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Biomedical subjects

R Lindsay

Publications and source records attributed to R Lindsay.

At least 253 records · Page 14Linked to original sources
PubMed1973

Oestrogen replacement therapy for prevention of osteoporosis after oophorectomy.

The value of oestrogen therapy in the prevention of osteoporosis after oophorectomy was assessed in 114 middle-aged women who participated in a double-blind controlled trial of mestranol in an average daily dose of 23 mug. The skeletal response to treatment was measured by a photon absorption technique. Where treatment was started within two months of operation subsequent bone mineral loss was prevented. Treatment started three years after oophorectomy caused a highly significant increase in bone mineral content. When treatment was delayed for six years mestranol failed to prevent subsequent bone mineral loss with age. These effects occurred independently of the associated humoral changes in calcium and phosphorus homoeostasis. Mestranol in this dosage appeared to be relatively safe, but it is too early to evaluate the long-term hazards of such therapy.

Age Factors↗
PubMed1973

Osteoporosis after oophorectomy for non-malignant disease in premenopausal women.

The role of oophorectomy in the development of osteoporosis was assessed retrospectively in 258 women who had been hysterectomized premenopausally for non-malignant disease. Bone density was assessed using the radiographic density of the third metacarpal. Oophorectomy before the age of 45 years was found to be associated with a significantly increased prevalence of osteoporosis within three to six years of operation. The bone density of women oophorectomized after the age of 45 years was indistinguishable three to six years after operation from that found in healthy women with intact ovaries. These findings confirm the major part played by loss of ovarian function in the development of postmenopausal osteoporosis.

Absorptiometry, Photon↗
PubMed1971

Effect of Na, metabolic inhibitors and ATP on Ca movements in L cells.

1. The Ca movements in normal and ;ghost' L cells have been examined; all measurements were made using (45)Ca.2. Normal cells have a Ca concentration of about 1 m-mole/l. of cell volume, and exchange Ca in a complex way but with great rapidity; the time taken for the initial Ca(*) content to fall to half was less than 2 min.3. Poisoning normal cells with DNP 10(-3)M + IAA 10(-4)M causes a marked reduction in the Ca efflux, no change in Ca influx and an increase in total Ca.4. Variation in internal or external Na concentration does not alter the Ca fluxes or concentrations. Application of cyanide or ouabain and alteration of external K concentration had no effect on the Ca fluxes.5. The sulphydryl reagents, ethacrynic acid and N-ethylmaleimide (NEM), have a rapid and marked effect on reducing the Ca efflux.6. L cell ghosts previously poisoned with DNP+IAA have a low Ca efflux. When ATP or CTP is incorporated into such cells the Ca efflux becomes normal.7. An extra amount of phosphate is produced by L cell ghosts when pumping Ca. This is equivalent to the splitting of 1.8 moles of ATP per mole of Ca pumped.8. It is concluded that L cells have a Ca pump driven by ATP, and that Na has no effect on Ca movements in these cells.

Adenosine Triphosphate↗
PubMedDate not supplied

Long-term effects of raloxifene on bone mineral density, bone turnover, and serum lipid levels in early postmenopausal women: three-year data from 2 double-blind, randomized, placebo-controlled trials.

BACKGROUND: In postmenopausal women, raloxifene hydrochloride has favorable effects on bone and lipid metabolism and does not stimulate reproductive tissues. The studies reported herein evaluated the long-term (3-year) effects of raloxifene treatment on bone mineral density (BMD), serum lipid levels, and drug tolerability in healthy postmenopausal women. METHODS: A total of 1145 healthy European and North American postmenopausal women aged 45 through 60 years were enrolled in 2 parallel, double-blind, randomized, placebo-controlled trials of identical design and randomly assigned to receive raloxifene hydrochloride, 30, 60, or 150 mg, or placebo daily; all groups received 400 to 600 mg of elemental calcium. Assessments included measurements for BMD by dual-energy x-ray absorptiometry, markers of bone turnover, and serum lipid levels. RESULTS: Lumbar spine BMD changed from baseline to 36 months as follows: placebo (mean percentage change + SE), -1. 32% +0.22%; raloxifene, 30 mg, 0.71% +0.23%; raloxifene, 60 mg, 1. 28% +0.23%; and raloxifene, 150 mg, 1.20% +0.24%. Comparable BMD changes were observed in the hip and total body. Biochemical markers of bone turnover were suppressed by raloxifene to normal premenopausal ranges through 3 years. Serum low-density lipoprotein cholesterol was reduced 7% to 12% below baseline through 3 years. Study withdrawals due to any reason (37%) and withdrawals due to adverse events (14%) were not different among groups. The only significant adverse effect of therapy was hot flashes (25% in the 60-mg raloxifene group vs 18% in the placebo group); hot flashes were typically reported as mild and were not associated with study withdrawal (1.7% for 60-mg raloxifene vs 2.4% for placebo). CONCLUSIONS: Raloxifene preserves BMD at important skeletal sites, lowers serum low-density lipoprotein cholesterol levels, and has a tolerability profile comparable to placebo. These results indicate a favorable benefit-risk profile of raloxifene for long-term use in healthy postmenopausal women. Arch Intern Med. 2000;160:3444-3450.

Bone Density↗
PubMedDate not supplied

Patient responsiveness to calcitonin salmon nasal spray: a subanalysis of a 2-year study.

A subanalysis of results from a randomized, double-blind, placebo-controlled, parallel-group, 2-year study was conducted to evaluate the response of individual patients to therapy with 200 IU/d calcitonin salmon nasal spray compared with placebo in postmenopausal women who had low bone mass. All patients received 500 mg/d of oral supplemental calcium. A response to therapy was defined as an increase from baseline in lumbar vertebral bone mineral density, measured by use of dual-energy x-ray absorptiometry, at the end of 2 years of treatment. Of 41 valid completers (ie, patients who met the entry criteria, were compliant with the protocol, and completed the study) treated with calcitonin salmon nasal spray, 31 (76%) responded positively to treatment. Of 40 valid completers who received placebo, 25 (63%) lost bone mass (P = 0.001 between groups). The relative risk of bone loss for patients receiving calcitonin salmon nasal spray was 0.19 (95% confidence interval, 0.07 to 0.50), representing an 81% risk reduction. This subanalysis demonstrates that the benefits of calcitonin salmon nasal spray therapy were seen in the majority of women studied. Calcitonin salmon nasal spray represents an effective therapeutic alternative for osteoporotic women more than 5 years postmenopause who reject or cannot tolerate estrogens or for whom estrogens are contraindicated.

Absorptiometry, Photon↗
PubMedDate not supplied

Hypercalcaemia causing declining cognitive function in a head injured patient.

Although hypercalcaemia in young children or adolescents immobilized by fractures or spinal cord injury is well recognized, hypercalcaemia in adult immobilized patients is rare without a pre-existing bone disease. To our knowledge, hypercalcaemia in a head-injured, immobilized patient has not been previously reported. We report here a case where a previously normocalcaemic, immobilized, head-injured adult patient developed cognitive decline secondary to hypercalcaemia five months after injury, when transient interruption of enteral feedings led to mild dehydration. Indices of bone turnover were elevated and parathyroid hormone was appropriately suppressed. Possible predisposing factors in our patient included a severe degree of immobilization and a very high level of athletic activity prior to injury. Careful fluid management and specific monitoring of calcium levels, even several months post-injury, should be performed to avoid the added complications of hypercalcaemia in head-injured patients.

Adult↗