31 research outputs found
Enhancement of donor cell chimerism in whole organ allograft recipients by adjuvant bone marrow transplantation
Augmentation of chimerism with perioperative donor bone marrow infusion in organ transplant recipients: A 44 month follow-up
Mechanisms underlying the development of T-cell tolerance following interruption of signalling at the CD28/B7 and CD40/gp39 interface
Prevention of T-cell activation by rhCTLA4-Ig and anti-CD40L monoclonal antibody results in indefinite islet allograft survival
Combined simultaneous kidney/bone marrow transplantation
On the basis of observations in patients with longterm (28-30 years) renal allograft survival, all of whom had evidence of systemic microchimerism, we began a program of combined simultaneous kidney/bone marrow transplantation. Between 12/14/92, and 10/31/94,36 kidney transplant recipients received 3-5 x 108 unmodified bone marrow cells/kg; 6 patients also received pancreatic islets, and 7 patients also received a pancreas. The mean recipient age was 39.0 ±10.8 years, and the mean donor age was 31.8 ±16.1 years; the mean cold ischemia time was 23.0±9.1 hr. Twenty control patients received kidneys alone, mainly because of refusal by the donor family to consent to vertebral body recovery; 3 of these patients also received a pancreas. The mean recipient age was 47.9 ±11.7 years, and the mean donor age was 41.5 ±17.9 years; the mean cold ischemia time was 28.6 ±6.2 hr. All patients received tacrolimus-based therapy, without radiation, cytoreduction, or induction antilymphocyte preparations. Blood was drawn prior to and at regular intervals after transplantation for detection of chimerism and for immunologic studies. With a mean follow-up of 11.1 ±5.8 months, all 36 study patients are alive, and 33 (92%) have functioning allografts with a mean serum creatinine of 1.9±1.2 mg/dl and a BUN of 26±9 mg/dl. Graft vs. host disease was not seen in any patient. The incidence of rejection was 72%; 11% of the patients required OKT3 or ATG for steroid-resistant rejection. The incidence of CMV was 14%, and that of delayed graft function was 17%. A total of 18 (90%) control patients are alive, and 17 (85%) have functioning allografts, with a mean serum creatinine of 2.1 ±1.3 mg/ dl, and a BUN of 30±13 mg/dl. The incidence of rejection was 60%, and 10% required OKT3 or ATG. CMV was seen in 15%, and delayed graft function in 20% (P=NS). In the study patients, chimerism was detected in the peripheral blood of 30 of 31 (97%) evaluable patients by either PCR or flow cytometry. In the control patients, chimerism was seen in 9 of 14 (64%) evaluable patients (P<.02). Decreasing donor-specific responsiveness was seen in 6/29 (21%) evaluable study, and 4/14 (29%) evaluable control patients (P=NS). We conclude that combined kidney/bone marrow transplantation is associated with acceptable patient and graft survival, augmentation of chimerism, and no change in the early events after transplantation. © 1995 by Williams & Wilkins
Immune modulation in organ allograft recipients by single or multiple donor bone marrow infusions
Synthese sur le seisme tsunamigene (Mw=8.9) du 26 decembre 2004 (ouest de l’asie) : le risque tsunami dans le bassin mediteraneen et sur le littoral en algerie
De caractkre plutBt Cpisodique dans la frequence dc leur occurrence, les siismes tsunamigknes (ou gCnCrateurs de tsunamis), relkvent de la simultaneitt de deux phenomi.nes : une expression de type sismologique rtsultant le plus d'une dynamique de tectonique dcs plaques et un effet induit par un mouvement et une deformation gComorphologique du plancher oceanique donc de rupture d'equilibre dont le tsunami en est la manifestation en surface. L'approche dcscriptive dite de causes effet peut singulii.rement occulter la complexit6 de ce phenomkne dont les origines se situent en aval par reference a une sismicitk averce et en aval dans la predisposition locale ( presence d'un plan d'eau) i developper un tsunami. L'extrapolation d'un phenomkne nature1 observe en un point du globe vers une autrc region est - elle envisageable ? Si tel est le cas, quel risque de siisme tsunamigene encourt alors le bassin meditcrranien en general et le littoral algerien en particulier
Characterization of a reservoir in a south Algerian prospect using the instantaneous seismic attributes: efficiency and reliability of the instantaneous frequency parameter using the joint time-frequency analysis
Present day, exploration for oil and gas requires a combined effort based on the successful integration of the most part of geophysical methods for optimizing the location of data acquisition, identifying and evaluating the productive potential of unexplored regions or extending existing productive traps. Exploration seismology has been focussed on imaging the structural features of the Earth's subsurface. This approach is now commonplace in most seismic evaluation project due to the ability of this technique under favorable hypothesis to predict reservoirs properties (depth, lateral extension, discrimination between reservoir fluids ... ). However, after the fantastic software improvement, new robust processing tools (principally in signal processing techniques) have been developed for extracting indirect information provided by structure imaging. These new tools can significantly increase the probability of success associated with a given project. In this context, the success of direct hydrocarbons detection is primary due to the identification oflarge negative amplitudes known as bright spot which can define a necessary but not sufficient condition for identifying oil and gas pitfalls. Robust methods in volve computed and correlated sesimic attributes such as the instantaneous ones (intantaneous phase, instantaneous frequency, instantaneous amplitude, inversion polarity ... ) have enjoyed in many cases considerable suc cess for characterizing potential hydrocarbon traps. In the present work, we have precisely used a set of instantaneous attributes to characterize a reservoir located in a permit of the South Algerian Sahara.However, we take the following question: how about the efficiency and the reliability of each instantaneous seismic attribute ? To do this, the instantaneous frequency parameter has been selected because it provides a power indicator of the variations in the energy distribution of the sei smic signal, principally in a noisy environment. More recently, adapted signal processing tools are performed; one can cite the joint time-frequency analysis and its corollaries the Wigner-Ville Distribution, the Wigner bispectrum and the Pseudo-Wigner-Ville representation which are simultaneously tested in the present work on a noisy hyperbolic swept frequency signa