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Biomedical subjects

F L Datz

Publications and source records attributed to F L Datz.

At least 55 records · Page 3Linked to original sources
PubMed1991

Gastric emptying after gastric interposition for cancer of the esophagus or hypopharynx.

Transhiatal esophagectomy with primary anastomosis to the stomach (gastric pull-up) is an attractive surgical alternative to colic interposition in patients with cancer of the esophagus and hypopharynx. However, the lack of intrinsic gastric peristalsis and complaints by patients of postprandial regurgitation prompted us to measure the effect of body posture on the rates of gastric emptying in these patients. The rates of solid and liquid gastric emptying were measured in 14 patients who had undergone gastric interposition for esophageal and hypopharyngeal carcinoma. Rates of emptying were measured in both the supine and upright position using a dual-isotope radiolabeling technique. In these patients, the rate of gastric emptying of both solids and liquids was significantly slower in the supine position than in the upright position. Emptying in supine patients was also prolonged when compared with supine normal volunteers. Conversely, the upright rate of solid and liquid emptying in the patients was accelerated when compared with published values for upright normal volunteers. We conclude that gastric emptying after gastric interposition is dependent on upright posture after meals.

Adult↗
PubMed1991

Confirmation of short solid-food lag phase by continuous monitoring of gastric emptying.

Reports on the existence of a lag phase before solid-food gastric emptying are conflicting. We studied solid-phase gastric emptying in ten normal-weight male subjects using two opposed cameras and continuous monitoring. Each ingested a 300-g meal containing 99mTc-labeled liver pate. Identical computer-interfaced cameras continuously monitored gastric activity from anterior and posterior projections. Lag phase was determined by three techniques: (1) inspection of the emptying curve; (2) time to a 2% decrease in stomach activity; and (3) the time of visual appearance of duodenal activity. A short lag phase time was found using all methods, averaging 8.6 min. We concluded that a short solid meal lag phase exists that can be missed with conventional radionuclide gastric emptying methods not employing continuous measurements.

Food↗
PubMed1990

Exercise increases solid meal gastric emptying rates in men.

Gastric emptying rates of radiolabeled beef stew meals were measured in 10 healthy, young (median age = 27 years) male subjects on each of three randomly chosen study days. The subjects either (1) stood at rest, (2) walked on an exercise treadmill at 3.2 km/hr, or (3) at 6.4 km/hr during the study while gastric emptying was being monitored by externally positioned gamma cameras. Compared to the standing at rest study, exercise significantly increased gastric emptying (at rest emptying half-time (t1/2) = 72.6 +/- 7.6 (SEM) min; 3.2 km/hr t1/2 = 44.5 +/- 3.9 min, P = 0.0051; 6.4 km/hr t1/2 = 32.9 +/- 1.9 min, P = 0.0051). The 6.4 km/hr emptying time was significantly (P = 0.0249) faster than the 3.2 km/hr emptying time. Thus, the amount of exercise is a physiological factor that alters solid meal gastric emptying rates.

Adult↗
PubMed1990

Unilateral parathyroidectomy: the role of thallium-technetium subtraction scans.

The rationale for using the thallium-technetium subtraction scan as a preoperative localizing study in previously untreated patients with primary hyperparathyroidism is presented. The concept of unilateral parathyroidectomy is also presented, and the role of preoperative localizing studies in this approach to parathyroid surgery is carefully analyzed.

Adenoma↗
PubMed1990

Comparison of methods for calculating glomerular filtration rate: technetium-99m-DTPA scintigraphic analysis, protein-free and whole-plasma clearance of technetium-99m-DTPA and iodine-125-iothalamate clearance.

True glomerular filtration rate (GFR) was measured in normal volunteers and in patients with normal and impaired renal function by the iothalamate clearance (IC) method of Sigman. Within 24 hr, GFR was also determined by two other methods: technetium-99m- (99mTc) DTPA scintigraphic analysis (SA) utilizing a modification of the Gates computer program, and by measuring disappearance of 99mTc-DTPA from whole plasma (WPC) and from protein-free ultrafiltered plasma (PFPC). Determinations of GFR by IC and by PFPC methods were virtually identical (mean absolute error 5.36 ml/min, r = 0.99, p greater than 0.05). GFRs measured in protein-free, ultrafiltered plasma differed significantly from those obtained from whole plasma only in sicker patients and in those taking multiple medications (in whom alterations in protein-binding of DTPA may be seen). The SA method correlated less well with the iodine-125-(125I) IC method than did either the protein-free or whole-plasma clearance methods (mean absolute error 32.36 ml/min, r = 0.74, p less than 0.05). However, the SA method provided useful information with respect to differential (split) renal function.

Adult↗
PubMed1990

Diagnostic use of angiotensin converting enzyme (ACE)-inhibited renal scintigraphy in the identification of selective renal artery stenosis in the presence of multiple renal arteries: a case report.

In patients with renovascular hypertension, it is unknown whether the angiotensin converting enzyme-(ACE) inhibited renal scan will identify stenosis of a segmental branch of a single renal artery or of an accessory artery where multiple renal arteries are present. Since multiple renal arteries may be present in approximately 25% of all individuals, it will be important to establish whether the ACE-inhibited renal scan is useful in this population. We report a case of stenosis involving a renal artery in a patient with multiple renal arteries, successfully identified by ACE-inhibited renal scintigraphy.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1988

Effect of body posture on radionuclide measurements of gastric emptying.

The purpose of this investigation was to compare the effect of body posture on gastric emptying measurements of radiolabeled meals. Eight healthy male subjects were studied on four separate days. During each study subjects were fed a standardized meal of beef stew labeled with technetium-99m sulfur colloid, and orange juice. Measurements of solid-phase gastric emptying rates were obtained by a gamma camera. Subjects were studied in the lying, sitting, standing, or combined sitting-standing postures. The results demonstrated that the lying position significantly slowed gastric emptying compared to all other positions. Conversely, a decrease in emptying times of 51% and 35% occurred in the combined sitting-standing position compared to the lying and sitting position. These results support a marked effect of body posture on the radionuclide measurement of gastric emptying.

Adult↗
PubMed1988

Uptake of cadmium-109, a metallothionein-binding radiometal, by tumors in mice as a function of the transformed phenotype.

Metallothionein (MT) is an intracellular protein that binds many metals with isotopes having imaging or radiotherapeutic potential. To determine whether uptake of radioisotopes that bind to MT is increased in tumors, we measured the uptake of cadmium-109 (Cd-109) in tumors and in normal tissues of mice. Tumors were grown in Balb/C mice from cultured Balb/3T3 cells transformed by the Moloney murine sarcoma virus (MMSV). Uptake of Cd-109 by MMSV tumors exceeded that by normal tissues examined, with the exception of liver and kidney (the organs known to be richest in metallothionein). The MMSV tumor:background ratios of activity were greater for Cd-109 than for gallium-67 for many of the normal tissues examined. The magnitude of uptake of Cd-109 by tumors from four related cell lines paralleled their degree of expression of two indices of the transformed, or malignant, phenotype. We conclude that metals that bind to MT may be useful for imaging or radiotherapy of cancer.

Animals↗
PubMed1988

Radioimmunodetection of human melanoma with indium-111-labeled monoclonal antibody.

The purpose of the study was threefold: (1) to evaluate the efficacy of an 111In-labeled murine monoclonal antibody (ZME-018) directed against a heavy molecular weight melanoma associated glycoprotein in localizing metastatic disease; (2) to determine the effect of unlabeled antibody mass (2.5, 5, 10, 20, and 40 mg) on labeled antibody blood clearance, biodistribution and lesion detection; (3) to estimate radiation dosimetry. Twenty-five patients with previously documented disease received an intravenous infusion of 2.5 to 40 mg of monoclonal antibody with 1 mg of the antibody labeled with 5 mCi of 111In. There were no acute reactions. Patients were scanned without computer enhancement or background subtraction techniques at 24 and 72 hr after injection. Imaging detected tumor in 14/18 (78%) patients with active disease, identified 24/44 (77%) of lesions greater than 1 cm and changed or specifically directed patient management in 22% (4/18) patients with tumor. There was a prolongation in blood clearance associated with decreased liver and spleen activity following administration of 20 and 40 mg of antibody compared to the three lower antibody dose levels. Assuming a biodistribution similar to [111In]ZME-018, the radiation dose delivered to normal tissues by [90Y]ZME-018 would restrict its use as a routine vehicle for radioimmunotherapy; however, it may be possible to deliver substantial tumor doses in selected patients.

Adult↗
PubMed1987

Multigated radionuclide study of the total artificial heart.

A permanent total artificial heart, the Jarvik-7, was implanted into a 61-year-old male with a severe cardiomyopathy. Gated radionuclide studies were performed in the patient both prior to surgery and following implantation. Preoperative gated radionuclide cardiac studies revealed marked left ventricular enlargement, severe hypokinesis and a left ventricular ejection fraction of 10%. The right ventricle was moderately enlarged with a 27% ejection fraction. Following implantation of the Jarvik-7 artificial heart, gated cardiac studies were performed with a computer gated by a signal from the heart controller. The left ventricular ejection fraction was 69% and the right ventricular ejection fraction was 62%. This compared to a theoretical ejection fraction of 74% for each ventricle based on chamber anatomy. There was excellent ventricular emptying. Phase analysis showed uniform diaphragm motion. The use of gated cardiac studies in humans may prove helpful in evaluating mechanical problems with the artificial heart, such as malfunction of the diaphragm, before they become clinically apparent.

Heart↗
PubMed1987

Erythema nodosum leprosum reaction of leprosy causing the double stripe sign on bone scan. Case report.

Leprosy is a disease that is widely distributed in underdeveloped tropical regions, with cases also occurring in the United States. The bone scan findings in a patient with leprosy who had developed a reactional state of the disease, erythema nodosum leprosum, are presented. His scan showed bilaterally symmetrical double stripe signs involving the distal tibias, similar to those seen in hypertrophic osteoarthropathy. Physicians should be aware that this reactive phase of leprosy can also produce the double stripe sign.

Adult↗
PubMed1987

Cause and significance of cold bone defects on indium-111-labeled leukocyte imaging.

Although photon deficient defects on bone scan have received a great deal of interest, such defects in bones on Indium-111 (111In) leukocyte imaging have not been as well recognized. We therefore undertook a retrospective review to determine the frequency and significance of such "cold" defects on 111In-labeled leukocyte imaging. Three hundred thirty-two scans on 290 patients were reviewed and 40 cases of decreased activity involving bone were found, for an incidence of 12%. The causes of the defects were: fracture (eight), nontraumatic avascular necrosis (eight), solid tumor (six), prostheses and other orthopedic hardware (four), advanced age (four), radiation (three), leukemia (two), osteomyelitis (two), myelofibrosis (one), postlaminectomy (one), and idiopathic (one). To determine the frequency of cold defects in osteomyelitis, all 15 cases of osteomyelitis in this series were reviewed and 12 showed increased activity, two were cold, and one was normoactive. Thus, 14% of cases of osteomyelitis presented as cold defects. We conclude that cold bone defects do occur on 111In-labeled leukocyte scans and that the causes of such defects are similar to those reported for bone and bone marrow scanning.

Bone Diseases↗