RESUMEN
OBJECTIVES: Many patients with vitamin B12 deficiency do not have anemia or macrocytosis, but the prevalence of B12 deficiency in patients without macrocytosis is not known. METHODS: We investigated the prevalence of B12 deficiency among patients with normocytosis and microcytosis and recommended a screening strategy. All patients (n = 3714) with serum B12 measured at the Prince of Wales Hospital in 1996 were reviewed. The prevalence of serum B12 less than 140 pmol/L was determined for the following patient subgroups: younger than 70 y, older than 70 y, anemic, non-anemic, macrocytic, normocytic, microcytic, documented iron deficiency, and documented thalassemia. RESULTS: The prevalence of B12 deficiency (<140 pmol/L) ranged from 4.8% to 9.8% among the different subgroups. CONCLUSIONS: Whatever screening criteria were used, a significant number of B12-deficient patients will be missed. Therefore, there may be a case for universal vitamin B12 screening.
Asunto(s)
Deficiencia de Vitamina B 12/epidemiología , Vitamina B 12/sangre , Factores de Edad , Anciano , Anemia/epidemiología , Anemia Macrocítica/epidemiología , Anemia Perniciosa/epidemiología , Recuento de Células Sanguíneas , China/epidemiología , Femenino , Evaluación Geriátrica , Humanos , Masculino , Tamizaje Masivo , Prevalencia , Estudios RetrospectivosRESUMEN
Pasteurization conditions for grape juice were examined and the concept of pasteurizing grape juice utilizing solar energy was explored in this study. The z-values of four selected micro-organisms in grape juice were approximately 5-8 C, whereas polyphenol oxidase in fresh grapes had a z-value of 8.0 C at pH 3 .4. Using a 0.5 m2 solar collector test module constructed for this study, 2.5 h were required to heat the grape juice from 10 to 85 C. The solar pasteurized juice and commercially pasteurized juice were different in flavor and color but not in pH, titratable acidity or soluble solids.