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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

Rapid clearance of inhaled aerosols of Technetium-99M DTPA in patients with pneumocystis carinii pneumonia  

SciTech Connect

Because infection with Pheumocystis carinii pneumonia (PCP) causes alteration of the type I epithelial cells as the primary event, the authors studied patients with PCP to determine if PCP causes rapid clearance of Tc-99m DTPA. Twenty normal non-smoking subjects and 7 non-smoking patients with histologically proven PCP were studied. Serial studies were obtained in three patients. Following a two-minute inhalation of 1.6 ..mu..m aerosol particles of Tc-99m DTPA in saline, the activity over three peripheral regions of interest (ROI) of each lung was monitored for the next 7 minutes. The rate of decline of activity over each ROI was expressed as per cent decline/min. In 7 patients with PCP, the average clearance was 7.5 +- 3.6% min., normal, 1.3 +- 0.6% min.(SD). Three patients studied from 5 to 38 days following therapy had improvement in the rate of clearance. This has been demonstrated to be persistent even after clinical recovery of the patient. The ability to quantitate injury to the pulmonary epithelium may directly reflect the ability of Pneumocystis carinii to invade the lung. The authors conclude that Tc-99m DTPA clearance may be a useful test to help diagnosis and monitor the activity of PCP infections.

Mason, G.R.; Duane, G.B.; Effros, R.M.; Mena, I.

1985-05-01

3

Detection of urinary extravasation by delayed technetium-99m DTPA renal imaging  

SciTech Connect

Delayed imaging with Tc-99m DTPA renal scintigraphy demonstrated urinary extravasation in a patient with acute anuria in whom early sequential imaging showed no abnormal extrarenal radionuclide accumulation.

Taki, J.; Tonami, N.; Aburano, T.; Hisada, K.

1986-08-01

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

Impaired permeability in radiation-induced lung injury detected by technetium-99m-DTPA lung clearance  

Microsoft Academic Search

This study evaluates the use of the {sup 99m}Tc-DTPA aerosol lung clearance method to investigate radiation-induced lung changes in eight patients undergoing radiotherapy for lung or breast carcinoma. The sensitivity of the method was compared with chest radiography for detecting radiation-induced changes in the lung, regional alterations within and outside the treatment ports, effect of irradiated lung volume, and dependence

Herbert Susskind; David A. Weber; Yat Hong Lau

1997-01-01

6

Impaired permeability in radiation-induced lung injury detected by technetium-99m-DTPA lung clearance  

SciTech Connect

This study evaluates the use of the {sup 99m}Tc-DTPA aerosol lung clearance method to investigate radiation-induced lung changes in eight patients undergoing radiotherapy for lung or breast carcinoma. The sensitivity of the method was compared with chest radiography for detecting radiation-induced changes in the lung, regional alterations within and outside the treatment ports, effect of irradiated lung volume, and dependence on time after radiotherapy. Serial DTPA lung clearance studies were performed before the first radiation treatment (baseline), then weekly during a 5- to 7-wk course, and up to 12 times post-therapy over periods of 56-574 days. The total activity deposited in the lungs for each study was {approx}150 {mu}Ci ({approx}5.6 MBq). DTPA clearance, expressed in terms of the biological half-time, t{sub 1/2}, was computed from the slopes of the least-squares fit regression lines of the time-activity curves for the first 10 min for irradiated and shielded lung regions. Major findings include: (a) significant and early DTPA t{sub 1/2} changes were observed in all patients during and after radiotherapy; (b) changes in DTPA t{sub 1/2} values were observed in both irradiated and shielded lung regions in all patients suggesting a radiation-induced systemic reaction; (c) changes in DTPA t{sub 1/2} values were correlated (p < 0.05) with the irradiated lung volumes; (d) significantly reduced DTPA t{sub 1/2} values were observed in three patients who subsequently presented with clinical symptoms and/or radiographic changes consistent with radiation pneumonitis (t{sub 1/2} fell to 19% {+-} 6% of baseline values, compared with 64% {+-} 17% in the remaining patients [p < 0.01]); (e) the onset of decreased DTPA t{sub 1/2} values in these three patients occurred 35-84 days before clinical symptoms and/or radiographic changes; and (f) DTPA t{sub 1/2} tended to approach baseline values with time after radiotherapy, suggesting a long-term recovery in lung injury.

Susskind, H.; Weber, D.A.; Lau, Yat Hong [Brookhaven National Lab., Upton, NY (United States)]|[University Hospital, Stony Brook, NY (United States)] [and others

1997-06-01

7

Deposition of aqueous aerosol of technetium-99m diethylene triamine penta-acetic acid generated and delivered by a novel system (AER x ) in healthy subjects  

Microsoft Academic Search

.   Deposition of technetium-99m diethylene triamine penta-acetic acid aqueous radioaerosols generated by a novel aerosol delivery\\u000a system (AERx) was studied in six healthy subjects using both planar and single-photon emission tomography (SPET) imaging. AERx is a microprocessor-controlled, bolus inhalation device that is actuated at pre-programmed values of inspiratory flow rate\\u000a and volume. The aims of the study were to determine

Hak-Kim Chan; Evangelia Daviskas; Stefan Eberl; Michael Robinson; George Bautovich; Iven Young

1999-01-01

8

Deposition of aqueous aerosol of technetium-99m diethylene triamine penta-acetic acid generated and delivered by a novel system (AERx) in healthy subjects.  

PubMed

Deposition of technetium-99m diethylene triamine penta-acetic acid aqueous radioaerosols generated by a novel aerosol delivery system (AERx) was studied in six healthy subjects using both planar and single-photon emission tomography (SPET) imaging. AERx is a microprocessor-controlled, bolus inhalation device that is actuated at pre-programmed values of inspiratory flow rate and volume. The aims of the study were to determine the effects of posture and inhaled volume upon deposition of the aerosol in the lungs. Each subject inhaled the radioaerosol in two positions (supine vs sitting) and with two inspiratory manoeuvres [vital capacity (VC) vs "fixed volume" of 1 l above functional residual capacity]. Simultaneous transmission-emission planar and tomographic images were acquired. The results showed diffuse deposition of the aerosol in the lung. Neither the breathing manoeuvre nor the posture was found to affect the distribution of the aerosol as measured by the ratio of the activity (counts per pixel) in the peripheral:central (penetration index, PI) or in the apex:base regions of the planar lung images (P>0.1). A small, albeit statistically significant, difference in PI (P<0.03) was found between VC and fixed volume sitting manoeuvres with SPET only. The PI values themselves indicate that the radioaerosol was well distributed in the lung, with the periphery having 45%-64% of the activity of the central region. Superposition of transmission SPET lung outline on emission SPET visually confirmed the excellent peripheral deposition of the aerosol. The AERx system showed high efficiency of delivery, with approximately 50% of the extruded dose in the device depositing in the lung. The uniformity of radioactivity distributed throughout the lung is attributed to the fine particle size (mass median aerodynamic diameter of 2 microm) of the aerosol and the electronic control of aerosol inhalation by the device. In conclusion, the AERx system can be ideal for diffuse aerosol deposition of therapeutic or diagnostic agents and is largely unaffected by inhaled volume and posture. The efficiency of the device device can limit the total radiation exposure of patients and staff administering the radioaerosols, and can make it suitable for delivery of expensive drugs. PMID:10199936

Chan, H K; Daviskas, E; Eberl, S; Robinson, M; Bautovich, G; Young, I

1999-04-01

9

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

10

Radiolabelling of platelets with technetium-99m.  

PubMed

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. PMID:2140207

Sundrehagen, E; Urdal, P; Heggli, D E; Lindegaard, M W; Jacobsen, E

1990-03-01

11

Lung ventilation studies with technetium-99m Pseudogas  

SciTech Connect

Technetium-99m Pseudogas is an ultrafine near monodisperse aerosol of 0.12-microgram diam particle size. This report describes initial clinical experiences with 27 patients referred for investigation of suspected pulmonary embolism, and in whom Pseudogas ventilation images were compared with a high quality commercial aerosol. An additional group of ten patients with severe COPD was examined in a comparative trial of Pseudogas with 81mKr. Pseudogas was better than a conventional aerosol in reaching a diagnosis of pulmonary embolism using a simple blinded comparison with coded images. In addition, bronchial deposition was minimal unless COPD was severe. Moderately well patients had no difficulty inhaling the necessary activity in one or two breaths, and even severely ill and frail aged persons could accomplish the passive breathing maneuver in less than a minute. Clearance of Pseudogas was directly to the systemic circulation with a half-time of 10 min in normal subjects extending up to 100 min in patients with airways disease.

Burch, W.M.; Sullivan, P.J.; Lomas, F.E.; Evans, V.A.; McLaren, C.J.; Arnot, R.N.

1986-06-01

12

Cyclotron Production of Technetium-99m  

NASA Astrophysics Data System (ADS)

Technetium-99m (99mTc) has emerged as the most widely used radionuclide in medicine and is currently obtained from a 99Mo/ 99mTc generator system. At present, there are only a handful of ageing reactors worldwide capable of producing large quantities of the parent isotope, 99Mo, and owing to the ever growing shutdown periods for maintenance and repair of these ageing reactors, the reliable supply 99mTc has been compromised in recent years. With an interest in alternative strategies for producing this key medical isotope, this thesis focuses on several technical challenges related to the direct cyclotron production of 99mTc via the 100Mo(p,2n)99mTc reaction. In addition to evaluating the 100Mo(p,2n)99mTc and 100Mo(p,x)99Mo reactions, this work presented the first experimental evaluation of the 100Mo(p,2n) 99gTc excitation function in the range of 8-18 MeV. Thick target calculations suggested that large quantities of cyclotron-produced 99mTc may be possible. For example, a 6 hr irradiation at 500 ?A with an energy window of 18?10 MeV is expected to yield 1.15 TBq of 99mTc. The level of coproduced 99gTc contaminant was found to be on par with the current 99Mo/99mTc generator standard eluted with a 24 hr frequency. Highly enriched 100Mo was required as the target material for 99mTc production and a process for recycling of this expensive material is presented. An 87% recovery yield is reported, including metallic target preparation, irradiation, 99mTc extraction, molybdate isolation, and finally hydrogen reduction to the metal. Further improvements are expected with additional optimization experiments. A method for forming structurally stable metallic molybdenum targets has also been developed. These targets are capable of withstanding more than a kilowatt of beam power and the reliable production and extraction of Curie quantities of 99mTc has been demonstrated. With the end-goal of using the cyclotron-produced 99mTc clinically, the quality of the cyclotron-produced 99mTc has been extensively compared with relevant United States Pharmacopeia (USP) specifications for the existing 99Mo/99mTc production strategy. Additional quality testing, including biodistribution studies of [ 99mTc]pertechnetate and [99mTc]disofenin in both mice and rabbits was also evaluated. Using the strategies and results presented throughout this dissertation, this thesis concludes with the world's first cyclotron-based 99mTc patient images obtained as part of a Phase I Clinical Trial at the University of Alberta using [99m Tc]pertechnetate.

Gagnon, Katherine M.

13

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

ScienceCinema

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

2013-05-28

14

Rest technetium 99m-sestamibi tomoscintigraphy in hibernating myocardium  

Microsoft Academic Search

The myocardial uptake of rest-injected technetium 99m sestamibi on single-photon-emission computed tomographic images was assessed in 25 patients. All had an area of myocardial dysfunction that could be related to a coronary artery stenosis. None of the patients had clinical evidence of a myocardial infarction. Three months after revascularization, viability was demonstrated by contrast angiography and center-line analysis in 21

Jean C. Maublant; Bernard Citron; Janusz Lipiecki; Daniele Mestas; Patrick Bailly; Annie Veyre; Charles de Riberolles; Jean Ponsonnaille

1995-01-01

15

Technetium-99m-labeled monoclonal antibody with preserved immunoreactivity and high in vivo stability  

SciTech Connect

Recent availability of monoclonal antibodies (MoAb) and their radiolabeling through the use of the bifunctional chelating agents (BCA) have become an alternative procedure for in vivo radioimmunodetection. Using a newly synthesized BCA, a p-carboxyethylphenylglyoxal-di(N-methylthiosemicarbazone) (CE-DTS), the coupling and technetium-99m (/sup 99m/Tc) labeling of monoclonal IgG against hCG were carried out. In the system presented, factors affecting stability and immunoreactivity were examined. Immunoreactivity of the original IgG (56C) was preserved by conjugating one CE-DTS molecule per molecule of IgG (56C) using the phosphorylazide method, however, /sup 99m/Tc labeling pH affected the immunoreactivity and limited the /sup 99m/Tc labeling reaction between pH 4.5 and 6.2. A screening of labeling conditions, such as pH, reaction time, and reducing agent system were then carried out. Technetium-99m-labeled IgG (56C), (/sup 99m/Tc)CE-DTS-IgG (56C), showed good stability upon incubation with mice sera and comparable mice biodistribution to that of indium-111 (/sup 111/In) DTPA-IgG (56C). Thus, these results indicate the excellent potential of CE-DTS as a BCA for labeling MoAb with /sup 99m/Tc.

Arano, Y.; Yokoyama, A.; Furukawa, T.; Horiuchi, K.; Yahata, T.; Saji, H.; Sakahara, H.; Nakashima, T.; Koizumi, M.; Endo, K.

1987-06-01

16

Technetium-99m NGA functional hepatic imaging: preliminary clinical experience  

SciTech Connect

Technetium-99m galactosyl-neoglycoalbumin ( (Tc)NGA) is a radiolabeled ligand to hepatic binding protein, a receptor which resides at the plasma membrane of hepatocytes. This receptor-binding radiopharmaceutical and its kinetic model provide a noninvasive method for the assessment of liver function. Eighteen patients were studied: seven with hepatoma, eight with liver metastases, four with cirrhosis, and one patient with acute fulminant non-A, non-B hepatitis. Technetium-99m NGA liver imaging provided anatomic information of diagnostic quality comparable to that obtained with other routine imaging modalities, including computed tomography, angiography, ultrasound, and (Tc)sulfur colloid scintigraphy. Kinetic modeling of dynamic (Tc)NGA data produced estimates of standardized hepatic blood flow, Q (hepatic blood flow divided by total blood volume), and hepatic binding protein concentration, (HBP). Significant rank correlation was obtained between (HBP) estimates and CTC scores. This correlation supports the hypothesis that (HBP) is a measure of functional hepatocyte mass. The combination of decreased Q and markedly reduced (HBP) may have prognostic significance; all three patients with this combination died of hepatic failure within 6 wk of imaging.

Stadalnik, R.C.; Vera, D.R.; Woodle, E.S.; Trudeau, W.L.; Porter, B.A.; Ward, R.E.; Krohn, K.A.; O'Grady, L.F.

1985-11-01

17

Mechanism of renal concentration of technetium-99m glucoheptonate  

SciTech Connect

Seventy female Sprague-Dawley rats were studied to determine the mechanism of tubular localization and the effects of commonly encountered changes in hydration and acid-base balance on renal uptake and urinary excretion of technetium-99m glucoheptonate ((/sup 99m/Tc)GHA). The in-vivo protein binding and protein-free plasma clearance of (/sup 99m/Tc)GHA also were quantitated. Kidney uptake of (/sup 99m/Tc)GHA averaged 11% of the injected dose in control animals. This varied slightly among groups but was significantly reduced by probenecid blockade and para-aminohippuric acid (PAH) competition to 4 and 2, respectively. Technetium-99m DMSA was not affected in its renal accumulation by these maneuvers. The total plasma clearance of (/sup 99m/Tc)GHA was lower than iodine-125( SVI)iothalamate but the clearance of the protein free supernate was higher, raising a possibility of some tubular secretion. Hepatic uptake was minimal in all groups averaging less than 1% injected dose. These data demonstrate that renal accumulation of (/sup 99m/Tc)GHA is blocked by probenecid and PAH suggesting that it is actively concentrated in the proximal tubule by enzyme systems similar to those involved in PAH and hippuran transport. It appears that (/sup 99m/Tc)GHA uptake measures a different aspect of kidney function than (/sup 99m/Tc)DMSA.

Lee, H.B.; Blaufox, M.D.

1985-11-01

18

Technetium-99m nanocolloid scintigraphy in rheumatic inflammation in children.  

PubMed

Technetium-99m HSA (human serum albumin) is a nanometer-sized albumin-based inert colloid, which has a specific ability to accumulate in inflamed soft tissue lesions. With a particle size smaller than 30 nm, Tc-99m HSA spills into the extravascular space in the sites of inflammation because of the changed capillary permeability. The conventional tracer in joint scintigraphy, technetium-99m methylene diphosphonate (Tc-99m-MDP) is a boneseeking compound, which strongly accumulates in the epiphyseal area of growing bones. This makes the estimation of the inflammatory process in the joints of growing children difficult. The nanocolloid compound has not this disturbing tendency. This fact makes the joint scans more specific and the detection of inflammatory lesions is easier especially in children. In our study Tc-99m HSA is used for the detection of rheumatic inflammation in children with juvenile rheumatoid arthritis. We examined 24 children with juvenile rheumatoid arthritis, age 3-19 years, 20 girls and 4 boys, who all had clinically active inflammation in the joints or in the tendon sheets. The uptake pattern of nanocolloid parallels the severity of the inflammatory process in periarticular tissues and tendon sheets. In suspicious cases, the comparison with the contralateral area helps in the detection of the lesion. Therefore, when investigating paired joints, the scintigraphy of symmetrical parts is necessary. PMID:1845410

Mäkelä, A L; Soini, I; Mäkelä, P

1991-01-01

19

Bronchoalveolar lavage and technetium-99m glucoheptonate imaging in chronic eosinophilic pneumonia  

SciTech Connect

A patient with chronic eosinophilic pneumonia was evaluated using bronchoalveolar lavage, technetium-99m glucoheptonate, and transbronchial lung biopsy. Bronchoalveolar lavage revealed 43 percent eosinophils and correlated well with results of transbronchial lung biopsy. Technetium-99m glucoheptonate lung imaging demonstrated intense parenchymal uptake. After eight weeks of corticosteroid therapy, the bronchoalveolar lavage eosinophil population and the technetium-99m glucoheptonate uptake had returned to normal. We suggest that bronchoalveolar lavage, with transbronchial lung biopsy, is a less invasive way than open lung biopsy to diagnose chronic eosinophilic pneumonia. The mechanism of uptake of technetium-99m glucoheptonate in this disorder remains to be defined.

Lieske, T.R.; Sunderrajan, E.V.; Passamonte, P.M.

1984-02-01

20

Technetium-99m antimony colloid for bone-marrow imaging  

SciTech Connect

Technetium-99m antimony colloid was prepared in our laboratory for bone-marrow imaging. Optimal production of colloid particles of size range 1 to 13 nm was achieved by the use of polyvinylpyrrolidone of mol. wt. 44,000. Electron microscopy was used to size the particles. Studies in rabbits showed exclusive concentration in the subendothelial dendritic phagocytes of the bone marrow. Pseudopods from these cells were found to traverse interendothelial junctions and concentrate colloid from the sinusoids. Imaging studies of bone marrow in rabbits showed the superiority of the Tc-99m antimony colloid over the much larger colloidal particle of Tc-99m sulfur colloid. Tissue distribution studies in the rat confirmed that bone-marrow uptake of Tc-99m antimony colloid was greater than that of Tc-99m sulfur colloid, although blood clearance was much slower.

Martindale, A.A.; Papadimitriou, J.M.; Turner, J.H.

1980-11-01

21

Technetium-99m galactosyl-neoglycoalbumin: preparation and preclinical studies  

SciTech Connect

Technetium-99m galactosyl-neoglycoalbumin ((Tc) NGA), a labeled analog ligand to the hepatocyte-specific receptor, hepatic binding protein (HBP), was prepared and tested for labeling yield, stability, biodistribution, toxicity, and dosimetry. The ligand was synthesized by the covalent coupling of a carbohydrate bifunctional reagent, 2-imino-2-ethyloxymethyl-1-thiogalactose, to human serum albumin. Testing in mice and rabbits revealed the product to be nontoxic and apyrogenic. Biodistribution studies in rabbits demonstrated the liver as the single focus of tracer uptake. Dosimetry was based on kinetic studies in three baboons. Absorbed doses to liver, small intestine, urinary bladder wall, and uterus were 0.089, 0.28, 0.56, and 0.88 rad/mCi, respectively. Total body, lens of the eye, red marrow, ovaries, and testes were less than 0.06 rad/mCi. High liver specificity imparted by receptor binding combined with high labeling yield, stability, acceptable dosimetry, and safety provide (Tc)NGA with the attributes required for routine clinical assessment of hepatocyte function.

Vera, D.R.; Stadalnik, R.C.; Krohn, K.A.

1985-10-01

22

Technetium-99m-EC and other potential new agents in renal nuclear medicine.  

PubMed

Search for the ideal radiopharmaceutical to measure effective renal plasma flow (ERPF) has been underway since the early 1960s. Although ortho-iodohippuran (OIH) has biological properties suited for measurement of ERPF, the imaging characteristics are less than desirable. With the advent of the molybdenum-99/technetium-99m generators, efforts have focused on the development of a technetium-99m agent to measure ERPF. Over the last 10 to 15 years several promising technetium-99m renal imaging agents have been developed. Early examples of technetium-99m renal agents such as 99mTc-CO2DADS and 99mTc-PAHIDA, although not ideal replacements for OIH, demonstrated that a technetium-99m complex could be actively transported by the renal tubules and provided the impetus for development of new technetium-99m renal agents. The next breakthrough in technetium-99m renal agents was the development of the triamide mercaptide class of chelating agents by Fritzberg et al. To date the most promising compound in this class is mercaptoacetyltriglycine (MAG3). 99mTc-MAG3 is currently the agent of choice, but it is by no means the perfect replacement for OIH. Problems with high plasma protein binding and clearances that are only 50% to 60% of the OIH clearance make measurement of ERPF difficult. The serendipitous discovery that metabolites of the brain agent 99mTc-ethylenedicysteine diethylester (99mTc-L,L-ECD) are rapidly excreted in the urine has led to the evaluation of 99mTc-L,L-ethylenedicysteine (99mTc-L,L-ECD) as a potential renal imaging agent. Studies that have evaluated 99mTc-L,L-EC in animals, normal human volunteers, and patients with various renal disorders reveal that the renal clearance of 99mTc-L,L-EC is higher than 99mTc-MAG3 and more closely approaches that of OIH. Other approaches that are being examined in the development of the ideal renal imaging agent include substitution of various amino acids for glycine residue in MAG3 and technetium-99m labeled organic cations. PMID:10321823

Moran, J K

1999-04-01

23

Can technetium-99m-mercaptoacetyltriglycine replace technetium-99m-dimercaptosuccinic acid in the exclusion of a focal renal defect?  

PubMed

The presence of focal renal damage dictates different management of a child with urinary tract infection (UTI) compared with children who have normal kidneys. Technetium-99m-dimercaptosuccinic (DMSA) has a high sensitivity in the detection of a focal defect, and allows estimation of differential function. The introduction of 99mTc-MAG3 with high renal extraction suggests that this may be useful in children with UTI but its role remains speculative. Fifty-nine children with previous UTI underwent both 99mTc-DMSA and MAG3 within 4 wk of each other. Differential function and assessment of the images were undertaken. There is close correlation (R2 = 0.97) between the differential function. Analysis of the 99mTc-DMSA and functional MAG3 images showed that the functional image had a specificity of 88% and a sensitivity of 88% in the detection of a focal parenchymal defect. Technetium-99m-MAG3 in the clinical setting of a child with UTl allows accurate assessment of differential function and a high probability of detecting a focal renal abnormality. PMID:1334134

Gordon, I; Anderson, P J; Lythgoe, M F; Orton, M

1992-12-01

24

Guava extract ( Psidium guajava ) alters the labelling of blood constituents with technetium-99m  

Microsoft Academic Search

Psidium guajava (guava) leaf is a phytotherapic used in folk medicine to treat gastrointestinal and respiratory disturbances and is used\\u000a as anti-inflammatory medicine. In nuclear medicine, blood constituents (BC) are labelled with technetium-99m (99mTc) and used to image procedures. However, data have demonstrated that synthetic or natural drugs could modify the labelling\\u000a of BC with 99mTc. The aim of this

P. R. C. Abreu; M. C. Almeida; R. M. Bernardo; L. C. Bernardo; L. C. Brito; E. A. C. Garcia; A. S. Fonseca; M. Bernardo-Filho

2006-01-01

25

Technetium99m-labeling and synthesis of thymidine analogs: Potential candidates for tumor imaging  

Microsoft Academic Search

The technetium-99m-labeling and synthesis of a series of thymidine analogs were studied. The target molecules were obtained by using 6-hydrazinopyridine-3-carboxylic acid (HYNIC) as a bifunctional coupling agent and using N-(2-hydroxy-1,1-bis(hydroxymethyl)ethyl)glycine (tricine) and ethylenediamine-N,N?-diacetic acid (EDDA) as coligands. The effects of different spacers between thymidine analog with HYNIC on radiochemical yield were also studied.

Bao Teng; Yunpeng Bai; Yu Chang; Shizhen Chen; Zhaolong Li

2007-01-01

26

Cardiac and pleuropulmonary AL amyloid imaging with technetium-99m labelled aprotinin  

Microsoft Academic Search

Antiproteases are known to be present in amyloid deposits. We evaluated the possibility of using an anti-serine protease (aprotinin) labelled with technetium-99m (TcA), usually employed as a cortical renal tracer, for the imaging of amyloid deposits. Because of the known high uptake of TcA by the kidneys, we limited our analysis to extra-abdominal amyloid localizations. We report the scintigraphic findings

Carlo Aprile; Gabriella Marinone; Raffaella Saponaro; Chiara Bonino; Giampaolo Merlini

1995-01-01

27

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

28

Can technetium 99m bisdiethylphosphinoethanebis- t butylisocyanide ( 99m Tc-DEPIC) be used for routine radionuclide ventriculography?  

Microsoft Academic Search

Radionuclide ventriculography is a useful investigation in the evaluation of cardiac function. Generally, in vivo technetium 99m-labelled red blood cells (RBC) yield good quality images in ventriculography. However, it is widely believed that some drugs have an adverse effect on RBC labelling. Zanelli et al. (1987) developed a radiopharmaceutical (technetium 99m bisdiethylphosphinoethanebis-t-butylisocyanide,99mTc-DEPIC) to obtain better results in patients using such

John M. H. de Klerk; Peter P. van Rijk; Alice J. van Dongen; Marco Deenstra; Johan H. Z. Bànki; Alfred D. van het Schip

1991-01-01

29

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

30

Labeling Polyamidoamine (PAMAM) Dendrimers with Technetium-99m via Hydrazinonicotinamide (HYNIC).  

PubMed

Dendrimers are branched nanomolecules, with a three dimensional structure, very low polydispersity and high functionality. Poly(amidoamine) (PAMAM) dendrimers are the most investigated class of dendrimers. In this study, PAMAM G4 dendrimer conjugated with HYNIC (hydrazinonicotinamide), an efficient bifunctional chelator, was characterized. Structure of the derivatized dendrimer was confirmed by (1)H-NMR and (13)C-NMR spectra and MALDI-TOF mass spectrometry. HYNIC-dendrimer was labeled with technetium-99m testing three different co-ligands (tricine, nicotinic acid and ethylenediaminodiacetic acid). The radiolabeled complexes were characterized by reverse phase HPLC, as well as their stabilities. Radiolabeling yield was about 99% with all co-ligands and complexes were found stable for 24 h. Biodistribution studies were performed administrating tricine-(99m)Tc-HYNIC-dendrimer, nicotinic acid-(99m)Tc-HYNICdendrimer and EDDA-(99m)Tc-HYNIC-dendrimer to normal mice; results showed blood clearance with hepatic and renal depuration in all cases. In this sense, labeling of PAMAM G4 dendrimer with technetium-99m using HYNIC could be obtained in high yield in a simple method and with high specific activity. PMID:25175622

Kovacs, Luciana; Tassano, Marcos; Cabrera, Mirel; Fernandez, Marcelo; Porcal, Williams; Anjos, Roberto M; Cabral, Pablo

2014-01-01

31

Technetium-99m-labeled nanofibrillar cellulose hydrogel for in vivo drug release.  

PubMed

Nanoscale celluloses have recently gained an increasing interest in modern medicine. In this study, we investigated the properties of plant derived nanofibrillar cellulose (NFC) as an injectable drug releasing hydrogel in vivo. We demonstrated a reliable and efficient method of technetium-99m-NFC labeling, which enables us to trace the in vivo localization of the hydrogel. The release and distribution of study compounds from the NFC hydrogel after subcutaneous injection in the pelvic region of BALB/c mice were examined with a multimodality imaging device SPECT/CT. The drug release profiles were simulated by 1-compartmental models of Phoenix® WinNonlin®. The NFC hydrogel remained intact at the injection site during the study. The study compounds are more concentrated at the injection site when administered with the NFC hydrogel compared with saline solutions. In addition, the NFC hydrogel reduced the elimination rate of a large compound, technetium-99m-labeled human serum albumin by 2 folds, but did not alter the release rate of a small compound (123)I-?-CIT (a cocaine analogue). In conclusion, the NFC hydrogels is easily prepared and readily injected, and it has potential use as a matrix for controlled release or local delivery of large compounds. The interactions between NFC and specific therapeutic compounds are possible and should be investigated further. PMID:25245005

Laurén, Patrick; Lou, Yan-Ru; Raki, Mari; Urtti, Arto; Bergström, Kim; Yliperttula, Marjo

2014-12-18

32

Characterization of technetium-99m-L,L-ECD for brain perfusion imaging, Part 1: Pharmacology of technetium-99m ECD in nonhuman primates  

SciTech Connect

Technetium-99m ethyl cysteinate dimer (({sup 99m}Tc)ECD) is a neutral, lipophilic complex which rapidly crosses the blood-brain barrier. Brain retention and tissue metabolism of ({sup 99m}Tc)ECD is dependent upon the stereochemical configuration of the complex. While both L,L and D,D enantiomers are extracted by the brain, only the L,L but not the D,D form, is metabolized and retained in the monkey brain (4.7% injected dose initially, T 1/2 greater than 24 hr). Dynamic single photon emission computed tomography imaging studies in one monkey indicates {sup 99m}Tc-L,L-ECD to be distributed in a pattern consistent with regional cerebral blood flow for up to 16 hr postinjection. Dual-labeled {sup 99m}Tc-L,L-ECD and ({sup 14}C)iodoantipyrine autoradiography studies performed 1 hr after administration show cortical gray to white matter ratios of both isotopes to be equivalent (approximately 4-5:1). These data suggest that {sup 99m}Tc-L,L-ECD will be useful for the scintigraphic assessment of cerebral perfusion in humans.

Walovitch, R.C.; Hill, T.C.; Garrity, S.T.; Cheesman, E.H.; Burgess, B.A.; O'Leary, D.H.; Watson, A.D.; Ganey, M.V.; Morgan, R.A.; Williams, S.J. (E.I. Du Pont de Nemours Co., Inc., No. Billerica, MA (USA))

1989-11-01

33

Future of low specific activity molybdenum-99/technetium-99m generator.  

PubMed

In last few years, the shortage of molybdenum-99 (99Mo) was felt in the developed and developing countries hospitals, where diagnostic nuclear medicine is practiced. To overcome the shortage of 99Mo various routes of its production by accelerators and reactors generating low and high specific activity products have been planned. High specific activity 99Mo obtained by fission of uranium-235 (235U) has completely dominated in the manufacturing of technetium-99m (99mTc) generators in last 3-4 decades, but due to proliferation and dirty bomb, issues non fission routes of 99Mo production are emphasized. Future of low specific activity 99Mo is discussed. PMID:22642420

Mushtaq, A

2012-10-01

34

Is technetium-99 m-pyrophosphate scintigraphy valuable in the diagnosis of cardiac amyloidosis  

SciTech Connect

Amyloidosis is a systemic disease frequently involving the myocardium and leading to functional disturbances of the heart. Amyloidosis can mimic other cardiac diseases. A conclusive clinical diagnosis of cardiac involvement can only be made by a combination of different diagnostic methods. In 7 patients with myocardial amyloidosis we used a combined first-pass and static scintigraphy with technetium-99 m-pyrophosphate. There was only insignificant myocardial uptake of the tracer. The first-pass studies however revealed reduced systolic function in 4/7 patients and impaired diastolic function in 6/7 patients. Therefore, although cardiac amyloid could not be demonstrated in the static scintigraphy due to amyloid fibril amount and composition, myocardial functional abnormalities were seen in the first-pass study.

Hartmann, A.; Frenkel, J.; Hopf, R.; Baum, R.P.; Hoer, G.S.; Schneider, M.; Kaltenbach, M. (Frankfurt Univ. Medical Center (West Germany))

1990-01-01

35

Prediction of mortality in heart transplant recipients by stress technetium-99m tetrofosmin myocardial perfusion imaging.  

PubMed

Cardiac allograft vasculopathy is a major cause of mortality in heart transplant recipients. The aim of this study was to assess the prognostic value of stress myocardial perfusion imaging in heart transplant recipients. We studied 166 patients (age 54 +/- 10 years, 140 men) by symptom-limited bicycle exercise or dobutamine (up to 40 microg/kg/min) stress myocardial perfusion imaging 7.4 +/- 2.5 years after heart transplantation. An intravenous dose of 370 MBq of technetium-99m tetrofosmin was injected at peak stress and 24 hours after the stress test. An abnormal test was defined as reversible or fixed perfusion defects. Perfusion abnormalities were detected in 55 patients (33%). During a median follow-up of 2.5 years, 54 deaths (33%) occurred, 16 of which were due to cardiac causes. The incidence of perfusion abnormalities was higher in patients with subsequent cardiac death than in patients without subsequent cardiac death (69% vs 29%, p = 0.01). In an incremental multivariate Cox analysis, cardiac death was not predicted by age, gender, duration of transplantation, number of rejection episodes, or cytomegalovirus infection. In the next step, stress test parameters were added. The peak rate-pressure product was the only significant predictor at this step (risk ratio 0.84, 95% confidence interval 0.73 to 0.97, chi-square 7.7, p = 0.006). In the final step, the presence of abnormal myocardial perfusion was an independent predictor of cardiac death (risk ratio 3.5, 95% confidence interval 1.6 to 11.7, chi-square 4.7, incremental to clinical and stress test variables, p = 0.01). It is concluded that stress myocardial perfusion imaging with technetium-99m tetrofosmin single-photon emission computed tomography provides incremental data for the prediction of cardiac death in heart transplant recipients. PMID:11950436

Elhendy, Abdou; van Domburg, Ron T; Vantrimpont, Pascal; Poldermans, Don; Bax, Jeroen J; van Gelder, Teun; Baan, Carla C; Schinkel, A; Roelandt, Jos R T C; Balk, Aggie H M M

2002-04-15

36

Usefulness of radio-guided surgery using technetium-99m methoxyisobutylisonitrile for primary and secondary hyperparathyroidism.  

PubMed

The efficacy of technetium-99m methoxyisobutylisonitrile (99mTc-MIBI)-guided surgery for detecting abnormal parathyroid glands in patients with secondary hyperparathyroidism (2-HPT) was evaluated and compared with the results from the same examination in patients with primary hyperparathyroidism (1-HPT). The results were also compared with those found by ultrasonography (US) and preoperative 99mTc-MIBI scintigraphy was also made. At operation 99mTc-MIBI accumulated in 64 nodules of 15 cases of 2-HPT, and all of 60 parathyroid swellings were detected (true-positives 60, sensitivity 100%, accuracy 94%). In the cases of 1-HPT, 99mTc-MIBI revealed 11 hot nodules in 10 cases, and the evaluation was true-positive 10, sensitivity 100%, and accuracy 91%. US and preoperative 99mTc-MIBI scintigraphy in patients with 2-HPT had a sensitivity of 75% and 67% and an accuracy of 70% and 66%, respectively. The usefulness of 99mTc-MIBI-guided surgery for detecting abnormal parathyroid tissue in 2-HPT patients was similar to that in 1-HPT patients but was superior to US and preoperative 99mTc-MIBI scintigraphy. Intraoperative 9mTc-MIBI for patients with 2-HPT is effective and makes the surgery easier, especially when the parathyroid glands are ectopic or when a few glands are markedly enlarged but the other glands are atrophied. PMID:15366748

Takeyama, Hiroshi; Shioya, Hisashi; Mori, Yutaka; Ogi, Shigeyuki; Yamamoto, Hiroyasu; Kato, Naohiko; Kinoshita, Satoki; Yoshida, Kazuhiko; Uchida, Ken; Yamazaki, Yoji

2004-06-01

37

Technetium-99m radiolabeled ouabagenin-cysteine conjugate: biological evaluation in animal models.  

PubMed

Two ouabagenin-cysteine conjugates were synthesized by condensing 3-beta monochloroacetyl and 3-beta, 11-alpha dichloroacetyl ouabagenin with cysteine. The resulting ligands were radiolabeled with technetium-99m (99mTc) to furnish a single homogenous 99mTc chelate in each case with good stability. The animal experiments with these 99mTc-labeled conjugates established the superiority of guinea pig over rat and rabbit as an animal model, as previously observed for other tritiated or radioidinated cardiac glycosides or aglycones. In biodistribution experiments in guinea pig, these 99mTc chelates showed a favorable heart to liver (and other nontarget organ) uptake ratio, comparable to that of recently reported 125I-digoxigenin iodohistamine-3-oxime. The low heart to blood ratio in animal experiments with ouabagenin derivatives could be attributed to the absence of 3-beta sugar residues in these molecules, which is in agreement with the previous observation reported in connection with radioiodinated digoxin and digoxigenin derivatives. PMID:8868282

Chatterjee, M; Ganguly, S; Sarkar, B R; Banerjee, S

1996-02-01

38

Suppression by perchlorate of technetium-99m and iodine-123 secretion in milk of lactating goats  

SciTech Connect

Lactating goats were infused with either technetium-99m (/sup 99m/Tc) or iodine-123 (/sup 123/I) together with chlorine-36 (/sup 36/Cl) through an indwelling catheter previously placed in an external pudic mammary artery. The radioisotope infusions were repeated together with 100 mg of sodium perchlorate. There was a rapid transfer of /sup 99m/Tc and /sup 123/I into milk, reaching a peak concentration 30 min after a 15-min infusion. The fractional secretion of /sup 99m/Tc and /sup 123/I in milk was reduced by 70%-80% and 60%-66%, respectively, by perchlorate. The fractional secretion of /sup 36/Cl was not affected by perchlorate, and the shape of the /sup 36/Cl secretion curve differed from those of /sup 99m/Tc and /sup 123/I, which were similar. It is probable, therefore, that the latter nuclides were secreted by a transport route different from that of chloride. Available data describing the secretion of /sup 99m/Tc in human milk after pertechnetate administration was reviewed, and it was concluded that perchlorate pretreatment significantly reduced the secretion of /sup 99m/Tc in human breast milk.

Mountford, P.J.; Heap, R.B.; Hamon, M.; Fleet, I.R.; Coakley, A.J.

1987-07-01

39

Guava extract (Psidium guajava) alters the labelling of blood constituents with technetium-99m.  

PubMed

Psidium guajava (guava) leaf is a phytotherapic used in folk medicine to treat gastrointestinal and respiratory disturbances and is used as anti-inflammatory medicine. In nuclear medicine, blood constituents (BC) are labelled with technetium-99m ((99m)Tc) and used to image procedures. However, data have demonstrated that synthetic or natural drugs could modify the labelling of BC with (99m)Tc. The aim of this work was to evaluate the effects of aqueous extract of guava leaves on the labelling of BC with (99m)Tc. Blood samples of Wistar rats were incubated with different concentrations of guava extract and labelled with (99m)Tc after the percentage of incorporated radioactivity (%ATI) in BC was determined. The results suggest that aqueous guava extract could present antioxidant action and/or alters the membrane structures involved in ion transport into cells, thus decreasing the radiolabelling of BC with (99m)Tc. The data showed significant (P<0.05) alteration of ATI in BC from blood incubated with guava extract. PMID:16691636

Abreu, P R C; Almeida, M C; Bernardo, R M; Bernardo, L C; Brito, L C; Garcia, E A C; Fonseca, A S; Bernardo-Filho, M

2006-06-01

40

A neutral lipophilic technetium-99m complex for regional cerebral blood flow imaging  

SciTech Connect

Technetium-99m-DMG-2MP (Chloro(bis(2,3-butanedionedioxime(1-)-0)(2,3- butanedionedioximato (2-)-N,N{prime},N{double prime},N{prime}{double prime},N{double prime}{double prime},N{prime}{double prime}{double prime}) (2-methylpropyl borato (2-))technetium)), also known as SQ 32097 is a member of a family of neutral lipophilic compounds generally known as boronic acid adducts of technetium dioxime complexes (BATOs). After i.v. administration, the concentration of ({sup 99m}Tc)DMG-2MP in various regions of the brain appears to be proportional to blood flow. In rats, 1.1% ID was in the brain at 5 min postinjection when the blood contained less than 3% ID. Over 24 hr excretion was 59% in the feces and 23% in the urine. The activity in monkey brain at 5 min was 2.8% ID and it cleared with a t1/2 of 86 min. Autoradiographs of monkey brain sections showed excellent regional detail with a gray/white ratio of 3.6 at 10 min. The distribution of ({sup 99m}Tc)DMG-2MP in the monkey brain corresponds to the known cytoarchitectural pattern of cerebral glucose metabolism. The properties of ({sup 99m}Tc)DMG-2MP make it a potentially useful agent for cerebral perfusion imaging in man.

Narra, R.K.; Nunn, A.D.; Kuczynski, B.L.; DiRocco, R.J.; Feld, T.; Silva, D.A.; Eckelman, W.C. (Squibb Institute for Medical Research, New Brunswick, NJ (USA))

1990-08-01

41

Assessment of tissue viability after frostbite injury by technetium-99m-sestamibi scintigraphy in an experimental rabbit model  

Microsoft Academic Search

.   Frostbite causes injury to the tissue by direct ice-crystal formation at the cellular level with cellular dehydration and\\u000a microvascular occlusion. Muscle that initially appears viable on reperfusion may subsequently become necrotic because of microcirculatory\\u000a collapse. Since muscle is a sensitive tissue in frostbite injury, we used technetium-99m-sestamibi limb scintigraphy to assess\\u000a tissue viability in an experimental rabbit model. Twelve

Ismet Sarikaya; A. Cemal Aygit; Latife Candan; Ali Sarikaya; Murat Türkyilmaz; ?akir Berkarda

2000-01-01

42

Development of a radiopharmaceutical activity schedule for technetium-99m dimercaptosuccinic acid in children based on image quality criteria  

Microsoft Academic Search

.   The aim of this study was to determine an activity schedule (amount of administered activity in relation to body weight) for\\u000a technetium-99m dimercaptosuccinic acid examinations in children, from information present in renal scintigraphic images. Scans\\u000a from 48 children (5 weeks to 14.8 years old) were graded for image quality according to the clarity of both kidney outline\\u000a and internal

Terry Smith; Isky Gordon; Kenneth Evans; Peter J. Anderson; Mark F. Lythgoe

1997-01-01

43

Effect of renal maturation on the clearance of technetium-99m mercaptoacetyltriglycine.  

PubMed

To investigate the effect of growth and maturation on the global kidney clearance of technetium-99m mercaptoacetyltriglycine (99mTc-MAG3), we investigated 509 children who attended for 99mTc-MAG3 renography in our department. In order to estimate the normal maturation of the kidney, only children who were classified as "normal" using diagnostic criteria were included in this study (n = 109). Kidney clearance was calculated using a gamma camera technique and a 20-min blood sample. There was a progressive increase in the clearance of 99mTc-MAG3 throughout childhood and into adolescence (mean clearance value below 2 month was 31.4 ml/min, mean clearance value above 12 years was 287 ml/min). When clearance was normalised to body surface area (BSA) a different pattern was seen, with a progressive increase from 3 weeks of age (mean value < 0.2 years: 208 ml/min/1.73 m2) to a plateau at the end of the first year of life (mean value > 2 years: 303 ml/min/1.73 m2). Maturation of the kidney as defined by the normalised clearance of 99mTc-MAG3 is therefore complete by the end of the 1st year of life, after which any change in non-corrected clearance values may be attributed to growth. To investigate the appropriate normalisation factor for 99mTc-MAG3 clearance in children, clearance values were compared to height, weight and BSA. The relationships were described using a linear model; the correlation coefficients demonstrated that BSA has the highest strength of relationship with 99mTc-MAG3 clearance. Body surface area may be used over 1 year of age to normalise the clearance values of 99mTc-MAG3.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7875172

Lythgoe, M F; Gordon, I; Anderson, P J

1994-12-01

44

Technetium-99m hexamethyl propylene amine oxime granulocyte scintigraphy in Crohn's disease: diagnostic and clinical relevance.  

PubMed Central

Scintigraphy with autologous granulocytes labelled by technetium-99m hexamethyl, propylene amine oxime (99mTc-HMPAO) was performed in 103 Crohn's disease patients and 52 healthy controls. In 31 patients endoscopic and histologic activity was compared with scan activity index. In the 98 patients with a positive scan, the extent of Crohn's disease, assessed by scintigraphy, was compared with that evaluated by small bowel x ray or colonoscopy with biopsies. In 48 patients, Crohn's disease activity index, activity index, simple index, erythrocyte sedimentation rate, C-reactive protein were correlated with the scan results. In 16 patients the five parameters and scan were repeated after treatment with methyl-prednisolone (10 cases), enteral nutrition (3), and 5-acetylsalicylic acid (3). The results showed that 99mTc-HMPAO granulocyte scan had a 95% sensitivity and 100% specificity to detect active inflammation; it correctly showed an abscess or a fistula in all the 24 cases found. The correlation between histological inflammatory activity and scan activity index was highly significant (r = 0.85; p < 0.01), less significant (r = 0.65; p < 0.01) between endoscopy and scan activity index. The evaluation for the extent of Crohn's disease by scan was completely correct in the small bowel (100%) and 93% correct in the large bowel. No correlation was seen between the three clinical activity parameters and scanning; in more than 80% of the cases in remission on the basis of a clinical or laboratory index, scintigraphy remained positive. Medical treatment was effective on the clinical indices but not on the active inflammation in the ileum, whereas it led to a negative scan in 5/11 cases in the large intestine. Scintigraphy with 99mTc-HMPAO granulocyte plays an important part in Crohn's disease for the diagnosis of complications, for activity and assessment of the extent, and for the treatment results evaluation. Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:8244102

Sciarretta, G; Furno, A; Mazzoni, M; Basile, C; Malaguti, P

1993-01-01

45

Congenital lymphatic hypoplasia in unilateral lower limb with abnormal technetium-99m sulphur colloid uptake in both breasts  

PubMed Central

We present a patient with Meige like lymphedema (left lower limb hypoplasia) with asymptomatic minimal accumulation of Technetium-99m sulfur colloid in bilateral breasts. We attribute the possible pathology to accumulation of interstitial fluid in hypoplastic left lower limb leading to dilatation of the remaining outflow tracts and valvular incompetence. This may be causing reversal of flow from subcutaneous tissues into the dermal plexus involving the breast. Other possibilities include formation of spontaneous lymphovenous shunt or lymphatic intercommunication at lower trunk level as a result of increased pressure leading to minimal lymph accumulation in breasts. Later a mammogram was performed which was found to be normal. MR also confirmed no cisterna chyli abnormalities or aberrant lymphatic channels in lower thorax region that may be the explanation for the abnormal sulphur colloid uptake in both breasts. PMID:25400372

Padma, Subramanyam; Sundaram, Palaniswamy Shanmuga

2014-01-01

46

Prognostic value of exercise stress technetium-99m-tetrofosmin myocardial perfusion imaging in patients with normal baseline electrocardiograms.  

PubMed

Exercise stress electrocardiography is the recommended method for cardiac evaluation of patients with normal electrocardiograms (ECGs). There are no data to indicate an independent value of myocardial perfusion imaging (MPI) in predicting mortality in these patients. This study assessed the value of exercise stress MPI in predicting mortality in patients with normal baseline ECGs. We studied 319 patients (55 +/- 10 years of age; 180 men) with normal ECGs by exercise stress technetium-99m tetrofosmin MPI. End points during follow-up were cardiac and all-cause mortalities and hard cardiac events. A normal scan was detected in 190 patients (60%). Myocardial perfusion abnormalities were fixed in 59 patients (18%) and reversible in 70 (23%). During a mean follow-up of 7 +/- 1.2 years, 46 patients (14%) died. Death was considered cardiac in 28 patients (9%). Nonfatal myocardial infarction occurred in 12 patients (4%). Annual cardiac death rates were 0.4% in patients with normal perfusion, and 2.7% in patients with reversible defects. Annual total mortality rates were 1.1% in patients with normal perfusion and 3.4% in patients with reversible defects. In a multivariate analysis model, reversible perfusion abnormalities were associated with cardiac death (RR 2.8, 95% confidence interval 1.6 to 5.1) and hard cardiac events (RR 2.7, 95% confidence interval 1.5 to 4.5). Perfusion abnormalities in multivessel distribution were predictive of all-cause mortality (RR 2, 95% confidence interval 1.4 to 3.2). ST-segment depression was not significantly associated with events. In conclusion, stress technetium-99m tetrofosmin MPI provides independent information for predicting cardiac and overall mortalities in patients with normal ECGs. Reversible perfusion abnormalities, but not ischemic electrocardiographic changes, are predictive of outcome in these patients. PMID:16923441

Elhendy, Abdou; Schinkel, Arend F L; van Domburg, Ron T; Bax, Jeroen J; Valkema, Roelf; Huurman, Aukje; Feringa, Harm H H; Poldermans, Don

2006-09-01

47

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

48

Use of Technetium-99m macroaggregated albumin to evaluate the position and condition of totally implanted venous and arterial access devices  

SciTech Connect

Technetium-99m macroggregated albumin is used to assess the proper location and condition of a totally implanted venous and arterial access system prior to infusion therapy. The risk of drug extravasation is thus avoided. Delivery of the chemotherapeutic agents to the intended location is assured.

Lee, R.G.L.; Hill, T.C.; Lokich, J.J.; Bothe, A. Jr; Moore, C.; Clouse, M.E.

1984-02-01

49

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

50

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

51

Technetium-99m-labeled poly(DL-lactide-co-glycolide) nanoparticles as an alternative for sentinel lymph node imaging.  

PubMed

The present investigation was focused on developing Technetium-99m (??(m)Tc)-labeled poly(dl-lactide-co-glycolide) (PLGA) nanoparticles as an alternative to ??(m)Tc-labeled sulfur colloid/albumin nanocolloid for sentinel lymph node detection. PLGA nanoparticles were prepared by emulsion solvent evaporation technique and the system was characterized with respect to particle size and morphology. They showed spherical morphology with a mean particle diameter of ?131?nm and a low polydispersity index indicative of homogenous distribution. The developed colloidal system was further stabilized by lyophilization, and the lyoprotective action of various carbohydrate cryoprotectants was investigated. The lyophilized product was characterized with respect to particle size, appearance, and reconstitution ability. Further, the PLGA nanoparticles were labeled with ??(m)Tc using SnCl? as the reducing agent. ??(m)Tc-labeling yield was not high, requiring purification of labeled product, but purified product was stable for up to 12 hours when stored at 4°C in saline. Biodistribution and scintigraphic imaging studies performed in Wistar rats revealed localization of ??(m)Tc-labeled PLGA nanoparticles in the sentinel nodes. Although further modification of labeling route is required for a clinically suitable product, the developed ??(m)Tc-PLGA nanoparticle system provides an adequate proof-of-concept for PLGA-based systems as an advantageous replacement to currently used sentinel lymph node detection tools. PMID:21204757

Subramanian, Suresh; Dandekar, Prajakta; Jain, Ratnesh; Pandey, Usha; Samuel, Grace; Hassan, Puthusserickal Abdulrahiman; Patravale, Vandana; Venkatesh, Meera

2010-12-01

52

Value of positive myocardial technetium-99m-pyrophosphate scintigraphy in the noninvasive diagnosis of cardiac amyloidosis  

SciTech Connect

Ten consecutive patients with tissue-proven amyloidosis, seven of whom presented with congestive heart failure, were found to exhibit intense diffuse uptake of technetium-99m-pyrophosphate (Tc-99m-PYP) on cardiac radionuclide imaging. The patients exhibited echocardiographic and systolic time interval abnormalities suggesting combined restrictive and congestive cardiomyopathic changes. On M-mode echocardiograms, there was symmetrically increased thickness of the interventricular septum and left ventricular (LV) posterior wall in diastole (10 of 10), decreased fractional shortening of the LV minor axis diameter in systole (eight of nine), and decreased percent thickening of the LV minor axis diameter in systole (eight of nine) and LV posterior wall (10 of 10) in systole. Three patients demonstrated enlarged LV end-diastolic diameter. All 10 patients had abnormal PEP/LVET and eight had shortened LVETI. When combined with noninvasive tests of LV performance, positive myocardial pyrophosphate (PYP) scanning provides a new and useful adjunct in the diagnosis of amyloid heart disease.

Wizenberg, T.A.; Muz, J.; Sohn, Y.H.; Samlowski, W.; Weissler, A.M.

1982-04-01

53

Development of a radiopharmaceutical activity schedule for technetium-99m dimercaptosuccinic acid in children based on image quality criteria.  

PubMed

The aim of this study was to determine an activity schedule (amount of administered activity in relation to body weight) for technetium-99m dimercaptosuccinic acid examinations in children, from information present in renal scintigraphic images. Scans from 48 children (5 weeks to 14.8 years old) were graded for image quality according to the clarity of both kidney outline and internal structure. Numerical image data (kidney and background counts, signal-to-noise ratio) were associated with these subjective gradings to formulate three criteria, specifying the required values of the above-measured parameters to yield optimum grades of image quality. When applied to derived functions, a kidney uptake of 20% was required to satisfy the criterion based on the signal-to-noise ratio. Using this value with the other two criteria predicts the form of the weight-dependent activity schedule as a function of imaging time. Examples of schedules for imaging times of 300 and 600 s are compared with a schedule based on surface area. PMID:9371868

Smith, T; Gordon, I; Evans, K; Anderson, P J; Lythgoe, M F

1997-11-01

54

Comparison of technetium 99m methoxy isobutyl isonitrile and thallium 201 for evaluation of coronary artery disease by planar and tomographic methods  

Microsoft Academic Search

To compare stress\\/rest technetium 99m methoxy isobutyl isonitrile (Tc-MIBI) with stress redistribution thallium 201(T1-201) myocardial perfusion imaging, 36 patients were studied by single photon emission computerized tomography (SPECT) and planar methods. For SPECT, overall sensitivities for identification of patients with coronary artery disease were 93% (14\\/15) by Tc-MIBI and 80% (12\\/15) by TI-201 (p = NS). For planar methods, overall

H. Kiat; J. Maddahi; L. T. Roy; K. Van Train; J. Friedman; K. Resser; D. S. Berman

1989-01-01

55

Comparison of Baseline–Nitrate Technetium99m Sestamibi With Rest–Redistribution Thallium201 Tomography in Detecting Viable Hibernating Myocardium and Predicting Postrevascularization Recovery  

Microsoft Academic Search

Objectives. This study aimed to define the optimal criteria for detecting viable myocardium with rest–redistribution thallium-201 (Tl-201) or baseline–nitrate technetium-99m (Tc-99m) sestamibi single-photon emission computed tomography (SPECT) using discriminant analysis and to compare the accuracy of the two tracers in predicting postrevascularization recovery.Background. Rest–redistribution Tl-201 imaging is currently used for detection of myocardial viability, but the optimal variables for territory

Roberto Sciagrà; Gianni Bisi; Giovanni M Santoro; Francesca Zerauschek; Stelvio Sestini; Paola Pedenovi; Ruggiero Pappagallo; Pier Filippo Fazzini

1997-01-01

56

A Monte Carlo investigation of artifacts caused by liver uptake in single-photon emission computed tomography perfusion imaging with technetium 99m-labeled agents  

Microsoft Academic Search

Background  Significant hepatobiliary accumulation of technetium 99m-labeled cardiac perfusion agents has been shown to cause alterations\\u000a in the apparent localization of the agents in the cardiac walls. A Monte Carlo study was conducted to investigate the hypothesis\\u000a that the cardiac count changes are due to the inconsistencies in the projection data input to reconstruction, and that correction\\u000a of the causes of

Michael A. King; Weishi Xia; Daniel J. deVries; Tin-Su Pan; Benard J. Villegas; Seth Dahlberg; Benjamin M. W. Tsui; Michael H. Ljungberg; Hugh T. Morgan

1996-01-01

57

The efficacy of technetium-99m ciprofloxacin (Infecton) imaging in suspected orthopaedic infection: a comparison with sequential bone\\/gallium imaging  

Microsoft Academic Search

Technetium-99m ciprofloxacin (Infecton) has recently become established as a new radiopharmaceutical for the imaging of infection. This study was performed to determine the value of Infecton imaging in demonstrating orthopaedic infection and to compare the results with bone\\/gallium imaging. Twenty-two patients (12 female, 10 male; mean age 51.7ᆤ.8 years) with suspected orthopaedic infective conditions were included in the study. The

Zeynep Yapar; Mustafa Kibar; Fuat A. Yapar; Emre To?rul; Ufuk Kayaselçuk; Yaman Sarpel

2001-01-01

58

Simultaneous technetium-99m/thallium-201 SPECT imaging with model-based compensation for cross-contaminating effects  

NASA Astrophysics Data System (ADS)

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 with 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 with a NMSE of 0.091 for the subtraction-based compensation method. The application of a preliminary model for cross-talk 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 probably 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.

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

1999-07-01

59

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

60

Successful application of technetium-99m-labeled octreotide acetate scintigraphy in the detection of ectopic adrenocorticotropin-producing bronchial carcinoid lung tumor: a case report  

PubMed Central

Introduction The diagnostic efficacy of somatostatin receptor scintigraphy labeling with 111 indium in the localization of tumors has been assessed in a limited number of patients with contradictory outcomes. Here, we describe the case of a patient with an ectopic adrenocorticotropic hormone-producing bronchial carcinoid tumor diagnosed preoperatively using technetium-99m-labeled octreotide acetate scintigraphy. Case presentation A 29-year-old Asian man presented to our hospital with the typical clinical features of Cushing's syndrome, which he had had for a duration of 18 months. The results of a biochemical evaluation revealed he had adrenocorticotropic hormone-dependent Cushing's syndrome. The results of a spiral abdominal computed tomography scan showed he had bilateral adrenal hypertrophy. A magnetic resonance image of the patient's brain showed he had a normal hypophysis. Whole body technetium-99m-labeled octreotide acetate scintigraphy was performed to check for the presence of an ectopic adrenocorticotropic hormone-producing tumor. The scan results showed a small focal increase in uptake in the lower lobe of our patient's right lung, just above his diaphragm. A spiral chest computed tomography scan also revealed a small non-specific lesion in the same region. A transthoracic biopsy was then performed. Pathological evaluation confirmed the diagnosis of a carcinoid tumor, of the adrenocorticotropic hormone-producing type. After surgical removal, the patient's symptoms resolved and significant clinical improvement was achieved. Conclusions This case report shows that technetium-99m-labeled octreotide acetate scintigraphy can effectively detect an ectopic adrenocorticotropic hormone-producing bronchial carcinoid. PMID:20955547

2010-01-01

61

Comparison of shunt fraction estimation using transcolonic iodine-123-iodoamphetamine and technetium-99m-pertechnetate in a group of dogs with experimentally-induced chronic biliary cirrhosis  

SciTech Connect

Portosystemic shunt fraction estimation using transcolonic iodine-123-iodoamphetamine (IMP) has been previously validated relative to portal vein macroaggregated albumin injections using an experimental model of cirrhosis. Transcolonic technetium-99m-pertechnetate (TcO4-) has been proposed as an alternative tracer to IMP to study portal circulation in cirrhotic patients. We compared shunt fraction estimates from paired transcolonic IMP and TcO4- studies performed on a group of dogs before and after common bile duct ligation surgery. Pertechnetate over-estimated shunt fraction in 6/7 postoperative studies relative to IMP. A good correlation between the two methods was demonstrated, however, the slope of the regression line was substantially less than 1.0 with TcO4- values reaching 100% at IMP shunt values of approximately 60%. This apparent inability to accurately assess high shunt flows may limit the quantitative aspects of TcO4- studies on patients with severe portosystemic shunting.

Koblik, P.D.; Hornof, W.J.; Yen, C.K.; Komtebedde, J.; Breznock, E.; Fisher, P. (Univ. of California, Davis (USA))

1991-01-01

62

Anti-sense oligonucleotide labeled with technetium-99m using hydrazinonictinamide derivative and N-hydroxysuccinimidyl S-acetylmercaptoacetyltriglycline: A comparison of radiochemical behaviors and biological properties  

PubMed Central

AIM: To explore and compare the radiochemical behavior and biological property of anti-sense oligonucleotide (ASON) labeled with technetium-99m using N-hydroxysuccinimidyl S-acetylmercaptoacetyltriglycline (NHS-MAG3) and hydrazinonictinamide derivative (HYNIC). METHODS: After HYNIC and NHS-MAG3 were synthesized, ASON was labeled with technetium-99m using HYNIC and NHS-MAG3 as a bifunctional chelator. The in vivo and in vitro stability, binding rates of labeled compounds to serum albumen, biodistribution of 99mTc-MAG3-ASON and 99mTc-HYNIC-ASON in BALB/C mouse and its HT29 tumor cellular uptake were compared. RESULTS: The labeling efficiency and stability of 99mTc-MAG3-ASON were significantly higher than those of 99mTc-HYNIC-ASON (P = 0.02, and P = 0.03, respectively). 99mTc-MAG3-ASON had a significantly lower rate of binding to serum albumen than 99mTc-HYNIC-ASON (P < 0.05). In contrast to 99mTc-HYNIC-ASON, the biodistribution of 99mTc-MAG3-ASON was significantly lower in blood, heart, liver and stomach (P < 0.05), slightly lower in intestines and spleen (P > 0.05) and significantly higher in lung and kidney (P < 0.05). The HT29 tumor cellular uptake rate of 99mTc-MAG3-ASON was significantly higher than that of 99mTc-HYNIC-ASON (P < 0.05). CONCLUSION: 99mTc-MAG3-ASON shows superior radiochemical behaviors and biological properties than 99mTc-HYNIC-ASON. 99mTc-MAG3-ASON is a potential radiopharmaceutical agent for in vivo application. PMID:18407601

Li, Yun-Chun; Tan, Tian-Zhi; Zheng, Jian-Guo; Zhang, Chun

2008-01-01

63

Comparison of usefulness of dipyridamole stress myocardial contrast echocardiography to technetium-99m sestamibi single-photon emission computed tomography for detection of coronary artery disease (PB127 Multicenter Phase 2 Trial results)  

Microsoft Academic Search

We hypothesized that assessment of hyperemic myocardial blood flow (MBF) velocity using myocardial contrast echocardiography (MCE) can detect coronary artery disease (CAD). We also postulated that only a single MCE study during stress is required for the detection of CAD in patients with normal function at rest. Patients with known or suspected CAD referred for dipyridamole stress technetium-99m sestamibi single-photon

Kevin Wei; Linda Crouse; James Weiss; Flordeliza Villanueva; Nelson B. Schiller; Tasneem Z. Naqvi; Robert Siegel; Mark Monaghan; Jonathan Goldman; Paul Aggarwal; Harvey Feigenbaum; Anthony DeMaria

2003-01-01

64

p-Tertbutylcalix[4]arene nanoemulsion: preparation, characterization and comparative evaluation of its decontamination efficacy against Technetium-99m, Iodine-131 and Thallium-201.  

PubMed

This study aimed to develop p-tertbutylcalix[4]arene o/w nanoemulsion for decontamination of radioisotopes from skin. Formulation was characterized using dynamic light scattering (DLS), transmission electron microscopy (TEM), multi-photon confocal microscopy techniques and in vitro dissolution studies. In vivo evaluation of nano-emulsion was done using nuclear medicine technique. Stability studies and dermal toxicity studies were also carried out. Comparative decontamination efficacy (DE) studies were performed on synthetic human tissue equivalent material and Sprague Dawley rat against three commonly used medical radioisotopes, i.e., Technetium-99m ((99m)Tc), Iodine-131 ((131)I) and Thallium-201 ((201)Tl). Decontamination was performed using cotton swabs soaked in nanoemulsion at different time intervals of contaminants exposure. Whole body imaging and static counts were recorded using gamma camera before and after each decontamination attempt data was analyzed using one way analysis of variance (ANOVA) and found to be statistically significant (p<0.05). DE of the nanoemulsion loaded with p-tertbutylcalix[4]arene was observed to be 88±5%, 90±3% and 89±3% for (99m)Tc, (131)I and (201)Tl respectively. Dermal toxicity studies revealed no significant differences between treated and control animals. Skin histopathology slides with and without API (Active pharmaceutical ingredients) also found to be comparable. p-Tertbutylcalix[4]arene loaded nanoemulsion shows great promise for skin decontamination against broad ranges of radiological contaminants besides being stable and safe. PMID:24632037

Rana, Sudha; Sharma, Navneet; Ojha, Himanshu; Shivkumar, Hosakote Gurumalappa; Sultana, Sarwat; Sharma, Rakesh Kumar

2014-05-01

65

Biological and imaging characteristics and radiation dose rates associated with the use of technetium-99m-labelled imidodiphosphate in the horse.  

PubMed Central

The biological and imaging characteristics of technetium-99m imidodiphosphate (Tc99m-IDP) were measured in 4 horses once and in 1 horse twice. All computational results are expressed with 95.5% (mean +/- 2 SD) confidence limits. The clearance half-time of the radiopharmaceutical from the blood was 29.6 +/- 2.3 min. The percentage of the administered dose circulating in the whole-blood volume at 4 h was 3.9 +/- 0.8%. The Tc99m-IDP radioactivity confined at the plasma fraction of the whole blood at 4 h was 85.3 +/- 1.6%. At 8 h, approximately 45 +/- 16% of the dose administered had been excreted via the urine. The mean effective half-time of the urine activity concentration was 1.1 +/- 0.3 h. The ratios of bone-to-soft tissue activities increased with time postinjection. Urinary radioactivity concentration measurements and radiation dose rate measurements immediately behind the elbows were analysed and it was determined that 24 h is an appropriate radioisolation time for mature horses administered 3.7 GBq (100 mCi) Tc99m-IDP. Images Figure 2. PMID:8785724

Riddolls, L J; Byford, G G; McKee, S L

1996-01-01

66

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

67

Aptamers directly radiolabeled with technetium-99m as a potential agent capable of identifying carcinoembryonic antigen (CEA) in tumor cells T84.  

PubMed

Aptamers are small oligonucleotides that are selected to bind with high affinity and specificity to a target molecule. Aptamers are emerging as a new class of molecules for radiopharmaceutical development. In this study a new method to radiolabel aptamers with technetium-99m ((99m)Tc) was developed. Two aptamers (Apt3 and Apt3-amine) selected against the carcinoembryonic antigen (CEA) were used. Labeling was done by the direct method and the developed complex was subjected to quality control tests. Radiochemical purity and stability were monitored by Thin Layer Chromatography. Binding and specificity assays were carried out in the T84 cell line (CEA+) to evaluate tumor affinity and specificity after radiolabeling. Aptamers were successfully labeled with (99m)Tc in high radiochemical yields, showing in vitro stability in presence of plasma and cystein. In binding assays the radiolabeled aptamer Apt3-amine showed the highest affinity to T84 cells. When evaluated with HeLa cells (CEA-), lower uptake was observed, suggesting high specificity for this aptamer. These results suggest that the Apt3-amine aptamer directly labeled with (99m)Tc could be considered a promising agent capable of identifying the carcinoembryonic antigen (CEA) present in tumor cells. PMID:24675379

Correa, Cristiane Rodrigues; de Barros, André Luís Branco; Ferreira, Carolina de Aguiar; de Goes, Alfredo Miranda; Cardoso, Valbert Nascimento; de Andrade, Antero Silva Ribeiro

2014-04-15

68

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

69

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

70

Presurgical identification of hibernating myocardium by combined use of technetium-99m hexakis 2-methoxyisobutylisonitrile single photon emission tomography and fluorine-18 fluoro-2-deoxy-d-glucose positron emission tomography in patients with coronary artery disease  

Microsoft Academic Search

We tested the possibility of identifying areas of hibernating myocardium by the combined assessment of perfusion and metabolism using single photon emission tomography (SPET) with technetium-99m hexakis 2-methoxyisobutylisonitrile (99mTc-MIBI) and positron emission tomography (PET) with fluorine-18 fluoro-2-deoxy-d-glucose (18F-FDG). Segmental wall motion, perfusion and 18F-FDG uptake were scored in 5 segments in 14 patients with coronary artery disease (CAD), for a

G. Lucignani; G. Paolini; C. Landoni; M. Zuccari; G. Paganelli; L. Galli; G. Di Credico; G. Vanoli; C. Rossetti; M. A. Mariani; M. C. Gilardi; F. Colombo; A. Grossi; F. Fazio

1992-01-01

71

Technetium-99m nitrido dithiocarbamate complex with lateral ester groups: A potential agent for cerebral perfusion. Direct labeling and kinetic results in baboons  

SciTech Connect

Previous studies have shown that technetium-99m-nitrido (TcN) complexes of ester derivatives of dithiocarbamate cross the brain-blood barrier and one term of this class, namely the complex formed with sarcosine methyl ester dithiocarbamate (TcN-PR13) is retained in the brain of Cynomolgus monkeys. However these compounds were obtained through an in situ esterification of preformed TcN dicarboxylic derivative. We have been able to synthesize one term of this class of ligands, the sarcosine methylester dithiocarbamate, by reacting sarcosine with thionyl chloride in methanol to give the sarcosine methyl ester, which was reacted with carbon disulfide and NaOH in methanol to give the sodium salt of the dithiocarbamate derivative which was isolated as an oil. The corresponding TcN complex was obtained with a radiochemical purity greater than 96% by a kit method. The complex was injected in baboons and its radioactive distribution compared to that obtained with Tc-HMPAO. Blood and plasma kinetics were calculated from arterial sampling whereas tissue kinetics (brain, lungs) were obtained by ROI`s analysis. The values of the half-life in the blood were comparable for the two tracers, although the absolute activity was about 20% lower for TcN-PR13. The brain uptake of TcN-PR13 was 10% lower than that observed for Tc-HMPAO, and remained stable during 2 hours. TcN-PR13 displayed lower lung uptake and faster clearance from this organ than Tc-HMPAO. Brain/Lung ratios were 1.11 and 1.65 at 30 and 60 min for TcN-PR13 compared to 0.93 and 0.99 at the same time for Tc-HMPAO.

Bottlaender, M.; Bourguignon, M.; Maziere, M. [Service Hospitalier Frederic Joliot CEA Orsay, Yvette (France)] [and others

1994-05-01

72

Evaluation of myocardial viability with technetium-99m hexakis-2-methoxyisobutyl isonitrile and iodine-123 phenylpentadecanoic acid and single photon emission tomography.  

PubMed

The detection of viable myocardium in infarcted regions, i.e. hibernating myocardium, is a major goal in clinical cardiology today. We applied combined planar and single photon emission tomography (SPET) to the non-invasive estimation of the left ventricular ejection fraction (LVEF), myocardial blood flow and free fatty acid uptake in the heart. Of the 31 patients with coronary artery disease, 25 (81%) had had a previous myocardial infarction. All patients had at least one persistent perfusion defect on the stress-rest technetium-99m hexakis-2-methoxyisobutyl isonitrile (Sestamibi) study, and the results revealed 57/124 (46%) persistent perfusion defects. As a part of the perfusion study, the LVEF was measured at rest using the first-pass 99mTc-Sestamibi injection, and the mean LVEF was 47% +/- 9% (mean +/- 1 standard deviation). Iodine-123 phenylpentadecanoic acid (123I-pPPA) imaging at rest was performed within 2 weeks from the perfusion study. Then 6-mm transaxial, sagittal and coronal slices of the perfusion and 123I-pPPA studies were reconstructed. The bull's eye displays of the coronal slices were visually surveyed and divided into 4 quadrants: anterior, lateral, posterior and septal. The following image score was used: 0 = fixed defect, 1 = partial uptake and 2 = normal uptake. Moreover an index of metabolic reserve (MR) was calculated by dividing the bull's eye of the 123I-pPPA study by the bull's eye of resting 99mTc-Sestamibi, and its maximum value was normalized to 100%.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1451705

Kuikka, J T; Mussalo, H; Hietakorpi, S; Vanninen, E; Länsimies, E

1992-01-01

73

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

74

Synthesis, physicochemical and biological evaluation of technetium-99m labeled lapatinib as a novel potential tumor imaging agent of Her-2 positive breast cancer.  

PubMed

Tumors that are Her-2-positive tend to grow and spread more quickly than other types of breast cancer. Overexpression of Her-2 can be a predictive biomarker for stratification of patients for therapy with Herceptin (containing humanized IgG1 monoclonal antibody trastuzumab) or Tykerb (containing lapatinib di-p-toluenesulfonate) drug. Usually, Her-2 status is determined by immunohistochemical (IHC) as well as fluorescent or chromogenic in situ hybridisation (FISH or CISH) analysis of biopsy material. The objective of the present work was to standardize the conjugation of anti-cancer drug lapatinib (which recognizes selectively the Her-2 extracellular domain) with technetium-99m complex, of type '4+1', to obtain (99m)Tc(NS3)(CN-lapatinib) conjugate for use as in vivo tracer of the Her-2 expression in breast cancer. The conjugate (99m)Tc(NS3)(CN-lapatinib) was formed with high yield, high radiochemical purity and specific activity within the range 25-30 GBq/?mol. The biological in vitro and in vivo studies of the conjugate showed its high affinity to Her-2 receptor (Kd = 3.5 ± 0.4 nM, Ki = 2.9 ± 0.5 nM, Bmax = 2.4 ± 0.3 nM, approximate number of 2.4 × 10(6) binding sites per cell, IC50 = 41.2 ± 0.4 nM) and also pointed out to the clearance through the hepatic and renal route in comparable degree. Basing on these results one can conclude that (99m)Tc(NS3)(CN-lapatinib) conjugate could be a promising radiopharmaceutical for in vivo diagnosis of the Her-2 status in breast with impact on treatment planning. PMID:25440878

Gniazdowska, Ewa; Ko?mi?ski, Przemys?aw; Ba?kowski, Krzysztof; Luniewski, Wojciech; Królicki, Leszek

2014-11-24

75

Attenuation of apoptosis by telmisartan in atherosclerotic plaques of apolipoprotein E-/- mice: evaluation using technetium 99m-annexin A5.  

PubMed

Technetium 99m (99mTc)-annexin A5, a marker of ongoing apoptosis, is supposed to be useful in the detection of metabolically active atheroma. The aim of this study was to determine the potential of 99mTc-annexin A5 for evaluating the therapeutic effects of an angiotensin II receptor type 1 blocker (ARB) (telmisartan) on atherosclerosis. Male apolipoprotein E-/- mice were divided into telmisartan-treated (3 mg/kg/d, n ?=? 10) and control (n ?=? 10) groups. After 16 to 21 weeks of treatment, 99mTc-annexin A5 was injected and cryostat sections of aortic tissues (n ?=? 10-12/aorta) were prepared. The 99mTc-annexin A5 accumulation level in the plaques was evaluated by autoradiography. Serial sections of the plaques were histologically examined to identify the lesion phenotypes (normal vessels, early lesions, atheromatous lesions, and fibrotic lesions), plaque size, macrophage infiltration levels, and lipid deposition levels. Telmisartan treatment significantly decreased the plaque size (0.05 ± 0.05 vs 0.11 ± 0.08, mm2), macrophage infiltration level (0.02 ± 0.02 vs 0.03 ± 0.02, mm2), lipid deposition level (0.01 ± 0.01 vs 0.02 ± 0.02, mm2), and 99mTc-annexin A5 accumulation level (1.30 ± 1.09 vs 2.15 ± 1.91, × 10-6/g). 99mTc-annexin A5 accumulation levels in the plaques positively correlated with macrophage infiltration (r ?=? .69, p < .05) and lipid deposition (r ?=? .66, p < .05) levels. Apoptosis imaging with 99mTc-annexin A5 may be useful for evaluating the therapeutic effects of ARBs on atherosclerosis. PMID:23763985

Zhao, Yan; Zhao, Songji; Kuge, Yuji; Strauss, H William; Blankenberg, Francis G; Tamaki, Nagara

2013-01-01

76

Technetium-99m dimercaptosuccinic acid scan in evaluation of renal cortical scarring: Is it mandatory to do single photon emission computerized tomography?  

PubMed Central

Objectives: Renal cortical scintigraphy with technetium-99m (Tc-99m) dimercaptosuccinic acid (DMSA) is the method of choice to detect acute pyelonephritis and cortical scarring. Different acquisition methods have been used: Planar parallel-hole or pinhole collimation and single photon emission tomography (SPECT). This study compared planar parallel-hole cortical scintigraphy and dual-head SPECT for detection of cortical defects. Patients and Methods: We retrospectively reviewed 190 consecutive patients with 380 kidneys and 200 DMSA scans referred to rule out renal cortical scarring. The diagnoses were 52 vesicoureteric reflux, 61 recurrent urinary tract infection, 39 hydronephrosis, 20 renal impairment, and 18 hypertension. All patients were imaged 3 h after injection of Tc-99m DMSA with SPECT and planar imaging (posterior, anterior, left, and right posterior oblique views). For each patient, planar and SPECT images were evaluated at different sittings, in random order. Each kidney was divided into three cortical segments (upper, middle and lower) and was scored as normal or reduced uptake. The linear correlation coefficient for the number of abnormal segments detected between planner and SPECT techniques was calculated. Results: From 200 DMSA scans, 100 scans were positive for scar in SPECT images, from which only 95 scans were positive for scar in planner imaging. Out of the five mismatched scans, three scans were for patients with renal impairment and high background activity and two scans were for very small scars. No significant difference was seen in the average number of abnormal segments detected by planar versus SPECT imaging (P = 0.31). The average correlation coefficient between was high (r = 0.91 – 0.92). Conclusions: Tc-99m DMSA renal cortical scanning using SPECT offers no statistically significant diagnostic advantage over multiple views planar imaging for detection of cortical defect. PMID:25589802

Saleh Farghaly, Hussein Rabie; Mohamed Sayed, Mohamed Hosny

2015-01-01

77

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

78

Measurement of Technetium-99m Sestamibi Signals in Rats Administered a Mitochondrial Uncoupler and in a Rat Model of Heart Failure  

PubMed Central

Background Many methods have been used to assess mitochondrial function. Technetium-99m sestamibi (99mTc-MIBI), a lipophilic cation, is rapidly incorporated into myocardial cells by diffusion and mainly localizes to the mitochondria. The purpose of this study was to investigate whether measurement of 99mTc-MIBI signals in animal models could be used as a tool to quantify mitochondrial membrane potential at the organ level. Methods and Results We analyzed 99mTc-MIBI signals in Sprague-Dawley (SD) rat hearts perfused with carbonyl cyanide m-chlorophenylhydrazone (CCCP), a mitochondrial uncoupler known to reduce the mitochondrial membrane potential. 99mTc-MIBI signals could be used to detect changes in the mitochondrial membrane potential with sensitivity comparable to that obtained by two-photon laser microscopy with the cationic probe tetramethylrhodamine ethyl ester (TMRE). We also measured 99mTc-MIBI signals in the hearts of SD rats administered CCCP (4 mg/kg intraperitoneally) or vehicle. 99mTc-MIBI signals decreased in rat hearts administered CCCP, and the ATP content, as measured by 31P magnetic resonance spectroscopy, decreased simultaneously. Next, we administered 99mTc-MIBI to Dahl salt-sensitive rats fed a high-salt diet, which leads to hypertension and heart failure. The 99mTc-MIBI signal per heart tissue weight was inversely correlated with heart weight, cardiac function, and the expression of atrial natriuretic factor, a marker of heart failure, and positively correlated with the accumulation of labeled fatty acid analog. The 99mTc-MIBI signal per liver tissue weight was lower than that per heart tissue weight. Conclusion Measurement of 99mTc-MIBI signals can be an effective tool for semiquantitative investigation of cardiac mitochondrial membrane potential in the SD rat model by using a chemical to decrease the mitochondrial membrane potential. The 99mTc-MIBI signal per heart tissue weight was inversely correlated with the severity of heart failure in the Dahl rat model. PMID:25594546

Kawamoto, Akira; Kato, Takao; Shioi, Tetsuo; Okuda, Junji; Kawashima, Tsuneaki; Tamaki, Yodo; Niizuma, Shinichiro; Tanada, Yohei; Takemura, Genzou; Narazaki, Michiko; Matsuda, Tetsuya; Kimura, Takeshi

2015-01-01

79

Incremental value of exercise technetium-99m tetrofosmin myocardial perfusion single-photon emission computed tomography for the prediction of cardiac events.  

PubMed

Technetium-99m (Tc-99m) tetrofosmin single-photon emission computed tomography (SPECT) is a useful alternative to thallium-201 scintigraphy for the assessment of myocardial perfusion. This study assessed the incremental value of exercise Tc-99m tetrofosmin SPECT for the prediction of cardiac events in patients with known or suspected coronary artery disease. Exercise Tc-99m tetrofosmin SPECT imaging was performed in 655 consecutive patients. Follow-up was successful in 648 patients (98.9%). Ten patients underwent early coronary revascularization and were excluded. End points were cardiac death, nonfatal infarction, and late (>60 days) coronary revascularization. An abnormal study was defined as the presence of fixed and/or reversible perfusion defects. A summed stress score (SSS) was derived to estimate the extent and severity of perfusion defects. An abnormal scan was detected in 344 patients (54%). During a mean follow-up period of 4 +/- 1.3 years, 56 patients (9%) died (22 cardiac deaths). Nonfatal myocardial infarction occurred in 19 patients (3%), and 89 patients (14%) underwent late coronary revascularization. An abnormal scan was an independent predictor of cardiac death (hazard ratio 3.5, confidence intervals [CI] 1.1 to 12.2) and provided incremental information over clinical and exercise test data (log-likelihood -133 to -125, p <0.05). The SSS provided incremental prognostic information over clinical data as well (log-likelihood -133 to -127, p <0.05) (hazard ratio 1.23, CI 1.10 to 1.38). An abnormal scan (hazard ratio 3.3, CI 1.1 to 12.2)) and the SSS (hazard ratio 1.25, CI 1.07 to 1.45)) were powerful independent predictors of the combined end point of any cardiac event. Thus, exercise Tc-99m tetrofosmin myocardial perfusion SPECT provides information incremental to clinical data for the prediction of cardiac events in patients with known or suspected coronary artery disease. PMID:12586253

Schinkel, Arend F L; Elhendy, Abdou; van Domburg, Ron T; Bax, Jeroen J; Vourvouri, Eleni C; Bountioukos, Manos; Rizzello, Vittoria; Agricola, Eustachio; Valkema, Roelf; Roelandt, Jos R T C; Poldermans, Don

2003-02-15

80

Prevalence and prognostic value of perfusion defects detected by stress technetium-99m sestamibi myocardial perfusion single-photon emission computed tomography in asymptomatic patients with diabetes mellitus and no known coronary artery disease.  

PubMed

Coronary artery disease (CAD) is the leading cause of morbidity and mortality in diabetics. Early diagnosis of CAD and identification of high-risk subgroups, followed by appropriate therapy, may therefore enhance survival. This study sought to determine the value of stress myocardial perfusion single-photon emission computed tomography (SPECT) with technetium-99m sestamibi to detect perfusion defects and predict cardiac events in asymptomatic diabetics. One hundred eighty asymptomatic diabetics without known CAD who underwent 2-day stress technetium-99m sestamibi SPECT were followed up for 36 +/- 18 months. End points were defined as hard (myocardial infarction or cardiac death) or total events (myocardial infarction, cardiac death, or late revascularization). Logistic regression analysis evaluated clinical variables, type of stress, exercise treadmill test (ETT), and SPECT as predictors of end points. Perfusion defects were found in 26% of patients (15% reversible, 6% mixed, and 5% fixed). Clinical or ETT variables were not associated with perfusion defect type or with hard events. However, male gender predicted total events (chi-square 3.3; p = 0.01). An abnormal SPECT significantly increased the risk of hard events (chi-square 5.4; p = 0.001) and total events (chi-square 7.4; p = 0.0001). Extensive defects determined the highest risk of total events (chi-square 18.8; p = 0.0001). Event rates increased according to SPECT: 2% of hard events per year and 5% of total events per year in patients with normal SPECT versus 9% per year and 38% per year, respectively, in those with abnormal SPECT. Importantly, a normal SPECT identified a relatively low-risk subgroup of patients. Thus, stress technetium-99m sestamibi SPECT was useful in evaluating asymptomatic diabetics for the presence of CAD, and effectively risk-stratified this population. PMID:12372568

De Lorenzo, Andrea; Lima, Ronaldo S L; Siqueira-Filho, Aristarco G; Pantoja, Mauricio R

2002-10-15

81

Clearance of Tc-99m DTPA aerosol from coal miners' lungs  

SciTech Connect

Alterations in regional epithelial permeability were assessed in 22 retired West Virginia coal miners' lungs by measuring the clearance of inhaled 0.5-..mu..m Tc-99m DTPA aerosol. Activity was measured in both lungs and in regions of interest placed over the lung periphery in the apical, middle, and basal portions of each lung. Clearance rates (T/sub 1/2/) for 5 nonsmokers, 8 ex-smokers, and 9 smokers were significantly faster than for comparable subjects measured elsewhere, who were not coal miners. Regional apex-to-base distributions of DTPA were measured as a function of clearance time and compared with regional ventilation and perfusion. Regional, as well as overall lung clearance curves of 8 smokers and 4 ex-smokers had two components, with overall T/sub 1/2/ of <7 min for the faster one. No correlations were found between T/sub 1/2/ and DLCO or with P(A-a)O/sub 2/. The results of our study suggest that measurement of DTPA clearance is a potentially useful noninvasive technique to assess lung injury in miners exposed to coal dust. 14 refs., 6 figs., 2 tabs.

Susskind, H.; Brill, A.B.; Harold, W.H.

1985-07-01

82

Comparison of Tc-99m DTPA aerosol ventilation studies with pulmonary function testing in cystic fibrosis.  

PubMed

In 43 patients with cystic fibrosis, the results of 122 Tc-99m DTPA aerosol ventilation (DAV) studies were compared with pulmonary function tests (PFTs) that were performed within 24 hours of the DAV studies. The DAV studies were evaluated blindly for (A) number of pulmonary segments showing little or no ventilation, (B) number of foci of bronchial deposition of aerosol, and (C) subjective overall improvement, lack of change, or worsening from the previous study. (A) and (B) correlated significantly with all PFTs (p's < .001, r's = -.51 to -.73). Changes in (A) and (B) also correlated with changes in PFTs (p's < or = .001, r's = -.37 to -.58). The three populations in (C) were significantly different from each other with respect to changes in all PFTs (p < or = .002). Intervals between studies showing subjective improvement, no change, and worsening averaged 60, 133, and 306 days, respectively. These results suggest that DAV is an indicator of both regional and global pulmonary function and may be useful in evaluating patients with cystic fibrosis. PMID:8422713

Kuni, C C; Budd, J R; Regelmann, W E; Ducret, R P; Boudreau, R J

1993-01-01

83

Detection of somatostatin receptor-positive tumours using the new 99m Tc-tricine-HYNIC- d -Phe 1 Tyr 3 -octreotide: first results in patients and comparison with 111 In-DTPA- d -Phe 1 -octreotide  

Microsoft Academic Search

.   Indium-111 labelledDTPA-d-Phe1-octreotide (DTPA-OC, OctreoScan) has been introduced into clinical routine for the detection of somatostatin receptor (SSTR)-positive\\u000a tumours, which are predominantly of neuroendocrine origin. Potential further applications in other SSTR-positive cancers (e.g.\\u000a small cell lung cancer, breast cancer, melanoma) have been limited mainly by the restricted availability and the high radionuclide\\u000a costs. Previous attempts to introduce technetium-99m labelled analogues

M. Bangard; M. Béhé; S. Guhlke; R. Otte; H. Bender; H. R. Maecke; H. J. Biersack

2000-01-01

84

Quantitative comparison of yttrium-90 (90Y)-microspheres and technetium-99m (99mTc)-macroaggregated albumin SPECT images for planning 90Y therapy of liver cancer.  

PubMed

Yttrium-90 ((90)Y)-microspheres administered via the hepatic artery has been used for the treatment of unresectable primary or metastatic cancer in the liver. Prior to (90)Y therapy, however, the (90)Y administered activity and the percent shunting to lungs must be determined, most commonly by gamma camera imaging of technetium-99m ((99m)Tc)-macroaggregated albumin (MAA). The purpose of the current study was to identify and evaluate an objective measure of the correlation of (90)Y and MAA activity distributions and thus assess the reliability of MAA imaging for evaluation of (90)Y administered activity and tumor and liver radiation doses. The MAA study consisted of two acquisitions. After administration of 185 MBq of MAA, a partial-body or so-called breakthrough scan was performed in order to determine the percent shunting to lungs. Immediately after a breakthrough scan, a combined single-photon emission computed tomography (SPECT)/transmission computed tomography (CT) scanner was used to image MAA distribution in order to derived the prescribed (90)Y administered activity based on tumor and liver dosimetry. (90)Y SPECT/CT was performed 2-4 weeks later and activities used were in the range of 777-2,442 MBq. In order to compare (90)Y and MAA SPECT images, first the respective CT image sets were registered using a transform based on normalized mutual information. The transform thus derived was used to align the 90Y and MAA SPECT image sets, and the Spearman's (rho) rank correlation as well as image distance (L2-norm) between the registered SPECT images were then calculated. The Spearman's rank correlation values ranged from 0.451 to 0.818 and the L2 distances from 0.626 to 2.889. Based on visual inspection, the registration of the (90)Y and MAA SPECT images appeared reasonably accurate. The regression coefficient (r) between visual scoring and the Spearman's rank correlation was 0.65 and between visual scoring and L2 distance 0.61. The Spearman's rank correlation thus appears to be more reliable than the image distance for assessing the correlation of the (90)Y and MAA images. PMID:20441235

Knesaurek, Karin; Machac, Josef; Muzinic, M; DaCosta, Michael; Zhang, Zhuangyu; Heiba, Sherif

2010-06-01

85

Clinical value of technetium-99m-labeled octreotide scintigraphy in local recurrent or metastatic medullary thyroid cancers: a comparison of lesions with 18F-FDG-PET and MIBI images  

PubMed Central

Aim Various studies have been conducted for determining the most optimal method for the early diagnosis of local recurrent or distant metastatic thyroid cancers. The aim of this study was to evaluate the clinical utility of technetium-99m (Tc-99m)-labeled octreotide derivatives in the detection of recurrence or distant metastases in medullary thyroid cancer patients and to compare the lesions with those detected using 18F-fluorodeoxyglucose (18F-FDG)-PET and Tc-99m MIBI studies in the same patient group. Patients and methods Sixteen medullary thyroid cancer patients [two male and 14 female; mean age 52.0±14.1 years (range 13–72 years)] were included in this study. All patients underwent a whole-body scan 1 and 4 h after injection with octreotide derivatives and single photon emission computed tomography images were taken of the sites suspicious for metastasis. The lesions seen in Tc-99m HYNIC octreotide studies were compared with those seen in 18F-FDG-PET and Tc-99m MIBI studies. Results Among the Tc-99m-labeled octreotide scintigraphy studies, nine were evaluated as true positive (56.2%) and one was evaluated as false positive (6.2%); six were false negative (37.5%). In 16 patients, the total number of lesions seen on octreotide scintigraphy was 21. Thirteen of the 16 patients underwent 18F-FDG-PET imaging. Of the 13 patients studied, 10 showed true-positive (76.9%) and three showed false-negative (23.1%) results. The total number of lesions seen on 18F-FDG-PET was 23. The Tc-99m MIBI study yielded positive results in seven of 16 patients (43.7%) and negative results in nine patients (56.3%). The total number of lesions on Tc-99m MIBI was 12. Conclusion The Tc-99m-labeled somatostatin receptor scintigraphy analogs HYNIC-tyrosine octreotide and HYNIC-TATE are useful imaging alternatives in somatostatin receptor-expressing thyroid cancers. Radiolabeling using these analogs is easy and they are readily available for routine use. PMID:24121313

Kabasakal, Levent; Ocak, Meltem; Maecke, Helmut; Uslu, Lebriz; Halaç, Metin; Asa, Sertac; Sager, Günes; Önsel, Çetin; Kanmaz, Bedii

2013-01-01

86

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

87

Technetium-99m pertechnetate imaging in diagnosis of Meckel's diverticulum  

PubMed Central

Abdominal imaging after intravenous injection of 99mTc pertechnetate is a simple, safe, and noninvasive diagnostic procedure to show ectopic gastric mucosa, which is present in most cases of symptomatic Meckel's diverticulum. It was performed in 13 infants and children suspected of having a Meckel's diverticulum, mainly because of unexplained rectal bleeding. Two of the three proven Meckel's diverticula were correctly identified by scintiscanning, while meticulous contrast x-ray studies were negative in each case. It is concluded that abdominal imaging is useful in the pre-operative diagnosis of symptomatic Meckel's diverticulum. ImagesFIG. 1FIG. 2FIG. 3FIG. 4 PMID:4544769

Leonidas, John C.; Germann, Donald R.

1974-01-01

88

Technetium-99m-tetrofosmin uptake in sarcoidosis stage I.  

PubMed

The uptake of 99mTc-tetrofosmin in enlarged lymph nodes, of the lung hilus, in the case of sarcoidosis Stage I (histopathologically confirmed by mediastinoscopic biopsy) is demonstrated. On a routine chest radiograph of a 78-yr-old woman, hilar lymphadenopathy was first detected. In the following mammography, disseminated micro calcifications were found in the left breast and a 99mTc-tetrofosmin study was performed for detection of breast cancer. Scintigraphy using 99mTc-tetrofosmin showed clear uptake in the hilar lymph nodes, but not in the left breast. The 99mTc-tetrofosmin uptake in the hilar lymph nodes was due to sarcoidosis confirmed by histology. Therefore, 99mTc-tetrofosmin scintigraphy may be useful in patients with suspected sarcoidosis, especially in Stage I. PMID:9374356

Tschabitscher, D; Gallowitsch, H J; Mikosch, P; Kresnik, E; Gomez, I; Molnar, M; Dinges, H P; Kroiss, A; Lind, P

1997-11-01

89

Labeling cellular elements of blood with Technetium-99m  

SciTech Connect

The purpose of this proposal is to develop new technique of labeling platelets and white cells with Tc-99m radionuclide. The conditions of labeling canine platelets and white cells with the lipid-soluble Tc-99m HMPAO have been optimized. The function of labeled platelets were evaluated by the determination of platelet survival time and recovery and these values were compared with that of In-111 tropolone labeled platelets. We developed the bilateral femoral catheterization model for the evaluation of platelet-thrombosis on control and heparin-bonded catheters in dogs. We are evaluating platelet thrombosis in the hollow-fiber hemodialyzer with Tc-99m and In-111 labeled platelets. We have developed the flow-loop for in vitro studies and are using a pig model for quantitation of platelet-consumption during hemodialysis. We are currently evaluating the new technique of platelet and white cell-labeling with Tc-99m and testing them in animal models of thrombosis and infection (osteo-myelitis). We are also using the Tc-99m HMPAO labeled mixed white cells in the early diagnosis (3-hour post-injection) of acute and chronic infection in patients and comparing the results with that of IN-111 oxine labeled white cells.

Dewanjee, M.K.

1990-08-01

90

Bilateral urinothorax identified by technetium-99m DPTA renal imaging  

SciTech Connect

A case of unilateral urinary tract obstruction with extravasation resulting in bilateral pleural effusions is presented. The fluid within the pleural cavities was established to originate from the kidney using (/sup 99m/Tc)diethylenetriaminepentaacetic acid and scintillation camera imaging.

Ralston, M.D.; Wilkinson, R.H. Jr.

1986-01-01

91

Axillary lymph node uptake of technetium-99m-MDP  

SciTech Connect

We sought to determine the frequency and significance of axillary lymph node visualization on bone scans performed with diphosphonates. Consecutive {sup 99m}Tc-methylene diphosphonate ({sup 99m}Tc-MDP) bone scans (2435) were inspected for axillary soft-tissue uptake. In positive cases, the results of physical examination, correlative imaging studies and serial bone scans were recorded, as was the site of venipuncture. Forty-eight studies (2%) showed axillary uptake ipsilateral to the injection site. Extravasation of tracer, documented by focal activity near the injection site, was present in every case. There was no association with axillary adenopathy, mass, induration of radiographically visible calcification. On some images, foci adjacent to the axilla were superimposed on the rib, scapula, or humerus. The bone-to-background ratio was frequently reduced; repeat imaging after 1-2 hr usually improved osseous detail. Ipsilateral axillary lymph node visualization due to extravasation of {sup 99m}Tc-MDP is frequently associated with additional foci superimposed on osseous structures simulating pathology. Delayed skeletal uptake is common in such cases and necessitates a greater time interval between injection and imaging. 7 refs., 3 figs.

Ongseng, F.; Goldfarb, C.R.; Finestone, H. [Beth Israel Medical Center, New York, NY (United States)

1995-10-01

92

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

93

Synthesis of a novel antiestrogen radioligand (99mTc-TOR-DTPA).  

PubMed

This study was aimed at developing a hydrophilic radioligand as an antiestrogen drug derivative to be used for imaging breast tumors. Toremifene [TOR; 4-chloro-1,2-diphenyl-1-(4-(2-(N,N-di-methylamino)ethoxy)phenyl)-1-butene, as citrate salt] was selected as the starting material to be derived, since it has been used extensively as an antiestrogen drug for treatment and prevention of human breast cancer. An antiestrogen drug derivative, TOR attached to diethylenetriamine pentaacetic acid (DTPA), was synthesized by two experimental treatments, including a purification and a reaction step. We described the synthesis of this TOR derivative, (3Z)-4-{4-[2-(dimethylamino) ethoxy] phenyl}-3,4-diphenylbut-3-en-1-ylN,N-bis[2-(2,6-dioxomorpholin-4-yl)ethyl]glycinate (TOR-DTPA), in detail. Mass spectroscopy confirmed the expected structures. TOR-DTPA was labeled with technetium-99m ((99m)Tc), using stannous chloride (SnCl(2)) as the reducing agent. Biodistribution studies were performed on female Albino Wistar rats. Quality controls, radiochemical yield, and stability studies were done utilizing high-performance liquid chromatography, radioelectrophoresis, thin-layer chromatography, and thin-layer radiochromatography methods. The synthesized compound was found to be hydrophilic and anionic, with high stability for the duration of the testing period in vitro. The results indicated that the radiolabeled compound has estrogen-receptor specificity, especially for the breast tissue. It is highly possible that this compound could be used for imaging breast tumors as a novel technetium-labeled hydrophilic estrogen derivative radioligand. PMID:20025551

Yurt, Ayfer; Muftuler, Fazilet Zumrut B; Unak, Perihan; Yolcular, Seniha; Acar, Cigdem; Enginar, Huseyin

2009-12-01

94

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

95

Technetium-99m-exametazine: Pitfalls in preparation and quality control  

SciTech Connect

The Food and Drug Administration recently approved the drug exametazine (Cretec or hexamethylenepropylene-amineoxime) for use in preparation of a {sup 99m}Tc-chelate suitable for human use. This radiopharmaceutical is indicated for detection of altered regional cerebral perfusion in patients with stoke. Unlike the majority of radiopharmaceuticals containing stannous ion (Sn{sup 2+}), which can be prepared by addition of varying volumes and activities of ({sup 99m}Tc)pertechnetate, successful preparation of {sup 99m}Tc-exametazime requires careful control of both volume and activity. The necessity for careful control of the final chemical concentration and radioconcentration is based on the minimal amount of Sn{sup 2+} ion present.

Karesh, S.M. (Loyola Univ. of Medical Center, Maywood, IL (USA))

1989-12-01

96

Failure to visualize acutely injured kidneys with technetium-99m DMSA does not preclude recoverable function  

SciTech Connect

A 35-yr-old patient developed severe acute tubular necrosis requiring hemodialysis. A (99mTc)dimercaptosuccinic acid scan of the kidneys showed no renal uptake at 4 or 24 hr, but the patient subsequently recovered normal renal function as judged by a normal serum creatinine. Based on this case report and a review of the literature, one cannot assume irreversible loss of function in patients with acute renal failure, based on the absence of radiopharmaceutical uptake by the kidneys.

Taylor, A. Jr.; Akiya, F.; Gregory, M.C.

1986-03-01

97

Abdominal varices mimicking an acute gastrointestinal hemorrhage during technetium-99m red blood cell scintigraphy  

SciTech Connect

Abdominal varices consisting of a caput medusae and dilated mesenteric veins resulted in pooling of Tc-99m tagged red blood cells (RBC) within these dilated vessels in a 57-year-old man with severe Laennec's cirrhosis. The atypical radiotracer localization within the abdomen mimicked an acute gastrointestinal hemorrhage. Clinical suspicion and careful evaluation of scintigraphic gastrointestinal bleeding studies will avoid false-positive interpretations.

Moreno, A.J.; Byrd, B.F.; Berger, D.E.; Turnbull, G.L.

1985-04-01

98

Imaging of inflammatory arthritis with technetium-99m-labeled IgG  

SciTech Connect

The accumulation of nonspecific polyclonal human immunoglobulin G (IgG) radiolabeled with 99mTc was compared to that of (99mTc)albumin and (99mTc)nanocolloid in rats with collagen induced arthritis. Serial scintigrams were acquired directly, 4 and 24 hr after injection. A clearly discernable image of the site of synovitis was seen with (99mTc)IgG as early as 4 hr postinjection. The relative intensity of the inflammatory lesion was maximal at 24 hr. Discrimination between arthritic and nonarthritic joints as well as correlations between the relative intensity of the arthritic joint and clinical indices of joint inflammation were superior with IgG compared to albumin or nanocolloid. These studies show that localization and severity of inflammatory joint disease can be detected with radiolabeled nonspecific IgG.

Breedveld, F.C.; van Kroonenburgh, M.J.; Camps, J.A.; Feitsma, H.I.; Markusse, H.M.; Pauwels, E.K. (University Hospital, Leiden (Netherlands))

1989-12-01

99

Technetium99m generators based on neutron irradiated 12-molybdocerate as column matrix  

Microsoft Academic Search

Neutron irradiated 12-molybdocerate(IV) is evaluated as a column matrix for use in preparation of small chromatographic column type99mTc generators. Greater than 87% of the generated99mTc activity is immediately and reproducibly eluted with passing 10 cm3 of saline or chromated saline solutions through 3.0 g of molybdocerate column bed at flow rates of about 1.0 cm3\\/min. The elution performance of99mTc does

M. A. El-Absy; I. M. El-Naggar; A. I. Audah

1994-01-01

100

Technetium99m generator based on 12-molybdocerate — 99 Mo precipitate as column matrix  

Microsoft Academic Search

The preparation of insoluble 12-molybdocerate(IV) from99Mo of low specific activity, produced by thermal neutron irradiation of MoO3, is described. Samples of the material are dried at 50, 100 and 200°C and used as column matrices from which the generated99mTc activity is periodically eluted with saline solution or saline solution containing 5·10–5M K2CrO4 as an oxidant. The elution yields of99mTc are

M. A. El Absy; I. M. El Naggar; A. I. Audah

1993-01-01

101

Technetium-99m red blood cell labeling in patients treated with doxorubicin  

SciTech Connect

Radionuclide angiography is useful in monitoring cardiotoxicity of doxorubicin, but in vivo RBC labeling in these patients is believed to be poorer than that in general patients. The left ventricle-to-background activity ratio (R) was not significantly lower in patients treated with doxorubicin (3.24 +/- 1.15, N = 13) than in control patients (3.89 +/- 1.60, N = 14). With both modified in vivo and in vitro labeling, R was significantly improved in patients treated with doxorubicin (4.37 +/- 0.91, N = 8, and 4.37 +/- 1.22, N = 13, respectively). However, with the modified in vivo method, labeling efficiency remained a function of hematocrit, whereas the in vitro method removed this dependency. Both modified in vivo and in vitro labeling result in improved image quality over in vivo labeling in patients treated with doxorubicin, and the choice of method can be based on other factors.

Ballinger, J.R.; Gerson, B.; Gulenchyn, K.Y.; Ruddy, T.D.; Davies, R.A.

1988-03-01

102

Location of parathyroid adenomas by thallium-201 and technetium-99m subtraction scanning  

Microsoft Academic Search

Solitary parathyroid adenomas were correctly located before surgery in 20 out of 21 cases by using 201mT1 and 99mTc in a subtraction technique. The technique was not useful in identifying hyperplastic parathyroid glands. The technique is recommended as a useful procedure before surgery for primary hyperparathyroidism.

A E Young; J I Gaunt; D N Croft; R E Collins; C P Wells; A J Coakley

1983-01-01

103

Synthesis and biological evaluation of technetium-99m MAG3 as a hippuran replacement  

SciTech Connect

A new technetium-chelating agent based on a triamide monomercaptide tetradentate set of donor groups, mercaptoacetylglycylglycylglycine (MAG3), was synthesized and evaluated. Chelation with /sup 99m/Tc resulted in a single radiochemical product as expected. Studies in mice of (/sup 99m/Tc)MAG3 indicated excretion rates faster than omicron-iodohippurate (OIH) both in normal and in probenecid treated animals. Specificity for renal excretion was essentially complete. Clearance studies in rats resulted in 2.84 ml/min/100 g for (/sup 99m/Tc)MAG3, 2.17 for OIH, and 1.29 for (125I)iothalamate. Extraction efficiencies were 85% for (/sup 99m/Tc)MAG3, 69% for OIH and 39% for (125I)iothalamate. Probenicid depressed the clearance both of (/sup 99m/Tc)MAG3 and OIH at 25 and 50 mg/kg/hr, but to a greater extent with (/sup 99m/Tc)MAG3. The greater effect is offset, however, by the larger fraction secreted by the renal tubular cells. The animal results suggest that (/sup 99m/Tc)MAG3 may be a useful alternative to (131I)OIH.

Fritzberg, A.R.; Kasina, S.; Eshima, D.; Johnson, D.L.

1986-01-01

104

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

105

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

E-print Network

appreciation to the committee members, Drs. Dan Hightower, Don Clark, and Gary Joiner, for t. heir technical assistance and expert advice throughout the author's graduate training. A special appreciation is extended to Dr. Gary Joiner for his support..., the patient undergoes only an intravenous injection of a radiopharmaceutical rather than left ventricular catheter- ization, arterial puncture, or intraventricular injection of large volumes of hypertonic contrast media. 2 While both the traditional...

Sanford, Jeffrey Clayton

2012-06-07

106

Myocardial perfusion imaging with technetium-99m SQ30217: Comparison with thallium-201 and coronary anatomy  

SciTech Connect

Myocardial perfusion in ten normal volunteers and 20 patients with coronary artery disease documented by recent coronary arteriography was studied with 99mTc-labeled SQ30217 and /sup 201/TI. Plantar /sup 201/TI imaging followed standard treadmill exercise and planar SQ30217 imaging followed upright bicycle exercise, performed to angina, or the same double product achieved on the treadmill test. Upright anterior, 30 degrees left anterior oblique, and 60 degrees left anterior oblique images were obtained for 3, 6, and 9 min, respectively, starting 2 min after injection of 15 mCi of 99mTc SQ30217. A second 15-mCi dose was injected at rest approximately 2 hr later, and the same imaging protocol was followed. No adverse reactions or laboratory abnormalities attributable to SQ30217 were observed. All scans on the normal volunteers were interpreted as normal. Qualitative readings of both tests were equally sensitive for detecting patients with coronary disease (SQ30217 - 16/20, TI - 17/20, p = NS) and identifying abnormal vessels (SQ30217 - 19/45, TI - 21/45, p = NS). Both agents were falsely positive in 1/15 vessels. Ten vascular regions showed persistent abnormalities on resting SQ30217 scans; eight of these were distal to stenoses of at least 90% and three were also abnormal on thallium redistribution images. Hepatic uptake of SQ30217 obscured inferoapical segments in some views in 14/20 patients but did not interfere with abnormal vessel identification.

Seldin, D.W.; Johnson, L.L.; Blood, D.K.; Muschel, M.J.; Smith, K.F.; Wall, R.M.; Cannon, P.J.

1989-03-01

107

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

108

Cyclic minigastrin analogues for gastrin receptor scintigraphy with technetium-99m: preclinical evaluation.  

PubMed

Two cyclized minigastrin analogues for gastrin receptor scintigraphy were synthesized and derivatized with HYNIC at the N-terminus for labeling with 99mTc. Radiolabeling efficiency, stability, cell internalization, and receptor binding on CCK-2 receptor expressing AR42J cells were studied and the biodistribution evaluated in tumor bearing nude mice, including NanoSPECT/CT imaging. Metabolites in urine, liver, and kidneys were analyzed by radio-HPLC. Radiolabeled cyclic MG showed high stability in vitro and receptor mediated uptake in AR42J cells. In the animal tumor model, fast renal clearance and low nonspecific uptake in most organs were observed. A tumor uptake >3% was calculated ex vivo 1 h p.i. for both 99mTc-EDDA-HYNIC-cyclo-MG1 and 99mTc-EDDA-HYNIC-cyclo-MG2. In an imaging study with 99mTc-EDDA-HYNIC-cyclo-MG1, the tumor was clearly visualized. The metabolite analysis indicated rapid enzymatic degradation in vivo. PMID:19591486

von Guggenberg, Elisabeth; Sallegger, Werner; Helbok, Anna; Ocak, Meltem; King, Robert; Mather, Stephen J; Decristoforo, Clemens

2009-08-13

109

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

110

Technetium-99m labeling of red blood cells: in vitro evaluation of a new approach  

SciTech Connect

By titration of two different stannous kits for 99mTc labeling of red blood cells (RBC) we found concentrations of 1-2 micrograms tin per ml of blood to give the highest labeling yield. Using a new kit containing 2 micrograms of tin and 0.1% hypochlorite (NaOCl) as an oxidizing agent we labeled RBC with 99mTc avoiding centrifugation of cells. To evaluate this new procedure we assessed the dependency of tin incubation time, and addition of 4.4% EDTA as a chelating agent on labeling efficiency. We also measured the dependency of EDTA on the stability of the label. Optimal conditions for labeling of 1 ml of whole blood using the new stannous kit were: 5-10 min of tin incubation, 0.2 ml of 0.1% hypochlorite, and 15 min of 99mTc incubation. This procedure resulted in a labeling efficiency of at least 96%. The overall effect of EDTA was not an increased labeling efficiency, and EDTA increased the stability of the label with only a few percent. The promising results of this new labeling approach encourage to further laboratory investigations and eventual clinical evaluation of the procedure.

Kelbaek, H.

1986-11-01

111

Technetium-99m-ubiquicidin scintigraphy in the detection of infective endocarditis.  

PubMed

We present a case of infective endocarditis (IE) diagnosed by the increased (99m)Tc-UBI specific uptake in the tricuspid valve region. In conclusion, our case data may indicate a first pass-like distribution with strong avidity of the tracer to infective endocarditis, facilitating image interpretation. PMID:24563884

Taghizadeh Asl, Mina; Mandegar, Mohammad-Hossein; Assadi, Majid

2014-01-01

112

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

113

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

114

The preparation and biodistribution of a technetium-99m triaminodithiol complex designed to reflect regional cerebral blood flow  

SciTech Connect

Recently, interest in the development of radiotracers for brain imaging has increased. Technetium complexes of diaminodithiol (DADT) ligands have been shown to be stable, neutral, lipid soluble, and shown to cross the blood:brain barrier. A new ligand, N-Piperidinylethyl-DADT has been synthesized which forms two complexes with Tc-99m when stannous chloride is used as a reducing agent for Tc-99m pertechnetate. Biodistribution studies of both complexes in mice showed one to have a 2.2% of the injected dose of the tracer in the brain at 5 minutes post intravenous injection with 0.53% of the dose remaining in the brain at 30 minutes post injection. Brain-to-blood ratios at these times were 5.3 and 3.0 respectively. Imaging studies were conducted in a monkey and a baboon in which rapid uptake of the tracer in the brain was observed and clear brain images were obtained. Time activity curves showed peak uptake in the brain at approximately 5 to 7 minutes post intravenous injection followed by a plateau of about 11 minutes. The half-lives for clearance of the tracer from the brains of the monkey and baboon were found to be 63 and 58 minutes respectively. This preliminary evaluation suggests that this tracer shows promise for brain imaging in humans.

Lever, S.Z.; Burns, H.D.; Kervitsky, T.M.; Goldfarb, H.W.; Woo, D.V.; Wong, D.F.; Epps, L.A.; Kramer, A.V.; Wagner, H.N. Jr.

1985-05-01

115

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

116

Technetium-99m DISIDA hepatobiliary agent in diagnosis of hepatocellular carcinoma: relationship between detectability and tumor differentiation  

SciTech Connect

The present investigation was aimed to assess the usefulness of biliary agents scintigraphy in the diagnosis of hepatocellular carcinoma (HCC) and to ascertain the relationship between the uptake of these agents and the degree of HCC differentiation. Forty-four patients with this hepatic cancer were included in the study. Liver scans were performed 20 min and 3 hr after the administration of 99mTc diisopropyliminodiacetic acid (DISIDA). DISIDA scintigraphy could not be assessed in six cases. In 16 (42%) out of the remaining 38 patients, the tumor exhibited equal or greater radioactivity uptake than the surrounding liver. In six out of these 16 patients, tumor uptake was apparent in the early and delayed hepatic scans, while in the other ten subjects radioactivity uptake by the HCC could only be detected in the 3-hr delayed scans. In the remaining 22 patients, HCC appeared as a cold area. Tumor location by this technique did not differ from that observed by 99mTc-sulfur colloid scan or ultrasound. DISIDA uptake was significantly related to tumor differentiation: 70% of those well differentiated tumors exhibited DISIDA uptake, whereas it was found in only 30% of those moderately differentiated and in none of those poorly differentiated (p less than 0.05). These results show that DISIDA scintigraphy can be useful in the diagnosis of HCC. Since its sensitivity is related to the degree of tumor differentiation, it may be indicated when aspiration cytology is unable to distinguish between well differentiated HCC and reactive changes due to hepatic cirrhosis.

Calvet, X.; Pons, F.; Bruix, J.; Bru, C.; Lomena, F.; Herranz, R.; Brugera, M.; Faus, R.; Rodes, J.

1988-12-01

117

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

118

RP463: a stabilized technetium-99m complex of a hydrazino nicotinamide derivatized chemotactic peptide for infection imaging.  

PubMed

A HYNIC-conjugated chemotactic peptide (fMLFK-HYNIC) was labeled with (99m)Tc using tricine and TPPTS as coligands. The combination of fMLFK-HYNIC, tricine, and TPPTS with (99m)Tc produced a ternary ligand complex [(99m)Tc(fMLFK-HYNIC)(tricine)(TPPTS)] (RP463). RP463 was synthesized either in two steps, in which the binary ligand complex [(99m)Tc(fMLFK-HYNIC)(tricine)(2)] (RP469) was formed first and then reacted with TPPTS, or in one step by direct reduction of [(99m)Tc]pertechnetate with stannous chloride in the presence of fMLFK-HYNIC, tricine, and TPPTS. The radiolabeling yield for RP463 was usually >/=90% using 10 microg of fMLFK-HYNIC and 100 mCi of [(99m)Tc]pertechnetate. Unlike RP469, which decomposed rapidly in the absence of excess tricine coligand, RP463 was stable in solution for at least 6 h. [(99)Tc]RP463 was prepared and characterized by HPLC and electrospray mass spectrometry. In an in vitro assay, [(99)Tc]RP463 showed an IC(50) of 2 nM against binding of [(3)H]fMLF to receptors on PMNs. [(99)Tc]RP463 also induces effectively the superoxide release of polymorphonuclear leukocytes (PMNs) with an EC(50) value of 0.2 +/- 0.2 nM. The localization of RP463 in the infection foci was assessed in a rabbit infection model. RP463 was cleared from the blood faster than RP469 and was excreted mainly through the renal system. As a result of rapid blood clearance and increased uptake, the target-to-background ratios continuously increased from 1.5 +/- 0.2 at 15 min postinjection to 7.5 +/- 0.4 at 4 h postinjection. Visualization of the infected area could be as early as 2 h. A transient decrease in white blood cell count of 35% was observed during the first 30 min after injection of the HPLC-purified RP463 in the infected rabbit. This suggests that future research in this area should focus on developing highly potent antagonists for chemotactic peptide receptor or other receptors on PMNs and monocytes. PMID:10502357

Edwards, D S; Liu, S; Ziegler, M C; Harris, A R; Crocker, A C; Heminway, S J; Barrett, J A; Bridger, G J; Abrams, M J; Higgins, J D

1999-01-01

119

Two technetium-99m-labeled cholecystokinin-8 (CCK8) peptides for scintigraphic imaging of CCK receptors.  

PubMed

A broad spectrum of radiolabeled peptides with high affinity for receptors expressed on tumor cells is currently under preclinical and clinical investigation for scintigraphic imaging and radionuclide therapy. The present paper evaluates two (99m)Tc-labeled forms of the C-terminal octapeptide of cholecystokinin (CCK8): sulfated (s)CCK8, with high affinity for CCK1 and CCK2 receptors, and nonsulfated (ns)CCK8, with high affinity for CCK2 receptors but low affinity for CCK1 receptors. Peptides were conjugated with the bifunctional chelator N-hydroxysuccinimidyl hydrazino niconitate (s-HYNIC). (99m)Tc-labeling, performed in the presence of nicotinic acid and tricine, was highly efficient (approximately 95%) and yielded products with a high specific activity (approximately 700 Ci/mmol) and good stability (approximately 5% release of radiolabel during 16 h incubation in phosphate buffered saline at 37 degrees C). Chinese hamster ovary cells stably expressing the CCK1 receptor (CHO-CCK1 cells) internalized approximately 3% of added (99m)Tc-sCCK8 per confluent well during 2 h at 37 degrees C. Internalization was effectively blocked by excess unlabeled sCCK8. CHO-CCK1 cells did not internalize (99m)Tc-nsCCK8. Displacement of (99m)Tc-sCCK8 and -nsCCK8 by unlabeled CCK-8 (performed at 0 degrees C to prevent internalization) revealed 50% inhibitory concentrations (IC(50)) of 8 nM and >1 microM, respectively. CHO-CCK2 cells internalized approximately 25% and approximately 5% of added (99m)Tc-sCCK8 and -nsCCK8, respectively. In both cases internalization was blocked by excess unlabeled peptide. IC(50) values for the displacement of (99m)Tc-sCCK8 and -nsCCK8 were 3 nM and 10 nM, respectively. CHO-CCK1 cell-derived tumors present in one flank of athymic mice accumulated 2.0% of injected (99m)Tc-sCCK8 per gram tissue at 1 h postinjection. This value decreased to 0.6% following coinjection with excess unlabeled peptide. Uptake of (99m)Tc-nsCCK8 was low (0.2%) and not did change by excess unlabeled peptide (0.3%). Accumulation of (99m)Tc-sCCK8 and -nsCCK8 by CHO-CCK2 cell-derived tumors (present in the other flank) amounted to 4.2% and 0.6%, respectively. In both cases uptake was significantly reduced by excess unlabeled peptide to 1.0% and 0.4% for sCCK8 and nsCCK8, respectively. Accumulation of (99m)Tc-sCCK8 was also high in pancreas (11.7%), stomach (2.0%), and kidney (2.1%), whereas uptake of (99m)Tc-nsCCK8 was high in stomach (0.7%) and kidney (1.4%). Both radiolabeled peptides showed a rapid blood clearance. In conclusion, these data show that CCK8 analogues can be efficiently labeled with (99m)Tc using s-HYNIC as chelator and nicotinic acid/tricine as coligand system without compromising receptor binding. Furthermore, the present study demonstrates that CCK1 tumors hardly accumulate (99m)Tc-nsCCK8, CCK2 tumors accumulate 2 times more (99m)Tc-sCCK8 than CCK1 tumors, and CCK2 tumors accumulate 15 times more (99m)Tc-sCCK8 than (99m)Tc-nsCCK8. Although accumulation in some nontarget organs was also higher with (99m)Tc-sCCK8, this may not reflect the human situation due to a different receptor expression pattern in humans as compared to mice. Therefore, further studies are warranted to investigate the possible use of (99m)Tc-sCCK8 for scintigraphic imaging of CCK receptor-positive tumors in humans. PMID:15149184

Laverman, Peter; Béhé, Martin; Oyen, Wim J G; Willems, Peter H G M; Corstens, Frans H M; Behr, Thomas M; Boerman, Otto C

2004-01-01

120

Two technetium-99m-labeled cholecystokinin-8 (CCK8) peptides for scintigraphic imaging of CCK receptors  

Microsoft Academic Search

A broad spectrum of radiolabeled peptides with high affinity for receptors expressed on tumor cells is currently under preclinical and clinical investigation for scintigraphic imaging and radionuclide therapy. The present paper evaluates two (99m)Tc-labeled forms of the C-terminal octapeptide of cholecystokinin (CCK8): sulfated (s)CCK8, with high affinity for CCK1 and CCK2 receptors, and nonsulfated (ns)CCK8, with high affinity for CCK2

Peter Laverman; M. Behe; Wim J. G. Oyen; Peter H. G. M. Willems; Frans H. M. Corstens; Thomas M. Behr; Otto C. Boerman

2004-01-01

121

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

122

Effect of plasmapheresis on the liver uptake of ApoB-lipoproteins labeled with technetium-99m  

SciTech Connect

To study liver low density lipoprotein (LDL)-receptor activity before and after plasmapheresis, ({sup 99m}Tc) very low density lipoprotein (VLDL) was used. Autologous VLDL was labeled, sterilized by filtration, and administered intravenously to patients under a gamma camera. The uptake of lipoproteins in the liver was measured by scintiscanning. Liver activity curves were generated for each patient. The liver activity in patients with the heterozygous form of familial hypercholesterolemia (FH) and in patients with symptomatic atherosclerosis (SA) without hereditary deficit of LDL receptors was reduced as compared to healthy people. Plasmapheresis enhanced the liver uptake of the {sup 99m}Tc-labeled lipoproteins in atherosclerotic patients. Thus, labeled metabolites could presumably be of use in assessing the effect of plasmapheresis on liver function.

Anisimova, O.Ju.; Konovalov, G.A.; Agapov, I.I.; Fuki, I.V.; Sergienko, V.B.; Repin, V.S.; Kukharchuk, V.V. (USSR Cardiology Research Center, Moscow (USSR))

1989-12-01

123

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

SciTech Connect

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.

Adams, B.K.; Fataar, A.; Byrne, M.J.; Levitt, N.S.; Matley, P.J. (Groote Schuur Hospital, Cape Town (South Africa))

1990-01-01

124

Effects of aging on the cerebral distribution of technetium-99m hexamethylpropylene amine oxime in healthy humans  

Microsoft Academic Search

Some brain functions decline at a linear rate throughout adulthood. Others remain relatively stable until very late in the life cycle. This study characterized the effects of aging on the regional cerebral distribution of hexamethylpropylene amine oxime (HMPAO) in healthy human volunteers. The sample consisted of 26 men and 18 women with a mean age of 41.6ᆢ.9 years (range: 19-73).

P. David Mozley; Ahmed M. Sadek; Abass Alavi; Ruben C. Gur; Larry R. Muenz; Barry J. Bunow; Hee-Joung Kim; Mark H. Stecker; Paul Jolles; Andrew Newberg

1997-01-01

125

Use of technetium-99m-HM-PAO in the assessment of patients with dementia and other neuropsychiatric conditions  

SciTech Connect

One hundred fourteen patients suffering from neuropsychiatric conditions have been studied using 99mTc-labeled hexamethylpropyleneamine oxime (HM-PAO) and single photon emission computed tomography (SPECT). Ninety-one patients had a firm clinical diagnosis while 23 were examined without knowledge of the clinical diagnosis. Of the 91 patients, 51 were suffering from dementia, 25 multi-infarct type and 26 Alzheimer's disease. In 19 of the Alzheimer's patients, a characteristic pattern of decreased perfusion in the parieto-occipital regions was demonstrated while those with multi-infarct type showed varying degrees of irregular uptake in the cerebral cortex. These appearances are similar to those shown with positron emission tomography (PET) and we believe that HM-PAO will provide a widely available method for identifying patients with Alzheimer's disease. Twenty-nine patients were suffering from diseases involving the basal ganglia. Fifteen patients with Parkinson's disease showed no significant abnormality in basal ganglia uptake, while 7 or 8 patients with Huntington's disease who had full examinations showed decreased uptake in the caudate nuclei. Similarly, four of six patients with other basal ganglia diseases showed impaired uptake by basal ganglia, and it is concluded that HM-PAO may be useful for the diagnosis and management of this type of patient. Twenty-three patients received HM-PAO imaging as part of their diagnostic work-up; in 19 of them, detailed follow-up was obtained, which indicated that in 7 cases the result of the HM-PAO scan altered the clinical diagnosis and in 9 cases resulted in a change in management. In the remaining 13 cases, the study was found to be helpful in confirming the diagnosis.

Smith, F.W.; Besson, J.A.; Gemmell, H.G.; Sharp, P.F.

1988-12-01

126

Technetium99m HYNIC-annexin V: a potential radiopharmaceutical for the in-vivo detection of apoptosis  

Microsoft Academic Search

.   Either inadequate or excessive apoptosis (programmed cell death) is associated with many diseases. A method to image apoptosis\\u000a in vivo, rather than requiring histologic evaluation of tissue, could assist with therapeutic decision making in these disorders.\\u000a Programmed cell death is associated with a well-choreographed series of events resulting in the cessation of normal cell function,\\u000a and the ultimate disappearance

Katsuichi Ohtsuki; Koichi Akashi; Yoshikazu Aoka; Francis G. Blankenberg; Susan Kopiwoda; Jonathan F. Tait; H. William Strauss

1999-01-01

127

Orally administered DTPA penta-ethyl ester for the decorporation of inhaled (241)Am.  

PubMed

Diethylenetriaminepentaacetic acid (DTPA) is an effective decorporation agent to facilitate the elimination of radionuclides from the body, but its permeability-limited oral bioavailability limits its utility in mass-casualty emergencies. To overcome this limitation, a prodrug strategy using the penta-ethyl ester form of DTPA is under investigation. Pharmacokinetic and biodistribution studies were conducted in rats by orally administering [(14) C]DTPA penta-ethyl ester, and this prodrug and its hydrolysis products were analyzed as a single entity. Compared with a previous reporting of intravenously administered DTPA, the oral administration of this prodrug resulted in a sustained plasma concentration profile with higher plasma exposure and lower clearance. An assessment of the urine composition revealed that the bioactivation was extensive but incomplete, with no detectable levels of the penta- or tetra-ester forms. Tissue distribution at 12 h was limited, with approximately 73% of the administered dose being associated with the gastrointestinal tract. In the efficacy study, rats were exposed to aerosols of (241) Am nitrate before receiving a single oral treatment of the prodrug. The urinary excretion of (241) Am was found to be 19% higher than with the control. Consistent with prior reports of DTPA, the prodrug was most effective when the treatment delays were minimized. PMID:24619514

Sueda, Katsuhiko; Sadgrove, Matthew P; Huckle, James E; Leed, Marina G D; Weber, Waylon M; Doyle-Eisele, Melanie; Guilmette, Raymond A; Jay, Michael

2014-05-01

128

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

129

Sonic dispersion of soil DTPA solution suspension as an extraction procedure for DTPA micronutrient test  

Microsoft Academic Search

To examine sonic dispersion as an extraction procedure for DTPA micronutrient test, soil DTPA solution suspensions were sonicated to extract Fe, Zn, Mn, and Cu. The elements extracted after 15 or 60 seconds sonication were compared with those extracted after 1\\/2 or 2 hours shaking.The mean differences between Fe, Zn, Mn, or Cu extracted after 15 seconds sonication and those

Adam Khan

1979-01-01

130

Influence of chest background on pulmonary [sup 99m][Tc]-DTPA clearance in interstitial lung disease  

SciTech Connect

The authors examined the effect of chest extracellular [sup 99m][Tc]-diethylenetriamine pentaacetate (DTPA) as a background in the measurement of pulmonary [sup 99m][Tc]-DTPA clearance in patients with interstitial lung disease (ILD). Eight healthy nonsmokers (HN) and eight patients with ILD were studied. They monitored changes in gamma counts after the inhalation of [sup 99m][Tc]-DTPA aerosol by using a gamma camera placed over the anterior chest. The rate constant of pulmonary [sup 99m][Tc]-DTPA clearance (k; %/min) was assessed by calculating the slope of the decrease in the gamma counts. The chest background, estimated by [sup 99m][Tc]-DTPA intravenous injection, was subtracted from the original data to obtain the corrected DTPA clearance (k[sub c]; %/min). In patients with ILD, k was significantly greater [2.19 [+-] 1.03 (SD) %/min; n = 8] compared with HN (0.86 [+-] 0.17%/min; n = 8; P < 0.01). In patients with ILD, k[sub c] was also greater (2.80 [+-] 1.15%/min; n = 8; P < 0.01) compared with HN (1.20 [+-] 0.12%/min; n = 8). There was no difference in percent underestimation of k between the two groups (29.1 [+-] 8.8% for HN, 22.5 [+-] 7.9% for patients with ILD). There was a significant correlation between k and k[sub c] among all subjects (r = 0.987, P < 0.01). They conclude that background causes significant underestimation of pulmonary [sup 99m][Tc]-DTPA clearance. 16 refs., 2 figs., 2 tabs.

Ishizaka, Akitoshi; Kanazawa, Minoru; Suzuki, Yukio; Hasegawa, Naoki; Kubo, Atsushi; Kawashiro, Takeo (Keio Univ., Tokyo (Japan))

1992-11-01

131

Ni-DTPA doped agarose gel--a phantom material for Gd-DTPA enhancement measurements.  

PubMed

In order to study the relationship between the concentration of Gd-DTPA in tissue, and the resulting changes in relaxation times and signal intensity, a phantom material that has similar relaxation times to tissue and that can be doped with Gd-DTPA is required. The "tissue-equivalent" material should not contain Gd; nor should it alter the relaxivities of Gd-DTPA from their values in aqueous solution (R1 = 4.5 sec-1 mM-1; R2 = 5.5 sec-1 mM-1 at 1.5 T). Conventional materials, based on CuSO4-, MnCl2-, or GdCl3/LaCl3-agarose mixtures, are not suitable, since Gd is displaced from the Gd-DTPA chelate. The new material, consisting of Ni-DTPA dissolved in agarose, is easy to prepare and does not interact with Gd-DTPA. Its relaxation times are stable; relaxivity R1 was within 4% of its aqueous value over 109 days. T1s have low dependence on temperature (0.2-1.0%/degrees C at 21 degrees C) and on field strength, allowing the material to be used as a relaxation time standard for quality assurance. Equations giving the concentration of Ni-DTPA and agarose to produce a required T1 and T2 are provided. PMID:8423715

Tofts, P S; Shuter, B; Pope, J M

1993-01-01

132

Holmium-166-DTPA as a liquid source for endovascular brachytherapy.  

PubMed

Liquid radiation sources with beta emitters have advantages of accurate positioning and uniform dose distribution to the vessel walls to prevent the restenosis of coronary artery. As a liquid radiation source, 166Ho-DTPA was prepared and evaluated its in-vivo pharmacokinetic behavior through animal studies.166Ho-DTPA was prepared by simple mixing the Holmium with DTPA at room temperature. The radiolabelling yield was 100% when the DTPA/Holmium molar ratio was >2. Radiolabelling of 166Ho-DTPA was not dependent on the pH range of 1.7-7.5. High radiochemical stability (>98%) was maintained over a period of 6 hours even with a radioactivity ( approximately 11.1 GBq/12 mg of DTPA) stored at room temperature. Biodistribution of 166Ho-DTPA in rats and gamma camera images in rabbits showed that 166Ho-DTPA was quickly excreted via the urinary system. The average of T(max) and T(1/2) of 166Ho-DTPA in the kidneys of rabbits were 3.71 +/- 1.18 min and 9.15 +/- 3.15 min. 166Ho-DTPA is a potential liquid radiation source for radiation brachytherapy to prevent the restenosis of the coronary artery using a liquid-filled balloon. PMID:12453593

Hong, Young-Don; Park, Kyung-Bae; Jang, Beom-Su; Choi, Sun-Ju; Choi, Sang-Moo; Kim, Young-Mi

2002-11-01

133

Comparison of Thyroid Blood Flow and Uptake Indices Using Technetium-99m Pertechnetate in Patients with Graves’ Disease and Euthyroid Subjects  

PubMed Central

Objective: The aim of the present study was to evaluate parameters of early blood flow (EBF) including duration of EBF, perfusion index (PI), uptake indexes 1 and 2 (UI1 and UI2) derived from dynamic thyroid scintigraphy in patients with Graves’ disease (GD), and euthyroid (EI). Maximum instant uptake and maximum uptake of the thyroid gland were also assessed. Methods: A total of 50 patients with GD and EI were included in this study. Each patient underwent two dynamic scans of 1-minute (20 images at 3 seconds) and 20-minute (20 images at 1 minute) with 99mTcO4. The time-activity curve of a 1-minute scan was employed to derive EBF parameters; likewise, the time-activity curve of a 20-minute scan was used to determine maximum instant uptake, and the gradient of the curve from the 10th to 20th minute was used to assess maximum uptake. Results: Values of EBF duration, PI, UI1, UI2, and maximum instant uptake were significantly lower in patients with GD than in those with EI (p<0.05). The calculated gradient of the second half of the curves for all of the patients ranged from 0 to 0.88 and was significantly higher in patients with GD than in those with EI. Conclusion: Lower values of PI, UI1, UI2 and durations of EBF, along with faster maximum instant uptake in patients with GD in comparison to EI are indicators of a heightened desire for hyper-functioning thyroid glands of patients with GD to absorb 99mTcO4. Additionally, because of the uprising gradient at the end of the 20-minute time-activity curve, a maximum thyroid uptake of 99mTcO4 was achieved at more than 20 minutes after the radiopharmaceutical injection. PMID:25541933

Javadi, Hamid; Pashazadeh, Ali Mahmoud; Mogharrabi, Mehdi; Nabipour, Iraj; Kalantarhormozi, Mohammadreza; Assadi, Majid

2014-01-01

134

Acid-citrate-dextrose compared with heparin in the preparation of in vivo/in vitro technetium-99m red blood cells  

SciTech Connect

Red blood cells labeled in vivo/in vitro with Tc-99m (Tc-99m RBC) were prepared in a series of 21 patients and two normal volunteers. In each subject both heparin and acid-citrate-dextrose (ACD) solutions were used to label tandem blood samples. The immediate preinjection binding efficiency (BE) was then determined. In each of the 23 studies, the ACD preparation yielded superior BE. The average BE was 93.47% (+/- 3.78) with ACD and 87.23% (+/- 4.29) with heparin. With the ACD method the effect of carrier Tc-99 may be as great as a 24% reduction in BE observed when initial eluates from long-ingrowth-time generators were used. Improved image quality with minimal renal and urinary-bladder activity results with ACD labeling. It is concluded that the use of ACD results in superior RBC labeling with less nontarget activity relative to heparin and is preferred over heparin for preparing in vivo/in vitro Tc-99m RBC.

Porter, W.C.; Dees, S.M.; Freitas, J.E.; Dworkin, H.J.

1983-05-01

135

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

136

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

137

Infl uence of bifl orin on the labelling of red blood cells, plasma protein, cell protein, and lymphocytes with technetium-99m: in vitro study  

Microsoft Academic Search

In this paper we report the results of an in vitro study involving the infl uence of bifl orin (an o-quinone isolated from Capraria bifl ora L. that has potent antimicrobial activity) on the Tc-99m labeling of red blood cells, plasma protein, cells protein, and lymphocytes. Blood was withdrawn from Wistar rats and incubated with various concentrations of bifl orin,

Thiago M. Aquino; Elba L. C. Amorim; Gláucio Diré Feliciano; Elaine A. C. Lima; Maria L. Gomes; Cláudia S. A. Lima; Ulysses P. Albuquerque; Mário Bernardo-Filho

138

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

139

Radiation dose to technicians per nuclear medicine procedure: comparison between technetium-99m, gallium-67, and iodine-131 radiotracers and fluorine-18 fluorodeoxyglucose  

Microsoft Academic Search

.   The aim of this study was to determine the non-extremity gamma dose received by a technician while performing an ordinary\\u000a nuclear medicine procedure or a static (i.e. without blood sampling) fluorine-18 fluorodeoxyglucose (FDG) positron emission\\u000a tomography (PET) study. The dose per patient was measured by means of a commercial electronic pocket Geiger Mueller dosimeter,\\u000a worn in the upper left

C. Chiesa; V. De Sanctis; F. Crippa; M. Schiavini; C. E. Fraigola; A. Bogni; C. Pascali; D. Decise; R. Marchesini; E. Bombardieri

1997-01-01

140

Characterization of DTPA complexes and conjugated antibodies of astatine  

Microsoft Academic Search

The complex formation of astatine\\/I\\/ cation with diethylene triamine pentaacetic acid \\/DTPA\\/ and characterization of the complexes were investigated by electromigration in free electrolytes and by gel-chromatography on Sephadex G 25. We describe the conjugation procedure for the production of At-DTPA conjugated polyclonal antibodies.

S. Milesz; Yu. V. Norseev; Z. Szücs; L. Vasáros

1989-01-01

141

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

142

USTUR WHOLE BODY CASE 0269: DEMONSTRATING EFFECTIVENESS OF I.V. CA-DTPA FOR PU  

SciTech Connect

This whole body donation case (USTUR Registrant) involved a single acute inhalation of an acidic Pu(NO3)4 solution in the form of an aerosol ‘mist.’ Chelation treatment with i.v. Ca-EDTA was initiated on the day of the intake, and continued intermittently over 6 months. After 2½ years with no further treatment, a course of i.v. Ca-DTPA was administered. A total of 400 measurements of 239+240Pu excreted in urine were recorded; starting on the first day (both before and during the initial Ca-EDTA chelation), and continuing for 37 years. This sampling included all intervals of chelation. In addition, 91 measurements of 239+240Pu-in-feces were recorded over this whole period. The Registrant died about 38 years after the intake, at age 79 y, with extensive carcinomatosis secondary to adenocarcinoma of the prostate gland. At autopsy, all major soft tissue organs were harvested for radiochemical analyses of their 238Pu, 239+240Pu and 241Am content. Also, all types of bone (comprising about half the skeleton) were harvested for radiochemical analyses, as well as samples of skin, subcutaneous fat and muscle. This comprehensive dataset has been applied to derive ‘chelation-enhanced’ transfer rates in the ICRP Publication 67 plutonium biokinetic model, representing the behaviour of blood-borne and tissue-incorporated plutonium during intervals of therapy. The resulting model of the separate effects of i.v. Ca-EDTA and Ca-DTPA chelation shows that the therapy administered in this case succeeded in reducing substantially the long-term burden of plutonium in all body organs, except for the lungs. The calculated reductions in organ content at the time of death are approximately 40% for the liver, 60% for other soft tissues (muscle, skin, glands, etc.), 50% for the kidneys, and 50% for the skeleton. Essentially all of the substantial reduction in skeletal burden occurred in trabecular bone. This modeling exercise demonstrated that 3-y-delayed Ca-DTPA therapy was as effective as promptly administered Ca-EDTA.

James, Anthony C.; Sasser , Lyle B.; Stuit, Dorothy B.; Glover, Samuel E.; Carbaugh, Eugene H.

2008-01-28

143

DTPA AND MEHLICH-3 MICRONUTRIENT EXTRACTABILITY IN NATURAL SOILS  

Microsoft Academic Search

Most soils of the humid area in the Iberian Peninsula are characterized by acid, desaturated, organic rich surface horizons. In this study micronutrients (Cu, Fe, Mn and Zn) were extracted using DTPA and Mehlich-3. Total contents were also determined by digestion with nitric acid. Seven natural soil profiles, representing major acid soil types developed over a wide variety of parent

Raquel Caridad Cancela; Cleide Aparecida de Abreu; Antonio Paz-González

2002-01-01

144

Acute and chronic effects of marijuana smoking on pulmonary alveolar permeability  

Microsoft Academic Search

Pulmonary clearance of technetium (99mTc)-labeled diethylene triamine pentaacetate (DTPA), a sensitive test of alveolar epithlelial permeability, was measured twice in 34 healthy subjects, including 10 control nonsmokers (NS), 10 habitual smokers of marijuana alone (MS) (? 10 joints\\/wk), 9 regular smokers of tobacco alone (TS) (? 15 cigarettes\\/day) and 4 habitual smokers of both marijuana and tobacco (MTS). In smokers,

E. Gil; B. Chen; E. Kleerup; M. Webber; D. P. Tashkin

1995-01-01

145

10 CFR 35.204 - Permissible molybdenum-99, strontium-82, and strontium-85 concentrations.  

Code of Federal Regulations, 2011 CFR

...kilobecquerel of molybdenum-99 per megabecquerel of technetium-99m (0.15 microcurie of molybdenum-99 per millicurie of technetium-99m); or (2...licensee that uses molybdenum-99/technetium-99m generators for...

2011-01-01

146

10 CFR 35.204 - Permissible molybdenum-99, strontium-82, and strontium-85 concentrations.  

Code of Federal Regulations, 2010 CFR

...kilobecquerel of molybdenum-99 per megabecquerel of technetium-99m (0.15 microcurie of molybdenum-99 per millicurie of technetium-99m); or (2...licensee that uses molybdenum-99/technetium-99m generators for...

2010-01-01

147

Synthesis and characterization of two (111)In-labeled DTPA-peptide conjugates.  

PubMed

This report describes the synthesis and characterization of two (111)In-labeled DTPA-peptide conjugates (DTPA-MA and DTPA-BA). It is surprising to find that (111)In(DTPA-MA) and (111)In(DTPA-BA) are more hydrophilic than their corresponding (90)Y analogues, suggesting a different coordination sphere in (111)In and(90)Y complexes of the same DTPA-peptide conjugate. By a reversed phase HPLC method, both (111)In(DTPA-MA) and (111)In(DTPA-BA) showed only one radiometric peak in their respective HPLC chromatogram due to a rapid interconversion of different isomers (particularly cis and trans isomers for (111)In(DTPA-MA); cis-cis, cis-trans, trans-cis, and trans-trans isomers for (111)In(DTPA-BA)). The interconversion of different isomers involves the "wagging" of the diethylenetriamine backbone, "shuffling" of the NO or NO(2) donor sets, and a rapid inversion at the terminal amine-nitrogen atoms. PMID:11459469

Liu, S; Edwards, D S

2001-01-01

148

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

149

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

150

Spectroscopic studies on interaction of BSA and Eu(III) complexes with H5ph-dtpa and H5dtpa ligands.  

PubMed

An novel aromatic aminopolycarboxylic acid ligand, N-(2-N,N-Dicarboxymethylaminophenyl) ethylenediamine-N,N',N'-triacetic acid (H5ph-dtpa), was synthesized by improving experimental method and its corresponding Eu(III) complex, Na2[Eu(III)(ph-dtpa)(H2O)]·6H2O, was successfully prepared through heat-refluxing method. As a comparison, the Eu(III) complex with diethylenetriamine-N,N,N',N',N?-pentaacetic acid (H5dtpa) ligand, Na2[Eu(III)(dtpa)(H2O)]·6H2O, was also prepared by the same method. And then, the interaction between prepared Eu(III) complexes ([Eu(III)(dtpa)(H2O)](2)(-) and [Eu(III)(ph-dtpa)(H2O)](2)(-)) and bovine serum albumin (BSA) in aqueous solution were studied by the combination of ultraviolet-visible (UV-vis), fluorescence and circular dichroism (CD) spectroscopies. In addition, the binding sites of Eu(III) complexes ([Eu(III)(dtpa)(H2O)](2)(-) and [Eu(III)(ph-dtpa)(H2O)](2)(-)) to BSA molecules were also estimated by synchronous fluorescence. Moreover, the theoretical and experimental results show that the Van der Waals, hydrogen bond and ?-? stacking interactions are the mainly impulse to the reaction. The binding distances (r) between Eu(III) complexes ([Eu(III)(dtpa)(H2O)](2)(-) and [Eu(III)(ph-dtpa)(H2O)](2)(-)) and BSA were obtained according to Förster's non-radiative energy transfer theory. Also, the determined UV-vis absorption spectroscopy, synchronous fluorescence and circular dichroism (CD) spectra showed that the conformation of BSA could be changed in the presence of Eu(III) complexes. The obtained results can help understand the action mode between rare earth metal complexes of aminopolycarboxylic acid ligands with BSA and they are also expected to provide important information of designs of new inspired drugs. PMID:25617848

Kong, Deyong; Qin, Cui; Fan, Ping; Li, Bing; Wang, Jun

2015-04-01

151

Clearance of Tc-99m DTPA in hemodialysis and peritoneal dialysis: concise communication  

SciTech Connect

The clearance of Tc-99m DTPA was studied in 14 patients undergoing hemodialysis (HD) or peritoneal dialysis (PD). Mean Tc-99m DTPA clearance during HD was 37.8% +/- 10.1 of creatinine clearance. Mean Tc-99m DTPA clearance in PD was 65.1% +/- 10.3 of creatinine clearance. Tc-99m DTPA, with a larger molecular weight than that of creatinine, is cleared relatively better during PD than during HD. Thus Tc-99m DTPA may be used in the assessment of the effectiveness of different dialytic treatments for substances of similar molecular weight. In addition, our study shows that clearance of DTPA both in HD and PD is sufficiently high to allow the removal of this chelating agent in patients with renal failure.

Wainer, E.; Boner, G.; Lubin, E.; Rosenfeld, J.B.

1981-09-01

152

Liquid hyper-absorption as a cause of increased DTPA clearance in the cystic fibrosis airway  

PubMed Central

Background Airway liquid hyper-absorption is a key pathophysiological link between the genetic mutations of cystic fibrosis (CF) and the development of lung disease. Here we consider whether the clearance of radiolabeled diethylene triamine pentaacetic acid (DTPA) might be used to detect changes in airway liquid absorption. Methods Tc99m-DTPA was added to the apical (luminal) surface of primary human bronchial epithelial cell cultures from CF and non-CF lungs. Liquid absorption rates were assessed using an optical method and compared to DTPA absorption rates. Measurements of transepithelial electrical resistance (TER) were made to determine the effect of epithelial permeability. DTPA absorption was assessed after stimuli known to influence liquid absorption (volume addition and osmotic gradients) and in cultures containing different proportions of CF and non-CF cells. Results DTPA absorption rate was increased in CF cultures matching previous in vivo studies in individuals with CF. DTPA and liquid absorption rates were proportional. There was no relationship between TER and DTPA absorption rate when measured in individual cultures. Apical volume addition increased both DTPA and liquid absorption rates. DTPA absorption increased in a dose-dependent manner after basolateral mannitol addition was used to create transepithelial osmotic gradients favoring liquid absorption. Conversely, apical mannitol (a candidate therapy) slowed DTPA absorption in CF cultures. Conclusions These results imply that DTPA absorption is directly related to liquid absorption, consistent with increased rates of airway surface liquid absorption in the CF airway, and that modification of liquid absorption from osmotic therapies might be detectable through DTPA absorption measurements in vivo. Trial registration none PMID:23446051

2013-01-01

153

Preparation and premilinary evaluation of astatine-211 labeled IgG via DTPA anhydride  

Microsoft Academic Search

A method for211At labeling of human IgG via DTPA anhydride is described. DTPA-IgD was prepared and211At was conjugated to human IgG by adding Na211At to the DTPA-IgG and reaction for 30 minutes at room temperature. The astatinated IgG was isolated by a Sephadex G50 column and identified by size exclusion HPLC. The labeling procedure was executed in 1.5 hours and

Liu Ning; Jin Jiannan; Mo Shangwu; Chen Hengliu; Yu Yanping

1998-01-01

154

Complexation of Curium(III) with DTPA at 10-70 °C: Comparison with Eu(III)-DTPA in Thermodynamics, Luminescence, and Coordination Modes.  

PubMed

Separation of trivalent actinides (An(III)) from trivalent lanthanides (Ln(III)) is a challenging task because of the nearly identical chemical properties of these groups. Diethylenetriaminepentaacetate (DTPA), a key reagent used in the TALSPEAK process that effectively separates An(III) from Ln(III), is believed to play a critical role in the An(III)/Ln(III) separation. However, the underlying principles for the separation based on the difference in the complexation of DTPA with An(III) and Ln(III) remain unclear. In this work, the complexation of DTPA with Cm(III) at 10-70 °C was investigated by spectrophotometry, luminescence spectroscopy, and microcalorimetry, in conjunction with computational methods. The binding strength, the enthalpy of complexation, the coordination modes, and the luminescence properties are compared between the Cm(III)-DTPA and Eu(III)-DTPA systems. The experimental and computational data demonstrated that the difference between Cm(III) and Eu(III) in the binding strength with DTPA can be attributed to the stronger covalence bonding between Cm(III) and the nitrogen donors of DTPA. PMID:25654313

Tian, Guoxin; Zhang, Zhiyong; Martin, Leigh R; Rao, Linfeng

2015-02-16

155

Tropospheric Aerosols  

NASA Astrophysics Data System (ADS)

It is widely believed that "On a clear day you can see forever," as proclaimed in the 1965 Broadway musical of the same name. While an admittedly beautiful thought, we all know that this concept is only figurative. Aside from Earth's curvature and Rayleigh scattering by air molecules, aerosols - colloidal suspensions of solid or liquid particles in a gas - limit our vision. Even on the clearest day, there are billions of aerosol particles per cubic meter of air.Atmospheric aerosols are commonly referred to as smoke, dust, haze, and smog, terms that are loosely reflective of their origin and composition. Aerosol particles have arisen naturally for eons from sea spray, volcanic emissions, wind entrainment of mineral dust, wildfires, and gas-to-particle conversion of hydrocarbons from plants and dimethylsulfide from the oceans. However, over the industrial period, the natural background aerosol has been greatly augmented by anthropogenic contributions, i.e., those produced by human activities. One manifestation of this impact is reduced visibility (Figure 1). Thus, perhaps more than in other realms of geochemistry, when considering the composition of the troposphere one must consider the effects of these activities. The atmosphere has become a reservoir for vast quantities of anthropogenic emissions that exert important perturbations on it and on the planetary ecosystem in general. Consequently, much recent research focuses on the effects of human activities on the atmosphere and, through them, on the environment and Earth's climate. For these reasons consideration of the geochemistry of the atmosphere, and of atmospheric aerosols in particular, must include the effects of human activities. (201K)Figure 1. Impairment of visibility by aerosols. Photographs at Yosemite National Park, California, USA. (a) Low aerosol concentration (particulate matter of aerodynamic diameter less than 2.5 ?m, PM2.5=0.3 ?g m-3; particulate matter of aerodynamic diameter less than 10 ?m, PM10=1.1 ?g m-3; estimated coefficient of light scattering by particulate matter, ?ep, at 570 nm=12 Mm-1). (b) High aerosol concentration (PM2.5=43.9 ?g m-3; PM10=83.4 ?g m-3; estimated ?ep at 570 nm=245 Mm-1) (reproduced by permission of National Park Service, 2002). Although comprising only a small fraction of the mass of Earth's atmosphere, aerosol particles are highly important constituents of the atmosphere. Special interest has focused on aerosols in the troposphere, the lowest part of the atmosphere, extending from the land or ocean surface typically to ˜8 km at high latitudes, ˜12 km in mid-latitudes, and ˜16 km at low latitudes. That interest arises in large part because of the importance of aerosol particles in geophysical processes, human health impairment through inhalation, environmental effects through deposition, visibility degradation, and influences on atmospheric radiation and climate.Anthropogenic aerosols are thought to exert a substantial influence on Earth's climate, and the need to quantify this influence has sparked much of the current interest in and research on tropospheric aerosols. The principal mechanisms by which aerosols influence the Earth radiation budget are scattering and absorbing solar radiation (the so-called "direct effects") and modifying clouds and precipitation, thereby affecting both radiation and hydrology (the so-called "indirect effects"). Light scattering by aerosols increases the brightness of the planet, producing a cooling influence. Light-absorbing aerosols such as black carbon exert a warming influence. Aerosols increase the reflectivity of clouds, another cooling influence. These radiative influences are quantified as forcings, where a forcing is a perturbation to the energy balance of the atmosphere-Earth system, expressed in units of watts per square meter, W m-2. A warming influence is denoted a positive forcing, and a cooling influence, negative. The radiative direct and indirect forcings by anthropogenic aerosols are thought to be of comparable magnitude to the posi

Buseck, P. R.; Schwartz, S. E.

2003-12-01

156

Technetium 99m ethylcysteinate dimer single-photon emission computed tomography (SPECT) during intellectual stress test in children and adolescents with pure versus comorbid attention-deficit hyperactivity disorder (ADHD).  

PubMed

Children and adolescents with the Diagnostic and Statistical Manual of Mental Disorders-IV (DSM-IV) diagnosis of attention-deficit hyperactivity disorder (ADHD) can have comorbid conditions such as conduct disorder, oppositional defiant disorder, and obsessive-compulsive disorder (comorbid type). The purpose of our study was to compare the pattern of regional cerebral perfusion in these two groups of children with ADHD during a computerized performance test. Nineteen children and adolescents were enrolled in the study. Seven boys and one girl with pure ADHD (group 1: mean age 12 years, range 9-16 years) and nine boys and two girls with comorbid ADHD (group 2: mean age 11 years, range 8-16 years) were studied by single-photon emission computed tomography (SPECT). The patients were not receiving any medication for at least 48 hours prior to the study. All patients were injected with 99mTc-ethylcysteinate dimer while doing a computerized performance test. Nine age-matched control children (five boys and four girls, mean age 12 years, range 9-17 years) with a normal brain SPECT served as controls. All patients in group 2 showed significantly decreased perfusion in the temporal lobes (P < .005). Five patients had decreased frontal lobe perfusion. Additionally, two patients in group 2 had decreased perfusion in the basal ganglia (not significant). Four of eight patients in group 1 had decreased frontal lobe perfusion (not significant). In addition, two patients had bilateral temporal lobe abnormalities, whereas two patients had a normal SPECT. Three patients in group 1 also had decreased basal ganglia perfusion. In contrast to previous studies of brain perfusion in ADHD that focused mainly on frontal and prefrontal cortical abnormalities, our study demonstrates that temporal lobe perfusion abnormalities are more common in patients with the comorbid type of ADHD. We postulate that these findings can have therapeutic implications and explain the decreased response to stimulants in this group of patients. PMID:15072100

Lorberboym, Mordechai; Watemberg, Nathan; Nissenkorn, Andreea; Nir, Batia; Lerman-Sagie, Tally

2004-02-01

157

Sucralose sweetener in vivo effects on blood constituents radiolabeling, red blood cell morphology and radiopharmaceutical biodistribution in rats  

Microsoft Academic Search

Effects of sucralose sweetener on blood constituents labelled with technetium-99m (99mTc) on red blood cell (RBC) morphology, sodium pertechnetate (Na99mTcO4) and diethylenetriaminepentaacetic acid labeled with 99mTc (99mTc-DTPA) biodistribution in rats were evaluated. Radiolabeling on blood constituents from Wistar rats was undertaken for determining the activity percentage (%ATI) on blood constituents. RBC morphology was also evaluated. Na99mTcO4 and 99mTc-DTPA biodistribution was

G. S. Rocha; M. O. Pereira; M. O. Benarroz; J. N. G. Frydman; V. C. Rocha; M. J. Pereira; A. S. Fonseca; A. C. Medeiros; M. Bernardo-Filho

2011-01-01

158

Preparation of 111In-DTPA morpholino oligomer for low abdominal accumulation  

PubMed Central

An ability to quantitate the beta cell mass by noninvasive nuclear imaging will be very useful in the prevention, diagnosis, and treatment of diabetes. However, to be successful, radioactivity from the pancreas must not be obscured by the background radioactivity in the abdomen. Pretargeting offers the promise of achieving high target organ to normal tissue ratios. In preparation for pancreas imaging studies by pretargeting using morpholino oligomers (MORF/cMORF), it was necessary to develop a simple and efficient method to radiolabel the cMORF effector. Because we have shown that labeling the cMORF with 111In via DTPA reduces excretion into the intestines compared to labeling with 99mTc via MAG3, the conjugation of DTPA to cMORF were investigated for the 111In labeling. The amine-derivatized cMORF was conjugated with DTPA using EDC (1-Ethyl-3(3-dimethylaminopropyl)carbodiimide hydrochloride) as an alternative to the conventional cyclic anhydride. The conjugation efficiency (represented by the number of DTPA groups attached per cMORF) was investigated by changing the EDC, DTPA and cMORF molar ratios. Different open columns were considered for the purification of DTPA-cMORF. Before conjugation, each cMORF molecule was confirmed to have an amine by trinitrobenzene sulfonic acid (TNBS) assay using the ?-amino butyric acid as positive standrad and the non-amine derivatized cMORF as negative standard. The average number of DTPA groups per cMORF was 0.15–0.20 following the conjugation with DTPA over a cMORF/DTPA molar ratio of 0.5 to 5 and over a cMORF/EDC molar ratio of 20 to 60. The conjugation efficiency was lower than expected probably due to steric hindrance. A 1×50 cm P-4 column using ammonia acetate as eluting buffer provided an adequate separation of DTPA-cMORF from free DTPA. The 111In labeling efficiency by transchelation from acetate exceeded 95%, thus avoiding the need for postlabeling purification. Despite the lower than expected conjugation efficiency in which no more than one-fifth of the cMORF were DTPA-derivatized, a specific radioactivity of at least 300 µCi/µg or 1.90 Ci/µmol of cMORF was achieved. In conclusion, a protocol is described for 111In-DTPA-cMORF that provides the high specific activity favorable to beta cell imaging because of the low mass fraction of beta cells in pancreas (1–2%) and obviates the need for postlabeling purification. PMID:20359901

Liu, Guozheng; Dou, Shuping; Rusckowski, Mary; Greiner, Dale; Hnatowich, Donald

2010-01-01

159

[MR tomography following lumbar disk surgery: differential diagnostic potentials using Gd-DTPA].  

PubMed

55 patients were examined by magnetic resonance imaging after lumbar disk operation. The results indicate that with Gd-DTPA there is a significantly increased signal intensity along the surgical approach directly after surgery and during the early postoperative period. Whereas herniated or sequestered disk did not enhance with Gd-DTPA, in epidural fibrosis - regardless of the age of the scarification - diagnostic enhancement was obvious. In 82 percent nerve roots engulfed by scar tissue were differentiated after Gd-DTPA; even enlarged nerve roots and changes of arachnoiditis could be differentiated from each other. PMID:2548244

Steiner, H

1989-08-01

160

Measurement of Gd-DTPA diffusion through PVA hydrogel using a novel magnetic resonance imaging method.  

PubMed

Polyvinyl alcohol-cryogel (PVA-C) is a hydrogel that is an excellent tissue mimic. In order to characterize mass transfer in this material, as well as to demonstrate in principle the ability to noninvasively measure solute diffusion in tissue, we measured the diffusion coefficient of the magnetic resonance (MR) contrast agent gadolinium diethylene triaminopentaacetic acid (Gd-DTPA) through PVA-C using a clinical MR imager. The method involved filling thick-walled rectangular PVA-C "cups" with known concentrations of Gd-DTPA solutions. Then by using a fast inversion recovery spin echo MR imaging protocol, a signal "null" contour was created in the MR image that corresponded to a second, known concentration of Gd-DTPA. By collecting a series of MR images through the PVA-C wall as a function of time, the displacement of this second known isoconcentration contour could be tracked. Application of Fick's second law of diffusion yielded the diffusion coefficient. Seven separate experiments were performed using various combinations of initial concentrations of Gd-DTPA within the PVA-C cups (3.2, 25.6, or 125 mM) and tracked isoconcentrations contours (0.096, 0.182, or 0.435 mM Gd-DTPA). The experimental results and the predictions of Fick's law were in excellent agreement. The diffusivity of Gd-DTPA through 10% PVA hydrogel was found to be (2.6 +/- 0.04) x 10(-10) m(2)/s (mean +/- s.e.m.). Separate permeability studies showed that the diffusion coefficient of Gd-DTPA through this hydrogel did not change with an applied pressure of up to 7.1 kPa. Accurate measurements could be made within 30 min if suitable Gd-DTPA concentrations were selected. Due to the excellent repeatability and fast data acquisition time, this technique is very promising for future in vivo studies of species transport in tissue. PMID:10506421

Gordon, M J; Chu, K C; Margaritis, A; Martin, A J; Ethier, C R; Rutt, B K

1999-11-20

161

Hemophilic arthropathy of the knee joint: static and dynamic Gd-DTPA — enhanced MRI  

Microsoft Academic Search

A total of 17 patients with hemophilic arthropathy of the knee joint were studied with static and dynamic MRI before and after an IV bolus injection of Gadolinium-DTPA (Gd-DTPA; 0.1 mmol\\/kg body weight). The T1-weighted spin-echo (SE) and gradient-echo (fast-field echo [FFE]) sequences were applied. The FFE sequences of eight consecutive scans carried out over a time interval of 160

M. Nägele; R. Brüning; V. Kunze; H. Eickhoff; W. Koch; M. Reiser

1995-01-01

162

1H T1 and T2 measurements of the MR imaging contrast agents Gd-DTPA and Gd-DTPA BMA at 1.5T  

Microsoft Academic Search

.   We report in vitro T1 and T2 relaxation studies for the open-chain complexes Gd-DTPA and Gd-DTPA BMA. Measurements were performed on phantoms containing\\u000a aqueous and plasma solutions of different concentrations by MR imaging in a 1.5T superconducting whole-body scanner. Longitudinal\\u000a relaxation times T1 were evaluated from serial turbo-FLASH experiments for concentrations less than 1 mM, whereas for larger concentrations

J. R. Reichenbach; T. Hackländer; T. Harth; M. Hofer; M. Rassek; U. Mödder

1997-01-01

163

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

164

Linker Effects on Biological Properties of 111In-Labeled DTPA Conjugates of a Cyclic RGDfK Dimer  

PubMed Central

In this report, we present in vitro and in vivo evaluation of three 111In-labeled DTPA conjugates of a cyclic RGDfK dimer: DTPA-Bn-SU016 (SU016 = E[c(RGDfK)]2; DTPA-Bn = 2-(p-isothiocyanobenzyl)diethylenetriaminepentaacetic acid), DTPA-Bn-E-SU016 (E = glutamic acid) and DTPA-Bn-Cys-SU016 (Cys = cysteic acid). The integrin ?v?3 binding affinities of SU016, DTPA-Bn-SU016, DTPA-Bn-E-SU016 and DTPA-Bn-Cys-SU016 were determined to be 5.0 ± 0.7 nM, 7.9 ± 0.6 nM, 5.8 ± 0.6 nM and 6.9 ± 0.9 nM, respectively, against 125I-c(RGDyK) in binding to integrin ?v?3, suggesting that E or Cys residue has little effect on the integrin ?v?3 affinity of E[c(RGDfK)]2. It was also found that the 111In-labeling efficiency of DTPA-Bn-SU016 and DTPA-Bn-E-SU016 is 3–5 times better than that of DOTA analogs due to fast chelation kinetics and high-yield 111In-labeling under mild conditions (e.g. room temperature). Biodistribution studies were performed using BALB/c nude mice bearing U87MG human glioma xenografts. 111In-DTPA-Bn-SU016, 111In-DTPA-Bn-E-SU016 and 111In-DTPA-Bn-Cys-SU016 all displayed a rapid blood clearance. Their tumor uptake was comparable between 0.5 h and 4 h postinjection (p.i.) within experimental error. 111In-DTPA-Bn-E-SU016 had a significantly lower (p < 0.01) kidney uptake than 111In-DTPA-Bn-SU016 and 111In-DTPA-Bn-Cys-SU016. The liver uptake of 111In-DTPA-Bn-SU016 was 1.69 ± 0.18 %ID/g at 24 h p.i. while the liver uptake of 111In-DTPA-Bn-E-SU016 and 111In-DTPA-Bn-Cys-SU016 was 0.55 ± 0.11 %ID/g and 0.79 ± 0.15 %ID/g at 24 h p.i., respectively. Among the three 111In radiotracers evaluated in this study, 111In-DTPA-Bn-E-SU016 has the lowest liver and kidney uptake and the best tumor/liver and tumor/kidney ratios. Results from metabolism studies indicated that there is little (<10%) metabolism for three 111In radiotracers at 1 h p.i. Imaging data showed that tumors can be clearly visualized at 4 h p.i. with good contrast in the tumor-bearing mice administered with 111In-DTPA-Bn-E-SU016. It is concluded that using a glutamic acid linker can significantly improve excretion kinetics of the 111In-labeled E[c(RGDfK)]2 from liver and kidneys. PMID:18069778

Jia, Bing; Liu, Zhaofei; Shi, Jiyun; Yu, Zilin; Yang, Zhi; Zhao, Huiyun; He, Zhengjie; Liu, Shuang; Wang, Fan

2008-01-01

165

A practical method for assessing cadmium levels in soil using the DTPA extraction technique with graphite furnace analysis  

SciTech Connect

Using the DTPA extraction procedure and a graphite furnace atomic absorption spectrophotometer, a practical method for determining soil cadmium levels was developed. Furnace parameters, instrument parameters, solvent dilution factor, and solvent characteristics were determined using experimental field samples and standardized control samples. The DTPA extraction method gave reproducible results and removed approximately 20 to 60% of total soil cadmium. 14 refs., 5 tabs.

Bailey, V.L.; Grant, C.A.; Bailey, L.D. [Agriculture and Agri-Food Canada, Manitoba (Canada)] [and others

1995-09-01

166

Chelating DTPA amphiphiles: ion-tunable self-assembly structures and gadolinium complexes.  

PubMed

A series of chelating amphiphiles and their gadolinium (Gd(III)) metal complexes have been synthesized and studied with respect to their neat and lyotropic liquid crystalline phase behavior. These amphiphiles have the ability to form ion-tunable self-assembly nanostructures and their associated Gd(III) complexes have potential as magnetic resonance imaging (MRI) contrast enhancement agents. The amphiphiles are composed of diethylenetriaminepentaacetic acid (DTPA) chelates conjugated to one or two oleyl chain(s) (DTPA-MO and DTPA-BO), or isoprenoid-type chain(s) of phytanyl (DTPA-MP and DTPA-BP). The thermal phase behavior of the neat amphiphiles was examined by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and cross polarizing optical microscopy (POM). Self-assembly of neat amphiphiles and their associated Gd complexes, as well as their lyotropic phase behavior in water and sodium acetate solutions of different ionic strengths, were examined by POM and small and wide angle X-ray scattering (SWAXS). All neat amphiphiles exhibited lamellar structures. The non-complexed amphiphiles showed a variety of lyotropic phases depending on the number and nature of the hydrophobic chain in addition to the ionic state of the hydration. Upon hydration with increased Na-acetate concentration and the subtle changes in the effective headgroup size, the interfacial curvature of the amphiphile increased, altering the lyotropic liquid crystalline structures towards higher order mesophases such as the gyroid (Ia3d) bicontinuous cubic phase. The chelation of Gd with the DTPA amphiphiles resulted in lamellar crystalline structures for all the neat amphiphiles. Upon hydration with water, the Gd-complexed mono-conjugates formed micellar or vesicular self-assemblies, whilst the bis-conjugates transformed only partially into lyotropic liquid crystalline mesophases. PMID:22890045

Moghaddam, Minoo J; de Campo, Liliana; Kirby, Nigel; Drummond, Calum J

2012-10-01

167

Global Atmospheric Aerosol Modeling  

NASA Technical Reports Server (NTRS)

Global aerosol models are used to study the distribution and properties of atmospheric aerosol particles as well as their effects on clouds, atmospheric chemistry, radiation, and climate. The present article provides an overview of the basic concepts of global atmospheric aerosol modeling and shows some examples from a global aerosol simulation. Particular emphasis is placed on the simulation of aerosol particles and their effects within global climate models.

Hendricks, Johannes; Aquila, Valentina; Righi, Mattia

2012-01-01

168

[MRT using gadolinium-DTPA in spinal intradural space-occupying lesions].  

PubMed

The results of contrast enhanced MRI in 36 patients with suspected spinal intradural tumours are described. All intramedullary tumors showed distinctive enhancement and solid tumors could be delineated clearly, even if they were not clearly visible on unenhanced scans. The differentiation between neoplasm and non-neoplastic syrinx was markedly improved. The sensitivity of MRI for demonstrating intradural extramedullary tumours was greatly improved by gadolinium DTPA and even small lesions or flat meningeal infiltrates could be visualised. In addition, gadolinium DTPA improved the delineation and localisation of larger lesions, even if they had already been seen on unenhanced images. PMID:2554417

Kahn, T; Roosen, N; Fürst, G; Lins, E; Bock, W J; Lenard, H G; Mödder, U

1989-11-01

169

Contrast-enhanced NMR imaging: animal studies using gadolinium-DTPA complex  

SciTech Connect

Gadolinium (Gd)-DTPA complex was assessed as a nuclear magnetic resonance (NMR) contrast-enhancing agent by experimentally imaging normal and diseased animals. After intravenous injection, Gd-DTPA, a strongly paramagnetic complex by virtue of unpaired electrons, was rapidly excreted into the urine of rats, producing an easily observable contrast enhancement on NMR images in kidney parenchyma and urine. Sterile soft-tissue abscesses demonstrated an obvious rim pattern of enhancement. A focus of radiation-induced brain damage in a canine model was only faintly detectable on spin-echo NMR images before contrast administration; after 0.5 mmol/kg Gd-DTPA administration, the lesion intensity increased from 3867 to 5590. In comparison, the normal brain with an intact blood-brain barrier remained unchanged in NMR characterization. Gd-DTPA is a promising new NMR contrast enhancer for the clinical assessment of renal function, of inflammatory lesions, and of focal disruption of the blood-brain barrier.

Brasch, R.C.; Weinmann, H.J.; Wesbey, G.E.

1984-03-01

170

Assessment of liver function in primary biliary cirrhosis using Gd-EOB-DTPA-enhanced liver MRI  

PubMed Central

Objectives Gd-EOB-DTPA (gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid) is a gadolinium-based hepatocyte-specific contrast agent for magnetic resonance imaging (MRI). The aim of this study was to determine whether the hepatic uptake and excretion of Gd-EOB-DTPA differ between patients with primary biliary cirrhosis (PBC) and healthy controls, and whether differences could be quantified. Methods Gd-EOB-DTPA-enhanced liver MRI was performed in 20 healthy volunteers and 12 patients with PBC. The uptake of Gd-EOB-DTPA was assessed using traditional semi-quantitative parameters (Cmax, Tmax and T1/2), as well as model-free parameters derived after deconvolutional analysis (hepatic extraction fraction [HEF], input-relative blood flow [irBF] and mean transit time [MTT]). In each individual, all parameters were calculated for each liver segment and the median of the segmental values was used to define a global liver median (GLM). Results Although the PBC patients had relatively mild disease according to their Model for End-stage Liver Disease (MELD), Child–Pugh and Mayo risk scores, they had significantly lower HEF and shorter MTT values compared with the healthy controls. These differences significantly increased with increasing MELD and Child–Pugh scores. Conclusions Dynamic hepatocyte-specific contrast-enhanced MRI (DHCE-MRI) has a potential role as an imaging-based liver function test. The high spatial resolution of MRI enables hepatic function to be assessed on segmental and sub-segmental levels. PMID:20887325

Nilsson, Henrik; Blomqvist, Lennart; Douglas, Lena; Nordell, Anders; Jonas, Eduard

2010-01-01

171

Posttraumatic lumbar cerebrospinal fluid leak: detection by retrograde In-111-DTPA myeloscintography  

SciTech Connect

A case of lumbar cerebrospinal fluid (CSF) extravasation with an unsuspected traumatic meningocele after a gunshot wound was detected by means of retrograde myeloscintography using isobaric In-111-DTPA. Our experience and a review of the literature have provided evidence retrograde myeloscintography may be useful for detecting and delineating significant traumatic thoracic and lumbar CSF leaks.

Colletti, P.M.; Siegel, M.E.

1981-09-01

172

Noninvasive determination of regional cerebral blood flow in rats using dynamic imaging with Gd(DTPA)  

PubMed

A method for the noninvasive, quantitative determination of regional cerebral blood flow (rCBF) in small laboratory animals, such as the rat, is described. The change in magnetic susceptibility in the vicinity of brain capillaries evoked by iv infusion of Gd(DTPA), a paramagnetic agent not crossing the blood-brain barrier, is detected as an attenuation of the 1H signal in T2-weighted MRI sequences. The reduction of the MR signal intensity after 1 or 2 min of Gd(DTPA) infusion correlates well (r greater than 0.95) with the rCBF values obtained using the well-established [14C]iodoantipyrine method. At a slice thickness of 3 mm, the pixel size typically is 0.15 x 0.5 mm2. The clearance rate of Gd(DTPA) from blood allows repeated measurements of CBF to be made using this technique approximately every 30 min. The experimental results obtained in normal and ischemic rat brain have been rationalized within the frame of a two-compartment model, allowing the definition of optimal experimental conditions for a given CBF: for normal and reduced CBF values (less than 150 ml/100 g/min) the reduction in MR signal intensity, measured after 1 or 2 min of Gd (DTPA) infusion, correlates closely with the CBF. However, for CBF values greater than 150 ml/100 g/min, a more reliable parameter would be the time constant of the MR signal attenuation during the infusion. PMID:1798393

Rudin, M; Sauter, A

1991-11-01

173

Uptake of iron by isolated rat hepatocytes from a hydrophilic impermeant ferric chelate, Fe(III)-DTPA.  

PubMed

We studied uptake of iron from Fe(III)-diethylenetriamine pentaacetate (DTPA) in isolated rat hepatocytes. This uptake is specific with an affinity of 600 nM and shows an optimum pH of 6. The specificity is indicated by inhibition by ferric citrate and diferric transferrin. Iron uptake from Fe(III)-DTPA is completely inhibited by trypsinization of the cell surface, by strong impermeant ferric chelators (DTPA, apo-transferrin, polymer-conjugated desferrioxamine), both hexacyanoferrates, copper and zinc, and partly by dipyridyl, manganese, cobalt, N-ethylmaleimide, and citrate. The lysosomotropic agent chloroquin inhibits weakly; proton pump inhibitors are without effect. Ascorbate and Tiron both effectively stimulate the uptake and also mobilize iron from DTPA in vitro. Approximately 75% of the freshly acquired intracellular iron is found in ferritin even after uptake at lowered temperature (16 degrees C). We conclude that a rate-limiting mobilization of iron from the DTPA chelate by a cell-surface activity is required before iron can actually enter the cell. This can be enhanced by mediators of iron release, but does not seem to require reduction of iron. The use of DTPA as chelator offers the possibility of studying this putative activity because the Fe(III)-DTPA chelate is stable in the presence of transferrin or desferroxamine, in contrast to ferric citrate or Fe(NTA)2. PMID:8611022

Scheiber, B; Goldenberg, H

1996-02-15

174

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

175

Renal tolerance of gadolinium-DTPA/dimeglumine in patients with chronic renal failure.  

PubMed

Safety data for renal tolerance of gadolinium-DTPA(Gd-DTPA)/dimeglumine were evaluated in 21 patients (age: mean +/- standard deviation [SD], 58 +/- 12 years) with impaired renal function. The mean +/- SD serum creatinine level at baseline was 213 +/- 101 mumol/L (range, 89.2-551 mumol/L). Creatinine clearance at baseline averaged 34.5 +/- 19.2 mL/minute (range, 7.2-70 mL/minute). Gd-DTPA was injected at a dose of 0.1 mmol/kg body weight. Serum parameters (creatinine, sodium, and potassium) were determined before and 6, 24, 48, and 120 hours after administration of Gd-DTPA. Urinary parameters (N-acetyl-beta-D-glucosaminidase [beta-NAG], protein, and albumin) were determined before (spot urine sample) and after treatment for collection periods 0 to 3, 3 to 6, 6 to 12, 12 to 24, and 24 to 48 hours. A final spot urine sample was taken at 120 hours. There was no significant statistical change of serum creatinine level within the observation period, and there was no single patient matching the criteria of acute renal failure (increase of serum creatinine level of 88.4 mumol/L [1 mg/dL] or more within 48 hours after injection). Serum values of sodium and potassium levels remained unchanged. Beta-NAG was slightly increased 0 to 3 hours after injection, but returned to baseline values during the collection periods up to 120 hours. There was no increase of protein or albumin excretion. These preliminary results suggest Gd-DTPA has good renal tolerance in patients with pre-existing chronic renal failure. PMID:1601607

Haustein, J; Niendorf, H P; Krestin, G; Louton, T; Schuhmann-Giampieri, G; Clauss, W; Junge, W

1992-02-01

176

Detection of pleural effusions and increased lung water by Tc-99m DTPA imaging  

SciTech Connect

The purpose of this study is to report a systematic observation of uptake or retention of Tc-99m DTPA in pleural effusions and other abnormal states of increased lung water. 24 patients who underwent renal imaging with 10 mCi Tc-99m DTPA were included. Imaging was performed with a large field of view camera for 0-03 minutes after injection and delayed images acquired 2-4 hours later. The images encompassed the mid and lower thorax as well as kidneys. 15 patients showed, at 0-5 minutes, cold areas at lung bases that later showed relatively increased activity at 2-4 hours (hot on delayed images). 14 of these 15 patients showed pleural effusions on chest x-ray. Small bilateral effusions were more clearly demonstrated by scan than by x-ray in 8 of 15 patients. One patient with pneumonia showed an immediate hot area in the infected lobe, and two with pulmonary edema and congestive failure showed diffuse lung retention of Tc-99m on delayed images. Among 9 patients who did not demonstrate abnormal cold or hot areas in their lungs on DTPA images, none had clinical or x-ray evidence of pleural effusion, pneumonia, or congestive failure (100% negative predictive value). Differences in rate constants for diffusion into vs. out of pleural fluid provide a plausible explanation for the observed retention of tracer in effusions, as seen on delayed images. This study indicates that imaging with Tc-99m DTPA provides information of diagnostic value in the detection of pleural effusions. Futhermore, the data suggests that DTPA imaging may also be useful as a simple, cost-effective method to detect other conditions in which regional lung water is abnormally increased.

Glass, E.C.; Karelitz, J.R.; Bennett, L.R.

1985-05-01

177

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...

178

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 ...

179

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...

180

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...

181

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 is disclosed. 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.

1992-03-17

182

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

183

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.

Prescott, Donald S. (Shelley, ID); Schober, Robert K. (Midwest City, OK); Beller, John (Idaho Falls, ID)

1992-01-01

184

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

185

Aerosol scintigraphy in the assessment of therapy for cystic fibrosis.  

PubMed

Thirteen patients with cystic fibrosis (aged 11 to 32 years) who were hospitalized for exacerbation and who had sputum cultures positive for Pseudomonas organisms were treated initially for 4 days with bronchodilators and physiotherapy followed by the addition of antibiotic (14 days, n = 8) or placebo (14 days, n = 4; 7 days, n = 1). Tc-99m DTPA aerosol scintigraphy was performed on the day before bronchodilators and physiotherapy, on the day before antibiotic or placebo, and on the day after completion of antibiotic or placebo therapy. Scintigrams were evaluated for change in the number of nonventilated segments and change in the number of bronchial deposits of aerosol. Sixty-nine percent of patients showed improvement after bronchodilators and physiotherapy alone. Sixty-two percent showed further improvement after antibiotic or placebo was added; this improvement was independent of whether antibiotic or placebo was administered (P greater than 0.1). These aerosol scintigraphy results failed to demonstrate that the effectiveness of bronchodilators and physiotherapy is enhanced by antibiotics in the treatment of cystic fibrosis exacerbations. PMID:1563189

Kuni, C C; Regelmann, W E; duCret, R P; Boudreau, R J; Budd, J R

1992-02-01

186

Aerosol penetration ratio: a new index of ventilation.  

PubMed

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, [99mTc]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. PMID:3525781

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

187

Evaluation of Gd(III)DTPA-terminated poly(propylene imine) dendrimers as contrast agents for MR imaging  

Microsoft Academic Search

Different generations of Gd(III)DTPA-terminated poly(propylene imine) dendrimers {G1 (n ¼ 4 Gd(III) ions per molecule), G3 (n ¼ 16) and G5 (n ¼ 64)} and reference Gd(III)DTPA complex (G0 (n ¼ 1)) were characterized in terms of (i) longitudinal (r1) and transverse (r2) relaxivities in mouse blood plasma, (ii) concentration detection limits in vitro and (iii) in vivo contrast-enhanced MR

Sander Langereis; Quido G. de Lussanet; Marcel H. P. van Genderen; E. W. Meijer; Regina G. H. Beets-Tan; Arjan W. Griffioen; Jos M. A. van Engelshoven; Walter H. Backes

2006-01-01

188

Preclinical evaluation of 111In-DTPA-INCA-X anti-Ku70/Ku80 monoclonal antibody in prostate cancer  

PubMed Central

The aim of this investigation was to assess the Ku70/Ku80 complex as a potential target for antibody imaging of prostate cancer. We evaluated the in vivo and ex vivo tumor targeting and biodistribution of the 111In-labeled human internalizing antibody, INCA-X (111In-DTPA-INCA-X antibody), in NMRI-nude mice bearing human PC-3, PC-3M-Lu2 or DU145 xenografts. DTPA-conjugated, non-labeled antibody was pre-administered at different time-points followed by a single intravenous injection of 111In-DTPA-INCA-X. At 48, 72 and 96 h post-injection, tissues were harvested, and the antibody distribution was determined by measuring radioactivity. Preclinical SPECT/CT imaging of mice with and without the predose was performed at 48 hours post-injection of labeled DTPA-INCA-X. Biodistribution of the labeled antibody showed enriched activity in tumor, spleen and liver. Animals pre-administered with DTPA-INCA-X showed increased tumor uptake and blood content of 111In-DTPA-INCA-X with reduced splenic and liver uptake. The in vitro and in vivo data presented show that the 111In-labeled INCA-X antibody is internalized into prostate cancer cells and by pre-administering non-labeled DTPA-INCA-X, we were able to significantly reduce the off target binding and increase the 111In-DTPA-INCA-X mAb uptake in PC-3, PC-3M-Lu2 and DU145 xenografts. The results are encouraging and identifying the Ku70/Ku80 antigen as a target is worth further investigation for functional imaging of prostate cancer. PMID:24982817

Evans-Axelsson, Susan; Vilhelmsson Timmermand, Oskar; Welinder, Charlotte; Borrebaeck, Carl AK; Strand, Sven-Erik; Tran, Thuy A; Jansson, Bo; Bjartell, Anders

2014-01-01

189

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

190

Sodium bicarbonate?DTPA test for macro?and micronutrient elements in soils  

Microsoft Academic Search

Individual soil tests are used to assess plant nutrient element needs. Separate soil tests, however, are time consuming and costly. Our objective was to develop a 0.5M sodium bicarbonate (NaHCO3) soil phosphorus (P) test in combination with 0.005M diethylenetriaminepentaacetic acid (DTPA) so macronutrient dements: ammonium?nitrogen (NH4?N), nitrate?nitrogen (NO3?N), P, potassium (K), calcium (Ca), and magnesium (Mg); and micronutrients: iron (Fe),

J. B. Rodriguez; J. R. Self; G. A. Peterson; D. G. Westfall

1999-01-01

191

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

192

Gd-DTPA-Enhanced MR Imaging of the Brain in Patients with Meningitis: Comparison with CT  

Microsoft Academic Search

Plain and Gd-DTPA-enhanced MR images of the brain were obtained in 18 consecutive patients with meningitis (eight with tuberculous, five with bacterial, three with viral, and two with fungal infections); the MR images were compared with CT scans. MR images were obtained on a 2.O-T superconducting unit with both Ti- and T2-weighted pulse sequences before injectionand with a TI-weighted sequence

Kee Hyun Chang; Moon Hee Han; Jae Kyu Roh; Man Chung Han; Chu-Wan Kim

193

Synthesis and characterization of a novel chemically designed (Globo)3–DTPA–KLH antigen  

PubMed Central

In recent years, many experiments have been conducted for the production and evaluation of anticancer glycoconjugated vaccines in developed countries and many achievements have been accomplished with Globo H derivatives. In the current experiment, a new chemically designed triplicate version of (Globo H)3–diethylenetriamine pentaacetic acid (DTPA)–KLH antigen was synthesized and characterized. Immunization with (Globo H)3-DTPA-KLH, a hexasaccharide that is a member of a family of antigenic carbohydrates that are highly expressed in various types of cancers conjugated with DTPA and KLH protein, induced a high level of antibody titer along with an elevated level of IL-4 in mice. Treatment of tumors with the collected sera from immunized mice decreased the tumor size in nude mice as well. None of the immunized mice illustrated any sign of tumor growth after injection of MCF-7 cells compared to the control animals. These findings, based on the newly presented structure of the Globo H antigen, lend exciting and promising evidence for clinical advancement in the development of a therapeutic vaccine in the future. PMID:25565775

Hajmohammadi, Mehdi; Siadat, Seyed Davar; Ghorbani, Masoud; Shafiee Ardestani, Mehdi; Teimourian, Shahram; Asgari, Vahid; Ahangari Cohan, Reza; Hajmohammadi, Mostafa; Hajmohammadi, Akram; Behzadi, Ramezan; Rajab Nezhad, Saied; Namvar Asl, Nabiollah

2015-01-01

194

Isomerism and solution dynamics of (90)Y-labeled DTPA--biomolecule conjugates.  

PubMed

This report describes the synthesis of two DTPA-conjugated cyclic peptides, cyclo(Arg-Gly-Asp-D-Phe-Lys)DTPA (SQ169) and [cyclo(Arg-Gly-Asp-D-Phe-Lys)](2)DTPA (SQ170), and a chromatographic study of their (90)Y complexes (RP762 and RP763, respectively). The goal is to study the solution structure and the possible isomerism of (90)Y-labeled DTPA-biomolecule conjugates at the tracer level (approximately 10(-10) M). RP762 was prepared in high radiochemical purity (RCP > 95%) by reacting 2 microg of SQ169 with 20 mCi of (90)YCl(3) (corresponding to a SQ169:Y ratio of approximately 4:1) in the 0.5 M ammonium acetate buffer (pH 8.0) at room temperature. RP763 was prepared in a similar fashion using SQ170. In both cases, the (90)Y-chelation was instantaneous. By a reversed-phase HPLC method, it was found that RP762 exists in solution as a mixture of two detectable isomers (most likely cis and trans isomers), which interconvert at room temperature. The interconversion of different isomeric forms of RP762 involves a rapid exchange of "wrapping isomers" via the "wagging" of the diethylenetriamine backbone, "shuffling" of the two NO(2) donor sets, and inversion at the ternimal amine-nitrogen atom. The inversion at a terminal nitrogen atom requires simultaneous dissociation of the NO(2) donor set. For RP763, the interconversion of different isomers is much faster than that for RP762 due to the weak bonding of two carbonyl-oxygen donors. Therefore, RP763 shows only one broad radiometric peak in its HPLC chromatogram. The rapid interconversion of different isomers is intramolecular via a partial dissociative mechanism. The results obtained in this study are consistent with the lack of kinetic inertness of (90)Y- and (111)In-labeled DTPA-biomolecule conjugates. Thus, the design of new BFCs should be focused on those which form lanthanide complexes with high thermodynamic stability and more importantly kinetic inertness. PMID:11170370

Liu, S; Cheung, E; Rajopadhye, M; Williams, N E; Overoye, K L; Edwards, D S

2001-01-01

195

Aerosol MTF revisited  

NASA Astrophysics Data System (ADS)

Different views of the significance of aerosol MTF have been reported. For example, one recent paper [OE, 52(4)/2013, pp. 046201] claims that the aerosol MTF "contrast reduction is approximately independent of spatial frequency, and image blur is practically negligible". On the other hand, another recent paper [JOSA A, 11/2013, pp. 2244-2252] claims that aerosols "can have a non-negligible effect on the atmospheric point spread function". We present clear experimental evidence of common significant aerosol blur and evidence that aerosol contrast reduction can be extremely significant. In the IR, it is more appropriate to refer to such phenomena as aerosol-absorption MTF. The role of imaging system instrumentation on such MTF is addressed too.

Kopeika, Norman S.; Zilberman, Arkadi; Yitzhaky, Yitzhak

2014-05-01

196

10 CFR 35.2204 - Records of molybdenum-99, strontium-82, and strontium-85 concentrations.  

Code of Federal Regulations, 2011 CFR

...maintain a record of the molybdenum-99 concentration or strontium-82...For each measured elution of technetium-99m, the ratio of the measures...kilobecquerel of molybdenum-99 per megabecquerel of technetium-99m (or microcuries of...

2011-01-01

197

10 CFR 35.2204 - Records of molybdenum-99, strontium-82, and strontium-85 concentrations.  

Code of Federal Regulations, 2010 CFR

...maintain a record of the molybdenum-99 concentration or strontium-82...For each measured elution of technetium-99m, the ratio of the measures...kilobecquerel of molybdenum-99 per megabecquerel of technetium-99m (or microcuries of...

2010-01-01

198

10 CFR 30.34 - Terms and conditions of licenses.  

Code of Federal Regulations, 2011 CFR

...Commission. (g) Each licensee preparing technetium-99m radiopharmaceuticals from molybdenum-99/technetium-99m generators or rubidium-82 from strontium-82...test the generator eluates for molybdenum-99 breakthrough or strontium-82 and...

2011-01-01

199

Acceleration of natural-abundance solid-state MAS NMR measurements on bone by paramagnetic relaxation from gadolinium-DTPA  

NASA Astrophysics Data System (ADS)

Reducing the data collection time without affecting the signal intensity and spectral resolution is one of the major challenges for the widespread application of multidimensional nuclear magnetic resonance (NMR) spectroscopy, especially in experiments conducted on complex heterogeneous biological systems such as bone. In most of these experiments, the NMR data collection time is ultimately governed by the proton spin-lattice relaxation times (T1). For over two decades, gadolinium(III)-DTPA (Gd-DTPA, DTPA = Diethylene triamine pentaacetic acid) has been one of the most widely used contrast-enhancement agents in magnetic resonance imaging (MRI). In this study, we demonstrate that Gd-DTPA can also be effectively used to enhance the longitudinal relaxation rates of protons in solid-state NMR experiments conducted on bone without significant line-broadening and chemical-shift-perturbation side effects. Using bovine cortical bone samples incubated in different concentrations of Gd-DTPA complex, the 1H T1 values were calculated from data collected by 1H spin-inversion recovery method detected in natural-abundance 13C cross-polarization magic angle spinning (CPMAS) NMR experiments. Our results reveal that the 1H T1 values can be successfully reduced by a factor of 3.5 using as low as 10 mM Gd-DTPA without reducing the spectral resolution and thus enabling faster data acquisition of the 13C CPMAS spectra. These results obtained from 13C-detected CPMAS experiments were further confirmed using 1H-detected ultrafast MAS experiments on Gd-DTPA doped bone samples. This approach considerably improves the signal-to-noise ratio per unit time of NMR experiments applied to bone samples by reducing the experimental time required to acquire the same number of scans.

Mroue, Kamal H.; Zhang, Rongchun; Zhu, Peizhi; McNerny, Erin; Kohn, David H.; Morris, Michael D.; Ramamoorthy, Ayyalusamy

2014-07-01

200

Solid dispersions of the penta-ethyl ester prodrug of diethylenetriaminepentaacetic acid (DTPA): formulation design and optimization studies.  

PubMed

The penta-ethyl ester prodrug of diethylenetriaminepentaacetic acid (DTPA), which exists as an oily liquid, was incorporated into a solid dispersion for oral administration by the solvent evaporation method using blends of polyvinylpyrrolidone (PVP), Eudragit® RL PO and ?-tocopherol. D-optimal mixture design was used to optimize the formulation. Formulations that had a high concentration of both Eudragit® RL PO and ?-tocopherol exhibited low water absorption and enhanced stability of the DTPA prodrug. Physicochemical properties of the optimal formulation were evaluated using Fourier transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC). In vitro release of the prodrug was evaluated using the USP Type II apparatus dissolution method. DSC studies indicated that the matrix had an amorphous structure, while FTIR spectrometry showed that DTPA penta-ethyl ester and excipients did not react with each other during formation of the solid dispersion. Dissolution testing showed that the optimized solid dispersion exhibited a prolonged release profile, which could potentially result in a sustained delivery of DTPA penta-ethyl to enhance bioavailability. In conclusion, DTPA penta-ethyl ester was successfully incorporated into a solid matrix with high drug loading and improved stability compared to prodrug alone. PMID:24047113

Yang, Yu-Tsai; Di Pasqua, Anthony J; Zhang, Yong; Sueda, Katsuhiko; Jay, Michael

2014-11-01

201

Hydrothermally synthesized PEGylated calcium phosphate nanoparticles incorporating Gd-DTPA for contrast enhanced MRI diagnosis of solid tumors.  

PubMed

Organic-inorganic hybrid nanoparticles with calcium phosphate (CaP) core and PEGylated shell were developed to incorporate magnetic resonance imaging (MRI) contrast agent diethylenetriaminepentaacetic acid gadolinium (III) (Gd-DTPA) for noninvasive diagnosis of solid tumors. A two-step preparation method was applied to elaborate hybrid nanoparticles with a z-average hydrodynamic diameter about 80nm, neutral surface ?-potential and high colloidal stability in physiological environments by self-assembly of poly(ethylene glycol)-b-poly(aspartic acid) block copolymer, Gd-DTPA, and CaP in aqueous solution, followed with hydrothermal treatment. Incorporation into the hybrid nanoparticles allowed Gd-DTPA to show significant enhanced retention ratio in blood circulation, leading to high accumulation in tumor positions due to enhanced permeability and retention (EPR) effect. Moreover, Gd-DTPA revealed above 6 times increase of relaxivity in the nanoparticle system compared to free form, and eventually, selective and elevated contrast enhancements in the tumor positions were observed. These results indicate the high potential of Gd-DTPA-loaded PEGylated CaP nanoparticles as a novel contrast agent for noninvasive cancer diagnosis. PMID:24211705

Mi, Peng; Kokuryo, Daisuke; Cabral, Horacio; Kumagai, Michiaki; Nomoto, Takahiro; Aoki, Ichio; Terada, Yasuko; Kishimura, Akihiro; Nishiyama, Nobuhiro; Kataoka, Kazunori

2014-01-28

202

Cesar water vapor, aerosol  

E-print Network

Fig ure A: Cesar water vapor, aerosol and Clo ud lidar (Cae li) Fig ure B: IIR 3-channe l composite) Fig ure C: Lidar returns on 13 Sept. 2006 from Caeli (To p) and CALIPSO (bottom) 1) KNMI Royal aerosol property profiles measured with lidar M. de Graaf 1,2 , D.P. Donovan 1 , A. Apituley 2 , K

Graaf, Martin de

203

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...

204

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 ...

205

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...

206

Global Aerosol Observations  

Atmospheric Science Data Center

... across the deserts of Mali, Niger and Chad, while in southern Africa, this is the least hazy time of year. During June through ... and November thick aerosol cover is limited to portions of southern Africa and the Congo, but moderately high aerosol optical thickness ...

2013-04-19

207

The SPARC Aerosol Assessment  

NASA Astrophysics Data System (ADS)

Stratospheric Processes and their Role in Climate (SPARC), a project of the WMO/ICSU/IOC World Climate Research Programme, was responsible for the recent SPARC Assessment of Upper Tropospheric and Stratospheric Water Vapour. SPARC has now decided to generate an analogous document for the stratospheric aerosol, using many of the measurements that have been developed in the last twenty years, but relying heavily on the SAGE II data set. The stratospheric aerosol assessment involves a large international collection of atmospheric scientists whose special area of expertise is the stratospheric aerosol. Key questions that have been identified as requiring answers include: How have aerosol properties such as surface area density varied with time? How representative are satellite-based climatologies? What is the non-volcanic bacground for stratospheric aerosol and can a trend in it be detected? How well can models reproduce observed aerosol properties? We report on the ``kickoff" workshop that was held at the CNES headquarters in Paris on November 4-6, 2001. We shall describe some of the interesting results that were based on the SAGE II data set. The assessment will be carried out by five working groups each focussing on one of the following aspects: processes, aerosol precursors, climatology, trends and modeling. The long records from SAGE II, HALOE and other space based instruments will play a prominent role in construction of a climatology. It is expected that a valuable result of this assessment will be a set of ``standard" stratospheric aerosol parameters for use by modelers.

Hamill, P.; Thomason, L. W.; Peter, T.

2002-05-01

208

Continuous Monitoring of Aerosols  

NASA Technical Reports Server (NTRS)

Online spectrometer monitors composition of individual aerosol particles. Single aerosol particles up to about 5 microns in diameter are analyzed for chemical composition, yielding valuable information on nature of pollution source. Tests show system has promise for monitoring oxidation of sulfur dioxide to sulfates important in controlling pollution from coal-fired power plants.

Mahadeva, S. P.; Giffin, C. E.; Norris, D. D.; Friedlander, S. K.

1983-01-01

209

Direct Aerosol Forcing Uncertainty  

DOE Data Explorer

Understanding sources of uncertainty in aerosol direct radiative forcing (DRF), the difference in a given radiative flux component with and without aerosol, is essential to quantifying changes in Earth's radiation budget. We examine the uncertainty in DRF due to measurement uncertainty in the quantities on which it depends: aerosol optical depth, single scattering albedo, asymmetry parameter, solar geometry, and surface albedo. Direct radiative forcing at the top of the atmosphere and at the surface as well as sensitivities, the changes in DRF in response to unit changes in individual aerosol or surface properties, are calculated at three locations representing distinct aerosol types and radiative environments. The uncertainty in DRF associated with a given property is computed as the product of the sensitivity and typical measurement uncertainty in the respective aerosol or surface property. Sensitivity and uncertainty values permit estimation of total uncertainty in calculated DRF and identification of properties that most limit accuracy in estimating forcing. Total uncertainties in modeled local diurnally averaged forcing range from 0.2 to 1.3 W m-2 (42 to 20%) depending on location (from tropical to polar sites), solar zenith angle, surface reflectance, aerosol type, and aerosol optical depth. The largest contributor to total uncertainty in DRF is usually single scattering albedo; however decreasing measurement uncertainties for any property would increase accuracy in DRF. Comparison of two radiative transfer models suggests the contribution of modeling error is small compared to the total uncertainty although comparable to uncertainty arising from some individual properties.

Mccomiskey, Allison

210

Direct Aerosol Forcing Uncertainty  

SciTech Connect

Understanding sources of uncertainty in aerosol direct radiative forcing (DRF), the difference in a given radiative flux component with and without aerosol, is essential to quantifying changes in Earth's radiation budget. We examine the uncertainty in DRF due to measurement uncertainty in the quantities on which it depends: aerosol optical depth, single scattering albedo, asymmetry parameter, solar geometry, and surface albedo. Direct radiative forcing at the top of the atmosphere and at the surface as well as sensitivities, the changes in DRF in response to unit changes in individual aerosol or surface properties, are calculated at three locations representing distinct aerosol types and radiative environments. The uncertainty in DRF associated with a given property is computed as the product of the sensitivity and typical measurement uncertainty in the respective aerosol or surface property. Sensitivity and uncertainty values permit estimation of total uncertainty in calculated DRF and identification of properties that most limit accuracy in estimating forcing. Total uncertainties in modeled local diurnally averaged forcing range from 0.2 to 1.3 W m-2 (42 to 20%) depending on location (from tropical to polar sites), solar zenith angle, surface reflectance, aerosol type, and aerosol optical depth. The largest contributor to total uncertainty in DRF is usually single scattering albedo; however decreasing measurement uncertainties for any property would increase accuracy in DRF. Comparison of two radiative transfer models suggests the contribution of modeling error is small compared to the total uncertainty although comparable to uncertainty arising from some individual properties.

Mccomiskey, Allison

2008-01-15

211

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 -.

212

Definitive Diagnosis of Cerebrospinal Fluid Leak Into the Pleural Space Using 111In-DTPA Cisternography.  

PubMed

A 58-year-old woman with a calcified disk extrusion causing severe spinal stenosis underwent T8 to T9 diskectomy and spinal fusion. A postoperative pseudomeningocele was treated with lumbar drain and fibrin glue. Performed for persistent right pleural effusion, CT myelogram failed to show communication between the cerebrospinal fluid (CSF) and pleural space-even on 2-hour delayed images. Subsequent In-DTPA cisternogram clearly demonstrated CSF leakage into the right pleural space at 2 hours, and surgical repair yielded good results. Radionuclide cisternography is a highly useful method to detect CSF leak, especially when it is occult on CT yet suspected clinically. PMID:25243944

Howard, Brandon A; Gray, Linda; Isaacs, Robert E; Borges-Neto, Salvador

2014-09-18

213

Glomerular filtration rate in transplantation patients: estimation of renal function using Tc-99m DTPA.  

PubMed

The clinical assessment of a transplanted kidney is often difficult, especially in the immediate postoperative period. The biochemical parameters used to monitor renal function change slowly and can take several days to reflect the actual renal status. We have modified a technique for determining the glomerular filtration rate (GFR) from a Tc-99m DTPA renal scan and have found that it correlates with the actual GFR throughout the postoperative course. In addition, we describe a method for changing dose calibrator measurements into administered counts. This technique for determining the GFR provides a quick and accurate assessment of renal function and is useful to guide therapeutic decisions. PMID:3892582

Reinig, J W; Gordon, L; Frey, D; Garrick, E; Daniel, W T

1985-08-01

214

Aqueous aerosol SOA formation: impact on aerosol physical properties.  

PubMed

Organic chemistry in aerosol water has recently been recognized as a potentially important source of secondary organic aerosol (SOA) material. This SOA material may be surface-active, therefore potentially affecting aerosol heterogeneous activity, ice nucleation, and CCN activity. Aqueous aerosol chemistry has also been shown to be a potential source of light-absorbing products ("brown carbon"). We present results on the formation of secondary organic aerosol material in aerosol water and the associated changes in aerosol physical properties from GAMMA (Gas-Aerosol Model for Mechanism Analysis), a photochemical box model with coupled gas and detailed aqueous aerosol chemistry. The detailed aerosol composition output from GAMMA was coupled with two recently developed modules for predicting a) aerosol surface tension and b) the UV-Vis absorption spectrum of the aerosol, based on our previous laboratory observations. The simulation results suggest that the formation of oligomers and organic acids in bulk aerosol water is unlikely to perturb aerosol surface tension significantly. Isoprene-derived organosulfates are formed in high concentrations in acidic aerosols under low-NO(x) conditions, but more experimental data are needed before the potential impact of these species on aerosol surface tension may be evaluated. Adsorption of surfactants from the gas phase may further suppress aerosol surface tension. Light absorption by aqueous aerosol SOA material is driven by dark glyoxal chemistry and is highest under high-NO(x) conditions, at high relative humidity, in the early morning hours. The wavelength dependence of the predicted absorption spectra is comparable to field observations and the predicted mass absorption efficiencies suggest that aqueous aerosol chemistry can be a significant source of aerosol brown carbon under urban conditions. PMID:24601011

Woo, Joseph L; Kim, Derek D; Schwier, Allison N; Li, Ruizhi; McNeill, V Faye

2013-01-01

215

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

216

( 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

217

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

218

Transmetallation of Gd-DTPA by Fe3+, Cu2+ and Zn2+ in water: batch experiments and coagulation-flocculation simulations.  

PubMed

The study investigates the stability of gadolinium-DTPA complex in presence of competing metallic ions, Fe(3+), Cu(2+) and Zn(2+) using batch experiments and coagulation-flocculation simulations. High performance liquid chromatography with fluorescence detection was used for simultaneous analysis of chelate gadolinium (Gd-DTPA) and free Gd(III) ion in water. It was shown that Cu(2+) has a strong affinity for DTPA and could lead to a complete release of Gd(3+). Fe(3+) appeared also to compete strongly with Gd(3+) for DTPA binding since up to 80% of Gd-complex was dissociated under iron excess condition. Finally, zinc had a lower influence on Gd speciation: only 15% of Gd(3+) was released with addition of a 5-fold excess of Zn(2+). During coagulation-flocculation simulation, Fe(3+) was able to displace about 27% of Gd-DTPA, and no adsorption was observed onto flocs. PMID:24183629

Rabiet, Marion; Letouzet, Marine; Hassanzadeh, Sepideh; Simon, Stéphane

2014-01-01

219

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

Microsoft Academic Search

Purpose  Cetuximab is a recombinant, human\\/mouse chimeric IgG1 monoclonal antibody that binds to the epidermal growth factor receptor (EGFR\\/HER1). Cetuximab is approved for the treatment\\u000a of patients with HER1-expressing metastatic colorectal cancer. Limitations in currently reported radiolabeled cetuximab for\\u000a 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

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

2010-01-01

220

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

221

Tracking World Aerosol Hazards  

NSDL National Science Digital Library

Worldwide patterns and sources of aerosols are analyzed and evaluated for potential hazards to aircraft safety. Using aerosol index maps created from data gathered by the TOMS instrument, student groups will analyze and compare aerosol data from either eight consecutive or eight random days. Each group will graph the data, rank the hazard level of their study area and analyze the patterns and probable causes of those aerosols. Directions and materials are included for classes with computer access and for those without computer access. The URL opens to the investigation directory, with links to teacher and student materials, lesson extensions, resources, teaching tips, and assessment strategies. Note that this is the last of three investigations found in the Grades 5-8 Module 1 of Mission Geography. The Mission Geography curriculum integrates data and images from NASA missions with the National Geography Standards. Each of the three investigations in Module 1, while related, can be done independently.

2013-02-13

222

Aerosol lenses propagation model.  

PubMed

We propose a model based on the properties of cascading lenses modulation transfer function (MTF) to reproduce the irradiance of a screen illuminated through a dense aerosol cloud. In this model, the aerosol cloud is broken into multiple thin layers considered as individual lenses. The screen irradiance generated by these individual layers is equivalent to the point-spread function (PSF) of each aerosol lens. Taking the Fourier transform of the PSF as a MTF, we cascade the lenses MTF to find the cloud MTF. The screen irradiance is found with the Fourier transform of this MTF. We show the derivation of the model and we compare the results with the Undique Monte Carlo simulator for four aerosols at three optical depths. The model is in agreement with the Monte Carlo for all the cases tested. PMID:21886230

Tremblay, Grégoire; Roy, Gilles

2011-09-01

223

Stratospheric aerosol layer detection.  

NASA Technical Reports Server (NTRS)

The earth's daytime horizon was scanned on several occasions between 1963 and 1968. The limb was observed at six wavelengths in the ultraviolet and visible spectrum with a narrow field of view instrument on the X-15 aircraft. The inversion of such horizon observations to yield atmospheric density and the concentrations of ozone and aerosol extinctions is discussed. The most significant features of the X-15 data are effects attributed to stratospheric aerosols. Observations of both the 20-km aerosol layer and a layer at approximately 50 km are inferred from the data. Both layers apparently possess considerable variability. It is pointed out that the existence of substantial aerosol concentrations above 30 km is an important limitation of the nadir technique of determining ozone concentrations in which the earth's radiance is observed at ultraviolet wavelengths from a satellite.

Cunnold, D. M.; Gray, C. R.; Merritt, D. C.

1973-01-01

224

Monodisperse aerosol generator  

DOEpatents

An aerosol generator is described which is capable of producing a monodisperse aerosol within narrow limits utilizing an aqueous solution capable of providing a high population of seed nuclei and an organic solution having a low vapor pressure. The two solutions are cold nebulized, mixed, vaporized, and cooled. During cooling, particles of the organic vapor condense onto the excess seed nuclei, and grow to a uniform particle size.

Ortiz, Lawrence W. (Los Alamos, NM); Soderholm, Sidney C. (Pittsford, NY)

1990-01-01

225

In Situ Aerosol Detector  

NASA Technical Reports Server (NTRS)

An affordable technology designed to facilitate extensive global atmospheric aerosol measurements has been developed. This lightweight instrument is compatible with newly developed platforms such as tethered balloons, blimps, kites, and even disposable instruments such as dropsondes. This technology is based on detection of light scattered by aerosol particles where an optical layout is used to enhance the performance of the laboratory prototype instrument, which allows detection of smaller aerosol particles and improves the accuracy of aerosol particle size measurement. It has been determined that using focused illumination geometry without any apertures is advantageous over using the originally proposed collimated beam/slit geometry (that is supposed to produce uniform illumination over the beam cross-section). The illumination source is used more efficiently, which allows detection of smaller aerosol particles. Second, the obtained integral scattered light intensity measured for the particle can be corrected for the beam intensity profile inhomogeneity based on the measured beam intensity profile and measured particle location. The particle location (coordinates) in the illuminated sample volume is determined based on the information contained in the image frame. The procedure considerably improves the accuracy of determination of the aerosol particle size.

Vakhtin, Andrei; Krasnoperov, Lev

2011-01-01

226

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

227

Utility of radioisotopic filtration markers in chronic renal insufficiency: Simultaneous comparison of sup 125 I-iothalamate, sup 169 Yb-DTPA, sup 99m Tc-DTPA, and inulin. The Modification of Diet in Renal Disease Study  

SciTech Connect

Assessment of glomerular filtration rate (GFR) with inulin is cumbersome and time-consuming. Radioisotopic filtration markers have been studied as filtration markers because they can be used without continuous intravenous (IV) infusion and because analysis is relatively simple. Although the clearances of 99mTc-DTPA, 169Yb-DTPA, and 125I-iothalamate have each been compared with inulin, rarely has the comparability of radioisotopic filtration markers been directly evaluated in the same subject. To this purpose, we determined the renal clearance of inulin administered by continuous infusion and the above radioisotopic filtration markers administered as bolus injections, simultaneously in four subjects with normal renal function and 16 subjects with renal insufficiency. Subjects were studied twice in order to assess within-study and between-study variability. Unlabeled iothalamate was infused during the second half of each study to assess its effect on clearances. We found that renal clearance of 125I-iothalamate and 169Yb-DTPA significantly exceeded clearance of inulin in patients with renal insufficiency, but only by several mL.min-1.1.73m-2. Overestimation of inulin clearance by radioisotopic filtration markers was found in all normal subjects. No differences between markers were found in the coefficient of variation of clearances either between periods on a given study day (within-day variability) or between the two study days (between-day variability). The true test variability between days did not correlate with within-test variability. We conclude that the renal clearance of 99mTc-DTPA, 169Yb-DTPA, or 125I-iothalamate administered as a single IV or subcutaneous injection can be used to accurately measure GFR in subjects with renal insufficiency; use of the single injection technique may overestimate GFR in normal subjects.

Perrone, R.D.; Steinman, T.I.; Beck, G.J.; Skibinski, C.I.; Royal, H.D.; Lawlor, M.; Hunsicker, L.G. (National Institute of Diabetes, Digestive, and Kidney Diseases, Bethesda, MD (USA))

1990-09-01

228

Pneumocystis pneumonia increases the clearance rate of inhaled /sup 99m/Tc DTPA from lung to blood  

SciTech Connect

Despite no radiographic change, a patient with Pneumocystis pneumonia showed increased clearance of inhaled /sup 99m/Tc DTPA from lung to blood. Gas transfer for carbon monoxide was also reduced, but improved with treatment. This was paralleled by serial increase in the t1/2 LB.

Jones, D.K.; Higenbottam, T.W.

1985-10-01

229

Is DTPA a good competing chelating agent for Th(IV) in human serum and suitable in targeted alpha therapy?  

PubMed

The interaction between thorium and human serum components was studied using difference ultraviolet spectroscopy (DUS), ultrafiltration and high-pressure-anion exchange chromatography (HPAEC) with external inductively conducted plasma mass spectrometry (ICP-MS) analysis. Experimental data are compared with modelling results based on the law of mass action. Human serum transferrin (HSTF) interacts strongly with Th(IV), forming a ternary complex including two synergistic carbonate anions. This complex governs Th(IV) speciation under blood serum conditions. Considering the generally used Langmuir-type model, values of 10(33.5) and 10(32.5) were obtained for strong and weak sites, respectively. We showed that trace amounts of diethylene triamine pentaacetic acid (DTPA) cannot complex Th(IV) in the blood serum at equilibrium. Unexpectedly this effect is not related to the competition with HSTF but is due to the strong competition with major divalent metal ions for DTPA. However, Th-DTPA complex was shown to be stable for a few hours when it is formed before addition in the biological medium; this is related to the high kinetic stability of the complex. This makes DTPA a potential chelating agent for synthesis of (226)Th-labelled biomolecules for application in targeted alpha therapy. PMID:22388013

Le Du, Alicia; Sabatié-Gogova, Andrea; Morgenstern, Alfred; Montavon, Gilles

2012-04-01

230

99m T c-DTPA Study to Validate an Experimental Model of Ureteral Obstruction in Rabbits: Preliminary Results  

PubMed Central

Objective. To create a ureteral obstruction experimental model that can be proved through 99mTc-DTPA renal scintigraphy and histopathological studies, without causing total renal function loss. Materials and Methods. Ten New Zealand white rabbits were submitted to a surgical experiment to create a model of unilateral obstruction to urinary flow. Surgery procedure provided unilateral ureteral obstruction (left kidney) to urinary flow and posteriorly was evaluated by 99mTc-DTPA renal scintigraphy and histopathological study. 99mTc-DTPA renal study was performed to detect and quantify signs of obstruction and to evaluate renal function. Statistical analysis was performed through the Student t-test with a significance level of P<0.05. Results. Nine of the ten rabbits presented left renal unit obstruction and one nonobstructive on the 99mTc-DTPA and histopathological studies. All the right renal units, which were not submitted to surgical procedure, were nonobstructed by the studies. There was a general agreement between scintigraphy and histopathological results in both groups. Conclusion. The experimental model promoted the creation of ureteral obstruction in rabbits, confirmed by nuclear medicine scintigraphy and histopathology, and could be used in further studies to better understand urinary obstruction. PMID:24489538

de Lima, Marcelo Lopes; Bertti, Rodolfo; Moro, Juliano César; Coltro Neto, Fábio; Miyaoka, Ricardo; Fregonesi, Adriano; de Lima, Mariana da Cunha Lopes; Ramos, Celso Darío

2013-01-01

231

Gd-EOB-DTPA-Enhanced MR Guidance in Thermal Ablation of Liver Malignancies  

PubMed Central

Objective To evaluate the potency of Gd-EOB-DTPA to support hepatic catheter placement in laser ablation procedures by quantifying time-dependent delineation effects for instrumentation and target tumor within liver parenchyma. Monitoring potential influence on online MR thermometry during the ablation procedure is a secondary aim. Materials and Methods 30 cases of MR-guided laser ablation were performed after i.v. bolus injection of gadoxetic acid (0.025 mmol/Kg Gd-EOB-DTPA; Bayer Healthcare, Berlin, Germany). T1-weighted GRE sequences were used for applicator guidance (FLASH 3D) in the catheter placement phase and for therapy monitoring (FLASH 2D) in the therapy phase. SNR and consecutive CNR values were measured for elements of interest plotted over time both for catheter placement and therapy phase and compared with a non-contrast control group of 19 earlier cases. Statistical analysis was realized using the paired Wilcoxon test. Results Sustainable signal elevation of liver parenchyma in the contrast-enhanced group was sufficient to silhouette both target tumor and applicator against the liver. Differences in time dependent CNR alteration were highly significant between contrast-enhanced and non-contrast interventions for parenchyma and target on the one hand (p?=?0.020) and parenchyma and instrument on the other hand (p?=?0.002). Effects lasted for the whole procedure (monitoring up to 60 min) and were specific for the contrast-enhanced group. Contrasting maxima were seen after median 30 (applicator) and 38 (tumor) minutes, in the potential core time of a multineedle procedure. Contrast influence on T1 thermometry for real-time monitoring of thermal impact was not significant (p?=?0.068–0.715). Conclusion Results strongly support anticipated promotive effects of Gd-EOB-DTPA for MR-guided percutaneous liver interventions by proving and quantifying the delineating effects for therapy-relevant elements in the procedure. Time benefit, cost effectiveness and oncologic outcome of the described beneficiary effects will have to be part of further investigations. PMID:25541950

Rosenberg, Christian; Jahn, Andrea; Pickartz, Tilman; Wahnschaffe, Ulrich; Patrzyk, Maciej; Hosten, Norbert

2014-01-01

232

Increased Gulf Aerosol Formation due to Oil Research aircraft performing measurements to characterize aerosol plume  

E-print Network

or Secondary Organic Aerosol Sea spray constitutes most OA, but SOA was shown greatly spiked aerosol particleIncreased Gulf Aerosol Formation due to Oil Research aircraft performing measurements to characterize aerosol plume Abundant VOC's increase aerosol formation Aerosols usually formed as Organic Aerosol

Toohey, Darin W.

233

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

234

SURVIVAL OF BACTERIA DURING AEROSOLIZATION  

EPA Science Inventory

One form of commercial application of microorganisms, including genetically engineered microorganisms is as an aerosol. To study the effect of aerosol-induced stress on bacterial survival, nonrecombinant spontaneous antibiotic-resistant mutants of four organisms, Enterobacter clo...

235

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

236

Highly stable aerosol generator  

DOEpatents

An improved compressed air nebulizer has been developed such that a uniform aerosol particle size and concentration may be produced over long time periods. This result is achieved by applying a vacuum pressure to the makeup assembly and by use of a vent tube between the atmosphere and the makeup solution. By applying appropriate vacuum pressures to the makeup solution container and by proper positioning of the vent tube, a constant level of aspirating solution may be maintained within the aspirating assembly with aspirating solution continuously replaced from the makeup solution supply. This device may also be adapted to have a plurality of aerosol generators and only one central makeup assembly. 2 figs.

DeFord, H.S.; Clark, M.L.

1981-11-03

237

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

238

Utilization of synergetic aerosol retrieval  

NASA Astrophysics Data System (ADS)

A synergetic aerosol retrieval method SYNAER which exploits a combination of a radiome-ter and a spectrometer onboard ENVISAT and METOP has been developed. This method enables retrieval of aerosol optical depth and an estimation of the aerosol composition. Due to the sampling characteristics and available information content of the combined sensor data the utilization of the results has to be done with appropriate care. On the other hand the specifically new information on aerosol composition enables new applications in the fields of aerosol monitoring (differntiating components), air quality (fine particulate matter assessment and data assimilation), and climate research (aerosol-cloud interaction analysis for different aerosol components). The paper will show examples of applications in the various fields. The paper will be based on ongoing reprocessing of SYNAER for ENVISAT 2003-2009 within ESA GSE PROMOTE and on experimental selected results for METOP. Implications of the different sampling of the two sensor combinations for the differnt applications will be assessed.

Holzer-Popp, Thomas

239

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

240

Aerosol processing of materials  

SciTech Connect

Recent advances in aerosol generation of materials are reviewed. Gas-to-particle and spray processes (spray pyrolysis) for powder generation and various routes for film generation are discussed from the experimental and theoretical perspectives. The range of materials generated by these routes has increased in recent years to include fullerenes and ceramic superconductors. Many metals and various oxide and nonoxide ceramics have also been added to the list of materials generated by gas-phase routes. Established aerosol routes such as vapor condensation have found widespread applications for generation of nanophase materials. The formation of quantum dots via aerosol approaches has also been demonstrated. The theoretical understanding of gas-to-particle conversion routes has advanced to include the finite rate of particle fusion or sintering occurring after collisions of particles. The modeling of spray pyrolysis systems has provided insight into the control of particle morphology and reactor design. In this review, these recent developments in aerosol generation of powders and films via gas-phase and spray routes are discussed with an emphasis on the material chemistries involved and the synthesis of nanophase materials. 351 refs., 20 figs.

Gurav, A.; Kodas, T.; Pluym, T.; Xiong, Y. (Univ. of New Mexico, Albuquerque, NM (United States))

1993-11-01

241

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 ...

242

EXPOSURES TO ACIDIC AEROSOLS  

EPA Science Inventory

Ambient monitoring of acid aerosol in four U.S. cities and in a rural region of southern Ontario clearly show distinct periods of strong acidity. easurements made in Kingston, TN, and Stuebenville, OH, resulted in 24-hr H+ ion concentrations exceeding 100 nmole/m3 more than 10 ti...

243

Stratospheric Aerosol Layer Detection  

Microsoft Academic Search

The earth's daytime horizon was scanned on several occasions between 1963 and 1968. The limb was observed at six wavelengths in the ultraviolet and visible spectrum with a narrow field of view instrument on the X-15 aircraft. The inversion of such horizon observations to yield atmospheric density and the concentrations of ozone and aerosol extinctions is discussed. The most significant

D. M. Cunnold; C. R. Gray; D. C. Merritt

1973-01-01

244

Mesospheric Aerosol Sampling Spectrometer  

NASA Astrophysics Data System (ADS)

An instrument has been developed to detect charged, sub-visible aerosol particles in the polar mesosphere. Two of these instruments were launched in August, 2007 from Andoya, Norway as part of the Mesospheric Aerosol Sampling Spectrometer (MASS) campaign and both detected charged aerosols. These in-situ measurements coincided with measurements by the Aeronomy of Ice in the Mesosphere (AIM) satellite and the German/Norwegian Existence and Charge state Of Meteoric dust grains in the middle Atmosphere (ECOMA) rocket campaign. This instrument has a 25 square centimeter entrance slit that admits a continuous flow of air. Venting ports are placed lower on the detector in order to reduce pressure buildup. The air sample flows between three pairs of graphite electrodes biased symmetrically with increasing bias potentials. Electrons, light ions, cluster ions and heavy charged aerosol particles of both polarities are collected mass-selectively on the electrodes that are connected to sensitive electrometers. Direct Simulation Monte Carlo (DSMC) codes have been used to optimize the supersonic airflow within and around the instrument. The calibration of the MASS instrument as well as preliminary results will be shown. Acknowledgement: This project is supported by NASA.

Knappmiller, S.; Robertson, S.; Horanyi, M.; Kohnert, R.; Sternovsky, Z.; Baumgarten, G.; Latteck, R.; Rapp, M.

2007-12-01

245

Mesospheric aerosol sampling spectrometer  

NASA Astrophysics Data System (ADS)

. The Mesospheric Aerosol Sampling Spectrometer (MASS) instrument has been launched on two sounding rockets in August, 2007 from Andoya, Norway to detect charged sub-visible aerosol particles in the polar mesosphere. The MASS instrument is designed to collect charged aerosols, cluster ions, and electrons on four pairs of graphite electrodes, three of which are biased with increasing voltage. The design of the MASS instrument was complicated by the short mean free path in the mesosphere. The opening to MASS was deliberately built to increase the mean free path and to reduce the shock wave within the instrument. The design procedure began with aerodynamics simulations of the flow through the instrument using Direct Simulation Monte Carlo (DSMC) in 3-D. The electric fields within the instrument were calculated using a Laplace solver in 3-D. With the aerodynamic and electric field simulations completed, an algorithm was created to find the trajectories of charged aerosols including collisions within MASS. Using this algorithm the collection efficiencies for each electrode was calculated as a function of the charge to mass ratio of the incoming particle. The simulation results have been confirmed experimentally using an Argon RF ion beam. The data from the August launches have been analyzed and the initial results show the MASS instrument operated as expected. Additional studies are underway to determine if there were effects from payload charging or spurious charge generation within the instrument. This project is supported by NASA.

Knappmiller, Scott; Robertson, Scott; Sternovsky, Zoltan; Horanyi, Mihaly; Kohnert, Rick

246

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...

247

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

248

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

249

Zinc, copper, and nickel availabilities as determined by soil solution and DTPA extraction of a sludge?amended soil  

Microsoft Academic Search

Extracting sludge?amended soil with DTPA does not always give a reliable measure of plant?available heavy metals. The major purpose of this greenhouse pot study was to help explain why. Two anaerobically digested sludges from sewages treated with either Ca(OH)2or FeCl3were applied to 3?kg samples of a Mollic Albaqualf previously limed with Ca(OH)2rates of 0, 2.5, and 10g\\/pot that resulted in

J. F. Adams; D. E. Kissel

1989-01-01

250

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

251

Assessment of extradural degenerative disease with Gd-DTPA-enhanced MR imaging: correlation with surgical and pathologic findings.  

PubMed

To test whether gadolinium-DTPA-enhanced MR would increase the conspicuity of extradural degenerative disease in the previously unoperated patient, we prospectively studied a group of 30 patients with symptoms suggestive of disk disease. Surgical findings and pathologic correlations were used as an objective measure of accuracy. Gadolinium-DTPA increased the confidence of diagnosis at one of eight operated cervical levels (six patients) and changed the diagnosis from extradural degenerative disease to tumor in one patient. The mechanism of enhancement of the epidural space and peridiskal region appears to be related to accumulation of contrast material within the epidural venous plexus, as well as to epidural fibrosis associated with disk disruption and herniation. While the immediate clinical utility of gadolinium-DTPA for morphologic analysis seems limited to difficult cervical spine cases, the presence of enhancement as a marker of epidural fibrosis and attempted healing may prove to be of great importance in studying the natural history and basic pathophysiology of degenerative disk disease. PMID:2104701

Ross, J S; Modic, M T; Masaryk, T J; Carter, J; Marcus, R E; Bohlman, H

1990-01-01

252

Detection of renal ischemic lesions using Gd-DTPA enhanced turbo FLASH MRI: Experimental and clinical results  

SciTech Connect

Our goal was to investigate the role of Gd-DTPA-enhanced dynamic MRI in the evaluation of renal ischemic lesions. With a turbo FLASH sequence before and after injection of Gd-DTPA, nine foxhound dogs after 60-120 min of renal ischemia underwent MR examination. In addition, five patients with a tumor in a solitary kidney were examined before and after nephron-sparing renal surgery to evaluate renal perfusion and function. The experimental and clinical findings were correlated with conventional measurements of kidney function and with histological findings. Complete renal ischemia leads to a poor corticomedullary differentiation in Gd-DTPA-enhanced turbo FLASH MRI. The signal-intensity-versus-time plots of kidneys with significant postischemic changes show a less steep increase of signal intensity in the cortex and a steeper increase of signal intensity in the medulla than those of normal kidneys. Dynamic MRI demonstrate renal morphology and reflect the functional status of the renal vasculature. 21 refs., 8 figs., 1 tab.

Vosshenrich, R.; Fischer, U.; Funke, M.; Kopka, L.; Grabbe, E. [Univ. of Goettingen (Germany)] [and others] [Univ. of Goettingen (Germany); and others

1996-03-01

253

The determination of relative renal function in a pediatric population using Tc-99m DTPA and Tc-99m DMSA  

SciTech Connect

Three methods for evaluating relative renal function in a pediatric population were compared. The clinical and nuclear medicine data of 73 patients were reviewed. Pertinent data included patient age, serum creatinine and the referral diagnosis (reflux, hypertension, obstructive uropathy). Time activity curves for renal regions of interest (ROI) were obtained by renography with Tc-99m DTPA, and deconvolved by an externally detected blood pool curve Furosemide was then administered to evaluate the renal collecting system (if indicated). This was followed by DMSA administration. Relative function was determined in 3 ways: 1) Accumulated renal DTPA activity 60-120 sec. following injection. 2) Amplitude of the tubular phase of the deconvolved renal curve and, 3) Accumulated Tc-99m DMSA activity in renal ROI 4 or 24 hrs. post-injection. Regression analysis revealed: 1) The basic relationship of relative functional data obtained by all three methods was not affected by creatinine, age or other factors. 2) The relationship between the three methods is linear and highly correlated. 3) The DMSA values may be predicted from either method of analyzing the DTPA study using appropriate predictor equations. The authors conclude that Tc-99m DMSA, due to its higher cost and more radiation exposure should not be used for the routine evaluation of relative renal function.

Rosen, P.R.; Kuruc, A.; Treves, S.T.

1985-05-01

254

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

255

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

256

Tumor-Targeted HPMA Copolymer-(RGDfK)-(CHX-A?-DTPA) Conjugates Show Increased Kidney Accumulation  

PubMed Central

N-(2-hydroxypropyl) methacrylamide (HPMA) copolymer-RGDfK conjugates targeting the ?v?3 integrin have shown increased accumulation in solid tumors and promise for selective delivery of radiotherapeutics to sites of angiogenesis- or tumor-expressed ?v?3 integrin. An unresolved issue in targeting radiotherapeutics to solid tumors is toxicity to non-target organs. To reduce toxicity of radiolabeled conjugates, we have synthesized HPMA copolymer-RGDfK conjugates with varying molecular weight and charge content to help identify a polymeric structure that maximizes tumor accumulation while rapidly clearing from non-targeted organs. Endothelial cell binding studies showed that copolymer conjugates of approximately 43, 20 and 10 kD actively bind to the ?v?3 integrin. Scintigraphic images showed rapid clearance of indium-111 radiolabeled conjugates from the blood pool and high kidney accumulation within 1 h in tumor bearing mice. Biodistribution data confirms images with high accumulation in kidney (max 210% ID/g for 43 kD conjugate) and lower tumor accumulation (max 1.8% ID/g for 43kD conjugate). While actively binding to the ?v?3 integrin in vitro, HPMA copolymer-RGDfK conjugates with increased negative charge through increased CHX-A?-DTPA chelator content in the side chains causes increased kidney accumulation with a loss of tumor binding in vivo. PMID:18687371

Borgman, Mark P.; Coleman, Tomika; Kolhatkar, Rohit B.; Geyser-Stoops, Sandra; Line, Bruce R.; Ghandehari, Hamidreza

2008-01-01

257

The predictive value of Tc-99m DTPA renography in obstructive uropathy using animal model.  

PubMed

There is no simple analytical test. Radionuclide diuretic renography (RDR), being a dynamic imaging study reflecting the function of the kidney and the urodynamics of the urinary tracts, has the potential to predict the outcome of surgery in obstructive uropathy. In 12 sheep, we occluded one ureter for a maximum of seven weeks and followed up for a maxim of five weeks after release of occlusion. Repeated Tc-99m DTPA diuretic renography studies were performed and the results were correlated with the duration of complete ureteric occlusion. The renal uptake percentage and the extraction slope of the time activity curve (TAC) showed progressive and steady decrease over the period of the occlusion. By the fifth week there was very low uptake (less than 18%) and the TAC was almost flat, suggestive of severe nephropathy. The parenchymal transit time index (PTTI) showed immediate rise after occlusion but with no progressive increase in its value. By the fifth week it dropped down to normal. After release, the recovery of function showed good correlation with the renal uptake percentage and extraction slope of TAC before release of occlusion. Therefore both these parameters, rather than PTTI, can be used to predict the outcome of surgery before the release of complete obstruction of the ureter. PMID:2285520

Bahar, R H; Elgazzar, A H; Abu-Zidan, F M; Sabha, M; Francis, I M; Kouris, K; Awdeh, M; Abdel-Dayem, H M; Nilsson, T; Britton, K E

1990-01-01

258

Measurements of stratospheric aerosols  

NASA Astrophysics Data System (ADS)

The history of measurements of the stratospheric aerosol layer is briefly reviewed. Balloon-borne measurements played a major role both in the discovery of the layer and in the susequent study of its nature. Following this introduction, stratospheric aerosol sources and balloon-borne measurement techniques are reviewed. Finally, the current status of this research area is outlined with data obtained mainly by balloon-borne techniques. It is concluded that a great deal has been learned in the past five years, due mainly to the increase of the occurrence of major volcanic eruptions, which are the predominant source of stratospheric particles, but also due to the development of instrumentation and techniques which have seen considerable application on the balloon platform.

Hofmann, D. J.

1985-06-01

259

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

260

LIDAR Measurements During Aerosols99  

NASA Technical Reports Server (NTRS)

The Aerosols99 cruise took place during the period from January 14, to February 8 1999 on the R/V Ron Brown. The cruise track was almost a straight line from Norfolk, Va. to Cape Town, South Africa and afforded the opportunity to sample several different aerosol regimes over the North and South Atlantic. A Micro Pulse LIDAR system was used continually during this cruise to profile the aerosol vertical structure. Inversions of this data illustrated a varying vertical structure depending on the dominant air mass. In clean maritime aerosols in the Northern and Southern Hemispheres the aerosols were capped at 1 km. When a Dust event from Africa was encountered the aerosol extinction increased its maximum height to above 2 km. During a period in which the air mass was dominated by biomass burning from Southern Africa, the aerosol layer extended to 4 km. Comparisons of the aerosol optical depth derived from LIDAR inversion and surface sunphotometers showed an agreement within +/- 0.05 RMS Similar comparisons between the extinction measured with a nephelometer and particle soot absorption photometer (at 19 m altitude) and the lowest LIDAR measurement (75 m) showed good agreement (+/- 0.014/km . The LIDAR underestimated surface extinction during periods when an elevated aerosol layer was present over a relatively clean surface layer, but otherwise gave accurate results.

Voss, Kenneth J.; Welton, Ellsworth J.; Quinn, Patricia K.; Johnson, James; Thompson, Anne; Einaudi, Franco (Technical Monitor)

2000-01-01

261

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

262

Lidar measurements during Aerosols99  

NASA Astrophysics Data System (ADS)

The Aerosols99 cruise (January 14 to February 8, 1999) went between Norfolk, Virginia, and Cape Town, South Africa. A Micropulse lidar system was used almost continually during this cruise to profile the aerosol vertical structure. Inversions of this data illustrated a varying vertical structure depending on the dominant air mass. In clean maritime aerosols in the Northern and Southern Hemispheres the aerosols were capped at 1 km. When a dust event from Africa was encountered, the aerosol extinction increased its maximum height to above 2 km. During a period in which the air mass was dominated by biomass burning from southern Africa, the aerosol layer extended to 4 km. Comparisons of the aerosol optical depth (AOD) derived from lidar inversion and surface Sun photometers showed an agreement within ±0.05 RMS. Similar comparisons between the extinction measured with a nephelometer and particle soot absorption photometer (at 19 m altitude) and the lowest lidar measurement (75 m) showed good agreement (±0.014 km-1). The lidar underestimated surface extinction during periods when an elevated aerosol layer (total AOD > 0.10) was present over a relatively clean (aerosol extinction < 0.05 km-1) surface layer, but otherwise gave accurate results.

Voss, Kenneth J.; Welton, Ellsworth J.; Quinn, Patricia K.; Johnson, James; Thompson, Anne M.; Gordon, Howard R.

2001-09-01

263

Aerosol Absorption and Radiative Forcing  

NASA Technical Reports Server (NTRS)

We present a comprehensive examination of aerosol absorption with a focus on evaluating the sensitivity of the global distribution of aerosol absorption to key uncertainties in the process representation. For this purpose we extended the comprehensive aerosol-climate model ECHAM5-HAM by effective medium approximations for the calculation of aerosol effective refractive indices, updated black carbon refractive indices, new cloud radiative properties considering the effect of aerosol inclusions, as well as by modules for the calculation of long-wave aerosol radiative properties and instantaneous aerosol forcing. The evaluation of the simulated aerosol absorption optical depth with the AERONET sun-photometer network shows a good agreement in the large scale global patterns. On a regional basis it becomes evident that the update of the BC refractive indices to Bond and Bergstrom (2006) significantly improves the previous underestimation of the aerosol absorption optical depth. In the global annual-mean, absorption acts to reduce the shortwave anthropogenic aerosol top-of-atmosphere (TOA) radiative forcing clear-sky from -0.79 to -0.53 W m(sup -2) (33%) and all-sky from -0.47 to -0.13W m(sup -2 (72%). Our results confirm that basic assumptions about the BC refractive index play a key role for aerosol absorption and radiative forcing. The effect of the usage of more accurate effective medium approximations is comparably small. We demonstrate that the diversity in the AeroCom land-surface albedo fields contributes to the uncertainty in the simulated anthropogenic aerosol radiative forcings: the usage of an upper versus lower bound of the AeroCom land albedos introduces a global annual-mean TOA forcing range of 0.19W m(sup -2) (36%) clear-sky and of 0.12W m(sup -2) (92%) all-sky. The consideration of black carbon inclusions on cloud radiative properties results in a small global annual-mean all-sky absorption of 0.05W m(sup -2) and a positive TOA forcing perturbation of 0.02W m(sup -2). The long-wave aerosol radiative effects are small for anthropogenic aerosols but become of relevance for the larger natural dust and sea-salt aerosols.

Stier, Philip; Seinfeld, J. H.; Kinne, Stefan; Boucher, Olivier

2007-01-01

264

Aerosol absorption and radiative forcing  

NASA Astrophysics Data System (ADS)

We present a comprehensive examination of aerosol absorption with a focus on evaluating the sensitivity of the global distribution of aerosol absorption to key uncertainties in the process representation. For this purpose we extended the comprehensive aerosol-climate model ECHAM5-HAM by effective medium approximations for the calculation of aerosol effective refractive indices, updated black carbon refractive indices, new cloud radiative properties considering the effect of aerosol inclusions, as well as by modules for the calculation of long-wave aerosol radiative properties and instantaneous aerosol forcing. The evaluation of the simulated aerosol absorption optical depth with the AERONET sun-photometer network shows a good agreement in the large scale global patterns. On a regional basis it becomes evident that the update of the BC refractive indices to Bond and Bergstrom (2006) significantly improves the previous underestimation of the aerosol absorption optical depth. In the global annual-mean, absorption acts to reduce the short-wave anthropogenic aerosol top-of-atmosphere (TOA) radiative forcing clear-sky from -0.79 to -0.53 W m-2 (33%) and all-sky from -0.47 to -0.13 W m-2 (72%). Our results confirm that basic assumptions about the BC refractive index play a key role for aerosol absorption and radiative forcing. The effect of the usage of more accurate effective medium approximations is comparably small. We demonstrate that the diversity in the AeroCom land-surface albedo fields contributes to the uncertainty in the simulated anthropogenic aerosol radiative forcings: the usage of an upper versus lower bound of the AeroCom land albedos introduces a global annual-mean TOA forcing range of 0.19 W m-2 (36%) clear-sky and of 0.12 W m-2 (92%) all-sky. The consideration of black carbon inclusions on cloud radiative properties results in a small global annual-mean all-sky absorption of 0.05 W m-2 and a positive TOA forcing perturbation of 0.02 W m-2. The long-wave aerosol radiative effects are small for anthropogenic aerosols but become of relevance for the larger natural dust and sea-salt aerosols.

Stier, P.; Seinfeld, J. H.; Kinne, S.; Boucher, O.

2007-10-01

265

Aerosol absorption and radiative forcing  

NASA Astrophysics Data System (ADS)

We present a comprehensive examination of aerosol absorption with a focus on evaluating the sensitivity of the global distribution of aerosol absorption to key uncertainties in the process representation. For this purpose we extended the comprehensive aerosol-climate model ECHAM5-HAM by effective medium approximations for the calculation of aerosol effective refractive indices, updated black carbon refractive indices, new cloud radiative properties considering the effect of aerosol inclusions, as well as by modules for the calculation of long-wave aerosol radiative properties and instantaneous aerosol forcing. The evaluation of the simulated aerosol absorption optical depth with the AERONET sun-photometer network shows a good agreement in the large scale global patterns. On a regional basis it becomes evident that the update of the BC refractive indices to Bond and Bergstrom (2006) significantly improves the previous underestimation of the aerosol absorption optical depth. In the global annual-mean, absorption acts to reduce the short-wave anthropogenic aerosol top-of-atmosphere (TOA) radiative forcing clear-sky from -0.79 to -0.53 W m-2 (33%) and all-sky from -0.47 to -0.13 W m-2 (72%). Our results confirm that basic assumptions about the BC refractive index play a key role for aerosol absorption and radiative forcing. The effect of the usage of more accurate effective medium approximations is comparably small. We demonstrate that the diversity in the AeroCom land-surface albedo fields contributes to the uncertainty in the simulated anthropogenic aerosol radiative forcings: the usage of an upper versus lower bound of the AeroCom land albedos introduces a global annual-mean TOA forcing range of 0.19 W m-2 (36%) clear-sky and of 0.12 W m-2 (92%) all-sky. The consideration of black carbon inclusions on cloud radiative properties results in a small global annual-mean all-sky absorption of 0.05 W m-2 and a positive TOA forcing perturbation of 0.02 W m-2. The long-wave aerosol radiative effects are small for anthropogenic aerosols but become of relevance for the larger natural dust and sea-salt aerosols.

Stier, P.; Seinfeld, J. H.; Kinne, S.; Boucher, O.

2007-05-01

266

ARTICLE IN PRESS Aerosol Science ( )  

E-print Network

ARTICLE IN PRESS Aerosol Science ( ) ­ www.elsevier.com/locate/jaerosci Langevin PDF simulation, for example thermal and nuclear systems, cyclone separators, spray cooling and which is also present.-P. Langevin PDF simulation of particle deposition in a turbulent pipe flow. Journal of Aerosol Science (2008

Chibbaro, Sergio

267

INDOOR AEROSOLS AND EXPOSURE ASSESSMENT  

EPA Science Inventory

This chapter provides an overview of both indoor aerosol concentration measurements, and the considerations for assessment of exposure to aerosols in non-occupational settings. The fixed-location measurements of concentration at an outdoor location, while commuting inside an a...

268

Mechanics of plutonium metal aerosolization  

Microsoft Academic Search

Reliable estimates of hazards posed by a plutonium release are contingent on the availability of technical data to define the source term for aerosolization of plutonium oxide particles and the resulting size distribution. The release of aerosols from the oxidation of plutonium metal depends partly on the forces acting on the particles while they remain attached to the bulk material

Alvis

1996-01-01

269

Aerosol in the Pacific troposphere  

NASA Technical Reports Server (NTRS)

The use of near real-time optical techniques is emphasized for the measurement of mid-tropospheric aerosol over the Central Pacific. The primary focus is on measurement of the aerosol size distribution over the range of particle diameters from 0.15 to 5.0 microns that are essential for modeling CO2 backscatter values in support of the laser atmospheric wind sounder (LAWS) program. The measurement system employs a LAS-X (Laser Aerosol Spectrometer-PMS, Boulder, CO) with a custom 256 channel pulse height analyzer and software for detailed measurement and analysis of aerosol size distributions. A thermal preheater system (Thermo Optic Aerosol Descriminator (TOAD) conditions the aerosol in a manner that allows the discrimination of the size distribution of individual aerosol components such as sulfuric acid, sulfates and refractory species. This allows assessment of the relative contribution of each component to the BCO2 signal. This is necessary since the different components have different sources, exhibit independent variability and provide different BCO2 signals for a given mass and particle size. Field activities involve experiments designed to examine both temporal and spatial variability of these aerosol components from ground based and aircraft platforms.

Clarke, Antony D.

1989-01-01

270

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...

271

Satellite Measurement of Aerosol Properties  

NASA Astrophysics Data System (ADS)

A component of the EU programme Particles in the upper Troposphere and lower Stratosphere and their role in the climate system (PARTS) is to develop algorithms for determining aerosol properties from satellite measurements. We report on the development status of two algorithms. The first determines aerosol effective radius, surface area and particle volume from SAGE II spectral measurements. It is based on the optimal estimation (OE) technique which has the advantage that error in the estimated quantities is produced as part of the retrieval process. The second algorithm, also using OE, determines aerosol optical depth from high resolution (1 x 1 km at nadir) measurements by the ATSR/2 instrument. This algorithm is being applied for the time period 1995-2001. An additional component of PARTS is to construct an aerosol history based on satellite and ancillary surface and in situ measurements. Initial maps describing the evolution of the atmospheric aerosol in the UTLS region will be shown.

Grainger, R.; Marsh, S.; Wurl, D.

2003-04-01

272

The Aerosol Modeling Testbed: A Tool to Facilitate Improved Aerosol Process Modules  

Microsoft Academic Search

Predictions of aerosol mass, composition, size distribution, hygroscopicity, and optical properties still contain large uncertainties. For example, the formation and transformation of secondary organic aerosols and the nature of many cloud-aerosol interactions are still poorly understood and consequently inadequately represented in models. When new aerosol treatments are developed, they are usually implemented into an existing aerosol model and evaluated using

J. D. Fast; W. I. Gustafson; E. G. Chapman; R. C. Easter; J. Rishel

2009-01-01

273

Thermophoretically Dominated Aerosol Coagulation  

NASA Astrophysics Data System (ADS)

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.

Rosner, Daniel E.; Arias-Zugasti, Manuel

2011-01-01

274

Aerosol Remote Sensing  

NASA Technical Reports Server (NTRS)

This book gives a much needed explanation of the basic physical principles of radia5tive transfer and remote sensing, and presents all the instruments and retrieval algorithms in a homogenous manner. For the first time, an easy path from theory to practical algorithms is available in one easily accessible volume, making the connection between theoretical radiative transfer and individual practical solutions to retrieve aerosol information from remote sensing. In addition, the specifics and intercomparison of all current and historical methods are explained and clarified.

Lenoble, Jacqueline (Editor); Remer, Lorraine (Editor); Tanre, Didier (Editor)

2012-01-01

275

Multifunctional chitosan nanoparticles encapsulating quantum dots and Gd-DTPA as imaging probes for bio-applications  

Microsoft Academic Search

Chitosan was used to encapsulate both CdSe\\/ZnS quantum dots (QDs) and\\u000a the magnetic resonance imaging (MRI) contrast agent\\u000a gadolinium-diethylenetriaminepentaacetate (Gd-DTPA), forming\\u000a multi-functional nanoparticles that can be used in a wide range of in\\u000a vitro or in vivo studies as fluorescent biological labels as well as MRI\\u000a contrast agents, respectively. Multi-color QDs at pre-determined molar\\u000a ratios were encapsulated into chitosan nanoparticles

Wee Beng Tan; Yong Zhang

2007-01-01

276

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

277

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

278

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

279

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

280

Aerosol growth in Titan's ionosphere.  

PubMed

Photochemically produced aerosols are common among the atmospheres of our solar system and beyond. Observations and models have shown that photochemical aerosols have direct consequences on atmospheric properties as well as important astrobiological ramifications, but the mechanisms involved in their formation remain unclear. Here we show that the formation of aerosols in Titan's upper atmosphere is directly related to ion processes, and we provide a complete interpretation of observed mass spectra by the Cassini instruments from small to large masses. Because all planetary atmospheres possess ionospheres, we anticipate that the mechanisms identified here will be efficient in other environments as well, modulated by the chemical complexity of each atmosphere. PMID:23382231

Lavvas, Panayotis; Yelle, Roger V; Koskinen, Tommi; Bazin, Axel; Vuitton, Véronique; Vigren, Erik; Galand, Marina; Wellbrock, Anne; Coates, Andrew J; Wahlund, Jan-Erik; Crary, Frank J; Snowden, Darci

2013-02-19

281

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

282

Changes in Aerosol and Aerosol Direct Radiative Effects Near Clouds  

NASA Astrophysics Data System (ADS)

Aerosols and their radiative effects change in the vicinity of clouds. The high relative humidity (RH) of the environment near low-level clouds causes hygroscopic aerosols to swell, thereby changing their optical properties. Aircraft observations of relative humidity and particle concentrations taken during INDOEX are used to document the increases in RH and the changes in particle concentrations in the vicinity of clouds. These changes along with the chemical composition of the aerosol are used to estimate the changes in optical properties and the effect of these changes on the aerosol direct radiative effects as a function of distance from low-level clouds. Observations from the multichannel cloud radiometer (MCR) during INDOEX are used to compare the calculated changes with those observed. Part of the changes in the observed radiances are due to changes in particle concentrations and to particle growth, but part is also due to the increased illumination of the cloud-free column as a result of radiation reflected by the sides and tops of nearby clouds. Visible and near infrared radiances from the MCR are used to estimate the relative magnitudes of the different contributions to the changes. As such effects decrease with distance from cloud, daytime CALIPSO lidar observations are used to determine the sizes of cloud-free ocean regions in which low-level clouds reside. This distribution provides the probability of distances to cloud for aerosols in the cloud-free regions. The observed changes and the distribution of sizes for cloud-free ocean regions are used to estimate the contribution of the changes in the direct radiative effects of aerosol in the vicinity of low-level clouds to the total direct radiative effects of aerosols for oceans. These changes are estimated to be comparable to the ~1 Wm-2 uncertainty in the ~4.6 Wm-2 direct aerosol effect derived from CERES observations.

Coakley, J. A.; Twohy, C. H.; Tahnk, W. R.; Hayes, C. R.

2007-12-01

283

Aerosol optical depth measurements during the Aerosols99 experiment  

NASA Astrophysics Data System (ADS)

The Aerosols99 cruise took place during the period from January 14 to February 8, 1999, on the R/V Ronald Brown. The cruise track was almost a straight line in the southeast direction from Norfolk, Virginia, to Cape Town, South Africa, and afforded the opportunity to sample several different aerosol regimes over the North and South Atlantic. Handheld sunphotometers, a shadowband radiometer (FRSR), and a LIDAR were used to measure the aerosol optical depth (AOD) during the cruise. The AOD and angstrom exponent ? (spectral dependence of the AOD) varied strongly between regimes. Maritime regions typically had AOD (500 nm) of approximately 0.10±0.03, with ? around 0.3±0.3. An African dust event was encountered in which the AOD (500 nm) averaged 0.29±0.05 with an ? of 0.36±0.13. At the Intertropical Convergence Zone (ITCZ), no measurements were obtained because of cloudiness; however, after the ITCZ we encountered a biomass burning aerosol with high average AOD (500 nm) of 0.36±0.13, and a high ? (0.88±0.30). Farther south the aerosol went back to the low levels of a typical marine aerosol.

Voss, Kenneth J.; Welton, Ellsworth J.; Quinn, Patricia K.; Frouin, Robert; Miller, Mark; Reynolds, R. Michael

2001-09-01

284

Maritime Aerosol Network as a component of Aerosol Robotic Network  

NASA Astrophysics Data System (ADS)

The paper presents the current status of the Maritime Aerosol Network (MAN), which has been developed as a component of the Aerosol Robotic Network (AERONET). MAN deploys Microtops handheld Sun photometers and utilizes the calibration procedure and data processing (Version 2) traceable to AERONET. A web site dedicated to the MAN activity is described. A brief historical perspective is given to aerosol optical depth (AOD) measurements over the oceans. A short summary of the existing data, collected on board ships of opportunity during the NASA Sensor Intercomparison and Merger for Biological and Interdisciplinary Oceanic Studies (SIMBIOS) Project is presented. Globally averaged oceanic aerosol optical depth (derived from island-based AERONET measurements) at 500 nm is ˜0.11 and Angstrom parameter (computed within spectral range 440-870 nm) is calculated to be ˜0.6. First results from the cruises contributing to the Maritime Aerosol Network are shown. MAN ship-based aerosol optical depth compares well to simultaneous island and near-coastal AERONET site AOD.

Smirnov, A.; Holben, B. N.; Slutsker, I.; Giles, D. M.; McClain, C. R.; Eck, T. F.; Sakerin, S. M.; Macke, A.; Croot, P.; Zibordi, G.; Quinn, P. K.; Sciare, J.; Kinne, S.; Harvey, M.; Smyth, T. J.; Piketh, S.; Zielinski, T.; Proshutinsky, A.; Goes, J. I.; Nelson, N. B.; Larouche, P.; Radionov, V. F.; Goloub, P.; Krishna Moorthy, K.; Matarrese, R.; Robertson, E. J.; Jourdin, F.

2009-03-01

285

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

286

HEALTH ASPECTS OF WASTEWATER AEROSOLS  

EPA Science Inventory

The Health Effects Research Laboratory of the U.S. Environmental Protection Agency arranged for several studies, by universities or research institutions, to gather information on health effects associated with wastewater aerosols. Five studies were conducted at wastewater treatm...

287

Wind Power Charged Aerosol Generator  

SciTech Connect

This describes experimental results on a Charged Aerosol Wind/Electric Power Generator, using Induction Electric Charging with a water jet issuing under water pressure from a small diameter (25-100 ..mu..m) orifice.

Marks, A.M.

1980-07-01

288

7, 469497, 2007 Segregated aerosol  

E-print Network

/regional and transported pollution with maximum in summer and the latter to dust from deserted areas in Northern Africa) or aerosol products from physical mechanisms (e.g. rock grinding, sea water droplet formation) mostly produce

Paris-Sud XI, Université de

289

Method for producing monodisperse aerosols  

DOEpatents

An aerosol generator is described which is capable of producing a monodisperse aerosol within narrow limits utilizing an aqueous solution capable of providing a high population of seed nuclei and an organic solution having a low vapor pressure. The two solutions are cold nebulized, mixed, vaporized, and cooled. During cooling, particles of the organic vapor condense onto the excess seed nuclei, and grow to a uniform particle size.

Ortiz, Lawrence W. (Los Alamos, NM); Soderholm, Sidney C. (Pittsford, NY)

1990-01-01

290

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

291

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

292

Aragonite–calcite–vaterite: A temperature influenced sequential polymorphic transformation of CaCO{sub 3} in the presence of DTPA  

SciTech Connect

Highlights: ? Crystallization of CaCO{sub 3} between 60 and 230 °C in the presence of DTPA. ? Formation of exclusive and individual polymorphs at different temperatures. ? Violation of second law of thermodynamics/Ostwald rule of stages has been observed. - Abstract: Calcium carbonate was precipitated from calcium chloride using sodium carbonate in the presence of diethylenetriaminepentaacetic acid (DTPA) between 60 and 230 °C. The samples were characterized by FTIR, Raman, XRD and SEM techniques. CaCO{sub 3} with different crystal morphologies such as spherolite/datura pod, dumbbell, peanut, were obtained depending on the experimental conditions. The results showed that pure aragonite, calcite and vaterite were formed at low, moderate and high temperatures respectively. A binary mixture of calcite and vaterite was resulted between 150 and 200 °C. The data suggested an unusual conversion of stable calcite to meta stable vaterite at higher temperature in presence of DTPA. The study revealed a novel methodology for the exclusive/individual preparation of different crystalline polymorphs of CaCO{sub 3}. Formation of pure vaterite above 200 °C divulged the possibility of DTPA as a potential scale inhibitor and boiler sludge conditioner at elevated temperatures.

Gopi, Shanmukhaprasad [Department of Chemistry, Annamalai University, Annamalainagar 608002, Tamilnadu (India); Subramanian, V.K., E-mail: drvksau@gmail.com [Department of Chemistry, Annamalai University, Annamalainagar 608002, Tamilnadu (India); Palanisamy, K. [Department of Chemistry, Annamalai University, Annamalainagar 608002, Tamilnadu (India)

2013-05-15

293

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

294

Marine aerosols: A review  

NASA Astrophysics Data System (ADS)

The background aerosol in the boundary layer over the remote oceans is not aged continental aerosol but, rather, is largely of marine origin. Total particle concentrations are quite uniform throughout the tropical trade wind regions and normally are in the range of 100-300 cm -3. Precipitation reduces particle concentrations, but there is apparently an in situ source of small particles which allows particle concentrations to recover to their normal background level. The fine particle mode ( r < 0.3 ?m), which comprises 90-95% of the particles but only about 5% of the total mass, cosists primarily of non-sea-salt sulfate (nss-sulfate). There is considerable evidence that nss-sulfate, which is present in concentrations ranging from about 0.2 to 1.5 ?g m -3, is formed by gas-to-particle conversion of the oxidation products of organosulfur gases (principally DMS) emitted by the ocean. The principal gas-to-particle conversion mechanisms are particle formation by homogeneous nucleation of low-volatility gas-phase reaction products, condensation of these products on existing particles, and SO 2-to-sulfate conversion in cloud droplets. The submicron portion of the particle size distribution is bimodal with peaks at 0.03 ?m and 0.1 ?m radius. The peak at 0.1 ?m is believed to be due to the growth of CCN-sized particles as a result of incloud SO 2-to-sulfate conversion. It has been speculated that the sea-to-air flux of DMS affects the number of CCN and thereby affects cloud droplet size, cloud albedo and, consequently, climate. Coarse particles ( r > 0.5 ?m) are composed primarily of sea salt. The concentration of sea salt shows a strong dependence of wind speed and ranges from about 2 ?g m -3 to as much as 50 ?g m -3 or more at wind speeds in excess of 15 m s -1. The background coarse mode also contains smaller amounts of nitrate and mineral dust. The concentration of each of these components is normally less than 5% of the mass of sea salt, although dust concentrations can occasionally equal the sea salt loading during fresh intrusions of continental dust. Nitrate is formed by gas-to-particle conversion but the relative importance of the ocean, the stratosphere and lightning as a source of the nitrogen-containing precursor gases remains uncertain. Since nitrate is not found on the fine mode particles, it probably does not result from condensation of gas-phase reaction products or from aqueous-phase oxidation of NO x in cloud droplets.

Fitzgerald, James W.

295

Affective design: modulating the pleasantness and forcefulness of aerosol sprays by manipulating aerosol spraying sounds  

Microsoft Academic Search

We investigated whether people's perception of the pleasantness and forcefulness of aerosol sprays can be influenced by the particular sounds that aerosols make when used. Participants had to rate the pleasantness and forcefulness of aerosol samples sprayed either in front of them (Experiment 1) or else onto their own bodies (Experiment 2). The aerosol sprays were perceived as being significantly

C. Spence; M. Zampini

2007-01-01

296

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

297

Toxicity of Atmospheric Aerosols on Marine Phytoplankton  

NASA Astrophysics Data System (ADS)

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 well-characterized aerosol samples in incubation experiments, we demonstrate, however, that the response of phytoplankton growth to aerosol additions depends on the specific aerosol chemistry 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. This could be due to high copper, consistent with direct copper addition experiments. Toxicity affected picoeukaryotes and Synechococcus, the second most abundant marine phytoplankter, but not Prochlorococcus. Anthropogenic emissions are increasing atmospheric copper deposition sharply and based on coupled atmosphere-ocean calculations, potentially altering patterns of marine primary production and community structure in high aerosol deposition, low chlorophyll areas.

Paytan, A.; Mackey, K. R.; Chen, Y.; Lima, I. D.; Doney, S. C.; Mahowald, N.; Labiosa, R.; Post, A. F.

2008-12-01

298

Potential 166Ho radiopharmaceuticals for endovascular radionuclide therapy. II. Preparation and evaluation of 166Ho-DTPA.  

PubMed

166Ho, with its favourable radiation characteristics of t(1/2) 26.8 h and Ebeta 1.85 and 1.75 MeV, is proposed as a suitable choice for the endovascular radionuclide therapy (EVRT) technique of liquid filled, low pressure balloon angioplasty. 166Ho was produced by the (n,gamma) reaction on a natural Ho2O3 target. The specific activity obtained was approximately 100 mCi x mg(-1) when irradiated at a flux of 2 x 10(13) n x cm(-2) s(-1) for approximately 7 days, and the possible contaminant 166Ho(m) was not detected. 166Ho was easily complexed with diethylenetriaminepentaacetic acid (DTPA) at a ligand to metal molar ratio ([L]:[M]) of 1:1 at room temperature (22-23 degrees C) and a reaction time of a few minutes. The radiochemical purity was >99%, as determined by paper chromatography using a mixture of pyridine, ethanol and water (1:2:4) as solvent. The complex had good stability up to 72 h at 37 degrees C in a serum environment. In a study using Swiss mice > 85% of the injected dose was cleared into the urine within 30 min post-injection, with insignificant retention in any major tissues. The studies show that the 166Ho-DTPA complex could be an alternative to the more expensive and difficult to access 188Re based products for EVRT, and provide adequate uniform radiation dose for the arterial vessel wall under treatment. PMID:11233559

Majali, M A; Saxena, S K; Joshi, S H; Unni, P R; Ramamoorthy, N

2001-01-01

299

Evaluation of a maleimido derivative of CHX-A” DTPA for site-specific labeling of Affibody molecules  

PubMed Central

Affibody molecules are a new class of small targeting proteins based on a common threehelix bundle structure. Affibody molecules binding a desired target may be selected using phage-display technology. An Affibody molecule ZHER2:342 binding with subnanomolar affinity to the tumor antigen HER2 has recently been developed for radionuclide imaging in vivo. Introduction of a single cysteine into the cysteine-free Affibody scaffold provides a unique thiol group for site-specific labeling of recombinant Affibody molecules. The recently developed maleimido-CHX-A” DTPA was site-specifically conjugated at the C-terminal cysteine of ZHER2:2395-C, a variant of ZHER2:342, providing a homogenous conjugate with a dissociation constant of 56 pM. The yield of labeling with 111In was > 99% after 10 min at room temperature. In vitro cell tests demonstrated specific binding of 111In-CHX-A” DTPAZ2395-C to HER2-expressing cell-line SKOV-3 and good cellular retention of radioactivity. In normal mice, the conjugate demonstrated rapid clearance from all non-specific organs except kidney. In mice bearing SKOV-3 xenografts, the tumor uptake of 111In-CHX-A” DTPAZ2395-C was 17.3 ± 4.8 % IA/g and the tumor-to-blood ratio 86 ± 46 (4 h post-injection). HER2-exprssing xenografts were clearly visualized 1 h post-injection. In conclusion, coupling of maleimido-CHX-A” DTPA to cysteine-containing Affibody molecules provides welldefined uniform conjugate, which can be rapidly labeled at room temperature and provides high-contrast imaging of molecular targets in vivo. PMID:18620447

Tolmachev, Vladimir; Xu, Heng; Wållberg, Helena; Ahlgren, Sara; Hjertman, Magnus; Sjöberg, Anna; Sandström, Mattias; Abrahmsén, Lars; Brechbiel, Martin W.; Orlova, Anna

2008-01-01

300

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

301

Coated bedpans: their cleaning and disinfection.  

PubMed Central

This paper reports on tests of cleaning and disinfection of stainless steel bedpans which have been coated with either a silicone grease or polytetrafluoroethylene (PTFE). The coatings were applied manually using an aerosol spray (silicone grease and PTFE), and by an industrial process (PTFE). Soils used comprised (i) British Standard Soil (B.S., 1966), (ii) human serum albumin labelled with technetium-99m (HSA-Tc), and (iii) a suspension of Streptococcus faecalis in broth. Tests of cleaning and disinfection were carried out in automatic washing and steam disinfector machines. Results show that aerosol spraying impairs the cleaning process but that bedpans coated by the industrial process with PTFE are superior to uncoated bedpans. Images Plate 3 Plate 2 Plate 1 PMID:1068198

Mostafa, A. B.; Chackett, K. F.; Deverill, C. E.

1976-01-01

302

Coated bedpans: their cleaning and disinfection.  

PubMed

This paper reports on tests of cleaning and disinfection of stainless steel bedpans which have been coated with either a silicone grease or polytetrafluoroethylene (PTFE). The coatings were applied manually using an aerosol spray (silicone grease and PTFE), and by an industrial process (PTFE). Soils used comprised (i) British Standard Soil (B.S., 1966), (ii) human serum albumin labelled with technetium-99m (HSA-Tc), and (iii) a suspension of Streptococcus faecalis in broth. Tests of cleaning and disinfection were carried out in automatic washing and steam disinfector machines. Results show that aerosol spraying impairs the cleaning process but that bedpans coated by the industrial process with PTFE are superior to uncoated bedpans. PMID:1068198

Mostafa, A B; Chackett, K F; Deverill, C E

1976-10-01

303

Electromagnetic Attenuation by Solid Particle Aerosols  

Microsoft Academic Search

Theories of electromagnetic attenuation by absorption and scattering from aerosols of solid particles were evaluated and experimentally verified. Particles having specific physical and morphological properties were tested to maximize the mass extinction coefficients of the aerosols in several bands of the electromagnetic spectrum. Particulate materials were chosen based on theoretical predictions and compatible aerosolization schemes were developed for each material.

Erica Ray Petersen

1991-01-01

304

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

305

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

306

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

307

ATI TDA 5A aerosol generator evaluation  

SciTech Connect

Oil based aerosol ``Smoke`` commonly used for testing the efficiency and penetration of High Efficiency Particulate Air filters (HEPA) and HEPA systems can produce flammability hazards that may not have been previously considered. A combustion incident involving an aerosol generator has caused an investigation into the hazards of the aerosol used to test HEPA systems at Hanford.

Gilles, D.A.

1998-07-27

308

8, 7194, 2008 Sea salt aerosol  

E-print Network

ACPD 8, 71­94, 2008 Sea salt aerosol refractive indices R. Irshad et al. Title Page Abstract Discussions Laboratory measurements of the optical properties of sea salt aerosol R. Irshad 1 , R. G. Grainger salt aerosol refractive indices R. Irshad et al. Title Page Abstract Introduction Conclusions

Paris-Sud XI, Université de

309

The Nearby Supernova Factory Ozone + Aerosol + Rayleigh  

E-print Network

The Nearby Supernova Factory Ozone + Aerosol + Rayleigh Water Rayleigh + Aerosol Aerosol + Rayleigh) Kim, et al. (1997) Spectral Time Series Lightcurves in any color Nearby Supernova Factory W.M. Wood CENTRA SNfactory Search Flow Schematic Type Ia supernovae are excellent distance indicators. After

310

Laser-Assisted Analysis of Aerosol Particles  

NASA Technical Reports Server (NTRS)

Proposed instrument makes rapid mass-spectrometric analyses of individual particles in aerosols. Each particle vaporized and ionized by intense laser pulse, which creates ions of minimum complexity. Ability to analyze single aerosol particles continuously makes technique suitable for detection of toxic aerosol particles on real-time basis and for identification of their sources.

Sinha, M. P.; Giffin, C. E.; Norris, D. D.; Friedlander, S. K.

1985-01-01

311

Modelling Aerosol Dispersion in Urban Street Canyons  

Microsoft Academic Search

Flow patterns within an urban street canyon are influenced by various micrometeorological factors. It also represents an environment where pollutants such as aerosols accumulate to high levels due to high volumes of traffic. As adverse health effects are being attributed to exposure to aerosols, an investigation of the dispersion of aerosols within such environments is of growing importance. In particular,

B. K. Tay; D. P. Jones; M. W. Gallagher; G. B. McFiggans; A. P. Watkins

2009-01-01

312

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 ...

313

6, 1135711389, 2006 SAGE III aerosol  

E-print Network

defect within the Arctic vortex. 11358 #12;ACPD 6, 11357­11389, 2006 SAGE III aerosol extinctionACPD 6, 11357­11389, 2006 SAGE III aerosol extinction validation L. W. Thomason et al. Title Page Chemistry and Physics Discussions SAGE III aerosol extinction validation in the Arctic winter: comparisons

Paris-Sud XI, Université de

314

Wind reduction by aerosol particles  

NASA Astrophysics Data System (ADS)

Aerosol particles are known to affect radiation, temperatures, stability, clouds, and precipitation, but their effects on spatially-distributed wind speed have not been examined to date. Here, it is found that aerosol particles, directly and through their enhancement of clouds, may reduce near-surface wind speeds below them by up to 8% locally. This reduction may explain a portion of observed ``disappearing winds'' in China, and it decreases the energy available for wind-turbine electricity. In California, slower winds reduce emissions of wind-driven soil dust and sea spray. Slower winds and cooler surface temperatures also reduce moisture advection and evaporation. These factors, along with the second indirect aerosol effect, may reduce California precipitation by 2-5%, contributing to a strain on water supply.

Jacobson, Mark Z.; Kaufman, Yoram J.

2006-12-01

315

Real time infrared aerosol analyzer  

DOEpatents

Apparatus for analyzing aerosols in essentially real time includes a virtual impactor which separates coarse particles from fine and ultrafine particles in an aerosol sample. The coarse and ultrafine particles are captured in PTFE filters, and the fine particles impact onto an internal light reflection element. The composition and quantity of the particles on the PTFE filter and on the internal reflection element are measured by alternately passing infrared light through the filter and the internal light reflection element, and analyzing the light through infrared spectrophotometry to identify the particles in the sample.

Johnson, Stanley A. (Countryside, IL); Reedy, Gerald T. (Bourbonnais, IL); Kumar, Romesh (Naperville, IL)

1990-01-01

316

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

317

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

318

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

319

Aerosol generation by raindrop impact on soil.  

PubMed

Aerosols are investigated because of their significant impact on the environment and human health. To date, windblown dust and sea salt from sea spray through bursting bubbles have been considered the chief mechanisms of environmental aerosol dispersion. Here we investigate aerosol generation from droplets hitting wettable porous surfaces including various classifications of soil. We demonstrate that droplets can release aerosols when they influence porous surfaces, and these aerosols can deliver elements of the porous medium to the environment. Experiments on various porous media including soil and engineering materials reveal that knowledge of the surface properties and impact conditions can be used to predict when frenzied aerosol generation will occur. This study highlights new phenomena associated with droplets on porous media that could have implications for the investigation of aerosol generation in the environment. PMID:25586153

Joung, Young Soo; Buie, Cullen R

2015-01-01

320

Aerosol generation by raindrop impact on soil  

NASA Astrophysics Data System (ADS)

Aerosols are investigated because of their significant impact on the environment and human health. To date, windblown dust and sea salt from sea spray through bursting bubbles have been considered the chief mechanisms of environmental aerosol dispersion. Here we investigate aerosol generation from droplets hitting wettable porous surfaces including various classifications of soil. We demonstrate that droplets can release aerosols when they influence porous surfaces, and these aerosols can deliver elements of the porous medium to the environment. Experiments on various porous media including soil and engineering materials reveal that knowledge of the surface properties and impact conditions can be used to predict when frenzied aerosol generation will occur. This study highlights new phenomena associated with droplets on porous media that could have implications for the investigation of aerosol generation in the environment.

Joung, Young Soo; Buie, Cullen R.

2015-01-01

321

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

322

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...

323

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

324

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

325

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...

326

7, 1350313535, 2007 Aerosol radiative  

E-print Network

ACPD 7, 13503­13535, 2007 Aerosol radiative forcing over land from meteosat-7 T. Elias and J and first results T. Elias1 and J.-L. Roujean2 1 LMD, Ecole Polytechnique, 91128 Palaiseau cedex, France 2 2007 ­ Accepted: 4 September 2007 ­ Published: 14 September 2007 Correspondence to: T. Elias (thierry.elias

327

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

328

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

329

Breath-hold spin-echo MR imaging for evaluation of dynamic enhancement of native and treated hepatocellular carcinoma after intravenous Gd-DTPA administration.  

PubMed

Using a simple modification of a standard spin-echo sequence which enable acquisition of three breath-hold images in 15 s, dynamic enhancement of 30 histologically proven hepatocellular carcinomas (17 native tumors, 6 completely necrotic tumors after nonsurgical treatments, and 7 tumors with viable and necrotic portions) after intravenous injection of gadolinium-DTPA was evaluated. Native hepatocellular carcinomas and viable portions in treated nodules showed elective enhancement in images obtained 40 s after contrast injection. Contrast between these lesions and the normal liver decreased thereafter. No contrast uptake was seen in entirely necrotic nodules and necrotic portions of treated nodules. Because of the capability to demonstrate the elective arterial blood supply typical of hepatocellular carcinoma, breath-hold T1-weighted spin-echo sequence should replace conventional T1-weighted images for the evaluation of intravenously administered gadolinium-DTPA enhancement of this tumor before and after nonsurgical treatments. PMID:8749733

Lencioni, R; Mascalchi, M; Paolicchi, A; Zampa, V

1995-01-01

330

Aerosol Absorption Measurements in MILAGRO.  

NASA Astrophysics Data System (ADS)

During the month of March 2006, a number of instruments were used to determine the absorption characteristics of aerosols found in the Mexico City Megacity and nearby Valley of Mexico. These measurements were taken as part of the Department of Energy's Megacity Aerosol Experiment - Mexico City (MAX-Mex) that was carried out in collaboration with the Megacity Interactions: Local and Global Research Observations (MILAGRO) campaign. MILAGRO was a joint effort between the DOE, NSF, NASA, and Mexican agencies aimed at understanding the impacts of a megacity on the urban and regional scale. A super-site was operated at the Instituto Mexicano de Petroleo in Mexico City (designated T-0) and at the Universidad Technologica de Tecamac (designated T-1) that was located about 35 km to the north east of the T-0 site in the State of Mexico. A third site was located at a private rancho in the State of Hidalgo approximately another 35 km to the northeast (designated T-2). Aerosol absorption measurements were taken in real time using a number of instruments at the T-0 and T-1 sites. These included a seven wavelength aethalometer, a multi-angle absorption photometer (MAAP), and a photo-acoustic spectrometer. Aerosol absorption was also derived from spectral radiometers including a multi-filter rotating band spectral radiometer (MFRSR). The results clearly indicate that there is significant aerosol absorption by the aerosols in the Mexico City megacity region. The absorption can lead to single scattering albedo reduction leading to values below 0.5 under some circumstances. The absorption is also found to deviate from that expected for a "well-behaved" soot anticipated from diesel engine emissions, i.e. from a simple 1/lambda wavelength dependence for absorption. Indeed, enhanced absorption is seen in the region of 300-450 nm in many cases, particularly in the afternoon periods indicating that secondary organic aerosols are contributing to the aerosol absorption. This is likely due to carbonyl- and nitro- functional groups on conjugated and aromatic organic structures (e.g. PAH, and terpene derived products). Using 12-hour fine (0.1-1.0 micron) aerosol samples collected in the field on quartz filters, uv/vis and infrared spectra were obtained in the laboratory using integrating spheres and diffuse reflectance spectroscopy, respectively. An inter-comparison of the "real-time" measurements made by the photo-acoustic, aethalometer and MAAP techniques have been described. In addition, the in situ aethalometer (seven-channel) results are compared with continuous integrating sphere uv-visible spectra to examine the angstrom absorption coefficient variance. These results will be briefly overviewed and the specific posters detailing these results will be highlighted highlighted. This work was performed as part of the Department of Energy's Megacity Aerosol Experiment - Mexico City under the support of the Atmospheric Science Program. "This researchwas supported by the Office of Science (BER), U. S. Department of Energy, Grant No. DE-FG02-07ER64329.

Gaffney, J. S.; Marley, N. A.; Arnott, W. P.; Paredes-Miranda, L.; Barnard, J. C.

2007-12-01

331

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

332

Aerosol clouds and their transmission properties: Research, models and applications  

NASA Astrophysics Data System (ADS)

Theories and models for the study of optical transmission pattern in aerosol clouds, on the basis of the attenuation characteristics for aerosols and the dispersion properties of clouds are discussed. Computation and measurement methods are described. The state of the art of research on aerosols and aerosol clouds in Sweden is reviewed. The use of protective aerosols in military applications is treated.

Wahlborn, S.

1983-05-01

333

Aerosol clouds and their transmission properties: Research, models and applications  

Microsoft Academic Search

Theories and models for the study of optical transmission pattern in aerosol clouds, on the basis of the attenuation characteristics for aerosols and the dispersion properties of clouds are discussed. Computation and measurement methods are described. The state of the art of research on aerosols and aerosol clouds in Sweden is reviewed. The use of protective aerosols in military applications

S. Wahlborn

1983-01-01

334

Using the OMI Aerosol Index and Absorption Aerosol Optical Depth to evaluate the NASA MERRA Aerosol Reanalysis  

NASA Astrophysics Data System (ADS)

A radiative transfer interface has been developed to simulate the UV Aerosol Index (AI) from the NASA Goddard Earth Observing System version 5 (GEOS-5) aerosol assimilated fields. The purpose of this work is to use the AI and Aerosol Absorption Optical Depth (AAOD) derived from the Ozone Monitoring Instrument (OMI) measurements as independent validation for the Modern Era Retrospective analysis for Research and Applications Aerosol Reanalysis (MERRAero). MERRAero is based on a version of the GEOS-5 model that is radiatively coupled to the Goddard Chemistry, Aerosol, Radiation, and Transport (GOCART) aerosol module and includes assimilation of Aerosol Optical Depth (AOD) from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor. Since AI is dependent on aerosol concentration, optical properties and altitude of the aerosol layer, we make use of complementary observations to fully diagnose the model, including AOD from the Multi-angle Imaging SpectroRadiometer (MISR), aerosol retrievals from the Aerosol Robotic Network (AERONET) and attenuated backscatter coefficients from the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) mission to ascertain potential misplacement of plume height by the model. By sampling dust, biomass burning and pollution events in 2007 we have compared model produced AI and AAOD with the corresponding OMI products, identifying regions where the model representation of absorbing aerosols was deficient. As a result of this study over the Saharan dust region, we have obtained a new set of dust aerosol optical properties that retains consistency with the MODIS AOD data that were assimilated, while resulting in better agreement with aerosol absorption measurements from OMI. The analysis conducted over the South African and South American biomass burning regions indicates that revising the spectrally-dependent aerosol absorption properties in the near-UV region improves the modeled-observed AI comparisons. Finally, during a period where the Asian region was mainly dominated by anthropogenic aerosols, we have performed a qualitative analysis in which the specification of anthropogenic emissions in GEOS-5 is adjusted to provide insight into discrepancies observed in AI comparisons.

Buchard, V.; da Silva, A. M.; Colarco, P. R.; Darmenov, A.; Randles, C. A.; Govindaraju, R.; Torres, O.; Campbell, J.; Spurr, R.

2014-12-01

335

Toxicity of atmospheric aerosols on marine phytoplankton.  

PubMed

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. PMID:19273845

Paytan, Adina; Mackey, Katherine R M; Chen, Ying; Lima, Ivan D; Doney, Scott C; Mahowald, Natalie; Labiosa, Rochelle; Post, Anton F

2009-03-24

336

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

337

Toxicity of atmospheric aerosols on marine phytoplankton  

PubMed Central

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. PMID:19273845

Paytan, Adina; Mackey, Katherine R. M.; Chen, Ying; Lima, Ivan D.; Doney, Scott C.; Mahowald, Natalie; Labiosa, Rochelle; Post, Anton F.

2009-01-01

338

Physicochemical Characterization of Capstone Depleted Uranium Aerosols I: Uranium Concentration in Aerosols as a Function of Time and Particle Size  

Microsoft Academic Search

During the Capstone Depleted Uranium (DU) Aerosol Study, aerosols containing depleted uranium were produced inside unventilated armored vehicles (i.e., Abrams tanks and Bradley Fighting Vehicles) by perforation with large-caliber DU penetrators. These aerosols were collected and characterized, and the data were subsequently used to assess human health risks to personnel exposed to DU aerosols. The DU content of each aerosol

MaryAnn Parkhurst; Yung-Sung Cheng; Judson L. Kenoyer; Richard J. Traub

2009-01-01

339

Role of ammonia chemistry and coarse mode aerosols in global climatological inorganic aerosol distributions  

E-print Network

1 Role of ammonia chemistry and coarse mode aerosols in global in a three dimensional chemical transport model to understand the roles of ammonia chemistry and natural inorganic thermodynamic equilibrium, ammonia chemistry and dust and seasalt aerosols improve agreement

Zender, Charles

340

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

341

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

342

Registration of parametric dynamic F-18-FDG PET/CT breast images with parametric dynamic Gd-DTPA breast images  

NASA Astrophysics Data System (ADS)

This study was undertaken to register 3D parametric breast images derived from Gd-DTPA MR and F-18-FDG PET/CT dynamic image series. Nonlinear curve fitting (Levenburg-Marquardt algorithm) based on realistic two-compartment models was performed voxel-by-voxel separately for MR (Brix) and PET (Patlak). PET dynamic series consists of 50 frames of 1-minute duration. Each consecutive PET image was nonrigidly registered to the first frame using a finite element method and fiducial skin markers. The 12 post-contrast MR images were nonrigidly registered to the precontrast frame using a free-form deformation (FFD) method. Parametric MR images were registered to parametric PET images via CT using FFD because the first PET time frame was acquired immediately after the CT image on a PET/CT scanner and is considered registered to the CT image. We conclude that nonrigid registration of PET and MR parametric images using CT data acquired during PET/CT scan and the FFD method resulted in their improved spatial coregistration. The success of this procedure was limited due to relatively large target registration error, TRE = 15.1+/-7.7 mm, as compared to spatial resolution of PET (6-7 mm), and swirling image artifacts created in MR parametric images by the FFD. Further refinement of nonrigid registration of PET and MR parametric images is necessary to enhance visualization and integration of complex diagnostic information provided by both modalities that will lead to improved diagnostic performance.

Magri, Alphonso; Krol, Andrzej; Lipson, Edward; Mandel, James; McGraw, Wendy; Lee, Wei; Tillapaugh-Fay, Gwen; Feiglin, David

2009-02-01

343

Shortwave aerosol radiative forcing over cloud-free oceans from Terra: 1. Angular models for aerosols  

NASA Astrophysics Data System (ADS)

Using multiple satellite instruments, we demonstrate a new empirical method for obtaining shortwave (SW) aerosol angular distribution models (ADMs) over cloud-free oceans. We use nearly a year's worth of multispectral Moderate Resolution Imaging Spectroradiometer (MODIS) data to obtain aerosol properties within a Clouds and Earth Radiant Energy System (CERES) footprint and Special Sensor Microwave Imager (SSM/I) data to obtain near surface wind speed. The new aerosol ADMs are built as functions of near-surface ocean wind speed and MODIS aerosol optical depth at 0.55 ?m (?0.55). Among the new features are ADMs as a function of the ratio of fine mode to total aerosol optical depth (?), which contains information on aerosol type, and the combination of the CERES rotation azimuth plane scan mode CERES data and MODIS aerosol products to characterize aerosol properties over glint regions. The instantaneous aerosol forcing efficiencies (SW flux per unit optical depth at ?0.55) are 80.5, 63.1, and 73.0 Wm-2, derived using the Earth Radiation Budget Experiment (ERBE), Tropical Rainfall Measuring Mission (TRMM), and the current Terra ADMs, respectively. This study highlights the necessity for building empirical aerosol ADMs as a function of wind speed, ?0.55 and ?, and gives examples of newly constructed aerosol ADMs over cloud-free oceans. We conclude that an overall uncertainty of 10% will be introduced in the derived SW aerosol direct forcing over cloud-free oceans if the ADMs are constructed without considering aerosol darkening effect over glint regions and aerosol brightening over nonglint regions (like ERBE ADMs) or the variations in aerosol properties (like TRMM ADMs). In a companion paper (Zhang et al., 2005), these new ADMs are used to calculate the shortwave aerosol radiative forcing over the global oceans.

Zhang, Jianglong; Christopher, Sundar A.; Remer, Lorraine A.; Kaufman, Yoram J.

2005-05-01

344

Aerosol volatility in a boreal forest environment  

NASA Astrophysics Data System (ADS)

Climate and health effects of atmospheric aerosols are determined by their properties such as their chemical composition. Aerosol chemical composition can be studied indirectly by measuring volatility of aerosol particles. The volatility of submicron aerosol particles (20-500 nm) was studied in a boreal forest site at SMEAR II (Station for Measuring Ecosystem-Atmosphere Relations II) station (Vesala et al., 1998) in Hyytiälä, Finland, during 01/2008-05/2010. The instrument used for the measurements was VDMPS (Volatility Differential Mobility Particle Sizer), which consists of two separate instruments: DMPS (Differential Mobility Particle Sizer, Aalto et al., 2001) and TD (Thermodenuder, Wehner et al., 2002). Aerosol evaporation was examined by heating the aerosol and comparing the total aerosol mass before and after heating. In the VDMPS system ambient aerosol sample was heated up to temperatures ranging from 80 °C to 280 °C. The higher the heating temperature was the more aerosol material was evaporated. There was a non-volatile residual present in aerosol particles when heated up to 280 °C. This residual explained (20±8)% of the total aerosol mass. Aerosol non-volatile mass fraction was highest during winter and smallest during summer months. The role of black carbon in the observed non-volatile residual was determined. Black carbon explained 40 to 90% of the non-volatile mass. Especially during colder seasons noticeable amount of non-volatile material, something else than black carbon, was observed. According to Kalberer et al. (2004) some atmospheric organic species can form polymers that have high evaporation temperatures. Also low-volatile organic salts may contribute to the non-volatile aerosol (Smith et al., 2010). Aerosol mass composition measured directly with AMS (Aerosol Mass Spectrometer, Jayne et al., 2000) was analyzed in order to examine the properties of the non-volatile material (other than black carbon). The AMS measurements were performed during spring and autumn 2008. Results from the aerosol mass spectrometry indicate that the non-volatile residual consists of nitrate and organic compounds, especially during autumn. These compounds may be low-volatile organic nitrates or salts. During winter and spring the non-volatile core (black carbon removed) correlated markedly with carbon monoxide, which is a tracer of anthropogenic emissions. Due to this, the non-volatile residual may also contain other pollutants in addition to black carbon. Thus, it seems that the amount of different compounds in submicron aerosol particles varies with season and as a result the chemical composition of the non-volatile residual changes within a year. This work was supported by University of Helsinki three-year research grant No 490082 and Maj and Tor Nessling Foundation grant No 2010143. Aalto et al., (2001). Physical characterization of aerosol particles during nucleation events. Tellus B, 53, 344-358. Jayne, et al., (2000). Development of an aerosol mass spectrometer for size and composition analysis of submicron particles. Aerosol Sci. Technol., 33(1-2), 49-70. Kalberer et al., (2004). Identification of Polymers as Major Components of Atmospheric Organic Aerosols. Science, 303, 1659-1662. Smith et al., (2010). Observations of aminium salts in atmospheric nanoparticles and possible climatic implications. P. Natl. Acad. Sci., 107(15). Vesala et al., (1998). Long-term field measurements of atmosphere-surface interactions in boreal forest combining forest ecology, micrometeorology, aerosol physics and atmospheric chemistry. Trends Heat, Mass Mom. Trans., 4, 17-35. Wehner et al., (2002). Design and calibration of a thermodenuder with an improved heating unit to measure the size-dependent volatile fraction of aerosol particles. J. Aerosol Sci., 33, 1087-1093.

Häkkinen, S. A. K.; ?ijälä, M.; Lehtipalo, K.; Junninen, H.; Virkkula, A.; Worsnop, D. R.; Kulmala, M.; Petäjä, T.; Riipinen, I.

2012-04-01

345

UV spectroscopy of submicron sulfuric acid aerosol  

SciTech Connect

Reactions of gas phase species with sulfuric acid particles play important roles in the chemistry of the stratosphere. We have developed a technique to measure the kinetics of reactive uptake by submicron sulfuric acid aerosol. The kinetics are measured by monitoring the concentration of a gas phase reactant as a function of contact distance with a well characterized aerosol flow. The aerosol size distribution is extracted from measurements of the UV transmission of the aerosol and the particle number density, by using Mie theory. In this talk I will describe the experimental method used for the kinetic measurements, with emphasis on the aerosol characterization. Recent gas/aerosol kinetic results will also be presented.

Lovejoy, E.R.; Hanson, D.R. [Aeronomy Lab., Boulder, CO (United States)

1995-12-31

346

Aerosol measurements in the troposphere and stratosphere.  

PubMed

Light scattering measurements from a searchlight beam were carried out in New Mexico to determine the aerosol properties of the atmosphere. Although data were acquired to an altitude of about 70 km, the results show the aerosol attenuation parameters to be significant to about 35 km. The expression for the aerosol attenuation coefficient is derived based on the field geometry in conjunction with Rayleigh and aerosol scattering considerations. The results are categorized into moderate-structured, medium-structured and full-structured aerosol profiles. Examples of each are discussed and measurements presented which show variation over a 6-h period. A quantitative examination is made of the 20-km aerosol layer. Also, a medium-structured profile is selected and treated more extensively to provide preliminary information pertaining to atmospheric scattering and transmission. Ultimately, the data accumulated will provide a substantial number of profiles that will form a basis for various atmospheric studies. PMID:20057624

Elterman, L

1966-11-01

347

Aerosol Modeling for the Global Model Initiative  

NASA Technical Reports Server (NTRS)

The goal of this project is to develop an aerosol module to be used within the framework of the Global Modeling Initiative (GMI). The model development work will be preformed jointly by the University of Michigan and AER, using existing aerosol models at the two institutions as starting points. The GMI aerosol model will be tested, evaluated against observations, and then applied to assessment of the effects of aircraft sulfur emissions as needed by the NASA Subsonic Assessment in 2001. The work includes the following tasks: 1. Implementation of the sulfur cycle within GMI, including sources, sinks, and aqueous conversion of sulfur. Aerosol modules will be added as they are developed and the GMI schedule permits. 2. Addition of aerosol types other than sulfate particles, including dust, soot, organic carbon, and black carbon. 3. Development of new and more efficient parameterizations for treating sulfate aerosol nucleation, condensation, and coagulation among different particle sizes and types.

Weisenstein, Debra K.; Ko, Malcolm K. W.

2001-01-01

348

Aerosol Therapy for Obstructive Lung Diseases  

PubMed Central

Inhaled aerosol therapies are the mainstay of treatment of obstructive lung diseases. Aerosol devices deliver drugs rapidly and directly into the airways, allowing high local drug concentrations while limiting systemic toxicity. While numerous clinical trials, literature reviews, and expert panel guidelines inform the choice of inhalational drugs, deciding which aerosol device (ie, metered-dose inhaler, nebulizer, or dry powder inhaler) best suits a given patient and clinical setting can seem arbitrary and confusing. Similar confusion regarding Current Procedural Terminology (CPT) coding for administration of aerosol therapies can lead to lost revenue from underbilling and wasted administrative effort handling denied claims. This article reviews the aerosol devices currently available, discusses their relative merits in various clinical settings, and summarizes appropriate CPT coding for aerosol therapy. PMID:21896522

2011-01-01

349

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...

350

CCN closure and composition analysis of droplet-forming aerosol  

E-print Network

Cloud condensation nuclei, aerosol chemical composition, and aerosol size measurements were determined at a field site subject to a variety of aerosol sources. A pumped counterflow virtual impactor was utilized to directly ...

Friedman, Beth

351

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

352

Spatial variability of soil total and DTPA-extractable cadmium caused by long-term application of phosphate fertilizers, crop rotation, and soil characteristics.  

PubMed

Increasing cadmium (Cd) accumulation in agricultural soils is undesirable due to its hazardous influences on human health. Thus, having more information on spatial variability of Cd and factors effective to increase its content on the cultivated soils is very important. Phosphate fertilizers are main contamination source of cadmium (Cd) in cultivated soils. Also, crop rotation is a critical management practice which can alter soil Cd content. This study was conducted to evaluate the effects of long-term consumption of the phosphate fertilizers, crop rotations, and soil characteristics on spatial variability of two soil Cd species (i.e., total and diethylene triamine pentaacetic acid (DTPA) extractable) in agricultural soils. The study was conducted in wheat farms of Khuzestan Province, Iran. Long-term (27-year period (1980 to 2006)) data including the rate and the type of phosphate fertilizers application, the respective area, and the rotation type of different regions were used. Afterwards, soil Cd content (total or DTPA extractable) and its spatial variability in study area (400,000 ha) were determined by sampling from soils of 255 fields. The results showed that the consumption rate of di-ammonium phosphate fertilizer have been varied enormously in the period study. The application rate of phosphorus fertilizers was very high in some subregions with have extensive agricultural activities (more than 95 kg/ha). The average and maximum contents of total Cd in the study region were obtained as 1.47 and 2.19 mg/kg and DTPA-extractable Cd as 0.084 and 0.35 mg/kg, respectively. The spatial variability of Cd indicated that total and DTPA-extractable Cd contents were over 0.8 and 0.1 mg/kg in 95 and 25 % of samples, respectively. The spherical model enjoys the best fitting and lowest error rate to appraise the Cd content. Comparing the phosphate fertilizer consumption rate with spatial variability of the soil cadmium (both total and DTPA extractable) revealed the high correlation between the consumption rate of P fertilizers and soil Cd content. Rotation type was likely the main effective factor on variations of the soil DTPA-extractable Cd contents in some parts (eastern part of study region) and could explain some Cd variation. Total Cd concentrations had significant correlation with the total neutralizing value (p < 0.01), available P (p < 0.01), cation exchange capacity (p < 0.05), and organic carbon (p < 0.05) variables. The DTPA-extractable Cd had significant correlation with OC (p < 0.01), pH, and clay content (p < 0.05). Therefore, consumption rate of the phosphate fertilizers and crop rotation are important factors on solubility and hence spatial variability of Cd content in agricultural soils. PMID:22948289

Jafarnejadi, A R; Sayyad, Gh; Homaee, M; Davamei, A H

2013-05-01

353

Satellite stratospheric aerosol measurement validation  

NASA Astrophysics Data System (ADS)

The validity of the stratospheric aerosol measurements made by the satellite sensors SAM II and SAGE was tested by comparing their results with each other and with results obtained by other techniques (lider, dustsonde, filter, and impactor). The latter type of comparison required the development of special techniques that convert the quantity measured by the correlative sensor (e.g., particle backscatter, number, or mass) to that measured by the satellite sensor (extinction) and quantitatively estimate the uncertainty in the conversion process. The results of both types of comparisons show agreement within the measurement and conversion uncertainties. Moreover, the satellite uncertainty is small compared to aerosol natural variability (caused by seasonal changes, volcanoes, sudden warmings, and vortex structure). It was concluded that the satellite measurements are valid.

Russell, P. B.; McCormick, M. P.

354

Satellite stratospheric aerosol measurement validation  

NASA Technical Reports Server (NTRS)

The validity of the stratospheric aerosol measurements made by the satellite sensors SAM II and SAGE was tested by comparing their results with each other and with results obtained by other techniques (lider, dustsonde, filter, and impactor). The latter type of comparison required the development of special techniques that convert the quantity measured by the correlative sensor (e.g., particle backscatter, number, or mass) to that measured by the satellite sensor (extinction) and quantitatively estimate the uncertainty in the conversion process. The results of both types of comparisons show agreement within the measurement and conversion uncertainties. Moreover, the satellite uncertainty is small compared to aerosol natural variability (caused by seasonal changes, volcanoes, sudden warmings, and vortex structure). It was concluded that the satellite measurements are valid.

Russell, P. B.; Mccormick, M. P.

1984-01-01

355

Satellite stratospheric aerosol measurement validation  

NASA Technical Reports Server (NTRS)

The validity of the stratospheric aerosol measurements made by the satellite sensors SAM II and SAGE was tested by comparing their results with each other and with results obtained by other techniques (lider, dustsonde, filter, and impactor). The latter type of comparison required the development of special techniques that convert the quantity measured by the correlative sensor (e.g. particle backscatter, number, or mass) to that measured by the satellite sensor (extinction) and quantitatively estimate the uncertainty in the conversion process. The results of both types of comparisons show agreement within the measurement and conversion uncertainties. Moreover, the satellite uncertainty is small compared to aerosol natural variability (caused by seasonal changes, volcanoes, sudden warmings, and vortex structure). It was concluded that the satellite measurements are valid.

Russell, P. B.; Mccormick, M. P.

1984-01-01

356

Sensitivity of TOMS aerosol index to boundary layer height: Implications for detection of mineral aerosol sources  

E-print Network

Sensitivity of TOMS aerosol index to boundary layer height: Implications for detection of mineral) is proposed as a powerful tool in determining the sources of mineral aerosols. The sensitivity of the AI to the height of the aerosol layer has been noted previously, but the implications of this sensitivity

Mahowald, Natalie

357

Aerosol lidar and MODIS satellite comparisons for future aerosol loading forecast  

NASA Astrophysics Data System (ADS)

Knowledge of the concentration and distribution of atmospheric aerosols using both airborne lidar and satellite instruments is a field of active research. An aircraft based aerosol lidar has been used to study the distribution of atmospheric aerosols in the California Central Valley and eastern US coast. Concurrently, satellite aerosol retrievals, from the MODIS (Moderate Resolution Imaging Spectroradiometer) instrument aboard the Terra and Aqua satellites, were take over the Central Valley. The MODIS Level 2 aerosol data product provides retrieved ambient aerosol optical properties (e.g., optical depth (AOD) and size distribution) globally over ocean and land at a spatial resolution of 10 km. The Central Valley topography was overlaid with MODIS AOD (5x5 km2 resolution) and the aerosol scattering vertical profiles from a lidar flight. Backward air parcel trajectories for the lidar data show that air from the Pacific and northern part of the Central Valley converge confining the aerosols to the lower valley region and below the mixed layer. Below an altitude of 1 km, the lidar aerosol and MODIS AOD exhibit good agreement. Both data sets indicate a high presence of aerosols near Bakersfield and the Tehachapi Mountains. These and other results to be presented indicate that the majority of the aerosols are below the mixed layer such that the MODIS AOD should correspond well with surface measurements. Lidar measurements will help interpret satellite AOD retrievals so that one day they can be used on a routine basis for prediction of boundary layer aerosol pollution events.

De Young, Russell; Szykman, James; Severance, Kurt; Chu, D. Allen; Rosen, Rebecca; Al-Saadi, Jassim

2006-08-01

358

Aerosol Science and Technology 36: 617631 (2002) c 2002 American Association for Aerosol Research  

E-print Network

Aerosol Science and Technology 36: 617­631 (2002) c° 2002 American Association for Aerosol Research of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 2 Center for Aerosol in expan- sions of a gas-particle suspension through either a single lens or a single nozzle have been

Jimenez, Jose-Luis

359

Aerosol Lidar and MODIS Satellite Comparisons for Future Aerosol Loading Forecast  

NASA Technical Reports Server (NTRS)

Knowledge of the concentration and distribution of atmospheric aerosols using both airborne lidar and satellite instruments is a field of active research. An aircraft based aerosol lidar has been used to study the distribution of atmospheric aerosols in the California Central Valley and eastern US coast. Concurrently, satellite aerosol retrievals, from the MODIS (Moderate Resolution Imaging Spectroradiometer) instrument aboard the Terra and Aqua satellites, were take over the Central Valley. The MODIS Level 2 aerosol data product provides retrieved ambient aerosol optical properties (e.g., optical depth (AOD) and size distribution) globally over ocean and land at a spatial resolution of 10 km. The Central Valley topography was overlaid with MODIS AOD (5x5 sq km resolution) and the aerosol scattering vertical profiles from a lidar flight. Backward air parcel trajectories for the lidar data show that air from the Pacific and northern part of the Central Valley converge confining the aerosols to the lower valley region and below the mixed layer. Below an altitude of 1 km, the lidar aerosol and MODIS AOD exhibit good agreement. Both data sets indicate a high presence of aerosols near Bakersfield and the Tehachapi Mountains. These and other results to be presented indicate that the majority of the aerosols are below the mixed layer such that the MODIS AOD should correspond well with surface measurements. Lidar measurements will help interpret satellite AOD retrievals so that one day they can be used on a routine basis for prediction of boundary layer aerosol pollution events.

DeYoung, Russell; Szykman, James; Severance, Kurt; Chu, D. Allen; Rosen, Rebecca; Al-Saadi, Jassim

2006-01-01

360

Nonsphericity of dust-like tropospheric aerosols: Implications for aerosol remote sensing and climate modeling  

Microsoft Academic Search

T-matrix computations of light scattering by polydispersions of randomly oriented nonspherical aerosols and Mie computations for equivalent spheres are compared. Findings show that even moderate nonsphericity results in suubstantial errors in the retrieved aerosol optical thickness if satellite reflectance measurements are analyzed using Mie theory. On the other hand, the use of Mie theory for nonspherical aerosols produces negligible errors

M. I. Mishchenko; A. A. Lacis; B. E. Carlson; L. D. Travis

1995-01-01

361

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

362

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

363

The Aerosol/Cloud/Ecosystems Mission (ACE)  

NASA Technical Reports Server (NTRS)

The goals and measurement strategy of the Aerosol/Cloud/Ecosystems Mission (ACE) are described. ACE will help to answer fundamental science questions associated with aerosols, clouds, air quality and global ocean ecosystems. Specifically, the goals of ACE are: 1) to quantify aerosol-cloud interactions and to assess the impact of aerosols on the hydrological cycle and 2) determine Ocean Carbon Cycling and other ocean biological processes. It is expected that ACE will: narrow the uncertainty in aerosol-cloud-precipitation interaction and quantify the role of aerosols in climate change; measure the ocean ecosystem changes and precisely quantify ocean carbon uptake; and, improve air quality forecasting by determining the height and type of aerosols being transported long distances. Overviews are provided of the aerosol-cloud community measurement strategy, aerosol and cloud observations over South Asia, and ocean biology research goals. Instruments used in the measurement strategy of the ACE mission are also highlighted, including: multi-beam lidar, multiwavelength high spectra resolution lidar, the ocean color instrument (ORCA)--a spectroradiometer for ocean remote sensing, dual frequency cloud radar and high- and low-frequency micron-wave radiometer. Future steps for the ACE mission include refining measurement requirements and carrying out additional instrument and payload studies.

Schoeberl, Mark

2008-01-01

364

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

365

Aerosol composition of the tropical upper troposphere  

NASA Astrophysics Data System (ADS)

Aerosol composition was measured by the NOAA single-particle mass spectrometer (PALMS) aboard the NASA WB-57 high altitude aircraft platform during two Aura Validation Experiment (AVE) campaigns based in Costa Rica in 2004 and 2006. These studies yielded the most complete set of aerosol composition measurements to date throughout the tropical tropopause layer (TTL) and tropical lower stratosphere. We describe the aerosol properties of the tropical atmosphere and use composition tracers to examine particle sources, the role of recent convection, and cirrus-forming potential in the TTL. Tropical dynamics and regional air sources played principal roles in dictating tropospheric aerosol properties. There was a sharp change in aerosol chemical composition at about 12 km altitude coincident with a change in convective influence. Below this level, maritime convection lofted condensable material that generated acidic, sulfate-rich aerosol. These particles contained significant amounts of methanesulfonic acid (MSA) and showed evidence of cloud processes. In contrast, continental convection injected particles and precursors directly into the TTL, yielding a population of neutralized, organic-rich aerosol. The organics were often highly oxidized and particles with oxidized organics also contained nitrate. Above the tropopause, chemical composition gradually changed toward sulfuric acid particles but neutralized particles were still abundant 2 km above the tropopause. Deep continental convection, though sporadic and geographically localized, may strongly influence TTL aerosol properties on a global scale. The abundance of organic-rich aerosol may inhibit ice nucleation and formation of tropopause level cirrus.

Froyd, K. D.; Murphy, D. M.; Sanford, T. J.; Thomson, D. S.; Wilson, J. C.; Pfister, L.; Lait, L.

2009-07-01

366

Aerosol composition of the tropical upper troposphere  

NASA Astrophysics Data System (ADS)

Aerosol composition was measured by the NOAA single particle mass spectrometer (PALMS) aboard the NASA WB-57 high altitude aircraft platform during two Aura Validation Experiment (AVE) campaigns based in Costa Rica in 2004 and 2006. These studies yielded the most complete set of aerosol composition measurements to date throughout the tropical tropopause layer (TTL) and tropical lower stratosphere. We describe the aerosol properties of the tropical atmosphere and use composition tracers to examine particle sources, the role of recent convection, and cirrus-forming potential in the TTL. Tropical dynamics and regional air sources played principal roles in dictating tropospheric aerosol properties. There was a sharp change in aerosol chemical composition at about 12 km altitude coincident with a change in convective influence. Below this level, maritime convection lofted condensable material that generated acidic, sulfate-rich aerosol. These particles contained significant amounts of methanesulfonic acid (MSA) and showed evidence of cloud processes. In contrast, continental convection injected particles and precursors directly into the TTL, yielding a population of neutralized, organic-rich aerosol. The organics were often highly oxidized and particles with oxidized organics also contained nitrate. Above the tropopause, chemical composition gradually changed toward sulfuric acid particles but neutralized particles were still abundant 2 km above the tropopause. Deep continental convection, though sporadic and geographically localized, may strongly influence TTL aerosol properties on a global scale. The abundance of organic-rich aerosol may inhibit ice nucleation and formation of tropopause level cirrus.

Froyd, K. D.; Murphy, D. M.; Sanford, T. J.; Thomson, D. S.; Wilson, J. C.; Pfister, L.; Lait, L.

2009-04-01

367

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

368

Comparison of sestamibi single-photon emission computed tomography with positron emission tomography for estimating left ventricular myocarclial viability  

Microsoft Academic Search

Technetium-99m methoxyisobutyl isonitrile (technetium-99m sestamibi [MIBI]) is distributed in the myocardium according to blood flow. Reports comparing stress rest sestamibi protocols with reinfection thallium or resting fluorodeoxyglucose (FDG), or both, in patients with coronary artery disease have shown appreciable discordance regarding myocardial viability in these settings. We performed this analysis with regard to regional comparisons within discordant segments and made

Robert Soufer; Holley M. Dey; Chin K. Ng; Barry L. Zaret

1995-01-01

369

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; Müller, Jan M.; Alke, Andrea; Seidl, Christof; Bruchertseifer, Frank; Morgenstern, Alfred; Senekowitsch-Schmidtke, Reingard; Essler, Markus

2009-01-01

370

Aerosol Blanket Likely Thinned During 1990s  

NASA Technical Reports Server (NTRS)

Each day, a blanket of tiny particles drifting through the Earth's atmosphere filters out some of the sunlight headed for the planet's surface. These aerosols, including dust, smoke, and human-produced pollution, can reflect incoming light or absorb it, directly affecting the Earth's energy balance and climate. Aerosols also influence the climate indirectly, by affecting the brightness and amount of clouds. Research by NASA scientists on global aerosol patterns since the 1990s indicate the global aerosol blanket has likely thinned, allowing more sunlight to reach the Earth's surface over the past decade. The thinning of the blanket is shown by this trio of images based on satellite observations of aerosol optical thickness, a measurement that scientists use to describe how much the aerosols filter the incoming sunlight. Higher optical thickness (orange and red) means more sunlight blocking. The globes show average aerosol optical thickness for 1988-1991 (top), 2002-2005 (middle), and the change between the two time periods (bottom). Overall, the 1988-1991 image appears redder, a sign that aerosols were blocking more incoming sunlight; the 2002-2005 image has more light yellow areas. In the bottom image, small pockets of red (increased aerosol optical thickness), mostly near land masses in the Northern Hemisphere, are far outnumbered by blue areas (decreased aerosol optical thickness). Because they block incoming sunlight from reaching Earth's surface, aerosols may counterbalance greenhouse gas warming. The decline in the dimming power of aerosols over the past decade may have made the greenhouse warming trend more evident in the past decade than in previous decades. The scientists describe their results as a 'likely' trend because the National Oceanic and Atmospheric Administration satellite sensors they used in their analysis were not specifically designed to observe aerosols, and may contain some errors. However, specific, major aerosol events, such as large volcanic eruptions, show up in the right place at the right time in the observations, and the data also agree with available ground-based observations. Ongoing NASA missions such as the Terra, Aqua, Aura, and Cloudsat/CALIPSO, as well as upcoming missions such as Glory, will provide the data scientists need to monitor aerosol trends over time. NASA image created by Jesse Allen, using data provided courtesy of Michael Mischenko and Igor Geogdzhayev, NASA Goddard Institute of Space Studies.

2007-01-01

371

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

372

Radiative impact of atmospheric aerosols and clouds  

NASA Astrophysics Data System (ADS)

The effect of aerosols and clouds on Earth's shortwave radiation budget is studied in this thesis. An expression for the global annual mean radiative forcing due to sulfate aerosols is extended for absorbing aerosols using a two-stream approximation. This expression depends on the backscattering fraction of the aerosol which varies with the effective radius of the aerosol size distribution. This variation leads to a factor of 2.0 variation in the radiative forcing of slightly absorbing aerosols. Water vapor condenses onto hygroscopic aerosols which results in a change in size and a change in the concentration of the chemical components of the aerosol. The original Köhler equation accurately describes the equilibrium size of a hygroscopic aerosol. Use of the modified Köhler equation leads to errors due to its thermodynamically inconsistent nature. On a global annual average, the direct radiative forcing of hygroscopic sulfate aerosol is -0.69 W m-2. Over highly polluted regions, the local radiative forcing can be as high as -7 W m-2 which is comparable to the forcing due to increased greenhouse gas concentrations. Using a plane-parallel model, an analytical expression is derived for the cloud radiative forcing ratio which is used as a measure of enhanced shortwave radiation absorption of clouds. With this model, high values of this ratio can be achieved by thick clouds with absorptances of approximately 0.3. High values of the ratio can also be obtained with low level clouds if the transmittance of the atmosphere above the cloud is reduced to approximately 0.8. This can be achieved by a high concentration of strongly absorbing aerosols.

Wong, Jeff

1998-11-01

373

Improved global aerosol datasets for 2008 from Aerosol_cci  

NASA Astrophysics Data System (ADS)

Within the ESA Climate Change Initiative (CCI) the Aerosol_cci project has meanwhile produced and validated global datasets from AATSR, PARASOL, MERIS, OMI and GOMOS for the complete year 2008. 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 three nadir sensors. For AATSR three algorithms were applied. AOD validation was conducted against AERONET sun photometer observations also in comparison to MODIS and MISR datasets. Validation included level2 (pixel level) and level3 (gridded daily) datasets. Several validation metrices were used and in some cases developed further in order to comprehensively evaluate the capabilities and limitations of the datasets. The metrices include standard statistical quantities (bias, rmse, Pearson correlation, linear regression) as well as scoring approaches to quantitatively assess the spatial and temporal correlations against AERONET. Over open ocean also MAN data were used to better constrain the aerosol background, but in 2008 had limited coverage. The validation showed that the PARASOL (ocean only) and AATSR (land and ocean) datasets have improved significantly and now reach the quality level and sometimes even go beyond the level of MODIS and MISR. However, the coverage of these European datasets is weaker than the one of the NASA datasets due to smaller instrument swath width. The MERIS dataset provides better coverage but has lower quality then the other datasets. A detailed regional and seasonal analysis revealed the strengths and weaknesses of each algorithm. Also, Angstrom coefficient was validated and showed encouraging results (more detailed aerosol type information provided in particular from PARASOL was not yet evaluated further). Additionally, pixel uncertainties contained in each dataset were statistically assessed which showed some remaining issues but also the added value. Users (MACC/ECMWF, AEROCOM) confirmed the relevance of this additional information and encouraged Aerosol_cci to release the current uncertainties. A thorough comparison was conducted for the three AATSR algorithms. Care was taken to compare equal data amounts by common point filtering. It was found that in some cases different filtering led to contradicting validation results. This is not yet completely understood and needs further analysis. Obviously one aspect is the anti-correlation between coverage and accuracy and thus the importance of the applied quality control methods (in particular to avoid cloud contamination). Also limitations of the available reference datasets over open ocean and in the Southern hemisphere became obvious. The validation showed that all three AATSR algorithms produce almost equal accuracy, but show differences in the resulting datasets (similar to those between MODIS and MISR). In conclusion the team recommends to use a combination of the three AATSR algorithms, since none of them can be identified which performs best under all conditions. The intensive validation provides a large wealth of information which needs to be fully exploited and can be used to determine future algorithm development priorities. The paper will summarize and discuss the validation results and conclude with an outline of future steps for validation and algorithm improvement.

Holzer-Popp, Thomas; de Leeuw, Gerrit

2013-04-01

374

Aerosol Optical Depth Measurements in the Southern Ocean Within the Framework of Maritime Aerosol Network  

NASA Astrophysics Data System (ADS)

Aerosol production sources over the World Ocean and various factors determining aerosol spatial and temporal distribution are important for understanding the Earth's radiation budget and aerosol-cloud interactions. The Maritime Aerosol Network (MAN) as a component of AERONET has been collecting aerosol optical depth data over the oceans since 2006. A significant progress has been made in data acquisition over areas that previously had very little or no coverage. Data collection included intensive study areas in the Southern Ocean and off the coast of Antarctica including a number of circumnavigation cruises in high southern latitudes. It made an important contribution to MAN and provided a valuable reference point in atmospheric aerosol optical studies. The paper presents results of this international and multi-agency effort in studying aerosol optical properties over Southern Ocean and adjacent areas. The ship-borne aerosol optical depth measurements offer an excellent opportunity for comparison with global aerosol transport models, satellite retrievals and provide useful information on aerosol distribution over the World Ocean. A public domain web-based database dedicated to the MAN activity can be found at http://aeronet.gsfc.nasa.gov/new_web/maritime_aerosol_network.html.

Smirnov, A.; Holben, B. N.; Sayer, A. M.; Sakerin, S. M.; Radionov, V. F.; Courcoux, Y.; Broccardo, S. P.; Evangelista, H.; Croot, P. L.; Disterhoft, P.; Piketh, S.; Milinevsky, G. P.; O'Neill, N. T.; Slutsker, I.; Giles, D. M.

2013-12-01

375

Quantification of Myocardial Viability Distribution with Gd(DTPA) Bolus-Enhanced Signal Intensity-Based Percent Infarct Mapping  

PubMed Central

Introduction A substantial, common shortcoming of the currently used semiautomated techniques for the quantification of myocardial infarct with Delayed Enhancement Magnetic Resonance Imaging is the assumption that the whole myocardial slab that corresponds to the hyperenhanced tomographic area is 100% non-viable. This assumption is, however, incorrect. To resolve this conflict, we have recently proposed the signal intensity percent-infarct-mapping method and validated it in an ex-vivo, canine experiment. The purpose of the current study has been the validation of the signal intensity percent-infarct-mapping method in vivo, using a porcine model of reperfused myocardial infarct. Methods In swines (n=6) reperfused myocardial infarct was generated occluding for 90 min by an angioplasty balloon either the Left Anterior Descending or the Left Circumflex coronary artery. To obtain DE images, Gd(DTPA) enhanced inversion-recovery fast gradient-echo acquisitions were carried out on day 28 after myocardial infarction. Scanning started 15 minutes after intravenous injection of 0.2 mmol/kg Gd(DTPA). At the end of the MRI session the animal was sacrificed and 2,3,5-triphenyltetrazolium chloride staining was used to validate the existence and to determine the accurate size of the myocardial infarct. Tissue samples were taken and stained with Hematoxylin-Eosin and Masson’s trichrome for histological assessment of the infarct and the periinfarct zone. The signal intensity percent-infarct-mapping data were compared with corresponding data from the Delayed Enhancement images analyzed with SIremote+2SD thresholding, and with corresponding triphenyltetrazolium-chloride staining data using Friedman’s Repeated Measure Analysis of Variance on Ranks. Results The infarct volume determined by the triphenyltetrazolium chloride, SIremote+2SD, and signal intensity percent-infarct-mapping methods were 3.04 ml [2.74, 3.45], 13.62 ml [9.06, 18.45], and 4.27 ml [3.45, 6.33], respectively. Median infarct volume determined by SIremote+2SD significantly differed from that determined by triphenyltetrazolium chloride (p<0.05). The Bland-Altman’s overall bias was 12.49% of the volume of the left ventricle. Median infarct volume determined by signal intensity percent-infarct-mapping, however, did not differ significantly (NS) from that obtained by triphenyltetrazolium chloride. Signal intensity percent-infarct-mapping yielded only a 1.99% Bland-Altman’s overall bias of the left ventricular volume. Conclusions This in vivo study in the porcine, reperfused myocardial infarct model demonstrates that signal intensity percent-infarct-mapping is a highly accurate method for the determination of the extent of myocardial infarct. MRI images for signal intensity percent-infarct-mapping are obtained with the pulse sequence of conventional Delayed Enhancement imaging and are acquired within clinically acceptable scanning time. This makes signal intensity percent-infarct-mapping a practical method for clinical implementation. PMID:21546192

Kirschner, Robert; Varga-Szemes, Akos; Simor, Tamas; Brott, Brigitta C.; Litovsky, Silvio; Elgavish, Ada; Elgavish, Gabriel A.

2011-01-01

376

Semi-automatic detection of Gd-DTPA-saline filled capsules for colonic transit time assessment in MRI  

NASA Astrophysics Data System (ADS)

Functional gastrointestinal disorders result in a significant number of consultations in primary care facilities. Chronic constipation and diarrhea are regarded as two of the most common diseases affecting between 2% and 27% of the population in western countries 1-3. Defecatory disorders are most commonly due to dysfunction of the pelvic floor or the anal sphincter. Although an exact differentiation of these pathologies is essential for adequate therapy, diagnosis is still only based on a clinical evaluation1. Regarding quantification of constipation only the ingestion of radio-opaque markers or radioactive isotopes and the consecutive assessment of colonic transit time using X-ray or scintigraphy, respectively, has been feasible in clinical settings 4-8. However, these approaches have several drawbacks such as involving rather inconvenient, time consuming examinations and exposing the patient to ionizing radiation. Therefore, conventional assessment of colonic transit time has not been widely used. Most recently a new technique for the assessment of colonic transit time using MRI and MR-contrast media filled capsules has been introduced 9. However, due to numerous examination dates per patient and corresponding datasets with many images, the evaluation of the image data is relatively time-consuming. The aim of our study was to develop a computer tool to facilitate the detection of the capsules in MRI datasets and thus to shorten the evaluation time. We present a semi-automatic tool which provides an intensity, size 10, and shape-based 11,12 detection of ingested Gd-DTPA-saline filled capsules. After an automatic pre-classification, radiologists may easily correct the results using the application-specific user interface, therefore decreasing the evaluation time significantly.

Harrer, Christian; Kirchhoff, Sonja; Keil, Andreas; Kirchhoff, Chlodwig; Mussack, Thomas; Lienemann, Andreas; Reiser, Maximilian; Navab, Nassir

2008-03-01

377

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

378

Explorations of TALSPEAK chemistry in extraction chromatography: Comparisons of TTHA with DTPA and HDEHP with HEH[EHP  

SciTech Connect

An advanced nuclear fuel cycle includes a reprocessing stage for the group separation of the lanthanides from the trivalent actinides. The TALSPEAK (Trivalent Actinide - Lanthanide Separation by Phosphorus reagent Extraction from Aqueous Komplexes) solvent extraction process provides the An3+/Ln3+ separation through the use of an organic lanthanide extractant (bis-2-ethyl(hexyl) phosphoric acid, HDEHP) and an aqueous actinide-selective holdback reagent (diethylenetriamine-N,N,N’,N’’,N’’-pentaacetic acid, DTPA). Organic phase interactions in TALSPEAK have proven sufficiently complex that, even with substantial research effort, a descriptive thermodynamic model has yet to be developed. If one were to consider an extraction chromatographic (EXC) version of TALSPEAK, the presence of concentrated extractant on the resin surface should augment the multifaceted organic phase chemistry. This study examines the previously unexplored impact of each aqueous phase TALSPEAK component (holdback reagent, carboxylic acid buffer, and pH) on the chemistry of the EXC system. The presence of alternative reagents, 2-ethyl(hexyl) phosphonic acid mono-2-ethyl(hexyl) ester acid (HEH[EHP]) and triethylenetetramine-N,N,N’,N’’,N’’’,N’’’-hexaacetic acid (TTHA) are also considered. Results indicate the concentrated extractant appears to enhance solid-phase reactions that most likely involve water, lactate and sodium. The presumed water, lactate and sodium partitioning consumes resin capacity sufficiently that the weaker hold-back reagent under TALSPEAK aqueous conditions (pH ~ 3.6), TTHA, provides preferential Am3+/Ln3+ separations performance. If a TALSPEAK-EXC process were to be developed, a resin with solvent diluted extractant or covalently bound functional groups may be preferential to reduce the complexity of the solid-phase chemistry.

Braley, Jenifer C.; McAlister, Daniel; Horwitz, E. P.; Nash, Kenneth L.

2013-03-01

379

Estimating marine aerosol particle volume and number from Maritime Aerosol Network data  

NASA Astrophysics Data System (ADS)

As well as spectral aerosol optical depth (AOD), aerosol composition and concentration (number, volume, or mass) are of interest for a variety of applications. However, remote sensing of these quantities is more difficult than for AOD, as it is more sensitive to assumptions relating to aerosol composition. This study uses spectral AOD measured on Maritime Aerosol Network (MAN) cruises, with the additional constraint of a microphysical model for unpolluted maritime aerosol based on analysis of Aerosol Robotic Network (AERONET) inversions, to estimate these quantities over open ocean. When the MAN data are subset to those likely to be comprised of maritime aerosol, number and volume concentrations obtained are physically reasonable. Attempts to estimate surface concentration from columnar abundance, however, are shown to be limited by uncertainties in vertical distribution. Columnar AOD at 550 nm and aerosol number for unpolluted maritime cases are also compared with Moderate Resolution Imaging Spectroradiometer (MODIS) data, for both the present Collection 5.1 and forthcoming Collection 6. MODIS provides a best-fitting retrieval solution, as well as the average for several different solutions, with different aerosol microphysical models. The "average solution" MODIS dataset agrees more closely with MAN than the "best solution" dataset. Terra tends to retrieve lower aerosol number than MAN, and Aqua higher, linked with differences in the aerosol models commonly chosen. Collection 6 AOD is likely to agree more closely with MAN over open ocean than Collection 5.1. In situations where spectral AOD is measured accurately, and aerosol microphysical properties are reasonably well-constrained, estimates of aerosol number and volume using MAN or similar data would provide for a greater variety of potential comparisons with aerosol properties derived from satellite or chemistry transport model data.

Sayer, A. M.; Smirnov, A.; Hsu, N. C.; Munchak, L. A.; Holben, B. N.

2012-06-01

380

Estimating marine aerosol particle volume and number from Maritime Aerosol Network data  

NASA Astrophysics Data System (ADS)

As well as spectral aerosol optical depth (AOD), aerosol composition and concentration (number, volume, or mass) are of interest for a variety of applications. However, remote sensing of these quantities is more difficult than for AOD, as it is more sensitive to assumptions relating to aerosol composition. This study uses spectral AOD measured on Maritime Aerosol Network (MAN) cruises, with the additional constraint of a microphysical model for unpolluted maritime aerosol based on analysis of Aerosol Robotic Network (AERONET) inversions, to estimate these quantities over open ocean. When the MAN data are subset to those likely to be comprised of maritime aerosol, number and volume concentrations obtained are physically reasonable. Attempts to estimate surface concentration from columnar abundance, however, are shown to be limited by uncertainties in vertical distribution. Columnar AOD at 550 nm and aerosol number for unpolluted maritime cases are also compared with Moderate Resolution Imaging Spectroradiometer (MODIS) data, for both the present Collection 5.1 and forthcoming Collection 6. MODIS provides a best-fitting retrieval solution, as well as the average for several different solutions, with different aerosol microphysical models. The "average solution" MODIS dataset agrees more closely with MAN than the "best solution" dataset. Terra tends to retrieve lower aerosol number than MAN, and Aqua higher, linked with differences in the aerosol models commonly chosen. Collection 6 AOD is likely to agree more closely with MAN over open ocean than Collection 5.1. In situations where spectral AOD is measured accurately, and aerosol microphysical properties are reasonably well-constrained, estimates of aerosol number and volume using MAN or similar data would provide for a greater variety of potential comparisons with aerosol properties derived from satellite or chemistry transport model data. However, without accurate AOD data and prior knowledge of microphysical properties, such attempts are fraught with high uncertainties.

Sayer, A. M.; Smirnov, A.; Hsu, N. C.; Munchak, L. A.; Holben, B. N.

2012-09-01

381

Remote sensing of ocean color and aerosol properties: resolving the issue of aerosol absorption  

NASA Astrophysics Data System (ADS)

Current atmospheric correction and aerosol retrieval algorithms for ocean color sensors use measurements of the top-of-the-atmosphere reflectance in the near infrared, where the contribution from the ocean is known for case 1 waters, to assess the aerosol optical properties. Such measurements are incapable of distinguishing between weakly and strongly absorbing aerosols, and the atmospheric correction and aerosol retrieval algorithms fail if the incorrect absorption properties of the aerosol are assumed. We present an algorithm that appears promising for the retrieval of in-water biophysical properties and aerosol optical properties in atmospheres containing both weakly and strongly absorbing aerosols. By using the entire spectrum available to most ocean color instruments (412 -865 nm), we simultaneously recover the ocean s bio-optical properties and a set of aerosol models that best describes the aerosol optical properties. The algorithm is applied to simulated situations that are likely to occur off the U.S. East Coast in summer when the aerosols could be of the locally generated weakly absorbing Maritime type or of the pollution-generated strongly absorbing urban-type transported over the ocean by the winds. The simulations show that the algorithm behaves well in an atmosphere with either weakly or strongly absorbing aerosol. The algorithm successfully identifies absorbing aerosols and provides close values for the aerosol optical thickness. It also provides excellent retrievals of the ocean bio-optical properties. The algorithm uses a bio-optical model of case 1 waters and a set of aerosol models for its operation. The relevant parameters of both the ocean and atmosphere are systematically varied to find the best (in a rms sense) fit to the measured top-of-the-atmosphere spectral reflectance. Examples are provided that show the algorithm s performance in the presence of errors, e.g., error in the contribution from whitecaps and error in radiometric calibration.

Gordon, Howard R.; Du, Tao; Zhang, Tianming

1997-11-01

382

Remote sensing of ocean color and aerosol properties: resolving the issue of aerosol absorption.  

PubMed

Current atmospheric correction and aerosol retrieval algorithms for ocean color sensors use measurements of the top-of-the-atmosphere reflectance in the near infrared, where the contribution from the ocean is known for case 1 waters, to assess the aerosol optical properties. Such measurements are incapable of distinguishing between weakly and strongly absorbing aerosols, and the atmospheric correction and aerosol retrieval algorithms fail if the incorrect absorption properties of the aerosol are assumed. We present an algorithm that appears promising for the retrieval of in-water biophysical properties and aerosol optical properties in atmospheres containing both weakly and strongly absorbing aerosols. By using the entire spectrum available to most ocean color instruments (412-865 nm), we simultaneously recover the ocean's bio-optical properties and a set of aerosol models that best describes the aerosol optical properties. The algorithm is applied to simulated situations that are likely to occur off the U.S. East Coast in summer when the aerosols could be of the locally generated weakly absorbing Maritime type or of the pollution-generated strongly absorbing urban-type transported over the ocean by the winds. The simulations show that the algorithm behaves well in an atmosphere with either weakly or strongly absorbing aerosol. The algorithm successfully identifies absorbing aerosols and provides close values for the aerosol optical thickness. It also provides excellent retrievals of the ocean bio-optical properties. The algorithm uses a bio-optical model of case 1 waters and a set of aerosol models for its operation. The relevant parameters of both the ocean and atmosphere are systematically varied to find the best (in a rms sense) fit to the measured top-of-the-atmosphere spectral reflectance. Examples are provided that show the algorithm's performance in the presence of errors, e.g., error in the contribution from whitecaps and error in radiometric calibration. PMID:18264417

Gordon, H R; Du, T; Zhang, T

1997-11-20

383

5, 75777611, 2005 A look at aerosol  

E-print Network

ACPD 5, 7577­7611, 2005 A look at aerosol formation using data mining techniques S. Hyv and Physics Discussions A look at aerosol formation using data mining techniques S. Hyv¨onen1 , H. Junninen2­00014 University of Helsinki, Finland 2 Department of Physics, University of Helsinki, P.O. Box 64, FIN

Boyer, Edmond

384

Aerosol Spray Synthesis of Porous Molybdenum Sulfide  

E-print Network

Aerosol Spray Synthesis of Porous Molybdenum Sulfide Powder Submitted by SARA E. SKRABALAK. CLASSIFICATION Form: porous, fine powder Function: hydrodesulfurization catalyst Preparation: aerosol spray ABSTRACT Highly porous, nanostructured MoS2 spheres have been prepared by ultrasonic spray pyrolysis (USP

Suslick, Kenneth S.

385

EVIDENCE FOR ORGANOSULFATES IN SECONDARY ORGANIC AEROSOL  

EPA Science Inventory

Recent work has shown that particle-phase reactions contribute to the formation of secondary organic aerosol (SOA), with enhancements of SOA yields in the presence of acidic seed aerosol. In this study, the chemical composition of SOA from the photooxidations of a-pinene and isop...

386

Optical manipulation of aerosol particle arrays  

NASA Astrophysics Data System (ADS)

Aerosols play a crucial role in many areas of science, ranging from atmospheric chemistry and physics, to drug delivery to the lungs, combustion science and spray drying. The development of new methods to characterise the properties and dynamics of aerosol particles is of crucial importance if the complex role that particles play is to be more fully understood. Optical tweezers provide a valuable new tool to address fundamental questions in aerosol science. Single or multiple particles 1-15 ?m in diameter can be manipulated over indefinite timescales using optical tweezing. Linear and non-linear Raman and fluorescence spectroscopies can be used to probe a particle's composition and size. In this paper we will report on the latest developments in the use of holographic optical trapping (HOT) to study aerosols. Although widely used to trap and manipulate arrays of particles in the condensed phase, the application of HOT to aerosols is still in its infancy. We will explore the opportunities provided by the formation of complex optical landscapes for controlling aerosol flow, for comparing the properties of multiple particles, for performing the first ever digital microfluidic operations in the aerosol phase and for examining interparticle interactions that can lead to coalescence/coagulation. Although aerosol coagulation is the primary process driving the evolution of particle size distributions, it remains very poorly understood. Using HOT, we can resolve the time-dependent motion of trapped particles and the light scattering from particles during the coalescence process.

Reid, J. P.; Haddrell, A. E.; Walker, J. S.; Power, R.; Bones, D. L.; Davies, J. F.

2011-10-01

387

5, 41434182, 2005 Mexico City aerosol  

E-print Network

ACPD 5, 4143­4182, 2005 Mexico City aerosol during MCMA-2003 using an AMS ­ Part I D. Salcedo et al and Physics Discussions Characterization of ambient aerosols in Mexico City during the MCMA-2003 campaign Morelos, Cuernavaca, Morelos, Mexico 2 Cooperative Institute for Research in the Environmental Sciences

Paris-Sud XI, Université de

388

5, 41834221, 2005 Mexico City aerosol  

E-print Network

ACPD 5, 4183­4221, 2005 Mexico City aerosol during MCMA-2003 using an AMS ­ Part II D. Salcedo et and Physics Discussions Characterization of ambient aerosols in Mexico City during the MCMA-2003 campaign´imicas, Universidad Aut´onoma del Estado de Morelos, Cuernavaca, Mexico 2 Cooperative Institute for Research

Paris-Sud XI, Université de

389

7, 1463914674, 2007 Aerosol effects on  

E-print Network

ACPD 7, 14639­14674, 2007 Aerosol effects on convective clouds U. Lohmann Title Page Abstract/14639/2007/ © Author(s) 2007. This work is licensed under a Creative Commons License. Atmospheric Chemistry and Physics Discussions Global anthropogenic aerosol effects on convective clouds in ECHAM5-HAM U. Lohmann Institute

Boyer, Edmond

390

Aerosols from 2003 Southern California Fires (WMS)  

NSDL National Science Digital Library

A devastating series of fires occurred in Southern California during October 2003. The effects of these fires were detectable from space. The Total Ozone Mapping Spectrometer (TOMS) instrument measures aerosol particles (microscopic airborne dust and smoke). TOMS was able to detect aerosols from these fires moving West over the Pacific Ocean and East over the continental United States.

Delabeaujardiere, Jeff; Newman, Paul; Bhartia, Pawan

2005-03-14

391

Agglomeration characteristics of fast reactor HCDA aerosols  

Microsoft Academic Search

The behavior of vaporized mixed oxide fuel aerosols postulated to result from fast reactor core disruptive accidents is a subject which is intensely evaluated in fast reactor safety analysis, containment design, and site selection licensing procedure. In this program, surrogate uranium oxide aerosols produced by vapor condensation of super-heated liquid UOâ have been produced in a variety of ways and

G. W. Parker; G. E. Creek; A. L. Jr. Sutton

1978-01-01

392

Aerosol feed direct methanol fuel cell  

NASA Technical Reports Server (NTRS)

Improvements to fuel cells include introduction of the fuel as an aerosol of liquid fuel droplets suspended in a gas. The particle size of the liquid fuel droplets may be controlled for optimal fuel cell performance by selection of different aerosol generators or by separating droplets based upon size using a particle size conditioner.

Kindler, Andrew (Inventor); Narayanan, Sekharipuram R. (Inventor); Valdez, Thomas I. (Inventor)

2002-01-01

393

Flame aerosol synthesis of ceramic powders  

Microsoft Academic Search

Flame aerosol technology is used for large-scale manufacture of ceramic commodities such as pigmentary titania, fumed silica and alumina. In addition, the introduction of this technology to the manufacture of optical fibers and its potential for cheap synthesis of ultrafine particles (e.g. nanoparticles) has renewed the research interest for better understanding of flame aerosol reactors. Here, after an overview of

Sotiris E. Pratsinis

1998-01-01

394

CHARACTERIZATION AND GENERATION OF METAL AEROSOLS  

EPA Science Inventory

The report reviews techniques of metal aerosol generation for the purpose of establishing the state-of-the-art of the technology and guiding future researchers. Exposure to metal or metallic compound submicron aerosols is widespread in both industrial and general environments. Re...

395

ENCAPSULATION EFFECTS ON CARBONACEOUS AEROSOL LIGHT ABSORPTION  

E-print Network

ENCAPSULATION EFFECTS ON CARBONACEOUS AEROSOL LIGHT ABSORPTION Arthur Sedlacek, Brookhaven National of aerosol absorption on direct radiative forcing is still an active area of research, in part, because. This poster presents data on black carbon (BC) light absorption measured by Photothermal Interferometry

396

Aerosols, Climate, and the Hydrological Cycle  

Microsoft Academic Search

Human activities are releasing tiny particles (aerosols) into the atmosphere. These human-made aerosols enhance scattering and absorption of solar radiation. They also produce brighter clouds that are less efficient at releasing precipitation. These in turn lead to large reductions in the amount of solar irradiance reaching Earth's surface, a corresponding increase in solar heating of the atmosphere, changes in the

V. Ramanathan; P. J. Crutzen; J. T. Kiehl; D. Rosenfeld

2001-01-01

397

CONTINUOUS MEASUREMENTS OF AEROSOLS AND WATER  

E-print Network

Online Remotely operated #12;The Instrument telescope laser electronics computer cooling Light sensors Second survived 1 month Unwanted visitors #12;Example: Water Vapor Profiles Embrapa military airport: 2 molecular + aerosol #12;ACONVEX Aerosol, Clouds, cONVection EXperiment in the Amazon Intensive Campaign, Aug

Barbosa, Henrique

398

Aerosol light-scattering in The Netherlands  

Microsoft Academic Search

The relation between the (midday) aerosol light-scattering and the concentrations of nitrate and sulfate has been assessed at a site near the coast of the North Sea in The Netherlands. Midday was selected for the measurements because this is the time at which the aerosol is most effective in the scattering of solar radiation. Automated thermodenuders were used for the

H. M. Ten Brink; J. P. Veefkind; A. Waijers-Ijpelaan; J. C. van der Hage

1996-01-01

399

EFFECTS OF SULFURIC ACID AEROSOLS ON VEGETATION  

EPA Science Inventory

A continuous flow system for exposing plants to submicron aerosols of sulfuric acid has been developed and an operational model has been constructed. Exposure chambers have been designed to allow simultaneous exposures of the same plant to aerosol and control environments. All su...

400

The Aerosol Modeling Testbed: A Tool to Facilitate Improved Aerosol Process Modules  

NASA Astrophysics Data System (ADS)

Predictions of aerosol mass, composition, size distribution, hygroscopicity, and optical properties still contain large uncertainties. For example, the formation and transformation of secondary organic aerosols and the nature of many cloud-aerosol interactions are still poorly understood and consequently inadequately represented in models. When new aerosol treatments are developed, they are usually implemented into an existing aerosol model and evaluated using a limited number of measurements from a specific case study. One consequence of the current modeling paradigm is that the performance and computational efficiency of several treatments for a specific aerosol process cannot be adequately quantified because many other processes among aerosol models are different as well. For example, predictions of aerosol properties from several models have been compared, but different grid configurations, meteorology, and emission rates are often employed so that variations in predicted aerosol properties among the models were not due entirely to the treatment of aerosol processes. Thus, these studies do not quantify the range of uncertainty associated only with the predicted aerosol properties, nor does this type of uncertainty analysis provide much information on which aerosol process needs improving the most. Reducing the uncertainties associated with aerosols predictions requires that we know the advantages and disadvantages of specific aerosol treatments when the meteorology, chemistry, and other aerosol processes are identical. To address these issues, an Aerosol Modeling Testbed (AMT) has been developed that will simplify and greatly increase the efficiency of evaluating new aerosol treatments for regional and global models. The AMT consists of a modular and user-friendly version of the Weather Research and Forecasting model (WRF-Chem), a series testbed cases consisting of extensive in situ and remote sensing measurements of meteorological, trace gas, and aerosol properties, and a suite of tools to evaluate the performance of aerosol process modules. The first testbed case completed is based on the Megacities Initiative: Local and Global Research Observations (MILAGRO) field campaign conducted in the vicinity of Mexico City during March 2006. In addition to standard in situ measurements of aerosol properties, aerosol composition from several Aerodyne Aerosol Mass Spectrometers, profiles of aerosol backscatter and extinction from the NASA High Resolution Spectral Lidar (HRSL), and aerosol optical depth from satellite instrumentation are included in the MILAGRO testbed case. Two other testbed cases are also being developed. An example of how the AMT can be used to assess the strengths and weaknesses of two aerosol models in WRF-Chem, one using a simple modal approach to represent the aerosol size distribution and the other using a more comple sectional approach, will be presented using both in situ and remote sensing data collected during MILAGRO. How the AMT can be used by the scientific community to foster collaborations and coordinate aerosol modeling research will also be discussed.

Fast, J. D.; Gustafson, W. I.; Chapman, E. G.; Easter, R. C.; Rishel, J.

2009-12-01

401

A review of atmospheric aerosol measurements  

NASA Astrophysics Data System (ADS)

Recent developments in atmospheric aerosol measurements are reviewed. The topics included complement those covered in the recent review by Chow (JAWMA 45: 320-382, 1995) which focuses on regulatory compliance measurements and filter measurements of particulate composition. This review focuses on measurements of aerosol integral properties (total number concentration, CCN concentration, optical coefficients, etc.), aerosol physical chemical properties (density, refractive index, equilibrium water content, etc.), measurements of aerosol size distributions, and measurements of size-resolved aerosol composition. Such measurements play an essential role in studies of secondary aerosol formation by atmospheric chemical transformations and enable one to quantify the contributions of various species to effects including light scattering/absorption, health effects, dry deposition, etc. Aerosol measurement evolved from an art to a science in the 1970s following the development of instrumentation to generate monodisperse calibration aerosols of known size, composition, and concentration. While such calibration tools permit precise assessments of instrument responses to known laboratory-generated aerosols, unquantifiable uncertainties remain even when carefully calibrated instruments are used for atmospheric measurements. This is because instrument responses typically depend on aerosol properties including composition, shape, density, etc., which, for atmospheric aerosols, may vary from particle-to-particle and are often unknown. More effort needs to be made to quantify measurement accuracies that can be achieved for realistic atmospheric sampling scenarios. The measurement of organic species in atmospheric particles requires substantial development. Atmospheric aerosols typically include hundreds of organic compounds, and only a small fraction (˜10%) of these can be identified by state-of-the-art analytical methodologies. Even the measurement of the total particulate organic carbon mass concentration is beset by difficulties including the unknown extent of evaporative losses during sampling, adsorption of gas-phase organic compounds onto sampling substrates, and the unknown relationship between carbon mass and mass of the particulate organics. The development of improved methodologies for such measurements should be a high priority for the future. Mass spectrometers that measure the composition of individual particles have recently been developed. It is not clear that these instruments will provide quantitative information on species mass concentrations, and more work is needed to routinely interpret the vast quantities of data generated during field sampling. Nevertheless, these instruments substantially expand the range of atmospheric aerosol issues that can be explored experimentally. These instruments represent the most significant advance in aerosol instrumentation in recent years.

McMurry, Peter H.

402

Global Analysis of Aerosol Properties Above Clouds  

NASA Technical Reports Server (NTRS)

The seasonal and spatial varability of Aerosol Above Cloud (AAC) properties are derived from passive satellite data for the year 2008. A significant amount of aerosols are transported above liquid water clouds on the global scale. For particles in the fine mode (i.e., radius smaller than 0.3 m), including both clear sky and AAC retrievals increases the global mean aerosol optical thickness by 25(+/- 6%). The two main regions with man-made AAC are the tropical Southeast Atlantic, for biomass burning aerosols, and the North Pacific, mainly for pollutants. Man-made AAC are also detected over the Arctic during the spring. Mineral dust particles are detected above clouds within the so-called dust belt region (5-40 N). AAC may cause a warming effect and bias the retrieval of the cloud properties. This study will then help to better quantify the impacts of aerosols on clouds and climate.

Waquet, F.; Peers, F.; Ducos, F.; Goloub, P.; Platnick, S. E.; Riedi, J.; Tanre, D.; Thieuleux, F.

2013-01-01

403

Beijing Olympics as an aerosol field experiment  

NASA Astrophysics Data System (ADS)

During the 2008 Olympic Summer Games, emission reductions were enforced in Beijing to improve air quality. Here we explore their effect on the regional aerosol load. We compare satellite-retrieved aerosol optical thickness (AOT) of that period with previous years, both in absolute terms and in a neural network approach taking into account the meteorological conditions. A statistically significant reduction of aerosol load is found in Beijing that decreases in magnitude and significance with increasing region size. Locally, the aerosol load (log(AOT)) was about 0.4 to 0.75 standard deviations below the levels expected for the prevailing meteorological situation. The small size of this effect relative to meteorological variability highlights the importance of regional aerosol transport.

Cermak, J.; Knutti, R.

2009-05-01

404

Mechanics of plutonium metal aerosolization  

SciTech Connect

Reliable estimates of hazards posed by a plutonium release are contingent on the availability of technical data to define the source term for aerosolization of plutonium oxide particles and the resulting size distribution. The release of aerosols from the oxidation of plutonium metal depends partly on the forces acting on the particles while they remain attached to the bulk material and partly on the ability of the airstream around the metal ingot to transport the particles when they detach. The forces that attach or detach the plutonium oxide particles can be described as binding of the particle to the metal or oxide layer around it and expansion and contraction stresses and external vibration. Experimental data forms the basis for defining size distributions and release fractions for plutonium oxide. The relevance of the data must be evaluated in the light of the chemical and physical properties of plutonium metal, plutonium oxide, and intermediate Plutonium compounds. The effects of temperature on reaction kinetics must also be understood when evaluating experimental data. Size distribution functions are remarkably similar for products of all Pu+gas reactions. The distributions are all bimodal. Marked differences are seen in the sizes of large particles depending on reaction temperature and reaction rate. However, the size distributions of small particles are very similar. The bimodal distribution of small particles vanishes as the sizes of the large particles decrease to the point of equal dimensions with the small particles. This is the situation realized for the fine plutonium oxide powder produced by air oxidation at room temperature. This report addresses important factors for defining the formation of an aerosol from the oxidation of plutonium metal. These factors are oxidation kinetics of plutonium metal and plutonium hydride, the particle distribution of products formed by the reactions, and the kinetics of processes limiting entrainment of particles.

Alvis, J.M. [Texas A& M Univ., College Station, TX (United States)

1996-06-01

405

AEROSOL PARTICLE COLLECTOR DESIGN STUDY  

SciTech Connect

A computational evaluation of a particle collector design was performed to evaluate the behavior of aerosol particles in a fast flowing gas stream. The objective of the work was to improve the collection efficiency of the device while maintaining a minimum specified air throughput, nominal collector size, and minimal power requirements. The impact of a range of parameters was considered subject to constraints on gas flow rate, overall collector dimensions, and power limitations. Potential improvements were identified, some of which have already been implemented. Other more complex changes were identified and are described here for further consideration. In addition, fruitful areas for further study are proposed.

Lee, S; Richard Dimenna, R

2007-09-27

406

Electromagnetic Attenuation by Solid Particle Aerosols.  

NASA Astrophysics Data System (ADS)

Theories of electromagnetic attenuation by absorption and scattering from aerosols of solid particles were evaluated and experimentally verified. Particles having specific physical and morphological properties were tested to maximize the mass extinction coefficients of the aerosols in several bands of the electromagnetic spectrum. Particulate materials were chosen based on theoretical predictions and compatible aerosolization schemes were developed for each material. Direct measurements of attenuation by the resulting aerosols were conducted in instrumented cloud chambers and a new measurement system using "stationary aerosols" was developed. The method of producing the stationary aerosols was optimized experimentally and results of the two measurement techniques were compared, validating the stationary aerosol approach as a viable alternative to chamber testing. Theoretical results were used to determine ideal particles for maximizing attenuation and particles with the appropriate parameters were designed and produced in the laboratory. A combination of aerosol and stationary aerosol testing was used to measure attenuations and extinction coefficients were computed as the figures of merit in evaluating the efficacy of each material. Materials with less than ideal parameters were tested to further validate the theoretical predictions. Materials produced as testing particulates included deflagrated graphitic oxides, charge transfer salts, iron whiskers, and aluminum flake with varying levels of passivation. Product characterizations were done using electron microscopies and image analysis, x-ray spectroscopies and electron spectroscopies. The same methods were used to verify manufacturers' specifications for commercially available materials tested. Characterization results were used to calculate theoretical predictions. Dissemination schemes investigated included sonic velocity pneumatic nozzles, mechanical systems, magnetic systems and material specific reaction systems. Figures of merit for dissemination systems were determined in terms of aerosolized yields, fall rates, and extents of agglomeration.

Petersen, Erica Ray

1991-02-01

407

Radiative forcing under mixed aerosol conditions  

NASA Astrophysics Data System (ADS)

The mixture of mineral dust with biomass burning or urban-industrial aerosols presents significant differences in optical properties when compared to those of the individual constituents, leading to different impacts on solar radiation levels. This effect is assessed by estimating the direct radiative forcing (?F) of these aerosols from solar flux models using the radiative parameters derived from the Aerosol Robotic Network (AERONET). These data reveal that, in oceanic and vegetative covers (surface albedo (SA) < 0.30), the aerosol effect at the top of atmosphere (TOA) is always cooling the Earth-atmosphere system, regardless of the aerosol type. The obtained average values of ?F range between -27 ± 15 Wm-2 (aerosol optical depth (AOD) at 0.55 ?m, 0.3 ± 0.3) for mineral dust mixed with urban-industrial aerosols, registered in the East Asia region, and -34 ± 18 Wm-2 (AOD = 0.8 ± 0.4) for the mixture of the mineral dust and biomass burning particles, observed in the Central Africa region. In the intermediate SA range (0.30-0.50) the TOA radiative effect depends on the aerosol absorption properties. Thus, aerosols with single scattering albedo at 0.55 ?m lower than ˜0.88 lead to a warming of the system, with ?F of 10 ± 11 Wm-2 for the mixture of mineral dust and biomass burning. Cases with SA > 0.30 are not present in East Asia region. At the bottom of atmosphere (BOA) the maximum ?F values are associated with the highest AOD levels obtained for the mixture of mineral dust and biomass burning aerosols (-130 ± 44 Wm-2 with AOD = 0.8 ± 0.4 for SA < 0.30).

GarcíA, O. E.; Expósito, F. J.; DíAz, J. P.; DíAz, A. M.

2011-01-01

408

Cellular Zn depletion by metal ion chelators (TPEN, DTPA and chelex resin) and its application to osteoblastic MC3T3-E1 cells  

PubMed Central

Trace mineral studies involving metal ion chelators have been conducted in investigating the response of gene and protein expressions of certain cell lines but a few had really focused on how these metal ion chelators could affect the availability of important trace minerals such as Zn, Mn, Fe and Cu. The aim of the present study was to investigate the availability of Zn for the treatment of MC3T3-E1 osteoblast-like cells and the availability of some trace minerals in the cell culture media components after using chelexing resin in the FBS and the addition of N,N,N',N'-tetrakis-(2-pyridylmethyl)ethylenediamine (TPEN, membrane-permeable chelator) and diethylenetriaminepentaacetic acid (DTPA, membrane-impermeable chelator) in the treatment medium. Components for the preparation of cell culture medium and Zn-treated medium have been tested for Zn, Mn, Fe and Cu contents by atomic absorption spectrophotometer or inductively coupled plasma spectrophotometer. Also, the expression of bone-related genes (ALP, Runx2, PTH-R, ProCOL I, OPN and OC) was measured on the cellular Zn depletion such as chelexing or TPEN treatment. Results have shown that using the chelexing resin in FBS would significantly decrease the available Zn (p<0.05) (39.4 ± 1.5 µM vs 0.61 ± 10.15 µM) and Mn (p<0.05) (0.74 ± 0.01 µM vs 0.12 ± 0.04 µM). However, levels of Fe and Cu in FBS were not changed by chelexing FBS. The use of TPEN and DTPA as Zn-chelators did not show significant difference on the final concentration of Zn in the treatment medium (0, 3, 6, 9, 12 µM) except for in the addition of higher 15 µM ZnCl2 which showed a significant increase of Zn level in DTPA-chelated treatment medium. Results have shown that both chelators gave the same pattern for the expression of the five bone-related genes between Zn- and Zn+, and TPEN-treated experiments, compared to chelex-treated experiment, showed lower bone-related gene expression, which may imply that TPEN would be a stronger chelator than chelex resin. This study showed that TPEN would be a stronger chelator compared to DTPA or chelex resin and TPEN and chelex resin exerted cellular zinc depletion to be enough for cell study for Zn depletion. PMID:20535382

Cho, Young-Eun; Lomeda, Ria-Ann R.; Ryu, Sang-Hoon; Lee, Jong-Hwa; Beattie, John H.

2007-01-01

409

In vivo transport of Gd-DTPA2- into human meniscus and cartilage assessed with delayed gadolinium-enhanced MRI of cartilage (dGEMRIC)  

PubMed Central

Background Impaired stability is a risk factor in knee osteoarthritis (OA), where the whole joint and not only the joint cartilage is affected. The meniscus provides joint stability and is involved in the early pathological progress of OA. Delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) has been used to identify pre-radiographic changes in the cartilage in OA, but has been used less commonly to examine the meniscus, and then using only a double dose of the contrast agent. The purpose of this study was to enable improved early OA diagnosis by investigate the temporal contrast agent distribution in the meniscus and femoral cartilage simultaneously, in healthy volunteers, using 3D dGEMRIC at two different doses of the contrast agent Gd-DTPA2-. Methods The right knee in 12 asymptomatic volunteers was examined using a 3D Look-Locker sequence on two occasions after an intravenous injection of a double or triple dose of Gd-DTPA2- (0.2 or 0.3 mmol/kg body weight). The relaxation time (T1) and relaxation rate (R1?=?1/T1) were measured in the meniscus and femoral cartilage before, and 60, 90, 120 and 180 minutes after injection, and the change in relaxation rate (?R1) was calculated. Paired t-test and Analysis of Variance (ANOVA) were used for statistical evaluation. Results The triple dose yielded higher concentrations of Gd-DTPA2- in the meniscus and cartilage than the double dose, but provided no additional information. The observed patterns of ?R1 were similar for double and triple doses of the contrast agent. ?R1 was higher in the meniscus than in femoral cartilage in the corresponding compartments at all time points after injection. ?R1 increased until 90-180 minutes in both the cartilage and the meniscus (p?DTPA2- (0.2 mmol/kg body weight). PMID:25005036

2014-01-01

410

Evaluation and comparison of a new DOTA and DTPA-bombesin agonist in vitro and in vivo in low and high GRPR expressing prostate and breast tumor models.  

PubMed

We evaluated and compared a new bombesin analog [Tyr-Gly5, Nle(14)]-BBN(6-14) conjugated to DOTA or DTPA and radiolabeled with In-111 in low and high GRPR expressing tumor models. Both peptides were radiolabeled with high radiochemical purity and specific activity. In vitro assays on T-47D, LNCaP and PC-3 cells showed that the affinity of peptides is similar and a higher binding and internalization of DOTA-peptide to PC-3 cells was observed. Both peptides could target PC-3 and LNCaP tumors in vivo and both tumor types could be visualized by microSPECT/CT. PMID:25479439

Pujatti, Priscilla B; Foster, Julie M; Finucane, Ciara; Hudson, Chantelle D; Burnet, Jerome C; Pasqualoto, Kerly F M; Mengatti, Jair; Mather, Stephen J; de Araújo, Elaine B; Sosabowski, Jane K

2015-02-01

411

Aerosol processing of materials: Aerosol dynamics and microstructure evolution  

NASA Astrophysics Data System (ADS)

Spray pyrolysis is an aerosol process commonly used to synthesize a wide variety of materials in powder or film forms including metals, metal oxides and non-oxide ceramics. It is capable of producing high purity, unagglomerated, and micrometer to submicron-size powders, and scale-up has been demonstrated. This dissertation deals with the study of aerosol dynamics during spray pyrolysis of multicomponent systems involving volatile phases/components, and aspects involved with using fuel additives during spray processes to break apart droplets and particles in order to produce powders with smaller sizes. The gas-phase aerosol dynamics and composition size distributions were measured during spray pyrolysis of (Bi, Pb)-Sr-Ca-Cu-O, and Sr-Ru-O and Bi-Ru-O at different temperatures. A differential mobility analyzer (DMA) was used in conjunction with a condensation particle counter (CPC) to monitor the gas-phase particle size distributions, and a Berner-type low-pressure impactor was used to obtain mass size distributions and size-classified samples for chemical analysis. (Bi, Pb)-Sr-Ca-Cu-O powders made at temperatures up to 700sp°C maintained their initial stoichiometry over the whole range of particle sizes monitored, however, those made at 800sp°C and above were heavily depleted in lead in the size range 0.5-5.0 mum. When the reactor temperature was raised from 700 and 800sp°C to 900sp°C, a large number ({˜}10sp7\\ #/cmsp3) of new ultrafine particles were formed from PbO vapor released from the particles and the reactor walls at the beginning of high temperature runs (at 900sp°C). The metal ruthenate systems showed generation of ultrafine particles (<40-50 nm) at the beginning of runs at 800-900sp°C and also as a steady state process at a reactor temperature of 1000sp°C. The methods of aerosol dynamics measurements were also used to monitor the gas-phase particle size distributions during the generation of fullerene (Csb{60}) nano-particles (30 to 50 nm size) via vapor condensation at 400-650sp°C using Nsb2 carrier gas. In general, during laboratory-scale aerosol processing of materials containing a volatile component, significant evaporative losses and formation of new ultrafine particles were observed at synthesis temperatures at which the saturation vapor pressure of the volatile species exceeded about 0.1-0.5 mTorr. Spray calcination synthesis of pigment-size titania from titanium hydrolysate (TiOsb{x}(SOsb4)sb{y}(OH)sb{z}) using fuel additives such as ethyl alcohol, sugar and urea was also investigated. When pure water was used as a medium of suspension, agglomerates of 0.5 to 1.5 mum were produced by spray calcination. Use of pure ethanol as a solvent as well as small amounts (5-10 wt.%) urea additions to the suspension of Ti-hydrolysate in water were successful in producing predominantly unagglomerated, single crystalline titania particles of 0.1 to 0.3 mum size. Such additions of fuels such as alcohols, sugar and urea to suspensions and solutions used in spray processes are promising for making powders having smaller sizes and unagglomerated, denser morphologies.

Gurav, Abhijit Shankar

412

ELECTRICAL AEROSOL DETECTOR (EAD) MEASUREMENTS AT THE ST. LOUIS SUPERSITE  

EPA Science Inventory

The Model 3070A Electrical Aerosol Detector (EAD) measures a unique aerosol parameter called total aerosol length. Reported as mm/cm3, aerosol length can be thought of as a number concentration times average diameter, or simply as d1 weighting. This measurement falls between nu...

413

What is the "Clim-Likely" aerosol product?  

Atmospheric Science Data Center

The "Clim-Likely" aerosol climatology data set was developed as an initial step in identifying a range of components and mixtures for the MISR Standard Aerosol Retrieval Algorithm climatology, and as one standard against which to compare MISR aerosol air mass type retrieval results. Six component aerosols included in the ...

2014-12-08

414

Calculating Capstone Depleted Uranium Aerosol Concentrations from Beta Activity Measurements  

Microsoft Academic Search

Beta activity measurements were used as surrogate measurements of uranium mass in aerosol samples collected during the field testing phase of the Capstone Depleted Uranium (DU) Aerosol Study. These aerosol samples generated by the perforation of armored combat vehicles were used to characterize the depleted uranium (DU) source term for the subsequent human health risk assessment (HHRA) of Capstone aerosols.

Frances Szrom; Gerald A. Falo; MaryAnn Parkhurst; Jeffrey J. Whicker; David P. Alberth

2009-01-01

415

Marine aerosols. (Latest citations from Oceanic abstracts). Published Search  

SciTech Connect

The bibliography contains citations concerning the optical, chemical and physical properties of marine aerosols. The citations examine seasonal variations in aerosol composition, analysis of chemical pollutants contained in the aerosols, and identification of the sources of these pollutants. Attention is also given to mathematical modeling and computerized simulation of marine aerosols. (Contains 250 citations and includes a subject term index and title list.)

Not Available

1993-03-01

416

Informing Aerosol Transport Models With Satellite Multi-Angle Aerosol Measurements  

NASA Technical Reports Server (NTRS)

As the aerosol products from the NASA Earth Observing System's Multi-angle Imaging SpectroRadiometer (MISR) mature, we are placing greater focus on ways of using the aerosol amount and type data products, and aerosol plume heights, to constrain aerosol transport models. We have demonstrated the ability to map aerosol air-mass-types regionally, and have identified product upgrades required to apply them globally, including the need for a quality flag indicating the aerosol type information content, that varies depending upon retrieval conditions. We have shown that MISR aerosol type can distinguish smoke from dust, volcanic ash from sulfate and water particles, and can identify qualitative differences in mixtures of smoke, dust, and pollution aerosol components in urban settings. We demonstrated the use of stereo imaging to map smoke, dust, and volcanic effluent plume injection height, and the combination of MISR and MODIS aerosol optical depth maps to constrain wildfire smoke source strength. This talk will briefly highlight where we stand on these application, with emphasis on the steps we are taking toward applying the capabilities toward constraining aerosol transport models, planet-wide.

Limbacher, J.; Patadia, F.; Petrenko, M.; Martin, M. Val; Chin, M.; Gaitley, B.; Garay, M.; Kalashnikova, O.; Nelson, D.; Scollo, S.

2011-01-01

417

Solar Mesosphere Explorer satellite measurements of el Chichon stratospheric aerosols. 2: Aerosol mass and size parameters  

NASA Technical Reports Server (NTRS)

Spatially and temporally extensive observations of the stratospheric aerosol cloud produced by the eruption of el Chichon in 1982 were made by the Solar Mesosphere Explorer satellite. Measurements of thermal emission at 6.8 microns are inverted to give aerosol extinction coefficients. At this wavelength the extinction coefficient is proportional to the cube of the particle radius, so the measured radiance is proportional to the slant column mass density of aerosols, independent of size distribution. Vertical column mass densities of aerosols and total aerosol mass are found from the 6.8-microns data. The evolution of the aerosol cloud in time and space is discussed. A peak column mass density above 22 km of 0.43 g/sq m occurred near 20 deg N latitude 8 weeks after the eruption. A maximum total global aerosol burden above 22 km of 1.3 x 10(exp 13) g occurred a week later. The aerosol mass determinations are used in conjunction with observations of scattered sunlight from the aerosols at 1.27 and 1.87 microns to derive single-mode log normal columnar size distributions for the aerosol cloud. The results are presented and the time evolution of the particle sizes is discussed.

Eparvier, F. G.; Rusch, D. W.; Clancy, R. T.; Thomas, G. E.

1994-01-01

418

Aerosol Size Distribution in the marine regions  

NASA Astrophysics Data System (ADS)

We would like to present the data obtained during the regular research cruises of the S/Y Oceania over a period of time between 2009 - 2012. The Baltic Sea is a very interesting polygon for aerosol measurements, however, also difficult due to the fact that mostly cases of a mixture of continental and marine aerosols are observed. It is possible to measure clear marine aerosol, but also advections of dust from southern Europe or even Africa. This variability of data allows to compare different conditions. The data is also compared with our measurements from the Arctic Seas, which have been made during the ARctic EXperiment (AREX). The Arctic Seas are very suitable for marine aerosol investigations since continental advections of aerosols are far less frequent than in other European sea regions. The aerosol size distribution was measured using the TSI Laser Aerosol Spectrometer model 3340 (99 channels, measurement range 0.09 ?m to 7 ?m), condensation particle counter (range 0.01 ?m to 3 ?m) and laser particle counter PMS CSASP-100-HV-SP (range 0.5 ?m to 47 ?m in 45 channels). Studies of marine aerosol production and transport are important for many Earth sciences such as cloud physics, atmospheric optics, environmental pollution studies and interaction between ocean and atmosphere. All equipment was placed on one of the masts of S/Y Oceania. Measurements using the laser aerosol spectrometer and condensation particle counter were made on one level (8 meters above sea level). Measurements with the laser particle counter were performed at five different levels above the sea level (8, 11, 14, 17 and 20 m). Based on aerosol size distribution the parameterizations with a Log-Normal and a Power-Law distributions were made. The aerosol source functions, characteristic for the region were also determined. Additionally, poor precision of the sea spray emission determination was confirmed while using only the aerosol concentration data. The emission of sea spray depends on the size of energy lost by the wind waves in the process of a collapse. We present the dependence between aerosol size distribution versus meteorological and micrometeorological parameters, such as wind speed, Monin-Obuchov Length, friction velocity and also turbulent fluxes of heat, momentum and humidity.

Markuszewski, Piotr; Petelski, Tomasz; Zielinski, Tymon; Pakszys, Paulina; Strzalkowska, Agata; Makuch, Przemyslaw; Kowalczyk, Jakub

2014-05-01

419

Physical and Radiative Properties of Arctic Atmospheric Aerosols  

NASA Technical Reports Server (NTRS)

Atmospheric aerosols sampled in the Arctic basin by impactors have been analyzed for the total aerosol and its black carbon fraction. The mass of black carbon aerosol in the lower troposphere is one percent (1 g black carbon in 100 g total aerosol), reduced to one part in 10(exp 4) in the stratosphere. The aerosol single scatter albedos vary between 1.0 in the stratosphere, currently dominated by high light scattering due to Pinatubo volcanic aerosol, and 0.94 in the lower troposphere. The aerosol has the potential to regionally warm the earth-atmosphere system because of the high surface albedo of snow-covered surfaces in the Arctic.

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

1994-01-01

420

Impact of Aerosol Processing on Orographic Clouds  

NASA Astrophysics Data System (ADS)

Aerosol particles undergo significant modifications during their residence time in the atmosphere. Physical processes like coagulation, coating and water uptake, and aqueous surface chemistry alter the aerosol size distribution and composition. At this, clouds play a primary role as physical and chemical processing inside cloud droplets contributes considerably to the changes in aerosol particles. A previous study estimates that on global average atmospheric particles are cycled three times through a cloud before being removed from the atmosphere [1]. An explicit and detailed treatment of cloud-borne particles has been implemented in the regional weather forecast and climate model COSMO-CLM. The employed model version includes a two-moment cloud microphysical scheme [2] that has been coupled to the aerosol microphysical scheme M7 [3] as described by Muhlbauer and Lohmann, 2008 [4]. So far, the formation, transfer and removal of cloud-borne aerosol number and mass were not considered in the model. Following the parameterization for cloud-borne particles developed by Hoose et al., 2008 [5], distinction between in-droplet and in-crystal particles is made to more physically account for processes in mixed-phase clouds, such as the Wegener-Bergeron-Findeisen process and contact and immersion freezing. In our model, this approach has been extended to allow for aerosol particles in five different hydrometeors: cloud droplets, rain drops, ice crystals, snow flakes and graupel. We account for nucleation scavenging, freezing and melting processes, autoconversion, accretion, aggregation, riming and selfcollection, collisions between interstitial aerosol particles and hydrometeors, ice multiplication, sedimentation, evaporation and sublimation. The new scheme allows an evaluation of the cloud cycling of aerosol particles by tracking the particles even when scavenged into hydrometeors. Global simulations of aerosol processing in clouds have recently been conducted by Hoose et al. [6]. Our investigation regarding the influence of aerosol processing will focus on the regional scale using a cloud-system resolving model with a much higher resolution. Emphasis will be placed on orographic mixed-phase precipitation. Different two-dimensional simulations of idealized orographic clouds will be conducted to estimate the effect of aerosol processing on orographic cloud formation and precipitation. Here, cloud lifetime, location and extent as well as the cloud type will be of particular interest. In a supplementary study, the new parameterization will be compared to observations of total and interstitial aerosol concentrations and size distribution at the remote high alpine research station Jungfraujoch in Switzerland. In addition, our simulations will be compared to recent simulations of aerosol processing in warm, mixed-phase and cold clouds, which have been carried out at the location of Jungfraujoch station [5]. References: [1] Pruppacher & Jaenicke (1995), The processing of water vapor and aerosols by atmospheric clouds, a global estimate, Atmos. Res., 38, 283295. [2] Seifert & Beheng (2006), A two-moment microphysics parameterization for mixed-phase clouds. Part 1: Model description, Meteorol. Atmos. Phys., 92, 4566. [3] Vignati et al. (2004), An efficient size-resolved aerosol microphysics module for large-scale transport models, J. Geophys. Res., 109, D22202 [4] Muhlbauer & Lohmann (2008), Sensitivity studies of the role of aerosols in warm-phase orographic precipitation in different flow regimes, J. Atmos. Sci., 65, 25222542. [5] Hoose et al. (2008), Aerosol processing in mixed-phase clouds in ECHAM5HAM: Model description and comparison to observations, J. Geophys. Res., 113, D071210. [6] Hoose et al. (2008), Global simulations of aerosol processing in clouds, Atmos. Chem. Phys., 8, 69396963.

Pousse-Nottelmann, Sara; Zubler, Elias M.; Lohmann, Ulrike

2010-05-01