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Biomedical subjects

D Kuntz

Publications and source records attributed to D Kuntz.

At least 109 records · Page 6Linked to original sources
PubMed1985

[Value of the femorotibial angle in 244 patients without knee arthrosis].

Measurement of the femorotibial angle was performed in 244 patients (134 women and 110 men) without knee arthrosis with roentgenograms taken in the upright position. The values were grouped according to sex and to decade of life. The average value was approximately 0. As defined by the average upper and lower values of the two types of angulation, the normal value in women was 4 degrees of varus and 4 degrees of valgus. In men, the normal value of the right leg was 5 degrees of varus and 5 degrees of valgus; the left leg demonstrated up to 6 degrees of varus and 5 degrees of valgus. After sixty years of age, 5 percent of patients had angulation above these normal values in valgus and varus.

Adult↗
PubMed1985

[Analysis of bone calcium by localized neutron activation in the hand and dorsal spine].

The measurement of the mineral content of bone by localised neutron activation was performed in the hand in 58 women aged between 23 and 87 years and simultaneously in the hand and the thoracic spine (from the 5th to the 9th thoracic vertebra) in 46 women aged between 50 and 80 years, all free of any bone disease. The neutron flow was emitted by Californium 252. The bone calcium mass was calculated from the peak of radioactivity emitted by Ca 49 with an energy of 3.10 MeV, measured by means of a sodium iodide scintillation detector. The bone volumes were estimated indirectly by planimetry. The results were expressed as the volumic concentration of calcium in the bones of the hand and the vertebrae. The calcium concentration of the bones of the hand decreases with age, especially between 50 and 60 years. The calcium concentration of the vertebrae decreases more markedly with a significant negative correlation (r = - 0.550; p less than 0.05). The correlation is particularly significant (r = - 0.878) in the 16 women aged between 50 and 65 years with a calcium concentration in the bones of the hand within the normal range. The correlation between the calcium concentration in the vertebrae and age was no longer significant after the age of 65 years, whatever the value of the calcium concentration of the bones of the hand. A significant correlation (r = 0.660; p less than 0.05) was observed between the vertebral calcium and the calcium in the bones of the hands in women aged between 50 and 65 years, which disappeared after this age.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

Destructive spondylarthropathy in hemodialyzed patients. A new syndrome.

Spinal radiologic lesions suggestive of destructive spondylarthropathy were found in 10 patients on long-term hemodialysis. These lesions were characterized by severe narrowing of the intervertebral disc, associated with erosions and geodes of the adjacent vertebral plates without osteophytosis. In 9 of the 10 patients the lesions were located in the cervical spine, and in 1 patient, in the lumbar spine. Microbial spondylitis, degenerative disc disease, and destructive spondylarthropathy of calcium pyrophosphate dihydrate deposition disease were each, in turn, ruled out. The finding of apatite crystals by transmission electron microscopy in 1 disc specimen suggests that these crystals may be associated with destructive vertebral disc lesions in dialysis patients.

Aged↗
PubMed1984

Extended treatment of primary osteoporosis by sodium fluoride combined with 25 hydroxycholecalciferol.

Nineteen patients suffering from primary osteoporosis, all having at least one vertebral collapse, initially received 50 mg of sodium fluoride alone per day for 6-18 months. Subsequently fluoride was associated with 25-50 micrograms of 25 OH cholecalciferol (calcifediol) per day for 6-18 months in 12 of these patients and 9 were treated for 31-58 months. As control group, 9 patients were given placebo for 6-18 months. The effect of the treatment was assessed by three methods: 1) the metacarpal index (MI) determined by radiogrammetry, 2) the calcium content of the hand bone (Ca) measured by local neutron activation, 3) the iliac bone histomorphometry. MI and (Ca) did not change significantly at any time in any group. In each group there was a significant increase in trabecular bone volume, osteoid volume, osteoid surfaces and a significant decrease in mineralization fronts. On the other hand, the changes in osteoblastic surfaces, osteoclastic surfaces, number of osteoclasts/mm2 were not significant in any group. No change was observed in the placebo group. These data suggest that the increase in the trabecular volume of fluorided bone is mainly due to the increase in osteoid which itself is due to a bone mineralization defect despite the association of calcifediol. This is probably one of the reasons why (Ca) does not change significantly.

Aged↗
PubMed1984

[Phosphorus metabolism in a case of tumoral calcinosis].

Hyperphosphataemia with levels of 65 mg/l was found in a black African aged 20 with a 10-year history of tumour calcinosis. Levels of blood calcium, plasma ionised calcium, serum alkaline phosphatase, 24-hour urinary calcium and phosphate were all normal, as was renal function. Tubular phosphate reabsorption (TmP) was greater than 90 mg per litre of glomerular filtrate (N = 22-42). Levels of circulating parathyroid hormone, nephrogenic cAMP and serum vitamin D metabolites [25 OH D3, 24,25 (OH)2 D3 and 1,25 (OH)2 D3] were normal. The TmP fell by 36% on exogenous PTH stimulation (N = 30.25 +/- 6.7), and by 7.9% 120 min. after injection of acetazolamide. Our results confirm the conclusions of recent studies: patients with tumour calcinosis have disordered renal phosphate excretion with normal PTH secretion, normal PTH action on the renal tubule and normal vitamin D metabolism. In fact in these hyperphosphataemic patients, circulating 1,25 (OH)2 D3 levels would be expected to be low, whereas they were normal in our patient. An attempt at treatment with acetazolamide and phosphate chelating agents gave no significant results.

Acetazolamide↗
PubMed1983

Advantage of hand bone calcium content measurement by local neutron activation analysis for following up hemodialysis patients.

Hand bone calcium content [Ca] has been measured by local neutron analysis in hemodialyzed patients free of signs of osteomalacia before and 6-12 months after treatment with vitamin D metabolites, and it has been compared to some iliac bone histomorphometric parameters. With 1,25-(OH)2D3 alone, [Ca] increases significantly at the 6th month of treatment (p less than 0.001) but not from the 6th to the 12th month. With 1 alpha-(OH)D3 + 25-(OH)D3 the same phenomenon is observed at the 6th and 12th months of treatment. Before treatment, [Ca] was correlated negatively with the osteoid surfaces (OS) (r = -0.62, p = 0.01) and the number of osteoclasts per square millimeter (Ocl/mm2) (r = -0.79, p less than 0.001). At the 6th month of treatment, [Ca] was still correlated negatively with OS (r = -0.42, p = 0.05) and with Ocl/mm2 (r = -0.60, p less than 0.005). At the 12th month, the two negative correlations decreased but remained significant (r = -0.42, p = 0.05; r = -0.45, p = 0.05). These data suggest that (1) hand bone calcium analysis by neutron activation permits to follow up the peripheral bone mineral content in hemodialyzed patients and (2) the [Ca] increase only observed during the first months of treatment with vitamin D metabolites probably result from an attenuation of secondary hyperparathyroidism.

Adult↗
PubMed1983

Evidence for defective osteoblastic function. A role for alcohol and tobacco consumption in osteoporosis in middle-aged men.

In a group of 11 men ranging in age from 35 to 50 years with idiopathic osteoporosis, most were mild alcoholics and heavy smokers. Two had absorptive hypercalciuria. Histomorphometry showed that the patients had low trabecular bone volume and mean trabecular thickness when compared with age-matched control subjects. Mean wall thickness was also markedly reduced in patients as compared with control subjects. The quantity of resorbed bone was extrapolated from the calculated mean interstitial bone thickness. Resorption was not significantly different in patients and control subjects. Consequently, in this group of patients with severe osteoporosis, the pathogenesis was characterized by markedly decreased bone formation.

Adult↗
PubMed1982

Nonosteomalacic osteopathy associated with chronic hypophosphatemia.

We studied bone histomorphometry in 19 patients with chronic hypophosphatemia related to an idiopathic renal phosphate wasting and without histological osteomalacia. Nine patients had renal lithiasis (group 1), three had radiological osteoporosis (group 2), and seven had lumbar pain (group 3). In the whole group of 19 patients, serum phosphate levels were low (24.9 +/- 2.1 mg/l), calcium in blood was normal, calcium in urine was increased, and iPTH was low. Histomorphometric data showed decreased osteoblastic surfaces with normal resorption surfaces, normal osteoid volume and calcification front. There was no correlation between serum phosphate level and histomorphometric parameters. There was no statistical difference between the data of the 3 groups of hypophosphatemic patients. We concluded that chronic hypophosphatemia in the adult doses not always lead to osteomalacia but to an unusual osteopathy characterized by an osteopenia due to an isolated decrease in bone formation. The respective importance of phosphate deficiency and of decreased iPTH level in the pathogenesis of this osteopathy is uncertain.

Adult↗
PubMed1981

Bone histomorphometric reproducibility in normal patients.

To study bone histomorphometry reproducibility in normal subjects, we performed during orthopedic surgery bone biopsies in 16 postmenopausal women. Each woman had four bone biopsies, two at the usual site in the iliac crest, one on the left and one on the right side, and two other biopsies just behind the usual site, one at each side. We performed measurements of trabecular bone volume, relative osteoid volume, osteoid surfaces, osteoclastic resorption surfaces and calcification front. The average values of the 16 patients were compared, on the one hand, two by two, by a student test, and on the other hand, by a variance analysis. By these two methods the results showed no significant difference between the average values of the 16 patients at each location for any of the histomorphometric parameters studied. However, there was a location variation which was estimated by the intra-individual variation for a given patient. On the other hand, we calculated from the variance analysis the location variance for a group of 10 to 100 patients. In any case all the parameters had a location variation which was high for osteoclastic resorption surfaces and relative osteoid volume when expressed in % of the absolute value of these parameters. The variation of the trabecular bone volume was 0--46. 15% (95% confident limit interval) in a single patient and the hypothetical value of the location variation was 41.6% for a group of 10 patients and 13.0% for a group of 100 patients.

Aged↗
PubMed1981

Bone histomorphometry in hemodialysed patients.

We performed bone histomorphometry in thirty hemodialysed patients. Ten patients had a double iliac bone biopsy to estimate bone histomorphometry reproductibility. There was no difference between the mean results for each of the 10 patients at each site. However, there was an intra-individual variation which was small for the parameters of formation and particularly osteoid thickness and mineralizing rate and greater for resorption parameters. Mineralization rate appeared the most reliable and discriminant parameter. These 30 patients were separated in two groups according to their mineralizing rate (MR); patients with an MR greater than 0.3 mu/day were in group I and had severe hyperparathyroidism without major impairment of bone mineralization and high formation rate. They also had high serum alkaline phosphatases and high serum parathyroid levels measured with a COOH terminal antibody (iPTH). Patients with a low MR less than 0.3 mu/day (group II) had a severe mineralization defect with low formation rate, normal alkaline phosphatase and significantly lower levels of iPTH than in group I. This last type of histological bone lesion could not be due to aluminum intoxication since the level of serum aluminum was the same in the two groups. The mineralizing defect appeared to be inversely correlated with the percent of osteoid surfaces covered by osteoblast and with the iPTH level. These data suggest that during the course of renal osteodystrophy PTH stimulates not only bone resorption but also bone mineralization by increasing osteoblastic number.

Adolescent↗
PubMed1981

[Comparison of radiodensitometry and histomorphometry in normal and abnormal bone (author's transl)].

85 adults of both sexes, suffering from variety of bone disorders were studied by means of humeral radiodensitometry and histomorphometric analysis of iliac bone biopsies. Trabecular bone volume (TBV) was not related to cortical thickness. Bone mineral density was related to iliac TBV only in female subjects. The value of these measures is limited in osteoporosis because of measurement errors and skeletal inhomogeneity. In osteoporosis, variable histomorphometric features were observed. However, radiodensitometry proved a good measure of the state of mineralization in osteomalacia.

Absorptiometry, Photon↗
PubMed1981

[In vivo analysis of bone calcium by localized neutron activation of the hand in osteoporosis].

The calcium concentration of the bones of the hand measured by neutron activity was lowered in 93% of osteoporotic women aged between 50 and 60 years and in 66% of women between 60 and 70 years, whereas from the 8th decade onwards, only 5% had a bone calcium concentration of the hand less than that of controls. In the male sex, nearly 80% of osteoporotic patients, had a calcium concentration of the hand less than that of controls whatever their age. Considering the radiological criterion retained for the diagnosis of osteoporosis, the existence of at least one fracture of a vertebral body, the authors discuss the significance of these facts.

Adult↗