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101.
Perceived failure is reported to have detrimental effects on subsequent performance in patients with major depressive disorder. We investigated the error-related negativity (ERN)/error negativity (Ne), an electrophysiological correlate of response monitoring, using a 64-channel EEG. Sixteen patients with DSM-IV major depressive disorder and 16 matched controls participated in an Eriksen flanker task with continuous performance feedback that signaled monetary reward. Compared to controls, patients with major depressive disorder showed a less negative ERN/Ne in error trials following error trials. This result might reflect impaired response monitoring processes in major depressive disorder resulting from an underactivity in a central reward pathway and/or a deficit in strategic reasoning. 相似文献
102.
Fischbach C Seufert J Staiger H Hacker M Neubauer M Göpferich A Blunk T 《Tissue engineering》2004,10(1-2):215-229
In vivo and in vitro studies have demonstrated both promise and current limitations in tissue engineering of fat. Herein, we report the establishment of a well-defined three-dimensional (3-D) in vitro model useful for systematic investigations of 3-D adipogenesis. Polyglycolic acid fiber meshes were dynamically seeded with 3T3-L1 preadipocytes; subsequently, cell-polymer constructs were hormonally induced and cultivation under three different conditions was evaluated. Regarding tissue coherence and intracellular lipid content, culture of cell-polymer constructs either dynamically in well plates or in stirred bioreactors yielded similar results, which were distinctly improved compared with static conditions in well plates. At the protein and mRNA levels, significantly increased expression of genes characteristic for a mature adipose phenotype was demonstrated for constructs dynamically cultured in well plates, as compared with static conditions. Furthermore, investigation of lipolysis under stimulating and inhibiting conditions demonstrated functionality of the dynamically differentiated constructs. Using dynamic culture conditions, the presented in vitro model system is suggested as a valuable tool serving both fat tissue engineering and basic research by facilitating investigations of tissue-inherent features not possible under conventional 2-D culture conditions. 相似文献
103.
104.
Robinson PN Booms P Katzke S Ladewig M Neumann L Palz M Pregla R Tiecke F Rosenberg T 《Human mutation》2002,20(3):153-161
The Marfan syndrome (MFS) is a pleiotropic, autosomal dominant disorder of connective tissue with highly variable clinical manifestations including aortic dilatation and dissection, ectopia lentis, and a series of skeletal anomalies. Mutations in the gene for fibrillin-1 (FBN1) cause MFS, and at least 337 mainly unique mutations have been published to date. FBN1 mutations have been found not only in MFS but also in a range of connective tissue disorders collectively termed fibrillinopathies ranging from mild phenotypes, such as isolated ectopia lentis, to severe disorders including neonatal MFS, which generally leads to death within the first two years of life. The present article intends to provide an overview of mutations found in MFS and related disorders and to discuss potential genotype-phenotype correlations in MFS. 相似文献
105.
106.
Mouse models of atopic eczema critically evaluated 总被引:2,自引:0,他引:2
Gutermuth J Ollert M Ring J Behrendt H Jakob T 《International archives of allergy and immunology》2004,135(3):262-276
Atopic eczema (AE) is a chronic relapsing inflammatory skin disorder with increasing prevalence in Western societies. Even though we have made considerable progress in understanding the cellular and molecular nature of cutaneous inflammation, the precise pathomechanisms of AE still remain elusive. Experimental animal models are indispensable tools to study the pathogenic mechanisms and to test novel therapeutic approaches in vivo. For AE a considerable number of mouse models have been proposed and have been used to study specific aspects of the disease, such as genetics, skin barrier defects, immune deviations, bacteria-host interactions or the role of cytokines or chemokines in the inflammatory process. While some models closely resemble human AE, others appear to reflect only specific aspects of the disease. Here we review the currently available mouse models of AE in light of the novel World Allergy Organization classification of eczematous skin diseases and evaluate them according to their clinical, histopathological and immunological findings. The pathogenetic analogies between mice and men will be discussed. 相似文献
107.
Peter Gross Will W. Minuth Markus Ketteler Eberhard Frömter Rita Böhm 《Pflügers Archiv : European journal of physiology》1988,412(4):434-441
The ionic conductive properties were studied of epithelia of collecting duct principal cells which had been grown in primary tissue culture from renal cortex/capsule explants. When pretreated with aldosterone (10–6 mol/l) and bathed on either surface with isotonic HCO
3
–
-free Ringer's solution, the transepithelial voltage,V
te, varied between –21 and –72 mV (apical surface negative) while the transepithelial resistance,R
te, ranged from 0.4 to 1.5 kcm2. By 10:1 step-changes in Na+ concentration the apical cell membrane was shown to have a high conductivity for sodium, inhibitable by amiloride, 10–6 mol/l. However, contrary to observations in natural collecting duct under control conditions, amiloride never reversed the polarity ofV
te even at 10–4 mol/l. Both the apical and the basolateral cell membranes were conductive for potassium and both conductivities were inhibitable by Ba2+ (5 mmol/l). 10:1 reduction of apical Cl– concentration strongly hyperpolarizedV
te with a monophasic time course suggesting the presence of a paracellular shunt conductance for Cl–. In addition there may be a small Cl– conductance present in the apical cell membrane since apical application of the chloride channel blocker 5-nitro-2-(3-phenylpropylamino)-benzoic acid (NPPAB) at 10–7 mol/l produced a minute but significant hyperpolarization. On the other hand, 10:1 reduction of basolateral Cl– concentration caused a biphasic change inV
te (initial depolarization, followed by repolarization) which indicates the presence of a large Cl– conductance in the basolateral cell membrane. The latter was not inhibitable by 10–7 mol/l NPPAB. Higher concentrations of this and of an other Cl– channel blocker produced non-specific effects. In conclusion, our studies of a pure principal cell epithelium confirm findings described for the intact cortical collecting duct and add new information concerning chloride conductivity and related blocking agents.Dedicated to Prof. Dr. H. Sitte, Homburg, FRG, upon his 60th birthday. 相似文献
108.
CD4+ and CD8+ cells in cryopreserved human PBMC maintain full functionality in cytokine ELISPOT assays 总被引:10,自引:0,他引:10
Kreher CR Dittrich MT Guerkov R Boehm BO Tary-Lehmann M 《Journal of immunological methods》2003,278(1-2):79-93
The frequency and the cytokine signature of antigen-specific T cells in the blood reflect the magnitude and the quality of T cell immunity in vivo. Recently, cytokine enzyme-linked immunospot (ELISPOT) assays performed on freshly isolated peripheral blood mononuclear cells (PBMC) emerged as a promising tool for monitoring these key parameters, providing direct feedback information on the efficacy of vaccinations and immune therapies. However, performing ELISPOT assays with freshly isolated cells is not readily feasible in the context of clinical trials. The ability to obtain valid ELISPOT data on cryopreserved samples would greatly enhance ex vivo immune monitoring capabilities. We have therefore systematically studied antigen-specific T cell responses in freshly isolated PBMC and after cryopreservation. Four healthy donors were selected that displayed T cell responses to six recall antigens. The antigen reactive T cells were defined as CD4 or CD8 cells, and their cytokine effector class was established measuring interferon (IFN)-gamma, interleukin (IL)-2, IL-4 and IL-5. The donors were bled at three different time points, and their PBMC were tested fresh and after freeze-thawing. The results showed that the frequencies and type 1/type 2 cytokine signatures of recall antigen-specific CD4 and CD8 cells are unaffected after cryopreservation. In contrast to these data obtained on human PBMC, cryopreservation of murine spleen cells causes a decrease in cytokine secretion. 相似文献
109.
Rapid expansion and IL-4 expression by Leishmania-specific naive helper T cells in vivo 总被引:2,自引:0,他引:2
CD4 T cells are pivotal for effective immunity, yet their initial differentiation into effector subsets after infection remains poorly defined. We examined CD4 T cells specific for the immunodominant Leishmania major LACK antigen using MHC/peptide tetramers and IL-4 reporter mice. Comprising approximately 15 cells/lymph node in naive mice, LACK-specific T cells expanded over 100-fold, and 70% acquired IL-4 expression by 96 hr. Despite their pathogenic role in susceptible mice, LACK-specific precursor frequency, expansion, and IL-4 expression were comparable between susceptible and resistant mice. When injected with unrelated antigen, Leishmania efficiently activated IL-4 expression from naive antigen-specific T cells. CD4 subset polarization in this highly characterized model occurs independently from IL-4 expression by naive T cells, which is activated indiscriminately after parasitism. 相似文献
110.
Identification of a novel coronavirus in patients with severe acute respiratory syndrome 总被引:1,自引:0,他引:1
Drosten C Günther S Preiser W van der Werf S Brodt HR Becker S Rabenau H Panning M Kolesnikova L Fouchier RA Berger A Burguière AM Cinatl J Eickmann M Escriou N Grywna K Kramme S Manuguerra JC Müller S Rickerts V Stürmer M Vieth S Klenk HD Osterhaus AD Schmitz H Doerr HW 《The New England journal of medicine》2003,348(20):1967-1976