A multimodal neuroimaging classifier for alcohol dependence

With progress in magnetic resonance imaging technology and a broader dissemination of state-of-the-art imaging facilities, the acquisition of multiple neuroimaging modalities is becoming increasingly feasible. One particular hope associated with multimodal neuroimaging is the development of reliable data-driven diagnostic classifiers for psychiatric disorders, yet previous studies have often failed to find a benefit of combining multiple modalities. As a psychiatric disorder with established neurobiological effects at several levels of description, alcohol dependence is particularly well-suited for multimodal classification. To this aim, we developed a multimodal classification scheme and applied it to a rich neuroimaging battery (structural, functional task-based and functional resting-state data) collected in a matched sample of alcohol-dependent patients (N = 119) and controls (N = 97). We found that our classification scheme yielded 79.3% diagnostic accuracy, which outperformed the strongest individual modality - grey-matter density - by 2.7%. We found that this moderate benefit of multimodal classification depended on a number of critical design choices: a procedure to select optimal modality-specific classifiers, a fine-grained ensemble prediction based on cross-modal weight matrices and continuous classifier decision values. We conclude that the combination of multiple neuroimaging modalities is able to moderately improve the accuracy of machine-learning-based diagnostic classification in alcohol dependence

A multimodal neuroimaging classifier for alcohol dependence

With progress in magnetic resonance imaging technology and a broader dissemination of state-of-the-art imaging facilities, the acquisition of multiple neuroimaging modalities is becoming increasingly feasible. One particular hope associated with multimodal neuroimaging is the development of reliable data-driven diagnostic classifiers for psychiatric disorders, yet previous studies have often failed to find a benefit of combining multiple modalities. As a psychiatric disorder with established neurobiological effects at several levels of description, alcohol dependence is particularly well-suited for multimodal classification. To this aim, we developed a multimodal classification scheme and applied it to a rich neuroimaging battery (structural, functional task-based and functional resting-state data) collected in a matched sample of alcohol-dependent patients (N = 119) and controls (N = 97). We found that our classification scheme yielded 79.3% diagnostic accuracy, which outperformed the strongest individual modality - grey-matter density - by 2.7%. We found that this moderate benefit of multimodal classification depended on a number of critical design choices: a procedure to select optimal modality-specific classifiers, a fine-grained ensemble prediction based on cross-modal weight matrices and continuous classifier decision values. We conclude that the combination of multiple neuroimaging modalities is able to moderately improve the accuracy of machine-learning-based diagnostic classification in alcohol dependence

Effect of medium conductivity and composition on the uptake of propidium iodide into electropermeabilized myeloma cells

AbstractThe effects of ionic composition and conductivity of the medium on electropermeabilization of the plasma membrane of mammalian cells were studied. Temporal and spatial uptake of propidium iodide (PI) into field-treated cells was measured by means of flow cytometry, spectrofluorimetry and confocal laser scanning microscopy. Murine myeloma cells were electropulsed in iso-osmolar solutions. These contained 10–100 μg ml−1 PI at different conductivities (0.8–14 mS cm−1) and ionic strengths, adjusted by varying concentrations of K+, Na+, Cl− and SO42−. Field-induced incorporation of PI into reversibly permeabilized cells was (almost) independent of ionic composition and strength (at a fixed medium conductivity), but increased dramatically with decreasing medium conductivity at a fixed field strength. The time-course of PI uptake (which apparently reflected the resealing process of the membrane) could be fitted by a single-exponential curve (relaxation time about 2 min in the absence of Ca2+) and was independent of medium conductivity and composition. These and other data suggested that the expansion of the ‘electroleaks’ during the breakdown process is field-controlled and depends, therefore, on the (conductivity-dependent) discharging process of the permeabilized membrane. The threshold field strength for dye uptake increased with increasing K+ concentration (about 0.6 kV cm−1 in K+-free, NaCl-containing medium and about 0.9 kV cm−1 in 30 mM KCl-containing medium). Also, the spatial uptake pattern of PI shifted from an asymmetric permeation through the cell hemisphere facing the anode to a more symmetric uptake through both hemispheres. These results suggested that the generated potential is superimposed on the (K+-dependent) resting membrane potential. Taking this into account, the breakdown voltage of the membrane was estimated to be about 1 V

Impact of Long‐Term Alcohol Consumption and Relapse on Genome‐Wide DNA Methylation Changes in Alcohol‐Dependent Subjects: A Longitudinal Study

Background: Genetic factors play an important role in the development and maintenance of alcohol use disorder (AUD). Significant and widespread differences in methylation levels of multiple regions within the genome have been reported between AUD patients and healthy controls in large epigenome-wide association studies (EWASs). Also, within patient populations, methylation changes over time (both during and after withdrawal) have been identified as sensitive indicators for disease activity. The detection of changes in methylation levels is a powerful tool to further explore and understand the biological correlates and underpinnings of AUD. Although there is strong and convincing evidence for differences in methylation of various sites between AUD patients and controls, only few studies assessed changes within patients over longer periods of time while taking into account alcohol consumption, relapse, and abstinence. So far, the longest period assessed as a within-subject design using EWASs was 4 weeks. Methods: Here, we investigated changes in whole-genome methylation levels within a sample of 69 detoxified AUD patients over a period as long as 12 months for the first time, comparing patients that relapsed within the follow-up period to those that remained abstinent. Results: Whole-genome methylation patterns of individual CpG sites over time did not differ between abstinent and relapsing patients. However, there was a negative association between global mean methylation at the 12-month follow-up and alcohol consumption within our sample. Conclusion: Although the present study represents the largest study of methylation levels in a sample of AUD patients with a follow-up period of 1 year and accounting for alcohol consumption and relapse to date, the sample size might still not be large enough to detect genome-wide significant effects. Therefore, large-scale, long-term studies with AUD subjects are needed to determine the utility of DNA methylation for the assessment and monitoring of persons with alcohol use disorders

Laboratory alcohol self-administration experiments do not increase subsequent real-life drinking in young adult social drinkers

BACKGROUND: While the utility of experimental free-access alcohol self-administration paradigms is well established, little data exist addressing the question of whether study participation influences subsequent natural alcohol consumption. We here present drinking reports of young adults before and after participation in intravenous alcohol self-administration studies. METHODS: Timeline Follow-back drinking reports for the 6 weeks immediately preceding the first, and the 6 weeks after the last experimental alcohol challenge were examined from subjects completing 1 of 2 similar alcohol self-administration paradigms. In study 1, 18 social drinkers (9 females, mean age 24.1 years) participated in 3 alcohol self-infusion sessions up to a maximum blood alcohol concentration (BAC) of 160 mg%. Study 2 involved 60 participants (30 females, mean age 18.3 years) of the Dresden Longitudinal Study on Alcohol Use in Young Adults (D-LAYA), who participated in 2 sessions of alcohol self-infusion up to a maximum BAC of 120 mg%, and a nonexposed age-matched control group of 42 (28 females, mean age 18.4 years) subjects. RESULTS: In study 1, participants reported (3.7%) fewer heavy drinking days as well as a decrease of 2.5 drinks per drinking day after study participation compared to prestudy levels (p < 0.05, respectively). In study 2, alcohol-exposed participants reported 7.1% and non-alcohol-exposed controls 6.5% fewer drinking days at poststudy measurement (p < 0.001), while percent heavy drinking days and drinks per drinking day did not differ. CONCLUSIONS: These data suggest that participation in intravenous alcohol self-administration experiments does not increase subsequent real-life drinking of young adults

Endoscopic vacuum therapy for in- and outpatient treatment of colorectal defects

Background. Evidence for endoscopic vacuum therapy (EVT) for colorectal defects is still based on small patient series from various institutions, employing different treatment algorithms and methods. As EVT was invented at our institution 20 years ago, the aim was to report the efficacy and safety of EVT for colorectal defects as well as to analyze factors associated with efficacy, therapy duration, and outpatient treatment. Methods. Cohort study with analysis of prospectively collected data of patients receiving EVT for colorectal defects at a tertiary referral center in Germany (n=281). Results. The majority of patients had malignant disease (83%) and an American Society of Anesthesiologists classification of III/IV (81%). Most frequent indications for EVT were anastomotic leakage after sigmoid or rectal resection (67%) followed by rectal stump leakage (20%). EVT was successful in 256 out of 281 patients (91%). EVT following multi-visceral resection (P = 0.037) and recent surgical revision after primary surgery (P = 0.009) were risk factors for EVT failure. EVT-associated adverse events occurred in 27 patients (10%). Median treatment duration was 25 days. Previous chemo-radiation (P = 0.006) was associated with a significant longer duration of EVT. Outpatient treatment was conducted in 49% of patients with a median hospital stay reduction of 15 days and 98% treatment success. Younger patient age (P = 0.044) was associated with the possibility of outpatient treatment. Restoration of intestinal continuity was achieved in 60% of patients where technically possible with a 12-month rate of 52%. Conclusions. In patients with colorectal defects, EVT appears to be a safe and effective, minimally invasive option for in- and outpatient treatment

A multimodal neuroimaging classifier for alcohol dependence

With progress in magnetic resonance imaging technology and a broader dissemination of state-of-the-art imaging facilities, the acquisition of multiple neuroimaging modalities is becoming increasingly feasible. One particular hope associated with multimodal neuroimaging is the development of reliable data-driven diagnostic classifiers for psychiatric disorders, yet previous studies have often failed to find a benefit of combining multiple modalities. As a psychiatric disorder with established neurobiological effects at several levels of description, alcohol dependence is particularly well-suited for multimodal classification. To this aim, we developed a multimodal classification scheme and applied it to a rich neuroimaging battery (structural, functional task-based and functional resting-state data) collected in a matched sample of alcohol-dependent patients (N = 119) and controls (N = 97). We found that our classification scheme yielded 79.3% diagnostic accuracy, which outperformed the strongest individual modality - grey-matter density - by 2.7%. We found that this moderate benefit of multimodal classification depended on a number of critical design choices: a procedure to select optimal modality-specific classifiers, a fine-grained ensemble prediction based on cross-modal weight matrices and continuous classifier decision values. We conclude that the combination of multiple neuroimaging modalities is able to moderately improve the accuracy of machine-learning-based diagnostic classification in alcohol dependence

Adolescent women induce lower blood alcohol levels than men in a laboratory alcohol self-administration experiment

Background Adolescence is a critical period for the development of alcohol use disorders; drinking habits are rather unstable and genetic influences, such as male sex and a positive Family History of alcoholism (FH), are often masked by environmental factors such as peer pressure. Methods We investigated how sex and FH modulate alcohol use in a sample of 18-19-year-olds from the Dresden Longitudinal Study on Alcohol use in Young Adults (D-LAYA). Adolescents reported their real-life drinking in a TimeLine Follow-Back (TLFB) interview. They subsequently completed a training and an experimental session of free-access intravenous Alcohol Self-Administration (i.v. ASA) using the computer-assisted alcohol infusion system in order to control for environmental cues as well as for biological differences in alcohol pharmacokinetics. During i.v. ASA, we assessed subjective alcohol effects at eight time points. Results Women reported significantly less real-life drinking than men and achieved significantly lower mean arterial Blood Alcohol Concentrations (aBACs) in the laboratory. At the same time, women reported greater sedation relative to men and rated negative effects as high as did men. A positive FH was associated with lower real-life drinking in men but not in women. In the laboratory, FH was not linked to i.v. ASA. Greater real-life drinking was significantly positively associated with higher mean aBACs in the laboratory, and all i.v. ASA indices were highly correlated across the two sessions. Conclusions We conclude that adolescent women chose lower aBACs because they experienced adverse alcohol effects, namely sedation and negative effects, at lower aBACs than men. A positive FH was not apparent as risk factor for drinking in our young sample. The i.v. ASA method demonstrated good external validity as well as test-retest reliability, the latter indicating that a separate training session is not required when employing the i.v. ASA paradigm

The human papillomavirus type 11 and 16 E6 proteins modulate the cell-cycle regulator and transcription cofactor TRIP-Br1

AbstractThe genital human papillomaviruses (HPVs) are a taxonomic group including HPV types that preferentially cause genital and laryngeal warts (“low-risk types”), such as HPV-6 and HPV-11, or cancer of the cervix and its precursor lesions (“high-risk types”), such as HPV-16. The transforming processes induced by these viruses depend on the proteins E5, E6, and E7. Among these oncoproteins, the E6 protein stands out because it supports a particularly large number of functions and interactions with cellular proteins, some of which are specific for the carcinogenic HPVs, while others are shared among low- and high-risk HPVs. Here we report yeast two-hybrid screens with HPV-6 and -11 E6 proteins that identified TRIP-Br1 as a novel cellular target. TRIP-Br1 was recently detected by two research groups, which described two separate functions, namely that of a transcriptional integrator of the E2F1/DP1/RB cell-cycle regulatory pathway (and then named TRIP-Br1), and that of an antagonist of the cyclin-dependent kinase suppression of p16INK4a (and then named p34SEI-1). We observed that TRIP-Br1 interacts with low- and high-risk HPV E6 proteins in yeast, in vitro and in mammalian cell cultures. Transcription activation of a complex consisting of E2F1, DP1, and TRIP-Br1 was efficiently stimulated by both E6 proteins. TRIP-Br1 has an LLG E6 interaction motif, which contributed to the binding of E6 proteins. Apparently, E6 does not promote degradation of TRIP-Br1. Our observations imply that the cell-cycle promoting transcription factor E2F1/DP1 is dually targeted by HPV oncoproteins, namely (i) by interference of the E7 protein with repression by RB, and (ii) by the transcriptional cofactor function of the E6 protein. Our data reveal the natural context of the transcription activator function of E6, which has been predicted without knowledge of the E2F1/DP1/TRIP-Br/E6 complex by studying chimeric constructs, and add a function to the limited number of transforming properties shared by low- and high-risk HPVs

Pavlovian-to-Instrumental Transfer in Alcohol Dependence: A Pilot Study

This publication is with permission of the rights owner freely accessible due to an alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.Background: Pavlovian processes are thought to play an important role in the development, maintenance and relapse of alcohol dependence, possibly by influencing and usurping ongoing thought and behavior. The influence of pavlovian stimuli on ongoing behavior is paradigmatically measured by pavlovian-to-instrumental transfer (PIT) tasks. These involve multiple stages and are complex. Whether increased PIT is involved in human alcohol dependence is uncertain. We therefore aimed to establish and validate a modified PIT paradigm that would be robust, consistent and tolerated by healthy controls as well as by patients suffering from alcohol dependence, and to explore whether alcohol dependence is associated with enhanced PIT. Methods: Thirty-two recently detoxified alcohol-dependent patients and 32 age- and gender-matched healthy controls performed a PIT task with instrumental go/no-go approach behaviors. The task involved both pavlovian stimuli associated with monetary rewards and losses, and images of drinks. Results: Both patients and healthy controls showed a robust and temporally stable PIT effect. Strengths of PIT effects to drug-related and monetary conditioned stimuli were highly correlated. Patients more frequently showed a PIT effect, and the effect was stronger in response to aversively conditioned CSs (conditioned suppression), but there was no group difference in response to appetitive CSs. Conclusion: The implementation of PIT has favorably robust properties in chronic alcohol-dependent patients and in healthy controls. It shows internal consistency between monetary and drug-related cues. The findings support an association of alcohol dependence with an increased propensity towards PIT.Peer Reviewe