Myocardial scintigraphy with iodine-123 phenylpentadecanoic acid and thallium-201 in patients with coronary artery disease: a comparative dual-isotope study.
Explore the source record for details and available documents.
Coronary Disease↗
Biomedical subjects
J Kropp
Publications and source records attributed to J Kropp.
Inhalation scintigraphy with an ultrafine aerosol in infants with functional bronchial stenoses.
Evaporation of Tc-99m pertechnetate at about 2500 degrees C on a carbon surface generates an ultrafine aerosol of Tc-99m-labeled carbon clusters (Technegas). The small particle size of about 100 nm enables the aerosol to behave similarly to a gas in its ability to penetrate. After inhalation, the radioactive particles adhere to the walls of the respiratory bronchioles and alveoli, or to the greater bronchial tubes if the airflow is not laminar. The high concentration of radioactivity in the argon carrier gas makes it possible to perform inhalation scintigraphy after only a few breaths. The authors investigated 24 infants with multiple events of bronchitis, most of whom had pneumonia. Seventeen patients had inhalation scintigraphy and bronchoscopy. Of these, 11 had scans diagnostic of bronchial stenosis and 6 had normal scans. Except for two pathologic scans, all scintigraphic findings matched well with the results of bronchoscopy. Seven patients had scintigraphy only, of which four were normal. Inhalation scintigraphy with Technegas is a reliable, nonhazardous procedure to preselect young patients for directed bronchoscopy.
Aerosols↗
Tc-99m labeled monoclonal antibodies against granulocytes (BW 250/183) in the detection of appendicitis.
Scintigraphy with Tc-99m labeled antigranulocyte antibodies (BW 250/183 MoABs) was performed in 32 patients with suspected appendicitis. Abdominal imaging (planar/SPECT) was performed 2 hours after injection of the tracer. All patients also had surgery and a histologic examination of the resected tissue. Of the patients, 17 suffered from "acute appendicitis" and 12 had right positive scans (sensitivity = 70.6%). In 15 patients, acute appendicitis could have been ruled out, and in 11 of these cases the scan was true negative (specificity = 73.3%). The overall accuracy was 71.8% (23/32 cases). The use of Tc-99m antigranulocyte MoABs may overcome the problems associated with the Tc-99m HMPAO granulocyte and In-111 oxine approaches, which include nonspecific intestinal activity or the lack of timeliness. The use of Tc-99m labeled antigranulocyte antibodies is suitable as an emergency procedure and may play a role in the management of patients with suspected appendicitis.
Adolescent↗
Site-specific/stable radioiodination of 1,2-Pal-3-IPPA: an agent for the potential clinical evaluation of pancreatic insufficiency by urine analysis.
To measure pancreatic lipase activity, we synthesized a triglyceride containing a radioiodinated fatty acid. The urinary excretion of radioactivity was measured in five rats following administration of the agent by feeding tube. We attached 15-phenylpentadecanoic acid (PPA) to position-3 of 1,2-dipalmitoyl-rac-glycerol (1,2-Pal) to form 1,2-Pal-3-PPA. The 1,2-Pal-3-IPPA (expected lipase substrate) was prepared by the thallation-iodide displacement method. In a dual-label study, the 125I-1,2-Pal-3-IPPA triglyceride was administered with the 131I-IPPA free acid to rats (n = 5) by oral gavage. Urine and feces were collected daily and the tissue distribution of both tracers was evaluated over a five-day period. A significant portion of the administered activity was excreted in 24 hr in the urine (125I, 30.31% + 4.32%; 131I, 35.0% + 7.29%), which cochromatographed with hippuric acid by thin layer chromatography. Release of the acidic components from the conjugated excretory products by acid hydrolysis of the urine provided the radioactive acidic metabolites. Analysis of the Folch extracts of fat samples demonstrated that the radioactive components cochromatographed in the triglyceride region. This agent appears useful for the evaluation of various gastrointestinal diseases.
Animals↗
Incorporation of radioiodinated IPPA and BMIPP fatty acid analogues into complex lipids from isolated rat hearts.
Heart lipids were extracted by the Folch technique from Langendorff-perfused rat hearts after administration of 15-(p-[131I]iodophenyl)pentadecanoic acid and 15-(p-[125I]iodophenyl)-3-R,S-methylpentadecanoic acid. Techniques utilizing successive high performance liquid chromatographic (HPLC) analyses have been developed for the evaluation of the uptake of the tracers into neutral lipids and phospholipids of the rat hearts. Phospholipids were separated on a SiO2 column eluted with a gradient of acetonitrile/water (97.5/2.5) and acetonitrile/water (85/15) followed by separation of the neutral lipids on a C-18 reversed phase column with a gradient consisting of acetonitrile and 2-propanol/hexane (60/40) containing 1 N H2SO4 (5 microL/100 mL). Both tracers show the incorporation into the expected major lipid classes.
Animals↗
Effects of head-down tilt and saline loading on body weight, fluid, and electrolyte homeostasis in man.
We studied the effects of head-down tilt bedrest (HDT) on body weight, fluid and sodium homeostasis. A fluid load session with rapid intravenous infusion of 22 ml/kg body weight (BW) isotonic saline was performed before, during and after HDT. During the pre- and post HDT periods the test subjects were given a diet containing 2600 kcal/day. The energy intake was reduced to 2000 kcal/day during HDT. Water intake was kept constant at 40 ml/kg BW, sodium intake was 2.2 mmol/kg BW and protein intake was 1.4 g/kg BW, while the daily fat and carbohydrate intake was reduced during the HDT period. As expected plasma volume and BW changed rapidly in the beginning of HDT and during early recovery. A total body water loss of 0.6 l was observed within the second day after tilting. Plasma volume was reduced by 16% during HDT-bedrest. The time course of the body fluid loss paralleled a decrease in body sodium that then remained fairly constant during the HDT-bedrest period (except for the interference caused by the fluid loading on day S06). A restoration of body fluid and body sodium content occurred early in the recovery period. Fluid loading caused a negative fluid balance of 0.6-0.9 l over a 48 hr period following infusion regardless of the phase of the HDT study. These results demonstrate that under our strictly controlled conditions 1) HDT alters body fluid and sodium balances, 2) a standard fluid loading causes a net negative 3-day fluid balance during all phases of the study.
Adult↗
Technetium-99m-labeled anti-granulocyte antibodies in suspected bone infections.
The introduction of 99mTc-labeled anti-granulocyte antibodies seemed to provide advantages in comparison with formerly used in vitro methods to label autologous white blood cells for inflammation imaging. For this reason, we have undertaken a study to evaluate the clinical significance of this method. Thirty unselected patients with suspected bone infections were studied prospectively using the monoclonal 99mTc-labeled anti-granulocyte antibody. Twenty patients were referred with suspected infections of the peripheral bones (Group I), as well as 10 patients with suspected infections of the spine (Group II). Planar whole-body scans were performed 4 hr and 20 to 24 hr after administration of 500 MBq of the labeled antibody. Scans were considered positive for a bacterial (septic) infection when a focally increased antibody accumulation occurred. All scans were evaluated in blinded fashion by two experienced readers. Of the 20 studies from Group I patients, four false-positive scintigraphic findings were observed, and one false-negative, resulting in a specificity of only 64% and a sensitivity of 89%. In Group II (10 studies), five scans were true-negative, and five false-negative. For both groups, the specificity of the scintigraphic method was quite low (75%), and the sensitivity was also relatively low (57%). The results of this study demonstrate that in an unselected patient population in whom the diagnosis is not known, scintigraphy with 99mTc-anti-granulocyte antibodies is not a reliable method for detecting septic inflammatory lesions: In addition, use of this method excludes septic lesions with only a moderate likelihood (83% negative predictive value).
Adolescent↗
Dependence of blood volume changes on oral sodium uptake.
Explore the source record for details and available documents.
Adult↗
[Scintigraphy with 123I-labelled fatty acids in coronary heart disease].
Forty-two patients (6 women, 36 men; mean age 55 [39-69] years), with one-, two- or three-vessel disease on coronary angiography, were studied using single-photon emission computer tomography with 15-p-123I-iodophenyl-pentadecanoic acid (IPPA), in order to evaluate this new method of demonstrating abnormalities of myocardial perfusion. The reference range for fatty acid turnover was determined in eleven controls (4 women, 7 men; mean age 41 [20-51] years) with no coronary stenosis. 185 MBq (5 mCi) of IPPA was administered intravenously during submaximal stress on a bicycle ergometer. Comparison between different regions of the tomograms revealed changes in fatty acid utilization typical of ischaemia. The sensitivity, specificity and predictive value of a positive result compared with coronary angiography were 95%, 89% and 93%, respectively, for the area supplied by the anterior interventricular artery, 92%, 91% and 93% for the circumflex branch and 89%, 91% and 90% for the right coronary artery. In 25 out of 31 patients (81%) with myocardial infarction, IPPA scintigraphy infarct localization agreed with the clinical findings. In two cases with unremarkable scintigrams left ventriculography showed hypokinesia, while in four cases neither method demonstrated any abnormality. There was one false-positive scintigram. IPPA scintigraphy has greater sensitivity and specificity than conventional nuclear medicine techniques in the demonstration of coronary heart disease.
Adult↗
Single photon emission tomography imaging of myocardial oxidative metabolism with 15-(p-[123I]iodophenyl) pentadecanoic acid in patients with coronary artery disease and aorto-coronary bypass graft surgery.
A total of 29 patients with coronary artery disease (CAD) were investigated with 15-(p-[123I] iodophenyl)pentadecanoic acid (123I-IPPA) and sequential single photon emission tomography (SPET). Of these, 19 were studied after aorto-coronary bypass graft surgery. Some 13 patients without evidence of CAD served as a control group. Two SPET studies (early and late) were carried out within 45 min after intravenous administration of 200 MBq 123I-IPPA at peak sub-maximal exercise. Semi-quantification of uptake (related to perfusion) and turnover (linked to metabolism) was obtained by segmental comparison of oblique slices. Taking coronary arteriography as the "gold standard", 123I-IPPA scintigraphy had the following figures of merit for sensitivity and specificity in the diagnosis of CAD: for the left anterior descending artery territory 93% and 95%, for the left circumflex artery region 96% and 92%, and for the right coronary artery territory 77% and 92%, respectively. In all, 90% of the reperfused myocardial segments showed an improvement of uptake. Of these, 61% exhibited increased turnover after revascularization and 39% had pathologic turnover and thus a dissociation of improvement of perfusion and oxidative metabolism after surgery.
Adult↗
Effects of 10 days 6 degrees head-down tilt on the responses to fluid loading and lower body negative pressure.
In an international collaborative project six normal male subjects were studied before, during and after 10 days 6 degrees HDT. Fluid intake was controlled at 40 ml/(kgbw day). Urine volume and body weight were determined daily. Fluid loading and LBNP were performed in all three phases of the study. Body weight diminished by 2.6% because of fluid loss. Blood volume diminished by 13%. The responses to fluid loading were similar in the three phases of the study. Sixty minutes after end of infusion only 5.5% of the infused saline remained in the intravascular compartment. Excess interstitial fluid was eliminated in the next 24 hs but a negative balance was recorded also in the following day. The compliance of the lower limbs expressed as the rate of limb volume change/unit LBNP change was increased at the end of the HDT phase and during the post HDT phase. The set point of intravascular volume was defended, as shown by the response to FL. HDT increased the compliance of the lower limbs.
Adult↗
Single photon emission computed tomography imaging of brain tumors.
Five radiotracers may be used for single-photon emission computed tomography (SPECT) imaging of brain tumors, namely technetium 99m pertechnetate, iodine-123 amphetamine derivatives, 99mTc-hexamethyl propylene amine oxime (HMPAO), thallium 201, and 123I alpha methyl tyrosine. Of these, pertechnetate may be considered as an "historical" procedure in brain tumors. However, there may be some equivocal cases in computed tomography or magnetic resonance imaging, where this procedure may still be used. In 1981, 123I isopropyl amphetamine was first used in brain tumors. Further studies showed, however, that IMP is not a useful tool for brain imaging in tumorous lesions. In 1986, 99mTc HMPAO appeared on the European market as a new tumor imaging agent. Some useful clinical results were obtained in patients before and after chemotherapy or radiotherapy. Thallium-201 was incidentally noted to accumulate in tumors. Using a threshold index, this agent can be used to distinguish low-versus high-grade lesions. The most promising agent for brain tumor SPECT is 123I-alpha methyl tyrosine, which shows potential to evaluate therapeutic procedures in brain tumors and may improve the differentiation between abscess and glioblastoma. The most promising aspect is the differentiation of tumor recurrences and scar tissue after brain surgery.
Brain Neoplasms↗
[A comparison of 201Tl and 99mTc-MIBI in the follow-up of differentiated thyroid carcinomas].
12 patients with suspected recurrence of differentiated thyroid carcinoma following thyroidectomy, radioiodine therapy and, in some cases, external radiation therapy had 201Tl and 99mTc-MIBI scintigraphy. Except in one case, the findings concerning tumor localization and extension were identical. In all cases, locoregional lymph node metastases as well as osseous metastases were imaged by 201Tl and 99mTc-MIBI scintigraphy. MRI images obtained in all patients with suspected lymph node metastases revealed inoperable situations in 2 cases, whereas there was no correlation in 1 patient with positive 201Tl and 99mTc-MIBI scintigraphy. In contrast, the sensitivity of the two methods was relatively low in the detection of pulmonary metastases which were imaged in 1 out of 3 patients only. Discrepancies between 201Tl and 99mTc-MIBI were observed in a case of axillary lymph node metastasis. Although tumor-/background ratios were slightly higher for 201Tl, 99mTc-MIBI SPECT showed a higher imaging quality compared to 201Tl SPECT, especially in deeply situated tumor lesions. In conclusion, 99mTc-MIBI seems to be a promising alternative imaging agent in the follow-up of differentiated thyroid carcinomas.
Adenocarcinoma↗
The effects of microsphere injections into the left atrium on the myocardial blood supply measured by thermal conductance probes.
Former experiments with thermal conduction probes showed signs of reductions or increases of myocardial perfusion shortly after injection of microspheres into the left atrium. Because of this, 210 measurements made during experiments on 66 dogs under propionyl-promazine/pentobarbital narcosis were newly analysed to verify a possible influence of microspheres (9 microns phi) injected into the left atrium on microcirculation. Using 20 additional dogs in identically performed experiments, the myocardial perfusion was measured using thermal conductance probes, following injections of isotonic NaCl solution (8 ml each), Ringer's solution, 5% glucose, the subject's blood, and isotonic NaCl solution mixed with the surface-active substance Tween 80. These suspension media were injected both with and without unlabelled microspheres (8.6 microns phi). The results led to the following conclusions: An obligatory decrease in the blood supply as the result of a mechanical blocking of capillaries by microspheres can be ruled out. The particles, the suspension media, and a suspension temperature not sufficiently adjusted to the body temperature induce reactive negative or positive changes in the microcirculation of the myocardium. This was found in approx. 45%-75% of cases. Solutions containing particles cause, in the majority of cases, a decrease. The suspension medium with the smallest effect proved to be isotonic NaCl solution. From the results one can conclude that artefacts may arise from the application of the heat conductance probe method when the temperatures are not perfectly matched. However, the injected solution itself can often lead to various reactions in microcirculation which may last up to 5 min. (ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗
Catabolism of 15-(p-iodophenyl)-3-R,S-methylpentadecanoic acid (BMIPP) by isolated rat hearts.
Explore the source record for details and available documents.
Animals↗
[Inhalation scintigraphy of the lung using the new ultrafine aerosol Technegas].
Evaporation of 99mTc-pertechnetate at about 2500 degrees C on a carbon surface generates an ultrafine aerosol of labelled carbon clusters. Its particle size of about 2-5 nm enables the aerosol to behave similarly to a gas regarding the ability of penetration. After inhalation, the radioactive particles adhere to the walls of the respiratory bronchioli and alveoli. The high concentration of the radioactivity in the argon carrier gas makes it possible to record a scintigram after a single deep breath. We studied four healthy volunteers and 79 patients including 34 with a tentative diagnosis of pulmonary embolism, 20 with bronchus carcinoma, and 15 with various other lung diseases. Ten of these patients were infants, the youngest being nine months old. All patients also had a perfusion scintigraphy.
Administration, Inhalation↗
[SPECT in reversible symptoms of cerebrovascular diseases].
In 16 patients with reversible symptoms of cerebrovascular disease a HMPAO- and/or IMP-SPECT was performed. 12 of these patients were suffering from TIA, 4 from PRIND. Using HMPAO-SPECT in 8 out of 9 patients with TIA and in 1 of 2 with PRIND a hypoperfusion could be demonstrated; IMP-SPECT showed a pathological pattern in 3 of 5 patients with TIA and in none of 2 patients with PRIND. A semiquantitative evaluation showed a tracer accumulation reduced by 13 +/- 12% (HMPAO) and 8 +/- 7% (IMP), respectively, in the clinically involved hemisphere, compared to the contralateral side. In circumscript SPECT lesions a reduction by 21 +/- 8% (HMPAO) or 17 +/- 7% (IMP) was observed. The interhemispheric ratio from the HMPAO-SPECT showed a significant correlation to that of the 133Xe-rCBF measurement (r = 0.86; p less than 0.001). SPECT was positive in a higher percentage than TCT, Doppler sonography, radioangiography and 133Xe-rCBF measurement. This does not imply a higher specificity or sensitivity, because a slight inhomogeneous SPECT pattern may occasionally be observed even in normal persons.
Adult↗
The effect of speed of deoxygenation on the percentage of aligned hemoglobin in sickle cells. Application of differential polarization microscopy.
We have used differential polarization microscopy, which provides images of linear dichroism, to measure the percentage of aligned hemoglobin (Hb) in 1086 deoxygenated red blood cells from subjects with sickle cell anemia. The percentage was found to be only slightly dependent on the speed of deoxygenation, thus showing that the percentage of aligned Hb was thermodynamically controlled (as has been found previously for the percentage of polymerized Hb in vitro). A slight decrease in the percentage of aligned Hb due to increasing speed of deoxygenation is primarily due to the increase in the number of cells containing no detectable aligned Hb. This class of cells was also the most variable between the different subjects studied. We were able to identify two other groups of cells that contain different numbers of domains of aligned Hb and show that these groups contain statistically different percentages of aligned Hb. The differences between these classes of cells was shown to be primarily due to different numbers of initial nucleation sites within each cell. It appears that the presence of preformed nucleation sites within cells at ambient oxygen tensions results in the thermodynamic control of aligned Hb polymer.
Algorithms↗