus tipo 2 (DM2) con un 12% y la hipertensión arterial con un 28% resultados que preocupan por su importante incremento. La investigación tuvo un diseño observacional de corte transversal. Se realizó en 69 pacientes con DM2 e hipertensos esenciales, entre 40 y 80 años de edad, pertenecientes al Sistema salud municipal (SMS) y privado (SPS) en la ciudad de Iquique. Se realizó encuesta alimentaria, medición antropométrica y exámenes bioquímicos y presión arterial. Al analizar ambos grupos se destaca los siguientes resultados: actividad física 17,24% SPS y 42,5% en SSM, presión arterial controlada 55,2% SPS y 87,5% en SSM, control de hemoglobina glicosilada 26,9% SPS y 52,5% en SSM, colesterol total alterado 17,9% SPS y 45% en SSM, síntomas depresivos 96,5% SPS y 26,3% en SSM. Se evidenció una prevalencia de mal nutrición por exceso de un 89,7% SPS y 95% SSM, riesgo cardiovascular (RCV) según circunferencia de cintura (CC) 96,5% SPS y 92,3% SSM. En relación a la encuesta alimentaria se observó que un 44,8% en usuarios SPS y 52,5% de SSM presentaron consumo alimentario hipercalórico. Los usuarios de atención privada y pública presentaron factores de riesgo cardiovascular, donde destacan la obesidad, sedentarismo y RCV según CC. Al comparar ambos grupos los usuarios SPS presentan menor control metabólico de su enfermedad y factores de riesgo cardiovascular aumentados en relación a los usuarios SSM.

Cardiovascular disease is one of the main causes of morbidity and mortality in Chile, according to the results provided by the 2017 National Health Survey, 3.3% of the population has presented acute myocardial infarction, 2.6% reported have suffered a cerebrovascular accident, 74% of Chileans are obese and 87% have sedentary behavior, belonging to type 2 diabetes mellitus (DM2) into 12% and arterial hypertension into 28%, alarming results due to their significant increase. The research had a cross-sectional observational study design. 69 patients with DM2 and essential hypertensive patients, between 40 and 80 years of age were studied, belonging to the municipal (SSM) and private (SPS) health systems in the city of Iquique. A food intake survey, anthropometric measurements, and biochemical and blood pressure tests were taken. When analyzing both groups, the following results stand out: physical activity 17.24% in SPS and 42.5% in SSM, controlled blood pressure 55.2% in SPS and 87.5% in SSM, controlled glycosylated hemoglobin 26.9% in SPS and 52.5% in SSM, altered values of total cholesterol 17.9% in SPS and 45% in SSM, depression symptoms 96.5% in SPS and 26.3% in SSM. Prevalence of malnutrition due to excess 89.7% in SPS and 95% in SSM, cardiovascular risk (RCV) according to waist circumference (CC) 96.5% in SPS and 92.3% in SSM were evidenced. In relation to the food intake survey, it was observed that 44.8% of SPS users and 52.5% of SSM users consume hypercaloric diet. The users of private and public care presented cardiovascular risk factors, where the obesity, sedentary lifestyle and RCV related to CC stand out. When comparing both groups, SPS users have less control of their disease in relation to SSM users.

Uncertainty and detection limits of 241Pu determination by liquid scintillation counting (LSC).

Determination of 241Pu is an essential issue for radiation protection, as it is the precursor of some nuclides with high radiotoxicity. 241Pu is a low energy beta emitter, which makes its measurement more challenging than that of Pu alpha emitters. The most widely used method for the measurement of 241Pu is liquid scintillation counting (LSC). In this method, the assessment of Pu radiochemical yield is done by measuring the sample by alpha spectrometry before being lixiviated and measured by LSC. This double measurement affects uncertainty analysis, as well as decision threshold and detection limit, considering that both components of the total yield (radiochemical and lixiviation) should be contemplated. In this paper, and for quality assurance (QA) purposes, in-depth uncertainty and detection limit formulae for the proposed method, controlling correlations and considering all the parameters involved including chemical and lixiviation yields, have been developed. A sensitivity analysis of the uncertainty budget together with an assessment of 242Pu tracer quantity to be used, ensuring a total yield of at least 50% and a relative uncertainty of the leaching yield of at most 5%, have been carried out. In addition, an analysis of the impact of the real lixiviation yield value and its uncertainty on the results has been done. As a general conclusion, and considering the values of the parameters chosen for this work (samples of 1 g measured for 24 h by LSC), the 241Pu uncertainties range from 5% to 30% depending on the activity concentration values and the detection limits range from 14 to 30 Bq kg-1, depending on yield values. The main components of the uncertainty budget are the net 241Pu and background counts obtained in the LSC measurement for low contaminated samples while this is the case for the alpha gross count rate in LSC measurement of the alpha calibration source for highly contaminated samples. In addition, an analysis of possible interference by Pu alpha emitters in the 241Pu signal and a comparison of quench standard curves of 3H and 241Pu are also performed.

Analysis of the use of the IAEA rapid method of 89Sr and 90Sr in milk for environmental monitoring.

Rapid methods that are used during nuclear accidents or incident situations must first be implemented and validated in radioactivity measurement laboratories, so they can be ready to provide quick answers to governments, regulatory organizations and people in such situations. As these accident situations are rare and the methods are thus not frequently used, the best way to achieve this is to use the same methods for both routine environmental monitoring and rapid or emergency situations. Before this can be done, however, an analysis of the conditions under which a rapid method could be effectively used in routine situations should be carried out. This work analyses the performance of the rapid method for the simultaneous determination of 89Sr and 90Sr in milk, published by the IAEA, and compares it with another, more conventional method used for routine environmental purposes. Through numerical calculations and considering different 89Sr and 90Sr activities, we also conducted a study to obtain the optimum values for determination parameters - such as sample mass, counting times, time lapse between measurements and background counting times - that will allow the use of the IAEA rapid method as a routine environmental one.

Radiological characterisation and radon equilibrium factor in the outdoor air of a post-industrial urban area.

The radiological characterisation of outdoor air is always a complicated task due to the several radioactive emissions coming from the different radionuclides and also because of the very short half-lives of radionuclides in the natural radioactive series. In some places, this characterisation could result in unusual values because the natural presence of radionuclides with terrestrial origin can be modified by manmade activities. Nonetheless, this characterisation is useful not only for air quality control purposes but also because radon and its progeny in the outdoor air are the main contributors to human exposure from natural sources. In this study, we have carried out air particle sampling, followed by gamma-ray spectrometry, alpha spectrometry and beta counting determinations for this purpose. Subsequently, the outdoor air has been radiologically characterised through the obtained data and using a pre-existing analytical method to take into account the radioactive decays of short half-life radionuclides during sampling, sample preparation and measuring times. Bilbao was chosen to carry out this work. It is a medium-sized town located in northern Spain, close to the Atlantic Ocean and at sea level. This city has a recent industrial past as there were numerous steel mills and other heavy industries, including some quarries, and some open pit mines close to it, which concluded in a remediation program. So, it is a place where the air is potentially modified by manmade activities. The obtained results show that activity concentration values for long-lived radionuclides that precede radon and thoron are in the order of 10(-6) Bq m(-3) and long-lived ones after radon are around 10(-4) Bq m(-3). Thoron progeny are around 2 × 10(-2) Bq m(-3) and radon progeny are around 1.8 Bq m(-3). The mean radon equilibrium factor was 0.18. All of these values are close to the minimum UNSCEAR values, but show some variability, which highlights the importance of determining activity concentrations for each naturally occurring radionuclide and the equilibrium factor in the outdoor air.

Effective dose in SMAW and FCAW welding processes using rutile consumables.

The shielded metal arc welding (SMAW) and flux cored arc welding (FCAW) processes use covered electrodes and flux cored wire as consumables. Among these consumables, ones containing rutile are the most widely used, and since they have a considerable natural radioactive content, they can be considered as NORM (naturally occurring radioactive material). To calculate the effective dose on workers during their use in a conservative situation, samples of slag and aerosols and particles emitted or deposited during welding were taken and measured by gamma, alpha and beta spectrometry. An analytical method was also developed for estimating the activity concentration of radionuclides in the inhaled air. (222)Rn activity concentration was also assessed. With all these data, internal and external doses were calculated. The results show that external doses are negligible in comparison with internal ones, which do not exceed 1 mSv yr(-1), either in this conservative situation or in any other more favourable one. Radionuclides after Rn in the radioactive natural series are emitted at the same activity concentration to the atmosphere, this being around 17 times higher than that corresponding to radionuclides before Rn. Taking into account these conclusions and the analytical method developed, it can be concluded that one way to assess the activity concentration of natural radionuclides in inhaled air and hence effective doses could be the early gamma-ray spectrometry of aerosols and particles sampled during the welding process.

Effective dose in the manufacturing process of rutile covered welding electrodes.

Shielded metal arc welding using covered electrodes is the most common welding process. Sometimes the covering contains naturally occurring radioactive materials (NORMs). In Spain the most used electrodes are those covered with rutile mixed with other materials. Rutile contains some detectable natural radionuclides, so it can be considered a NORM. This paper mainly focuses on the use of MCNP (Monte Carlo N-Particle Transport Code) as a predictive tool to obtain doses in a factory which produces this type of electrode and assess the radiological impact in a specific facility after estimating the internal dose.To do this, in the facility, areas of highest radiation and positions of workers were identified, radioactive content of rutile and rutile covered electrodes was measured, and, considering a worst possible scenario, external dose at working points has been calculated using MCNP. This procedure has been validated comparing the results obtained with those from a pressurised ionisation chamber and TLD dosimeters. The internal dose has been calculated using DCAL (dose and risk calculation). The doses range between 8.8 and 394 µSv yr(-1), always lower than the effective dose limit for the public, 1 mSv yr(-1). The highest dose corresponds to the mixing area.

Trasplante pulmonar con donantes de edad marginal (≥ 55 años) / No disponible

Objetivo: Analizar la supervivencia a corto (un mes), medio (un año) y largo plazo (cinco años)en todos los pacientes sometidos a un trasplante pulmonar (TP) cuyo donante tuviera al menos 55 años.Pacientes y métodos: Se incluyó a todos los pacientes sometidos a un TP cuyo donante tuviera55 años o más. Se analizó la asociación de las diferentes variables estudiadas con la mortalidad precoz, anual y al quinto año. Se utilizó la regresión logística en el estudio de factores de riesgo para mortalidad precoz y se utilizó la regresión de riesgos proporcionales de Cox en el estudio de factores de riesgo para la mortalidad al año y al quinto año, introduciendo las variables con un valor de p < 0,2 en el análisis bivariante. Se efectuó un análisis de supervivencia mediante el método de Kaplan-Meier.Resultados: Se analizó un total de 33 pacientes sometidos a un TP con donantes de 55 años omás. La probabilidad de supervivencia fue del 90,9, el 78,5 y el 44,8% al mes, año y cinco años respectivamente. La edad elevada del receptor (p = 0,16) y la realización de un trasplante unipulmonar(p = 0,09) fueron las variables que se asociaron o mostraron tendencia a la asociación con la mortalidad.Conclusiones: La decisión final en la aceptación de un injerto pulmonar se debe basar en la evaluación individual de cada donante y receptor. Sin embargo, dada la escasez de injertos pulmonares, parece adecuado considerar de inicio para la donación pulmonar a los pacientes de 55 o más años (AU)

[Lung transplantation using donors 55 years and older]. / Trasplante pulmonar con donantes de edad marginal (≥ 55 años).

OBJECTIVE: We analyzed short, medium and long-term mortality in transplant recipients who received lungs from donors aged 55 years or more. PATIENTS AND METHODS: All patients who underwent lung transplantation from donors aged 55 years or more were included. The association between the different study variables and early death and death at 1 year and 5 years was studied. A logistic regression model was used to study the association between early death and variables with a trend towards significance (P<.2) in the bivariate analysis. The risk factors for mortality at 1 year and 5 years were analyzed with a Cox regression model. The Kaplan-Meier method was used to analyze survival. RESULTS: A total of 33 patients were included. The probability of survival was 90.9%, 78.5% and 44.8% at 1 month, 1 year, and 5 years after lung transplantation, respectively. The elevated age of the recipient (P=.16) and single-lung transplantation (P=.09) were the variables associated to or with a trend towards significant associations with mortality. CONCLUSIONS: The final decision to accept a lung graft should be based on individual evaluation of each donor and recipient. However, given the lack of lung donors, donors aged 55 years or more should be considered for lung transplantation.

Trastorno de juego por internet: ¿una nueva entidad nosológica? / Internet game disorder: a new nosological entity?

En los últimos 20, años el problema de la adicción a nuevas tecnologías ha suscitado controversias y ha generado un importante debate internacional. El DSM-5 incorpora en la sección de "Condiciones para un mayor estudio", el Trastorno de Juego por Internet. El ojetivo de este trabajo es revisar la literatura científica actual sobre el Trastorno de Juego por Internet y explorar si la evidencia disponible permite respaldar este diagnóstico como una nueva entidad nosológica. Se realiza una revisión del contexto en que surge esta propuesta, los criterios diagnósticos, las controversias y se discute la relevancia de la validez y confiabilidad de los diagnósticos en psiquiatría.

In the last 20 years, the problem of addiction to new technologies has generated controversy and an important international debate. The DSM-5 incorporates in section of "Conditions for a further study", the Internet Gaming Disorder. The aim of this article is review the current scientific literature about Internet Gaming Disorder, and to explore if the available evidence let it support this diagnosis as a new nosological entity. A brief review of the context in which this proposal emerges, the diagnostic criteria, and the controversies was performed; also, it was discussed the relevance of the validity and reliability of the diagnoses in psychiatry

Prevalence and management of gastrointestinal complications in lung transplant patients: MITOS study group.

INTRODUCTION: No studies have yet been performed to evaluate the prevalence of gastrointestinal (GI) complications in solid organ transplant recipients in Spain. MATERIALS AND METHODS: An observational, cross-sectional study to evaluate the prevalence and management of GI complications in transplanted patients was conducted via a written questionnaire given to doctors at their practice. RESULTS: A total of 58 lung transplant recipients were included. Their mean age was 52.6 +/- 10.8 years; 65% of the patients were men; and the mean time since the transplant was 2.1 +/- 2.3 years. GI complications were seen in 48.6% of the lung transplant patients. Regarding the management, the most frequently used measure was the prescription of gastric protectors (70.5%). In seven patients, the immunosuppressive treatment was also modified (reduced, discontinued temporarily, or discontinued permanently); however, the figure is so low that no conclusions can be drawn from this result. CONCLUSIONS: The prevalence of GI complications in lung transplant was over 50%, and these complications affected patients' daily activities in most cases. In lung transplant recipients, there was a higher prevalence of nausea and abdominal pain and a lower of diarrhea and dyspepsia than what was observed in other type of transplant recipients.

[Hormone expression and opioid receptors in fetal and adult lung]. / Expresión hormonal y de receptores opioides en pulmón fetal y del adulto.

OBJECTIVES: To describe the cellular distribution and level of expression of certain hormones and opioid receptors during fetal development and in the lung of the healthy adult. METHOD: We sampled lung tissue from fetuses at three stages of development (pseudoglandular, canalicular and saccular) (3 samples per stage), from newborn infants (3), from 10-month-old infants (2) and from adults (3) who had died without lung disease. After specific immunohistochemical staining for hormones (calcitonin, parathormone, serotonin and adrenocorticotropic hormone - ACTH) and opioid receptors, we assessed the percentage of positive cells for each cell type in each sample. RESULTS: Serotonin is the first to appear (pseudoglandular stage in isolated neuroendocrine cells) and it disappears later. Calcitonin appears in the canalicular stage in neuroendocrine and lung cells. Expression is at its peak at birth and is less in the adult lung. We found no ACTH or parathormone production. Opioid receptors appear in the canalicular stage and peak at birth. In adult lung, bronchiolar muscle and mesothelial cells, only delta-type opioid receptors are present. CONCLUSIONS: Pulmonary hormone secretion is significant during fetal development and peaks at birth. Calcitonin is the main hormone produced in the fetal lung. Opioid receptors are present during fetal development in various types of cells and peak at birth. An understanding of the expression of active substances could have therapeutic relevance in certain conditions, such as bronchial asthma or respiratory distress syndrome in the child.

Expresión hormonal y de receptores opioides en pulmón fetal y del adulto / Hormone expression and opioid receptors in fetal and adult lung

OBJETIVOS: Describir la distribución celular y el grado de expresión de diversas hormonas y receptores de opioides en el desarrollo embrionario y en el pulmón sano del adulto. MÉTODO: Seleccionamos tejido pulmonar de las tres etapas del desarrollo fetal (seudoglandular, canalicular y sacular, tres muestras por etapa), de recién nacidos (tres), niños de 10 meses (dos) y adultos (tres) fallecidos sin afección pulmonar. Practicamos tinción inmunohistoquímica para hormonas específicas (calcitonina, parathormona, serotonina y hormona adrenocorticotropa [ACTH]) y receptores de opioides tipo delta y mu. Valoramos el porcentaje de células positivas así como el tipo celular reactivo en cada caso. RESULTADOS: La serotonina es la primera en aparecer (estadio seudoglandular en células neuroendocrinas aisladas) para posteriormente desaparecer. La calcitonina aparece en el estadio canalicular en células neuroendocrinas y neumocitos. Su expresión máxima es al nacimiento y disminuye en el pulmón adulto. No hemos encontrado producción de ACTH ni de parathormona. Los receptores de opioides aparecen en la fase canalicular y alcanzan el máximo grado en el nacimiento. En el adulto sólo existen receptores para opioides tipo delta en neumocitos, células musculares bronquiolares y mesoteliales. CONCLUSIONES: La hormonosecreción pulmonar es importante durante el desarrollo fetal y alcanza su máxima expresión en el nacimiento. La principal hormona que produce el pulmón fetal es la calcitonina. Existen receptores opioides durante el desarrollo fetal en diferentes tipos celulares y alcanzan su máxima expresión al nacimiento. El conocimiento de la expresión de sustancias activas podría tener consecuencias terapéuticas en determinados procesos patológicos como el síndrome de distrés respiratorio en el niño o el asma bronquial (AU)

Escombrointoxicación por consumo de bonito / Mackerel poisoning (Scomber intoxication) due to ingestion

La escombrointoxicación es un cuadro clínico consistente en náuseas, vómitos, diarrea, abdominalgia, quemazón oral, urticaria, eritema facial, cefalea, palpitaciones, hipotensión arterial y, excepcionalmente, distrés respiratorio y shock. Estas manifestaciones aparecen desde pocos minutos a horas tras la ingesta de pescado de la familia de los escómbridos (atún, bonito, caballa...), que no ha sido mantenido en óptimas condiciones de conservación, dando lugar a la proliferación de enterobacterias que transforman la histidina del músculo del pescado en histamina, sustancia responsable del cuadro. El diagnóstico de confirmación precisa determinar la concentración de histamina en las muestras del pescado sospechoso, pudiendo también realizarse en la orina y sangre de los pacientes. Es importante establecer un diagnóstico diferencial con una reacción alérgica alimentaria e identificar precozmente la fuente de intoxicación. El tratamiento básico consiste en antihistamínicos H1 y H2. Está por clarificar la eficacia de los corticoides. Presentamos cinco casos que atendimos recientemente (AU)

[The validation of a portable 3-channel recording system (Oxyflow, Edentec) for the diagnosis of the sleep apnea syndrome]. / Validación de un sistema portátil de registro de tres canales (Oxyflow, Edentec) para el diagnóstico del síndrome de apnea del sueño.

OBJECTIVE: To evaluate the usefulness of a portable recording device (Oxyflow, EdenTec) to measure oronasal airflow, oxygen saturation and arterial pulse for diagnosing sleep apnea syndrome (SAS) using conventional polysomnography as the gold standard. METHODS: Sixty-two subjects suspected of having SAS were studied prospectively by simultaneously recording conventional polysomnography and Oxyflow data in the sleep laboratory. Two different investigators, blinded to each other's findings, interpreted the data from each method. The apnea-hypopnea index (AHI) cut-off points used were?? 10, 15 and 30. The sensitivity, specificity, positive predictive value and negative predictive value of the Oxyflow indices for each AHI cut-off point were calculated. Both computer-generated and manually collected data from the Oxyflow device were analyzed. Manual readings were recorded by two independent investigators and interobserver agreement was calculated. The usefulness of both automatic and manual analyses for SAS diagnosis was assessed using receiver operating characteristic curves (ROC). RESULTS: Fifty-eight (93.5%) men and 4 (6.5%) women with a mean age (+/- SD) of 53 +/- 11 years (29-73) were enrolled. An AHI > or = 10 was observed in 58% of the patients and mean AHI was 25 +/- 28 (0-125). The index of respiratory disturbance per hour of analysis with desaturation events > or = 4% (RDI4%) was the parameter with the largest area under the ROC curve (0.90 for AHI > or = 10; 0.94 for AHI > or = 15 and 0.96 for AHI > or 30). Manual reading was practical and reproducible (agreement 0.93, kappa coefficient 0.82) but its efficiency was no greater than that of automatic analysis. CONCLUSIONS: The Oxyflow device may be a useful diagnostic tool for SAS. Its portability and simplicity makes it potentially useful for in-home studies.

Validación de un sistema portátil de registro de tres canales (Oxyflow, Edentec) para el diagnóstico del síndrome de apnea del sueño / Validation of a portable three-channel recording system (Oxyflow, EdenTec) for diagnosing sleep apnea syndrome

Objetivo: Evaluar la utilidad de un sistema de registro portátil (Oxyflow, Edentec), que mide flujo nasobucal, saturación de oxígeno y pulso arterial, para el diagnóstico del síndrome de apnea del sueño (SAS), utilizando la polisomnografía convencional como patrón de referencia. Métodos: Se estudiaron prospectivamente 62 sujetos con sospecha de SAS, realizándose simultáneamente polisomnografía convencional y registro con Oxyflow en el laboratorio de sueño. Dos investigadores diferentes interpretaron los registros de cada uno de los métodos, a ciegas respecto al otro. Se utilizaron diferentes puntos de corte para el índice de apneas-hipopneas (IAH) (>= 10, 15 y 30). Se calcularon la sensibilidad, especificidad, valor predictivo positivo y valor predicto negativo de los índices del Oxyflow para cada punto de corte del IAH. Al analizar los registros del Oxyflow, se emplearon tanto datos generados por el software incluido en el sistema como los obtenidos con una interpretación manual de los mismos. El análisis manual fue realizado por dos investigadores independientes, y se calculó la concordancia interobservador. La utilidad del análisis manual y el automático para el diagnóstico del SAS fue evaluado usando curvas receptor-operador (ROC). Resultados: Se incluyeron en el estudio 58 varones (93,5 por ciento) y 4 mujeres (6,5 por ciento), con una edad media (ñ DE) de 53 ñ 11 años (29-73). El 58 por ciento de los pacientes tenían un IAH >= 10 (IAH medio: 25 ñ 28 [0-125]). De todos los parámetros analizados, el RDI4 por ciento (índice de episodios respiratorios por hora de registro, con desaturaciones >= 4 por ciento) presentó el mayor área bajo la curva ROC (0,90 para IAH >= 10; 0,94 para IAH >= 15 y 0,96 para IAH >= 30). El análisis manual fue factible y reproducible (concordancia: 0,93; coeficiente kappa: 0,82), pero su eficiencia no fue mayor que la del análisis automático. Conclusiones: El sistema Oxyflow puede ser una herramienta útil para el diagnóstico del SAS. Su portabilidad y simplicidad lo hacen potencialmente útil para estudios domiciliarios. (AU)

[The characteristics of patients who have died from tuberculosis]. / Características de los pacientes fallecidos por tuberculosis.

OBJECTIVE: To analyze the characteristics of the patients died from tuberculosis (TB) in our hospital. METHOD: We retrospectively reviewed the records of the 46 patients died in-hospital from TB between january, 1992 and june, 1997. MEAN AGE: 55 +/- 19 years (19-85). 35 (76%) males and 11 (24%) females. DIAGNOSIS: pulmonary (63%), disseminated (26%) and extrapulmonary (11%) TB. 87% of the patients had previous comorbidity (35% were seropositive for HIV). The only differences between HIV-infected and non-HIV-infected cases were a greater proportion of normal chest roentgenograms and of toxicity from therapy in seropositive patients. The disease was diagnosed at death in 17% of cases. Chemoprophylaxis had not been used in 5 patients, although they fulfilled criteria for receiving it. Poor compliance with treatment was noted in 6 (13%) patients. CONCLUSIONS: We have found a high prevalence of comorbidity in these patients, which might account for the mortality. Delays in diagnosis, misuse of chemoprophylaxis and poor compliance with therapy might also be implicated in some cases.

[Varicella pneumonia in the previously healthy adult]. / Neumonía varicelosa en el adulto previamente sano.

Varicella (chickenpox) is a contagious, self-limited, usually benign disease common in childhood but uncommon in adulthood. Pneumonia is the most frequent complication of the disease in adults. We retrospectively review 7 cases of varicella pneumonia in previously healthy adults diagnosed in our hospital between 1992 and 1996. All of them were treated with intravenous acyclovir with good therapeutic response save for a patient who developed respiratory insufficiency and died 8 days after his admission. Smoking was the only risk factor detected. Clinical features of our patients are described and the need of an early diagnosis and treatment of varicella pneumonia is emphasized.

Neumonía varicelosa en el adulto previamente sano / Varicella penumonia in the previously healthy adult

La varicela es una enfermedad contagiosa autolimitada y generalmente benigna propia de la infancia, y poco común en el adulto. La neumonía es la complicación mas frecuente de la enfermedad en el adulto. Revisamos retrospectivamente 7 casos de neumonía varicelosa en adultos previamente sanos diagnosticados en nuestro hospital entre 1992 y 1996. Todos ellos fueron tratados con Aciclovir endovenoso, presentando buena evolución salvo un paciente que desarrolló insuficiencia respiratoria y falleció 8 días tras su ingreso. El tabaco fue el único factor de riesgo detectado. Presentamos las particularidades clínicas de nuestros pacientes y destacamos la necesidad de un diagnóstico y tratamiento precoz de la neumonía por varicela (AU)