PubMed Health⌕ Search

Biomedical subjects

W N Tauxe

Publications and source records attributed to W N Tauxe.

At least 19 recordsLinked to original sources
PubMed1992

The use of quantitative scintigraphy in the measurement of portal-systemic shunting in rats.

Portal-systemic shunting was studied in 54 portal hypertensive rats both in vivo and in vitro using radioactive microspheres. The animals underwent partial portal vein ligation around needles of varying diameter to produce a wide range of shunting. Two to four weeks later, quantitative lung-liver scintigraphic and whole body images were obtained in vivo following ileocolic vein injection with 99mTc-MAA. After sacrifice, the lung and liver activities were determined by the gamma camera, a dose calibrator, and a well counter. Portal-systemic shunting ranged from 0.1-97.6%. When shunting was compared in vivo and in vitro, an excellent correlation was found (r = 0.99, p < 0.001). A subgroup of 24 animals had consecutive injections of 99mTc-MAA and 51Cr-labeled 15 microns microspheres, which, although different in size, yielded similar results (r = 0.89, p < 0.001). We conclude that in small laboratory animals a wide range of shunting can be measured accurately in vivo by quantitative scintigraphy.

Animals↗
PubMed1991

Evaluation of portal-systemic shunting in rats from mesenteric and splenic beds.

In rats with partial portal vein ligation, 95 +/- 0.9% of the splenic blood flow is shunted from the portal to the systemic circulation when an intrasplenic injection of microspheres is used to determine the degree of shunting. Despite this magnitude of portal-systemic shunting, several biochemical and endocrine consequences of portal-systemic shunting occur at levels below what is expected for the degree of shunting found. In an effort to resolve these discordant findings, shunting from both the splenic and the mesenteric bed was studied in anesthetized portal hypertensive rats with various degrees and/or duration of portal vein stenosis. The shunting from the mesenteric bed averaged 66.7 +/- 29.9% (range 5.1-99.1%) and was influenced both by the degree and duration of portal vein stenosis. In contrast, shunting from the splenic bed averaged 97.3 +/- 4.0% (range 79-99.9%) and demonstrated no variation between groups determined by the degree of portal vein stenosis. The shunting from the splenic bed was consistently greater than that found from the mesenteric bed. Mesenteric but not splenic shunting correlated with serum bile acid levels. Mesenteric shunting was related inversely to the weight-adjusted liver mass and to serum testosterone levels. Based upon these data obtained in portal hypertensive rats, it is concluded that splenic injections of microspheres overestimate portal-systemic shunting. In contrast, mesenteric injections of microspheres yield values for shunting that correlate well with independently determined biochemical and endocrine consequences of shunting. These observations support the validity of the mesenteric shunting measurements obtained.

Animals↗
PubMed1991

ECG-gated thallium-201 myocardial SPECT in patients with old myocardial infarction compared with ECG-gated blood pool SPECT.

We evaluated one of the merits of ECG-gated thallium-201 single photon emission computed tomography (g-T1 SPECT), i.e., the ability to appreciate left ventricular (LV) wall motion. LV wall motion assessed by g-T1 SPECT and by ECG-gated Blood Pool SPECT (g-BP SPECT) was classified into three grades and compared segment by segment. T1-201 uptake by g-T1 SPECT was also classified into three grades and compared with those of wall motion in g-BP SPECT. Fifty patients with prior myocardial infarction were injected intravenously at rest with 111 to 185 M Bq (3 to 5 mCi) of Tl-201. The left ventricular regions were divided into anterior, septal, inferior and lateral segments (50 patients X 4 segments = 200 segments in total). The grades of wall motion and Tl-201 uptake detected by g-Tl SPECT correlated well with those of wall motion in g-BP SPECT (94.5% and 85%, respectively). With g-Tl SPECT it was possible to evaluate left ventricular wall motion, providing clear perfusion images.

Adult↗
PubMed1991

Detection of complications after liver transplantation by technetium-99m mebrofenin hepatobiliary scintigraphy.

Fifty-five hepatobiliary scintigraphic studies using 99mTc-Mebrofenin were performed in 52 orthotopic liver transplant patients to evaluate suspected biliary complications, namely biliary extravasation and extrahepatic obstruction. Final diagnosis was made by analysis of the clinical course and other procedures. Three out of three studies of biliary leak and four out of five studies of biliary obstruction were detected. There were no false positives in either complication. The sensitivity, specificity and accuracy were 100, 100, 100% for ectravasation and 80, 100, 98% for obstruction, respectively. Hepatobiliary scintigraphy appears to be an accurate means of detecting biliary leak and obstruction associated with the transplanted liver.

Adolescent↗
PubMed1991

Phantom kidney: a CT correlation.

The phantom kidney is a "kidney-like" apparition which may be seen in dynamic renal scintigraphy typically in post-nephrectomy patients or in patients with unilateral renal agenesis. We report a case of a phantom kidney demonstrated in the angiographic phase of renal scintigraphy with 99mTc-dimercaptosuccinic acid (99mTc-DMSA) in a patient who was nephrectomized 14 years previously. After comparison with the CT images, we conclude that our patient's finding was caused by an increased mesenteric vascularity, possibly postprandial. Several conditions which may cause the phantom kidney effect, have been reported, but increased mesenteric vascularity seems to be the most common cause.

Adult↗
PubMed1991

A comparison of the renal effects (ERPF, GFR, and FF) of FK 506 and cyclosporine in patients with liver transplantation.

1. The mean "cost" in milliliters per minute of ESLD alone, prior to transplantation, was 35% + 23% (1 SD). In GFR it was 15%. 2. The additional burden of CyA + OLT increases the loss in ERPF an additional 18%; in GFR, it increases loss another 10%. Thus, the total loss in CyA-treated patients was 53% and 25%, respectively. 3. The decrease imposed by FK 506 + OLT on ERPF was only 7%, with no decrease in GFR. 4. Therefore, from the renal point of view, FK 506 would appear to be the superior drug. 5. The large error around mean values underlines the desirability of performing these tests on the individual patient rather than on information from groups, since many values fall near the threshold of the azotemic range (ERPF approximately 175 mL/min). 6. As renal mass was compromised, ie, fall in the ERPF, the GFR increased relatively, ie, the renal filtering membrane became more permeable and the FFs gradually increased. 7. The loss of renal function was significantly less in OLT patients on FK 506 than CyA. However, the greatest loss in expected renal function was due to the basic ESLD itself.

Adult↗
PubMed1991

Assessment of systolic thickening with thallium-201 ECG-gated single-photon emission computed tomography: a parameter for local left ventricular function.

We measured left ventricular (LV) systolic thickening expressed as a systolic thickening ratio in 28 patients, using 201Tl ECG-gated SPECT. Five normals, 15 patients with prior myocardial infarction, 5 with hypertrophic cardiomyopathy, and 3 with dilated cardiomyopathy were studied. The systolic thickening ratio was calculated as [(end-systolic--end-diastolic pixel counts) divided by end-diastolic pixel counts], using the circumferential profile technique of both end-diastolic and end-systolic short axial images. Functional images of the systolic thickening ratio were also displayed with the "bull's-eye" method. The mean systolic thickening ratio thus calculated were as follows: normals, 0.53 +/- 0.05 (mean +/- 1 s.d.); non-transmural prior myocardial infarction, 0.33 +/- 0.09; transmural prior myocardial infarction, 0.14 +/- 0.05; hypertrophic cardiomyopathy in relatively nonhypertrophied areas, 0.56 +/- 0.11; hypertrophic cardiomyopathy in hypertrophied areas, 0.23 +/- 0.07; and dilated cardiomyopathy, 0.19 +/- 0.02. The systolic thickening ratio analysis by gated thallium SPECT offers a unique approach for assessing LV function.

Cardiomyopathy, Dilated↗
PubMed1990

Technetium-99m MDP scintigraphy of rhabdomyolysis induced by exertional heat stroke: a case report.

A case of rhabdomyolysis induced by exertional heat stroke in a police officer recruit is reported. Technetium-99m methylene diphosphonate scintigraphy demonstrated marked uptake of the injured skeletal muscle. This bone-scanning agent provided an excellent means of localizing and evaluating the muscle injury of rhabdomyolysis. Nuclear medicine physicians should be aware of the special conditions and causes in which bone scan may demonstrate striking findings.

Adult↗
PubMed1990

Colorectal carcinoma metastases: detection with In-111-labeled monoclonal antibody CCR 086.

A phase I/II clinical trial with indium-111-labeled antimucin murine monoclonal antibody (MoAb) CCR 086 was conducted. Seventeen patients with histologically proved colorectal carcinoma and known metastatic disease underwent external scintigraphy after administration of 5.5 mCi (203.5 MBq) of In-111 CCR 086 at doses of 5 and 20 mg. Of 25 known lesions, 17 were detected (sensitivity, 68%). The smallest detected lesion in the lung was 1 cm and in the liver was 1.5 cm. The serum half-life of In-111-labeled CCR 086 MoAb was approximately 64 hours. The formation of human antimouse antibody (HAMA) was detected in the serum of four of five patients who received 20 mg of MoAb. No HAMAs were detected in four patients receiving 5 mg of MoAb. No side effects were encountered. Because of effective detection of liver and lung metastases with lower doses (5-20 mg) of CCR 086 conjugated with In-111, further investigations are warranted to assess clinical and therapeutic potentials of CCR 086 in the management of colorectal cancer.

Adult↗
PubMed1990

In vivo cross-match by chromium-51 urinary excretion from labeled erythrocytes: a case of anti-Gerbich.

We studied a patient with an alloantibody to the high-frequency red blood cell (RBC) antigen Gerbich. A nationwide search for rare Gerbich-negative blood (less than 1:45,000 donors) located only seven units, and our supply was quickly exhausted. By using an in vivo cross-matching method, we demonstrated that this anti-Gerbich did not cause RBC destruction. Regular Gerbich-positive transfusions could then proceed without hemolysis. This cross-match test was based on the determination of the urinary excretion rates of injected radioactive chromium-labeled donor erythrocytes by which it was possible to determine compatibility only 24 hr after the test was begun. The procedure provides an easy and accurate means for in vivo cross-matching of conventionally incompatible donor blood.

Aged↗
PubMed1988

Distinguishing avascular necrosis from segmental impaction of the femoral head following an acetabular fracture: preliminary report.

To distinguish segmental impaction from avascular necrosis of the femoral head, 26 consecutive patients who sustained an acute displaced acetabular fracture were assessed preoperatively with routine radiographs, computed tomography, and radionuclide imaging using pinhole collimation and single photon emission computed tomography (SPECT). The diagnostic criterion for avascular necrosis was a photopenic defect of the femoral head, whereas, the criterion for segmental impaction was an area of impaction of at least 1 cm2 noted at the time of surgery. Of this series, 3 incurred a segmental impaction while 1 showed evidence consistent with avascular necrosis on SPECT imaging. None of the patients possessed diagnostic features of both complications. The distinction between these two complications of an acetabular fracture should contribute to the application of appropriate surgical techniques to correct segmental impaction and avascular necrosis.

Acetabulum↗
PubMed1988

Radioimmunoimaging of metastatic medullary carcinoma of the thyroid gland using an indium-111-labeled monoclonal antibody to CEA.

Elevated levels of carcinoembryonic antigen (CEA) or calcitonin after surgical therapy for medullary carcinoma of the thyroid gland (MCT) indicate the presence of residual or metastatic disease. CEA elevations appear to be prognostically more reliable in patients with metastatic disease and suggest a more virulent tumor. Attempts to stage the disease with use of conventional imaging techniques are usually inadequate, as is the therapy for disseminated or recurrent MCT. An indium-111-labeled anti-CEA monoclonal antibody (ZCE-025) was used to image metastases in a patient with MCT. Potential applications of monoclonal antibody technology in the management of MCT would include (1) preoperative differentiation of unicentric from multicentric thyroid gland involvement, (2) detection of regional or distant metastases or both, (3) measurement of response to systemic therapy, and (4) the facilitation of radionuclide immunoconjugate therapy.

Antibodies, Monoclonal↗
PubMed1987

Comparison of measurement of glomerular filtration rate by single sample, plasma disappearance slope/intercept and other methods.

Various in vitro methods employing radioactive indicators have been presented for the determination of glomerular filtration rate (GFR) including slope/intercept (S/I) and single sample (SS) methods. The S/I technique utilizes the analysis of the slope of a certain segment of the plasma disappearance curve of a suitable radioactive indicator and its intercept on the y axis. The SS method is based on the theoretical volumes of distribution derived from a single plasma concentration at some specific time after intravenous injection of the indicator. Using GFRs estimated from the compartmental analysis of the entire plasma disappearance curve as a reference standard, we have compared the errors of GFR estimation calculated from 12 S/I methods, 3 SS methods and 2 techniques in which original formulae were derived. The errors of the SS method of Tauxe et al. gave the lowest standard error of estimate (Sy X x) of all the methods. The S/I methods gave lowest errors when sampling times were taken between 60 min and 240 min. Almost all the errors observed here were significantly less than those observed using scintillation camera techniques. The SS method seems to be the method of choice for estimation of GFR by single injection techniques. The use of the scintillation camera in conjunction with the SS technique would provide a useful right to left ratio so that individual kidney GFR could be calculated.

Adolescent↗