PubMed Health⌕ Search

Biomedical subjects

L R Bennett

Publications and source records attributed to L R Bennett.

At least 37 records · Page 2Linked to original sources
PubMed1982

Lymphoscintigraphy with Tc-99m-labeled dextran.

Current agents for lymphoscintigraphy have limitations because of slow migration of the colloidal tracers from the injection site and the unknown effect of phagocytosis on the removal of the labeled particles. The usefulness of Tc-99m dextran (TcDx) with a molecular weight of 110,000 has been tested for lymphoscintigraphy. Computer-assisted dynamic imaging and serial blood sampling in 13 dog experiments demonstrated that the tracer cleared only by lymph drainage from an interstitial injection site. Following interdigital injection of 1.0 ml (0.5-5.0 mCi), TcDx reached the knee or elbow lymph nodes in 12.4 +/- 6.5 (1 s.d.) sec, and the inguinal or axillary lymph nodes in 98.0 +/- 42.3 sec. It cleared from the injection site with a half-time of 31.5 min. In a dog with surgically induced lymphedema, tracer migration was markedly delayed in the edematous leg and the radionuclide lymphoscintigram resembled the contrast lymphangiogram. Initial studies in man yielded high-quality radionuclide lymphograms of the leg, and the pelvic and paraaortic lymph nodes. We conclude that TcDx is very promising for lymphoscintigraphy.

Animals↗
PubMed1981

Antihypertensive activity of 6-arylpyrido[2,3-d]pyrimidin-7-amine derivatives.

A series of 51 6-arylpyrido[2,3-d]pyrimidin-7-amine derivatives was prepared and evaluated for antihypertensive activity in the conscious spontaneously hypertensive rat. A number of these compounds, notably 6-(2,6-dichlorophenyl)-2-methylpyrido[2,3-d]pyrimidin-7-amine (36), lowered blood pressure in these rats in a gradual and sustained manner to normotensive levels at oral doses of 10-50 mg/kg. Normalized blood pressure levels could then be maintained by single daily oral doses. The effect of structural variation in the 6-aryl group and in the 2 and 4 positions of the pyridopyrimidine ring on activity is reported and discussed.

Animals↗
PubMed1980

Evaluation of aplastic anemia with indium chloride In 111 scanning.

Twenty-one patients (12 male, nine female) with diverse causes of aplastic anemia underwent indium chloride in 111 bone marrow scintigraphy. Good correlation of the scan interpretation with other clinical values, including the peripheral blood counts and bone marrow biopsy, was found in 25 of the 26 studies. These encouraging results with a noninvasive procedure that permits evaluatin of the entire bone marrow organ suggest a broader use for indium bone marrow scintigraphy in aplastic anemia.

Adolescent↗
PubMed1978

Changes in circulating iodothyronines in euthyroid and hyperthyroid subjects given ipodate (Oragrafin), an agent for oral cholecystography.

A dose (3 g) of sodium ipodate used routinely in oral cholecystography caused a fall in serum 3,5,3'-triiodothyronine and a rise in serum 3,3',5'-triiodothyronine in three patients taking thyroxine (T4), four euthyroid subjects,and four hyperthyroid patients. Serum T4 fell in patients with hperthyroidism, whereas it rose in the other two groups. Sodium ipodate appears to alter peripheral T4 metabolism and, in addition, produces thyroid-inhibiting effects in hyperthyroidism.

Graves Disease↗
PubMed1977

Nuclear imaging, tomographic nuclear imaging, and gray scale ultrasound in the evaluation of the porta hepatis.

Twenty-six patients with an eqivocal portal defect on conventional nuclear images were evaluated with a multiplane tomographic nuclear scanner and gray scale ultrasound. In most cases the correct determination (normal or abnormal) for an area of decreased uptake could be made from the multiplane tomographic scans. When an abnormality was thus confirmed, further characterization was provided by ultrasound.

Adult↗
PubMed1977

Total and individual kidney function assessment with iodine-123 ortho-iodohippurate.

A simple and reliable method of preparing 123l o-iodohippurate (l-123 OIH) is described. The agent was used to evaluate renal function in 329 patients; its use results in significant dose reduction for those with obstruction, hypertension, or transplant. Images from l-123 OIH provide 2.4 times more detectable photons per mCi administered to the patient than images obtained from l-131 OIH. Diagnoses are expected to be more reliable with l-123 OIH due to the decreased random variation of each data point.

Adult↗
PubMed1976

A radioimmunoassay for measurement of 3,3'-L-diiodothyronine (T2).

A sensitive, specific and reproducible radioimmunoassay (RIA) for measurement of 3,3'-L-diiodothyoride (T2) in concentrated ethanol extracts of serum and amniotic fluid is described. The T2 binding antiserum was prepared aby immunization of rabbits with T2-human serum albumin conjugate. Of various thyroid hormone derivatives tested, only 3-L-monoiodothyonine cross-reacted significantly with T2 binding sites on the antiserum...

Amniotic Fluid↗
PubMed1976

Brain imaging.

Imaging with radionuclides should be used in a complementary fashion with other neuroradiologic techniques. It is useful in the early detection and evaluation of intracranial neoplasm, cerebrovascular accident and abscess, and in postsurgical follow-up. Cisternography yields useful information about the functional status of cerebrospinal fluid pathways. Computerized axial tomography is a new technique of great promise that produces a cross-sectional image of the brain.

Adult↗
PubMed1975

Radionuclide photoscanning. Usefulness in preoperative evaluation of melanoma patients.

The results of radionuclide scans (liver, bone, and brain scans and whole-body scans using bleomycin tagged with radioactive indium [111In]) performed on 100 melanoma patients during their initial evaluation were reviewed to determined whether or not they effected a change in clinical staging or therapeutic decision. Patients were classified as stage I (primary disease) or stage II (regional disease) on the basis of regional lymph node dissections. Only one patient (stage II) of 73 stage I and II patients had an abnormal finding on the initial radionuclide scan. Fifteen of 26 patients thought to be stage III (disseminated disease) on clinical grounds had abnormal findings on at least one scan. A therapeutic change as a result of scanning occurred in the stage II patient after abnormal bone and whole-body scans. As an initial routine screening test for stage I and II melanoma patients, radionuclide scanning was unproductive and rarely influenced therapeutic decisions.

Adult↗
PubMed1975

Human CNS perfusion scanning with 123I-iodoantipyrine.

Regional perfusion scanning of the central nervous system requires lipophilic radionuclides that rapidly penetrate the intact blood brain barrier. The first compound of this type to be developed for human use is 123I-iodoantipyrine. 123I-iodoantipyrine rapidly crosses the blood brain barrier and is flow-limited in its delivery to the brain. This makes possible the CNS perfusion scanning of the human brain, thereby showing regional distribution of microcirculatory blood flow.

Animals↗
PubMed1975

Bone scanning.

Scanning is based on the uptake of a nuclide by the crystal lattice of bone and is related to bone blood flow. Cancer cells do not take up the tracer. Normally, the scan visualizes the highly vascular bones. Scans are useful and are indicated in metastatic bone disease, primary bone tumors, hematologic malignancies and some non-neoplastic diseases. The scan is more sensitive than x-ray in the detection of malignant diseases of the skeleton.

Adult↗
PubMed1975

Evaluation of intracardiac shunts.

This article will review the qualitative and quantitative methods of radionuclide evaluation of intracardiac shunts. Radionuclide angiocardiography of the cardiopulmonary system has proven adequate, with few exceptions, for qualitative detection of left-to-right and right-to-left intracardiac shunts. Numerous authors have reported on the detection of intracardiac shunts using qualitative methods such as rapid sequential visualization of nuclide angiocardiography using the scintillation camera with Polaroid, 35mm or 70mm film. Recent development of videotape storage systems and computers offers a quantitative technique of permanently recording the nuclide angiocardiogram and thus the capability for replay and analysis of the study. Quantitative analysis of the nuclide angiogram in the form of heart chamber dilution curves or pulmonary dilution curves permits 1) determination of the presence or absence of left-to-right, right-to-left, or bi-directional intracardiac shunts, including shunts which might go undetected using the qualitative techniques, 2) shunt location at the atrial or ventricular level, 3) determination of the functional status of a corrective left-to-right shunt, and 4) shunt quantitation. By quantitative analysis of the isotope dilution curves, it is possible to calculate the size of left-to-right or right-to-left intracardiac shunts (Qp/Qs ratio) to within 10% of the values obtained at cardiac catheterization.

Adolescent↗