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Biomedical subjects

L S Malmud

Publications and source records attributed to L S Malmud.

At least 37 records · Page 2Linked to original sources
PubMed1986

Infection in diabetic osteoarthropathy: use of indium-labeled leukocytes for diagnosis.

Indium-111 labeled leukocyte imaging was compared with three-phase skeletal scintigraphy as a means of determining whether osteomyelitis was complicating diabetic osteoarthropathy. Three-phase scintigraphy demonstrated increased activity in both infected and noninfected osteopathic bone, with a sensitivity of 75% and a specificity of 56% for osteomyelitis. Leukocyte imaging had the same sensitivity but was most helpful for excluding infection (specificity, 89%) when three-phase imaging could not. Abnormal leukocyte localization was seen at the primary site of infection in all cases within 4 hours after injection. Disadvantages of leukocyte imaging included long preparation time, low count rates resulting in poor spatial resolution, and absence of bone landmarks, which made it difficult to differentiate soft tissue from bone infection.

Adult↗
PubMed1986

Scintigraphic techniques for the study of gastrointestinal motor function.

A variety of scintigraphic techniques has been added to the gastroenterologist's armamentarium for the evaluation of motor dysfunction of the upper gastrointestinal tract and hepatobiliary tree. These methods include: esophageal transit scintigraphy for the measurement and quantitation of aboral movement of liquids through the esophagus, and for the measurement of esophageal clearance; gastroesophageal reflux scintigraphy for the detection and quantitation of gastroesophageal reflux, gastric scintigraphy for the physiological measurement of the simultaneous rates of emptying of liquids and solids from the stomach; hepatobiliary scintigraphy for the detection of acute cholecystitis, biliary tract obstruction, bile leaks; and enterogastric reflux scintigraphy for the detection and quantitation of bile reflux from the small bowel into the stomach. Each of these methods is relatively physiologic in comparison to other modalities in that none requires intubation or other nonphysiologic maneuvers. Each offers the practicing internist, surgeon, and gastrointestinal physiologist, the ability to measure normal and abnormal function in patients. Because of the low radiation burdens involved and high patient acceptance, these methods are suitable for serial studies in the same patient, particularly before and after the application of various therapeutic modalities.

Biliary Tract Diseases↗
PubMed1986

Colonic transit scintigraphy. A physiologic approach to the quantitative measurement of colonic transit in humans.

Colonic transit scintigraphy was developed to quantitatively evaluate colonic transit. Using this technique the progression of a radiolabeled marker from cecal instillation to defecation was studied in 7 normal male volunteers. An 8-ml bolus containing 50 mu Ci of indium 111-diethylene triamine pentaacetic acid was instilled into the cecum via a 2-mm tube, which was passed orally, and serial scintigrams were obtained over 48 h. By 48 h, 70.7% +/- 9.1% (mean +/- SEM) of the instilled activity had been defecated. The cecum and ascending colon emptied rapidly, with a half-emptying time of 87.6 +/- 27.0 min. Geometric center analysis showed an initial logarithmic progression of activity in the proximal colon and a linear progression distally. This study suggests that the transverse colon, not the cecum and ascending colon, may be the primary site for fecal storage. Colonic transit scintigraphy is a safe, physiologic, and quantitative method for evaluating the colonic transit of fecal material and may provide a useful tool for evaluating normal and abnormal large intestinal physiology.

Adult↗
PubMed1985

Cholinergic effects on gallbladder emptying in humans.

The role of cholinergic mechanisms in the control of gallbladder emptying has not been defined. In this report a scintigraphic technique using 2,6-dimethylphenylcarbamoylmethyl iminodiacetic acid labeled with technetium 99m to visualize the gallbladder and its emptying and diethylenetriamine pentaacetic acid labeled with indium 111 to visualize the stomach and its emptying was used to study 43 normal subjects and 18 patients with vagotomies. Direct cholinergic stimulation with bethanechol induced significant gallbladder emptying. Cholinergic blockade with atropine sulfate decreased the gallbladder emptying responses to a liquid meal, a solid meal, and the infusion of cholecystokinin-octapeptide. In patients with vagotomies, gallbladder emptying was decreased despite accelerated gastric emptying of an ingested liquid meal. The gallbladder emptying response to cholecystokinin-octapeptide was augmented in patients who had undergone vagotomy. These studies suggest that cholinergic receptors may be important in the regulation of human gallbladder emptying.

Adult↗
PubMed1985

Cardiac function assessed by attenuation-corrected radionuclide pressure-volume indices.

Using attenuation-corrected radionuclide volumes and arm-cuff peak systolic pressures, we established the mean value for the ratio of left ventricular (LV) peak systolic pressure/end systolic volume at rest for 15 healthy persons. In 43 patients with coronary disease, this ratio was more sensitive as an indicator of abnormal LV function and for predicting coronary artery disease than the resting ejection fraction. The slope of an end systolic pressure-volume line was also calculated from data obtained under three loading conditions: at rest, during isometric handgrip testing, and after the sublingual administration of nitroglycerin. The sensitivity of the slope for predicting the presence of coronary artery disease was not significantly different from the resting peak systolic pressure/end systolic volume ratio but was helpful in identifying patients with coronary artery disease. These results represent an improvement over previous radionuclide pressure-volume measurements that have not used attenuation correction and show the need for accurate, nongeometric measurements of the LV end systolic volume.

Adult↗
PubMed1985

Fragment E1 labeled with I-123 in the detection of venous thrombosis.

Fragment E1, which has been shown to have specific binding affinity for thrombi in an animal model, was investigated in humans for its safety and ability to bind to venous thrombi. Human Fragment E1 was labeled with I-123 and administered intravenously to patients with proved or suspected deep vein thrombosis. The vascular distribution of radioactivity was documented by obtaining gamma camera images of the patients' legs for 30 minutes following administration of I-123-Fragment E1. All patients (n = 5) with documented venous thrombi had rapid localization of labeled Fragment E1 in the area of thrombus. Patients without evidence of thrombi (n = 5) showed no focal localization, although two of these patients showed diffuse uptake along the length of the veins, due to superficial phlebitis. Analysis of blood samples in four patients indicated that disappearance of Fragment E1 from the circulation was more rapid in individuals with thrombosis (t 1/2 = 20 min) than in individuals without thrombosis (t 1/2 = 90 min), and a radiolabeled species of high molecular weight was found in patients with thrombosis but was absent from patients without thrombosis. These early results suggest that radiolabeled Fragment E1 is a safe and potentially valuable agent for the rapid detection of venous thrombosis.

Adolescent↗
PubMed1984

Preoperative nuclear scans in patients with melanoma.

One hundred forty-one liver scans, 137 brain scans, and 112 bone scans were performed in 192 patients with clinical Stage 1 melanoma. One liver scan was interpreted as abnormal; liver biopsy of that patient showed no metastasis. There were 11 suggestive liver scans; three of the patients with suggestive liver scans had negative liver biopsies. The remaining eight patients were followed from 4 to 6 years and none of those patients developed clinical evidence of hepatic metastases. All of the brain scans were normal. Five patients had suggestive bone scans and none of those patients had manifested symptoms of osseous metastases with a follow-up of 2 to 4.5 years. This study demonstrates that the use of preoperative liver, brain and bone scan in the evaluation of patients with clinical Stage 1 melanoma is virtually unproductive.

Adolescent↗
PubMed1984

Absolute left ventricular volume by an iterative build-up factor analysis of gated radionuclide images.

A method for determining absolute left ventricular (LV) volumes from radionuclide gated blood-pool (GBP) images was validated in 34 patients. The technique is nongeometric, corrects for tissue attenuation, and uses an experimentally determined set of build-up factors to account for the effects of scatter. Only four parameters are needed to determine LV volumes: the LV count rates from a left anterior oblique (LAO) and a right posterior oblique (RPO) image (180 degrees opposed to the LAO), a venous blood sample, and a patient thickness measurement. A computer algorithm is used to reach an iterative solution to two simultaneous equations that yield LV volumes. Phantom studies showed less than 4% error for volume determinations at all investigated depths. For the patients studied the correlation between volumes obtained by GBP and contrast ventriculography was 0.97 for diastole and 0.96 for systole.

Adult↗
PubMed1984

Assessment of systolic ventricular muscle function in man: the end systolic index.

Accurate assessment of ventricular muscle contractile function in patients with heart disease is impaired by alterations in afterload, preload and wall thickness which often accompany the disease. The relationship between pressure and volume at end systole is considered to provide a contractile index which is independent of preload and which accounts for afterload. Use of the index prerequisites determinations of the left ventricular end systolic pressure, wall thickness as well as the dimensions or volumes, respectively, which may be assessed with either invasive or noninvasive methods. In patients with aortic stenosis and congestive heart failure, there was a significantly reduced slope (0.9 +/- 0.5) of the end systolic stress-volume relationship as compared with healthy subjects (5.8 +/- 1.3) or patients with aortic stenosis without congestive heart failure (3.9 +/- 1.3), while the ejection fraction showed no significant differences. In patients with mitral regurgitation with no or only minimal symptoms postoperatively, preoperatively the end systolic index (ESS/ESVI) was higher (3.3 +/- 0.4) than in patients with marked symptoms postoperatively or those who died perioperatively (2.2 +/- 0.2) and the values of both patient groups were lower than those of normals. In contrast, the values for ejection fraction among the normals and both groups of patients showed substantial overlap. In patients with aortic insufficiency and congestive heart failure, as opposed to patients with aortic insufficiency and only slight symptoms, there was a significantly compromised ejection fraction as well as diminished end systolic index (ESS/ESVI). Patients with hypertension accompanied by congestive heart failure had a significantly diminished slope of the relationship between end systolic left ventricular stress and volume while the values for hypertensive patients without congestive heart failure were within normal limits; in both groups of patients, the ejection fraction was normal. In patients with mitral stenosis, the end systolic index at 5.28 +/- 0.53 did not differ significantly from that of healthy subjects at 4.87 +/- 0.53, while the velocity of circumferential fiber shortening was diminished. Patients with large atrial septal defects and symptoms of congestive heart failure did not differ with respect to end systolic index or ejection fraction as compared with atrial septum defect patients without symptoms. In children with aortic stenosis and high pressure gradients, there was an increased ejection fraction together with a normal end systolic index.(ABSTRACT TRUNCATED AT 400 WORDS)

Anemia, Sickle Cell↗
PubMed1984

Tc-99m HIDA dosimetry in patients with various hepatic disorders.

The pharmacodynamics of Tc-99m dimethyliminodiacetic acid were studied for normal subjects and for patients with a variety of hepatobiliary disorders. It was determined that, in normal subjects, approximately 65% of the gallbladder agent bypassed the gallbladder and was excreted directly from the liver into the small intestine. This bypassing of the gallbladder was even higher in patients with cystic-duct or common-duct obstruction. The radiation burdens to the gallbladder wall and other critical organs were calculated using the dynamic data obtained from patients with a variety of gallbladder disease. The dose to the gallbladder wall was found to be significantly lower than previously reported. Gallbladder ejection and clearance characteristics when stimulated by food intake were studied for normal subjects. Dosimetry calculations demonstrated a fivefold reduction of absorbed dose to the gallbladder wall when the gallbladder was stimulated to contract using a fatty meal. Accordingly, a fatty meal is recommended for patients at the end of all gallbladder imaging studies.

Biliary Tract Diseases↗
PubMed1983

Absolute left ventricular volume from gated blood pool imaging with use of esophageal transmission measurement.

A new method for determining absolute left ventricular (LV) volume from equilibrium gated blood pool images was validated in 36 patients by comparing gated blood pool (GBP) imaging with contrast ventriculography (CV) using both Simpson's rule (SR) and area-length (AL) calculations. The technique is geometry-independent and is the first to correct for tissue attenuation with use of an in vivo point source. An orally administered capsule containing 1 to 2 mCi of technetium-99m (Tc-99m) sulfur colloid is used for this purpose. Left ventricular volumes are determined by dividing attenuation and background-corrected count rates obtained from semiautomated LV regions of interest by the count rate per milliliter from a blood sample. The correlation between GBP and CV (SR) was 0.96 (CV [SR] = 0.99 GBP + 1.32 ml; standard error of the estimate [SEE] = 21.2 ml) for diastole and 0.97 (CV [SR] = 0.93 GBP - 0.03 ml; SEE = 11.9 ml) for systole. The correlation between GBP and CV (AL) was 0.92 (CV [AL] = 0.90 GBP + 16.72 ml; SEE = 27.8 ml) for diastole and 0.95 (CV [AL] = 0.87 GBP + 4.56 ml; SEE = 14.4 ml) for systole. The method is noninvasive and can be performed easily as part of routine gated blood pool imaging and analysis.

Adult↗
PubMed1983

Long-term effects of dietary fiber on glucose tolerance and gastric emptying in noninsulin-dependent diabetic patients.

Effects of long-term (2 months) supplementation of diet with 20 g of guar gum and 10 g of wheat bran on metabolic control was studied in 12 obese, poorly controlled noninsulin-dependent diabetic patients. Addition of fiber reduced urinary excretion of glucose from 30.5 +/- 6 to 8.3 +/- 2 g/24 h, (p less than 0.025), fasting plasma glucose concentration from 301 +/- 24 to 184 +/- 15 mg/dl (p less than 0.025), and plasma cholesterol concentration from 277 +/- 24 to 193 +/- 9 mg/dl (p less than 0.025). No significant changes were observed in the patients weight and serum concentrations of triglycerides, high-density lipoproteins, free fatty acids, and insulin. Addition of fiber also delayed gastric emptying of liquids and solids. This effect became statistically significant 60 and 90 min after intake of a test meal for liquids and solids, respectively. We conclude that addition of guar and bran to the diet resulted in long-term improvement of metabolic control in these patients and that delayed gastric emptying may be one of the mechanisms responsible for this beneficial effect.

Adolescent↗
PubMed1983

Specific uptake of radioiodinated fragment E1 by venous thrombi in pigs.

Fragment E1, a product of plasmic digestion of cross-linked fibrin, binds specifically in vitro to polymerized fibrin but not to fibrinogen. Purified human Fragment E1 was radiolabeled with 125I or 131I by the Iodogen technique. The uptake of radioiodinated Fragment E1 in vitro into forming or preformed clots was demonstrated. Animal biodistribution studies of radioiodinated Fragment E1 showed its rapid removal from the circulation; radioactive catabolites did not reside long in any organ and were excreted in the urine. The uptake in vivo was evaluated in pigs with preexisting venous thrombi of various ages from 1 h up to 5 d at the time of intravenous systemic injection of the tracer. Radioiodinated fibrinogen was also injected into the same animals to compare the uptake of the two tracers. Thrombus-to-blood ratios for Fragment E1 averaged 43:1 (range 10-108) and 29:1 (range 8-107) in thrombi 1-6 h and 1-5 d old, respectively. In contrast, mean thrombus-to-blood ratios for fibrinogen were, in the same time intervals, 26:1 (range 17-41) and 2:1 (range 0.5-3.9), respectively. It is concluded that radioiodinated Fragment E1 is a specific marker of thrombi in vivo: its uptake by fresh thrombi is better than that of labeled fibrinogen and, in contrast to radioiodinated fibrinogen, this fragment is incorporated into old thrombi as well.

Animals↗
PubMed1983

Multiple scintigraphic findings in a patient with a primary myocardial sarcoma.

Primary myocardial sarcomas are rare. We report the scintigraphic findings observed with TI-201, Ga-67, Tc-99m pyrophosphate, and Tc-99m pertechnetate labeled red cell gated cardiac imaging in a patient with this tumor. We found that thallium and gated blood pool imaging can be used both in the diagnosis of these tumors and the assessment of the effects of chemotherapy on the tumor and normal myocardium. The thallium study was particularly helpful in identifying the malignant nature of the tumor by showing extensive infiltration into surrounding areas.

Adult↗
PubMed1983

Radiation dose estimates for oral agents used in upper gastrointestinal disease.

Radiation dosimetry was calculated for a number of orally administered radiopharmaceuticals used for study of upper gastrointestinal function. These include: Tc-99m sulfur colloid in water, in a cooked egg, and in chicken liver labeled in vivo; In-111 DTPA; Tc-99m DTPA; In-113m DTPA; Tc-99m ovalbumin in cooked egg; and In-111 colloid in chicken liver labeled in vivo. Radiation burdens to the stomach, small intestine, upper and lower large intestine, ovaries, testes, and total body are calculated for each preparation.

Administration, Oral↗
PubMed1982

Abnormal gallbladder emptying in patients with gallstones.

In this study, gallbladder and gastric emptying were compared in 15 normal subjects and 15 patients with gallstones. A noninvasive technique which used two gamma-emitting radiopharmaceutical agents to image the gallbladder and stomach simultaneously was employed. Technetium-99m-HIDA was used as a gamma-emitting marker for the gallbladder and indium-111-DTPA was mixed with a standard liquid meal in order to stimulate gallbladder emptying and to measure gastric emptying. In patients with gallstones, gallbladder emptying was diminished significantly compared to normal subjects. In contrast, emptying of the stomach was normal. The gallbladder emptying responses to octapeptide of cholecystokinin, administered either as bolus or infusion doses, were similar in normal subjects and patients with gallstones. These studies suggest that gallbladder emptying may be abnormal in patients with gallstones. The explanation for this abnormality and its relationship to the development of gallstones has not been determined.

Adult↗