Conjunctival impression cytology with transfer in the assessment of vitamin A status in Nigerian children.

OBJECTIVE: To determine vitamin A status by conjunctival impression cytology with transfer (CIC-T) and assess its ability to predict low and deficient serum retinol concentrations. STUDY DESIGN: CIC-T was performed on 128 healthy, well-nourished and 230 malnourished children aged under 6 years by a 3-5-second application of cellulose acetate paper to each bulbar conjunctiva followed by transfer of the adhered cells onto glass slides. The slides were stained with Alcian green 2GX, and smears were classified as normal, borderline normal, borderline abnormal and deficient. Corresponding serum retinol levels were determined in each subject. RESULTS: The results showed that CIC-T is a simple procedure with a failure rate of 7.3% caused by tearing and agitation. The power of CIC-T to predict vitamin A status varied with both the CIC-T smear classification used and serum retinol concentration threshold. CIC-T smear classification as abnormal and normal appears to be the most robust and predictive of serum retinol, < 10 and > 10 < 20 micrograms/dL, respectively. CONCLUSION: The simplicity, sensitivity and specificity of CIC-T suggest that this procedure is a good screening tool for epidemiologic survey of vitamin A status.

Preparation of 16-formylestradiol and the 16-(alpha-methylenebutanolide) derivative.

Routes to the preparation of 16-formylestradiol are described. Estrone was converted to (E)-16-methoxymethylene estrone via the 16-hydroxymethylene estrone. Reduction of the methoxymethylene estrone with NaBH4 in the presence of CeCl3 gave 16-methoxymethylene estradiol. Deprotection by acid afforded the desired 16-formylestradiol. Attempts to prepare the 16-formylestradiol via the 16-butylthiomethylene derivative gave only 16-formylestra-1,3,5(10),16-tetraen-3-ol, and a route through the 16-dimethoxymethyl derivative gave a mixture of the 16-formyltetraen-3-ol and the 16-formylestradiol in low yield. The 16-formylestradiol was subsequently converted to the alpha-methylene lactone conjugate, 4-(3,17 beta-dihydroxyestra-1,3,5(10)trien-16-yl)-2-methylene-4-butanol ide by reaction with methyl alpha-(bromomethyl) acrylate and zinc.