Abnormal proteins in the cerebrospinal fluid of a patient with Creutzfeldt-Jakob disease following administration of human pituitary growth hormone

A Brazilian case of Creutzfeldt-Jakob disease in a hypopituitary patient who had received cadaver-derived human pituitary growth hormone between 1968 and 1977 is reported. The clinical diagnosis was confirmed during his lifetime by the demonstration of two abnormal 30-kDa proteins in the cerebrospinal fluid by two-dimensional gel electrophoresis. These proteins, characteristic of Creutzfeldt-Jakob disease, present isoelectric points of 5.1 and 5.2. Furthermore, both proteins migrate as doublets, each one displaying a molecular weight variant of about 29-kDa. This is one of 16 cases of the disease associated to therapy with cadaver-derived human growth hormone and one of the few examples among such cases of confirmation of the clinical diagnosis by biochemical characterization of abnormal proteins in the cerebrospinal fluid

Synaptosomal apyrase in the hypiothalamus of adult rats

1. The synaptosomal fraction isolated from hypothalamus of adult rats on sucrose density gradient hydrolyzes the labile phosphatase from ATP and ADP, thereby satisfying the general definition of apyrase activity. 2. The parallel behavior of ATPase and ADPase activities under different reaction conditions suggests the presence of a "true" apyrase enzyme. The optimum conditions for the are the same for both nucleotides: pH 8.0, 0.6 mM nucleotide and 1.5 mM cation. At temperatures between 10 and 40-C, both activities increase with no change in the ATP/ADP hydrolysis ratio. Thermal inactivation or inhibition of the enzyme activity by iodoacetamide, p-hydroxynercuribenzoate or 2- mercaptoethanol affected the hydrolysis of both substrates in a similar manner. 3- Adenylate Kinase and phyrophosphatase activities were not detected in the preparation. 4. The enzyme is located on the outer surface of the synaptosomal membrane: intact and lysed synaptosomes have similar activity and the supernatant obtained by centrifugation of intact synaptosomal preparations does not hydrolyze ATP or ADP

Mouse brain tau proteins: microheterogeneity and phosphorylation

Tau proteins are involved in polymerization of tubulin into microtubules. They comprise a heterogeneous group of proteins that can be resolved by two-dimensional gel electrophoresis using a non-equilibrium pH gradient in the first dimension. Developmental studies show that mouse brain Tau proteins are more heterogeneous in 15-day old mice than in newborn pups or adults. Tau phosphorylation is also more heterogeneous at this stage