Short-term course of 1,25(OH)2D3 stimulates osteoblasts but not osteoclasts in osteoporosis and osteoarthritis.

We investigated the effect of short-term, 1,25-dihydroxyvitamin D3 therapy (4 micrograms/day for 4 days) on calcium metabolism in 27 postmenopausal women (11 cases with osteoporosis and 16 cases with osteoarthritis). Bone mass at the axial and appendicular skeleton was higher in osteoarthritis than in osteoporosis. Initial values of calcium metabolism were similar. Osteoporotic and osteoarthritic patients responded with a similar significant increase in serum osteocalcin (+61% and +54%, respectively), fasting urinary calcium excretion (+178% and +124%, respectively) and 24 hour calcium excretion (+148% and +142%, respectively). Parathyroid hormone (PTH) levels decreased significantly in both groups (-30% and -18%, respectively). Osteoclastic bone resorption, evaluated by urinary hydroxyproline excretion, was not stimulated in either group. We conclude that in osteoporosis and also in osteoarthritis (1) 1,25-dihydroxy-vitamin D3 (1,25(OH)2D3) stimulation of osteoblast function is similar in production of osteocalcin; (2) the vitamin D target tissues react adequately to 1,25(OH)2D3 stimulation; (3) short-term high dose of 1,25(OH)2D3 does not stimulate bone resorption; and (4) the differences in bone mass between osteoarthritis and osteoporosis are not related to an alteration of the responsiveness to stimulation by 1,25 (OH)2D3.

Seasonal variation in bone metabolism in young healthy subjects.

Serum vitamin D metabolites and urinary calcium excretion; parameters of bone formation (serum alkaline phosphatase, serum osteocalcin); parameters of bone resorption (24 hour hydroxyprolinuria, 2 hour fasting urinary hydroxyproline/creatinine ratio); and parameters of cortical and trabecular bone density, parathyroid hormone (iPTH, COOH terminal assay), and serum minerals (calcium, phosphorus) were followed serially in 55 young adults (21 women and 34 men) from December 1985 until January 1987 at four different times during the year. The effect of a low-dose cyclooxygenase inhibitor (piroxicam 5 mg daily) on the same parameters of bone density and bone turnover when given from December until May, was also evaluated in this study. At the end of the treatment period parameters of bone turnover and bone density were comparable between placebo and piroxicam-treated groups. Therefore, the results of all subjects were pooled in order to investigate seasonal variation. In both sexes, seasonal variation was found not only for 250HD3 but also for 1,25(OH)2D3, serum calcium and phosphorus, urinary calcium excretion, and for bone density at the lumbar spine. Parameters of bone formation (serum osteocalcin and alkaline phosphatase), bone resorption (24 hour urinary hydroxyprolinuria and fasting urinary hydroxyproline/creatinine ratio) and PTH were influenced by this seasonal variation. We conclude that in young adults, a significant seasonal variation occurs, with low winter and high summer values, for serum 25 and 1,25(OH)2D3 for urinary calcium apparently without important influence on parameters of bone turnover or parathyroid activity and for lumbar spine density. Treatment with a low-dose cyclooxygenase inhibitor was without influence on the observed changes.

[Evaluation of the amnesia caused by restricted thalamic infarcts--6 cases]. / Bilan de l'amnesie des infarctus thalamiques restreints--6 cas.

The amnesic syndrome is analysed in 6 infarctions restricted to the thalamic area. Bilateral lesions were linked to more definite deficits; the anterograde forgetting was unequivocal at the initial stage and affected both verbal and visual memory. In unilateral lesions, deficits were far more discrete and there was no evidence enough for assuming a strict hemispheric specialisation, left for verbal memory, and right for visual memory. These cases and others from the literature suggested that amnesia is more important and pure in infarctions of the anterior part of the thalamus.

[Ocular and head movements in infarctions of the thalamic region]. / La motricité oculaire et céphalique dans les infarctus de la région thalamique.

Oculomotor disorders in 22 infarctions in the thalamic region are recorded. Clinical examination and electro-oculography (17 cases) showed that paramedian thalamo-subthalamic lesions were responsible for clear deficits: upgaze paralysis and in some cases downgaze paralysis, partial paresis of the oculomotor nerve, deficits of lateral eye movements, myosis, paralysis of head flexion combined with downgaze paralysis. Postero-median choroid artery infarction was associated with upgaze paresis, slight deficit of lateral eye movements and myosis. Postero-lateral choroid artery infarction resulted in a partial visual field defect and in some cases, a contralateral hypometria; myosis was slight and inconstant. Infarctions of the internal capsule (anterior choroid artery, deep branches of the middle cerebral artery) were associated with a deficit of contralateral saccades. Ocular pursuit, when possible, was often saccadic, whatever the site of the infarction. This prevailed with gaze towards the lesion side.

Comparative study of the sensitivity of CT and quantitative angioscintigraphy in cerebrovascular disease.

A method for multiparametric quantitative cerebral angioscintigraphy is described. For the evaluation of the symmetry of hemispherical bolus transit the following parameters were used: the cumulative L/R hemispheric ratios expressed in arctangent values and the sequential hemispheric activity difference. Both the sensitivity and specificity of this technique for detection of proven stenosis of carotid or cerebral arteries (25 cases) were 80%, in comparison with 60% for computerized axial tomography. A few clinical examples illustrate the diagnostic utility of quantitative cerebral angioscintigraphy. The value of the different quantitative parameters is discussed and compared with other similar studies. With regard to the complementary role of computerized axial tomography and serial cerebral scintigraphy the results of other authors were confirmed. Considering the broad field of application for dynamic brain scintigraphy and the fact that both sensitivity and specificity of this exploration are comparable to, or even better than, CT, it is our opinion that isotopic exploration remains a reliable detection method for cerebrovascular disease.