Diagnostics and therapy of bilateral choanal atresia in association with CHARGE syndrome.

BACKGROUND: Bilateral choanal atresia in patients with CHARGE syndrome becomes symptomatic immediately after birth. A prompt diagnosis, the implementation of sufficient preliminary measures, and the delivery of surgical therapy are crucial. This article is intended to assist in terms of diagnostics and a therapy recommendation. METHODS: We performed a retrospective study using the medical records of all newborns in the University Hospital in Bonn, diagnosed with bilateral choanal atresia and CHARGE syndrome and underwent surgery at the Department of Otorhinolaryngology, Head and Neck Surgery. RESULTS: A total of 21 patients have been treated with a unilateral or bilateral choanal atresia. 14 patients were primarily treated with transnasal endoscopy or underwent transnasal endoscopic surgery as a follow-up intervention (73.68%). Nine patients had a syndromal appearance, which was considered a definite diagnosis in six patients (five with CHARGE syndrome). All five patients with CHARGE syndrome received transnasal endoscopic treatment and a stent was inserted. DISCUSSION: Bilateral choanal atresia can be a life-threatening situation requiring acute measures. The therapeutic trend goes towards transnasal endoscopic resection. Primary intervention should be: minimally invasive, one-stage surgery, functional, and associated with low complication rates. Patency can be increased by saline irrigations, topical corticosteroids, endoscopic controls, and regular dilatation. The insertion of stents is controversially discussed but can be useful in syndromal patients. However, adjuvant therapy with a stent and mitomycin C is increasingly being abandoned. A significantly higher recurrence rate must be expected in association with CHARGE syndrome. Stenting should be considered on an individual basis. Continuous training and support of the parents are obligatory.

TIMP3 is Regulated by Pericytes upon Shear Stress Detection Leading to a Modified Endothelial Cell Response.

OBJECTIVES: Atherosclerosis is a hallmark of cardiovascular disease. Shear stress on endothelial cells has been linked to atherogenesis and to fibrous cap thinning and rupture. Pericytes reside in the sub-endothelial space of vessels and have vasoprotective effects. They are subjected to shear stress when endothelial cell integrity is disrupted. The aim was to investigate the susceptibility and response of pericytes to shear stress. METHODS: Endothelial cells and pericytes were seeded in two dimensional monocultures and co-cultures, and in a novel three dimensional co-culture system and were subjected to no, low and high shear stress (0, 10, 30 dyne/cm2) for 48 h. The morphological response to flow was assessed by histology and the expression of extracellular matrix proteins was analysed using quantitative polymerase chain reaction, immunoblotting, and ELISA. RESULTS: While endothelial cells aligned into flow direction, pericytes aligned perpendicularly (p < .001), indicating that they must be capable of sensing flow. When pericytes were embedded into a 3D matrix they showed similar alignment and pericytes built long processes towards the lumen. Under shear stress endothelial cells upregulated "a disintegrin and metalloproteinase with thrombospondin motif 1" (ADAMTS-1) (p < .01) and pericytes upregulated "tissue inhibitor of matrix metalloproteinase" (TIMP) 3 (p < .05), an inhibitor of ADAMTS-1, meanwhile differential expression of extracellular matrix (ECM) proteins could be detected in co-cultures of both cells. For TIMP3 expression direct cell-cell contact between endothelial cells and pericytes was required. CONCLUSION: The experiments highlight that pericytes are able to sense direct flow thereby regulating ECM proteins known to be involved in vascular remodelling. Furthermore, pericytes counter-regulate endothelial ADAMTS-1 by protective TIMP3 expression to prevent matrix degradation and maintain vascular stability. For this protective effect direct cell contact was necessary. This observation might represent an adaptive, protective mechanism of pericytes to counteract endothelial damage in the onset of atherosclerosis.

Resonant Raman transitions into singlet and triplet states in InGaAs quantum dots containing two electrons.

Semiconductor quantum dots containing two electrons, also called artificial quantum-dot helium atoms, are model structures to investigate the most fundamental many-particle states induced by Coulomb interaction and the Pauli exclusion principle. Here, electronic excitations in quantum-dot helium are investigated by resonant Raman spectroscopy in magnetic fields. We observe transitions from the ground state into the excited singlet state and, in the depolarized Raman configuration which allows spin-flip processes, into the triplet state.

Optical Properties of GaAs Quantum Dots Fabricated by Filling of Self-Assembled Nanoholes.

Experimental results of the local droplet etching technique for the self-assembled formation of nanoholes and quantum rings on semiconductor surfaces are discussed. Dependent on the sample design and the process parameters, filling of nanoholes in AlGaAs generates strain-free GaAs quantum dots with either broadband optical emission or sharp photoluminescence (PL) lines. Broadband emission is found for samples with completely filled flat holes, which have a very broad depth distribution. On the other hand, partly filling of deep holes yield highly uniform quantum dots with very sharp PL lines.

Involvement of interleukin-4 and -10 in inflammatory bowel disease.

The pathogenesis of ulcerative colitis (UC) and Crohn's disease (CD) may be associated with a decreased production of cytokines suppressing macrophage and T-cell functions: interleukins (IL) -4 and IL-10. Serum concentrations of IL-4 and IL-10 were measured using an ELISA technique, and intestinal IL-4 and IL-10 mRNA was detected by a reverse transcriptase polymerase chain reaction (RT-PCR) in 34 patients with inflammatory bowel disease (IBD) (20 with UC and 14 with CD) and compared to 12 control subjects. The superoxide production was measured spectrophotometrically in activated PMNs initially incubated in the presence of IL-4 or IL-10. No differences were found in numbers of cells that might be potential IL-4 or IL-10 producers (T cells, macrophages, B cells, and mast cells) in biopsy specimens using immuno- and histochemistry. IL-4 mRNA was detectable in specimens from 77.8% of the UC patients (P > 0.05) and 0% of the CD patients (P < 0.05), as compared to 81.8 in controls, and was significantly different (P < 0.0001) between UC and CD patients. The IL-10 amplification product was detectable in specimens from 30.0% UC patients (P < 0.003), but not in CD patients (78.6%, P > 0.05) as compared to controls (91.7%). The circulating protein levels of IL-4 were below the detection limit in all groups (detection limit 4 pg/ml), while the median IL-10 concentration was 12.5 pg/ml in UC, 18.1 pg/ml in CD, and 19.5 pg/ml among controls (detection limit 3 pg/ml), which did not differ in any of the three groups (P > 0.05). Finally, the superoxide production was inhibited and delayed by the addition of IL-10 (P < 0.01), whereas IL-4 only delayed this parameter. In conclusion, apart from the well-known suppressive effect on proinflammatory cytokine production, IL-4 delays and IL-10 inhibits superoxide generation. IL-4 mRNA expression is decreased in intestinal tissue from CD patients, while IL-10 mRNA expression is decreased in majority of UC patients, suggesting different immunopathogenesis of the two diseases.