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Biomedical subjects

D Kuntz

Publications and source records attributed to D Kuntz.

At least 55 records · Page 3Linked to original sources

Inhibition of human endothelial cell growth by human monocytes in coculture.

Previous studies conducted in different experimental models have shown that human monocytes (Mo) possess both stimulating and inhibiting factors for endothelial cell growth. Since Mo are frequently found in the vicinity of endothelial cells, we examined the direct effect of human peripheral blood Mo on the proliferation of human umbilical vein endothelial cells (HEC) in in vitro culture systems. Mo obtained either by counter centrifugation elutriation or by selective adhesion on gelatin-autologous plasma or purified fibronectin coated plastic surfaces inhibited HEC growth as determined by HEC count or 3H-methyl thymidine incorporation. This growth inhibitory effect was dependent on the number of monocytes: 50% inhibition of 3H-thymidine uptake by HEC was achieved for a Mo-EC ratio of 1:4. Mo isolation by selective adhesion on gelatin-plasma resulted in a significantly higher inhibitory effect (p less than 0.02) than that observed with Mo isolated on fibronectin coated surfaces or by elutriation techniques, suggesting a possible stimulation of Mo by contact with gelatin-plasma. Endothelial cell growth factor plus heparin did not reverse this inhibition of HEC growth. Results obtained in diffusion chamber and coculture systems showed that soluble products of Mo origin can inhibit HEC proliferation but the inhibition was greater when Mo and HEC were in contact. The effect was not due to cytotoxicity as evaluated by cell counting and 51Chromium release from HEC. These in vitro results suggest that normal monocytes could exert a regulatory role on the proliferation of endothelial cells.

Animals↗

[Age at the onset and incidence of chronic pain in knee osteoarthrosis].

The incidence and age of onset of daily knee pain for more than 3 months each year were determined in the various topographical varieties of knee osteoarthrosis (404 knees, 258 patients: 195 women and 63 men). Statistical calculation revealed no significant difference between the incidence of forms without chronic pain in the various topographical types of knee osteoarthrosis. In women, the mean age of onset of chronic pain in lateral femoro-patellar osteoarthrosis was 56.6 +/- 12, in medial femora-tibial osteoarthrosis was 62.7 +/- 12, in the combination of the two 65.2 +/- 10 and in lateral femoro-tibial osteoarthrosis was 69.2 +/- 10. In men, this age in lateral femoro-patellar osteoarthrosis was 60.5 +/- 10 and in medial femoro-tibial osteoarthrosis was 64 +/- 10. Thus lateral femoro-patellar osteoarthrosis caused chronic pain an average of 5 years before medial femoro-tibial osteoarthrosis, and the latter an average of 7 years before lateral femoro-tibial osteoarthrosis.

Age Factors↗

[Treatment of common osteoporosis with fluoride: current trends].

The pharmacology of fluoride is reviewed. Efficacy criteria of sodium fluoride in osteoporosis are analysed. An increase in bone mass of the order of 8 per cent per year is seen in 60-70 per cent of osteoporotics whether evaluated by histomorphometry or by bone densitometry in double-blind controlled trials. Fluoride has no effect on bone mass in 30 to 40 per cent of osteoporotics. The reason(s) for such resistance is/are not fully understood. It is not possible at present to state that there is a decrease in the incidence of vertebral fractures on the basis of data from double-blind trials. The incidence of bone fissures affecting the bones of the lower limbs is significantly increased in osteoporotics treated with fluoride, above all if doses of elemental fluoride are greater than 25 mg or in the presence of unrecognised renal insufficiency. The incidence of these fissures is of the order of 20 to 30 per cent.

Fluorides↗

Bone mastocytosis. A report of nine cases with a bone histomorphometric study.

Bone mastocytosis is characterized radiographically in some patients by diffuse osteosclerosis and in others by demineralization. The reason for these apparently conflicting bone features is unknown. Bone remodeling and marrow mastocytosis infiltration were studied in nine cases of mastocytosis with bone marrow involvement. Six men, ranging from 42 to 78 years of age, and three women, 43, 55, and 73 years old, comprised the series. Two patients had severe and diffuse osteosclerosis. Seven had diffuse demineralization, with crushed vertebrae in four, suggesting common osteoporosis. In three of the seven, cutaneous mastocytosis was absent. Bone biopsies were undecalcified and stained with toluidine blue. In the seven patients with demineralization, the number of marrow mastocytes was increased (154 +/- 24 versus 2 +/- 0.5/mm2 in normal postmenopausal osteoporosis). Mastocyte nodules covering 1-9% of the marrow area were present in all seven patients. These patients showed a significant increase in remodeling; bone formation rate was increased, coupled with a decrease in mean wall thickness. Concomitantly, osteoclast surfaces were increased, with an increased amount of bone resorbed. The two patients with diffuse osteosclerosis had a markedly different histology; mast cell infiltration was dramatically increased (mastocyte count greater than 1000/mm2) with diffuse marrow fibrosis. Bone volume was increased as well, and most of the bone was woven with an intratrabecular mineralization defect. High bone remodeling and decreased osteoblast activity can explain bone loss in mastocytosis with demineralization. Mastocytosis with osteosclerosis is characterized by a more extensive marrow mast-cell infiltration and fibrosis.

Adult↗

Stress fractures of the lower limbs in osteoporotic patients treated with fluoride.

We report clinical and bone morphometric findings in 18 osteoporotic patients who experienced stress fractures during fluoride therapy. Patients were treated with either sodium fluoride (n = 15), or sodium monofluorophosphate (n = 3). Oral calcium supplementation was given in 11 patients, and vitamin D in 13. Stress fractures occurred after 17.1 +/- 10.3 months of therapy (range: 5-41 months). Atraumatic sudden pain in a lower limb bone extremity, normal initial roentgenogram, high 99technetium uptake on early bone scan, and a 3 to 4 week delay in linear bone condensation area at the same site were characteristics of stress fracture. The most frequent sites were the tibial metaphysis (n = 13), femoral neck (n = 10), and calcaneus (n = 4). Biochemical data showed increased plasma alkaline phosphatase levels in 11 patients, and mild renal failure in 2. Bone histomorphometry was performed on an iliac crest specimen in 10 patients at the time of the stress fracture. Trabecular bone volume was normal, and formation parameters were increased. Features of osteomalacia were encountered in only 2 patients with decreased renal function. Trabecular resorption was increased, as assessed by the osteoclastic surface (1.01 +/- 1.15% bone surface), and the number of osteoclasts (0.44 +/- 0.49 per mm2 bone section). The clinical course was favorable in all patients who stopped fluoride, although 5 patients who continued the treatment had either completion of femoral neck stress fractures to hip fractures (n = 2), or recurrent stress fractures (n = 2), or both (n = 1). Fluoride appears to be a key factor in the pathogenesis of stress fractures, and may be associated with increased trabecular resorption in some treated patients.

Aged↗

Provocation test coupled with bronchoalveolar lavage in diagnosis of drug (nilutamide)-induced hypersensitivity pneumonitis.

A 79-year-old man was given a cumulative dose of 16.5 g of nilutamide for treatment of prostate cancer. He then presented with a respiratory illness having clinical, radiologic and functional characteristics of interstitial pneumonitis. No other cause of pneumonitis was found. Bronchoalveolar lavage showed a lymphocytic alveolitis with an inverted lymphocyte subset ratio. After an 11-week period of drug withdrawal, clinical, radiologic and functional improvement was observed along with a normal alveolar lymphocytosis. Nilutamide therapy was then resumed for five weeks and induced the recurrence of clinical, functional and alveolar abnormalities. Nilutamide treatment was finally stopped and two months later, clinical and functional abnormalities resolved. This observation seems to exemplify the possible diagnostic value of coupling provocation test with BAL cell data in hypersensitivity pneumonitis induced by drugs. In addition, these data support the role of a cell-mediated immunologic mechanism in the pathogenesis of nilutamide-induced pneumonitis.

Aged↗

Beta 2-microglobulin amyloidosis: a sternoclavicular joint biopsy study in hemodialysis patients.

The incidence of beta 2-microglobulin deposits appears to increase with time on dialysis. However, the precise prevalence of the disease is not known at present because adequate, noninvasive diagnostic procedures are still lacking. We performed systematic synovial biopsies of the sternoclavicular joint during surgical parathyroidectomy in 22 chronic hemodialysis patients with severe hyperparathyroidism. Nine of the patients proved to have beta 2-microglobulin amyloid deposits as demonstrated by Congo red staining and by immunofluorescence. They had undergone dialysis for longer time periods (12.6 vs 8.5 years, p less than 0.02) and tended to be older than the 13 amyloid-negative patients. They also had a significantly higher body aluminum overload, as demonstrated by a higher increase of plasma aluminum after desferrioxamine infusion. Finally, the presence of Congo-red-positive deposits correlated well with clinical and x-ray findings suggestive of dialysis amyloidosis.

Amyloidosis↗

[Obesity and arthritis of the knee].

More than 45 p. cent of patients with degenerative knee arthritis are obese. The overweight is more marked when the medial tibio-femoral and the lateral femoro-patellar aspects are affected. With the same degree of weight gain, the relationship between obesity and degenerative knee arthritis is more marked in women than in men. The significance of the overweight increases the probability of developing degenerative knee arthritis, increasing its functional severity. The obesity precedes the arthritis, and is not its consequence. It is a mechanical effect by increase of the articular strains. It is unknown how long the obesity must be present in order to be pathogenic for the knee and what functional and anatomical improvement may be expected from a weight loss.

Female↗

Adult-onset Still's disease revealed by a pleuropericarditis.

We report a case of adult-onset Still's disease (AOSD) revealed by pleuropericardial manifestations. A 40 yr old black woman was admitted for flu-like syndrome with pharyngitis, hectic fever, polymorphonuclear hyperleucocytosis and pleuropericarditis. The diagnosis of AOSD was supported by 3 major and 3 minor criteria after exclusion of infectious, haematological and connective tissue diseases. Pulmonary involvement is infrequent in AOSD, and consists of transient pulmonary infiltrates and chronic restrictive pattern. However, pleuritis, like pericarditis, is present in 25% of cases. Initial onset of pleuritis, associated with fever and hyperleucocytosis preceding articular manifestations could be responsible for a delay in diagnosis and a subsequent worsening in the prognosis of the disease. A rapid improvement is usually observed under nonsteroidal anti-inflammatory drug or corticosteroid treatment.

Adult↗