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Biomedical subjects

N A Hamdy

Publications and source records attributed to N A Hamdy.

49 records · Page 3Linked to original sources
PubMed1987

Effects of intravenous etidronate disodium on skeletal and calcium metabolism.

The induction of hypercalcemia in malignant disease is almost invariably associated with increased bone resorption. However, tumor-induced changes in bone formation and renal tubular resorption of calcium are also important factors that induce hypercalcemia in some patients. In addition, alterations in calcium fluxes to and from the extracellular fluid secondary to hypercalcemia are important in maintaining or aggravating the hypercalcemic effects of increased bone resorption. These factors significantly affect the responses to treatment of hypercalcemia with inhibitors of bone resorption. This study examined the relative importance of these factors and the effects of intravenous etidronate disodium (etidronate) in neoplastic bone disease with and without hypercalcemia and in Paget's disease of bone. It is concluded that intravenous etidronate is an effective inhibitor of bone resorption, which accounts in large measure for its effects on serum calcium concentrations. These studies of etidronate in hypercalcemia suggest the response is sustained for several weeks.

Aged↗
PubMed1987

Aminohexane diphosphonate in the treatment of Paget's disease of bone.

We studied the effects of the intravenous or oral administration of aminohexane diphosphonate (AHDP) in 42 patients with active Paget's disease of bone. Treatment of mouth (400 mg daily for 1 month) or intravenously (25 mg or 50 mg daily for 5 days) induced marked suppression of biochemical indices of disease activity. Urinary excretion of hydroxyproline fell to 39 and 42% of pretreatment values (oral and IV treatments respectively), and was followed by a similar decrease in the serum activity of alkaline phosphatase. In both groups of patients, disease activity remained suppressed for the 6 months of followup, and pain improved in 34 out of 37 patients who had bone pain attributed to Paget's disease. Both biopsies indicated that osteoblast and osteoclast numbers decreased with no adverse effects on mineralization. Neither regime was associated with significant side effects. We conclude that short courses of AHDP provide a promising treatment for the long-term control of Paget's disease.

Administration, Oral↗
PubMed1987

Treatment of the hypercalcaemia of malignancy with intravenous clodronate.

We studied the effects of intravenous clodronate (100-300 mg daily for 3-10 days) in 27 episodes of hypercalcaemia due to malignancy. Comparisons were also made between responses in patients with haematological malignancies and those with solid tumours. Following extracellular volume expansion, clodronate induced a significant decrease in serum calcium within 2 days of the start of treatment which was maximal at 7 days. This was associated with a decrease in bone resorption as judged by decreases in urinary excretion of hydroxyproline and calcium. Hypercalcaemia recurred 5-7 days after stopping treatment. Patients with solid tumours had higher pretreatment serum calcium values than those with haematological malignancies despite comparable values for fasting urinary excretion of calcium suggesting that renal tubular reabsorption of calcium was more markedly increased in patients with solid tumours. No difference was observed in the final calcium values between patients with solid tumours and haematological malignancies except in those patients in whom renal tubular reabsorption of calcium was markedly increased before treatment. We conclude that intravenous clodronate provides a safe and effective treatment of hypercalcaemia due to a wide range of tumour types provided that increased bone resorption contributes significantly to the hypercalcaemia. When increased renal reabsorption of calcium is the predominant mechanism for the maintenance of hypercalcaemia, the response to clodronate is incomplete.

Adult↗
PubMed1987

Clodronate in the medical management of hyperparathyroidism.

The skeletal manifestations of hyperparathyroidism are due to the stimulation of osteoclast-mediated bone resorption by high circulating concentrations of parathyroid hormone (PTH). Since diphosphonates inhibit PTH-mediated bone resorption, we assessed the effects of clodronate in 42 patients with hypercalcaemia and increased bone resorption due to primary hyperparathyroidism (20 patients), secondary hyperparathyroidism in chronic renal failure (12 patients on haemodialysis replacement therapy) and tertiary hyperparathyroidism following successful renal transplantation (10 patients). Clodronate (0.8-1.6 g daily by mouth or 300 mg given as an intravenous infusion following five consecutive dialysis treatments) significantly decreased serum calcium and biochemical indices of bone resorption in the three groups studied. In primary and tertiary hyperparathyroidism, serum calcium values remained above the upper limit of the reference range despite suppression of bone resorption due to the unopposed effect of PTH on renal tubular reabsorption of calcium. Prolonged treatment (3 months) was associated with a partial recurrence of hypercalcaemia in 8 of 12 patients with primary hyperparathyroidism despite continued effects on bone resorption, possibly due to a secondary decrease in bone formation. These studies indicate that clodronate is capable of suppressing PTH-mediated bone resorption in disorders of parathyroid secretion and may prove to be a useful adjunct in their medical management.

Administration, Oral↗
PubMed1986

Sedation for gastroscopy: a comparative study of midazolam and Diazemuls in patients with and without cirrhosis.

A double-blind controlled study comparing the effects of intravenous Diazemuls (0.15 mg kg-1) with midazolam (0.07 mg kg-1) in patients with normal liver function and with cirrhosis and portal hypertension is described. The clinical effect of the two drugs was assessed by serial tests of psychomotor function before and at varying intervals after administration. Using this dosage regime, midazolam caused significantly greater impairment in psychomotor function in both cirrhotic and non cirrhotic subjects, and the time taken for recovery of normal function was also significantly prolonged. Patients with cirrhosis showed a significantly prolonged recovery time following administration of either benzodiazepine compared with the controls. Administration of midazolam in a lower dose might reduce the degree of sedation and shorten the recovery time, but this could also lead to a loss of some of the amnesic effect. Caution is recommended in the administration of benzodiazepines to patients with cirrhosis.

Adult↗
PubMed1986

Renal micropolyarteritis: a treatable condition.

A 10-year retrospective study of 36 patients is presented; the patients comprised 27 with renal micropolyarteritis nodosa (microPAN) and nine with Wegener's granulomatosis. At presentation, 29 patients had significant renal impairment (creatinine greater than 150 mumol/l), with 18 requiring dialysis at some time during their illness. Eighteen patients showed rapid recovery of renal function, a further two with apparently chronic renal failure recovered renal function after 4 months dialysis and continued immunosuppression. Seven patients required chronic dialysis. No benefit was shown for any particular immunosuppressive regime, with three patients recovering renal function (two initially on dialysis) without any immunosuppression. Prognosis was better than in previous published series, especially considering the elderly population (mean 52.9 years), with an 80% 1-year and a 64% 5-year survival.

Anti-Inflammatory Agents↗
PubMed1986

Pathogenesis of osteomalacia in chronic renal failure and its relationship to vitamin D.

Considerable confusion arises in defining osteomalacia in the presence of renal disease. There are no radiographic or biochemical features which satisfactorily identify all patients with osteomalacia. Histological definitions need to distinguish increased amounts of osteoid due to defective mineralisation from that due to increased bone turnover, both of which may coexist in chronic renal failure. The pathogenesis of osteomalacia in renal failure is multifactorial and not always due to defective metabolism of vitamin D. Deficient production of 25-hydroxyvitamin D may occur because of nutritional privation or urinary losses in the nephrotic syndrome, but these are rare causes of osteomalacia in patients on haemodialysis treatment. It is not clear to what extent defective production of calcitriol, characteristic of end-stage chronic renal failure is causally related to osteomalacia, in part due to uncertainties as to whether vitamin D acts directly on bone to promote mineralisation or whether its effects are mediated indirectly by modulating calcium and phosphate transport at other sites. Following the institution of renal replacement therapy, the incidence of osteomalacia varies markedly between renal units due to the skeletal retention of aluminium caused by the contamination of dialysis fluid or by the chronic ingestion of aluminium-containing phosphate binding agents. This form of osteomalacia is associated with a high risk of fracture, probably more related to depressed bone formation than to the presence of osteomalacia. Rarer causes of osteomalacia include parathyroidectomy and calcium and phosphate deficiency.

Aluminum↗
PubMed1985

Intravenous clodronate in the treatment and retreatment of Paget's disease of bone.

The effects of short courses (5 days) of intravenous clodronate 300 mg daily were studied in 31 patients with active Paget's disease of bone. The diphosphonate induced a striking reduction in biochemical indices of disease activity, which was sustained for at least 6 months after withdrawal of treatment. Apparent resistance to further treatment in patients previously treated for Paget's disease was an artefact due to incomplete relapse before retreatment. There was no significant difference in the degree of suppression of alkaline phosphatase activity between patients given intravenous clodronate and 45 patients given clodronate 1.6 g daily by mouth for 6 months. Short-term intravenous clodronate provides a useful alternative strategy for the treatment of patients with Paget's disease.

Administration, Oral↗