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Biomedical subjects

T Bardin

Publications and source records attributed to T Bardin.

At least 55 records · Page 3Linked to original sources
PubMed1994

[Mechanism of crystal deposition in the joints].

The mechanism of crystal deposition in joints varies with the chemical nature of the crystal. Crystallisation of monosodium urate, characteristic of gout, requires a neutral pH and supersatured tissues, which is the basis for the clinical definition of the upper limit of normal blood uric acid level. The appearance of crystals also is dependent on time since crystallisation of monosodium urate is very slow. Inhibitory or promoting factors could intervene and explain rare cases of gout without hyperuricemia or the rapid crystallisation which seems to characterise some types of drug-induced gout. Crystal deposits of calcium pyrophosphate dihydrate form mainly in the cartilage where they seem favoured by ageing or by trauma, which could deplete cartilage of crystallisation inhibitors, notably proteoglycans. High pyrophosphate levels within cartilage also play an important role. The appearance of these pyrophosphates in the interstitial cartilagenous medium would be in large part due to the activity of an ectoenzyme, nucleoside triphosphate pyrophosphatase; increased activity of this ectoenzyme could be responsible for some chondrocalcinosis. Chronic hypercalcaemia can also be involved in the pathogenesis of cartilage deposition of calcium pyrophosphate dihydrate by raising the calcium-pyrophosphate product, or by decreasing the activity of alkaline phosphatase, an enzyme responsible for breakdown of extracellular pyrophosphates. The pathophysiology of calcium phosphate deposits is poorly understood. For some authors, these deposits occur within matrix vesicles, but for others, within collagen fibres. Increase in the calcium-phosphate product can also be a cause, for example, during renal osteodystrophy or vitamin D intoxication.(ABSTRACT TRUNCATED AT 250 WORDS)

Arthritis↗
PubMed1994

Paradiaphyseal calcific tendinitis with cortical bone erosion.

OBJECTIVE: To determine the clinical, radiologic, and histologic features of calcific tendinitis with cortical bone erosion. METHODS: The records of 6 patients with paradiaphyseal calcific tendinitis and adjacent bone cortex erosion were reviewed. RESULTS: Calcific tendinitis involved the linea aspera in 4 patients, the bicipital groove in 1 patient, and the deltoid insertion in another. Calcium deposits were associated with cortical bone erosions, revealed on plain radiographs in 4 patients and computed tomography scans in 2. Bone scans were performed in 2 patients and showed local hyperfixation of the isotope. In 4 patients, suspicion of a neoplasm led to a biopsy. Calcium deposits appeared to be surrounded by a foreign body reaction with numerous giant cells. Apatite crystals were identified by transmission electron microscopy and elemental analysis in 1 surgical sample. CONCLUSION: Paradiaphyseal calcific tendinitis with cortical bone erosion is an uncommon presentation of apatite deposition disease.

Adult↗
PubMed1994

Metabolic arthropathies.

In this article, recent advances in the understanding of some of the metabolic arthropathies are reviewed. Among hemoglobinopathies, sickle-cell disease is frequently the source of rheumatic syndromes, as emphasized in recent epidemiologic studies. Avascular necrosis is one of the most common features and may be disabling, leading to total joint replacement of the hip or knee. Joint effusions more rarely are observed and have been associated with subchondral bone infarctions. The clinical and radiologic presentations of the arthropathy of hemochromatosis have been extensively reviewed. Screening for the disease appears important, because it is the only way to prevent progressive worsening of organ involvement and arthropathy in particular. The rheumatic involvement in type IIa and type III hyperlipoproteinemias recently was confirmed in a case-control study. Magnetic resonance imaging appears to be useful in assessing the extent and activity of bone marrow involvement in Gaucher's disease. Replacement therapy is developing. Dialysis-associated amyloidosis remains the target of active research, which recently led to the identification of several newly recognized components, including alpha 2-macroglobulin and hyaluronan. The main component of this amyloid, beta 2-microglobulin, has been shown to be modified by advanced glycosylation products, and these changes appear to confer inflammatory properties on the molecule.

Amyloidosis↗
PubMed1994

[Osteoarthritis with rice bodies rich in calcium microcrystals. 4 cases with ultrastructural study].

Rice bodies are often found in inflammatory joint fluid specimens, especially from rheumatoid arthritis patients, but have rarely been reported in osteoarthritis. We found rice bodies in knee joint fluid specimens from four of 88 patients with osteoarthritis. There were three males and one female. Age ranged from 61 to 86 years. Three patients had slowly progressive knee osteoarthritis and one had rapidly destructive disease. Abundant, recurrent effusions occurred in all four patients despite one to five local corticosteroid injections per patient and radiation synovectomy in two patients. The joint fluid specimens contained 120 to 320 cells/mm3 and large numbers of rice bodies that stained with alizarin red S. Transmission electron microscopy studies showed that the rice bodies were composed of fibrin and contained numerous intra- and extra-cellular calcium crystals composed of apatite alone in two cases and of a combination of apatite and calcium pyrophosphate dihydrate in the two others. Collagen fibers and fragments of bone and cartilage were present in a few rice bodies. Phagocytic cells, type C synoviocytes, chondrocytes and a few inflammatory cells were also seen. These rice bodies composed mainly of fibrin and apatite may have played a role in the pathogenesis of the recurrent joint effusions in our patients.

Aged↗
PubMed1994

[Primary hyperparathyroidism. Clinical, epidemiological and histological aspects].

Primary hyperparathyroidism is most frequently caused by a single parathyroid adenoma and is more frequent in females than in males. Its frequency increases with age. Its annual incidence has been estimated at 41 per 100,000 in Rochester, and its prevalence at 4.3 per 1000 in Stockholm. Since the introduction of automated serum calcium measurements, the recognition of primary hyperparathyroidism has increased and the clinical presentation of the disease has changed. Classical osseous and renal features of the disease have become rare, due to the increased proportion of asymptomatic forms and to earlier diagnosis. Primary hyperparathyroidism is nowadays usually recognized because serum calcium is measured either systematically or in the clinical setting of mild manifestations, such as arthenia, anxiety, hypertension... Bone histology gives evidences of an accelerated bone turn-over, without major unbalance between formation and resorption. Bone densitometry has shown only minor decrease of mineral content of the lumbar spine in several modern series, so that the deleterious effect of mild or asymptomatic hyperparathyroidism on cancelous bone is presently questioned by several authors.

Adult↗
PubMed1994

Magnetic resonance imaging findings in shoulders of hemodialyzed patients.

Twenty two patients (24 shoulders) who had undergone hemodialysis for a mean of 13.4 years, and who had reported chronic shoulder pain for > 6 months, were examined by magnetic resonance imaging (MRI), including T1 and T2 echo gradient images in the frontal plane and T1 images after gadolinium. An increase in thickness of the rotator cuff as well as synovitis and bursitis were documented. Twenty shoulders demonstrated a mean thickness of 8.05 mm. Most often, the signal intensity of T2 and T1 weighted images was intermediate, and T1 images failed to show an uptake of gadolinium. Of the 24 shoulders, 20 had subacromial subdeltoid bursitis and 21 had glenohumeral synovitis. These results indicate that MRI is of help in the early diagnosis of arthropathy in long term hemodialyzed patients. Magnetic resonance imaging findings are more precise than those of ultrasound, particularly for thickness measurements. Moreover, MRI films are easier to read and permit the detection of synovial involvements. The therapeutic value of MRI lies in the fact that it can isolate the two principal causes of shoulder pain in hemodialyzed patients. The increase in cuff thickness leading to impingement syndrome can be treated by surgical decompression; the synovitis can be treated by radioisotope synovectomy.

Adult↗
PubMed1993

Analysis of a T-cell receptor V beta segment implicated in susceptibility to rheumatoid arthritis: V beta 2 germline polymorphism does not encode susceptibility.

OBJECTIVES: The assessment of allelic polymorphism of the T cell receptor gene segment, TCRBV2S1, in rheumatoid arthritis. METHODS: A total of 136 patients with rheumatoid arthritis (RA) (ACR criteria) and 150 controls were TCRBV2S1 genotyped using a nested PCR amplification strategy followed by single-strand conformation polymorphism (SSCP) analysis. RESULTS: The SSCP typing method detected two previously unknown alleles of the TCRBV2S1 gene segment. The TCRBV2S1 allele, genotype and inferred phenotype frequencies were similar in the RA patients and controls. No differences were apparent after the RA patients had been partitioned according to their HLA-DR genotypes. CONCLUSIONS: SSCP analysis is a rapid and efficient method of typing T cell receptor germline polymorphisms. Allelic polymorphism of the T cell receptor variable segment, TCRBV2S1, does not influence susceptibility to RA.

Alleles↗
PubMed1993

[Vitamin-resistant hypophosphatemic rickets and spinal cord compression. Apropos of 2 cases].

Adults with X-linked vitamin-resistant hypophosphatemic rickets can develop spinal cord compression as a result of spinal canal stenosis due to involvement of the spine with the increased periosteal and ligamentary calcification which is typical of the disease. Two cases are reported. In both patients, spinal cord compression manifested as rapidly progressive spastic paraplegia due to compression at T9 and T5, respectively. Decompressive laminectomy ensured full recovery in one case but was ineffective in the other. In both cases, paraplegia developed approximately one year after initiation of therapy combining a metabolite of vitamin D and phosphorus in high doses. Current imaging techniques (CT scan, magnetic resonance imaging) provide highly accurate information on the anatomic mechanism of the stenosis, its often multiple locations, and its course. Three factors are involved in the stenosis, in variable degrees: thickening of the laminae, hypertrophy of the facet joints, thickening and calcification of the yellow ligament. Magnetic resonance imaging is the investigation of choice in these patients. A deleterious effect vitamin D-phosphorus treatment cannot be outruled. The appropriateness of initiating this treatment should be prudently discussed and treated patients should be closely monitored.

Follow-Up Studies↗
PubMed1993

[Rheumatological complications of dialysis].

The articular complications observed in dialysed chronic renal failure failures, whose incidence increases with the duration of dialysis, are closely correlated with the development of beta 2-microglobulin amyloidosis, responsible for nerve tunnel syndromes, arthralgia and chronic joint swelling with frequently multiple subchondral cysts on x-rays. Microcrystalline pathology is dominated by apatite deposits, which may also be involved in the pathogenesis of destructive arthropathy. Articular complications with destruction of the large joints or involvement of the first carpometacarpal joint interfere with the functional prognosis. Sepsis must be excluded in cases of destructive cervical spondyloarthropathies. The pathogenesis of destructive arthropathies is probably multifactorial, consisting of apatite and amyloid deposits, secondary hyperparathyroidism and aluminium poisoning.

Amyloid beta-Peptides↗
PubMed1992

Antibiotic treatment of venereal disease and Reiter's syndrome in a Greenland population.

OBJECTIVE: To assess the effects of antibiotic treatment of urethritis or cervicitis on the incidence of recurrences of articular symptoms in Reiter's syndrome patients. METHODS: Retrospective evaluation of the medical charts of 109 patients living in Greenland. RESULTS: Thirty-seven percent of the episodes of genitourinary tract inflammation that were not treated or were treated with penicillin were followed by arthritis, compared with 10% of those treated with tetracycline or erythromycin. CONCLUSION: Antibiotics active against Chlamydia trachomatis reduced the risk of postvenereal arthritis in the population studied.

Adult↗
PubMed1992

Renal osteodystrophy, disorders of vitamin D metabolism, and hypophosphatasia.

Recent advances in renal osteodystrophy deal with the pathogenesis of the disease, in particular in early renal failure, with the mechanisms of skeletal resistance to parathyroid hormone, with the potential role of iron, and with increased knowledge of adynamic bone disease. For the control of phosphatemia, aluminum-containing phosphate binders are more and more avoided, whereas calcium acetate or carbonate are more and more prescribed. X-linked hyphophosphatemia continue to cause great interest as well as the various iatrogenic osteomalacias.

Chronic Kidney Disease-Mineral and Bone Disorder↗
PubMed1992

Tumoral calcifications in hemodialysis patients: possible role of aluminum intoxication.

Uremic patients may develop extraskeletal calcifications. Among the latter, periarticular tumoral calcifications (TC) represent massive, multiloculated calcium-phosphate deposits. The aim of this report was to analyze a series of 10 cases of TC in hemodialysis patients who were admitted at the Necker Hospital between 1974 and 1988. They were all male. An increased plasma calcium x phosphorus product was observed in 8 of the 10 patients. Plasma calcium level was increased in only 2 patients. In contrast, hyperphosphatemia was a constant feature in all the patients, as was the absence of an increase in plasma alkaline phosphatase activity. Using the bone histomorphometry technique, osteitis fibrosa of mild degree was observed in 2 patients, of moderate degree in 2 and of severe degree in 2 others. Evidence of aluminum (Al) overload was found in the 8 patients in whom it was searched based on bone histomorphometry, bone histochemistry, bone Al content and increased serum Al levels either in the basal state or after a deferoxamine test. In addition, Al overload was strongly suspected in the 2 remaining patients because of prolonged exposure to Al-contaminated dialysate. Various treatment strategies, including parathyroidectomy (PTx), were undertaken that remained unsuccessful in modifying the course of TC to a significant extent. Remarkably, TC occurred for the first time after PTx in 1 patient and worsened after PTx in 2 others. In conclusion, overt secondary hyperparathyroidism appears not to be an essential prerequisite for TC development in hemodialysis patients, and PTx must not be performed in such patients on the sole basis of the presence of TC.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

[Destructive arthropathy of the shoulder].

Destructive arthropathy of the shoulder consists of cartilaginous deterioration combined with subchondral osteolysis. The various diseases able to induce joint destruction (infection, neurological disease, chondrocalcinosis, tumour...) are excluded from this description which only concerns the forms with no obvious cause. Since the description of "senile haemorrhagic caries of the shoulder", several authors have reported, under various names, very similar diseases whose common denominator is destruction of the shoulder joint. The pathogenic factors remain unclear, but various theories have been proposed, involving mechanical factors secondary to lesions of the rotator cuff or suggesting the role of apatite microcrystals.

Calcinosis↗
PubMed1992

[Long-term survival and prognostic factors in stage II-III multiple myeloma treated with conventional chemotherapy].

In this retrospective study, survival and prognostic factors were analysed in 65 patients with stage II-III multiple myeloma with osteolytic lesions. Multiple myeloma was diagnosed from 1976 to 1984, and patients were treated with conventional chemotherapy. The response rate to initial chemotherapy was 46%. The median survival time was 31 months. The 10-year survival rate was 10%. Four variables were individually prognostic: response to initial chemotherapy, bone marrow plasma cell percentage, the Durie and Salmon staging system, a biological staging system derived from Durie and Salmon's biological criteria regardless of bone lesions. In the multivariate analysis, only two prognostic variables were retained, namely the response to chemotherapy and the biological staging system. No prognostic value was observed for the extent of osteolytic lesions. This study suggests that, in conventionally treated multiple myeloma, long-term survival has improved compared with the previous decade. It also indicates that the extent of osteolytic lesions has little value for the definition of high-risk myeloma.

Adult↗
PubMed1992

[Microcrystal deposit arthropathies of the wrist].

Microcrystalline arthropathies of the wrist include three main forms of microcrystalline pathology: gout, chondrocalcinosis and apatite calcifications. Gout of the wrist is now rare and may be missed, particularly in its chronic form, occasionally associated with tophi and large, often asymmetrical erosions on the X-rays. Chondrocalcinosis is frequent and easy to diagnose in the wrist and may be responsible for a very typical arthropathy predominantly involving the radiocarpal joint, while the frequency and specificity of scapho-trapezoid involvement are controversial. Apatite deposits in the wrist involve various tendons and ligaments, especially the tendon of flexor carpi ulnaris, but may also be responsible for intra-articular pathology.

Apatites↗
PubMed1992

[Therapeutic maintenance and tolerance of sulfasalazine in rheumatoid polyarthritis. Retrospective study of 95 patients].

This retrospective study evaluated treatment with sulfasalazine (SAS) in a mean dosage of 2.1 g/day in 95 patients with rheumatoid arthritis (RA) who were followed-up for 3 months to 4 years. Mean disease duration was 7 years; 79 patients had previously received at least one disease-modifying drug. Four per cent of patients were lost to follow-up. Mean duration of treatment was 15 months (3 weeks-50 months). Treatment continuation rates were 57% at one year, 40% at two years, and 26% at three years. Reasons for discontinuation of SAS included adverse effects (n = 24), inefficacy (n = 33), and death unrelated to SAS therapy (n = 2). In four patients, SAS was discontinued within three months of the first dose because of a severe adverse effect (diffuse erythematous rash, diffuse bullous rash, hepatitis with jaundice, agranulocytosis). SAS-induced biologic markers for lupus were seen in one patient. Furthermore, 12% of evaluable patients developed antinuclear antibodies during SAS therapy. The SAS treatment continuation rate was higher (p = 0.05) among patients under 40 years of age (n = 18) than among older patients. This difference was due to a correlation between age and tolerance with less SAS-induced side effects in patients under 40 years of age (p = 0.03). The SAS treatment continuation rate was unrelated to the duration of rheumatoid arthritis or number of previous maintenance treatments. This study suggests that rheumatoid arthritis patients under 40 years of age exhibit better tolerance to SAS therapy.

Adolescent↗