[Bone marrow edema syndrome from the perspective of appraisers and insurance clerks]. / Knochenmarködemsyndrom aus Sicht von Gutachter und Sachbearbeiter.

Various diseases or groups of diseases can trigger bone marrow edema (BME). The task of the appraiser is to work out the role of a diagnosed BME in the context of the causality based on liability; however, the inconsistent ICD 10 coding of the BME complex also poses a problem, especially for medically untrained insurance clerks. The coding of the BME as a fracture provided by the coding guidelines poses a problem when assessing reserves for damage settlement. Based on the etiology of BME an algorithm is presented that should make it easier for the expert as well as for the insurance clerk in the case of liability and also for the private accident insurance to classify the diagnosis of BME in the case.

Efficient apical IgG recycling and apical-to-basolateral transcytosis in polarized BeWo cells overexpressing hFcRn.

The human neonatal Fcgamma-receptor (hFcRn) involved in overall maternal-fetal IgG transmission is expressed in placental villous syncytiotrophoblast. However, the role of hFcRn in IgG transport and trafficking across this cell layer is poorly characterized. To gain insight into this mechanism we have overexpressed functional hFcRn in trophoblast-derived BeWo cells (BeWo/hFcRn cells) [Ellinger I, Reischer H, Lehner C, Leitner K, Hunziker W, Fuchs R. Placenta 2005;26:171-82] since parental BeWo cells endogenously express low levels of the receptor. We now demonstrate that hFcRn overexpression differentially affected apical-to-basolateral transcytosis and apical recycling: whereas IgG transcytosis was reduced by 35%, IgG recycling was stimulated by 100% as compared to parental cells, indicating that hFcRn plays a role in both processes. The endosomal compartments involved in hFcRn/IgG transport after apical IgG internalization were then analyzed by confocal immunofluorescence microscopy using compartment specific markers. hFcRn/IgG were found in apical early endosomes, in transferrin recycling compartments and in vesicles near the basolateral plasma membrane, presumably transcytotic vesicles. Neither hFcRn nor IgG was routed to the degradative pathway to lysosomes. These transport and localization data are in accordance with efficient hFcRn-mediated apical IgG recycling and basolateral directed IgG transcytosis in placental trophoblasts.

Overexpression of the human neonatal Fc-receptor alpha-chain in trophoblast-derived BeWo cells increases cellular retention of beta2-microglobulin.

Major histocompatibility complex (MHC) class I and MHC class I-type molecules such as the neonatal Fcgamma-receptor, FcRn, are heterodimers consisting of a transmembrane alpha-chain non-covalently associated with beta2-microglobulin (beta2m). Human placental villous syncytiotrophoblast (STB) lacks MHC class I molecules, but express hFcRn that mediates materno-fetal transmission of immunoglobulin G (IgG). Trophoblast-derived BeWo cells that are used to study placental IgG transport likewise express beta2m and low levels of hFcRn alpha-chain. The contribution of FcRn alpha-chain in retention and subcellular distribution of beta2m in STB and BeWo cells is unclear. To investigate this issue, we increased expression of hFcRn alpha-chain in BeWo cells (BeWo/hFcRn) by cDNA transfection. Overexpressed hFcRn protein exhibited the characteristic pH-dependent IgG binding and association with beta2m. In comparison to parental BeWo cells, beta2m mRNA levels in BeWo/hFcRn cells were not significantly altered, but total cell-associated beta2m protein was increased by 120%. Treatment of BeWo and BeWo/hFcRn cells with brefeldin A, an inhibitor of the secretory pathway, abrogated this effect, demonstrating that hFcRn alpha-chain expression retained otherwise secreted beta2m. Flow cytometry revealed that beta2m plasma membrane expression was unaffected by alpha-chain overexpression whereas by fluorescence microscopy a preferential staining of beta2m in peripheral endosomes was observed.

Placental alkaline phosphatase expression at the apical and basal plasma membrane in term villous trophoblasts.

Human placental alkaline phosphatase (PLAP) was localized at the apical and basal plasma membrane of syncytiotrophoblasts and at the surface of cytotrophoblasts in term chorionic villi using immunoelectron microscopy. Similarly, apical and basolateral PLAP expression was found in polarized trophoblast-derived BeWo cells. Trophoblasts isolated from term placentas exhibited mainly vesicular PLAP immunofluorescence staining immediately after isolation. After in vitro differentiation into syncytia, PLAP plasma membrane expression was upregulated and exceeded that observed in mononuclear trophoblasts. These data call for caution in using PLAP as a morphological marker to differentiate syncytiotrophoblasts from cytotrophoblasts or as a marker enzyme for placental brush-border membranes. (J Histochem Cytochem 49:1155-1164, 2001)

Molecular determinant for run-down of L-type Ca2+ channels localized in the carboxyl terminus of the 1C subunit.

1. The role of the sequence 1572-1651 in the C-terminal tail of the alpha1C subunit in run-down of Ca2+ channels was studied by comparing functional properties of the conventional alpha1C,77 channel with those of three isoforms carrying alterations in this motif. 2. The pore-forming alpha1C subunits were co-expressed with alpha2delta and beta2a subunits in HEK-tsA201 cells, a subclone of the human embryonic kidney cell line, and studied by whole-cell and single-channel patch-clamp techniques. 3. Replacement of amino acids 1572-1651 in alpha1C,77 with 81 different amino acids leading to alpha1C,86 significantly altered run-down behaviour. Run-down of Ba2+ currents was rapid with alpha1C,77 channels, but was slow with alpha1C,86. 4. Transfer of the alpha1C,86 segments L (amino acids 1572-1598) or K (amino acids 1595-1652) into the alpha1C,77 channel yielded alpha1C,77L and alpha1C,77K channels, respectively, the run-down of which resembled more that of alpha1C,77. These results demonstrate that a large stretch of sequence between residues 1572 and 1652 of alpha1C,86 renders Ca2+ channels markedly resistant to run-down. 5. The protease inhibitor calpastatin added together with ATP was able to reverse the run-down of alpha1C,77 channels. Calpastatin expression was demonstrated in the HEK-tsA cells by Western blot analysis. 6. These results indicate a significant role of the C-terminal sequence 1572-1651 of the alpha1C subunit in run-down of L-type Ca2+ channels and suggest this sequence as a target site for a modulatory effect by endogenous calpastatin.

Large-scale synthesis of hematoregulatory nonapeptide SK&F 107647 by fragment coupling.

Linear and convergent routes for the large-scale preparation of the hematoregulatory nonapeptide (Glp-Glu-Asp)2-DAS-(Lys)2 (2, SK&F 107647) were investigated. A convergent approach ('3 + 2'-route employing Boc-and benzyl ester protecting groups) was selected for the preparation of multihundred-gram quantities of 2. Key steps were the preparation and the coupling of tripeptide hydrochloride (HCl.H)2-DAS-(Lys(Z)-OBn)2 (6, DAS-2,7-L,L-diaminosuberic acid) and tripeptide Glp-Glu(OBn)-Asp(OBn)-OH (26). Several coupling reagents were investigated in order to reduce the amount of epimerization of this fragment coupling. TDBTU [O-(3,4-dihydro-4-oxo-1,2,3-benzotriazin-3-yl-1,1,3,3-tetrameth yluronium tetrafluoroborate] was identified as the condensation reagent of choice. Using this synthetic route > 97% pure final product in an overall yield of 35% calculated on di-Boc protected 2,7-L,L-diaminosuberic acid was prepared.

The S-layer proteins of two Bacillus stearothermophilus wild-type strains are bound via their N-terminal region to a secondary cell wall polymer of identical chemical composition.

Two Bacillus stearothermophilus wild-type strains were investigated regarding a common recognition and binding mechanism between the S-layer protein and the underlying cell envelope layer. The S-layer protein from B. stearothermophilus PV72/p6 has a molecular weight of 130,000 and assembles into a hexagonally ordered lattice. The S-layer from B. stearothermophilus ATCC 12980 shows oblique lattice symmetry and is composed of subunits with a molecular weight of 122,000. Immunoblotting, peptide mapping, N-terminal sequencing of the whole S-layer protein from B. stearothermophilus ATCC 12980 and of proteolytic cleavage fragments, and comparison with the S-layer protein from B. stearothermophilus PV72/p6 revealed that the two S-layer proteins have identical N-terminal regions but no other extended structurally homologous domains. In contrast to the heterogeneity observed for the S-layer proteins, the secondary cell wall polymer isolated from peptidoglycan-containing sacculi of the different strains showed identical chemical compositions and comparable molecular weights. The S-layer proteins could bind and recrystallize into the appropriate lattice type on native peptidoglycan-containing sacculi from both organisms but not on those extracted with hydrofluoric acid, leading to peptidoglycan of the A1gamma chemotype. Affinity studies showed that only proteolytic cleavage fragments possessing the complete N terminus of the mature S-layer proteins recognized native peptidoglycan-containing sacculi as binding sites or could associate with the isolated secondary cell wall polymer, while proteolytic cleavage fragments missing the N-terminal region remained unbound. From the results obtained in this study, it can be concluded that S-layer proteins from B. stearothermophilus wild-type strains possess an identical N-terminal region which is responsible for anchoring the S-layer subunits to a secondary cell wall polymer of identical chemical composition.

[Configurations of attitudes, experiences and expectations of social welfare recipients]. / Konfigurationen der Einstellungen, Erfahrungen und Forderungen von Sozialhilfeempfängern.

A taxonomy of welfare work clients, based upon their attitudes, experiences, and demands with respect to welfare work, was established by using cluster analysis and, subsequently, discriminant analysis. In a second step, typologically relevant variables and hypotheses were statistically tested by a configuration-frequency-analysis on the basis of a sample of another 885 clients. 7 configurations of variable scores reached significance, thus confirming the hypothesis predominantly. Furthermore, these results are important for planning strategies of welfare work.