scholarly journals Determination of Non-Invasive Biomarkers for the Assessment of Fibrosis, Steatosis and Hepatic Iron Overload by MR Image Analysis. A Pilot Study

Diagnostics ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1178
Author(s):  
Alba Meneses ◽  
José Manuel Santabárbara ◽  
Juan Antonio Romero ◽  
Roberto Aliaga ◽  
Alicia María Maceira ◽  
...  
Keyword(s):  
Human Serum Albumin ◽  
Iron Overload ◽  
Serum Albumin ◽  
Human Serum ◽  
Relaxation Times ◽  
Hepatic Iron ◽  
Mr Image ◽  
Non Invasive ◽  
Hepatic Iron Overload ◽  
Paravertebral Muscles

The reference diagnostic test of fibrosis, steatosis, and hepatic iron overload is liver biopsy, a clear invasive procedure. The main objective of this work was to propose HSA, or human serum albumin, as a biomarker for the assessment of fibrosis and to study non-invasive biomarkers for the assessment of steatosis and hepatic iron overload by means of an MR image acquisition protocol. It was performed on a set of eight subjects to determine fibrosis, steatosis, and hepatic iron overload with four different MRI sequences. We calibrated longitudinal relaxation times (T1 [ms]) with seven human serum albumin (HSA [%]) phantoms, and we studied the relationship between them as this protein is synthesized by the liver, and its concentration decreases in advanced fibrosis. Steatosis was calculated by means of the fat fraction (FF [%]) between fat and water liver signals in “fat-only images” (the subtraction of in-phase [IP] images and out-of-phase [OOP] images) and in “water-only images” (the addition of IP and OOP images). Liver iron concentration (LIC [µmol/g]) was obtained by the transverse relaxation time (T2* [ms]) using Gandon’s method with multiple echo times (TE) in T2-weighted IP and OOP images. The preliminary results showed that there is an inverse relationship (r = −0.9662) between the T1 relaxation times (ms) and HSA concentrations (%). Steatosis was determined with FF > 6.4% and when the liver signal was greater than the paravertebral muscles signal, and thus, the liver appeared hyperintense in fat-only images. Hepatic iron overload was detected with LIC > 36 µmol/g, and in these cases, the liver signal was smaller than the paravertebral muscles signal, and thus, the liver behaved as hypointense in IP images.

Investigation of relaxation times in 5-fluorouracil and human serum albumin mixtures

2019 ◽  
Vol 44 (4) ◽  
pp. 524-529 ◽  
Author(s):  
Sibel Korunur ◽  
Bilgin Zengin ◽  
Ali Yilmaz
Keyword(s):  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Relaxation Times ◽  
Solution Temperature ◽  
Cancer Drug ◽  
Human Blood Plasma ◽  
Albumin Concentration ◽  
Protein Drug ◽  
Relaxation Rates

Abstract Background Human serum albumin (HSA) is often selected as a subject of any study because albumin is the most abundant protein in human blood plasma. NMR is recognized as a valuable method to determine the structure of proteins-ligand and protein-drug complexes. Objective – Aim of the study In this study, protein drug interactions were investigated using 5-Fluorouracil anti-cancer drug and human serum albumin protein. Materials and methods In this context 400 MHz NMR spectrometry was used and NMR relaxation rates in drug-albumin complex were investigated with respect to increase albumin concentration and increase in 5-Fluorouracil (5-FU)-albumin solution temperature. Results The results of this study indicated that 5-FU had a weak association with albumin, and it easily dissociated from the protein to which it was attached. Conclusion The obtained results also gave us useful information about molecular dynamics of drug-albumin interactions.

Liver Blood Flow: Non-Invasive Estimation Using a Gamma Camera

1992 ◽  
Vol 206 (2) ◽  
pp. 99-103 ◽  
Author(s):  
W B Tindale ◽  
D C Barber ◽  
H L Smart ◽  
D R Triger
Keyword(s):  
Blood Flow ◽  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Computer Analysis ◽  
Gamma Camera ◽  
Liver Blood Flow ◽  
Time Activity ◽  
Non Invasive ◽  
First Pass

A non-invasive radioisotope technique for the measurement of total liver blood flow (TBF) is described. The method requires the use of two intravenously administered tracers, 99mTc (technetium 99m) human serum albumin (HSA) and 99mTc colloid. Computer analysis of first-pass time activity curves for HSA for liver and lung tissues yields values for the arterial and portal contributions to liver blood flow, from which TBF can be determined. These values are then corrected for attenuation using the images of the colloid distribution. The use of the method is illustrated in 17 subjects. Assumptions, limitations and possible applications of the technique are discussed.

Complexation of Zn(II) to a native sequence tripeptide of human serum albumin studied by 13C nuclear magnetic resonance

1980 ◽  
Vol 58 (8) ◽  
pp. 757-766 ◽  
Author(s):  
Helen Lakusta ◽  
Charles M. Deber ◽  
Bibudhendra Sarkar
Keyword(s):  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Metal Binding ◽  
Chemical Shifts ◽  
Relaxation Times ◽  
Spin Lattice Relaxation ◽  
Serum Albumins ◽  
13C Nuclear Magnetic Resonance ◽  
Native Sequence

Serum albumins from several species, which specifically bind and transport several divalent metals in blood, contain an Asp-X-His or Glu-X-His amino acid triad as their NH2-terminal sequence. We have synthesized a tripeptide, Asp-Ala-His-N-methylamide, corresponding to the native sequence of the human serum albumin N-terminus, and examined its interaction with Zn(II) ions in aqueous solution using carbon-13 nmr techniques. Variations in carbon chemical shifts and spin–lattice relaxation times (T1's) as a function of pH and increments of added Zn(II) were used to delineate sites of Zn(II):peptide interactions. Trends in T1 values indicated that local motions of several of the tripeptide carbons were restricted by an induced order accompanying metal binding. Analysis of spectral data suggested that Zn(II) is coordinated to the His imidazole nitrogen atom and the Asp β-carboxylate oxygen atom(s) in each peptide molecule. Similar experiments using a tripeptide analogue, Gly-Gly-His-N-methylamide, demonstrated that in the absence of a side chain carboxylate group, Zn(II) ions will complex the peptide through the His imidazole group and the N-terminal Gly α-amino group. These results support the possibility of a biologically functional role for the Asp-X-His triad as a liganding template for Zn(II)/protein binding.

II. Lokalisation der Placenta mit 113Inm- Human-Serum-Albumin

1969 ◽  
Vol 08 (01) ◽  
pp. 15-21 ◽  
Author(s):  
K. E. Scheer ◽  
J. Heep ◽  
W. Maier-Borst ◽  
W. J. Lorenz ◽  
H. Sinn ◽  
...  
Keyword(s):  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Vena Cava ◽  
Placenta Praevia ◽  
Wird Eine

ZusammenfassungNach tierexperimentellen Voruntersuchungen wurde die Placentographie mit trägerfreiem 113Inm -HSA als klinische Methode eingeführt. Vor Amniocentesen und bei Verdacht auf Placenta praevia werden Placentographien geschrieben. Den Schwangeren wird eine Aktivität von 500 μCi in die Cubitalvene injiziert. Die der Aktivität entsprechende Indiummenge ist kleiner als 0,1 ng. Die fetale Strahlenbelastung liegt unter lOmrad. Bei Anwendung von 113Inm-HSA entfällt eine Blockade der mütterlichen und fetalen Schilddrüsen. Die genaue Abgrenzung einer Placenta praevia wird nicht durch eine Blasenaktivität beeinträchtigt.Es wurden bisher 19 Placentalokalisationen durchgeführt. In allen Fällen konnte der Placentasitz eindeutig festgestellt werden. Bedingt durch die lange Liegezeit beim Aufnehmen eines Szintigramms kam es in zwei Fällen zu einem Vena-Cava-Kompressions-Syndrom. Zur Verhinderung dieser klinischen Zwischenfälle werden inzwischen Placentographien mit der Anger-Kamera aufgenommen. Mit Hilfe des divergierenden Kollimators konnte der gesamte Abdominalbereich erfaßt werden. Die Aufnahmezeit konnte auf 7 — 10 Minuten verkürzt werden. Die intravenöse injizierte Aktivität betrug bei dieser Methode ebenfalls 500 μCi. Der diagnostische Aussagewert der Kamerabilder ist szintigraphischen Aufnahmen gleichwertig.

Sign in / Sign up

Export Citation Format

Share Document