Biomedical subjects
Publications and source records attributed to V W Lee.
Radionuclide scintigraphy can give a specific diagnosis when a hypervascular "cold" defect on colloid scans "fills in" with gallium scanning. The majority of hepatocellular carcinomas will also accumulate hepatobiliary agents especially in delayed images. Magnetic resonance imaging is superior to other modalities in providing anatomic detail, such as location and relation to vessels, needed by the surgeon in operative planning.
We studied the role of luteinising hormone (LH) and human chorionic gonadotropin (hCG) in regulation of rat granulosa cell inhibin production. Whereas pregnant mare serum gonadotropin (PMSG) or purified rat follicle-stimulating hormone (FSH) stimulated inhibin accumulation in culture media up to 6-fold in a dose-dependent manner, hCG or LH alone were without significant effect. Concomitant addition of hCG or LH to cultures containing half maximal or maximal stimulating concentrations of PMSG did, however, result in a dose-dependent inhibition of PMSG/FSH-induced inhibin production. However, in the 2-step culture system a biphasic effect of hCG treatment on FSH-primed granulosa cell inhibin and progesterone production was evident. hCG was only inhibitory when the cells in the 2-step system were primed with PMSG. These data indicate that granulosa cell inhibin production is under direct control of both FSH and LH, and provide a possible explanation for alterations in inhibin activity around the time of ovulation in vivo.
Hepatobiliary imaging in a patient with an amebic abscess showed an early cold defect that later showed rim enhancement. A Tc-99m SC scan did not show prominent flow (making hepatoma unlikely) and showed the previously noted defect to appear larger and without rim enhancement. The differential damage to Kupffer cells and hepatocytes or edema may account for these findings. Amebic abscess should be included in the differential diagnosis of lesions that give increased Tc-99m IDA but cold Tc-99m SC images.
A patient with hyperthyroid Graves' disease presented with ptosis, leading to a workup for myasthenia gravis. An enlarged thymus gland was noted on computed tomography. A scan with gallium-67 citrate showed prominent and diffuse thyroid gland activity as well as prominent lacrimal activity. This finding of thyroid uptake of gallium led to the correct diagnosis of Graves' disease. Such a finding has not been reported previously. The associated thymic, thyroid, and orbital findings in Graves' disease are discussed.
The usefulness of gated blood pool (GBP) scintigraphy in evaluating cardiac contusion among trauma patients was examined. In ten of 62 patients who sustained blunt chest trauma, phase images of GBP studies demonstrated delayed onset of right ventricular (RV) contractions (RV tardokinesis). Clinical charts of these ten patients were reviewed to determine the significance of this finding. Only one had no supportive evidence of cardiac injury. Four patients were determined to have clinically significant cardiac contusion on the basis of the occurrence of arrhythmias of cardiac failure during their hospital course. These patients had ventricular histogram widths greater than 30 degrees of the entire cardiac cycle at half maximum height and had a bifid peak in their ventricular contraction histograms. Of the 52 patients who did not have RV tardokinesis, only one had a clinically significant cardiac contusion, resulting in a false-negative rate of 2% for the test. This new observation of RV tardokinesis may be clinically useful in establishing the difficult diagnosis of cardiac contusion.
No simple, noninvasive method is available for evaluating extracutaneous Kaposi sarcoma in AIDS patients or for following the tumor's response to treatment. We report our preliminary experience with thallium-201 scintigraphy in nine AIDS patients with proved Kaposi sarcoma. Eight of the nine had abnormal uptake of the radionuclide in skin, lymph nodes, oral cavity, vagina, and lungs. Only four of the nine had cutaneous Kaposi sarcoma at the time of scanning. All cutaneous and mucosal lesions were thallium avid. Two of the six patients with thallium-avid nodes underwent nodal biopsy. Both biopsies confirmed the diagnosis of Kaposi sarcoma. Cutaneous Kaposi sarcoma developed later in one of these patients, showing the efficacy of thallium scintigraphy for the early detection of extracutaneous lesions. These preliminary results show thallium avidity in Kaposi sarcoma involving the skin and various extracutaneous sites (lymph nodes, lung, mucosa, and vagina). Thallium scintigraphy is a potentially useful procedure for detecting extracutaneous Kaposi sarcoma in AIDS patients.
Twenty-one patients with hepatocellular carcinoma who had gallium scans were retrospectively reviewed. Four of them demonstrated iso-intense gallium uptake compared to the adjacent liver parenchyma. The importance is therefore emphasized of using radiocolloid scan with tracer angiogram performed at the same time in order to avoid the potential diagnostic pitfall of not recognizing the tumor on gallium scan alone.
The nevus sebaceous of Jadassohn (NSJ) syndrome is a not uncommon pediatric dermatosis, with malignant potential. It is the cutaneous manifestation of another phakomatosis, characterized by neurologic, ophthalmic, cardiovascular, skeletal, and urogenital involvement. The features of this syndrome overlap those of the oculo-auriculo-vertebral dysplasia of Goldenhar and tuberous sclerosis. The extent of system involvement suggests a developmental insult during the first few weeks of gestation. A clearly genetic basis has not been established. An infant with NSJ syndrome is described who had associated optic nerve hypoplasia. His clinical, pathologic, and radiologic findings, including computed tomography (CT) and magnetic resonance imaging, are presented.
Seven cases of gallium uptake in myositis ossificans are described. Gallium scans are done frequently in paraplegics, quadriplegics, and comatose patients to look for occult infection. It is important to be aware of possible gallium uptake in myositis ossificans, particularly in the extremities, which is frequent in these patients. Gallium uptake may be present prior to any abnormalities seen on plain films or CT scans. It is important to correlate roentgenograms with abnormal gallium scans, particularly in the extremities, to avoid potential pitfalls in diagnosis and prevent unnecessary antibiotic treatment. A bone scan should be obtained whenever possible, particularly when roentgenograms are negative, to confirm the diagnosis.
The direct effect of somatomedin-C (Sm-C) and FSH on inhibin production by rat granulosa cells in vitro has been examined. FSH stimulated accumulation of inhibin in culture media in a dose-dependent manner with maximal stimulation (6-fold) being observed at a dose of 300 ng FSH/ml. Addition of Sm-C (30 ng/ml) either alone or in the presence of FSH (3-300 ng/ml) increased inhibin production (up to 5-fold). Sm-C alone was effective over the physiological dose range of 3-100 ng/ml. Concomitant addition of FSH (100 ng/ml) and Sm-C (3-100 ng/ml) resulted in a significant increase in inhibin production at all doses of Sm-C. The dose-dependent effects of FSH and Sm-C were also time dependent with a synergistic effect apparent after 48 h of culture. The Sm-C induced FSH inhibitory activity of granulosa cell culture media was confirmed as authentic inhibin by the demonstration of a dose-dependent neutralization of this activity by a monoclonal antibody raised against purified bovine inhibin. The data indicate a direct role for both FSH and Sm-C in ovarian inhibin production and provide additional evidence for an autocrine-paracrine role for Sm-C in granulosa cell differentiation.
A rapid 2-day quantitative assay for inhibin bioactivity based on FSH secretion from pituitary cells of immature female rats is described. The bioassay exhibited steeper slopes, improved precision and greater (fourfold) sensitivity compared with a previously established pituitary FSH cell content assay. Whole pituitary glands were used for the preparation of pituitary cells and the method for cell dispersion required a single enzymatic treatment with trypsin. Cells (180,000 viable cells per well) were dispensed into culture media containing inhibin and incubated for 48 h. Media were removed and assayed for FSH by radioimmunoassay. Using a ram rete testis fluid preparation as standard the inhibin dose-response curves of 25 consecutive experiments showed indices of precision of -0.08(mean)[range -0.04 to -0.17] and Finney's G values of 0.017[0.003-0.06]. The mean ED40 was 0.17 units of inhibin activity per well with interassay variation of 16.2% at this point of the dose-response curve. The assay had a practical capacity of 400 wells, permitting the measurement of dose-response curves of at least 40 unknowns with three dose points and triplicate wells per dose. The assay is specific for inhibin-containing preparations from several animal species. Overall, the assay is simple, precise, and sensitive, indicative of its applicability to the measurement of inhibin samples with low inhibin bioactivity and to the screening of large numbers of fractions during inhibin purification.
Radiotracer scintigraphy has been commonly used in this country to confirm and document the clinical diagnosis of brain death. Whether the presence of radiotracer activity in the region of sagittal venous sinus (SVS) represents actual blood flow to the brain in the absence of demonstrable cerebral arterial flow remains a controversial issue. Our retrospective study was performed to review the significance of such sagittal tracer activity. Of the 53 patients showing no cerebral arterial flow, 26 showed tracer activity in the region of SVS. The clinical status, EEG findings, and outcome of all 53 patients were the same irrespective of the presence or absence of SVS tracer activity. We conclude that the mere presence of SVS in the absence of demonstrable cerebral arterial flow activity is not clinically significant and does not contradict the diagnosis of brain death.
In the past few years, we have occasionally observed linear bands in the phase images of gated cardiac blood-pool scans along the interventricular septum region among patients with normal septal motions. Our retrospective study investigated the cause of out-of-phase bands of 12 patients. We documented through review of cines, computer analysis of gated cardiac blood-pool scintigraphy data, and correlation with echocardiograms that this phenomenon was artifact introduced by rotational movements of the heart. It is important for nuclear physicians to recognize this rotational artifact on the phase analysis image in order to avoid the erroneous misdiagnosis of wall motion abnormalities of the septum.
We report a case of renal oncocytoma with a unique scintigraphic pattern. The tumor showed strong avidity for [123I]iodohippurate, but no affinity for [99mTc] glucoheptonate. We offer an explanation for such exceptional scintigraphic finding, which may potentially enable us to make a pre-operative diagnosis of renal oncocytoma in the future.
A case of hepatocellular carcinoma (HCC) complicated by the Budd-Chiari syndrome is described. The antemortem diagnosis of both conditions was made with the unique findings of multitracer scintigraphy. The difficulty of diagnosing these two conditions by the conventional approach is reviewed. The advantages of using multitracer scintigraphy for evaluation of hepatic lesions are also discussed.
A study has been performed to evaluate the efficacy of gallium imaging in the detection of renal amyloidosis. Ten of the 11 patients who had biopsy-proven renal amyloidosis demonstrated marked uptake in both kidneys. One patient revealed moderate gallium uptake in his kidneys. None of the patients had underlying renal or extrarenal pathology other than amyloidosis, which could account for renal gallium uptake (renal infection, neoplasm, hepatic failure or frequent blood transfusions). Four patients also had extrarenal foci of abnormal gallium uptake, suggesting other sites of amyloid deposits. Our data strongly suggest that gallium imaging has a high sensitivity for detection of renal amyloidosis. Its specificity is enhanced significantly by careful review of the clinical history to exclude other known causes of renal gallium uptake. Potentially, gallium imaging may be used to monitor the progress of patients under experimental therapy.
Ovaries from rats treated with pregnant mare serum gonadotrophin were used as a source of inhibin for raising monoclonal antibodies. The antisera were screened for binding to rat ovarian tissue sections and examined for their ability to neutralize inhibin bioactivity in vitro, i.e. the ability to abolish the suppressive action of rat inhibin on pituitary FSH secretion. Two monoclonal antibodies to rat ovarian inhibin were raised, one exhibiting complete (antibody PHM15) and the other incomplete (antibody MCA-3) neutralizing ability. Both antisera bound well to antral granulosa cells, as judged by the degree of staining using an indirect horseradish peroxidase technique. Ascites fluid from mice injected with hybridoma cells secreting antibody PHM15 also showed inhibin-neutralizing ability, and was effective against inhibin prepared from ovarian follicular fluid of rats, sheep, pigs and cows. The latter observation indicates the potential application of this antibody to the preparation and measurement of inhibin from several animal species.
The accuracy of scintigraphy in diagnosing hepatocellular carcinoma (HCC) at Boston City Hospital between January 1, 1978 and September 30, 1983 is retrospectively reviewed. A combined protocol using technetium-99m sulfur colloid (TsSC), gallium (Ga), and scintiangiography (STA) was employed in order to enhance diagnostic specificity. There were 14 cases of HCC, of which 10 were proven histologically. The others were diagnosed clinically and angiographically. With one exception, all patients who had triple tracer scintigraphy showed a specific pattern of findings: (1) cold defects with TcSC; (2) Ga-avid foci, and (3) increased vascular supply from hepatic arteries. One false-positive study and one false-negative study were originally reported, although in both cases, strict adherence to the three criteria above would have avoided diagnostic error. These results indicate that triple tracer scintigraphy may be an effective diagnostic test for HCC. The relative efficacy of scintigraphy, ultrasonography, and computerized tomography in diagnosing HCC is also discussed.