Abstract Introduction: starvation is usual in patients referred for endoscopic gastrostomy (PEG). A high risk of refeeding syndrome (RS) may contribute to poor prognosis. Objectives: this study aims to: a) evaluate serum phosphorus and magnesium when patients underwent PEG; b) determine the mortality rate during the first week and first month of enteral nutrition; and c) assess if hypophosphatemia or hypomagnesemia are associated with early mortality. Material and methods: retrospective study with patients followed in the Artificial Nutrition Clinic and died under PEG feeding. General nutritional assessment included NRS 2002, anthropometry and serum proteins. Serum phosphorus and magnesium were measured immediately before gastrostomy. Survival was recorded and compared to electrolyte and nutritional status. Results: one hundred and ninety-seven patients (137 men/60 women) aged 26-100 years. Most underwent PEG due to neurologic disorders (60.9%) and were malnourished according to body mass index (BMI) and serum proteins. Low phosphorus and magnesium were found in 6.6% and 4.6%, respectively. Hypophosphatemia was associated with malnutrition (p < 0.05). Mean survival was 13.7 ± 15.4 months. Mortality was 4.6% in the first week and 13.2% in the first month post-gastrostomy. Overall survival was shorter in malnourished patients but malnutrition did not directly influence early mortality (p > 0.05). Hypophosphatemia was associated with mortality during the first week (p = 0.02) and the first month of PEG feeding (p = 0.02). Conclusions: hypophosphatemia was uncommon but predicted early mortality after PEG. Although RS may be less frequent than expected, hypophosphatemia may be used as a RS marker and RS is the probable cause of increase early mortality in hypophosphatemic PEG-fed patients.

Resumen Introducción: la inanición es habitual en pacientes referenciados para gastrostomía endoscópica (PEG). Un riesgo alto de síndrome de realimentación (SR) puede contribuir a un mal pronóstico. Objetivos: este estudio pretende: a) estudiar el fósforo y el magnesio séricos cuando los pacientes son sometidos a PEG; b) determinar la tasa de mortalidad durante la primera semana y el primer mes de nutrición entérica; y c) evaluar si la hipofosfatemia y la hipomagnesemia se asocian con una mortalidad temprana. Material y métodos: estudio retrospectivo con pacientes seguidos en la consulta de nutrición artificial y que fallecieron utilizando alimentación por PEG. La evaluación nutricional genérica ha incluido el NRS 2002, la antropometría y la determinación de las proteínas séricas. El fósforo y el magnesio séricos se han determinado inmediatamente antes de la gastrostomía. La sobrevida fue registrada y comparada con el perfil iónico y el estado nutricional de los pacientes. Resultados: el estudio se realizó en 197 pacientes (137 hombres/60 mujeres) de 26-100 años. La mayoría se sometieron a PEG por trastornos neurológicos (60,9%) y estaban desnutridos de acuerdo con el índice de masa corporal (IMC) y las proteínas séricas. El fósforo y el magnesio séricos estaban bajos, con un 6,6% y un 4,6%, respectivamente. La hipofosfatemia se asoció con la desnutrición (p < 0,05). La sobrevida media fue de 13,7 ± 15,4 meses. Se ha registrado una mortalidad del 4,6% en la primera semana y del 13,2% en el primer mes después de la gastrostomía. La sobrevida general fue más corta en los pacientes desnutridos, pero la desnutrición no ha afectado directamente a la mortalidad temprana (p > 0,05). La hipofosfatemia se asoció con la mortalidad durante la primera semana (p = 0,02) y el primer mes de alimentación con PEG (p = 0,02). Conclusiones: la hipofosfatemia fue infrecuente, pero predijo una mortalidad temprana después del PEG. Aunque el SR es aparentemente menos frecuente de lo esperado, la hipofosfatemia puede ser utilizada como un marcador del SR y el SR es probablemente la causa de una mortalidad temprana en pacientes hipofosfatémicos alimentados con PEG.

ABSTRACT: We developed a mid infrared (MIR) solar telescope, centered at 10µm. Various optical layouts were analyzed based on computer simulations and a Ritchey-Chretien 6-inches telescope was selected with a plate scale of 2.5′′/mm using a pyroelectric 4 × 16 pixels detector. The angular resolution is 36′′/pixel with a field of view of 9.6′ × 2.4′. Two germanium filters are used, one at the aperture of the telescope and another near its focal plane. The detector was characterized with a laboratory black-body. The count values follow a linear relation with the black-body temperature. The control systems for both the telescope and the detector were developed. Proper mechanical supports were designed for the filters, detector and electronics. The system has been integrated and a user interface was developed. Preliminary observations have been made giving a signal-to-noise ratio of ≈ 1000.

RESUMEN: Desarrollamos un telescopio solar en el infrarrojo medio (MIR), centrado en 10µm. Estudiamos varios diseños ópticos, con base en simulaciones de computadora y seleccionamos un telescopio Ritchey-Chretien de 6 pulgadas con escala de placa de 2.5′′/mm, con un detector piroeléctrico de 4 × 16 pixeles. La resolución angular es de 36′′/pixel con un campo de visión de 9.6′ × 2.4′. Se usan dos filtros de germanio, uno en la apertura del telescopio y otro cerca del plano focal. El detector se caracterizó con un cuerpo negro de laboratorio. Los valores, en cuentas, siguen una relación lineal con la temperatura del cuerpo negro. Se hicieron los sistemas de control del telescopio y del detector. Se diseñaron soportes mecánicos para los filtros, el detector y la electrónica. El sistema se integró y se hizo una interfaz para el usuario. Las observaciones preliminares muestran que se obtiene una relación señal a ruido de ≈ 1000.

Introdução: O estudo do intestino delgado tem evoluído extraordinariamente, mas ainda não está definido um método referencial. Descreve-se a utilização em Tomografia Computorizada de um contraste oral usado em Ressonância Magnética. Objectivos: Avaliação da Enterografia Peroral por Tomografia Computorizada com goma de alfarroba-sorbitol no estudo do intestino delgado. Material e Métodos: Doze doentes realizaram Enterografia Peroral por Tomografia Computorizada: 7 por suspeita de doença de Crohn, 2 para estudo de doença de Crohn conhecida e 3 por hemorragia digestiva e/ou anemia. Efectuouse o estudo num aparelho multicorte, após admnistração endovenosa de contraste iodado, com distensão prévia do intestino com solução oral hiperosmolar (goma de alfarroba-sorbitol). Avaliou-se: tolerância, distensibilidade intestinal e acuidade diagnóstica deste método. Resultados: O exame foi bem tolerado em todos os doentes. Confirmou o diagnóstico de doença de Crohn em 4, avaliou complicações desta doença em 2, diagnosticou tumores no delgado em 1 e no cólon em 1. A distensibilidade intestinal foi boa ou óptima em todos. Registaram-se apenas complicações minor do contraste oral: desconforto abdominal em 1 e diarreia em 3. Conclusões: A Enterografia Peroral por Tomografia Computorizada com goma de alfarroba-sorbitol revelou-se uma técnica simples, bem tolerada e útil no estudo do intestino delgado.

Introduction: Despite advances in the study of the small bowel, a gold standard method has not yet been defined. Here we report our experience with Computed Tomography with an oral contrast material used for Magnetic Resonance Imaging. Purpose: To assess Computed Tomographic Enterography with locust bean gum-sorbitol in evaluating the small bowel. Materials and Methods: Twelve patients underwent Computed Tomographic Enterography: 7 suspected of having Crohn’s disease, 2 for assessment of known Crohn’s disease and 3 with gastrointestinal bleeding/anemia. After intravenous administration of iodinated contrast material and prior small bowel distension using an osmotic oral contrast material (locust bean gum-sorbitol), images were obtained with a multi-detector row helical computed tomography scanner. We assessed: i) patients tolerance, ii) small bowel distension and iii) accuracy of this method. Results: Computed Tomographic Enterography was well tolerated in all patients. It diagnosed Crohn’s disease in 4 patients, helped assess complications of the disease in 2 and detected tumours in the small bowel in 1 and in the colon in 1. The degree of small bowel distension was good or optimal in all cases. The patients reported minor side effects associated with the oral contrast material: abdominal pain in 1 and diarrhea in 3. Conclusion: Computed Tomographic Enterography with locust bean gum-sorbitol is a simple, non-invasive and effective method of evaluating the small bowel.

Peginterferon alfa plus ribavirin is currently the treatment of choice for chronic hepatitis C. Peginterferon alfa-2a (40KD) plus ribavirin has given an overall sustained virological response of 18% in F3/F4 previous nonresponder US patients. We evaluated the effectiveness of peginterferon alfa-2a (40KD) plus ribavirin in Brazilian patients who were relapsers or nonresponders to previous interferon-based therapy. One-hundred-thirty-four patients with biopsy-proven chronic hepatitis C, HCV RNA positive, elevated ALT and who were either relapsers (n=37) or nonresponders (n=97) to at least 24 weeks of conventional interferon/ribavirin therapy were retreated with peginterferon alfa-2a (40KD) 180mg/qw and ribavirin 800mg bid for 48 weeks. Efficacy was assessed as virological response (defined as undetectable HCV RNA) at the end of treatment (EoT) and at the end of follow-up (SVR - Sustained Virological Response). Safety assessments consisted of clinical and laboratory evaluations. In the patient sample, 72% were genotype 1 and 34% were cirrhotic. In an intention-to-treat analysis, relapser patients showed 78% EoT response and 51% SVR. Nonresponders showed 57% EoT response and 26% SVR. Positive predictive factors of SVR were non-1 genotype and relapser state. Six percent of the patients interrupted treatment because of adverse events and 45% had dose reduction (mainly associated with leucopenia and anemia). Brazilian patient relapsers and nonresponders to conventional interferon and ribavirin treatment can achieve a sustained virological response when retreated with peginterferon alfa-2a (40KD) and ribavirin. The safety profile is similar to that of naive patients.

Observando a literatura pode ser verificado um crescente número de trabalhos que determinam potenciais contaminantes presentes em matrizes de interesse ambiental. É importante ressaltar que quando se estuda o ambiente, os dados analíticos são uma das ferramentas usadas para se avaliar a extensão dos problemas observados que conseqüentemente influenciam as tomadas de decisão. Assim a confiabilidade desses dados é de extrema importância. Neste contexto, este trabalho visa avaliar a confiabilidade analítica das determinações de Carbono Orgânico Total (COT), ferramenta empregada no monitoramento da matéria orgânica em diversos estudos ambientais. Para essa avaliação foram analisados alguns parâmetros de desempenho como limite de detecção e quantificação, repetibilidade e linearidade.

Observing the literature an increasing number of works can be verified that determine potential contaminants that can be present in matrices of environmental interest. It is important to stand out that when studying the environment, the analytical data are one of the tools used to evaluate the extension of the observed problems that consequently influence a decision. Thus the reliability of these data is of extreme importance. In this context, this work aims to evaluate the analytical reliability of the Total organic Carbon (TOC) determination, a tool used in the monitoring of organic substances in diverse ambient studies. For this evaluation some parameters of performance had been analyzed as limit of detection and quantification, repeatability and linearity.

Aim: To evaluate the number of platelets and the title of anti-platelet antibodies IgG Ac-PI (by flow cytometry) in patients with non-complicated malaria. Methods: Descriptive, prospective and longitudinal study from 45 patients (aged among 14-67). Thirty patients were followed during 7 days. Results: A) Pretreatment: it was found malarial thrombocytopenia (MT) in 71 % and significant association between MT and Ac-PI in 33 %. MT was not associated to residence zone, to have had malaria in the last year and Plasmodium species but sex associated (males, p= 0,02078195), although, the Ac-PI titers of male and female was similar. Correspondingly, the number of platelets was statistically similar to the values of above variables. There was a low and an inverse lineal correlation between platelets and titres of Ac-P1 (r= -0,342 (p= 0,02310)). B) During the following, multiple linear regression among platelets, age, years of residence in the zone, number of malaria episodes in the last year, parasitaemia (logarithmically expressed) and Ac-P1 titers showed no significant coefficient and the maximum explanation achieved (17%) was parasitaemia and Ac-P1 titers. Similar analysis among Ac-P1 and age, years of residence in the zone number of malaria episodes in the last year, parasitaemia (logarithmically expressed) showed that the first three explain 38 % of the changes in Ac-P1, whereas malaria episodes and years of residence in the zone explain 28%.

Objetivo: evaluar plaquetas y anticuerpos antiplaquetarios IgG Ac-Pl (medidos por citometría de flujo) en pacientes de Turbo (Antioquia, Colombia) con paludismo no complicado. Metodología: estudio descriptivo, prospectivo y longitudinal de 45 pacientes (14-67 años). Treinta enfermos se siguieron 7 días. Resultados: A) Pretratamiento: hubo trombocitopenia malárica (TM) en 71% y Ac-Pl en 33%, con asociación significativa entre TM y Ac-Pl. La TM no se asocia con zona de residencia, haber tenido malaria en último año ni especie actual de Plasmodium, pero si con sexo (hombres) (p = 0,02078195), pero la concentración de Ac-Pl es similar en hombres y mujeres. Igualmente, la cantidad de plaquetas es estadísticamente igual entre los valores de las variables anteriores. La presencia de Ac-Pl no se relacionó con las anteriores variables. Hay baja e inversa correlación lineal entre plaquetas y Ac-Pl (r = -0,342 (p = 0,02310). B) Durante el seguimiento, la regresión lineal múltiple entre plaquetas y edad, años de residencia, número de episodios de malaria en el último año, parasitemia (expresada logarítmicamente) y concentración de Ac-Pl demostró que ningún coeficiente es significativo y la máxima explicación lograda (17%) la dan la parasitemia y los Ac-Pl. El mismo análisis entre Ac-Pl y edad, años de residencia en la zona, número de episodios de malaria en el último año, parasitemia (expresada logarítmicamente) demostró que las tres primeras explican 38% de los cambios en Ac-Pl, mientras que los episodios de malaria y el tiempo de residencia en la zona explican el 28%.

A general mesh independent filter as a mean to control the complexity of topology optimization designed structures is discussed. A new mesh-independent filter, applied over the move-limits of the sequential linear programming is proposed, and it is shown that its use alleviates common problems in the continuum topology optimization, like checkerboarding, mesh dependency, as well as effects associated to non-structured meshes, like numerical anisotropy. The structural optimization formulation adopted in this work is the minimization of a penalized function of the volume, with constraints on the compliance of each load case. Aspects of this penalized objective function are discussed, and several numerical examples are shown.

We describe how to produce periodically-poled lithium niobate (PPLN), which can be used to generate electromagnetic radiation of different frequencies through quasi-phase-matching. First we describe the basic principles of quasi-phase-matching and of ferroelectric crystals (which are used to obtain quasi-phase-matching), and then we give a detailed description of the fabrication process of PPLN. Using this technique we obtained PPLN samples over 5 cm long of high enough quality to obtain optical parametric generation through quasi-phase-matching.

En este trabajo describimos el proceso de fabricación de niobato de litio periódicamente polarizado (PPLN), el cual es un material ferroeléctrico en donde la dirección de la polarización espontánea es invertida periódicamente; este material se usa primordialmente para la generación de radiación electromagnética de frecuencia sintonizable mediante la técnica del cuasiempatamiento de fases. Se describen brevemente los principios básicos de cuasiempatamiento de fases y de los cristales ferroeléctricos y posteriormente se describe en detalle el proceso de fabricación de PPLN. Con esta técnica elaboramos muestras de PPLN de más de 5 cm de largo con la calidad necesaria para obtener generación óptica paramétrica mediante cuasiempatamiento de fases.

A discrete-ordinate radiative transfer model is employed to develop a regional clear sky ultraviolet (UV) diagnosis system. The clear sky UV radiation, weighted by the spectral sensitivity of human skin is calculated using the Total Ozone Mapping Spectrometer (TOMS) data sets. Examples of the geographical clear sky UV Index distributions are presented and the model results are compared with surface UV measurements from the University of Colima for 1999.

Utilizando un modelo de transferencia de radiación de ordenadas discretas se desarrolla un sistema para el diagnóstico de la distribución de radiación ultravioleta para cielo despejado en la República Mexicana. La radiación para cielo despejado se obtiene utilizando la respuesta espectral de la piel humana y los datos de satélite de ozono total registrados por el espectrómetro TOMS. Se presentan ejemplos del índice de radiación ultravioleta (UV Index) calculados con el modelo y se comparan con las mediciones en superficie obtenidas en la Universidad de Colima durante 1999.

Esta pesquisa foi desenvolvida entre 1993 e 1996 com o objetivo de estudar a estrutura da comunidade de macroinvertebrados bentônicos, relacionando-a a algumas variáveis abióticas, em um lago amazônico (lago Batata), que recebeu durante dez anos rejeito de bauxita. Os macroinvertebrados bentônicos foram coletados com um coletor tipo core e as variáveis abióticas medidas foram: oxigênio dissolvido, material em suspensão, profundidade, transparência (disco de secchi), temperatura da coluna d’água e nitrogênio total, fósforo disponível e matéria orgânica do sedimento. A partir da aplicação da Análise de Componentes Principais (PCA) foi possível demonstrar que as estações de coleta foram diferenciadas em relação às variáveis abióticas, principalmente em relação às concentrações de N-total, P-disponível e matéria orgânica do sedimento, sendo encontradas em maiores concentrações nas estações naturais. A PCA referente à comunidade de macroinvertebrados bentônicos também distinguiu as estações naturais da estação impactada. A estação impactada foi positivamente agrupada à Ephemeroptera (Campsurus sp.) e as estações naturais à Chironomidae, Chaoboridae, Oligochaeta e Bivalvia. Os resultados obtidos nesta pesquisa evidenciaram que as áreas impactadas com rejeito de bauxita apresentaram alteração das características abióticas e da estrutura das comunidades de macroinvertebrados bentônicos.

This research was developed between 1993 and 1996, aiming to study the structure of the benthic macroinvertebrate community, relating it to some abiotic variables, in an amazonian lake (lago Batata), that received for ten years a great amount of bauxite tailings. The benthic macroinvertebrates were collected with a core and the abiotic variables that were measured were: dissolved oxygen, suspended material, depth, transparency (secchi disc), temperature of the water column and total nitrogen, available phosphorus and organic matter in the sediment. With the use of a Principal Components Analysis (PCA), we were able to show that the sampling sites differed regarding the abiotic variables, especially total-N, available-P and organic matter in the sediment, all of which were found in greater concentrations in the natural areas. The PCA concerning the benthic macroinvertebrate community also distinguished the natural sites from the impacted one. The impacted site was positively grouped with the Ephemeroptera (Campsurus sp.) and the natural sites were grouped together with the Chironomidae, Chaoboridae, Oligochaeta and Bivalvia. The results achieved in this research made clear that the sites under influence of the bauxite tailings had alterations of their abiotic characteristics and of their benthic macroinvertebrate structure.

Accidental transmission of Chagas' disease to man by blood transfusion is a serious problem in Latin-America. This paper describes the testing of several synthetic, semi-synthetic, and natural compounds for their activity against blood trypomastigotes in vitro at 4-C. The compounds embody several types of chemical structures: benzoquinone, naphthoquinone, anthracenequinone, phenanthrenequinone, imidazole, piperazine, quinoline, xanthene, and simple benzenic and naphthalenic derivates. Some of them are for the first time tested against Trypanosoma cruzi. The toxic effect these compounds on this parasite was done by two quite distinct sets of experiments. In one set, the compounds were added to infected blood as ethanolic solution. In this situation the most active one was a furan-1, 2-naphthoquinone, in the same range as gentian violet, a new fact to be considered in the assessment of structure-activity relationships in this class of compounds. In other set, we tentatively evaluated the biological activity of water insoluble compounds by adding them in a pure form without solvent into infected blood. In this way some appear to be very active and it was postulated that the effectiveness of such compounds must result from interactions between them and specific blood components.