Stability of individual carotenoids, retinol, and tocopherol in stored plasma.

Clinical Chemistry (Impact Factor: 7.77). 10/1988; 34(9):1947.
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    ABSTRACT: We have quantitatively analyzed human plasma for the following carotenoids: all-trans-lutein, all-trans-zeaxanthin, a-cryptoxanthin, ß-cryptoxan- thin, the sum of all-trans-lycopene and its cis isomers, (/-carotene and |i-carotene. In addition, we have tenta tively identified and quantified 13-as-lute ¡n and 13- ci's-zeaxanthin in human plasma. The latter two cis isomers are also apparent in samples of two common food items, spinach and corn meal. We have analyzed the ratios of all of the members of the ß,ß family of carotenoids (zeaxanthin, ß-cryptoxanthin and li-caro tene) to their corresponding ß,E structural isomers (lutein, a-cryptoxanthin and a-carotene) in human plasma. There are marked differences in these ratios, with ß-carotene and ß-cryptoxanthin predominating in the carotene and monohydroxy-xanthophyll classes and lutein predominating in the dihydroxy-xanthophyll class. These differences could be attributable to di etary intake or to specific mechanisms in the way humans absorb and utilize these compounds. J. Nutr. 120:1654-1662, 1990. INDEXINGKEYWORDS:
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    ABSTRACT: Summary. Assessment of nutritional status through the measurement of retinol and α-tocopherol in dried blood spots A study has been carried out to assess the applicability of an analytical method for the measurement of retinol and α-tocopherol in dried blood spots collected on filter paper, by comparing serum samples with dried blood spots collected simultaneously from healthy volunteers. The protocol for extraction and chromatographic analysis allows the detection of retinol and α-tocopherol in small dried capillary blood samples equivalent to 1,5 μL serum and it shows a good both within- and between-day precision (<7%) over the entire physiological range studied. Concentrations of retinol, but not α–tocopherol, show a good correlation with values obtained in serum («gold standard») (r>0,82, P<0,001) and they are interchangeable with those in serum regardless of adjusting for hematocrit values. For retinol, deviation of concentrations in dried blood spots from those in serum is acceptable and the procedure shows a good sensitivity and specificity to detect subjects at risk (serum retinol <1,05μmol/L). The results suggest that this protocol, although must be optimized for a-tocopherol quantification, is a simple, rapid, sensitive and useful one for assessing retinol status by using reduced dried capillary blood spots collected on filter paper and allows its applicability in clinical practice (hospital and home care). RESUMEN Con el objetivo de evaluar la aplicabilidad de un protocolo para la determinación de retinol y α-tocoferol en gotas de sangre secas fijadas sobre papel de filtro, se han comparado especímenes de suero y sangre capilar seca obtenidas y procesadas de forma simultánea en voluntarios sanos. El protocolo de extracción y análisis cromatográfico permite la detección de retinol y α-tocoferol en especímenes de sangre capilar seca equivalentes a 1,5 μL de suero, mostrando una buena precisión intra e interdiaria (<7%) en todo el intervalo fisiológico evaluado. Las concentraciones de retinol, pero no de α-tocoferol, muestran una buena correlación con las determinadas en suero («patrón de referencia») (r >0,82; P<0,001) y una buena intercambiabilidad con los valores en suero, independientemente del ajuste de las concentraciones con valores de hematocrito. La desviación frente a los valores en suero es aceptable en el caso de retinol y el protocolo muestra una buena sensibilidad y especificidad para la detección de sujetos en situación de riesgo (retinol en suero <1,05 μmol/L). Los resultados sugieren que este protocolo es sencillo, rápido, sensible y debe ser optimizado para la determinación de α-tocoferol y es potencialmente válido para la determinación de retinol, y α-tocoferol en volúmenes reducidos de sangre capilar seca fijada sobre papel permitiendo su potencial aplicabilidad en la práctica clínica (ámbito hospitalario y atención a domicilio).
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    ABSTRACT: This paper reports the prevalence of chronic esophagitis and nutritional status among 538 young persons aged 15 to 26 years from the high risk area for esophageal cancer. Of these subjects, 166 were from households with history of esophageal cancer and 372 were from households without history of esophageal cancer. The incidences of chronic esophagitis among male and female adolescents were 37. 6% and 36% respectively, which was significantly higher than those in the low risk area (17%). The frequency of chronic esophagitis in the adolescents in the households with history of esophageal cancer was also higher than in those in the households without history of esophageal cancer. The deficiencies of vitamins, especially of riboflavin and ascorbate, are prevalent and severe among these adolescents. Ascorbate deficiency is correlated with the severity of the chronic esophagitis. These results indicate that chronic esophagitis may be involved in the natural history of esophageal carcinogenesis. Nutrient deficiencies may create an environment favorable to the development of precancerous lesions.
    Chinese Journal of Cancer Research 12/1992; 4(4):69-75. DOI:10.1007/BF02996406 · 0.93 Impact Factor


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