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Biomedical subjects

L A Stone

Publications and source records attributed to L A Stone.

At least 19 recordsLinked to original sources

The coexistence of tics and dystonia.

We studied nine patients with motor and phonic tics and other features of Tourette's syndrome, who developed persistent dystonia in addition to their tics. All, except one, were males (mean age, 35.8 years; range, 8 to 59 years), and had onset of tics prior to age 18 years (mean age, 9 years; range, 1.5 to 17 years). None of the patients were treated with neuroleptic drugs prior to the onset of dystonia. Torticollis and blepharospasm were the most common forms of dystonia. Seven patients had a history of tics in first degree relatives. While these patients were seen in a specialized movement disorder clinic and may, therefore, represent a population with atypical and more severe symptoms, the high prevalence rate of dystonia (5.0% of all patients with Tourette's syndrome seen in the clinic) suggests that some patients with tics may have an increased risk for dystonia.

Adolescent

Vitamin D receptors and compensatory tissue growth in spontaneously diabetic BB rats.

Untreated diabetic (BB) rats exhibited compensatory intestinal growth which was associated with hyperplasia and was accompanied by an increase in unoccupied vitamin D receptors. Although vitamin D receptors were increased, low circulating 1,25-dihydroxy-vitamin D3 [1,25(OH)2D3] prevented amplification of the action of 1,25(OH)2D3, as evidenced by reductions in calbindin D-9K and alkaline phosphatase activity in the BB rat intestine compared to control. In the kidney, a lesser degree of compensatory growth was observed which was not associated with hyperplasia, and no significant effect of diabetes on vitamin D receptors or calbindin D-28K was observed. These studies suggest tissue-specific changes in 1,25(OH)2D3 metabolism during spontaneous diabetes which may be related to the hyperplasia which occurs during compensatory tissue growth.

Animals

Vitamin D receptors in intestine, kidney and thymus of streptozotocin diabetic rats.

Our data confirms previous reports of intestinal and kidney compensatory growth, low plasma 1,25(OH)2D3 and up regulation of intestinal VDRs during untreated diabetes. All of these parameters were normalized in diabetic rats treated with exogenous insulin. There were no alterations in VDR numbers in kidneys or thymus of untreated diabetic animals, indicating that up-regulation of VDRs during untreated diabetes did not occur in all vitamin D target tissues. Compensatory growth of the intestine during untreated diabetes was associated with both hypertrophy and hyperplasia, whereas diabetic kidney growth appeared to be associated with hypertrophy without hyperplasia. Diabetes did not affect somatic index of thymus. The data suggests that the up regulation of VDRs during untreated diabetes may be unique to the intestine and further that VDR up regulation may be related to hyperplasia. Calbindin D-9K was significantly lower in diabetic intestine, suggesting that low circulating 1,25(OH)2D3 prevented amplification of 1,25(OH)2D3's action despite up regulation of intestinal VDRs.

Alkaline Phosphatase

Multidimensional scaling of pictorial informativeness.

The dimensions used in the judgment of the informativeness of picture sections were investigated by means of a recently proposed methodology, multidimensional similarity analysis. 10 judges (college students) rated the informational similarity of 32 areas within a single picture. The five extracted dimensions accounted for 86% of the judgmental variance and were all readily interpretable. These dimensions were discussed with respect to an earlier study in which eye movements of subjects viewing this picture were recorded.

Adult