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Biomedical subjects

M Maisey

Publications and source records attributed to M Maisey.

35 records · Page 2Linked to original sources
PubMed1989

Experience in imaging medullary thyroid carcinoma using 99mTc (V) dimercaptosuccinic acid (DMSA).

99mTc (V) dimercaptosuccinic acid (DMSA) is a new tumor imaging agent that has been successfully used to image patients with medullary thyroid carcinoma (MTC). Since 1986, studies have been performed in 32 patients with histologically proven MTC at Guy's Hospital, London, England. Five patients with primary tumor were studied prior to surgery, four patients were studied after successful removal of the primary tumor, and 26 patients with biochemical evidence of recurrence were studied. Eight patients were studied serially to assess progression of disease, and four patients were studied before and after surgery. Twenty-one of the 26 patients with disease had positive scans with four false-negative scans and three true negative scans. One patient had a false-positive scan (sensitivity 80%, specificity 75%). Two of the false-negative scans were obtained in patients with moderate but stable elevations of calcitonin but no other evidence of recurrence. One false-negative scan was obtained in a patient who was discovered on screening to have an abnormal pentagastrin response, and a small 1 cm tumor was subsequently removed. Uptake in local neck recurrence was frequently intense, but uptake at sites of bone metastases was less marked. 99mTc (V) DMSA is an inexpensive radiopharmaceutical which produces good quality images and has been shown to have an acceptable sensitivity and specificity in the follow-up of patients with MTC and thereby contributes significantly to the management of these patients.

Adolescent↗
PubMed1988

Family screening in medullary thyroid carcinoma presenting without a family history.

Systematic screening of the families of a series of 39 patients with apparently sporadic medullary thyroid carcinoma detected seven new cases in four families. A negative family history in a patient presenting with medullary thyroid carcinoma is not reliable in excluding familial disease, and family screening should be considered for new patients with medullary thyroid carcinoma.

Adolescent↗
PubMed1986

Tc-99m DTPA scans in renal allograft rejection and cyclosporine nephrotoxicity.

Renal allograft dysfunction arising from rejection or cyclosporine (CsA) nephrotoxicity can currently only be distinguished reliably by allograft biopsy. We have assessed Technetium (Tc)-99m diethylamine pentacetic acid (DTPA) scanning in 30 CsA-treated patients with allograft dysfunction. Scintigrams were performed during 20 biopsy-proved episodes of rejection and during 14 episodes of CsA nephrotoxicity. These results were compared with the scintigrams of 15 allografts showing stable function. Quantitative indices expressing allograft perfusion (flow index) and function (uptake index) derived from the DTPA scintigrams showed no significant differences between the groups of patients with rejection, CsA nephrotoxicity, or stable or improving function. Similarly, the flow and uptake indices of individual allografts obtained during periods of stable or improving function and then during episodes of dysfunction due to rejection or CsA nephrotoxicity did not significantly change. We conclude that Tc-99m DTPA scintigrams are of limited value in the management of allograft dysfunction in patients immunosuppressed with CsA.

Cyclosporins↗
PubMed1986

Monoclonal antibody HMFG-2 retains activity in vivo and binds to high molecular weight components expressed by metastatic breast cancers.

The monoclonal antibody HMFG-2 was raised against components of the human milk fat globule and human milk epithelial cells. It recognizes an epitope on glycoproteins of varying molecular weight; it is tumour-associated and expressed heterogeneously by most breast cancers. An intravenous injection of 131I-labelled HMFG-2 has been given to patients with recurrent cutaneous metastasis from breast carcinomas. Clearance of radioactivity from the plasma was measured and the label was shown to be carried on intact circulating antibody that had the ability to bind in vitro to the specific determinant as expressed by both the patients own tumour and by cultured breast cancer cells. Antibody was found to be associated with biopsy material taken from skin metastases 24 hours after administration of labelled antibody. However, the amount of radioactivity was insufficient for the production of a positive isotopic scan.

Antibodies, Monoclonal↗
PubMed1985

A prospective scintigraphic study of avascular necrosis of bone in renal transplant patients.

Avascular necrosis of bone (AVN) may cripple a patient who has had a successful renal transplant. The authors have attempted to gain more knowledge of this condition by undertaking a prospective survey to determine as accurately as possible the incidence of AVN in renal transplant patients. Routine six-month whole body bone scans were performed with 99mTechnetium Methylene Diphosphonate in 42 consecutive surviving renal transplant patients. The survey started in 1978-79, and patients were followed for a minimum of two years and a maximum of three years. As a result, seven were found to have AVN that would have remained undetected in two of the patients if routine whole body bone scanning had not been conducted. Despite a reduction in steroid dosage in recent years, the incidence of AVN in the authors' patients remains high at 17%. Bone scan appearances in renal transplant patients were classified and subdivided into four groups. By linking bone scans and radiographic and postmortem appearances of the femoral head, one very early case of AVN was detected. Routine bone scanning provided a more accurate estimation of the incidence of fractures in renal transplant patients (12%).

Adolescent↗
PubMed1980

Cardiac tumours: non-invasive detection and assessment by gated cardiac blood pool radionuclide imaging.

Four patients with cardiac tumours were investigated by gated cardiac blood pool radionuclide imaging and echocardiography. Contrast angiocardiography was performed in three of the cases. Two left atrial tumours were detected by all three techniques. In one of these cases echocardiography alone showed additional mitral valve stenosis, but isotope imaging indicated tumour size more accurately. A large septal mass was detected by all three methods. In this patient echocardiography showed evidence of left ventricular outflow obstruction, confirmed at cardiac catheterisation, but gated isotope imaging provided a more detailed assessment of the abnormal cardiac anatomy. In the fourth case gated isotope imaging detected a large right ventricular tumour which had not been identified by echocardiography. Gated cardiac blood pool isotope imaging is a complementary technique to echocardiography for the non-invasive detection and assessment of cardiac tumours.

Adult↗
PubMed1980

Assessment of chest pain in hypertrophic cardiomyopathy using exercise thallium-201 myocardial scintigraphy.

Exercise thallium-201 myocardial scintigraphy was performed in 23 patients with hypertrophic cardiomyopathy. Eighteen patients presented with chest pain which was a persistent symptom in 11. Selective coronary arteriography was performed in 16 patients and showed normal coronary arteries in 15 and insignificant luminal irregularities in one patient. Eighteen patients had abnormal scintigrams. Three had an abnormal distribution of tracer entirely attributable to asymmetric septal hypertrophy, whereas 15 had discrete tracer uptake defects which could not be explained solely by myocardial hypertrophy. In this latter group of patients three scintigraphic patterns were identified: (1) in 10 patients defects were seen in scintigrams immediately after exercise but not in delayed images obtained four to six hours later. Eight of these patients had chest pain. (2) Four patients had uptake defects seen in both initial and delayed images. One patient had chest pain. (3) In three patients, one of whom had chest pain, tracer defects were seen only in delayed images and were not apparent in the initial scintigrams. Chest pain occurred in eight out of 10 patients with scintigraphic evidence of myocardial ischaemia but was present in only three out of 13 patients with non-ischaemic scintigrams. The value of exercise thallium-201 myocardial imaging as a diagnostic technique in hypertrophic cardiomyopathy appears limited. Scintigraphic evidence of regional myocardial ischaemia in the absence of significant coronary artery disease, however, contributes to an understanding of the mechanism of angina production in patients with hypertrophic cardiomyopathy.

Adult↗