Association of the alcohol dehydrogenase gene polymorphism rs1789891 with gray matter brain volume, alcohol consumption, alcohol craving and relapse risk.

Alcohol metabolizing enzymes, such as the alcohol dehydrogenases and the aldehyde dehydrogenases, regulate the levels of acetaldehyde in the blood and play an important role in the development and maintenance of alcohol addiction. Recent genome-wide systematic searches found associations between a single nucleotide polymorphism (rs1789891, risk allele: A, protective allele: C) in the alcohol dehydrogenase gene cluster and the risk of alcohol dependence. The current study investigated the effect of this single nucleotide polymorphism on alcohol consumption, craving for alcohol, relapse risk and brain gray matter volume. Alcohol-dependent patients (n = 74) and controls (n = 43) were screened, genotyped and underwent magnetic resonance imaging scanning, and relapse data were collected during 3 months following the experiment. Alcohol-dependent A allele carriers reported increased alcohol craving and higher alcohol consumption compared with the group of alcohol-dependent individuals homozygous for the C allele, which displayed craving values similar to the control group. Further, follow-up data indicated that A allele carriers relapsed earlier to heavy drinking compared with individuals with two C alleles. Analyses of gray matter volume indicated a significant genotype difference in the patient group: individuals with two C alleles had reduced gray matter volume in the left and right superior, middle and inferior temporal gyri. Findings of the current study further support the relevance of genetic variants in alcohol metabolizing enzymes to addictive behavior, brain tissue volume and relapse risk. Genotype-dependent differences in acetaldehyde formation, implicated by earlier studies, might be the biological substrate of the genotype differences.

Cortical surface-based threshold-free cluster enhancement and cortexwise mediation.

Threshold-free cluster enhancement (TFCE) is a sensitive means to incorporate spatial neighborhood information in neuroimaging studies without using arbitrary thresholds. The majority of methods have applied TFCE to voxelwise data. The need to understand the relationship among multiple variables and imaging modalities has become critical. We propose a new method of applying TFCE to vertexwise statistical images as well as cortexwise (either voxel- or vertexwise) mediation analysis. Here we present TFCE_mediation, a toolbox that can be used for cortexwise multiple regression analysis with TFCE, and additionally cortexwise mediation using TFCE. The toolbox is open source and publicly available (https://github.com/trislett/TFCE_mediation). We validated TFCE_mediation in healthy controls from two independent multimodal neuroimaging samples (N = 199 and N = 183). We found a consistent structure-function relationship between surface area and the first independent component (IC1) of the N-back task, that white matter fractional anisotropy is strongly associated with IC1 N-back, and that our voxel-based results are essentially identical to FSL randomise using TFCE (all PFWE <0.05). Using cortexwise mediation, we showed that the relationship between white matter FA and IC1 N-back is mediated by surface area in the right superior frontal cortex (PFWE  < 0.05). We also demonstrated that the same mediation model is present using vertexwise mediation (PFWE  < 0.05). In conclusion, cortexwise analysis with TFCE provides an effective analysis of multimodal neuroimaging data. Furthermore, cortexwise mediation analysis may identify or explain a mechanism that underlies an observed relationship among a predictor, intermediary, and dependent variables in which one of these variables is assessed at a whole-brain scale. Hum Brain Mapp 38:2795-2807, 2017. © 2017 Wiley Periodicals, Inc.

GATA4 variant interaction with brain limbic structure and relapse risk: A voxel-based morphometry study.

Atrial natriuretic peptide (ANP) receptors are highly expressed in the amygdala, caudate and hypothalamus. GATA4 gene encodes a transcription factor of ANP associated with the pathophysiology of alcohol dependence. We have previously demonstrated that the GATA4 single nucleotide polymorphism (SNP) rs13273672 revealed stronger alcohol-specific amygdala activation associated with lowered relapse risk to heavy drinking at 90 days in the AA-homozygotes. Our understanding however with respect to GATA4 variation on gray matter (GM) regional amygdala, caudate and hypothalamus volume is limited. We investigated GM differences specific to GATA4 and hypothesized that GM alterations will be predictive of heavy relapse. Eighty-three recently detoxified alcohol dependent patients were included. Neuroimaging data was analyzed using Voxel Based Morphometry (VBM). The main effects of GM volume and genotype as well as their interaction effect on time to heavy relapse (60 and 90 days) were analyzed using cox regression. Significant higher GM volume was found for the AA-genotype group compared with AG/GG-genotype in the hypothalamus and caudate. A significant interaction was revealed between caudate and amygdala GM volume and GATA4 genotype on time to heavy relapse. The interaction was expressed by means of higher GM in the AA genotype group to be associated with reduced risk to relapse whereas in the AG/GG group higher GM was associated with increased risk to relapse. This is the first report on GM regional volume alterations specific to GATA4 genotype [(SNP) rs13273672] and its association with relapse in alcohol dependence. Current findings further support the role of GATA4 in alcoholism.

The effects of single nucleotide polymorphisms in glutamatergic neurotransmission genes on neural response to alcohol cues and craving.

The aim of the current study was to determine genotype effects of four single nucleotide polymorphisms (SNPs) in the genes of the N-Methyl-d-aspartate receptor (GRIN1, GRIN2A, GRIN2C) and kainate receptor (GRIK1), which have been previously associated with alcoholism, on behavior, neural cue-reactivity and drinking outcome. Eighty-six abstinent alcohol dependent patients were recruited from an in-patient setting. Neuropsychological tests, genotyping and functional magnetic resonance imaging (fMRI) were used to study genotype effects. GRIN2C risk allele carriers displayed increased alcohol cue-induced activation in the anterior cingulate cortex (ACC) and dorsolateral prefrontal cortex (dlPFC). Neural activation in the ACC positively correlated with craving for alcohol (r = 0.201, P = 0.032), whereas activation in the dlPFC showed a negative association (r = -0.215, P = 0.023). In addition, dlPFC activation predicted time to first relapse (HR = 2.701, 95%CI 1.244-5.864, P = 0.012). GRIK1 risk allele carriers showed increased cue-induced activation in the medial prefrontal (PFC) and orbitofrontal cortex (OFC) and in the lateral PFC and OFC. Activation in both clusters positively correlated with alcohol craving (rmedOFC, medPFC = 0.403, P = 0.001, rlatOFC, latPFC = 0.282, P = 0.008), and activation in the cluster that encompassed the medial OFC predicted time to first relapse (HR = 1.911, 95%CI 1.030-3.545, P = 0.040). Findings indicate that SNPs in the GRIN2C and GRIK1 genes are associated with altered cue-induced brain activation that is related to craving for alcohol and relapse risk.

Increased mesolimbic cue-reactivity in carriers of the mu-opioid-receptor gene OPRM1 A118G polymorphism predicts drinking outcome: a functional imaging study in alcohol dependent subjects.

The endogenous opioid system is involved in the pathophysiology of alcohol-use disorders. Genetic variants of the opioid system alter neural and behavioral responses to alcohol. In particular, a single nucleotide polymorphism rs1799971 (A118G) in the mu-opioid receptor gene (OPRM1) is suggested to modulate alcohol-related phenotypes and neural response in the mesocorticolimbic dopaminergic system. Little is known about the clinical implications of these changes. The current study investigated the relationship of genotype effects on subjective and neural responses to alcohol cues and relapse in a sample of abstinent alcohol-dependent patients. Functional magnetic resonance imaging (fMRI) was used to investigate alcohol cue-reactivity and drinking outcome of 81 abstinent alcohol-dependent patients. G-allele carriers displayed increased fMRI cue-reactivity in the left dorsal striatum and bilateral insulae. Neural responses to alcohol cues in these brain regions correlated positively with subjective craving for alcohol and positive expectations of alcohol׳s effects. Moreover, alcohol cue-reactivity in the left dorsal striatum predicted time to first severe relapse. Current results show that alcohol-dependent G-allele carriers׳ increased cue-reactivity is associated with an increased relapse risk. This suggests that genotype effects on cue-reactivity might link the OPRM1 A118G risk allele with an increased relapse risk that was reported in earlier studies. From a clinical perspective, risk-allele carriers might benefit from treatments, such as neuro-feedback or extinction-based therapy that are suggested to reduce mesolimbic reactivity.

Effects of D-cycloserine on extinction of mesolimbic cue reactivity in alcoholism: a randomized placebo-controlled trial.

RATIONALE: Mesocorticolimbic reactivity to alcohol-associated cues has been shown to be associated with relapse to renewed drinking and to be decreased by cue-exposure-based extinction training (CET). Evidence from preclinical studies suggests that the extinction of conditioned alcohol-seeking behavior might be facilitated by drugs increasing N-methyl-D-aspartate (NMDA) receptor-associated memory consolidation. OBJECTIVES: In this study, we assessed the efficacy of CET treatment supplemented with the partial NMDA-receptor agonist D-cycloserine (DCS) at reducing mesolimbic cue reactivity (CR), craving, and relapse risk in alcoholism. METHODS: In a randomized, placebo-controlled, double-blind study, we recruited 76 recently detoxified abstinent alcohol-dependent patients. Thirty-two (16 DCS, 16 placebo) patients showed cue-induced ventral-striatal activation measured with functional magnetic resonance imaging (fMRI) prior to treatment and were thus included in the efficacy analyses. After inpatient detoxification, patients underwent nine sessions of CET spaced over 3 weeks, receiving either 50 mg DCS or placebo 1 h prior to each CET session. FMRI was conducted before treatment and 3 weeks after treatment onset. RESULTS: Following treatment with CET plus DCS, cue-induced brain activation in the ventral and dorsal striatum was decreased compared to treatment with CET plus placebo. Elevated posttreatment ventral striatal CR and increased craving (assessed using the Obsessive Compulsive Drinking Scale) were associated with increased relapse risk. CONCLUSIONS: DCS was shown to augment the effect of CET for alcohol-dependent subjects. The interaction between craving and ventral-striatal CR on treatment outcome suggests that CET might be especially effective in patients exhibiting both high craving and elevated CR.

Development and validation of the craving automated scale for alcohol.

BACKGROUND: Alcohol consumption has been suggested to be associated with a dysregulation in habit formation and execution in dependent patients. Although there are established craving questionnaires assessing various components of craving, to our knowledge, no questionnaire exists to assess habitual and automated substance intake. In this study, we present and validate the "Craving Automated Scale for Alcohol" (CAS-A), a newly developed questionnaire assessing craving and other components of automated addictive behavior. METHODS: Forty-three recently detoxified alcohol-dependent patients were examined in an inpatient setting using a cross-sectional design. The CAS-A, a self-report questionnaire, was applied. According to classical test theory, we conducted principal component analyses (PCAs) to identify the components of CAS-A, after which we validated it using established craving questionnaires. Thirty-two healthy participants served as a control group. RESULTS: Our first-order PCA identified a 5-factor solution. A second-order analysis then identified 2 general factors. These factors were partially associated with established craving measures and with the severity of dependence. CONCLUSIONS: Our findings suggest that CAS-A assesses additional components of addictive behavior compared to established measures. We interpret the 5 CAS-A factors as "only aware in hindsight," "no deliberate decision," "contrary to intention," "no perception," and "no control." We suggest the 2 general factors be interpreted as "unaware" and "nonvolitional." Our results indicate that the CAS-A indeed assesses some components of automated craving and automated drinking behavior in a more sophisticated way than established questionnaires. The CAS-A as a retrospective questionnaire can be considered to be a trait rather than a state measure.

Genetic variation in the atrial natriuretic peptide transcription factor GATA4 modulates amygdala responsiveness in alcohol dependence.

BACKGROUND: Two genome-wide association studies recently showed alcohol dependence to be associated with a single-nucleotide polymorphism (rs13273672) located on a gene (GATA4) that encodes a transcription factor of atrial natriuretic peptide (ANP). A growing body of evidence suggests that ANP might be involved in the symptomology of alcohol dependence. This study examined whether reactivity to alcohol cues in the ANP target region amygdala, a key area implicated in addictive behavior, differs depending on the GATA4 genotype of a patient. We also investigated potential associations between these differences in amygdala activation and relapse behavior. METHODS: Eighty-one abstinent, alcohol-dependent patients completed a functional magnetic resonance imaging cue-reactivity task in a 3-Tesla scanner and provided blood samples for DNA extraction. RESULTS: The results showed significantly lower alcohol-cue-induced activations in G-allele carriers as compared with AA-homozygotes in the bilateral amygdala. A survival analysis revealed that a stronger alcohol-specific amygdala response predicted a lowered risk for relapse to heavy drinking in the AA-homozygotes, whereas this effect could not be observed in G-allele carriers. CONCLUSIONS: These results illuminate potential underlying mechanisms of the involvement of the GATA4 gene in the etiology of alcohol dependence via its influence on ANP and amygdala processing.

Increased neural activity during high working memory load predicts low relapse risk in alcohol dependence.

Working memory (WM) impairments are often observed in alcohol-dependent individuals, especially in early abstinence, which may contribute to an increased relapse risk after detoxification. Brain imaging studies on visuospatial WM in alcohol-dependent patients compared to controls indicate that information processing requires compensatory increased neural activation to perform at a normal level. However, to date, no study tested whether such increased neural WM activation patterns or the lack thereof predict relapse behavior in alcohol-dependent individuals, and whether such differences persist when adequately correcting for individual grey matter differences. We combined analyses of neural activation during an n-back task and local grey matter volumes using Biological Parametric Mapping in 40 detoxified alcohol-dependent patients and 40 matched healthy controls (HC), and assessed prospective relapse risk during a 7-month follow-up period. Despite equal task performance, we found increased functional activation during high versus low cognitive WM load (2-back-0-back) in bilateral rostral prefrontal cortex (BA10) and bilateral ventrolateral prefrontal cortex (BA45,47) in prospective abstainers versus relapsers, and further in left/right lateral/medial premotor cortex (BA6,8) in abstainers versus HC. In prospective abstainers, but not relapsers, subtle cognitive impairment was associated with increased neural task activity in the premotor cortex. These findings suggest that in prospective abstainers, higher functional engagement of presumably less impaired neural resources in executive behavioral control brain areas (BA10, 45, 47, 6, 8) may constitute a resilience factor associated with good treatment outcome.

Paucity of mycobacteria in mucosal bowel biopsies from adults and children with early inflammatory bowel disease.

BACKGROUND: The presence of Mycobacterium avium subspecies paratuberculosis (MAP) has previously been inferred in the genesis of Crohn's disease (CD), and a higher incidence of MAP PCR positivity has been demonstrated in the gut and peripheral blood of CD patients than in healthy individuals. The objective of this prospective study was to assess the potential etiological role of MAP in the pathogenesis of CD. METHODS: The presence of mycobacteria was assessed in bowel biopsies from newly diagnosed, treatment naïve Norwegian patients with IBD, including CD and ulcerative colitis (UC), as compared to a hospital-based cohort of CD and UC patients. Biopsies were collected from the small and large bowel in 354 individuals with suspected IBD. Detection of mycobacteria was performed by long-term cultivation in combination with direct detection by MAP IS900-specific PCR. RESULTS: Among the specimens included from the patients with early IBD, samples from only two of the patients with CD (2.7%) and two of the non-IBD controls (1.5%) exhibited a positive growth signal. None of the CD patients and only one of the non-IBD controls was MAP PCR positive. Only the single PCR positive non-IBD control was also mycobacterial culture positive with Mycobacterium avium subsp. hominissuis. In the referral patients with long-term IBD, the prevalence of growth signal and MAP PCR positivity was higher (52 and 9%, respectively). CONCLUSIONS: These findings demonstrate the paucity of MAP in the gut of treatment naïve CD patients. This study does not provide evidence for a role of MAP in early IBD.

Molecular detection and identification of zygomycetes species from paraffin-embedded tissues in a murine model of disseminated zygomycosis: a collaborative European Society of Clinical Microbiology and Infectious Diseases (ESCMID) Fungal Infection Study Group (EFISG) evaluation.

The present study was performed to assess the interlaboratory reproducibility of the molecular detection and identification of species of Zygomycetes from formalin-fixed paraffin-embedded kidney and brain tissues obtained from experimentally infected mice. Animals were infected with one of five species (Rhizopus oryzae, Rhizopus microsporus, Lichtheimia corymbifera, Rhizomucor pusillus, and Mucor circinelloides). Samples with 1, 10, or 30 slide cuts of the tissues were prepared from each paraffin block, the sample identities were blinded for analysis, and the samples were mailed to each of seven laboratories for the assessment of sensitivity. A protocol describing the extraction method and the PCR amplification procedure was provided. The internal transcribed spacer 1 (ITS1) region was amplified by PCR with the fungal universal primers ITS1 and ITS2 and sequenced. As negative results were obtained for 93% of the tissue specimens infected by M. circinelloides, the data for this species were excluded from the analysis. Positive PCR results were obtained for 93% (52/56), 89% (50/56), and 27% (15/56) of the samples with 30, 10, and 1 slide cuts, respectively. There were minor differences, depending on the organ tissue, fungal species, and laboratory. Correct species identification was possible for 100% (30 cuts), 98% (10 cuts), and 93% (1 cut) of the cases. With the protocol used in the present study, the interlaboratory reproducibility of ITS sequencing for the identification of major Zygomycetes species from formalin-fixed paraffin-embedded tissues can reach 100%, when enough material is available.

Leptotrichia amnionii, an emerging pathogen of the female urogenital tract.

Leptotrichia amnionii, a recently described, very fastidious, gram-negative anaerobic bacterium, is an opportunistic pathogen of the female urogenital tract. We report a case of second-trimester abortion in a patient with chorioamnionitis and L. amnionii bacteremia and a case of renal abscess in a female 5 weeks postpartum.

18S rDNA polymerase chain reaction and sequencing in onychomycosis diagnostics.

Diagnostic approaches to onychomycosis have traditionally been based on a combination of culture and microscopy. In the present study clinical specimens from 346 patients with suspected onychomycosis were analysed by 18S polymerase chain reaction (detection) followed by sequencing and subsequent database search (identification) in parallel with routine culture on agar (detection and identification). In 49 samples Trichophyton rubrum was identified by culture and sequencing. In 67 additional culture negative samples, a positive dermatophyte sequence was obtained (T. rubrum in 54, T. mentagrophytes in 5, and T. species in 8 samples). Fifteen samples cultured positive while no sequence was obtained. Two hundred and seven samples were negative by culture as well as by sequencing. Nails from 10 healthy controls were negative by culture and sequencing. In conclusion, the number of specimens that were positive by polymerase chain reaction was more than double the number that were positive by culture alone.