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1

Technetium-99m DTPA aerosol and gallium scanning in acquired immune deficiency syndrome  

SciTech Connect

In 11 non-smoking AIDS patients suspected of pneumocystis carinii pneumonia (PCP), the results of Tc-99m DTPA aerosol clearances, gallium scans, and arterial blood gases were compared with those of bronchoalveolar lavage (BAL). Nine patients had PCP. All had increased clearances five times higher than the normal (5.6 +/- 2.3% X min-1 vs 1.1 +/- 0.34% X min-1, N = 10, P less than 0.001), suggesting an increased alveolar permeability. Gallium scans were abnormal in six patients but normal or slightly abnormal in the three others. Four of these nine patients had normal chest x-rays. In two of these the gallium scan was abnormal, but in the two others, only the increased Tc-99m DTPA clearances showed evidence of lung disease. Two patients had normal BAL, with normal clearances and gallium scans. Four out of the nine patients with PCP were studied after treatment. Three recovered and had normal clearance and gallium scans. One still had PCP with increased clearance but normal gallium scan. Gallium scanning and Tc-99m DTPA clearance are useful for detecting lung disease in AIDS patients with suspected PCP and for prompting BAL when chest x-rays and PaO/sub 2/ levels are normal. Due to its high sensitivity, a normal Tc-99m DTPA clearance could avoid BAL.

Picard, C.; Meignan, M.; Rosso, J.; Cinotti, L.; Mayaud, C.; Revuz, J.

1987-07-01

2

Effect of ethanol on droplet size, efficiency of delivery, and clearance characteristics of technetium-99m DTPA aerosol  

SciTech Connect

With recent technical advances in aerosol technology, the study of regional ventilation using (/sup 99m/Tc)DTPA aerosol has become increasingly popular. Using a cascade impactor, the authors have assessed droplet size distribution from a newly designed nebulizer. Delivery efficiency of (/sup 99m/Tc)DTPA aerosol to normal subjects was improved 70% with a 10% concentration of ethanol in the nebulizer. Using filter paper fixed to the delivery end of the aerosol device, and varying ethanol concentrations from 0-10%, an 87% increase of deposited radioactivity is measured. The addition of ethanol did not alter clearance characteristics of (/sup 99m/Tc)DTPA from the lung nor did it affect droplet size distribution.

Sirr, S.A.; Juenemann, P.J.; Tom, H.; Boudreau, R.J.; Chandler, R.P.; Loken, M.K.

1985-06-01

3

Technetium 99m radiolabeling of aerosolized drug particles from metered dose inhalers.  

PubMed

To assess mechanisms of bronchodilation and effectiveness of metered dose inhalers, it may be useful to determine sites of drug deposition in the lung. To establish suitable test aerosols, two brands of metered dose inhalers containing bronchodilator (Brethaire, Proventil) were radiolabeled with technetium ( 99mTc) and tested to determine if the distribution of radioisotope in the aerosol was representative of the distribution of agonist activity. Cascade impaction was used to determine the particle size distribution of the radioisotope and drug aerosols by assaying each state of the cascade using scintillation and HPLC techniques. Possible influences of the radiolabeling method and delivery techniques on the particle distribution were assessed by analyzing distributions from nonradiolabeled inhalers using HPLC. For these drugs, there was an excellent correlation between the distribution of radioactivity and the drug within the captured aerosol (Brethaire r = 0.994, Proventil r = 0.998, 20 - 200 consecutive puffs). Distributions were close to log-normal and differences in mass median aerodynamic diameter (MMAD) between the radioisotope and agonist activities were not significant (Brethaire, MMAD +/- sigma g, radiolabel vs drug = 4.7 +/- 2.1 mum, vs 4.4 +/- 1.7 mum, and Proventil, 2.5 +/- 2.1 mum, vs 2.4 +/- 2.0 mum. Non-labeled inhalers produced similar drug distributions (Brethaire, 4.2 +/- 1.8 mum, and Proventil 2.0 +/- 1.9 mum). Pausing between actuations resulted in slightly smaller distributions (Brethaire, 3.6 +/- 1.8 mum, Proventil 1.8 +/- 1.8 mum, 20 puffs-60 sec pauses) but the differences were not significant. In addition, to search for multimodal distributions and assess the accuracy of the MMAD measurement via our cascade impactor (Delron), we also measured the distribution of the mass of material within the aerosols using a weight-sensitive cascade (California Measurements). Using the latter device (1 puff), the mass distributions of both aerosols were similar to the values obtained from the puffs with pauses (Brethaire 3.8 +/- 2.3 mum, Proventil 1.4 +/- 2.2 mum). Multi-modal distributions were not found. By all assessments, the distributions were nearly log-normal with drug activity well described by the radiolabel. PMID:10147689

Aug, C; Perry, R J; Smaldone, G C

1991-01-01

4

Evaluation of technetium-99m DTPA for localization of site of acute upper gastrointestinal bleeding  

SciTech Connect

Intravenous Tc-99m DTPA was evaluated in 34 patients with active upper gastrointestinal bleeding. Active bleeding was detected in 25 patients: nine in the stomach, 12 in the duodenum, and four from esophageal varices. No active bleeding was seen in nine patients (two gastric ulcers and seven duodenal ulcers). Results were correlated with endoscopic and/or surgical findings. All completely correlated except: 1) one case of esophageal varices in which there was disagreement on the site, 2) three cases of duodenal ulcers that were not bleeding on endoscopy but showed mild oozing on delayed images and 3) one case of gastric ulcer, in which no bleeding was detected in the Tc-99m DTPA study, but was found to be bleeding at surgery 24 hours later. The Tc-99m DTPA study is a reliable method for localization of upper gastrointestinal bleeding with an agreement ratio of 85%. This method also can be used safely for follow-up of patients with intermittent bleeding. It is less invasive than endoscopy, is easily repeatable, and has the same accuracy.

Abdel-Dayem, H.M.; Mahajan, K.K.; Ericsson, S.; Nawaz, K.; Owunwanne, A.; Kouris, K.; Higazy, E.; Awdeh, M.

1986-11-01

5

Detection of diffuse glomerular lesions in rats: II. Comparison of indium-111 cationic small macromolecules with technetium-99m DTPA  

Microsoft Academic Search

Dextrans with average molecular weights of 5000, 10,000, and 17,500 and inulin were rendered cationic by amination with 2-bromoethylamine hydrobromide. After limited coupling with DTPA cyclic dianhydride, they were labeled with 111In. A good correlation was found between their early renal uptake quantitated by camera-computer techniques and their renal clearance from multiple plasma samples in rats with glomerular damage induced

J. G. McAfee; F. D. Thomas; G. Subramanian; R. D. Schneider; B. Lyons; M. Roskopf; C. Zapf-Longo; D. Whaley

1986-01-01

6

The Effect of Vincristine on the Biodistribution of Technetium99m DTPA, GHA, and DMSA in Balb\\/c Female Mice  

Microsoft Academic Search

Objective: Vincristine has been widely used in various chemotherapeutic protocols in oncology. The purpose of this study was to evaluate the effect of vincristine on the biodistri- bution of 99mTc-DMSA, 99mTc-GHA, and 99mTc-DTPA in Balb\\/c female mice. Methods: Vincristine (0.03 mg, 0.3 mL) was injected into female isogenic Balb\\/c mice (n 5 15), in 3 doses over an interval of

Deise Mara; M. Mattos; Maria Luisa Gomes; Rosimeire S. Freitas; Edson M. Boasquevisque; Valbert N. Cardoso; Emilio F. Paula; Mario Bernardo-Filho

7

Radiolabelling of platelets with technetium-99m  

SciTech Connect

A method for labelling of platelets with technetium-99m (Tc-99m) is presented. In principle, aminobenzoic acid and tartaric acid are used as reagents, allowing Tc-99m complexes of intermediate chemical stability to be formed. These complexes react rapidly with proteins, such as platelet proteins, when added. We have examined the isolation procedure for the platelets and the labelling procedure using residual aggregational ability and residual content of beta-thromboglobulin (beta-TG) as indicators of damage to the platelets. In its final version the method allowed a 32.6 +/- 2.7% (mean +/- SD) incorporation of Tc-99m into platelets which again showed a 66 +/- 15% residual aggregational ability, tested by 50 mumol/l of ADP, and a 79 +/- 17% residual content of beta-TG releasable by 10 IU/ml of thrombin. In a pilot clinical study involving 28 patients we found labelled autologous platelets useful in detecting lung embolism and deep vein thrombosis.

Sundrehagen, E.; Urdal, P.; Heggli, D.E.; Lindegaard, M.W.; Jacobsen, E. (Norwegian Radium Hospital, Oslo (Norway))

1990-03-01

8

Technetium-99m APD compared with technetium-99m MDP as a bone scanning agent  

SciTech Connect

The authors have investigated the possibilities of technetium-99m-(-3-aminohydroxypropylidene)-1-1-bisphosphonate ((/sup 99m/Tc)APD) as a bone scanning agent in 14 normal subjects and 28 patients. Similar studies in the same normal subjects and patients were carried out with /sup 99m/Tc-methylene-bisphosphonate ((/sup 99m/Tc)MDP). The compounds were labeled with /sup 99m/Tc by means of an electrolytical method; the free pertechnetate content was always under 1%. The (/sup 99m/Tc)APD T1/2 of the third component of the disappearance plasma curve in six normal subjects was 152 +/- 46 min (mean +/- s.d.), while the 24-hr whole-body retention (WBR) was 17.6% +/- 4.6. The (99mTc)MDP value of the 24-hr WBR was 28.6% +/- 3.9. The bone/soft-tissue ratio (B/ST) was investigated in eight control subjects on the eleventh thoracic and the fourth lumbar vertebrae. The B/ST ratios were similar for both APD and MDP studies. In 28 patients with suspected bone metastasis or primary bone disease, bone scintigraphy was carried out; both compounds showed similar findings and the same number of positive results. In five of these patients, the lesion/normal bone ratio was determined with values of 4.6 +/- 2.0 in APD studies and 4.8 +/- 2.3 with MDP. APD was also used in 126 patients; no adverse reactions were observed. The APD dose used i.v. for bone scanning was 200-fold less than those employed by mouth per day, for the treatment of bone disease for long periods. In our experience, APD appears to be an adequate agent for bone scintigraphy.

Degrossi, O.J.; Oliveri, P.; Garcia del Rio, H.; Labriola, R.; Artagaveytia, D.; Degrossi, E.B.

1985-10-01

9

Accelerator Generation and Thermal Separation (AGATS) of Technetium-99m  

SciTech Connect

Accelerator Generation and Thermal Separation (AGATS) of Technetium-99m is a linear electron accelerator-based technology for producing medical imaging radioisotopes from a separation process that heats, vaporizes and condenses the desired radioisotope. You can learn more about INL's education programs at http://www.facebook.com/idahonationallaboratory.

None

2010-01-01

10

Myocardial redistribution of technetium-99m-methoxyisobutyl isonitrile (SESTAMIBI)  

SciTech Connect

To determine whether technetium-99m-hexakis-2-methoxyisobutyl isonitrile (SESTAMIBI) remains fixed in the myocardium following its initial uptake or undergoes time-related redistribution, anesthetized dogs underwent occlusion of the anterior descending coronary artery for 6 min, followed by 3-hr reperfusion. Technetium-99m-SESTAMIBI and thallium-201 (201Tl) were injected intravenously after 1 min occlusion and regional myocardial blood flow was measured with radioactive microspheres. Tomographic imaging of Tc-SESTAMIBI revealed a perfusion defect with slight but definite filling in over 2 hr. Quantitative analysis indicated a significant rise in the nadir and decrease in the width of the defect in circumferential profile curves. After 3-hr of reperfusion, Tc-SESTAMIBI activity in the previously ischemic area was always greater than the activity of microspheres injected during coronary occlusion (mean normalized values, 0.32 versus 0.11, p less than 0.0001). Our results indicate that following transient ischemia and reperfusion, Tc-SESTAMIBI clearly undergoes myocardial redistribution, although more slowly and less completely than {sup 201}Tl.

Li, Q.S.; Solot, G.; Frank, T.L.; Wagner, H.N. Jr.; Becker, L.C. (Johns Hopkins Medical Institutions, Baltimore, MD (USA))

1990-06-01

11

Detection of esophageal ulcerations with technetium-99m albumin sucralfate  

SciTech Connect

Technetium-99m albumin-sucralfate ((/sup 99m/Tc)Su) can be used to demonstrate peptic ulcer disease in man and animals. We evaluated the usefulness of (/sup 99m/Tc)Su for detecting various grades of esophagitis. (/sup 99m/Tc)Su adhered to the distal esophagus for up to 3 hr in five of six patients with esophageal ulcers but adhered to only two of nine with lesser degrees of esophagitis. No adherence was seen in five patients without esophagitis. Thus, (/sup 99m/Tc)Su may not be useful for detecting any but the most severe grade of esophagitis. Based on these results, we speculate that the previously documented beneficial effects of sucralfate on mild to moderate esophagitis may be due to other mechanisms besides adherence to the ulcerated mucosa.

Goff, J.S.; Adcock, K.A.; Schmelter, R.

1986-07-01

12

Imaging considerations for a technetium-99m myocardial perfusion agent  

SciTech Connect

Myocardial perfusion imaging with /sup 201/Tl chloride suffers from a number of physical, geometric, and dosimetric constraints that could be diminished if an agent labeled with /sup 99m/Tc were available. The cationic complex /sup 99m/Tc hexakis-(t-butylisonitrile)technetium(I) ((/sup 99m/Tc)TBI) has been shown to concentrate in the myocardial tissue of both animals and humans, with preliminary clinical studies demonstrating a number of technical attributes not possible with /sup 201/Tl. Technetium-99m-TBI is a promising myocardial imaging agent that may permit high quality planar, gated, and tomographic imaging of both myocardial ischemia and infarction with reduced imaging times and improved resolution.

English, R.J.; Jones, A.G.; Davison, A.; Lister-James, J.; Campbell, S.; Holman, B.L.

1986-03-01

13

Sustained Availability of Technetium-99m - Possible Paths Forward  

SciTech Connect

The availability of technetium-99m (99mTc) for single-photon imaging in diagnostic nuclear medicine is crucial, and current availability is based on the molybdenum-99 (99Mo)/99mTc generator fabricated from fission-based molybdenum (F 99Mo) produced by use of highly enriched uranium (HEU) targets. The use of HEU targets is being phased out because of risks related to nuclear material proliferation, so alternative strategies for production of both 99Mo and 99mTc are being evaluated intensely. There are evidently no plans for replacement of the limited number of reactors that have primarily provided most of the 99Mo. The uninterrupted, dependable availability of 99mTc is a crucial issue. For these reasons, new options being pursued include both reactor- and accelerator-based strategies to sustain the continued availability of 99mTc without the use of HEU. In this paper the scientific and economic issues for transitioning from HEU to non-HEU are also discussed. In addition, the comparative advantages, disadvantages, technical challenges, present status, future prospects, security concerns, economic viability, and regulatory obstacles are reviewed. In addition, the international actions in progress towards evolving possible alternative strategies to produce 99Mo and/or 99mTc are analyzed. The breadth of technologies and new strategies under development to provide 99Mo and 99mTc reflects both the broad interest in and the importance of the pivotal role of 99mTc in diagnostic nuclear medicine.

Pillai, M R A [Bhabha Atomic Research Centre, Mumbai, India; Dash, A [Bhabha Atomic Research Centre, Mumbai, India; Knapp Jr, Russ F [ORNL

2013-01-01

14

Evaluation of focal defects on technetium-99m sulfur colloid scans with new hepatobiliary agents  

SciTech Connect

In 3600 patients evaluated with technetium-99m sulfur colloid for metastatic liver disease, 40 had equivocal scans due to a solitary defect in the inferior margin of the right lobe. In these patients, the authors differentiated the gallbladder fossa from a metastatic focus using one of two new hepatobiliary agents: technetium-99m labeled pyridoxylideneglutamate and paraisopropylacetanilido iminodiacetic acid. The need for laparoscopic biopsy was obviated in a majority (78%) of the patients by identifying the gallbladder fossa.

Rao, B.K.; Pastakia, B.; Lieberman, L.M.

1980-08-01

15

Lung deposition of aerosol—a comparison of different spacers  

Microsoft Academic Search

AIMSTo investigate (1) aerosol lung deposition obtained from two small volume conventional spacers (Babyhaler and Aerochamber) and a home made spacer (modified 500 ml plastic cold drink bottle); (2) the effect of using a face mask or mouthpiece; and (3) the relation between age and pulmonary deposition.METHODSLung deposition of aerosolised technetium-99m DTPA inhaled via spacer was measured in 40 children

H J Zar; E G Weinberg; H J Binns; F Gallie; M D Mann

2000-01-01

16

Extracranial metastatic glioblastoma: Appearance on thallium-201-chloride/technetium-99m-HMPAO SPECT images  

SciTech Connect

Sequential thallium-201-chloride and technetium-99m-hexamethylpropyleneamine oxime single-photon emission computed tomography (SPECT) images were obtained in a patient with extracranial metastatic glioblastoma multiforme. Thallium-201 uptake was high (three times the scalp background) in all pathologically confirmed extracranial metastases and moderate (1.6 times scalp background) intracranially, where most biopsy specimens showed gliosis with scattered atypical astrocytes. Technetium-99m-HMPAO uptake was decreased intracranially in the right frontal and parietal lobes which had been irradiated. It was also decreased in one well-encapsulated scalp lesion and high in another scalp mass with less defined borders. Possible mechanisms of tumor uptake of these agents are reviewed.

Carvalho, P.A.; Schwartz, R.B.; Alexander, E. III; Loeffler, J.S.; Zimmerman, R.E.; Nagel, J.S.; Holman, B.L. (Brigham and Women's Hospital, Boston, MA (USA))

1991-02-01

17

Demonstration of reperfusion after thrombolysis with technetium-99m isonitrile myocardial imaging  

SciTech Connect

Technetium-99m isonitrile myocardial perfusion imaging was employed in a patient undergoing thrombolytic therapy with recombinant tissue plasminogen activator for acute anteroseptal myocardial infarction. Technetium-99m isonitrile does not demonstrate significant myocardial redistribution after intravenous injection. The imaging agent was administered in the emergency room, prior to the initiation of thrombolytic therapy. The initial area at risk for infarction was visualized on images obtained after the patient had been effectively treated. Imaging performed 5 days later, after repeat injection of (99mTc)isonitrile, showed a smaller myocardial perfusion defect indicating salvage of myocardium. Thus, this technique offers promise as a noninvasive means of assessing the area at risk, the success of reperfusion, and the presence of salvaged myocardium, early in the course of acute myocardial infarction.

Kayden, D.S.; Mattera, J.A.; Zaret, B.L.; Wackers, F.J.

1988-11-01

18

The value of technetium99m pyrophosphate scanning in the diagnosis of myocardial contusion  

SciTech Connect

Twelve patients who sustained significant blunt chest trauma and had abnormal electrocardiographic changes unrelated to hypotension, hypoxia, or pre-existing myocardial disease were studied prospectively during a one-year period. The patients were divided into two groups on the basis of serum creatine phosphokinase (CPK)/MB isoenzyme concentrations: Group A (six patients) had normal CPK/MB isoenzymes (less than 8 IU), and Group B (six patients) had elevated CPK/MB isoenzymes (greater than 8 IU). All patients underwent cardiac scanning with technetium99m pyrophosphate. All studies were interpreted as normal. These data suggest that technetium99m pyrophosphate scanning is not a reliable adjunctive test to confirm myocardial contusion in patients with significant blunt trauma of the chest. However, the diagnosis of myocardial contusion in such patients can be established by the presence of abnormal electrocardiographic changes associated with an elevation of the serum CPK/MB isoenzyme concentration.

Rodriguez, A.; Shatney, C.

1982-09-01

19

Technetium99m hexamethylpropylene amine oxime single photon emission tomography in febrile convulsions  

Microsoft Academic Search

We report our initial experience with technetium-99m hexamethyl propylene amine oxime (99mTC-HMPAO) brain single photon emission tomography (SPET) in the investigation of 19 children presenting with febrile convulsions. Two patients with complex febrile convulsions showed focal SPET lesions contralateral to the neurological deficit. However, in 9 out of 17 patients with simple febrile convulsions, focally disturbed perfusion was shown. In

R. A. Dierckx; K. Melis; L. Dom; G. Janssens; E. Luysterborgh; P. P. Deyn; J. Vandevivere

1992-01-01

20

Technical aspects of myocardial SPECT imaging with technetium-99m sestamibi  

Microsoft Academic Search

Most reports to date using single photon emission computed tomography (SPECT) with technetium-99m (Tc-99m) sestamibi have used acquisition parameters that were optimized for thallium-201. To fully utilize the superior imaging characteristics of Tc-99m sestamibi, there is a need to optimize the technical aspects of SPECT imaging for this agent. Performance can be enhanced through the careful selection of optimal radiopharmaceutical

Ernest V. Garcia; C. David Cooke; Kenneth F. Van Train; Russell Folks; John Peifer; E. Gordon DePuey; Jamshid Maddahi; Naomi Alazraki; James Galt; Norberto Ezquerra

1990-01-01

21

A Case of Cerebral Sparganosis : Technetium99mECD Brain SPECT experience  

Microsoft Academic Search

Cerebral sparganosis is a rare intracranial parasitic infectious disease. The best treatment seems to be the surgical removal of the worm and granuloma. However, it has not been proved possible to determine whether the worm is dead or alive by a single Brain CT or MRI findings. We report clinical and technetium-99m-ethyl cysteinate dimer (99mTc- ECD) cerebral perfusion SPECT findings

Sang Won Han; Dong Chul Park; Byung In Lee

22

Evaluation of technetium-99m phosphate imaging for predicting skin ulcer healing  

SciTech Connect

We have developed criteria for radionuclide angiography to assess skin ulcer perfusion as an indicator of healing capacity. Twenty-six studies were performed on 21 consecutive patients with nonhealing ulcers of the lower leg; 20 mCi of technetium-99m phosphate was injected intravenously with immediate sequential scintillation camera imaging of the ulcer and surrounding area at 2 second intervals, followed by blood pool and delayed static images. Two radiologists without clinical bias graded the perfusion to the ulcer on the images as normal, increased, or reduced with respect to the opposite limb. Patients were either followed as outpatients for more than 10 days, as inpatients for at least 10 days, or both to determine whether ulcers showed clinical evidence of wound healing with optimal outpatient and in-hospital care. Of the 17 patients whose ulcers healed, imaging with technetium-99m phosphate predicted the outcome in 16. In nine patients the ulcers did not heal. This was correctly predicted by technetium-99m phosphate in eight of the patients. Overall, the sensitivity was 94 percent and the specificity was 89 percent. This technique appears to be a simple, reliable way to predict the microcirculatory adequacy for ulcer healing.

Lawrence, P.F.; Syverud, J.B.; Disbro, M.A.; Alazraki, N.

1983-12-01

23

Technical considerations in gastric ulcer localization using technetium-99m sucralfate  

SciTech Connect

After the completion and evaluation of 17 patients studies using technetium-99m-labeled sucralfate for the detection of ulcerated areas, the authors felt that the technical aspects of the studies should be evaluated. The factors for evaluation are: the time the patient is kept fasting; the time the patient is being imaged and rotated for various anatomic views; the technologist time and camera time that are involved in one study; and the cost factor of the testing procedure. Based on the findings of their small sample of patients, the sensitivity of the test is uncertain.

Garrett, S.G.; Wcislo, W.J.

1985-09-01

24

Technetium-99m-HIDA visualization of an obstructed gallbladder via an accessory hepatic duct  

SciTech Connect

Technetium-99m-labeled iminodiacetic acid (HIDA) and paraisopropyliminodiacetic acid (PIPIDA) scintigraphy after sonographic evaluation of the gallbladder have been advocated recently for the diagnosis of acute obstructive cholecystitis and cholelithiasis. Several authors have stated or inferred that gallbladder visualization with /sup 99m/Tc-HIDA excludes acute cholecystitis and cystic duct obstruction. We describe a patient with surgically proven cystic duct obstruction whose gallbladder visualized on a /sup 99m/Tc-HIDA scan via an accessory hepatic duct which directly entered the gallbladder.

Reimer, D.E.; Donald, J.W.

1981-09-01

25

Effect of mitochondrial viability and metabolism on technetium-99m-sestamibi myocardial retention  

Microsoft Academic Search

This study investigated the mechanism of myocardial retention of technetium-99m-sestamibi.99mTc-sestamibi was injected intravenously into guinea pigs, and the myocardium was homogenized and fractionated by differential centrifugation. More than 90% of myocardial99mTc-sestamibi was localized within the mitochondrial fraction. Calcium was found to release99mTc-sestamibi from the mitochondrial fraction, with an IC50 of 2.54±0.98 mM. This effect was potentiated by NaCl, and inhibited

Paul Crane; Robert Laliberté; Stuart Heminway; Martin Thoolen; Cesare Orlandi

1993-01-01

26

Technetium-99m pyrophosphate imaging in acute renal failure associated with nontraumatic rhabdomyolysis  

SciTech Connect

Technetium-99m pyrophosphate (Tc-PYP) imaging was performed in five patients with acute renal failure associated with nontraumatic rhabdomyolysis. Four patients had phencyclidine intoxication and one had viral pneumonia. During the acute phase, marked uptake of pyrophosphate was seen in all patients in several muscle groups, but always in the thigh adductors. The results show that phencyclidine intoxication can result in diffuse muscle uptake of Tc-PYP without overt evidence of muscle injury. Tc-PYP imaging may provide a clue to the cause of acute renal failure in patients with suspected rhabdomyolysis in whom elevations of serum creatine phosphokinase concentrations are equivocal.

Patel, R.; Mishkin, F.S.

1986-10-01

27

Technetium-99m HIDA hepatobiliary scanning in evaluation of afferent loop syndrome  

SciTech Connect

A study of 118 patients, operated on with Billroth II gastrectomy for peptic disease and affected by postgastrectomy syndromes, was carried out. Fifty patients were investigated by means of technetium-99m HIDA hepatobiliary scanning. In 18 patients, in whom an afferent loop syndrome was clinically suspected, hepatobiliary scanning demonstrated an altered afferent loop emptying in 8 and atonic distension of the gallbladder without afferent loop motility changes in 10. Among the patients in the first group, four were treated with a biliary diversion surgical procedure and in the second group, two patients underwent cholecystectomy. Our findings indicate that biliary vomiting, right upper abdominal pain pyrosis, and biliary diarrhea in Billroth II gastrectomized patients are not always pathognomonic symptoms of afferent loop syndrome. Technetium-99m HIDA hepatobiliary scanning represents the only diagnostic means of afferent loop syndrome definition. A differential diagnosis of abnormal afferent loop emptying and gallbladder dyskinesia is necessary for the management planning of these patients, and furthermore, when a surgical treatment is required, biliary diversion with Roux-Y anastomosis or Braun's biliary diversion seems the treatment of choice for afferent loop syndrome, whereas cholecystectomy represents the best procedure for atonic distension of the gallbladder.

Sivelli, R.; Farinon, A.M.; Sianesi, M.; Percudani, M.; Ugolotti, G.; Calbiani, B.

1984-08-01

28

Sensitivity of technetium-99m-pyrophosphate scintigraphy in diagnosing cardiac amyloidosis  

SciTech Connect

To determine the value of technetium-99m-pyrophosphate myocardial scintigraphy in the diagnosis of amyloid heart disease this procedure was prospectively performed in 20 consecutive patients with biopsy-proven primary amyloidosis. Eleven patients had echocardiographic abnormalities compatible with amyloid cardiomyopathy, 9 of whom had congestive heart failure. Diffuse myocardial pyrophosphate uptake was of equal or greater intensity than that of the ribs in 9 of the 11 patients with echocardiograms suggestive of amyloidosis, but in only 2 of the 9 with normal echocardiograms, despite abnormal electrocardiograms (p less than 0.01). Increased wall thickness measured by M-mode echocardiography correlated with myocardial pyrophosphate uptake (r . 0.68, p less than 0.01). None of 10 control patients with nonamyloid, nonischemic heart disease had a strongly positive myocardial pyrophosphate uptake. Thus, myocardial technetium-99m-pyrophosphate scanning is a sensitive and specific test for the diagnosis of cardiac amyloidosis in patients with congestive heart failure of obscure origin. It does not appear to be of value for the early detection of cardiac involvement in patients with known primary amyloidosis without echocardiographic abnormalities.

Falk, R.H.; Lee, V.W.; Rubinow, A.; Hood, W.B. Jr.; Cohen, A.S.

1983-03-01

29

Influence of tobacco on the labelling of red blood cells and plasma proteins with technetium-99m.  

PubMed

Technetium-99m-labelled red blood cells (RBC) have been used as radiopharmaceutical in nuclear medicine. The influence of drug interaction in this labelling process has been described along with the biological effects of tobacco on the labelling of blood elements with technetium-99m. The labelling of RBC and plasma proteins can be decreased in presence of tobacco. This can be due to either a direct or indirect effect (reactive oxygen species) of tobacco by (i) oxidation of the stannous ion, (ii) possible damages caused in plasma membrane and/or (iii) possible chelating action on the stannous and/or pertechnetate ions. PMID:9646232

Vidal, M V; Gutfilen, B; da Fonseca, L M; Bernardo-Filho, M

1998-03-01

30

Assessment of alveolar epithelial permeability with Tc-99m DTPA aerosol scintigraphy in patients with Sjogren syndrome.  

PubMed

Sjögren's syndrome (SjS) is a systemic autoimmune disease that mainly affects the exocrine glands and usually presents as persistent dryness of the mouth and eyes. Lung disease in SjS has been reported to occur early following clinical presentation of the disease. In this study, technetium-99m diethylene triamine penta-acetic acid (Tc-99m DTPA) aerosol inhalation scintigraphy was used to assess the pulmonary membrane permeability in patients with primary SjS. A total of 18 patients with primary SjS and 13 healthy controls were investigated. Clinical evaluation, chest X-ray examination, pulmonary function tests, Tc-99m DTPA aerosol scintigraphy were performed in all the cases. The presence of respiratory symptoms (dyspnea and cough), duration of sicca symptoms were recorded. The clearance half time of Tc-99m DTPA radioaerosols in patients with SjS (20.49 +/- 2.56 min) was faster when compared to normal controls (42.32 +/- 13.28 min) (P = 0.000) which means that there is a significant increase in lung permeability in patients with SjS compared to the controls. There is also a significant difference between PI of patients with SjS (0.34 +/- 0.09) and that of controls (0.42 +/- 0.07) (P = 0.012). According to the results of our preliminary study, one can detect pulmonary involvement by Tc-99m DTPA aerosol inhalation scintigraphy in patients with primary SjS. PMID:19582462

Pirildar, Timur; Gumuser, Gul; Ruksen, Ebru; Sakar, Aysin; Dinc, Gonul; Sayit, Elvan

2010-03-01

31

The role of technetium-99m iminodiacetic acid (IDA) cholescintigraphy in acute acalculous cholecystitis  

SciTech Connect

Technetium-99m iminodiacetic acid (IDA) cholescintigraphy was performed in 15 patients with acute acalculous cholecystitis. Fourteen of the 15 patients with acute disease had positive findings, indicating the presence of cystic duct or common duct obstruction. One case in which the gallbladder was visualized failed to respond to sincalide stimulation; this was classified as a suggestive finding of disease. The diagnostic accuracy of /sup 99//sup m/Tc-IDA cholescintigraphy was far superior to the other imaging studies used (8 sonograms, 1 intravenous cholangiogram, 3 oral cholecystograms, 1 percutaneous transhepatic cholangiogram). The /sup 99//sup m/Tc-IDA study is recommended as the imaging procedure of choice for examining patients with suspected acute acalculous cholecystitis.

Weissmann, H.S. (Montefiore Hospital and Medical Center, Bronx, NY); Berkowitz, D.; Fox, M.S.; Gliedman, M.L.; Rosenblatt, R.; Sugarman, L.A.; Freeman, F.M.

1983-01-01

32

The role of technetium-99m iminodiacetic acid (IDA) cholescintigraphy in acute acalculous cholecystitis  

SciTech Connect

Technetium-99m iminodiacetic acid (IDA) cholescintigraphy was performed in 15 patients with acute acalculous cholecystitis. Fourteen of the 15 patients with acute disease had positive findings, indicating the presence of cystic duct or common duct obstruction. One case in which the gallbladder was visualized failed to respond to sincalide stimulation; this was classified as a suggestive finding of disease. The diagnostic accuracy of /sup 99m/Tc-IDA cholescintigraphy was far superior to the other imaging studies used (8 sonograms, 1 intravenous cholangiogram, 3 oral cholecystograms, 1 percutaneous transhepatic cholangiogram). The /sup 99m/Tc-IDA study is recommended as the imaging procedure of choice for examining patients with suspected acute acalculous cholecystitis.

Weissmann, H.S.; Berkowitz, D.; Fox, M.S.; Gliedman, M.L.; Rosenblatt, R.; Sugarman, L.A.; Freeman, L.M.

1983-01-01

33

Diagnosis of acute cholecystitis using hepatobiliary scan with technetium-99m PIPIDA  

SciTech Connect

Sixty patients were evaluated for acute abdominal pain using technetium-99m PIPIDA hepatobiliary imaging. The sensitivity of the test was 90.6 percent in all patients and the accuracy was 93.3 percent. In the evaluation of acutely ill patients with right upper quadrant pain, fever, nausea and vomiting, hepatobiliary imaging with PIPIDA is the preferred test for diagnosing acute cholecystitis. If the test is positive, disease of the gallbladder and probably acute cholecystitis are present. Early operation can proceed if desirable. If the test is negative and the bilirubin level is less than 5.0 mg/dl, acute cholecystitis is not present. In such cases conservative treatment is appropriate, and follow-up tests should be performed to evaluate the possibility of chronic cholecystitis. When the bilirubin level exceeds 5.0 mg/dl, the test is often indeterminate.

Bennett, M.T.; Sheldon, M.I.; dos Remedios, L.V.; Weber, P.M.

1981-09-01

34

Effect of reperfusion and hyperemia on the myocardial distribution of technetium-99m t-butylisonitrile  

SciTech Connect

Technetium-99m t-butylisonitrile ((/sup 99m/Tc)TBI) is a promising new radiotracer for myocardial imaging. Its myocardial uptake is sufficiently high in humans to permit planar, tomographic, and gated images of excellent technical quality. We studied the behavior of (/sup 99m/Tc)TBI in the dog at rest and under conditions of hyperemia and reperfusion in order to determine the relationship between (/sup 99m/Tc)TBI myocardial concentration and blood flow. After permanent occlusion of the left anterior descending artery, the correlation between the relative myocardial concentration of (/sup 99m/Tc)TBI and regional myocardial blood flow (RMBF) measured with radiolabeled microspheres was excellent. In a dog model of transient hyperemia, the concentration of (/sup 99m/Tc)TBI was directly related to blood flow but underestimated the degree of hyperemia. Technetium-99m TBI redistributed into transiently ischemic myocardium. The myocardial concentrations of (/sup 99m/Tc)TBI and thallium-201(/sup 201/TI) in transiently ischemic myocardium were similar at 10 and 30 min following reperfusion and were significantly higher than blood flow prior to reperfusion. When (/sup 99m/Tc)TBI was injected into the left anterior descending artery, the washout was slow, falling to 78% of initial activity at 120 min after injection. In conclusion, (/sup 99m/Tc)TBI reflects regional myocardial blood flow accurately in ischemic and normal resting myocardium and underestimates blood flow at high flows. The rate of myocardial redistribution after reperfusion is similar for (/sup 99m/Tc)TBI and /sup 201/TI.

Holman, B.L.; Campbell, C.A.; Lister-James, J.; Jones, A.G.; Davison, A.; Kloner, R.A.

1986-07-01

35

Comparison of technetium-99m MAG3 kit with HPLC-purified technetium-99m MAG3 and OIH in rats.  

PubMed

Technetium-99m (99mTc) mercaptoacetylglycylglycylyglycine (MAG3) in high (greater than or equal to 95%) radiochemical purity is prepared from lyophilized kits containing benzoylMAG3, sodium tartrate, lactose, and stannous chloride by adding sodium [99mTC]pertechnetate and heating the contents briefly. Constant-infusion renal whole-blood clearance obtained with [99mTc] MAG3 kits was compared with that obtained with high performance liquid chromatography (HPLC) pure [99mTc]MAG3 and with co-infused iodine-131 (131I) iodohippurate (OIH) in anesthetized rats. Average renal whole-blood clearance of [99mTc]MAG3 from kits was 3.9 +/- 0.4 ml/min/100 g body weight (mean +/- s.e.m. n = 5) and that for HPLC-pure [99mTc]MAG3 was 4.6 +/- 0.3 (n = 3). Renal whole-blood clearance ratios for [99mTc]MAG3 to co-infused iodine-131 (131I) OIH were greater than unity for both kit formulation (1.7 +/- 0.1) and HPLC-pure [99mTc]MAG3 (1.9 +/- 0.2). Differences in these two measures were not significant. Plasma binding (determined from blood drawn at the end of the infusion) of [99mTc]MAG3 prepared from both kits (75 +/- 2%, n = 4) and HPLC-separation (76 +/- 4%) were greater than that of [131I]OIH in corresponding plasma samples (31 +/- 1% and 32 +/- 2%) respectively). Renograms performed in anesthetized rats revealed no statistically significant differences between kit-prepared [99mTc]MAG3 and [131I]OIH in terms of time-to-peak renal activity (5.0 +/- 1.7 min, n = 6; and 2.2 +/- 0.2 min, n = 3, mean +/- s.e.m. for [99mTc]MAG3 and [131I]OIH, respectively), in terms of time to fall to half-maximal activity (15.3 +/- 2.4 min and 9.6 +/- 2.1 min, respectively), or in terms of fraction of peak radioactivity in right kidney (0.53 +/- 0.01 for both substances). To assess possible interference from hepatobiliary uptake and excretion in renal failure, radioactivity in liver regions of interest was followed by gamma camera scintigraphy for 30 min after intravenous injection of [131I]OIH and kit and HPLC-purified [99mTc]MAG3 in anesthetized rats rendered anephric by ligating renal peduncles. Liver activity was 25% of total for both preparations of [99mTc]MAG3 and was 22% of total for [131I]OIH. There were no significant differences among the substances. PMID:2960790

Coveney, J R; Robbins, M S

1987-12-01

36

Use of technetium-99m disofenin clearance as a test for hepatic function  

SciTech Connect

Technetium-99m disofenin is one of the newest of several radioactive labeled iminodiacetic-acid derivatives used to visualize the gallbladder and associated biliary structures. This study examined the pharmacokinetics of disofenin to investigate its ability to distinguish quantitatively hepatobiliary disease from non-disease states, and to determine the association between the clearance of disofenin and enzyme markers of hepatic dysfunction. A total of 30 subjects were studied. Six healthy volunteers and three patients who had no evidence of liver disease served as controls. The test group was 20 patients with various disorders of liver function. A second test group consisted of four patients receiving total parental nutrition (TPN) who had suspected cholestasis. Following an intravenous injection of disofenin, blood samples were collected at 2 to 90 minutes after the dose was given, and the radioactivity of each specimen was measured. Simultaneous external scintillation counting directly over the liver occurred during the 90 minutes. In patients studies, plasma total body clearance, C1(T), and half-life of liver excretion. T1/2(E), provided the best discrimination between the control group and the test groups. The C1(T) was particularly sensitive to both severe and milder forms of liver/biliary disease.

Love, J.E. Jr.

1985-01-01

37

Technetium-99m-Labeled Autologous Serum Albumin: A Personal-Exclusive Source of Serum Component  

PubMed Central

Technetium-99m human serum albumin (99mTc-HSA) is an important radiopharmaceutical required in nuclear medicine studies. However, the risk of transfusion-transmitted infection remains a major safety concern. Autopreparation of serum component acquired from patient provides a “personal-exclusive” source for radiolabeling. This paper is to evaluate the practicality of on-site elusion and subsequent radiolabeling efficacy for serum albumin. Results showed that the autologous elute contained more albumin fraction than serum without extraction procedure. Good radiochemical purity and stability were demonstrated after radiolabeling. Biodistribution study showed that labeled albumin accumulated immediately in the lung, liver, and kidney. It was cleared steadily and excreted in the urine. The biologic half-life was defined, and all samples passed the pyrogenicity and sterility tests. In conclusion, autoalbumin could be extracted and radiolabeled properly in a nuclear medicine setting. Moreover, the risk of transfusion-transmitted infection associated with nonautologous, multisource 99mTc-HSA agents can be reduced. PMID:21541233

Wang, Yuh-Feng; Chen, Yi-Chun; Li, Dian-Kun; Chuang, Mei-Hua

2011-01-01

38

A propolis extract and the labeling of blood constituents with technetium-99m.  

PubMed

Since ancient times propolis has been employed for many human purposes because to their favourable properties. Blood constituents labeled with technetium-99m (99mTc) have been used in nuclear medicine procedures. Some authors have reported that synthetic or natural drugs can interfere with the labeling of blood constituents with 99mTc. The aim of this work was to evaluate the action of a propolis extract on the labeling of blood elements with 99mTc. Samples of whole blood of male Wistar rats were incubated in sequence with an aqueous propolis extract at different concentrations, stannous chloride and 99mTc, as sodium pertechnetate. Blood samples were centrifuged to separate plasma and blood cells, soluble and insoluble fractions of plasma and blood cells were also separated after precipitation in trichloroacetic acid solution and centrifugation. The radioactivity was counted and the percentage of incorporated radioactivity (%ATI) for each fraction was calculated. The data obtained showed that the aqueous propolis extract used decreased significantly the %ATI in plasma proteins at higher concentration studied. Results suggest that at high concentration the constituents of this extract could alter the labeling of plasma proteins competing with same binding sites of the 99mTc on the plasma proteins or acting as antioxidant compounds. PMID:16841470

Jesus, L M; Abreu, P R C; Almeida, Marcela C; Brito, Lavínia C; Soares, Sheila F; de Souza, D E; Bernardo, Luciana C; Fonseca, A S; Bernardo-Filho, M

2006-06-01

39

Usefulness of early positive technetium-99m stannous pyrophosphate scan in predicting reperfusion after thrombolytic therapy for acute myocardial infarction  

Microsoft Academic Search

To test the hypothesis that scans with technetium-99m pyrophosphate (Tc-99m-PPi) are positive when performed early after successful thrombolytic therapy for acute myocardial infarction (AMI), 16 consecutive patients with AMI who received thrombolytic therapy within 5 hours after the onset of chest pain were studied. Patients were included if chest pain lasted for greater than 30 minutes, was unresponsive to sublingual

D. E. Manyari; C. R. Thompson; H. J. Duff; M. L. Knudtson; R. Kloiber; E. R. Smith; I. Belenkie

1988-01-01

40

Sipple's syndrome with liver tumors examined by iodine-131 MIBG and technetium-99m(V)-DMSA  

Microsoft Academic Search

This case report describes the localization and categorization of tumors using \\/sup 99m\\/Tc(V)-dimercaptosuccinic acid and (¹³¹I)metaiodobenzylguanidine scans in a very uncommon case of medullary thyroid carcinoma associated with pheochromocytoma (Sipple's syndrome) and hepatocellular carcinoma. Technetium-99m(V)-dimercaptosuccinic acid showed accumulation only in medullary thyroid carcinoma, but (¹³¹I)metaiodobenzylguanidine scans were positive in both medullary thyroid carcinoma and pheochromocytoma. In advanced Sipple's syndrome, combined

H. Ohta; K. Endo; T. Fujita; M. Koizumi; J. Konishi; A. Maki; K. Mori; K. Ozawa; G. Inoue; Y. Nakano

1988-01-01

41

Rapid diagnosis of pedal osteomyelitis in diabetics with a technetium-99m-labeled monoclonal antigranulocyte antibody  

Microsoft Academic Search

An in vivo method of labeling white cells that diagnoses diabetic pedal osteomyelitis safely, rapidly, and accurately is desirable. The objectives of this investigation were to evaluate a technetium-99m-labeled monoclonal antigranulocyte antibody for diagnosing diabetic pedal osteomyelitis, compared with indium-111-labeled leukocyte and 3-phase bone imaging for this purpose. Twenty-five diabetic patients with pedal ulcers, 22 in the forefoot and 3

Christopher J. Palestro; Russell Caprioli; Charito Love; Hugh L. Richardson; Samuel L. Kipper; Frederick L. Weiland; Maria B. Tomas

2003-01-01

42

Early detection of the no-reflow phenomenon in reperfused acute myocardial infarction using technetium-99m tetrofosmin imaging  

Microsoft Academic Search

.   Evaluation of myocardial perfusion in the early stage of acute myocardial infarction (MI) is clinically important for adjunctive\\u000a therapies to minimize infarct size. To determine the role of early scintigraphic detection of impaired myocardial reperfusion\\u000a after primary coronary angioplasty (PTCA) in patients with acute MI, semiquantitative technetium-99m tetrofosmin single-photon\\u000a emission tomographic (SPET) imaging was performed before primary PTCA (before;

Shinichi Hamada; Seishi Nakamura; Tetsuro Sugiura; Takashi Murakami; Toshinori Fujimoto; Junko Watanabe; Masato Baden; Kengo Hatada; Toshiji Iwasaka

1999-01-01

43

Myocardial perfusion imaging with technetium-99m sestamibi SPECT in the evaluation of coronary artery disease  

SciTech Connect

Technetium-99m (Tc-99m) sestamibi is a new myocardial perfusion imaging agent that offers significant advantages over thallium-201 (Tl-201) for myocardial perfusion imaging. The results of the current clinical trials using acquisition and processing parameters similar to those for Tl-201 and a separate (2-day) injection protocol suggest that Tc-99m sestamibi and Tl-201 single photon emission computed tomography (SPECT) provide similar information with respect to detection of myocardial perfusion defects, assessment of the pattern of defect reversibility, overall detection of coronary artery disease (CAD) and detection of disease in individual coronary arteries. Tc-99m sestamibi SPECT appears to be superior to Tc-99m sestamibi planar imaging because the former provides a higher defect contrast and is more accurate for detection of disease in individual coronary arteries. Research is currently under way addressing optimization of acquisition and processing of Tc-99m sestamibi studies and development of quantitative algorithms for detection and localization of CAD and sizing of transmural and nontransmural myocardial perfusion defects. It is expected that with the implementation of the final results of these new developments, further significant improvement in image quality will be attained, which in turn will further increase the confidence in image interpretation. Development of algorithms for analysis of end-diastolic myocardial images may allow better evaluation of small and nontransmural myocardial defects. Furthermore, gated studies may provide valuable information with respect to regional myocardial wall motion and wall thickening. With the implementation of algorithms for attenuation and scatter correction, the overall specificity of Tc-99m sestamibi SPECT should improve significantly. 32 references.

Maddahi, J.; Kiat, H.; Van Train, K.F.; Prigent, F.; Friedman, J.; Garcia, E.V.; Alazraki, N.; DePuey, E.G.; Nichols, K.; Berman, D.S. (Cedars-Sinai Medical Center, Los Angeles, CA (USA))

1990-10-16

44

Technetium-99m Bone Scan and Panoramic Radiography in Detection of Bone Invasion by Oral Carcinoma  

PubMed Central

Objective: The correct extension of cancer in the bone usually remains undetected on static imaging which may lead to inadequate or over excision. The conventional radiography as well as other anatomical imaging modalities like computed tomography, magnetic resonance imaging often fails to detect functional changes in the bone. However, bone scinitigraphy is highly sensitive in detecting earlier changes in the bone but lack anatomical definition. The purpose of the study was to evaluate the accuracy of combining technetium-99m bone scan and panoramic radiography (Tc scan/PR) over using single diagnostic modality in detection of jaw bone invasion by oral carcinomas. The accuracy of these imaging modalities either alone or in combination were determined by comparing with the histopathological findings. Materials and Methods: Twenty patients with biopsy-proven oral malignant tumors were randomly selected from Oral Medicine and Radiology department over a period of two years. All patients were investigated preoperatively by Tc scan and PR. Lewis – Jones’s designed diagnostic criterion was applied on Tc scan/PR to evaluate bone involvement by cancer. To test the accuracy of Tc scan, PR and Tc scan/PR, their results were compared with the histopathological findings of resected specimen. Results: Hybrid Tc scan/PR had higher specificity, accuracy and positive predictive value (83.3%, 94.7%, 92.8%) than Tc scan alone (50%, 84.2%, 81.2%) and higher sensitivity and negative predictive value (100%, 100%) than PR (69.2%, 55.5%). Conclusion: Combination of Tc scan and PR was more accurate in detecting jaw bone invasion by oral squamous cell carcinoma than Tc scan and PR alone. PMID:24995244

John, Ani

2014-01-01

45

The retention mechanism of technetium-99m-HM-PAO: intracellular reaction with glutathione.  

PubMed

Preparations of d,l- and meso-hexamethylpropyleneamine oxime (HM-PAO) labeled with technetium-99m were added to rat brain homogenates diluted with phosphate buffer (1:10). The conversion of d,l-HM-PAO to hydrophilic forms took place with an initial rate constant of 0.12 min-1. Incubation of the brain homogenate with 2% diethyl maleate for 5 h decreased the homogenate's measured glutathione (GSH) concentration from 160 to 16 microM and decreased the conversion rate to 0.012 min-1. Buffered aqueous solutions of glutathione rapidly converted the HM-PAO tracers to hydrophilic forms having the same chromatographic characteristics as found in the brain homogenates. The rate constant for the conversion reaction of d,l-HM-PAO in GSH aqueous solution was 208 and 317 L/mol/min in two different assay systems and for meso-HM-PAO the values were 14.7 and 23.2 L/mol/min, respectively. Rat brain has a GSH concentration of about 2.3 mM and the conversion of the d,l-HM-PAO due to GSH alone should proceed with a rate constant of 0.48 to 0.73 min-1 and be correspondingly 14-fold slower for meso-HM-PAO. In human brain, the in vivo data of Lassen et al. show a conversion rate constant of 0.80 min-1. This correspondence of values supports the notion that GSH may be important for the in vivo conversion of 99mTc-labeled HM-PAO to hydrophilic forms and may be the mechanism of trapping in brain and other cells. A kinetic model for the trapping of d,l- and meso-HM-PAO in tissue is developed that is based on data of GSH concentration in various organs.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3192641

Neirinckx, R D; Burke, J F; Harrison, R C; Forster, A M; Andersen, A R; Lassen, N A

1988-12-01

46

Work in progress. Gastrointestinal ulcerations: detection using a technetium-99m-labeled ulcer-avid agent  

SciTech Connect

Technetium-99m-labeled sucralfate, an ulcer-avid material, was shown in preliminary animal and human studies to be stable in vivo with good sensitivity. Eight experimentally produced discrete gastric ulcers in three rabbits were visualized using this material. Of seven human studies, four studies were true-positive and three were true-negative. It is suggested that Tc-99m-labeled sucralfate may prove to have significant clinical advantages for the evaluation of gastrointestinal ulcer disease and other diseases that are associated with loss of mucosal integrity. The method for labeling sucralfate with Tc-99m was developed by the authors.

Vasquez, T.E.; Bridges, R.L.; Braunstein, P.; Jansholt, A.L.; Meshkinpour, H.

1983-07-01

47

Sequential technetium-99m sulfur colloid/indium-111 white blood cell imaging in macroglobulinemia of Waldenstrom  

SciTech Connect

Technetium-99m sulfur colloid (SC) and indium-111 labeled leukocyte (In-111 WBC) scintigraphy was performed on a 77-year-old female patient to rule out a left periprosthetic infection. Anterior Tc-99m SC and In-111 WBC images of the pelvis and femurs revealed no abnormal deposition of radiotracer about the Austin-Moore prosthesis. Absent radiotracer uptake, however, was demonstrated within the left hemipelvis. A left iliac bone marrow aspirate and biopsy revealed a lymphoplasmacytic infiltrate consistent with Waldenstrom's macroglobulinemia.

Fink-Bennett, D.; Balon, H.R.; Irwin, R. (William Beaumont Hospital, Royal Oak, MI (USA))

1990-06-01

48

Myocardial clearance of technetium-99m-teboroxime in reperfused injured canine myocardium  

PubMed Central

Background Recent technical developments using solid-state technology have enabled rapid image acquisition with single photon emission computed tomography (SPECT) and have led to a renewed interest in technetium-99m-teboroxime (Tc-99m-teboroxime) as a myocardial imaging agent. Tc-99m-teboroxime has demonstrated high myocardial extraction, linear myocardial uptake relative to flow even at high flow rates, rapid uptake and clearance kinetics, and differential clearance in the setting of ischemia. However, the myocardial clearance kinetics of Tc-99m-teboroxime in a model of myocardial injury has not been previously reported. Thus, the purposes of this study were to use a canine model of ischemia-reperfusion to (1) compare Tc-99m-teboroxime clearance kinetics in normal and ischemic-reperfused myocardium and (2) assess the utility of Tc-99m-teboroxime clearance kinetics in determining the severity of injury following ischemia-reperfusion. Methods Thirteen dogs underwent left circumflex coronary artery (LCx) occlusion for either 30 min (IR30, n?=?6) or 120 min (IR120, n?=?7), followed by reperfusion, and finally Tc-99m-teboroxime administration 120 min after reperfusion. Microsphere blood flows were determined at baseline, during occlusion, after reperfusion, and before euthanasia. Post-mortem, area at risk was determined using Evans blue dye, and viability was determined using triphenytetrazolium chloride (TTC) staining. The hearts were then subdivided into 24 pieces and Tc-99m activity was measured in a well counter. Results TTC-determined infarct area as a percentage of total left ventricular myocardium was 1.1%?±?0.3% for the IR30 group and 7.5%?±?2.9% for the IR120 group (p?

2014-01-01

49

Thallium-201 versus technetium-99m pyrophosphate myocardial imaging in detection and evaluation of patients with acute myocardial infarction  

SciTech Connect

Thallium-201 myocardial imaging is of value in the early detection and evaluation of patients with suspected acute infarction. Thallium imaging may have a special value in characterizing patients with cardiogenic shock and in detecting patients at risk for subsequent infarction or death or death or both, before hospital discharge. Approximately 95 percent of pateints with transmural or nontransmural myocardial infarction can be detected with technetium-99m pyrophosphate myocardial imaging if the imaging is performed 24 to 72 hours after the onset of symptoms. Pyrophosphate imaging may have an important role in the evaluation of patients during the early follow-up period after hospital discharge from an episode of acute infarction. The finding of a persistently positive pyrophosphate image suggests a poor prognosis and is associated with a relatively large incidence of subsequent myocardial infarction and death.

Pitt, B.; Thrall, J.H.

1980-12-18

50

Early estimation of acute myocardial infarct size soon after coronary reperfusion using emission computed tomography with technetium-99m pyrophosphate  

SciTech Connect

Early appearance of positive findings on a technetium-99m pyrophosphate scan has been shown to be associated with the presence of a reperfused acute myocardial infarction (AMI). Early technetium-99m pyrophosphate imaging was performed by emission computed tomography to evaluate reperfusion and to test the feasibility of estimating infarct size soon after coronary reperfusion based on acute positive tomographic findings. Twenty-seven patients with transmural AMI who were treated with intracoronary urokinase infusion followed by percutaneous transluminal coronary angioplasty underwent pyrophosphate imaging 8.7 +/- 2.1 hours after the onset of AMI. None of the 8 patients in whom reperfusion was unsuccessful had acute positive findings. Of 19 patients in whom reperfusion was successful, 17 had acute positive findings (p less than 0.001). In these 17, tomographic infarct volumes were determined from reconstructed transaxial images. The threshold for areas of increased pyrophosphate uptake within the infarct was set at 60% of peak activity by the computerized edge-detection algorithm. The total number of pixels in all transaxial sections showing increased tracer uptake were added and multiplied by a size factor and 1.05 g/cm3 muscle to determine infarct volume. The correlations of tomographic infarct volumes with peak serum creatine kinase (CK) levels (r = 0.82) and with cumulative release of CK-MB isoenzyme (r = 0.89) were good. Moreover, the time to positive imaging was significantly shorter than that to peak CK level (8.5 +/- 2.3 vs 10.4 +/- 2.2 hours, p less than 0.005).

Hashimoto, T.; Kambara, H.; Fudo, T.; Tamaki, S.; Nohara, R.; Takatsu, Y.; Hattori, R.; Tokunaga, S.; Kawai, C.

1987-11-01

51

The role of technetium-99m stannous pyrophosphate in myocardial imaging to recognize, localize and identify extension of acute myocardial infarction in patients  

NASA Technical Reports Server (NTRS)

The ability of technetium-99m stannous pyrophosphate myocardial scintigrams to aid diagnostically in recognizing, localizing, and identifying extension of acute myocardial infarction in patients was evaluated. The present study is an extension of previous animal and patient evaluations that were recently performed utilizing this myocardial imaging agent.

Willerson, J. T.; Parkey, R. W.; Bonte, F. J.; Stokely, E. M.; Buja, E. M.

1975-01-01

52

Reversible regional wall motion abnormalities on exercise technetium-99m–gated cardiac single photon emission computed tomography predict high-grade angiographic stenoses  

Microsoft Academic Search

ObjectivesWe sought to determine the level of angiographic stenosis at which reversible regional wall motion abnormalities (RWMA) are present on exercise stress technetium-99m (Tc-99m)– gated single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI), and whether assessments of stress and rest RWMA add incremental diagnostic information.

Louise Emmett; Robert M Iwanochko; Michael R Freeman; Alan Barolet; Douglas S Lee; Mansoor Husain

2002-01-01

53

Early identification of amyloid heart disease by technetium-99m-pyrophosphate scintigraphy: a study with familial amyloid polyneuropathy  

SciTech Connect

To determine whether technetium-99m-pyrophosphate (Tc-99m-PYP) scanning or two-dimensional echocardiography can detect amyloid heart disease in an earlier stage of familial amyloid polyneuropathy, 15 patients were examined. Although 10 of the 15 patients had no clinical evidence of congestive heart failure, as well as normal ventricular wall thickness and normal values for left ventricular systolic function, five (50%) of them showed mild or moderate myocardial uptake. On the other hand, none had characteristic highly refractile myocardial echoes on the two-dimensional echocardiographic images (p less than 0.01), and values for diastolic function were reduced in four of the five and normal in the remaining one. In 85 control subjects, diffuse positive pyrophosphate scans of the heart were found in four (5%) of them (three with dilated cardiomyopathy and one with sarcoidosis), and highly refractile granular sparkling echoes were observed in nine (11%) (five with hypertrophic cardiomyopathy, three with aortic stenosis, and one with hypereosinophilic syndrome). We conclude that Tc-99m-PYP scanning is a more sensitive and specific method and may have the potential ability to detect amyloid heart disease in the earlier stage of familial amyloid polyneuropathy than two-dimensional echocardiography.

Hongo, M.; Hirayama, J.; Fujii, T.; Yamada, H.; Okubo, S.; Kusama, S.; Ikeda, S.

1987-03-01

54

Modulation of the multidrug resistance P-glycoprotein: Detection with technetium-99m-sestamibi in vivo  

SciTech Connect

Overexpression of the multidrug resistance (MDR1) P-glycoprotein (Pgp) has been documented in nearly all forms of human cancers and increased levels of Pgp in some tumors correlate with poor response to treatment. Technetium-99m-sestamibi has recently been validated as a Pgp transport substrate. Pgp is also normally expressed along the biliary canalicular surface of hepatocytes and the luminal side of proximal tubule cells in the kidney, while not expressed in heart. Focused on these organs with known Pgp status, we present the findings on {sup 99m}Tc-sestamibi showed normal, prompt clearance of the radiotracer from the liver and kidneys relative to the heart. After administration of the Pgp modulator, {sup 99m}Tc-sestamibi was selectively retained in the liver and kidneys. Hepatobiliary and renal clearance of {sup 99m}Tc-sestamibi are Pgp-mediated, and inhibition of Pgp transport in these organs can be successfully imaged using {sup 99m}Tc-sestamibi in patients. Similar results might be expected with this and related radiopharmaceuticals for functional imaging of Pgp transport and modulation in tumors. 34 refs., 2 figs.

Luker, G.D.; Fracasso, P.M.; Dobkin, J.; Piwnica-Worms, D. [Washington Univ. School of Medicine, St. Louis, MO (United States)

1997-03-01

55

Dynamic SPECT with technetium-99m HM-PAO in meningiomas--a comparison with iodine-123 IMP  

SciTech Connect

Technetium-99m hexamethylpropyleneamine oxime ((/sup 99m/Tc)HM-PAO) has recently been introduced as an alternative to N-isopropyl-p-/sup 123/I-iodoamphetamine ((/sup 123/I)IMP) for measurement of regional cerebral blood flow. This study compares dynamic SPECT studies using the two tracers in seven patients with meningiomas. Regions of interest were placed over the lesion and contralateral homologous presumed normal area. The counting-rate ratio for the lesion to the contralateral homologous area (L/N ratio) was then calculated in the first image. L/N ratios of ((/sup 99m/Tc)HM-PAO) single photon emission computed tomography (SPECT) were lower than those of ((/sup 123/I)IMP) SPECT, particularly in hypervascular meningiomas. Furthermore, time-activity curves showed that the washout of ((/sup 99m/Tc)HM-PAO) in the tumors was very slow or incomplete, preventing an accurate assessment of vascularity of meningiomas with ((/sup 99m/Tc)HM-PAO), as is generally possible with ((/sup 123/I)IMP).

Nakano, S.; Kinoshita, K.; Jinnouchi, S.; Hoshi, H.; Watanabe, K.

1989-06-01

56

High-risk angina patient. Identification by clinical features, hospital course, electrocardiography and technetium-99m stannous pyrophosphate scintigraphy  

SciTech Connect

We evaluated 193 consecutive unstable angina patients by clinical features, hospital course and electrocardiography. All patients were managed medically. Of the 193 patients, 150 (78%) had a technetium-99m pyrophosphate (Tc-PYP) myocardial scintigram after hospitalization. Of these, 49 (33%) had positive scintigrams. At a follow-up of 24.9 +/- 10.8 months after hospitalization, 16 of 49 patients (33%) with positive scintigrams died from cardiac causes, compared with six of 101 patients (6%) with negative scintigrams (p less than 0.001). Of 49 patients with positive scintigrams, 11 (22%) had had nonfatal myocardial infarction at follow-up, compared with seven of 101 patients (7%) with negative scintigrams (p less than 0.01). Age, duration of clinical coronary artery disease, continuing angina during hospitalization, ischemic ECG, cardiomegaly and a history of heart failure also correlated with cardiac death at follow-up. Ischemic ECG and a history of angina with a crescendo pattern also correlated with nonfatal infarction at follow-up. Patients with continuing angina, an ischemic ECG and a positive scintigram constituted a high-risk unstable angina subgroup with a survival rate of 58% at 6 months, 47% at 12 months and 42% at 24 and 36 months. We conclude that the assessment of clinical features, hospital course, ECG and Tc-PYP scintigraphy may be useful in identifying high-risk unstable angina patients.

Olson, H.G.; Lyons, K.P.; Aronow, W.S.; Stinson, P.J.; Kuperus, J.; Waters, H.J.

1981-10-01

57

High-risk angina patient: identification by clinical features, hospital course, electrocardiography, and technetium-99m stannous pyrophosphate scintigraphy  

SciTech Connect

We evaluated 193 consecutive unstable angina patients by clinical features, hospital course and electrocardiography. All patients were managed medically. Of the 193 patients, 150 (78%) had a technetium-99m pyrophosphate (Tc-PYP) myocardial scintigram after hospitalization. Of these, 49 (33%) had positive scintigrams. At a follow-up of 24.9 +- 10.8 months after hospitalization, 16 of 49 patients (33%) with positive scintigrams died from cardiac causes, compared with six of 101 patients (6%) with negative scintigrams (p < 0.001). Of 49 patients with positive scintigrams, 11 (22%) had had nonfatal myocardial infarction at follow-up, compared with seven of 101 patients (7%) with negative scintigrams (p < 0.01). Age, duration of clinical coronary artery disease, continuing angina during hospitalization, ischemic ECG, cardiomegaly and a history of heart failure also correlated with cardiac death at follow-up. Ischemic ECG and a history of angina with a crescendo pattern also correlated with nonfatal infarction at follow-up. Patients with continuing angina, an ischemic ECG and a positive scintigram constituted a high-risk unstable angina subgroup, with a survival rate of 58% at 6 months, 47% at 12 months and 42% at 24 and 36 months. We conclude that the assessment of clinical features, hospital course, ECG and Tc-PYP scintigraphy may be useful in identifying high-risk unstable angina patients.

Olson, H.G. (Univ. of California, Irvine); Lyons, K.P.; Aronow, W.S.; Stinson, P.J.; Kuperus, J.; Waters, H.J.

1981-10-01

58

Quantification of inflammatory bowel disease activity using technetium-99m HMPAO labelled leucocyte single photon emission computerised tomography (SPECT).  

PubMed Central

Technetium-99m HMPAO labelled white cell bowel uptake was quantified in 23 patients with suspected colitis by means of the novel technique of single photon emission computerised tomography (SPECT) using a standard gamma-camera. Uptake in colon segments was quantified on transaxial images and expressed as a fraction of marrow uptake (SPECT score). Segmental histological disease activity was assessed at colonoscopy (20) or at surgery (3). Segmental histology score correlated with SPECT score r = 0.79 (p < 0.001). Overall SPECT score for all affected segments correlated with Crohn's disease activity index (CDAI) r = 0.66, p = 0.001 and with laboratory activity indices; erythrocyte sedimentation rate r = 0.44, p = 0.03, C reactive protein r = 0.38, p = 0.05, and albumin r = -0.46, p = 0.03. Small bowel SPECT score in 13 patients correlated with CDAI r = 0.65, p < 0.01 but not with erythrocyte sedimentation rate or C reactive protein. Five patients with positive small bowel white cell uptake had normal C reactive protein and erythrocyte sedimentation rate. Overall SPECT score for disease at all sites correlated with both CDAI and with laboratory indices of inflammation. 99mTc HMPAO SPECT provides non-invasive and accurate quantification of inflammatory bowel disease activity in both large and small bowel and may be useful in the objective evaluation of treatment for inflammatory bowel disease. Images Figure 1 Figure 3 Figure 4 PMID:7883224

Weldon, M J; Masoomi, A M; Britten, A J; Gane, J; Finlayson, C J; Joseph, A E; Maxwell, J D

1995-01-01

59

Technetium-99m-sestamibi redistribution after exercise stress test identified by a novel cardiac gamma camera: two case reports.  

PubMed

Single photon emission computer tomography (SPECT) myocardial perfusion imaging (MPI) employing technetium-99m (Tc-99m)-based imaging tracers is the mainstay of nuclear cardiology for the detection of myocardial ischemia. Current guidelines for same day rest/stress Tc-99m-sestamibi SPECT MPI recommend image acquisition 15-60 minutes after the stress testing. A novel sensitive SPECT imaging technique, D-SPECT, allows fast acquisition of images and captures rapid changes in radiotracer distribution. Here we report 2 cases of SPECT MPI in patients with angiographically confirmed coronary artery disease (CAD) where Tc-99m-sestamibi exhibited marked redistribution between early (6-8 min) and late (60-70 min) post-stress imaging leading to an underestimation of the extent and severity of ischemia on late images. These observations suggest that early imaging maybe more sensitive for CAD detection. Fast SPECT imaging techniques, such as D-SPECT, will facilitate similar studies in the future as they will allow fast image acquisition at several time points after the stress test. PMID:20358533

Sheikine, Yuri; Berman, Daniel S; Di Carli, Marcelo F

2010-04-01

60

Modified in vitro method to label equine red blood cells with technetium 99m in concentrated whole blood.  

PubMed

An in vitro method to label equine RBC with technetium 99m was modified to achieve quantitative labeling of cells in concentrated whole blood. After a blood sample was incubated with a reducing agent (stannous citrate), an oxidizing reagent (NaOCl) and a chelating agent (EDTA) were added to inactivate residual Sn2+ in the plasma. This step prevented premature reduction of pertechnetate in plasma. Labeling of RBC from 9 healthy horses, using a standard whole blood protocol, resulted in only moderate labeling efficiency (44 to 85%) and indicated a linear relationship between labeling efficiency and PCV. Effects of increased incubation time, increased incubation temperature, prelabeling sedimentation, and double addition of NaOCl/EDTA were investigated in whole blood from 10 healthy horses. Labeling efficiency was improved by each independent factor and by combination of factors. Highest labeling efficiencies (96 to 97%) were achieved when blood samples were sedimented for 20 minutes before being labeled, regardless of incubation time or incubation temperature. Morphologic features of RBC were unaffected by labeling procedures. In vivo whole blood clearance time for labeled cells was determined in 5 healthy horses. Sedimented blood samples were labeled, using a standard 15-minute incubation time at 20 to 22 C. Mean clearance half-time for 5 horses was approximately 20 hours. More than 95% of 99mTc activity was associated with the cells during the 24 hours after reinjection. PMID:2540685

Koblik, P D; Hornof, W J; Srivastava, S C

1989-04-01

61

An Automated Method for Preparation of [18F]Sodium Fluoride for Injection, USP to Address the Technetium-99m Isotope Shortage  

PubMed Central

The worldwide shortage of technetium-99m has created an immediate and urgent need for access to [18F]sodium fluoride for PET imaging of bone metastasis. In order to facilitate global availability of [18F]sodium fluoride for diagnostic nuclear medicine imaging procedures, a straightforward method for rapid production of [18F]sodium fluoride for injection, USP, using a modified GE Tracerlab FX-FN is presented. PMID:19762249

Hockley, Brian G.

2009-01-01

62

Optimization of X-ray mammography and technetium-99m methoxyisobutylisonitrile scintimammography in the diagnosis of non-palpable breast lesions  

Microsoft Academic Search

.   The purpose of this study was to evaluate the contribution of technetium-99m methoxyisobutylisonitrile (MIBI) scintimammography\\u000a to the early diagnosis of breast cancer in 78 patients with non-palpable breast lesions detected by mammography. In all cases\\u000a biopsy was indicated and they were classified into three groups according to the mammographic findings: high (28), intermediate\\u000a (30) and low (20) mammographic probability

Isabel Uriarte; Jose Manuel Carril; Remedios Quirce; Ceferino Gutiérrez-Mendiguchía; Isabel Blanco; Ignacio Banzo; Alfonso Vega; Ana Hernández

1998-01-01

63

Simultaneous Technetium-99m/Thallium-201 SPECT Imaging with Model-Based Compensation for Cross-Contaminating Effects  

PubMed Central

Simultaneous acquisition of dual-isotope SPECT data offers a number of advantages over separately acquired data; however, simultaneous acquisition can result in cross-contamination between isotopes. In this work we propose and evaluate two frameworks for iterative model-based compensation of cross-contamination in dual-isotope SPECT. The methods were applied to cardiac imaging with Technetium-99m-sestamibi and Thallium-201, and they were compared to a subtraction-based compensation method using a cross-talk estimate obtained from an auxiliary energy window. Monte Carlo simulations were performed to carefully study aspects of bias and noise for the methods, and a torso phantom with cardiac insert was used to evaluate the performance of the methods for experimentally acquired data. The cross-talk compensation methods substantially improved lesion contrast and significantly reduced quantitative errors for simultaneously acquired data. Thallium image normalized mean square error (NMSE) was reduced from 0.522 without cross-talk compensation to as low as 0.052 with model-based cross-talk compensation. This is compared to a NMSE of 0.091 for the subtraction-based compensation method. The application of a preliminary model for crosstalk arising from lead fluorescence x-rays and collimator scatter gave promising results, and the future development of a more accurate model for collimator interactions would likely benefit simultaneous Tc/Tl imaging. Model-based compensation methods provide feasible cross-talk compensation in clinically acceptable times, and they may ultimately make simultaneous dual-isotope protocols an effective alternative for many imaging procedures. PMID:10442716

Kadrmas, Dan J.; Frey, Eric C.; Tsui, Benjamin M.W.

2009-01-01

64

Effect of Thuya occidentalis on the labeling of red blood cells and plasma proteins with technetium-99m.  

PubMed

Thuya occidentalis is used in popular medicine in the treatment of condyloma and has antibacterial action. Red blood cells (RBC) labeled with technetium-99m (99mTc) are used for several evaluations in nuclear medicine. This labeling depends on a reducing agent, usually stannous ion. Any drug which alters the labeling of the tracer could be expected to modify the disposition of the radiopharmaceutical. We have evaluated the influence of T. occidentalis extract on the labeling of RBC and plasma proteins with 99mTc. Blood was withdrawn and incubated with T. occidentalis (0.25; 2.5; 20.5; and 34.1 percent v/v). Stannous chloride (1.2 micrograms/ml) was added and then 99mTc was added. Plasma (P) and blood cells (BC) were isolated, also precipitated with trichloroacetic acid and soluble (SF) and insoluble fractions (IF) separated. The analysis of the results shows that there is a decrease in radioactivity (from 97.64 to 75.89 percent) in BC with 34.1 percent of the drug. In the labeling process of RBC with 99mTc, the stannous and pertechnetate ions pass through the membrane, so we suggest that the T. occidentalis effect can be explained (i) by an inhibition of the transport of these ions, (ii) by damage in membrane, (iii) by competition with the cited ions for the same binding sites, or (iv) by possible generation of reactive oxygen species that could oxidize the stannous ion. PMID:9436292

Oliveira, J F; Braga, A C; Avila, A S; Fonseca, L M; Gutfilen, B; Bernardo-Filho, M

1996-01-01

65

Uptake of myocardial imaging agents by rejecting and nonrejecting cardiac transplants. A comparative clinical study of thallium-201, technetium-99m, and gallium-67  

SciTech Connect

To study the scintigraphic detectability of cardiac rejection, we performed 135 planar myocardial scans (({sup 99m}Tc)pyrophosphate, 85; {sup 201}Tl, 36; {sup 67}Ga, 14) together with endomyocardial biopsies in ten patients for a (mean) 17-mo postoperative period. Specificity of each agent exceeded 89%. Technetium-99m pyrophosphate showed results that significantly correlated with the severity of rejection (p = 0.03), as shown by biopsy, but neither {sup 201}Tl nor 67Ga did so (p = 0.63 and 0.81, respectively). Technetium-99m pyrophosphate showed better diagnostic accuracy (85%) than {sup 201}Tl (69%) and {sup 67}Ga (64%). Technetium-99m pyrophosphate also showed higher negative predictive value (91%) than thallium (76%) and gallium (69%). Thus, a normal {sup 99m}Tc pyrophosphate scan was usually associated with absence of cardiac rejection. However, all three agents showed unacceptably poor sensitivity (0% to 30%) and thus were not useful as a screening test for cardiac rejection, even when the same agent was used serially in imaging a given patient.

Yamamoto, S.; Bergsland, J.; Michalek, S.M.; Carroll, M.; Gona, J.M.; Balu, D.; Carr, E.A. Jr. (Buffalo Veterans Administration Medical Center, New York, NY (USA))

1989-09-01

66

Personalized predictive lung dosimetry by technetium-99m macroaggregated albumin SPECT/CT for yttrium-90 radioembolization  

PubMed Central

Background For yttrium-90 (90Y) radioembolization, the common practice of assuming a standard 1,000-g lung mass for predictive dosimetry is fundamentally incongruent with the modern philosophy of personalized medicine. We recently developed a technique of personalized predictive lung dosimetry using technetium-99m (99mTc) macroaggregated albumin (MAA) single photon emission computed tomography with integrated CT (SPECT/CT) of the lung as part of our routine dosimetric protocol for 90Y radioembolization. Its rationales are the technical superiority of SPECT/CT over planar scintigraphy, ease and convenience of lung auto-segmentation CT densitovolumetry, and dosimetric advantage of patient-specific lung parenchyma masses. Methods This is a retrospective study of our pulmonary clinical outcomes and comparison of lung dosimetric accuracy and precision by 99mTc MAA SPECT/CT versus conventional planar methodology. 90Y resin microspheres (SIR-Spheres) were used for radioembolization. Diagnostic CT densitovolumetry was used as a reference for lung parenchyma mass. Pulmonary outcomes were based on follow-up diagnostic CT chest or X-ray. Results Thirty patients were analyzed. The mean lung parenchyma mass of our Southeast Asian cohort was 822?±?103 g standard deviation (95% confidence interval 785 to 859 g). Patient-specific lung parenchyma mass estimation by CT densitovolumetry on 99mTc MAA SPECT/CT is accurate (bias ?21.7 g) and moderately precise (95% limits of agreement ?194.6 to +151.2 g). Lung mean radiation absorbed doses calculated by 99mTc MAA SPECT/CT and planar methodology are both accurate (bias <0.5 Gy), but 99mTc MAA SPECT/CT offers better precision over planar methodology (95% limits of agreement ?1.76 to +2.40 Gy versus ?3.48 to +3.31 Gy, respectively). None developed radiomicrosphere pneumonitis when treated up to a lung mean radiation absorbed dose of 18 Gy at a median follow-up of 4.4 months. Conclusions Personalized predictive lung dosimetry by 99mTc MAA SPECT/CT is clinically feasible, safe, and more precise than conventional planar methodology for 90Y radioembolization radiation planning. PMID:25024931

2014-01-01

67

Low-dose dobutamine nitrate-enhanced technetium 99m sestamibi gated spect versus low-dose dobutamine echocardiography for detecting reversible dysfunction in ischemic cardiomyopathy  

Microsoft Academic Search

Background  The simultaneous assessment of perfusion and function with the use of technetium 99m sestamibi gated single photon emission\\u000a computed tomography (SPECT) is helpful for the detection of myocardial viability, but its value in comparison with more established\\u000a methods is not yet defined.\\u000a \\u000a \\u000a \\u000a Methods and Results  This study compared low-dose dobutamine (LDD) nitrate-enhanced gated SPECT with LDD echocardiography for predicting recovery\\u000a of

Mario Leoncini; Francesco Bellandi; Mauro Maioli; Stelvio Sestini; Gabriella Marcucci; Angela Coppola; Fabio Frascarelli; Alberto Mennuti; Roberto P. Dabizzi

2002-01-01

68

Extramedullary Pulmonary Hematopoiesis Causing Pulmonary Hypertension and Severe Tricuspid Regurgitation Detected by Technetium-99m Sulfur Colloid Bone Marrow Scan and Single-Photon Emission Computed Tomography/CT  

PubMed Central

Extramedullary pulmonary hematopoiesis is a rare entity with a limited number of case reports in the available literature only. We report the case of a 66-year-old man with known primary myelofibrosis, in whom a Technetium-99m sulfur colloid bone marrow scan with single-photon emission computed tomography (SPECT)/CT revealed a pulmonary hematopoiesis as the cause of pulmonary hypertension and severe tricuspid regurgitation. To the best of our knowledge, this is the first description of Technetium-99m sulfur colloid SPECT/CT imaging in this rare condition. PMID:24843243

Clarke, Michael John; Kannivelu, Anbalagan; Chinchure, Dinesh; Srinivasan, Sivasubramanian

2014-01-01

69

Comparative study of regional cerebral blood flow images by SPECT using xenon-133, iodine-123 IMP, and technetium-99m HM-PAO  

SciTech Connect

Regional cerebral blood flow (rCBF) was measured by single photon emission computed tomography (SPECT) using /sup 133/Xe, N-isopropyl-p-(/sup 123/I)iodoamphetamine ((/sup 123/I)IMP) and (/sup 99m/Tc) hexamethylpropyleneamine oxime ((/sup 99m/Tc)HM-PAO) in 24 patients with cerebrovascular diseases. The greatest advantage of /sup 133/Xe SPECT was to be able to provide absolute rCBF values without arterial sampling. However, its image quality was very poor. Iodine-123 IMP SPECT provided rCBF images of higher quality and it had good correlation to /sup 133/Xe SPECT. Iodine-123 IMP SPECT provided the best images to detect mild ischemic lesions. It could detect obstructive or stenotic changes of large cerebral arteries very well except for a moderate stenosis of internal carotid artery. Technetium-99m HM-PAO SPECT also provided very good rCBF images and it had good correlation to /sup 133/Xe SPECT. However, the count-density ratios for the ischemic lesions to the contralateral presumed normal areas of (/sup 99m/Tc) HM-PAO SPECT were significantly higher than those of (/sup 123/I)IMP SPECT.

Nakano, S.; Kinoshita, K.; Jinnouchi, S.; Hoshi, H.; Watanabe, K.

1989-02-01

70

Regional cerebral blood flow imaging: A quantitative comparison of technetium-99m-HMPAO SPECT with C15O2 PET  

SciTech Connect

The aim of this study was to compare technetium-99m-hexamethylpropyleneamineoxime ({sup 99m}Tc-HMPAO) single-photon emission computed tomography (SPECT) with regional cerebral blood flow (rCBF) imaging using positron emission tomography (PET). As investigation of dementia is likely to be one of the main uses of routine rCBF imaging, 18 demented patients were imaged with both techniques. The PET data were compared quantitatively with three versions of the SPECT data. These were, first, data normalized to the SPECT cerebellar uptake, second, data linearly corrected using the PET cerebellar value and, finally, data Lassen corrected for washout from the high flow areas. Both the linearly-corrected (r = 0.81) and the Lassen-corrected (r = 0.79) HMPAO SPECT data showed good correlation with the PET rCBF data. The relationship between the normalized HMPAO SPECT data and the PET data was nonlinear. It is not yet possible to obtain rCBF values in absolute units from HMPAO SPECT without knowledge of the true rCBF in one reference region for each patient.

Gemmell, H.G.; Evans, N.T.; Besson, J.A.; Roeda, D.; Davidson, J.; Dodd, M.G.; Sharp, P.F.; Smith, F.W.; Crawford, J.R.; Newton, R.H. (Aberdeen Bio-Medical Imaging Cyclotron Centre, Aberdeen (Scotland))

1990-10-01

71

[Evaluation of technetium-99m-MIBI scintigraphy in metastatic differentiated thyroid cancer--comparison study with 131I and 201Tl].  

PubMed

Detectability of metastasis in differentiated thyroid cancer using technetium-99m-methoxyisobutyl isonitrile (99mTc-MIBI) was compared with that of 131I and 201Tl. Forty patients after total thyroidectomy were evaluated. The scan results were compared with those of 131I and 201Tl whole body scintigraphy per patient. The positive rate was 68% in 99mTc-MIBI, 84% in 131I, 60% in 201Tl respectively. As to the lymph node metastasis, the positive rates were 56% in 99mTc-MIBI, 78% in 131I, 39% in 201Tl. In lung metastasis, the positive rate was 46% in 99mTc-MIBI, 82% in 131I and 55% in 201Tl. Serum thyroglobulin (Tg) was significantly higher in 201Tl and/or 99mTc-MIBI positive group compared to that of negative group independent of 131I scan results. Although the detectability of both 99mTc-MIBI and 201Tl were inferior to that of 131I, 9 to 22% of metastasis were detected only by these radiopharmaceuticals. Both 99mTc-MIBI and 201Tl, therefore, should be used in cases with high serum Tg even with negative 131I uptake. Basing on the fact there was no prominent difference between 99mTc-MIBI and 201Tl in the detectability of metastasis, 99mTc-MIBI might be more suitable tracer because of better quality image. PMID:10783567

Nagamachi, S; Jinnouchi, S; Nishii, R; Flores, L G; Nakahara, H; Futami, S; Tamura, S; Toshimori, H; Kawai, K

2000-03-01

72

Evaluation of the in vitro effect of a Lantana camara extract on the labeling of blood constituents of rats with technetium-99m.  

PubMed

Blood constituents labeled with technetium-99m (99mTc) have been used in nuclear medicine procedures and drugs are capable to interfere on this labeling. Lantana camara (lantana) has medicinal properties and it has been used in folk medicine. The aim is to verify the effect of a lantana extract on the labeling of blood constituents with 99mTc. Blood of rats was incubated with extract, stannous chloride and 99mTc, as sodium pertechnetate. Plasma (P) and blood cells (BC) were isolated, also precipitated with trichloroacetic acid and soluble (SF) and insoluble fractions (IF) were separated. The % of radioactivity (%ATI) in these samples was calculated. Samples of labeled BC were washed and the %ATI maintained (%ATI-M) in the BC was determined. The results showed that lantana extract decreased significantly (p < 0.05) in the IF-P from 70.24 +/- 2.59 to 11.95 +/- 3.07. This effect was not observed in the BC and IF-BC. The BC-%ATI-M was significantly (p < 0.05) decreased in all concentrations tested when the BC was washed. This fact was not observed in the control. Substances present on the extract should have redoxi action decreasing the concentration of the stannous ion and this condition could justify the effect on the IF-P. The results about the BC-%ATI-M should indicate a possible effect on the transport of ions through the erythrocyte membrane. PMID:18390001

Maiworm, A I; Santos-Filho, S D; Presta, G A; Giani, T S; Paoli, S; Bernardo-Filho, M

2008-03-01

73

Clinical significance of reverse redistribution on technetium-99m tetrofosmin single-photon emission computed tomography: an 18-month follow-up study  

PubMed Central

Background The clinical and prognostic significance of reverse redistribution on technetium-99m (99mTc) single-photon emission computed tomography (SPECT) is unclear. Objectives To determine outcomes of chest pain patients showing reverse redistribution after 99mTc tetrofosmin SPECT versus SPECT showing no reverse redistribution. Methods Patient outcomes (death, nonfatal myocardial infarction, coronary artery bypass grafting and percutaneous transluminal coronary angioplasty) within 18 months after 99mTc tetrofosmin SPECT were determined in two populations of ambulatory patients, most of whom had been evaluated because of chest pain: a population of 57 patients whose SPECT images showed reverse redistribution without reversible or fixed defects, versus a control population of 98 patients whose SPECT images were normal (no reverse redistribution, no reversible defects, no fixed defects). Results Stepwise logistic regression analysis showed that the population of patients with reverse redistribution did not have a worse 18-month outcome in comparison with the control population of patients without reverse redistribution (3.5% versus 9.2%, respectively; p=0.15 corrected for age and gender). Conclusion Reverse redistribution on 99mTc tetrofosmin SPECT does not appear to be an unfavourable prognostic factor in ambulatory chest pain patients.

Swinkels, B.M.; Hooghoudt, T.E.H.; Schoenmakers, E.A.J.M.; Zinder, C.G.; de Boo, T.M.; Verheugt, F.W.A.

2003-01-01

74

Myocardial infarction determined by technetium-99m pyrophosphate single-photon tomography complicating elective coronary artery bypass grafting for angina pectoris  

SciTech Connect

The incidence of acute myocardial infarction (AMI) complicating coronary artery bypass grafting (CABG) has previously been based on concordance of electrocardiographic, enzymatic and scintigraphic criteria. Technetium-99m pyrophosphate (Tc-PPi) single-photon emission computed tomography now enables detection of AMI with high sensitivity and specificity. Using this technique, perioperative AMI was detected in 12 of 58 patients (21%) undergoing successful elective CABG for stable angina pectoris. Stepwise multivariate logistic regression analysis was performed to compare the predictive value of preoperative (New York Heart Association class, left ventricular ejection fraction and use of beta blockers) and intraoperative (number of grafts constructed, use of internal mammary anastomoses, use of sequential saphenous vein grafts, smallest grafted distal vessel lumen caliber and aortic cross-clamp time) variables. Preoperative New York Association class (p = 0.04) and smallest grafted distal vessel lumen caliber (p = 0.03) were significant multivariate predictors of perioperative AMI. Only 1 perioperative patient with AMI (and 1 pyrophosphate-negative patient) developed new Q waves. Serum creatine kinase-MB was higher in patients with AMI by repeated measures analysis of variance (p = 0.0003). Five AMIs occurred in myocardial segments revascularized using sequential saphenous vein grafts, and 7 in segments perfused by significantly stenosed epicardial vessels with distal lumen diameter and perfusion territory considered too small to warrant CABG. At 6-month follow-up, the mean left ventricular ejection fraction increased from 0.61 to 0.65 in Tc-PPI-negative patients (p = 0.01), but not in perioperative patients with AMI.

Burns, R.J.; Gladstone, P.J.; Tremblay, P.C.; Feindel, C.M.; Salter, D.R.; Lipton, I.H.; Ogilvie, R.R.; David, T.E.

1989-06-15

75

Detection of myocardial perfusion abnormalities: standard dual-source coronary computed tomography angiography versus rest/stress technetium-99m single-photo emission CT  

PubMed Central

We compared coronary dual-source computed tomography angiography (corDSCTA) with technetium-99m single-photon emission computed tomography (SPECT) for the detection of myocardial perfusion abnormalities. Fifty-five consecutive patients underwent both gated myocardial perfusion SPECT and corDSCTA, the latter during a single arterial-phase injection of contrast agent. The perfusion defects visualised by corDSCTA correlated with the findings of rest/stress SPECT. Abnormal findings on stress SPECT, which were due to either ischaemia or infarct, were found in 24 patients. In comparison to SPECT at rest, corDSCTA detected perfusion defects with a sensitivity and specificity of 100% and 78%, respectively. Compared to SPECT at stress, the sensitivity and specificity values of corDSCTA were 83.3% and 90.3%, respectively. On corDSCTA , the average attenuation values of perfusion defects that corresponded to chronic infarcts (?8.5±22.2 HU) were significantly lower (p = 0.002) than those of non-infarct-related perfusion defects (43.1±17.5 HU). Using rest/stress SPECT is the gold standard for the diagnosis of myocardial ischaemia, corDSCTA was able to diagnose ischaemic disease (defined as the presence of high-grade stenotic CAD (?50% luminal narrowing)) with a sensitivity and specificity of 59% and 89%, respectively, in patients with no known history of myocardial infarction (n = 4). Thus, corDSCTA may serve as a diagnostic tool for the detection of perfusion abnormalities (first) visualised by SPECT. There appears to be a limited correlation between coronary stenotic disease and SPECT findings. PMID:20413446

Cheng, W; Zeng, M; Arellano, C; Mafori, W; Goldin, J; Krishnam, M; Ruehm, S G

2010-01-01

76

Effect of metabolic alterations on the accumulation of technetium-99m-labeled d, l-HMPAO in slices of rat cerebral cortex  

SciTech Connect

It is widely recognized that the distribution of technetium-99m-labeled d,l-hexamethylpropylene amine oxime ({sup 99m}Tc-HMPAO) in the brain is determined by the regional blood flow. However, other factors may affect this process including the metabolism of the brain tissue. To examine this possibility we studied the effects of metabolic alterations on {sup 99m}Tc-HMPAO uptake in rat brain cortex slices, with concurrent measurement of oxygen consumption (QO{sub 2}). {sup 99m}Tc-HMPAO uptake was determined by incubating slices of rat cerebral cortex at 37{degrees}C in Krebs-Ringer phosphate glucose medium containing {sup 99m}Tc-HMPAO with and without test substances. Differential gradients for {sup 99m}Tc activity between the tissue and the suspending medium (T/M ratio) were derived from the equation T/M[{sup 99m}Tc] = counts per gram of tissue/counts per milliliter of medium. The QO{sub 2} of the brain slices was measured using a biological oxygen monitor equipped with a polarographic oxygen probe. Inhibitors affecting oxidative phosphorylation caused parallel suppression of the T/M ratio and QO{sub 2}. Agents that uncouple oxidation from phosphorylation increased the QO{sub 2} and decreased the T/M ratio. Incubation of slices at 22{degrees}C depressed the T/M ratio and QO{sub 2}. The presence of inhibitors of oxidative phosphorylation in the incubation medium increased the release of {sup 99m}Tc activity from slices that had been prelabeled with {sup 99m}Tc-HMPAO. These findings suggest that the altered metabolic status of the brain tissue modulates the kinetics and net accumulation of {sup 99m}Tc-HMPAO at the cellular level by either depressing uptake, increasing back-diffusion, or both. 33 refs., 4 figs., 3 tabs.

Ahn, C.S.; Tow, D.E.; Yu, C.C.; Greene, R.W. [Virginia Medical Center, Brockton, VA (United States)]|[Harvard Medical School, Boston, MA (United States)

1994-03-01

77

Usefulness of technetium-99m-MIBI and thallium-201 in tomographic imaging combined with high-dose dipyridamole and handgrip exercise for detecting coronary artery disease  

SciTech Connect

Forty-two patients with known stable coronary artery disease, referred for coronary angiography, were examined with technetium-99m-hexakis-2-methoxy-2-methylpropyl-isonitrile (MIBI) tomography combined with a high-dose dipyridamole infusion (0.7 mg/kg) and handgrip stress. MIBI tomography was unable to show coronary artery disease only in 2 patients, thus yielding a sensitivity figure of 95%. MIBI tomography correctly identified 27 (82%) of 33 stenotic lesions (greater than or equal to 50% diameter stenosis) of the left anterior descending artery, 17 (61%) of 28 of those of the left circumflex artery, and 28 (90%) of 31 of those of the right coronary artery. The overall vessel sensitivity was 78%. The computed lumen diameter stenoses were more advanced in cases detected than in those not detected with MIBI tomography: 87 {plus minus} 14 vs 76 {plus minus} 14% (p less than 0.01). The 50 to 69% stenoses did not show any tendency to produce less positive findings than those with greater than or equal to 70% stenoses. In the subgroup of 21 patients who also presented for thallium scintigraphy, the overall diseased vessel identification rate was 76% for thallium tomography and 83% for MIBI tomography (p = not significant). Minor noncardiac side effects related to the dipyridamole-handgrip test occurred only in 5% of 63 study sessions. A high-dose dipyridamole combined with isometric exercise is a safe stress method, and when used during scintigraphy, MIBI tomography is at least as efficient a tool as thallium tomography in detecting diseased vessel territories in patients in coronary artery disease.

Kettunen, R.; Huikuri, H.V.; Heikkilae, J.T.; Takkunen, J.T. (Department of Internal Medicine, Oulu University Central Hospital (Finland))

1991-09-01

78

Quantitative assessment of overall inflammatory bowel disease activity using labelled leucocytes: a direct comparison between indium-111 and technetium-99m HMPAO methods.  

PubMed Central

The ideal imaging method in inflammatory bowel disease would reliably detect inflammation, identify the correct intestinal location, and assess the severity of the disease. The aim of this study was to compare scintigraphic methods of quantifying overall disease activity using both indium-111 (111In) and technetium-99M (99mTc) HMPAO labelled leucocyte scans. The four day faecal excretion of 111In was measured after 111In scintigraphy in 24 patients known to have inflammatory bowel disease. The same patients also underwent 99mTc HMPAO scanning. The scans were performed 10 days or less apart with no changes in treatment between scans. Bowel activity on the 99mTc HMPAO scans was assessed using a computer based method (scan score) and a visual grading method in a further 54 99mTc HMPAO. The results showed a close correlation between inflammatory activity defined by faecal 111In excretion and the scan score generated from the computer analysis of the 99mTc HMPAO image (Spearman rank correlation: rs = 0.78; p < 0.001). Accurate information to localise inflammatory activity could be obtained by simple visual assessment of both types of scan images, although image quality was superior with 99mTc HMPAO. Qualification of disease activity from 99mTc HMPAO images by visual grading was associated with a large variability, only 69% of scans had similar scores when graded by three observers. Computer generated image analysis was more reproducible. In conclusion, in inflammatory bowel disease 99mTc HMPAO scintigraphy and faecal 111In excretion correlated well. Either method can quantify and localise the inflammation. As 99mTc HMPAO scanning provides a quicker result, with a lower radiation dose, and avoids faecal collection, it may be the preferred method. Images Figure 2 PMID:8549945

Mansfield, J C; Giaffer, M H; Tindale, W B; Holdsworth, C D

1995-01-01

79

Technetium-99m-labeled white blood cells: a new method to define the local and systemic role of leukocytes in acute experimental pancreatitis.  

PubMed Central

OBJECTIVE: We developed a new method to quantitate leukocyte accumulation in tissues and used it to examine the time course and severity of acute experimental pancreatitis. BACKGROUND: Leukocyte activation and infiltration are believed to be critical steps in the progression from mild to severe pancreatitis and responsible for many of its systemic complications. METHODS: Pancreatitis of graded severity was induced in Sprague-Dawley rats with a combination of caerulein and controlled intraductal infusion. Technetium-99m (99mTc)-labeled leukocytes were quantified in pancreas, lung, liver, spleen, and kidney and compared with myeloperoxidase activity. The severity of pancreatitis was ascertained by wet/dry weight ratio, plasma amylase, and trypsinogen activation peptide in the pancreas. The time course of leukocyte accumulation was determined over 24 hours. RESULTS: Pancreatic leukocyte infiltration correlated well with tissue myeloperoxidase concentrations. In mild pancreatitis, leukocytes accumulated only in the pancreas. Moderate and severe pancreatitis were characterized by much greater leukocyte infiltration in the pancreas than in mild disease (p < 0.01), and increased 99mTc radioactivity was detectable in the lung as early as 3 hours. 99mTc radioactivity correlated directly with the three levels of pancreatitis. CONCLUSIONS: Mild pancreatitis is characterized by low-level leukocyte activation and accumulation in the pancreas without recruitment of other organs; marked leukocyte accumulation was found in the pancreas and in the lung in more severe grades of pancreatitis. These findings provide a basis for the pathophysiologic production of cytokines and oxygen free radicals, which potentiate organ injury in severe pancreatitis. This study validates a new tool to study local and systemic effects of leukocytes in pancreatitis as well as new therapeutic hypotheses. PMID:9445115

Werner, J; Dragotakes, S C; Fernandez-del Castillo, C; Rivera, J A; Ou, J; Rattner, D W; Fischman, A J; Warshaw, A L

1998-01-01

80

Protection of plasmid DNA by a Ginkgo biloba extract from the effects of stannous chloride and the action on the labeling of blood elements with technetium-99m.  

PubMed

Ginkgo biloba extract (EGb) is a phytotherapeutic agent used for the treatment of ischemic and neurological disorders. Because the action of this important extract is not fully known, assays using different biological systems need to be performed. Red blood cells (RBC) are labeled with technetium-99m (Tc-99m) and used in nuclear medicine. The labeling depends on a reducing agent, usually stannous chloride (SnCl2). We assessed the effect of different concentrations of EGb on the labeling of blood constituents with Tc-99m, as sodium pertechnetate (3.7 MBq), and on the mobility of a plasmid DNA treated with SnCl2 (1.2 microg/ml) at room temperature. Blood was incubated with EGb before the addition of SnCl2 and Tc-99m. Plasma (P) and RBC were separated and precipitated with trichloroacetic acid, and soluble (SF-P and SF-RBC) and insoluble (IF-P and IF-RBC) fractions were isolated. The plasmid was incubated with Egb, SnCl2 or EGb plus SnCl2 and agarose gel electrophoresis was performed. The gel was stained with ethidium bromide and the DNA bands were visualized by fluorescence in an ultraviolet transilluminator system. EGb decreased the labeling of RBC, IF-P and IF-RBC. The supercoiled form of the plasmid was modified by treatment with SnCl2 and protected by 40 mg/ml EGb. The effect of EGb on the tested systems may be due to its chelating action with the stannous ions and/or pertechnetate or to the capability to generate reactive oxygen species that could oxidize the stannous ion. PMID:14762583

Moreno, S R F; Freitas, R S; Rocha, E K; Lima-Filho, G L; Bernardo-Filho, M

2004-02-01

81

Effect of interleukin-2 on the biodistribution of technetium-99m-labelled anti-CEA monoclonal antibody in mice bearing human tumour xenografts.  

PubMed

We have evaluated whether interleukin-2 (IL-2) at low doses can enhance delivery of radionuclides to tumour sites by improving the access of the radio-labelled antibody. The effects of 1000 or 2000 units of IL-2 on the biodistribution of technetium-99m-labelled anticarcinoembryonic antigen (CEA) monoclonal antibody, ZCE025, in athymic mice bearing human CEA-positive tumour (MKN45) xenografts were investigated. Treatment with IL-2 resulted in a significantly higher tumour uptake (1.2-1.5-fold) compared with the control group. Some normal organs, such as heart, lung, liver, spleen and kidneys, showed increased 99mTc uptake following the IL-2 treatment. Pretreatment with IL-2 also induced an enhancement of the permeability index for mouse IgG in tumours and in normal organs, whereas the blood flow in both normal organs and tumours remained at control levels. The effects of IL-2 were found to be dose-dependent. The IL-2 treatment increased the plasma CEA levels but not the CEA content in tumour tissues, suggesting that IL-2 enhanced the leakage of CEA from tumour to blood. The enhancement ratios of the tumour 99mTc-ZCE025 uptake following treatment with IL-2 were 1.4 and 1.8 in mice bearing small and large tumours, respectively. Our experimental results indicated that the low dose of IL-2 enhanced the vascular permeability sufficiently to increase the amount of antibody delivered to the tumour target. Administration of IL-2 would render radioimmunotherapy more effective, especially in patients with large tumour burdens. PMID:7995285

Nakamura, K; Kubo, A

1994-09-01

82

Technetium-99m generator system  

DOEpatents

A {sup 99}Mo/{sup 99m}Tc generator system includes a sorbent column loaded with a composition containing {sup 99}Mo. The sorbent column has an effluent end in fluid communication with an anion-exchange column for concentrating {sup 99m}Tc eluted from the sorbent column. A method of preparing a concentrated solution of {sup 99m}Tc includes the general steps of: (a) providing a sorbent column loaded with a composition containing {sup 99}Mo, the sorbent column having an effluent end in fluid communication with an anion-exchange column; (b) eluting the sorbent column with a salt solution to elute {sup 99m}Tc from the sorbent and to trap and concentrate the eluted {sup 99m}Tc on the ion-exchange column; and (c) eluting the concentrated {sup 99m}Tc from the ion-exchange column with a solution comprising a reductive complexing agent. 1 fig.

Mirzadeh, S.; Knapp, F.F. Jr.; Collins, E.D.

1998-06-30

83

Assessment of whole body MRI and sestamibi technetium-99m bone marrow scan in prediction of multiple myeloma disease progression and outcome: a prospective comparative study  

PubMed Central

Objectives This study aims primarily to determine whether whole body MRI (WB-MRI) and Sestamibi Technetium-99m-bone marrow (MIBI) scans in the same patients produce the same estimate of disease load and location, and secondly, to study possible association between the bone disease detected by these scans and the effect on disease outcome and survival. Bone disease occurs in about 90% of multiple myeloma (MM) patients. There are no data comparing the new diagnostic modalities with WB-MRI and MIBI in MM. Design A prospective comparative study between WB-MRI and MIBI scans in assessing bone disease and outcome of MM. Participants and methods Sixty-two consecutive patients with confirmed MM underwent simultaneous WB-MRI (both axial T1 and turbo spin echo short tau inversion recovery (STIR)) and MIBI scans at a single institution from January 2010 to January 2011, and their survival status was determined in January 2012. The median age was 62?years (range 37–88) with a male-to-female ratio of 33?:?29. Results In vertebrae and long bones, MRI scan detected more disease compared with MIBI scan (p<0.001) but there was less difference in the skull (p=0.09). In the ribcage, the MIBI scan detected more lytic lesions of the ribs compared with MRI scan (p<0.001). Thirteen of the 62 patients died during the 24-month follow-up. Increased disease detected in all bones by both scans was associated with increased mortality risk (MIBI p=0.001; MRI-STIR p=0.044; but not MRI-T1 p=0.44). In all combined bone groups, the mean MIBI scan results provided a better prediction of mortality than MRI scan over the follow-up period (MRI-T1 vs MIBI p=0.019; MRI-STIR vs MIBI p=0.047). Conclusions Although WB-MRI detected more MM bone disease, MIBI scan predicted overall disease outcome and mortality better than MRI scan. Further studies to define optimum use of these imaging techniques are warranted. Trial registration number The study was registered prospectively in the Australian and New Zealand Clinical Trials Registry at http://www.ANZCTR.org.au under No: ACTRN12609000761268. PMID:23315438

Khalafallah, Alhossain A; Snarski, Andrew; Heng, Robert; Hughes, Ryan; Renu, Shamsunnaher; Arm, Jameen; Dutchke, Richard; Robertson, Iain K; To, Luen B

2013-01-01

84

Effect of eggplant (Solanum melongena) extract on the in vitro labeling of blood elements with technetium-99m and on the biodistribution of sodium pertechnetate in rats.  

PubMed

The use of eggplant has been suggested to treat different diseases. We studied the effect of eggplant extract on the labeling of red blood cells (RBC) and plasma proteins with technetium-99m (Tc-99m) and on biodistribution of sodium pertechnetate (Tc-99m) in rats. Blood was incubated with an eggplant extract (final concentrations 3.12 to 250.00 mg/ml) for 60 min. Then, stannous chloride (SnCl2) (0.06 or 1.2 microg/ml) and Tc-99m, as sodium pertechnetate, were added. Samples of RBC and plasma (P) were separated and also precipitated and soluble (SF) and insoluble (IF) fractions were isolated. The percent of radioactivity (%ATI) in the fractions was calculated. In the biodistribution study, Wistar rats were treated with eggplant extract (300 mg/ml) for 4 weeks, in drinking water. Tc-99m was administered in the rats, after 90 min they were sacrificed and organs and blood were isolated. When 0.06 microg/ml SnCl2 was used, eggplant extract: i/ inhibited the label of RBC (97.14 +/- 2.01 to 52.21 +/- 3.97%ATI), ii/ decreased the labeling in IF-P from 38.79 +/- 11.73 to 5.49 +/- 2.65%ATI, and iii/ diminished the labeling in IF-RBC from 90.04 +/- 2.65 to 46.17 +/- 9.49%ATI. This inhibitory effect was not observed with SnCl2 1.2 microg/ml. In the biodistribution study, the %ATI: i/ increased in the liver from 2.15 +/- 0.54 to 3.11 +/- 1.29 and ii/ in the other organs the Tc-99m uptake was not modified. The uptake of Tc-99m in red blood cells protein (IF-RBC) decreased from 66.62 +/- 19.67 to 31.66 +/- 8.84%. It is possible to suggest that some components of the eggplant extract present an oxidation power able to alter the fixation of the Tc-99m on the blood elements. Moreover, as eggplant is metabolized in the liver, this fact could justify the alteration of the uptake in this organ. PMID:12619974

Capriles, P V S Z; Dias, A P M; Costa, T E M M; Oliveira, M B N; Faria, M V C; Moura, E G; Abreu, B A L; Bernardo-Filho, M

2002-11-01

85

The use of technetium-99m-labeled human serum albumin diethylenetriamine pentaacetic acid single-photon emission CT scan in the follow-up of type II endoleak treatment.  

PubMed

An 84-year-old woman presented with persistent type II endoleak with sac expansion from 57 mm to 75 mm during 4-year follow-up after endovascular abdominal aortic aneurysm repair. The patient underwent transabdominal embolization with coils and N-butyl cyanoacrylate/ethiodized oil (Lipiodol; Guerbet, Villepinte, France) mixture (2.5 mL). Because of the anticipated embolization artifacts on follow-up computed tomography (CT), technetium-99m-labeled human serum albumin diethylenetriamine pentaacetic acid single-photon emission computed tomography ((99m)Tc-HSAD SPECT) was performed before and after the intervention. Perigraft accumulation on (99m)Tc-HSAD SPECT corresponding to the endoleak disappeared after embolization. CT scan performed 12 months after embolization showed no signs of sac expansion. (99m)Tc-HSAD SPECT may be useful for evaluating therapeutic effect after embolization for endoleak. PMID:24581463

Nakai, Motoki; Sato, Hirotatsu; Ikoma, Akira; Sonomura, Tetsuo; Sato, Morio

2014-03-01

86

Use of technetium-99m isonitrile (RP-30A) in assessing left ventricular perfusion and function at rest and during exercise in coronary artery disease, and comparison with coronary arteriography and exercise thallium-201 SPECT imaging  

SciTech Connect

This study compared the results of stress and rest single-photon emission computed tomography imaging of myocardial perfusion using technetium-99m isonitrile (RP-30A) with the results of stress and redistribution tomographic thallium imaging and the results of coronary arteriography in 39 patients, 11 without and 28 with coronary artery disease (CAD). Each patient underwent 2 exercise studies at identical workload, heart rate and double product. In a subset of 13 patients, concomitant evaluation of left ventricular (LV) function using first-pass radionuclide angiography with a multi-crystal camera also was performed with bolus injections of isonitrile. Isonitrile had similar sensitivity (82 vs 82%, difference not significant), a slightly--but not significantly--higher specificity (100 vs 82%) and similar predictive accuracy (87 vs 82%) to thallium-201. The tracer uptake was assessed in 20 segments/study. There was concordance between the isonitrile and thallium-201 images in 723 of the 780 segments (93%) (kappa = 0.83 +/- 0.02). In general, the isonitrile images were considered of better quality than the thallium-201 images. All 10 patients with CAD who underwent concomitant first-pass radionuclide angiography had either perfusion abnormalities or an abnormal ejection fraction response to exercise. Thus, technetium-99m isonitrile provides a reliable method of assessment of CAD with a sensitivity, specificity and predictive accuracy comparable to that of exercise thallium-201 imaging. Additional advantages include better image quality and the ability to obtain concomitant assessment of LV function with the use of first-pass radionuclide angiography.

Iskandrian, A.S.; Heo, J.; Kong, B.; Lyons, E.; Marsch, S. (Philadelphia Heart Institute, PA (USA))

1989-08-01

87

Comparison of early myocardial technetium-99m pyrophosphate uptake to early peaking of creatine kinase and creatine kinase-MB as indicators of early reperfusion in acute myocardial infarction  

SciTech Connect

The value of technetium-99m pyrophosphate (Tc-99m-PYP) scintigraphy as an indicator of reperfusion 2.8 to 8 hours after the onset of symptoms of acute myocardial infarction was compared with the value of early peak creatine kinase (CK) and CK-MB release within 16 hours after the onset of symptoms. In 29 patients who received thrombolytic therapy, recanalization was seen (group 1) and in 7 it was not (group 2). In 23 patients (79%) in group 1 scintigraphic findings were positive and in all 7 in group 2 they were negative. In 15 patients (52%) in group 1 and 1 patient (14%) in group 2, CK reached its peak level within 16 hours. In 20 patients (69%) in group 1 and 3 (43%) in group 2 the CK-MB level reached a peak within 16 hours. The sensitivity, specificity and predictive accuracy of positive results of early Tc-99m-PYP scintigraphy in predicting the reperfusion were 79%, 100% and 83%. These values are significantly higher than or similar to those of early peaking of CK and CK-MB release. In contrast to measurements of enzyme release, reperfusion data for Tc-99m-PYP scintigraphy are available immediately after thrombolytic therapy. Therefore, early Tc-99m-PYP scintigraphy (3 to 8 hours after onset of symptoms) is valuable as a noninvasive technique for early diagnosis of reperfusion.

Kondo, M.; Yuzuki, Y.; Arai, H.; Shimizu, K.; Morikawa, M.; Shimono, Y.

1987-10-01

88

Effect of extract of medicinal plants on the labeling of blood elements with Technetium-99m and on the morphology of red blood cells: I--a study with Paullinia cupana.  

PubMed

Drugs can alter the labeling and the morphology of red blood cells. As Paullinia cupana is used in popular medicine, we evaluated its influence on the labeling process using technetium-99m (Tc-99m). Blood was incubated with P. cupana, stannous chloride and Tc-99m. Samples were centrifuged and plasma (P) and blood cells (BC) were separated and precipitated with trichloroacetic acid. Soluble (SF) and insoluble fractions (IF) were isolated. The morphology of the blood cells was evaluated under an optical microscope. The results showed a significant (P = 0.05) decrease in the uptake of radioactivity for the RBC (97.93 +/- 0.74 to 36.90 +/- 4.71%), in IF-P and in IF-BC due to P. cupana extract. The study of the morphology of the RBC revealed alterations in the shape of these cells. We suggest that the P. cupana effect could be explained by an inhibition of the stannous and pertechnetate ions or oxidation of the stannous ion or by damages in the plasma membrane. PMID:12234573

de Oliveira, J F; Avila, A S; Braga, A C S; de Oliveira, M B N; Boasquevisque, E M; Jales, R L; Cardoso, V N; Bernardo-Filho, M

2002-07-01

89

Evaluation of the phytic acid effect on the labeling of blood elements with technetium-99m and on the survival of a strain of Escherichia coli treated with stannous fluoride.  

PubMed

The labeling of red blood cells with technetium-99m (99mTc) depends on a reducing agent and stannous ions, as chloride or fluoride, are widely utilized. This labeling may also be altered by drugs. Moreover, some authors have reported that the survival of Escherichia coli (E. coli) cultures decreases in presence of stannous ions. Phytic acid is present in the daily diet and we evaluated its influence on: (i) the labeling of blood elements with 99mTc and (ii) on the survival of an E. coli strain treated with stannous fluoride. Heparinized whole blood was withdrawn from Wistar rats and it was incubated with stannous chloride and with 99mTc, as sodium pertechnetate, centrifuged and plasma (P) and blood cells (BC) were isolated. Samples of P and BC were also precipitated with trichloroacetic acid, centrifuged and soluble (SF) and insoluble fractions (IF) isolated. E. coli culture was treated with stannous fluoride in presence of phytic acid. As phytic acid altered the fixation of 99mTc on BC, on IF-P and on IF-BC and, moreover, it abolished the lethal effect of stannous fluoride on the E. coli culture, we can suggest that, probably, phytic acid would have chelating properties to the stannous ions. PMID:12841639

Lima-Filho, G L; Lima, G M T; Freitas, R S; Aleixo, L C M; Moreno, S R F; Catanho, M T J A; Bernardo-Filho, M

2003-05-01

90

Quality control of Tc-99m DTPA for measurement of glomerular filtration: concise communication  

SciTech Connect

When technetium-99m DTPA is used to measure glomerular filtration rate (GFR), the accuracy depends on the supplier of the radiopharmaceutical. The error in GFR is due to protein binding, as we have shown by direct measurement. In 19 patients, GFR measured with Tc-DTPA and corrected for protein binding agreed with that measured simultaneously using Yb-169 DTPA (correlation coefficient 0.991). Without correction, Tc-DTPA gave falsely low values in patients having good renal function, in whom unbound activity cleared rapidly while bound activity remained in the circulation. When Tc-DTPA is used to measure GFR, the in vivo protein binding should be measured and used to correct the data.

Russell, C.D. (Univ. of Alabama, Birmingham); Bischoff, P.G.; Rowell, K.L.; Kontzen, F.; Lloyd, L.K.; Tauxe, W.N.; Dubovsky, E.V.

1983-08-01

91

Validation of technetium-99m stannous pyrophosphate myocardial scintigraphy for diagnosing acute myocardial infarction more than 48 hours old when serum creatine kinase-MB has returned to normal  

SciTech Connect

Determination of lactic dehydrogenase (LDH) isoenzymes is the current method of choice for diagnosing acute myocardial infarction (AMI) greater than 48 hours old. However, other causes of enzyme elevation make the availability of an alternate method of diagnosis worthwhile. Accordingly, serial technetium-99m pyrophosphate scintigrams were obtained in 61 patients with transmural AMI and in 46 patients with subendocardial AMI. Imaging was performed in all 107 patients at the time creatine kinase isoenzyme (CK-MB) was present 37 +/- 18 hours (range 12 to 72) after the onset of AMI, and at the time CK-MB was absent 106 +/- 34 hours (range 48 to 168) after the onset of AMI. At the time CK-MB was absent, the sensitivity using either a regional or a diffuse positive scintigram was 95% (58 of 61 patients) for transmural AMI and 65% (30 of 46 patients) for subendocardial AMI. The sensitivity using a regional positive scintigram was 82% (50 of 61 patients) for transmural AMI and 37% (17 of 46 patients) for subendocardial AMI. The sensitivity using a high-grade regional positive scintigram was 36% (22 of 61 patients) for transmural AMI and 11% (5 of 46 patients) for subendocardial AMI. The specificity was 70% (143 of 204 patients) for either a regional or a diffuse abnormality, 92% (187 of 204 patients) for a regional abnormality, and 100% (204 of 204 patients) for a high-grade regional abnormality. Thus, pyrophosphate scintigraphy is useful in confirming the diagnosis of AMI, particularly transmural, greater than 48 hours old and when CK-MB has returned to normal. A positive scintigram with a high-grade regional abnormality is specific for a recent AMI and may be contributory in establishing the diagnoses when LDH isoenzymes are inconclusive.

Olson, H.G.; Lyons, K.P.; Butman, S.; Piters, K.M.

1983-08-01

92

Biliary excretion of technetium-99m-sestamibi in wild-type dogs and in dogs with intrinsic (ABCB1-1Delta mutation) and extrinsic (ketoconazole treated) P-glycoprotein deficiency.  

PubMed

P-glycoprotein (P-gp), the product of ABCB1 gene, is thought to play a role in the biliary excretion of a variety of drugs, but specific studies in dogs have not been performed. Because a number of endogenous (ABCB1 polymorphisms) and exogenous (pharmacological P-gp inhibition) factors can interfere with normal P-gp function, a better understanding of P-gp's role in biliary drug excretion is crucial in preventing adverse drug reactions and drug-drug interactions in dogs. The objectives of this study were to compare biliary excretion of technetium-99m-sestamibi ((99m)Tc-MIBI), a radio-labelled P-gp substrate, in wild-type dogs (ABCB1 wild/wild), and dogs with intrinsic and extrinsic deficiencies in P-gp function. Dogs with intrinsic P-gp deficiency included ABCB1 mut/mut dogs, and dogs with presumed intermediate P-gp phenotype (ABCB1 mut/wild). Dogs with extrinsic P-gp deficiency were considered to be ABCB1 wild/wild dogs treated with the P-gp inhibitor ketoconazole (5 mg/kg PO q12h x 9 doses). Results from this study indicate that ABCB1 mut/mut dogs have significantly decreased biliary excretion of (99m)Tc-MIBI compared with ABCB1 wild/wild dogs. Treatment with ketoconazole significantly decreased biliary excretion of (99m)Tc-MIBI in ABCB1 wild/wild dogs. P-gp appears to play an important role in the biliary excretion of (99m)Tc-MIBI in dogs. It is likely that concurrent administration of a P-gp inhibitor such as ketoconazole will decrease P-gp-mediated biliary excretion of other substrate drugs as well. PMID:19754906

Coelho, J C; Tucker, R; Mattoon, J; Roberts, G; Waiting, D K; Mealey, K L

2009-10-01

93

Effect of an extract of cauliflower (leaf) on the labeling of blood elements with technetium-99m and on the survival of Escherichia coli AB1157 submitted to the treatment with stannous chloride.  

PubMed

The labeling of red blood cells (RBC) with technetium-99m (99mTc) depends on a reducing agent and stannous chloride (SnCl(2)) and is widely utilized. This labeling may also be altered by drugs, and SnCl(2) reduces the survival of Escherichia coli cultures. Cauliflower (Brassica oleracea L. var. botrytis) is used in folk medicine and we evaluated its influence on (i) the labeling of blood elements with 99mTc, and (ii) on the survival of an E. coli strain. Blood was withdrawn from rats that drank the extract of cauliflower (15 days). Blood was incubated with SnCl(2) and with 99mTc, as sodium pertechnetate, centrifuged and plasma (P) and RBC were isolated. Samples of P and RBC were also precipitated, centrifuged and soluble and insoluble fractions isolated. E. coli culture was treated with SnCl(2) in the presence of cauliflower. The extract of cauliflower did not alter the fixation of 99mTc on blood fractions; however, it abolished the lethal effect of SnCl(2) on the E. coli culture. We suggest that the substances present in the extract of cauliflower probably, would have redox property with different mechanisms of action. The oxidant action of the substances of the extract would not be strong enough to oxidise the stannous ions altering the 99mTc-labeling. However, the referred substances could oxidise these ions sufficiently to protect the E. coli culture against the lethal effect of the stannous ion. PMID:12065213

Lima, E A C; Diré, G; Mattos, D M M; Freitas, R S; Gomes, M L; de Oliveira, M B N; Faria, M V C; Jales, R L; Bernardo-Filho, M

2002-07-01

94

Feasibility of aerosol drug delivery to sleeping infants: a prospective observational study  

PubMed Central

Objectives Delivery of inhaled medications to infants is usually very demanding and is often associated with crying and mask rejection. It has been suggested that aerosol administration during sleep may be an attractive alternative. Previous studies in sleeping children were disappointing as most of the children awoke and rejected the treatment. The SootherMask (SM) is a new, gentle and innovative approach for delivering inhaled medication to infants and toddlers. The present pilot study describes the feasibility of administering inhaled medications during sleep using the SM. Design Prospective observational study. Setting Out patients. Participants 13 sleeping infants with recurrent wheezing who regularly used pacifiers and were <12?months old. Intervention Participants inhaled technetium99mDTPA-labelled normal saline aerosol delivered via a Respimat Soft Mist Inhaler (SMI) (Boehringer-Ingelheim, Germany) and SM + InspiraChamber (IC; InspiRx Inc, New Jersey, USA). Outcomes The two major outcomes were the acceptability of the treatment and the lung deposition (per cent of emitted dose). Results All infants who fulfilled the inclusion criteria successfully received the SM treatment during sleep without difficulty. Mean lung deposition (±SD) averaged 1.6±0.5% in the right lung. Conclusions This study demonstrated that the combination of Respimat, IC and SM was able to administer aerosol therapy to all the sleeping infants who were regular pacifier users with good lung deposition. Administration of aerosols during sleep is advantageous since all the sleeping children accepted the mask and ensuing aerosol therapy under these conditions, in contrast to previous studies in which there was frequent mask rejection using currently available devices. Clinical Trial Registry NCT01120938. PMID:24670428

Amirav, Israel; Newhouse, Michael T; Luder, Anthony; Halamish, Asaf; Omar, Hamza; Gorenberg, Miguel

2014-01-01

95

Evaluation of lung epithelial permeability in the volatile substance abuse using Tc99m DTPA aerosol scintigraphy  

Microsoft Academic Search

Aim  Chronic inhalant use is associated with significant toxic effects, including neurological, renal, hepatic, and pulmonary damage.\\u000a However, there is a paucity of reports regarding respiratory complications in inhalant abusers. The aim of this study was\\u000a to evaluate pulmonary epithelial permeability in the volatile substance abuse (VSA) using Tc-99m DTPA aerosol scintigraphy.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  This study included 18 patients with volatile substance abuse

Derya Cayir; Koray Demirel; Meliha Korkmaz; Gokhan Koca

96

Gallbladder visualization with technetium-99m glucoheptonate: concise communication  

SciTech Connect

Marked gallbladder concentration of glucoheptonate during renal function studies in dogs prompted a prospective study in order to assess the frequency of similar findings in human subjects. Of a total of 62 patients studied, the gallbladder was visualized clearly in 17 of the 18 patients (94%) who had documented normal hepatobiliary and renal function, and who were examined in a fasted state. In 38 nonfasting patients, only eight (22%) had gallbladder visualization. These findings may prove important in the interpretation of glucoheptonate renal studies in order to avoid confusion caused by a glucoheptonate-filled gallbladder lying close to the right kidney.

Tyler, J.L. (Veterans Administration Medical Center, Nashville, TN); Powers, T.A.

1982-10-01

97

Septal infarction demonstrated on technetium-99m PYP SPECT  

SciTech Connect

The case of a 62-year-old man with an acute myocardial infarction detected by planar Tc-99m PYP imaging is presented. The use of SPECT imaging provided more information with regard to infarct localization by demonstrating uptake by the septum, a finding not apparent on the conventional planar images.

Intenzo, C.M.; Koh, Y.B.; Madsen, M.T.; Park, C.H.

1986-02-01

98

Colonic varices demonstrated by technetium-99m red cell scintigraphy  

SciTech Connect

Colonic varices is a rare condition, generally associated with portal hypertension, which normally presents as acute, severe, gastrointestinal blood loss. A case is presented in which the varicosities were observed serendipitously in a patient with a pancreatic tumor, in whom the bleeding was not variceal but due to two small unrelated gastric hemangiomas. The literature is reviewed and scintigraphic features described.

Brill, D.R.

1987-03-01

99

Leukocyte labeling with technetium-99m tin colloids.  

PubMed

Triple density gradients of metrizamide in plasma (MP) were used to characterize label distribution in human leukocyte preparations incubated with 99mTc tin colloids. Less than 50% of the cell-associated radioactivity was specifically bound to leukocytes when heparinized blood was rotated with stannous fluoride colloid ([Tc]SFC). Labeling efficiency in leukocyte rich plasma (LRP) averaged 44%, of which greater than 90% was specifically bound to leukocytes. MP-gradient analysis also revealed that leukocyte labeling did not occur with stannous chloride colloid, nor when citrate was present during rotation with [Tc]SFC. When citrate was added after labeling to "solubilize" unbound [Tc]SFC, radiocolloid was removed from the leukocytes, indicating that the mechanism of [Tc]SFC labeling is adherence rather than phagocytosis. Technetium-labeled neutrophils exhibited normal in vitro chemotaxis and no lung uptake in vivo. Technetium-labeled mononuclear leukocytes, on the other hand, exhibited prolonged lung transit in vivo. Neither [Tc]SFC cell preparation showed signs of in vivo reoxidation to pertechnetate. PMID:3625299

Mock, B H; English, D

1987-09-01

100

Technetium-99m-labeled lymphocytes: a radiotoxicity study  

SciTech Connect

Radiolabeled white blood cells offer a unique clinical diagnostic technique. However, radiotoxicity to these radiosensitive cells must be carefully considered. Indium-111 has been shown to produce significant chromosomal alteration even at subscintigraphic doses. It has been suggested that /sup 99m/Tc is less radiotoxic and may be desirable even though labeling is less efficient. The radiotoxicity of bound /sup 99m/Tc was investigated in human lymphocytes by determination of division delay and chromosomal aberration as a function of increasing /sup 99m/Tc activity concentration. This data revealed that human lymphocytes demonstrate significant division delay above 0.580 mCi/10(7) cells with chromosomal damage equivalent to 1 Gy of 250 keV x-ray at this level.

Merz, T.; Tatum, J.; Hirsch, J.

1986-01-01

101

Technetium-99m biliary imaging in pediatric surgical problems  

SciTech Connect

The results of scintigraphic imaging of the hepatobiliary system with 99mTc-PIPIDA (IDA derivative p-isopropylacetanilidoiminodiacetic acid) in forty children are reported. 99mTc-PIPIDA imaging is a noninvasive, rapid, safe examination that provides both functional and anatomical information about the hepatobiliary system. Although interpretation is limited by elevated direct serum bilirubin, this agent allows diagnostic information to be obtained with direct serum bilirubin levels up to 8 mg/dl.

Sty, J.R.; Glicklich, M.; Babbitt, D.P.; Starshak, R.J.

1981-10-01

102

Splenic uptake of both technetium-99m diphosphonate and technetium-99m sulfur colloid in sickle cell beta degrees thalassemia  

SciTech Connect

A 19-year-old black woman with sickle cell beta degrees thalassemia had experienced more than 100 hospital admissions for sickle cell crisis and aseptic necrosis of both femoral heads. Her spleen was enlarged threefold and accumulated both radiocolloid and bone-seeking agent on two occasions, demonstrating an exception to the rule in sickle cell anemia that spleens that take up bone-seeking agents demonstrate functional asplenia. In the context of fever, left upper quadrant pain, and splenomegaly, the pattern of calcification in the patient's spleen as revealed in ultrasound and CT studies suggested possible abscess and led to unnecessary splenectomy. The nuclear medicine studies did not support this diagnosis. Nuclear medicine physicians should not be misled by splenic findings of sickle cell thalassemia (and possibly of other heterozygous sickle cell disorders) that differ from those of the more familiar homozygous sickle cell anemia.

Heck, L.L.; Brittin, G.M. (Methodist Hospital of Indiana, IN (USA))

1989-08-01

103

Comparison of technetium-99m-HMPAO and technetium-99m-ECD cerebral SPECT images in Alzheimer`s disease  

SciTech Connect

SPECT has shown increasing promise as a diagnostic tool in Alzheimer`s disease (AD). Recently, a new SPECT brain perfusion agent, {sup 99m}Tc-ethyl cysteinate dimer ({sup 99m}Tc-ECD) has emerged with purported advantages in image quality over the established tracer, {sup 99m}Tc-hexamethylpropyleneamine oxime ({sup 99m}Tc-HMPAO). This research aimed to compare cerebral images for ({sup 99m}Tc-HMPAO). This research aimed to compare cerebral images for {sup 99}mTc-HMPAO and {sup 99m}Tc-ECD in discriminating patients with AD form control subjects. 51 refs., 5 figs., 3 tabs.

Dyck, C.H. van; Lin, C.H.; Smith, E.O. [Yale Univ. School of Medicine, New Haven, CT (United States)] [and others

1996-11-01

104

Assessment of Left Ventricular Volume Using ECG-Gated SPECT with Technetium99m-MIBI and Technetium99m-Tetrofosmin  

Microsoft Academic Search

We evaluated ECG-gated SPECT (g-SPECT)in the measurement of absolute left ventricular (LV) volume by comparing it with left ventriculography (LVG) and with cine-MRI. Methods: Projection data from 31 patients were acquired with a three-headed SPECT system in 12 min using a 64 x 64 matrix with 1.5 zoom (1 pixel = 4.27 mm). The R-R interval from simultaneously acquired EGGwas

Teruhito Mochizuki; Hiroaki Tanaka; Ken Hamamoto; W. Newlon Tauxe

105

Production of Molybdenum-99 by (n, ) activation and direct separation of Technetium-99m without column generator fabrication: A viable strategy for enhanced availability of technetium-99m  

SciTech Connect

Fission-produced 99Mo (F 99Mo) is traditionally used for fabrication of 99Mo/99mTc adsorption-type column generators. In this paper, several emerging strategies that are being pursued or have been suggested to overcome the continuing shortages of F 99Mo are discussed. To provide an alternative source of 99Mo, the principal focus of this analysis is a detailed discussion of the advantages and strategies for enhanced production of low-specific-activity 99Mo (LSA 99Mo) by direct activation of molybdenum targets in nuclear reactors. In order to enhance the availability of 99Mo, development of an increased network of reactors for production of LSA 99Mo is described, as well as utilization of currently unused reactors. The time spent in manufacturing of 99Mo/99mTc column generators is responsible for the loss of more than 50% of F99Mo produced. Hence, the authors propose a paradigm shift in the use of 99Mo by recovering clinical-grade 99mTc from 99Mo solution as an alternative to use of 99Mo/99mTc column generators, thereby avoiding substantial decreased availability of 99Mo from radioactive decay. Implementation of the suggested strategies would be expected to increase availability of 99mTc to the clinical user community by several folds. Additional important advantages of the use of LSA 99Mo include precluding the need for fission product waste management and phasing out the need for high- and low-enriched uranium as target materials for medical radioisotope production.

Knapp Jr, Russ F [ORNL; Pillai, M R A [Bhabha Atomic Research Centre, Mumbai, India

2012-01-01

106

DTPA (Diethylenetriamine pentaacetate)  

MedlinePLUS

... to Top Who can take DTPA? Doctors and public health authorities will work together to decide who likely will ... internal radioactive contamination. In this case, doctors and public health authorities may prescribe a single dose of Ca-DTPA, ...

107

Quantitative planar imaging with technetium-99m methoxyisobutyl isonitrile: Comparison of uptake patterns with thallium-201  

SciTech Connect

To compare the myocardial uptake pattern of 99mTc-labeled methoxyisobutyl isonitrile (( 99mTc) MIBI) and 201TI, planar scintigraphy were performed in both patients with documented coronary artery disease and subjects with a low likelihood of disease. Quantitative analysis was employed using a standard interpolative background subtraction algorithm and a new algorithm modified to better accommodate for the differences in extracardiac activity seen with (99mTc)MIBI rest images. Among patients with coronary artery disease, the standard algorithm yielded no significant difference in relative defect magnitude between (99mTc)MIBI and 201TI on stress scintigrams (p = 0.48), although the magnitude of (99mTc)MIBI defects was greater on resting images (p = 0.02). When the modified algorithm was employed, defect magnitude was similar for both stress (p = 0.91) and rest (p = 0.20) images. Normal segmental uptake ratios derived from a comparison of contralateral segments (e.g., septal:posterolateral) in the low likelihood patients were similar for both (99mTc)MIBI and 201TI. Thus, modification of the standard interpolative background subtraction algorithm is necessary for quantitative planar (99mTc)MIBI perfusion imaging. When appropriate background subtraction is employed, myocardial uptake and quantitative defect magnitude of (99mTc)MIBI and 201TI planar images are similar.

Sinusas, A.J.; Beller, G.A.; Smith, W.H.; Vinson, E.L.; Brookeman, V.; Watson, D.D. (Univ. of Virginia Health Sciences Center, Charlottesville (USA))

1989-09-01

108

Technetium-99m galactosyl-neoglycoalbumin (Tc-NGA) liver imaging: Application in liver transplantation  

SciTech Connect

Tc-NGA is a new liver imaging agent which binds to hepatic binding protein (HBP), a hepatocyte-specific membrane receptor. The purpose of the present study was to evaluate the potential role of Tc-NGA imaging in liver transplantation. The molar Tc-NGA dose was standardized according to patient weight (0.7 nmole/kg). After a 30 minute dynamic imaging study (5 mCi, IV), kinetic analysis of time activity data (heart, liver), provided values for receptor concentration, (HBP), and hepatic blood flow, Q. Eleven Tc-NGA imaging studies were performed in transplant candidates and 22 studies were performed in seven transplant recipients. Preservation damage was manifested by diffuse patchiness in tracer distribution which resolved during the following two weeks. Histologically proven, localized hepatic infarcts were demonstrated in three recipients. Lobar infarction was demonstrated in one recipient. Hepatic regeneration was later demonstrated in this patient after hepatic lobectomy. Hepatic blood flow was markedly decreased in the early postoperative period, but improved with time. Increased (HBP) was demonstrated with regeneration. Markedly decreased (HBP) and Q were obtained in several candidates who died awaiting transplantation. These studies indicate that TC-NGA liver imaging provides a valuable new means for: (1) evaluation of preservation damage, (2) early demonstration of hepatic infarction, (3) evaluation of hepatic rejection, and (4) selection of patients for hepatic transplantation.

Woodle, E.S.; Ward, R.E.; Vera, D.R.; Stadalnik, R.C.

1985-05-01

109

Technetium-99m colloidal bismuth subcitrate: A novel method for the evaluation of peptic ulcer disease  

SciTech Connect

The therapeutic agent colloidal bismuth subcitrate (CBS) selectively binds to peptic ulcers. The authors have developed a method for labeling this agent with Tc-99m. Chromatographic quality control studies of the agent on silica gel coated strips (ITLC-SG) showed that more than 97% of Tc-99m was bound to CBS. During in-vitro stability testing, the radio-label was stable for a minimum of 6 hours. The chromatographic findings are in agreement with the in-vivo distribution of the agent which showed no significant radioactivity in thyroid, kidneys, liver, or bladder. The resulting Tc-99m-CBS solution is administered orally in drinking water. Preliminary animal studies have been conducted on 5 adult 3 kg New Zealand rabbits sedated with 50 mg Ketamine I.M. The rabbits were intubated with I.V. tubing advanced to the stomach. They were given a gastric erosive suspension of 600-1000 mg/kg of pulverized ASA in 10 cc tap water. Four hours later they were given 3-4 mCi of the radiotracer in a 5 cc volume of water. Serial in-vivo images were obtained for 2 hours which included thyroid, abdomen, and urinary bladder. Next the stomachs were excised, opened along the greater curvature, imaged, vigorously washed and reimaged. All 5 rabbits showed avid localized binding of radiotracer which remained fixed even with vigorous washing. Areas of normal appearing mucosa were relatively devoid of radiotracer. This new compound may have significant clinical usefulness in the detection of peptic ulcer disease. In addition, such a non-invasive technique, carrying none of the risks or discomfort of endoscopy could also find application in the evaluation of the response to therapy.

Vasquez, T.E.; Lyons, K.P.; Raiszadeh, M.; Fardi, M.; Snider, P.

1984-01-01

110

Preparation and evaluation of technetium-99m labeled cardiac glycoside derivatives as potential myocardial imaging agent.  

PubMed

Three cardiac glycosides, two natural, cymarin and convallotoxin and one synthetic, strophanthidin-beta-D-glucoside were converted to their thiosemicarbazone and subsequently radiolabeled with 99mTc by chelation. The resulting radioactive chelate complexes were evaluated in animals to determine the suitability of this class of compounds for myocardial imaging. It was observed from the animal biodistribution data of the three radioactive compounds, there was a considerable variation in the heart to non-target organ uptake ratio. A possible explanation of this variation was offered in the light of their lipophilic character, protein binding ability and affinity towards non-target receptors. It is anticipated that this study may help to develop a 99mTc-cardiac glycoside complex with better distribution characteristics, and such a compound may offer a suitable alternative to 201Tl, which is at present used for myocardial imaging. PMID:3255737

Misra, M; Sarkar, H S; Chatterjee, M; Banerjee, S

1988-01-01

111

The use of Technetium-99m stannous pyrophosphate imaging as an index of myocardial infarction  

E-print Network

OF FIGURES Figure Page 1. Infarction Grading System Based Upon Morphologic Changes in Heart Muscle. . 2. A Typical Electrocardiographic Sequence During Myocardial Infarction. 3. Modified Infa. rction Grading System Used For Indexing Morphologic..., decreases peripheral vascular resistance, increases venous return to the heart, and relaxes most smooth muscles. Excessive doses can produce a sharp drop in mean arterial pressure, and repeated administration of large doses may result in cardiac...

Sanford, Jeffrey Clayton

2012-06-07

112

Erythromycin hepatotoxicity. A rare cause of a false-positive technetium-99m DISIDA study  

SciTech Connect

An unusual cause of a cholescintigraphic, false-positive, erythromycin-induced hepatotoxicity is presented. This occurred in the presence of preservation of hepatic uptake and the normal appearance of gut activity. Serial scintigraphy and serum chemistries documented underlying gallbladder normalcy.

Swayne, L.C.; Kolc, J.

1986-01-01

113

Gallbladder visualization during technetium-99m-labeled red cell scintigraphy for gastrointestinal bleeding  

SciTech Connect

Localization of radionuclide activity in the gallbladder was seen on delayed views following injection of 99mTc-labeled red blood cells for gastrointestinal bleeding in five patients. The mechanism for this unusual finding probably relates to labeling of heme, the biochemical precursor of bilirubin. All patients had had prior transfusions. All but one had severe renal impairment, probably an important predisposing factor.

Brill, D.R.

1985-12-01

114

Gallbladder visualization during technetium-99m RBC blood pool imaging. Case report and literature review  

SciTech Connect

Gallbladder visualization occurred after a Tc-99m red blood cell (RBC) cardiac gated blood pool scan. To date, seven cases of gallbladder visualization after the intravenous injection of Tc-99m RBCs have been reported. In the previous six patients the gallbladder was visualized incidentally during a search for gastrointestinal (GI) bleeding. All of the patients were anemic, six of seven had chronic renal failure, and five of seven had received multiple blood transfusions. When interpreting GI bleeding scans in patients with anemia and renal failure, awareness of the possibility of gallbladder visualization in the delayed images is important to avoid false-positive results. 3 references.

Kotlyarov, E.V.; Mattay, V.S.; Reba, R.C.

1988-07-01

115

Technetium-99m pyrophosphate scintigraphy for the detection of acute myocardial infarction. How useful is it  

SciTech Connect

To evaluate the contribution of Tc-99m pyrophosphate scintigraphy (TPS) on the overall management of patients suspected of having acute myocardial infarction (AMI), hospital records of 58 consecutive patients who underwent TPS, were evaluated in depth. The results indicate that TPS was essential for the diagnosis of AMI in 16% of the patients. TPS was most rewarding in perioperative patients and in patients with borderline or uninterpretable electrocardiographic and enzyme changes. Also, in some cases, TPS was able to confirm or exclude the diagnosis of AMI prior to the confirmation by serial electrocardiograms (ECG) and serial enzyme changes. TPS was less rewarding in patients with clinically low index of suspicion for AMI. It may also be confusing in patients with high clinical likelihood of AMI and a history of prior myocardial infarction because of the possibility of persistently positive TPS in some of these patients. Considering the limitations of ECGs, the cardiac enzymes, and atypical clinical presentations in the patient population we evaluated, TPS appears to be fairly accurate when the scintigraphic findings are compared with the final diagnosis at the time of discharge from the hospital.

Desai, A.G.; Berger, B.C.; Shin, Y.W.; Park, C.H.; Madsen, M.T.

1985-09-01

116

Adrenal imaging with technetium-99m-labelled low density lipoproteins  

SciTech Connect

Plasma low density lipoproteins (LDL) are a major source of cholesterol for adrenal cortical steroid hormones synthesis. To test whether LDL labelled with Tc-99m could be used to assess adrenal cortical function, the authors prepared Tc-99m-LDL by dithionite reduction of Tc0/sub 4//sup -/ in the presence of LDL. About 80% of the Tc-LDL bonds were covalent. Purified Tc-99m-LDL was injected intravenously into 16 rabbits (4 t 8mCi/rabbit). External imaging was carried out 16 to 18 hrs later, at which time the adrenals were visualized clearly; the animals were sacrificed, the organs dissected out, weighed, and counted. The biodistribution demonstrated that 0.8l +- 0.19% of the injected radioactivity was taken up per gm of whole adrenal gland. This compared with an uptake of 0.19 +- 0.02% per gm by liver, 0.22 +- 0.04% per gm by spleen, and 0.11 +- 0.02% per gm by kidney. To verify that they were indeed imaging the adrenals, additional rabbits were tested with dexamethasone. First they were injected with Tc-99m-LDL; 28 hrs later the adrenals were again well visualized. Then the rabbits were given dexamethasone for 5 days to suppress adrenal cortical function. The adequacy of suppression was monitored by serum cortisol measurements. When Tc-99m-LDL was injected again, the adrenals could not be seen 18 hrs later. Counts of the adrenals from the suppressed rabbits were at background levels. These data indicate that Tc-99m-LDL is a useful radiopharmaceutical for evaluating adrenal cortical function.

Isaacsohn, J.L.; Lees, A.M.; Lees, R.S.; Kovach, M.B.; Strauss, H.W.

1984-01-01

117

Rapid washout of technetium-99m-MIBI from a large parathyroid adenoma  

SciTech Connect

The authors report a case of rapid {sup 99m}Tc-methoxyisobutylisonitrile (MIBI) clearance from a parathyroid adenoma. A double-phase {sup 99m}Tc-MIBI parathyroid scintigraphy was performed on a 62-yr-old female evaluated for primary hyperparathyroidism. A large parathyroid adenoma was visualized caudal to the left lobe of the thyroid gland with an unusually rapid washout of the tracer from tumor tissue. Histologic tissue examination confirmed the presence of a parathyroid adenoma and the absence of oxyphil cells. Care should be taken in interpretation of {sup 99m}Tc-MiBI parathyroid scintigrams because some adenomas can present a rapid release of the radiotracer in a double-phase study. Technitium-99m-MIBI retention could be related to the number of mitochondria-rich cells in parathyroid adenomas or to hyperplasia. 7 refs., 2 figs.

Benard, F.; Lefebvre, B.; Beuvon, F. [Universite de Sherbrooke, Quebec (Canada)] [and others

1995-02-01

118

Technetium 99m-methylene diphosphonate bone scans in children with reflex neurovascular dystrophy  

SciTech Connect

Eleven children with reflex neurovascular dystrophy were investigated by technetium-labeled methylene diphosphonate bone scanning. Eight of 12 scans demonstrated abnormal findings, four showing diffusely decreased uptake and four diffusely increased uptake of the radionuclide in the affected site. Three scans showed normal findings initially, as did one previously abnormal scan when repeated in the asymptomatic patient 6 months later. Diffusely abnormal findings can be helpful in the diagnosis of childhood reflex neurovascular dystrophy, but a normal scan does not exclude the diagnosis.

Laxer, R.M.; Allen, R.C.; Malleson, P.N.; Morrison, R.T.; Petty, R.E.

1985-03-01

119

New technetium-99m generator technologies utilizing polyethylene glycol-based aqueous biphasic systems  

SciTech Connect

Two new schemes for TcO{sub 4}{sup {minus}}/MoO{sub 4}{sup 2{minus}} separations from OH{sup {minus}} and MoO{sub 4}{sup 2{minus}} media using polyethylene glycol (PEG)-based aqueous biphasic systems (ABS) have been developed. The two most important salt solutions in current {sup 99m}Tc-generator technologies, OH{sup {minus}} and MoO{sub 4}{sup 2{minus}}, also salt out PEG to form ABS. In liquid/liquid PEG- ABS, pertechnetate can be separated from molybdate with separation factors as high as 10,000. Stripping is accomplished by reduction of the TcO{sub 4}{sup {minus}} and back extraction into a salt solution. the strip solution can be the salt of an imaging agent (e.g., Na{sub 4}HEDPA) and thus may, under the appropriate conditions, be injected directly into the human body. {sup 99m}TcO{sub 4}{sup {minus}} can also be concentrated from a dilute load solution of {sup 99}MoO{sub 4}{sup 2{minus}} in NaOH using an aqueous biphasic extraction chromatographic technique (ABEC). A rinse with K{sub 2}CO{sub 3} assures that all {sup 99}MoO{sub 4}{sup 2{minus}} is removed from the column and this is confirmed by a rapid drop in {sup 99}Mo activity by the fourth free column volume (fcv) of rinse. The {sup 99m}TcO{sub 4}{sup {minus}} is then eluted with water. This chromatographic separation affords 94% of the {sup 99m}TcO{sub 4}{sup {minus}} activity in 5 fcv, with the y spectrum showing less than 2 {times} 10{sup {minus}4} of the original {sup 99}Mo activity.

Rogers, R.D.; Bond, A.H.; Zhang, Jianhua [Northern Illinois Univ., De Kalb, IL (United States). Dept. of Chemistry; Horwitz, P. [Argonne National Lab., IL (United States)

1995-12-31

120

Dose to the liver and spleen in pediatric patients undergoing technetium-99m sulfur colloid scans  

Microsoft Academic Search

Quantitative conjugate view external counting techniques were applied to determine radiation dose to the liver and spleen in pediatric patients undergoing \\/sup 99m\\/Tc-sulfur colloid (Tc-SC) liver scans. The effective half-life of \\/sup99m\\/Tc-SC was 5.8 +- 0.23 hours and 5.2 +- 0.68 hours in the liver and spleen, respectively. Dose per administered activity ranged from 0.34 to 0.63 rad\\/mCi (92 to

S. R. Thomas; R. C. Purdom; J. G. Kereiakes; M. J. Gelfand; H. R. Maxon

1979-01-01

121

Value of obtaining renal images following brain scintigraphy with technetium-99m glucoheptonate  

SciTech Connect

The value of adding an extra view of the kidneys immediately following brain imaging with Tc-99m glucoheptonate was investigated in a two-year retrospective study at our institution. Between October 1982 and October 1984, 561 individuals underwent Tc-99m glucoheptonate brain imaging with the added renal view. Twenty-nine of these individuals (5.2%) demonstrated renal abnormalities. The abnormal renal findings were clinically correlated in 24 of these persons. Sixteen (67%) of these 24 individuals were unaware of any renal abnormality. Useful information can be obtained from renal images incidental to brain imaging at no added expense or radiation exposure to the patient, and at a minimal cost in time to the imaging clinic.

Moreno, A.J.; Rodriguez, A.A.; Spicer, M.J.; Jackson, R.E.; Byrd, B.F.; Turnbull, G.L.

1986-08-01

122

Evaluation in dogs and humans of three potential technetium-99m myocardial perfusion agents  

SciTech Connect

The biodistribution of the three cationic /sup 99m/Tc complexes (/sup 99m/Tc(TMP)6)+, (/sup 99m/Tc(POM-POM)3)+, and (/sup 99m/Tc(TBIN)6)+--where TMP represents trimethylphosphite, POM-POM represents 1,2-bis(dimethyoxyphosphino)ethane, and TBIN represents t-butylisonitrile--have been evaluated in humans and dogs. Each agent was studied in three normal volunteers at rest, while (/sup 99m/Tc(POM-POM)3)+ and (/sup 99m/Tc(TBIN)6)+ were each studied in one normal volunteer at exercise. Even though all three agents yield good myocardial images in dogs, none appear suitable for clinical use as myocardial perfusion imaging radiopharmaceuticals. In humans, (/sup 99m/Tc(TMP)6)+ and (/sup 99m/Tc(POM-POM)3)+ clear very slowly from the blood and provide myocardial images only several hours after injection. (/sup 99m/Tc(TBIN)6)+ clears rapidly from the blood, but accumulation in the lung obscures the myocardial image for the first hour after injection; at later times, activity in the liver and spleen masks the apical wall. These results correlate with the blood-binding properties of the three complexes. (/sup 99m/Tc(TMP)6)+ and (/sup 99m/Tc(POM-POM)3)+ bind tightly to the plasma of human blood, but not to the plasma of dog blood; (/sup 99m/Tc(TBIN)6)+ does not bind tightly to the plasma of either dog or human blood. Among the Tc(I) complexes studied to date in humans, (/sup 99m/Tc(TBIN)6)+ appears to be unique in biodistribution pattern, blood-binding properties, and the fact that exercise improves the ultimate myocardial image. All the Tc(I) complexes appear to undergo myocardial accumulation by a mechanism different from that utilized by Tc(III) complexes. Animal studies alone are not adequate to evaluate the potential utility of /sup 99m/Tc cationic complexes for myocardial perfusion studies.

Gerundini, P.; Savi, A.; Gilardi, M.C.; Margonato, A.; Vicedomini, G.; Zecca, L.; Hirth, W.; Libson, K.; Bhatia, J.C.; Fazio, F.

1986-03-01

123

Comparison of iodine-131 OIH and technetium-99m MAG3 renal imaging in volunteers.  

PubMed

Animal studies have suggested that the nonisomeric N3S triamide mercaptide ligand, 99mTc mercaptoacetyltriglycine (MAG3), may provide a satisfactory 99mTc-labeled replacement for 131I hippurate (OIH). Sequential 30-min [99mTc]MAG3 (5-10 mCi) and [131I]OIH (300 microCi) imaging studies were performed in ten normal volunteers in order to compare the image quality, renal excretion, blood clearance, and time to peak height of the renogram curve. In addition, [99mTc] MAG3 (5 mCi) and [131I]OIH (150 microCi) were administered simultaneously in eight volunteers for comparison of 180-min blood and plasma clearances and urine excretion. In the sequential imaging studies, the blood clearance of [99mTc]MAG3 was more rapid than [131I]OIH with a mean clearance of 1.30 l/min compared with 0.88 l/min for [131I]OIH (p less than 0.05). Seventy-three percent of the injected dose of the MAG3 was excreted by 30 min compared with 66.8% for [131I]OIH. Whole kidney and cortical renogram curves showed no significant difference in the time to peak height for MAG3 and [131I]OIH. In all subjects, the quality of the [99mTc]MAG3 images were clearly superior to [131I]OIH. Following simultaneous injection, blood and plasma clearances for [131I]OIH were more rapid than MAG3 when determined for multiple time intervals from 0-30 to 0-180 min (p less than or equal to 0.05). The 0-30-min clearances of MAG3 and [131I]OIH were only slightly greater than the 0-180-min clearances and can be used to obtain valid comparisons of the two agents. As in the sequential study, 30-min urine excretion was greater for MAG3 than [131I]OIH (73.1 compared with 69.6%) but the difference was not statistically significant. Although the differences in the MAG3 clearances following sequential and simultaneous administration are not satisfactorily explained, the fact that both clearances were rapid, the MAG3 and OIH renogram curves were quite similar, and 30-min urine excretions of MAG3 and OIH were essentially identical suggests that MAG3 may become a 99mTc replacement for [13I]OIH and further clinical evaluation is warranted. PMID:2940350

Taylor, A; Eshima, D; Fritzberg, A R; Christian, P E; Kasina, S

1986-06-01

124

Extensive gastric varices demonstrated by technetium-99m red blood cell scintigraphy  

SciTech Connect

An alcohol abuse patient complicated by chronic pancreatitis had splenic vein thrombosis leading to gastric varices and underwent abdominal Tc-99m red blood cell scintigraphy. First pass study, sequential images up to 1 hour, and a 2.5 hour image showed abnormal radioactivity in the left side of the abdomen and midabdomen. In 24 hour images, the high level of activity in the left side persisted; in addition, there was accumulation of radioactivity in the cecum, ascending, transverse colon, the splenic flexure, and descending colon. A splenectomy was performed and during the surgical procedure, a large dilated vein in the greater omentum was noted. It is reemphasized that delayed imaging up to 24 hours is important when the results of earlier images are equivocal or negative.

Shih, W.J.; Domstad, P.A.; Loh, F.G.; Pulmano, C.

1987-04-01

125

Imaging of experimental myocardial infarction with technetium-99m 2,3-dimercaptosuccinic acid  

SciTech Connect

We have studied the use of Tc-99m-labeled 2,3-dimercaptosuccinic acid(Tc-99m DMSA) to scintigraph acute myocardial infaction after coronary occlusion in dogs. Optimal images were obtained 5 hr after injection of radiotracer, with consistent delineation 48 hr after occlusion. Delivery of tracer was dependent on blood flow. Uptake of tracer correlated to extent of infarction as determined by the myocardial depletion of creatine kinase. Myocardial Tc-99m DMSA was protein-bound.

Karlsberg, R.P.; Milne, N.; Lyons, K.P.; Aronow, W.S.

1981-03-01

126

In vivo hybridization of technetium-99m-labeled peptide nucleic acid (PNA)  

Microsoft Academic Search

Hybridization of a radiolabeled single-stranded DNA oligonucleotide with its single-stranded complement in vivo has not yet been convincingly demonstrated. A contributing factor may be unfavorable in vivo properties of the phosphodiester and phosphorothioate DNAs. Peptide nucleic acid (PNA) oligomers have been reported to possess in vivo properties more suitable for radiopharmaceutical applications. We have radiolabeled an amine-derivatized 15-base PNA oligomer

G. Mardirossian; K. Lei; M. Rusckowski

1997-01-01

127

In vivo hybridization of technetium-99m-labeled peptide nucleic acid (PNA)  

SciTech Connect

Hybridization of a radiolabeled single-stranded DNA oligonucleotide with its single-stranded complement in vivo has not yet been convincingly demonstrated. A contributing factor may be unfavorable in vivo properties of the phosphodiester and phosphorothioate DNAs. Peptide nucleic acid (PNA) oligomers have been reported to possess in vivo properties more suitable for radiopharmaceutical applications. We have radiolabeled an amine-derivatized 15-base PNA oligomer with {sup 99m}Tc through a modified MAG{sub 3} chelator. The ability of the PNA to hybridize in vitro with its complement appeared to be unimpaired after conjugation and radiolabeling. Size-exclusion, high-performance liquid chromatography (HPLC) analysis of 37{degree}C serum after 24 hr of incubation showed the radiolabel to be present predominately as labeled PNA with indications of labeled serum proteins and a low molecular weight catabolite. Whole-body clearance in mice was rapid, with 50% of the label eliminated in about 2 hr. After 2.5 hr, the highest uptake (kidneys) was only 1.5% of the injected dose/g; less than 0.07%/g was present in all sampled tissues at 24 hr. To evaluate in vivo hybridization, beads were implanted subcutaneously in both thighs of normal mice. In the left thigh only, the beads were conjugated with complementary single-stranded PNA. At 23 hr following intraperitoneal administration of the labeled PNA, the left/right thigh radioactivity ratio was 6:1. Whole-body images at this time showed only bladder, kidneys and the left thigh. Unlike the radiolabeled DNAs investigated in this laboratory, {sup 99m}Tc-PNA displays stability and pharmacokinetic properties suitable for eventual use as radiopharmaceuticals.

Mardirossian, G.; Lei, K.; Rusckowski, M. [Univ. of Massachusetts Medical Center, Worcester, MA (United States)] [and others

1997-06-01

128

Patent umbilical vein. Diagnosis by technetium-99m tagged red blood cell scintigraphy  

SciTech Connect

Abdominal scanning with Tc-99m labeled red blood cells serendipitously demonstrated collateral flow in a patent umbilical vein in a patient with unsuspected advanced cirrhotic liver disease and portal hypertension. Knowledge of this was crucial in planning the optimal surgical approach in this patient, referred for resection of a bladder carcinoma. Furthermore, the nuclide study was helpful in clarifying several questions posed by a prior abdominal pelvic CT scan.

Gouse, J.C.; Williamson, B.R.; Brookeman, V.A.; Teates, C.D.

1987-06-01

129

The relationship between technetium 99m pertechnetate gastric scanning and gastric contents.  

PubMed

In order to elucidate the gastric handling of 99Tcm, we performed scintiscanning under basal and stimulated conditions while simultaneously monitoring gastric outputs of water and sodium, hydrogen and 99Tcm pertechnetate ions in six healthy fasting volunteers. Our results showed that gastric scintiscanning correlated well with gastric luminal 99Tcm activity (r = 0.99). However, clearance of 99Tcm from plasma into the gastric lumen showed only a poor correlation with hydrogen ion output (r = 0.68) and no correlation with sodium output. Explanation of these results on a cellular basis can be achieved by assuming a two-component mechanism for 99Tcm secretion, with both the parietal cells (H+ ion secretory) and non-parietal cells (Na+ ion secretory) contributing to 99Tcm gastric output. The relative contribution of each cell type to total 99Tcm secretion is dependent on the degree of gastric stimulation, with non-parietal 99Tcm secretion dominating in the basal state and parietal 99Tcm secretion dominating in the stimulated state. It is concluded therefore, that gastric scintiscanning with 99Tcm pertechnetate should stand only as an empirical test of gastric function and not as a means of measuring acid output. PMID:6313111

O'Connor, M K; O'Connell, R; Keane, F B; Byrne, P J; Hennessy, T P

1983-11-01

130

The in vitro stability in human plasma of two different technetium-99m-fibrinogen compounds.  

PubMed

Two 99mTc -labeling methods of human fibrinogen resulted in different complexes. This was concluded from different dissociation rates in human plasma. The dissociation could be described by a simple exponential function. PMID:6327361

Spicher, E; Gieux, B; Fridrich, R

1984-06-15

131

Hormonal enhancement of technetium-99m pertechnetate uptake in experimental Meckel's diverticulum  

SciTech Connect

A canine model simulating Meckel's diverticulum was used to evaluate the effects of pentagastrin, glucagon, and a combination of the two hormones on the gastrointestinal localization of 99mTc. Pentagastrin produced accelerated uptake of the radionuclide in both the stomach and the ectopic gastric mucosa but resulted in early visualization of the duodenum and a washout effect on the radioisotope within the Meckel's diverticulum. Glucagon provided prolonged retention of the radionuclide in the stomach and ectopic mucosa and prevented duodenal visualization. A combination of both hormones produced increased activity in the stomach and experimental Meckel's and decreased duodenal filling. This enhanced target to background contrast and provided improved visualization of the ectopic gastric mucosa.

Anderson, G.F.; Sfakianakis, G.; King, D.R.; Boles, E.T. Jr.

1980-12-01

132

Technetium-99m BIDA biliary scintigraphy in the evaluation of the jaundiced patient  

SciTech Connect

Biliary scintigraphy using 99mTc p-butyl acetanilidiminodiacetic acid (BIDA) was performed as part of the diagnostic evaluation on 96 patients with jaundice (serum bilirubin greater than 2 mg/dl) to assess its value in this group of patients. The results of scintigraphy revealed no obstruction to the flow of the scintigraphic agent into the duodenum in 54 patients, delayed appearance of the agent (normal upper limit 60 min) in the duodenum indicating partial obstruction in 22 patients, and complete obstruction of the duct demonstrated by absence of agent in the duodenum in 20 patients. The findings were correlated with the final diagnosis and the overall results show accuracy of 92.7%, sensitivity of 97.3%, and specificity of 89.8%. Biliary scintigraphy was thus found to be useful in differentiating nonobstructive, partially obstructive, and completely obstructive causes of jaundice.

Lee, A.W.; Ram, M.D.; Shih, W.J.; Murphy, K.

1986-09-01

133

Distribution of technetium-99m-labeled multilamellar liposomes in patients with Hodgkin's disease  

SciTech Connect

The distribution of /sup 99m/Tc-labeled multilamellar liposomes composed of dimyristoyl phosphatidylcholine (DMPC) and dimyristoyl phosphatidylglycerol (DMPG) at a molar ratio of 7:3, administered intravenously, was studied in ten patients with Hodgkin's disease (HD). Whole-body imaging techniques were used, and for each organ an uptake index was calculated as the percent photographic density (PD) relative to the PD of the liver. Results were compared to those in a group of six patients with other malignancies. Patients with HD had a significantly higher uptake by bone marrow and lungs than patients with other malignancies. Among patients with HD, the uptake by bone marrow and lungs were higher in those with constitutional symptoms and with liver involvement. These results suggest that patients with HD have a different pattern of distribution of multilamellar liposomes which may be related to a combination of nonspecific stimulation of the reticuloendothelial system and tumor uptake. It does not appear that liposomal /sup 99m/Tc is capable of adequately imaging HD for clinical diagnosis.

Perez-Soler, R.; Lopez-Berestein, G.; Kasi, L.P.; Cabanillas, F.; Jahns, M.; Glenn, H.; Hersh, E.M.; Haynie, T.

1985-07-01

134

Pulmonary epithelial permeability after inhaling saline, distilled water ''fog'' and cold air  

SciTech Connect

It is recognized that hyperventilation of cold air and the inhalation of fine mists of distilled water provoke significant bronchoconstriction in the asthmatic individual, yet little is known as to how these provocations affect the structural integrity of the alveolar epithelial membrane. In 11 normal subjects, the following effects have been studied: cold air hyperventilation for three minutes, inhalation of 80 L of ultrasonically nebulized distilled water ''fog,'' and 80 L of isotonic saline ''fog'' on the half time clearance (T1/2) from the alveoli of technetium 99m diethylene triamine pentaacetate (DTPA), inhaled as an aerosol. The DTPA T1/2 provided a measurement of pulmonary epithelial permeability.

Borland, C.; Chamberlain, A.; Barber, B.; Higenbottam, T.

1985-03-01

135

Imaging the Postdeposition Dispersion of an Inhaled Surfactant Aerosol  

PubMed Central

Abstract Background Aerodynamic forces provide the primary means of distributing aerosol medications within the lungs. Partial airway obstructions can limit both air flow and aerosol penetration into diseased zones. We hypothesize that low surface tension additives may help to disperse aerosol medications after deposition in the airways, improving dose uniformity and drug delivery to underventilated regions. To test this, we performed a pilot scintigraphy study of surfactant and saline deposition and postdeposition dispersion. Methods Because inhaled antibiotics for cystic fibrosis provide an example of where self-dispersing medications may be useful, we administered calfactant and saline aerosols with added Technetium 99m sulfur colloid (Tc-SC; 100?nm filtered) on different days in randomized order to eight cystic fibrosis (CF) subjects (average FEV1%, p=85±12%). Nebulized delivery was matched (similar aerosol sizes and volume delivery rates, fixed breathing patterns). Tc-SC distribution in the lungs was imaged continuously for 30?min after delivery. Results Both aerosols were well tolerated. Aerosol distribution was mostly peripheral (58/42%) and initially similar for saline and surfactant. Changes in whole lung counts after 30?min were also similar. Peripheral lung activity decreased more rapidly on average with calfactant though the difference versus saline was not statistically significant. Central to peripheral count ratio decreased with saline and increased with calfactant and c/p changes approached significance (?0.05±0.16 vs. 0.10±0.10; p=0.07 Wilcoxon). Conclusions Our results lack statistical significance, but suggest that inhaled calfactant increased peripheral clearance, due to either surfactant-based dispersion or mucociliary effects. Further studies are needed to define the potential for low surface tension carriers to improve drug delivery. PMID:22393908

Thomas, Kristina M.; Garoff, Stephen; Tilton, Robert D.; Przybycien, Todd M.; Pilewski, Joseph M.

2012-01-01

136

Pulmonary deposition of a nebulised aerosol during mechanical ventilation.  

PubMed Central

BACKGROUND: There is increasing use of therapeutic aerosols in patients undergoing mechanical ventilation. Few studies have measured aerosol delivery to the lungs under these conditions with adequate experimental methods. Hence this study was performed to measure pulmonary aerosol deposition and to determine the reproducibility of the method of measurement during mechanical ventilation. METHODS: Nine male patients were studied during mechanical ventilation after open heart surgery and two experiments were performed in each to determine the reproducibility of the method. A solution of technetium-99m labelled human serum albumin (99mTc HSA (50 micrograms); activity in experiment 1, 74 MBq; in experiment 2, 185 MBq) in 3 ml saline was administered with a Siemens Servo 945 nebuliser system (high setting) and a System 22 Acorn nebuliser unit. Pulmonary deposition was quantified by means of a gamma camera and corrections derived from lung phantom studies. RESULTS: Pulmonary aerosol deposition was completed in 22 (SD 4) minutes. Total pulmonary deposition (% nebuliser dose (SD)) was 2.2 (0.8)% with 1.5% and 0.7% depositing in the right and left lungs respectively; 0.9% of the nebuliser activity was detected in the endotracheal tube or trachea and 51% was retained within the nebuliser unit. Considerable variability between subjects was found for total deposition (coefficient of variation (CV) 46%), but within subject reproducibility was good (CV 15%). CONCLUSIONS: Administration of aerosol in this way is inefficient and further research is needed to find more effective alternatives in patients who require mechanical respiratory support. This method of measurement seems suitable for the assessment of new methods of aerosol delivery in these patients. Images PMID:8493630

Thomas, S H; O'Doherty, M J; Fidler, H M; Page, C J; Treacher, D F; Nunan, T O

1993-01-01

137

Effective penetration of the lung periphery using radioactive aerosols: concise communication  

SciTech Connect

Radioactive microspheres could offer several advantages over gases in the investigation of pulmonary ventilation. Monodisperse microspheres of human serum albumin have been produced using a spinning-disc generator, and kits were prepared for subsequent labeling with technetium-99m. The average labeling efficiency was 88% and unlabeled Tc-99m was removed before aerosol delivery. A simple system was constructed to nebulize and deliver dry monodisperse microspheres. The ventilation images obtained were compared quantitatively with the corresponding krypton-81m images, subdividing the lung regions into inner, central, and peripheral zones. No significant difference was found in the proportions of the total counts for any lung region. There was good agreement between the distributions of microspheres obtained on separate days (r=0.97, p<0.001). An ''aerosol penetration index'' was defined as the ratio of the peripheral to the inner counts for the microspheres normalized by the corresponding ratio for krypton-81m. The mean value of this index for 16 normal subjects was 0.98 +/- 0.23 (s.d.), indicating that the microspheres had achieved penetration of the lung periphery. For patients with chronic obstructive lung disease, more localized defects were observed with the microspheres than with krypton-81m. The mean penetration index for this group was only 0.69 +/- 0.21 (s.d.). This was significantly different from the value for normal subjects (p<0.002).

Hannan, W.J. (Royal Infirmary, Edinburgh, Scotland); Emmett, P.C.; Aitken, R.J.; Love, R.G.; Millar, A.M.; Muir, A.L.

1982-10-01

138

Effective penetration of the lung periphery using radioactive aerosols: concise communication  

SciTech Connect

Radioactive microspheres could offer several advantages over gases in the investigation of pulmonary ventilation. Monodisperse microspheres of human serum albumin have been produced using a spinning-disc generator, and kits were prepared for subsequent labelling with technetium-99m. The average labeling efficiency was 88% and unlabeled Tc-99m was removed before aerosol delivery. A simple system was constructed to nebulize and deliver dry monodisperse microspheres. The ventilation images obtained were compared quantitatively with the corresponding krypton-81m images, subdividing the lung regions into inner, central, and peripheral zones. No significant difference was found in the proportions of the total counts for any lung region. There was good agreement between the distributions of microspheres obtained on separate days (r . 0.97, p less than 0.0001), An ''aerosol penetration index'' was defined as the ratio of the peripheral to the inner counts for the microspheres normalized by the corresponding ratio for krypton-81m. The mean value of this index for 16 normal subjects was 0.98 +/- 0.23 (s.d.), indicating that the microspheres had achieved penetration of the lung periphery. For patients with chronic obstructive lung disease, more localized defects were observed with the microspheres than with krypton-81m. The mean penetration index for this group was only 0.69 +/- 0.21 (s.d.). This was significantly different from the value for normal subjects (p less than 0.002).

Hannan, W.J.; Emmett, P.C.; Aitken, R.J.; Love, R.G.; Millar, A.M.; Muir, A.L.

1982-10-01

139

Global Xenon-133 Emission Inventory Caused by Medical Isotope Production and Derived from the Worldwide Technetium-99m Demand  

NASA Astrophysics Data System (ADS)

Emissions from medical isotope production are the most important source of background for atmospheric radioxenon measurements, which are an essential part of nuclear explosion monitoring. This article presents a new approach for estimating the global annual radioxenon emission inventory caused by medical isotope production using the amount of Tc-99m applications in hospitals as the basis. Tc-99m is the most commonly used isotope in radiology and dominates the medical isotope production. This paper presents the first estimate of the global production of Tc-99m. Depending on the production and transport scenario, global xenon emissions of 11-45 PBq/year can be derived from the global isotope demand. The lower end of this estimate is in good agreement with other estimations which are making use of reported releases and realistic process simulations. This proves the validity of the complementary assessment method proposed in this paper. It may be of relevance for future emission scenarios and for estimating the contribution to the global source term from countries and operators that do not make sufficient radioxenon release information available. It depends on sound data on medical treatments with radio-pharmaceuticals and on technical information on the production process of the supplier. This might help in understanding the apparent underestimation of the global emission inventory that has been found by atmospheric transport modelling.

Kalinowski, Martin B.; Grosch, Martina; Hebel, Simon

2014-03-01

140

Compartmental analysis of technetium-99m-teboroxime kinetics employing fast dynamic SPECT at rest and stress  

SciTech Connect

The authors have examined the feasibility of compartmental analysis of {sup 99m}Tc-teboroxime kinetics in measuring physiological changes in response to adenosine-induced coronary vasodilation. To evaluate the effect of tracer recirculation on {sup 99m}Tc-teboroxime kinetics in the myocardium, they also compared compartmental analysis with washout analysis (monoexponertial fitting), which does not account for this effect. Eight healthy male volunteers were imaged using fast dynamic SPECT protocols (5 sec per tomographic image) at rest and during adenosine infusion. A two-compartment model was used and compartmental parameters K1 and k2 (characterizing the diffusion of {sup 99m}Tc-teboroxime from the blood to the myocardium and from the myocardium to the blood, respectively) were fitted from myocardial time-activity curves and left ventricular input functions. Both K1 and washout estimates for the whole left ventricular myocardium changed significantly in response to coronary vasodilation. Mean stress-to-rest (S/R) ratios were almost two times higher for K1 (S/R = 2.7 {plus_minus} 1.1) than for washout estimates (S/R = 1.5 {plus_minus} 0.3). Estimation of K1 for all local regions, except the septal wall, is feasible because variations in K1 estimates for all local regions, except the septum during stress, are comparable with those for the global region. The authors conclude that quantitative compartmental analysis of {sup 99m}Tc-teboroxime kinetics provides a sensitive indicator for changes in response to adenosine-induced coronary vasodilation. 39 refs., 7 figs., 1 tab.

Chiao, P.C.; Ficaro, E.P.; Dayaniki, F. [Univ. of Michigan Medica Center, Ann Arbor, MI (United States)] [and others

1994-08-01

141

Technetium-99m red blood cell blood-pool imaging in functional asplenia due to leukemic infiltration  

SciTech Connect

Tc-99m labeled RBC blood-pool and Tc-99m sulfur colloid imaging were performed in a patient with chronic myelogenous leukemia (CML) in blast crisis. Functional asplenia was demonstrated on the sulfur colloid study despite intact organ perfusion as demonstrated by blood-pool imaging. Tc-99m RBC blood-pool imaging appears to be an ideal noninvasive technique to document intact spleen perfusion in functional asplenia.

Yoo, J.H.; Orzel, J.A.; Bagnall, J.W.; Weiland, F.L.

1986-07-01

142

Assessment of skin ulcer healing capability by technetium-99m phosphate angiogram and blood-pool images  

SciTech Connect

The accuracy of radionuclide angiography and blood-pool imaging using (/sup 99m/Tc)-phosphate to assess skin ulcer perfusion as an indicator of healing capacity was determined in 50 studies performed on 45 patients with nonhealing ulcers of the lower extremities. Two nuclear medicine physicians without clinical bias, graded the perfusion of the ulcer on the images as normal, increased or reduced with respect to the opposite limb. Patients were followed closely with aggressive local wound care for at least 14 days. Of the 31 ulcers which healed, the radionuclide study correctly predicted 30; of the 19 ulcers which did not heal, 14 were correctly predicted. Eight patients had osteomyelitis; four of those healed and four did not. The radionuclide study predicted healing in seven. This technique is a simple, reliable way to predict the microcirculatory adequacy for ulcer healing. Specificity is diminished in the presence of osteomyelitis.

Alazraki, N.; Dries, D.; Lawrence, P.; Morton, K.; Datz, F.; Taylor, A.

1985-06-01

143

Evaluation of technetium-99m-triamide-mercaptide complexes designed to identify properties favoring renal tubular transport  

SciTech Connect

To aid in the design of an improved {sup 99m}Tc-labeled renal agent, several new [{sup 99m}TcO(MAG{sub 3})]{sup 2{minus}} analogs were synthesized to determine the effects of varying the position and chemical form of the terminal charged group on renal clearance. Clearance, extraction efficiency and plasma protein binding were measured in six Sprague-Dawley rats per complex for ortho, meta and para isomers of [{sup 99m}TcO(MAG{sub 2{minus}}ABA)]{sup 2{minus}}, with MAG{sub 2{minus}} = mercaptoacetylglycylglycyl- and ABA = aminobenzoate; [{sup 99m}TcO(MAG{sub 2{minus}}pASA)]{sup 2{minus}}, with pASA = p-aminosalicylate; [{sup 99m}TcO(MAG{sub 2{minus}}AMS)]{sup 3{minus}}, with AMP = aminomethylphosphonate. For agents with relatively poor clearances, hepatobiliary excretion was evaluated by using a camera-based method. The clearances of the ortho, meta and para isomers of [{sup 22m}TcO(MAG{sub 2{minus}}ABA)]{sup 2{minus}} were 17%, 20% and 59% of those of OIH, respectively. The clearances of [{sup 99m}TcO(MAG{sub 2{minus}}pASA)]{sup 2{minus}}, [{sup 99m}TcO(MAG{sub 2{minus}}AMS)]{sup 2{minus}} and [{sup 99m}TcO(MAG{sub 2{minus}}AMP)]{sup 3{minus}} were 32%, 46% and 39% those of OIH, respectively. Optimal tubular transport appears to require a terminal anionic group; a planar carboxylate is preferred over nonplanar -SO{sup {minus}}{sub 3} or -PO{sup 2{minus}}{sub 3} substituents, suggesting that the smaller size and/or planar shape of the carboxylate group are probably more important than the total charge or charge distribution. Optimal transport also appears to depend on the oxo-carboxylate conformation (syn or anti) and the oxo-carboxylate distance, although these relationships can be modulated by steric interactions. These structure-distribution relationships are important factors to consider in the future design of renal radiopharmaceuticals. 25 refs., 2 figs., 4 tabs.

Hansen, L.; Marzilli, L.G.; Eshima, D. [Emory Univ., Atlanta, GA (United States)]|[Univ. of New Mexico, Albuquerque, NM (United States)] [and others

1994-07-01

144

Prospective evaluation of technetium-99m ECD SPET in mild traumatic brain injury for the prediction of sustained neuropsychological sequels.  

PubMed

Our aim was to evaluate whether single photon emission tomography (SPET) versus computed tomography (CT) in acute phase of mild traumatic brain injury (MTBI) was better for the prediction of sustained neuropsychological symptoms beyond a typical recovery period. Forty five patients with MTBI were prospectively evaluated with clinical and neuropsychological exams, structural imaging using CT and perfusion study by(99m)Tc-ethylene cysteinate dimer ((99m)Tc-ECD) SPET within a week of the head trauma. After an interval ranging from 6 to 12 (median: 9) months, all patients were re-evaluated by standard neuropsychological tests for the assessment of sustained personality changes, imbalance and memory deficits. Our results showed that, 25 patients had abnormal brain perfusion on (99m)Tc-ECD SPET. In 19 cases of total 20 normal (99m)Tc-ECD SPET studies, no sign of memory deficit and imbalance was observed. Negative predictive value (NPV) for both complications was 95%. NPV of CT for the prediction of memory deficit and imbalance were 77.4% and 90.3%, respectively. The risk of developing sustained memory deficits and imbalance in patients with positive (99m)Tc-ECD SPET were 40% and 20%, respectively. A perfusion abnormality on (99m)Tc-ECD SPET was associated with a greater chance of long-standing memory deficits (odds ratio=13.49, P=0.020)while neither CT nor (99m)Tc-ECD SPET could independently predict the personality changes in these patients. The patients with abnormalities on both CT and SPET images faced a significant relative risk of complications, 1.63 times, higher than the others. In conclusion, our study indicated that (99m)Tc-ECD SPET imaging or CT imaging alone, could not predict the occurrence of sustained complications after MTBI. Concurrent use of both imaging modalities performed shortly after MTBI may yield the best results, as the combination of abnormalities in both cerebral structure and perfusion could indicate the patients with 1.63 times higher risk of sustained memory deficits, personality changes and imbalance. PMID:22087443

Mehrazin, Masoud; Nezameddini-Kachooei, Seyed Akbar; Fallahi, Babak; Derakhshan, Mohammad Kamran; Beiki, Davood; Ghodsi, Seyed Mohammad; Assadi, Majid; Pooyafard, Farzaneh; Eftekhari, Mohammad

2011-01-01

145

Platelet accumulation in carotid atherosclerotic lesions: semiquantitative analysis with Indium111 platelets and Technetium99m human serum albumin  

Microsoft Academic Search

To evaluate platelet accumulation in carotid atherosclerotic lesions semiquantitatively, a dual-tracer technique was applied, using In-111 platelets and Tc-99m human serum albumin. With this approach the authors investigated the ratio of radioactivity in In-111 platelets deposited on the vascular wall to those circulating in the blood pool, platelet accumulation index (PAI). This study included 12 normal subjects and 25 patients

Y. Isaka; K. Kimura; S. Yoneda; M. Kusunoki; H. Etani; O. Uyama; Y. Tsuda; H. Abe

1984-01-01

146

Indium-111-antimyosin antibody imaging for detecting different stages of myocardial infarction: Comparison with technetium-99m-pyrophosphate imaging  

SciTech Connect

The diagnostic value of {sup 111}In-antimyosin (AM) imaging for identifying myocardial infarction was evaluated in comparison with {sup 99m}Tc-pyrophosphate (PPi) imaging. Twenty-four patients with various stages of myocardial infarction, ranging from three days to nine months after the onset of infarction, underwent both AM and PPi scans. Of 26 infarct lesions AM scan identified 22 (85%), while PPi scans detected 10 (38%) (p less than 0.01). When less than a week had passed since the onset both scans demonstrated all infarct lesions. For seven subacute lesions studied within one to two weeks of onset, AM scans detected (100%), while PPi scans identified only 2 (29%). Furthermore, AM scans showed discrete myocardial uptake in 7 (64%) of those studied more than two weeks after onset. The intensity of AM uptake in the infarcts studied more than seven days after onset was less than that in acute infarcts studied within seven days of onset (p less than 0.05). These preliminary data indicate that the abnormal myocardial uptake of AM persists beyond the first two weeks when PPi no longer accumulates. Thus, AM scans can be considered to provide a sensitive diagnosis of subacute as well as acute myocardial necrosis.

Tamaki, N.; Yamada, T.; Matsumori, A.; Yoshida, A.; Fujita, T.; Ohtani, H.; Watanabe, Y.; Yonekura, Y.; Endo, K.; Konishi, J. (Kyoto Univ. Faculty of Medicine (Japan))

1990-02-01

147

Radionuclide imaging of the spleen with heat denatured technetium-99m RBC when the splenic reticuloendothelial system seems impaired  

SciTech Connect

Imaging of the spleen of 10 patients who had been hematologically diagnosed with sickle-cell anemia (SCA) was studied with (/sup 99m/Tc)tin colloid and heat denatured (/sup 99m/Tc)RBCs. In all ten patients, there was faint or nonvisualization of the spleen with (/sup 99m/Tc)tin colloid. However, with heat denatured (/sup 99m/Tc)RBCs, nine spleens were well visualized, and the uptake was homogenous. One spleen had two patchy areas of uptake. The results indicate that when splenic phagocytic function is impaired as reflected by nonvisualization of the spleen with (/sup 99m/Tc)tin colloid, it is still possible to image such a spleen with heat denatured (/sup 99m/Tc)RBCs

Owunwanne, A.; Halkar, R.; Al-Rasheed, A.; Abubacker, K.C.; Abdel-Dayem, H.

1988-03-01

148

Technetium-99m white blood cell imaging: False-negative result in salmonella osteomyelitis associated with sickle cell disease  

SciTech Connect

The authors report a case of sickle cell anemia associated osteomyelitis where the Tc-99m white blood cell imaging was negative, and bone imaging showed increased uptake in the region in question. The reasons for the possible false-negative image are discussed.

Guze, B.H.; Hawkins, R.A.; Marcus, C.S.

1989-02-01

149

Mismatch between iodine-123 IMP and technetium-99m HM-PAO brain perfusion imaging in a patient with meningioma  

SciTech Connect

The discrepancy between three methods for cerebral perfusion imagings in the case of a man with meningioma is presented. Imaging with N-isopropyl-P-(I-123) iodoamphetamine (IMP) showed no activity in the tumor. Imaging with Tc-99m hexamethylpropyleneamine oxime (HM-PAO) and the local cerebral blood flow (LCBF) image with Xe-133 inhalation showed high tumor activity. IMP is a more accurate method for imaging the brain tissue blood flow.

Hoshi, H.; Jinnouchi, S.; Watanabe, K.; Nakano, S.; Kinoshita, K.

1987-09-01

150

In vivo kinetics of canine leukocytes labeled with technetium-99m HM-PAO and indium-111 tropolonate  

SciTech Connect

Two weeks after the introduction of osteomyelitis in three dogs, autologous leukocytes were dual-labeled with both (/sup 99m/Tc)HM-PAO and (/sup 111/In)tropolonate, and reinjected. Blood sampling and imaging were then performed. Two weeks later, the same dogs received simultaneous injections of singly-labeled (/sup 99m/Tc)WBC and (/sup 111/In)WBC for comparison. For both studies, blood samples were drawn over 6 hr to determine the respective blood clearance half-time (TB) and % recovery (%R0) of cell-bound radioactivity. There were no significant differences in the average TB results of the /sup 99m/Tc and /sup 111/In groups, either within or between the dual- and singly-labeled studies. The %R0 of singly-labeled (/sup 99m/Tc)WBC was about half that of the other groups (p less than 0.01); however, this difference was attributed to the dissimilar radiochemical purity of the (/sup 99m/Tc)HM-PAO reagents. Region of interest analysis of the 6 and 24 hr images revealed no significant differences between either cell label in the relative or absolute in vivo uptake at known sites of osteomyelitis, noninfected surgery, and normal bone marrow.

Mock, B.H.; Schauwecker, D.S.; English, D.; Young, K.A.; Wellman, H.N.

1988-07-01

151

Evaluation of extremity pain in children using technetium-99m MDP bone scan: A general hospital experience  

SciTech Connect

This study was undertaken to evaluate the efficacy of three-phase bone scan in detection of significant pathology i.e., osteomyelitis (OM), septic joint, cellulitis, etc., in children with symptoms of extremity pain. A total of 100 consecutive patients (age 9 days - 16 yrs, 63 boys and 37 girls) were studied. The authors reviewed their scans, x-rays and hospital records. The final diagnoses were based on the findings of needle aspiration, surgical drainage, biopsy, culture, and on the therapeutic response. In 87%, sufficiently long clinical follow-up was available to confirm the final diagnoses. In the remaining 13%, the symptoms resolved quickly and follow-up was not felt necessary. The scan was essential in pinpointing the lesions in pts with referred or nonlocalizing extremity pain. The +ve and -ve predictive values of the scan and OM were 89% and 96% respectively. One spiral fracture was misinterpreted as diffuse OM. One ''Subacute epiphyseal OM'' was not detected. In two cases, cellulitis and septic joint obscured underlying OM. Prior antibotic therapy resulted in one equivocal scan. Although less sensitive (29%) in early OM, radiographs play an important complimentary role. Bone scans detected underlying pathology for extremity pain in 61% of all pts studied.

Park, H.M.; Rothschild, P.A.; Kernek, C.B.

1984-01-01

152

Diagnosis of sclerosing cholangitis with technetium 99m-labeled iminodiacetic acid planar and single photon emission computed tomographic scintigraphy  

SciTech Connect

The purpose of this study was to determine whether /sup 99m/Tc-iminodiacetic acid planar biliary scintigraphy combined with single photon emission computed tomography could detect sclerosing cholangitis and provide additional information regarding the extent and severity of disease. Thirteen patients with sclerosing cholangitis and 13 normal control subjects were studied. Scintigraphic results were also compared with previously reported studies of patients with isolated common bile duct obstruction and with primary biliary cirrhosis. The planar scintigraphy in patients with sclerosing cholangitis showed beading or bandlike constrictions of the biliary tract corresponding to lesions seen on cholangiography, and the image pattern was distinctly different from images obtained from patients with isolated common bile duct obstruction or primary biliary cirrhosis. The single photon emission computed tomography images of the liver in patients with sclerosing cholangitis demonstrated multiple focal areas of /sup 99m/Tc-iminodiacetic acid retention, representing bile stasis in intrahepatic bile ducts. Compared to controls, the mean hepatic clearance half-time of /sup 99m/Tc-iminodiacetic acid was markedly delayed in patients with sclerosing cholangitis (6-10 times normal). Individual patients with sclerosing cholangitis had wider variation in isotope clearance half-time from three regions of the liver than patients with isolated common bile duct obstruction, consistent with regional difference in disease severity and variable impairment of bile flow. In 4 patients with sclerosing cholangitis with incomplete filling of the right and left hepatic ducts at cholangiography, planar and single photon emission computed tomographic scintigraphy provided evidence of significant intrahepatic sclerosing cholangitis.

Rodman, C.A.; Keeffe, E.B.; Lieberman, D.A.; Krishnamurthy, S.; Krishnamurthy, G.T.; Gilbert, S.; Eklem, M.J.

1987-03-01

153

Pentavalent technetium-99m (V)-DMSA uptake in a pheochromocytoma in a patient with Sipple's syndrome  

Microsoft Academic Search

This case report describes {sup 99m}Tc(V)-dimercaptosuccinic acid (DMSA) accumulation in a pheochromocytoma in a patient with Sipple's syndrome. Scintigraphy with {sup 99m}Tc(V)-DMSA demonstrated uptake in medullary carcinoma of the thyroid gland (MCT). Iodine-131 metaiodobenzylguanidine (MIBG) scintigraphy showed the bilateral pheochromocytomas but did not demonstrate uptake in the MCT.

B. K. Adams; A. Fataar; M. J. Byrne; N. S. Levitt; P. J. Matley

1990-01-01

154

Effect of Peumus boldus on the labeling of red blood cells and plasma proteins with technetium-99m.  

PubMed

Peumus boldus is used in popular medicine in Brazil. The influence of Peumus boldus on the labeling of red blood cells and plasma proteins with 99mTc was studied. Stannous chloride and 99mTc pertechnetate were incubated with blood and a tincture of Peumus boldus. Aliquots of plasma and blood cells were isolated from the mixture and treated with trichloroacetic acid (TCA). After separation, analysis of the soluble and insoluble fractions showed a rapid uptake of the radioactivity by blood cells in the presence of the drug, whereas there was a slight decrease in the amount of 99mTc radioactivity in the TCA-insoluble fraction of plasma. PMID:10376326

Reiniger, I W; de Oliveira, J F; Caldeira-de-Araújo, A; Bernardo-Filho, M

1999-08-01

155

Tracer kinetic modeling approaches for the quantification of hepatic function with technetium-99m DISIDA and scintigraphy  

SciTech Connect

Serial scintigraphic images following injection of ({sup 99m}Tc)iminodiacetic acid compounds such as ({sup 99m}Tc)diisopropyl-iminodiacetic acid (DISIDA) provide qualitative information about liver function. We have investigated approaches for quantitatively describing liver function in terms of the kinetics of DISIDA extraction and excretion by the liver. Several compartmental model configurations were evaluated. A three-compartment model (blood, hepatic parenchyma, intrahepatic bile) was found to fit the data best and was used in conjunction with dynamic image data to obtain estimates of rate constants for liver extraction and excretion of DISIDA, and mean residence time (MRT) of DISIDA in the liver. A noncompartmental approach based on a parametric deconvolution technique was also used to estimate the noncompartmental mean residence time (MRTnc). To assess limitations of the noncompartmental approach, computer simulations were performed using the three-compartment model to generate time-activity curves followed by analysis of these curves by the noncompartmental method. The effect of plasma total bilirubin level on DISIDA uptake and MRT was also investigated. These techniques are readily adaptable to standard nuclear medicine computing facilities, and could be used in the clinical setting to numerically describe serial DISIDA studies (especially in liver transplant patients) efficiently and noninvasively.

Gambhir, S.S.; Hawkins, R.A.; Huang, S.C.; Hall, T.R.; Busuttil, R.W.; Phelps, M.E. (Univ. of California, Los Angles (USA))

1989-09-01

156

Detection of a local staphylococcal infection in mice with technetium-99m-labeled polyclonal human immunoglobulin  

SciTech Connect

The purpose of this study was to investigate both the ability of 99mTc-labeled polyclonal human immunoglobulin (HIG) to localize an infection and the modes of action involved in this process. Mice, infected with Staphylococcus aureus ATCC 25923 in a thigh muscle, received HIG intravenously. Scintigrams were made 1, 4, and 24 hr later; subsequently the mice were killed and the activity in several organs and thighs was determined. The radiopharmaceutical demonstrated a time-dependent accumulation at the site of infection. It was found that vascular permeability or Fc binding alone could not account for the mode of action of HIG. Neither the origin of Ig (human versus murine) nor the total amount of protein (0.01-1.0 mg Ig per mouse) affected the target-to-background (T/B) ratios. Ratios were not different for leukocytopenic animals. A correlation (p less than 0.001) was demonstrated between the number of bacteria at the site of infection and the T/B ratio. This was also found after antibiotic treatment (p less than 0.02).

Calame, W.; Feitsma, H.I.; Ensing, G.J.; Goedemans, W.T.; Camps, J.A.; van Furth, R.; Pauwels, E.K. (University Hospital, Leiden (Netherlands))

1991-03-01

157

Respiratory clearance of 99mTc-DTPA and pulmonary involvement in sarcoidosis  

SciTech Connect

To investigate the relationships between the respiratory epithelial clearance of micronic aerosolized /sup 99m/Tc-DTPA (RC-DTPA) and pulmonary function, serum angiotensin-converting enzyme (SACE), and lymphocytic alveolitis in patients with sarcoidosis, RC-DTPA was measured in 49 nonsmokers with pulmonary sarcoidosis and 38 normal nonsmokers. Pulmonary involvement was evaluated on chest roentgenograms (type O = normal, type I = hilar adenopathies, type II = hilar adenopathies associated with parenchymal shadows, type III = parenchymal shadows without adenopathy) and by pulmonary function tests. Serum angiotensin-converting enzyme was determined, and a bronchoalveolar lavage was performed for alveolar lymphocyte differential counting (Ly%). RC-DTPA was increased (greater than or equal to 1.96%/min) in 12 of 31 patients with type II or III involvement but was normal in all 18 patients with type O or I involvement (p = 0.002). Patients with increased RC-DTPA had low FVC, TLC, FEV1, and resting Pao2 (p less than 0.05); resting and exercise AaPo2 were increased (p less than 0.05), but RC-DTPA correlated negatively with FEV1 (p less than 0.01), Pao2 at rest (p less than 0.005), and DLCO (p less than 0.05) and positively with resting and exercise AaPO2 (p less than 0.01). In patients with increased RC-DTPA (42 +/- 17%), Ly% did not differ from Ly% in patients with normal RC-DTPA (34 +/- 16%). SACE was increased in patients with increased RC-DTPA (56 +/- 26 U/ml versus 38 +/- 16 U/ml; p = 0.007) and correlated positively with RC-DTPA (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Dusser, D.J.; Collignon, M.A.; Stanislas-Leguern, G.; Barritault, L.G.; Chretien, J.; Huchon, G.J.

1986-09-01

158

A Noninvasive [ 99m Tc]DTPA SPECT\\/CT Imaging Methodology as a Measure of Lung Permeability in a Guinea Pig Model of COPD  

Microsoft Academic Search

Purpose  The purposes of this study are (1) to develop an efficient aerosol inhalation system for the delivery of [99mTc]DTPA aerosol into guinea pig airways with high uniformity for measuring lung clearance using SPECT\\/CT imaging, as a measure\\u000a of lung permeability, and (2) to use [99mTc]DTPA studies in guinea pig model of chronic obstructive pulmonary disease (COPD) to determine its usefulness

Yanjun Wu; Charles J. Kotzer; Sokratis Makrogiannis; Gregory A. Logan; Hyking Haley; Mary S. Barnette; Susanta K. Sarkar

159

Lung clearance of inhaled /sup 99m/Tc-DTPA in the dog  

SciTech Connect

A study was made of the reproducibility of measuring an index of permeability of respiratory epithelium in dogs using aerosolized /sup 99m/Tc-DTPA (diethylenetriaminepentaacetate). The method uses a gamma camera to measure the rate of clearance of soluble radioactive aerosol deposited in the lung. A solution of /sup 99m/Tc-DTPA in normal saline was aerosolized by an ultrasonic nebulizer. Eleven anesthetized dogs breathing spontaneously inhaled the resulting droplets for 2 min. Mass median aerodynamic diameter of the droplets was 4.4 ..mu..m with a geometric standard deviation of 2.1. Clearance from the lung was monitored by quantitative gamma camera imaging for up to 2 h. For a 60-min observation period, the biological half-life for clearance of /sup 99m/Tc-DTPA from both lungs was 66 +/- 11 (SD) min. Apical regions cleared significantly slower than basal regions, probably because of a larger portion of bronchial tissue in the apical region of the dog's lung. The best reproducibility of absorption of /sup 99m/Tc-DTPA in the dog was obtained from basal regions and peripheral zones of the lung within 30 min after inhalation of the radioaerosol.

Oberdoerster, G.; Utell, M.J.; Weber, D.A.; Ivanovich, M.; Hyde, R.W.; Morrow, P.E.

1984-01-01

160

Environmental Fate of EDTA and DTPA  

Microsoft Academic Search

\\u000a EDTA can be extremely persistent in WWTP and also in natural waters; DTPA seems more biodegradable. However, the biodegradability\\u000a of DTPA might be of negligible significance as EDTA is reported to be one of its decomposition products. EDTA, and in some\\u000a cases also DTPA, are generally found in the receiving waters of many industrial areas, thus being classified as one

Mika SillanpiHi

161

Comparison of Ca-DTPA and Zn-DTPA in removing 234Th from the rat.  

PubMed

The relative effectiveness of Ca-DTPA and Zn-DTPA as a function of the dose, number of doses and time of their administration in removing 234Th that had been administered as the citrate or nitrate from various rat organs was investigated. With a single early treatment (1.5 min after intravenous injection of 234Th), Zn-DTPA was clearly less effective than Ca-DTPA over the whole dose range (30 mumol/kg body weight-1000 mumol/kg body weight) tested. In the skeleton, 1000 mumol Zn-DTPA/kg removed as much 234Th (about 50%) as 30 mumol Ca DTPA/kg. Prompt treatment with 100 mumol Ca-DTPA/kg body weight diminished the skeletal 234Th content by about 70%; but when it was delayed by 6 h or 4 d, the 234Th content was reduced by only about 20% and 10%, respectively. The effect of DTPA in the bone was independent of 234Th compound, while in the soft tissues 234Th injected as nitrate was less affected than the citrate. The effect of DTPA was potentiated when treatment was repeated; the end effect was dependent on the time of the first DTPA injection and on the total number of doses. Thus, about 90% and 50% less 234Th was found in the bones after repeated treatment started at 1.5 min and 4 d after administration of 234Th, respectively. Under the conditions of a delayed repeated treatment, Ca-DTPA and Zn-DTPA were equally effective. PMID:4030331

Peter-Witt, E; Volf, V

1985-09-01

162

Pulmonary epithelial clearance of 99mTc-DTPA after thrombin-induced pulmonary microembolism  

SciTech Connect

We investigated the effect of thrombin-induced pulmonary microembolism on the pulmonary clearance rate of aerosolized 99mTc diethylenetriamine pentaacetic acid (99mTc-DTPA) in awake, chronically prepared sheep. Chest activity was recorded after administration of a 0.44 micron aerosol of 99mTc-DTPA. Decay-corrected data were fit to an exponential and expressed as percent decrease per min (%/min). Sheep were given alpha-thrombin intravenously (80 U/kg for 10 min) 60 min after the aerosol administration. The clearance rate prior to alpha-thrombin was 0.35 +/- 0.05 %/min (mean +/- SEM). During alpha-thrombin administration, the clearance rate increased to 5.84 +/- 0.70 %/min (p less than 0.001 from baseline), but returned to 0.41 +/- 0.06 %/min within 30 min after the end of the thrombin infusion. The increased clearance rate during alpha-thrombin administration was not due to increased lung volume since alpha-thrombin did not change functional residual capacity. Moreover, the clearance rate was unchanged during gamma-thrombin administration, which does not induce coagulation, or during alpha-thrombin challenge in defibrinogenated animals. alpha-thrombin administration in neutrophil-depleted sheep caused a transient increase in DTPA clearance similar to that in control sheep, suggesting that the increase occurred independently of neutrophils. The results indicate that alpha-thrombin causes a large, transient increase in 99mTc-DTPA clearance, which may be the result of increased epithelial permeability. This response is dependent on the activation of intravascular coagulation.

Cooper, J.A.; Feustel, P.J.; Line, B.R.; Malik, A.B.

1986-10-01

163

Myocardial distribution of indium-111-antimyosin Fab in acute inferior and right ventricular infarction: comparison with technetium-99m-pyrophosphate imaging and histologic examination  

SciTech Connect

In a postmortem study of a 69-yr-old female patient who had suffered 2 yr previously a non-Q-wave anterior infarction and who had sustained just seven days earlier a left inferior and right ventricular infarction, the distribution of {sup 111}In-antimyosin Fab was compared to the results of {sup 99}mTc-pyrophosphate imaging and histologic examination. Indium-111-antimyosin Fab imaging could not be performed because of cardiogenic shock. However, postmortem gamma scintillation counting revealed increased activities of antimyosin Fab in the inferoapical and right ventricular infarcted regions in which {sup 99}mTc-pyrophosphate positive imagings were observed; in contrast, a histologically confirmed old subendocardial anterior infarction had no definite activity. Thus, the myocardial distribution of {sup 111}In-antimyosin Fab corresponded well to the results of {sup 99}mTc scintigrams and histologic examinations in a human heart, suggesting that this technique could be useful in vivo for detecting several-day-old myocardial infarction of the right ventricle as well as the left ventricle. Tissue from the 2-yr-old infarction was not identified by this technique.

Nakata, T.; Sakakibara, T.; Noto, T.; Shoji, T.; Tsuda, T.; Kubota, M.; Hattori, A.; Iimura, O. (Sapporo Medical College, (Japan))

1991-05-01

164

Computer-assisted superimposition of magnetic resonance and high-resolution technetium-99m-HMPAO and thallium-201 SPECT images of the brain  

SciTech Connect

A method for registering three-dimensional CT, MR, and PET data sets that require no special patient immobilization or other precise positioning measures was adapted to high-resolution SPECT and MRI and was applied in 14 subjects (five normal volunteers, four patients with dementia (Alzheimer's disease), two patients with recurrent glioblastoma, and three patients with focal lesions (stroke, arachnoid cyst and head trauma)). T2-weighted axial magnetic resonance images and transaxial 99mTc-HMPAO and 201Tl images acquired with an annular gamma camera were merged using an objective registration (translation, rotation and rescaling) program. In the normal subjects and patients with dementia and focal lesions, focal areas of high uptake corresponded to gray matter structures. Focal lesions observed on MRI corresponded to perfusion defects on SPECT. In the patients who had undergone surgical resection of glioblastoma followed by interstitial brachytherapy, increased 201Tl corresponding to recurrent tumor could be localized from the superimposed images. The method was evaluated by measuring the residuals in all subjects and translational errors due to superimposition of deep structures in the 12 subjects with normal thalamic anatomy and 99mTc-HMPAO uptake. This method for superimposing magnetic resonance and high-resolution SPECT images of the brain is a useful technique for correlating regional function with brain anatomy.

Holman, B.L.; Zimmerman, R.E.; Johnson, K.A.; Carvalho, P.A.; Schwartz, R.B.; Loeffler, J.S.; Alexander, E.; Pelizzari, C.A.; Chen, G.T. (Brigham and Women's Hospital, Boston, MA (USA))

1991-08-01

165

Poor accumulation of technetium-99m glucoheptonate in sarcoidosis and other diffuse infiltrative lung diseases as compared with gallium-67 citrate  

SciTech Connect

Forty-two patients with diffuse infiltrative lung diseases were imaged with Ga-67 citrate and Tc-99m glucoheptonate (GH). Twenty patients had sarcoidosis, six had fibrosis, six had tuberculosis, nine had lung infiltration, and one had pleural empyema. The main difference between Ga-67 and Tc-99m GH was the much greater uptake of Ga-67 in sarcoidosis than that of Tc-99m GH. Fifteen patients with sarcoidosis had positive Ga-67 scans but only six had positive Tc-99m GH scans. The results in other diffuse infiltrative lung diseases were almost equal with Ga-67 and Tc-99m GH. Although Tc-99m GH is less expensive and simpler to use, it is not an adequate substitute for Ga-67 in diffuse infiltrative lung diseases.

Vorne, M.; Sahlstroem, K.A.; Alanko, K.

1988-02-01

166

Synthesis, characterization and biodistribution of a new technetium-99m complex with trimethylsilylmethylisonitrile. Comparison with 99mTc-TBI and 99mTc-MIBI  

Microsoft Academic Search

An isonitrile ligand with a silicium component was synthesized and a copper salt of this ligand was then used to form a 99mTc complex. We evaluated the physicochemical characteristics of the complex and its biodistribution in rat. The chemical properties, i.e. lipophilic affinity and charge, were comparable to those of other 99mTc complexes formed with similar isonitrile compounds (99mTc-MIBI and

S. Bouquillon; Y. Coulais; M. Dartiguenave; J. A. M. Tafani; R. Guiraud

1995-01-01

167

Immunoscintigraphy using a technetium-99m labelled monoclonal anti-CEA antibody in the follow-up of colorectal cancer and other tumours producing CEA.  

PubMed Central

Using the intact monoclonal IgG1 anti-CEA antibody BW 431/26 (Behringwerke Marburg, FRG) labelled with 99mTc by a new labelling procedure (Schwarz method), 72 patients suspected of tumour recurrences (colorectal cancer, n = 59) and with rising serum carcinoembryonic antigen (CEA) levels were studied. Sixty-nine of 72 studies had a positive result by immunoscintigraphy of which 52 have since been proven histologically/clinically. In six patients only immunoscintigraphy revealed a tumour recurrence while all other diagnostic modalities were negative. Of 52 studies 46 were true positive (diagnostic sensitivity 88%). In this series there was one false positive result. About one-third of all patients injected with the antibody developed a human anti-mouse response (HAMA), but no severe side effects were seen even after four applications. For the follow-up of colorectal and other CEA positive adenocarcinomas this 99mTc-labelled monoclonal antibody seems to be very promising in patients with rising serum CEA, especially if conventional diagnostic imaging procedures remain negative. Images Figure 1 Figure 2 PMID:2166552

Hertel, A.; Baum, R. P.; Lorenz, M.; Baew-Christow, T.; Encke, A.; HA?r, G.

1990-01-01

168

The effect of flow on technetium-99m-teboroxime (SQ30217) and thallium-201 extraction and retention in rabbit heart.  

PubMed

In order to evaluate the accuracy of blood flow measurement, the single-pass extraction, retention/wash-out and relative net uptake of 99mTc-teboroxime (SQ30217) and 201Tl were evaluated and compared in 20 isolated blood-perfused rabbit hearts at coronary flow rates ranging from 0.49 to 2.85 ml/g wet wt min-1. The average peak extraction of 201Tl (+/- s.d.) (0.67 +/- 0.11) marginally exceeded that of SQ30217 (0.62 +/- 0.12) (p = 0.06). Flow significantly affected the maximum net extraction of 201Tl and the 40-min net extractions of both 201Tl and SQ30217. Unexpectedly, the rate of 201Tl myocardial washout was significantly faster (p less than 0.05) than SQ30217 washout at all flow rates evaluated. Increasing coronary blood flow rate was associated with a more rapid clearance of both tracers from the myocardium (p less than 0.05 for both comparisons). The slope of the linear correlations between relative net SQ30217 uptake versus flow and relative net 201Tl uptake versus flow were found to be similar for up to 10 min after isotope injection. These data were interpreted to indicate that: 1. Thallium-201 might be slightly better extracted than SQ30217. 2. SQ30217 is cleared more slowly from the myocardium. 3. Thallium-201 and SQ30217 appear to be comparable tracers of myocardial perfusion for up to 10 min after injection under the single-pass conditions currently employed. 4. Additional studies are needed to clarify myocardial SQ30217 kinetics. PMID:1919742

Marshall, R C; Leidholdt, E M; Zhang, D Y; Barnett, C A

1991-10-01

169

Uptake of technetium-99m methylene diphosphonate by fractured and osteoporotic bone after a pulse dose of Vitamin D/sub 3/. [Rats  

SciTech Connect

The effect of a pulse dose of Vitamin D/sub 3/ on uptake of (/sup 99m/Tc)MDP by fractured and osteoporotic bone, respectively, was compared with D/sub 3/'s effect on uptake by normal bone in rats. At 4, 7, and 14 days, respectively, after femoral fracture, basal uptake was significantly increased at the fracture site by 336.8, 276.1, and 183.5%, respectively, over the contralateral control site. D/sub 3/-treated rats had lower uptakes than untreated controls at all three fracture sites and at 12 of 15 normal bone sites but analysis of variance showed the uptake differences were not significant. Cortisone-induced osteoporosis caused a significant decrease in basal uptake. The decrease occurred in all nine bone areas studied. D/sub 3/ caused a significant increase in uptake by these osteoporotic bones, but a significant decrease in uptake by the same bones in normal controls. Thus, D/sub 3/ had an effect on uptake by the bone lesion, osteoporosis, that differed from D/sub 3/'s effect on uptake by fracture or normal bone.

Carr, E.A. Jr.; Carroll, M.; Montes, M.; Zielezny, M.

1985-04-01

170

Effect of vitamin D/sub 3/ on imaging of experimental myocardial infarcts with technetium-99m pyrophosphate: further studies of the role of calcium. [Dogs; rats  

SciTech Connect

The authors previously found that a pulse dose of vitamin D/sub 3/ increased /sup 99m/Tc)PPi uptake by rat myocardial necrosis. Vitamin D/sub 3/ raised serum and lesion (Ca) but not, they now report, lesion (Fe). D/sub 3/ increased /sup 99m/Tc)PPi uptake by myocardial infarcts (L) in dogs. Vitamin D/sub 3/ decreased uptake by dog bone (B) as measured in rib and sternum. Scintigrams graded by a blinded observer, showed 4+, 4+, and 3+ infarcts, respectively, in three D/sub 3/-treated dogs, and 2+, 2+, and 1+, respectively, in three untreated. One untreated and one treated dog were negative; the latter showed the least response to D/sub 3/ in serum (Ca) and /sup 99m/Tc) in tissue samples. Vitamin D/sub 3/ can increase L/B in dogs, enhancing scintigraphic images.

Carr, E.A. Jr.; Carroll, M.; Gona, J.M.; Balderman, S.C.; Montes, M.; Steinbach, J.J.

1985-02-01

171

Pharmacokinetics and biodistribution of technetium 99m labelled standard heparin and a low molecular weight heparin (enoxaparin) after intravenous injection in normal volunteers.  

PubMed

For a better understanding of low molecular weight heparin pharmacokinetics, 99m technetium labelled heparin and enoxaparin were injected intravenously to four normal volunteers, after approval by the Ethics Committee and preliminary animals studies. In vitro and in vivo, the labelled products proved to be stable and identical to the non-labelled drugs. Radioactivity curves in blood, organs and urines were similar for both products. Anti Xa plasma half-life was 3 times longer for enoxaparin than for heparin. Anti IIa plasma half-lives were similar. However, radioactivity persisted much longer than biological activities for both products. After chromatography, most of the radioactivity was bound to AT III, where an anti Xa activity peak was also detected. The anti Xa activity peak seen after adding AT III to plasma was much higher with heparin than with enoxaparin. In urine, biological activities, measured with AT III supplementation, were higher with enoxaparin than with heparin. These results suggest that phenomena other than biodistribution are responsible for the differences in pharmacokinetics observed between these two products. The two most likely explanations are differences in metabolism and/or a release of an endogenous factor. PMID:1848441

Laforest, M D; Colas-Linhart, N; Guiraud-Vitaux, F; Bok, B; Bara, L; Samama, M; Marin, J; Imbault, F; Uzan, A

1991-02-01

172

Technetium-99m-labeled platelets: comparison of labeling with a new lipid-soluble Sn(II)-mercaptopyridine-N-oxide and 99mTc-HMPAO.  

PubMed

Platelets pretinned with a neutral Sn(II)-2-mercaptopyridine-N-oxide (SN-MPO) were labeled with 99mTc and compared to those labeled with 99mTc-HMPAO. The conditions of labeling platelets, e.g. concentrations of platelets and Sn(II)-MPO, 99mTc in ACD-saline or ACD-plasma media, pH and incubation time, were optimized using canine platelets. Moderate labeling efficiency was obtained with 20 micrograms of tin(II) chloride and 30 min incubation with Sn-MPO and pertechnetate. The viability of labeled platelets was determined by platelet recovery and platelet survival times in Beagle dogs. The labeling efficiency with platelets from 43 mL of blood was 62.8 +/- 7.6%. The platelet recovery was 35.7 +/- 5.0% and exponential survival time was 34.6 +/- 3.1 h compared to 43.3 +2- 12.0% and 29.5 +/- 3.3 h for 99mTc-HMPAO-labeled platelets. These values were significantly (P less than 0.01) lower than 111In-labeled platelets. Biodistribution in dogs indicates lower retention in blood, spleen and liver after some initial 99mTc excretion in urine. The platelet deposition with 99mTc platelets (Sn-MPO method) on polyurethane angio-catheters was similar to 99mTc-HMPAO-labeled platelets. This study indicates that the platelets could be successfully labeled with pertechnetate in a cost-effective manner for the evaluation of thromboembolic complications. PMID:1917515

Dewanjee, M K; Robinson, R P; Hellman, R L; Ganz, W I; Serafini, A N; Sfakianakis, G N

1991-01-01

173

Radiolabeled, nonspecific, polyclonal human immunoglobulin in the detection of focal inflammation by scintigraphy: Comparison with gallium-67 citrate and technetium-99m-labeled albumin  

SciTech Connect

The accumulation of nonspecific polyclonal human immunoglobulin (IgG) radiolabeled with /sup 125/I or /sup 111/In was compared to that of (/sup 67/Ga)citrate and (/sup 99m/Tc)albumin in rats with deep thigh inflammation due to Escherichia coli infection. Serial scintigrams were acquired at 1, 3, 24, and in some cases, 48 hr after injection. As early as 3 hr postinjection, (/sup 111/In)IgG showed greater accumulation at the lesion than (/sup 99m/Tc)HSA (p less than 0.01). Both (/sup 125/I)IgG and (/sup 111/In)IgG showed greater accumulation than (/sup 67/Ga)citrate (p less than 0.01). At 24 hr, IgG image definition increased, while HSA image definition decreased, and the intensity of accumulation of both IgG preparations was greater than that of (/sup 67/Ga)citrate or (/sup 99m/Tc)HSA (p less than 0.01). At all imaging times, (/sup 67/Ga)citrate accumulation was surprisingly low. In inflammation produced by Pseudomonas aeruginosa, Staphylococcus aureus, Klebsiella pneumoniae, Candida albicans, or turpentine, (/sup 111/In)IgG accumulation was similar to the results obtained with Escherichia coli. These studies suggest that focal sites of inflammation can be detected with radiolabeled nonspecific human polyclonal IgG.

Rubin, R.H.; Fischman, A.J.; Needleman, M.; Wilkinson, R.; Callahan, R.J.; Khaw, B.A.; Hansen, W.P.; Kramer, P.B.; Strauss, H.W.

1989-03-01

174

Kinetic Behavior of Technetium99m-HMPAO in the Human Brain and Quantification of Cerebral Blood Flow Using Dynamic SPECT  

Microsoft Academic Search

The kinetic behavior of 9~Tc-hexamethylpropyleneamine ox- ime (HMPAO) in the human brain was investigated in 11 patients with various brain diseases (176 regions), using dynamic SPECT and a four-compartment model with five parameters (KI: rate constant for the transport of HMPAO from blood to brain, K2: backdiffusion from brain to blood, K3: conversion to a hydrophilic form in the brain,

Shuji Tanada; Hitoshi Fujita; Saburo Sakaki; Ken Hamamoto

175

Organic synthesis and biological evaluation of novel “3 + 1” mixed ligands of technetium-99m Gabapentin as receptor imaging agents  

Microsoft Academic Search

This work focuses on the “3 + 1” mixed ligands of 99mTc labeled Gabapentin as ?2? receptor imaging agents in the brain. Gabapentin 1-(aminomethyl)cyclohexanacetic acid as monodentate\\u000a and two tridentates: tridentate A; 3-(2-imino-thiozolidin-4-one)-quinozoline-4-(3H)-one and tridentate B; N-(4-chlorophenyl)-2-imino-2H-chromene-3-Carbothioamide which were synthesized and characterized by infrared analysis (IR),\\u000a 1H nuclear magnetic resonance (NMR), and mass spectrum. 99mTc-complexes were prepared by the “3 + 1” mixed ligand

A. M. Amin; K. Abou Zid; N. A. Bayoumi; M. Abd EL-hamid

2010-01-01

176

The CONRAD approach to biokinetic modeling of DTPA decorporation therapy.  

PubMed

Diethylene Triamine Pentaacetic Acid (DTPA) is used for decorporation of plutonium because it is known to be able to enhance its urinary excretion for several days after treatment by forming stable Pu-DTPA complexes. The decorporation prevents accumulation in organs and results in a dosimetric benefit, which is difficult to quantify from bioassay data using existing models. The development of a biokinetic model describing the mechanisms of actinide decorporation by administration of DTPA was initiated as a task in the European COordinated Network on RAdiation Dosimetry (CONRAD). The systemic biokinetic model from Leggett et al. and the biokinetic model for DTPA compounds of International Commission on Radiological Protection Publication 53 were the starting points. A new model for biokinetics of administered DTPA based on physiological interpretation of 14C-labeled DTPA studies from literature was proposed by the group. Plutonium and DTPA biokinetics were modeled separately. The systems were connected by means of a second order kinetics process describing the chelation process of plutonium atoms and DTPA molecules to Pu-DTPA complexes. It was assumed that chelation only occurs in the blood and in systemic compartment ST0 (representing rapid turnover soft tissues), and that Pu-DTPA complexes and administered forms of DTPA share the same biokinetic behavior. First applications of the CONRAD approach showed that the enhancement of plutonium urinary excretion after administration of DTPA was strongly influenced by the chelation rate constant. Setting it to a high value resulted in a good fit to the observed data. However, the model was not yet satisfactory since the effects of repeated DTPA administration in a short time period cannot be predicted in a realistic way. In order to introduce more physiological knowledge into the model several questions still have to be answered. Further detailed studies of human contamination cases and experimental data will be needed in order to address these issues. The work is now continued within the European Radiation Dosimetry Group, EURADOS. PMID:20838097

Breustedt, Bastian; Blanchardon, Eric; Bérard, Philippe; Fritsch, Paul; Giussani, Augusto; Lopez, Maria Antonia; Luciani, Andrea; Nosske, Dietmar; Piechowski, Jean; Schimmelpfeng, Jutta; Sérandour, Anne-Laure

2010-10-01

177

New insights into formation of trivalent actinides complexes with DTPA.  

PubMed

Complexation of trivalent actinides with DTPA (diethylenetriamine pentaacetic acid) was studied as a function of pcH and temperature in (Na,H)Cl medium of 0.1 M ionic strength. Formation constants of both complexes AnHDTPA(-) and AnDTPA(2-) (where An stands for Am, Cm, and Cf) were determined by TRLFS, CE-ICP-MS, spectrophotometry, and solvent extraction. The values of formation constants obtained from the different techniques are coherent and consistent with reinterpreted literature data, showing a higher stability of Cf complexes than Am and Cm complexes. The effect of temperature indicates that formation constants of protonated and nonprotonated complexes are exothermic with a high positive entropic contribution. DFT calculations were also performed on the An/DTPA system. Geometry optimizations were conducted on AnDTPA(2-) and AnHDTPA(-) considering all possible protonation sites. For both complexes, one and two water molecules in the first coordination sphere of curium were also considered. DFT calculations indicate that the lowest energy structures correspond to protonation on oxygen that is not involved in An-DTPA bonds and that the structures with two water molecules are not stable. PMID:23152978

Leguay, Sébastien; Vercouter, Thomas; Topin, Sylvain; Aupiais, Jean; Guillaumont, Dominique; Miguirditchian, Manuel; Moisy, Philippe; Le Naour, Claire

2012-12-01

178

Induction of Bordetella pertussis-specific immune memory by DTPa vaccines.  

PubMed

Several vaccines are available against pertussis, differing by the number of Bordetella pertussis antigens that they contain as well as their formulation. The GlaxoSmithKline Biologicals (GSK Bio) tricomponent DTPa vaccine (DTPa3, Infanrix™), and the Sanofi-Pasteur (SP) five-component formulation (DTPa5, Pediacel™) were shown to have comparable short-term efficacy in clinical trials. However, potential differences in long-term protection were recently suggested, which might reflect the elicitation of different specific immune memory by the two vaccines. Therefore, the purpose of the present study was to investigate in mice the immune responses against B. pertussis, and particularly the establishment of specific B cell memory after immunization with DTPa3 and DTPa5 vaccines. Whereas intranasal challenge experiments showed similar protection with both vaccines, DTPa3 induced higher antibody levels to FHA and PRN than DTPa5. Further, the frequency of memory B cells was investigated by B cell ELISPOT. Higher frequencies of PT- and PRN-specific memory B cells were evidenced after vaccination with DTPa3, compared with DTPa5. Although the origin of such difference is unclear, the use of two different adjuvants (aluminum phosphate versus hydroxide) is proposed as a possible explanation. In conclusion, this study proposes that the induction of higher levels of B. pertussis antigen-specific memory B cells with DTPa3 participate to the suggested longer persistence of protection observed with this vaccine, as compared with DTPa5. PMID:21382483

Morel, Sandra; Denoël, Philippe; Godfroid, Fabrice; Cortvrindt, Caroline; Vanderheyde, Nathalie; Poolman, Jan

2011-04-18

179

Abnormal gallbladder emptying in patients with gallstones  

Microsoft Academic Search

In this study, gallbladder and gastric emptying were compared in 15 normal subjects and 15 patients with gallstones. A noninvasive technique which uses 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

Robert S. Fisher; Frederick Stelzer; Elizabeth Rock; Leon S. Malmud

1982-01-01

180

Comparison of metabolic and receptor imaging in recurrent medullary thyroid carcinoma with histopathological findings  

Microsoft Academic Search

.   Early diagnosis of metastases of medullary thyroid carcinoma (MTC) provides the optimal condition for curative outcome. The\\u000a aim of this study was to appraise the detection of metastases in patients with recurrent MTC using [111In-DTPA-d-Phe1]-pentetreotide and pentavalent technetium-99m dimercaptosuccinic acid [99mTc(V)-DMSA] in comparison with histopathological findings. Eighteen MTC patients with persistently elevated tumour marker\\u000a (calcitonin, carcinoembryonic antigen) levels underwent

Stefan Adams; Richard P. Baum; Andreas Hertel; Petra Maria Schumm-Draeger; Klaus-Henning Usadel; Gustav Hör

1998-01-01

181

Species-dependent effective concentration of DTPA in plasma for chelation of 241Am  

PubMed Central

Diethylenetriaminepentaacetic acid (DTPA) is a chelating agent that is used to facilitate the elimination of radionuclides, such as americium, from contaminated individuals. Its primary site of action is in the blood, where it competes with various biological ligands, including transferrin and albumin, for the binding of radioactive metals. To evaluate the chelation potential of DTPA under these conditions, the competitive binding of 241Am between DTPA and plasma proteins was studied in rat, beagle and human plasma in vitro. Following incubation of DTPA and 241Am in plasma, the 241Am-bound ligands were fractionated by ultrafiltration and ion-exchange chromatography, and each fraction was assayed for 241Am content by gamma scintillation counting. Dose-response curves of DTPA for 241Am binding were established, and these models were used to calculate the 90% maximal effective concentration, or EC90, of DTPA in each plasma system. The EC90 were determined to be 31.4, 15.9 and 10.0 ?M in rat, beagle and human plasma, respectively. These values correspond to plasma concentrations of DTPA that maximize 241Am chelation while minimizing excess DTPA. Based on the pharmacokinetic profile of DTPA in humans, after a standard 30 ?mol kg?1 intravenous bolus injection, the plasma concentration of DTPA remains above EC90 for approximately 5.6 h. Likewise, the effective duration of DTPA in rat and beagle were determined to be 0.67 and 1.7 h, respectively. These results suggest that species differences must be considered when translating DTPA efficacy data from animals to humans and offer further insights into improving the current DTPA treatment regimen. PMID:23799506

Sueda, Katsuhiko; Sadgrove, Matthew P.; Jay, Michael; Di Pasqua, Anthony J.

2013-01-01

182

Species-dependent effective concentration of DTPA in plasma for chelation of 241Am.  

PubMed

Diethylenetriaminepentaacetic acid (DTPA) is a chelating agent that is used to facilitate the elimination of radionuclides such as americium from contaminated individuals. Its primary site of action is in the blood, where it competes with various biological ligands, including transferrin and albumin, for the binding of radioactive metals. To evaluate the chelation potential of DTPA under these conditions, the competitive binding of Am between DTPA and plasma proteins was studied in rat, beagle, and human plasma in vitro. Following incubation of DTPA and Am in plasma, the Am-bound ligands were fractionated by ultrafiltration and ion-exchange chromatography, and each fraction was assayed for Am content by gamma scintillation counting. Dose response curves of DTPA for Am binding were established, and these models were used to calculate the 90% maximal effective concentration, or EC90, of DTPA in each plasma system. The EC90 were determined to be 31.4, 15.9, and 10.0 ?M in rat, beagle, and human plasma, respectively. These values correspond to plasma concentrations of DTPA that maximize Am chelation while minimizing excess DTPA. Based on the pharmacokinetic profile of DTPA in humans, after a standard 30 ?mol kg intravenous bolus injection, the plasma concentration of DTPA remains above EC90 for approximately 5.6 h. Likewise, the effective duration of DTPA in rat and beagle were determined to be 0.67 and 1.7 h, respectively. These results suggest that species differences must be considered when translating DTPA efficacy data from animals to humans and offer further insights into improving the current DTPA treatment regimen. PMID:23799506

Sueda, Katsuhiko; Sadgrove, Matthew P; Jay, Michael; Di Pasqua, Anthony J

2013-08-01

183

Nitrate-enhanced gated technetium 99m sestamibi SPECT for evaluating regional wall motion at baseline and during low-dose dobutamine infusion in patients with chronic coronary artery disease and left ventricular dysfunction: Comparison with two-dimensional echocardiography  

Microsoft Academic Search

Background  The value of gated single photon emission computed tomography (SPECT) in the assessment of wall motion (WM) in patients with\\u000a severe perfusion defects and in the evaluation of low-dose dobutamine (LDD)-induced changes is not yet established. In patients\\u000a with chronic coronary artery disease who have left ventricular (LV) dysfunction, the results of nitrate-enhanced technetium\\u000a 99m sestamibi (sestamibi) gated SPECT for

Mario Leoncini; Gabriella Marcucci; Roberto Sciagrà; Fabio Frascarelli; Anna Maria Traini; Dante Mondanelli; Massimo Magni; Luciano Bini; Francesco Bellandi; Alberto Mennuti; Roberto Piero Dabizzi

2000-01-01

184

Diagnostic utility, safety, and cost-effectiveness of emergency department-initiated early scheduled technetium-99m single photon emission computed tomography imaging followed by expedited outpatient cardiac clinic visits in acute chest pain syndromes  

Microsoft Academic Search

Conventional emergency department (EMD) approach to triaging acute chest pain syndromes may lead to unnecessary admissions,\\u000a resulting to in-hospital bed occupancy and increased healthcare costs. We explore the diagnostic utility of early (less than\\u000a a week) outpatient scheduled single photon emission computed tomography (SPECT) in intermediate-risk chest pain subjects who\\u000a presented to EMD with non-diagnostic electrocardiogram and negative serum troponin

Raymond C. Wong; Arvind Kumar Sinha; Malcolm Mahadevan; Tiong Cheng Yeo

2010-01-01

185

Technetium-99m methylene diphosphonate uptake in the brachialis muscle hematoma in a patient with prostate cancer and coagulation disorder mimicking bone metastasis evaluated by single-photon emission tomography-computed tomography/computed tomography.  

PubMed

We report a case of 79-year-old male with prostate cancer and coagulation disorder presented with left shoulder pain. He underwent bone scintigraphy to rule out metastasis, which showed intense foci of tracer activity in the left axilla. Hybrid single-photon emission tomography-computed tomography (SPECT/CT) of the shoulder region localized tracer uptake to the left brachialis muscle hematoma. PMID:24379534

Kamaleshwaran, Koramadai Karuppusamy; Mohanan, Vyshakh; Madhavan, Devdas; Shinto, Ajit Sugunan

2013-10-01

186

Comparison of the predictive value of Exercise-Induced ST depression versus exercise technetium-99m sestamibi single-photon emission computed tomographic imaging for detection of coronary artery disease in patients with left ventricular hypertrophy  

Microsoft Academic Search

Scant knowledge exists regarding the significance of either additional ST depression in the presence of baseline depression or new stress-induced ST depression in patients with left ventricular (LV) hypertrophy. Accordingly, the purpose of this investigation is to determine whether the appearance and\\/or severity of ST abnormalities during exercise stress testing can accurately predict the prevalence of ischemic burden as measured

Dharmesh Patel; Timir S. Baman; George A. Beller

2004-01-01

187

Spinal cord tumors: gadolinium-DTPA-enhanced MR imaging  

Microsoft Academic Search

To assess the utility of gadolinium-DTPA (Gd) and of MR imaging in the evaluation of spinal cord tumors, ten consecutive patients were prospectively evaluated. T1-proton density-, and T2-weighted images were obtained in sagittal or axial planes. T1-weighted images were obtained before and after intravenous administration. Five tumors were within the cervical spinal cord; 3 neoplasms were within the thoracic cord;

M. C. Chamberlain; A. D. Sandy

1991-01-01

188

Tc-99m DTPA uptake in extramedullary plasmacytoma of the retroperitoneum  

SciTech Connect

A case is presented in which uptake of Tc-99m DTPA has been demonstrated in an extramedullary plasmacytoma of the retroperitoneum. Because Ga-67 citrate does not concentrate in the same areas as Tc-99m DTPA, a radionuclide-specific uptake mechanism may be present. Extramedullary plasmacytoma should be included in the list of possible causes if extrarenal or extracentral nervous system uptake of Tc-99m DTPA occurs.

Aburano, T.; Yokoyama, K.; Michigishi, T.; Tonami, N.; Hisada, K.

1988-12-01

189

Estimating blood and brain concentrations and blood-to-brain influx by magnetic resonance imaging with step-down infusion of Gd-DTPA in focal transient cerebral ischemia and confirmation by quantitative autoradiography with Gd-[14C]DTPA  

PubMed Central

An intravenous step-down infusion procedure that maintained a constant gadolinium-diethylene-triaminepentaacetic acid (Gd-DTPA) blood concentration and magnetic resonance imaging (MRI) were used to localize and quantify the blood–brain barrier (BBB) opening in a rat model of transient cerebral ischemia (n = 7). Blood-to-brain influx rate constant (Ki) values of Gd-DTPA from such regions were estimated using MRI–Patlak plots and compared with the Ki values of Gd-[14C]DTPA, determined minutes later in the same rats with an identical step-down infusion, quantitative autoradiography (QAR), and single-time equation. The normalized plasma concentration–time integrals were identical for Gd-DTPA and Gd-[14C]DTPA, indicating that the MRI protocol yielded reliable estimates of plasma Gd-DTPA levels. In six rats with a BBB opening, 14 spatially similar regions of extravascular Gd-DTPA enhancement and Gd-[14C]DTPA leakage, including one very small area, were observed. The terminal tissue–plasma ratios of Gd-[14C]DTPA tended to be slightly higher than those of Gd-DTPA in these regions, but the differences were not significant. The MRI-derived Ki values for Gd-DTPA closely agreed and correlated well with those obtained for Gd-[14C]DTPA. In summary, MRI estimates of Gd-DTPA concentration in the plasma and brain and the influx rate are quantitatively and spatially accurate with step-down infusions. PMID:19319145

Knight, Robert A; Karki, Kishor; Ewing, James R; Divine, George W; Fenstermacher, Joseph D; Patlak, Clifford S; Nagaraja, Tavarekere N

2014-01-01

190

Efficacy of different DTPA treatment schedules for removal of 234Th from simulated wounds in rats.  

PubMed

The translocation of 234Th from a simulated wound site and the efficacy of DTPA administration, as a function of the thorium compound injected as well as the DTPA treatment schedule, have been investigated in rats. Much more 234Th injected as citrate was translocated from the injection site than after administration as nitrate, whereas the distribution pattern of 234Th translocated to the various tissues was nearly identical for both 234Th compounds. Combined local and systematic treatment with DTPA was equally or more effective than each of the treatments alone in reducing the retention of 234Th at the injection site and in the organs. PMID:6607231

Peter-Witt, E; Volf, V

1984-01-01

191

Transmetallation of Gd-DTPA by Cu, Y and lanthanides and its impact on the hydrosphere  

Microsoft Academic Search

The concurrent exchange of REE3+ and Y3+ (combined to M3+) and Cu2+ for Gd3+ in Gd-DTPA (Gd-diethylenetriaminepentaacetic acid or gadopentetic acid) in the presence of clay is a very slow process if the concentrations of M3+, Cu2+ and Gd-DTPA in solution are in the range of 0.01–22nmol\\/L. The kinetics of transmetallation was followed for 1033h without reaching equilibrium, although the

Peter Möller; Peter Dulski

2010-01-01

192

Modification of the NH4 HCO3?DTPA soil test to omit carbon black  

Microsoft Academic Search

Recently Soltanpour and Schwabdeveloped an NH4HCO3 ?DTPA (AB?DTPA) soil test to simultaneously extract NO3, P, K, Zn, Fe, Mn, and Cu. In this test carbon black was used to clear the extract for the chromotropic acid method of nitrate determination. However, use of carbon black was inconvenient due to its staining and sometimes contaminative properties. The purpose of the study

P. N. Soltanpour; S. Workman

1979-01-01

193

Lanthanide-DTPA grafted silica nanoparticles as bimodal-imaging contrast agents  

Microsoft Academic Search

The design and synthesis of a combined MRI-optical probe for bio-imaging are reported. The materials studied join the properties of lanthanide (Ln3+) complexes and nanoparticles (NPs), offering an excellent solution for bimodal imaging. The hybrid SiO2@APS\\/DTPA:Gd:Ln (Ln = Eu3+ or Tb3+) (APS: 3-aminopropyltriethoxysilane, DTPA: diethylenetriamine pentaacetic acid) system increases the payload of the active magnetic centre (Gd3+) and introduces a Ln3+ long-life

Sonia L. C. Pinho; Henrique Faneca; Carlos F. G. C. Geraldes; Marie-Hélène Delville; Luís D. Carlos; João Rocha

194

Distribution and elimination characteristics of 111 In-DTPA-D-Phe 1 -octreotide and 111 In-DTPA-L-Phe 1 -octreotide in rats  

Microsoft Academic Search

Summary  The present study compares distribution and elimination characteristics of111In-DTPA-D-Phe1-octreotide and111In-DTPA-L-Phe1 octreotide in rats and evaluated the effect of the replacement of the terminal L-phenylalanine by D-phenylalanine on pharmacokinetic\\u000a profiles of the radiolabelled peptides. Both agents exhibited rapid radioactivity clearance from the blood and most organs\\u000a and tissues with no systematic and significant differences in activity accumulation. The long-term retention and

Alice Laznickova; M. LAZNICEKI; F. Trejtnar; L. Melicharova; Kazuko Horuichi Suzuki; Hiromichi Akizawa; Yasushi Arano; Akira Yokoyama

2002-01-01

195

Sulfonylurea receptor as a target for molecular imaging of pancreas beta cells with 99mTc-DTPA-glipizide  

PubMed Central

Objective This study was aimed to assess pancreas beta cell activity using 99mTc-diethyleneaminepentaacetic acid-glipizide (DTPA-GLP), a sulfonylurea receptor agent. The effect of DTPA-GLP on the blood glucose level in rats was also evaluated. Methods DTPA dianhydride was conjugated with GLP in the presence of sodium amide, yielding 60%. Biodistribution and planar images were obtained at 30–120 min after injection of 99mTc-DTPA-GLP (1 mg/rat, 0.74 and 11.1 MBq per rat, respectively) in normal female Fischer 344 rats. The control group was given 99mTc-DTPA. To demonstrate pancreas beta cell uptake of 99mTc-DTPA-GLP via a receptor-mediated process, a group of rats was pretreated with streptozotocin (a beta cell toxin, 55 mg/kg, i.v.) and the images were acquired at immediately—65 min on day 5 post-treatment. The effect on the glucose levels after a single administration (ip) of DTPA-GLP was compared to glipizide (GLP) for up to 6 h. Results The structure of DTPA-GLP was confirmed by NMR, mass spectrometry and HPLC. Radiochemical purity assessed by ITLC was >96%. 99mTc-DTPA-GLP showed increased pancreas-to-muscle ratios, whereas 99mTc-DTPA showed decreased ratios at various time points. Pancreas could be visualized with 99mTc-DTPA-GLP in normal rat, however, 99mTc-DTPA has poor uptake suggesting the specificity of 99mTc-DTPA-GLP. Pancreas beta cell uptake could be blocked by pre-treatment with streptozotocin. DTPA-GLP showed an equal or better response in lowering the glucose levels compared to the existing GLP drug. Conclusions It is feasible to use 99mTc-DTPA-GLP to assess pancreas beta cell receptor recognition. 99mTc-DTPA-GLP may be helpful in evaluating patients with diabetes, pancreatitis and pancreatic tumors. PMID:22237676

Oh, Chang-Sok; Kohanim, Saady; Kong, Fan-Lin; Song, Ho-Chun; Huynh, Nathan; Mendez, Richard; Chanda, Mithu; Kim, E. Edmund

2013-01-01

196

Atmospheric Aerosols  

NASA Technical Reports Server (NTRS)

Aerosols, defined as particles and droplets suspended in air, are always present in the atmosphere. They are part of the earth-atmosphere climate system, because they interact with both incoming solar and outgoing terrestrial radiation. They do this directly through scattering and absorption, and indirectly through effects on clouds. Submicrometer aerosols usually predominate in terms of number of particles per unit volume of air. They have dimensions close to the wavelengths of visible light, and thus scatter radiation from the sun very effectively. They are produced in the atmosphere by chemical reactions of sulfur-, nitrogen- and carbon-containing gases of both natural and anthropogenic origins. Light absorption is dominated by particles containing elemental carbon (soot), produced by incomplete combustion of fossil fuels and by biomass burning. Light-scattering dominates globally, although absorption can be significant at high latitudes, particularly over highly reflective snow- or ice-covered surfaces. Other aerosol substances that may be locally important are those from volcanic eruptions, wildfires and windblown dust.

Pueschel, R. F.; Lawless, James G. (Technical Monitor)

1994-01-01

197

De novo synthesis of a new diethylenetriaminepentaacetic acid (DTPA) bifunctional chelating agent.  

PubMed

Diethylene triamine pentaacetic acid (DTPA) has been in extensive use as a metal chelator in the development of radiopharmaceuticals and contrast agents. The former application uses DTPA mostly as a bifunctional chelating agent (BCA) conjugated to tumor-targeting vehicles (TTVs) such as monoclonal antibodies (MAbs) and receptor-directed peptides. A new bifunctional DTPA derivative was synthesized by a fully organic scheme. This compound, N(4),N(alpha),N(alpha),N(epsilon),N(epsilon)-[pentakis(carboxymethyl)]-N(4)-(carboxymethyl)-2,6-diamino-4-azahexanoic hydrazide (20) was prepared by a convergent synthesis strategy using N(alpha)-benzyloxycarbonyl-2,3-diaminopropionic acid as the starting compound. This commercially available material was used to build a functionalized triamine which served as the molecular core template for assembling the target molecule. To evaluate the conjugation and radiolabeling capabilities of this new molecule, it was covalently attached to the anti-TAG-72 MAb, Delta CH2HuCC49, and the conjugate was radiolabeled in near-quantitative yields with yttrium-90 ((90)Y) and lutetium-177 ((177)Lu). Biodistribution of the (177)Lu-labeled DTPA-Delta CH2HuCC49 in tumor-bearing nude mice demonstrated preservation of the immunoreactivity of the MAb as indicated by high tumor uptake. In addition to the introduction of a new bifunctional DTPA, this work reports on a novel synthetic approach for preparation of this useful metal chelator and introduces a new conjugation protocol. PMID:11906270

Safavy, Ahmad; Smith, Dale C; Bazooband, Alireza; Buchsbaum, Donald J

2002-01-01

198

Synthesis and evaluation of novel polysaccharide-Gd-DTPA compounds as contrast agent for MRI  

NASA Astrophysics Data System (ADS)

Macromolecular conjugates of two kinds of natural polysaccharides, that from Panax quinquefolium linn (PQPS) and Ganoderma applanatum pat (GAPS), with gadolinium-diethylenetriaminepenta-acetic acid (Gd-DTPA) have been synthesized and characterized by means of FTIR, elementary analysis and ICP-AES. Their stability was investigated by competition study with Ca 2+, EDTA (ethylenediaminetetraacetic acid) and DTPA. Polysaccharide-bound complexes exhibit T1 relaxivities of 1.5-1.7 times that of Gd-DTPA in D 2O at 25°C and 9.4 T. MR imaging of Sprague-Dawley (SD) rats showed remarkable enhancement in rat liver and kidney after i.v. injection of these two complexes: liver parenchyma 60.9±5.6%, 57.8±7.4% at 65-85 min; kidney 144.9±14.5%, 199.9±25.4% at 10-30 min for PQPS-Gd-DTPA, GAPS-Gd-DTPA at gadolinium dose of 0.083 and 0.082 mmol/kg, respectively. Our preliminary in vivo and in vitro study indicates that the two kinds of polysaccharide-bound complexes are potential tissue-specific contrast agents for MRI.

Sun, Guoying; Feng, Jianghua; Jing, Fengying; Pei, Fengkui; Liu, Maili

2003-09-01

199

Lung function declines in patients with pulmonary sarcoidosis and increased respiratory epithelial permeability to sup 99m Tc-DTPA  

SciTech Connect

Respiratory epithelial clearance of {sup 99m}Tc-DTPA (RC-Tc-DTPA) and pulmonary function tests (PFT) were determined at intervals of 6 or 12 months in 37 untreated, nonsmoking patients with sarcoidosis over a period of 6 to 36 months. PFT included the measurements of total lung capacity (TLC), vital capacity (VC), FEV1, and diffusing capacity for carbon monoxide. No difference was found between the respiratory clearance of {sup 113m}In-DTPA (2.25 +/- 1.00%/min) and RC-Tc-DTPA (2.29 +/- 1.11%/min) in eight patients with pulmonary sarcoidosis. Pulmonary function decreased 15% or more in at least 2 function tests during 11 follow-up periods, but it remained stable during 47 follow-up periods. In patients whose lung function deteriorated, RC-Tc-DTPA increased to 3.51 +/- 1.55%/min; in contrast, in patients whose lung function remained stable, regardless of the initial values, RC-Tc-DTPA was normal (1.00 +/- 0.50%/min; p less than 0.001). In eight patients who were treated with corticosteroids, RC-Tc-DTPA decreased from 3.48 +/- 1.31%/min to 1.56 +/- 0.64%/min (p less than 0.001), and PFT improved. We conclude that in nonsmokers with pulmonary sarcoidosis, increased RC-Tc-DTPA is not related to dissociation of 99mTc from DTPA, RC-Tc-DTPA is increased when pulmonary function decreases, and, when increased, RC-Tc-DTPA decreases with corticosteroid therapy.

Chinet, T.; Dusser, D.; Labrune, S.; Collignon, M.A.; Chretien, J.; Huchon, G.J. (Universite Rene Descartes, Paris (France))

1990-02-01

200

Gadolinium-DTPA enhanced magnetic resonance imaging of bone cysts in patients with rheumatoid arthritis.  

PubMed Central

OBJECTIVES--To examine the contents of intraosseous cysts in patients with rheumatoid arthritis (RA) through the signal intensity characteristics on gadolinium-DTPA (Gd-DTPA) enhanced magnetic resonance imaging. METHODS--The hand or foot joints of nine patients with the cystic form of RA (where the initial radiological abnormality consisted of intraosseous cysts without erosions) were imaged before and after intravenous administration of Gd-DTPA. A 0.6 unit, T1 weighted spin echo and T2* weighted gradient echo were used to obtain images in at least two perpendicular planes. RESULTS--Most cysts showed a low signal intensity on the non-enhanced T1 weighted (spin echo) images and a high signal intensity on the T2* weighted (gradient echo) images, consistent with a fluid content. No cyst showed an enhancement of signal intensity on the T1 weighted images after intravenous administration of Gd-DTPA, whereas synovium hyperplasia at the site of bony erosions did show an increased signal intensity after Gd-DTPA. Magnetic resonance imaging detected more cysts (as small as 2 mm) than plain films, and the cysts were located truly intraosseously. In six patients no other joint abnormalities were identified by magnetic resonance imaging; the three other patients also showed, after Gd-DTPA administration, an enhanced synovium at the site of bony erosions. CONCLUSIONS--It is suggested that intraosseous bone cysts in patients with RA do not contain hyperaemic synovial proliferation. The bone cysts in patients with the cystic form of RA may be the only joint abnormality. Images PMID:8257207

Gubler, F M; Algra, P R; Maas, M; Dijkstra, P F; Falke, T H

1993-01-01

201

Capture of Co(II) from its aqueous EDTA-chelate by DTPA-modified silica gel and chitosan.  

PubMed

The adsorption of Co(II) by diethylenetriaminepentaacetic acid (DTPA)-modified silica gel and chitosan in the presence of EDTA and other interfering species was studied. Co(II) removal ranged from 93% to 96% from the solutions where Co(II) was totally chelated by EDTA. The amount of oxalate or Fe(II) did not affect the adsorption of Co(II) in the case of DTPA-chitosan. However, increasing the amount of oxalate enhanced the adsorption performance of DTPA-silica gel, probably due to the formation of new active sites on the silica gel surface. DTPA-chitosan was also effective in simulated decontamination solutions. For DTPA-silica gel, the rate of adsorption of free Co(II) was controlled by pore diffusion, but the rate of adsorption of Co(II)EDTA was controlled by the surface chelation reaction, which was attributed to the inhibited diffusion of Co(II)EDTA inside the silica gel mesopores. However, the macroporous structure of DTPA-chitosan enabled pore diffusion of both Co(II) and Co(II)EDTA. The equilibrium isotherms of DTPA-silica gel were best described by a BiLangmuir model, in which there are two different adsorption sites on the silica gel surface assigned to different speciations of DTPA. For DTPA-chitosan, the data fit best with a Sips model, which indicates system heterogeneity. Finally, measurements with capillary electrophoresis showed an increase in dissolved EDTA during adsorption, demonstrating the ability of DTPA-modified adsorbents to release Co(II) from its EDTA chelate. This promising result can provide a basis for applying the studied materials to the treatment of water effluents containing Co(II) chelated by EDTA by a simple one-step adsorption process. PMID:21247694

Repo, Eveliina; Malinen, Leena; Koivula, Risto; Harjula, Risto; Sillanpää, Mika

2011-03-15

202

Kidney scintigraphy after ACE inhibition in the diagnosis of renovascular hypertension  

SciTech Connect

Suppression of the renin-angiotensin system (RAS) by angiotensin converting enzyme (ACE) inhibition may induce renal failure in patients with bilateral renal artery stenosis. Recent scintigraphic studies with the glomerular tracer technetium-99m-diethylenetriaminepenta-acetate (99m-Tc DTPA) indicate that in patients with unilateral renal artery stenosis, glomerular filtration rate (GFR) may be markedly reduced in the affected kidney after inhibition of ACE. This finding reflects the important role of the RAS in maintaining GFR (by increasing postglomerular resistance) in states of low renal perfusion pressure. Preliminary observations suggest that this scintigraphic test might be useful in the detection of renovascular hypertension.

Ghione, S.; Fommei, E.; Palombo, C.; Giaconi, S.; Mantovanelli, A.; Ragazzini, A.; Palla, L.

1986-01-01

203

Low-level determination of EDTA and DTPA in natural waters by gas chromatography  

Microsoft Academic Search

Summary  A new analytical method and the method validation for the determination of ethylenediaminetetraacetic acid (EDTA) and diethylenetriaminepentaacetic acid (DTPA) in lake and sea water is presented. An aqueous sample, after evaporation to dryness, was treated with an esterification reagent. The resulting ethyl ester derivates were determined by capillary gas chromatography using a nitrogen phosphorus specific detector (GC-NPD). The response was

M. Sillanpää; J. Sorvari; M.-L. Sihvonen

1996-01-01

204

Improved chelation therapy of intramuscularly deposited thorium by CaDTPA in the rat.  

PubMed

Comparative studies on the translocation and retention of intramuscularly (i.m.) injected thorium nitrate (234Th 46 ng + 232Th 5 microg per rat) in solutions of citrate, CaDTPA or citrate + CaDTPA in rats have been conducted. Results showed that only thorium in mixed-ligand solution was entirely translocated from the muscle, with the greatest part being excreted from the body. In this case, the whole-body retention of thorium decreased to 16% of the injected radioactivity within 2 d, 13% being retained in the skeleton. Studies on the decorporation of 234Th + 232Th nitrates from a rat wound simulated with i.m. injection have also been carried out. The greatest translocation of thorium and its excretion was achieved with a single local injection of the mixed-ligand (citrate + CaDTPA) solution when compared with those of citrate or CaDTPA alone. The efficiency of mixed-ligand treatment decreased with its delay. On day 2 post-therapy, the whole-body content of thorium decreased to 30, 37 and 55% of injected radioactivity when the local treatment started immediately, postponed to 1 h or 24 h, after i.m. injection of thorium, respectively. In control rats without treatment, there was only a slight decrease in the content of thorium in the whole body. PMID:14527020

Rencová, J; Vlková, A; Veselá, G

2003-01-01

205

Biodistribution of Ru-97-labeled DTPA, DMSA and transferrin. [Diagnostic potential  

SciTech Connect

Ruthenium-97 is being produced at the Brookhaven Linac Isotope Producer (BLIP). The favorable physical properties of Ru-97 and chemical reactivity of ruthenium offer a potential for using this isotope to label compounds useful for delayed scanning. Diethylenetriamine pentaacetic acid (DTPA), 2,3-Dimercaptosuccinic acid (DMSA), and Transferrin (TF) were labeled with Ru-97-chloride. Ru-97-DTPA and In-111-DTPA, injected intravenously, showed similar organ distribution, kinetics, and more than 80% excretion by 0.5 h. Ru-97-DTPA and In-111-DTPA injected into the cisterna magna of dogs showed similar kinetics in brain, blood, and urinary bladder. The energy deposited by 1 mCi In-111-DTPA is twice that from 1 mCi Ru-97-DTPA. High quality camera images of the CSF space in the dog were obtained with both isotopes. Ru-97-DMSA was prepared with and without the addition of SnCl/sub 2/.2H/sub 2/O. Tin-free DMSA was rapidly excreted via the kidneys, whereas for maximum cortical deposition, the tin-containing preparation was superior. This compound is suitable for delayed imaging of both normal and impaired kidneys. Tissue distribution studies were performed in abscess-bearing rats with Ru-97-transferrin. Although blood levels were higher than with Ga-67-citrate, the abscess had twice as much Ru-97-TF as Ga-67-citrate and the Ru-97 muscle activity was one-third that of Ga-67. Imaging of abscess-bearing rabbits with Ru-97-TF visualized the abscesses as early as 1/2 hr after injection. Since the initial images visualize the abscess so clearly and since the TF portion of the compound binds to the abscess, Tc-99m-TF is being studied for the same purpose. Ru-97-labeled compounds are a promising replacement for In-111 and possibly also for Ga-67 compounds with the advantages of lower radiation dose and high quality image. (ERB)

Som, P; Oster, Z H; Fairchild, R G; Atkins, H L; Brill, A B; Gil, M C; Srivastava, S C; Meinken, G E; Goldman, A G; Richards, P

1980-01-01

206

Aerosol mobility size spectrometer  

DOEpatents

A device for measuring aerosol size distribution within a sample containing aerosol particles. The device generally includes a spectrometer housing defining an interior chamber and a camera for recording aerosol size streams exiting the chamber. The housing includes an inlet for introducing a flow medium into the chamber in a flow direction, an aerosol injection port adjacent the inlet for introducing a charged aerosol sample into the chamber, a separation section for applying an electric field to the aerosol sample across the flow direction and an outlet opposite the inlet. In the separation section, the aerosol sample becomes entrained in the flow medium and the aerosol particles within the aerosol sample are separated by size into a plurality of aerosol flow streams under the influence of the electric field. The camera is disposed adjacent the housing outlet for optically detecting a relative position of at least one aerosol flow stream exiting the outlet and for optically detecting the number of aerosol particles within the at least one aerosol flow stream.

Wang, Jian (Port Jefferson, NY); Kulkarni, Pramod (Port Jefferson Station, NY)

2007-11-20

207

AEROSOL CHARACTERISTICS AND VISIBILITY  

EPA Science Inventory

This report summarizes progress in measuring the optical properties of aerosols and in relating aerosol characteristics to visibility reduction made in the author's laboratory during the period 1965-1971. An instrument, the integrating nephelometer, which measures the scattering ...

208

MODAL AEROSOL DYNAMICS MODELING  

EPA Science Inventory

The report described by this Project Summary presents the governing equations for representing aerosol dynamics, based on several different representations of the aerosol size distribution. Analytical and numerical solution techniques for these governing equations are also review...

209

URBAN AEROSOL MODELING  

EPA Science Inventory

Accurate numerical schemes have been developed for simulation of the condensation/evaporation processes with vapor conservation for a single component aerosol. These have been incorporated in modules which allow simulation of aerosol dynamics in models for dispersion and transpor...

210

AEROSOL AND GAS MEASUREMENT  

EPA Science Inventory

Measurements provide fundamental information for evaluating and managing the impact of aerosols on air quality. Specific measurements of aerosol concentration and their physical and chemical properties are required by different users to meet different user-community needs. Befo...

211

Improved solid aerosol generator  

DOEpatents

An improved solid aerosol generator used to produce a gas borne stream of dry, solid particles of predetermined size and concentration. The improved solid aerosol generator nebulizes a feed solution of known concentration with a flow of preheated gas and dries the resultant wet heated aerosol in a grounded, conical heating chamber, achieving high recovery and flow rates. 2 figs.

Prescott, D.S.; Schober, R.K.; Beller, J.

1988-07-19

212

MODAL AEROSOL DYNAMICS MODEL  

EPA Science Inventory

The Modal Aerosol Dynamics (MAD) model is a computationally efficient model for solving the General Dynamics Equation of Aerosols (GDE) (Friedlander, 1977). The simplifying assumption in the model is that aerosol size distributions can be approximated by overlapping modes, each r...

213

Aerosol penetration ratio: a new index of ventilation  

SciTech Connect

Superimposition of nuclear medicine scintigrams and standard radiographs provides a unique opportunity for merging functional information intrinsic to nuclear medicine images with the high resolution anatomic detail of radiographs. A newly developed image processing system allows the merging of two separate films of greatly varying sizes to form a single composite image. Subsequent quantitative analysis of the composite image may be performed. Using the superimposition technique, (/sup 99m/Tc)DTPA aerosol ventilation scans (4.5 X 4.5 cm) were superimposed upon chest radiographs (35.6 X 43.2 cm) in 17 cystic fibrosis (CF) patients. Subsequent quantification of the area of nuclear scan ventilation and the radiographic lung area was then performed. A new quantitative radiologic index of ventilation, the aerosol penetration ratio (APR), was defined. Linear correlation of aerosol penetration ratio with residual volume (RV) as percent of total lung capacity (TLC) measured by body plethysmography was good. We conclude that the APR has validity as a physiologic parameter which localized regional excessive residual volume and correlates well with RV/TLC, the gold standard pulmonary function index of obstructive airway disease.

Sirr, S.A.; Elliott, G.R.; Regelmann, W.E.; Juenemann, P.J.; Morin, R.L.; Boudreau, R.J.; Warwick, W.J.; Loken, M.K.

1986-08-01

214

Calcium and zinc DTPA administration for internal contamination with plutonium-238 and americium-241.  

PubMed

The accidental or intentional release of plutonium or americium can cause acute and long term adverse health effects if they enter the human body by ingestion, inhalation, or injection. These effects can be prevented by rapid removal of these radionuclides by chelators such as calcium or zinc diethylenetriaminepentaacetate (calcium or zinc DTPA). These compounds have been shown to be efficacious in enhancing the elimination of members of the actinide family particularly plutonium and americium when administered intravenously or by nebulizer. The efficacy and adverse effects profile depend on several factors that include the route of internalization of the actinide, the type, and route time of administration of the chelator, and whether the calcium or zinc salt of DTPA is used. Current and future research efforts should be directed at overcoming limitations associated with the use of these complex drugs by using innovative methods that can enhance their structural and therapeutic properties. PMID:22352730

Kazzi, Ziad N; Heyl, Alexander; Ruprecht, Johann

2012-08-01

215

External monitoring of kidney transplant function using Tc-99m(Sn)DTPA  

SciTech Connect

The purpose of this study was to evaluate the use of an external counting technique to provide daily monitoring of kidney transplant function by measuring the renal clearance of Tc-99m(SN)DTPA. During the first few weeks following transplant, 15 patients had their renal clearance of Tc-99m DTPA measured daily over periods of 5 to 24 h. Clearance rates were compared with daily plasma creatinine levels, and the effects of diurnal variation, drug treatment, and physical activity noted. The resuls show tht any significant fall in clearance rate of chelate, indicating a rejection episode, preceded a rise in plasma creatinine levels by at least 24 hr. It is considered that this noninvasive, low-dose, easy-to-perform technique is of considerable value in extended daily monitoring of renal function and is superior to standard daily or twice-weekly renography for the early detection of transplant rejection.

Sampson, W.F.D.; Macleod, M.A.; Warren, D.

1981-05-01

216

Characterization of Microcirculation in Multiple Sclerosis Lesions by Dynamic Texture Parameter Analysis (DTPA)  

PubMed Central

Objective Texture analysis is an alternative method to quantitatively assess MR-images. In this study, we introduce dynamic texture parameter analysis (DTPA), a novel technique to investigate the temporal evolution of texture parameters using dynamic susceptibility contrast enhanced (DSCE) imaging. Here, we aim to introduce the method and its application on enhancing lesions (EL), non-enhancing lesions (NEL) and normal appearing white matter (NAWM) in multiple sclerosis (MS). Methods We investigated 18 patients with MS and clinical isolated syndrome (CIS), according to the 2010 McDonald's criteria using DSCE imaging at different field strengths (1.5 and 3 Tesla). Tissues of interest (TOIs) were defined within 27 EL, 29 NEL and 37 NAWM areas after normalization and eight histogram-based texture parameter maps (TPMs) were computed. TPMs quantify the heterogeneity of the TOI. For every TOI, the average, variance, skewness, kurtosis and variance-of-the-variance statistical parameters were calculated. These TOI parameters were further analyzed using one-way ANOVA followed by multiple Wilcoxon sum rank testing corrected for multiple comparisons. Results Tissue- and time-dependent differences were observed in the dynamics of computed texture parameters. Sixteen parameters discriminated between EL, NEL and NAWM (pAVG?=?0.0005). Significant differences in the DTPA texture maps were found during inflow (52 parameters), outflow (40 parameters) and reperfusion (62 parameters). The strongest discriminators among the TPMs were observed in the variance-related parameters, while skewness and kurtosis TPMs were in general less sensitive to detect differences between the tissues. Conclusion DTPA of DSCE image time series revealed characteristic time responses for ELs, NELs and NAWM. This may be further used for a refined quantitative grading of MS lesions during their evolution from acute to chronic state. DTPA discriminates lesions beyond features of enhancement or T2-hypersignal, on a numeric scale allowing for a more subtle grading of MS-lesions. PMID:23874432

Heldner, Mirjam Rahel; Kellner-Weldon, Frauke; Kottke, Raimund; Ozdoba, Christoph; Weisstanner, Christian; Kamm, Christian Philipp; Wiest, Roland

2013-01-01

217

Measurement of glomerular filtration rate in ICU patients using 99mTc-DTPA and inulin  

Microsoft Academic Search

Measurements of glomerular filtration rate in ICU patients using 99mTc-DTPA and inulin. Improved and reliable methods for assessing glomerular filtration rate (GFR) in intensive care patients are needed in light of known deficiencies using creatinine clearance. We compared simultaneous two-hour clearances of inulin (CIn), creatinine (CCr), and 99mTc-diethylenetriaminepentaacetic acid (CDTPA) in 18 medical or surgical intensive care patients (range, 49

William W Wharton; Jill L Sondeen; Michael McBiles; Stephen E Gradwohl; Charles E Wade; David P Ciceri; Heinz G Lehmann; Richard E Stotler; Thomas R Henderson; W Roscoe Whitaker; Jill S Lindberg

1992-01-01

218

MRI visualization of proteoglycan depletion in articular cartilage via intravenous administration of Gd-DTPA  

Microsoft Academic Search

The effect of intravenous administration of gadolinium diethylenetriamine-pentaacetic acid (Gd-DTPA) on MR images was studied in vitro, using pathologic osteochondral specimens removed during surgery for total endoprosthesis, and in vivo, on a group of volunteers. In ex vivo specimens, lesions of different shape having lower T1 were detected which corresponded to areas with depleted proteoglycans found histologically. In vivo experiments

Siegfried Trattnig; Vladim??r Mly?arik; Martin Breitenseher; Monika Huber; Alexander Zembsch; Thomas Rand; Herwig Imhof

1999-01-01

219

Climate forcing by stratospheric aerosols  

NASA Technical Reports Server (NTRS)

It is illustrated how climate forcing by stratospheric aerosols depends on aerosol properties. The climate forcing is a function of aerosols size distribution, but the size dependence can be described well by a single parameter: the area-weighted mean radius, r(eff). If r(eff) is greater than about 2 microns, the global average greenhouse effect of the aerosols exceeds the albedo effect, causing a surface heating. The aerosol climate forcing is less sensitive to other characteristics of the size distribution, the aerosol composition, and the altitude of the aerosols. Thus stratospheric aerosol forcing can be defined accurately from measurements of aerosol extinction over a broad wavelength range.

Lacis, Andrew; Hansen, James; Sato, Makiko

1992-01-01

220

Evaluation of liver function using gadoxetate disodium (Gd-EOB-DTPA) enhanced MR imaging  

NASA Astrophysics Data System (ADS)

Indocyanine green (ICG) is widely used for its clearance test in the evaluation of liver function. Gadoxetate disodium (Gd-EOB-DTPA) is a targeted MR contrast agent partially taken up by hepatocytes. The objective of this study was to evaluate the feasibility of an estimation of the liver function corresponding to plasma disappearance rate of indocyanine green (ICG-PDR) by use of the signal intensity of the liver alone in Gd-EOB-DTPA enhanced MR imaging (EOB-MRI). We evaluated fourteen patients who had EOB-MRI and ICG clearance test within 1 month. 2D-GRE T1 weighted images were obtained at pre contrast, 3 min (equilibrium phase) and 20 min (hepatobiliary phase) after the intravenous administration of Gd-EOB-DTPA, and the mean signal intensity of the liver was measured. The correlation between ICG-PDR and many parameters derived from the signal intensity of the liver in EOB-MRI was evaluated. The correlation coefficient between ICG-PDR and many parameters derived from the signal intensity of the liver in EOBMRI was low and not significant. The estimation of the liver function corresponding to ICG-PDR by use of the signal intensity of the liver alone in EOB-MRI would not be reliable.

Yamada, Akira; Hara, Takeshi; Li, Feng; Doi, Kunio

2010-03-01

221

A new high affinity technetium analogue of bombesin containing DTPA as a pharmacokinetic modifier.  

PubMed

The bombesin (BN)/gastrin-releasing peptide (GRP) receptor is expressed in high density on the cell surface of a variety of tumors. This makes the receptors accessible as a molecular target for the detection of lesions in which they are expressed. In this study, we describe a high affinity hydrophilic (99m)Tc-labeled BN analogue, [DTPA(1), Lys(3)((99m)Tc-Hx-DADT), Tyr(4)]BN, having diethylenetriaminepentaacetic acid (DTPA), as a build-in pharmacokinetic modifier, to direct its excretion through the urinary system in order to lower abdominal background activity. In vitro binding studies using [(125)I-Tyr(4)]BN (K(d), 0.1 nM) and human prostate cancer PC-3 cell membranes showed that the inhibition constant (K(i)) of [DTPA(1), Lys(3)((99)Tc-Hx-DADT), Tyr(4)]BN was 19.9 +/- 8.0 nM. Biodistribution studies in normal mice showed fast blood clearance (0.15 +/- 0.01% ID/g, 4 h postinjection), low intestinal accumulation (9.16 +/- 2.35% ID/g, 4 h postinjection), and significant uptake in BN/GRP receptor rich tissues such as the pancreas (21.83 +/- 2.88% ID/g, 15 min postinjection). The pancreas/blood, pancreas/muscle, and pancreas/liver ratios were highest at 2 h postinjection at 23, 74, and 8.4, respectively. The uptake in the pancreas could be blocked by BN (11.96 +/- 1.17 vs 0.65 +/- 0.16% ID/g), partially blocked by neuromedin B (11.96 +/- 1.17 vs 6.66 +/- 0.51% ID/g), but not affected by somatostatin (11.96 +/- 1.17 vs 12.91 +/- 2.53% ID/g), indicating that the binding of [DTPA(1), Lys(3)((99m)Tc-Hx-DADT), Tyr(4)]BN to the receptors was specific. Scintigraphic imaging of human PC-3 prostate cancer xenografts in SCID mice gave a high target to nontarget ratio on the image. Thus, [DTPA(1), Lys(3)((99m)Tc-Hx-DADT), Tyr(4)]BN has the potential for imaging BN/GRP receptor-positive lesions. PMID:15546210

Lin, Kuo-Shyan; Luu, Andrew; Baidoo, Kwamena E; Hashemzadeh-Gargari, Hossein; Chen, Ming-Kai; Pili, Roberto; Pomper, Martin; Carducci, Michael; Wagner, Henry N

2004-01-01

222

Antarctic aerosols - a review  

SciTech Connect

Tropospheric aerosols with the diameter range of half a micron reside in the atmosphere for tens of days and teleconnect Antarctica with other regions by transport that reaches planetary scales of distances; thus, the aerosol on the Antarctic ice represents memory modules of events that took place at regions separated from Antarctica by tens of thousands of kilometers. In terms of aerosol mass, the aerosol species include insoluble crustal products (less than 5 percent), transported sea-salt residues (highly variable but averaging about 10 percent), Ni-rich meteoric material, and anomalously enriched material with an unknown origin. Most (70-90 percent by mass) of the aerosol over the Antarctic ice shield, however, is the natural acid sulfate aerosol, apparently deriving from biological processes taking place in the surrounding oceans. 137 references.

Shaw, G. E.

1988-02-01

223

10 CFR 30.34 - Terms and conditions of licenses.  

Code of Federal Regulations, 2012 CFR

...licensee preparing technetium-99m radiopharmaceuticals from molybdenum-99/technetium-99m generators or rubidium-82 from strontium-82...rubidium-82 generators shall test the generator eluates for molybdenum-99 breakthrough or strontium-82 and strontium-85...

2012-01-01

224

10 CFR 30.34 - Terms and conditions of licenses.  

...licensee preparing technetium-99m radiopharmaceuticals from molybdenum-99/technetium-99m generators or rubidium-82 from strontium-82...rubidium-82 generators shall test the generator eluates for molybdenum-99 breakthrough or strontium-82 and strontium-85...

2014-01-01

225

10 CFR 30.34 - Terms and conditions of licenses.  

Code of Federal Regulations, 2013 CFR

...licensee preparing technetium-99m radiopharmaceuticals from molybdenum-99/technetium-99m generators or rubidium-82 from strontium-82...rubidium-82 generators shall test the generator eluates for molybdenum-99 breakthrough or strontium-82 and strontium-85...

2013-01-01

226

10 CFR 30.34 - Terms and conditions of licenses.  

Code of Federal Regulations, 2011 CFR

...licensee preparing technetium-99m radiopharmaceuticals from molybdenum-99/technetium-99m generators or rubidium-82 from strontium-82...rubidium-82 generators shall test the generator eluates for molybdenum-99 breakthrough or strontium-82 and strontium-85...

2011-01-01

227

Thermoluminescent aerosol analysis  

NASA Technical Reports Server (NTRS)

A method for detecting and measuring trace amounts of aerosols when reacted with ozone in a gaseous environment was examined. A sample aerosol was exposed to a fixed ozone concentration for a fixed period of time, and a fluorescer was added to the exposed sample. The sample was heated in a 30 C/minute linear temperature profile to 200 C. The trace peak was measured and recorded as a function of the test aerosol and the recorded thermoluminescence trace peak of the fluorescer is specific to the aerosol being tested.

Rogowski, R. S.; Long, E. R., Jr. (inventors)

1977-01-01

228

Aerosols and protective clothing.  

PubMed

A complex test method for evaluating protective apparel in aerosol hazard conditions has been developed and examined under laboratory conditions. The effectiveness of the barrier or "collection efficiency" of aerosol protective apparel (APA) depends upon its structural properties such as porosity, thickness, and permeability as well as on its hydrodynamic properties, i.e., pressure drop. Aerosol generating systems and methods of measuring penetration and evaluating data are described. A method of testing protective apparel materials using a standard asbestos aerosol then is described and discussed in detail. PMID:2154085

Spurny, K R; Schoermann, J; Opiela, H

1990-01-01

229

PET imaging of HER1-expressing xenografts in mice with 86Y-CHX-A"-DTPA-cetuximab  

PubMed Central

Cetuximab is a recombinant, human/mouse chimeric IgG1, monoclonal antibody (mAb) that binds to the epidermal growth factor receptor (EGFR/HER1). Cetuximab is approved for the treatment of patients with HER1-expressing metastatic colorectal cancer. Limitations in currently reported radiolabeled cetuximab for PET applications prompted the development of 86Y-CHX-A”-DTPA-cetuximab as an alternative for imaging HER1-expressing cancer. 86Y-CHX-A”-DTPA-cetuximab can also serve as a surrogate marker for 90Y therapy. Methods Bifunctional chelate, CHX-A”-DTPA was conjugated to cetuximab and radiolabeled with 86Y. In vitro immunoreactivity was assessed in HER1-expressing A431 cells. In vivo biodistribution, PET imaging and non-compartmental pharmacokinetics were performed on mice bearing HER1-expressing human colorectal (LS-174T and HT29), prostate (PC-3 and DU145), ovarian (SKOV3) and pancreatic (SHAW) tumor xenografts. Receptor blockage was demonstrated by co-injection of either 0.1 or 0.2 mg cetuximab. Results 86Y-CHX-A”-DTPA-cetuximab was routinely prepared with a specific activity of 1.5– 2 GBq/mg and in vitro immunoreactivity ranging from 65–75 %. Biodistribution and PET imaging studies demonstrated high HER1-specific tumor uptake of the radiotracer and clearance from non-specific organs. In LS-174T tumor bearing mice injected with the 86Y-CHX-A”-DTPA-cetuximab alone, 86Y-CHX-A”-DTPA-cetuximab plus 0.1 mg cetuximab or 0.2 mg cetuximab, the tumor uptake values at 3 d were 29.3 ± 4.2, 10.4 ± 0.5 and 6.4 ± 0.3 % ID/g, respectively, demonstrating dose-dependent blockage of the target. Tumors were clearly visualized 1 d after injecting 3.8–4.0 MBq 86Y-CHX-A”-DTPA-cetuximab. Quantitative PET revealed highest tumor uptake in LS-174T (29.55 ± 2.67 % ID/cc) and lowest tumor uptake in PC-3 (15.92 ± 1.55 % ID/cc) xenografts at 3 d after injection. Tumor uptake values quantified by PET were closely correlated (r2= 0.9, n=18) to values determined by biodistribution studies. Conclusion This study demonstrates the feasibility in preparation of high specific activity 86Y-CHX-A”-DTPA-cetuximab and its application for quantitative non-invasive PET imaging of HER1-expressing tumors. 86Y-CHX-A”-DTPA-cetuximab offers an attractive alternative to previously labeled cetuximab for PET and warrants further investigation for clinical translation. PMID:20155263

Nayak, Tapan K.; Regino, Celeste A.S.; Wong, Karen J.; Milenic, Diane E.; Garmestani, Kayhan; Baidoo, Kwamena E.; Szajek, Lawrence P.; Brechbiel, Martin W.

2010-01-01

230

Salicylic acid failed to increase the efficacy of Ca-DTPA in the decorporation of plutonium and americium  

SciTech Connect

Male and female C57BL/Do mice were each given a single ip injection of /sup 237 + 239/Pu + /sup 241/Am as the citrate complex at 45 days of age. Twice-weekly ip injections of either 500 ..mu..mole/kg Ca-DTPA or 500 ..mu..mole/kg Ca-DTPA mixed just before injection with 2000 ..mu..mole/kg salicylic acid (SA) were begun 3 days after nuclide administration and continued for 5 weeks. Control mice were injected each time with isotonic saline. Nuclide retention was determined by in vivo ..gamma..-ray counting using a NaI(Tl) crystal spectrometer. At the end of treatment, total-body retention of Pu or Am in the mice given Ca-DTPA was significantly lower (P < 0.001) than that in the control animals. Mice treated with Ca-DTPA plus SA were statistically indistinguishable from mice treated with Ca-DTPA alone (P > 0.70 for /sup 237/Pu and P > 0.20 for /sup 241/Am).

Jones, C.W.; Lloyd, R.D.; Mays, C.W.

1980-10-01

231

Background stratospheric aerosol layer  

SciTech Connect

Balloonborne aerosol particle counter measurements are used in studying the stratospheric sulfate layer at Laramie, Wyoming, during 1978 and 1979, a 2-year volcanically quiescent period in which the layer appears to have been in a near equilibrium background state. Subtracting the background aerosol concentration from data obtained during an earlier volcanically active period indicates that the actual decay rate of volcanic aerosol is over 30% faster than one would obtain without this correction. At background, the aerosol size distribution is found to remain remarkably constant between the tropopause and an altitude of approx.25 km, with a sudden transition to a distribution dominated by smaller particles above this altitude. The observations, in some respects, compare favorably with equilibrium one-dimensional stratospheric aerosol models and thus to some extent support the concept of relatively inert tropospheric sulfurous gases, such as carbonyl sulfide and carbon disulfide, as the main background stratospheric aerosol sulfur source. Models which incorporate sulfur chemistry are apparently not able to predict the observed variation of particle size with altitude. The 2-year background period is not long enough in itself to establish long-term trends. The eruption of Mt. St. Helens in May 1980 has considerably disrupted the background stratospheric aerosol which will probably not recover for several years. A comparison of the 1978--79 observations with Junge's original measurements made some 20 years earlier, also during a period void of volcanic perturbations, does not preclude a long-term increase in the background stratospheric aerosol level.

Hofmann, D.J.; Rosen, J.M.

1981-01-01

232

WIDE RANGE AEROSOL CLASSIFIER  

EPA Science Inventory

The purpose of this project was to design, construct, calibrate, and field test a mobile ambient particulate matter sampler (Wide Range Aerosol Classifier) to collect size-classified samples of large aerosol particles. The sampler design was based on a similar stationary sampling...

233

Atmospheric aerosol measurement problems  

Microsoft Academic Search

The present knowledge of the atmospheric aerosols is summarized briefly with respect to geographical distribution, time variations, optical properties, chemical nature, and natural and artificial sources. The measurement techniques for determining aerosol properties are summarized with the limitations and results from each. The problems resulting from variations in refractive index, shape, composition, volatile constituents, relative humidity and time from collection

F. S. Harris Jr.

1978-01-01

234

HOUSTON AEROSOL CHARACTERIZATION STUDY  

EPA Science Inventory

An intensive field study of ambient aerosols was conducted in Houston between September 14 and October 14, 1978. Measurements at 12 sites were made using (1) two relocatable monitoring systems instrumented for aerosol and gaseous pollutants, (2) a network of high volume samplers ...

235

Surface science with aerosols  

Microsoft Academic Search

Experimental surface science with aerosol particles under atmospheric conditions is becoming a realistic possibility. The first part of this critical review focuses on nano-scopic aerosols generated in combustion of organic fuels at ambient pressures. The bizarre shape of soot agglomerates resists a simple definition of size and surface area. Yet a measure of the size known as the mobility diameter

H. Bluhm; H. C. Siegmann

2009-01-01

236

Portable Aerosol Contaminant Extractor  

DOEpatents

A compact, portable, aerosol contaminant extractor having ionization and collection sections through which ambient air may be drawn at a nominal rate so that aerosol particles ionized in the ionization section may be collected on charged plate in the collection section, the charged plate being readily removed for analyses of the particles collected thereon.

Carlson, Duane C. (N. Augusta, SC); DeGange, John J. (Aiken, SC); Cable-Dunlap, Paula (Waynesville, NC)

2005-11-15

237

ACID AEROSOLS ISSUE PAPER  

EPA Science Inventory

The report evaluates scientific information on direct health effects associated with exposure to acid aerosols. The present report is not intended as a complete and detailed review of all literature pertaining to acid aerosols. Rather, an attempt has been made to focus on the eva...

238

Tropical Atlantic Aerosols  

NSDL National Science Digital Library

Students will use real satellite data to determine 1) where the greatest concentrations of aerosols are located during the course of a year in the tropical Atlantic region and 2) their source of origin. This is an inquiry-style lesson where students pull real aerosol data and attempt to identify trends among data sets.

Roettger, Rex; Collection, Nasa -.

239

The kinetics of lanthanide complexation by EDTA and DTPA in lactate media.  

PubMed

The interaction of trivalent lanthanide and actinide cations with polyaminopolycarboxylic acid complexing agents in lactic acid buffer systems is an important feature of the chemistry of the TALSPEAK process for the separation of trivalent actinides from lanthanides. To improve understanding of metal ion coordination chemistry in this process, the results of an investigation of the kinetics of lanthanide complexation by ethylenediamine-N,N,N',N'-tetraacetic acid (EDTA) and diethylenetriamine-N,N,N',N'',N''-pentaacetic acid (DTPA) in 0.3 M lactic acid/0.3 M ionic strength solution are reported. Progress of the reaction was monitored using the distinctive visible spectral changes attendant to lanthanide complexation by the colorimetric indicator ligand Arsenazo III, which enables the experiment but plays no mechanistic role. Under the conditions of these experiments, the reactions occur in a time regime suitable for study by stopped-flow spectrophotometric techniques. Experiments have been conducted as a function of EDTA/DTPA ligand concentration, total lactic acid concentration, and pH. The equilibrium perturbation reaction proceeds as a first order approach to equilibrium over a wide range of conditions, allowing the simultaneous determination of complex formation and dissociation rate constants. The rate of the complexation reaction has been determined for the entire lanthanide series (except Pm(3+)). The predominant pathway for lanthanide-EDTA and lanthanide-DTPA dissociation is inversely dependent on the total lactate concentration; the complex formation reaction demonstrates a direct dependence on [H(+)]. Unexpectedly, the rate of the complex formation reaction is seen in both ligand systems to be fastest for Gd(3+). Correlation of these results indicates that in 0.3 M lactate solutions the exchange of lanthanide ions between lactate complexes and the polyaminopolycarboxylate govern the process. PMID:23080218

Nash, K L; Brigham, D; Shehee, T C; Martin, A

2012-12-28

240

??mTc carbonyl DTPA-rituximab: preparation and preliminary bioevaluation.  

PubMed

The anti CD20 antibody Rituximab was conjugated with para isothiocyanato benzyl diethylene triamine penta acetic acid (p-NCS-Bz-DTPA) and subsequent radiolabeling with (99m)Tc was carried out via the (99m)Tc carbonyl synthon. The (99m)Tc labeled antibody conjugate exhibited >95% radiochemical purity after purification and retained good in vitro stability when studied up to 24h at room temperature. In vitro cell binding studies carried out in Raji cells expressing CD20 antigen validated the biological efficacy of the preparation. PMID:24486518

Pandey, Usha; Kameswaran, Mythili; Dev Sarma, Haladhar; Samuel, Grace

2014-04-01

241

MRI of idiopathic orbital inflammatory syndrome using fat saturation and Gd-DTPA.  

PubMed

Idiopathic orbital inflammatory syndrome encompasses a group of inflammatory conditions for which no systemic or local cause can be found, and is commonly referred to as orbital pseudotumour. On conventional MRI sequences subtle areas of inflammation or enhancing tissue can easily be masked by the high signal intensity of orbital fat and involvement of the fat itself may not be appreciated. We describe the MRI features of three patients with idiopathic orbital inflammation using frequency-selective fat saturation and Gd-DTPA. PMID:7477863

Hardman, J A; Halpin, S F; Mars, S; Hourihan, M D; Lane, C M

1995-08-01

242

Climate forcing by stratospheric aerosols  

Microsoft Academic Search

We illustrate how climate forcing by stratospheric aerosols depends on aerosol properties. The climate forcing is a function of aerosol size distribution, but the size dependence can be described well by a single parameter: the area-weighted mean radius, reff.If reff is greater than about 2 ?m, the global average greenhouse effect of the aerosols exceeds the albedo effect, causing a

Andrew Lacis; James Hansen; Makiko Sato

1992-01-01

243

Climatic Effects of Atmospheric Aerosols  

Microsoft Academic Search

It is shown quantitatively how radiative climatic forcing by aerosols depends on the physical properties of the aerosols. The special case of atmospheric aerosols produced by volcanic explosions is considered, and evidence is presented which indicates that even the simple climate models available today may be able to capture some of the basic effects of aerosols on global climate. Possible

James E. Hansen; Andrew A. Lacis; Pauthon Lee; Wei-Chyung Wang

1980-01-01

244

Climate forcing by stratospheric aerosols  

Microsoft Academic Search

We illustrate how climate forcing by stratospheric aerosols depends on aerosol properties. The climate forcing is a function of aerosol size distribution, but the size dependence can be described well by a single parameter: the area-weighted mean radius, reff. If reff is greater than about 2mum, the global average greenhouse effect of the aerosols exceeds the albedo effect, causing a

Andrew Lacis; James Hansen; Makiko Sato

1992-01-01

245

7, 55535593, 2007 Nitrate aerosols  

E-print Network

ACPD 7, 5553­5593, 2007 Nitrate aerosols today and in 2030 S. E. Bauer et al. Title Page Abstract Discussions Nitrate aerosols today and in 2030: importance relative to other aerosol species and tropospheric, 5553­5593, 2007 Nitrate aerosols today and in 2030 S. E. Bauer et al. Title Page Abstract Introduction

Paris-Sud XI, Université de

246

A climatology of stratospheric aerosol  

Microsoft Academic Search

A global climatology of stratospheric aerosol is created by combining nearly a decade (1979-1981 and 1984-1990) of contemporaneous observations from the Stratospheric Aerosol and Gas Experiment (SAGE I and II) and Stratospheric Aerosol Measurement (SAM II) instruments. One goal of this work is to provide a representative distribution of the aerosol layer for use in radiative and chemical modeling. A

Matthew H. Hitchman; Megan McKay; Charles R. Trepte

1994-01-01

247

( sup 111 In-DTPA-D-Phe sup 1 )-octreotide, a potential radiopharmaceutical for imaging of somatostatin receptor-positive tumors: Synthesis, radiolabeling and in vitro validation  

SciTech Connect

As starting material for a potentially convenient radiopharmaceutical, a diethylenetriaminopentaacetic acid (DTPA) conjugated derivative of octreotide (SMS 201-995) was prepared. This peptide, (DTPA-D-Phe{sup 1})-octreotide (SDZ 215-811) binds more than 95% of added {sup 111}In in an easy, single-step labeling procedure without necessity of further purification. The specific somatostatin-like biologic effect of these analogues was proven by the inhibition of growth hormone secretion by cultured rat pituitary cells in a dose-dependent fashion by octreotide, (DTPA-D-Phe{sup 1})-octreotide and non-radioactive ({sup 115}In-DTPA-D-Phe{sup 1})-octreotide. The binding of ({sup 111}In-DTPA-D-Phe{sup 1})-octreotide to rat brain cortex membranes proved to be displaced similarly by natural somatosatin as well as by octreotide, suggesting specific binding of ({sup 111}In-DTPA-D-Phe{sup 1})-octreotide to somatostatin receptors. The binding of the indium-labeled compound showed a somewhat lower affinity when compared with the iodinated (Tyr{sup 3})-octreotide, but indium-labeled (DTPA-D-Phe{sup 1})-octreotide still binds with nanomolar affinity. In conjunction with in vivo studies, these results suggest that ({sup 111}In-DTPA-D-Phe{sup 1})-octreotide is a promising radiopharmaceutical for scintigraphic imaging of somatostatin receptor-positive tumors.

Bakker, W.H.; Albert, R.; Bruns, C.; Breeman, W.A.P.; Hofland, L.J.; Marbach, P.; Pless, J.; Pralet, D.; Stolz, B.; Koper, J.W.; Lamberts, S.W.J.; Visser, T.J.; Krenning, E.P. (Erasmus Univ., Rotterdam (Netherlands) Sandoz Pharma AG, Basel (Switzerland))

1991-01-01

248

Determination of EDTA and DTPA as their Fe(III) complexes in pulp and paper mill process and waste waters by liquid chromatography  

Microsoft Academic Search

A method for analysing ethylenediaminetetraacetic acid (EDTA) and diethylenetriaminepentaacetic acid (DTPA) was investigated to develop a liquid chromatographic (LC) method for the determination of concentrations of the aminopolycarboxylic acids EDTA and DTPA used as complexing agents in pulp and paper mills. All measurements were made using reversed-phase LC with UV detection. Ion-pairing reagent was added into the eluent to convert

Mika Sillanpää; Raimo Kokkonen; Marja-Liisa Sihvonen

1995-01-01

249

MRI-based estimation of liver function: Gd-EOB-DTPA-enhanced T1 relaxometry of 3T vs. the MELD score  

PubMed Central

Gd-EOB-DTPA is a hepatocyte-specific MRI contrast agent. Due to its hepatocyte-specific uptake and paramagnetic properties, functioning areas of the liver exhibit shortening of the T1 relaxation time. We report the potential use of T1 relaxometry of the liver with Gd-EOB-DTPA-enhanced magnetic resonance imaging (MRI) for estimating the liver function as expressed by the MELD score. 3 T MRI relaxometry was performed before and 20?min after Gd-EOB-DTPA administration. A strong correlation between changes in the T1 relaxometry and the extent of liver disease, expressed by the MELD score, was documented. Reduced liver function correlates with decreased Gd-EOB-DTPA accumulation in the hepatocytes during the hepatobiliary phase. MRI-based T1 relaxometry with Gd-EOB-DTPA may be a useful method for assessing overall and segmental liver function. PMID:25001391

Haimerl, Michael; Verloh, Niklas; Fellner, Claudia; Zeman, Florian; Teufel, Andreas; Feigl, Stefan Fichtner-; Schreyer, Andreas G.; Stroszczynski, Christian; Wiggermann, Philipp

2014-01-01

250

External monitoring of kidney transplant function using Tc-99m(Sn)DTPA  

SciTech Connect

The purpose of this study was to evaluate the use of an external counting technique to provide daily monitoring of kidney transplant function by measuring the renal clearance of Tc-99m(Sn)DTPA. During the first few weeks following transplant, 15 patients had their renal clearance of Tc-99m DTPA measured daily over periods of 5-24 hr. Clearance rates were compared with daily plasma creatinine levels, and the effects of diurnal variation, drug treatment, and physical activity noted. The results show that any significant fall in clearance rate of chelate, indicating a rejection episode, preceded a rise in plasma creatinine levels by at least 24 hr. One episode of transplant failure presented as a sudden deterioration in clearance rate of chelate; in the others the change was more gradual but was still apparent within hours. It is considered that this noninvasive, low-dose, easy-to-perform technique is of considerable value in extended daily monitoring of renal function and is superior to standard daily or twice-weekly renography for the early detection of transplant rejection.

Sampson, W.F.; Macleod, M.A.; Warren, D.

1981-05-01

251

Clearance of [sup 99m]Tc-DTPA and experimentally increased alveolar surfactant content  

SciTech Connect

The authors measured clearance of [sup 99m]Tc-labeled diethylenetriamine pentaacetic acid ([sup 99m]Tc-DTPA) in rabbits with experimentally increased alveolar surfactant content. In one group of animals, surfactant production was increased by treatment with ambroxol, and another group of animals was treated with tracheal instillation of natural surfactant. A group of untreated control animals and animals treated with instillation of saline were also studied. Clearance was measured during standard conditions of mechanical ventilation and during ventilation with large tidal volumes. In ambroxol- and surfactant-treated groups, clearance rate was reduced compared with untreated control animals. In contrast, clearance rate increased after saline instillation. The differences were observed at both modes of ventilation. The findings indicate that the pulmonary surfactant system is a rate-limiting factor for the clearance of [sup 99m]Tc-DTPA and that the volume dependence of clearance is not explained by stretching of the alveolar wall only. 28 refs., 2 figs., 1 tab.

Bos, J.A.H.; Wollmer, P.; Bakker, W.; Hannappel, E.; Lachmann, B. (Erasmus Univ., Rotterdam (Netherlands) Univ. of Lund (Sweden) Univ. of Erlangen (Germany))

1992-04-01

252

Atmospheric aerosol measurement problems  

NASA Technical Reports Server (NTRS)

The present knowledge of the atmospheric aerosols is summarized briefly with respect to geographical distribution, time variations, optical properties, chemical nature, and natural and artificial sources. The measurement techniques for determining aerosol properties are summarized with the limitations and results from each. The problems resulting from variations in refractive index, shape, composition, volatile constituents, relative humidity and time from collection until measurement are described. Needed measurements on atmospheric aerosols are outlined with some of the latest methods for obtaining them, including the needs and goals of some world-wide programs.

Harris, F. S., Jr.

1978-01-01

253

Measurement of Nanometer Aerosols  

Microsoft Academic Search

This paper is a review of my work during the past 18 years on nanometer, i.e., submicrometer, aerosols. These aerosols scatter negligible light so they are difficult to study and must be observed by indirect methods such as diffusion batteries and condensation nucleus counters. Several diffusion batteries are described: “cluster tube” batteries, 5.5 km of 1-mm-diam. straight tubing mounted in

David Sinclair

1986-01-01

254

RACORO aerosol data processing  

SciTech Connect

The RACORO aerosol data (cloud condensation nuclei (CCN), condensation nuclei (CN) and aerosol size distributions) need further processing to be useful for model evaluation (e.g., GCM droplet nucleation parameterizations) and other investigations. These tasks include: (1) Identification and flagging of 'splash' contaminated Twin Otter aerosol data. (2) Calculation of actual supersaturation (SS) values in the two CCN columns flown on the Twin Otter. (3) Interpolation of CCN spectra from SGP and Twin Otter to 0.2% SS. (4) Process data for spatial variability studies. (5) Provide calculated light scattering from measured aerosol size distributions. Below we first briefly describe the measurements and then describe the results of several data processing tasks that which have been completed, paving the way for the scientific analyses for which the campaign was designed. The end result of this research will be several aerosol data sets which can be used to achieve some of the goals of the RACORO mission including the enhanced understanding of cloud-aerosol interactions and improved cloud simulations in climate models.

Elisabeth Andrews

2011-10-31

255

Decorporation of thorium-228 from the rat by 3,4,3-LIHOPO and DTPA after simulated wound contamination.  

PubMed

1. With DTPA as a comparison, the siderophore analogue 3,4,3-LIHOPO has been examined for its ability to remove 228Th nitrate from the rat after subcutaneous (sc) and intramuscular (im) injection to simulate wound contamination. The commencement of treatment was delayed 30 min, 6 h or 1 d and the animals killed at 7 d. 2. In all cases 3,4,3-LIHOPO was appreciably more effective than DTPA although the efficacy of treatment and the relative effectiveness of the ligands decreased rapidly with their delay in administration. 3. Optimum removal with both ligands occurred when initial local administration at 30 min after exposure was followed by repeated intraperitoneal injection at 6 h, 1, 2 and 3 d. Under these conditions the body content of 228Th was reduced to 20% of controls after sc injection and 15% after im injection. The corresponding values using repeated DTPA administration were 80% and 54%. 4. It is concluded that 3,4,3-LIHOPO represents, potentially, a considerable advance on DTPA, the current agent of choice for the treatment of wounds contaminated by 228Th. PMID:7779440

Stradling, G N; Gray, S A; Pearce, M J; Wilson, I; Moody, J C; Burgada, R; Durbin, P W; Raymond, K N

1995-02-01

256

Assessment of Clinical Signs of Liver Cirrhosis Using T1 Mapping on Gd-EOB-DTPA-Enhanced 3T MRI  

PubMed Central

Objectives To assess the differences between normal and cirrhotic livers by means of T1 mapping of liver parenchyma on gadoxetic acid (Gd-EOB-DTPA)-enhanced 3 Tesla (3T) MR imaging (MRI). Methods 162 patients with normal (n = 96) and cirrhotic livers (n = 66; Child-Pugh class A, n = 30; B, n = 28; C, n = 8) underwent Gd-EOB-DTPA-enhanced 3T MRI. To obtain T1 maps, two TurboFLASH sequences (TI = 400 ms and 1000 ms) before and 20 min after Gd-EOB-DTPA administration were acquired. T1 relaxation times of the liver and the reduction rate between pre- and post-contrast enhancement images were measured. Results The T1 relaxation times for Gd-EOB-DTPA-enhanced MRI showed significant differences between patients with normal liver function and patients with Child-Pugh class A, B, and C (p < 0.001). The T1 relaxation times showed a constant significant increase from Child-Pugh class A up to class C (Child-Pugh class A, 335 ms ± 80 ms; B, 431 ms ± 75 ms; C, 557 ms ± 99 ms; Child-Pugh A to B, p < 0.001; Child-Pugh A to C, p < 0.001; Child-Pugh B to C, p < 0.001) and a constant decrease of the reduction rate of T1 relaxation times (Child-Pugh class A, 57.1% ± 8.8%; B, 44.3% ± 10.2%, C, 29.9% ± 6.9%; Child-Pugh A to B, p < 0.001; Child-Pugh A to C,p < 0.001; Child-Pugh B to C, p < 0.001). Conclusion Gd-EOB-DTPA-enhanced T1 mapping of the liver parenchyma may present a useful method for determining severity of liver cirrhosis. PMID:24392025

Haimerl, Michael; Verloh, Niklas; Zeman, Florian; Fellner, Claudia; Muller-Wille, Rene; Schreyer, Andreas G.; Stroszczynski, Christian; Wiggermann, Philipp

2013-01-01

257

AEROSOL CHARACTERIZATION WITH CENTRIFUCAL AEROSOL SPECTROMETERS: THEORY AND EXPERIMENT  

EPA Science Inventory

A general mathematical model describing the motion of particles in aerosol centrifuges has been developed. t has been validated by comparisons of theoretically predicted calibration sites with experimental data from tests sizing aerosols in instruments of three different spiral d...

258

5, 179215, 2005 Global aerosol  

E-print Network

simulation of sulfuric acid and sea spray aerosol. The model captures features of the aerosol size sulfuric acid-water binary nucle- ation occurs predominantly in the upper troposphere, but the model by primary particle production

Paris-Sud XI, Université de

259

Preparation of a stable /sup 99m/Tc complex of F(ab')/sub 2/-DTPA and its biodistribution in mice  

SciTech Connect

F(ab')/sub 2/ fragment was chosen for this study because it is divalent for antigen binding and it physiological t1/2 is suitable for /sup 99m/Tc. For a stable label, the authors used (Fab')/sub 2/-DTPA conjugate. A series of control experiments led the authors to a condition resulting in 85% DTPA-/sup 99m/Tc and 15% stable F(ab')/sub 2/-/sup 99m/Tc in competition with the formation of unstable F(ab')/sub 2/-/sup 99m/Tc. Free DTPA and F(ab')/sub 2/ (3.1 x 10/sup -5/ M, 155 ..mu..g)at a DTPA/F(ab')/sub 2/ ratio of 6 were incubated with Sn/sup 2+/ at a DTPA/Sn/sup 2+/ molar ratio of 1 in 0.1 M acetate buffer at pH 4.5 for 1 hr. This solution was then incubated with /sup 99m/Tc. The same condition was applied for radiolabeling the DTPA moiety of F(ab')/sub 2/-DTPA containing 2 DTPA molecules per F(ab')/sub 2/ and 4 free DTPA. Using the same amount of Sn/sup 2+/, F(ab')/sub 2/ was directly labeled with /sup 99m/Tc. /sup 99m/Tc labeled and affinity-purified F(ab')/sub 2/-DTPa (specific activities of l-2 ..mu..Ci per ..mu..g) containing 2approx. =4 ..mu..Ci was injected into the tail vein of mice in order to study their relative distributions in comparison to affinity purified F(ab')/sub 2/-DTPA-/sup 111/In. Biodistributions in %dose per g of both F(ab')/sub 2/-DTPA-/sup 99m/Tc and F(ab')/sub 2/-DTPA/sup 111/ In were similar: For F(ab')/sub 2/-DTPA-/sup 99m/Tc, lung(2.45), liver(3.28), spleen(2.24), kidney(9.10), bone (2.05), and blood(9.62). For F(ab')/sub 2/-DTPA-/sup 111/In, lung(6.27), liver(3.66), spleen(2.66), kidney(9.34), bone(l.43), and blood(19.67). Tissue accumulation of /sup 99m/Tc from directly labeled F(ab')/sub 2/ was much lower. This supports the hypothesis that stable /sup 99m/Tc labeled F(ab')/sub 2/ fragments of tumor antibody can be prepared by complexing /sup 99m/Tc with DTPA in F(ab')/sub 2/-DTPA conjugates.

Paik, C.H.; Sahami, M.S.; Hong, J.J.; Phan, L.N.B.; Reba, R.C.; Eckelman, W.C.

1984-01-01

260

Aerosol characterization with lidar methods  

NASA Astrophysics Data System (ADS)

Aerosol component analysis methods for characterizing aerosols were developed for various types of lidars including polarization-sensitive Mie scattering lidars, multi-wavelength Raman scattering lidars, and multi-wavelength highspectral- resolution lidars. From the multi-parameter lidar data, the extinction coefficients for four aerosol components can be derived. The microphysical parameters such as single scattering albedo and effective radius can be also estimated from the derived aerosol component distributions.

Sugimoto, Nobuo; Nishizawa, Tomoaki; Shimizu, Atsushi; Matsui, Ichiro

2014-08-01

261

Climate Forcing by Anthropogenic Aerosols  

Microsoft Academic Search

Although long considered to be of marginal importance to global climate change, tropospheric aerosol contributes substantially to radiative forcing, and anthropogenic sulfate aerosol in particular has imposed a major perturbation to this forcing. Both the direct scattering of short-wavelength solar radiation and the modification of the shortwave reflective properties of clouds by sulfate aerosol particles increase planetary albedo, thereby exerting

R. J. Charlson; S. E. Schwartz; J. M. Hales; R. D. Cess; J. A. Coakley Jr.; J. E. Hansen; D. J. Hofmann

1992-01-01

262

4, 58315854, 2004 Fluorescing aerosol  

E-print Network

way to characterize aerosols by a remote sensing technique. The stratospheric aerosol layer that we such as polycyclic aromatic hydrocarbons sticking to the aerosol particles, or bioaerosol such as bacteria, spores in the stratosphere (Jost et al., 2004). Even though these layers are optically thin, they are highly relevant because

Paris-Sud XI, Université de

263

Aerosols and climate  

SciTech Connect

The atmospheric burden of particles, or aerosols, has been measurably increased by human activities, especially in industrialized regions and those where slash-burn agricultural practices are followed. Some of these aerosols are directly produced when fossil fuels or other materials are burned (soot, smoke, fly ash); others are the result of photochemical reactions involving organic molecules, oxides of nitrogen, and sunlight (smog); and a third source is the oxidation of sulfur dioxide, produced when sulfur-bearing fuel is burned, to sulfuric acid thereby forming sulfate particles of droplets. In all cases, the resulting aerosols scatter and absorb both solar and infrared radiation, and therefore they influence the atmospheric heat balance. The question is the way in which they influence it, and the geographical and extent of this influence.

Kellogg, W.W.

1980-01-01

264

Indian aerosols: present status.  

PubMed

This article presents the status of aerosols in India based on the research activities undertaken during last few decades in this region. Programs, like International Geophysical Year (IGY), Monsoon Experiment (MONEX), Indian Middle Atmospheric Program (IMAP) and recently conducted Indian Ocean Experiment (INDOEX), have thrown new lights on the role of aerosols in global change. INDOEX has proved that the effects of aerosols are no longer confined to the local levels but extend at regional as well as global scales due to occurrence of long range transportation of aerosols from source regions along with wind trajectories. The loading of aerosols in the atmosphere is on rising due to energy intensive activities for developmental processes and other anthropogenic activities. One of the significant observation of INDOEX is the presence of high concentrations of carbonaceous aerosols in the near persistent winter time haze layer over tropical Indian Ocean which have probably been emitted from the burning of fossil-fuels and biofuels in the source region. These have significant bearing on the radiative forcing in the region and, therefore, have potential to alter monsoon and hydrological cycles. In general, the SPM concentrations have been found to be on higher sides in ambient atmosphere in many Indian cities but the NOx concentrations have been found to be on lower side. Even in the haze layer over Indian Ocean and surrounding areas, the NOx concentrations have been reported to be low which is not conducive of O3 formation in the haze/smog layer. The acid rain problem does not seem to exist at the moment in India because of the presence of neutralizing soil dust in the atmosphere. But the high particulate concentrations in most of the cities' atmosphere in India are of concern as it can cause deteriorated health conditions. PMID:12492171

Mitra, A P; Sharma, C

2002-12-01

265

Stratospheric Aerosol Measurements  

NASA Technical Reports Server (NTRS)

Stratospheric aerosols affect the atmospheric energy balance by scattering and absorbing solar and terrestrial radiation. They also can alter stratospheric chemical cycles by catalyzing heterogeneous reactions which markedly perturb odd nitrogen, chlorine and ozone levels. Aerosol measurements by satellites began in NASA in 1975 with the Stratospheric Aerosol Measurement (SAM) program, to be followed by the Stratospheric Aerosol and Gas Experiment (SAGE) starting in 1979. Both programs employ the solar occultation, or Earth limb extinction, techniques. Major results of these activities include the discovery of polar stratospheric clouds (PSCs) in both hemispheres in winter, illustrations of the impacts of major (El Chichon 1982 and Pinatubo 1991) eruptions, and detection of a negative global trend in lower stratospheric/upper tropospheric aerosol extinction. This latter result can be considered a triumph of successful worldwide sulfur emission controls. The SAGE record will be continued and improved by SAGE III, currently scheduled for multiple launches beginning in 2000 as part of the Earth Observing System (EOS). The satellite program has been supplemented by in situ measurements aboard the ER-2 (20 km ceiling) since 1974, and from the DC-8 (13 km ceiling) aircraft beginning in 1989. Collection by wire impactors and subsequent electron microscopic and X-ray energy-dispersive analyses, and optical particle spectrometry have been the principle techniques. Major findings are: (1) The stratospheric background aerosol consists of dilute sulfuric acid droplets of around 0.1 micrometer modal diameter at concentration of tens to hundreds of monograms per cubic meter; (2) Soot from aircraft amounts to a fraction of one percent of the background total aerosol; (3) Volcanic eruptions perturb the sulfuric acid, but not the soot, aerosol abundance by several orders of magnitude; (4) PSCs contain nitric acid at temperatures below 195K, supporting chemical hypotheses implicating manmade fluorocarbons as cause of the --'ozone hole'; (5) The current soot loading is too small to be of environmental (radiative and chemical) consequence. However, the fractal nature of soot distinguishes it aerodynamically and radiatively from sulfuric acid droplets such that its stratospheric residence time is longer, mainly because of vertical transport against gravity due to gravito-photophoretic forces. Thus it may accumulate and become of environmental concern in the future.

Pueschel, Rudolf, F.; Gore, Warren J. (Technical Monitor)

1998-01-01

266

A stratospheric aerosol increase  

NASA Technical Reports Server (NTRS)

Large disturbances were noted in the stratospheric aerosol content in the midlatitude Northern Hemisphere commencing about 7 months after the eruption of La Soufriere and less than 1 month after the eruption of Sierra Negra. The aerosol was characterized by a very steep size distribution in the 0.15 to 0.25 micron radius range and contained a volatile component. Measurements near the equator and at the South Pole indicate that the disturbance was widespread. These observations were made before the May 18 eruption of Mt. St. Helens.

Rosen, J. M.; Hofmann, D. J.

1980-01-01

267

Consumer aerosol products council: CFC myths still shake aerosol industry  

SciTech Connect

A recent Roper poll found that 55% of respondents believe CFC propellants are allowed in aerosol products. Another 31% did not know if CFCs can be used in aerosol products. In all, 86% of those polled answered incorrectly. To combat the public's misconceptions, the aerosol industry formed the Consumer Aerosol Products Council (CAPCO; Washington, DC). The council is made up of manufacturers, fillers and marketers of aerosol products. CAPCO's mandate from the aerosol industry is to educate the American public with the facts about CFCs, aerosols and the environment. To meet this directive, CAPCO has taken several approaches, including: informing and responding to the media; creating an educational video for use in schools and communities; and encouraging member companies to offer council materials and resources to their employees, customers and community groups.

Minogue, D. (Consumer Aerosol Products Council, Washington, DC (United States))

1993-01-01

268

Geometrical Optics of Dense Aerosols  

SciTech Connect

Assembling a free-standing, sharp-edged slab of homogeneous material that is much denser than gas, but much more rare ed than a solid, is an outstanding technological challenge. The solution may lie in focusing a dense aerosol to assume this geometry. However, whereas the geometrical optics of dilute aerosols is a well-developed fi eld, the dense aerosol limit is mostly unexplored. Yet controlling the geometrical optics of dense aerosols is necessary in preparing such a material slab. Focusing dense aerosols is shown here to be possible, but the nite particle density reduces the eff ective Stokes number of the flow, a critical result for controlled focusing. __________________________________________________

Hay, Michael J.; Valeo, Ernest J.; Fisch, Nathaniel J.

2013-04-24

269

{[GdAg 2(dtpa)(H 2O)] · 3H 2O} n : the first 2D Gd–Ag coordination polymer with Ag–Ag interaction  

Microsoft Academic Search

A novel 4d–4f coordination polymer {[GdAg2(dtpa)(H2O)]·3H2O}n (1) (dtpa=diethylenetriamine pentaacetate) was synthesized and characterized by magnetic and EPR studies. Its one-dimensional Gd–Ag ladder-like chains built upon tetranuclear rings are further connected by Ag–O bonds and Ag–Ag interactions to form a lamellar 2D packing.

Bin Zhao; Xiao-Yan Chen; Wen-Zhen Wang; Peng Cheng; Bin Ding; Dai-Zheng Liao; Shi-Ping Yan; Zong-Hui Jiang

2005-01-01

270

Enhancement of the Mutual Separation of Lanthanide Elements in the Solvent Extraction Based on the CMPO-TBP Mixed Solvent by Using a DTPA-Nitrate Solution  

Microsoft Academic Search

The mutual separation behavior of rare earth elements was studied in the system based on the neutral extractant CMPO (n-octyl(phenyl)-N,N-diisobutylcarbamoyl methylphosphine oxide) and aminopolyacetic acid DTPA (diethylenetriamine pentaacetic acid). The extractability of lanthanides decreased monotonously with increasing of atomic number in the system of 0.2 M CMPO-1.0 M TBP-n-dodecane (TRUEX solvent) and 0.05 M DTPA-NaNCO3 or hydroxylamine nitrate (HAN) solution.

Yoshikazu KOMA; Tomozo KOYAMA; Yasumasa TANAKA

1999-01-01

271

Aerosols in the atmosphere  

Microsoft Academic Search

An overview of the development of our understanding of the sources, formation mechanisms, physical and chemical transformations of atmospheric organic aerosol (OA) is presented. Until recently, organic particulate material was simply classified as either primary or secondary with the primary component being treated in models as nonvolatile and inert. However, this oversimplified view fails to explain the highly oxygenated nature

A. I. Miranda; S. Douglas

272

ACID AEROSOL MEASUREMENT WORKSHOP  

EPA Science Inventory

This report documents the discussion and results of the U.S. EPA Acid Aerosol Measurement Workshop, conducted February 1-3, 1989, in Research Triangle Park, North Carolina. t was held in response to recommendations by the Clean Air Scientific Advisory Committee (CASAC) regarding ...

273

Exploring Further Relationships: Aerosols  

NSDL National Science Digital Library

Student teams explore atmospheric aerosols, dust, and fires and their impact on the Earth's albedo using NASA Earth Observations (NEO) website. This is an extension activity in the student learning activity guide accompanying the GLOBE Earth System Poster, Exploring Connections in Year 2007. A series of six learning activities and associated assessment activities are included.

274

FORMATION OF PHOTOCHEMICAL AEROSOLS  

EPA Science Inventory

The objective was to develop a better understanding of smog aerosol formation with particular reference to haze in the Southern California area. This study combined laboratory work with ambient air studies. Counting of particles by light scattering was the principle physical tech...

275

A comparative study between Gd-DTPA and oral magnetic particles (OMP) as gastrointestinal (GI) contrast agents for MRI of the abdomen.  

PubMed

In the present study we compared two gastrointestinal contrast agents--Gd-DTPA, a positive signal, and oral magnetic particles (OMP), a negative signal contrast agent--in patients who were referred for MR imaging of the abdomen. Altogether 60 patients were examined with the former and 28 patients with the latter contrast before and after the administration of contrast media. Gd-DTPA was given either per os or per rectum. In comparing the results, it was shown that the diagnostic accuracy of postcontrast MRI in both groups was more or less similar to CT but much higher as compared with plain MRI. In the OMP series, first the contrast between the GI-filled lumen and the surrounding fat was much superior to that of the Gd-DTPA and, second, there was no evidence of any artifacts from bowel motion. However, the overall accuracy of the Gd-DTPA group was better compared with that of the OMP group. This was due to underfilling of the distal bowel because the OMP in those patients was administered only per os. Finally, Gd-DTPA had a more pleasant taste and fewer side effects. It is concluded that both contrast media are suitable for the upper abdomen because the results are comparable, whereas for the lower abdomen Gd-DTPA is superior because it can be used from both routes. PMID:7934658

Vlahos, L; Gouliamos, A; Athanasopoulou, A; Kotoulas, G; Claus, W; Hatziioannou, A; Kalovidouris, A; Papavasiliou, C

1994-01-01

276

Cerebrospinal fluid flow abnormalities in patients with neoplastic meningitis. An evaluation using /sup 111/In-DTPA ventriculography  

SciTech Connect

Cerebrospinal fluid flow dynamics were evaluated by /sup 111/In-diethylenetriamine pentaacetic acid (/sup 111/In-DTPA) ventriculography in 27 patients with neoplastic meningitis. Nineteen patients (70 percent) had evidence of cerebrospinal fluid flow disturbances. These occurred as ventricular outlet obstructions, abnormalities of flow in the spinal canal, or flow distrubances over the cortical convexities. Tumor histology, physical examination, cerebrospinal fluid analysis, myelograms, and computerized axial tomographic scans were not sufficient to predict cerebrospinal fluid flow patterns. These data indicate that cerebrospinal fluid flow abnormalities are common in patients with neoplastic meningitis and that /sup 111/In-DTPA cerebrospinal fluid flow imaging is useful in characterizing these abnormalities. This technique provides insight into the distribution of intraventricularly administered chemotherapy and may provide explanations for treatment failure and drug-induced neurotoxicity in patients with neoplastic meningitis.

Grossman, S.A.; Trump, D.L.; Chen, D.C.; Thompson, G.; Camargo, E.E.

1982-11-01

277

[In vitro comparative study of plasma protein binding of 99mTc-DTPA used in renal scintigraphy].  

PubMed

The radiopharmaceutical (99m)Tc-DTPA (diethylene-triamine-pentaacetic acid) is a tracer widely used in renal scintigraphy to assess glomerular filtration rate. The estimation of protein binding is very important due to its impact on clinical parameters biodistribution since only the free fraction is filtered by the kidney. A number of laboratory techniques have been developed to study protein binding. Precipitation and ultrafiltration are the mostly used techniques in pharmacology for studies of the binding between proteins and small molecules. The aim of this work is to apply and compare those two analytical methods in (99m)Tc-DTPA protein binding determination in vitro before in vivo application. The results obtained by precipitation with trichloroacetic acid are not enough reproducible, while those obtained by ultrafiltration seem more consistent and reproducible. PMID:24206594

Chemlal, L; Makram, S; Zoubir, B; Cherrah, Y; Faouzi, M A

2013-11-01

278

Aerosol contributions to speleothem geochemistry  

NASA Astrophysics Data System (ADS)

The term "aerosols" encompasses the suspension of both fine solid or liquid particles within a gaseous medium. Aerosols become suspended into the earth's atmosphere through a multitude of processes both natural and anthropogenic. Atmospheric aerosols enter cave networks as a result of cave ventilation processes and are either deposited, or cycled and removed from the system. Speleothem offer a multiproxy palaeoclimate resource; many of the available proxies have been extensively investigated and utilised for palaeoclimatic reconstructions in a range of studies. The potential contribution of aerosols to speleothem chemistry and their applicability for palaeoenvironmental reconstructions remains untested and the extent of their value as an addition to palaeoclimate sciences unknown. Aerosols through incorporation into speleothem may provide a novel palaeoenvironmental resource. The aerosol component of interest is that which is transported into the cave atmosphere and deposited and are available for incorporation into precipitated calcite. Aerosol deposition and therefore distribution in the cave has shown to be a complex function of ventilation and changing environmental factors. Through detailed monitoring aerosols have been detected, identified, characterised and quantified to determine their prominence in the cave system. Investigations are on a case study basis, searching for suitable aerosol proxies of environmentally significant emission processes. Case studies include: Palaeofires at Yarrangobilly Caves, Australia; anthropogenic emissions at St Michaels Cave, Gibraltar and Cheddar gorge, UK; and drip water aerosol production and geochemical addition in Obir cave, Austria. Monitoring has allowed for the temporal and spatial determination of aerosols in karst networks. Speleothem samples will be analysed in combination with in-situ monitoring to determine incorporation factors and record preservation. By understanding how aerosols are transmitted within the cave and ultimately incorporated into speleothems, a record of aerosol emission event frequency, intensity and timing can be produced and directly correlated with changing palaeoclimate. Speleothem through aerosol incorporation have the potential to preserve a record of a multitude of processes not yet constrained by previously investigated proxies, providing an additional dimension to speleological palaeoenvironmental investigations.

Dredge, J. A.; Fairchild, I. J.; Harrison, R.; Woodhead, J. D.; Hellstrom, J.

2011-12-01

279

Advanced Aerosol Lidar Ratio Determination Algorithms Using Aerosol Covariance Models  

NASA Astrophysics Data System (ADS)

We present an algorithm to determine the extinction to backscatter (lidar) ratio (Sa), an important parameter used in the determination of the aerosol extinction and subsequently the optical depth from lidar backscatter measurements. This scheme applies to Sa determination at 532 nm and 1064 nm for a space-based two-wavelength lidar such as CALIOP on the Cloud and Aerosol Lidar and Infrared Pathfinder Spaceborne Observations (CALIPSO) satellite. The algorithm applies the Mahalanobis distance to CALIOP measurements of backscatter and depolarization and initial estimates of Sa at both wavelengths to identify the most likely aerosol model from a family of a priori probability distributions of lidar ratio, backscatter and depolarization determined from previously generated classification of High Spectral Resolution Lidar (HSRL) aerosol measurements. The HSRL record includes aerosol type specific distributions of Sa at 532 nm. We use auxiliary measurements of pairs of 532 nm and 1064 nm Sa for Urban, Smoke, Marine, and Dust aerosols from AERONET and field measurements, the NASA African Monsoon Multidisciplinary Analyses (NAMMA) and Shoreline Environmental Aerosol Study (SEAS), to develop piecewise covariance matrices using the HSRL distributions of these four aerosol types. Covariance matrices including lidar ratio at both wavelengths can also be obtained through the Enhanced Constrained Ratio Aerosol Method (E-CRAM) applied to HSRL data. We explore the application of the aerosol model matching method to CALIOP data and compare the results with HSRL 532 nm Sa distributions for coincident flights.

Hostetler, C. A.; Omar, A. H.; Burton, S. P.; Vaughan, M.; Rogers, R.; Ferrare, R. A.; Reagan, J. A.; McPherson, C.

2011-12-01

280

Gd-DTPA in the hydrosphere: Kinetics of transmetallation by ions of rare earth elements, Y and Cu  

Microsoft Academic Search

The kinetics of transmetallation of Gd3+ in diethylenetriaminpentaacetic acid (Gd-DTPA) by rare earth elements (except Yb), Y3+ and Cu2+ has been studied in test solutions ranging from pH 5 to 6.5 in order to understand the distribution and longevity of their chelates in the hydrosphere. Chelated and non-chelated species were separated by adsorption of the free ions by clay minerals

Peter Möller; Peter Dulski

2010-01-01

281

Quantitative Evaluation of Enhancement Patterns in Focal Solid Liver Lesions with Gd-EOB-DTPA-Enhanced MRI  

PubMed Central

Purpose The objective was to investigate the dynamic enhancement patterns in focal solid liver lesions after the administration of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) by means of dynamic magnetic resonance imaging (MRI) including hepatobiliary phase (HP) images 20 min after Gd-EOB-DTPA administration. Materials and Methods Non-enhanced T1/T2-weighted as well as dynamic magnetic resonance (MR) images during the arterial phase (AP), the portal venous phase (PVP), the late phase (LP), and the HP (20 min) were obtained from 83 patients (54 male, 29 female, mean age 62.01 years) with focal solid liver lesions. MRI was conducted by means of a 1.5-T system for 63 patients with malignant liver lesions (HCCs: n?=?34, metastases: n?=?29) and for 20 patients with benign liver lesions (FNH lesions: n?=?14, hemangiomas: n?=?3, adenomas: n?=?3). For quantitative analysis, signal-to-noise ratios (SNR), contrast enhancement ratios (CER), lesion-to-liver contrast ratios (LLC), and signal intensity (SI) ratios were measured. Results The SNR of liver parenchyma significantly increased in each dynamic phase after Gd-EOB-DTPA administration compared to the SNR of non-enhanced images (p<0.001). The CER of HCCs and metastases significantly decreased between LP and HP images (p?=?0.0011, p<0.0001). However, FNH lesions did not show any significant difference, whereas an increased CER was found in hemangiomas. The mean LLCs of FNH lesions were significantly higher than those of HCCs and metastases. The LLC values of hemangiomas remained negative during the entire time course, whereas the LLC of adenomas indicated hyperintensity from the AP to the LP. Furthermore, adenomas showed hypointensity in HP images. Conclusion Gd-EOB-DTPA-enhanced MRI may help diagnose focal solid liver lesions by evaluating their enhancement patterns. PMID:24950259

Haimerl, Michael; Wächtler, Max; Zeman, Florian; Verloh, Niklas; Platzek, Ivan; Schreyer, Andreas Georg; Stroszczynski, Christian; Wiggermann, Philipp

2014-01-01

282

Diagnosis of cardiac sarcoidosis and evaluation of the effects of steroid therapy by gadolinium-DTPA–enhanced magnetic resonance imaging  

Microsoft Academic Search

BACKGROUND: Cardiac involvement is an important prognostic factor in patients with sarcoidosis. In this study, we evaluated the usefulness of gadolinium-DTPA (diethylene triamine pentaacetic acid)–enhanced magnetic resonance imaging (Gd-MRI) for diagnosing cardiac sarcoidosis and evaluating the effects of steroid therapy.METHODS: Sixteen patients with sarcoidosis diagnosed by histology or by Japanese Ministry of Health and Welfare criteria for cardiac sarcoidosis underwent

Toshio Shimada; Kazue Shimada; Takeshi Sakane; Koichi Ochiai; Hironori Tsukihashi; Motonari Fukui; Shin-ichi Inoue; Harumi Katoh; Yo Murakami; Yutaka Ishibashi; Riruke Maruyama

2001-01-01

283

Gd-DTPA as an intestinal contrast agent for MR imaging of the lower abdomen: phase III clinical trial.  

PubMed

Thirty-one patients were investigated with magnetic resonance (MR) imaging of the lower abdomen before and after the administration of gadopentetate dimeglumine (Gd-DTPA) solution per os or per rectum or from both routes for the opacification of the intestinal tract. The parameters evaluated were: (a) contrast medium distribution, (b) degree of filling of the bowel lumen, (c) contrast between the bowel lumen and the surrounding normal or pathological structures, and (d) whether the administration of the contrast agent improved the diagnostic ability of MR compared to computed tomography (CT) or plain MR of the same region. Gd-DTPA, at a concentration of 1 mmol/L, produced a positive signal irrespective of its dilution in the bowel and good contrast between the bowel lumen and the adjacent tissues or any possible pathological lesions. From the diagnostic point of view, after the administration of contrast medium, MR is comparable to CT and much superior to plain MR. It is concluded that opacification of the bowel with Gd-DTPA solution will improve the diagnostic yield of MR imaging of the lower abdomen. PMID:1426844

Vlahos, L; Gouliamos, A; Clauss, W; Kalovidouris, A; Athanasopoulou, A; Petroulakis, A; Hadjiioannou, A; Papavasiliou, C

1992-01-01

284

The effect of x rays, DTPA, and aspirin on the absorption of plutonium from the gastrointestinal tract of rats  

SciTech Connect

To measure the effect of radiation on plutonium transport, rats that were exposed to 250-kVp X rays were given /sup 238/Pu 3 days afterwards by either gavage or injection into a ligated segment of the duodenum. In a second group of experiments, rats were either injected intraduodenally with /sup 238/Pu-DTPA or administered the chelate intravenously and the /sup 238/Pu by gavage. In a third experiment, rats that had been gavaged with 200 or 400 mg/kg/day of aspirin for 2 days were injected intragastrically with /sup 238/Pu nitrate. Results of the first experiment showed a dose-dependent increase in /sup 238/Pu absorption between 800 and 1500 rad of lower-body X irradiation. Intravenous or intraduodenal injections of DTPA caused a marked increase in /sup 238/Pu absorption but resulted in decreased plutonium deposition in the skeleton and liver. Retention of /sup 238/Pu in the skeleton of rats given aspirin was double that of controls, but the effect on plutonium absorption was less marked than that of DTPA.

Sullivan, M.F.; Gorham, L.S.; Miller, B.M.

1983-04-01

285

Thermodynamic and kinetic study of scandium(III) complexes of DTPA and DOTA: a step toward scandium radiopharmaceuticals.  

PubMed

Diethylenetriamine-N,N,N',N'',N''-pentaacetic acid (DTPA) and 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) scandium(III) complexes were investigated in the solution and solid state. Three (45)Sc NMR spectroscopic references suitable for aqueous solutions were suggested: 0.1?M Sc(ClO4)3 in 1?M aq. HClO4 (?Sc =0.0?ppm), 0.1?M ScCl3 in 1?M aq. HCl (?Sc =1.75?ppm) and 0.01?M [Sc(ox)4](5-) (ox(2-) = oxalato) in 1?M aq. K2C2O4 (?Sc =8.31?ppm). In solution, [Sc(dtpa)](2-) complex (?Sc = 83?ppm, ?? = 770?Hz) has a rather symmetric ligand field unlike highly unsymmetrical donor atom arrangement in [Sc(dota)](-) anion (?Sc = 100?ppm, ?? = 4300?Hz). The solid-state structure of K8[Sc2(ox)7]?13?H2O contains two [Sc(ox)3](3-) units bridged by twice "side-on" coordinated oxalate anion with Sc(3+) ion in a dodecahedral O8 arrangement. Structures of [Sc(dtpa)](2-) and [Sc(dota)](-) in [(Hguanidine)]2[Sc(dtpa)]?3?H2O and K[Sc(dota)][H6 dota]Cl2?4?H2O, respectively, are analogous to those of trivalent lanthanide complexes with the same ligands. The [Sc(dota)](-) unit exhibits twisted square-antiprismatic arrangement without an axial ligand (TSA' isomer) and [Sc(dota)](-) and (H6 dota)(2+) units are bridged by a K(+) cation. A surprisingly high value of the last DOTA dissociation constant (pKa =12.9) was determined by potentiometry and confirmed by using NMR spectroscopy. Stability constants of scandium(III) complexes (log KScL 27.43 and 30.79 for DTPA and DOTA, respectively) were determined from potentiometric and (45)Sc NMR spectroscopic data. Both complexes are fully formed even below pH?2. Complexation of DOTA with the Sc(3+) ion is much faster than with trivalent lanthanides. Proton-assisted decomplexation of the [Sc(dota)](-) complex (?1/2 =45?h; 1?M aq. HCl, 25?°C) is much slower than that for [Ln(dota)](-) complexes. Therefore, DOTA and its derivatives seem to be very suitable ligands for scandium radioisotopes. PMID:24838869

Pniok, Miroslav; Kubí?ek, Vojt?ch; Havlí?ková, Jana; Kotek, Jan; Sabatie-Gogová, Andrea; Plutnar, Jan; Huclier-Markai, Sandrine; Hermann, Petr

2014-06-23

286

Atmospheric aerosols: Their Optical Properties and Effects  

NASA Technical Reports Server (NTRS)

Measured properties of atmospheric aerosol particles are presented. These include aerosol size frequency distribution and complex retractive index. The optical properties of aerosols are computed based on the presuppositions of thermodynamic equilibrium and of Mie-theory.

1976-01-01

287

MSA in Beijing aerosol  

Microsoft Academic Search

Methane sulphonate (MSA) and sulfate (SO42-), the main oxidation products of dimethyl sulfide (DMS), are the target of atmospheric chemistry study, as sulfate aerosol\\u000a would have important impact on the global climate change. It is widely believed that DMS is mainly emitted from phytoplankton\\u000a production in marine boundary layer (MBL), and MSA is usually used as the tracer of non-sea-salt

Hui Yuan; Ying Wang; Guoshun Zhuang

2004-01-01

288

Mesospheric sulfate aerosol layer  

NASA Astrophysics Data System (ADS)

We investigate the heretofore unstudied role of volcanic and nonvolcanic sulfur aerosols and gases in the mesosphere. Two-dimensional microphysical calculations show that sulfur may be an important source of particles below the cold summer mesopause. Observed increases in SO2 with altitude in the upper stratosphere had previously suggested ultraviolet destruction of H2SO4, discounting its survival in the mesosphere. Laboratory measurements have now ruled out ultraviolet photolysis of H2SO4, however, and a recent proposal of visible and near-infrared photolysis of H2SO4 explains the SO2 observations. Our calculations show that enough H2SO4 survives this weak photolysis mechanism to produce significant sulfate aerosol surface area in the mesosphere. Neutralization of H2SO4 by metals on the surfaces of meteoritic dust is modeled and affects the mesospheric aerosol negligibly. We discuss the possible implications for this new class of particles for the formation of polar mesospheric summer echoes and polar mesospheric clouds in volcanically quiescent and active periods.

Mills, Michael J.; Toon, Owen B.; Thomas, Gary E.

2005-12-01

289

Photothermal spectroscopy of aerosols  

SciTech Connect

In situ aerosol absorption spectroscopy was performed using two novel photothermal detection schemes. The first, based on a photorefractive effect and coherent detection, called phase fluctuation optical heterodyne (PFLOH) spectroscopy, could, depending on the geometry employed, yield particle specific or particle and gas absorption data. Single particles of graphite as small as 1 ..mu..m were detected in the particle specific mode. In another geometrical configuration, the total absorption (both gas and particle) of submicron sized aerosols of ammonium sulfate particles in equilibrium with gaseous ammonia and water vapor were measured at varying CO/sub 2/ laser frequencies. The specific absorption coefficient for the sulfate ion was measured to be 0.5 m/sup 2//g at 1087 cm/sup -1/. The absorption coefficient sensitivity of this scheme was less than or equal to 10/sup -8/ cm/sup -1/. The second scheme is a hybrid visible Mie scattering scheme incorporating photothermal modulation. Particle specific data on ammonium sulfate droplets were obtained. For chemically identical species, the relative absorption spectrum versus laser frequency can be obtained for polydisperse aerosol distributions directly from the data without the need for complex inverse scattering calculations.

Campillo, A.J.; Lin, H.B.

1981-04-01

290

Volcanic aerosols and lunar eclipses.  

PubMed

The moon is visible during total lunar eclipses due to sunlight refracted into the earth's shadow by the atmosphere. Stratospheric aerosols can profoundly affect the brightness of the eclipsed moon. Observed brightnesses of 21 lunar eclipses during 1960-1982 are compared with theoretical calculations based on refraction by an aerosol-free atmosphere to yield globally averaged aerosol optical depths. Results indicate the global aerosol loading from the 1982 eruption of El Chichón is similar in magnitude to that from the 1963 Agung eruption. PMID:17776243

Keen, R A

1983-12-01

291

Stratospheric aerosols - Observation and theory  

NASA Technical Reports Server (NTRS)

Important chemical and physical roles of aerosols are discussed, and properties of stratospheric aerosols as revealed by experimental data are described. In situ measurements obtained by mechanical collection and scattered-light detection yield the overall size distribution of the aerosols, and analyses of preserved aerosol precursor gases by wet chemical, cryogenic and spectroscopic techniques indicate the photochemical sources of particle mass. Aerosol chemical reactions including those of gaseous precursors, those in aqueous solution, and those on particle surfaces are discussed, in addition to aerosol microphysical processes such as nucleation, condensation/evaporation, coagulation and sedimentation. Models of aerosols incorporating such chemical and physical processes are presented, and simulations are shown to agree with measurements. Estimates are presented for the potential aerosol changes due to emission of particles and gases by aerospace operations and industrial consumption of fossil fuels, and it is demonstrated that although the climatic effects of existing levels of stratospheric aerosol pollution are negligible, potential increases in those levels might pose a future threat.

Turco, R. P.; Whitten, R. C.; Toon, O. B.

1982-01-01

292

Limitation on electrical measures of aerosols. [Aerosol monitors  

Microsoft Academic Search

Based upon the assumption that there is a constant, natural, background ion source, atmospheric conductivity has been used as a measure of the presence of aerosol particles because such particles remove the effective charge carriers from the atmosphere. Another variety of electrical measure is the total charge acquired by the aerosol under either natural or artificial charging conditions. Currently, the

Marlow

1976-01-01

293

Scanning Mobile Lidar for Aerosol Tracking and Biological Aerosol Identification  

Microsoft Academic Search

Optical properties of non-biological aerosols containing aromatic hydrocarbons, such as industrial chemicals and engine exhausts, have already been thoroughly studied using remote sensing techniques. However, because of their complex composition and characteristics, the identification of biological aerosols, such as fungi, pollen and bacteria that are present in the environment remains a rather difficult task. The collection of information on both

Tingyao He; Klemen Bergant; Andrej Filipcic; Biagio Forte; Fei Gao; Samo Stanic; Darko Veberic; Marko Zavrtanik

2010-01-01

294

Effect of Zn-DTPA therapy on the maternal transfer of /sup 241/Am or /sup 237/Pu to young mice  

SciTech Connect

Newborn mice exposed to /sup 241/Am or /sup 237/Pu during gestation and whose mothers were given Zn-DTPA at various times before parturition contained less radioactivity than comparable newborn mice given identical /sup 241/Am or /sup 237/Pu exposure without Zn-DTPA treatment of the mothers. There was no net increase in radionuclide transfer from mothers to unborn young as a result of maternal administration of Zn-DTPA, regardless of the pregnancy stage during which the radioactivity and decorporation treatments were given. Administration of /sup 241/Am followed after three days by extended Zn-DTPA therapy resulted in lower fetal content of radioactivity in litters conceived long after or soon after maternal exposure to /sup 241/Am. These data indicate that the risk from Am and Pu to unborn young can be reduced by Zn-DTPA treatment of the pregnant mother and of the female who becomes pregnant subsequently. This information may prove to be of significance with the increasing probability of Am or Pu exposure to women in the nuclear industry who could be pregnant at the time or who may conceive a child in the future.

Lloyd, R.D.; Jones, C.W.; Mays, C.W.; Brammer, T.W.; Burnham, J.W.

1985-09-01

295

Adsorption investigation of MA-DTPA chelating resin for Ni(II) and Cu(II) using experimental and DFT methods  

NASA Astrophysics Data System (ADS)

Melamine-diethylenetriamine pentaacetic acid (MA-DTPA) chelating resin was synthesized via the amide bond reaction between DTPA carboxyl groups and melamine amine groups. The adsorption performance of MA-DTPA resin towards Ni(II) and Cu(II) was investigated. FTIR and NMR measurements were carried out for characterization of the pristine resin and metal loaded resin. Chelating mechanism of MA-DTPA towards Ni(II) and Cu(II) has been studied using density functional theory together with a continuum solvation model. The geometrical parameters, energetic characteristic and charge population were also discussed, and then the complexation energies and complexation Gibbs free energies were calculated. The results indicate that the resin shows high affinity for heavy metal cations, and its adsorption performance of Cu(II) is better than that of Ni(II). FTIR and NMR spectra evidence the formation of amide groups and suggest that the carboxylic oxygen atoms may dominate in the coordination reaction. DFT calculations confirm that the coordination between carboxylic oxygen atom and metal cations is more favorable than that of amide nitrogen. MA-DTPA resin exhibits stronger binding capability for Cu(II) as compared to Ni(II).

Zhao, Xiaodan; Song, Laizhou; Zhang, Zhihui; Wang, Ru; Fu, Jie

2011-02-01

296

Mount St. Helens aerosol evolution  

SciTech Connect

Stratospheric aerosol samples were collected using a wire impactor during the year following the eruption of Mt. St. Helens. Analysis of samples show that aerosol volume increased for 6 months due to gas-to-particle conversion and then decreased to background levels in the following 6 months.

Oberbeck, V.R.; Farlow, N.H.; Fong, W.; Snetsinger, K.G.; Ferry, G.V.; Hayes, D.M.

1982-09-01

297

[Stability of shuang huanglian aerosol].  

PubMed

The contents of chlorogenic acid and baicalin in shuang huanglian aerosol were determined by HPLC. The process of chemical kinetics of the aerosol was studied by constant temperature acceleration tests, and the stability of the drug predicted. The results appeared close to those from the stored sample method. pH changes during degradation of the drug were also observed. PMID:1418537

Xu, K; Zhang, H; Wu, L; Lu, Y; Sun, K; Yao, Z

1992-03-01

298

6, 62996316, 2006 Aerosol pollution  

E-print Network

death. However, most of25 the air quality-monitoring stations are located close to major urban areasACPD 6, 6299­6316, 2006 Aerosol pollution assessment using POLDER-2 M. Kacenelenbogen et al. Title Chemistry and Physics Discussions Characterization of aerosol pollution events in France using ground

Paris-Sud XI, Université de

299

Comparison of Aerosol Sampler Inlets  

Microsoft Academic Search

This field study compared aerosol collection by nominal 15 ?m inlets for low volume (1 m\\/hr) aerosol samplers. The inlets were designed at Texas A & M University (TAMU), Colorado State University (CSU), the University of Minnesota–Lawrence Berkeley Laboratory (UMLBL), and the Aerovironment Corporation (AERO). The TAMU inlet design is currently used on most commercial dichotomous samplers, and recent wind

R. W. Shaw Jr; R. K. Stevens; C. W. Lewis; James H. Chance

1982-01-01

300

Mount St. Helens aerosol evolution  

NASA Technical Reports Server (NTRS)

Stratospheric aerosol samples were collected using a wire impactor during the year following the eruption of Mount St. Helens. Analysis of samples shows that aerosol volume increased for 6 months due to gas-to-particle conversion and then decreased to background levels in the following 6 months.

Oberbeck, V. R.; Farlow, N. H.; Fong, W.; Snetsinger, K. G.; Ferry, G. V.; Hayes, D. M.

1982-01-01

301

Preliminary aerosol generator design studies  

NASA Technical Reports Server (NTRS)

The design and construction of a prototype vaporization generator for highly dispersed sodium chloride aerosols is described. The aerosol generating system is to be used in the Science Simulator of the Cloud Physics Laboratory Project and as part of the Cloud Physics Laboratory payload to be flown on the shuttle/spacelab.

Stampfer, J. F., Jr.

1976-01-01

302

AEROSOL EXPOSURE, PHYSICS, AND CHEMISTRY  

EPA Science Inventory

A brief review is given of the "Knowledge" and the "Gaps in Knowledge" of aerosol exposure, physics and chemistry relevant to health effects of aerosols, and presented or discussed in platform or poster presentations at the Symposium on Particulate Air Pollution - Associations wi...

303

Glomerular filtration rate in children: validation and longitudinal use of determination from the 99mTc DTPA renogram  

SciTech Connect

The glomerular filtration rate (GFR) was estimated from the technetium diethylenetriaminepentacetic (/sup 99m/Tc DTPA) renogram by empirically correlating the renogram and clearance of the tracer as measured by plasma disappearance kinetics. To expand the potential application of this technique from its original description, minor changes in methodology were made; a new regression was generated with 30 subjects, and that formula was then validated prospectively. For the 50 children and adolescents in the prospective series whose GFR normalized for surface area (NGFR = GFR X 1.73 m2/SA; SA, surface area) was less than 120 mL/min/1.73 m2; renal function was estimated with a mean residual error of 8.0 mL/min/1.73 m2, and a mean relative error of 11%. These results are at least as good as those in the initial report, thus validating this method in a prospective series. To examine the use of this method longitudinally, 129 examinations were reviewed in 55 subjects who had NGFR estimated from the renogram (estimated) on at least two occasions. For 28 sets of serial examinations, NGFR was also measured by the plasma disappearance of /sup 99m/Tc DTPA (measured). The true change in function for each set of serial examinations was defined as the increment for whichever method (estimation or measurement) was more stable. The mean longitudinal errors were 2.1 and 4.8 mL/min/1.73 m2 for measured and estimated NGFR, respectively. The increments in NGFR for these methods were correlated with a regression line near identity and r = .852. This indicates that a change in estimated NGFR reflects a change in measured NGFR of similar magnitude. This method can accurately estimate GFR from the /sup 99m/Tc DTPA renogram, and it can be used longitudinally to follow children with renal disorders.

Shore, R.M.; Koff, S.A.; Hayes, J.R.; Smith, S.P.; Mentser, M.; Mahan, J.D.

1986-09-01

304

Fully automatic region of interest selection in glomerular filtration rate estimation from 99mTc-DTPA renogram.  

PubMed

Glomerular filtration rate (GFR) is a common accepted standard estimation of renal function. Gamma camera-based methods for estimating renal uptake of (99m)Tc-diethylenetriaminepentaacetic acid (DTPA) without blood or urine sampling have been widely used. Of these, the method introduced by Gates has been the most common method. Currently, most of gamma cameras are equipped with a commercial program for GFR determination, a semi-quantitative analysis by manually drawing region of interest (ROI) over each kidney. Then, the GFR value can be computed from the scintigraphic determination of (99m)Tc-DTPA uptake within the kidney automatically. Delineating the kidney area is difficult when applying a fixed threshold value. Moreover, hand-drawn ROIs are tedious, time consuming, and dependent highly on operator skill. Thus, we developed a fully automatic renal ROI estimation system based on the temporal changes in intensity counts, intensity-pair distribution image contrast enhancement method, adaptive thresholding, and morphological operations that can locate the kidney area and obtain the GFR value from a (99m)Tc-DTPA renogram. To evaluate the performance of the proposed approach, 30 clinical dynamic renograms were introduced. The fully automatic approach failed in one patient with very poor renal function. Four patients had a unilateral kidney, and the others had bilateral kidneys. The automatic contours from the remaining 54 kidneys were compared with the contours of manual drawing. The 54 kidneys were included for area error and boundary error analyses. There was high correlation between two physicians' manual contours and the contours obtained by our approach. For area error analysis, the mean true positive area overlap is 91%, the mean false negative is 13.4%, and the mean false positive is 9.3%. The boundary error is 1.6 pixels. The GFR calculated using this automatic computer-aided approach is reproducible and may be applied to help nuclear medicine physicians in clinical practice. PMID:21274591

Lin, Kun-Ju; Huang, Jia-Yann; Chen, Yung-Sheng

2011-12-01

305

Renal perfusion with Tc-99m DTPA--simple noninvasive determination of extraction fraction and plasma flow.  

PubMed

A simple, noninvasive method for the determination of extraction fraction and renal plasma flow in Tc-99m DTPA studies is presented. This method could be performed in conjunction with the measurement of glomerular filtration rate, providing additional information about renal plasma flow. Graphic analysis of the Patlak plot was employed for the determination of the unidirectional influx rate constant (ku) of Tc-99m DTPA from the blood to the kidney and the initial nonspecific distribution volume (Vn) in the kidney. The first pass extraction fraction was estimated from Ku and Vn, assuming a bolus input to the kidney. The glomerular filtration rate was measured by renal counting corrected for depth and dose. Using the estimated extraction fraction (EF) and glomerular filtration rate (GFR), the renal plasma flow (RPF) was calculated using the formula of RPF = GFR/EF. In a total of 76 kidneys in 38 patients (including 9 patients with normal renal function and without evidence of nephrourologic disease), the value of renal plasma flow showed good correlation with that of effective renal plasma flow measured by renal counting with I-131 orthoiodohippuran. There was a characteristic tendency for the extraction fraction to show a larger value as the renal plasma flow decreased. These results indicate that this method is valid for renal plasma flow estimation and the determinations of extraction fraction and renal plasma flow in Tc-99m DTPA studies is helpful as an adjunct to the measurement of glomerular filtration rate in order to adequately assess the pathophysiologic changes of renal disorders. PMID:8393752

Aburano, T; Shuke, N; Yokoyama, K; Matsuda, H; Takayama, T; Michigishi, T; Tonami, N; Hisada, K

1993-07-01

306

Thermophoretically dominated aerosol coagulation.  

PubMed

A theory of aerosol coagulation due to size-dependent thermophoresis is presented. This previously overlooked effect is important when local temperature gradients are large, the sol population is composed of particles of much greater thermal conductivity than the carrier gas, with mean diameters much greater than the prevailing gas mean free path, and an adequate "spread" in sizes (as in metallurgical mists or fumes). We illustrate this via a population-balance analysis of the evolution of an initially log-normal distribution when this mechanism dominates ordinary Brownian diffusion. PMID:21231753

Rosner, Daniel E; Arias-Zugasti, Manuel

2011-01-01

307

Heteronuclear Gd-99mTc Complex of DTPA-Bis(histidylamide) Conjugate as a Bimodal MR/SPECT Imaging Probe  

PubMed Central

The work describes the synthesis and in vivo application of heterotrimetallic complexes of the type {Gd(H2O)[(M(H2O)(CO)3)2(1)]} {1 = DTPA-bis(histidyl-amide); M = Re (3a); 99mTc (3b)} for dual modality MR/SPECT imaging. Here, the DTPA-bis(histidylamide) conjugate functions as a trinucleating chelate incorporating Gd in the DTPA core with Re or 99mTc in the pair of histidylamide side arms. The two complexes are chemically equivalent as revealed by HPLC, and their “cocktail mixture” (3a + 3b) has demonstrated itself to be essentially a single bimodal imaging probe. The present system has thus overcome the sensitivity difference problem between MRI and SPECT and paved the way for practical applications. PMID:24900467

2012-01-01

308

Nanomaterials from Aerosols Aerosols are suspensions of liquid or solid particles in a gas. Aerosol particles  

E-print Network

flame (DND APS, submitted Journal American Chemical Society). b) diffusion silica flame (ID02 ESRF of the aerosol in a free flame (fig. 1). Aerosol synthesis is the most promising route for large scale production in the chemical process industry, depends to some extent on understanding the details of nucleation and growth

Beaucage, Gregory

309

Exposures to acidic aerosols  

SciTech Connect

Ambient monitoring of acid aerosols in four U.S. cities and in a rural region of southern Ontario clearly show distinct periods of strong acidity. Measurements made in Kingston, TN, and Steubenville, OH, resulted in 24-hr H+ ion concentrations exceeding 100 nmole/m/sup 3/ more than 10 times during summer months. Periods of elevated acidic aerosols occur less frequently in winter months. The H+ determined during episodic conditions in southern Ontario indicates that respiratory tract deposition can exceed the effects level reported in clinical studies. Observed 12-hr H+ concentrations exceeded 550 nmole/m/sup 3/ (approximately 27 micrograms/m/sup 3/ H/sub 2/SO/sub 4/). The maximum estimated 1-hr concentration exceeded 1500 nmole/m/sup 3/ for H+ ions. At these concentrations, an active child might receive more than 2000 nmole of H+ ion in 12 hr and in excess of 900 nmole during the hour when H/sub 2/SO/sub 4/ exceeded 50 micrograms/m/sup 3/.

Spengler, J.D.; Keeler, G.J.; Koutrakis, P.; Ryan, P.B.; Raizenne, M.; Franklin, C.A.

1989-02-01

310

Exposures to acidic aerosols  

SciTech Connect

Ambient monitoring of acid aerosols in four U.S. cities and in a rural region of southern Ontario clearly show distinct periods of strong acidity. Measurements made in Kingston, TN, and Steubenville, OH, resulted in 24-hr H(+) ion concentrations exceeding 100 nmole/cu m more than 10 times during summer months. Periods of elevated acidic aerosols occur less frequently in winter months. The H(+) determined during episodic conditions in southern Ontario indicates that respiratory tract deposition can exceed the effects level reported in clinical studies. Observed 12-hr (H+) concentrations exceeded 550 nmole/cu m (approximately 27 microgram/cu m H{sub 2}SO{sub 4}). The maximum estimated 1-hr concentration exceeded 1500 nmole/cu m for H(+) ions. At these concentrations, an active child might receive more than 2000 nmole of H(+) ion in 12 hr and in excess of 900 nmole during the hour when H{sub 2}SO{sub 4} exceeded 50 microgram/cu m.

Spengler, J.D.; Keeler, G.J.; Koutrakis, P.; Ryan, P.B.; Raizenne, M.

1989-01-01

311

International Cooperative for Aerosol Prediction Workshop on Aerosol Forecast Verification  

NASA Technical Reports Server (NTRS)

The purpose of this workshop was to reinforce the working partnership between centers who are actively involved in global aerosol forecasting, and to discuss issues related to forecast verification. Participants included representatives from operational centers with global aerosol forecasting requirements, a panel of experts on Numerical Weather Prediction and Air Quality forecast verification, data providers, and several observers from the research community. The presentations centered on a review of current NWP and AQ practices with subsequent discussion focused on the challenges in defining appropriate verification measures for the next generation of aerosol forecast systems.

Benedetti, Angela; Reid, Jeffrey S.; Colarco, Peter R.

2011-01-01

312

Biogenically driven organic contribution to marine aerosol  

Microsoft Academic Search

Marine aerosol contributes significantly to the global aerosol load and consequently has an important impact on both the Earth's albedo and climate. So far, much of the focus on marine aerosol has centred on the production of aerosol from sea-salt and non-sea-salt sulphates. Recent field experiments, however, have shown that known aerosol production processes for inorganic species cannot account for

Colin D. O'Dowd; Maria Cristina Facchini; Fabrizia Cavalli; Darius Ceburnis; Mihaela Mircea; Stefano Decesari; Sandro Fuzzi; Young Jun Yoon; Jean-Philippe Putaud

2004-01-01

313

Aerosol survival of Staphylococcus epidermidis.  

PubMed

Recent studies have suggested that aerosol dispersal might play a role in the dissemination of meticillin-resistant Staphylococcus aureus (MRSA). Relatively little has been published about the ability of staphylococci to survive in aerosols. This study measured the survival of Staphylococcus epidermidis, a surrogate for S. aureus, in aerosols and investigated the effect of relative humidity on survival. We used a Goldberg drum to assess survival at relative humidities of <20%, 40-60%, 70-80% and >90%. We controlled for the effects of aerosol dilution and physical decay by comparing the recovery of S. epidermidis with that of the aerosol-stable spores of Bacillus atrophaeus, using the ratio of their recovery rates to estimate biological degradation of S. epidermidis over time. At all relative humidities investigated 13% [95% confidence interval (CI): 10.1-16.2%] of the initial aerosol was recovered after 5h (300 min). The mean percentage survival ratio (% S. epidermidis:% B. atrophaeus) after 5h was 47% (95% CI: 33.5-60.5%). Overlapping 95% CIs of mean percentage survival ratios at each humidity level indicated that humidity did not have a significant effect on the survival in aerosol form of S. epidermidis. Additional experiments indicated that S. epidermidis was recoverable after five days at 76% humidity. The sizes of particles within the bacterial aerosol were well within the respirable range (<2.1 ?m). The survival of aerosolised S. epidermidis demonstrated in this study suggests that staphylococci have the potential for aerosol dissemination in hospitals. PMID:21333383

Thompson, K-A; Bennett, A M; Walker, J T

2011-07-01

314

AERONET: The Aerosol Robotic Network  

DOE Data Explorer

AERONET collaboration provides globally distributed observations of spectral aerosol optical Depth (AOD), inversion products, and precipitable water in diverse aerosol regimes. Aerosol optical depth data are computed for three data quality levels: Level 1.0 (unscreened), Level 1.5 (cloud-screened), and Level 2.0 (cloud screened and quality-assured). Inversions, precipitable water, and other AOD-dependent products are derived from these levels and may implement additional quality checks.[Copied from http://aeronet.gsfc.nasa.gov/new_web/system_descriptions.html

315

Remote Sensing of Aerosol and Non-Aerosol Absorption  

NASA Technical Reports Server (NTRS)

Remote sensing of aerosol from the new satellite instruments (e.g. MODIS from Terra) and ground based radiometers (e.g. the AERONET) provides the opportunity to measure the absorption characteristics of the ambient undisturbed aerosol in the entire atmospheric column. For example Landsat and AERONET data are used to measure spectral absorption of sunlight by dust from West Africa. Both Application of the Landsat and AERONET data demonstrate that Saharan dust absorption of solar radiation is several times smaller than the current international standards. This is due to difficulties of measuring dust absorption in situ, and due to the often contamination of dust properties by the presence of air pollution or smoke. We use the remotely sensed aerosol absorption properties described by the spectral sin le scattering albedo, together with statistics of the monthly optical thickness for the fine and coarse aerosol derived from the MODIS data. The result is an estimate of the flux of solar radiation absorbed by the aerosol layer in different regions around the globe where aerosol is prevalent. If this aerosol forcing through absorption is not included in global circulation models, it may be interpreted as anomalous absorption in these regions. In a preliminary exercise we also use the absorption measurements by AERONET, to derive the non-aerosol absorption of the atmosphere in cloud free conditions. The results are obtained for the atmospheric windows: 0.44 microns, 0.66 microns, 0.86 microns and 1.05 microns. In all the locations over the land and ocean that were tested no anomalous absorption in these wavelengths, was found within absorption optical thickness of +/- 0.005.

Kaufman, Y. J.; Dubovik, O.; Holben, B. N.; Remer, L. A.; Tanre, D.; Lau, William K. M. (Technical Monitor)

2001-01-01

316

Aerosols over Eastern Asia  

NASA Technical Reports Server (NTRS)

This Sea-viewing Wide Field-of-view Sensor (SeaWiFS) image of eastern Asia from October 14, 2001, shows large amounts of aerosol in the air. A few possible point sources of smoke, probably fires, are visible north of the Amur River at the very top of the image. One of the larger of these plumes can be seen down river of the confluence of the Songhua and Amur rivers. At lower left, the Yangtze River plume in the East China Sea is also very prominent. Sediment suspended in the ocean water is quite brown near the shore, but becomes much greener as it diffuses into the water. The increasing greenness of the river plume is probably an indication of enhanced phytoplankton growth driven by the nutrients in the river runoff. Image courtesy the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE

2002-01-01

317

Aerosol lidar ``M4``  

SciTech Connect

Small carrying aerosol lidar in which is used small copper vapor laser ``Malachite`` as source of sounding optical pulses is described. The advantages of metal vapor laser and photon counting mode in acquisition system of lidar gave ability to get record results: when lidar has dimensions (1 x .6 x .3 m) and weight (65 kg), it provides the sounding of air industrial pollutions at up to 20 km range in scanning sector 90{degree}. Power feed is less than 800 Wt. Lidar can be disposed as stationary so on the car, helicopter, light plane. Results of location of smoke tails and city smog in situ experiments are cited. Showed advantages of work of acquisition system in photon counting mode when dynamic range of a signal is up to six orders.

Shelevoy, C.D.; Andreev, Y.M. [Super Computer Devices Co. Ltd., Tomsk (Russian Federation); [Siberian State Medical Univ., Tomsk (Russian Federation)

1994-12-31

318

Diffusion classification of submicron aerosols  

Microsoft Academic Search

An in-stack diffusion classifer has been designed, constructed, calibrated and field tested. The classifier utilizes a very fine-mesh stainless-steel wire screen for the actual aerosol classification. The in-stack unit uses five stages operated in parallel, each sampling at the same fixed flow rate, to provide five simultaneous size-classified aerosol samples. These samples are collected out on filter media for subsequent

D. A. Lundgren; C. N. Rangaraj

1982-01-01

319

The Juelich large Aerosol Chamber  

Microsoft Academic Search

The large Aerosol Chamber is designed for the investigation of nighttime atmospheric chemistry. The Aerosol Chamber is a dark chamber and is operated at ambient temperature and pressure conditions. It is constructed as a double wall system: a fully welded aluminum box (7m x 7m x 5.3m) and an equally sized fully heat sealed Teflon bag hanging from the ceiling.

Th. Mentel; A. Wahner; M. Folkers

2003-01-01

320

Monsoon shrinks with aerosol models  

SciTech Connect

Sulfur compounds in the atmosphere from burning fossilfuels have long been implicated in acid rain and smog, but climate modelers have only recently included them along with greenhouse gases as major determinants of global change. This paper summarizes work of German modelers who showed just how important the aerosols that form from the sulfur compounds may be in affecting regional climates. Among the model findings is the projection of a decrease in monsoons in India due to the increase in aerosol levels.

Mudur, G.

1995-12-22

321

CALIPSO Observations of Aerosol Properties Near Clouds  

NASA Technical Reports Server (NTRS)

Clouds are surrounded by a transition zone of rapidly changing aerosol properties. Characterizing this zone is important for better understanding aerosol-cloud interactions and aerosol radiative effects as well as for improving satellite measurements of aerosol properties. We present a statistical analysis of a global dataset of CALIPSO (Cloud-Aerosol Lidar and infrared Pathfinder Satellite Observation) Lidar observations over oceans. The results show that the transition zone extends as far as 15 km away from clouds and it is ubiquitous over all oceans. The use of only high confidence level cloud-aerosol discrimination (CAD) data confirms the findings. However, the results underline the need for caution to avoid biases in studies of satellite aerosol products, aerosol-cloud interactions, and aerosol direct radiative effects.

Marshak, Alexander; Varnai, Tamas; Yang, Weidong

2010-01-01

322

Satellite Remote Sensing: Aerosol Measurements  

NASA Technical Reports Server (NTRS)

Aerosols are solid or liquid particles suspended in the air, and those observed by satellite remote sensing are typically between about 0.05 and 10 microns in size. (Note that in traditional aerosol science, the term "aerosol" refers to both the particles and the medium in which they reside, whereas for remote sensing, the term commonly refers to the particles only. In this article, we adopt the remote-sensing definition.) They originate from a great diversity of sources, such as wildfires, volcanoes, soils and desert sands, breaking waves, natural biological activity, agricultural burning, cement production, and fossil fuel combustion. They typically remain in the atmosphere from several days to a week or more, and some travel great distances before returning to Earth's surface via gravitational settling or washout by precipitation. Many aerosol sources exhibit strong seasonal variability, and most experience inter-annual fluctuations. As such, the frequent, global coverage that space-based aerosol remote-sensing instruments can provide is making increasingly important contributions to regional and larger-scale aerosol studies.

Kahn, Ralph A.

2013-01-01

323

Spatial Heterogeneity of Soil DTPA-extractable Copper as Affected by City Pollution and Land Use in Cultivated Fields of Shenyang, China  

Microsoft Academic Search

Using the methods of soil analysis and geostatistics combined with GIS, this paper determined and mapped the spatial distribution of soil DTPA-extractable copper (Cu) in cultivated fields of Shenyang suburbs of China, aimed to assess the roles of industries and agricultural managements in affect ing the spatial heterogeneity of soil Cu in this region. The results showed that the soil

Yong Jiang; Ying Qin; Yuge Zhang; Qi Li; Wenju Liang

2008-01-01

324

Variability in soil micronutrients extracted by DTPA and Mehlich-3 at the plot scale in an acidic environment  

NASA Astrophysics Data System (ADS)

Land use practices affect soil properties and nutrient supply. Very limited data are available on micronutrient extractability in northwest Spain. The aim of this study was to analyse long-term effects of land use on the concentration, variability and spatial distribution of soil nutrients. To this end, neighboring forest and cultivated stands were compared. The study was carried out in an acid, rich in organic matter soil developed over sediments at the province of Lugo, northwestern of Spain. Adjacent plots with a surface of 100 m2 were marked on regular square grids with 2-m spacing. Fe, Mn, Zn and Cu were extracted both by Mehlich-3 and DTPA solutions and determined by ICP-MS. General soil chemical and physical properties were routinely analyzed. In arable land, microelement concentration ranges were as follows: Fe (100 and 135 mg kg-1), Mn (7.6 and 21.5 mg kg-1), Zn (0.6 and 3.7 mg kg-1), and Cu (0.2 and 0.7 mg kg-1). In forest land, these ranges were: Fe (62 and 309 mg kg-1), Mn (0.2 and 2.1 mg kg-1), Zn (0.2 and 2.9 mg kg-1), and Cu (0.1 and 0.2 mg kg-1). With the exception of Fe-DTPA, microelement concentrations extracted both with DTPA and Mehlich-3 were higher in the cultivated than in the forest stand. Coefficients of variation were higher for the microelement content of the soil under forest. Principal component analysis was performed to evaluate associations between extractable microelements and general physico-chemical properties. At the studied scale, nutrient management was the main factor affecting the agricultural site, whereas soil-plant interactions were probably responsible for the higher variation within the forest site. Patterns of spatial variability of the studied nutrients at the small plot scale also were assessed by geostatistical techniques. Results were discussed in the frame of sustainable land use and organic matter decline with conventional tillage and sustainable land use

Paz-Ferreiro, Jorge; Lado, Marcos; de Abreu, Cleide A.

2014-05-01

325

Satellite Retrieval of Aerosol Properties  

NASA Astrophysics Data System (ADS)

SATELLITE RETRIEVAL of AEROSOL PROPERTIES G. de Leeuw, C. Robles Gonzalez, J. Kusmierczyk-Michulec and R. Decae TNO Physics and Electronics Laboratory, The Hague, The Netherlands; deleeuw@fel.tno.nl Methods to retrieve aerosol properties over land and over sea were explored. The dual view offered by the ATSR-2 aboard ERS-2 was used by Veefkind et al., 1998. The retrieved AOD (aerosol optical depth) values compare favourably with collocated sun photometer measurements, with an accuracy of 0.06 +/- 0.05 in AOD. An algorithm developed for GOME on ERS-2 takes advantage of the low surface reflection in the UV (Veefkind et al., 2000). AOD values retrieved from ATSR-2 and GOME data over western Europe are consistent. The results were used to produce a map of mean AOD values over Europe for one month (Robles-Gonzalez et al., 2000). The ATSR-2 is al- gorithm is now extended with other aerosol types with the aim to apply it over the In- dian Ocean. A new algorithm is being developed for the Ozone Monitoring Instrument (OMI) to be launched in 2003 on the NASA EOS-AURA satellite. It is expected that, based on the different scattering and absorption properties of various aerosol types, five major aerosol classes can be distinguished. The experience with the retrieval of aerosol properties by using several wavelength bands is used to develop an algorithm for Sciamachy to retrieve aerosol properties both over land and over the ocean which takes advantage of the wavelengths from the UV to the IR. The variation of the AOD with wavelength is described by the Angstrom parameter. The AOD and the Angstrom parameter together yield information on the aerosol size distribution, integrated over the column. Analysis of sunphotometer data indicates a relation between the Angstrom parameter and the mass ratio of certain aerosols (black carbon, organic carbon and sea salt) to the total particulate matter. This relation has been further explored and was applied to satellite data over land to retrieve the spatial variation of black carbon con- centrations. An overview of algorithms developed at the TNO Physics and Electronics Laboratory will be presented. References Robles Gonzalez, C., J.P. Veefkind and G. de Leeuw, Geophys. Res. Lett. 27 (2000) 955-959. Veefkind, J.P., G. de Leeuw, and P.A. Durkee, Geophys. Res. Letters 25 (1998) 3135-3138. Veefkind, J.P., G. de Leeuw, P. Stammes and R.B.A. Koelemeijer, Remote sensing of the Environment 74 (2000) 377- 386.

de Leeuw, G.; Robles Gonzalez, C.; Kusmierczyk-Michulec, J.; Decae, R.

326

Modeling the Absorbing Aerosol Index  

NASA Technical Reports Server (NTRS)

We propose a scheme to model the absorbing aerosol index and improve the biomass carbon inventories by optimizing the difference between TOMS aerosol index (AI) and modeled AI with an inverse model. Two absorbing aerosol types are considered, including biomass carbon and mineral dust. A priori biomass carbon source was generated by Liousse et al [1996]. Mineral dust emission is parameterized according to surface wind and soil moisture using the method developed by Ginoux [2000]. In this initial study, the coupled CCM1 and GRANTOUR model was used to determine the aerosol spatial and temporal distribution. With modeled aerosol concentrations and optical properties, we calculate the radiance at the top of the atmosphere at 340 nm and 380 nm with a radiative transfer model. The contrast of radiance at these two wavelengths will be used to calculate AI. Then we compare the modeled AI with TOMS AI. This paper reports our initial modeling for AI and its comparison with TOMS Nimbus 7 AI. For our follow-on project we will model the global AI with aerosol spatial and temporal distribution recomputed from the IMPACT model and DAO GEOS-1 meteorology fields. Then we will build an inverse model, which applies a Bayesian inverse technique to optimize the agreement of between model and observational data. The inverse model will tune the biomass burning source strength to reduce the difference between modelled AI and TOMS AI. Further simulations with a posteriori biomass carbon sources from the inverse model will be carried out. Results will be compared to available observations such as surface concentration and aerosol optical depth.

Penner, Joyce; Zhang, Sophia

2003-01-01

327

YAG aerosol lidar  

NASA Technical Reports Server (NTRS)

The Global Atmospheric Backscatter Experiment (GLOBE) Mission, using the NASA DC-8 aircraft platform, is designed to provide the magnitude and statistical distribution of atmospheric backscatter cross section at lidar operating wavelengths. This is a fundamental parameter required for the Doppler lidar proposed to be used on a spacecraft platform for global wind field measurements. The prime measurements will be made by a CO2 lidar instrument in the 9 to 10 micron range. These measurements will be complemented with the Goddard YAG Aerosol Lidar (YAL) data in two wavelengths, 0.532 and 1.06 micron, in the visible and near-infrared. The YAL, is being designed to utilize as much existing hardware, as feasible, to minimize cost and reduce implementation time. The laser, energy monitor, telescope and detector package will be mounted on an optical breadboard. The optical breadboard is mounted through isolation mounts between two low boy racks. The detector package will utilize a photomultiplier tube for the 0.532 micron channel and a silicon avalanche photo detector (APD) for the 1.06 micron channel.

Sullivan, R.

1988-01-01

328

Black carbon aerosol mixing state, organic aerosols and aerosol optical properties over the UK  

NASA Astrophysics Data System (ADS)

Black carbon (BC) aerosols absorb sunlight thereby leading to a positive radiative forcing and a warming of climate and can also impact human health through their impact on the respiratory system. The state of mixing of BC with other aerosol species, particularly the degree of internal/external mixing, has been highlighted as a major uncertainty in assessing its radiative forcing and hence its climate impact, but few in situ observations of mixing state exist. We present airborne single particle soot photometer (SP2) measurements of refractory BC (rBC) mass concentrations and mixing state coupled with aerosol composition and optical properties measured in urban plumes and regional pollution over the UK. All data were obtained using instrumentation flown on the UK's BAe-146-301 large Atmospheric Research Aircraft (ARA) operated by the Facility for Airborne Atmospheric Measurements (FAAM). We measured sub-micron aerosol composition using an aerosol mass spectrometer (AMS) and used positive matrix factorization to separate hydrocarbon-like (HOA) and oxygenated organic aerosols (OOA). We found a higher number fraction of thickly coated rBC particles in air masses with large OOA relative to HOA, higher ozone-to-nitrogen oxides (NOx) ratios and large concentrations of total sub-micron aerosol mass relative to rBC mass concentrations. The more ozone- and OOA-rich air masses were associated with transport from continental Europe, while plumes from UK cities had higher HOA and NOx and fewer thickly coated rBC particles. We did not observe any significant change in the rBC mass absorption efficiency calculated from rBC mass and light absorption coefficients measured by a particle soot absorption photometer despite observing significant changes in aerosol composition and rBC mixing state. The contributions of light scattering and absorption to total extinction (quantified by the single scattering albedo; SSA) did change for different air masses, with lower SSA observed in urban plumes compared to regional aerosol (0.85 versus 0.9-0.95). We attribute these differences to the presence of relatively rapidly formed secondary aerosol, primarily OOA and ammonium nitrate, which must be taken into account in radiative forcing calculations.

McMeeking, G. R.; Morgan, W. T.; Flynn, M.; Highwood, E. J.; Turnbull, K.; Haywood, J.; Coe, H.

2011-05-01

329

Black carbon aerosol mixing state, organic aerosols and aerosol optical properties over the United Kingdom  

NASA Astrophysics Data System (ADS)

Black carbon (BC) aerosols absorb sunlight thereby leading to a positive radiative forcing and a warming of climate and can also impact human health through their impact on the respiratory system. The state of mixing of BC with other aerosol species, particularly the degree of internal/external mixing, has been highlighted as a major uncertainty in assessing its radiative forcing and hence its climate impact, but few in situ observations of mixing state exist. We present airborne single particle soot photometer (SP2) measurements of refractory BC (rBC) mass concentrations and mixing state coupled with aerosol composition and optical properties measured in urban plumes and regional pollution over the United Kingdom. All data were obtained using instrumentation flown on the UK's BAe-146-301 large Atmospheric Research Aircraft (ARA) operated by the Facility for Airborne Atmospheric Measurements (FAAM). We measured sub-micron aerosol composition using an aerosol mass spectrometer (AMS) and used positive matrix factorization to separate hydrocarbon-like (HOA) and oxygenated organic aerosols (OOA). We found a higher number fraction of thickly coated rBC particles in air masses with large OOA relative to HOA, higher ozone-to-nitrogen oxides (NOx) ratios and large concentrations of total sub-micron aerosol mass relative to rBC mass concentrations. The more ozone- and OOA-rich air masses were associated with transport from continental Europe, while plumes from UK cities had higher HOA and NOx and fewer thickly coated rBC particles. We did not observe any significant change in the rBC mass absorption efficiency calculated from rBC mass and light absorption coefficients measured by a particle soot absorption photometer despite observing significant changes in aerosol composition and rBC mixing state. The contributions of light scattering and absorption to total extinction (quantified by the single scattering albedo; SSA) did change for different air masses, with lower SSA observed in urban plumes compared to regional aerosol (0.85 versus 0.9-0.95). We attribute these differences to the presence of relatively rapidly formed secondary aerosol, primarily OOA and ammonium nitrate, which must be taken into account in radiative forcing calculations.

McMeeking, G. R.; Morgan, W. T.; Flynn, M.; Highwood, E. J.; Turnbull, K.; Haywood, J.; Coe, H.

2011-09-01

330

Volatile organic compounds in ambient aerosols  

NASA Astrophysics Data System (ADS)

In order to investigate the concentration levels of volatile organic compounds (VOCs) in ambient aerosols, monocyclic aromatic hydrocarbons (MAHs) and chlorinated hydrocarbons (CHs) in the particulate phase were measured simultaneously with those in the gas phase in the urban atmosphere. Six compounds were detected in the aerosols at concentrations from 0.051 (1,2-dichloroethane) to 1.75 ng m - 3 (benzene). Benzene was detected as the most dominant compound in the aerosols, although toluene was the most dominant compound in the gas phase. The VOCs in the aerosols had concentrations comparable to those reported for some semi-volatile organic compounds (SOCs) in the aerosols. The concentrations of the VOCs in the aerosols were primarily controlled by the aerosol mass loading. Temperature and relative humidity had no significant effect on the gas/particle partitioning of the VOCs. Our results also suggested that the hygroscopic properties of the aerosols should be considered to discuss the partitioning of the VOCs.

Matsumoto, Kiyoshi; Matsumoto, Kumi; Mizuno, Riichi; Igawa, Manabu

2010-07-01

331

Center for Aerosol Research (AEROCENTER)  

NASA Technical Reports Server (NTRS)

The newly established Center for Aerosol Research (AEROCENTER) located at the NASA/Goddard Space Flight Center in Greenbelt MD is dedicated to fostering interdisciplinary research in all aspects of aerosol science. AEROCENTER will be an incubator for innovative new analysis of existing data and ideas for new space missions. The plan is to tap and harvest ideas from a broad international and interdisciplinary science community and to incorporate these ideas into NASA's aerosol research effort for understanding and predicting the aerosol effect on climate and the environment. In order to achieve this goal the center aims to host several established and developing scientists for a period of 3-6 months each year. AEROCENTER will also develop a new technical infrastructure that will integrate the present aerosol research activities and data resources of GSFC/Greenbelt and GSFC/GISS, increase efficiency in the use of NASA remote sensing data, and increase the involvement of a larger national and international scientific community. The center aims to institutionalize and extend the present knowledge base within NASA into a national resource for the education and research communities.

Kleidman, Richard; Kaufman, Yoram; Lau, William K. M. (Technical Monitor)

2001-01-01

332

Aerosol Classification by Advanced Backscatter Lidar Techniques  

NASA Astrophysics Data System (ADS)

The high spectral resolution lidar (HSRL) method based on an iodine absorption filter and a frequency doubled pulsed Nd:YAG laser is presented. This method has the capability to directly measure the extinction and backscatter coefficients of aerosols and clouds. Measurements of an airborne HSRL system from four different field experiments are used to build up an aerosol classification. Two examples show the potential of this aerosol classification to distinguish between different aerosol types.

Groß, Silke; Wirth, Martin; Esselborn, Michael

333

Identification of aerosol species using polarization lidar  

NASA Astrophysics Data System (ADS)

This paper presents a new approach that has been developed to identify individual aerosol species using polarization lidar measurements. Individual aerosols can be identified based on their distinct ratios of extinction to backscatter, which are related to the depolarization ratio profile. Aerosol backscatter coefficients can be obtained from these ratios. Differential aerosol backscatter coefficients are proportional to the variation of the ratio of extinction to backscatter coefficient, and the coefficients increase, reach a peak value, and then decrease again, with increasing range.

Cao, Nianwen; Zhu, Cunxiong; Yang, Shaobo; Xie, Yinhai; Yang, Fengkai; Zhang, Feng

2014-09-01

334

Paint spray tests for respirators: aerosol characteristics  

Microsoft Academic Search

Liquid paint is sprayed from an atomizing nozzle to form an aerosol for testing paint spray respirators. The generated aerosol conditions are dependent upon liquid properties, spray-nozzle flow conditions and droplet evaporation. A technique was developed for controlling the aerosol concentrations reliably. Particle-size distributions of lacquer and enamel have been measured. The lacquer distribution was found to be multi-modal. Aerosol

MARK W. ACKLEY

1980-01-01

335

Climate forcing by carbonaceous and sulfate aerosols  

Microsoft Academic Search

An atmospheric general circulation model is coupled to an atmospheric chemistry model to calculate the radiative forcing\\u000a by anthropogenic sulfate and carbonaceous aerosols. The latter aerosols result from biomass burning as well as fossil fuel\\u000a burning. The black carbon associated with carbonaceous aerosols is absorbant and can decrease the amount of reflected radiation\\u000a at the top-of-the-atmosphere. In contrast, sulfate aerosols

J. E. Penner; C. C. Chuang; K. Grant

1998-01-01

336

Aerosol retrieval experiments in the ESA Aerosol_cci project  

NASA Astrophysics Data System (ADS)

Within the ESA Climate Change Initiative (CCI) project Aerosol_cci (2010-2013) algorithms for the production of long-term total column aerosol optical depth (AOD) datasets from European Earth Observation sensors are developed. Starting with eight existing pre-cursor algorithms three analysis steps are conducted to improve and qualify the algorithms: (1) a series of experiments applied to one month of global data to understand several major sensitivities to assumptions needed due to the ill-posed nature of the underlying inversion problem, (2) a round robin exercise of "best" versions of each of these algorithms (defined using the step 1 outcome) applied to four months of global data to identify mature algorithms, and (3) a comprehensive validation exercise applied to one complete year of global data produced by the algorithms selected as mature based on the round robin exercise. The algorithms tested included four using AATSR, three using MERIS and one using PARASOL. This paper summarizes the first step. Three experiments were conducted to assess the potential impact of major assumptions in the various aerosol retrieval algorithms. In the first experiment a common set of four aerosol components was used to provide all algorithms with the same assumptions. The second experiment introduced an aerosol property climatology, derived from a combination of model and sun photometer observations, as a priori information in the retrievals on the occurrence of the common aerosol components and their mixing ratios. The third experiment assessed the impact of using a common nadir cloud mask for AATSR and MERIS algorithms in order to characterize the sensitivity to remaining cloud contamination in the retrievals against the baseline dataset versions. The impact of the algorithm changes was assessed for one month (September 2008) of data qualitatively by visible analysis of monthly mean AOD maps and quantitatively by comparing global daily gridded satellite data against daily average AERONET sun photometer observations for the different versions of each algorithm. The analysis allowed an assessment of sensitivities of all algorithms which helped define the best algorithm version for the subsequent round robin exercise; all algorithms (except for MERIS) showed some, in parts significant, improvement. In particular, using common aerosol components and partly also a priori aerosol type climatology is beneficial. On the other hand the use of an AATSR-based common cloud mask meant a clear improvement (though with significant reduction of coverage) for the MERIS standard product, but not for the algorithms using AATSR.

Holzer-Popp, T.; de Leeuw, G.; Martynenko, D.; Klüser, L.; Bevan, S.; Davies, W.; Ducos, F.; Deuzé, J. L.; Graigner, R. G.; Heckel, A.; von Hoyningen-Hüne, W.; Kolmonen, P.; Litvinov, P.; North, P.; Poulsen, C. A.; Ramon, D.; Siddans, R.; Sogacheva, L.; Tanre, D.; Thomas, G. E.; Vountas, M.; Descloitres, J.; Griesfeller, J.; Kinne, S.; Schulz, M.; Pinnock, S.

2013-03-01

337

Measurements of Semi-volatile Aerosol and Its Effect on Aerosol Optical Properties During Southern Oxidant and Aerosol Study  

NASA Astrophysics Data System (ADS)

Semi-volatile compounds, including particle-bound water, comprise a large part of aerosol mass and have a significant influence on aerosol lifecycle and its optical properties. Understanding the properties of semi-volatile compounds, especially those pertaining to gas/aerosol partitioning, is of critical importance for our ability to predict concentrations and properties of ambient aerosol. A set of state-of-the-art instruments was deployed at the SEARCH site near Centerville, AL during the Southern Oxidant and Aerosol Study (SOAS) campaign in summer 2013 to measure the effect of temperature and relative humidity on aerosol size distribution, composition and optical properties. Light scattering and absorption by temperature- and humidity-conditioned aerosols was measured using three photo-acoustic extinctiometers (PAX) at three wavelengths (405 nm, 532 nm, and 870 nm). In parallel to these measurements, a long residence time temperature-stepping thermodenuder and a variable residence time constant temperature thermodenuder in combination with three SMPS systems and an Aerosol Chemical Speciation Monitor (ACSM) were used to assess aerosol volatility and kinetics of aerosol evaporation. It was found that both temperature and relative humidity have a strong effect on aerosol optical properties. The variable residence time thermodenuder data suggest that aerosol equilibrated fairly quickly, within 2 s, in contrast to other ambient observations. Preliminary analysis show that approximately 50% and 90% of total aerosol mass evaporated at temperatures of 100 C and 180C, respectively. Evaporation varied substantially with ambient aerosol loading and composition and meteorology. During course of this study, T50 (temperatures at which 50% aerosol mass evaporates) varied from 60 C to more than 120 C.

Khlystov, A.; Grieshop, A. P.; Saha, P.; Subramanian, R.

2013-12-01

338

8, 85858628, 2008 SW aerosol radiative  

E-print Network

Abstract The estimation of radiative forcing due to desert dust and forest fires aerosols is a very with the10 satellite-measured radiances. The aerosol direct radiative effect is shown to be very sensitive.55. In the presence of Forest Fire aerosols, over Cabo da Roca region, the average value of forcing efficiency is -28

Paris-Sud XI, Université de

339

6, 93519388, 2006 Aerosol-cloud  

E-print Network

ACPD 6, 9351­9388, 2006 Aerosol-cloud interaction inferred from MODIS and models G. Myhre et al Chemistry and Physics Discussions Aerosol-cloud interaction inferred from MODIS satellite data and global 6, 9351­9388, 2006 Aerosol-cloud interaction inferred from MODIS and models G. Myhre et al. Title

Paris-Sud XI, Université de

340

An Aerosol Condensation Model for Sulfur Trioxide  

Microsoft Academic Search

This document describes a model for condensation of sulfuric acid aerosol given an initial concentration and\\/or source of gaseous sulfur trioxide (e.g. fuming from oleum). The model includes the thermochemical effects on aerosol condensation and air parcel buoyancy. Condensation is assumed to occur heterogeneously onto a preexisting background aerosol distribution. The model development is both a revisiting of research initially

2008-01-01

341

5, 34373489, 2005 Global model aerosol  

E-print Network

on global sulfate aerosol except when the mass accommodation coefficient of sulfuric acid on the salt a relatively insignificant effect on boundary layer aerosol properties; (3) production of sulfate particles of sulfur emitted as primary particles) are 3438 #12;ACPD 5, 3437­3489, 2005 Global model aerosol

Boyer, Edmond

342

FEASIBILITY STUDY FOR AN ASBESTOS AEROSOL MONITOR  

EPA Science Inventory

The feasibility of discriminating and counting asbestos-fiber aerosol particles by means of their shapes, using a two-detector, optical, aerosol counter was determined. The assymmetry of their optical diffraction patterns would distinguish fibers from other, more regular aerosol ...

343

Stratospheric aerosol optical depths, 1850-1990  

Microsoft Academic Search

A global stratospheric aerosol database employed for climate simulations is described. For the period 1883-1990, aerosol optical depths are estimated from optical extinction data, whose quality increases with time over that period. For the period 1850-1882, aerosol optical depths are more crudely estimated from volcanological evidence for the volume of ejecta from major known volcanoes. The data set is available

Makiko Sato; James E. Hansen; M. Patrick McCormick; James B. Pollack

1993-01-01

344

3, 59195976, 2003 The nitrate aerosol  

E-print Network

ACPD 3, 5919­5976, 2003 The nitrate aerosol field over Europe M. Schaap et al. Title Page Abstract/5919/ © European Geosciences Union 2003 Atmospheric Chemistry and Physics Discussions The nitrate aerosol field.schaap@phys.uu.nl) 5919 #12;ACPD 3, 5919­5976, 2003 The nitrate aerosol field over Europe M. Schaap et al. Title Page

Paris-Sud XI, Université de

345

Light Absorbing Aerosols in Mexico City  

Microsoft Academic Search

The direct effects of aerosol radiative forcing has been identified by the IPCC as a major uncertainty in climate modeling. The DOE Megacity Aerosol Experiment-Mexico City (MAX-Mex), as part of the MILAGRO study in March of 2006, was undertaken to reduce these uncertainties by characterization of the optical, chemical, and physical properties of atmospheric aerosols emitted from this megacity environment.

N. A. Marley; K. L. Kelley; P. S. Kilaparty; J. S. Gaffney

2008-01-01

346

The physical state of UTLS aerosols  

Microsoft Academic Search

This paper gives an overview of the present knowledge on the physical state of aerosols in the upper troposphere (UT) and lower stratosphere (LS). Are UTLS aerosols liquid, solid or mixed-phase? And how does ice nucleate in\\/on such aerosols? Good progress has been made towards a quantitative theory of homogeneous nucleation of ice in purely liquid solutions of arbitrary composition

Th. Peter; C. A. Colberg; T. Corti; S. Fueglistaler; C. R. Hoyle; T. Koop; U. K. Krieger; B. P. Luo; C. Marcolli

2003-01-01

347

6, 30993133, 2006 Aerosol extinction-to-  

E-print Network

ACPD 6, 3099­3133, 2006 Aerosol extinction-to- backscatter ratio by lidar and MODIS Q. S. He et al Chemistry and Physics Discussions A study on aerosol extinction-to-backscatter ratio with combination;ACPD 6, 3099­3133, 2006 Aerosol extinction-to- backscatter ratio by lidar and MODIS Q. S. He et al

Paris-Sud XI, Université de

348

Aerosol retrieval experiments in the ESA Aerosol_cci project  

NASA Astrophysics Data System (ADS)

Within the ESA Climate Change Initiative (CCI) project Aerosol_cci (2010-2013), algorithms for the production of long-term total column aerosol optical depth (AOD) datasets from European Earth Observation sensors are developed. Starting with eight existing pre-cursor algorithms three analysis steps are conducted to improve and qualify the algorithms: (1) a series of experiments applied to one month of global data to understand several major sensitivities to assumptions needed due to the ill-posed nature of the underlying inversion problem, (2) a round robin exercise of "best" versions of each of these algorithms (defined using the step 1 outcome) applied to four months of global data to identify mature algorithms, and (3) a comprehensive validation exercise applied to one complete year of global data produced by the algorithms selected as mature based on the round robin exercise. The algorithms tested included four using AATSR, three using MERIS and one using PARASOL. This paper summarizes the first step. Three experiments were conducted to assess the potential impact of major assumptions in the various aerosol retrieval algorithms. In the first experiment a common set of four aerosol components was used to provide all algorithms with the same assumptions. The second experiment introduced an aerosol property climatology, derived from a combination of model and sun photometer observations, as a priori information in the retrievals on the occurrence of the common aerosol components. The third experiment assessed the impact of using a common nadir cloud mask for AATSR and MERIS algorithms in order to characterize the sensitivity to remaining cloud contamination in the retrievals against the baseline dataset versions. The impact of the algorithm changes was assessed for one month (September 2008) of data: qualitatively by inspection of monthly mean AOD maps and quantitatively by comparing daily gridded satellite data against daily averaged AERONET sun photometer observations for the different versions of each algorithm globally (land and coastal) and for three regions with different aerosol regimes. The analysis allowed for an assessment of sensitivities of all algorithms, which helped define the best algorithm versions for the subsequent round robin exercise; all algorithms (except for MERIS) showed some, in parts significant, improvement. In particular, using common aerosol components and partly also a priori aerosol-type climatology is beneficial. On the other hand the use of an AATSR-based common cloud mask meant a clear improvement (though with significant reduction of coverage) for the MERIS standard product, but not for the algorithms using AATSR. It is noted that all these observations are mostly consistent for all five analyses (global land, global coastal, three regional), which can be understood well, since the set of aerosol components defined in Sect. 3.1 was explicitly designed to cover different global aerosol regimes (with low and high absorption fine mode, sea salt and dust).

Holzer-Popp, T.; de Leeuw, G.; Griesfeller, J.; Martynenko, D.; Klüser, L.; Bevan, S.; Davies, W.; Ducos, F.; Deuzé, J. L.; Graigner, R. G.; Heckel, A.; von Hoyningen-Hüne, W.; Kolmonen, P.; Litvinov, P.; North, P.; Poulsen, C. A.; Ramon, D.; Siddans, R.; Sogacheva, L.; Tanre, D.; Thomas, G. E.; Vountas, M.; Descloitres, J.; Griesfeller, J.; Kinne, S.; Schulz, M.; Pinnock, S.

2013-08-01

349

Generation of a monodispersed aerosol  

NASA Technical Reports Server (NTRS)

The identity and laboratory test methods for the generation of a monodispersed aerosol are reported on, and are subjected to the following constraints and parameters; (1) size distribution; (2) specific gravity; (3) scattering properties; (4) costs; (5) production. The procedure called for the collection of information from the literature, commercial available products, and experts working in the field. The following topics were investigated: (1) aerosols; (2) air pollution -- analysis; (3) atomizers; (4) dispersion; (5) particles -- optics, size analysis; (6) smoke -- generators, density measurements; (7) sprays; (8) wind tunnels -- visualization.

Schenck, H.; Mikasa, M.; Devicariis, R.

1974-01-01

350

Influence of aerosols on weather conditions  

NASA Astrophysics Data System (ADS)

The accurate numerical weather prediction demands the better understanding and detailed representation of aerosol effects in the atmosphere. The presence of various types of aerosols as well as other chemical components in the atmosphere causes different effects on weather, climate and still keeps many unresolved aspects. Non-linear interactions between weather phenomena, in particular, precipitation and aerosols need to be additionally highlighted. To investigate features of the atmosphere sensitivity to aerosols the high resolution limited area model Harmonie (Hirlam Aladin Regional/Meso-scale Operational NWP In Europe) was used. The Harmonie is extensively developing weather forecast modeling system, in which the convection-permitting physics substantially promotes to the near-realistic representation of the aerosol effects complexity. Numerical experiments with modifications in aerosol concentrations were performed over the Finland domain. The direct effect of aerosols associates with changes in both radiation processes and precipitation formation. The presence of aerosols increases cloud drop concentration and reduces the effective drop size. A high density of nuclei population initializes coalescence growth, accelerates precipitation formation, increases cloud lifetime and lags precipitation. Since aerosols disperse and absorb the radiation they have a direct effect on the albedo, which depends on the aerosol type. The land aerosols increase the albedo mainly in the lower atmospheric layers. Higher up, the effect of land aerosols on the shortwave radiation coming down toward the surface is diminished in comparison with aerosols of the marine origin. The high concentrations of continental aerosols lead to changes in the precipitation rate, while sea aerosols mainly cause the displacement in time of the precipitation event.

Palamarchuk, Iuliia; Stepanenko, Sergiy; Ivanov, Sergiy; Ruban, Igor; Pavlova, Hanna

2014-05-01

351

Scanning Mobile Lidar for Aerosol Tracking and Biological Aerosol Identification  

NASA Astrophysics Data System (ADS)

Optical properties of non-biological aerosols containing aromatic hydrocarbons, such as industrial chemicals and engine exhausts, have already been thoroughly studied using remote sensing techniques. However, because of their complex composition and characteristics, the identification of biological aerosols, such as fungi, pollen and bacteria that are present in the environment remains a rather difficult task. The collection of information on both non-biological and biological aerosols is of great importance for understanding their interrelation, physical and chemical properties and their influence on human health and the environment. Biological and non-biological aerosols can be simultaneously detected, tracked and identified by a scanning mobile Mie-fluorescence lidar. The device developed at the University of Nova Gorica can perform azimuth and zenith angle scans with an angular resolution of 0.1°, as well as operate in both day and night-time conditions. Aerosols of biological origin are identified through the detection of the fluorescence of the amino acid tryptophan which is present in almost all substances of biological origin. In our system, the transmitter is a solid state Nd:YAG laser which is capable of simultaneous emission of light at a base wavelength of 1064 nm (IR) and its quadrupled wavelength of 266 nm (UV) at a maximum repetition rate of 10 Hz. Tryptophan contained in biological aerosols is excited by the 266 nm laser pulses and the returning fluorescence signals are detected in the spectral band centered at 295 nm. The receiver is a Newtonian telescope which uses a 300 mm parabolic mirror to direct received light into three detection channels - two elastic backscatter channels (IR and UV) and a fluorescence channel. First experiments show that the detection range of the lidar reaches 10 km in the IR channel and 3 km in the UV channel. Based on the preliminary simulations of the signal-to-noise ratio, the detection range for biological fluorescence signals at 295 nm is estimated to be 2 km. The measurements of the time-series indicate that the mobile lidar is capable of detecting and profiling clouds and aerosols in its detection range. Our future plans include establishing an automated, unattended environmental monitoring system that will allow full time continuous measurements in the desired solid angle around the lidar station.

He, Tingyao; Bergant, Klemen; Filip?i?, Andrej; Forte, Biagio; Gao, Fei; Stani?, Samo; Veberi?, Darko; Zavrtanik, Marko

2010-05-01

352

Aerosols of Mongolian arid area  

NASA Astrophysics Data System (ADS)

Sampling was performed in July-August 2005-2010 at Station Sain Shand (44°54'N, 110°07'E) in the Gobi desert (1000 m a.s.l.), West Mongolia. Aerosol samples were collected with a high volume sampler PM 10 (Andersen Instruments Inc., USA) onto Whatman-41 filters. The substance was extracted from the filters by de-ionized water. The solution was screened through an acetate-cellulose filter with 0.2 micron pore size. Ions of ammonium, sodium, potassium, magnesium, and calcium, as well as sulphate ions, nitrate ions, hydrocarbonate, chloride ions were determined in the filtrate by means of an atomic adsorption spectrometer Carl Zeiss Jena (Germany), a high performance liquid chromatographer «Milichrome A-02» (Russia), and an ionic chromatographer ICS-3000 (Dionex, USA). The PAH fraction was separated from aerosol samples using hexane extraction at room temperature under UV environment. The extract was concentrated to 0.1-0.2 ml and analysed by a mass-spectrometer "Agilent, GC 6890, MSD 5973 Network". Analysis of concentrations of aerosols components, their correlation ratios, and meteorological modeling show that the main factor affecting chemical composition of aerosols is a flow of contaminants transferred by air masses to the sampling area mainly from the south and south-east, as well as wind conditions of the area, dust storms in particular. Sulphate, nitrate, and ammonium are major ions in aerosol particles at Station Sain Shand. Dust-borne aerosol is known to be a sorbent for both mineral and organic admixtures. Polycyclic aromatic hydrocarbons (PAH) being among superecotoxicants play an important role among resistant organic substances. PAH concentrations were determined in the samples collected in 2010. All aerosol samples contained dominant PAHs with 5-6 benzene rings ( (benze(k)fluoranthen, benze(b)flouranthen, benze(a)pyren, benze(?)pyren, perylene, benze(g,h,i)perylene, and indene(1,2,3-c,d)pyrene). Their total quantity varied between 42 and 90%. Compounds with low molecular weight and 3 benzene rings in its composition (phenanthrene and anthracene) amounted to 9-38% of the total PAH. PAH percentage in aerosol samples is characteristic of the warm season. Elevated fraction of low molecular weight PAHs (29-38%) was found in aerosol samples collected on 12-14 August and 18-19 August. High molecular weight PAHs were found in aerosols sampled on 14 and 16 August. Benze(g,h,i)perylene, indene(1,2,3-c,d)pyrene, and di-benze(?,h)anthracene were found in aerosols on 10, 11, 14, 15, 17, 19, and 20 August, and their fraction of total PAH amounted to 14-30%. These compounds are indicative of automotive emissions. Benze(a)pyrene is the most hazardous cancerogene from the list of the prioritized PAHs. Cases of exceeding benze(a)pyrene maximum permissible concentrations (1 ng/m3) in the air at Station Sain Shand were not recorded.

Golobokova, L.; Marinayte, I.; Zhamsueva, G.

2012-04-01

353

A thermoluminescent method for aerosol characterization  

NASA Technical Reports Server (NTRS)

A thermoluminescent method has been used to study the interactions of aerosols with ozone. The preliminary results show that ozone reacts with many compounds found in aerosols, and that the thermoluminescence curves obtained from ozonated aerosols are characteristic of the aerosol. The results suggest several important applications of the thermoluminescent method: development of a detector for identification of effluent sources; a sensitive experimental tool for study of heterogeneous chemistry; evaluation of importance of aerosols in atmospheric chemistry; and study of formation of toxic, electronically excited species in airborne particles.

Long, E. R., Jr.; Rogowski, R. S.

1976-01-01

354

Review of models applicable to accident aerosols  

SciTech Connect

Estimations of potential airborne-particle releases are essential in safety assessments of nuclear-fuel facilities. This report is a review of aerosol behavior models that have potential applications for predicting aerosol characteristics in compartments containing accident-generated aerosol sources. Such characterization of the accident-generated aerosols is a necessary step toward estimating their eventual release in any accident scenario. Existing aerosol models can predict the size distribution, concentration, and composition of aerosols as they are acted on by ventilation, diffusion, gravity, coagulation, and other phenomena. Models developed in the fields of fluid mechanics, indoor air pollution, and nuclear-reactor accidents are reviewed with this nuclear fuel facility application in mind. The various capabilities of modeling aerosol behavior are tabulated and discussed, and recommendations are made for applying the models to problems of differing complexity.

Glissmeyer, J.A.

1983-07-01

355

Characterization of Aerosols Containing Microcystin  

PubMed Central

Toxic blooms of cyanobacteria are ubiquitous in both freshwater and brackish water sources throughout the world. One class of cyanobacterial toxins, called microcystins, is cyclic peptides. In addition to ingestion and dermal, inhalation is a likely route of human exposure. A significant increase in reporting of minor symptoms, particularly respiratory symptoms was associated with exposure to higher levels of cyanobacteria during recreational activities. Algae cells, bacteria, and waterborne toxins can be aerosolized by a bubble-bursting process with a wind-driven white-capped wave mechanism. The purposes of this study were to: evaluate sampling and analysis techniques for microcystin aerosol, produce aerosol droplets containing microcystin in the laboratory, and deploy the sampling instruments in field studies. A high-volume impactor and an IOM filter sampler were tried first in the laboratory to collect droplets containing microcystins. Samples were extracted and analyzed for microcystin using an ELISA method. The laboratory study showed that cyanotoxins in water could be transferred to air via a bubble-bursting process. The droplets containing microcystins showed a bimodal size distribution with the mass median aerodynamic diameter (MMAD) of 1.4 and 27.8 ?m. The sampling and analysis methods were successfully used in a pilot field study to measure microcystin aerosol in situ. PMID:18463733

Cheng, Yung Sung; Zhou, Yue; Irvin, C. Mitch; Kirkpatrick, Barbara; Backer, Lorraine C.

2007-01-01

356

PIXE Analysis of Indoor Aerosols  

NASA Astrophysics Data System (ADS)

We have performed a proton-induced X-ray emission (PIXE) analysis of aerosol samples collected in academic buildings at Union College to investigate the air quality in these buildings and the effectiveness of their air filtration systems. This is also the commissioning experiment for a new scattering chamber in the Union College Ion-Beam Analysis Laboratory. The aerosol samples were collected on Kapton foils using a nine-stage cascade impactor that separates particles according to their aerodynamic size. The foils were bombarded with beams of 2.2-MeV protons from the Union College 1.1-MV Pelletron Accelerator and the X-ray products were detected with an Amptek silicon drift detector. After subtracting the contribution from the Kapton foils, the X-ray energy spectra of the aerosol samples were analyzed using GUPIX software to determine the elemental concentrations of the samples. We will describe the collection of the aerosol samples, discuss the PIXE analysis, and present the results.

Johnson, Christopher; Turley, Colin; Moore, Robert; Battaglia, Maria; Labrake, Scott; Vineyard, Michael

2011-10-01

357

THE ATMOSPHERIC AEROSOL. A SURVEY  

Microsoft Academic Search

The classification of aerosol particles is possible according to varring ; viewpoints: (a) size, (b) origin and composition, (c) source, (d) significance ; and effect, and (e) investigation methods (measurement devices). The size ; classifications are: the small particles with radius under 0.1 m mu ; the medium ; particles up to 100 m mu ; the large particles up

Reeger

1960-01-01

358

7, 37193761, 2007 Aerosol indirect  

E-print Network

Abstract Introduction Conclusions References Tables Figures Back Close Full Screen / Esc Printer Abstract Introduction Conclusions References Tables Figures Back Close Full Screen / Esc Printer not led to a smaller uncertainty range of the indirect aerosol effect, because consider- 3720 #12;ACPD 7

Paris-Sud XI, Université de

359

Near UV Aerosol Group Report  

NASA Technical Reports Server (NTRS)

2012-13 Report of research on aerosol and cloud remote sensing using UV observations. The document was presented at the 2013 AEROCENTER Annual Meeting held at the GSFC Visitors Center, May 31, 2013. The Organizers of the meeting are posting the talks to the public Aerocentr website, after the meeting.

Torres, Omar

2013-01-01

360

Zero-gravity aerosol behavior  

NASA Technical Reports Server (NTRS)

The feasibility and scientific benefits of a zero gravity aerosol study in an orbiting laboratory were examined. A macroscopic model was devised to deal with the simultaneous effects of diffusion and coagulation of particles in the confined aerosol. An analytical solution was found by treating the particle coagulation and diffusion constants as ensemble parameters and employing a transformation of variables. The solution was used to carry out simulated zero gravity aerosol decay experiments in a compact cylindrical chamber. The results demonstrate that the limitations of physical space and time imposed by the orbital situation are not prohibitive in terms of observing the history of an aerosol confined under zero gravity conditions. While the absence of convective effects would be a definite benefit for the experiment, the mathematical complexity of the problem is not greatly reduced when the gravitational term drops out of the equation. Since the model does not deal directly with the evolution of the particle size distribution, it may be desirable to develop more detailed models before undertaking an orbital experiment.

Edwards, H. W.

1981-01-01

361

6, 55435583, 2006 Aerosol nucleation  

E-print Network

been at- tributed to neutral binary nucleation of water and sulfuric acid. However, classical global chemistry and transport mod-5 els. We find a weak aerosol production over the tropical oceans in the lower and middle troposphere, and a stronger production at higher latitudes, most notably downwind

Boyer, Edmond

362

MAESTRO Measurements of Atmospheric Aerosol  

NASA Astrophysics Data System (ADS)

MAESTRO (Measurements of Aerosol Extinction in the Stratosphere and Troposphere Retrieved by Occultation) is now in its 11th year on orbit as part of the Atmospheric Chemistry Experiment on the Canadian Space Agency's SCISAT satellite. MAESTRO data analysis has been dogged by a deficiency in accurate timing between the measurements made by the partner instrument, the ACE-FTS (Atmospheric Chemistry Experiment, Fourier Transform Spectrometer), that provides the atmospheric pressure-temperature profile and observation tangent altitudes used in the MAESTRO data analysis. Attempts have been made to use apparent air column density and oxygen A-band absorption as a mechanism to line up the tangent heights, but to no avail. A new product is now being produced, based on matching the modeled ozone slant columns from the ACE-FTS retrievals with the MAESTRO slant column measurements. The approach is very promising and indicates that a valuable product from the MAESTRO wavelength-dependent aerosol extinction likely result. The usefulness of the profile matching technique will be demonstrated and some aerosol absorption profiles will be presented in comparison with measurements made by the ACE Imager aerosol profile results. While the process optimizes the comparison between ACE-FTS ozone profile data and that from MAESTRO, it does not detract from the higher vertical resolution information provided by MAESTRO.

McElroy, Tom; Drummond, James; Zou, Jason

2014-05-01

363

Stratospheric Aerosol Geoengineering ALAN ROBOCK  

E-print Network

Stratospheric Aerosol Geoengineering ALAN ROBOCK ABSTRACT In response to global warming, one suggested geoengineering response involves creating a cloud of particles in the stratosphere to reflect some, the volcano analog also warns against geoengineering because of responses such as ozone depletion, regional

Robock, Alan

364

New Portable Ambient Aerosol Sampler  

Microsoft Academic Search

The NBS portable ambient aerosol sampler is designed to collect respirable (below 3-µm) and inhalable (below 15-µm) particle size fractions for gravimetric and chemical analyses. The sampler is light, quiet and unobtrusive. We selected the components of the sampler on the basis of size, weight, price, and availability as well as performance. The inlet was intended to maintain constant collection

DAVID S. BRIGHT; ROBERT A. FLETCHER

1983-01-01

365

Standard aerosols for particle velocimeters  

NASA Technical Reports Server (NTRS)

System consists of laser-scattering counter (LSC) and photographic system. Photographic system provides absolute method of measuring aerosol size-distribution independently of their light scattering properties. LSC comprises 1-mW He/Ne laser, input optics, collecting optics, photodetector, and signal-processing electronics.

Deepark, A.; Ozarski, R.; Thomson, J. A. L.

1976-01-01

366

7, 1268712714, 2007 Aerosols' influence  

E-print Network

and rain in warm cumulus cloud O. Altaratz 1 , I. Koren 1 , T. Reisin 2 , A. Kostinski 3 , G. Feingold 4 and precipitate less than clean clouds but produce larger rain5 drops. The evaporation process is more significant in the polluted cloud is due to a more efficient collection process. 1 Introduction10 The effect of aerosol

Boyer, Edmond

367

Crystallography of metallic aerosol precipitates  

Microsoft Academic Search

In a previous paper it was concluded from microscopical evidence that the radius of a basal raft nucleated on a freezing droplet of Zn or Cd expands to a fixed fraction of the droplet radius before thickening into a grain. Further studies on polycrystalline spheres from condensation aerosols, together with observations by other investigators working with much larger, sessile drops,

E. R. Buckle; K. C. Pointon; P. Tsakiropoulos

1980-01-01

368

AEROSOL FILTRATION BY SORBENT BEDS  

EPA Science Inventory

Fixed beds of sorbent media are used for the evaluation of polynuclear aromatic hydrocarbons (PAH) present in air. wo-stage sampling and separate extraction and analyses of PAH associated with aerosol particles and those present in the vapor state are usually performed. he abilit...

369

ACID AEROSOL MEASUREMENT INTERCOMPARISON WORKSHOP  

EPA Science Inventory

This report documents the discussions and results of the U.S. Environmental Protection Agency's (EPA's) Acid Aerosol Measurement Method intercomparison Workshop, held April 10-11, 1991 in Research Triangle Park, NC. he workshop was designed to achieve two objectives: (1) to repor...

370

The MODIS Aerosol Algorithm, Products and Validation  

NASA Technical Reports Server (NTRS)

The MODerate resolution Imaging Spectroradiometer (MODIS) aboard both NASA's Terra and Aqua satellites is making near global daily observations of the earth in a wide spectral range. These measurements are used to derive spectral aerosol optical thickness and aerosol size parameters over both land and ocean. The aerosol products available over land include aerosol optical thickness at three visible wavelengths, a measure of the fraction of aerosol optical thickness attributed to the fine mode and several derived parameters including reflected spectral solar flux at top of atmosphere. Over ocean, the aerosol optical thickness is provided in seven wavelengths from 0.47 microns to 2.13 microns. In addition, quantitative aerosol size information includes effective radius of the aerosol and quantitative fraction of optical thickness attributed to the fine mode. Spectral aerosol flux, mass concentration and number of cloud condensation nuclei round out the list of available aerosol products over the ocean. The spectral optical thickness and effective radius of the aerosol over the ocean are validated by comparison with two years of AERONET data gleaned from 133 AERONET stations. 8000 MODIS aerosol retrievals colocated with AERONET measurements confirm that one-standard deviation of MODIS optical thickness retrievals fall within the predicted uncertainty of delta tauapproximately equal to plus or minus 0.03 plus or minus 0.05 tau over ocean and delta tay equal to plus or minus 0.05 plus or minus 0.15 tau over land. 271 MODIS aerosol retrievals co-located with AERONET inversions at island and coastal sites suggest that one-standard deviation of MODIS effective radius retrievals falls within delta r_eff approximately equal to 0.11 microns. The accuracy of the MODIS retrievals suggests that the product can be used to help narrow the uncertainties associated with aerosol radiative forcing of global climate.

Remer, L. A.; Kaufman, Y. J.; Tanre, D.; Mattoo, S.; Chu, D. A.; Martins, J. V.; Li, R.-R.; Ichoku, C.; Levy, R. C.; Kleidman, R. G.

2003-01-01

371

Labeling fibroblasts with biotin-BSA-GdDTPA-FAM for tracking of tumor-associated stroma by fluorescence and MR imaging  

Microsoft Academic Search

Fibroblasts at the tumor- host interface can differentiate into myofibroblasts and pericytes, and contribute to the guidance and stabilization of endothelial sprouts. After intravenous ad- ministration of biotin-BSA-GdDTPA-FAM in mice with subcuta- neous MLS human ovarian carcinoma tumors, the distribution of the macromolecular MRI\\/optical contrast material was con- fined to blood vessels in normal tissues, while it co-registered with SMA-positive

D. Granot; L. A. Kunz-Schughart; M. Neeman

2005-01-01

372

Nucleation of atmospheric aerosol particles  

NASA Astrophysics Data System (ADS)

A significant fraction of the total number of particles present in the atmosphere is formed originally by nucleation from the gas phase. Binary nucleation of sulphuric acid and water, ternary nucleation of sulphuric acid, water and ammonia and ion-induced nucleation are thought to be the most important aerosol nucleation processes in the atmosphere. Within the last two decades, instrumentation to observe and characterize nucleation has improved greatly and numerous observations of nucleation have been made including quantification of the nucleation rate, characterization of the growth process and first chemical characterizations of the freshly formed particles. Nucleation has been observed at many different places in the atmosphere: in the boundary layer, in the free troposphere, in remote locations, in coastal areas, in boreal forests as well as urban areas and pollution plumes. In most cases gaseous sulphuric acid is assumed to be the key precursor gas. After nucleation, other supersaturated substances, especially low vapour pressure organics often take part in the subsequent aerosol growth. Iodine oxides seem to be responsible for nucleation observed in some coastal areas. Recent advances in modelling allow for a kinetic treatment of the nucleation process based on measured thermochemical data for the cluster formation. Considerable improvement over the classical nucleation treatment is expected from this approach. A detailed understanding of atmospheric aerosol nucleation processes is needed as the freshly formed particles directly influence the number concentration and size distribution of the atmospheric aerosol. The formation of clouds and precipitation is affected and influences on climate are anticipated. Anthropogenic emissions influence atmospheric aerosol nucleation processes considerably. Despite the comprehensive research efforts, substantial inconsistencies remain and conflicting results of laboratory studies, model studies as well as atmospheric observations persist. Several key questions about the predictability of atmospheric nucleation in general, about the substances, that take part in nucleation and subsequent growth and about the size and composition of the critical cluster, have not been resolved so far. To cite this article: J. Curtius, C. R. Physique 7 (2006).

Curtius, Joachim

2006-11-01

373

Using a new aerosol relative optical thickness concept to identify aerosol particle species  

NASA Astrophysics Data System (ADS)

We developed an aerosol relative optical thickness concept and then established an effective aerosol particle recognition model by analyzing variations in aerosol optical thicknesses in Beijing between 2001 and 2006. The accuracy of the model was verified using inverse calculations. The aerosol particle types and size distributions were assessed for several typical atmospheric phenomena, and the characteristic relative optical thicknesses for several typical aerosols were identified. Finally, we analyzed annual variations in the aerosol particle species in several eastern Asian cities using the model.

Yuan, Yuan; Shuai, Yong; Li, Xiao-Wei; Liu, Bin; Tan, He-Ping

2014-12-01

374

Early diagnosis and regional evaluation of radiation mucositis by newly developed TC-99M DTPA labelled agent  

SciTech Connect

We have developed a new drug for treating acute radiation mucositis which consists of a steroid with potent localized anti-inflammatory effect, and sodium alginate with strong adherence to mucosal surface, and since then we have treated many patients with success. In the present study, we labelled this agent with Tc-99m DTPA, and administered to 10 healthy volunteers and 35 patients with acute radiation mucositis, and determined the values of mean transit time (MTT) and T1/2 from the dynamic phase and the time taken for the mixture to reach to cardia according to Talliefer`s method. Abnormal radionuclide (RN) accumulation in the esophagus was evaluated at 10 minutes after the administration and, the ratio of abnormal RN accumulation count were calculated. In the healthy volunteers, the MTT was 2.67 seconds, T1/2 14.0 seconds, and the time for the drug to reach the stomach 5.25 seconds. Even in the patients with acute radiation mucositis, these values were not significantly different from the healthy controls. However, the images taken at 10 minutes after the administration revealed abnormal RN accumulation corresponding to the irradiated region in all patients. The ratio of this abnormal RN accumulation to the total RN count in the esophagus was 52.48%, the pre-administration RN ratio was 6.45%. None of the healthy volunteers produced abnormal RN accumulation. The ratio of total RN count in the esophagus to pre-administration RN count was only 1.87% in the healthy volunteers, whereas 11.39% in the radiation mucositis group. When Tc-99m DTPA-labelled water was used similarly, the region of radiation esophagitis was not identified on scintigraphy. It was thus suggested that diagnosis of radiation mucositis could be made only with this new agent of high viscosity and very strong mucous adhesive property. Owing to its repeatability and simplicity, this new agent seemed to be useful to make the early diagnosis and regional evaluation of radiation mucositis possible.

Tamamura, H.; Ohguchi, M.; Higashi, K. [Kanazawa Medical Univ., Ishikawa (Japan)] [and others

1994-05-01

375

Aerosol classification by airborne high spectral resolution lidar observations  

NASA Astrophysics Data System (ADS)

During four aircraft field experiments with the DLR research aircraft Falcon in 1998 (LACE), 2006 (SAMUM-1) and 2008 (SAMUM-2 and EUCAARI), airborne High Spectral Resolution Lidar (HSRL) and in situ measurements of aerosol microphysical and optical properties were performed. Altogether, the properties of six different aerosol types and aerosol mixtures - Saharan mineral dust, Saharan dust mixtures, Canadian biomass burning aerosol, African biomass burning aerosol, anthropogenic pollution aerosol, and marine aerosol have been studied. On the basis of this extensive HSRL data set, we present an aerosol classification scheme which is also capable to identify mixtures of different aerosol types. We calculated mixing lines that allowed us to determine the contributing aerosol types. The aerosol classification scheme was validated with in-situ measurements and backward trajectory analyses. Our results demonstrate that the developed aerosol mask is capable to identify complex stratifications with different aerosol types throughout the atmosphere.

Groß, S.; Esselborn, M.; Weinzierl, B.; Wirth, M.; Fix, A.; Petzold, A.

2012-10-01

376

Volume Change and Liver Parenchymal Signal Intensity in Gd-EOB-DTPA-Enhanced Magnetic Resonance Imaging after Portal Vein Embolization prior to Hepatectomy  

PubMed Central

Purpose. To investigate the liver volume change and the potential of early evaluation by contrast-enhanced magnetic resonance imaging (MRI) using gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) after portal vein embolization (PVE). Materials and Methods. Retrospective evaluations of computed tomography (CT) volumetry of total liver and nonembolized areas were performed before and 3 weeks after PVE in 37 cases. The percentage of future liver remnant (%FLR) and the change ratio of %FLR (%FLR ratio) were calculated. Prospective evaluation of signal intensities (SIs) was performed to estimate the role of Gd-EOB-DTPA-enhanced MRI as a predictor of hypertrophy in 16 cases. The SI contrast between embolized and nonembolized areas was calculated 1 week after PVE. The change in SI contrast before and after PVE (SI ratio) was also calculated in 11 cases. Results. %FLR ratio significantly increased, and SI ratio significantly decreased (both P < 0.01). There were significant negative correlations between %FLR and SI contrast and between %FLR and SI ratio (both P < 0.01). Conclusion. Hypertrophy in the nonembolized area after PVE was indicated by CT volumetry, and measurement of SI contrast and SI ratio in Gd-EOB-DTPA-enhanced MRI early after PVE may be useful to predict the potential for hepatic hypertrophy.

Mine, Takahiko; Amano, Yasuo; Kawano, Youichi; Uchida, Eiji; Kumita, Shin-ichiro

2014-01-01

377

DO AEROSOLS CHANGE CLOUD COVER AND AFFECT CLIMATE?  

E-print Network

;AEROSOL INFLUENCES ON CLIMATE AND CLIMATE CHANGE #12;DMS #12;AEROSOL IN MEXICO CITY BASIN #12;AEROSOL IN MEXICO CITY BASIN Light scattering by aerosols decreases absorption of solar radiation. #12;AEROSOLS AS SEEN FROM SPACE Fire plumes from southern Mexico transported north into Gulf of Mexico. #12;CLOUD

Schwartz, Stephen E.

378

Toxicity of atmospheric aerosols on marine phytoplankton  

USGS Publications Warehouse

Atmospheric aerosol deposition is an important source of nutrients and trace metals to the open ocean that can enhance ocean productivity and carbon sequestration and thus influence atmospheric carbon dioxide concentrations and climate. Using aerosol samples from different back trajectories in incubation experiments with natural communities, we demonstrate that the response of phytoplankton growth to aerosol additions depends on specific components in aerosols and differs across phytoplankton species. Aerosol additions enhanced growth by releasing nitrogen and phosphorus, but not all aerosols stimulated growth. Toxic effects were observed with some aerosols, where the toxicity affected picoeukaryotes and Synechococcus but not Prochlorococcus.We suggest that the toxicity could be due to high copper concentrations in these aerosols and support this by laboratory copper toxicity tests preformed with Synechococcus cultures. However, it is possible that other elements present in the aerosols or unknown synergistic effects between these elements could have also contributed to the toxic effect. Anthropogenic emissions are increasing atmospheric copper deposition sharply, and based on coupled atmosphere-ocean calculations, we show that this deposition can potentially alter patterns of marine primary production and community structure in high aerosol, low chlorophyll areas, particularly in the Bay of Bengal and downwind of South and East Asia.

Paytan, A.; Mackey, K.R.M.; Chen, Y.; Lima, I.D.; Doney, S.C.; Mahowald, N.; Labiosa, R.; Post, A.F.

2009-01-01

379

Do atmospheric aerosols form glasses?  

NASA Astrophysics Data System (ADS)

A new process is presented by which water-soluble organics might influence ice nucleation, ice growth, chemical reactions and water uptake of aerosols in the upper troposphere: the formation of glassy aerosol particles. Glasses are disordered amorphous (non-crystalline) solids that form when a liquid is cooled without crystallization until the viscosity increases exponentially and molecular diffusion practically ceases. The glass transition temperatures, Tg, homogeneous ice nucleation temperatures, Thom, and ice melting temperatures, Tm, of various aqueous inorganic, organic and multi-component solutions are investigated with a differential scanning calorimeter. The investigated solutes are: various polyols, glucose, raffinose, levoglucosan, an aromatic compound, sulfuric acid, ammonium bisulphate and mixtures of dicarboxylic acids (M5), of dicarboxylic acids and ammonium sulphate (M5AS), of two polyols, of glucose and ammonium nitrate, and of raffinose and M5AS. The results indicate that aqueous solutions of the investigated inorganic solutes show Tg-values that are too low to be of atmospheric importance. In contrast, aqueous organic and multi-component solutions readily form glasses at low but atmospherically relevant temperatures (?230 K). To apply the laboratory data to the atmospheric situation, the measured phase transition temperatures were transformed from a concentration to a water activity scale by extrapolating water activities determined between 252 K and 313 K to lower temperatures. The obtained state diagrams reveal that the higher the molar mass of the aqueous organic or multi-component solutes, the higher Tg of their respective solutions at a given water activity. To a lesser extent, Tg also depends on the hydrophilicity of the organic solutes. Therefore, aerosol particles containing larger and more hydrophobic organic molecules (?150 g mol-1) are more likely to form glasses at intermediate to high relative humidities in the upper troposphere. Our results suggest that the water uptake of aerosols, heterogeneous chemical reactions in aerosol particles, as well as ice nucleation and ice crystal growth can be significantly impeded or even completely inhibited in organic-enriched aerosols at upper tropospheric temperatures with implications for cirrus cloud formation and upper tropospheric relative humidity.

Zobrist, B.; Marcolli, C.; Pedernera, D. A.; Koop, T.

2008-05-01

380

Do atmospheric aerosols form glasses?  

NASA Astrophysics Data System (ADS)

A new process is presented by which water soluble organics might influence ice nucleation, ice growth, chemical reactions and water uptake of aerosols in the upper troposphere: the formation of glassy aerosol particles. Glasses are disordered amorphous (non-crystalline) solids that form when a liquid is cooled without crystallization until the viscosity increases exponentially and molecular diffusion practically ceases. The glass transition temperatures, Tg, homogeneous ice nucleation temperatures, Thom, and ice melting temperatures, Tm, of various aqueous inorganic, organic and multi-component solutions are investigated with a differential scanning calorimeter. The investigated solutes are: various polyols, glucose, raffinose, levoglucosan, an aromatic compound, sulfuric acid, ammonium bisulfate and mixtures of dicarboxylic acids (M5), of dicarboxylic acids and ammonium sulfate (M5AS), of two polyols, of glucose and ammonium nitrate, and of raffinose and M5AS. The results indicate that aqueous solutions of the investigated inorganic solutes show Tg values that are too low to be of atmospheric importance. In contrast, aqueous organic and multi-component solutions readily form glasses at low but atmospherically relevant temperatures (?230 K). To apply the laboratory data to the atmospheric situation, the measured phase transition temperatures were transformed from a concentration to a water activity scale by extrapolating water activities determined between 252 K and 313 K to lower temperatures. The obtained state diagrams reveal that the higher the molar mass of the aqueous organic or multi-component solutes, the higher Tg of their respective solutions at a given water activity. To a lesser extent, Tg also depends on the hydrophilicity of the organic solutes. Therefore, aerosol particles containing larger (?150 g mol-1) and more hydrophobic organic molecules are more likely to form glasses at intermediate to high relative humidities in the upper troposphere. Our results suggest that the water uptake of aerosols, heterogeneous chemical reactions in aerosol particles, as well as ice nucleation and ice crystal growth can be significantly impeded or even completely inhibited in organic-enriched aerosols at upper tropospheric temperatures with implications for cirrus cloud formation and upper tropospheric relative humidity.

Zobrist, B.; Marcolli, C.; Pedernera, D. A.; Koop, T.

2008-09-01

381

Quantifying the response of the ORAC aerosol optical depth retrieval for MSG SEVIRI to aerosol model assumptions  

E-print Network

Quantifying the response of the ORAC aerosol optical depth retrieval for MSG SEVIRI to aerosolRed Imager (MSG SEVIRI) to changes in the aerosol properties used in the dust aerosol model, using data from retrieval for MSG SEVIRI to aerosol model assumptions, J. Geophys. Res., 116, D05208, doi:10.1029/2010JD

Oxford, University of

382

MR Angiography of Collateral Arteries in a Hind Limb Ischemia Model: Comparison between Blood Pool Agent Gadomer and Small Contrast Agent Gd-DTPA  

PubMed Central

The objective of this study was to compare the blood pool agent Gadomer with a small contrast agent for the visualization of ultra-small, collateral arteries (diameter<1 mm) with high resolution steady-state MR angiography (SS-MRA) in a rabbit hind limb ischemia model. Ten rabbits underwent unilateral femoral artery ligation. On days 14 and 21, high resolution SS-MRA (voxel size 0.49×0.49×0.50 mm3) was performed on a 3 Tesla clinical system after administration of either Gadomer (dose: 0.10 mmol/kg) or a small contrast agent (gadopentetate dimeglumine (Gd-DTPA), dose: 0.20 mmol/kg). All animals received both contrast agents on separate days. Selective intra-arterial x-ray angiograms (XRAs) were obtained in the ligated limb as a reference. The number of collaterals was counted by two independent observers. Image quality was evaluated with the contrast-to-noise ratio (CNR) in the femoral artery and collateral arteries. CNR for Gadomer was higher in both the femoral artery (Gadomer: 73±5 (mean ± SE); Gd-DTPA: 40±3; p<0.01) and collateral arteries (Gadomer: 18±4; Gd-DTPA: 9±1; p?=?0.04). Neither day of acquisition nor contrast agent used influenced the number of identified collateral arteries (p?=?0.30 and p?=?0.14, respectively). An average of 4.5±1.0 (day 14, mean ± SD) and 5.3±1.2 (day 21) collaterals was found, which was comparable to XRA (5.6±1.7, averaged over days 14 and 21; p>0.10). Inter-observer variation was 24% and 18% for Gadomer and Gd-DTPA, respectively. In conclusion, blood pool agent Gadomer improved vessel conspicuity compared to Gd-DTPA. Steady-state MRA can be considered as an excellent non-invasive alternative to intra-arterial XRA for the visualization of ultra-small collateral arteries. PMID:21298092

Jaspers, Karolien; Versluis, Bas; Leiner, Tim; Dijkstra, Petra; Oostendorp, Marlies; van Golde, Jolanda M.; Post, Mark J.; Backes, Walter H.

2011-01-01

383

Examination of the Effects of Sea Salt Aerosols on Southeast Texas Ozone and Secondary Organic Aerosol  

E-print Network

Despite decades of study, we still do not fully understand aerosols and their interactions among gases or other aerosols in the atmosphere. Among their impacts, they influence radiative transfer in the atmosphere and contribute to cloud formation...

Benoit, Mark David

2013-02-06

384

CCN activity of aliphatic amine secondary aerosol  

NASA Astrophysics Data System (ADS)

Aliphatic amines can form secondary aerosol via oxidation with atmospheric radicals (e.g. hydroxyl radical and nitrate radical). The particle composition can contain both secondary organic aerosol (SOA) and inorganic salts. The fraction of organic to inorganic materials in the particulate phase influences aerosol hygroscopicity and cloud condensation nuclei (CCN) activity. SOA formed from trimethylamine (TMA) and butylamine (BA) reactions with hydroxyl radical (OH) is composed of organic material of low hygroscopicity (single hygroscopicity parameter, ? ? 0.25). Secondary aerosol formed from the tertiary aliphatic amine (TMA) with N2O5 (source of nitrate radical, NO3), contains less volatile compounds than the primary aliphatic amine (BA) aerosol. TMA + N2O5 form semi-volatile organics in low RH conditions that have ? ~ 0.20, indicative of slightly soluble organic material. As RH increases, several inorganic amine salts are formed as a result of acid-base reactions. The CCN activity of the humid TMA-N2O5 aerosol obeys Zdanovskii, Stokes, and Robinson (ZSR) ideal mixing rules. Higher CCN activity (? > 0.3) was also observed for humid BA+N2O5 aerosols compared with dry aerosol (? ~ 0.2), as a result of the formation of inorganic salts such as NH4NO3 and butylamine nitrate (C4H11N · HNO3). Compared with TMA, BA+N2O5 reactions produce more volatile aerosols. The BA+N2O5 aerosol products under humid experiments were found to be very sensitive to the temperature within the stream-wise continuous flow thermal gradient CCN counter. The CCN counter, when set above a 21 °C temperature difference, evaporates BA+N2O5 aerosol formed at RH ? 30%; ? ranges from 0.4 to 0.7 and is dependent on the instrument supersaturation (ss) settings. The aerosol behaves non-ideally, hence simple ZSR rules cannot be applied to the CCN results from the primary aliphatic amine system. Overall, aliphatic amine aerosol systems ? ranges from 0.2 < ? < 0.7. This work indicates that aerosols formed via nighttime reactions with amines are likely to produce hygroscopic and volatile aerosol whereas photochemical reactions with OH produce secondary organic aerosol of lower CCN activity. Thermal gradient CCN counters measurement will impact the observed CCN activity of volatile aerosol formed via a nitric acid pathway. The contributions of semi-volatile secondary organic and inorganic material from aliphatic amines must be considered for accurate hygroscopicity and CCN predictions from aliphatic amine systems.

Tang, X.; Price, D.; Praske, E.; Vu, D.; Purvis-Roberts, K.; Silva, P. J.; Cocker, D. R., III; Asa-Awuku, A.

2014-01-01

385

Aerosol Forcing: Rapporteur's Report and Summary  

NASA Astrophysics Data System (ADS)

This paper summarizes the discussions held during the session dedicated to Aerosol forcing at the Workshop Observing and Modelling Earth's Energy Flows. The session Aerosol forcing was convened by P. Ingmann and J. Heintzenberg and included 10 presentations given by R. Kahn, D. Winker, U. Baltensperger, J. Haywood, S. Schwartz, J. Heintzenberg, H. Le Treut, U. Lohmann, R. Wood, and E. Philipona. The presentations given ranged from overviews of current observational capabilities to analyses of aerosol-cloud interactions in observations and models of varying complexity. This paper is organized around a few key points, summarizing the major points of agreement, disagreement, and discussion that the presentations gave rise to. The focus is largely on the uncertainties that remain with regard to aerosol forcing, particularly related to aerosol-cloud interactions and indirect aerosol effects on climate.

Bender, Frida A.-M.

2012-07-01

386

Studies of the aerosol indirect effect from sulfate and black carbon aerosols  

Microsoft Academic Search

The indirect effect of anthropogenic aerosols is investigated using the global climate model National Center for Atmospheric Research Community Climate Model Version 3 (NCAR CCM3). Two types of anthropogenic aerosols are considered, i.e., sulfate and black carbon aerosols. The concentrations and horizontal distributions of these aerosols were obtained from simulations with a life-cycle model incorporated into the global climate model.

Jón Egill Kristjánsson

2002-01-01

387

AEROSOL INDUSTRY SUCCESS IN REDUCING CFC PROPELLANT USAGE  

EPA Science Inventory

Part I of this report discusses the U.S. aerosol industry's experience in converting from chlorofluorocarbon (CFC) propellants to alternative aerosol formulations. Detailed examples of non-CFC formulations are provided for 28 categories of aerosol products. ydrocarbon propellants...

388

Aerosol classification by airborne high spectral resolution lidar observations  

NASA Astrophysics Data System (ADS)

During four aircraft field experiments with the DLR research aircraft Falcon in 1998 (LACE), 2006 (SAMUM-1) and 2008 (SAMUM-2 and EUCAARI), airborne High Spectral Resolution Lidar (HSRL) and in situ measurements of aerosol microphysical and optical properties were performed. Altogether, the properties of six different aerosol types and aerosol mixtures - Saharan mineral dust, Saharan dust mixtures, Canadian biomass burning aerosol, African biomass burning mixture, anthropogenic pollution aerosol, and marine aerosol have been studied. On the basis of this extensive HSRL data set, we present an aerosol classification scheme which is also capable to identify mixtures of different aerosol types. We calculated mixing lines that allowed us to determine the contributing aerosol types. The aerosol classification scheme was supported by backward trajectory analysis and validated with in-situ measurements. Our results demonstrate that the developed aerosol mask is capable to identify complex stratifications with different aerosol types throughout the atmosphere.

Groß, S.; Esselborn, M.; Weinzierl, B.; Wirth, M.; Fix, A.; Petzold, A.

2013-03-01

389

Non-intrusive characterization of heat transfer fluid aerosol formation  

E-print Network

involves non-intrusive measurement of such aerosol sprays using a Malvern Instrument Diffraction Particle Analyzer. The aerosol is generated by plain orifice atomization to simulate the formation and dispersion of heat transfer fluid aerosols through leaks...

Krishna, Kiran

2012-06-07

390

Biogeochemical Recycling on Aerosol Particles  

NASA Astrophysics Data System (ADS)

Trace elements are recycled on sea-salt particles that are produced and later re-deposited in the surface ocean. This recycling process involves aluminum, iron, and other elements commonly associated with mineral dust. Non-crustal Al can amount to as much as ~ 30% of the total aerosol Al at Bermuda, but this occurs only during a few months of the year when the dust concentrations and deposition rates are low. Simple model calculations suggest that ~15 to 20% of the total Al dry deposition during December and January can be attributed to recycled sea salt, but when dust concentrations are higher, recycling accounts for only ~ 1% of the Al dry deposition. Non-crustal/non-sea salt (NC/NSS) sources account for > 70% of the aerosol Sb, Se, V, and Zn, but differences in the dry deposition velocities for particles of different sizes are such that the amount of Sb and Se recycled on sea spray approaches or exceeds their new inputs to the open ocean from dust and the NC/NSS sources. More recently, recycling on aerosol particles has been found to occur in other environments, including the deserts in the southwestern USA. In this case, the recycling of radionuclides released during nuclear weapons tests many years ago occurs via the resuspension of contaminated soil particles. Studies conducted near Carlsbad, NM have shown that the temporal variability in ^{239,240}Pu and ^{241}Am activities tracks that of Al, a mineral dust indictor, in aerosol samples. Analyses of soil samples from various sites have shown that plutonium is released from the particles by chemical procedures developed for removing iron oxides from mineral particles; this implies that the dust/plutonium relationship is mediated by iron oxides.

Arimoto, R.; Stewart, B.; Khaing, H.; Tatro, D. P.

2006-12-01

391

Aerosols Over Yellow Sea Sediments  

NASA Technical Reports Server (NTRS)

This SeaWiFS image shows complex phytoplankton distribution patterns in the Bohai and Yellow seas. A wide band of brownish water along the coast north and south of the mouth of the Yangtze River indicates a heavy load of suspended sediment. The air over eastern central China and the Yellow Sea is thick with aerosols. Farther north over the Manchurian Plain and Greater Khingan Range, the air is much clearer.

2002-01-01

392

Stratospheric aerosol optical depths, 1850-1990  

NASA Technical Reports Server (NTRS)

A global stratospheric aerosol database employed for climate simulations is described. For the period 1883-1990, aerosol optical depths are estimated from optical extinction data, whose quality increases with time over that period. For the period 1850-1882, aerosol optical depths are more crudely estimated from volcanological evidence for the volume of ejecta from major known volcanoes. The data set is available over Internet.

Sato, Makiko; Hansen, James E.; Mccormick, M. Patrick; Pollack, James B.

1993-01-01

393

Stratospheric aerosol optical depths, 1850-1990  

NASA Astrophysics Data System (ADS)

A global stratospheric aerosol database employed for climate simulations is described. For the period 1883-1990, aerosol optical depths are estimated from optical extinction data, whose quality increases with time over that period. For the period 1850-1882, aerosol optical depths are more crudely estimated from volcanological evidence for the volume of ejecta from major known volcanoes. The data set is available over Internet.

Sato, Makiko; Hansen, James E.; McCormick, M. Patrick; Pollack, James B.

1993-12-01

394

Determination of aerosol content in the atmosphere  

NASA Technical Reports Server (NTRS)

This investigation is designed to demonstrate the feasibility of determining the aerosol content in the atmosphere from contrast measurements of ground features, and from radiance measurements. Theoretical relationships between aerosol content and contrast reduction and radiance have been derived for ideal model atmospheres. The preliminary data analysis of the MSS transparencies has shown promising results for the contrast-aerosol content relationship in the Salton Sea/desert region.

Griggs, M.

1973-01-01

395

Nitric acid aerosols at the tropical tropopause  

NASA Technical Reports Server (NTRS)

It is thermodynamically possible for nitric acid aerosol particles to form in the lower stratosphere and upper troposphere in tropical latitudes. This aerosol would have essentially the same composition as the polar stratospheric clouds observed in the winter polar stratosphere. Calculations have been carried out, indicating that nitric acid aerosols may form at the same altitudes as layers observed in the tropics by the SAGE satellite system.

Hamill, Patrick; Fiocco, G.

1988-01-01

396

Stratospheric heating by potential geoengineering aerosols  

NASA Astrophysics Data System (ADS)

A fixed dynamical heating model is used to investigate the pattern of zonal-mean stratospheric temperature change resulting from geoengineering with aerosols composed of sulfate, titania, limestone and soot. Aerosol always heats the tropical lower stratosphere, but at the poles the response can be either heating, cooling, or neutral. The sign of the change in stratospheric Pole-Equator temperature difference depends on aerosol type, size and season. This has implications for modeling geoengineering impacts and the response of the stratospheric circulation.

Ferraro, A. J.; Highwood, E. J.; Charlton-Perez, A. J.

2011-12-01

397

Aerosol climate time series from ESA Aerosol_cci (Invited)  

NASA Astrophysics Data System (ADS)

Within the ESA Climate Change Initiative (CCI) the Aerosol_cci project (mid 2010 - mid 2013, phase 2 proposed 2014-2016) has conducted intensive work to improve algorithms for the retrieval of aerosol information from European sensors AATSR (3 algorithms), PARASOL, MERIS (3 algorithms), synergetic AATSR/SCIAMACHY, OMI and GOMOS. Whereas OMI and GOMOS were used to derive absorbing aerosol index and stratospheric extinction profiles, respectively, Aerosol Optical Depth (AOD) and Angstrom coefficient were retrieved from the other sensors. Global datasets for 2008 were produced and validated versus independent ground-based data and other satellite data sets (MODIS, MISR). An additional 17-year dataset is currently generated using ATSR-2/AATSR data. During the three years of the project, intensive collaborative efforts were made to improve the retrieval algorithms focusing on the most critical modules. The team agreed on the use of a common definition for the aerosol optical properties. Cloud masking was evaluated, but a rigorous analysis with a pre-scribed cloud mask did not lead to improvement for all algorithms. Better results were obtained using a post-processing step in which sudden transitions, indicative of possible occurrence of cloud contamination, were removed. Surface parameterization, which is most critical for the nadir only algorithms (MERIS and synergetic AATSR / SCIAMACHY) was studied to a limited extent. The retrieval results for AOD, Ångström exponent (AE) and uncertainties were evaluated by comparison with data from AERONET (and a limited amount of MAN) sun photometer and with satellite data available from MODIS and MISR. Both level2 and level3 (gridded daily) datasets were validated. Several validation metrics were used (standard statistical quantities such as bias, rmse, Pearson correlation, linear regression, as well as scoring approaches to quantitatively evaluate the spatial and temporal correlations against AERONET), and in some cases developed further, to evaluate the datasets and their regional and seasonal merits. The validation showed that most datasets have improved significantly and in particular PARASOL (ocean only) provides excellent results. The metrics for AATSR (land and ocean) datasets are similar to those of MODIS and MISR, with AATSR better in some land regions and less good in some others (ocean). However, AATSR coverage is smaller than that of MODIS due to swath width. The MERIS dataset provides better coverage than AATSR but has lower quality (especially over land) than the other datasets. Also the synergetic AATSR/SCIAMACHY dataset has lower quality. The evaluation of the pixel uncertainties shows first good results but also reveals that more work needs to be done to provide comprehensive information for data assimilation. Users (MACC/ECMWF, AEROCOM) confirmed the relevance of this additional information and encouraged Aerosol_cci to release the current uncertainties. The paper will summarize and discuss the results of three year work in Aerosol_cci, extract the lessons learned and conclude with an outlook to the work proposed for the next three years. In this second phase a cyclic effort of algorithm evolution, dataset generation, validation and assessment will be applied to produce and further improve complete time series from all sensors under investigation, new sensors will be added (e.g. IASI), and preparation for the Sentinel missions will be made.

Holzer-Popp, T.

2013-12-01

398

The continuous field measurements of soluble aerosol compositions at the Taipei Aerosol Supersite, Taiwan  

Microsoft Academic Search

The characteristics of ambient aerosols, affected by solar radiation, relative humidity, wind speed, wind direction, and gas–aerosol interaction, changed rapidly at different spatial and temporal scales. In Taipei Basin, dense traffic emissions and sufficient solar radiation for typical summer days favored the formation of secondary aerosols. In winter, the air quality in Taipei Basin was usually affected by the Asian

Shih-Yu Chang; Chung-Te Lee; Charles C.-K. Chou; Shaw-Chen Liu; Tian-Xue Wen

2007-01-01

399

Determining the aerosol type over case II waters through aerosol component concentration iteration algorithm  

Microsoft Academic Search

Uncertainties from aerosol type greatly affects the accuracy in water color remote sensing for casewaters. An algorithm, depicted as ACCIA, dedicated to define the aerosol types over casewaters is developed by iterating the four critical component concentrations in an aerosol type: dust like, water soluble, oceanic and soot. A software function module is also developed in Visual Studio 2010 by

Bin Peng; Qingjiu Tian; Ying Bao; Ling Wang

2011-01-01

400

Aerosol light scattering properties at Cape Grim, Tasmania, during the First Aerosol Characterization Experiment (ACE 1)  

Microsoft Academic Search

Large uncertainties remain in understanding the effects of ambient aerosols on climate. As part of the First Aerosol Characterization Experiment (ACE 1, November 15 to December 15, 1995), the total light scattering and backscattering coefficients by particles (cysp and CYbsp) were measured at Cape Grim, Tasmania. Such measurements were made to characterize aerosol radiative forcing relevant to climate change at

Christian M. Carrico; Mark J. Rood; John A. Ogren

1998-01-01

401

Implementation of bin scheme into sulfate aerosol module in aerosol climate model  

NASA Astrophysics Data System (ADS)

Atmospheric aerosols are known for inducing climate change, but uncertainty still remains about the assessment of aerosol climate impact. More accurate evaluation of their effects on climate system requires to reduce uncertainty of estimation of the entire climate change. Thus we are implementing a bin scheme into an aerosol transport-climate model, SPRINTARS, which is coupled with an AORI/NIES/JAMSTEC climate model, MIROC [Takemura et al., 2000, 2002, 2005, 2009] to refine the representation of interactions between aerosol particles and cloud droplets as well as the aerosol-radiation interaction. The scheme can represent the aerosol size distribution explicitly by segregating to a finite number of bins incorporating aerosol nucleation, condensation, and coagulation processes in detail. Nucleation of sulfuric acid is parameterized using Gong et al. [2003]. Based on a single column model [Suzuki et al., 2006, 2010], the condensation of sulfuric acid on pre-existing aerosol particles and the coagulation of sulfate aerosol particles are parameterized by the methods proposed by Bott [1989] and Bott [1997], respectively. The radii of sulfate aerosols range from 0.01?m to 1.0?m and are split into 20 bins. Implementation of the bin scheme into the aerosol model resulted in characteristic aerosol size distribution and indicated possibilities of representation of microphysical and optical properties in more detail. We will report the results of comparison between the original and the improved SPRINTARS. This work is supported by the Funding Program for Next Generation World-Leading Researchers (GR079).

Yamaguchi, Y.; Takemura, T.; Suzuki, K.; Goto, D.

2012-12-01

402

Contribution of different aerosol species to the global aerosol extinction optical thickness: Estimates from model results  

Microsoft Academic Search

We combine global distributions of aerosol loading resulting from transport models for soil dust, sulfate, sea salt, and carbonaceous aerosol. From the aerosol distributions we estimate optical thickness and compare them with Sun photometer measurements and satellite retrievals, thereby revealing problems with both model results and comparisons with such measurements. Globally, sulfate, dust, and carbonaceous particles appear to contribute equally

Ina Tegen; Peter Hollrig; Mian Chin; Inez Fung; Daniel Jacob; Joyce Penner

1997-01-01

403

Aerosol Science and Technology, 40:10471051, 2006 Copyright c American Association for Aerosol Research  

E-print Network

Aerosol Science and Technology, 40:1047­1051, 2006 Copyright c American Association for Aerosol of recently developed UV LEDs, in conjunction with novel optical design and custom electronics, to shrink the size of aerosol fluorescence detection systems. INTRODUCTION Ultraviolet laser-induced fluorescence

Davitt, Kristina

404

An emerging ground-based aerosol climatology: Aerosol optical depth from AERONET  

Microsoft Academic Search

Long-term measurements by the AERONET program of spectral aerosol optical depth, precipitable water, and derived Angstrom exponent were analyzed and compiled into an aerosol optical properties climatology. Quality assured monthly means are presented and described for 9 primary sites and 21 additional multiyear sites with distinct aerosol regimes representing tropical biomass burning, boreal forests, midlatitude humid climates, midlatitude dry climates,

B. N. Holben; D. Tanré; A. Smirnov; T. F. Eck; I. Slutsker; N. Abuhassan; W. W. Newcomb; J. S. Schafer; B. Chatenet; F. Lavenu; Y. J. Kaufman; J. Vande Castle; A. Setzer; B. Markham; D. Clark; R. Frouin; R. Halthore; A. Karneli; N. T. O'Neill; C. Pietras; R. T. Pinker; K. Voss; G. Zibordi

2001-01-01

405

Ice-condenser aerosol tests  

SciTech Connect

This report presents the results of an experimental investigation of aerosol particle transport and capture using a full-scale height and reduced-scale cross section test facility based on the design of the ice compartment of a pressurized water reactor (PWR) ice-condenser containment system. Results of 38 tests included thermal-hydraulic as well as aerosol particle data. Particle retention in the test section was greatly influenced by thermal-hydraulic and aerosol test parameters. Test-average decontamination factor (DF) ranged between 1.0 and 36 (retentions between {approximately}0 and 97.2%). The measured test-average particle retentions for tests without and with ice and steam ranged between DF = 1.0 and 2.2 and DF = 2.4 and 36, respectively. In order to apparent importance, parameters that caused particle retention in the test section in the presence of ice were steam mole fraction (SMF), noncondensible gas flow rate (residence time), particle solubility, and inlet particle size. Ice-basket section noncondensible flows greater than 0.1 m{sup 3}/s resulted in stable thermal stratification whereas flows less than 0.1 m{sup 3}/s resulted in thermal behavior termed meandering with frequent temperature crossovers between flow channels. 10 refs., 66 figs., 16 tabs.

Ligotke, M.W.; Eschbach, E.J.; Winegardner, W.K. (Pacific Northwest Lab., Richland, WA (United States))

1991-09-01

406

Amino acids in Arctic aerosols  

NASA Astrophysics Data System (ADS)

Amino acids are significant components of atmospheric aerosols, affecting organic nitrogen input to marine ecosystems, atmospheric radiation balance, and the global water cycle. The wide range of amino acid reactivities suggest that amino acids may serve as markers of atmospheric transport and deposition of particles. Despite this potential, few measurements have been conducted in remote areas to assess amino acid concentrations and potential sources. Polar regions offer a unique opportunity to investigate atmospheric processes and to conduct source apportionment studies of such compounds. In order to better understand the importance of amino acid compounds in the global atmosphere, we determined free amino acids (FAAs) in seventeen size-segregated aerosol samples collected in a polar station in the Svalbard Islands from 19 April until 14 September 2010. We used an HPLC coupled with a tandem mass spectrometer (ESI-MS/MS) to analyze 20 amino acids to quantify compounds at fmol m-3 levels. Mean total FAA concentration was 1070 fmol m-3 where serine and glycine were the most abundant compounds in almost all samples and accounted for 45-60% of the total amino acid relative abundance. The other eighteen compounds had average concentrations between 0.3 and 98 fmol m-3. The higher amino acid concentrations were present in the ultrafine aerosol fraction (<0.49 ?m) and accounted for the majority of the total amino acid content. Local marine sources dominate the boreal summer amino acid concentrations, with the exception of the regional input from Icelandic volcanics.

Scalabrin, E.; Zangrando, R.; Barbaro, E.; Kehrwald, N. M.; Gabrieli, J.; Barbante, C.; Gambaro, A.

2012-07-01

407

Amino acids in Arctic aerosols  

NASA Astrophysics Data System (ADS)

Amino acids are significant components of atmospheric aerosols, affecting organic nitrogen input to marine ecosystems, atmospheric radiation balance, and the global water cycle. The wide range of amino acid reactivities suggest that amino acids may serve as markers of atmospheric transport and deposition of particles. Despite this potential, few measurements have been conducted in remote areas to assess amino acid concentrations and potential sources. Polar regions offer a unique opportunity to investigate atmospheric processes and to conduct source apportionment studies of such compounds. In order to better understand the importance of amino acid compounds in the global atmosphere, we determined free amino acids (FAAs) in seventeen size-segregated aerosol samples collected in a polar station in the Svalbard Islands from 19 April until 14 September 2010. We used an HPLC coupled with a tandem mass spectrometer (ESI-MS/MS) to analyze 20 amino acids and quantify compounds at fmol m-3 levels. Mean total FAA concentration was 1070 fmol m-3 where serine and glycine were the most abundant compounds in almost all samples and accounted for 45-60% of the total amino acid relative abundance. The other eighteen compounds had average concentrations between 0.3 and 98 fmol m-3. The higher amino acid concentrations were present in the ultrafine aerosol fraction (< 0.49 ?m) and accounted for the majority of the total amino acid content. Local marine sources dominate the boreal summer amino acid concentrations, with the exception of the regional input from Icelandic volcanic emissions.

Scalabrin, E.; Zangrando, R.; Barbaro, E.; Kehrwald, N. M.; Gabrieli, J.; Barbante, C.; Gambaro, A.

2012-11-01

408

Assessing new remote sensing aerosol detection algorithms  

NASA Astrophysics Data System (ADS)

Atmospheric aerosols affect the weather and climate by changing cloud formation and the energy balance and, depending on their type and concentration, can negatively affect air quality. Important atmospheric aerosols include dust, ash, volcanic sulfate aerosols, sea salt, biogenic particles, urban/industrial pollution, and smoke. For more than a decade, the twin Moderate Resolution Imaging Spectroradiometers (MODIS) aboard NASA's Aqua and Terra satellites have provided regular global assessments of aerosol loading, and now, following its 2011 launch, the Visible Infrared Imaging Radiometer Suite (VIIRS) aboard the Suomi National Polar-orbiting Partnership (Suomi-NPP) satellite is ready to contribute to that assessment.

Schultz, Colin

2014-02-01

409

Separating Cloud Forming Nuclei from Interstitial Aerosol  

SciTech Connect

It has become important to characterize the physicochemical properties of aerosol that have initiated the warm and ice clouds. The data is urgently needed to better represent the aerosol-cloud interaction mechanisms in the climate models. The laboratory and in-situ techniques to separate precisely the aerosol particles that act as cloud condensation nuclei (CCN) and ice nuclei (IN), termed as cloud nuclei (CN) henceforth, have become imperative in studying aerosol effects on clouds and the environment. This review summarizes these techniques, design considerations, associated artifacts and challenges, and briefly discusses the need for improved designs to expand the CN measurement database.

Kulkarni, Gourihar R.

2012-09-12

410

Multi-Sensor Aerosol Products Sampling System  

NASA Technical Reports Server (NTRS)

Global and local properties of atmospheric aerosols have been extensively observed and measured using both spaceborne and ground-based instruments, especially during the last decade. Unique properties retrieved by the different instruments contribute to an unprecedented availability of the most complete set of complimentary aerosol measurements ever acquired. However, some of these measurements remain underutilized, largely due to the complexities involved in analyzing them synergistically. To characterize the inconsistencies and bridge the gap that exists between the sensors, we have established a Multi-sensor Aerosol Products Sampling System (MAPSS), which consistently samples and generates the spatial statistics (mean, standard deviation, direction and rate of spatial variation, and spatial correlation coefficient) of aerosol products from multiple spacebome sensors, including MODIS (on Terra and Aqua), MISR, OMI, POLDER, CALIOP, and SeaWiFS. Samples of satellite aerosol products are extracted over Aerosol Robotic Network (AERONET) locations as well as over other locations of interest such as those with available ground-based aerosol observations. In this way, MAPSS enables a direct cross-characterization and data integration between Level-2 aerosol observations from multiple sensors. In addition, the available well-characterized co-located ground-based data provides the basis for the integrated validation of these products. This paper explains the sampling methodology and concepts used in MAPSS, and demonstrates specific examples of using MAPSS for an integrated analysis of multiple aerosol products.

Petrenko, M.; Ichoku, C.; Leptoukh, G.

2011-01-01

411

AEROSOL METROLOGY FOR MARCH 14 15, 2011  

E-print Network

AEROSOL METROLOGY FOR CLIMATE MARCH 14 ­ 15, 2011 Opening Remarks James Whetstone Special Assistant Metrology Continuous Emission Mon. Test Bed Distributed GHG Source Metrology Flux Measurement Tools

412

Aerosol role in the climate system  

NASA Astrophysics Data System (ADS)

Aerosol, smoke and regional pollution suspended in the air, or desert dust and sea salt spray, have a lifetime of only a few days in the atmosphere; yet have a major effect on the regional and global radiation budgets and hydrologic cycle. The net effect of aerosols is to cool the climate system by reflecting sunlight to space and by increasing cloud extent and brightness through modifications of cloud microphysical properties. Black carbon aerosols from incomplete combustion absorb sunlight in the atmosphere, further cooling the surface but warming the atmosphere in the process, consequently changing the atmospheric profiles, rate of evaporation from the surface and atmospheric dynamics. These effects generate an array of pathways for aerosol to interfere with the hydrological cycle: 1) aerosol induced reduction of evaporation from the Mediterranean Sea is modeled to cause droughts in the region, 2) heating of the atmosphere by aerosol in South East Asia is modeled to change the regional circulation, advecting moisture and causing floods, 3) concentrated pollution downwind of urban regions was shown from satellites to reduce droplet size and stop precipitation, 4) however, introduction of large sea salt aerosol over the Indian ocean to the pollution aerosol restarts precipitation and cleans the atmosphere. To accurately study aerosol distribution, composition and effects, continuous observations from satellites, networks of ground-based instruments and dedicated field experiments, together with chemical transport and climate models are needed. Examples will be given in the talk.

Kaufman, Y. J.

2003-04-01

413

CLOUD DROPLET NUCLEATION AND ITS CONNECTION TO AEROSOL PROPERTIES  

E-print Network

CLOUD DROPLET NUCLEATION AND ITS CONNECTION TO AEROSOL PROPERTIES STEPHEN E. SCHWARTZ Environmental Chemistry Division, Brookhaven National Laboratory, Upton NY 11973 USA Abstract - Anthropogenic aerosols

Schwartz, Stephen E.

414

Estimating aerosol emissions by assimilating observed aerosol optical depth in a global aerosol model  

NASA Astrophysics Data System (ADS)

This study estimates the emission fluxes of a range of aerosol species and one aerosol precursor at the global scale. These fluxes are estimated by assimilating daily total and fine mode aerosol optical depth (AOD) at 550 nm from the Moderate Resolution Imaging Spectroradiometer (MODIS) into a global aerosol model of intermediate complexity. Monthly emissions are fitted homogenously for each species over a set of predefined regions. The performance of the assimilation is evaluated by comparing the AOD after assimilation against the MODIS observations and against independent observations. The system is effective in forcing the model towards the observations, for both total and fine mode AOD. Significant improvements for the root mean square error and correlation coefficient against both the assimilated and independent datasets are observed as well as a significant decrease in the mean bias against the assimilated observations. These improvements are larger over land than over ocean. The impact of the assimilation of fine mode AOD over ocean demonstrates potential for further improvement by including fine mode AOD observations over continents. The Angström exponent is also improved in African, European and dusty stations. The estimated emission flux for black carbon is 15 Tg yr-1, 119 Tg yr-1 for particulate organic matter, 17 Pg yr-1 for sea salt, 83 TgS yr-1 for SO2 and 1383 Tg yr-1 for desert dust. They represent a difference of +45 %, +40 %, +26 %, +13 % and -39 % respectively, with respect to the a priori values. The initial errors attributed to the emission fluxes are reduced for all estimated species.

Huneeus, N.; Chevallier, F.; Boucher, O.

2012-05-01

415

Estimating aerosol emissions by assimilating observed aerosol optical depth in a global aerosol model  

NASA Astrophysics Data System (ADS)

The emission fluxes of a range of aerosol species and aerosol precursor are estimated at the global scale. These fluxes are estimated by assimilating daily total and fine mode aerosol optical depth (AOD) at 550 nm from the Moderate Resolution Imaging Spectroradiometer (MODIS) into a global aerosol model of intermediate complexity. Monthly emissions are fitted homogenously for each species over a set of predefined regions. The assimilation system has been applied to the entire year 2002 and its performance is evaluated by comparing the AOD after assimilation against the MODIS observations and against independent observations. The system is effective in forcing the model towards the observations, for both total and fine mode AOD. Significant improvements for the root mean square error and correlation coefficient against both the assimilated and independent datasets are observed as well as a significant decrease in the mean bias against the assimilated observations. The estimated emission flux for black carbon is 14.5 Tg/yr, 119 Tg/yr for organic matter, 17 Pg/yr for sea salt, 82.7 TgS/yr for SO2 and 1383 Tg/yr for desert dust. They represent a difference of +45%, +40%, +26%, +13% and -39% respectively, with respect to the a priori values. The system has been applied to the year 2005 with similar performance in the reduction of the RMS and bias and increase in correlation. The study will be extended by applying it to the year 2010. The estimated fluxes corresponding to the years 2002, 2005 and 2010 will be presented and compared with different top-down and bottom-up estimates.

Huneeus, N.; Chevallier, F.; Boucher, O.

2012-04-01

416

Estimating aerosol emissions by assimilating observed aerosol optical depth in a global aerosol model  

NASA Astrophysics Data System (ADS)

This study estimates the emission fluxes of a range of aerosol species and aerosol precursor at the global scale. These fluxes are estimated by assimilating daily total and fine mode aerosol optical depth (AOD) at 550 nm from the Moderate Resolution Imaging Spectroradiometer (MODIS) into a global aerosol model of intermediate complexity. Monthly emissions are fitted homogenously for each species over a set of predefined regions. The performance of the assimilation is evaluated by comparing the AOD after assimilation against the MODIS observations and against independent observations. The system is effective in forcing the model towards the observations, for both total and fine mode AOD. Significant improvements for the root mean square error and correlation coefficient against both the assimilated and independent datasets are observed as well as a significant decrease in the mean bias against the assimilated observations. The assimilation is more efficient over land than over ocean. The impact of the assimilation of fine mode AOD over ocean demonstrates potential for further improvement by including fine mode AOD observations over continents. The Angström exponent is also improved in African, European and dusty stations. The estimated emission flux for black carbon is 14.5 Tg yr-1, 119 Tg yr-1 for organic matter, 17 Pg yr-1 for sea salt, 82.7 TgS yr-1 for SO2 and 1383 Tg yr-1 for desert dust. They represent a difference of +45%, +40%, +26%, +13% and -39% respectively, with respect to the a priori values. The initial errors attributed to the emission fluxes are reduced for all estimated species.

Huneeus, N.; Chevallier, F.; Boucher, O.

2012-01-01

417

Treatment of Peritoneal Carcinomatosis by Targeted Delivery of the Radio-Labeled Tumor Homing Peptide 213Bi-DTPA-[F3]2 into the Nucleus of Tumor Cells  

PubMed Central

Background ?-particle emitting isotopes are effective novel tools in cancer therapy, but targeted delivery into tumors is a prerequisite of their application to avoid toxic side effects. Peritoneal carcinomatosis is a widespread dissemination of tumors throughout the peritoneal cavity. As peritoneal carcinomatosis is fatal in most cases, novel therapies are needed. F3 is a tumor homing peptide which is internalized into the nucleus of tumor cells upon binding to nucleolin on the cell surface. Therefore, F3 may be an appropriate carrier for ?-particle emitting isotopes facilitating selective tumor therapies. Principal Findings A dimer of the vascular tumor homing peptide F3 was chemically coupled to the ?-emitter 213Bi (213Bi-DTPA-[F3]2). We found 213Bi-DTPA-[F3]2 to accumulate in the nucleus of tumor cells in vitro and in intraperitoneally growing tumors in vivo. To study the anti-tumor activity of 213Bi-DTPA-[F3]2 we treated mice bearing intraperitoneally growing xenograft tumors with 213Bi-DTPA-[F3]2. In a tumor prevention study between the days 4–14 after inoculation of tumor cells 6×1.85 MBq (50 µCi) of 213Bi-DTPA-[F3]2 were injected. In a tumor reduction study between the days 16–26 after inoculation of tumor cells 6×1.85 MBq of 213Bi-DTPA-[F3]2 were injected. The survival time of the animals was increased from 51 to 93.5 days in the prevention study and from 57 days to 78 days in the tumor reduction study. No toxicity of the treatment was observed. In bio-distribution studies we found 213Bi-DTPA-[F3]2 to accumulate in tumors but only low activities were found in control organs except for the kidneys, where 213Bi-DTPA-[F3]2 is found due to renal excretion. Conclusions/Significance In conclusion we report that 213Bi-DTPA-[F3]2 is a novel tool for the targeted delivery of ?-emitters into the nucleus of tumor cells that effectively controls peritoneal carcinomatosis in preclinical models and may also be useful in oncology. PMID:19479088

Miederer, Matthias; Blechert, Birgit; Vallon, Mario; Muller, Jan M.; Alke, Andrea; Seidl, Christof; Bruchertseifer, Frank; Morgenstern, Alfred; Senekowitsch-Schmidtke, Reingard; Essler, Markus

2009-01-01

418

Size distribution of near-surface aerosols and its relation to the columnar aerosol optical depths  

NASA Astrophysics Data System (ADS)

Simultaneous data on Aerosol Optical Depth (AOD) and size segregated, near-surface, aerosol mass concentration was obtained from a Multi wavelength Solar Radiometer (MWR) and Quartz Crystal Microbalance Impactor (QCM), respectively. These were used to examine the association between near-surface aerosol properties and columnar AOD. The spectral AODs were approximated to the Ångström relation ?p=??-?, and the wavelength exponent ? and turbidity coefficient ? have been obtained. In general, ? was found to be well associated with the relative abundance of accumulation mode aerosols (estimated from the simultaneous QCM data) while ? followed the variations of the coarse mode aerosol mass concentration; the association being closer during periods of continental airmass.

Pillai, P.; Krishna Moorthy, K.

2004-10-01

419

Characterization of aerosols produced by surgical procedures  

SciTech Connect

In many surgeries, especially orthopedic procedures, power tools such as saws and drills are used. These tools may produce aerosolized blood and other biological material from bone and soft tissues. Surgical lasers and electrocautery tools can also produce aerosols when tissues are vaporized and condensed. Studies have been reported in the literature concerning production of aerosols during surgery, and some of these aerosols may contain infectious material. Garden et al. (1988) reported the presence of papilloma virus DNA in the fumes produced from laser surgery, but the infectivity of the aerosol was not assessed. Moon and Nininger (1989) measured the size distribution and production rate of emissions from laser surgery and found that particles were generally less than 0.5 {mu}m diameter. More recently there has been concern expressed over the production of aerosolized blood during surgical procedures that require power tools. In an in vitro study, the production of an aerosol containing the human immunodeficiency virus (HIV) was reported when power tools were used to cut tissues with blood infected with HIV. Another study measured the size distribution of blood aerosols produced by surgical power tools and found blood-containing particles in a number of size ranges. Health care workers are anxious and concerned about whether surgically produced aerosols are inspirable and can contain viable pathogens such as HIV. Other pathogens such as hepatitis B virus (HBV) are also of concern. The Occupational Safety and Health funded a project at the National Institute for Inhalation Toxicology Research Institute to assess the extent of aerosolization of blood and other tissues during surgical procedures. This document reports details of the experimental and sampling approach, methods, analyses, and results on potential production of blood-associated aerosols from surgical procedures in the laboratory and in the hospital surgical suite.

Yeh, H.C.; Muggenburg, B.A.; Lundgren, D.L.; Guilmette, R.A.; Snipes, M.B.; Jones, R.K. [Inhalation Toxicology Research Institute, Albuquerque, NM (United States); Turner, R.S. [Lovelace Health Systems, Albuquerque, NM (United States)

1994-07-01

420

Assessing the Sensitivity of the ORAC Optimal Estimation Aerosol Retrieval Scheme for MSG SEVIRI to Input Aerosol Parameters  

E-print Network

Assessing the Sensitivity of the ORAC Optimal Estimation Aerosol Retrieval Scheme for MSG SEVIRI for the Meteosat Second Generation (MSG) Spinning Enhanced Visible Infrared Imager (SEVIRI) aerosol retrieval

Oxford, University of

421

Effect of complexans (EDTA, NTA and DTPA) on the exposure to high concentrations of cadmium, copper, zinc and lead  

SciTech Connect

The effects of complexans on the toxicity of short exposures to high chemical concentrations of heavy meals were examined. The heavy metals used were cadmium, zinc, lead and copper. Mortality every 24-h and the content of metal in each of three areas of fish - viscera, gills and other parts - were detemined both in the groups kept in water containing metal alone and in those whose aqueous environments contained complexan in mole concentrations three time that of the heavy metal. The carp (Cyprinus carpio L.) 8.0 + 0.5 cm were kept in groups of 8 to 10. There were altogether 49 such groups: 12 kept in three relatively high concentrations of each of the metals, Cu, Cd, Pb and Zn, alone; 36 groups in environments each containing only one of the three complexans, the tetrasodium salt of ethylene-diamine tetraacetic acid (EDTA), the trisodium salt of nitrilotriacetic acid (NTA), and the pentasodium salt of diethylenetriamine pentaacetic acid (DTPA) were used. Results indicate that the addition of the complexans resulted in the decrease of the tissue concentrations of Cd, Zn, Pb and Cu. It is considered that the heavy metals were not present merely as metal ions but formed complexes with the complexans, since the complexans were added at three times mole of the metal and therefore complex formation occurred in preference to the binding of the metals with the tissue proteins of the fish. It is furthermore assumed that the heavy metals can pass through the fish as metal-complexes, and so are not retained.

Muramoto, S.

1980-12-01

422

Quantitative 99mTc DTPA renal transplant scintigraphic parameters: assessment of interobserver agreement and correlation with graft pathologies  

PubMed Central

Various 99mTc DTPA scintigraphic quantitative parameters for renal graft function assessment have been recommended, but none is universally accepted. In this study, 439 dynamic renal transplant scintigraphies (DRTS) were retrospectively analysed. In the first set of studies, four observers analysed the 47 random DRTS and interobserver agreement of eleven derived parameters was assessed. In the other set of studies, 181 instances of DRTS, performed on 127 recipients with renal biopsies within five days of each other were selected for correlation with pathology. Hilson’s Perfusion index (HI), ?P, P:Pl, P:U & T10 were selected for this analysis. The pathologies were categorized into renal vascular compromise (RVC; n = 20), acute tubular necrosis (ATN; n = 40), vascular rejection (VR; n = 34), interstitial rejection (IR; n = 33), normal (NOR; n = 36) and unclassified pathologies (n = 18). A majority of the parameters showed good Intraclass correlation (ICC). HI differentiated well between grafts with RVC and the remainder of the study cohort, (p < 0.0001; AUC = 0.84); at a cut-off > 278, it had 84% sensitivity and 78% specificity (Likelihood ratio = 3.8). At < 278, it had 98% ‘negative’ predictive value for RVC. HI also showed reasonable association with VR (p = 0.02; AUC = 0.62) and IR (p = 0.009; AUC = 0.65). However, significant overlap of HI values between various subgroups was noted. Other parameters had good ICC but were not effective in differentiating graft pathologies. Of the measured parameters, only HI proved to be useful for the pathological assessment, particularly in the identification of vascular compromise. This parameter, however, has lower specificity in differentiating the other pathologies. PMID:24795835

Gupta, Sandeep K; Lewis, Guy; Rogers, Kerry M; Attia, John; Rostron, Kirk; O’Neill, Leanne; Skillen, Annah; Viswanathan, Suresh

2014-01-01