Cortical local circuit axons do not mature after early deafferentation.

The processes underlying development, refinement, and retention of the intracortical connections critical for the function of the mammalian brain are unknown. Horseradish peroxidase-labeled fibers in mouse somatosensory barrel cortex, which is patterned like the whiskers on the contralateral face from which it receives inputs, were evaluated by automated image analysis. The sensory nerve to the whiskers was sectioned on postnatal day 7, after the whisker map is set. The deprived barrel cortices, examined in adults, showed drastically diminished intracortical projections relative to normal controls, although the map of the whiskers in the cortex was unchanged. This demonstrates anatomically that the normal pattern of intracortical connections, like the normal sensory map, is dependent upon the sensory periphery four synapses away.     

Frequency and clinicopathological features of fibroelastotic changes in the gastrointestinal tract

Fibroelastotic changes (FEC) and especially elastotic polyps of the gastrointestinal (GI) tract are considered rare benign lesions. They consist of accumulations of elastic fibers within the mucosal, submucosal, or muscular layer, occurring in all parts of the GI tract and often appearing as polyps, but also as diffuse non-polyp-forming deposits. They have been the subject of only a few studies. To explore the clinical and histopathological features of FEC in the GI tract, a series of 162 elastotic lesions was collected within a 2-year period. The clinical data and endoscopic findings were correlated. FEC appeared as polyp-forming lesions of the large intestine in 23 samples (14 %), all other samples concerning histological findings without an identifiable gross mass. Frequently related findings were postinterventional status (9 %), previous irradiation (7 %), and history of GI lymphoma (4 %). Eight samples (5 %) presented endoscopically with lesions justifying surgical intervention. We identified three different histological patterns of FEC, which we have called fibroelastosis, angioelastosis, and elastofibroma. Consistent with previous studies, CD34 immunohistochemical staining (performed on 38 polypoid FEC specimens) showed an increase of CD34-positive mesenchymal cells in 95 % of immunostained samples, suggesting a potential role for CD34-positive mesenchymal cells in the accumulation of elastic fibers. In conclusion, FEC are more common in the GI tract than previously recognized. They often present as a benign polyp. Many accompany other diseases like ulcers and atrophic gastritis or represent a residual finding after an intervention.     

Regulation of the tolerogenic function of steady‐state DCs

Dendritic cells (DCs) are master regulators of T‐cell responses. After sensing pathogen‐derived molecular patterns (PAMPs), or signals of inflammation and cellular stress, DCs differentiate into potent activators of naïve CD4⁺ and CD8⁺ T cells through a process that is termed DC maturation. By contrast, DCs induce and maintain peripheral T‐cell tolerance in the steady state, that is in the absence of overt infection or inflammation. However, the immunological steady state is not devoid of DC‐activating stimuli, such as commensal microorganisms, subclinical infections, or basal levels of proinflammatory mediators. In the presence of these activating stimuli, DC maturation must be calibrated to ensure self‐tolerance yet allow for adequate T‐cell responses to infections. Here, we review the factors that are known to control DC maturation in the steady state and discuss their effect on the tolerogenic function of steady‐state DCs.     

Decreased osteoclastogenesis in serotonin-deficient mice

Peripheral serotonin, synthesized by tryptophan hydroxylase-1 (TPH(1)), has been shown to play a key role in several physiological functions. Recently, controversy has emerged about whether peripheral serotonin has any effect on bone density and remodeling.We therefore decided to investigate in detail bone remodeling in growing and mature TPH(1) knockout mice (TPH(1)(-/-)). Bone resorption in TPH(1)(-/-) mice, as assessed by biochemical markers and bone histomorphometry, was markedly decreased at both ages. Using bone marrow transplantation, we present evidence that the decrease in bone resorption in TPH(1)(-/-) mice is cell-autonomous. Cultures from TPH(1)(-/-) in the presence of macrophage colony-stimulating factor and receptor activator for NF-KB ligand (RANKL) displayed fewer osteoclasts, and the decreased differentiation could be rescued by adding serotonin. Our data also provide evidence that in the presence of RANKL, osteoclast precursors express TPH(1) and synthesize serotonin. Furthermore, pharmacological inhibition of serotonin receptor 1B with SB224289, and of receptor 2A with ketanserin, also reduced the number of osteoclasts. Our findings reveal that serotonin has an important local action in bone, as it can amplify the effect of RANKL on osteoclastogenesis.     

Schockraummanagement Polytrauma

Trauma management in the emergency room is an important part of the treatment chain of the severely injured. Important decisions with respect to diagnostics and treatment must be made under time pressure. Successful trauma management in the emergency room requires a hospital tailored treatment protocol. This written protocol needs consent from all participating disciplines and must be known by all members of the resuscitation team. The ATLS® and the recently published clinical practice guidelines on multiple trauma can be of help in order to establish or update such protocols. In order to continuously evaluate and improve performance in the emergency room local quality circles are needed that truly follow that aim. Important factors are reliability of agreement between the different disciplines and continuous communication of results to the team members. In order to be successful such quality circles need people that care.