Metachromatic leukodystrophy (MLD) in hospitalized adult schizophrenic patients resistant to drug treatment.

Metachromatic leukodystrophy (MLD) is a rare inherited neurodegenerative disease associated with a defect in the catabolism of sulphatide (galactocerebroside-sulphate) which accumulates in the nervous system. MLD can be diagnosed biochemically by demonstrating deficiency in the activity of the enzyme arylsulphatase A (ASA) and an excess of sulphatide in urine and tissues. Clinically adult MLD may present as a schizophrenic-like psychosis, which typically develops years before the onset of neurologial signs which are not inevitable.

Metabolic changes in Alzheimer's disease.

Patients with Alzheimer's disease (AD) and matched controls fasted for 24 hours, and serial glucose, pyruvate, lactate, beta-hydroxybutyrate, acetoacetate, insulin, and glucagon levels were measured. Patients with AD showed a glucose insulin correlation pattern over the 24 hours that differed from the control group. These differences may be secondary to weight loss or to other metabolic or nutritional factors affecting the AD patients.

Tay-Sachs disease: B1 variant.

This first child of non-Jewish parents had nystagmus at 4 months of age, bilateral cherry-red macular spots at 7 months of age, and hyperacusis at 8 months of age; the patient has deteriorated progressively following a clinical course typical of Tay-Sachs disease B variant. Total beta-N-acetylhexosaminidase assayed with 4-methylumbelliferyl-beta-glucosamine (4 MU GlcNAc) as substrate was within the normal range in plasma and cultured dermal fibroblasts and 2/3 the normal mean in leukocytes. The hexosaminidase A activity, assayed with the same substrate in plasma and cultured fibroblasts, approximated Tay-Sachs disease heterozygote levels; however, the activity of hexosaminidase A assayed with 4 MU Glc NAc-6-sulfate in the plasma, leukocytes, and cultured fibroblasts was less than 8, 2, and 1%, respectively of the control mean.

Hyperammonemia in Alzheimer's disease.

Postprandial blood ammonia levels were significantly higher in 22 patients with Alzheimer's disease than in 37 control subjects. In the Alzheimer group, fasting blood ammonia levels were significantly higher in patients whose EEGs showed triphasic waves than in patients without this change. The direction of change from fasting to postprandial blood ammonia levels was also significantly different between these two groups.

Defective heparan sulfate metabolism in the Sanfilippo syndrome and assay of this defect in the assessment of the mucopolysaccharidoses patient.

The Sanifilippo syndrome is an inherited dementia caused by defective degradation of heparan sulfate. In the course of its catabolism the heparan sulfate polymer must be desulfated. Heparan sulfate sulfatase activity was demonstrated in homogenates of normal tissues and cultured skin fibroblasts, and in normal urine.