Prevalence of partial cerebroside sulfate sulfatase (arylsulfatase A) defect in adult psychiatric patients.

Metachromatic leukodystrophy (MLD) is a disease caused by a deficiency of the enzyme sulfatide sulfatase, also known as arylsulfatase A (ASA). We compared the activity of this enzyme in adult psychiatric patients and normal volunteers using nitrocatechol sulfate (ASA-NCS) and cerebroside sulfate (ASA-CS) as substrates. Our results showed that ASA-NCS activity in urine and leukocytes was significantly lower in psychiatric than in normal individuals, but that there were no differences between these two groups in the sulfatide excretion in urine or the ASA-CS activity in leukocytes. There was no correlation between enzyme activity in urine and in leukocytes, indicating that activity in urine does not truly reflect the levels of the enzyme in tissues. The correlation between ASA-NCS and ASA-CS activity in leukocytes was poor (0.51 for psychiatric patients and 0.59 for normals), suggesting that for a valid measure of the enzyme activity the assays should be carried out with CS as substrate. Results of our study also indicate that in 39 of the 145 psychiatric patients studied, the ASA-CS activity in leukocyte was less than 4 nmoles/mg protein/hr, which is below 50% of the normal means, whereas only one of the 30 normal subjects had a value this low. The presence of low levels of ASA-CS activity in a significantly large number of adult patients with varying psychiatric manifestations suggests that such patients may be asymptomatic carriers of the sulfatidase defect (heterozygotes for MLD), and that behavioral and functional disturbances in these patients may at least in part be related to sulfatidase deficiency. The significance of the ASA-NCS abnormality (reduction) in psychiatric patients is unclear.

Epidemiological monitoring of environmental lead exposures in California State Hospitals.

Blood lead screening of 8062 state hospital residents in California revealed 143 residents with excessive lead levels (greater than or equal to 30 micrograms/dL). This screening was part of the Childhood Lead Project and was performed in 1978. The purpose of this study was to identify "critical" lead sources in California State Hospitals. Accurate identification is crucial if subsequent abatement programs are to be effective. The strategy involved the following sequence of steps: 1) Selection of cases based on blood lead and erythrocyte protoporphyrin screening. 2) Determination of pica habits and environmental exposures through interviews with ward's staff and/or parents. 3) Measurement of lead levels in environmental samples reflecting exposures. 4) Interpreting these data in order to identify critical lead sources. 5) Reducing exposure to critical lead sources. 6) Following up of cases and controls to validate the effects of this strategy. A group of 36 lead-burdened cases with pica (30-60 micrograms Pb/dL blood) and 36 matched controls (PbB less than 20 micrograms/dL) were selected from among the developmentally disabled residents of two California State Hospitals. These subjects were studied in order to identify the lead sources to which they were exposed and to abate the major ones. Three major lead sources were found in the state hospitals: wall and furniture paints (100-45,400 micrograms Pb/g paint); surface soil (33-570 micrograms Pb/g soil); educational format was presented to all involved staff. The results have indicated a trend towards lower lead intake by the lead-burdened cases. In one of the two hospitals a "lead-free unit" had been established. All the lead-burdened cases were transferred to this unit in August 1981. A few months later the blood lead levels of all the cases dropped below 30 micrograms/dL. Initial epidemiological monitoring indicated where there were preventable hazards, which abatement efforts succeeded in reducing. Further monitoring of such problems is indicated in this and other developmentally-disabled populations.