We used biotinylated LPS (LPSb) and flow cytometry to study LPS-monocyte interaction and LPS-induced cellular activation in whole blood from septic patients (SP). Expression of surface activation ...markers was evaluated on monocytes (HLA-DR) and T lymphocytes (CD69 and CD95), and intracellular TNF- alpha on monocytes. Saturating curve and kinetics of LPSb detection on monocytes were similar in SP and healthy volunteers (HV). LPSb bound to monocytes was detected after 5 min of incubation in both groups, with a more pronounced decay in SP. Monocytes from SP had a lower expression of HLA-DR as compared to HV, both constitutive and upon LPS stimulation. The proportion of monocytes producing TNF- alpha after LPS stimulus was higher in HV than SP (mean plus or minus SD = 25.2 plus or minus 14.2% and 2.2 plus or minus 2.6%, respectively, P < 0.001). LPS-induced CD69 on T CD8 super(+) and CD8 super(-) lymphocytes was similar for patients and controls. Expression of CD95 on T lymphocytes was higher in SP as compared to HV on T CD8 super(+) cells (GMFI, mean plus or minus SD = 22.3 plus or minus 14.6 and 8.6 plus or minus 5.0, respectively, P = 0.01) and CD8 super(-) cells (GMFI, mean plus or minus SD = 28.3 plus or minus 7.7 and 14 plus or minus 4.3 respectively, P < 0.001). Thus, monocytes and lymphocytes seem to respond differently to LPS in septic patients. Monocyte hyporesponsiveness appears not to be related to a decreased binding capacity of LPS, but rather to an impaired signal transduction.
The outcome of patients with sepsis arises from multiple factors affecting both the host and the invading microorganisms. Age, presence of underlying disease, source of infection and some specific ...etiological agents have been related to prognosis. Appropriateness of antimicrobial therapy, considering the in vitro susceptibility tests for the infecting bacteria, has been strongly associated with the outcome. Therefore even after the cascade of sepsis has been triggered, the control of bacteria growth is still fundamental for the outcome of the infection. This is a major distinction point from experimental studies in which whole killed bacteria and their products are used as model of sepsis. However, even within the setting of adequate antimicrobial use, patients still die of sepsis. Thus, strategies focusing on further therapy targets are an important area of interest for basic and clinical research. Although such adjunctive sepsis therapy has failed to achieve consistent better survival rates so far, nevertheless, it improved our understanding of the pathophysiological events seen in sepsis that the possibility that a new and effective treatment may arise has been warmly considered. In this paper we aim to review some aspects of the pathogenesis of sepsis, focusing on recent advances and on possible targets for adjunctive therapy. Published clinical trials and experimental data supporting such trials are commented on.
The direct measurement of reaction cross sections at astrophysical energies often requires the use of solid targets of known thickness, isotopic composition, and stoichiometry that are able to ...withstand high beam currents for extended periods of time. Here, we report on the production and characterisation of isotopically enriched Ta\(_2\)O\(_5\) targets for the study of proton-induced reactions at the Laboratory for Underground Nuclear Astrophysics facility of the Laboratori Nazionali del Gran Sasso. The targets were prepared by anodisation of tantalum backings in enriched water (up to 66% in \(^{17}\)O and up to 96% in \(^{18}\)O). Special care was devoted to minimising the presence of any contaminants that could induce unwanted background reactions with the beam in the energy region of astrophysical interest. Results from target characterisation measurements are reported, and the conclusions for proton capture measurements with these targets are drawn.
Généralités / Generalità Tassaux, Francis; Vedaldi Iasbez, Vanna; Rigato, D ...
Mélanges de l'école française de Rome,
1997, Letnik:
109, Številka:
1
Reference
Odprti dostop
Tassaux Francis, Vedaldi Iasbez Vanna, Rigato D., Cicala V. Généralités / Generalità. In: Mélanges de l'École française de Rome. Antiquité, tome 109, n°1. 1997. pp. 268-296.
