413,032 research outputs found
Heterotopic heart transplantation in the rat receiving FK-506 alone or with cyclosporine.
In rats, FK significantly prolonged heterotopic heart graft survival over a wide dose range when given for 2 weeks starting on the day of the operation. Brief courses of FK for one to four days preoperatively, and especially beginning four days postoperatively, allowed long subsequent survival of heart grafts in otherwise untreated recipients. The seeming acceptance of the grafts with postoperative FK treatment was largely but not exclusively donor specific when tested eight days after the last FK dose by second grafts from the same donor v third-party donor grafts. FK in minimally therapeutic doses was synergistic with suboptimal doses of CyA
Divergence of the correlation length for critical planar FK percolation with via parafermionic observables
Parafermionic observables were introduced by Smirnov for planar FK
percolation in order to study the critical phase . This
article gathers several known properties of these observables. Some of these
properties are used to prove the divergence of the correlation length when
approaching the critical point for FK percolation when . A crucial
step is to consider FK percolation on the universal cover of the punctured
plane. We also mention several conjectures on FK percolation with arbitrary
cluster-weight .Comment: 26 page
Randomized trial of FK 506/prednisone vs FK 506/azathioprine/prednisone after renal transplantation: preliminary report.
FK 506 was used as a primary immunosuppressive agent in 125 cases of renal transplantation in a randomized trial comparing FK 506/prednisone with FK 506/azathioprine/prednisone. With a mean follow-up of 5.5 +/- 2.5 months, there has been a 6-month actuarial patient survival of 99% and graft survival of 88%. There is no difference thus far between the two-drug and three-drug groups, although there may be less rejection and diabetes in the three-drug group. These results suggest that FK 506 is a useful immunosuppressive agent in kidney transplantation
Studies on mechanisms of augmentation of liver regeneration by cyclosporine and FK 506
Evidence could not be found of immune modulation of liver regeneration. The powerful immunosuppressive drug FK 506, which augments the response after partial hepatectomy in normal rats, had the same effect in T cell—deficient nude rats. The cytotoxicity of natural killer cells in treated nude rats was not significantly changed by FK 506 therapy. However, the serum of FK 506—treated nude rats increased hepatocyte proliferation when added to third‐party hepatocyte cultures, suggesting that FK 506 had induced a serum growth factor in the nude rats or had suppressed an inhibitory factor. A hypothesis was advanced that FK 506 (and cyclosporine) affects hepatic growth by nonimmunological pathways. (HEPATOLOGY 1991;14:140–143.) Copyright © 1991 American Association for the Study of Liver Disease
FK 506 pre-treatment is associated with reduced levels of tumor necrosis factor and interleukin 6 following hepatic ischemia/reperfusion
Using a rat model, the effect of pre-treatment with FK 506 on hepatic ischemia/reperfusion injury was investigated. All control animals died within 72 h of the ischemia/reperfusion injury. Pre-treatment of the animals with FK 506 (0.3 mg/kg in 0.5 ml saline) administered intravenously improved survival. The most striking protection against fatal ischemia/reperfusion injury was achieved in rats that were given FK 506 6 and 24 h prior to the induction of the hepatic ischemic insult (70% and 80% 10-day survival rates, respectively). The hepatoprotective effect of FK 506 was assessed further in a second experiment in which the serum levels of tumor necrosis factor (TNF) and interleukin 6 (IL-6) were measured. These results suggest that a 60-min period of hepatic ischemia and subsequent reperfusion triggers the release of both TNF and IL-6, and that FK 506 pre-treatment (6 h before the ischemic episode) significantly inhibits the production and/or release of these two cytokines compared to untreated controls. These data provide additional information concerning the immunosuppressive and hepatoprotective activities of FK 506. Based upon these data, it is probable that FK 506 attenuates hepatic ischemia/reperfusion injury, at least in part, by reducing TNF and IL-6 levels. © 1993 Elsevier Scientific Publishers Ireland Ltd. All rights reserved
The Solar-Interior Equation of State with the Path-Integral Formalism I. Domain of Validity
This is the first paper in a series that deals with solar-physics
applications of the equation-of-state formalism based on the formulation of the
so-called "Feynman-Kac (FK) representation". Here, the FK equation of state is
presented and adapted for solar applications. Its domain of validity is
assessed. The practical application to the Sun will be dealt with in Paper II.
Paper III will extend the current FK formalism to a higher order. Use of the FK
equation of state is limited to physical conditions for which more than 90% of
helium is ionized. This incudes the inner region of the Sun out to about .98 of
the solar radius. Despite this limitation, in the parts of the Sun where it is
applicable, the FK equation of state has the power to be more accurate than the
equations of state currently used in solar modeling. The FK approach is
especially suited to study physical effects such as Coulomb screening, bound
states, the onset of recombination of fully ionized species, as well as
diffraction and exchange effects. The localizing power of helioseismology
allows a test of the FK equation of state. Such a test will be beneficial both
for better solar models and for tighter solar constraints of the equation of
state.Comment: Completely rewritten revised version. Accepted for publication in
Astronomy & Astrophysic
Cytomegalovirus infection of the upper gastrointestinal tract following liver transplantation—incidence, location, and severity in cyclosporine- and FK506-treated patients
One hundred and forty randomly selected liver transplant recipients were studied before and after primary orthotopic liver transplantation for the presence or absence of CMV enteritis. Following OLTx, 65 patients were treated with cyclosporine A and 75 were treated with FK506. The two groups were similar with regard to the incidence, location, and outcome of their upper gastrointestinal CMV infection. Prior to OLTx, only one patient had evidence of enteric CMV infection. The incidence of CMV enteritis post-OLTx was 27.7% in the CsA-treated group and 20% in the FK-treated group. During the first posttransplant month, no patient in the FK-treated group developed CMV enteritis, compared with 11.5% of the patients who were treated with CsA (P<0.05). Gastric CMV was found in over 80% of those positive for any organ in either group. In addition to CMV infection of the upper gastrointestinal tract, clinically evident CMV disease involved more nonenteric organs in the CsA-treated group than in the FK-treated group. In the CsA-treated group, CMV-negative patients had a statistically higher 1-year survival rate (100%) than CMV-positive patients (77.8%) (P<0.05). In the FK-treated group, no difference in survival was observed between CMV-positive or CMV-negative cases at 1 year. Of the patients on CsA, 20% received OKT3 for persistent rejection, as compared with 13% in the FK-treated group. The patients receiving both CsA and OKT3 had a higher rate of upper gastrointestinal CMV infection than did FK-treated patients who also received OKT3 therapy (38.5% versus 20%, respectively). Based upon these data, it can be concluded that (1) patients receiving FK have a lower incidence of enteric CMV infection; (2) following OLTx, upper gastrointestinal CMV infection presents later in FK-treated patients; (3) the stomach is the most frequently involved organ in the UGIT; (4) FK-treated liver recipients have less severe enteric CMV infection than do CsA-treated patients; (5) enteric CMV is not a major cause of mortality in liver trans lant recipients; and (6) in patients receiving FK, those who require OKT3 therapy do not appear to be at a greater risk for the development of CMV enteritis than those who do not. © 1992 by Williams & Wilkins
Asymptotic Dynamics in Perturbative Quantum Gravity and BMS Supertranslations
Recently it has been shown that infrared divergences in the conventional
S-matrix elements of gauge and gravitational theories arise from a violation of
the conservation laws associated with large gauge symmetries. These infrared
divergences can be cured by using the Faddeev-Kulish (FK) asymptotic states as
the basis for S-matrix elements. Motivated by this connection, we study the
action of BMS supertranslations on the FK asymptotic states of perturbative
quantum gravity. We compute the BMS charge of the FK states and show that it
characterizes the superselection sector to which the state belongs.
Conservation of the BMS charge then implies that there is no transition between
different superselection sectors, hence showing that the FK graviton clouds
implement the necessary vacuum transition induced by the scattering process.Comment: 39 page
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