Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 100
Filtrar
1.
Rev Neurol ; 78(11): 295-305, 2024 Jun 01.
Artigo em Espanhol, Inglês | MEDLINE | ID: mdl-38813787

RESUMO

AIM: To determine post-surgical cognitive risk and associated factors according to lesion location in a sample of patients evaluated for epilepsy surgery with Wada test at the Fundacion Instituto Neurologico de Colombia. MATERIALS AND METHODS: An observational, retrospective, analytical study was completed in patients with drug-resistant temporal lobe epilepsy candidates for epilepsy surgery treated from 2001 to 2021, who completed the Wada test as part of the pre-surgical evaluation. A descriptive analysis of sociodemographic, clinical, imaging and neuropsychological variables was completed; a multivariate logistic regression was performed analyzing factors associated with resection risk in patients with left lesions. RESULTS A total of 369 patients were included, 54.74% of the cases were women, with a median age of seizure onset of 11 years. 92.66% of the cases had lesional epilepsy and 68.56% were secondary to hippocampal sclerosis. Left hemisphere was the most frequently affected (65.68%) being dominant for memory and language in most of the patients with a proportion of 42.82% and 81.3%, respectively. The median functional adequacy was 43.75 (IQR 0-75) and the functional reserve was 75 (IQR 25 -93.75). In 104 patients, the Wada test determined a resection risk. In patients with a left lesion, it was found that functional reserve (PRadjusted 0.99, CI 95% 0.9997-0.9998) and having a right hemispheric dominance for memory (PRadjusted 0.92, CI 95% 0.547-0.999) were protective factors for post-surgical resection risk. CONCLUSION: Wada test is a useful tool for surgical decision-making in patients with drug-resistant temporal lobe epilepsy. When considering cognitive risk, components such as memory dominance and functional reserve should be considered as protective factors for postsurgical cognitive function preservation in patients with left lesions.


TITLE: Evaluación de la memoria y el lenguaje mediante el test de Wada en pacientes candidatos a cirugía de epilepsia.Objetivo. Determinar el riesgo cognitivo posquirúrgico y factores asociados según la localización de la lesión en una muestra de pacientes evaluados para cirugía de epilepsia con el test de Wada en la Fundación Instituto Neurológico de Colombia. Materiales y métodos. Se realizó un estudio observacional, retrospectivo y analítico en pacientes con epilepsia farmacorresistente del lóbulo temporal candidatos a cirugía de epilepsia tratados entre 2001 y 2021, que completaron el test de Wada como parte de la evaluación prequirúrgica. Se realizó un análisis descriptivo de variables sociodemográficas, clínicas, imagenológicas y neuropsicológicas. Se realizó una regresión logística multivariada analizando factores asociados al riesgo de resección en pacientes con lesiones izquierdas. Resultados. Se incluyó a 369 pacientes, el 54,74% de los casos fueron mujeres, con una mediana de edad de inicio de las convulsiones de 11 años. El 92,66% de los casos presentó epilepsia lesional; de éstos, el 68,56% fue secundario a esclerosis hipocampal. El hemisferio izquierdo fue el más frecuentemente afectado (65,68%), y éste fue dominante para la memoria y el lenguaje en la mayoría de los pacientes, con una proporción del 42,82 y el 81,3%, respectivamente. La mediana de adecuación funcional fue de 43,75 (rango intercuartílico: 0-75) y la reserva funcional de 75 (rango intercuartílico: 25-93,75). En 104 pacientes, el test de Wada determinó un riesgo de resección. En pacientes con lesiones izquierdas se encontró que la reserva funcional (razón de prevalencia ajustada: 0,99; intervalo de confianza al 95%: 0,9997-0,9998) y tener dominancia del hemisferio derecho para la memoria (razón de prevalencia ajustada: 0,92; intervalo de confianza al 95%: 0,547-0,999) fueron factores asociados para determinar el riesgo de resección posquirúrgico en el test de Wada. Conclusión. El test de Wada es una herramienta útil para la toma de decisiones quirúrgicas en pacientes con epilepsia del lóbulo temporal farmacorresistente. Componentes como la dominancia de la memoria y la reserva funcional en el test de Wada deben considerarse como factores que se deben tener en cuenta en la predicción de la preservación de la función cognitiva posquirúrgica en pacientes con lesiones izquierdas.


Assuntos
Epilepsia Resistente a Medicamentos , Epilepsia do Lobo Temporal , Humanos , Feminino , Masculino , Estudos Retrospectivos , Adulto , Medição de Risco , Epilepsia do Lobo Temporal/cirurgia , Epilepsia Resistente a Medicamentos/cirurgia , Testes Neuropsicológicos , Complicações Pós-Operatórias/etiologia , Adulto Jovem , Adolescente , Criança , Idioma
2.
Heliyon ; 8(4): e09329, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35520622

RESUMO

An analysis of the scientific production of Ecuador is performed by means of the composite indicator computed for Ecuador-based authors as compared to their counterparts of other South American countries. The dataset employed was obtained from the Databricks platform of the ELSEVIER's International Center for Science Research, ICSR. Therefore, this analysis is limited to the metadata of the documents published in journals indexed in SCOPUS. Comparison of the results obtained for two decades: 2001-2010 and 2011-2020 showed that the number of Ecuador-based researchers has significantly increased in different areas of knowledge. Moreover, comparison between the total number of authors that worked in Ecuador at any given year of the 2011-2020 period and the number of authors that are still working in this country up to the date of the data extraction (i.e., June 2021) showed an average of ∼68% of permanency. Analysis of the percentage distribution in terms of range quarters of the composite indicator (i.e., Q4: 0-1.5, Q3: 1.5-3.0, Q2: 3.0-4.5, and Q1: 4.5-6.0) showed that nearly the totality of the Ecuador-based researchers has composite indicators that lay in the Q4 and Q3 ranges for all the scientific fields considered. The latter was observed to be an effect of the scientific impact of South American countries, with larger investments in science and technology in comparison to Ecuador (i.e., Argentina, Brazil, and Chile). Exclusion of this group of countries in the calculation of the composite indicator of Ecuador-based authors resulted in a noticeable increment of scientists with composite indicators within Q2. Finally, our results suggest, in agreement with previous studies, a correlation between the sustained growth of scientific productivity in the decade 2011-2020 with the scientific programs and policies created by the state, where the initiative of scientific culture is shown as a strategy for growth and development.

3.
Chemosphere ; 281: 130821, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34000653

RESUMO

Water pollution is an environmental problem in constant raising because of population growing, industrial development, agricultural frontier expansion, and principally because of the lack of wastewater treatment technology to remove organic recalcitrant and toxic pollutants from industrial and domestic wastewater. Recalcitrant compounds are a serious environmental and health problem mainly due to their toxicity and potential hazardous effects on living organisms, including human beings. Conventional wastewater treatments have not been able to remove efficiently pollutants from water; however, electrochemical advanced oxidation processes (EAOPs) are able to solve this environmental concern. One of the most recent EAOPs technology is photoelectrocatalysis (PEC), it consists in applying an external bias potential to a semiconductor film placed over a conductive substrate to avoid the recombination of photogenerated electron-hole (e-/h+) pairs, increasing h+ availability and hydroxyl radicals' formation, responsible for promoting the degradation/mineralization of organic pollutants in aqueous medium. This review summarizes the recent advances in PEC as a promising technology for wastewater treatment. It addresses the fundamentals and kinetic aspects of PEC. An analysis of photoanode materials and of the configuration of photoelectrochemical reactors is also presented, including an analysis of the influence of the main operational parameters on the treatment of contaminated water. Finally, the most recent applications of PEC are reviewed, and the challenges and perspectives of PEC in wastewater treatment are discussed.


Assuntos
Poluentes Ambientais , Poluentes Químicos da Água , Purificação da Água , Humanos , Oxirredução , Águas Residuárias/análise , Água , Poluentes Químicos da Água/análise
4.
Carbohydr Polym ; 252: 117171, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33183620

RESUMO

The gelation process, elasticity, and mechanical recovery after shear were studied in mixed oleogels of ethylcellulose (EC), monoglycerides (MG), and candelilla wax (CW). EC oleogels produced without MG showed grainy texture due to incomplete dissolution of crystalline fractions of raw EC in the vegetable oil (150 °C). These fractions were eliminated by dissolving the raw EC/MG mixture in ethanol, evaporating the solvent, dispersing, and dissolving the solid residue in the vegetable oil (150 °C) prior gelation. The EC polymeric network, and MG, and CW crystals had a positive interaction on the elasticity of mixed oleogels. Mixed oleogels produced under static conditions showed a 100 % of elasticity recovery after shearing, a phenomenon associated with an EC interchain hydrogen bonding mediated by hydroxyl groups of MGs. This tentatively resulted from the formation of junction zones of the type EC-[MG]n-EC. The rheological behavior of these olegels was remarkably close to that of commercial shortenings.

5.
Rev Neurol ; 70(4): 149-158, 2020 Feb 16.
Artigo em Espanhol | MEDLINE | ID: mdl-32043537

RESUMO

INTRODUCTION: Migraine is a very prevalent disorder that is estimated to affect about 15% of adult subjects. Recently, the efficacy and safety of monoclonal antibodies that act on the calcitonin gene-related peptide pathway (MA-CGRP) has been evaluated in migraine. Several groups around the world have developed consensus guidelines about the use of monoclonal antibodies, however, in some regions is difficult to extrapolate the recommendations. AIM: To provide recommendations for the use of MA-CGRP in migraine in Argentina. DEVELOPMENT: A group of neurology experts from Argentina, by using the online surveys methodology as well as face to face meetings developed the intended consensus for the use of MA-CGRP in migraine in Argentina. Recommendations were established based on published evidence and the expert opinion. Recommendations focused on how, when, treatment duration and patients follow up. CONCLUSION: The recommendations of this consensus guidelines attempt to optimize the use of MA-CGRP in migraine in Argentina.


TITLE: Consenso sobre el uso de anticuerpos monoclonales en la migraña en Argentina.Introducción. La migraña es un trastorno muy prevalente que se estima que afecta a alrededor del 15% de los sujetos adultos. Durante los últimos años, se ha evaluado la eficacia y la seguridad de los anticuerpos monoclonales que actúan sobre la vía del péptido relacionado con el gen de la calcitonina (AM-PRGC) en la migraña. Diversos grupos de trabajo internacionales han intentado clarificar y normatizar el uso de estos medicamentos en la migraña. Sin embargo, en muchas ocasiones se extrapolan datos de otras regiones que no contemplan la realidad de cada lugar o son difíciles de implementar. Objetivo. Proveer recomendaciones sobre el uso de AM-PRGC en pacientes con migraña en Argentina. Desarrollo. Un grupo de expertos de Argentina conformado por neurólogos, mediante metodología de ronda de encuestas en la distancia y reuniones presenciales, llevó adelante la elaboración del consenso pretendido para el uso de AM-PRGC en pacientes con migraña en Argentina. Se establecieron las recomendaciones basadas en la evidencia publicada y en el criterio de los expertos que participaron. Las recomendaciones se enfocaron en el momento de usar los AM-PRGC en la migraña tanto crónica como episódica, la duración, los cuidados y el entorno para hacerlo. Conclusión. Las recomendaciones establecidas en el presente consenso permitirán optimizar el manejo de los AM-PRGC en pacientes con migraña en Argentina.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Transtornos de Enxaqueca/tratamento farmacológico , Argentina , Humanos , Guias de Prática Clínica como Assunto
6.
Lupus ; 28(2): 249-252, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30616452

RESUMO

Childhood-onset systemic lupus erythematosus (cSLE) is a chronic inflammatory multisystem autoimmune disease that requires multiple differential diagnoses. Munchausen by proxy syndrome (MBPS) is a form of child abuse, where a caregiver intentionally creates a medical history and induces or fabricates signs or disease in a patient. To our knowledge, there is no case report of MBPS mimicking cSLE diagnosis. We reported herein a 9-year-old male patient, with a history of multiple hospitalizations due to seizures with altered levels of consciousness. The mother reported malar rash, photosensitivity, alopecia, arthralgia, arterial hypertension, macroscopic hematuria, seizure and positive antinuclear antibodies. In the other service, he was treated with intravenous methylprednisolone, prednisone and mycophenolate mofetil. At 8 years and 8 months, he was admitted to our tertiary center with history of fever and macroscopic hematuria. Laboratory examinations were normal, including negative for antinuclear antibodies, anti-double stranded DNA, anticardiolipin, anti-Ro/SSA, anti-La/SSB, anti-RNP and anti-Sm antibodies. Multiple urine cultures revealed the presence of Enterococcus faecium, Acinetobacter sp., Stenotrophomonas maltophilia and Serratia marcescens, without any association with pyuria. At 8 years and 9 months, he was readmitted at emergency room with history of severe fever, headache, vomiting, photophobia, phonophobia and dizziness. The physical examination showed agitation, confusion, ataxic gait, slurred speech, horizontal nystagmus, painful facial expressions, tachycardia and weight loss. Brain magnetic resonance angiography and cerebrospinal fluid analysis were normal. During hospitalization, he had an acute episode of epistaxis and otalgia with excoriation in the auditory canal. At that moment, the suspicion of MBPS mimicking cSLE was raised and phenytoin intoxication was confirmed (peak phenytoin concentration was 45.4 mcg/mL, therapeutic range 10-20 mcg/mL). The mother and the patient were immediately separated, and she was replaced by another legal guardian. One week later, the neurological and other signs and symptoms were completely resolved. The child was placed under paternal custody with a court order and moved to another state. After that, the mother reported phenytoin use for her child and was referred to psychiatric follow-up. In conclusion, the first case of MBPS mimicking cSLE, resulting in multiple unnecessary examinations and treatments with delayed diagnosis was reported.


Assuntos
Síndrome de Munchausen Causada por Terceiro/diagnóstico , Idade de Início , Criança , Diagnóstico Tardio , Diagnóstico Diferencial , Humanos , Lúpus Eritematoso Sistêmico/diagnóstico , Masculino , Procedimentos Desnecessários
7.
Rev Sci Instrum ; 88(8): 084705, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28863641

RESUMO

A scanning system for specific absorption rate of ferrofluids with superparamagnetic nanoparticles is presented in this study. The system contains an induction heating device designed and built with a resonant inverter in order to generate magnetic field amplitudes up to 38 mT, over the frequency band 180-525 kHz. Its resonant circuit involves a variable capacitor with 1 nF of capacitance steps to easily select the desired frequency, reaching from 0.3 kHz/nF up to 5 kHz/nF of resolution. The device performance is characterized in order to compare with the theoretical predictions of frequency and amplitude, showing a good agreement with the resonant inverters theory. Additionally, the setup is tested using a synthetic iron oxide with 10 ± 1 nm diameter suspended in liquid glycerol, with concentrations at 1%. Meanwhile, the temperature rise is measured to determine the specific absorption rate and calculate the dissipated power density for each f. This device is a suitable alternative to studying ferrofluids and analyzes the dependence of the power absorption density with the magnetic field intensity and frequency.

8.
J Appl Microbiol ; 121(2): 435-44, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27225974

RESUMO

AIMS: The aim of this study was to investigate the potential of aureocin A53, a staphylococcal antimicrobial peptide, for improving food safety. METHODS AND RESULTS: The antimicrobial activity of aureocin A53 against strains of Listeria monocytogenes isolated from food was tested and the bacteriocin proved to be bactericidal and bacteriolytic against the listerial strains. Aureocin A53 was neither toxic to eukaryotic cell lines nor haemolytic against sheep erythrocytes. It also exhibited a remarkable stability during storage at different temperatures and sensitivity to both simulated gastric juice and bile salts. When the antibacterial activity of aureocin A53 (256 AU ml(-1) ) was tested in skimmed milk artificially inoculated with a L. monocytogenes strain (1·0 × 10(4)  CFU ml(-1) ) isolated from food, during storage at 4°C, the bacteriocin reduced the viable counts by 7·7-log10 units up to 7 days of incubation, when compared with the controls not treated with the bacteriocin. CONCLUSIONS: Aureocin A53 exhibited several features considered important for biopreservation and remained fully active in a food matrix. SIGNIFICANCE AND IMPACT OF THE STUDY: Taken together, the results confirmed that aureocin A53 has potential to be used as a food preservative, representing an alternative to the use of nisin in biopreservation of dairy products.


Assuntos
Antibacterianos/farmacologia , Conservação de Alimentos/métodos , Conservantes de Alimentos/farmacologia , Leite/microbiologia , Peptídeos/farmacologia , Animais , Peptídeos Catiônicos Antimicrobianos , Conservação de Alimentos/instrumentação , Listeria monocytogenes/efeitos dos fármacos , Listeria monocytogenes/isolamento & purificação , Ovinos
9.
Food Res Int ; 89(Pt 1): 828-837, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28460985

RESUMO

Vegetable oil organogelation is one of the most promising strategies to eliminate trans fatty acids in plastic fats. Organogels prepared with edible wax are stable at refrigerator and room temperature. Some functional properties (i.e., texture) of wax organogels can be improved by adding saturated triacylglycerols. Mixtures of fully hydrogenated soybean oil (FH) and candelilla wax (CW) were studied with and without the addition of high oleic safflower oil (HOSFO). Crystallization and melting behavior, X-ray diffraction, and crystalline microstructure of the mixtures were analyzed. The elastic modulus (G'), and the structural recovery after shear of the organogels were also assessed. Mixtures without HOSFO formed solid dispersions of CW and FH crystals, where up to ~10% CW crystals were incorporated into the FH crystal lattice. The vegetable oil solutions of FH/CW mixtures crystallized from the melt, developed mixed crystal networks composed of FH crystals in the ß polymorph and CW in an orthorhombic subcell packing. As the systems crystallized in the most stable polymorph, only minor microstructural changes were shown along 28days of storage at 25°C. CW and FH crystals showed a synergistic effect on the elasticity of organogels. This was attributed to the large number FH crystals nucleated on the surface of CW crystals. The structural recovery after shear was superior for mixed organogels composed of CW platelets and grainy FH crystals compared to that of CW organogels. A recovery of up to 65.7% the G' of gels formed under static conditions was observed upon shearing.

10.
J Environ Manage ; 131: 103-9, 2013 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-24157410

RESUMO

Arsenic (As) in groundwater for domestic use poses a worldwide threat to public health, most notably in rural areas. The aims of this study were: first, determine groundwater composition in a mining area in central Mexico (Huautla); second, assess As exposure through human groundwater consumption and; third, develop and test a household filter to obtain drinking water for these rural communities. From the 17th century through the 1990s, mines in the area produced Ag-galena and sphalerite from volcanic rock. Groundwater flooded the mines when they were abandoned due to low silver prices. Local households now use the water to meet domestic needs. Water from the mines was found to have high As content (0.04-0.26 mg L(-1)) and Fe, Mn, Pb and Cd were also above Mexican drinking water standards and WHO guidelines. All the population in the Huautla community was exposed to the metalloid through water used in food preparation. The best As removal was obtained with a filter using oxidized commercial fiber (HCl 2N as oxidant). Concentrations in the effluent were below Mexican drinking water standards (0.025 mg As L(-1) water) during the 105-day (2520 h) filter operation, with a maximum As removal efficiency of 95.4%. The household filter was simple, low-cost and may be very attractive for As removal in rural areas in developing countries.


Assuntos
Arsênio/química , Ferro/química , Aço Inoxidável/química , Poluentes Químicos da Água/química , Purificação da Água/métodos
11.
Anal Biochem ; 443(2): 249-51, 2013 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-24050966

RESUMO

This work presents a rapid and simple freeze centrifugation method to concentrate dilute protein solutions for detection by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) Coomassie blue staining. Moreover, a simple way to assemble a cryoconcentration device is presented, and its use is discussed. Commercial purified protein standard and an enzyme with high fructosyltransferase (FTase) activity, coming from target fractions obtained by chromatographic separation, were used as an example. FTase, coming directly from the chromatographic fractions, was difficult to view through SDS-PAGE analysis; however, it was easily visualized, and its activity was enhanced, after the application of the freeze centrifugation protocol presented here.


Assuntos
Centrifugação/instrumentação , Eletroforese em Gel de Poliacrilamida/métodos , Proteínas/isolamento & purificação , Animais , Aspergillus/enzimologia , Desenho de Equipamento , Congelamento , Hexosiltransferases/isolamento & purificação , Cavalos
12.
Free Radic Res ; 47(10): 781-92, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23952573

RESUMO

The relevance of reactive oxygen species (ROS) production relies on the dual role shown by these molecules in aerobes. ROS are known to modulate several physiological phenomena, such as immune response and cell growth and differentiation; on the other hand, uncontrolled ROS production may cause important tissue and cell damage, such as deoxyribonucleic acid oxidation, lipid peroxidation, and protein carbonylation. The manganese superoxide dismutase (MnSOD) antioxidant enzyme affords the major defense against ROS within the mitochondria, which is considered the main ROS production locus in aerobes. Structural and/or functional single nucleotide polymorphisms (SNP) within the MnSOD encoding gene may be relevant for ROS detoxification. Specifically, the MnSOD Ala16Val SNP has been shown to alter the enzyme localization and mitochondrial transportation, affecting the redox status balance. Oxidative stress may contribute to the development of type 2 diabetes, cardiovascular diseases, various inflammatory conditions, or cancer. The Ala16Val MnSOD SNP has been associated with these and other chronic diseases; however, inconsistent findings between studies have made difficult drawing definitive conclusions. Environmental factors, such as dietary antioxidant intake and exercise have been shown to affect ROS metabolism through antioxidant enzyme regulation and may contribute to explain inconsistencies in the literature. Nevertheless, whether environmental factors may be associated to the Ala16Val genotypes in human diseases still needs to be clarified.


Assuntos
Antioxidantes/metabolismo , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo , Animais , Exposição Ambiental , Humanos , Estresse Oxidativo , Polimorfismo de Nucleotídeo Único , Espécies Reativas de Oxigênio/metabolismo
13.
Anal Biochem ; 426(1): 4-12, 2012 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-22475503

RESUMO

One of the recurrent methodological problems in preparative biochemical work is the concentration of dilute protein solutions, including culture supernatants resulting from biotechnological processes. A procedure was developed to concentrate enzymes by a novel cryoconcentration system. This approach includes a new device that facilitates the sample freezing and the subsequent solute elution from the frozen matrix by centrifugation. The optimal centrifugation conditions for this cryoconcentration system were obtained using whey protein solution as a model. The procedure was applied to concentrate dilute solutions of commercial pectinase, measuring the endopolygalacturonase (EPG) activity of this enzyme in the concentrate by a method based on the on-line torque measurement, and of recombinant fructan:fructan 1-fructosyltransferase (1-FFT) protein of Pichia pastoris from a culture in a bioreactor, as an expression system. The optimal centrifugation speed, time, and temperature were 6150 g, 20 min, and 4 °C, respectively. The concentration factors for the dilute protein solutions were 9.2-, 11.2-, and 17.1-fold for 1-FFT, whey, and commercial pectinase, respectively. Recoveries ranged from 87% to 93%. The procedure allowed concentrating proteins efficiently without affecting their enzymatic activity.


Assuntos
Hexosiltransferases/metabolismo , Poligalacturonase/metabolismo , Centrifugação , Diálise , Congelamento , Hexosiltransferases/genética , Hexosiltransferases/isolamento & purificação , Pichia/metabolismo , Poligalacturonase/isolamento & purificação , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo
14.
J Food Sci ; 77(3): S135-9, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22384966

RESUMO

Absolute threshold and just noticeable difference (JND) were determined for the perception of pungency using chili pepper in aqueous solutions. Absolute threshold and JND were determined using 2 alternative forced-choice sensory tests tests. High-performance liquid chromatography technique was used to determine capsaicinoids concentration in samples used for sensory analysis. Sensory absolute threshold was 0.050 mg capsaicinoids/kg sample. Five JND values were determined using 5 reference solutions with different capsaicinoids concentration. JND values changed proportionally as capsaicinoids concentration of the reference sample solutions changed. Weber fraction remained stable for the first 4 reference capsaicinoid solutions (0.05, 0.11, 0.13, and 0.17 mg/kg) but changed when the most concentrated reference capsaicinoids solution was used (0.23 mg/kg). Quantification limit for instrumental analysis was 1.512 mg/kg capsaicinoids. Sensory methods employed in this study proved to be more sensitive than instrumental methods. Practical Application: A better understanding of the process involved in the sensory perception of pungency is currently required because "hot" foods are becoming more popular in western cuisine. Absolute thresholds and differential thresholds are useful tools in the formulation and development of new food products. These parameters may help in defining how much chili pepper is required in a formulated product to ensure a perceptible level of pungency, as well as in deciding how much more chili pepper is required in a product to produce a perceptible increase in its pungency.


Assuntos
Capsaicina/análise , Capsicum/química , Sensação/fisiologia , Percepção Gustatória , Adolescente , Adulto , Capsaicina/química , Cromatografia Líquida de Alta Pressão , Limiar Diferencial , Feminino , Frutas/química , Humanos , Limite de Detecção , Pessoa de Meia-Idade , Limiar Sensorial , Adulto Jovem
15.
Water Sci Technol ; 63(10): 2395-402, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21977666

RESUMO

The country of Mexico is facing serious problems with water quality and supply for human use and consumption in rural communities, mainly due to topographic and isolation. In Mexico the average annual precipitation is 1,500 cubic kilometers of water, if 3% of that amount were used, 13 million Mexicans could be supplied with drinking water that they currently do not have access. Considering the limited infrastructure and management in rural communities, which do not receive services from the centralized systems of large cities, a modified pilot multi-stage filtration (MMSF) system was designed, developed, and evaluated for treating collected rainwater in three rural communities, Ajuchitlan and Villa Nicolas Zapata (Morelos State) and Xacxamayo (Puebla State). The efficiencies obtained in the treatment system were: colour and turbidity >93%. It is worth mentioning that the water obtained for human use and consumption complies with the Mexican Standard NOM-127-SSA1-1994.


Assuntos
Filtração/instrumentação , Purificação da Água , Abastecimento de Água , México , Projetos Piloto , Chuva , População Rural
16.
J Food Sci ; 75(6): E347-52, 2010 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-20722919

RESUMO

Mucilage of Opuntia ficus-indica (OFI) was extracted and characterized by its composition and molecular weight distribution. Mucilage film-forming dispersions were prepared under different pHs (3, 4, 5.6, 7, and 8) and calcium concentration (0% and 30% of CaCl(2), with respect to mucilage's weight), and their particle size determined. Mucilage films with and without calcium (MFCa and MF, respectively) were prepared. The effect of calcium and pH on mucilage films was evaluated determining thickness, color, water vapor permeability (WVP), tensile strength (TS), and percentage of elongation (%E). The average molecular weight of the different fractions of mucilage was: 3.4 x 10(6) (0.73%), 1 x 10(5) (1.46%), 1.1 x 10(3) (45.79%), and 2.4 x 10(2) Da (52.03%). Aqueous mucilage dispersions with no calcium presented particles with an average size d(0.5) of 15.4 microm, greater than the dispersions with calcium, 13.2 microm. MFCa films showed more thickness (0.13 mm) than the MF films (0.10 mm). The addition of calcium increased the WVP of the films from 109.94 to 130.45 gmm/m(2)dkPa. Calcium and pH affected the mechanical properties of the films; the largest TS was observed on MF films, whereas the highest %E was observed on MFCa films. The highest differences among MF and MFCa films were observed at pHs 5.6 and 7 for TS and at pHs 4 and 8 for %E. No effect of pH and calcium was observed on luminosity and hue angle. Chroma values were higher for MF when compared with MFCa, and increased as pH of the films increased. Practical Application: In this study mucilage from nopal was extracted and characterized by its ability to form edible films under different pHs, and with or without the addition of calcium. Opuntia ficus-indica mucilage had the ability to form edible films. In general, it can be considered that mucilage films without modification of pH and without the addition of calcium have the best water vapor barrier properties and tensile strength. Mucilage from nopal could represent a good option for the development of edible films in countries where nopal is highly produced at low cost, constituting a processing alternative for nopal.


Assuntos
Cloreto de Cálcio/química , Embalagem de Alimentos , Opuntia/química , Componentes Aéreos da Planta/química , Extratos Vegetais/química , Cálcio da Dieta/análise , Fenômenos Químicos , Carboidratos da Dieta/análise , Elasticidade , Concentração de Íons de Hidrogênio , Concentração Osmolar , Tamanho da Partícula , Permeabilidade , Pigmentação , Extratos Vegetais/isolamento & purificação , Proteínas de Plantas/análise , Vapor , Resistência à Tração , Água/análise
17.
J Agric Food Chem ; 56(4): 1511-6, 2008 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-18232658

RESUMO

Pulp from "slightly ripe", "moderately ripe", or "fully ripe" mangoes was digested in vitro in the absence and presence of processed chicken as a source of exogenous fat and protein to examine the impact of stage of ripening of mango on micellarization during digestion and intestinal cell uptake (i.e., bioaccessibility) of beta-carotene. The quantity of beta-carotene transferred to the micelle fraction during simulated digestion significantly increased as the fruit ripened and when chicken was mixed with mango before digestion. Qualitative and quantitative changes that occur in pectin from mango pulp during the ripening process influenced the efficiency of micellarization of beta-carotene. Finally, the uptake of beta-carotene in micelles generated during simulated digestion by Caco-2 human intestinal cells confirmed the bioaccessibility of the provitamin A carotenoid in mango.


Assuntos
Gorduras na Dieta/farmacologia , Digestão , Mangifera/química , beta Caroteno/farmacocinética , Animais , Disponibilidade Biológica , Células CACO-2 , Galinhas , Humanos , Micelas
18.
J Agric Food Chem ; 55(16): 6628-35, 2007 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-17625873

RESUMO

A liquid chromatography-mass spectrometry (LC-MS) method was developed to simultaneously identify and quantify carotenoids and tocopherols in the fruit of seven mango cultivars grown in Mexico. Fruit maturity was characterized objectively, and carotenoids and tocopherols were isolated by solvent extraction and analyzed by HPLC coupled to a C30 stationary phase and diode array, fluorescence, and mass (time-of-flight) detectors. All cultivars had a similar carotenoid pattern, in which all-trans-beta-carotene and dibutyrates of all-trans-violaxanthin and 9-cis-violaxanthin were the most abundant. The content of all-trans-beta-carotene ranged between 0.4 and 2.8 mg/100 g, and 'Haden' and 'Ataulfo' mangoes had the highest amount. The amounts of all-trans-violaxanthin and 9-cis-violaxanthin (as dibutyrates) ranged between 0.5 and 2.8 mg/100g and between 0.4 and 2.0 mg/100 g, respectively. The content of alpha-tocopherol was low (200-500 microg/100 g). The results of this study indicate that all-trans-beta-carotene, all-trans-violaxanthin, and 9-cis-violaxanthin are the most abundant carotenoids in mango grown in Mexico.


Assuntos
Carotenoides/análise , Frutas/química , Mangifera/química , Tocoferóis/análise , Xantofilas/análise , Cromatografia Líquida de Alta Pressão , Ésteres/análise , Frutas/crescimento & desenvolvimento , Espectrometria de Massas , México
19.
Cytogenet Genome Res ; 114(1): 89-92, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16717456

RESUMO

About 15% of patients with a clinical phenotype of Angelman syndrome (AS) have an unknown etiology. We report a patient with features reminiscent of AS, including a pattern of characteristic facial anomalies as well as speech impairment, developmental delay and frequent laughter. In addition, the patient had features not commonly associated with AS such as heart malformations and scoliosis. She was negative in SNURF-SNRPN exon 1 methylation studies and the G-banded karyotype was normal. Array-based comparative genomic hybridization disclosed a deletion of maximally 1 Mb at 17q21.31. The deleted region contains the MAPT gene, implicated in late onset neurodegenerative disorders, and the STH and NP_056258.1 genes. Another gene, such as CRHR1, might also be included based on maximum possible size of the deletion. We suggest that microdeletions within the 17q21.31 segment should be considered as a possible cause of phenotypes resembling AS, particularly when easily controlled seizures and/or cardiac abnormalities are also present.


Assuntos
Cromossomos Humanos Par 17 , Deficiência Intelectual/genética , Proteínas do Tecido Nervoso/genética , Anormalidades Múltiplas/genética , Síndrome de Angelman/genética , Pré-Escolar , Expressão Facial , Feminino , Humanos , Deleção de Sequência , Proteínas tau
20.
Comp Biochem Physiol B Biochem Mol Biol ; 135(2): 373-83, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12798946

RESUMO

Protein food modulates the activity of proteases of the midgut gland of Penaeus vannamei. Shrimp fed with food containing 15, 30 and 50% protein exhibited differences in trypsin and chymotrypsin activity and trypsin mRNA levels. Shrimp fed with 30% protein showed higher trypsin and chymotrypsin activities than those fed 15 or 50% protein. An additional paralogue trypsin was observed with electrophoretic analysis in shrimp fed 30% protein. Shrimp fed 30% protein showed the highest trypsin to mRNA concentration, suggesting that trypsin genes expression is regulated transcriptionally.


Assuntos
Proteínas Alimentares/farmacologia , Sistema Digestório/enzimologia , Penaeidae/enzimologia , Tripsina/metabolismo , Animais , Peso Corporal , Quimotripsina/análise , Quimotripsina/biossíntese , Regulação da Expressão Gênica , Tamanho do Órgão , Penaeidae/anatomia & histologia , Penaeidae/genética , RNA Mensageiro/metabolismo , Proteínas Ribossômicas/genética , Proteínas Ribossômicas/metabolismo , Tripsina/biossíntese , Tripsina/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA