Neural Signatures of Error Processing in Depressed Adolescents with Comorbid Non-Suicidal Self-Injury (NSSI).

Non-suicidal self-injury (NSSI), as a highly prevalent psychiatric symptom in adolescents and young adults, is defined as the deliberate destruction of body tissue without suicidal intent. Impulsivity and dysfunctional response inhibition have been suggested to play a central role in adolescents' vulnerability to self-harm. To investigate the potentially distinct neurobiology of NSSI, we used a well-established Go/No Go task in which activation of the inferior frontal gyrus (IFG) and dorsal anterior cingulate cortex (dACC) is interpreted as a neural correlate of processing failed response inhibition. Task-based functional magnetic resonance imaging data were obtained from 14 adolescents with a diagnosis of major depression and a history of NSSI (MD-NSSI), 13 depressed adolescents without NSSI (MD-only), and 14 healthy controls (HC). In line with hypotheses of dysfunctional response inhibition, we observed increased rates of commission errors in MD-NSSI along with significantly reduced error-related activations of the dACC and IFG. Intact response inhibition, as reflected by low commission error rates not different from HC, was observed in MD-only, along with increased activation of the error-processing network. Our findings support the hypothesis of a distinct neurobiological signature of NSSI. Further research on biomarkers of NSSI could focus on behavioral and neural correlates of failed response inhibition.

Neural signature of error processing in major depression.

The clinical presentation of major depression (MD) is heterogenous and comprises various affective and cognitive symptoms including an increased sensitivity to errors. Various electrophysiological but only few functional magnetic resonance imaging (fMRI) studies investigated neural error processing in MD with inconsistent findings. Thus, reliable evidence regarding neural signatures of error processing in patients with current MD is limited despite its potential relevance as viable neurobiological marker of psychopathology. We therefore investigated a sample of 16 young adult female patients with current MD and 17 healthy controls (HC). During fMRI, we used an established Erikson-flanker Go/NoGo-paradigm and focused on neural alterations during errors of commission. In the absence of significant differences in rates of errors of commission in MD compared to HC, we observed significantly (p < 0.05, FWE-corrected on cluster level) enhanced neural activations of the dorsal anterior cingulate cortex (dACC) and the pre-supplementary motor area (pre-SMA) in MD relative to HC and thus, in brain regions consistently associated to neural error processing and corresponding behavioral adjustments. Considering comparable task performance, in particular similar commission error rates in MD and HC, our results support the evidence regarding an enhanced responsivity of neural error detection mechanisms in MD as a potential neural signature of increased negative feedback sensitivity as one of the core psychopathological features of this disorder.

From zero to hero--design-based systems metabolic engineering of Corynebacterium glutamicum for L-lysine production.

Here, we describe the development of a genetically defined strain of l-lysine hyperproducing Corynebacterium glutamicum by systems metabolic engineering of the wild type. Implementation of only 12 defined genome-based changes in genes encoding central metabolic enzymes redirected major carbon fluxes as desired towards the optimal pathway usage predicted by in silico modeling. The final engineered C. glutamicum strain was able to produce lysine with a high yield of 0.55 g per gram of glucose, a titer of 120 g L(-1) lysine and a productivity of 4.0 g L(-1) h(-1) in fed-batch culture. The specific glucose uptake rate of the wild type could be completely maintained during the engineering process, providing a highly viable producer. For these key criteria, the genetically defined strain created in this study lies at the maximum limit of classically derived producers developed over the last fifty years. This is the first report of a rationally derived lysine production strain that may be competitive with industrial applications. The design-based strategy for metabolic engineering reported here could serve as general concept for the rational development of microorganisms as efficient cellular factories for bio-production.

The role of domestic hygiene in inflammatory bowel diseases: hepatitis A and worm infestations.

BACKGROUND: Environmental factors are likely to be involved in the pathogenesis of inflammatory bowel disease (IBD), as the incidence of both Crohn's disease (CD) and ulcerative colitis (UC) increased with improved living standards in Europe after World War II. On the basis of earlier reports suggesting that hygienic standards may also play a role in the pathogenesis of IBD, we investigated the influence of hepatitis A seroprevalence as an indicator for poorer hygienic conditions and worm infestations in IBD. METHODS: Hepatitis A seroprevalence was examined in patients with UC and CD. Patients with minor endocrinological disorders served as controls. All patients were questioned about immunizations, parasitic infections (worms), contact with animals, living on a farm, and ever traveling abroad. Patients were excluded for active hepatitis A immunization or recent passive immunization. Results are presented as Mantel-Haenszel odds ratios with 95% confidence interval, adjusted for age group. RESULTS: The sample included 307 patients (73 CD, 48 UC, and 186 controls). Hepatitis A seroprevalence was strongly associated with age older than 50 years. Age adjusted Mantel-Haenszel odds ratios were 0.25 (0.09-0.71) for UC and 0.75 (0.38-1.46) for CD versus controls. For parasitic infections, the odds ratios were 1.15 (0.52-2.53) for UC and 0.34 (0.13-0.89) for CD. CONCLUSION: We were able to demonstrate a negative association of hepatitis A infection with UC only. In contrast, a novel finding was a strong protective effect of worm infestations for the occurrence of CD, but not UC.