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Biomedical subjects

L D Hordon

Publications and source records attributed to L D Hordon.

At least 19 recordsLinked to original sources
PubMed1997

Assessment of renal osteodystrophy in dialysis patients: use of bone alkaline phosphatase, bone mineral density and parathyroid ultrasound in comparison with bone histology.

Bone biopsies were studied in 73 patients to determine if a two-site radioimmunometric assay for serum bone alkaline phosphatase (BAP), total serum alkaline phosphatase (ALP), serum intact parathyroid hormone (iPTH), hand X-rays, regional bone mineral density (BMD) measurements and parathyroid enlargement detected by ultrasonography could accurately predict renal osteodystrophy. In the patients studied 57 had hyperparathyroid bone disease, 4 mixed renal osteodystrophy, 3 adynamic bone disease, 1 osteomalacia and 8 normal histology. Serum BAP, ALP and iPTH correlated positively with mineral apposition rate, osteoblastic, osteoid and eroded surface. In the diagnosis of hyperparathyroid bone disease serum iPTH was the most sensitive investigation, detecting 81% of patients at a level > 100 pg/ml but with a specificity of only 66%. Serum BAP was more sensitive, 70% at a level of > 10 ng/ml, than serum total ALP, 30% at a level of 300 IU/l, with similar specificities, 92 and 100%, respectively. Ultrasound detection of an enlarged parathyroid gland had a sensitivity of 64% and a specificity of 100% for the diagnosis of hyperparathyroid bone disease. Hand X-rays had a poor sensitivity, 47%, but a high specificity, 92%, for the detection of hyperparathyroid bone disease. The majority of patients had regional BMD values within the normal reference range and this test was of poor discriminatory value. The non-invasive markers were unable to distinguish between patients with low turnover, mild hyperparathyroidism and patients with normal histology. In conclusion the measurement of serum iPTH is a useful screening tool for the detection of hyperparathyroid bone disease which can be confirmed by the finding of a raised serum BAP or parathyroid enlargement. For definitive diagnosis, however, the gold standard remains bone biopsy and at present one cannot recommend any non-invasive method as an adequate substitute.

Adult↗
PubMed1994

Methotrexate mishap.

Explore the source record for details and available documents.

Arthritis, Rheumatoid↗
PubMed1994

Endocrine disorders.

The effect of endocrine disorders on bone mass is being increasingly studied. It is suggested that the preceding thyroid disorder, rather than thyroxine replacement itself, may reduce bone mass. Fracture rate does not appear to be increased in primary hyperparathyroidism once the condition is diagnosed. Although osteopenia is widely accepted to be associated with diabetes mellitus, two studies report increased bone mass in this condition. However, diabetes appears to adversely affect bone formation and urinary calcium excretion. Osteopenia is not a problem in acromegaly despite that patients are often hypogonadal. The possible associations of thyroid disease with connective tissue disorders are discussed, and the role of androgens in the pathogenesis of connective tissue disease is debated.

Bone Density↗
PubMed1993

Primary generalized osteoarthritis and bone mass.

The association of OA with increased bone mass is controversial. This study measured BMD at the hip and spine and total body bone mineral (TBBM) by dual energy X-ray absorptiometry, and BMD at the distal forearm by single photon absorptiometry in 20 post-menopausal women with primary generalized OA. The data were compared with those from 89 normal controls. Osteoarthritic women had significantly increased BMD at the spine (P < 0.001), distal forearm (P < 0.05) and increased TBBM (P < 0.01), but no difference was seen at the femoral neck. These differences were not explained by obesity. The influence of mobility is discussed.

Aged↗
PubMed1993

Endocrine disease.

The effects of endocrine disease on bone mass continue to attract attention. Investigations include the effects on the skeleton of thyroid disease, primary hyperparathyroidism, and their treatment. The effect of growth hormone replacement in adults with panhypopituitarism has also been investigated; children with treated growth hormone deficiency appear to reach adulthood with low bone mass. The indications for surgery in asymptomatic primary hyperparathyroidism have recently been reviewed. The associations between autoimmune thyroid disease and connective tissue disease have been investigated. Although patients with Graves' disease are frequently positive for antinuclear antibodies, there appears to be no increased risk of systemic autoimmune disease. The possible pathogenesis of diabetic bone disease via calcium malabsorption, hypercalciuria, reduced bone formation, and collagen abnormalities has been reviewed. A long-term study has clarified the links among diabetic control, limited joint mobility, nephropathy, and retinopathy. The possible mechanisms by which pregnancy may induce remission in rheumatoid arthritis have been discussed.

Endocrine System Diseases↗
PubMed1992

Urinary excretion of pyridinium crosslinks of collagen in patients with osteoporosis and the effects of bone fracture.

Values for the urinary excretion of pyridinium crosslinks of collagen, pyridinoline and deoxypyridinoline, in a group of 30 elderly women with femoral fractures associated with osteoporosis and a group of 20 women without recent fracture but with overt or suspected osteoporosis were compared with 27 control subjects matched for age. Relative to the control group, the excretion of the crosslinks was significantly higher in the group with fractures and the group with osteoporosis. Fractures contributed markedly to the excretion of pyridinium crosslinks as the patients with fractures showed significantly higher excretion of pyridinoline and deoxypyridinoline than the group without recent fractures. This was confirmed by the fact that excretion of pyridinium crosslinks in patients with accidental bone fractures was significantly higher than for healthy control subjects matched for age and sex. The crosslinks appear to provide valid indices of bone resorption, but the effects of bone fracture must be considered in the clinical application of this technique.

Aged↗
PubMed1992

Endocrine disorders.

The effect of thyroxine replacement therapy on bone mass continues to attract attention. Although the advice of the American Thyroid Association to normalize serum thyroxine and thyroid-stimulating hormone concentrations is recommended, even physiologic doses of thyroxine may have an adverse effect on bone mass. The diagnosis and treatment of osteomyelitis in the diabetic foot is aided by magnetic resonance imaging, and long-term review of cases of diabetic femoral neuropathy emphasizes the good prognosis. Adrenal insufficiency as a complication of antiphospholipid syndrome is reviewed, and a useful physical sign, the acromegalic rosary, rediscovered. The association of sex steroids, oral contraception, and parity with rheumatoid arthritis is discussed. The outcome of pregnancy in women with juvenile rheumatoid arthritis is good, and quiescent disease does not appear to be permanently reactivated. Calcium deficiency, rather than vitamin D deficiency, is a cause of rickets in some Nigerian children.

Adrenal Gland Diseases↗
PubMed1991

Renal tubular dysfunction in rheumatic diseases.

Evidence of renal tubular dysfunction as defined by abnormal urinary levels of alpha 1 and beta 2 microglobulin with or without microalbuminuria was found in 47 (16.5%) of 285 patients with a variety of rheumatic diseases, compared with a prevalence of less than 1% in 500 healthy adults. Previous work from this unit has shown a prevalence of tubular dysfunction of 24% in patients with severe rheumatic disease admitted to hospital, probably associated with severe rheumatoid arthritis. Although our study confirms a high prevalence of renal tubular dysfunction, we have shown that it is related to age and intercurrent illness, particularly urinary tract infection, rather than to rheumatic disease or drug therapy, although it is possible drug therapy could add to a compound insult on ageing or damaged kidney.

Aged↗
PubMed1991

Endocrine disorders.

Recent studies emphasize the adverse effects of endocrine disorders on bone mass. Successful surgery for hyperparathyroidism results in an increase in bone mass, although impact on future fracture rates in these patients is unknown. The etiology of reduced bone mass in diabetes is still unclear, and the adverse effects of thyroxine replacement treatment on bone mass need to be carefully balanced against beneficial effects on hypercholesterolemia. Musculoskeletal problems in chronic renal failure are common, but investigations into their pathogenesis are complicated by the coexistence of renal endocrine failure and beta 2-microglobulin-related amyloid deposition in long-term dialysis patients. An improved definition of dialysis arthropathy is needed. The type of dialysis membrane does not appear to be important in the pathogenesis of this condition.

Bone Diseases↗
PubMed1990

The architecture of cancellous and cortical bone in femoral neck fracture.

The architecture of cancellous bone as well as quantity and quality is considered important in maintaining mechanical integrity. To determine whether abnormalities of architecture occur in femoral neck fracture we measured trabecular width and number in iliac crest bone biopsies of 68 women with femoral fracture and compared them with data from a postmortem series of age-matched women without known bone disease. Cortical thickness was measured in 27 of the fracture patients and 17 controls. After exclusion of ten biopsies with increased osteoid surface no significant difference was seen in mean trabecular width or number between fracture patients and subjects without fracture. Both thinning of trabeculae and loss of trabeculae contributed to low bone volume in femoral fracture patients. Direct measurements of trabecular number correlated with calculated mean trabecular plate density (P less than 0.001), and the percentage of trabeculae at any one of a range of trabecular widths in the fracture biopsies was similar to that in non-fracture subjects. No difference was seen in the architecture of cancellous bone with age, fracture trauma or between subcapital and intertrochanteric fracture in fracture subjects. Cortical thickness, however, was related to age in both fracture and control subjects (P less than 0.05). There was no difference in cortical thickness between age-matched fracture and control subjects. Patients with intertrochanteric fracture had lower cortical thickness (P less than 0.02) and were older (P less than 0.01) than patients with subcapital fracture.

Aged↗
PubMed1990

Osteomalacia and osteoporosis in femoral neck fracture.

Iliac crest bone histomorphometry, plasma and urine biochemistry and clinical history were examined in 78 unselected patients (68 women, 10 men) at the time of femoral fracture. Histological abnormalities occurred in 56 of the 78 biopsies. The commonest of these was a low bone volume of less than 15% which, irrespective of other abnormal histological features, was present in 37 of the biopsies. On the basis of the histomorphometry, patients could be classified into four main groups. Normal histomorphometry (bone volume greater than 15%, osteoid surfaces less than 24%, mineralising surface greater than 60%) was present in 22 patients, 23 had osteoporosis as the only abnormality (bone volume less than 15%, osteoid surface less than 24%, mineralising surface greater than 60%), nine had osteomalacia (osteoid surfaces greater than 24%, mineralising surface less than 60%, osteoid width greater than 13 microns) and 13 had decreased mineralising surfaces. Of the remainder, five had increased osteoid surface and six had insufficient osteoid to assess mineralising surface. Plasma and urine biochemistry in the four groups showed that, compared to age-matched controls, all groups had reduced plasma albumin. In comparison to the group with normal histomorphometry, patients with osteoporosis had a higher plasma calcium (P less than 0.01), tubular reabsorption of calcium (P less than 0.05) and plasma vitamin D binding protein (P less than 0.01); patients with osteomalacia had a higher plasma creatinine (P less than 0.02) and parathyroid hormone (P less than 0.02) and lower plasma 24,25-dihydroxyvitamin D (P less than 0.02), urinary calcium/creatinine ratio (P less than 0.02) and tubular reabsorption of phosphate (P less than 0.02). The biochemistry in patients with decreased mineralising surface was no different from patients with a normal biopsy. The prevalence of both osteoporosis and osteomalacia increased with age and, in subjects over the age of 90, osteoporosis occurred in 71% of patients and osteomalacia occurred in 29% of patients. The osteomalacic group were significantly older than the other three groups (P less than 0.05). The histomorphometry did not relate to the site of fracture (subcapital or intertrochanteric). A history of stroke, gastrectomy, rheumatoid arthritis, steroid treatment, thyroid disease, alcohol abuse and anti-convulsant therapy was present in patients with femoral fracture but did not relate to any particular histomorphometric classification.

Age Factors↗
PubMed1988

Haematuria in rheumatoid arthritis: a follow up study.

Twenty one patients with seropositive rheumatoid arthritis and previously documented isolated haematuria were recalled at a median 7.7 years (range 3-12) after initial investigation. Eighteen subjects had previously undergone renal biopsy, which had shown mesangial glomerulonephritis in all but four cases. Renal function was found to have remained normal in all patients with previous mesangial changes despite the presence of persistent haematuria in most cases.

Arthritis, Rheumatoid↗