Diagnostic validity of the MINI-KID disorder classifications in specialized child and adolescent psychiatric outpatient clinics in Sweden.

BACKGROUND: Missing diagnostic information often results poor accuracy of the clinical diagnostic decision process. The Mini International Neuropsychiatric Interview for Children and Adolescents (MINI-KID) is a short standardized diagnostic interview and covers a rather broad range of diagnoses applicable to children and adolescents. MINI-KID disorder classifications have shown test-retest reliability and validity comparable to other standardized diagnostic interviews and is claimed to be a useful tool for diagnostic screening in Child and Adolescent Psychiatric care. The concordance between the Swedish language version of the MINI-KID Interview and LEAD (Longitudinal, Expert, All Data) research diagnoses was studied in secondary child and adolescent psychiatric outpatient care. METHODS: MINI-KID interviews were performed for 101 patients, boys n = 50, girls n = 51, aged 4 to 18 years. The duration of the interview was on average 46 min, the child/adolescent participating together with the parent(s) in most cases. The seven most prevalent diagnoses were included in the analyses. RESULTS: The average overall percent agreement (OPA) between MINI-KID and LEAD was 79.5%, the average percent positive agreement (PPA) 35.4 and the average percent negative agreement (NPA) 92.7. OPA was highest for Obsessive-Compulsive Disorder (OCD) (0.89), Tic disorders (0.88) and Pervasive developmental disorders (0.81). There were similar results in diagnostic agreement comparing the two versions: the standard MINI-KID and MINI-KID for parents. The specific screening questions in MINI-KID resulted in additional preliminary diagnoses compared with the regular initial clinical assessment. CONCLUSIONS: Overall, there was an acceptable agreement between MINI-KID disorder classifications and research diagnoses according to LEAD. The standardized interview MINI-KID could be considered as a tool with the possibility to give valuable information in the diagnostic process in child and adolescent care which is similar to the setting in the present study.

Bioactivation of sitaxentan in liver microsomes, hepatocytes, and expressed human P450s with characterization of the glutathione conjugate by liquid chromatography tandem mass spectrometry.

Sitaxentan is a selective endothelin-A receptor antagonist that was marketed as Thelin in several European countries and Canada for pulmonary arterial hypertension. Sitaxentan was undergoing further clinical trials in the United States but due to four deaths and one case of liver transplantation from severe liver toxicity that appeared to be idiosyncratic in nature, it was withdrawn worldwide in December, 2010. Sitaxentan contains a 1,3-benzodioxole ring that undergoes enzymatic demethyleneation to an ortho-catechol metabolite that can further oxidize to a reactive ortho-quinone metabolite. Here, we report the detection and mass spectral characterization of a glutathione conjugate of this sitaxentan quinone reactive metabolite that was trapped in vitro using mouse, rat, dog, and human liver microsomes supplemented with NADPH and glutathione and that was also observed in rat and human hepatocytes. Using human liver microsomes, we also demonstrated that P450 3A4 undergoes time-dependent inhibition. Density functional calculations on the catechol metabolite of sitaxentan indicated that the reaction leading to the quinone was thermodynamically favorable with an enthalpy change of -6.3 kcal/mol. Using density functional methodology, we modeled the attack of glutathione on the quinone with an S-methyl thiolate anion which allowed us to predict, based on the difference in transition state energies, that the 2-position on the phenyl ring was more likely than the 5-position as the site of glutathione conjugation. Overall, our results demonstrated that sitaxentan is capable of facile formation of a reactive ortho-quinone metabolite capable of reacting with glutathione and may rationalize the idiosyncratic nature of the hepatotoxicity that led to its withdrawal.

A pragmatic approach using first-principle methods to address site of metabolism with implications for reactive metabolite formation.

A majority of xenobiotics are metabolized by cytochrome P450 (CYP) enzymes. The discovery of drug candidates with low propensity to form reactive metabolites and low clearance can be facilitated by understanding CYP-mediated xenobiotic metabolism. Being able to predict the sites where reactive metabolites form is beneficial in drug design to produce drug candidates free of reactive metabolite issues. Herein, we report a pragmatic protocol using first-principle density functional theory (DFT) calculations for predicting sites of epoxidation and hydroxylation of aromatic substrates mediated by CYP. The method is based on the relative stabilities of the CYP-substrate intermediates or the substrate epoxides. Consequently, it concerns mainly the electronic reactivity of the substrates. Comparing to the experimental findings, the presented protocol gave excellent first-ranked epoxidation site predictions of 83%, and when the test was extended to CYP-mediated sites of aromatic hydroxylation, satisfactory results were also obtained (73%). This indicates that our assumptions are valid and also implies that the intrinsic reactivities of the substrates are in general more important than their binding poses in proteins, although the protocol may benefit from the addition of docking information.

Efficient chemoenzymatic dynamic kinetic resolution of 1-heteroaryl ethanols.

The scope and limitation of the combined ruthenium-lipase induced dynamic kinetic resolution (DKR) through O-acetylation of racemic heteroaromatic secondary alcohols, i.e., 1-heteroaryl substituted ethanols, was investigated. After initial screening of reaction conditions, Candida antarctica lipase B (Novozyme 435, N435) together with 4-chloro-phenylacetate as acetyl-donor for kinetic resolution (KR), in conjunction with the ruthenium-based Shvo catalyst for substrate racemization in toluene at 80 degrees C, enabled DKR with high yields and stereoselectivity of various 1-heteroaryl ethanols, such as oxadiazoles, isoxazoles, 1H-pyrazole, or 1H-imidazole. In addition, DFT calculations based on a simplified catalyst complex model for the catalytic (de)hydrogenation step are in agreement with the previously reported outer sphere mechanism. These results support the further understanding of the mechanistic aspects behind the difference in reactivity of 1-heteroaryl substituted ethanols in comparison to reference substrates, as often referred to in the literature.

ProSAR: a new methodology for combinatorial library design.

A method is introduced for performing reagent selection for chemical library design based on topological (2D) pharmacophore fingerprints. Optimal reagent selection is achieved by optimizing the Shannon entropy of the 2D pharmacophore distribution for the reagent set. The method, termed ProSAR, is therefore expected to enumerate compounds that could serve as a good starting point for deriving a structure activity relationship (SAR) in combinatorial library design. This methodology is exemplified by library design examples where the active compounds were already known. The results show that most of the pharmacophores on the substituents for the active compounds are covered by the designed library. This strategy is further expanded to include product property profiles for aqueous solubility, hERG risk assessment, etc. in the optimization process so that the reagent pharmacophore diversity and the product property profile are optimized simultaneously via a genetic algorithm. This strategy is applied to a two-dimensional library design example and compared with libraries designed by a diversity based strategy which minimizes the average ensemble Tanimoto similarity. Our results show that by using the PSAR methodology, libraries can be designed with simultaneously good pharmacophore coverage and product property profile.

Structure-interaction relationships between the bile acid GCA and pharmaceuticals using multivariate data analysis and capillary electrophoresis.

Capillary electrophoresis (CE) has been used in an interaction study of 66 pharmaceutical compounds with the bile acid glycocholate (GCA). The developed method proved to have a high precision in its ability to determine the mobility of drugs in buffer and buffer bile acids solutions. The relationship between solute structure and interaction with GCA was studied using two-dimensional descriptors with the in-house software SELMA and a three-dimensional model (quantum mechanical descriptors) in combination with the experimental CE-interaction data. The multivariate analysis method used was projection to latent structures by means of partial least squares (PLS). Two selections of training and test set were used for evaluation of a two-class model on interaction data. In the first selection all observations were used for training set, for example, creating a model, and re-predicting the observations on the model. A successful prediction on 85% of the drugs was observed using this model. The second selection used the 21 first tested compounds in the training set, where 78% of the compounds were correctly predicted using the two-dimensional model (SELMA) on the remaining 45 compounds and, respectively, 82% using the three-dimensional (quantum mechanical) model. Analysis of the impact of the descriptors showed that descriptors relating to hydrophobicity have a large positive effect on the interaction. Descriptors relating to polar properties have a pronounced negative effect on the interaction of drugs with bile acids.

Characterization of glutathione conjugates of the remoxipride hydroquinone metabolite NCQ-344 formed in vitro and detection following oxidation by human neutrophils.

Remoxipride is an atypical antipsychotic displaying selective binding to the dopamine D2 receptor. Several cases of aplastic anemia led to the withdrawal of remoxipride from the market in December 1993. The remoxipride metabolite NCQ-344 is a hydroquinone while the structural isomer NCQ-436 is a catechol, both of which have been suggested to be capable of forming a reactive para- and ortho-quinone, respectively. Recently, these two remoxipride metabolites were shown to induce apoptosis in human bone marrow progenitor cells. Furthermore, NCQ-344 also caused necrosis of these cells unlike NCQ-436. Although NCQ-344 has been detected in plasma of humans dosed with remoxipride, to date, no experimental evidence for the formation of the corresponding para-quinone has been obtained. Here, we report the detection of three glutathione (GSH) conjugates of NCQ-344 in vitro that were formed following a chemical reaction and characterized by tandem mass spectrometry and for a cyclized conjugate additionally with derivatization and deuterium exchange. In contrast, NCQ-436 did not form a GSH conjugate. Hypochlorous acid oxidized NCQ-344 to the para-quinone while NCQ-436 was resistant to oxidation. Upon incubation with NCQ-344, stimulated human neutrophils produced from 2- to 5-fold greater amounts of glutathione conjugates than unstimulated neutrophils. Ab initio calculations on these remoxipride metabolites indicated that the reaction leading to the respective quinone was spontaneous for the para-quinone (e.g., from NCQ-344) while ortho-quinone (e.g., from NCQ-436) formation was not. These results demonstrate that NCQ-344 is capable of facile formation of a reactive para-quinone capable of reacting with GSH and may rationalize previous findings regarding the biological effects observed in vitro with these two remoxipride metabolites.