Biomedical subjects
Publications and source records attributed to J C Leonard.
Multiple diagnostic imaging techniques are currently available to the clinician but the complementary nature of these techniques is frequently overlooked. A case is presented to illustrate the contributions of ultrasound, radiology, and nuclear medicine in evaluating renal disease.
Gallium-67 citrate imaging for the staging of lymphomas was performed in three patients receiving Corynebacterium parvum (C. parvum) immunotherapy. Unexpected uptake at the site of C. parvum injections was identified and although the mechanism of localization is not determined by this study, similarities between C. parvum's known actions and the postulated mechanism of 67Ga-citrate localization are compared.
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A study was carried out on serum carcinoembryonic antigen (CEA) and alpha-feto-protein (AFP) levels, both measured by radioimmunoassay, in 88 children with malignant solid tumours and in 26 children with nonmalignant disorders, who presented during the years 1973-77. Slightly or moderately raised CEA levels were found at presentation in 11 of 66 children with malignant tumours, in 2 others with recurrent tumours, and in 4 children with nonmalignant disorders. Raised CEA levels generally indicated advanced malignant disease, often affecting the liver, or other hepatic disorders, but were not associated with a specific tumour type. Except in the first months of life, significantly raised AFP levels were detected only in 11 patients with yolk sac-derived tumours, or hepatomas, and in one child with tyrosinosis who later developed a malignant hepatoma. Serial measurements of AFP accurately reflected the clinical response to treatment and in 2 patients indicated recurrence before this could be detected clinically.
Geriatrics has consistently failed to attract enough staff, and hence geriatric units often cannot provide a full service for the elderly. Meanwhile beds in general medical units may be blocked by elderly patients. This division between geriatric and medical units is arbitrary and wasteful. There are no clinical processes or techniques unique to geriatrics, which is probably why the specialty is unattractive; few doctors want to confine their attention only to the elderly. Geriatrics as a separate specialty should therefore be largely abandoned and the care of the elderly reintegrated into general medicine.
A suppressor mutation specific for a missense codon in the L-ribulokinase structural gene of the L-arabinose operon of Escherichia coli B/r enhanced L-arabinose utilization by the strain containing the missense codon. Electrophoretic comparisons of the wild-type, missense, and suppressed missense L-ribulokinases indicated that the suppressor changed the structure of the missense kinase, thereby increasing its catalytic activity. Hyperinducibility imposed on an operator-distal gene by the missense codon was not affected by the suppressor mutation.
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Carcinoembryonic antigen (CEA) has been measured in parallel with seven serum proteins and seromucoids in the sera of patients with malignant neoplasia and non-neoplastic disease. In the total group significant correlations were found between CEA and seromucoids and between CEA and several serum proteins. However, with two exceptions, when the individual disease groups were examined no correlation was seen. It is concluded that abnormal concentrations of the specific proteins measured do not consistently interfere in the CEA radioimmunoassay and do not explain the high CEA levels in patients with non-neoplastic diseases.
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Carcinoembryonic antigen (CEA) levels have been measured in the serum of 490 patients and 93 normal controls using the double antibody radioimmunoassay technique. Levels were elevated in 71 of patients with carcinomata of the gastrointestinal tract and in 42% with other types of malignancy. In patients with non-neoplastic disease of the gastrointestinal tract and liver, elevated levels were found in 14 and 66% respectively. In general the CEA level tends to be higher in cancer patients with haematogenous dissemination. Following complete surgical removal of a tumour, levels fall to normal within 14 days in the majority of patients. Of 33 patients studied during follow up, elevated levels were found in 12, 10 of whom had evidence of recurrence. The significance of these findings and the possible application of CEA assay in clinical practice are discussed.
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A standard nuclear medicine computer system was modified to accept video input and utilized to perform digital intravenous and intra-arterial angiography, substration of CT images and enhance ultrasound images as well as to read video and magnetic tape. This system provides greater versatility and adaptability than presently conceptualized and produced digital systems and deserves further evaluation as a multipurpose imaging device.
Serum carcinoembryonic antigen (C.E.A.) levels were measured in 381 undiagnosed patients who presented with clinical problems commonly associated with gastrointestinal malignancy. The results were compared with the final diagnosis after follow-up for up to 5 years to see whether C.E.A.-testing added any useful information. Of 307 patients presenting with upper gastrointestinal symptoms, lower gastrointestinal symptoms, or irom deficiency anaemia, C.E.A. levels greater than 20 ng/ml indicated malignancy in 5 but in 3 of these malignancy was also diagnosed after routine investigation. Of 74 patients presenting with obstructive jaundice, hepatomegaly, or abnormal liver function, malignancy was diagnosed in 38. In 9 of these patients the diagnosis of malignancy could otherwise have been reached only by laparotomy. The serum-C.E.A. thus reached only by laparotomy. The serum-C.E.A. thus seems to be of value in the assessment of liver disease but not in patients with gastric or colonic symptoms or iron-deficiency anaemia.
We report a case of cervical teratoma in a term female infant born to a 20-year-old white woman. There are rare tumors in neonates, occurring in approximately 1 in 20,000 to 1 in 40,000 live births. These tumors are accurately defined by ultrasound. Although benign, cervical teratomas cause respiratory compromise. In this case the tumor was removed surgically with no recurrence at the 10-month follow-up.
PURPOSE: To describe a patient whose non-Hodgkin's lymphoma (NHL) appeared to be localized by standard modalities but who was upstaged after Gallium scintigraphy suggested disseminated disease. PATIENT AND METHODS: A patient with biopsy proven NHL in the maxillary sinus was staged as having localized disease based on computed tomography (CT) scans, bone scintigraphy, and evaluation of bone marrow and spinal fluid. Open biopsy of a bony lesion, standard modalities for lymphoma staging, and Gallium scintigraphy were obtained. RESULTS: Gallium scanning showed bony lesions not previously seen with the standard modalities. Open biopsy of one of these lesions confirmed disseminated disease. CONCLUSIONS: Gallium scanning aids in the early identification of metastases in some patients with NHL and should be included in a standard evaluation of apparently localized disease.