Linking canonical microcircuits and neuronal activity: Dynamic causal modelling of laminar recordings.

Neural models describe brain activity at different scales, ranging from single cells to whole brain networks. Here, we attempt to reconcile models operating at the microscopic (compartmental) and mesoscopic (neural mass) scales to analyse data from microelectrode recordings of intralaminar neural activity. Although these two classes of models operate at different scales, it is relatively straightforward to create neural mass models of ensemble activity that are equipped with priors obtained after fitting data generated by detailed microscopic models. This provides generative (forward) models of measured neuronal responses that retain construct validity in relation to compartmental models. We illustrate our approach using cross spectral responses obtained from V1 during a visual perception paradigm that involved optogenetic manipulation of the basal forebrain. We find that the resulting neural mass model can distinguish between activity in distinct cortical layers - both with and without optogenetic activation - and that cholinergic input appears to enhance (disinhibit) superficial layer activity relative to deep layers. This is particularly interesting from the perspective of predictive coding, where neuromodulators are thought to boost prediction errors that ascend the cortical hierarchy.

Descending mediastinitis in Epstein-Barr virus infection.

Our case report describes a previously healthy 34-year-old male who develops a descending mediastinitis as a complication of an Epstein-Barr virus (EBV) infection. The mediastinitis was suspected to have developed by a breakthrough of a peritonsillar abscess through the space between the alar and prevertebral space.

Age dependency of coagulation parameters during childhood and puberty.

BACKGROUND: Use of age-adjusted reference values is crucial for correct diagnosis and management of thrombotic and hemorrhagic disease in children. They vary with utilized reagents and analyzers. OBJECTIVES: We established reference values with the Sysmex CA-1500 System and in parallel with the Behring BCS System using reagents from Siemens Healthcare Diagnostics Products GmbH. METHODS: After informed consent, blood samples were obtained from 218 healthy children and 52 healthy adults, grouped as 1-6 months (n = 29), 7-12 months (n = 25), 1-5 years (n = 57), 6-10 years (n = 57), 11-18 years (n = 50) and > 19 years (n = 52). RESULTS: Most coagulation parameters demonstrate good comparability between analyzers with the exception of PT and APTT. Single coagulation factors fibrinogen, factor (F) II, FIX, FXI and XII were significantly decreased in the youngest children; the strongest age dependency was found for coagulation inhibitors Protein C and S, both significantly decreased in infancy and young childhood. We confirmed that high levels of von Willebrand factor are found in the youngest children without increased levels of FVIII followed by decreased von Willebrand levels in the subsequent age group. In children with blood group O a less distinct increase in time was found, compared with individuals with one of the other blood groups. CONCLUSIONS: The correlation between the CA-1500 and the BCS system was remarkable. Differences were most pronounced between children < 12 months and older children and adults, confirming the phenomenon of developmental hemostasis. The rationale for age-related changes in the hemostatic system remains unraveled. Our results underline the need for age-specific reference ranges.

Functional magnetic resonance imaging for preoperative localisation of eloquent brain areas relative to brain tumours: clinical implementation in a regional hospital.

The purpose of this study was to evaluate the implementation of functional magnetic resonance imaging (fMRI) for clinical use in patients with a brain tumour in the setting of a regional hospital. Twenty-three patients underwent a fMRI examination as preoperative evaluation for a tumour adjacent to a eloquent brain area. The location and distance of the tumour relative to the fMRI activation area for this eloquent brain area was determined. Presence of postoperative neurological deficits was compared to the result of the fMRI examination. The fMRI examination was not interpretable in four of the twenty-three patients. In nine patients the eloquent brain area was located more than two centimetres from the tumour: seven showed no neurological deficit postoperatively, one patient experienced a temporary deficit, and one patient has not been operated yet. In the remaining ten patients the eloquent brain area was located less than two centimetres from the tumour: after (partial) resection of the tumour often using intra-operative cortical stimulation, six patients showed no neurological deficits, and three patients had temporary or permanent deficits. One patient was not operated. The clinical implementation of fMRI was successful in the preoperative evaluation of patients with a brain tumour and useful to plan the surgical intervention and to minimize postoperative neurological deficits.

[Mivazerol and other benzylimidazoles with alpha-2 adrenergic properties]. / Mivazerol et autres benzylimidazoles á properiétés alpha-2 adrénergiques.

4-Benzyl-imidazole compounds derived from Salbutanol are evaluated for potential adrenergic activities. The prevalent property of a series of new bioisosteres of catecholamines either of the saligenol-(ucb LO61) or benzamide-(Mivazerol) type is a selective alpha-adrenergic agonism, at the presynaptic level. The present study stresses the structural features responsible for the alpha-2-agonistic property.

The influence of components on the rectal absorption of cefazolin in rats.

A study has been made to identify the component(s) responsible for the absorption-promoting effect of MGK medium chain glyceride preparation commercially available as a mixture of glyceryl-1-monooctanoate, glyceryl-1,3-dioctanoate, glyceryl-1,2-dioctanoate, glyceryl trioctanoate, octanoic acid and glycerol. The action of the individual constituents has been evaluated on the rectal absorption of cefazolin in conscious rats. The results indicate that the action of MGK can be completely explained by the effect of glyceryl-1-monooctanoate, which both enhanced the extent and rate of cefazolin uptake.