[Virtual reality in teaching using mentally ill patient avatars]. / Virtuelle Realität in der Lehre mit psychisch kranken Patientenavataren.

BACKGROUND: Medical interaction and exploration techniques are the most important tools that medical students have to acquire in the subject of psychiatry and psychotherapy. The new digital technologies currently available, such as virtual reality (VR), as important supplements can contribute to a significant improvement in the teaching of psychiatric-psychopathological learning content as well as, in particular, the technique of ascertaining the psychiatric history and diagnosis. OBJECTIVE: Evaluation of the Bochum Avatar Exploration Project (AVEX) as part of the curricular course in medical studies at the Ruhr University Bochum for its possibilities to convey learning content and techniques of anamnesis and diagnosis in the subject of psychiatry and psychotherapy. METHODS: In AVEX, a total of 87 medical students in the clinical study section have so far been able to enter into a dialogue with "mentally ill" avatars and gain experience with VR technology as a learning and teaching method in the subject of psychiatry and psychotherapy. RESULTS: Despite the limited possibilities for interaction with the digital avatars, it is possible to achieve a substantial transfer of learning content in psychiatry; however, the students must be well supported by the lecturers. CONCLUSION: The AVEX project already shows promising possibilities for supplementing the teaching of medical students, even if the fit of questions and replies in dialogue with the virtual avatars still needs to be improved. As advances in the linguistic communication of emotions and the visual effects of the avatar representation can be predicted, the significance of this technology will continue to increase.

Emotional Context Effects on the Rating of Ambiguous Facial Expressions in Depression and Schizophrenia Spectrum Disorders.

ObjectiveTo investigate the influence of visual contextual information on emotion recognition of ambiguous facial expressions in depression and schizophrenia spectrum disorders. Method: Ambiguous facial expressions and emotional contexts representing anger, disgust, fear, joy, sadness and surprise were validated in a pre-test with healthy independent raters. Afterwards, 20 healthy participants (8 women, 12 men; mean age 24.35 ± 2.85 years), 20 participants with schizophrenia spectrum disorders (9 women, 11 men; mean age 40.25 ± 11.68 years) and 19 participants with depression (11 women, 8 men; mean age 43.74 ± 12.65 years) rated the emotional content of nine different faces in seven different emotion-suggesting contexts. The proportions of context-congruent answers and differences between emotion ratings in each context were analysed using non-parametric Kruskal-Wallis and explorative, paired Wilcoxon tests. Correlational analyses explored the influence of clinical symptoms assessed by clinician-administered scales. Results: The overall proportion of context-congruent answers did not differ between participants with depression and schizophrenia spectrum disorders compared to healthy participants. Participants with schizophrenia spectrum disorders were more susceptible to anger-suggesting contexts and participants with depression were more susceptible to fear-suggesting contexts. Differences in emotion recognition were associated with the severity of depressive, but not psychotic, symptoms. Conclusion: Despite increased susceptibility to anger-suggesting cues in schizophrenia and to fear-suggesting cues in depression, visual contextual influence remains largely consistent with healthy participants. Preserved emotional responsiveness suggests an efficacy of emotion training but emphasizes the need for additional research focusing on other factors contributing to social interaction deficits.

A novel SfaNI-like restriction-modification system in Caldicellulosiruptor extents the genetic engineering toolbox for this genus.

Caldicellulosiruptor is a genus of thermophilic to hyper-thermophilic microorganisms that express and secrete an arsenal of enzymes degrading lignocellulosic biomasses into fermentable sugars. Because of this distinguished feature, strains of Caldicellulosiruptor have been considered as promising candidates for consolidated bioprocessing. Although a few Caldicellulosiruptor strains with industrially relevant characteristics have been isolated to date, it is apparent that further improvement of the strains is essential for industrial application. The earlier identification of the HaeIII-like restriction-modification system in C. bescii strain DSM 6725 has formed the basis for genetic methods with the aim to improve the strain's lignocellulolytic activity and ethanol production. In this study, a novel SfaNI-like restriction-modification system was identified in Caldicellulosiruptor sp. strain BluCon085, consisting of an endonuclease and two methyltransferases that recognize the reverse-complement sequences 5'-GATGC-3' and 5'-GCATC-3'. Methylation of the adenine in both sequences leads to an asymmetric methylation pattern in the genomic DNA of strain BluCon085. Proteins with high percentage of identity to the endonuclease and two methyltransferases were identified in the genomes of C. saccharolyticus strain DSM 8903, C. naganoensis strain DSM 8991, C. changbaiensis strain DSM 26941 and Caldicellulosiruptor sp. strain F32, suggesting that a similar restriction-modification system may be active also in these strains and respective species. We show that methylation of plasmid and linear DNA by the identified methyltransferases, obtained by heterologous expression in Escherichia coli, is sufficient for successful transformation of Caldicellulosiruptor sp. strain DIB 104C. The genetic engineering toolbox developed in this study forms the basis for rational strain improvement of strain BluCon085, a derivative from strain DIB 104C with exceptionally high L-lactic acid production. The toolbox may also work for other species of the genus Caldicellulosiruptor that have so far not been genetically tractable.

[Psychopathology and Theory of Perceptual Disturbances]. / Psychopathologie und Theorie von Wahrnehmungsstörungen.

Current classification systems for psychiatric disorders are primarly based on categorial typologies and describe these as distinct nosological entities. A dimensional perspective allows descriptions of a gradual transition between pathologies as well as between normality and pathologies of psychiatric symptoms. Using acoustic hallucinations as most common form of perception disturbances as example, psychiatric-psychopathological and theoretical pros and cons for a dimensional classification of psychiatric symptomatology are sketched in this article. Although doubts concerning the similarity of real perceptions and acoustic hallucinations which underlie such mental events are controversially discussed, many hints could be found for a continuum of hallucinatoric symptoms from the mentally healthy population up to the group of patients with schizophrenia. Studies which investigate the neurophysiological mechanisms of acoustic hallucinations such as hearing voices in healthy persons in comparison to those in patients with schizophrenia could contribute to further differentiation.

Development and validation of two analytical methods for urea determination in compound feed, including pet food, and yeast using high-performance liquid chromatography coupled with fluorescence detection and tandem mass spectrometry.

Urea is authorised in the European Union (EU) as feed additive for ruminants. Because of its high molecular nitrogen content, it is a substance for potential protein adulteration in non-ruminant feed. The EU defines a spectro-colorimetric method as an official control method for the determination of urea in feed, whereas the Association of Official Analytical Chemists (AOAC) in the United States recommends an enzymatic method. Discrepancies between results obtained by these different approaches have been reported, especially at low concentrations. Therefore, we developed and validated two methods for urea determination in compound feed, including pet food, and yeast (Saccharomyces cerevisiae) over a wide concentration range using high-performance liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) and fluorescence detection (HPLC-FLD) and compared performance with a commercial enzyme kit. Limit of detection (LOD) and limit of quantification (LOQ) were found to be 3 and 8 mg kg-1 for LC-MS/MS and 2 and 7 mg kg-1 for HPLC-FLD, respectively. For both methods, the variation coefficients ranged between 1.4% and 7.2% in ruminant feed used as reference material as well as spiked samples of complete feed for chicken, pet food for dogs and cats, as well as yeast. Recovery rates for spiked samples ranged from 86% to 105%. For real samples of complete feed for poultry, wet and dry pet food for cats and dogs and yeast amounts of urea between < LOD and 200 mg kg-1 relative to a feedingstuff with a moisture content of 12% were found. In comparison with the enzyme kit, the newly developed methods proved to be less time-consuming in sample preparation and more stable regarding matrix effects.

Proliferation and Survival of Embryonic Sympathetic Neuroblasts by MYCN and Activated ALK Signaling.

Neuroblastoma (NB) is a childhood tumor that arises from the sympathoadrenal lineage. MYCN amplification is the most reliable marker for poor prognosis and MYCN overexpression in embryonic mouse sympathetic ganglia results in NB-like tumors. MYCN cooperates with mutational activation of anaplastic lymphoma kinase (ALK), which promotes progression to NB, but the role of MYCN and ALK in tumorigenesis is still poorly understood. Here, we use chick sympathetic neuroblasts to examine the normal function of MYCN and MYC in the control of neuroblast proliferation, as well as effects of overexpression of MYCN, MYC, and activated ALK, alone and in combination. We demonstrate that MYC is more strongly expressed than MYCN during neurogenesis and is important for in vitro neuroblast proliferation. MYC and MYCN overexpression elicits increased proliferation but does not sustain neuroblast survival. Unexpectedly, long-term expression of activated ALKF1174L leads to cell-cycle arrest and promotes differentiation and survival of postmitotic neurons. ALKF1174L induces NEFM, RET, and VACHT and results in decreased expression of proapototic (BMF, BIM), adrenergic (TH), and cell-cycle genes (e.g., CDC25A, CDK1). In contrast, neuroblast proliferation is maintained when MYCN and ALKF1174L are coexpressed. Proliferating MYCN/ALKF1174L neuroblasts display a differentiated phenotype but differ from ALK-expressing neurons by the upregulation of SKP2, CCNA2, E2F8, and DKC1 Inhibition of the ubiquitin ligase SKP2 (S-phase kinase-associated protein 2), which targets the CDK inhibitor p27 for degradation, reduces neuroblast proliferation, implicating SKP2 in the maintained proliferation of MYCN/ALKF1174L neuroblasts. Together, our results characterize MYCN/ALK cooperation leading to neuroblast proliferation and survival that may represent initial steps toward NB development. SIGNIFICANCE STATEMENT: MYCN overexpression combined with activated anaplastic lymphoma kinase (ALK) is sufficient to induce neuroblastoma (NB) in mouse sympathoadrenal cells. To address cellular and molecular effects elicited by MYCN/ALK cooperation, we used cultures of chick sympathetic neuroblasts. We demonstrate that MYCN increases proliferation but not survival, whereas long-term expression of ALKF1174L elicits cell-cycle exit, differentiation, and survival of postmitotic neurons. Combined MYCN/ALKF1174L expression allows long-term proliferation and survival of neuroblasts with differentiated characteristics. In the presence of ALKF1174L signaling, MYCN induces the expression of the ubiquitin ligase SKP2 (S-phase kinase-associated protein 2), which targets p27 for degradation and is also upregulated in high-risk NB. SKP2 inhibition supports a function for SKP2 in the maintained neuroblast proliferation downstream of MYCN/ALK, which may represent an early step toward tumorigenesis.

Lin28B and Let-7 in the Control of Sympathetic Neurogenesis and Neuroblastoma Development.

The RNA binding protein Lin28B is expressed in developing tissues and sustains stem and progenitor cell identity as a negative regulator of the Let-7 family of microRNAs, which induces differentiation. Lin28B is activated in neuroblastoma (NB), a childhood tumor in sympathetic ganglia and adrenal medulla. Forced expression of Lin28B in embryonic mouse sympathoadrenal neuroblasts elicits postnatal NB formation. However, the normal function of Lin28B in the development of sympathetic neurons and chromaffin cells and the mechanisms involved in Lin28B-induced tumor formation are unclear. Here, we demonstrate a mirror-image expression of Lin28B and Let-7a in developing chick sympathetic ganglia. Lin28B expression is not restricted to undifferentiated progenitor cells but, is observed in proliferating noradrenergic neuroblasts. Lin28 knockdown in cultured sympathetic neuroblasts decreases proliferation, whereas Let-7 inhibition increases the proportion of neuroblasts in the cell cycle. Lin28B overexpression enhances proliferation, but only during a short developmental period, and it does not reduce Let-7a. Effects of in vivo Lin28B overexpression were analyzed in the LSL-Lin28B(DBHiCre) mouse line. Sympathetic ganglion and adrenal medulla volume and the expression level of Let-7a were not altered, although Lin28B expression increased by 12- to 17-fold. In contrast, Let-7a expression was strongly reduced in LSL-Lin28B(DbhiCre) NB tumor tissue. These data demonstrate essential functions for endogenous Lin28 and Let-7 in neuroblast proliferation. However, Lin28B overexpression neither sustains neuroblast proliferation nor affects let-7 expression. Thus, in contrast to other pediatric tumors, Lin28B-induced NB is not due to expansion of proliferating embryonic neuroblasts, and Let-7-independent functions are implicated during initial NB development. SIGNIFICANCE STATEMENT: Lin28A/B proteins are highly expressed in early development and maintain progenitor cells by blocking the biogenesis and differentiation function of Let-7 microRNAs. Lin28B is aberrantly upregulated in the childhood tumor neuroblastoma (NB). NB develops in sympathetic ganglia and adrenal medulla and is elicited by forced Lin28B expression. We demonstrate that Lin28A/B and Let-7 are essential for sympathetic neuroblast proliferation during normal development. Unexpectedly, Lin28B upregulation in a mouse model does not affect neuroblast proliferation, ganglion size, and Let-7 expression during early postnatal development. Lin28B-induced NB, in contrast to other pediatric cancers, does not evolve from neuroblasts that continue to divide and involves Let-7-independent functions during initial development.

Midkine and Alk signaling in sympathetic neuron proliferation and neuroblastoma predisposition.

Neuroblastoma (NB) is the most common extracranial solid tumor in childhood and arises from cells of the developing sympathoadrenergic lineage. Activating mutations in the gene encoding the ALK tyrosine kinase receptor predispose for NB. Here, we focus on the normal function of Alk signaling in the control of sympathetic neuron proliferation, as well as on the effects of mutant ALK. Forced expression of wild-type ALK and NB-related constitutively active ALK mutants in cultures of proliferating immature sympathetic neurons results in a strong proliferation increase, whereas Alk knockdown and pharmacological inhibition of Alk activity decrease proliferation. Alk activation upregulates NMyc and trkB and maintains Alk expression by an autoregulatory mechanism involving Hand2. The Alk-ligand Midkine (Mk) is expressed in immature sympathetic neurons and in vivo inhibition of Alk signaling by virus-mediated shRNA knockdown of Alk and Mk leads to strongly reduced sympathetic neuron proliferation. Taken together, these results demonstrate that the extent and timing of sympathetic neurogenesis is controlled by Mk/Alk signaling. The predisposition for NB caused by activating ALK mutations may thus be explained by aberrations of normal neurogenesis, i.e. elevated and sustained Alk signaling and increased NMyc expression.

Caboxamycin, a new antibiotic of the benzoxazole family produced by the deep-sea strain Streptomyces sp. NTK 937.

Caboxamycin, a new benzoxazole antibiotic, was detected by HPLC-diode array screening in extracts of the marine strain Streptomyces sp. NTK 937, which was isolated from deep-sea sediment collected in the Canary Basin. The structure of caboxamycin was determined by mass spectrometry, NMR experiments and X-ray analysis. It showed inhibitory activity against Gram-positive bacteria, selected human tumor cell lines and the enzyme phosphodiesterase.

Albidopyrone, a new alpha-pyrone-containing metabolite from marine-derived Streptomyces sp. NTK 227.

Albidopyrone, a new alpha-pyrone-containing secondary metabolite, was produced by Streptomyces sp. NTK 227, a strain isolated from Atlantic Ocean sediment and found to be a member of the Streptomyces albidoflavus 16S rRNA gene clade. The structure of the compound was determined by MS and NMR spectroscopy, and found to have a moderate inhibitory activity against protein-tyrosin phosphatase B.

Metabolic engineering for microbial production of shikimic acid.

Shikimic acid is a high valued compound used as a key starting material for the synthesis of the neuramidase inhibitor GS4104, which was developed under the name Tamiflu for treatment of antiviral infections. An excellent alternative to the isolation of shikimic acid from fruits of the Illicium plant is the fermentative production by metabolic engineered microorganisms. Fermentative production of shikimic acid was most successfully carried out by rational designed Escherichia coli strains by blocking the aromatic amino acid pathway after the production of shikimic acid. An alternative is to produce shikimic acid as a result of dephosphorylation of shikimate-3-phosphate. Engineering the uptake of carbon, the regulatory circuits, central metabolism and the common aromatic pathway including shikimic acid import that have all been targeted to effect higher productivities and lower by-product formation are discussed.

The genetic basis of the phase variation repertoire of lipopolysaccharide immunotypes in Neisseria meningitidis.

Neisseria meningitidis strains express a diverse range of lipopolysaccharide (LPS) structures that have been classified into 12 immunotypes. A feature of meningococcal LPS is the reversible, high-frequency switching of expression (phase variation) of terminal LPS structures. A number of studies are strongly suggestive of a key role for these terminal structures, and their phase-variable expression, in pathogenesis. In a previous study, a locus of three LPS biosynthetic genes, IgtABE, involved in the biosynthesis of one of these terminal structures, lacto-N-neotetraose, was described. The molecular mechanism of phase-variable expression of this structure is by high-frequency mutation in a homopolymeric tract of G residues in the IgtA gene. To investigate the genetic basis of the structural differences between the immunotypes, and the potential for strains to express alternative immunotypes, this locus was examined in all of the immunotype strains. Initially, the Igt locus of strain 126E, an L1 immunotype strain, was cloned and sequenced, revealing two active genes, IgtC and IgtE. The remnants of the IgtA and IgtB genes and an inactive IgtD gene were also present, indicating that the locus may have once contained five active genes, similar to a locus previously reported in Neisseria gonorrhoeae strain F62. Probes based on each of the Igt genes (ABCDE), and the recently reported IgtG gene, were used to determine the presence or absence of Igt genes within individual strains, allowing the prediction of the phase variation repertoire of these strains. Sequencing to determine the nature of homopolymeric tract regions within the Igt genes was carried out to establish the potential for LPS switching. In general, the set of strains examined could be sorted into two distinct groups: one group which phase-vary the alpha-chain extension via IgtA or IgtC but cannot make beta-chain; the second group phase-vary the beta-chain extension via IgtG but do not vary alpha-chain (lacto-N-neotetraose).