The relevance of therapeutic drug monitoring in plasma and erythrocytes in anti-cancer drug treatment.

Therapeutic drug monitoring generally focuses on the plasma compartment only. Differentiation between the total plasma concentration and the free fraction (plasma water) has been described for a number of limited drugs. Besides the plasma compartment, blood has also a cellular fraction which has by far the largest theoretical surface and volume for drug transport. It is with anti-cancer drugs that major progress has been made in the study of partition between the largest cellular blood compartment, i.e., erythrocytes, and the plasma compartment. The aim of the present review is to detail the progress made in predicting what a drug does in the body, i.e., pharmacodynamics including toxicity and plasma and/or red blood cell concentration monitoring. Furthermore, techniques generally used in anti-cancer drug monitoring are highlighted. Data for complex Bayesian statistical approaches and population kinetics studies are beyond the scope of this review, since this is generally limited to the plasma compartment only.     

Syntheses of Novel Pyridazinomorphinans by Inverse Electron Demand Cycloaddition and their Binding to μ and κ Receptors

A number of novel pyridazinomorphinans have been synthesized by the inverse electron demand Diels-Alder reaction of various 3,6-disubstituted 1,2,4,5-tetrazines with enamines derived from dihydrocodeinone and with codeinone. Reduction of some of the pyridazinomorphinans did not furnish the expected pyrroloepoxymorphinans; in all cases investigated reductive cleavage of the epoxybridge was observed to yield dihydropyridazino- or pyrrolomorphinans. The structures of all new compounds were assigned by the spectral data, that of the cycloadduct of codeinone was additionally verified by X-ray crystallography. Compounds 5a, 8, 11a , and 16 have been evaluated for their affinity at μ and κ opioid receptors in radioligand binding assays. Their ability to inhibit [³H]DAMGO binding at μ and [³H]U 69.593 binding at κ receptors, respectively as compared to codeine has been found to be lower.     

Toxicity of 2,3,7,8-tetrabromodibenzo-p-dioxin in rats after single oral administration.

Five male and female rats per dose-group received 2,3,7,8-tetrabromodibenzo-p-dioxin (2,3,7,8-TBDD) once on the first day of the study. Doses of 10, 33, 100, or 300 micrograms 2,3,7,8-TBDD/kg body wt. and the vehicle control were administered by gavage. About 20% of 2,3,7,8-TBDD was excreted via feces. Severe body weight retardation was observed in the 100 and 300 micrograms/kg dose-groups. Most animals in the 300 micrograms/kg dose-group and the females receiving 100 micrograms/kg showed emaciation, rough coat and a poor health (wasting syndrome). Of the animals dosed with 300 micrograms/kg, 3 males and all females died. After 100 micrograms 2,3,7,8-TBDD/kg 3 females died. Measured 4 weeks after dosing, triiodothyronine (T3) was increased and thyroxin (T4) was reduced dose dependently in serum. A dose-dependent decrease in thymus weights was observed at necropsy and histological examinations showed that thymus and spleen were depleted of mature lymphocytes. An increase in liver-to-body weight ratio was observed in all dose-groups. The histological examination revealed hypertrophy of centrilobular hepatocytes in the liver of animals treated with 100 micrograms/kg, which was less severe at the 33 micrograms/kg dose. Hypertrophic hepatocytes were also detected in some animals at the lowest dose. Induction of enzyme activities of the mixed function oxidases ethoxycoumarin O-deethylase (ECOD), ethoxyresorufin O-deethylase (EROD) and aryl hydrocarbon hydroxylase (AHH) in liver tissue differed for each of the three enzymes. Two days after administration, enzyme activities were increased but did not differ substantially between dose-groups. Twenty-eight days after dosing the increase in activity after 10 micrograms/kg was largest and the EROD of the 100 micrograms/kg dose-group in females was close to that of the control. This inverse dose-response relationship may be due to impaired liver cell function at higher doses.     

The HemoCue®, a point of care B-hemoglobin photometer, measures hemoglobin concentrations accurately when mixedin vitro with canine plasma and three hemoglobin-based oxygen carriers (HBOC)

PURPOSE: Accuracy of measurement of low hemoglobin concentrations using the HemoCue, a B-hemoglobin photometer (HemoCue AB, Angelholm, Sweden) may exhibit significant variability. Infusion of hemoglobin-based oxygen carriers (HBOC) results in low concentrations of plasma hemoglobin. Our study assessed B-hemoglobin photometer measurement accuracy of three HBOC: (hemoglobin glutamer-200 (bovine; Oxyglobin, Biopure Corp., Cambridge, MA, USA); hemoglobin glutamer-250 (bovine; Hemopure, Biopure Corp, Cambridge, MA, USA), and hemoglobin-raffimer, (human; Hemolink, Hemosol, Inc., Toronto, Ontario, Canada). METHODS: In the laboratory, 45 split canine plasma samples were mixed with hemoglobin glutamer-200 (8.13, 16.25, 32.5 g x L(-1) concentrations), 45 samples were mixed with hemoglobin glutamer-250 (8.13, 16.25, 32.5 g x L(-1) concentrations), 45 with hemoglobin-raffimer (12.5, 25.0, 50.0 g x L(-1) concentrations), and measured. Plasma samples without HBOC served as control. Hemoglobin concentration was determined by a laboratory analyzer (Coulter Corporation, Hiafeah, FL, USA) and B-hemoglobin photometer (HemoCue, Angelholm, Sweden). Two independent technicians performed blinded sample measurements and randomly tested each sample five times. Results were analyzed according to Bland and Altman analysis. RESULTS: B-hemoglobin photometer demonstrated high repeatability for all three HBOCs. Repeatability coefficients were 0.37 g x L(-1) and 0.48 g x L(-1) for hemoglobin glutamer-200, 0.39 g x L(-1) and 0.4 g x L(-1) for hemoglobin glutamer-250 and 1.07 g x L(-1) and 0.85 g x L(-1) for hemoglobin-raffimer. An acceptable agreement was found between the B-hemoglobin photometer and the laboratory analyzer for all three HBOCs tested. CONCLUSION: The B-hemoglobin photometer accurately determined the concentration of three HBOC solutions dissolved in canine plasma.     

Modification of hemorheologic parameters by beta-receptor blockers with special reference to propranolol and talinolol

There are no systematic and complex investigations regarding the hemorheologic action of the betablockers propranolol and talinolol. The results on the other ones are contradictory. On the basis of a critical survey of the literature, in-vitro-experiments and studies in animals (rats) and humans may conclude that there are no remarkable deteriorations of rheological parameters in the therapeutic dose range. This is valid for diseases only where the haemodynamic regulation doesn't prevail.     

The internal anatomy of the median nerve in the region of the elbow.

The internal anatomy of the median nerve in the region of the elbow has been studied by microdissection in 20 cadavers. Gross branching patterns were studied in an additional 14 cadavers. There are four major branches or branch groups: I to pronator teres, II to flexor carpi radialis, flexor digitorum superficialis, and palmaris longus; III to the anterior interosseous nerve; and IV to flexor digitorum superficialis. Three of these could be traced proximally within the main trunk of the median nerve, the average being I-10 cm; III-7.5 cm; IV-2 cm. This information should have clinical applications in repair and grafting of the median nerve near the elbow and in understanding clinical nerve compression sydromes.     

Azulene als Dienophile in der [4+2]-Cycloaddition mit inversem Elektronenbedarf,eine Ergänzung

Azulenes as Dienophiles in the [4+2]-Cycloaddition with Inverse Electron Demand, a Supplement [4+2] Cycloadditions of azulene ( 2 ) und 1-Nitroazulene ( 14 ) with the extremely electron-deficient, s-cis-fixed diazadiene system of 3,6-bis(trifluoromethyl)-1,2,4,5-tetrazine ( 1 ) are described. In addition to earlier findings 1 reacts with 2 probably in a two step [4+2] cycloaddition via 8 and 10 to yield the benzo[f]phthalazine 5a , via 8 and 9 to furnish the azuleno[d]pyridazine 3 and the azine 4 . The reaction of 1 with 1-Nitroazulene ( 14 ) leads to the azuleno[d]pyridazines 3 and 19 in low yield.