79 research outputs found
Rundfunkbeitragsbefreiung: Ineffizient, anreizfeindlich und ungerecht
Nach der Umstellung der geräteabhängigen Rundfunkgebühren zu einem Rundfunkbeitrag pro Wohnung ist die Beitragsbefreiung der Mindestsicherungsempfänger geblieben. Hierdurch entstehen Grenzfälle, die mit negativen Anreizen verbunden sind. Die Autoren fordern daher, dass der Rundfunkbeitrag der Grundsicherung zugeschlagen wird und nicht der ARD ZDF Deutschlandradio Beitragsservice die Bedürftigkeit prüfen muss.In Germany, recipients of social assistance transfers and of long term unemployment benefits (Arbeitslosengeld II) are exempted from paying contributions to public service broadcasting. But this exemption brings about allocative inefficiencies by creating negative incentives for the recipients to avoid or to reduce the need for help and by causing needless administrative efforts. Furthermore, the exemption from payment of contributions is questionable with regard to distributional goals. It would therefore be better to raise benefits by the amount of the contribution to public service broadcasting and to cancel the exemption
The interleukin-6 -174promoter polymorphism is associated with long-term kidney allograft survival
The interleukin-6 -174promoter polymorphism is associated with long-term kidney allograft survival.BackgroundTh1-dependent effector mechanisms may be responsible for allograft rejection. Recently, interleukin-6 (IL-6) has been shown to antagonize CD4+ T cells to effector Th2 cells and, in the process, differentiate them into Th1 cells.MethodsTo assess the role of IL-6 in long-term allograft survival, 158 patients after first cadaveric kidney transplantation were analyzed for the biallelic –174G→C promoter polymorphism of the IL-6 gene.ResultsCarriers of the –174C-allele (genotype GC/CC) had an inferior three-year graft survival (71/104 = 68.3%; P = 0.0059) with a 3.7-fold increased relative risk of graft loss compared to carriers of the –174GG-genotype (48/54 = 88.9%). The –174GC/CC-genotype retained its negative impact on graft survival when other established prognostic factors and further cytokine polymorphisms (-308TNF-α, TGF-β1 codon 10 & 25, -592/-819/-1082IL-10 and +874IFN-γ) were considered simultaneously.ConclusionsSince the clinical impact on transplant outcome seems as important as matching for histocompatibility antigens, genotyping of the IL-6 -174polymorphism may offer a new method for identifying patients at increased risk of allograft loss
Structure of Reovirus σ1 in Complex with Its Receptor Junctional Adhesion Molecule-A
Viral attachment to specific host receptors is the first step in viral infection and serves an essential function in the selection of target cells. Mammalian reoviruses are highly useful experimental models for studies of viral pathogenesis and show promise as vectors for oncolytics and vaccines. Reoviruses engage cells by binding to carbohydrates and the immunoglobulin superfamily member, junctional adhesion molecule-A (JAM-A). JAM-A exists at the cell surface as a homodimer formed by extensive contacts between its N-terminal immunoglobulin-like domains. We report the crystal structure of reovirus attachment protein σ1 in complex with a soluble form of JAM-A. The σ1 protein disrupts the JAM-A dimer, engaging a single JAM-A molecule via virtually the same interface that is used for JAM-A homodimerization. Thus, reovirus takes advantage of the adhesive nature of an immunoglobulin-superfamily receptor by usurping the ligand-binding site of this molecule to attach to the cell surface. The dissociation constant (KD) of the interaction between σ1 and JAM-A is 1,000-fold lower than that of the homophilic interaction between JAM-A molecules, indicating that JAM-A strongly prefers σ1 as a ligand. Analysis of reovirus mutants engineered by plasmid-based reverse genetics revealed residues in σ1 required for binding to JAM-A and infectivity of cultured cells. These studies define biophysical mechanisms of reovirus cell attachment and provide a platform for manipulating reovirus tropism to enhance vector targeting
Decreased Production of Interferon in Whole Blood Cultures Derived from Patients With Psoriasis
Patients suffering from psoriasis show many alterations with respect to their immune system as documented by in vitro test systems. In the present study we investigated the in vitro production of interferons (IFN) of leukocytes from psoriatic patients to stimulation with a variety of IFN inducers. Furthermore, the lymphoproliferative responses were tested. Whole blood cultures of 30 psoriatic patients showing moderate to severe disease activity and 21 cultures from healthy controls were stimulated with the mitogens PHA, ConA, and PWM, with PPD and Tetanus Antigen as IFN γ inducers and with C. parvum, PolyI-PolyC, and Herpes simplex virus as inducers of IFN α. Interferon activity was tested in the supernatant of 48-h cultures by using an antiviral assay. Lympho-proliferation was assayed in 5-d cultures in parallel. Psoriatic patients showed a significantly decreased IFN production to all the stimuli tested. There were no significant differences in the lymphoproliferative responses; only the response to PWM was slightly decreased. The decreased IFN production by leukocytes from psoriatic patients seems to be very remarkable since increased susceptibility to infections is not generally known in these patients
Spezielle Therapiesituationen beim metastasierten kolorektalen Karzinom
Specific Treatment Situations in Metastatic Colorectal Cancer As far as the management of primary resectable liver metastases is concerned, three approaches are currently competing with each other: surgery alone, surgery with pre- and postoperative chemotherapy, and surgery with postoperative chemotherapy alone. The core of the argument for pre- and postoperative chemotherapy in these patients is the European Organisation for Research and Treatment of Cancer (EORTC) 40983 study, which concluded that, in comparison with surgery alone, perioperative chemotherapy improved the 3-year progression-free survival (PFS) by 7 months. In contrast to this, there are two smaller studies - at a somewhat lower strength of evidence - indicating that adjuvant chemotherapy extends PFS by 9.1 months compared with surgery alone. In Germany, the adjuvant approach continues to be favored in many places; this can also be seen in the formulation of the S3 guideline. In patients with unresectable liver metastases - with the associated difficulty of classification due to the lack of clear and definitive criteria preoperative systemic therapy to induce `conversion' is indicated, in order to allow secondary resection. In KRAS wild-type tumors, high response rates ( in terms of a reduction in size of the metastases, such as according to RECIST ( Response Evaluation Criteria in Solid Tumors)) and a high conversion rate are achieved using a cetuximab/chemotherapy combination. Triple chemotherapy combinations with 5-fluorouracil (5-FU), oxaliplatin and irinotecan also produce high response rates. Bevacizumab/chemotherapy combinations have led to a high number of complete and partial pathohistological remissions in phase II studies; these seem to correlate with long survival times. In the absence of long-term survival data, it therefore seems to remain unclear as to what is the best parameter to use in order to assess the success of preoperative treatment. Lung metastases, too, or local peritoneal carcinomatosis can nowadays be operated on in selected patients with a good prospect of long-term remission or even cure. The surgery should, however, generally only be carried out in experienced centers, especially in the case of peritoneal carcinomatosis. For synchronous metastasization, the appropriate management depends on the size and extent of liver metastases and of the primary tumor. Small, peripherally lying and safely resectable liver metastases can be removed before or at the same time as the primary tumor, especially if a hemicolectomy is being carried out. If the metastases are unresectable and there is no bleeding or stenosis, the primary tumor can also be left in situ and systemic chemotherapy can be carried out first. However, it should be borne in mind that, according to current data, palliative resection of the primary tumor combined with systemic therapy leads to longer overall survival than does chemotherapy alone. Whether resection or chemotherapy should be done first therefore depends on the patient's clinical situation
Finite-Temperature Transport in Finite-Size Hubbard Rings in the Strong-Coupling Limit
We study the current, the curvature of levels, and the finite temperature
charge stiffness, D(T,L), in the strongly correlated limit, U>>t, for Hubbard
rings of L sites, with U the on-site Coulomb repulsion and t the hopping
integral. Our study is done for finite-size systems and any band filling. Up to
order t we derive our results following two independent approaches, namely,
using the solution provided by the Bethe ansatz and the solution provided by an
algebraic method, where the electronic operators are represented in a
slave-fermion picture. We find that, in the U=\infty case, the
finite-temperature charge stiffness is finite for electronic densities, n,
smaller than one. These results are essencially those of spinless fermions in a
lattice of size L, apart from small corrections coming from a statistical flux,
due to the spin degrees of freedom. Up to order t, the Mott-Hubbard gap is
\Delta_{MH}=U-4t, and we find that D(T) is finite for n<1, but is zero at
half-filling. This result comes from the effective flux felt by the holon
excitations, which, due to the presence of doubly occupied sites, is
renormalized to
\Phi^{eff}=\phi(N_h-N_d)/(N_d+N_h), and which is zero at half-filling, with
N_d and N_h being the number of doubly occupied and empty lattice sites,
respectively. Further, for half-filling, the current transported by any
eigenstate of the system is zero and, therefore, D(T) is also zero.Comment: 15 pages and 6 figures; accepted for PR
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