[Pharmacogenetics in psychiatry: state of the art]. / Pharmakogenetik in der Psychiatrie: eine Standortbestimmung.

In this article, the current literature on pharmacogenetics of antidepressants, antipsychotics and lithium are summarized by the section of Neurobiology and Genetics of the German Society of Psychiatry, Psychotherapy and Neurology (DGPPN). The publications of international expert groups and regulatory authorities are reviewed and discussed. In Germany, a statement on pharmacogenetics was also made by the gene diagnostics committee of the Ministry of Health. The DGPPN supports two recommendations: 1) to perform CYP2D6 genetic testing prior to prescription of tricyclic antidepressants and 2) to determine the HLA-B*1502 genotype in patients of Asian origin before using carbamazepine. The main obstacle for a broad application of pharmacogenetic tests in psychiatry remains the lack of large prospective studies, for both single gene-drug pair and cobinatorial pharmacogenetic tests, to evaluate the benefits of genetic testing. Psychiatrists, geneticists and funding agencies are encouraged to increase their efforts for the future benefit of psychiatric patients.

The role of the ITIH3 rs2535629 variant in antipsychotic response.

INTRODUCTION: There is mounting evidence that schizophrenia risk variants influence response to antipsychotic medication. Common single nucleotide polymorphisms (SNPs) in or near the inter-alpha-trypsin inhibitor heavy chain H3 (ITIH3) gene have been repeatedly associated with schizophrenia and related psychiatric disorders in genome-wide association studies. Here, we provide the first study to assess the relevance of the ITIH3 rs2535629 SNP in response to antipsychotic medication. METHODS: The rs2535629 SNP was genotyped in N=256 patients receiving various antipsychotics for up to 26weeks. Treatment response was assessed using the Brief Psychiatric Rating Scale (BPRS) including its positive and negative subscales. Follow-up analyses were performed after stratifying for ethnicity and medication. RESULTS: We found significant association of rs2535629 with improvement of negative symptoms in patients of European ancestry after six months of clozapine treatment (F1,87=8.8, pcorr=0.032). Patients homozygous for the minor A-allele showed the best improvement of negative BPRS scores. However, we observed no association between rs2535629 and changes in total BPRS score in the entire sample or the clozapine-treated subgroup. DISCUSSION: Although there was no association of genotype with overall changes in BPRS scores, the greater improvement of negative symptoms in minor allele carriers indicates that rs2535629 may help to identify a subset of schizophrenia patients with better treatment response to clozapine. Therefore, our findings provide the first suggestive evidence that rs2535629 is relevant in antipsychotic response.

Genome-wide association study on antipsychotic-induced weight gain in the CATIE sample.

Antipsychotic-induced weight gain (AIWG) is a common side effect with a high genetic contribution. We reanalyzed genome-wide association study (GWAS) data from the Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE) selecting a refined subset of patients most suitable for AIWG studies. The final GWAS was conducted in N=189 individuals. The top polymorphisms were analyzed in a second cohort of N=86 patients. None of the single-nucleotide polymorphisms was significant at the genome-wide threshold of 5x10(-8). We observed interesting trends for rs9346455 (P=6.49x10(-6)) upstream of OGFRL1, the intergenic variants rs7336345 (P=1.31 × 10(-5)) and rs1012650 (P=1.47 × 10(-5)), and rs1059778 (P=1.49x10(-5)) in IBA57. In the second cohort, rs9346455 showed significant association with AIWG (P=0.005). The combined meta-analysis P-value for rs9346455 was 1.09 × 10(-7). Our reanalysis of the CATIE GWAS data revealed interesting new variants associated with AIWG. As the functional relevance of these polymorphisms is yet to be determined, further studies are needed.The Pharmacogenomics Journal advance online publication, 1 September 2015; doi:10.1038/tpj.2015.59.

Influence of CYP2D6 and CYP2C19 gene variants on antidepressant response in obsessive-compulsive disorder.

Numerous studies have reported on pharmacogenetics of antidepressant response in depression. In contrast, little is known of response predictors in obsessive-compulsive disorder (OCD), a disorder with among the lowest proportion of responders to medication (40-60%). Our study is the largest investigation to date (N=184) of treatment response and side effects to antidepressants in OCD based on metabolizer status for CYP2D6 and CYP2C19. We observed significantly more failed medication trials in CYP2D6 non-extensive compared with extensive metabolizers (P=0.007). CYP2D6 metabolizer status was associated with side effects to venlafaxine (P=0.022). There were nonsignificant trends for association of CYP2D6 metabolizer status with response to fluoxetine (P=0.056) and of CYP2C19 metabolizer status with response to sertraline (P=0.064). Our study is the first to indicate that CYP genes may have a role in antidepressant response in OCD. More research is required for a future clinical application of genetic testing, which could lead to improved treatment outcomes.

The genome-wide supported microRNA-137 variant predicts phenotypic heterogeneity within schizophrenia.

We examined the influence of the genome-wide significant schizophrenia risk variant rs1625579 near the microRNA (miRNA)-137 (MIR137) gene on well-established sources of phenotypic variability in schizophrenia: age-at-onset of psychosis and brain structure. We found that the MIR137 risk genotype strongly predicts an earlier age-at-onset of psychosis across four independently collected samples of patients with schizophrenia (n=510; F1,506=17.7, P=3.1 × 10(-5)). In an imaging-genetics subsample that included additional matched controls (n=213), patients with schizophrenia who had the MIR137 risk genotype had reduced white matter integrity (F3,209=13.6, P=3.88 × 10(-8)) throughout the brain as well as smaller hippocampi and larger lateral ventricles; the brain structure of patients who were carriers of the protective allele was no different from healthy control subjects on these neuroimaging measures. Our findings suggest that MIR137 substantially influences variation in phenotypes that are thought to have an important role in clinical outcome and treatment response. Finally, the possible consequences of genetic risk factors may be distinct in patients with schizophrenia compared with healthy controls.

Association study of polymorphisms in leptin and leptin receptor genes with antipsychotic-induced body weight gain.

BACKGROUND: Antipsychotic-induced weight gain (AIWG) is a serious side-effect of antipsychotic medication leading to metabolic syndrome and increased cardiovascular morbidity. Unfortunately, there are still no valid predictors to assess an individual's risk to gain weight. Previous studies have indicated an impact of genetic variation in the genes encoding leptin, LEP, and leptin receptor, LEPR, on AIWG, but results have not been conclusive. Thus, we investigated polymorphisms in both genes for an association with AIWG. METHODS: A total of 181 schizophrenic and schizoaffective patients treated with various antipsychotics were included. In a small subset of patients, leptin plasma levels were additionally obtained. Five polymorphisms in LEP and LEPR (LEP: rs7799039 (-2548G/A polymorphism), rs10954173, rs3828942; LEPR: rs1327120, rs1137101 (Q223R polymorphism) were genotyped using TaqMan assays. Statistical association with % weight change from baseline weight was performed using ANCOVA with baseline weight as covariate. RESULTS: ANCOVA showed a non-significant trend for genotype association of the rs7799039 marker (p=.068). No significant association of the other LEP and LEPR SNPs with AIWG was detected. However, we found a significant association between a haplotype of LEP rs7799039G-rs10954173G-rs3828942G (p=.035) and AIWG. The rs7799039 G-allele (p=.042) and G-allele of rs3828942 (p=.032) were associated with higher weight gain. CONCLUSION: Our study supports the hypothesis of an impact of LEP gene variation on AIWG. Limitations of our study include heterogeneous samples, short treatment duration and multiple comparisons. Our findings were compared to previous studies in detail in order to provide the readers with a more conclusive picture. However, further studies are warranted including more gene variants and interaction analyses with other genes of the leptin-melanocortin pathway.

[Genetics of weight gain associated with antipsychotic medications]. / Genetik der Antipsychotika-assoziierten Gewichtszunahme.

Weight gain is a serious adverse event during neuroleptic or antipsychotic treatment of schizophrenic disorders. The risk of weight gain varies among the class of neuroleptics, however no reliable predictors exist that adequately estimate individual risk. It is hoped that molecular genetic tests will help determine individual risk in the future. This article summarizes studies performed till now and concludes that gene variants of the serotonin 2C receptor and leptin significantly correlated with weight gain in several studies. Further interesting findings were obtained with variants of CYP2D6, the synaptosome-associated protein of 25 kDa (SNAP-25) as well as with the adrenergic alpha-2A genes. The group sizes were however small, and more studies are required for genetic tests to become available. Nonetheless the first steps towards genetic risk assessment have been performed, and its application in the near future has become likely.

Prevalence and characterization of Listeria monocytogenes in the feces of healthy Austrians.

The aims of the study were to determine the prevalence of Listeria monocytogenes in the feces of healthy Austrians and to characterize the isolates by various typing methods. Stool specimens from 505 healthy volunteers from the Tyrol were tested for the presence of L. monocytogenes using cold enrichment for 6 months and five different detection methods: conventional plating onto Palcam and Rapid'L.MONO agar, immunomagnetic separation (IMS) followed by conventional plating, enzyme-linked fluorescent immunoassay (ELFA), ELISA, and PCR. L. monocytogenes was isolated by conventional plating from one specimen (0.2%), and a further three were positive on immunomagnetic separation (0.8%). Only one specimen tested positive with ELFA and EIA, although it tested negative by conventional culture, IMS, and PCR. Eighteen of 505 samples were positive by PCR (3.6%), and this included three of the four culture-confirmed specimens. Serotyping, phage-typing, arsenic cadmium, antimicrobial-resistance typing and pulsed-field gel electrophoresis showed that multiple L. monocytogenes isolates from three of the four carriers were indistinguishable. Our data indicate that the Austrian fecal carriage rate is at least 0.8%. In view of a listeriosis incidence of 0.16/100,000 per year, the chances of fecal carriage developing into listeriosis appear to be very low.

Unique signaling properties of B cell antigen receptor in mature and immature B cells: implications for tolerance and activation.

Immature B cells display increased sensitivity to tolerance induction compared with their mature counterparts. The molecular mechanisms underlying these differences are poorly defined. In this study, we demonstrate unique maturation stage-dependent differences in B cell Ag receptor (BCR) signaling, including BCR-mediated calcium mobilization responses. Immature B cells display greater increases in intracellular calcium concentrations following Ag stimulation. This has consequences for the induction of biologically relevant responses: immature B cells require lower Ag concentrations for activation than mature B cells, as measured by induction of receptor editing and CD86 expression, respectively. BCR-induced tyrosine phosphorylation of CD79a, Lyn, B cell linker protein, and phospholipase Cgamma2 is enhanced in immature B cells and they exhibit greater capacitative calcium entry in response to Ag. Moreover, B cell linker protein, Bruton's tyrosine kinase, and phospholipase Cgamma2, which are crucial for the induction of calcium mobilization responses, are present at approximately 3-fold higher levels in immature B cells, potentially contributing to increased mobilization of calcium. Consistent with this possibility, we found that the previously reported lack of inositol-1,4,5-triphosphate production in immature B cells may be explained by enhanced inositol-1,4,5-triphosphate breakdown. These data demonstrate that multiple mechanisms guarantee increased Ag-induced mobilization of calcium in immature B cells and presumably ensure elimination of autoreactive B cells from the repertoire.

Comparison of different approaches to quantify Staphylococcus aureus cells by real-time quantitative PCR and application of this technique for examination of cheese.

Two different real-time quantitative PCR (RTQ-PCR) approaches were applied for PCR-based quantification of Staphylococcus aureus cells by targeting the thermonuclease (nuc) gene. Purified DNA extracts from pure cultures of S. aureus were quantified in a LightCycler system using SYBR Green I. Quantification proved to be less sensitive (60 nuc gene copies/microl) than using a fluorigenic TaqMan probe (6 nuc gene copies/microl). Comparison of the LightCycler system and the well-established ABI Prism 7700 SDS with TaqMan probes revealed no statistically significant differences with respect to sensitivity and reproducibility. Application of the RTQ-PCR assay to quantify S. aureus cells in artificially contaminated cheeses of different types achieved sensitivities from 1.5 x 10(2) to 6.4 x 10(2) copies of the nuc gene/2 g, depending on the cheese matrix. The coefficients of correlation between log CFU and nuc gene copy numbers ranged from 0.979 to 0.998, thus enabling calculation of the number of CFU of S. aureus in cheese by performing RTQ-PCR.

Detection and quantification of the iap gene of Listeria monocytogenes and Listeria innocua by a new real-time quantitative PCR assay.

A real-time quantitative polymerase chain reaction (PCR) assay for direct detection and enumeration of Listeria monocytogenes and Listeria innocua was developed and applied to artificially contaminated milk samples. The iap gene present in both species was used as a target for amplification of a 175-bp (L. monocytogenes) and a 309-bp (L. innocua) fragment. To ensure that L. monocytogenes and L. innocua are specifically detectable, tests were carried out using 42 L. monocytogenes strains and 33 L. innocua strains belonging to different serovars. Specificity was also confirmed using 22 bacterial strains not belonging to the genus Listeria, including closely related bacteria. In addition to specificity, the reported assay is characterized by a wide dynamic range of quantification and a high sensitivity, as we could detect as few as six copies of the iap gene per PCR using purified DNA as template. When applied to direct detection and quantification of L. monocytogenes in milk, the more rapid real-time quantitative PCR assay was as sensitive as the traditional plate count method, but real-time quantitative PCR-derived iap gene copy numbers were one to two logs higher than colony-forming units obtained by the plate count method.

An approach towards public health and foodborne human listeriosis--the Austrian Listeria monitoring.

The Institute for Milk Hygiene, Milk Technology and Food Science has launched a Listeria monitoring for Austrian cheese factories in 1988 which is nowadays a valuable tool to control the safety of cheese production. It is a means to qualify the proper hygienic conditions in the participating cheese plants. Proper hygiene protects cheese plants from getting contaminated by L. monocytogenes. The preventive elimination of foodborne pathogens facilitates a thriving economical development of the domestic cheese industry as contamination by L. monocytogenes may lead to a stop of delivery, product recall and other costly measures. This report comprehensively describes the principle of the monitoring including a description of the microbiological and molecular tools. It summarizes data on the detection frequency of Listeria contamination with respect to the different matrices under investigation. Furthermore an overview is given on the course of 17 contamination periods in 10 cheese plants and the outcome of the decontamination endeavours is described. Apart from epidemiological investigations, this report summarizes data regarding molecular species confirmation in the genus Listeria as the species assignment was comparatively examined by both conventional microbiology and molecular tools. Genotyping by Pulsed Field Gel Electrophoresis was applied in three plants which were confronted with a long term contamination period. The data presented in this paper rely on results which were collected through a decade of investigation (1990-2000).

Epidemiologic application of pulsed-field gel electrophoresis to an outbreak of Campylobacter jejuni in an Austrian youth centre.

We report the first documented Campylobacter jejuni outbreak in an Austrian youth centre. Sixty-four children were involved of which 38 showed classical signs of campylobacter gastroenteritis. Since unpasteurized milk distributed by a local dairy was suspected to be the source of infection, stool samples were collected from 20 cows providing the milk. Five of the cows tested positive for C. jejuni. These isolates together with 37 clinical samples were compared by pulsed-field-gel electrophoresis (PFGE). The PFGE patterns, using the restriction endonucleases SmaI and SalI, were identical for the human and bovine isolates. This finding confirmed that the outbreak was caused by the consumption of unpasteurized milk contaminated with C. jejuni.

Development of a multiple primer RAPD assay as a tool for phylogenetic analysis in Listeria spp. strains isolated from milkproduct associated epidemics, sporadic cases of listeriosis and dairy environments.

A total of 82 Listeria strains comprising four species were examined by amplification with a multiple primer random amplified polymorphic DNA (RAPD) assay. It was the objective of the study to set up a procedure suitable for analysis of the relationships among strains from milkproduct-associated epidemics, strains from sporadic cases of listeriosis and field strains from dairy products and dairy environments. In a preliminary study, 205 primers, each 10 bp long, were screened for suitability as primers and 44 primers showing reliable and reproducible RAPD patterns at a defined reaction condition were selected. The 82 strains were assigned to 54 RAPD groups positioned in 13 major clusters. Strains isolated during milk product-associated epidemics were found to belong to a single cluster I. Human isolates from sporadic cases of listeriosis predominantly were assigned to four separate clusters. It was found that strains of clinical origin were mainly assigned to other clusters than strains of non-clinical origin.

[Detection of the annatto dye norbixin/bixin in cheese using derivative spectroscopy and high performance liquid chromatography (HPLC)]. / Zum Nachweis des Annattofarbstoffes Norbixin/Bixin in Käse unter Anwendung der Derivativspektroskopie sowie der Hochleistungsflüssigchromatographie (HPLC).

A derivative spectroscopic method and a HPLC-method are described for the determination of the annatto dye-stuffs, norbixin and bixin, in cheese. Both methods enable a simple and quick sample preparation since the separation of beta-carotene and fat is not required. The sample preparation step consists of extraction with acetone, filtration, evaporation of the extract and separation of water residues by the addition of a few milliliters of absolute ethanol. This is followed by evaporation and extraction of the residual solution with chloroform/acetic acid (99.5 +/- 0.5) for the derivative spectroscopic method or with acetone for the HPLC method. The qualitative detection (detection limit greater than 0.67 mg/kg, depending on the genuine beta-carotene content) as well as the quantitative determination is possible by means of the derivative spectroscopic method. Therefore, this technique may be used within the rigorous Austrian regulations or for controlling the quantities and limits of annatto dye-stuffs in cheese, if its application is allowed. The method also has the advantage of quick detection (only 75 s) and saving of material used. The HPLC method allows for the separation and quantification of norbixin and bixin as well as the other carotenoids such as beta-carotene, beta-apo-8'-carotenal and beta-apo-8'-carotenoic acid--ethylester, which may also be found in varieties of cheese (detection limit of norbixin and bixin: 0.2 mg/kg). The time required for the separation of the above mentioned substances is 20 min and the HPLC method is proposed for the confirmation of low concentrations of these substances.

[The spectrophotometric determination of natamycin in cheese]. / Zur Spektralphotometrischen Bestimmung von Natamycin auf Käse.

Derivative spectroscopy was used for quantitative determination of natamycin in cheese. When measuring a methanolic cheese extract against methanol, the second derivative of the UV-spectrum is measured between 340 and 290 nm. The natamycin concentration can be determined by measuring the vertical distance between the minimum at 318 nm and the maximum at 311 nm. Under these conditions the detection limit of natamycin in a pure methanolic solution lies at 20 ng/ml, in cheese extracts at 150 ng/ml. The latter corresponds to a natamycin concentration of 2.5 ppm in the case of a 3 g test sample or 0.03 mg/dm2 in the case of a 25 cm2 cheese surface. The introduction of derivative spectroscopy makes it possible to reduce the interference of cheese substances in the photometric measurements and to increase the sensitivity and selectivity of the detection process. Besides the advantage that work and expenses are reduced - as no pimaricin-free sample has to be extracted from the interior of the cheese - it is also possible to determine natamycin photometrically in cheese, in which it is distributed homogeneously.

[Ovulation induction by cyclofenil (author's transl)]. / Ovulationsinduktion durch Cyclofenil.

The ovulation-inducing action of cyclofenil was investigated in 135 sexually mature women aged 20--35 years. The patients were only included in the trial if no ovulation in 2 consecutive cycles with the following criteria: basal temperature, cervix score, ascorbic acid retention, basophil count, serum hormone levels, e. g. LH and progesterone and the estrogens in the 24-hour urine could be determined. Ovulation was only considered to have occurred when all the parameters named indicated it. The lack of ovulation was accompanied by amenorrhea in 21 of the 135 patients. The ovulation rate in the 241 cycles observed was 101, corresponding to 42%. In the 114 patients with anovulatory cycles, the ovulation rate in the 184 cycles observed was 95, corresponding to 50%. In the 21 amenorrheic patients, ovulation occurred 6 times in the 57 cycles observed. Nausea or vomiting occurred as side effects in only 2 cases.