Neural correlates of metaphor processing

Metaphoric language is used to express meaning that is otherwise difficult to conceptualize elegantly. Beyond semantic analysis, understanding the figurative meaning of a metaphor requires mental linkage of different category domains normally not related to each other. We investigated processing of metaphoric sentences using event-related functional magnetic resonance imaging (fMRI). Stimuli consisted of 60 novel short German sentence pairs with either metaphoric or literal meaning. The pairs differed only in their last one to three words and were matched for syntax structure, word frequency, connotation and tense. Fifteen healthy subjects (six female, nine male, 19-51 years) read these sentences silently and judged by pressing one of two buttons whether they had a positive or negative connotation. Reading metaphors in contrast to literal sentences revealed signal changes in the left lateral inferior frontal (BA 45/47), inferior temporal (BA 20) and posterior middle/inferior temporal (BA 37) gyri. The activation in the left inferior frontal gyrus may reflect semantic inferencing processes during the understanding of a metaphor. This is in line with the results from other functional imaging studies showing an involvement of the left inferior frontal gyrus in integrating word and sentence meanings. Previous results of a right hemispheric involvement in metaphor processing might reflect understanding of complex sentences.     

Successful episodic memory retrieval of newly learned faces activates a left fronto-parietal network

It is easier to recognize a familiar face than a newly learned face. The neural basis of familiar face recognition has been elucidated in functional imaging and lesion studies. Behavioural and neuropsychological data indicate, however, that brain systems involved in episodic retrieval of familiar and newly learned faces are distinct. In our study, 12 subjects viewed 30 novel faces in an encoding session. In the study condition, event-related functional magnetic resonance imaging (fMRI) was used to compare brain activation during correct recognition of the recently learned faces to that observed during correct rejection of unknown control faces. Differences were present in the left inferior parietal (BA 40) and left medial frontal/anterior cingulate (BA 32/9) cortex. These two regions may be part of a pathway in the dorsal visual stream, responsible for a "feeling of familiarity" in contrast to the ventral pathway in the temporal lobes, which is mainly involved in the recognition of personal identity.     

Refining HPV 16 L1 purification from E. coli: Reducing endotoxin contaminations and their impact on immunogenicity

HPV 16 L1 capsomeres purified from Escherichia coli represent a promising and potentially cost-effective alternative to the recently licensed VLP-based vaccines for the prevention of cervical cancer. However, recombinant protein preparations from bacteria always bear the risk of contaminating endotoxins which are highly toxic in humans and therefore have to be eliminated from vaccine preparations. In this study, we measured the LPS concentration at various stages of the purification of HPV 16 L1 from E. coli and determined that it enhances the immunogenicity of HPV 16 VLPs and capsomeres. We confirmed the immunogenicity of the L1 capsomeres in TLR4^−/− mice without the enhancing effect of the LPS and then elaborated a suitable protocol using Triton X-114 phase separation for the removal of LPS without any significant protein loss or influence on the structural integrity of the particles. The LPS-free capsomeres purified from E. coli induced neutralizing L1-specific antibodies. Our results demonstrate the excellent potential of capsomeres as an economically interesting alternative vaccine to prevent cervical cancer that could be made available in developing countries.     

Factory packed and expired – about emergency insect sting kits

Background: Patients allergic to insect venom are instructed to always carry emergency medication–an emergency kit. According to the current guidelines, these emergency kits should contain a H1‐receptor‐blocking antihistamine and corticosteroid for oral use, as well as an epinephrine inhaler and in particular situations an epinephrine auto‐injector. Patients and Methods: For quality management reasons patients with wasp venom allergy who presented for sting challenge provocation test were told to demonstrate their emergency kits. Concomitantly, constituents of the patient's emergency kits were checked for date of expiry of the medication and the patients were interviewed on storage and use of the emergency kits. Results: In total 42 patients with a median duration time of systemic immunotherapy of 2.5 year were evaluated. Medication post date of expiration was found in 54% of the kits (n = 39). Only 31% of the patients could demonstrate how to use the kits correctly. Problems were especially evident concerning for using the application of the inhaler and auto‐injector. 50% of the patients demonstrated using epinephrine auto‐injectors in such way that an accidental injection into the fingers would have resulted. Conclusion: To assure safe and effective handling of all components of the emergency kit, continuous training and repeated supervised practice is necessary.     

Fenestrated-branched endografts and visceral debranching plus stenting (hybrid) for complex aortic aneurysm repair

Objective

The aim of this study was to assess the immediate postoperative and midterm outcome of complex aortic aneurysm treatment necessitating four-vessel revascularization with either a total endovascular approach (fenestrated-branched stent graft [FBSG]) or a hybrid technique of visceral debranching plus stenting.

The neural correlates of perceiving one's own movements

Feedforward mechanisms are important for movement control. They may also contribute to the identification of self-produced actions by attenuating the sensory consequences of self-produced movements. In our study, subjects opened and closed their hand slowly and continuously (0.5 Hz). This movement was filmed with an MRI compatible video camera and projected online onto a screen, viewed by the subject while BOLD contrast was measured with fMRI. The temporal delay between movement and feedback was parametrically varied (0-200 ms). In each trial, subjects judged whether there was a delay or not. There was a positive correlation between the extent of the temporal delay and activation in the right posterior superior temporal cortex (pSTS) and a negative correlation in the left putamen. A second analysis addressed the neural correlates of subjective judgement under conditions of uncertainty. This contrast showed a differential activation in the cerebellum. These results support the assumption of a forward model implying that predictions generated in motor areas attenuate sensory areas. They also suggest that efference copy mechanisms are not located within specific brain areas but are implemented as a specific form of interaction between perceptual and motor areas depending on the modalities and the type of actions involved. Further, conscious detection of small temporal deviations might be based on signals generated in the cerebellum which provide fine-grained temporal information. These results might be useful to refine theories about the role of forward mechanisms in the emergence of disorders of the self, such as in schizophrenia.