Cr-EDTA

Intestinal inflammation was assessed by fecal excretion of " In-labeled neutrophils while blood loss was quantitated via fecal excretion of 51Cr4abeled red cells. The urinary excretion ratio or51 Cr-EDTA//.-rhamnose was used as an index of intestinal permeability. ... 

For instance, Cr(III) ions may coexist with Co(II) and Cu(II) ions in a complex sample. The latter two ions may produce CL emission under similar conditions as for Cr(III). Fortunately, the formation rate of the Cr-EDTA complex is relatively slower, making possible the selective determination of this metal ion in waste water [8], urine, blood, and hair [9], Owing to the small number of CL reagents explored in recent years, the elements covered by CL techniques are still rather limited. Up to now only a few elements have been found to produce direct CL emission when reacted with CL reagents. Most of the publications so far involve indirect methods for the detection of elements. 

Chromium(II) is a very effective and important reducing agent that has played a significant and historical role in the development of redox mechanisms (Chap. 5). It has a facile ability to take part in inner-sphere redox reactions (Prob. 9). The coordinated water of Cr(II) is easily replaced by the potential bridging group of the oxidant, and after intramolecular electron transfer, the Cr(III) carries the bridging group away with it and as it is an inert product, it can be easily identified. There have been many studies of the interaction of Cr(II) with Co(III) complexes (Tables 2.6 and 5.7) and with Cr(III) complexes (Table 5.8). Only a few reductions by Cr(II) are outer-sphere (Table 5.7). By contrast, Cr(edta) Ref. 69 and Cr(bpy)3 are very effective outer-sphere reductants (Table 5.7). 

Chromiain(ii) Complexes.—The oxidation of chromium(ii) in alkaline solution has been studied polarographically and the reaction shown to be irreversible with = — 1.65 V vs. S.C.E. In the presence of nitrilotriacetic acid, salicylate, ethylenediamine, and edta the values were determined as —1.075, —1.33, — 1.38, and —1.48 V, respectively. The production of [Cr(edta)NO] from [Cr (edta)H20] and NO, NOJ, or NO2 suggests that this complex is able to react via an inner-sphere mechanism in its redox reactions. ... 

The structure of [Cr(edta)] 1- in aqueous solution is still under active investigation. Two series of salts can be isolated Rb+ (92) or K[Cr(edta)] 2H20 with N204 hexadentate coordination in the solid state (93), and [Cr(Hedta)(OH2)] (94, 95) with one G-ring dechelated and protonated. The system is very labile (rechelation rates exceed stopped-flow measurement), and several acid-base equilibria are involved (Fig. 14). 

Starting with [Cr(Hedta)(OH2)], alkalimetric titration gives pK as 2.10 (97), and from [Cr(edta)], a similar titration gives pK = 7.42 (98). The questions under debate are (i) what is the coordination number of the edta ligand bound to Cr(III) in the pH range 4-7, and (ii) if the ligand is hexadentate, can a seventh position in the inner coordination sphere be occupied by a water molecule The latter proposal is not unreasonable, as 7-coordination is observed in the solid-state hexaden-... 

Substitution is at the MoVI centre with retention of the Co—O bond. The first-order [H+]-dependent term is consistent with [HMo04] as a reactant, and the [H+]-independent term is assigned to the reaction of [HM0O4]- with [Co(NH3)50H]2+. An interesting situation arises in the reaction of [M0O4]2- with [Cr(edta)(H20)] at pH7.3-8.7.184 As in the case of... 

The kinetics of reactions of M0O4- leading to the binuclear complexes Co(NH3)5OMo03 and Cr(edta)OMo03- have been studied around pH = 7.55 Interestingly, the reaction mechanisms for the formation of these two species differ. The Co complex is formed by equation (4)... 

Ciesla P, Karocki A, Stasicka Z. Photoredox behaviour of the Cr-EDTA complex and its environmental aspects. J Photochem Photobiol A Chem 2004 162 537 14. 

DNA sequence The nucleotide sequence data are available from the EMBL, GenBank, and DDBJ Nucleotide Sequence Databases under accession number X52255 Half-life About 20 min (experimentally determined for human cystatin C in rat plasma. The similarity in distribution volume and renal clearance between human cystatin C and acknowledged markers of human glomerular filtration, i.e., iohexol and 51 Cr-EDTA, suggests that the substances are eliminated at the same rate in humans with a half-life of approximately 2 h in individuals with normal renal function)... 

Fig. 7. Renal plasma clearance of 125I-cystatin C (Ccy) compared to that of 51 Cr-EDTA (Cq-—edta) in rats with normal glomerular filtration ( ), and in rats with renal blood flow reduced to 25-50% of control by constricting the aorta above the renal arteries (o). The clearance measurements were completed 2.5-6.0 min after tracer injection. Ccy = 0.944 x Ccr-EDTA f = 0.989.

However, it is still debatable which method most accurately predicts individual values of glomerular filtration rate or creatinine clearance. Whereas the Cr-EDTA method is the most accurate method of estimating... 

Ultra-high-dose carboplatin can be safely administered as long as clinicians individualize and adjust the therapy to renal function using Cr-EDTA glomerular filtration rate there was only one death attributed to carboplatin in 31 patients who died of acute renal insufficiency (226). 

The use of hypertonic saline was first introduced in the clinic by Schilsky et al. [19] who concluded than when 3% saline was used as a vehicle for cisplatin, no renal toxicity was observed as measured by serum creatinine and creatinine clearance in patients treated with a high dose of cisplatin. However, when Cr-EDTA was used as a measure of glomerular filtration rate, a significant decrease in the latter was observed despite the use of 3% saline [12,13]. Thus the interest of hypertonic saline in the prevention of high dose cisplatin nephrotoxicity will have to be further delineated... 

Radiopharmaceuticals that have been used include (1) Cr-(2) Tc-diethylenetriaminepentaacetic acid (DTPA), and (3) I-iothalamate. Cr-EDTA is preferred to 99mgamma camera imaging. T-iothalamate is no longer approved for intravascular use in some countries. GFR measurements may be based on either the urinary or plasma clearance of the marker. To ensure accuracy when measuring GFR using urinary clearance methods it is essential that (1) renal... 

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