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Biomedical subjects

I Fogelman

Publications and source records attributed to I Fogelman.

At least 199 records · Page 11Linked to original sources
PubMed1990

Impact of bone mineral measurements on osteoporosis.

Dual photon absorptiometry enables measurement of bone mineral to be carried out at the clinically relevant sites of the spine and femur. Few would argue that it provides a powerful research tool, but defining its role in clinical practice has been somewhat more difficult. With the advent of X-ray based systems, studies can be rapidly carried out with improved precision, which has led to increased clinical interest. It is probable that this technology will be incorporated into routine use in the near future. In the present review we have addressed the role of dual photon absorptiometry in areas pertinent to osteoporosis and the direction in which recent developments are leading with regard to future research.

Absorptiometry, Photon↗
PubMed1990

The relationship between plasma estradiol and the increase in bone density in postmenopausal women after treatment with subcutaneous hormone implants.

Twenty-three postmenopausal women with a median of 2 years past menopause (range, 1 to 12 years) and a median age of 52 years (range, 39 to 62 years) were recruited to participate in a longitudinal study designed to investigate the factors that influence the increase in bone density with subcutaneous estradiol and testosterone implants. All women received 75 mg of estradiol with 100 mg testosterone subcutaneously. Bone density was measured at the spine and hip by dual-photon absorptiometry before therapy and after 1 year of subcutaneous hormonal therapy. The mean pretreatment bone density at the lumber vertebrae and neck of the femur was 0.84 grams of hydroxyapatite per square centimeter (SD, 0.11) and 0.73 grams of hydroxyapatite per square centimeter (SD, 0.10), respectively. The bone density at both sites increased with values of 0.91 grams of hydroxyapatite per square centimeter (SD, 0.11) and 0.75 grams of hydroxyapatite per square centimeter (SD, 0.11), respectively. These values represent an increase of 8.3% (p less than 0.0001) at the spine and 2.8% (p less than 0.01) at the neck of the femur. The plasma estradiol level increased from a median of 80.5 pmol/L to 453 pmol/L (p less than 0.001). The percentage increase of vertebral bone density was not related to age, number of years past the menopause, pretreatment bone density, or serum testosterone levels, but a significant correlation was found between the percentage increase in bone density at the spine and the serum estradiol level (p less than 0.02, r = 0.45).

Adult↗
PubMed1990

Exercise myocardial perfusion scintigraphy with technetium-99m methoxy isobutylisonitrile: a comparative study with thallium-201.

The evaluation of technetium-99m methoxy isobutylisonitrile for the diagnosis of coronary artery disease requires comparative validation against thallium-201, the established perfusion imaging agent. We have compared myocardial and lung uptake of both radiotracers following maximal exercise in 52 patients: 40 with angiographically proven coronary disease. Qualitative and quantitative image analysis showed the diagnostic sensitivity of technetium-99m methoxy isobutylisonitrile to compare favourably with that of thallium-201 as reflected by the mean number of ischaemic segments identified: 5.6 +/- 2.5 vs 4.8 +/- 2.1 by qualitative analysis, and 5.7 +/- 3.2 vs 5.0 +/- 2.6 segments by quantitative analysis. More reversibly ischaemic segments per patient were identified with technetium-99m methoxy isobutylisonitrile than with thallium-201: 3.6 +/- 2.3 vs 1.8 +/- 1.9. There was a higher exercise myocardial to background count ratio with technetium-99m methoxy isobutylisonitrile: 3.16:1 vs 2.58:1, and the mean exercise lung uptake normalised to left ventricular uptake ('lung index'), was lower for technetium-99m methoxy isobutylisonitrile than for thallium-201 (36 +/- 8% vs 40 +/- 10%). Five of the six patients with abnormal elevation of the thallium-201 exercise lung index also had elevation of the technetium-99m methoxy isobutylisonitrile exercise lung index, and all had extensive coronary artery disease. These results indicate that technetium-99m methoxy isobutylisonitrile is at least as effective as thallium-201 for detecting exercise induced myocardial ischaemia. However, technetium-99m methoxy isobutylisonitrile provides a better image quality and may be a more sensitive marker of defect reversibility. For both radiotracers lung uptake is increased with extensive coronary artery disease and measurement of this variable provides prognostic information.

Coronary Disease↗
PubMed1990

Premenopausal bone loss in the lumbar spine and neck of femur: a study of 225 Caucasian women.

Two hundred and twenty-five premenopausal women were studied to evaluate age-related changes in trabecular bone mass. Measurements were made at the lumbar spine and femoral neck by dual photon absorptiometry. It was found that spinal bone density increased significantly from the 20s to reach a peak in the mid-30s. Identical trends were observed in total bone mass and bone mass normalized by length. Bone loss then proceeded at a rate of 1% per year, and by the early 50s, 10% of peak spinal density was lost. There was no peak in femoral neck density; loss commenced in the late 20s and continued at a rate of 0.4% per year. The cumulative premenopausal loss from the femur at 9% was comparable to that in the spine. It is concluded that significant amounts of trabecular bone are lost from both the spine and femoral neck before the menopause. The implications of these findings for the prevention of osteoporosis are discussed.

Absorptiometry, Photon↗
PubMed1990

Selection of patients with breast cancer for routine follow-up bone scans.

Routine radionuclide bone scans have not been considered cost-effective for the routine follow-up after treatment of primary breast cancer. However subgroups of patients exist in whom early relapse in the skeleton is likely and this study examines again the role of the bone scan in routine follow-up. Serial radionuclide bone scans were performed every 6 months during the first 2 years of follow-up of 560 patients with breast cancer. Tumor characteristics which predict early relapse in bone were identified and the scan conversion rate from negative to positive determined for each prognostic group. A total of 199 (28%) of patients have relapsed, 50 (9%) with first recurrence in bone within two years of diagnosis. All were identified on the bone scan with a median lead time of 4 months over radiological evidence of bone involvement. The overall scan conversion rate was 2.8%. This was significantly higher in poor prognosis patients with T4 tumours (6.3%), more than four involved axillary lymph nodes (6.1%) and inoperable tumours (6.5%), than in good prognosis patients with T1 tumours (1.1%), negative axillary lymph node involvement (1.2%) or well-differentiated ductal grade tumours (1.1%). We do not recommend routine bone scans in the follow-up of all patients with breast cancer. In patients with a good prognosis after primary treatment they cannot be considered cost-effective. However, in those with features which predict early recurrence in the skeleton the frequency of scan conversion is sufficient to justify serial bone scanning during the first two years of follow-up.

Adult↗
PubMed1990

Lung scanning for pulmonary embolism: clinical and pulmonary angiographic correlations.

A group of 78 patients with suspected pulmonary embolism was studied by both ventilation perfusion lung scanning and pulmonary angiography. Symptoms and clinical signs were analysed using Bayesian techniques to produce pre-test odds for pulmonary embolism in individual patients. While, as a group, those with embolism could be discriminated from those without on this basis, major overlap existed between the groups, invalidating the use of this approach for individual patients. Strict diagnostic criteria for interpretation of lung scans were accurate using pulmonary angiography as the 'gold standard', but at the expense of a significant number of patients (38 per cent) in the indeterminate (non-diagnostic) group. In the 48 patients in whom the test yielded a diagnostic result, there was a sensitivity of 100 per cent (15/15) and a specificity of 97 per cent (32/33). In the series as a whole, the likelihood of lung scanning correctly diagnosing pulmonary embolism was 55 per cent (15/27) and of correctly excluding embolism, 63 per cent (32/51). By the use of strict criteria for interpretation of lung scanning, reliable information can be obtained on the presence or absence of pulmonary embolism in a large proportion of patients suspected of having the condition. Such information is more discriminating than clinical signs and symptoms.

Adult↗
PubMed1989

Advances in the prevention of osteoporosis.

Recent advances in the techniques for measuring bone mass and the advent of hormone replacement therapy have markedly improved the outlook for patients with osteoporosis. The ability to predict which women are at high risk will enable preventive measures to be taken.

Bone Density↗
PubMed1989

Effect of etidronate disodium on bone turnover following surgical menopause.

A longitudinal study was performed to document the effect of surgical menopause and postmenopausal etidronate disodium therapy on several nonhistomorphometric indices of bone turnover. Twenty healthy, premenopausal women undergoing oophorectomy for nonmalignant conditions were studied preoperatively and at 3 monthly intervals postoperatively. Sequential measurements of serum calcium (Ca), alkaline phosphatase (AP), bone Gla protein (BGP), and urinary calcium and hydroxyproline excretion, expressed as a ratio of urinary creatinine (UCa/Cr and UOHp/Cr, respectively) were obtained. Twenty-four-hour whole body retention of diphosphonate (WBR) and radial bone density were also measured. When a postoperative increase in bone turnover was observed, patients were randomized to receive either 400 mg etidronate disodium daily or placebo for 3 months. Oophorectomy was associated with a significant increase in WBR, Ca, AP, and BGP and an insignificant rise in UCa/Cr. A variable pattern of UOHp/Cr was seen. Patients on placebo maintained these elevated levels of Ca, BGP, and UCa/Cr. WBR and AP continued to rise. Etidronate disodium therapy resulted in a fall towards premenopausal levels in WBR, Ca, and UCa/Cr. AP and BGP were unchanged. Three months after stopping etidronate, BGP fell significantly and the decrease in Ca was maintained; however, WBR and UCa/Cr had returned towards pretreatment values. Bone density measurements did not change significantly. An increase in several of the indices of bone turnover was seen following oophorectomy. Etidronate disodium suppressed this increase, affecting indices of both resorption and formation.(ABSTRACT TRUNCATED AT 250 WORDS)

Alkaline Phosphatase↗
PubMed1989

An evaluation of the contribution of bone mass measurements to clinical practice.

Measurement of bone mass by dual photon absorptiometry (DPA) provides a powerful research tool, but its role in clinical practice is contentious. In the present review, several questions of clinical relevance relating to bone mass are addressed and the contribution of DPA assessed. While there is currently much conflicting data in the literature, it is nevertheless predicted that with the recent improvements in DPA (X-ray systems) there will be much wider clinical application.

Bone and Bones↗
PubMed1989

Bone mineral content of women receiving tamoxifen for mastalgia.

Dual photon absorptiometry (DPA) has been used to measure the effect of short and medium-term administration of tamoxifen on bone density in the axial skeleton of women with mastalgia. This provided a unique opportunity to monitor the effect of this 'anti-oestrogenic' agent in predominantly premenopausal women, not suffering from malignancy. In addition, plasma levels of calcium, phosphate, alkaline phosphatase and serum levels of oesteocalcin (GLA) have been assayed, both before and after 3 months of starting either tamoxifen or placebo treatment. No significant alterations in bone density were seen. Osteocalcin, alkaline phosphatase and electrolytes were unchanged and there was no dose response observed in women receiving either 10 mg or 20 mg of tamoxifen. Although possessing anti-oestrogenic properties, tamoxifen is also a partial agonist. Administration for the short periods does not measurably influence spinal or femoral bone density and thus the agent can probably be given safely for the short-term treatment of mastalgia.

Bone and Bones↗
PubMed1989

Bone mass in hirsute women with androgen excess.

The spinal and femoral bone mass of 32 hirsute women with oligomenorrhoea and androgen excess was measured using dual photon absorptiometry and compared with the bone mass of 32 control women with regular menstrual cycles. Despite significantly lower oestradiol levels in the hirsute population there was no significant difference in the bone mass. Furthermore there was no significant difference in bone mass in five hirsute women with undetectable levels of oestradiol. It is concluded that androgen excess can maintain normal bone mass in the face of low or undetectable oestradiol levels.

Absorptiometry, Photon↗
PubMed1989

The effect of anorexia nervosa on skin thickness, skin collagen and bone density.

The effects of anorexia nervosa on skin thickness, skin collagen content and bone density were investigated in a cross-sectional study of 36 women with anorexia nervosa with a 4-year median duration of amenorrhoea and compared with a group of 33 women of comparable age without anorexia and with normal periods. The median skin thickness, assessed radiologically, was significantly reduced (P less than 0.01) from 0.88 mm in the comparison group to 0.70 mm in the anorectic group and the median collagen content was significantly reduced from 209 micrograms/mm2 in the comparison group to 164 micrograms/mm2 in the anorectic group (P less than 0.05). The median bone density in the comparison group was 0.93 gHA/cm2 at the lumbar spine and 0.84 gHA/cm2 at the proximal femur. These values were greatly reduced in the women with anorexia nervosa to 0.77 gHA/cm2 and 0.65 gHA/cm2 respectively (P less than 0.01). Our findings confirm the loss of bone mass with anorexia and demonstrate the coexistent loss of skin thickness and skin collagen content. This association supports the hypothesis that a generalized loss of collagen is a major factor in the causation of osteoporosis following oestrogen deficiency.

Adolescent↗
PubMed1989

Serum concentrations of alkaline phosphatase isoenzymes and osteocalcin in normal pregnancy.

We measured serum alkaline phosphatase isoenzymes and osteocalcin levels in 40 healthy women at 4-week intervals throughout uncomplicated pregnancies and 6 weeks after delivery in 17 women. Serum bone alkaline phosphatase was significantly higher in the third trimester than in early pregnancy (P less than 0.001), and this elevation was still apparent at the end of the puerperium, suggesting increased bone turnover. Serum osteocalcin was not detected (less than 0.2 micrograms/L) after the first trimester in the majority of women, and it reappeared within 48 h after delivery. The disappearance of osteocalcin after the first trimester and its rapid reappearance after delivery suggest placental clearance of this peptide. We conclude that serum osteocalcin measurements cannot be used as a marker of bone metabolism during pregnancy.

Adult↗
PubMed1989

The localization of myocardial ischaemia with technetium-99m methoxy isobutyl isonitrile and single photon emission computed tomography.

Thirty-two patients with suspected coronary artery disease were studied by single photon emission computed tomography (SPECT) imaging with oblique reconstructions of the myocardium following the intravenous administration of technetium-99m methoxy isobutyl isonitrile at peak exercise. All patients also underwent three-vessel coronary angiography. The SPECT technique produced very detailed images allowing easy delineation of localized myocardial defects. Segmental myocardial uptake defects were compared with diseased vessels as shown at angiography. A good correlation was shown between right coronary artery (RCA) disease and mid and proximal inferior segments and between left circumflex (LCx) artery disease and mid and proximal lateral segments, allowing accurate localization of a defect to one of these two vessels' territories. Sensitivity and specificity of detection of disease of the RCA and LCx artery were high. Defects associated with a lesion of the left anterior descending vessel were more variable.

Adult↗