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Bauer F, Bisplinghoff J, Büsser K, Busch M, Colberg T, Demirörs L, Dahl C, Eversheim PD, Eyser O, Felden O, Gebel R, Greiff J, Hinterberger F, Jonas E, Krause H, Lehmann C, Lindlein J, Maier R, Meinerzhagen A, Pauly C, Prasuhn D, Rohdjess H, Rosendaal D, von Rossen P, Schirm N, Scobel W, Ulbrich K, Weise E, Wolf T, Ziegler R. Measurement of spin-correlation parameters ANN, ASS, and ASL at 2.1 GeV in proton-proton elastic scattering. PHYSICAL REVIEW LETTERS 2003; 90:142301. [PMID: 12731910 DOI: 10.1103/physrevlett.90.142301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2002] [Indexed: 05/24/2023]
Abstract
At the Cooler Synchrotron COSY/Jülich spin-correlation parameters in elastic proton-proton (pp) scattering have been measured with a 2.11 GeV polarized proton beam and a polarized hydrogen atomic beam target. We report results for A(NN), A(SS), and A(SL) for c.m. scattering angles between 30 degrees and 90 degrees. Our data on A(SS)--the first measurement of this observable above 800 MeV--clearly disagrees with predictions of available pp scattering phase-shift solutions while A(NN) and A(SL) are reproduced reasonably well. We show that in the direct reconstruction of the scattering amplitudes from the body of available pp elastic scattering data at 2.1 GeV the number of possible solutions is considerably reduced.
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Häussler S, Lehmann C, Breselge C, Rohde M, Classen M, Tümmler B, Vandamme P, Steinmetz I. Fatal outcome of lung transplantation in cystic fibrosis patients due to small-colony variants of the Burkholderia cepacia complex. Eur J Clin Microbiol Infect Dis 2003; 22:249-53. [PMID: 12687415 DOI: 10.1007/s10096-003-0901-y] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The aim of this study was to investigate the possible role of small-colony variant morphotypes of Burkholderia cepacia-like organisms in infectious complications in cystic fibrosis patients following lung transplantation. Respiratory tract specimens from 470 cystic fibrosis patients were screened over a 22-month period for Burkholderia cepacia-like organisms. Nineteen patients were positive for these organisms, eight of whom harboured small-colony-variant morphotypes. Three patients underwent bilateral lung transplantation during the study, two of whom harboured small-colony variants in addition to clonally identical wildtypes of Burkholderia multivorans and Burkholderia cepacia genomovar III prior to lung transplantation. Both patients developed fatal systemic infections post transplantation due to small-colony variants. In vitro testing revealed that small-colony variants exhibited increased serum resistance in comparison to wildtypes. The results of this study indicate that diagnostic efforts should be undertaken to carefully identify small-colony variants of Burkholderia cepacia complex, since they might be an indicator of poor post-transplantation outcome in patients with cystic fibrosis.
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153
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Bauer R, Lehmann C, Hoch M. Gastrointestinal development in the Drosophila embryo requires the activity of innexin gap junction channel proteins. CELL COMMUNICATION & ADHESION 2003; 8:307-10. [PMID: 12064608 DOI: 10.3109/15419060109080743] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Cell to cell communication plays an essential role during pattern formation and morphogenesis of the diverse tissues and organs of the body. In invertebrates, such as the fruitfly Drosophila, the direct communication of closely apposed cells is mediated by gap junctions which are composed of oligomers of the innexin family of transmembrane channel proteins. Few data exist about the developmental role of the eight innexin genes which have been found in the Drosophila genome. We have investigated the role of the innexin 2 and ogre genes during gastrointestinal development of the fly embryo. Our findings suggest that innexins are involved in the formation of the proventriculus, an organ that develops at the foregut/midgut boundary by migration of primordial cells and subsequent infolding of epithelial tissue layers.
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154
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Huster D, Hoppert M, Lutsenko S, Zinke J, Lehmann C, Mössner J, Berr F, Caca K. Defective cellular localization of mutant ATP7B in Wilson's disease patients and hepatoma cell lines. Gastroenterology 2003; 124:335-45. [PMID: 12557139 DOI: 10.1053/gast.2003.50066] [Citation(s) in RCA: 120] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND & AIMS Wilson's disease, a hereditary disorder caused by mutations in the Wilson's disease gene (ATP7B), leads to hepatic and/or neurological pathology resulting from cellular copper overload. In vitro studies showed that ATP7B, located in the trans-Golgi network, traffics to a cytoplasmic vesicular compartment in response to increased copper concentration. Mislocalization and failed intracellular trafficking of ATP7B mutants are suggested to be among disease-causing mechanisms; however, the effect of mutations on ATP7B localization in human tissues has not been directly shown. Therefore, we characterized the subcellular localization of normal and mutant ATP7B in human livers and in hepatoma cell lines. METHODS Subcellular distribution of ATP7B in liver tissue from 3 control individuals and 3 Wilson's disease patients harboring a homozygous H1069Q-ATP7B mutation was analyzed by using immunogold electron microscopy. In addition, 14 ATP7B mutants tagged to green fluorescent protein were generated and expressed in HuH-7 and HepG2 cells; intracellular localization of these mutants was characterized by confocal microscopy. RESULTS In hepatocytes, ATP7B was localized in trans-Golgi vesicles, whereas H1069Q-ATP7B was trapped in the endoplasmic reticulum. Similar results were observed for wild-type ATP7B and H1069Q-ATP7B expressed in hepatoma cells. Most ATP7B proteins harboring missense mutations were distributed similarly to wild-type ATP7B. In contrast, truncated ATP7B mutants showed a diffuse, clustered, cytoplasmic pattern, distinct from the trans-Golgi network or endoplasmic reticulum. CONCLUSIONS These results provide a detailed demonstration of the ATP7B distribution in control and diseased human livers and indicate that several Wilson's disease mutations lead to incorrect localization of ATP7B to distinct cell compartments.
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Stowasser F, Lehmann C. Structure determination of anhydrous caffeine C8H10N4O2from X-ray powder diffraction data. Acta Crystallogr A 2002. [DOI: 10.1107/s0108767302095582] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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156
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Scheller FW, Wollenberger U, Lei C, Jin W, Ge B, Lehmann C, Lisdat F, Fridman V. Bioelectrocatalysis by redox enzymes at modified electrodes. J Biotechnol 2002; 82:411-24. [PMID: 11996219 DOI: 10.1016/s1389-0352(01)00055-1] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Self-assembled monolayers of thiolated compounds are used as promoters for protein-electrode reactions. They provide an anchor group based on thiol chemisorptions and also a functional group for effective interaction with the protein. These interactions are often governed by electrostatic attraction. For example, for positively charged proteins, such as cytochrome c and the selenoprotein glutathione peroxidase, mercaptoalkanoic acids have been used. Clay modification of the electrode surface has been found to facilitate the heterogeneous electron transfer process for heme proteins, e.g. cytochrome c, cytochrome P450 and myoglobin. Interestingly, nucleic acids at carbon electrodes and thiol-modified double stranded oligonucleotides act as promoters of the redox communication to proteins, whereas the mechanism is still subject to controversy interpretations. By interacting the protein immobilised at the electrode with species in solution, signal chains have been constructed. The interaction can result in a simple co-ordination or redox reaction, depending on the nature of the reaction partners. For analytical purposes, e.g. biosensors, the electrochemical redox conversion of the immobilised protein is evaluated.
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Steib A, Freys G, Lehmann C, Meyer C, Mahoudeau G. Intraoperative blood losses and transfusion requirements during adult liver transplantation remain difficult to predict. Can J Anaesth 2001; 48:1075-9. [PMID: 11744582 DOI: 10.1007/bf03020372] [Citation(s) in RCA: 127] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
PURPOSE To identify preoperative factors associated with high blood losses during liver transplantation for chronic end-stage liver disease. METHODS Four hundred and ten consecutive patients were included in this retrospective study. Blood losses were calculated, based on transfusion requirements. The population was divided into two groups: the upper quartile was defined as the high blood loss (HBL) group and the lower three quartiles as the low blood loss group. Fourteen preoperative variables were collected. Qualitative variables consisted of the type of hepatopathy, Child-Pugh's classification, sex, the surgical team's experience, previous abdominal surgery and portal hypertension. Quantitative variables were age, hemoglobin concentration Hb, platelet count, prothrombin time, activated partial thromboplastin time, fibrinogen concentration, fibrin degradation products (FDP) and euglobulin lysis time. Univariate analysis and stepwise multivariate analysis were conducted. RESULTS Patients in the HBL group required 12 units of red blood cell or more to maintain a Hb >/= 100g*L(-1). HBL was associated with severe liver disease, previous abdominal surgery, use of a venovenous bypass and little surgical experience in orthotopic liver transplantation (OLT). In the HBL group several hemostatic parameters were more disturbed before surgery. The multivariate analysis disclosed three independent variables associated with HBL: Hb and FDP concentrations and previous upper abdominal surgery. When combined, these resulted in a high specificity (98%) but low sensitivity to predict blood loss. CONCLUSION Despite our efforts we were unable to identify predictive risk factors of bleeding during OLT even in a homogeneous population. Centres should evaluate their practice individually in an attempt to identify patients at high risk of being transfused.
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Zysset S, Müller K, Lehmann C, Thöne-Otto AI, von Cramon DY. Retrieval of long and short lists from long term memory: a functional magnetic resonance imaging study with human subjects. Neurosci Lett 2001; 314:1-4. [PMID: 11698132 DOI: 10.1016/s0304-3940(01)02175-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Previous studies have shown that reaction time in an item-recognition task with both short and long lists is a quadratic function of list length. This suggests that either different memory retrieval processes are implied for short and long lists or an adaptive process is involved. An event-related functional magnetic resonance imaging study with nine subjects and list lengths varying between 3 and 18 words was conducted to identify the underlying neuronal structures of retrieval from long and short lists. For the retrieval and processing of word-lists a single fronto-parietal network, including premotor, left prefrontal, left precuneal and left parietal regions, was activated. With increasing list length, no additional regions became involved in retrieving information from long-term memory, suggesting that not necessarily different, but highly adaptive retrieval processes are involved.
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Harnack U, Lehmann C, Matthes E, Pecher G. Up-regulation of telomerase activity in Herpesvirus saimiri immortalized human T-lymphocytes. Anticancer Res 2001; 21:3969-72. [PMID: 11911278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
Human T-lymphocytes can be transformed to unlimited growth by Herpesvirus saimiri (HVS). We studied the telomerase activity of a recently established HVS immortalized human CD4 T cell clone in comparison to peripheral blood lymphocytes (PBL) and unstimulated or phytohemagglutinin (PHA)-stimulated CD4 T-cells by a Telomeric Repeat Amplification-Protocol (TRAP) -Assay. Telomerase activity in PHA-stimulated CD4 T-cells was seven-fold and in HVS-infected CD4 T-cells 14-fold higher than in untreated CD4 T-cells. The HVS immortalized T-cell clone provides a useful tool for studying the regulation of telomerase activity during carcinogenesis and for testing of telomerase-inhibitory drugs.
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Lehmann C, Wilkening A, Leiber D, Markus A, Krug N, Pabst R, Tschernig T. Lymphocytes in the bronchoalveolar space reenter the lung tissue by means of the alveolar epithelium, migrate to regional lymph nodes, and subsequently rejoin the systemic immune system. THE ANATOMICAL RECORD 2001; 264:229-36. [PMID: 11596005 DOI: 10.1002/ar.1163] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Lymphocytes in the bronchoalveolar space are routinely obtained and examined in lung diseases such as asthma or sarcoidosis. In a pig model, labeled lymphocytes were found in regional lymph nodes after intrabronchial instillation, indicating that reentry of lymphocytes from the bronchoalveolar space into the body is possible. In the present study, the route and kinetics of the reentry of bronchoalveolar lymphocytes were investigated in a congenic rat model using immunohistochemistry on cryostat and semithin sections and confocal laser scanning microscopy. As early as 15 min after intratracheal instillation lymphocytes were found to leave the bronchoalveolar space by transmigration through alveolar but not bronchial epithelium and were observed in interstitial alveolar tissue. At 6 hr after intratracheal instillation, T and B lymphocytes appeared in the draining lymph nodes of the lung with an increase after 24 and 48 hr. The kinetic pattern clearly differed in nondraining lymph nodes and other organs. After 6 hr, only single cells were found in nondraining lymph nodes, spleen, and blood with a slight increase after 24 hr, and only occasionally were single cells seen in the liver, thymus, or Peyer's patches 24 and 48 hr after instillation. In conclusion, T and B lymphocytes can leave the alveolar space by reentry into the lung tissue through alveolar epithelium. They reach regional lymph nodes by means of lymphatic vessels and are then distributed all over the body to rejoin the systemic immune system. Coming into contact with environmental antigens, these lymphocytes could perform an important function in the lung immune system and might be a target for inhalative therapy.
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Lehmann C, Zeis M, Uharek L. Activation of natural killer cells with interleukin 2 (IL-2) and IL-12 increases perforin binding and subsequent lysis of tumour cells. Br J Haematol 2001; 114:660-5. [PMID: 11552995 DOI: 10.1046/j.1365-2141.2001.02995.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Natural killer (NK) cells can lyse a variety of different tumour cells by exocytosis of perforin, subsequent binding of perforin to the target cell membrane and formation of lytic pores. Some tumour cells, however, are resistant to cellular cytotoxicity. Using the NK-resistant tumour cell lines ML-2, MONOMAC-1, RPMI and L540Cy, we demonstrated that activation of NK cells with interleukin 2 (IL-2) and IL-12 resulted in significant lysis of these tumour targets. To investigate the underlying mechanisms, we isolated the cytotoxic granules from non-activated and IL-2-/IL-12-activated NK cells and compared the killing of K562 leukaemia cells (sensitive to NK cell-mediated lysis) and ML-2 leukaemia cells (resistant to NK cell-mediated lysis). In contrast to K562 cells, which were easily killed by NK-cell granules, ML-2 cells were resistant to granules from non-activated NK cells. However, granules from NK cells activated with IL-2 and IL-12 were able to induce significant tumour cell lysis. Cell death of both K562 and ML-2 cells by granules from activated NK cells was completely blocked by anti-perforin antibodies, indicating that perforin mainly accounts for the lysis induced by NK granules. Comparing granules from non-activated and IL-2-/IL-12-activated NK cells, the increased cell death of ML-2 cells was caused by an improved binding of perforin to the target cell membrane. Functional assays, however, indicated that the differences in perforin binding were not as a result of an augmented production of perforin by activated NK cells. We conclude that activation of NK cells results in an increased binding of perforin and subsequent lysis of tumour cells.
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Lehmann C, König JP, Dettmann J, Birnbaum J, Kox WJ. Effects of iloprost, a stable prostacyclin analog, on intestinal leukocyte adherence and microvascular blood flow in rat experimental endotoxemia. Crit Care Med 2001; 29:1412-6. [PMID: 11445699 DOI: 10.1097/00003246-200107000-00019] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
OBJECTIVE To investigate the effects of iloprost, a stable prostacyclin analog, on leukocyte adherence in intestinal venules and intestinal microvascular blood flow in experimental endotoxemia. DESIGN Prospective, randomized, controlled animal study. SETTING Experimental laboratory. SUBJECTS Twenty-one male Wistar rats weighing 190 +/- 40 g. INTERVENTIONS The rats were divided equally into three groups: the first was a control group; the second received endotoxin (20 mg/kg lipopolysaccharide from Escherichia coli O55:B5 intravenously); and the third received endotoxin and intravenous iloprost infusion (2 ng.kg-1.min-1). MEASUREMENTS AND MAIN RESULTS The distal small intestine of the animals was examined by using intravital fluorescence videomicroscopy 2 hrs after endotoxin challenge. Leukocytes were stained in vivo by means of rhodamine 6G. Intestinal microvascular blood flow was measured by laser Doppler flowmetry in the terminal ileum. Iloprost treatment significantly attenuated the count of adherent leukocytes in collecting venules (control, 61 +/- 10 n/mm2; lipopolysaccharide, 364 +/- 60 n/mm2; iloprost, 232 +/- 29 n/mm2; p <.05) and in postcapillary venules (control, 96 +/- 14 n/mm2; lipopolysaccharide, 470 +/- 21 n/mm2; iloprost 390 +/- 41 n/mm2; p <.05). Intestinal microvascular blood flow was decreased significantly in the lipopolysaccharide group (-49%), whereas iloprost-treated animals showed no significant difference compared with the control group. CONCLUSIONS The study demonstrated that administration of iloprost attenuated leukocyte adherence in postcapillary and collecting intestinal venules and improved intestinal microvascular blood flow. Thus, iloprost treatment may impact endotoxin-induced intestinal injury.
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Peluso S, Rückle T, Lehmann C, Mutter M, Peggion C, Crisma M. Crystal structure of a synthetic cyclodecapeptide for template-assembled synthetic protein design. Chembiochem 2001; 2:432-7. [PMID: 11828474 DOI: 10.1002/1439-7633(20010601)2:6<432::aid-cbic432>3.0.co;2-6] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The structural prototype of a new generation of regioselectively addressable functionalized templates (RAFTs) for use in protein de novo design has been synthesized and crystallized. The structure of the aromatically substituted cyclodecapeptide was determined by X-ray diffraction; it consists of an antiparallel beta sheet spanned by heterochirally induced type IIprime prime or minute beta turns, similar to that observed in gramicidin S. The three-dimensional structure of the artificial template was also examined by an NMR spectroscopic analysis in solution and shown to be compatible with a beta-sheet plane suitable for accommodating secondary functional peptide fragments for the synthesis of template-assembled synthetic proteins (TASPs).
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Gait MJ, Lehmann C. A base-labile protecting group (fluorenylmethoxycarbonyl) for the 5'-hydroxy function of nucleosides. CURRENT PROTOCOLS IN NUCLEIC ACID CHEMISTRY 2001; Chapter 2:Unit 2.4. [PMID: 18428837 DOI: 10.1002/0471142700.nc0204s00] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Many popular synthesis strategies look for appropriate 2'-O-protection methods to use in conjunction with 5'-O-trityl chemistry. In contrast, this unit describes the use of FMOC as a 5'-protecting group in conjunction with a ketal-type 2'-O-protecting group, 4-methoxytetrahydropyran-4-yl (MTHP). The synthesis of all four 2'-O-MTHP-5'-O-FMOC-protected ribonucleosides and 5'-O-FMOC-2'-deoxythymidine is described, as is the preparation of the N-protected, 2'-O-MTHP-protected starting nucleosides.
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Lehmann C, Wollenberger U, Brigelius-Flohe R, Scheller FW. Modified Gold Electrodes for Electrochemical Studies of the Reaction of Phospholipid Hydroperoxide Glutathione Peroxidase with Glutathione and Glutathione Disulfide. ELECTROANAL 2001. [DOI: 10.1002/1521-4109(200104)13:5<364::aid-elan364>3.0.co;2-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Lehmann C, Georgiew A, Weber M, Birnbaum J, Kox WJ. Reduction in intestinal leukocyte adherence in rat experimental endotoxemia by treatment with the 21-aminosteroid U-74389G. Intensive Care Med 2001; 27:258-63. [PMID: 11280645 DOI: 10.1007/s001340000782] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
OBJECTIVES To investigate leukocyte adherence in intestinal venules in experimental endotoxemia after treatment with the 21-aminosteroid U-74389G. DESIGN AND SETTING Prospective, randomized, controlled animal study in an experimental laboratory. SUBJECTS Twenty-one male Wistar rats weighing 190 +/- 40 g. INTERVENTIONS The rats were divided equally into three groups: (a) control group, (b) endotoxemia (5 mg/kg lipopolysacharide from Escherichia coli O55:B5), and (c) endotoxemia and U-74389G administration 30 min before (3 mg/kg) and 60 min after endotoxin challenge (1.5 mg/ kg). MEASUREMENTS AND MAIN RESULTS The distal small intestine of the animals was examined using intravital fluorescence videomicroscopy 2 h after endotoxin challenge. Leukocytes were stained in vivo by means of rhodamine 6G. In the endotoxemic animals we observed a fourfold increase in the count of firmly adherent leukocytes in submucosal post-capillary and collecting venules. Treatment with the 21-aminosteroid U-74389G significantly attenuated the count of sticking leukocytes in the collecting venules (control, 61 +/- 10 cells/mm2; lipopolysaccharide, 237 +/- 42 cells/mm2; U-74389G 125 +/- 9 cells/mm2; p < 0.05). In these venules leukocyte rolling behavior was comparable to that in the control group without endotoxin challenge. CONCLUSIONS Administration of U-74389G, which has radical scavenging properties, attenuates leukocyte adherence in selected populations of intestinal venules which is found increased during endotoxemia. Thus, 21-aminosteroids may have an impact in the treatment of endotoxin-induced intestinal injury.
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Mira A, Lehmann C. Pre-analytical workflow analysis reveals simple changes and can result in improved hospital efficiency. CLINICAL LEADERSHIP & MANAGEMENT REVIEW : THE JOURNAL OF CLMA 2001; 15:23-9. [PMID: 11236191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
Workflow analysis is an ongoing process for laboratory managers. Throughout the years, laboratory managers have made many changes such as creating a core laboratory, consolidating technology, and implementing a new laboratory information system, all of which will have an immediate impact on laboratory operations. However, after implementation of any change in the laboratory, one should follow up with a pre- and/or postanalytical workflow assessment. This case study evaluates the pre-analytical impact of analytical changes made more than a year ago.
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Fuss B, Meissner T, Bauer R, Lehmann C, Eckardt F, Hoch M. Control of endoreduplication domains in the Drosophila gut by the knirps and knirps-related genes. Mech Dev 2001; 100:15-23. [PMID: 11118880 DOI: 10.1016/s0925-4773(00)00512-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Endoreduplication cycles that lead to an increase of DNA ploidy and cell size occur in distinct spatial and temporal patterns during Drosophila development. Only little is known about the regulation of these modified cell cycles. We have investigated fore- and hindgut development and we present evidence that the Drosophila knirps and knirps-related genes are key components to spatially restrict endoreduplication domains. Our lack and gain-of-function experiments show that knirps and knirps-related which encode nuclear orphan receptors transcriptionally repress S-phase genes of the cell cycle required for DNA replication and that this down-regulation is crucial for gut morphogenesis. Furthermore, we demonstrate that both genes are activated in overlapping expression domains in the fore- and hindgut in response to Wingless and Hedgehog activities emanating from epithelial signaling centers that control the regionalization of the gut tube. Our results provide a novel link between morphogen-dependent positional information and the spatio-temporal regulation of cell cycle activity in the gut.
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Lehmann C, Taymoorian K, Wauer H, Krausch D, Birnbaum J, Kox WJ. Effects of the stable prostacyclin analogue iloprost on the plasma disappearance rate of indocyanine green in human septic shock. Intensive Care Med 2000; 26:1557-60. [PMID: 11126272 DOI: 10.1007/s001340000662] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
OBJECTIVES To evaluate the effect of the stable prostacyclin analogue iloprost on the plasma disappearance rate of indocyanine green (PDR) in patients with septic shock. DESIGN AND SETTING A prospective clinical study in a university hospital intensive care unit. PATIENTS AND INTERVENTIONS 20 patients in septic shock. Patients received iloprost infusion (1 ng/kg per minute) for 24 h. MEASUREMENTS AND RESULTS PDR was determined by a femoral arterial fiberoptic catheter before, 1, 6, and 24 h after start and 1 h after end of iloprost infusion. PDR increased significantly 24 h after start of iloprost infusion (baseline: 13.9 +/- 1.7% vs. 18.6 +/- 2.2%/min) and decreased 1 h after end of infusion (13.7 +/- 1.7%/min; p < 0.002). There was no change in pHi, cardiac index, mean arterial pressure, heart rate, central venous pressure, or intrathoracic blood volume index. CONCLUSION Administration of the stable prostacyclin analogue iloprost significantly increases PDR, indicating improvement in liver function.
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Pulletz S, Lehmann C, Volk T, Schmutzler M, Ziemer S, Kox WJ, Scherer RU. Influence of heparin and hirudin on endothelial binding of antithrombin in experimental thrombinemia. Crit Care Med 2000; 28:2881-6. [PMID: 10966265 DOI: 10.1097/00003246-200008000-00032] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE During the last decade, experimental and clinical evidence has accumulated that antithrombin (AT) exerts anti-inflammatory effects when given in high doses. Meanwhile, AT substitution has been shown to significantly increase prostacyclin release. However, the link between endothelial AT binding and anti-inflammatory AT effects remains to be established in vivo, although heparin has been shown to counteract anti-inflammatory AT effects. We hypothesized that the administration of heparin in endotoxin-challenged rats would decrease endothelial AT binding and systemic prostacyclin concentrations. DESIGN Prospective, randomized, controlled experimental in vivo study. SETTING Research laboratory of a university hospital. ANIMALS Fifty-six Wistar rats. INTERVENTIONS Baseline values of coagulation variables were measured in six animals. Forty of 50 Wistar rats in the study groups were given endotoxin (50 mg x kg(-1) iv) and were treated with saline (group LPS), AT (15 units x kg(-1) x hr(-1)) (LPS+AT), AT and heparin (80 IU x kg(-1) x hr(-1)), or AT and hirudin (0.12 mg x kg(-1) x hr(-1)); the other 10 received saline instead of endotoxin and were treated with AT alone. Before endotoxin application, a tracheostomy was performed, and venous and arterial catheters were inserted for blood sampling and infusion. MEASUREMENTS Intravital endothelial AT binding was studied by using fluorescence isothiocyanate-marked antibodies during intravital microscopy of intestinal submucosal venules. Systemic prostacyclin, thrombin-AT complex, and fibrinogen concentrations were measured after 4 hrs. Intergroup differences were tested by Kruskal-Wallis analysis of variance on ranks. MAIN RESULTS AT and AT + heparin were equally effective in inhibiting systemic procoagulant turnover as reflected by fibrinogen concentrations. Only the administration of AT + hirudin significantly prevented fibrinogen consumption (p < .05). In contrast with all other treatments, the administration of heparin significantly reduced intravital endothelial AT binding (p < .05). However, prostacyclin concentrations were similarly increased in all endotoxin-challenged study groups irrespective of the anticoagulatory treatment. CONCLUSIONS There is evidence that heparin in contrast with hirudin prevents AT from being bound to the endothelial cell surface in this experimental model. Under low-dose AT substitution, systemic prostacyclin concentrations do not depend on whether heparin or hirudin is used for thrombin inhibition. These results support the view that heparin may counteract anti-inflammatory AT effects by keeping AT away from its endothelial binding sites; however, the results question the view that decreased endothelial prostacyclin release is solely responsible.
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Lehmann C, Zeis M, Schmitz N, Uharek L. Impaired binding of perforin on the surface of tumor cells is a cause of target cell resistance against cytotoxic effector cells. Blood 2000; 96:594-600. [PMID: 10887123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023] Open
Abstract
Exocytosis of perforin, subsequent binding of perforin to the target cell membrane, and formation of lytic pores form an important pathway involved in the induction of tumor cell death by cytotoxic effector cells. Here we describe a novel escape mechanism employed by tumor cells to protect themselves from granule-mediated cell death: We were able to demonstrate that the resistance of the human leukemia cell line ML-2 to natural killer (NK)-cell-mediated killing is not caused by impaired NK-cell activation but by resistance against effector molecules contained in the granules of cytotoxic cells. No resistance was observed against other pore-forming agents like complement and streptolysin O. By using the NK-susceptible leukemia cell line K562, we could show that the induction of cell death by cytotoxic granules can be blocked completely by anti-perforin antibodies, indicating that perforin is essentially involved in this process. Flow cytometric data revealed that an impaired binding of perforin on the tumor cell membrane is mainly responsible for target cell resistance, because perforin turned out to bind well on K562 cells but is not able to attach to the surface of ML-2 cells. After impaired binding of perforin was identified as a potential mechanism of tumor cell resistance, leukemia cells from 6 patients with acute myeloid leukemia (AML) were examined. As predicted, AML cells that failed to bind perforin on their surface demonstrated complete resistance toward NK-cell-mediated cytotoxicity. Thus, perforin resistance could represent an important tumor escape mechanism that should be considered when cytotoxic effector cells are used for cellular immunotherapy. (Blood. 2000;96:594-600)
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Wulff G, Matussek A, Hanf C, Gladow S, Lehmann C, Goddard R. Template-Induced, Stereoselective Cyclizations in the Cyclopolymerization of TADDOL-Dimethacrylate This work was supported by the Fonds der Chemischen Industrie. Angew Chem Int Ed Engl 2000; 39:2275-2277. [PMID: 10941062 DOI: 10.1002/1521-3773(20000703)39:13<2275::aid-anie2275>3.0.co;2-h] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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173
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Böhler T, Waiser J, Hepburn H, Gaedeke J, Lehmann C, Hambach P, Budde K, Neumayer HH. TNF-alpha and IL-1alpha induce apoptosis in subconfluent rat mesangial cells. Evidence for the involvement of hydrogen peroxide and lipid peroxidation as second messengers. Cytokine 2000; 12:986-91. [PMID: 10880243 DOI: 10.1006/cyto.1999.0633] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Apoptosis of mesangial cells (MC) plays a role in glomerulonephritis (GN). In this study we investigated cytokine-induced apoptosis of cultured rat MC by morphological and biochemical features. TNF-alpha and IL-1alpha induced apoptosis in rat MC in a time- and concentration-dependent fashion. RT-PCR experiments revealed that MC express the TNF-receptor 1 (p60) gene constitutively. TNF-alpha as well as IL-1alpha stimulated the production of reactive oxygen species (ROS) and induced lipid peroxidation. Coincubation with catalase inhibited TNF-alpha and IL-1alpha induced apoptosis as well as lipid peroxidation. TNF-alpha, but not IL-1alpha increased the expression of c-jun. These results provide evidence that TNF-alpha and IL-1alpha induce apoptosis in rat MC with hydrogen peroxide and lipid peroxidation as second messengers. Increased c-jun expression may be a downstream intracellular signal of TNF-alpha-, but not IL-1alpha-induced apoptosis.
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174
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Wenninger K, Kehrt R, von Rüden U, Lehmann C, Binder C, Wahn U, Staab D. Structured parent education in the management of childhood atopic dermatitis: the Berlin model. PATIENT EDUCATION AND COUNSELING 2000; 40:253-261. [PMID: 10838004 DOI: 10.1016/s0738-3991(99)00074-9] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Childhood atopic dermatitis (AD) is a common disease with the prevalence rates increasing. Its chronic course with frequent relapses puts a special burden on both children and their parents. To maximise positive long-term outcome in the management of AD it is important to support parents in dealing with the chronic condition of their child in addition to treating symptoms. In the present article, we describe in detail the goals, structure, and content of the Berlin education program for parents of children with AD. The program aims to contribute towards a comprehensive, family-oriented management of childhood AD. Its objective is to improve parent's self-management skills with regard to their child's disease and to positively impact the course of the disease as well as the family's quality of life. Medical, nutritional and psychological issues are covered in six group sessions which are conducted by a multiprofessional team of paediatricians, psychologists and dieticians. Preliminary data show that the program has a desirable effect on aspects of quality of life and coping.
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Lehmann C, Leiken AM. Diagnostic technology for laboratories in an integrated delivery system. CLINICAL LEADERSHIP & MANAGEMENT REVIEW : THE JOURNAL OF CLMA 2000; 14:118-23. [PMID: 11793532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
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