Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0036341 (schizophrenia)
 60,220 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Patients display significant differences in response to therapeutic agents which may be caused by a variety of factors. Among them, genetic components presumably play a major role. Pharmacogenetics is the field of research that attempts to unravel the relationship between genetic variation affecting drug metabolism (pharmacokinetic level) or drug targets (pharmacodynamic level) and interindividual differences in pharmacoresponse. In schizophrenia, pharmacokinetic studies have shown the role of genetic variants of the cytochrome P450 enzymes CYP2D6, CYP2C19, and CYP2C9 in the metabolism of neuroleptic drugs. At the level of the drug target, variants of the dopamine D3 and D4, and 5-HT2A and 5-HT2C receptors have been examined. A general problem of pharmacogenetic studies in schizophrenia is the high number of controversial findings which may be related to the lack of standardized phenotype definition. Recently, guidelines for an exact and comparable phenotype characterization have been proposed and will aid in designing and evaluating pharmacogenetic studies in the future. The final goal of pharmacogenetic studies-making a prediction of drug response at the level of the individual patient-will require a simultaneous look at a large number of response-determining genetic variants by applying the tools of pharmacogenomics, e.g. large-scale Single Nucleotide Polymorphism (SNP) detection and genotyping.
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PMID:Pharmacogenetics of schizophrenia. 1081 9

Given globalization trends in the conduct of clinical trials, the external validity of trial results across geographic regions is questioned. The objective of this study was to examine the efficacy of treatment in acute mania in bipolar disorder across regions and to explain potential differences by differences in patient characteristics. We performed a meta-analysis of individual patient data from 12 registration studies for the indication acute manic episode of bipolar disorder. Patients (n = 3207) were classified into one of three geographic regions: Europe (n = 981), USA (n = 1270), and other regions (n = 956). Primary outcome measures were mean symptom change score on the Young Mania Rating Scale (YMRS) from baseline to endpoint and responder status (50% improvement form baseline). Effect sizes were significantly smaller in the USA (g = 0.203, 95% confidence interval (CI) 0.062-0.344; odds ratio (OR) 1.406, 95% CI 0.998-1.980) than in Europe (g = 0.476, 95% CI 0.200-0.672; OR 2.380, 95% CI 1.682-3.368) or other regions (g = 0.533, 95% CI 0.399-0.667; OR 2.300, 95% CI 1.800-2.941). Regional differences in age, gender, initial severity, body mass index, placebo response, discontinuation rate, and type of compound could not explain the geographic differences in effect. Less severe symptoms at baseline in the US patients did explain some of the difference in responder status between patients in Europe and the USA. These findings suggest that the results of studies involving patients with acute mania cannot be extrapolated across geographic regions. Similar findings have been identified in schizophrenia, contraceptive, and in cardiovascular trials. Therefore, this finding may indicate a more general problem regarding the generalizability of pharmacological trials over geographic regions.
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PMID:Efficacy of drug treatment for acute mania differs across geographic regions: An individual patient data meta-analysis of placebo-controlled studies. 2603 9

Dysbindin-1 is implicated in several aspects of schizophrenia, including cognition and both glutamatergic and dopaminergic neurotransmission. Targeted knockout of dysbindin-1A (Dys-1A KO), the most abundant and widely expressed isoform in the brain, is associated with deficits in delay/interference-dependent working memory. Using an ethologically based approach, the following behavioural phenotypes were examined in Dys-1A KO mice: exploratory activity, social interaction, anxiety and problem-solving ability. Levels of monoamines and their metabolites were measured in striatum, hippocampus and prefrontal cortex using high-performance liquid chromatography with electrochemical detection. The ethogram of initial exploration in Dys-1A KO mice was characterised by increased rearing from a seated position; over subsequent habituation, stillness was decreased relative to wildtype. In a test of dyadic social interaction with an unfamiliar conspecific in a novel environment, female KO mice showed an increase in investigative social behaviours. Marble burying behaviour was unchanged. Using the puzzle-box test to measure general problem-solving performance, no effect of genotype was observed across nine trials of increasing complexity. Dys-1A KO demonstrated lower levels of 5-HT in ratio to its metabolite 5-HIAA in the prefrontal cortex. These studies elaborate the behavioural and neurochemical phenotype of Dys-1A KO mice, revealing subtle genotype-related differences in non-social and social exploratory behaviours and habituation of exploration in a novel environment, as well as changes in 5-HT activity in brain areas related to schizophrenia.
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PMID:Ethologically based behavioural and neurochemical characterisation of mice with isoform-specific loss of dysbindin-1A in the context of schizophrenia. 3261 48