815 research outputs found

    Improvement of lung preservation - From experiment to clinical practice

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    Background. Reperfusion injury represents a severe early complication following lung transplantation. Among the pathogenetic factors, the high potassium content of Euro-Collins(R) solution is discussed. Material and Methods: In a pig model of orthotopic left-sided lung transplantation we investigated the effect of Euro-Collins solution (EC: n=6) versus low potassium dextran (LPD: Perfadex(R): n = 6). Sham-operated (n = 6) animals served as control. Transplant function, cellular energy metabolism and endothelial morphology served as parameters. In a clinical investigation, 124 patients were evaluated following single (EC: n = 31; LPD n = 37) or double (EC: n = 17; LPD n = 39) lung transplantation, whose organs where preserved with EC (n = 48) or LPD (n = 76). Duration of ischemia, duration of ventilation and stay on ICU were registered. Primary transplant function was evaluated according to AaDO(2) values. Cause of early death (30 days) was declared. Results: Experimental results: After flush with EC and 18 h ischemia, a reduction of tissue ATP content (p < 0.01 vs inital value and LPD) was noted. Endothelial damage after ischemia was severe (p < 0.05 vs control), paO(2) was significantly decreased. Clinical results: In the LPD group, duration of ischemia was longer for the grafts transplanted first (SLTx and DLTx: p = 0.0009) as well as second (2. organ DLTx: p = 0.045). Primary transplant function was improved (day 0: SLTx: p = 0.0015; DLTx: p = 0.0095, both vs EC). Duration of ventilation and stay on ICU were shorter (n.s.). Reperfusion injury-associated death was reduced from 8% (EC) to 0 (LPD). Conclusion: In experimental lung preservation, LPD lead to an improved graft function. These results were confirmed in clinical lung transplantation. Clinical lung preservation, therefore, should be carried out by use of LPD. Copyright (C) 2002 S. Karger AG, Basel

    Application of Magnetic Nanoparticles in Pharmaceutical Sciences

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    # The Author(s) 2010. This article is published with open access at Springerlink.com KEY WORDS magnetic beads. magnetic bioseparation. magnetic nanoparticle

    The P_33(1232) resonance contribution into the amplitudes M_{1+}^{3/2},E_{1+}^{3/2},S_{1+}^{3/2} from an analysis of the p(e,e'p)\pi^0 data at Q^2 = 2.8, 3.2, and 4 (GeV/c)^2 within dispersion relation approach

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    Within the fixed-t dispersion relation approach we have analysed the TJNAF and DESY data on the exclusive p(e,e'p)\pi^0 reaction in order to find the P_{33}(1232) resonance contribution into the multipole amplitudes M_{1+}^{3/2},E_{1+}^{3/2},S_{1+}^{3/2}. As an input for the resonance and nonresonance contributions into these amplitudes the earlier obtained solutions of the integral equations which follow from dispersion relations are used. The obtained values of the ratio E2/M1 for the \gamma^* N \to P_{33}(1232) transition are: 0.039\pm 0.029, 0.121\pm 0.032, 0.04\pm 0.031 for Q^2= 2.8, 3.2, and 4 (GeV/c)^2, respectively. The comparison with the data at low Q^2 shows that there is no evidence for the presence of the visible pQCD contribution into the transition \gamma N \to P_{33}(1232) at Q^2=3-4 GeV^2. The ratio S_{1+}^{3/2}/M_{1+}^{3/2} for the resonance parts of multipoles is: -0.049\pm 0.029, -0.099\pm 0.041, -0.085\pm 0.021 for Q^2= 2.8, 3.2, and 4 (GeV/c)^2, respectively. Our results for the transverse form factor G_T(Q^2) of the \gamma^* N \to P_{33}(1232) transition are lower than the values obtained from the inclusive data. With increasing Q^2, Q^4G_T(Q^2) decreases, so there is no evidence for the presence of the pQCD contribution here too

    Knockout of proton-neutron pairs from 16^{16}O with electromagnetic probes

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    After recent improvements to the Pavia model of two-nucleon knockout from 16^{16}O with electromagnetic probes the calculated cross sections are compared to experimental data from such reactions. Comparison with data from a measurement of the 16^{16}O(e,e'pn) reaction show much better agreement between experiment and theory than was previously observed. In a comparison with recent data from a measurement of the 16^{16}O(γ\gamma,pn) reaction the model over-predicts the measured cross section at low missing momentum.Comment: 6 pages, 5 figure

    Networked buffering: a basic mechanism for distributed robustness in complex adaptive systems

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    A generic mechanism - networked buffering - is proposed for the generation of robust traits in complex systems. It requires two basic conditions to be satisfied: 1) agents are versatile enough to perform more than one single functional role within a system and 2) agents are degenerate, i.e. there exists partial overlap in the functional capabilities of agents. Given these prerequisites, degenerate systems can readily produce a distributed systemic response to local perturbations. Reciprocally, excess resources related to a single function can indirectly support multiple unrelated functions within a degenerate system. In models of genome:proteome mappings for which localized decision-making and modularity of genetic functions are assumed, we verify that such distributed compensatory effects cause enhanced robustness of system traits. The conditions needed for networked buffering to occur are neither demanding nor rare, supporting the conjecture that degeneracy may fundamentally underpin distributed robustness within several biotic and abiotic systems. For instance, networked buffering offers new insights into systems engineering and planning activities that occur under high uncertainty. It may also help explain recent developments in understanding the origins of resilience within complex ecosystems. \ud \u

    Impact of chlororespiration on non-photochemical quenching of chlorophyll fluorescence and on the regulation of the diadinoxanthin cycle in the diatom Thalassiosira pseudonana

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    In diatoms, metabolic activity during long dark periods leads to a chlororespiratory electron flow, which is accompanied by the build-up of a proton gradient strong enough to activate the diadinoxanthin (Ddx) de-epoxidation reaction of the Ddx cycle. In the present study, the impact of chlororespiration on non-photochemical quenching (NPQ) of chlorophyll fluorescence and the regulation of the Ddx cycle in the diatom Thalassiosira pseudonana was investigated by manipulation of the redox state of the photosynthetic electron transport chain during darkness. The response of a transfer of T. pseudonana cells from growth light conditions to 60 min darkness was found to depend on oxygen: in its presence there was no significant reduction of the PQ pool and no de-epoxidation of Ddx to diatoxanthin (Dtx). Under anaerobic conditions a high reduction state of the electron transport chain and a slow but steady de-epoxidation of Ddx was observed, which resulted in a significant accumulation of Dtx after 60 min of anaerobiosis. Unexpectedly, this high concentration of Dtx did not induce a correspondingly high NPQ as it would have been observed with Dtx formed under high light conditions. However, the sensitivity of NPQ to Dtx in cells kept under dark anaerobic conditions increased during reoxygenation and far-red (FR) light illumination. The results are discussed with respect to the activation of the de-epoxidation reaction and the formation of NPQ and their dependence on the extent of the proton gradient across the thylakoid membrane

    Building ProteomeTools based on a complete synthetic human proteome.

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    We describe ProteomeTools, a project building molecular and digital tools from the human proteome to facilitate biomedical research. Here we report the generation and multimodal liquid chromatography-tandem mass spectrometry analysis of \u3e330,000 synthetic tryptic peptides representing essentially all canonical human gene products, and we exemplify the utility of these data in several applications. The resource (available at http://www.proteometools.org) will be extended to \u3e1 million peptides, and all data will be shared with the community via ProteomicsDB and ProteomeXchange

    Bloodstream and endovascular infections due to Abiotrophia defectiva and Granulicatella species

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    BACKGROUND: Abiotrophia and Granulicatella species, previously referred to as nutritionally variant streptococci (NVS), are significant causative agents of endocarditis and bacteraemia. In this study, we reviewed the clinical manifestations of infections due to A. defectiva and Granulicatella species that occurred at our institution between 1998 and 2004. METHODS: The analysis included all strains of NVS that were isolated from blood cultures or vascular graft specimens. All strains were identified by 16S rRNA sequence analysis. Patients' medical charts were reviewed for each case of infection. RESULTS: Eleven strains of NVS were isolated during the 6-year period. Identification of the strains by 16S rRNA showed 2 genogroups: Abiotrophia defectiva (3) and Granulicatella adiacens (6) or "para-adiacens" (2). The three A. defectiva strains were isolated from immunocompetent patients with endovascular infections, whereas 7 of 8 Granulicatella spp. strains were isolated from immunosuppressed patients, mainly febrile neutropenic patients. We report the first case of "G. para-adiacens" bacteraemia in the setting of febrile neutropenia. CONCLUSION: We propose that Granulicatella spp. be considered as a possible agent of bacteraemia in neutropenic patients
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