Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Technetium-99m labelled human serum albumin for ventriculography: a comparative evaluation of six labelling kits (1993)
    Springer
    European journal of nuclear medicine 20 (1993), S. 465-472 
    Details
    ISSN: 1619-7089
    Keywords: Technetium-99m labelled human serum albumin ; Labelling kit ; Ventriculography ; Blood pool agent
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In this study we have compared the characteristics of six labelling kits for the preparation of technetium-99m labelled human serum albumin (99mTc-HSA) and evaluated the usefulness of the various 99mTc-HSA preparations as blood pool tracer agents. The amount of the principal ingredients, i.e. HSA and stannous ions, varies largely between the studied kits and this is probably a reason for the observed differences in the labelling rate. Analysis of the reaction mixtures after labelling of the respective kits with 99mTc showed in each preparation the presence of four to five radioactive components in variable relative amounts. The retention time of the main component on size-exclusion high-performance liquid chromatography (SEC-HPLC) was identical for all preparations. Biodistribution of the HPLC-isolated fractions was studied in mice. The components with the shortest and longest retention times on HPLC show poor retention in the plasma. The three intermediate fractions, including the principal peak, are initially retained relatively well in the blood (60%–70% of the injected dose after 10 min), but clearly to a lower degree than iodine-125 labelled HSA. Moreover, they diffuse out of the vascular compartment at a much higher rate than 125I-HSA. The biological behaviour of the main component of the various preparations was clearly different, despite the identical retention time on SEC-HPLC. Study of the total preparations in mice and a rabbit showed that two of them are cleared rapidly from the blood and cannot be considered valuable blood pool tracers. Diffusion of the other preparations out of the blood is slower but also considerable and compromises their use for ventriculography.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00175158
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Technetium-99m mercaptoalbumin as a potential substitute for technetium-99m labelled red blood cells (1993)
    Springer
    European journal of nuclear medicine 20 (1993), S. 473-482 
    Details
    ISSN: 1619-7089
    Keywords: 99mTc-labelled human serum albumin ; 99mTc-mercaptoalbumin ; Ventriculography ; 99mTc-labelled erythrocytes ; 99mTc-DMP-HSA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Technetium-99m labelled red blood cells (99mTc-RBCs) are far superior to 99mTc-labelled human serum albumin (99mTc-HSA) for radionuclide ventriculography, but their labelling is more complex, time consuming and risk bearing (in vitro labelling) or suffers from interference by some medications (in vivo labelling). We have now modified HSA by the introduction of mercapto groups with the purpose of preparing stable and practical 99mTc-mercaptoalbumin with long retention in the vascular system, that could replace 99mTc-RBCs. HSA was incubated with N-succinimidyl S-acetylthioacetate (SATA) or N-succinimidyl 2,3-di(S-acetylthio) propionate (SATP) to introduce a chain containing one or two protected sulfhydryl groups on some of the lysine amino groups. After purification by size-exclusion chromatography (SEC), the mercapto groups were deprotected by incubation at alkaline pH or by treatment with hydroxylamine. The reaction products were used with or without SEC purification for direct or exchange labelling experiments with 99mTc at neutral pH. SEC-HPLC was used to determine labelling yields and to isolate pure 99mTc-mercaptoalbumin. Stable 99mTc-mercaptoalbumin complexes could be formed in 90%–95% yield after coupling albumin with SATA or SATP in all molar ratios used followed by deacetylation in one of the mentioned conditions. The most favourable results were obtained after reaction of SATA or SATP with HSA in a 25: 1 ratio and deprotection with NH2OH. The stability of the resulting 99mTc-mercaptoacetyl-albumin (99mTc-MAHSA) and 99mTc-dimercaptopropionyl-albumin (99mTcDMP-HSA) and their retention in vivo in plasma of mice and rabbits are clearly higher than that of conventional 99mTc-HSA preparations. 99mTc-DMP-HSA approaches the behaviour of 125I-HSA quite well in both animal species. A preliminary study with 99mTc-DMP-HSA in a volunteer showed a retention in the vascular compartment almost identical to that of 99mTc-RBCs and clearly higher than that of a common 99mTc-HSA preparation. The results indicate that these 99mTc-mercaptoalbumins and especially 99mTc-DMP-HSA are very promising as a practical alternative to 99mTc-RBCs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00175159
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    First evaluation of technetium-99m dimercaptopropionyl albumin as a possible tracer agent for ventriculography in a volunteer (1994)
    Springer
    European journal of nuclear medicine 21 (1994), S. 906-912 
    Details
    ISSN: 1619-7089
    Keywords: Technetium-99m 2,3-dimercaptopropionylhuman serum albumin ; Ventriculography ; Technetium-99m-labelled red blood cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Technetium-99m labelled red blood cells (99mTc-RBCs) are the standard radiopharmaceutical for radionuclide ventriculography but suffer from some practical disadvantages such as risk of viral contamination and lengthy preparation (in vitro labelling) or poor labelling efficiency due to patient medication interactions (in vivo labelling). 99mTc-labelled human serum albumin (HSA) is not really a valuable alternative as the activity diffuses too rapidly out of the vascular space due to the weak binding of the radionuclide. We have modified HSA by reaction with N-hydroxysuccinimidyl 2,3di(S-acetylmercapto)propionate (SAMP) to introduce a varying number of 2,3-dimercaptopropionyl (DMP) side chains. The resulting DMP-HSA can be rapidly labelled with 99mTc at room temperature by simple addition of stannous ions and eluate of a 99mTc generator. After evaluation in mice and rabbits, two different 99mTc-DMP-HSA preparations — obtained after reaction of SAMP with albumin in a molar ratio of, respectively, 8:1 and 16:1 — were tested in a volunteer and compared to 99mTcRBCs. The blood time-activity curves of the three preparations were quite similar but both 99mTc-DMP-HSA preparations were excreted much less into the urine than 99mTc-RBCs. Ventriculography was performed with the three tracer agents, each time with a 1-week interval. In the three studies, the heart was clearly visualized and the left and right ventricle could be easily delineated. The ejection fractions obtained after administration of the three preparations were similar. With both 99mTc-DMP-HSA preparations the low activity in the spleen was a distinct advantage and facilitated delineation of the left ventricle. However, a slightly higher liver uptake was seen with 99mTc-DMP-HSA 16:1, whereas the liver uptake of 99mTc-DMP-HSA 8:1 and 99mTc-RBCs was the same. These first results suggest that 99mTc-DMP-HSA, and in particular 99mTc-DMP-HSA 8:1, could be used for ventriculography as a practical and reliable alternative to 99mTc-RBCs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00238113
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...