Div. Clin. Biochem., Dept. of Ped. Lab. Med. Hospital for Sick Children, University of Toronto, Toronto.

Div. Clin. Biochem., Dept. of Ped. Lab. Med. Hospital for Sick Children, University of Toronto, Toronto.

Division of Clin. Biochem., Dept.of Ped. Lab. Med., Hosp. For Sick Children, University of Toronto.

OBJECTIVE:To evaluate glycine conjugation of para-aminobenzoic acid (PABA) to the hippurated metabolites, para-aminohippuric acid (PAHA), and para-acetamidohippuric acid (PAAHA) as a quantitative liver function test in patients with liver disease.DESIGN AND METHODS:Serum concentrations of PABA and metabolites were measured by high pressure liquid chromatography in 24 controls and 50 patients with hepatobiliary disease.RESULTS:Hippurate formation was significantly decreased in all patient groups with chronic liver disease versus controls. The hippurate ratio (% hippurated metabolites formed) correlated with severity of disease, serum albumin, and factor VII concentrations. PAHA concentration was a better prognostic indicator than factor VII concentrations in patients with acute liver disease; concentrations of zero correctly predicted a poor outcome in patients with fulminant liver failure.CONCLUSIONS:Glycine conjugation of PABA may be useful as a quantitative liver function test in patients with hepatobiliary disease and as a prognostic index in patients with fulminant liver failure.

s Third International Congress of Therapeutic Drug Monitoring and Clinical Toxicology: PDF Only

s Third International Congress of Therapeutic Drug Monitoring and Clinical Toxicology: PDF Only

Near-UV-visible range photolysis of cis-Ru(II)(NH3)4(L)2 (L = pyridine (py), 4-picoline (4-pic), isonicotinamide (isn), or 4-acetylpyridine (4-acpy)) and cis-Ru(II)(NH3)4(isn)(L) (L = py, 4-pic, pyrazine, or 4-acpy) leads to isn, L, and ammonia aquation. The complexes were irradiated at 313, 365, 405, 436, 480, and 519 nm, in acidic (pH 3.5-4.0) aqueous solution and with approximately 10(-3) M Ru complex concentration. The cis complexes have ligand field (LF) and metal-to-ligand charge-transfer (MLCT) states as the lowest energy excited states. The relative yields of the photoreactions of the cis complexes show patterns consistent with the excited-state "tuning" model proposed to explain photochemical properties of the pentaammine analogues, Ru(II)(NH3)5(L), which undergo photosubstitution when LF is the lowest energy excited state, as is also the case for the trans complexes. For each cis complex, a fixed ratio of released ligands is observed at all irradiation wavelengths studied, this being a strong evidence that the observed photoreactions occur from one single LF excited state, or an ensemble of equilibrated LF excited states of the same electronic configuration. Ligands are more easily labilized along the axis with the weaker pi-acceptor ability. For a particular axis, the ligand with lower pi-acceptor ability is more easily labilized.

The present study has examined the cross-reactivity of fatty acids and mono- and di-glycerides in the fluorescence polarization immunoassay for digoxin. The ability of these compounds to inhibit 86Rb uptake by the erythrocyte as well as their ability to displace 3H-ouabain from membrane-bound dog kidney ATP-ase was also assessed. Some unsaturated fatty acids (palmitoleic, palmitelaidic, oleic, linoleic, linolelaidic, linolenic, gamma-linolenic and arachidonic) were found to cross-react significantly in the digoxin immunoassay and to inhibit 3H-ouabain binding to membrane-bound Na+/K+-ATPase. Of the monoglycerides studied mono-11-eicosenoin was found to cross-react in the digoxin immunoassay, inhibit red cell 86Rb uptake and displace 3H-ouabain from its receptor, membrane-bound Na+/K+-ATPase. Two other monoglycerides, 1-monolinoleoyl and 1-monolinolenoyl glycerides, were able to displace 3H-ouabain from membrane-bound Na+/K+-ATPase, but had no effect on the digoxin immunoassay or on red cell 86Rb uptake.

Benzotriazole reacts with the aquapentacyanoferrate(II) complex, at pH 4.5, producing a mixture of N-coordinated isomers. Characterization based on 1H and 13C nmr spectroscopy yielded an equilibrium constant K = 1.9 ± 0.3, favoring the less symmetric N1-isomer. Two reversible peaks of oxidation, corresponding to the N1 and N2 isomers, were observed in the cyclic voltammograms at high scan rates, with E1/2 = 0.43 and 0.53 V versus NHE, respectively. The cyclic voltammograms at intermediate scan rates were successfully analysed in terms of an isomerization reaction preceding reversible charge-transfer. The kinetic constants of isomerization, kf and kb, were 1.5 and 0.65 s−1, respectively. The limiting dissociative rates, k−L = 5.3 × 10−3 s−1, measured in the presence of dimethyl sulfoxide, support an intramolecular mechanism for the isomerization reaction.

In the search for evidence of precursor complexes in electron transfer reactions, a binuclear intermediate was detected in the system pentaammine(dimethylsulfoxide)cobalt(III) and aquopentacyanoferrate(II). Cyclic voltammetry measurements and careful analysis of the products indicated that the formation of a sulfuriron bond stabilizes the intermediate with respect to electron transfer reaction. Interpretation of the kinetics data is consistent to the formation of an outer sphere complex (K = 350 M−1) which undergoes internal substitution (k = 20 s−1 to yield the dimethyl sulfoxide bridged intermediate. The binuclear intermediate aquates by breaking the cobalt(III)sulfoxide bond, with a specific rate of 0.106 s−1. ΔH+ = 20 Kcal mol−1 and ΔS≠ = 4 cal mol−1 deg−1, at 25 °C and μ = 0.10 M (lithium perchlorate).

A number of new complexes containing the potentially tridentate ligand 2,2′-sulfinyldiethanol (sde) is reported. The compounds have the general formula M(sde)n (ClO4)2, in which M = Mn, Co, Ni, Cu, Zn (n = 2) and Fe, Co, Ni, Zn (n = 3). They are characterized and identified by chemical analysis and physical measurements. The compounds have effective magnetic moment values typical of high-spin octahedral complexes. Their i.r. and electronic spectra are discussed. Assignments for the electronic spectra are suggested on the basis of octahedral structure and ligand-field parameters are calculated for nickel and cobalt complexes. The results obtained in this work suggest that sde acts as a tridentate ligand in the 1:2 complexes and as a bidentate one in the 1:3 complexes.