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Biomedical subjects

V R McCready

Publications and source records attributed to V R McCready.

At least 73 records · Page 4Linked to original sources
PubMed1989

The clinical correlates of serum CA125 in 169 patients with epithelial ovarian carcinoma.

Serial CA125 measurements in 169 patients with epithelial ovarian carcinoma were obtained. Changes in serum CA125 measurements are shown to reflect changes in clinical status. For patients with macroscopic disease receiving chemotherapy, the sensitivity and specificity for predicting response are shown to be 95% and 86% respectively. For patients with no known disease, the sensitivity and specificity for detecting relapse are shown to be 86% and 91% respectively. The clinical correlates with the level of serum CA125 were examined and the most important is shown to be amount of residual disease.

Antigens, Tumor-Associated, Carbohydrate↗
PubMed1989

99Tcm-labelled meso-HMPAO and glutathione content of human lung tumours.

Levels of reduced glutathione (GSH) are increased in some types of malignant tumours and are known to influence the response to radio- and chemotherapy. In vitro studies suggest a correlation between cellular GSH concentration and retention of the meso form of hexamethyl propyleneamineoxime (HMPAO). This study investigates the relationship between in vivo tissue retention of 99Tcm-labelled HMPAO and GSH concentration in ten patients referred for thoracotomy for possible lung cancer. Retention of 99Tcm-HMPAO was measured using single photon emission computed tomography (SPECT). The tumour and normal lung concentration of reduced glutathione (GSH) was measured in tissue specimens collected peroperatively. Malignancy was confirmed in eight patients. Of seven patients undergoing curative resection for carcinoma, tumour GSH concentration was higher (mean 2.76 mM) than normal lung (mean 1.04 mM). In one neurofibroma, the GSH concentration was 1.80 mM. No correlation was found between 99Tcm meso-HMPAO retention and either the tumour GSH concentration or the tumour:lung GSH ratio. The results from this small series demonstrate that the intracellular GSH concentration of malignant lung tumours is generally higher than that in normal lung but that meso-HMPAO retention could not be used to predict these levels.

Carcinoma, Non-Small-Cell Lung↗
PubMed1989

The prognostic significance of the half-life of serum CA 125 in patients responding to chemotherapy for epithelial ovarian carcinoma.

Various prognostic factors were studied in 29 patients with stage III or IV ovarian cancer who responded to initial chemotherapy after initial diagnostic surgery. The half-life of CA 125 in serum during initial chemotherapy was the most important prognostic indicator for survival (P less than 0.001) and the chance of achieving complete remission (P = 0.012). A CA 125 half-life of less than 20 days, 20-40 days and greater than 40 days appears to identify patients with a good, intermediate or poor prognosis, the two year actuarial survival being 76%, 48% and 0% respectively. The change of achieving a complete remission was 15% and 67% respectively for patients with a serum CA 125 half-life of greater than 20 or less than 20 days.

Antigens, Tumor-Associated, Carbohydrate↗
PubMed1989

The future of PET.

Explore the source record for details and available documents.

Costs and Cost Analysis↗
PubMed1988

Initial experience with Tc-99m-HM-PAO in the study of brain tumors.

A preliminary study of the distribution of the 99mTc complex of hexamethylpropylene amine oxime (HM-PAO) in 12 patients with brain neoplasms before, during, and after radiotherapy has been performed. Untreated brain tumors were found to exhibit a range of 99mTc-HM-PAO uptake, varying from areas of markedly increased isotope activity to photopenic areas, when compared to normal brain tissue. A ratio of 99mTc-HM-PAO tumor uptake to contralateral normal tissue uptake was calculated prior to and during radiotherapy. This ratio tended to return towards unity in lesions responding to therapy. A predictable alteration in whole brain 99mTc-HM-PAO uptake during radiotherapy was not demonstrated. Unlike the radiolabeled amines, 99mTc-HM-PAO localizes in primary tumors, probably indicating that its uptake mechanism is independent of non specific amine receptors. 99mTc-HM-PAO may be useful in the study of brain tumor physiology and response to therapy.

Adult↗
PubMed1987

99mTc-HMPAO as a tumour blood flow agent.

The cerebral blood flow agent, 99mTc-HMPAO ('CeretecTM') has been investigated to see if it can be used to estimate tumour blood flow. Its distribution in Balb/c mice bearing either a subcutaneously implanted sarcoma or a plasmacytoma has been shown to be similar to that of 86RbCl. The changes in peripheral blood flow caused by the beta-blocker, propranolol, and by Nembutal anaesthesia, are manifested equally by 99mTc-HMPAO and 86Rb. We conclude, therefore, that HMPAO may be useful in estimating tumour perfusion.

Animals↗
PubMed1987

HM-PAO assessment of human tumour perfusion.

Technetium-99m-labelled hexamethylpropylene amine oxime (HM-PAO) has been used to investigate tumour perfusion in 11 tumour sites in 8 patients with a variety of histologies. In 8 out of 11 instances single photon emission tomography clearly distinguished between tumour and normal tissues; in 7 cases due to increased HM-PAO uptake and in 1 due to reduced tumour uptake compared with hepatobiliary excretion of HM-PAO in adjacent normal liver. Heterogeneous uptake within individual tumour masses was observed in 3 cases. In 2 where a correlation between the pathology of excised tumour and the scan findings could be made, the findings were consistent with HM-PAO uptake in well-perfused tissue. These preliminary observations suggest that Technetium-99m-HM-PAO may be a valuable clinical technique for displaying patterns of tumour perfusion.

Humans↗
PubMed1987

Measurement of radiation dose to the thyroid using positron emission tomography.

Measurements of the functioning volume of thyroid tissue have been made in 22 patients undergoing radioiodine therapy for thyrotoxicosis, using a prototype multiwire proportional counter positron camera. Tomographic images were produced of the distribution of 124I in the thyroid. Functioning volumes were found to be in the range 21-79 cm3 with volume errors of the order of +/- 4% to +/- 14%. Radioiodine uptake varied from 28% to 98%. Using a value of 6 days for the effective half-life of radioiodine in hyperactive thyroids, radiation doses from a standard therapy administration of 75 MBq of 131I varied from 11 to 48 Gy (compared with a recommended 50-70 Gy). In five cases PET imaging showed a non-uniform distribution of radioiodine in thyroids thought to have uniform uptake from conventional pinhole scintigraphy.

Humans↗
PubMed1987

Three-dimensional display of data obtained by single photon emission computed tomography.

Three-dimensional display of radioactive distributions has been achieved using data generated by single photon emission computed tomography (SPECT). Computer techniques for constructing images are presented and the special problems associated with manipulating SPECT data are reviewed. The potential role of three-dimensional imaging in nuclear medicine is discussed and SPECT studies from several illustrative cases are presented.

Adult↗
PubMed1986

An antibody-desferrioxamine conjugate labelled with 67Ga.

The optimum conditions for producing a 67Ga labelled antibody-desferrioxamine conjugate were determined. The mouse monoclonal antibody LICR-LON-M8 was coupled to the metal chelating compound desferrioxamine (DFO) using glutaraldehyde (GLUT). A DFO:GLUT:M8 molar ratio of 500:150:1 gave an immunoreactive antibody with low amounts (less than 5%) of high molecular weight polymer. The labelling efficiency with 67 Ga was greater than 90%, with a specific activity of 2-4 MBq/mg antibody. This 67Ga labelled antibody is suitable for evaluation as a diagnostic imaging agent.

Animals↗
PubMed1986

The doughnut sign in patients with multiple myeloma.

Bone lesions with a ring-shaped appearance (the doughnut sign) have been encountered during routine reporting of bone scintigrams performed on patients with multiple myeloma. Such a ring-shaped appearance has been revealed in four (8%) of the last 50 bone scintigrams performed on patients with myeloma at the Royal Marsden Hospital. In contrast, a review of the last 300 bone scintigrams performed on patients with bone metastases failed to reveal any such ring-shaped appearance. Examination of the case notes and radiographs of the multiple myeloma patients did not reveal any correlation between the presence of the ring-shaped appearances and the histology, biochemistry, treatment, or course of the disease nor were any specific radiographic features noted. Three of the four patients have had local radiotherapy to the sites of the lesions. We conclude that the ring-shaped appearance on bone scintigrams is usually related to myelomatous bone lesions, particularly following local radiotherapy to these lesions. The reason for this appearance in three of the four scintigrams may be the stimulation of vascularity and osteoblastic activity around the periphery of the myelomatous lesions by the response of the lesions to radiotherapy.

Bone Neoplasms↗
PubMed1986

Iodine kinetic studies during amiodarone treatment.

Iodine kinetic studies were performed serially in 15 patients taking 300 mg amiodarone/day for 6 months to assess the biological significance of the high iodine content of the drug. Urinary inorganic iodide excretion increased from 0.25 +/- 0.03 (+/- SE) mumol/mmol creatinine before treatment to over 7 mumol/mmol during therapy. Thyroid iodide clearance fell from 5.93 +/- 0.82 ml/min to less than 0.5 ml/min, while plasma inorganic iodide rose from 0.05 +/- 0.01 mumol/liter to approximately 2.2 mumol/liter during treatment. Thyroid absolute iodide uptake rose from 16.3 +/- 2.7 to 54.6 +/- 5.7 nmol/h after 6 weeks of therapy (P less than 0.001). Thereafter, it progressively declined, but it was still significantly elevated (32.0 +/- 4.3 nmol/h) after 24 weeks (P less than 0.01). The calculated daily excretion of inorganic iodide rose to over 80 mumol during the study, accounting for about 10% of amiodarone iodine. During this time, the patients all had the characteristic plasma thyroid hormone changes associated with amiodarone therapy, i.e. increased T4, free T4, and rT3 and decreased T3, while remaining clinically euthyroid. The massive increase in available inorganic iodide during amiodarone treatment is probably responsible for the induction of both the hypothyroidism and the thyrotoxicosis that can occur in patients receiving the drug.

Adult↗