On-line solid-phase extraction using a C18 minicolumn coupled to a flow injection system for determination of caffeine in green and roasted coffee beans.

A novel and fast method based on the solid phase extraction (SPE) coupled to a flow injection system for the determination of caffeine in coffee beans was developed. The caffeine extraction of coffee beans was carried out with hot water. A C18 reverse-phase mini-column was coupled to a continuous flow manifold to carry out the on-line SPE and the quantification of caffeine from aqueous extracts. Column length, retention time, elution volume, extracting solution and injection volume were evaluated. The retention time was of 90s and the elution was carried out with 400 µL of a methanol:water mixture (25:75). The proposed on-line SPE was compared against a chloroform extraction from aqueous extracts. With the proposed method the sample preparation was minimised and the sample throughput was increased (10 determination/h) because no dilution was required. Green coffee beans and beans with different roasting degree were analyzed.

El lactitol incrementa el glutation reducido y disminuye el óxido nítrico en ratas Sprague-Dawley / Lactitol increases reduced glutathione and decreases nitric oxide in Sprague Dawley rats

Existe un creciente uso de los alcohol-azúcares como el lactitol en la industria de los alimentos. El estrés oxidativo juega un papel importante en la génesis de patologías digestivas que van desde inflamación hasta cáncer. El propósito de este estudio fue determinar el efecto del lactitol sobre el malondialdehído (MDA), óxido nítrico (NO), glutation reducido (GSH), ácido ascórbico y ácido dehidroascórbico como marcadores del balance oxidación/antioxidación. Para ello se utilizaron 80 ratas macho Sprague-Dawley divididas en cuatro grupos , tres experimentales de 20 animales, a los cuales se les administró por sonda orogástrica, lactitol en dosis de 0,3; 1,0 y 5,0 g/Kg/día durante 12 semanas y un grupo control que recibió solución salina fisiológica por el mismo período de tiempo. El lactitol administrado en dosis de 0,3; 1,0 y 5,0 g/Kg/día produjo un incremento significativo (P<0,05) del GSH (326,5 ± 13,0 µg/ml; 328,5 ± 9,2 µg/ml y 398,2 ± 11,8 µg/ml) al ser comparado con sus respectivos valores basales (285,8 ± 4,0 µg/ml; 280,0 ± 6,2 µg/ml y 279,5 ± 9,1 µg/ml). El lactitol a dosis de 5 g/Kg/día produjo el más alto incremento de la concentración de GSH y al mismo tiempo provocó una disminución significativa del los niveles de NO (33,0 ± 1,2 µM) cuando se comparó con su concentración basal (46,2 ± 2,8 µM). No fueron observados cambios significativos sobre el resto de los marcadores del balance oxidación/antioxidación. Aunque el lactitol es un alcohol-azúcar que no se absorbe a nivel del tracto gastrointestinal, es posible que los productos finales obtenidos luego de su metabolismo por las bacterias intestinales, induzcan efectos sistémicos que pueden afectar el balance oxidación/antioxidación a favor de la antioxidación.

Sugar alcohols such as lactitol are increasingly being used in the food industry. Tissue oxidative stress is an important contributor to the genesis of inflammatory bowel disease and cancer. The purpose of this study was to determine the effect of lactitol on malondialdehyde (MDA), reduced glutathione (GSH), nitric oxide (NO), dehydroascorbic and ascorbic acid as redox markers. Eighty Sprague Dawley rats were divided into four groups; three experimental groups which received lactitol through an oral catheter at doses of 0.3; 1.0; 5 g/kg/day and an experimental group to which saline solution was administered during 12 weeks. Lactitol at doses of 0.3; 1.0; 5 g/kg/day produced a significant increase (P<0.05) on GSH (326.5 ± 13.0 µg/ml; 328.5 ± 9.2 µg/ml y 398.29 ± 11.8 µg/ml respectively) when compared with their respective basal values (285.8 ± 4.0 µg/ml; 280.0 ± 6.2 µg/ml y 279.5 ± 9.1 µg/ml). Lactitol dose of 5g/kg/day produced the highest increase on GSH levels and at the same time elicited a significant decrease on NO levels (33.0 ± 1.2 µM) when compared with basal values (46.2 ± 2.8 µM). No significant changes were observed on the remaining redox markers. Although lactitol is a sugar alcohol that is not absorbed in the small bowel, it is possible that its metabolisms end products, under intestinal bacterial effects, alter the redox balance in favor of antioxidants.

Effect of cigarette smoking on the oxidant/antioxidant balance in healthy subjects.

BACKGROUND AND PURPOSE: Cigarette smoking has been associated with the development of cardiovascular disease and cancer. Even though the molecular mechanism(s) are not clear, the pathology has been related to oxygen free radicals present in cigarette smoke. Thus, the main objective of this study was to establish the changes in the oxidation/antioxidation balance induced by cigarette smoking. METHODS: Thirty healthy subjects (15 smokers and 15 nonsmokers) of both sexes were studied. The smokers group had smoked a mean of 14 cigarettes per day for an average of 4.5 years. Fasting serum levels of malondialdehyde (MDA), a marker of oxidative stress, nitric oxide (NO), reduced glutathione (GSH), and vitamin C (ascorbic and dehydroascorbic acids) were measured. RESULTS: Fasting NO concentration was significantly higher in smokers (51.3 +/- 5.3 microM) than in nonsmokers (35.2 +/- 4.8 microM, P < 0.05). The smokers had significantly higher serum dehydroascorbic acid levels (2.4 +/- 0.5 mg/dL, P < 0.03) than the nonsmokers (1.08 +/- 0.08 mg/dL). No significant differences were observed in the levels of ascorbic acid, MDA, and GSH between the smokers and nonsmokers. CONCLUSIONS: Our results suggest that exposure to cigarette smoke increases NO synthesis, such that NO may act in a compensatory way as an inhibitor of lipid peroxidation. Smoking also activates other antioxidative mechanisms such as involving vitamin C. These protective mechanisms appear to be enough in preventing accumulation of oxidative products such as MDA and avoiding oxidative damage.

Adición de mayonesa a la dieta de rata Sprague-Dawley incrementa la glicemia y los triacilglicéridos con disminución del HDL-colesterol / Adding mayonnaise to the diet of Sprague-Dawley rats increases with triacilglycerides glycemia and decreased HDL-cholesterol

El objetivo del presente estudio fue evaluar el efecto del consumo de mayonesa, sobre algunos factores determinantes del riesgo de enfermedad cardiovascular (ECV). Para ello se utilizaron 24 ratas macho Sprague-Dawley a las cuales se les suministró por un período de 5 semanas, ratarina mezclada con mayonesa ad libitum en proporción de 25 por ciento. Antes y después de recibir la dieta modificada se les determinó, previo ayuno de 12 horas, las concentraciones séricas de glucosa, colesterol total, colesterol de HDL, VLDL y LDL, y triacilglicéridos. Los resultados mostraron un incremento significativo en la glicemia basal (101,3 ± 3,9 vs. 126,4 ± 4,5 mg/dl, p< 0,0001), triacilglicéridos (49,9 ± 3,4 vs. 117,4 ± 27,6 mg/dl; p<0,02) y colesterol de VLDL (10,0 ± 0,7 vs. 23,5 ± 5,5 mg/dl; p<0,02), y una disminución en la concentración de HDL-colesterol (40,8 ± 1,7 vs. 35,8 ± 1,0 mg/dl; p<0,001) sin cambios significativos en el colesterol total y LDL-colesterol. Podemos concluir que una ingesta elevada de aditivos alimenticios con alto contenido graso como la mayonesa, incrementa en las ratas los marcadores del riesgo de ECV lo cual llama a la reflexión por el efecto que dicho aditivo podría también tener en los humanos.

Lactitol en dosis elevadas incrementa la glicemia, HDL-colesterol y disminuye el LDL-colesterol sin cambios en el colesterol total en ratas Sprague-Dawley / Lactitol high dose increases the blood glucose, HDL-cholesterol and lowers LDL cholesterol without changes in total cholesterol in Sprague-Dawley rats

Con el fin de estudiar el efecto del lactitol sobre la glicemia y el perfil líp¡dico de ratas Sprague-Dawley, fue administrado lactitol durante 12 semanas a 80 ratas macho, jóvenes divididos en cuatro grupos que recibieron lactitol en dosis de 0,3 g/Kg/día; 1 g/Kg/día y 5 g/Kg/día y solución salina al 0,9 por ciento para medir antes y después del tratamiento glicemia, colesterol total, HDL-c, LDL-c, VLDL-c y triacilglicéridos. Los resultados indican que el lactitol a una dosis elevada (5g/Kg/día) es capaz de incrementar significativamente la glicemia (91,35±5,1 vs. 124,69±5,7 mg/dl; p<0,05), el HDL-c (32,09±1,8 vs. 59,92±2,2 mg/dl; p<0,05) y disminuir el LDL-c (31,45±4,5 vs. 17,71±3,1 mg/dl; p<0,05) sin producir cambios en la concentración de colesterol total. Estos resultados nos permiten concluir que el lactitol, a pesar de ser un polialcohol que no se absorbe en intestino, es capaz de modificar la glicemia y el perfil líp¡dico de ratas probablemente por acción de los productos de su degradación por la flora bacteriana intestinal.

Epidemiological assessment of mucocutaneous infections in patients with recurrent infection syndrome.

BACKGROUND: Recurrent infection syndrome (RIS) results from repeated interactions between hosts and environmental infectious agents and is considered normal (NRIS) because of its benign evolution and positive effects in the development of normal immune responses. Abnormal RIS (ARIS) is characterized by the unusually high frequency of severe infections, either as a result of anatomical or functional abnormalities or due to primary or secondary immunodeficiencies (PIDs and SIDs, respectively). Recurrent mucocutaneous infections (MCIs) can be manifestations of RIS or ARIS and could be more frequent in primary immunodeficiencies. Similarly, etiologic agents might vary from what is observed in the general population. METHODS: We carried out a descriptive study to determine the prevalence of aerobic bacterial and fungal mucocutaneous infections in 452 patients with recurrent infections, using clinical records to establish immunological status associated with the presence and characteristics of the infections. Microbiological analyses from mucocutaneous lesions were used to confirm the etiology. RESULTS: We found mucocutaneous infections in 50 patients for a total of 62 episodes (bacterial or fungal infections in 38 vs. 12 patients, respectively). Mucocutaneous infections were more frequent (21.8% vs. 9.1%; OR = 2.8) and recurrent (8.7% vs. 0.2%; P = 0.000) in primary immunodeficient patients. Furthermore, those with defects in phagocytic cells presented more mucocutaneous infections (56.2%) than patients with other primary immunodeficiencies (11.3%; OR = 10.1). CONCLUSIONS: Bacterial and fungal mucocutaneous infections are more frequent and severe in primary immunodeficient patients, particularly those with defective phagocytosis. Early and adequate assessment of the nature of mucocutaneous infections in ARIS should impact the ability of physicians to treat promptly, avoid complications and reduce the costs of medical assistance.

Increased serum malondialdehyde and decreased nitric oxide within 24 hours of thrombotic stroke onset.

BACKGROUND AND PURPOSE: Ischemia/reperfusion generates free oxygen radicals, which react with the unsaturated lipids of biomembranes resulting in the generation products such as malondialdehyde. Malondialdehyde could be a sensor for tissue damage and reperfusion. Nitric oxide, released due to the early arrival of leukocytes in the brain parenchyma, could be a sensor for nonflow phenomenon. Thereby, the purpose of this research was to evaluate the behavior of malondialdehyde and nitric oxide within the 24 hours after the stroke onset. METHODS: Fifteen patients up to an age of 49 years, admitted to the emergency of University Hospital and Chiquinquirá Hospital in Maracaibo, Venezuela, were examined by a neurologist and underwent 12-lead electrocardiograms and computed tomography for the diagnosis of thrombotic stroke. Serum malondialdehyde and nitric oxide were measured as thiobarbituric acid adducts and total nitrites. Data were collected within the 24 hours after the stroke onset. RESULTS: Malondialdehyde for patients with stroke had a significant increase (P<0.001) when compared with healthy controls (47.9 +/- 7.1 vs. 1.7 +/- 0.2 micromol/L). Conversely, serum nitric oxide for patients with stroke had a significant decrease (P<0.001) when compared with the control group (14.5 +/- 1.4 vs. 41.3 +/- 3.7 micromol/L). The lowest values of malondialdehyde and the highest values of nitric oxide were observed in two patients, who died. CONCLUSIONS: Serum levels of malondialdehyde increase, and serum levels of nitric oxide diminish within 24 hours after the onset of thrombotic stroke onset. This suggests that serum malondialdehyde level could be used as potentially reliable and sensitive marker for reperfusion, whereas nitric oxide levels could acts as potential biochemical sensor for nonreflow phenomenon.

Polimorfismo fenotípico de cepas autóctonas de sporothrix schenkii / Phenotypic polimorphism in indigenous strains of sporothrix schenkii

Se presentan los resultados macroscópicos, de asimilación de azúcares y de virulencia de 55 cepas de Sporothrix schenckii aisladas a partir de lesiones de pacientes con esporotricosis cútanea, que consultaron al laboratorio de micología de la Facultad de Medicina de la Universidad de Antioquia en Medellín, Colombia, y que fueron coleccionadas en el transcurso de 10 años. La morfología macroscópica de las colonias y su pigmentación se evaluaron tanto en agar mycosel como en extracto de malta. La mayoría de las cepas en los dos medios presentaban colonias con 2 ó 3 colores diferentes. En mycosel 5 cepas (9.1 por ciento) fueron monocromáticas y éste fue el medio más estable para definir las características de pigmentación. El 85 por ciento de las cepas en mycosel fueron café claras, café oscuras, plisadas o plisadas y umbilicadas. Todas las cepas asimilaron D-glucosa, glicerol y D-xilosa en el sistema Api 20C y 25 cepas se clasificaron en 9 biotipos de asimilación de la A a la I. La mayoría de las cepas tanto pigmentadas como albinas, resultaron virulentas para ratones. En éstos predominaron los cuerpos en cigarro en forma de naveta y no se visualizaron cuerpos asteroides en los exudados testiculares. Se demuestra así la gran heterogeneidad fenotípica de las cepas autóctonas de S. schenckii, se plantea la importancia de correlacionar estos hallazgos con los patrones de heterogeneidad gen ética informados por investigadores Japoneses y quizás explicar por esta diversidad fenotípica y genotípica, el polimorfismo clínico de la enfermedad y establecer mapas de distribución de los diferentes biotipos o genotipos en Colombia y América Latina. Incluso el cruzar cepas distantes en su biotipo o genotipo podría facilitar la obtención de la forma de reproducción sexual del microorganismo

We studied macroscopic colony findings, sugar assimilation patterns and virulence of 55 Sporothrix schenckij strains obtained from patients with cutaneous sporothrichosis. They were collected during a 10-year period at the Mycology Laboratory, University of Antioquia, School of Medicine, Medellín, Colombia. Pigmentation types and macroscopic morphological characteristics' were studied on mycosel agar and malt extract. In most cases 2 or 3 colony colors were present In both media. In mycosel agar only 5 strains (9.1%) were monochromatic. Pigmentation was very stable in that medium. Eighty five percent of the mycosel agar colonies were beige, brown, pleated or pleated and umbilicated. All strains assimilated D-glucosa, glycerol and D-xylosa. We established 9 patterns of assimilation (blotypes), from A to I In 25 strains. Both pigmented and albino strains were virulent for mice. We emphasize the diversity of our Indigenous strains, and the importance of genotypic characterization and of the correlation studies of phenotypic and genotypic variation with the clinical and geographical patterns of the disease