Distinct brain signatures of content and structure violation during action observation

Sentences, musical phrases and goal-directed actions are composed of elements that are linked by specific rules to form meaningful outcomes. In goal-directed actions including a non-canonical element or scrambling the order of the elements alters the action's content and structure, respectively. In the present study we investigated event-related potentials of the electroencephalographic (EEG) activity recorded during observation of both alterations of the action content (obtained by violating the semantic components of an action, e.g. making coffee with cola) and alterations of the action structure (obtained by inverting the order of two temporally adjacent pictures of sequences depicting daily life actions) interfering with the normal flow of the motor acts that compose an action. Action content alterations elicited a bilateral posterior distributed EEG negativity, peaking at around 400 ms after stimulus onset similar to the ERPs evoked by semantic violations in language studies. Alteration of the action structure elicited an early left anterior negativity followed by a late left anterior positivity, which closely resembles the ERP pattern found in language syntax violation studies. Our results suggest a functional dissociation between the processing of action content and structure, reminiscent of a similar dissociation found in the language or music domains. Importantly, this study provides further support to the hypothesis that some basic mechanisms, such as the rule-based structuring of sequential events, are shared between different cognitive domains.

[Biventricular stimulation for AV block]

Since the establishment of cardiac resynchronization therapy in left bundle branch block and mechanical asynchrony, the adverse effects of right ventricular apical pacing have gained increasing scientific interest. The sequelae of "iatrogenic desynchronization" on cardiac structure and function as well as on patients' prognosis could be well documented. "Minimally desynchronizing" stimulation strategies could be an alternative for patients needing ventricular pacing. The search for hemodynamically more advantageous alternative right ventricular pacing sites has failed so far to deliver well validated results, and due to the somewhat higher lead dislodgment rates pure left ventricular pacing cannot be recommended, at least not in pacemaker-dependent patients. Hence there is the question for primary biventricular stimulation in patients with AV block. The results of several biventricular studies with limited numbers of patients have been promising with respect to structural and functional surrogate endpoints. Two major controlled prospective and prognostically orientated studies, the BIOPACE study and the BLOCK-HF study, are currently underway and will report results in the next few years. According to the actual guidelines of the European Society of Cardiology (ESC) the implantation of a biventricular system is recommended in patients with AV block even without left bundle branch block (Class IIa, evidence level C) if they fulfill the remaining criteria that justify the implantation of a biventricular system. According to the guidelines for pacemaker therapy of the German Cardiac Society (GCS) biventricular pacing can be considered in these patients. Both societies do expressly permit the implantation of biventricular systems with ICD backup if indicated.

Komplizierter Verlauf eines Churg-Strauss-Syndroms mit eosinophiler Perimyokarditis und Perikard-Tamponade

HISTORY

A 30-year-old patient suffered from a dry cough and increasing dyspnea since two years; he further complained about non radiating chest pain and weight loss of 15 kg in the past 8 weeks.

EXAMINATIONS

Physical examination revealed pulsus paradoxus and distended neck veins. On chest x-ray, signs of cardiomegaly without infiltrations were found. Echocardiographic studies demonstrated a large pericardial effusion with signs of pericardial tamponade. Pericardiocentesis and pericardioscopy was performed and pericardial as well as epimyocardial biopsy samples were taken. Serum studies revealed increased markers of myocardial infarction and hypereosinophilia without clinical evidence of parasitic, myeloproliferative, or neoplastic diseases. Diagnosis of acute eosinophilic myocarditis was established in the epimyocardial biopsy samples.

DIAGNOSIS, TREATMENT AND COURSE

Based on the clinicopathologic findings, we diagnosed Churg Strauss syndrome with cardiac involvement. We instilled 500 mg triamcinolone intrapericardially and initiated systemic treatment with corticosteroids which resulted in normalization of the blood eosinophil count. During a follow up of 18 months, no recurrence of pericardial effusion was detected. However, while trying to reduce the steroids below 15 mg prednisolone equivalent per day, eosinophil numbers raised and wheezing increased. We suggested an immunosuppressive therapy including cyclophosphamide according to the Fauci protocol, which was denied by the patient due to potential adverse side effects.

CONCLUSION

We suggest a detailed invasive strategy including endomyocardial biopsy to rule out viral myocarditis before immunosuppressive therapy with steroids is initiated in patients with suspected cardiac involvement in Churg Strauss syndrome.

Well-shaped fibre tips by pulling with a foil heater

The length of the molten zone determines the length of pulled optical fibre tips. Tips produced by laser or filament heating are rather lengthy. By using a foil heater the taper length can be shortened and cone angles in the order of 30 degrees can reproducibly be obtained. For varying the drawing force there is an optimum temperature range where the taper shape is monotonic for the whole tip. The tip end diameter is well below 100 nm for optimized pulling conditions.

In activated mast cells, IL-1 up-regulates the production of several Th2-related cytokines including IL-9

Mast cells can play detrimental roles in the pathophysiology and mortality observed in anaphylaxis and other Th2-dominated allergic diseases. In contrast, these cells contribute to protective host defense mechanisms against parasitic worm infections. After IgE/Ag activation, mast cells can produce multiple cytokines that may enhance allergic inflammations, while a similar panel of Th2-related cytokines may support immunological strategies against parasites. Here we report that in primary mouse bone marrow-derived mast cells activated by ionomycin or IgE/Ag, the proinflammatory mediator IL-1 (alpha or beta) up-regulated production of IL-3, IL-5, IL-6, and IL-9 as well as TNF, i.e., cytokines implicated in many inflammatory processes including those associated with allergies and helminthic infections. IL-1 did not induce significant cytokine release in the absence of ionomycin or IgE/Ag, suggesting that Ca-dependent signaling was required. IL-1-mediated enhancement of cytokine expression was confirmed at the mRNA level by Northern blot and/or RT-PCR analysis. Our study reveals a role for IL-1 in the up-regulation of multiple mast cell-derived cytokines. Moreover, we identify mast cells as a novel source of IL-9. These results are of particular importance in the light of recent reports that strongly support a central role of IL-9 in allergic lung inflammation and in host defense against worm infections.