Tratamento da Doença de Chagas pelo Nifurtimox (Bayer 2502)

Foram tratados 77 pacientes com doença de Chagas pelo nifurtimox, subdivididos em quatro grupos. Grupo I, com 30 pacientes na fase aguda. Somente oito doentes usaram a droga durante 120 dias, na dose inicial de 15 mg/kg de peso corporal e posteriormente de 10 mg. Vinte e dois pacientes tomaram dose insuficiente. Em quatro doentes (50%) o xenodiagnóstico tornou-se negativo pós-tratamento; destes, três fizeram reação de Machado Guerreiro, a qual estava negativa. Houve um óbito por insuficiência cardíaca no 59 dia de tratamento. Seis pacientes apresentaram polineuropatia periférica. Grupo II, com 15 pacientes na fase crônica, tratados em ambulatório. Oito abandonaram o tratamento, mas cinco em dez que tomaram placebo fizeram o mesmo. Dos seis que tomaram a droga durante 120 dias e fizeram pelo menos um xenodiagnóstico pós-tratamento, havia quatro que estavam com os exames negativos. O tratamento não alterou o eletrocardiograma, a área cardíaca ou a radiografia do esôfago dos doentes e não evitou que um paciente viesse a desenvolver insuficiência cardíaca e um outro arritmia. Grupo III, com 15 pacientes na fase crônica, tratados com 10 mg/kg, durante 120 dias. Fizeram 12 xenodiagnósticos mensalmente, cada um com oito caixas contendo 10 T. infestans após o tratamento e somente 28,5% dos pacientes apresentaram todos os exames negativos. Houve acentuada redução da parasitemia, mesmo nos doentes não curados. O número de xenos positivos passou de 43% antes do tratamento para 24,4% após o mesmo e o número de caixas positivas caiu de 29,6% para 7%. Grupo IV, com 17 pacientes na fase crônica, tratados com 8 mg/kg ao dia, sendo que em oito durante 120 dias, em cinco durante 100 dias e em quatro durante 60 dias. A percentagem de doentes com os 12 xenos negativos pós-tratamento foi de 56,25. Também neste grupo houve redução de parasitemia, caindo a percentagem de xenos positivos de 76,5 antes do tratamento para 10,3 e a de caixas positivas de 28,6 para 3,1. Não há vantagem em se prolongar o uso do nifurtimox por mais de dois meses. As percentagens de cura são bem inferiores as obtidas na Argentina, Chile e Rio Grande do Sul. A droga produz muitas reações, sendo a mais importante a polineuropatia periférica.

Study and characterization of the ZnPc:C60/MoOx interface in organic solar cells by means of photoelectron spectroscopy

Dissertation to obtain the academic degree of Master in materials engineering submitted to the Faculty of science and engineering of Universidade Nova de Lisboa

Molecular characterization of the fibrinogen-erythrocyte interaction and its influence on cardiovascular pathologies by AFM-based force spectroscopy

Dissertação para obtenção do Grau de Mestre em Engenharia Biomédica

Monitoring and modelling of membrane bioreactors for wastewater treatment incorporating 2D fluorescence spectroscopy

Dissertação para obtenção do Grau de Doutor em Engenharia Química e Bioquímica, Especialidade em Engenharia Bioquímica

Importância do exame do liquor de controle em meningite bacteriana como critério de alta

Há controvérsias sobre indicação do exame do liquor de controle em pacientes recuperados clinicamente de meningite bacteriana como critério de cura. Alguns autores defendem alta hospitalar após normalização clínica e liqüórica, outros que a análise do liquor não se justifica em todos os pacientes. Esta série de casos com comparação de grupos investiga alterações no exame liqüórico de controle e avalia a importância do exame na decisão da alta. De 297 pacientes estudados, em 89,9%, o liquor de controle não mudou a intenção de alta (liquor resolutivo), já em 10,1% a alta foi suspensa (liquor não-resolutivo). Destes, o esquema antibiótico foi trocado em 30%. Entre as variáveis que pudessem ser preditivas de liquor não-resolutivo, à admissão, proteinorraquia maior que 100mg/dL (p=0,04) e glicorraquia menor ou igual a 20mg/dL (p=0,03) associaram-se a chance 2,5 vezes maior, podendo ser úteis como critérios para indicar exame do liquor como controle de cura para alta.

Proton magnetic resonance spectroscopy of the frontal lobe in schizophrenics: a critical review of the methodology

Schizophrenic patients undergoing proton magnetic resonance spectroscopy show alterations in N-acetyl aspartate levels in several brain regions, indicating neuronal dysfunction. The present review focuses on the main proton magnetic resonance spectroscopy studies in the frontal lobe of schizophrenics. A MEDLINE search, from 1991 to March 2004, was carried out using the key-words spectroscopy and schizophrenia and proton and frontal. In addition, articles cited in the reference list of the studies obtained through MEDLINE were included. As a result, 27 articles were selected. The results were inconsistent, 19 papers reporting changes in the N-acetyl aspartate levels, while 8 reported no change. Methodological analysis led to the conclusion that the discrepancy may be due the following factors: (i) number of participants; (ii) variation in the clinical and demographic characteristics of the groups; (iii) little standardization of the acquisition parameters of spectroscopy. Overall, studies that fulfill strict methodological criteria show N-acetyl aspartate decrease in the frontal lobe of male schizophrenics.

Espectroscopía de emisión de rayos x. Aplicación a la caracterización de materiales. X-ray emission spectroscopy. Application to materials characterization

La idea principal del proyecto abarca el estudio de parámetros y fenómenos físicos. Los avances logrados se aplicarán al desarrollo de software y metodologías para cuantificación de materiales mediante microanálisis con sonda de electrones y microscopía electrónica de barrido. El microanálisis no es una técnica absoluta, sino que requiere de estándares de referencia, para obviar el uso de ciertos parámetros geométricos y atómicos difíciles de conocer con una precisión adecuada. Para contar con un método sin estándares debe abordarse la determinación de parámetros atómicos e instrumentales, que es uno de los aspectos que se desea encarar en este proyecto. Por otro lado, también se pretende incluir los parámetros estudiados en un software de cuantificación desarrollado por integrantes del proyecto. Otro de los propósitos del plan de trabajo es estudiar la potencialidad de la resolución espacial de una microsonda de electrones con el fin de desarrollar una metodología para caracterizar interfases, bordes de granos e inclusiones, con resolución submicrométrica, ya que los métodos tradicionales de cuantificación se restringen al caso de muestras planas y homogéneas dentro del volumen de interacción, pero la caracterización de inhomogeneidades a nivel micrométrico no ha sido desarrollada todavía, salvo algunas excepciones. The main idea of this project involves the study of physical parameters and phenomena. The concretion of the different goals will permit the elaboration of softeare and methodologies for materials characterization by means of electron probe microanalysis and scanning microscopy. Electron probe microanalysis is not an absolute technique, but requires reference standards in order not to involve certain geometrical and atomic parameters for which high uncertainties cannot be avoided. In order to have standardless method, the determination of atomic and instrumental parameters must be accomplished, as will be faced through this project. Complementary, the parameters studied will be included in a quantification software developed in our research group of FaMAF. Another objective of this activity plan is to study the spatial resolution potentiality of a focalized electron beam, with the aim of characterizing interphases, grain boundaries and inclusions with submicron sensitivity, since the traditional quantification procedures are restricted to flat homogeneous samples, whereas the characterization of inhomogeneities has not been developed yet.

Development of a rehabilitation system for the red mud waste generated at the Aughinish Alumina Bayer Plant

Aughinish Alumina Limited (AAL) have an obligation by terms of their Integrated Pollution Control Licence (IPCL) and Planning Permission to establish vegetation on the red mud stack at their plant at Aughinish, Co. Limerick. High pH and high exchangeable sodium percentage are the main known factors limiting the establishment of vegetation on red mud. Gypsum addition has been known to assist in alleviating these problems in other countries. However, there is no experience or published information on red mud rehabilitation under Irish conditions. Red mud with organic and inorganic waste-derived ameliorants as well as selected grassland species were examined under laboratory controlled environment conditions as well as in field plot trials. Also, in order that it would be economically achievable, the research utilised locally available waste products as the organic amendments. Screening trials found that physical constraints severely limit plant germination and growth in red mud. Gypsum addition effectively lowers pH, exchangeable sodium percentage and the availability of A1 and Fe in the mud. A strong relationship between pH, ESP and A1 levels was also found. Gypsum addition increased germination percentages and plant growth for all species investigated. Greenhouse trials demonstrated that organic wastes alone did not greatly improve conditions for plant growth but when used in conjunction with gypsum plant performances for all species investigated was significantly increased. There was a high mortality rate for grasses in non-gypsum treatments. An emerging trend of preferential iron uptake and calcium deficiency in non-gypsum treatments was found at pot screening stage. Species also displayed manganese and magnesium deficiencies.

Study of human brain metabolites using magnetic resonance spectroscopy methods at 7 TESLA

Magdeburg, Univ., Fak. für Naturwiss., Diss., 2012

The investigation of glutamine and glutamate in the human brain using MR spectroscopy at 7 Tesla

Magdeburg, Univ., Fak. für Naturwiss., Diss., 2014

The Discrimination of Colored Acrylic, Cotton, and Wool Textile Fibers Using Micro-Raman Spectroscopy. Part 1 : In Situ Detection and Characterization of Dyes

Raman spectroscopy has been applied to characterize fiber dyes and determine the discriminating ability of the method. Black, blue, and red acrylic, cotton, and wool samples were analyzed. Four excitation sources were used to obtain complementary responses in the case of fluorescent samples. Fibers that did not provide informative spectra using a given laser were usually detected using another wavelength. For any colored acrylic, the 633-nm laser did not provide Raman information. The 514-nm laser provided the highest discrimination for blue and black cotton, but half of the blue cottons produced noninformative spectra. The 830-nm laser exhibited the highest discrimination for red cotton. Both visible lasers provided the highest discrimination for black and blue wool, and NIR lasers produced remarkable separation for red and black wool. This study shows that the discriminating ability of Raman spectroscopy depends on the fiber type, color, and the laser wavelength.

Compartmentalized Cerebral Metabolism of [1,6-(13)C]Glucose Determined by in vivo (13)C NMR Spectroscopy at 14.1 T.

Cerebral metabolism is compartmentalized between neurons and glia. Although glial glycolysis is thought to largely sustain the energetic requirements of neurotransmission while oxidative metabolism takes place mainly in neurons, this hypothesis is matter of debate. The compartmentalization of cerebral metabolic fluxes can be determined by (13)C nuclear magnetic resonance (NMR) spectroscopy upon infusion of (13)C-enriched compounds, especially glucose. Rats under light α-chloralose anesthesia were infused with [1,6-(13)C]glucose and (13)C enrichment in the brain metabolites was measured by (13)C NMR spectroscopy with high sensitivity and spectral resolution at 14.1 T. This allowed determining (13)C enrichment curves of amino acid carbons with high reproducibility and to reliably estimate cerebral metabolic fluxes (mean error of 8%). We further found that TCA cycle intermediates are not required for flux determination in mathematical models of brain metabolism. Neuronal tricarboxylic acid cycle rate (V(TCA)) and neurotransmission rate (V(NT)) were 0.45 ± 0.01 and 0.11 ± 0.01 μmol/g/min, respectively. Glial V(TCA) was found to be 38 ± 3% of total cerebral oxidative metabolism, accounting for more than half of neuronal oxidative metabolism. Furthermore, glial anaplerotic pyruvate carboxylation rate (V(PC)) was 0.069 ± 0.004 μmol/g/min, i.e., 25 ± 1% of the glial TCA cycle rate. These results support a role of glial cells as active partners of neurons during synaptic transmission beyond glycolytic metabolism.

Are glutamate and lactate increases ubiquitous to physiological activation? A (1)H functional MR spectroscopy study during motor activation in human brain at 7Tesla.

Recent studies at high field (7Tesla) have reported small metabolite changes, in particular lactate and glutamate (below 0.3μmol/g) during visual stimulation. These studies have been limited to the visual cortex because of its high energy metabolism and good magnetic resonance spectroscopy (MRS) sensitivity using surface coil. The aim of this study was to extend functional MRS (fMRS) to investigate for the first time the metabolite changes during motor activation at 7T. Small but sustained increases in lactate (0.17μmol/g±0.05μmol/g, p<0.001) and glutamate (0.17μmol/g±0.09μmol/g, p<0.005) were detected during motor activation followed by a return to the baseline after the end of activation. The present study demonstrates that increases in lactate and glutamate during motor stimulation are small, but similar to those observed during visual stimulation. From the observed glutamate and lactate increase, we inferred that these metabolite changes may be a general manifestation of the increased neuronal activity. In addition, we propose that the measured metabolite concentration increases imply an increase in ΔCMRO2 that is transiently below that of ΔCMRGlc during the first 1 to 2min of the stimulation.

In vivo measurement of tissue oxygenation by time-resolved luminescence spectroscopy: advantageous properties of dichlorotris(1, 10-phenanthroline)-ruthenium(II) hydrate.

Measuring tissue oxygenation in vivo is of interest in fundamental biological as well as medical applications. One minimally invasive approach to assess the oxygen partial pressure in tissue (pO2) is to measure the oxygen-dependent luminescence lifetime of molecular probes. The relation between tissue pO2 and the probes' luminescence lifetime is governed by the Stern-Volmer equation. Unfortunately, virtually all oxygen-sensitive probes based on this principle induce some degree of phototoxicity. For that reason, we studied the oxygen sensitivity and phototoxicity of dichlorotris(1, 10-phenanthroline)-ruthenium(II) hydrate [Ru(Phen)] using a dedicated optical fiber-based, time-resolved spectrometer in the chicken embryo chorioallantoic membrane. We demonstrated that, after intravenous injection, Ru(Phen)'s luminescence lifetime presents an easily detectable pO2 dependence at a low drug dose (1 mg∕kg) and low fluence (120 mJ∕cm2 at 470 nm). The phototoxic threshold was found to be at 10 J∕cm2 with the same wavelength and drug dose, i.e., about two orders of magnitude larger than the fluence necessary to perform a pO2 measurement. Finally, an illustrative application of this pO2 measurement approach in a hypoxic tumor environment is presented.