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Biomedical subjects

M V Merrick

Publications and source records attributed to M V Merrick.

At least 73 records · Page 4Linked to original sources
PubMed1985

The pathogenesis of post-irradiation chronic diarrhoea: measurement of SeHCAT and B12 absorption for differential diagnosis determines treatment.

The absorption of vitamin B12 and of a synthetic bile acid analogue 75SeHCAT was measured simultaneously in 26 patients presenting with persistent diarrhoea following pelvic irradiation for treatment of carcinoma of the cervix. Four groups were identified, namely patients with isolated bile acid malabsorption, patients with isolated B12 malabsorption, patients with malabsorption of both and those with malabsorption of neither compound. The therapeutic implications are different for each. Measurement of B12 and bile acid absorption comprises an important new test for the management of patients with this disabling and unpleasant complication of radiotherapy.

Cholestyramine Resin↗
PubMed1985

Bone scintigraphy in breast cancer: a nine-year follow-up.

The results of skeletal scintigraphy performed at presentation in 465 women with histologically confirmed carcinoma of the breast were correlated with tumour size, node status, clinical course and survival during a follow-up of at least 2 years and up to 9 years. Skeletal metastases were eventually confirmed in 17.6% of the population under study, but were identified at presentation by scintigraphy in only half of these. The incidence of significant scintigraphic abnormalities ranged from 1.5% in patients with T0 and T1 node negative tumours to 20.3% in T4 node positive tumours. Patients with scintigraphic evidence of metastases had a significantly shorter survival than those without; 13.6% of the patients with an abnormality considered to be significant on the criteria employed in this study failed to develop confirmatory evidence of skeletal metastases during the period of follow-up. Alternative criteria are proposed which would substantially decrease the incidence of false positives without increasing the incidence of false negatives. Even so, it is concluded that there is no evidence that routine skeletal scintigraphy affects management of newly diagnosed patients with carcinoma of the breast. Unless an algorithm can be defined which requires the information provided by skeletal scintigraphy in order to determine clinical management, this investigation is not justified as a routine staging procedure and should be reserved for patients in whom there is a clinical suspicion of metastases and for clinical trials.

Bone Neoplasms↗
PubMed1985

Observations on the natural history of Paget's disease.

Whole-body skeletal scintigraphy was performed in 4700 adult patients from south-east Scotland. In 3831 with proven or suspected malignant disease the prevalence of osteitis deformans in males is 0.006 in those aged 15-54 years, 0.026 in the age group 55-84 years and 0.24 over the age of 84 years. The corresponding figures in females are 0.002, 0.021 and 0.15. Previous estimates of prevalence should be increased by at least 25% to take account of peripheral and monostotic disease, which is more common than hitherto recognised. The increase in prevalence with age may not be linear. Possible associations with environmental and genetic factors which would account for such a distribution are considered. It is suggested that the conventional distinction between 'active' and 'burned out' Paget's disease may be incorrect.

Adolescent↗
PubMed1985

Prognostic significance of alkaline and acid phosphatase and skeletal scintigraphy in carcinoma of the prostate.

The prognostic significance of skeletal scintigraphy has been reassessed in relation to other tests by extended follow-up of 220 patients. Skeletal metastases increased in prevalence with T stage and were associated with shorter survival irrespective of age. Early disease, a normal acid or alkaline phosphatase at presentation and well differentiated tumours were associated with longer survival. Alkaline phosphatase alone accounted for all of the differences in survival. Scintigraphic change preceded elevation of the prostatic acid phosphatase in 81% of the patients whose initial scintigraphy and prostatic acid phosphatase were normal but who developed evidence of distant metastases on follow-up. The mean interval between scintigraphic conversion and the development of overt symptoms was 5.8 months. Our findings discount the value of skeletal scintigraphy for determining prognosis but do indicate that it is more sensitive than the acid phosphatase in identifying patients before they become symptomatic. Scintigraphy is indicated as a routine staging procedure in all new patients with carcinoma of prostate. In patients with a normal alkaline phosphatase, a baseline and regular follow-up are needed to identify patients likely soon to develop symptoms. If the alkaline phosphatase is elevated at presentation, scintigraphy is necessary to distinguish benign from malignant causes and to determine the extent of skeletal involvement.

Acid Phosphatase↗
PubMed1985

A comparison of the economics of xenon 127, xenon 133 and krypton 81m for routine ventilation imaging of the lungs.

We have compared the cost of providing routine lung ventilation scintigraphy using 127Xe with other radioactive gases in 100 patients. The physical properties of 127Xe permit a logical imaging sequence where a ventilation study is only carried out if indicated by perfusion scintigraphy which is performed first. With 133Xe, all patients must be ventilated prospectively, or a preselection carried out based on radiographic appearances at the time of imaging. This results in a greater number of ventilation studies than with 127Xe. Despite the greater cost per study of 127Xe, the overall cost of providing a routine diagnostic service with this gas is no more than that of using 133Xe in selected patients. The cost of ventilating all patients prospectively with 133Xe is considerably greater than using 127Xe only when indicated by abnormal perfusion images. If ventilation imaging is to be available at all times, either isotope of xenon costs very much less than 81Krm. We conclude that 127Xe is the radiopharmaceutical of choice for routine lung ventilation scintigraphy.

Costs and Cost Analysis↗
PubMed1984

Quantitative sacroiliac scintiscanning: a sensitive and objective method for assessing efficacy of nonsteroidal, anti-inflammatory drugs in patients with sacroiliitis.

Serial computer assisted quantitative sacroiliac scintiscanning (SI joint/sacrum ratios) 3 hours after low dosage (5 mCi) 99mTc methylene diphosphonate has been used as an objective index of sacroiliitis in a single blind 14-day cross-over comparison of azapropazone 600 mg b.d. and naproxen 500 mg b.d. in 18 patients with active sacroiliitis. Clinical assessments included visual analogue scales for measurement of pain and early morning stiffness, chest expansion, a modified Schober test, and goniometric measurement of thoracolumbar spinal flexion by means of an inclinometer. Statistically significant decreases in pain (p less than 0.001) and early morning stiffness (p less than 0.001) followed treatment with each NSAID, but there was no significant difference in the fall in these parameters, although 15 out of 18 patients expressed a preference for naproxen. Chest expansion and thoracolumbar flexion were not significantly affected by either drug. Serial quantitative scintigraphy showed a mean fall in joint sacrum ratios following each treatment which was statistically significant (p less than 0.02) only after naproxen. Serial quantitative scintigraphy can be used as an objective method of assessing sacroiliitis and was sufficiently sensitive to reflect the patients' subjective preference in a short-term comparison of 2 NSAID.

Adult↗
PubMed1983

Self-retaining catheters for congenital neuropathic bladder: a continuing evaluation.

Sixty (60) spina bifida children have had their neuropathic bladder managed with a continuous Foley catheter regime for periods up to 14 years. Technetium renogram and renal scan assessments prior to commencement of catheter and again recently have shown no overall significant deterioration in 66 kidneys. There is however significantly less (p less than 0.001) intermittent emptying and significantly more (p less than 0.01) renal scarring in those patients who have had a continuous catheter regime for more than 4 years. Remedial complications were reported in 28% patients and these were predominantly males.

Adolescent↗
PubMed1983

Skeletal scintigraphy in carcinoma of the kidney.

The scintigrams and radiographs of 32 patients with renal carcinoma were reviewed. False negative skeletal scintigrams were observed in four of 12 symptomatic patients with proven skeletal metastases from carcinoma of the kidney. A negative scintigram therefore does not exclude the possibility of skeletal metastases in this condition.

Bone Neoplasms↗
PubMed1983

Evaluation of ileal function using 23-selena-25-homotaurocholate, a-gamma-labeled conjugated bile acid. Initial clinical assessment.

23-Selena-25-homotaurocholate is a synthetic bile acid labeled with a gamma-ray-emitting radioisotope 75Se. It is readily measured using external detectors and is thus suitable for whole-body counting. Whole-body retention was measured at 0, 4, and 7 days after oral administration to normal controls and to patients with disease of the small intestine, colon, or ileocecal region. Whole-body retention of less than 25% of the administered radioactivity within 4 days is definitely abnormal, but there was overlap between normal and abnormal groups at this time. At 7 days, whole-body retention less than 12% is abnormal and greater than 19% is normal. Between these limits, values may represent minimal ileal dysfunction not demonstrable by older techniques. Excretion of 23-selena-25-homotaurocholate follows a biexponential curve. The faster component has a half-life similar to that of natural bile acid. It is uncertain whether the slower component represents a hitherto unrecognized slowly turning over pool of bile acid or is a metabolic product of 23-selena-25-homotaurocholate not yet identified in vitro. There is a significant relationship between the whole-body retention of 23-selena-25-homotaurocholate and total fecal and primary bile acids. 23-selena-25-homotaurocholate is simple and acceptable for investigating ileal function.

Adolescent↗
PubMed1982

The bone scan as a tumour marker in prostatic carcinoma.

The technetium methylene diphosphate bone scan was elevated in 100 consecutive new patients presenting with carcinoma of the prostate. 48% of the patients has a positive bone scan at the initial diagnosis. The scan was more helpful than the skeletal X-ray in the diagnosis of bone metastases: 23% of the X-ray-negative patients were scan-positive. Serial bone scans were more sensitive than either X-rays or serum acid phosphatase in following the progress of the disease. It is concluded that the bone scan in patients with prostatic carcinoma can be used as a reliable tumour marker, especially for monitoring the course of metastases.

Bone and Bones↗
PubMed1982

Absorbed dose to man from the Se-75 labeled conjugated bile salt SeHCAT: concise communication.

The absorbed radiation dose that would result from the oral or intravenous administration of SeHCAT (23-[75Se]selena-25-homotaurocholate) has been calculated using the MIRD tables and formulas and data from measurements of whole-body distribution and from long-term whole-body counting in rats, mice, and man. When SeHCAT is administered to normal subjects, the gallbladder is the critical organ, receiving 12 mrad (oral dose) or 22 mrad (i.v.) per microcurie. The whole-body dose is 1 mrad/microCi, whatever the route of administration. In severe hepatic failure the liver might receive 200 mrad/microCi. The activity likely to be used in routine clinical practice is 10 microCi. Where a whole-body counter is used, an activity of 1 microCi has proved adequate. Even at an administered activity of 25 microCi, the absorbed dose is small compared with established techniques of investigating the gastrointestinal tract.

Administration, Oral↗
PubMed1982

Enterohepatic circulation in man of a gamma-emitting bile-acid conjugate, 23-selena-25-homotaurocholic acid (SeHCAT).

A conjugated bile acid, 23-selena-25-homotaurocholic acid (SeHCAT), labeled with the gamma emitter Se-75, has been evaluated in man. Absorption and excretion were compared with that of simultaneously administered [23-14C]cholic acid. SeHCAT is absorbed quantitatively following oral administration, secreted into the bile at the same rate as cholic acid, reabsorbed from the small intestine, and resecreted. It is not absorbed when the terminal ileum has been excised or bypassed. SeHCAT is therefore the first of a new class of radiopharmaceuticals, namely, gamma-emitting tracers of the complete cycle of the enterohepatic circulation. Its use will simplify investigation of the functional state of the terminal ileum by eliminating the need to collect and process feces.

Administration, Oral↗