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Gadolinium based contrast agents (GBCAs) were found to play a role in nephrogenic systemic fibrosis in patients with and without renal impairment. Therefore, preserving the structural stability of GBCAs to reduce their propensity to liberate Gd³⁺ is of utmost importance. This study evaluates the effect of gadolinium concentration of GBCAs on soluti...
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Context 1
... HnL is the protonated form of free ligands. Properties of some of the clinically used GBCAs are provided in Table 1. From this table, it can be clearly inferred that stability of GBCAs varies depending on their structure (macrocycle or linear/open-chain) and charge. ...Context 2
... total of 10mL preparation from each GBCA was transferred to cylindrical tubes, implemented to MRI device (Achieva, 3.0 T X-Series, Phillips Medical Systems, Best, The Netherlands), and their temperatures were measured using an MRI compatible thermocouple (Neoptix, Isha Surgical, Kamataka, India). These GBCAs are marketed at concentrations provided in Table 1, in preparations with predetermined concentrations to inject intravenously. ...Context 3
... stability constants for GBCAs used for correlation determination were taken from previous studies (Table 1). Specifically, the conditional stability constants (log K cond ) for Gadoteric acid meglumine, Gadobutrol, Gadoxetic acid disodium salt, Gadoversetamide, and Gadodiamide are 19.3, ...Context 4
... plasma, on the other hand, Gadoxetic acid disodium salt and Gadodiamide at concentrations between 0.6mMol/L and 2.4mMol/L will lead to local temperature increase (warming) when exposed to magnetic field with a magnitude of 3T. Based on stability constants of these two (Table 1), such a finding seems interesting because Gadoxetic acid disodium salt (K cond = 18.7) and Gadodiamide (K cond = 14.9) stand at the opposite edges of the scale of stability constants of GBCAs studied here. In any case, the effect of temperature variation on the behavior of tissue specific cell lineages should be studied because dissociation and accumulation of gadolinium in tissues could affect behavior of host cells as demonstrated in the case of enhanced procollagen type I and procollagen type III expression in human dermal fibroblasts due to temperature variations. ...Context 5
... this implies higher temperature of the solutions at the exit (warming). With reference to commercially available GBCAs, Gadodiamide and Gadoversetamide have lower stability constants, while Gadoteric acid meglumine and Gadobutrol possess higher stability constants (Table 1). Therefore, it is possible to claim,in the concentration range studied here, that when administered in or come into contact with plasma, Gadoteric acid meglumine and Gadobutrol can lead to increased local temperatures. ...Citations
... Arda et al. [135] Study of the competition between low molecular weight ligands (LMWLs) and the sensor FluoZin-3 for Zn(II) ions. Stability constants were determined by fluorescence titrations. ...
A free energy-based conceptual theoretical framework from which the conditional equilibrium constant can be comprehensibly understood is presented. This constant is found to be a weighted geometric mean of the equilibrium constants of the reactions of all forms of the conditioned species under buffering conditions, where the weight is given by a function of their predominance in terms of their mole fractions. Once it is shown that this type of equilibrium constant can be easily deduced form free energy functions, it is shown how corrections for activity coefficient can be incorporated as well. The framework additionally permits to interpret side-reactions coefficients as free energy terms related to the chemical speciation of the system, allowing the use of the generalization of Hess' law to obtain conditional constants and a straightforward deduction of multiconditional equilibrium constants. Furthermore, different uses of the conditional constants along the actual literature are reviewed as well allowing to have a complete and updated panorama of the employment of this important concept in chemical and speciation analysis in many areas of research.
Gadolinium-based contrast agents (GBCAs) exert effects in different regions of the brain; however, studies on this topic are mostly focused on radiological outcomes of GBCA exposure. This paper is a preliminary attempt to identify whether there are changes in behavioral, cognitive, histopathological, radiological and biochemical characteristics with repeated exposure to gadobutrol and gadoteric acid.
The effects of GBCAs were tested with the assessment of 4 groups –each comprised of 6 rats [controls, gadobutrol, gadoteric acid (Doteram), and gadoteric acid (Clariscan)]. Respective treatments of 0.1 ml/kg were administered for 3 weeks, followed by a recovery period of 1 week without any treatment. At the end of this regimen, behavioral tests (open field and passive learning test) were performed. Additionally, histopathological analysis of the hippocampal CA1 and CA3 regions (GFAP measurement and total neuron count), biochemical measurements [TNF-a, Malondialdehyde (MDA), Superoxide dismutase (SOD), homovalinic acid (HVA) and choline acetyl transferase (ChAT) levels], and radiological findings (MRI-region of interest) were carried out in each group.
There was a significant impairment in all groups that had received gadolinium in open field and passive avoidance learning tests. Oxidative stress and inflammation markers were significantly elevated in all gadolinium groups. Additionally, increased hippocampal gliosis and decreased MRI-ROIs were observed in rats exposed to gadolinium.
Chronic gadoteric acid and gadobutrol exposure causes hippocampal gliosis and elevates oxidative stress and inflammation in rats. Radiological outcomes are also consistent with these findings. Long-term studies might be required to conclude whether gadolinium deposition in the brain causes subtle neurological deficits.
