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Biomedical subjects

E V McCloskey

Publications and source records attributed to E V McCloskey.

At least 19 recordsLinked to original sources

A randomized trial of the effect of clodronate on skeletal morbidity in multiple myeloma. MRC Working Party on Leukaemia in Adults.

In patients with multiple myeloma, despite a major reduction of bone pain achieved with chemotherapy, skeletal disease continues to progress. The effects of clodronate, an inhibitor of osteoclastic bone resorption, are evaluated on the natural history of skeletal disease in patients with newly diagnosed multiple myeloma. Within the framework of the VIth MRC Multiple Myeloma Trial, 536 patients (218 women, 318 men) with recently diagnosed multiple myeloma were randomized to receive either clodronate 1600 mg daily (n=264) or an outwardly identical placebo (n=272) in addition to chemotherapy. Treatment with clodronate was associated with a 50% decrease in the proportion of patients with severe hypercalcaemia (5.1% v 10.1%, P=0.06) and a similar reduction in reported non-vertebral fractures (6.8% v 13.2%, P=0.04). Fewer patients receiving clodronate sustained vertebral fractures after entry to the trial (38% v 55%, P=0.01) and patients also lost less height over 3 years compared to those receiving placebo (2.0 v 3.4 cm, P=0.01). Biochemical indices of bone turnover were significantly lower in patients receiving concomitant clodronate, both at plateau and at disease relapse. The frequencies of back pain and poor performance status were significantly lower at 24 months in clodronate than in placebo-treated patients (10.9% v 19.9%, P=0.05, and 18.3% v 30.5% P=0.03 respectively.) There was no statistically significant difference in survival between the clodronate and placebo treated patients. The study indicates that long-term oral clodronate slows the progression of skeletal disease in multiple myeloma and decreases the associated morbidity. Patients without overt skeletal disease at diagnosis were also found to benefit from clodronate, indicating that this treatment should be initiated as early in the course of the disease as possible.

Aged

Bone turnover and biochemical markers in malignancy.

There are three principal disturbances in bone remodelling that occur in neoplasia affecting the skeleton. The first is an increase in bone turnover that in solid tumors may be confined to sites of metastases or be a generalized phenomenon, most likely related to the secretion of parathyroid hormone-related protein. In the bone remodelling sequence, bone resorption precedes formation, so that increases in turnover result in substantial skeletal deficits more marked at cancellous than cortical bone sites. The second abnormality in bone remodelling is an imbalance between the amount resorbed and that formed at each remodelling site. This is a conspicuous feature of myelomatosis with moderate grades of plasma cell infiltration. The third phenomenon is the process of uncoupling. In osteolytic disease this is associated with the creation of erosion cavities that are never subsequently repaired. Progressive waves of bone resorption result in the destruction of skeletal elements and focal osteolysis. Osteosclerotic metastases formed by uncoupled bone formation represent the deposition of new bone either on quiescent bone surfaces or arising from stromal condensations within the marrow cavity. In solid tumors biopsy evidence suggests that uncoupled bone resorption and formation occur within the same metastases and that the radiographic expression (osteosclerosis, osteolysis) depends on the predominant component. The understanding that abnormalities of skeletal metabolism are mediated by authentic bone cells raises the possibility that skeletal specific markers of bone turnover might be utilized for the diagnosis of metastases, to assess the skeletal prognosis, or to monitor treatment. A variety of skeletal markers have been assessed. The pyridinium crosslinks currently provide the markers of greatest predictive value. Although they have high specificity, their sensitivity is low (< 30%). This indicates that many individuals with skeletal metastases would be missed. In contrast, skeletal markers have proven invaluable in the assessment of the natural history of the disease and response to intervention. They have been particularly useful in assessing the pharmacodynamics of bisphosphonate treatment. However, their day-to-day precision is sufficiently low that they are of limited value in the monitoring of individuals.

Biomarkers, Tumor

Clodronate.

Clodronate is a second-generation bisphosphonate of intermediate potency between etidronate and aminobisphosphonates. It is an effective inhibitor of bone resorption, but unlike etidronate does not impair the mineralization of bone. Unlike pamidronate, it can be given both intravenously and orally. There is wide experience in the use of clodronate in the management of patients of hypercalcemia. The most widely used therapeutic regimen is 300 mg intravenously repeated for 5 days or a single infusion of 1500 mg. Efficacy is nearly complete in patients with myelomatosis, less complete in solid tumors with hypercalcemia but without skeletal metastases, and intermediate in patients with solid tumors in the presence of skeletal metastases. Variations in effect appear to be due to differences in renal tubular reabsorption of calcium between the three disorders. Placebo-controlled studies examining the effects of clodronate on bone pain in the absence of hypercalcemia have shown significant decreases in the severity of bone pain. These findings, coupled with the knowledge that suppression of bone resorption persists for the duration of treatment, has led to the long term use of oral doses of clodronate to decrease the incidence of complications of osteolytic bone disease. The long term control of bone resorption with oral clodronate has been demonstrated by double blind histologic studies. The ultimate arbiter of the value of clodronate is whether it decreases the skeletal morbidity associated with osteolysis. Double blind prospective controlled studies suggest that the incidence of bone pain, fracture, and hypercalcemia can be decreased significantly in patients with breast carcinoma. In addition, the use of long term clodronate in patients with myelomatosis significantly decreases the progression of osteolytic bone lesions, the risk of fractures, and the incidence of hypercalcemia. These studies have raised the possibility that bone disease might be prevented in individuals at high risk. Double blind prospective studies in women with recurrent breast carcinoma but no evidence of skeletal metastases showed a small effect of clodronate in decreasing the proportion of women developing metastatic disease. However, there was a large and significant decrease in the number of skeletal metastases associated with a decrease in skeletal morbidity. These observations suggest that clodronate may modify the natural history of the expression of skeletal disease, and thereby significantly improve the quality of life of affected patients.

Bone Diseases

Alendronate in the treatment of Paget's disease of bone.

We studied four treatment regimens of oral alendronate in 60 patients with active Paget's disease. Two groups received an oral daily dose of either 40 or 80 mg of alendronate for 3 months, followed by placebo for a further 3 months: the other two groups received treatment with 40 or 80 mg per day for 6 months. Activity of alkaline phosphatase and urinary hydroxyproline excretion were measured before, during, and after treatment, at intervals for a total follow-up of 1 year. A transiliac bone biopsy was performed in 24 patients before and after the treatment. An additional 16 patients had a third biopsy more than a year after stopping treatment. Alendronate induced a marked suppression in the urinary excretion of hydroxyproline within 2 weeks (p < 0.01) followed by a fall in serum activity of alkaline phosphatase at 1 month (p < 0.01) in all treatment groups. Nine months after the start of treatment patients treated with 80 mg for 6 months had a significantly lower mean alkaline phosphatase activity compared to the other treatment groups (p < 0.02), which persisted at 1 year (p < 0.05). Alkaline phosphatase decreased to within the laboratory reference range in all patients given 80 mg for 6 months. In contrast, alkaline phosphatase decreased to within the laboratory reference range in 73-83% of patients given 80 mg for 3 months and the 40 mg dose. Histomorphometric assessment showed a decrease in indices of bone turnover in the pagetic biopsies. None of the biopsies taken after treatment showed evidence of impaired mineralization of bone. Gastrointestinal side effects occurred in 25% of patients of whom two withdrew from treatment. We conclude that oral alendronate is an effective agent for the treatment of Paget's disease of bone.

Aged

Elimination and biochemical responses to intravenous alendronate in postmenopausal osteoporosis.

Postmenopausal women with established vertebral osteoporosis were studied for 2 years to determine the terminal elimination half-life and the duration of response to treatment with intravenous alendronate (30 mg) given over 4 days. The urinary excretion of alendronate followed a multiexponential decline. Approximately 50% of the total dose was excreted over the first 5 days, and a further 17% was excreted in the succeeding 6 months. Thereafter, there was a much slower elimination phase with an estimated mean terminal half-life of greater than 10 years (n = 11). Urinary excretion of hydroxyproline and calcium decreased significantly from pretreatment values by day 3, reaching a nadir by 1 week (40% and 67% decrease, respectively). Thereafter, hydroxyproline remained suppressed for the following 2 years. In contrast, urinary calcium excretion returned gradually toward pretreatment values over the first year and during the second year was comparable to pretreatment values. Serum activity of alkaline phosphatase activity decreased over 3 months (23% reduction), increased gradually thereafter, and returned to pretreatment values at month 24. Bone mineral density measured at the spine increased by approximately 5% during the first year and remained significantly higher than pretreatment values at 2 years. We conclude that a short course of high doses of intravenous alendronate is associated with a prolonged skeletal retention of the agent. This open study also suggests that this regimen has a sustained effect on bone turnover persisting for at least 1 year.

Aged

Comparison of three intravenous regimens of clodronate in Paget disease of bone.

We compared the effects of three different regimens of intravenous clodronate in a retrospective study of 60 patients with Paget disease. A total dose of 1500 mg of clodronate was given as 300 mg for 5 consecutive days (n = 20), 1500 mg as a single infusion (n = 20), or 300 mg as a single infusion for 5 consecutive months (n = 20). The response to treatment and the duration of the effect were assessed from sequential changes in the activity of serum alkaline phosphatase. Treatment with clodronate induced a significant response in 85% of patients. The response rate was comparable in patients treated with 5 daily infusions (90%), with a single infusion (75%), and with 5 monthly infusions (90%). The median duration of response from the start of treatment was 11 months for those treated with five daily infusions and 12 months for the other two regimens. At one year, 22, 40, and 44% of patients had maintained their response in the daily, single, and monthly infusion regimen, respectively (NS). Six patients (32%) treated with 5 daily infusions achieved a remission (complete response) compared with 3 patients treated with a single infusion and 5 monthly infusions, respectively (16 and 15% respectively, NS). Patients attaining a complete response had a significantly longer duration of response compared with partial responders (median time 15.0 versus 11.5 months, respectively, p < 0.05). We conclude that intravenous clodronate (total dose 1500 mg) suppresses disease activity in the majority of patients with Paget disease of bone. The degree and duration of response were similar for the three regimens. Thus, in the treatment of Paget disease, the choice of regimen is a matter of convenience.

Aged

A precise method for the assessment of tibial ultrasound velocity.

We assessed a method for the measurement of ultrasound velocity in cortical bone of the human tibia using a probe designed to minimize the effects of surrounding soft tissues. Of four different measurement values, the maximum velocity (average of the five highest readings) gave the lowest errors of reproducibility in relation to the population variance (standardized coefficient of variation = 1.8%). The maximum velocity varied according to the tibial site measured and for practical reasons the mid-tibial site was chosen for further study. The short-term intra- and inter-observer reproducibilities (coefficients of variation) were 0.35% (n = 22) and 0.50% (n = 27) respectively. Long-term reproducibility over 4 months in 31 subjects was 0.68%. There was no significant difference in maximum ultrasound velocity between the dominant and nondominant tibia in 78 women (3764 +/- 209 vs 3763 +/- 199 m/s). Tibial ultrasound velocity was significantly higher in 73 premenopausal women (3999 +/- 102 m/s) than in 129 women referred for assessment of postmenopausal osteoporosis (3780 +/- 168 m/s), 26 women with steroid-induced osteoporosis (3790 +/- 188 m/s) and 4 women with hyperparathyroidism (3575 +/- 261 m/s). In premenopausal women, ultrasound velocity did not correlate significantly with age, height, weight or body mass index. In women with postmenopausal osteoporosis, ultrasound velocity decreased with age after the menopause (r = -0.47, p < 0.0001) and body weight exerted a weaker protective effect. The apparent annual decrease in velocity with age in postmenopausal osteoporosis (8.5 m/s) was comparable to the error of reproducibility. We conclude that the technique for measuring tibial ultrasound velocity is highly reproducible in relation to the distribution of values in the population and is sensitive to age- and osteoporosis-induced changes in bone. Further studies are required to examine its relationship to other indices of skeletal status to determine the biological and clinical relevance of the technique.

Adult

Clodronate and osteoporosis.

Bisphosphonates are widely used in disorders associated with increased resorption of bone, particularly in Paget's disease of bone and the hypercalcaemia of malignancy. Their undoubted efficacy and relatively low toxicity makes them attractive candidates for the management of osteoporosis. The three bisphosphonates widely tested are etidronate, pamidronate and clodronate. Whereas pamidronate can only be given by intravenous infusion, clodronate may be given intravenously or by mouth. Unlike etidronate, even high doses of clodronate do not impair the mineralisation of bone, making it suitable for long-term use in osteoporosis. Clodronate has been shown to inhibit experimentally induced increases in bone resorption and in patients prevents bone loss at the menopause and during immobilisation. Short-term and long-term studies indicate that clodronate appears to stop bone loss at the lumbar spine in patients with vertebral osteoporosis. Long-term studies of the effects at the hip are not yet reported. The effects of clodronate on the frequency of osteoporotic fractures are not yet known and will demand well controlled long-term prospective studies.

Administration, Oral

Duration of response with oral clodronate in Paget's disease of bone.

We studied retrospectively 51 patients with Paget's disease of bone treated with oral clodronate, 1600 mg daily given for 1 (n = 23), 3 (n = 13), or 6 months (n = 15), to compare the effect of a variable length of treatment on the response rate to treatment and the duration of disease suppression. Activity of alkaline phosphatase and urinary hydroxyproline excretion were measured before treatment at monthly intervals for a year and every 3 months thereafter until biochemical relapse. Before treatment, patients given the three regimens had similar disease activity as judged by serum alkaline phosphatase and urinary hydroxyproline values. There was no significant difference in the time to response between groups (median = 2 months). The proportion of patients attaining normal values of alkaline phosphatase activity was significantly higher in patients treated for 6 months (71%, p < 0.03) compared with those treated for 1 or 3 months (23% and 39%, respectively). The time to relapse from the start of treatment was significantly shorter in patients treated for 1 month compared with those treated for 3 or 6 months (median = 11, 18, and 23 months, respectively). Thus, at 2 years all patients treated for 1 month had relapsed, whereas 31% and 40% were still relapse-free in patients receiving treatment for 3 and 6 months, respectively. The length of treatment was the only variable identified by stepwise linear regression that significantly affected the duration of response. We conclude that oral clodronate (1600 mg daily) suppresses disease activity in the vast majority of patients with Paget's disease of bone. The magnitude of the response and its duration depend on the duration of treatment or the total dose administered, so that several months of treatment with oral clodronate are required when a durable response is desired.

Administration, Oral

Evaluation of the risk of hip fracture.

Hip fracture is the most serious complication of osteoporosis and the incidence is rising worldwide. Bone mineral density measurements can be used not only to diagnose osteoporosis at the hip, but also to give prognostic information on the lifetime risk of hip fracture. A number of additional risk factors enhance the ability of density measurements to assess risk. Candidates include markers of bone resorption, prior fragility fractures, hip axis length, and estimates of postural integrity, each of which improve prognostic value independently of bone mineral assessments. Their use in the stratification of risk will help define intervention thresholds for treatments and improve the design of population screening policies, particularly in elderly women in whom the burden of hip fracture is greatest.

Adult

Paget's disease of bone and unvaccinated dogs.

The etiology of Paget's disease is unknown, but several observations suggest a viral cause. Since canine distemper virus is among those proposed to be a causal agent, we investigated the hypothesis that dog ownership may increase the risk of Paget's disease of bone by means of a case control study. One hundred and fifty patients with Paget's disease and 185 controls were interviewed using a structured questionnaire administered by the same interviewer. Participants were asked about their socioeconomic background and their exposure to pets. The risk of Paget's disease was not significantly increased in individuals. However, ownership of a mongrel dog was associated with a significant increase in risk (OR = 1.6; 95% CI = 1.0-2.4) and the risk increased still further with the ownership of an unvaccinated dog (OR = 2.8; 95% CI = 1.8-4.5). Additionally, ownership of cats and birds excluding dog owners, increased the risk of Paget's disease (OR = 2.5; 95% CI = 1.0-5.0; OR = 2.3; 95% CI = 1.0-5.3, respectively). These data suggest that previous exposure to cats, birds, and dogs unvaccinated for canine distemper may increase the risk of an individual developing Paget's disease of bone.

Adult

Clodronate decreases the frequency of skeletal metastases in women with breast cancer.

The aims of this study were to determine the effects of the bisphosphonate, clodronate, on the incidence of skeletal metastases and associated morbidity in women with advanced breast cancer. 133 women with recurrent breast cancer, but no evidence of skeletal metastases, were randomly allocated to receive clodronate 1600 mg daily by mouth or an identical placebo for 3 years under double-blind conditions at two clinical oncology centers in the UK and Canada. Main outcome measures included the occurrence of skeletal metastases, as judged by sequential bone scans and radiographs, and the morbidity associated with skeletal metastases comprising the incidence of hypercalcemia, vertebral, and nonvertebral fractures, and bone pain assessed by the requirements for skeletal radiotherapy. The number of patients developing skeletal metastases was lower in clodronate-treated patients than with placebo (15 vs. 19), but was not significantly different. The number of skeletal metastases was significantly lower with clodronate treatment than with placebo (32 vs. 63; p < 0.005). The complications of skeletal disease were fewer by 26% in clodronate-treated patients compared to controls (p < 0.01). Compared to placebo, significant effects in favor of clodronate were observed for vertebral deformities (29%) and nonvertebral fractures (75%), but the event frequency of each was low. There was a small (22%) but nonsignificant treatment effect on the requirements for radiotherapy and hypercalcemia (39%). There was no effect of clodronate on survival. We conclude that clodronate by mouth significantly decreases the number and complications of skeletal metastases in women with advanced breast cancer.

Administration, Oral

Assessment of osteopenia from spine radiographs using two different methods: the Chingford Study.

Two methods for diagnosing radiological osteopenia in thoracic (TS) and lumbar (LS) spine radiographs were assessed: a subjective conventional method (A) and a semiquantitative method (B), by comparing them with bone mineral density (BMD) measured by dual energy X-ray absorptiometry (DEXA), in a population of "normal" women aged 45-70 years (n = 818). For both methods there was good intraobserver and interobserver reproducibility. BMDs were significantly lower with increasing radiological osteopenia grades (p < 0.001), and remained lower after adjustment for age and body mass index (p < 0.01). The proportion of subjects with DEXA-defined osteoporosis rose with increasing radiological osteopenia grades for both methods. The worst osteopenia categories identified 29.7-55.3% of women with DEXA-defined osteoporosis, compared with 6.1-11.7% in the "normal" categories. Both methods, however, showed a large degree of overlap of BMDs between the various radiological osteopenia grades. The sensitivity and specificity of method A in diagnosing osteoporosis were 45.3% and 78.4%, respectively, for the TS and 19.0% and 94.3%, respectively, for the LS. For method B the sensitivities and specificities were 8.8% and 96.1%, respectively (TS), and 10.2% and 95.6%, respectively (LS). Although both methods have poor sensitivities, "definite" or "high" grade osteopenia should be an indication for bone densitometry. The high specificities suggest that a "normal" (no osteopenia) X-ray is unlikely to have a significantly low BMD.

Absorptiometry, Photon

The effects of intravenous alendronate in Paget's disease of bone.

We studied the effects of intravenous alendronate on disease activity in 36 patients with active Paget's disease of bone. Alendronate was administered to 3 groups of 12 patients at doses of 2.5, 5, and 10 mg intravenously daily for 5 consecutive days. The patients were matched for disease activity. Symptomatic improvement was seen in at least 10 patients in each treatment group. Alendronate induced a dose-dependent suppression of biochemical indices of bone turnover in all patients. A significant reduction in the mean fasting urinary excretion of hydroxyproline occurred within 2 days of starting treatment, reaching a nadir at 2-4 weeks, which was most marked in patients receiving 10 mg of alendronate (p < 0.05). There was a slower fall in serum alkaline phosphatase activity with maximal suppression occurring 3 months after the start of treatment. The degree of suppression was least for those receiving 2.5 mg of alendronate (p < 0.05) but no difference in response was observed for the other dosages. The duration of response was also dose-related. A significant fall in the serum calcium and urinary excretion of calcium occurred from the second day of treatment but returned to pretreatment values by 4 months. A transient fall in the mean lymphocyte count was observed, which was similar for each group. This was associated with a short-lived fever in 3 patients receiving 10 mg, in 4 patients receiving 5 mg, and in 2 patients receiving 2.5 mg.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged

Sustained response to intravenous alendronate in postmenopausal osteoporosis.

We studied the effects of alendronate (amino-hydroxybutylidene bisphosphonate) on biochemical indices of bone turnover and on lumbar spinal bone mineral density in 15 postmenopausal women with vertebral osteoporosis. Alendronate 7.5 mg daily was administered intravenously as a slow infusion for four consecutive days. Treatment was associated with a significant decrease in serum calcium (p < 0.01), fasting urinary calcium excretion (p < 0.01) and hydroxyproline excretion within several days followed a later decrease in serum alkaline phosphatase activity that showed a significant reduction at two months after treatment (p < 0.05). Serum calcium reverted to pretreatment values by the second week after infusion, but the decrease in alkaline phosphatase, urinary calcium, and hydroxyproline excretion persisted to six months after infusion. There was a 3% mean increase in lumbar bone mineral density at six months (p < 0.01). A transient lymphopenia or leucopenia was noted in eight patients and a short-lived fever in six. No other side effects were observed. This study demonstrates that shortterm exposure to high intravenous doses of alendronate induces suppression of bone resorption in osteoporosis that persists for at least 6 months after infusion. We conclude that a short exposure to high intravenous doses induces sustained effects on bone turnover in much the same manner as that observed in Paget's disease of bone.

Absorptiometry, Photon