Increasing resistance against Phytophthora citrophthora in tangelo Nova fruits by modulating polymethoxyflavones levels.

The effect of 6-benzylaminopurine on polymethoxyflavone levels in tangelo Nova fruits and the possible participation of these secondary metabolites in defense mechanisms against Phytophthora citrophthora are studied. The in vitro study of the inhibitory effect of these compounds on fungal growth reveals that nobiletin is the most active agent followed by sinensetin, heptamethoxyflavone, and tangeretin. Treatment with 100 ppm of 6-benzylaminopurine increased the levels of these polymethoxyflavones in this Citrus hybrid and also enhanced the in vivo resistance of the fruit to the fungus by approximately 60%.

[Characteristics of diagnoses of malignant neoplasms in primary care]. / Características del diagnóstico de las neoplasias malignas en atención primaria.

OBJECTIVE: To describe the diagnostic process of malignant neoplasms according to the level of care, initial symptoms and diagnostic procedures.Design. Retrospective descriptive study. SETTING: Health centre on the periphery of a big city. PARTICIPANTS: Cases of malignant neoplasms recorded between 1990 and 2000 through the mortality register and specific recording in 2000. MAIN MEASUREMENTS: We reviewed the records, obtaining age and gender, location, initial symptoms, date of first consultation and at what care level, diagnostic tests requested in primary care (PC) and the time elapsed until they became available, until the patients referral and until the definitive diagnosis. 274 cases were included, with information lacking for 12. RESULTS: 42.4% were women, with average age 67.6. The most frequent types of cancer were digestive, respiratory and masculine genital-urinary. 75.2% consulted initially in PC. The most common symptoms were pain and haemorrhage. Of those attended in PC, diagnostic tests were requested for 46.7%, the most common of these being basic analysis (53.2%) and simple x-ray (24.8%). Mean time before results were available was 15.4 days. 67.2% of all cases were referred. Mean time from consultation to referral was 7.3 days; and to definitive diagnosis, 68.0 days. However, for those initially attended in PC, the mean wait was 81.0 days; and at other levels, 30 days (P<.0001). CONCLUSIONS: Most patients consult on their initial symptoms in PC. The time taken for the diagnostic process at this level is adequate, although the total length of the process is greater for those who first consulted in PC.

Características del diagnóstico de las neoplasias malignas en atención primaria / Characteristics of diagnoses of malignant neoplasms in primary care

Objetivo. Describir el proceso diagnóstico de las neoplasias malignas según el nivel asistencial, síntomas iniciales y procedimientos diagnósticos. Diseño. Estudio descriptivo, retrospectivo. Emplazamiento. Centro de salud de la periferia de una gran ciudad. Participantes. Casos de neoplasias malignas registrados desde 1990 hasta 2000 mediante fichero de mortalidad y registro específico durante el año 2000.Mediciones principales. Revisamos las historias, obteniendo edad y género, localización, síntomas iniciales, fecha de primera consulta y nivel asistencial de ésta, pruebas diagnósticas solicitadas en atención primaria (AP) y tiempo hasta que están disponibles, hasta la derivación del paciente y hasta el diagnóstico definitivo. Se incluyeron 274 casos, careciéndose de información en 12.Resultados. Un 42,4 por ciento eran mujeres; su edad media fue 67,6 años. Las localizaciones más frecuentes fueron en aparato digestivo, respiratorio y genitourinario masculino. El 75,2 por ciento consultó inicialmente en AP. Los síntomas más frecuentes fueron dolor y hemorragia. De los atendidos en AP, se solicitaron pruebas diagnósticas en un 46,7 por ciento, y las más utilizadas fueron la analítica básica (53,2 por ciento) y la radiografía simple (24,8 por ciento); la mediana de tiempo que se tardó en disponer de resultados fue de 15,4 días. Se derivó un 67,2 por ciento de todos los casos. La mediana de tiempo desde consulta hasta derivación fue de 7,3 días y hasta el diagnóstico definitivo de 68,0 días, aunque para los atendidos inicialmente en AP la mediana fue de 81,0 días y de 30,0 si consultaron en otros niveles (p < 0,0001).Conclusiones. Los pacientes consultan los síntomas iniciales mayoritariamente en AP, y la duración del proceso diagnóstico en este nivel es adecuada, aunque la duración total del proceso es mayor en quienes consultan en AP (AU)

Antioxidative activities of heterocyclic compounds formed in brewed coffee.

Typical volatile heterocyclic compounds found in brewed coffee extracts-pyrroles, furans, thiophenes, and thiazoles-were examined for antioxidative activity, which was determined by measuring the oxidative conversion of hexanal to hexanoic acid using gas chromatography. 2-Acetylpyrrole, 1-methylpyrrole, and pyrrole inhibited hexanal oxidation by 98, 87, and 78%, respectively, at a concentration of 500 microgram/mL over a period of 30 days. 2-Methylfuran, which inhibited hexanal oxidation by 90% at all concentrations tested (500, 200, and 100 microgram/mL) for a 30-day period, exhibited the greatest activity among furans tested. Similarly, 2-methylthiophene, which inhibited hexanal oxidation by almost 100% at a concentration of 500 microgram/mL over 30 days, exhibited the greatest activity among the thiophenes tested. In general, thiazoles were ineffective antioxidants at all concentrations tested. However, 4,5-dimethylthiazole was able to inhibit hexanal oxidation by 50% at the highest level tested (500 microgram/mL). 2-Acetylpyrrole, 2-methylfuran, and 2-methylthiophene at concentrations of 500, 200, and 100 microgram/mL and furan at a concentration of 500 microgram/mL exhibited antioxidative activities comparable to that of the synthetic antioxidant butylated hydroxytoluene at a concentration of 50 microgram/mL.

Effects of alpha- and gamma-tocopherols on the autooxidation of purified sunflower triacylglycerols.

The antioxidant effects of alpha- and gamma-tocopherols were evaluated in a model system based on the autooxidation of purified sunflower oil (p-SFO) triacylglycerols at 55 degrees C for 7 d. Both tocopherols were found to cause more than 90% reduction in peroxide value when present at concentrations >20 ppm. Alpha-tocopherol was a better antioxidant than gamma-tocopherol at concentrations < or =40 ppm but a worse antioxidant at concentrations >200 ppm. Neither alpha- nor gamma-tocopherol showed a prooxidant effect at concentrations as high as 2000 ppm. The amount of tocopherols consumed during the course of oxidation was positively correlated to the initial concentration of tocopherols, and the correlation was stronger for alpha- than for gamma-tocopherol. This correlation suggested that, besides reactions with peroxyl radicals, destruction of tocopherols may be attributed to unknown side reactions. Addition of FeSO4, as a prooxidant, caused a 12% increase in the peroxide value of p-SFO in the absence of tocopherols. When tocopherols were added together with FeSO4, some increase in peroxide value was observed for samples containing 200, 600 or 1000 ppm of alpha- but not gamma-tocopherol. The addition of FeSO4, however, caused an increase in the amount of alpha- and gamma-tocopherols destroyed and led to stronger positive correlations between the amount of tocopherols destroyed during oxidation and initial concentration of tocopherols. No synergistic or antagonistic interaction was observed when alpha- and gamma-tocopherols were added together to autooxidizing p-SFO.

Effect of ethylene on naringin, narirutin and nootkatone accumulation in grapefruit.

This paper studies the effect of different concentrations of ethephon on the levels of the sesquiterpene, nootkatone, and of the flavanones, naringin and narirutin, in grapefruit fruits. The results show that nootkatone synthesis and/or accumulation was stimulated by all the concentrations of ethephon assayed, while the levels of naringin and narirutin in the rind diminished. These results open up new perspectives concerning the possible regulation of the secondary metabolism of the plants.