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Biomedical subjects

E Roberts

Publications and source records attributed to E Roberts.

At least 253 records · Page 14Linked to original sources
PubMed1975

Fibroblasts in Huntington's disease.

We investigated the growth of skin fibroblasts in tissue culture from 10 patients with Huntington's disease and eight healthy, unrelated controls. The patients' ages ranged from 34 to 56 years (mean 48.5), and the mean duration of their clinical illness was 12.4 years. The controls' ages ranged from 32 to 64 years (mean, 42.3). No statistically significant differences were observed between the two groups in out-growth of cells from the biopsies nor during subsequent routine culturing of fibroblasts. This contradicts the finding of earlier investigators that skin fibroblasts from patients with Huntington's disease grow poorly in tissue culture. Matched pairs of Huntington's disease and control cultures grew at the same rate, but Huntington's disease cells grew to a significantly higher maximal density (P less than 0.02). This may indicate a genetically determined change in the cell surface or metabolic difference in Huntington's disease.

Adult↗
PubMed1975

Immunocytochemical localization of glutamate decarboxylase in rat spinal cord.

The GABA synthesizing enzyme, glutamate decarboxylase (GAD), has been localized by light and electron microscopy in the rat lumbosacral spinal cord using a peroxidase-labeling antibody technique. The light microscopic localization shows heavy, punctate reaction product for GAD in the dorsal horn laminae I-III. Moderately heavy reaction product is also seen in the deeper dorsal horn laminae IV-VI, the medial aspect of the intermediate gray (lamina VII) and the region around the central canal (lamina X). A moderately light concentration of GAD reaction product is observed in the ventral horn, and punctate deposits of reaction product also are seen on motoneuron cell bodies. The punctate distribution of reaction product for GAD in both ventral and dorsal horns, as visualized by light microscopy, corresponds to GAD-containing synaptic terminals seen by electron microscopy in comparable regions of the spinal gray. Many more GAD-positive terminals are observed in dorsal horn laminae I-III than in deeper laminae IV-VI. GAD-containing terminals in the dorsal horn are presynpatic to dendrites and cell bodies. Gad-containing terminals presynaptic to other axon terminals are observed also, and they are more numerous in laminae II and III. In the ventral horn motor nuclei, GAD-positive knobs are presynaptic to large and small dendrites and motoneuror cell bodies. In addition, small GAD-containing terminals also are presynaptic to larger axonal terminals which are in turn presynaptic to motoneuron somata. The observation of GAD-containing terminals presynaptic to dendrites and cell bodies in both dorsal and ventral horns is compatible with the evidence suggesting that GABA terminals may mediate postsynaptic inhibition of spinal interneurons and motoneurons. The additional finding of GAD-positive terminals presynaptic to other axonal terminals in the dorsal horn and motor nuclei is consistent with the growing evidence that GABA also may be the transmises mediating presynaptic inhibition via axo-axond synapses in the spinal cord.

Animals↗
PubMed1975

The fine structural localization of glutamate decarboxylase in developing axonal processes and presynaptic terminals of rodent cerebellum.

The immunocytochemical localization of L-glutamate decarboxylase (GAD), the enzyme which which forms gamma-aminobutyric acid (GABA), has been studied in developing rodent cerebellum. During the first 3-4 postnatal days, GAD is distributed along non-terminal portions of axonal processes in close association with small vesicles. Some of the axonal processes emanate from profiles which resemble growth cone varicosities, and are presumed to be foliopodia which extend distally from axonal growth regions. At the end of the first postnatal week the GAD-containing axonal processes are seen to form protosynaptic contacts, and GAD is localized around synaptic vesicles and at presynaptic junctional membranes. During the second and third postnatal weeks GAD gradually becomes localized to mature synaptic terminals in association with synaptic vesicle, mitochondrial, and presynaptic junctional membranes. The results suggest that GAD is present in growing neurites in close association with small vesicles prior to the time the neurites make protosynaptic contacts, and that differentiation of these contacts results in a sequestering of GAD into synaptic terminals.

Age Factors↗
PubMed1974

Immunochemical studies of brain glutamate decarboxylase and GABA-transaminase of six inbred strains of mice.

Six different inbred strains of mice (C57BL/6J, CBA/CaJ, CE/J, DBA/2J, LP/J and RF/J) were compared in terms of specific activities and immunochemical properties of brain L-glutamate decarboxylase (GAD) and gamma-aminobutyrate transaminase (GABA-T), the enzymes responsible for the synthesis and degradation of GABA, respectively. GAD from the brains of the different strains was indistinguishable on the basis of specific activities, double diffusion tests, immunoelectrophoresis and inhibition by antibody. However, microcomplement fixation tests showed GAD from DBA and C57BL mice to be most distinctly different from GAD extracted from the Swiss mouse, from which the original antigen was prepared and that the enzyme from the CE, LP and RF also differed. Similar fixation curves were obtained for the GAD from CBA and Swiss mice. GABA-T from the different strains was indistinguishable on the basis of all the tests employed.

4-Aminobutyrate Transaminase↗
PubMed1974

Immunohistochemical localization of glutamate decarboxylase in rat cerebellum.

Glutamate decarboxylase (L-glutamate l-carboxylase; EC 4.1.1.15), the enzyme in brain that forms gamma-aminobutyric acid, was made visible on sections of rat cerebellum by use of rabbit antiserum to purified mouse-brain glutamate decarboxylase. Cerebellar sections obtained from rats that were perfused with 4% paraformaldehyde were treated with antiserum against the enzyme or with serum from unimmunized rabbits, washed, and then incubated with peroxidase-labeled goat antibody against rabbit immunoglobulin. The glutamate decarboxylase was made visible on sections by means of the product formed by the action of peroxidase on 3,3'-diaminobenzidine and H(2)O(2). A weak and diffuse reaction was observed in Purkinje cell bodies, suggesting the occurrence of the enzyme within these cells. In addition, an intense, punctate deposition of reaction product was located around the Purkinje cells and around the neurons of the deep cerebellar nuclei, suggesting the impingement of many nerve terminals containing the enzyme upon these neuronal surfaces. No specific reaction product was observed in sections treated with serum from unimmunized rabbits. The distribution of glutamate decarboxylase observed in our preparations is consistent with a large body of indirect biochemical, physiological, and morphological data dealing with the synaptic role of gamma-aminobutyric acid neurons in the cerebellum.

Animals↗