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Frakturen des Os scaphoideum sind mit 60 % die häufigsten Frakturen der Handwurzelknochen und stellen ca. 2–3 % aller Frakturen dar. Meist heilen die Frakturen bei adäquater Behandlung vollständig aus. Bei fehlender Ruhigstellung oder nicht diagnostizierten bzw. übersehenen Frakturen steigt die Wahrscheinlichkeit einer Pseudoarthrose im weiteren Verlauf an. Bei der initialen Röntgendiagnostik werden ca. 70–80 % der Kahnbeinfrakturen festgestellt. Um eine Fraktur sicher auszuschließen oder zu bestätigen, sollte, bei entsprechender Klinik und negativem Röntgenbild, eine weiterführende Diagnostik mittels Mehrzeilenspiral-CT (MSCT) oder MRT erfolgen, wobei der MSCT die höhere Bedeutung zukommt. Neben der Frakturbeschreibung gehört die Einteilung der Pseudoarthrosestadien ebenfalls zu den Aufgaben der MSCT. Wegweisend zur Beurteilung der Vitalität der Fragmente ist die kontrastmittelverstärkte MRT-Untersuchung. The clinical relevance of scaphoid bone fractures is reflected by their high incidence, accounting for approximately 60 % among carpal fractures and for 2–3 % of all fractures. With adequate therapy most scaphoid bone fractures heal completely without complications. Insufficient immobilization or undiagnosed fractures increase the risk of nonunion and the development of pseudarthrosis. X-ray examination enables initial diagnosis of scaphoid fracture in 70–80 % of cases. Positive clinical symptoms by negative x‑ray results require further diagnostics by multi-slice spiral CT (MSCT) or MRI to exclude or confirm a fracture. In addition to the diagnosis and description of fractures MSCT is helpful for determining the stage of nonunion. Contrast enhanced MRI is the best method to assess the vitality of scaphoid fragments.

Annexin A1 (ANXA1) exerts anti-inflammatory effects through multiple mechanisms including inhibition of prostaglandin synthesis. Once secreted, ANXA1 can bind to G protein-coupled formyl peptide receptors (Fpr) and activate diverse cellular signaling pathways. ANXA1 is known to be expressed in cells of the juxtaglomerular apparatus, but its relation to the expression of cyclooxygenase 2 (COX-2) in thick ascending limb and macula densa cells has not been elucidated. We hypothesized that ANXA1 regulates the biosynthesis of COX-2. ANXA1 abundance in rat kidney macula densa was extensively colocalized with COX-2 (95%). Furosemide, an established stimulus for COX-2 induction, caused enhanced expression of both ANXA1 and COX-2 with maintained colocalization (99%). In ANXA1-deficient mice, COX-2-positive cells were more numerous than in control mice (+107%; normalized to glomerular number; P< 0.05) and renin expression was increased (+566%; normalized to glomerular number; P< 0.05). Cultured macula densa cells transfected with full-length rat ANXA1 revealed downregulation of COX-2 mRNA (−59%; P< 0.05). Similarly, treatment with dexamethasone suppressed COX-2 mRNA in the cells (−49%; P< 0.05), while inducing ANXA1 mRNA (+56%; P< 0.05) and ANXA1 protein secretion. Inhibition of the ANXA-1 receptor Fpr1 with cyclosporin H blunted the effect of dexamethasone on COX-2 expression. These data show that ANXA1 exerts an inhibitory effect on COX-2 expression in the macula densa. ANXA1 may be a novel intrinsic modulator of renal juxtaglomerular regulation by inhibition of PGE2synthesis.

Na+-K+-2Cl−cotransporter (NKCC2)-mediated NaCl reabsorption in the thick ascending limb (TAL) is stimulated by AVP via V2 receptor/PKA/cAMP signaling. This process is antagonized by locally produced eicosanoids such as 20-HETE or prostaglandin E2, which are synthesized in a phospholipase A2-dependent reaction cascade. Using microarray-based gene expression analysis, we found evidence for an AVP-dependent downregulation of the calcium-independent isoform of PLA2, iPLA2β, in the outer medulla of rats. In the present study, we therefore examined the contribution of iPLA2β to NKCC2 regulation. Immunoreactive iPLA2β protein was detected in cultured mTAL cells as well as in the entire TAL of rodents and humans with the exception of the macula densa. Administration of the V2 receptor-selective agonist desmopressin (5 ng/h; 3 days) to AVP-deficient diabetes insipidus rats increased outer medullary phosphorylated NKCC2 (pNKCC2) levels more than twofold in association with a marked reduction in iPLA2β abundance (−65%; P< 0.05), thus confirming microarray results. Inhibition of iPLA2β in Sprague-Dawley rats with FKGK 11 (0.5 μM) or in mTAL cells with FKGK 11 (10 μM) or (S)-bromoenol lactone (5 μM) for 1 h markedly increased pNKCC2 levels without affecting total NKCC2 expression. Collectively, these data indicate that iPLA2β acts as an inhibitory modulator of NKCC2 activity and suggest that downregulation of iPLA2β may be a relevant step in AVP-mediated urine concentration.

Vasopressin influences salt and water transport in renal epithelia. This is coordinated by the combined action of V2receptor-mediated effects along distinct nephron segments. Modulation of NaCl reabsorption by vasopressin has been established in the loop of Henle, but its role in the distal convoluted tubule (DCT), an effective site for fine regulation of urinary electrolyte composition and the target for thiazide diuretics, is largely unknown. The Na+-Cl−cotransporter (NCC) of DCT is activated by luminal trafficking and phosphorylation at conserved NH2-terminal residues. Here, we demonstrate the effects of short-term vasopressin administration (30 min) on NCC activation in Brattleboro rats with central diabetes insipidus (DI) using the V2receptor agonist desmopressin (dDAVP). The fraction of NCC abundance in the luminal plasma membrane was significantly increased upon dDAVP as shown by confocal microscopy, immunogold cytochemistry, and Western blot, suggesting increased apical trafficking of the transporter. Changes were paralleled by augmented phosphorylation of NCC as detected by antibodies against phospho-threonine and phospho-serine residues (2.5-fold increase at Thr53 and 1.4-fold increase at Ser71). dDAVP-induced phosphorylation of NCC, studied in tubular suspensions in the absence of systemic effects, was enhanced as well (1.7-fold increase at Ser71), which points to the direct mode of action of vasopressin in DCT. Changes were more pronounced in early (DCT1) than in late DCT as distinguished by the distribution of 11β-hydroxysteroid dehydrogenase 2 in DCT2. These results suggest that the vasopressin-V2receptor-NCC signaling cascade is a novel effector system to adjust transepithelial NaCl reabsorption in DCT.

In renal epithelia, vasopressin influences salt and water transport, chiefly via vasopressin V2receptors (V2Rs) linked to adenylyl cyclase. A combination of vasopressin-induced effects along several distinct portions of the nephron and collecting duct system may help balance the net effects of antidiuresis in cortex and medulla. Previous studies of the intrarenal distribution of V2Rs have been inconclusive with respect to segment- and cell-type-related V2R expression. Our study therefore aimed to present a high-resolution analysis of V2R mRNA expression in rat, mouse, and human kidney epithelia, supplemented with immunohistochemical data. Cell types of the renal tubule were identified histochemically using specific markers. Pronounced V2R signal in thick ascending limb (TAL) was corroborated functionally; phosphorylation of Na+-K+-2Cl−cotransporter type 2 (NKCC2) was established in cultured TAL cells from rabbit and in rats with diabetes insipidus that were treated with the V2R agonist desmopressin. We found solid expression of V2R mRNA in medullary TAL (MTAL), macula densa, connecting tubule, and cortical and medullary collecting duct and weaker expression in cortical TAL and distal convoluted tubule in all three species. Additional V2R immunostaining of kidneys and rabbit TAL cells confirmed our findings. In agreement with strong V2R expression in MTAL, kidneys from rats with diabetes insipidus and cultured TAL cells revealed sharp, selective increases in NKCC2 phosphorylation upon desmopressin treatment. Macula densa cells constitutively showed strong NKCC2 phosphorylation. Results suggest comparably significant effects of vasopressin-induced V2R signaling in MTAL and in connecting tubule/collecting duct principal cells across the three species. Strong V2R expression in macula densa may be related to tubulovascular signal transfer.

Der folgende Aufsatz ist der abschließende Beitrag zum Bau der Saalebrücke Beesedau, der sich mit Details der Ausführung der Strombrücke beschäftigt. Die Erfassung aller statischen Teilsysteme einschließlich der sich aus den Betonierzuständen ergebenden Steifigkeitsänderungen ist wesentlich für die Ermittlung der Schnittgrößen und Verformungen der Zwischenzustände und des Gesamttragwerkes. Die Arbeitsschritte der statischen Analyse werden dargestellt. Die Stahlbaumontage wurde alternativ zum ausgeschriebenen Verfahren ausgeführt. Wesentliche Elemente dieses Vorgehens werden erläutert. Die Herstellung der Fahrbahnplatte erfolgte mit Hilfe einer Systemschalung im Stahltrog und einer neu entwickelten Kragarmschalung. Das Schalungskonzept, das eine hohe Arbeitsgeschwindigkeit erlaubte, wird erläutert.

A description is given of the detector system which forms the large angle spectrometer and vertex detector of the EMC spectrometer. The apparatus is used in the NA9 experiment which studies the complete hadronic final state from the interaction of high energy muons.

The beetle Melanophila acuminatais highly dependent on forest fires. The burned wood serves as food for the larvae and the adults copulate on the burned areas to put their eggs in the freshly burned trees. To be able to detect forest fires from great distances the beetle developed a highly sensitive infrared receptor which works according to a photomechanical principle. The beetle has two pit organs, one on each lateral side, of which each houses around 70 dome shaped infrared receptors. These IR-receptors consist of a hard outer cuticular shell and an inner microfluidic core. When IR-radiation is absorbed, the pressure in the core increases due to the thermal expansion. This results in a deflection of a dendritic tip of a mechanosensitiv neuron which generates the signal. This biological principle was transferred into a new kind of un-cooled technical infrared receptor. To demonstrate the functional principle and the feasibility of this IR-sensor a macroscopic demonstrator sensor was build. It consisted of an inner fluid filled cavity (pressure chamber), an IR-transmissive window and a membrane. The deflection of the membrane due to the absorbed IR-energy was measured by a sensitive commercial capacitive sensor. In the experiments ethanol with added black ink, a mix of ethanol and glucose with additional absorber, air with additional absorber and water were used as fillings of the cavity and compared against each other. In order to get insights into the physics of the results of the experiments accompanying simulations using FEM methods and analytical calculations have been performed. The results showed that ethanol and air as fillings of the cavity caused the largest deflection of the membrane. Furthermore it turned out that the thermal expansion of the sensor housing material has an important influence. The comparison of the measured deflection with calculated deflections showed a good concordance.

The hetero‐1,3‐dienes (I) react with the azirine (II), forming the cycloadducts (III).

The 1,3‐diazabutadiene derivatives (Ia) and (Ib) react with HN3to give the azides (IIa) and (IIb) which undergo ring closure reaction to yield the triazoline derivatives (IIIa) and (IIIb).

The 1,3‐diazabuta‐1,3‐dienes (I) undergo ring closure with the hydrazines (II), forming the Δ2‐1,2,4‐triazolines (III).

The 4,4‐bis(trifluoromethyl) substituted hetero‐1,3‐dienes (I) react with epichlorohydrin (II) in the presence of 4‐dimethylaminopyridine to give the heterooxazepines (III).

The heterocycles (III) are formed in the reaction of the 4,4‐bis(trifluoromethyl)hetero‐1,3‐dienes (I) with trimethylsilyl cyanide (II).