Effect of subclinical lead intoxication on laryngeal cancer.

In this study we investigated the possible relationship of laryngeal cancer and subclinical lead intoxication, using the depression of aminolevulinic acid dehydratase (ALAD) activity in blood as indicator. Twenty-six patients with laryngeal cancer and 53 normal controls met the criteria to enter the study. Blood ALAD activity values in the patients with laryngeal cancer ranged from 27.1 to 75.3 U/l with a mean of 50.79 U/l. The respective values in the control group ranged from 36.2 to 98 U/l with a mean of 59.76 U/l. There was a statistically significant difference between the two means (0.001 < p < 0.01), whereas blood lead concentrations in all patients were within normal limits. These findings support the hypothesis that low level lead intoxication (subclinical blood lead levels), from cars, industries and products, may contribute to the risk of laryngeal cancer. Further investigation is needed to clarify the exact relationship between lead and cancer of the larynx.

Serum 25-hydroxycholecalciferol in Greek uremics.

Using a simplified competitive protein-binding assay, we measured serum 25-hydroxycholecalciferol (25-OH-D3) in 52 patients with chronic renal failure and in 21 normal subjects. Of the patients with chronic renal failure, 21 were undergoing hemodialysis. Low serum levels of 25-OH-D3 were found in nondialysis patients and normal levels in the dialysis group. A positive relationship between the levels of 25-OH-D3 and serum calcium and a negative relationship between the levels of 25-OH-D3 and serum creatinine were found in the nondialysis group. We postulate that the decreased 25-OH-D3 levels in chronic uremics is the result of the low level of vitamin D in their protein-restricted diets.