Biomedical subjects

M Pazianas

Publications and source records attributed to M Pazianas.

42 records · Page 3Linked to original sources

PubMed1992

Identification of risk factors for radiographic hyperparathyroidism in 422 patients with end-stage renal disease: development of a clinical predictive index.

The hand radiographs of 422 patients with end-stage renal failure were graded for severity of subperiosteal resorption. Two hundred and seventy-three patients (64.7%) had no evidence of resorption; 114 (27.0%) showed resorption, in 32 of whom it was severe (7.6% of the total). Thirty-five patients (8.3%) were assessed as having doubtful evidence of subperiosteal resorption. Age, gender, race, renal diagnosis, duration of renal failure and vitamin D status were assessed as potential risk factors for the development of subperiosteal resorption. Duration of renal failure, female gender, young age, and certain renal diagnostic groups namely obstructive uropathy, unknown diagnosis, presumed glomerulonephritis and tubulointerstitial disease emerged as independent risk factors. Diabetic patients appeared to be least at risk of developing subperiosteal resorption. Patients whose renal failure was of unknown duration showed a degree of risk similar to those whose duration was < 2 years. In order to identify prospectively patients likely to develop subperiosteal resorption by the time they reach renal replacement therapy, the relative risks were used to create a risk index. Use of such an index might allow prophylactic treatment to be given to those particularly at risk. The concept of a risk index requires testing by a prospective study, which is in progress.

Adolescent↗

PubMed1991

Racial origin and primary renal diagnosis in 771 patients with end-stage renal disease.

A total of 771 individuals with end-stage renal disease treated at one centre from 1964 to 1990 were studied. Data on racial origin, gender, age, and primary renal diagnosis were analysed. The male: female ratio (468:303) and proportions of individuals in different diagnostic groups (renal diagnosis based on European Dialysis and Transplant Association (EDTA) groups) were similar to EDTA data for the UK as a whole. Racial distribution was Caucasian 79.0%, Indian subcontinent (Is-c) 12.7%, Caribbean, 5.6%, African 1.6% and other Asian 1.2%. In Britain individuals from the Is-c constitute 2.2% of the general population and those from the Caribbean 1.0%. We found differences in the distribution of primary renal disease among patients from different racial groups. Adult polycystic kidney disease was almost entirely confined to Caucasians (75 to 79 patients). Diabetic nephropathy was relatively more common in individuals (especially males) from the Is-c. Hypertensive renal disease was relatively more common in those of Caribbean descent and in Africans, whilst 'Unknown diagnosis' was most common in patients from the Is-c.

Adolescent↗

PubMed1990

Aluminium deposition in bone after contamination of drinking water supply.

Two healthy individuals who drank water accidentally contaminated at source with aluminium sulphate solution were investigated 6-7 months later. Bone biopsy specimens showed discrete lines of positive staining for aluminium, the distribution being compatible with acute exposure some months previously. These findings show that under certain conditions normal individuals can absorb aluminium via the gut, and that such aluminium can be deposited in bone.

Adult↗

PubMed1990

Dialysis arthropathy: a clinical, biochemical, radiological and histological study of 36 patients.

Out of a population of 97 haemodialysis patients, 36 patients with dialysis arthropathy were identified. Dialysis arthropathy is a chronic symmetrical polyarthritis which affected 97 per cent of the patients who had been undergoing cuprophane haemodialysis for more than 10 years. It commonly affected the shoulders, hips, hands, knees and wrists, worsening with time and extending to other joints. Fifty-eight per cent of the patients complained of morning stiffness and 47 per cent complained of exacerbation of shoulder pain during or after haemodialysis. Half of the patients also suffered from carpal tunnel syndrome, which recurred and was associated with a long-lasting disability. The most common radiological abnormality was periarticular bone cysts, followed by articular erosions and a destructive spondyloarthropathy, but clinical symptoms were more common than radiological signs. Patients with dialysis arthropathy had a higher C-reactive protein level than patients without arthropathy (18.6 mg/l versus 11.4 mg/l), indicative of an inflammatory process. Some of the clinical manifestations of the disease correlated with levels of C-reactive protein and ferritin. Serum ferritin levels correlated strongly with the units of blood transfused in the past five years (RS = 0.83), and the logarithm of ferritin level correlated weakly with C-reactive protein (r = 0.32). Haemarthroses were documented in 19 per cent of patients. Mean serum beta 2-microglobulin was elevated in the patients with (57.3 mg/l) and without arthropathy (50.7 mg/l), and there was no difference in the parathormone or aluminium levels between these groups. Articular tissue was obtained in 25 patients; beta 2-microglobulin amyloid was present in 24. Larger deposits were present in the capsular tissue, and these appeared to replace collagen bundles in eight cases. Amyloid deposits replaced the lining layer in six cases. It is likely therefore that amyloid disrupts normal joint function by replacing normal joint tissue. Mild chronic synovitis with haemosiderin deposition were found in approximately 60 per cent of cases. These findings suggest that amyloid derived from beta 2-microglobulin has a primary role in the pathogenesis of dialysis arthropathy, but there was also evidence of inflammatory processes. It is suggested that iron overload or haemarthroses might contribute to the inflammation, but other factors, such as dialysis-related bioincompatibility reactions, may also have a role.

Adult↗

PubMed1987

Calcific aortic stenosis: a complication of chronic uraemia.

The incidence of aortic stenosis was studied in 174 consecutive patients aged less than 55 years at initiation of maintenance haemodialysis. Severe, calcific aortic stenosis developed in 6 patients a mean 9.7 years after starting haemodialysis (p = 0.0004 compared to population incidence). In 5 patients stenosis was due to severe premature calcification of a tricuspid aortic valve. Necropsy proven aortic valve calcification (with or without stenosis) was associated with an increased duration of haemodialysis, age greater than 35 years at starting dialysis and mitral annular calcification. There is an increased incidence of aortic stenosis in patients with chronic renal failure due to premature valvular calcification, which may be related to abnormal calcium and phosphate metabolism in uraemia.

Adult↗

PubMedDate not supplied

Role of the endothelial cell in osteoclast control: new perspectives.

The osteoclast is of central importance in the process of bone remodeling. Its function is regulated by hormones and locally produced factors. Endothelial cells occur in close proximity to the osteoclast. Some endothelial cell-derived products, including endothelins, nitric oxide, and reactive oxygen species, have been recently implicated as modulators of osteoclast function. Endothelins inhibit bone resorption and osteoclast margin ruffling (quiescence or Q effect) at concentrations similar to those effective for their primary vasoconstrictive action. Contrary to expectations, however, it has been shown that endothelin action on the osteoclast is not mediated through an elevation of cytosolic Ca2+. Nitric oxide (NO) produces marked cell retraction (retraction or R effect), but its detailed mode of action is unknown. However, it is clear that the effects of this autocoid are not due to enhanced cyclic guanosine monophosphate (cGMP) production, a transduction system commonly used by NO. Finally, the reactive oxygen species H2O2 has been shown recently to enhance osteoclastic activity. Thus, the reported effects of the endothelial cell-derived products on the osteoclast are generally consistent with a regulatory role for endothelial cells in osteoclast control and suggest the existence of unique activation pathways, well worth exploring further. Unravelling the responsible mechanisms may also help understand the pathophysiology of a range of bone and joint diseases. For example, in rheumatoid arthritis, there is increased H2O2 production from activated neutrophils, and bone resorption is a major pathophysiological feature.

Bone Remodeling↗