1
|
Transition to the Haldane phase driven by electron-electron correlations. Nat Commun 2023; 14:8524. [PMID: 38129389 PMCID: PMC10740019 DOI: 10.1038/s41467-023-44135-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 12/01/2023] [Indexed: 12/23/2023] Open
Abstract
One of the most famous quantum systems with topological properties, the spin [Formula: see text] antiferromagnetic Heisenberg chain, is well-known to display exotic [Formula: see text] edge states. However, this spin model has not been analyzed from the more general perspective of strongly correlated systems varying the electron-electron interaction strength. Here, we report the investigation of the emergence of the Haldane edge in a system of interacting electrons - the two-orbital Hubbard model-with increasing repulsion strength U and Hund interaction JH. We show that interactions not only form the magnetic moments but also form a topologically nontrivial fermionic many-body ground-state with zero-energy edge states. Specifically, upon increasing the strength of the Hubbard repulsion and Hund exchange, we identify a sharp transition point separating topologically trivial and nontrivial ground-states. Surprisingly, such a behaviour appears already at rather small values of the interaction, in a regime where the magnetic moments are barely developed.
Collapse
|
2
|
Signatures of Dissipation Driven Quantum Phase Transition in Rabi Model. PHYSICAL REVIEW LETTERS 2023; 130:210404. [PMID: 37295090 DOI: 10.1103/physrevlett.130.210404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 04/13/2023] [Indexed: 06/12/2023]
Abstract
By using the worldline Monte Carlo technique, matrix product state, and a variational approach à la Feynman, we investigate the equilibrium properties and relaxation features of the dissipative quantum Rabi model, where a two level system is coupled to a linear harmonic oscillator embedded in a viscous fluid. We show that, in the Ohmic regime, a Beretzinski-Kosterlitz-Thouless quantum phase transition occurs by varying the coupling strength between the two level system and the oscillator. This is a nonperturbative result, occurring even for extremely low dissipation magnitude. By using state-of-the-art theoretical methods, we unveil the features of the relaxation towards the thermodynamic equilibrium, pointing out the signatures of quantum phase transition both in the time and frequency domains. We prove that, for low and moderate values of the dissipation, the quantum phase transition occurs in the deep strong coupling regime. We propose to realize this model by coupling a flux qubit and a damped LC oscillator.
Collapse
|
3
|
Trocar vs. Seldinger small bore pleural drains: does the technique influence the outcomes? A prospective single-centre study. EUROPEAN REVIEW FOR MEDICAL AND PHARMACOLOGICAL SCIENCES 2023; 27:728-736. [PMID: 36734736 DOI: 10.26355/eurrev_202301_31075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVE The aim of this study is to compare two positioning techniques of 12-French (Fr) thoracic drains in terms of efficacy, safety, and patient comfort. PATIENTS AND METHODS This is a prospective, non-randomized, competitive, non-inferiority study comparing the Seldinger vs. Trocar technique. The primary endpoint was an analysis of the factors that led to unsuccessful drainage positioning. Between the two groups, clinical variables, procedure times, pain, and complications were compared. RESULTS Seventy-two patients were enrolled in group 1 (Seldinger) and 45 in group 2 (Trocar). The mean procedural time was 7.93±3.02 min vs. 7.09±3.67 min, respectively (p: 0.33). The mean VAS for procedural pain was 2.22±1.47 vs. 2.80±1.88, p: 0.07, and the mean at day 2 was 3.6±1.2 in the SBWGD group vs. 2.7±1.1 in the Unico Group (p: 0.04). There was no difference in terms of complications, residual effusion, and pneumothorax at the first post-procedural chest X-ray. Four days after the procedure, the drain removal rate was 11.6% in group 1 vs. 25% in group 2 p: 0.063). The chest tube was removed after a mean period of 8.87±7.20 days after resolution of pleural effusion or tube dislodgement (7 cases in group 1 vs. 11 in group 2, p: 0.053). CONCLUSIONS The two techniques resulted in comparable pain and complication rates. Both drains are well-tolerated and efficient at draining pleural effusion, with very low rates of complications and failure. We recommend inserting a longer tube for patients who require chest drainage for an extended period of time.
Collapse
|
4
|
Anti-glutathione S-transferase theta 1 antibodies correlate with graft loss in non-sensitized pediatric kidney recipients. Front Med (Lausanne) 2022; 9:1035400. [DOI: 10.3389/fmed.2022.1035400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Accepted: 11/14/2022] [Indexed: 12/05/2022] Open
Abstract
IntroductionImmunity to Human leukocyte antigen (HLA) cannot explain all cases of ABMR, nor the differences observed in the outcome of kidney recipients with circulating DSAs endowed with similar biologic characteristics. Thus, increasing attention has recently been focused on the role of immunity to non-HLA antigenic targets.MethodsWe analyzed humoral auto- and alloimmune responses to the non-HLA antigen glutathione S-transferase theta 1 (GSTT1), along with development of de novo (dn)HLA-DSAs, in a cohort of 146 pediatric non-sensitized recipients of first kidney allograft, to analyze its role in ABMR and graft loss. A multiplex bead assay was employed to assess GSTT1 antibodies (Abs).ResultsWe observed development of GSTT1 Abs in 71 recipients after transplantation, 16 with MFI > 8031 (4th quartile: Q4 group). In univariate analyses, we found an association between Q4-GSTT1Abs and ABMR and graft loss, suggesting a potential role in inducing graft damage, as GSTT1 Abs were identified within ABMR biopsies of patients with graft function deterioration in the absence of concomitant intragraft HLA-DSAs. HLA-DSAs and GSTT1 Abs were independent predictors of graft loss in our cohort. As GSTT1 Ab development preceded or coincided with the appearance of dnHLA-DSAs, we tested and found that a model with the two combined parameters proved more fit to classify patients at risk of graft loss.DiscussionOur observations on the harmful effects of GSTT1Abs, alone or in combination with HLA-DSAs, add to the evidence pointing to a negative role of allo- and auto-non-HLA Abs on kidney graft outcome.
Collapse
|
5
|
La représentation des femmes dans les comités éditoriaux des revues de psychiatrie : multiples défis et obstacles. BULLETIN DE L'ACADÉMIE NATIONALE DE MÉDECINE 2021; 205:1060-1061. [DOI: 10.1016/j.banm.2021.05.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/28/2023]
|
6
|
P-glycoprotein inhibition with verapamil overcomes mometasone resistance in Chronic Sinusitis with Nasal Polyps. Rhinology 2021; 59:205-211. [PMID: 33459729 DOI: 10.4193/rhin20.551] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND P-glycoprotein (P-gp) is a membrane efflux pump which is overexpressed in Chronic Rhinosinusitis with Nasal Polyps (CRSwNP) and promotes Type 2 inflammation. Glucocorticoids (GC) are substrates of P-gp suggesting that overexpression may additionally contribute to GC resistance in CRSwNP. This study aims to determine whether P-gp inhibition using verapamil enhances mometasone retention and efficacy in nasal polyp explants. METHODOLOGY IRB approved study in which organotypic polyp explants were exposed to mometasone (4.15 μg/mL) and verapa- mil (125 μg/mL) as mono and combination therapy. The effect of verapamil on mometasone tissue retention over time was deter- mined using HPLC. The effect of verapamil on mometasone anti-inflammatory function was determined using ELISA for secreted IL-5. Groups were compared using Kruskal-Wallis test. RESULTS P-gp expression strongly and significantly inversely correlated with mometasone retention 1hr after exposure, with a ne- arly 6-fold reduction in tissue retention between the lowest and highest P-gp expressing polyp explants. P-gp inhibition reversed this effect and significantly improved mometasone retention at 1hr relative to mometasone alone. The combination of mome- tasone and verapamil significantly reduced IL-5 secretion relative to vehicle control and outperformed either treatment alone. CONCLUSIONS Our study confirms that P-gp contributes to mometasone resistance. This P-gp mediated resistance was successfully reversed by addition of the P-gp inhibitor verapamil. Verapamil further significantly enhanced the anti-inflammatory effect of mometasone when given as a combination therapy.
Collapse
|
7
|
Post-transplant de novo non donor-specific HLA antibodies are not associated with poor graft outcome in non-sensitized pediatric recipients of kidney transplantation. Transpl Immunol 2021; 65:101375. [PMID: 33610675 DOI: 10.1016/j.trim.2021.101375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 02/13/2021] [Accepted: 02/15/2021] [Indexed: 10/22/2022]
Abstract
While de novo donor-specific HLA antibodies (dnDSAs) have a detrimental impact on kidney graft outcome, the clinical significance of de novo non donor-specific antibodies (dnNDSAs) is more controversial. We retrospectively evaluated for Ab development and characteristics of dnNDSAs serially collected post-transplant sera and, when available, graft biopsy eluates, from 144 non-sensitized, primary pediatric kidney recipients, consecutively transplanted at a single center between 2003 and 2017, using HLA class I and class II single-antigen flow-bead assays (SAB). The results were compared with clinical-pathologic data from HLA antibody negative and HLA dnDSA-positive patients. Forty-five out of 144 patients developed dnNDSAs (31%). Among the dnNDSA-positive patients, 86% displayed one or more class I/II antibodies recognizing antigens included in the CREG/shared epitope groups that also comprise the mismatched donor HLA antigens. Despite potential pathogenicity, as suggested by their occasional presence within the graft, dnNDSAs displayed significantly lower MFI, and limited complement binding and graft homing properties, when compared with dnDSAs. In parallel, the graft survival probability was significantly lower in patients with dnDSA than in those with dnNDSA or without HLA antibodies (p < 0.005). Indeed, the dnNDSA-positive patients remaining dnDSA-negative throughout the posttransplant period did not develop clinical antibody mediated rejection and graft loss, and maintained good graft function at a median follow-up of 9 years. The biological characteristics of dnNDSAs may account for the low graft damaging capability when compared to dnDSAs.
Collapse
|
8
|
Circulating B Cells With Memory and Antibody-Secreting Phenotypes Are Detectable in Pediatric Kidney Transplant Recipients Before the Development of Antibody-Mediated Rejection. Transplant Direct 2019; 5:e481. [PMID: 31579809 PMCID: PMC6739044 DOI: 10.1097/txd.0000000000000914] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Accepted: 05/16/2019] [Indexed: 12/18/2022] Open
Abstract
Development of anti-human leukocyte antigen donor-specific antibodies (DSAs) is associated with antibody-mediated rejection (AMR) and reduced allograft survival in kidney transplant recipients. Whether changes in circulating lymphocytes anticipate DSA or AMR development is unclear. METHODS We used time-of-flight mass cytometry to analyze prospectively collected peripheral blood mononuclear cells (PBMC) from pediatric kidney transplant recipients who developed DSA (DSA-positive recipients [DSAPOS], n = 10). PBMC were obtained at 2 months posttransplant, 3 months before DSA development, and at DSA detection. PBMC collected at the same time points posttransplant from recipients who did not develop DSA (DSA-negative recipients [DSANEG], n = 11) were used as controls. RESULTS DSAPOS and DSANEG recipients had similar baseline characteristics and comparable frequencies of total B and T cells. Within DSAPOS recipients, there was no difference in DSA levels (mean fluorescence intensity [MFI]: 13 687 ± 4159 vs 11 375 ± 1894 in DSAPOSAMR-positive recipients (AMRPOS) vs DSAPOSAMR-negative recipients (AMRNEG), respectively; P = 0.630), C1q binding (5 DSAPOSAMRPOS [100%] vs 4 DSAPOSAMRNEG [80%]; P = 1.000), or C3d binding (3 DSAPOSAMRPOS [60%] vs 1 DSAPOSAMRNEG [20%]; P = 0.520) between patients who developed AMR and those who did not. However, DSAPOS patients who developed AMR (n = 5; 18.0 ± 3.6 mo post-DSA detection) had increased B cells with antibody-secreting (IgD-CD27+CD38+; P = 0.002) and memory (IgD-CD27+CD38-; P = 0.003) phenotypes compared with DSANEG and DSAPOSAMRNEG recipients at DSA detection. CONCLUSIONS Despite the small sample size, our comprehensive phenotypic analyses show that circulating B cells with memory and antibody-secreting phenotypes are present at DSA onset, >1 year before biopsy-proven AMR in pediatric kidney transplant recipients.
Collapse
|
9
|
Failure to remove de novo donor-specific HLA antibodies is influenced by antibody properties and identifies kidney recipients with late antibody-mediated rejection destined to graft loss - a retrospective study. Transpl Int 2018; 32:38-48. [PMID: 30076765 DOI: 10.1111/tri.13325] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 05/03/2018] [Accepted: 07/31/2018] [Indexed: 12/15/2022]
Abstract
Current research is focusing on identifying bioclinical parameters for risk stratification of renal allograft loss, largely due to antibody-mediated rejection (AMR). We retrospectively investigated graft outcome predictors in 24 unsensitized pediatric kidney recipients developing HLA de novo donor-specific antibodies (dnDSAs), and treated for late AMR with plasmapheresis + low-dose IVIG + Rituximab or high-dose IVIG + Rituximab. Renal function and DSA properties were assessed before and longitudinally post treatment. The estimated GFR (eGFR) decline after treatment was dependent on a negative % eGFR variation in the year preceding treatment (P = 0.021) but not on eGFR at treatment (P = 0.74). At a median follow-up of 36 months from AMR diagnosis, 10 patients lost their graft. Altered eGFR (P < 0.001) and presence of C3d-binding DSAs (P = 0.005) at treatment, and failure to remove DSAs (P = 0.01) were negatively associated with graft survival in the univariable analysis. Given the relevance of DSA removal for therapeutic success, we analyzed antibody properties dictating resistance to anti-humoral treatment. In the multivariable analysis, C3d-binding ability (P < 0.05), but not C1q-binding, and high mean fluorescence intensity (P < 0.05) were independent factors characterizing DSAs scarcely susceptible to removal. The poor prognosis of late AMR is related to deterioration of graft function prior to treatment and failure to remove C3d binding and/or high-MFI DSAs.
Collapse
|
10
|
Computing Resonant Inelastic X-Ray Scattering Spectra Using The Density Matrix Renormalization Group Method. Sci Rep 2018; 8:11080. [PMID: 30038401 PMCID: PMC6056525 DOI: 10.1038/s41598-018-29218-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 07/06/2018] [Indexed: 11/08/2022] Open
Abstract
We present a method for computing the resonant inelastic x-ray scattering (RIXS) spectra in one-dimensional systems using the density matrix renormalization group (DMRG) method. By using DMRG to address this problem, we shift the computational bottleneck from the memory requirements associated with exact diagonalization (ED) calculations to the computational time associated with the DMRG algorithm. This approach is then used to obtain RIXS spectra on cluster sizes well beyond state-of-the-art ED techniques. Using this new procedure, we compute the low-energy magnetic excitations observed in Cu L-edge RIXS for the challenging corner shared CuO4 chains, both for large multi-orbital clusters and downfolded t-J chains. We are able to directly compare results obtained from both models defined in clusters with identical momentum resolution. In the strong coupling limit, we find that the downfolded t-J model captures the main features of the magnetic excitations probed by RIXS only after a uniform scaling of the spectra is made.
Collapse
|
11
|
Kidney Intragraft Homing of De Novo Donor-Specific HLA Antibodies Is an Essential Step of Antibody-Mediated Damage but Not Per Se Predictive of Graft Loss. Am J Transplant 2017; 17:692-702. [PMID: 27501275 DOI: 10.1111/ajt.14000] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Revised: 07/07/2016] [Accepted: 08/02/2016] [Indexed: 01/25/2023]
Abstract
Donor-specific HLA antibody (DSA)-mediated graft injury is the major cause of kidney loss. Among DSA characteristics, graft homing has been suggested as an indicator of severe tissue damage. We analyzed the role of de novo DSA (dnDSA) graft homing on kidney transplantation outcome. Graft biopsy specimens and parallel sera from 48 nonsensitized pediatric kidney recipients were analyzed. Serum samples and eluates from graft biopsy specimens were tested for the presence of dnDSAs with flow bead technology. Intragraft dnDSAs (gDSAs) were never detected in the absence of serum dnDSAs (sDSAs), whereas in the presence of sDSAs, gDSAs were demonstrated in 72% of biopsy specimens. A significantly higher homing capability was expressed by class II sDSAs endowed with high mean fluorescence intensity and C3d- and/or C1q-fixing properties. In patients with available sequential biopsy specimens, we detected gDSAs before the appearance of antibody-mediated rejection. In sDSA-positive patients, gDSA positivity did not allow stratification for antibody-mediated graft lesions and graft loss. However, a consistent detection of skewed unique DSA specificities was observed over time within the graft, likely responsible for the damage. Our results indicate that gDSAs could represent an instrumental tool to identify, among sDSAs, clinically relevant antibody specificities requiring monitoring and possibly guiding patient management.
Collapse
|
12
|
Spectral functions with the density matrix renormalization group: Krylov-space approach for correction vectors. Phys Rev E 2016; 94:053308. [PMID: 27967202 DOI: 10.1103/physreve.94.053308] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Indexed: 06/06/2023]
Abstract
Frequency-dependent correlations, such as the spectral function and the dynamical structure factor, help illustrate condensed matter experiments. Within the density matrix renormalization group (DMRG) framework, an accurate method for calculating spectral functions directly in frequency is the correction-vector method. The correction vector can be computed by solving a linear equation or by minimizing a functional. This paper proposes an alternative to calculate the correction vector: to use the Krylov-space approach. This paper then studies the accuracy and performance of the Krylov-space approach, when applied to the Heisenberg, the t-J, and the Hubbard models. The cases studied indicate that the Krylov-space approach can be more accurate and efficient than the conjugate gradient, and that the error of the former integrates best when a Krylov-space decomposition is also used for ground state DMRG.
Collapse
|
13
|
Acquisition of C3d-Binding Activity by De Novo Donor-Specific HLA Antibodies Correlates With Graft Loss in Nonsensitized Pediatric Kidney Recipients. Am J Transplant 2016; 16:2106-16. [PMID: 26725780 DOI: 10.1111/ajt.13700] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 12/23/2015] [Accepted: 12/28/2015] [Indexed: 01/25/2023]
Abstract
Alloantibody-mediated graft injury is a major cause of kidney dysfunction and loss. The complement-binding ability of de novo donor-specific antibodies (dnDSAs) has been suggested as a prognostic tool to stratify patients for clinical risk. In this study, we analyzed posttransplant kinetics of complement-fixing dnDSAs and their role in antibody-mediated rejection development and graft loss. A total of 114 pediatric nonsensitized recipients of first kidney allograft were periodically monitored for dnDSAs using flow bead assays, followed by C3d and C1q assay in case of positivity. Overall, 39 patients developed dnDSAs, which were C1q(+) and C3d(+) in 25 and nine patients, respectively. At follow-up, progressive acquisition over time of dnDSA C1q and C3d binding ability, within the same antigenic specificity, was observed, paralleled by an increase in mean fluorescence intensity that correlated with clinical outcome. C3d-fixing dnDSAs were better fit to stratify graft loss risk when the different dnDSA categories were evaluated in combined models because the 10-year graft survival probability was lower in patients with C3d-binding dnDSA than in those without dnDSAs or with C1q(+) /C3d(-) or non-complement-binding dnDSAs (40% vs. 94%, 100%, and 100%, respectively). Based on the kinetics profile, we favor dnDSA removal or modulation at first confirmed positivity, with treatment intensification guided by dnDSA biological characteristics.
Collapse
|
14
|
Gene expression in highly sensitized dialysis patients waiting for a kidney transplant: A real-time PCR analysis. Transpl Immunol 2015; 33:166-7. [PMID: 26475986 DOI: 10.1016/j.trim.2015.10.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Revised: 10/12/2015] [Accepted: 10/13/2015] [Indexed: 11/26/2022]
|
15
|
Abstract
Renal transplantation has become an effective form of treatment for end-stage renal failure. Unfortunately, as a consequence of immunological and nonimmunological pathogenic mechanisms, chronic allograft nephropathy is responsible for the loss of a large proportion of kidney grafts after several years and return to dialysis. We have reported herein our 24 years of experience with second kidney transplantations. Of 1,302 kidney transplantations between January 1983 and June 2007 performed in our transplantation center, 100 were second transplantations. Kidney retransplantation was performed in 74 men and 26 women of overall mean age of 35.4 +/- 12.6 years. Cadaveric donor grafts were transplanted in 92 patients, whereas the remaining 8 were living-related donor kidneys. At 1, 5, and 10 years after kidney transplantation, patient survival rates were 100%, 96%, and 92%, respectively, whereas graft survival rates were 85%, 72%, and 53%, respectively. Immunosuppressive therapy included induction therapy with polyclonal anti-lymphocyte antibodies (ALG/ATG) or (starting from 1999) monoclonal anti CD 25 antibody. Our results demonstrated good outcomes for kidney retransplantations with allocation based on anti- HLA antibody identification together with induction immunosuppression.
Collapse
|
16
|
Serum complement inactivation unveiled prepregnancy donor-specific HLA antibodies leading to postpartum kidney graft loss. Transpl Int 2015; 28:623-5. [DOI: 10.1111/tri.12521] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
17
|
Noise-assisted charge pump in elastically deformable molecular junctions. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2014; 26:365301. [PMID: 25122075 DOI: 10.1088/0953-8984/26/36/365301] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We study a charge pump realized with an elastically deformable quantum dot whose center of mass follows a nonlinear stochastic dynamics. The interplay of noise, nonlinear effects, dissipation and interaction with an external time-dependent driving on the pumped charge is fully analyzed. The results show that the quantum pumping mechanism not only is not destroyed by the force fluctuations, but it becomes stronger when the forcing signal frequency is tuned close to the resonance of the vibrational mode. The robustness of the quantum pump with temperature is also investigated and an exponential decay of the pumped charge is found when the coupling to the vibrational mode is present. Implications of our results for nanoelectromechanical systems are also discussed.
Collapse
|
18
|
DQ molecules are the principal stimulators ofde novodonor-specific antibodies in nonsensitized pediatric recipients receiving a first kidney transplant. Transpl Int 2014; 27:667-73. [DOI: 10.1111/tri.12316] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Revised: 01/13/2014] [Accepted: 03/11/2014] [Indexed: 11/27/2022]
|
19
|
Kidney transplantation from living donors genetically related or unrelated to the recipients: a single-center analysis. Transplant Proc 2013; 44:1892-6. [PMID: 22974864 DOI: 10.1016/j.transproceed.2012.05.061] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Living-donor programs have gradually become an attractive strategy to expand the donor pool for kidney transplantation (KT). Grafts from living-related donors (LRD) display superior function and longer survival than those obtained from cadaveric sources. Recent reports have shown that outcomes from living-unrelated donors (LUD) are not worse than those from LRD. In this study, we evaluated 135 procedures using living donors performed in our center between 1987 and 2010 (LRD: n = 111; LUD: n = 24). Among the LRD, most donors were mothers (n = 61; 54.95%), fathers (n = 25; 22.52%), and sisters (n = 16; 14.41%). The LUD included wives (n = 17; 70.83%) and husbands (n = 7; 29.17%). The mean recipient ages for LRD versus LUD were 26.94 ± 13.51 and 50.04 ± 8.86 years, respectively (P < .0001). The recipient female/male distribution was 33/78 (29.73%/70.27%) for the LRD versus 6/18 (25%/75%) for the LUD group (P = .643). The donor age was 48.79 ± 9 years in LRD and 49.25 ± 8.44 years in LUD (P = .696). The donor female/male distribution was 72/39 (64.86%/35.16%) in LRD and 17/7 (70.83%/29.17%) in LUD (P = .576). The follow up was 123.79 ± 87.87 months (range, 0.91-279.93). Overall patient and graft survivals were 94.1% and 67.6%, respectively. There was no significant difference in patient survival after stratifying for donor type (LRD: 93.9%; LUD: 95.8%; P = .961) or in graft survival after stratifying for donor type (LRD: 63.8%; LUD: 87.8%; P = .124). Entering donor type as an independent variable in a univariate Cox regression, we observed no significance for either recipient (P = .961) or graft survival (P = .142). The results of this study suggest that LUD utilization should be encouraged in KT programs.
Collapse
|
20
|
Posttransplant de novo donor-specific hla antibodies identify pediatric kidney recipients at risk for late antibody-mediated rejection. Am J Transplant 2012; 12:3355-62. [PMID: 22959074 DOI: 10.1111/j.1600-6143.2012.04251.x] [Citation(s) in RCA: 126] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The emerging role of humoral immunity in the pathogenesis of chronic allograft damage has prompted research aimed at assessing the role of anti-HLA antibody (Ab) monitoring as a tool to predict allograft outcome. Data on the natural history of allografts in children developing de novo Ab after transplantation are limited. Utilizing sera collected pretransplant, and serially posttransplant, we retrospectively evaluated 82 consecutive primary pediatric kidney recipients, without pretransplant donor-specific antibodies (DSA), for de novo Ab occurrence, and compared results with clinical-pathologic data. At 4.3-year follow up, 19 patients (23%) developed de novo DSA whereas 24 had de novo non-DSA (NDSA, 29%). DSA appeared at a median time of 24 months after transplantation and were mostly directed to HLA-DQ antigens. Among the 82 patients, eight developed late/chronic active C4d+ antibody-mediated rejection (AMR), and four C4d-negative AMR. Late AMR correlated with DSA (p < 0.01), whose development preceded AMR by 1-year median time. Patients with DSA had a median serum creatinine of 1.44 mg/dL at follow up, significantly higher than NDSA and Ab-negative patients (p < 0.005). In our pediatric cohort, DSA identify patients at risk of renal dysfunction, AMR and graft loss; treatment started at Ab emergence might prevent AMR occurrence and/or progression to graft failure.
Collapse
|
21
|
A single-center analysis to evaluate kidney function parameters after liver transplantation in adult patients. Transplant Proc 2012; 44:1992-8. [PMID: 22974890 DOI: 10.1016/j.transproceed.2012.06.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Severe renal dysfunction may occur after orthotopic liver transplantation (OLT). In this study, we retrospectively analyzed a single-center series of adult liver recipients (n = 62) seeking to identify patients prone to develop renal dysfunction during follow-up. Liver recipients (age range, 53.54 ± 8.19 years; female/male: 21/41) who underwent a first OLT from a brain dead donor were enrolled according to strict criteria. We enrolled only liver recipients with 5 serum creatinine (SCr) measurements after hospital discharge and at least 1 measurement/year with a follow-up period of not less than 2 years. We estimated glomerular filtration rate (eGFR) using the formula developed by the Mayo Clinic. The average rate of SCr change after OLT was 0.0065 ± 0.013 mg/dL/mo. By calculating the per-patient slope, the average rate of SCr change was 0.000165 ± 0.000383 mg/dL (0.000007 ± 0.000017 mg/dL/mo). In regression models evaluated with SCr as the dependent variable versus post-OLT time, no significance was observed (P = .130). The average rate of eGFR change after OLT was -0.462 ± 0.883 mL/min/mo. By calculating the per-patient slope, the average rate of eGFR change was -0.009 ± 0.0026 mL/min (-0.0004 ± 0.0012 mL/min/mo). In the regression models evaluated with eGFR as dependent variable versus post-OLT time, no significance occurred (P = .168). By applying the regression prediction to SCr at 3 to 5 versus the 1 to 2 post-OLT measurements, we noted 3 male liver recipients (MLR) whose SCr values were significantly higher than the predicted values: MLR1: P = .048 at measurement 4; MLR2: P = .019 at measurement 4; and MLR3: P = .017 at measurement 5. Conversely, we did not observed a significant difference between observed versus predicted eGFR values. Clinical decisions on immunosuppressive treatments for liver recipients should be determined also on the basis of the series of post-OLT kidney function, which should be studied with rigorous evaluation of fitted regression models.
Collapse
|
22
|
Regulatory Functions of Insulin-like Growth Factor Binding Proteins in Osteoarthritis. Int J Immunopathol Pharmacol 2011; 24:55-9. [DOI: 10.1177/03946320110241s211] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Insulin-like growth factor binding proteins (IGFBPs) are a group of secreted proteins, which bind to IGF-I (and IGF-II) with high affinity and modulate the biological actions of IGFs. Abundant evidence points the importance of the IGF-I/IGFBP system on both cell growth and differentiation. A role for the IGF-I/IGFBP system in the regulation of normal human cartilage has been previously reported. In this context, recent studies suggest an emerging role for IGFBPs in the failure of cartilage during osteoarthritis (OA). Indeed, increased IGFBP levels have been reported in both the articular cartilage and synovial fluid from patients with OA. Overexpression of IGFBPs, by altering the bioavailability and function of IGFs, is likely to deliver IGFs-independent signals for chondrocyte survival. This, at least in part, might explain the degenerative changes of the cartilage in OA. Further studies are necessary to clarify the mechanisms that cause the overexpression of IGFBPs in patients with OA. Advances in our understanding of the relationship between osteoarthritis and the IGF-I/IGFBP system may lead to new treatment strategies for this degenerative disease.
Collapse
|
23
|
Death of an infant after contacting a telephone triage call centre: is telephone triage really safe? CASE REPORTS 2010; 2010:2010/dec07_1/bcr0820092144. [DOI: 10.1136/bcr.08.2009.2144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
|
24
|
Application and validation of Cox regression models in a single-center series of double kidney transplantation. Transplant Proc 2010; 42:1098-103. [PMID: 20534233 DOI: 10.1016/j.transproceed.2010.03.037] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A useful approach to reduce the number of discarded marginal kidneys and to increase the nephron mass is double kidney transplantation (DKT). In this study, we retrospectively evaluated the potential predictors for patient and graft survival in a single-center series of 59 DKT procedures performed between April 21, 1999, and September 21, 2008. The kidney recipients of mean age 63.27 +/- 5.17 years included 16 women (27%) and 43 men (73%). The donors of mean age 69.54 +/- 7.48 years included 32 women (54%) and 27 men (46%). The mean posttransplant dialysis time was 2.37 +/- 3.61 days. The mean hospitalization was 20.12 +/- 13.65 days. Average serum creatinine (SCr) at discharge was 1.5 +/- 0.59 mg/dL. In view of the limited numbers of recipient deaths (n = 4) and graft losses (n = 8) that occurred in our series, the proportional hazards assumption for each Cox regression model with P < .05 was tested by using correlation coefficients between transformed survival times and scaled Schoenfeld residuals, and checked with smoothed plots of Schoenfeld residuals. For patient survival, the variables that reached statistical significance were donor SCr (P = .007), donor creatinine cleararance (P = .023), and recipient age (P = .047). Each significant model passed the Schoenfeld test. By entering these variables into a multivariate Cox model for patient survival, no further significance was observed. In the univariate Cox models performed for graft survival, statistical significance was noted for donor SCr (P = .027), SCr 3 months post-DKT (P = .043), and SCr 6 months post-DKT (P = .017). All significant univariate models for graft survival passed the Schoenfeld test. A final multivariate model retained SCr at 6 months (beta = 1.746, P = .042) and donor SCr (beta = .767, P = .090). In our analysis, SCr at 6 months seemed to emerge from both univariate and multivariate Cox models as a potential predictor of graft survival among DKT. Multicenter studies with larger recipient populations and more graft losses should be performed to confirm our findings.
Collapse
|
25
|
Long-term diabetic complications in elderly patients with variable levels of HMGA1 expression. BMC Geriatr 2010. [PMCID: PMC3290239 DOI: 10.1186/1471-2318-10-s1-a91] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
|
26
|
The transcription factor RFX protects MHC class II genes against epigenetic silencing by DNA methylation. THE JOURNAL OF IMMUNOLOGY 2009; 183:2545-53. [PMID: 19620312 DOI: 10.4049/jimmunol.0900376] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Classical and nonclassical MHC class II (MHCII) genes are coregulated by the transcription factor RFX (regulatory factor X) and the transcriptional coactivator CIITA. RFX coordinates the assembly of a multiprotein "enhanceosome" complex on MHCII promoters. This enhanceosome serves as a docking site for the binding of CIITA. Whereas the role of the enhanceosome in recruiting CIITA is well established, little is known about its CIITA-independent functions. A novel role of the enhanceosome was revealed by the analysis of HLA-DOA expression in human MHCII-negative B cell lines lacking RFX or CIITA. HLA-DOA was found to be reactivated by complementation of CIITA-deficient but not RFX-deficient B cells. Silencing of HLA-DOA was associated with DNA methylation at its promoter, and was relieved by the demethylating agent 5-azacytidine. Surprisingly, DNA methylation was also established at the HLA-DRA and HLA-DQB loci in RFX-deficient cells. This was a direct consequence of the absence of RFX, as it could be reversed by restoring RFX function. DNA methylation at the HLA-DOA, HLA-DRA, and HLA-DQB promoters was observed in RFX-deficient B cells and fibroblasts, but not in CIITA-deficient B cells and fibroblasts, or in wild-type fibroblasts, which lack CIITA expression. These results indicate that RFX and/or enhanceosome assembly plays a key CIITA-independent role in protecting MHCII promoters against DNA methylation. This function is likely to be crucial for retaining MHCII genes in an open chromatin configuration permissive for activation in MHCII-negative cells, such as the precursors of APC and nonprofessional APC before induction with IFN-gamma.
Collapse
|
27
|
[Desensitization protocols in immunized living donor kidney transplant recipients]. GIORNALE ITALIANO DI NEFROLOGIA : ORGANO UFFICIALE DELLA SOCIETA ITALIANA DI NEFROLOGIA 2009; 26:499-515. [PMID: 19644839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
It is well known that the presence of alloantibodies against human HLA class I (A, B, C) and class II (DR, DQ) antigens in transplant recipients waiting for a first or subsequent kidney transplant has a significant negative impact on graft outcome, with increased acute and chronic rejection rates. HLA antibodies, present in hyperimmunized patients (PRA > 80%) as a result of pregnancies, blood transfusions and previous failed grafts, once thought to be a formidable barrier to renal transplantation, can now be overcome with excellent results by means of desensitization protocols in kidney transplant recipients from living or cadaver donors. Such pretransplant desensitization protocols consist of high-dose intravenous immunoglobulin infusions (IVIg-HD), plasmapheresis associated with low-dose IVIg (IVIg-LD) and immunoabsorption by protein-A sepharose or Ig-sepharose columns. All of the above treatments, associated in many cases with the anti-CD20 monoclonal antibody Rituximab, have been widely applied in living donor kidney transplant recipients showing donor-specific anti-HLA antibodies. Similar desensitization protocols have been used for non-A2 AB0-incompatible living donor kidney transplants. These techniques have allowed successful transplantation in this high-risk patient category by providing live donor kidneys that function promptly with minimal risk of early loss, and have consequently increased the organ donor pool. Long-term follow- up of these patients and the application on a wider scale of these techniques, which for many patients may represent the only realistic chance of a successful transplant, will provide the definitive answers about their real efficacy.
Collapse
|
28
|
Sirolimus Therapy in Liver Transplant Patients: An Initial Experience at a Single Center. Transplant Proc 2008; 40:1950-2. [DOI: 10.1016/j.transproceed.2008.05.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
|
29
|
Medical report type in liver transplantation as a quality system document: new prospects for computerization. Transplant Proc 2007; 39:1910-7. [PMID: 17692651 DOI: 10.1016/j.transproceed.2007.05.029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The usage of a computerized system to organize data and ease the activity procedures of liver transplantation is useful in clinical transplantation. Preliminary cognitive research on systems of clinical transplantation database concerning medical reports was performed to verify their development level. The survey highlighted that, so far, there has been no experimentation that can be applied to a medical report type devoted to liver transplantation. Regulations in force substantially point out that the medical report ought to contain all items that have to be taken into account in handling the patient from pretransplantation to follow-up. The Department of Transplantation of Genoa chose its medical report model for liver transplantation. The medical report model included the following items: personal data; case history; diagnosis; initial examination for prelisting; fitness for transplantation; assistance context; clinical data including subjective, objective, and instrumental parameters; pharmacological therapies; informed consent, evaluation of fitness; nursing data; counseling and clinical evaluations according to protocols and guidelines of the national transplantation centers. If the computing is well trained, it is supposed to help maintain a whole data view provided it is supplied information in an adequate way. Immediate clinical procedural advantages and useful scientific observations may be obtained from a high-quality database. In fact, all functions have to be applied to specific clinical, administrative needs to be remotely shared and conveniently integrated with each other to make the liver transplantation medical report an easy and handy instrument for inputting and handling data. It must be a precise, complete instrument that may be accessible in real time from any site connected with the intranet network, be unchangeable, and be protected to ensure certification and forensic medicine value.
Collapse
|
30
|
Detection and analysis of HLA class I and class II specific alloantibodies in the sera of dialysis recipients waiting for a renal retransplantation. Clin Transplant 2007; 21:47-56. [PMID: 17302591 DOI: 10.1111/j.1399-0012.2006.00578.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The objective of this study was to evaluate the specificities of HLA class I (-A,-B) and class II (-DR,-DQ) antibodies (Ab) detected in the sera of alloimmunized patients waiting for a subsequent renal transplantation. The study group consisted of 62 dialysis patients (42 men and 20 women, mean age: 43 +/- 18 yr) on waiting list for a subsequent kidney transplant (52 for a second and 10 for a third transplant) at S. Martino Hospital Transplant Centre in Genoa/Italy, who were enrolled from 2002 to 2004 for HLA antibody screening. Complement dependent cytotoxicity (CDC) technique was used firstly to select anti-HLA class I sensitized patients; indeed sera from 50 individuals out of 62 (80.6%) were found to display persistent HLA class I PRA (panel reactive antibody) values >4% (range: 20-100). ELISA technique was subsequently adopted to analyze HLA class I Ab positive sera for the presence also of HLA class II Ab and to characterize class I and class II Ab specificities. Anti-class I immunized patients were divided in three groups according to the type of class I Ab specificities, that were classified as private, public, and multispecific. The first group included 35 patients (70% of the total number of positive patients) showing only antibodies directed against private HLA class I specificities, represented in 33 cases by those expressed by graft donors (first or second transplant). In this group anti-class I PRA% values ranged from 20% to 60%. HLA class II Ab, with an heterogeneous specificity pattern (private, public or multispecific), were present in 25 (78.1%) out of the 32 patients, whose sera were also available for this analysis. The second group comprised 12 patients (24%) who displayed antibodies directed against class I public epitopes belonging to CREGs (Cross reactive Groups) or an association of anti-private and anti-public antibodies. In this group PRA values ranged from 25% to 90%. Five patients (46.7%) were positive for HLA class II Ab, whose specificity pattern appeared also heterogeneous (private or multispecific). The third group was represented by three patients (6%) displaying multispecific antibodies with PRA values > or = 90%. No multispecific class II Ab were found in this group, where only two patients had class II Ab showing anti-private or anti-private plus public specificities. Globally, 74% of anti-class I Ab positive patients, having at least one HLA class II antigen mismatch, appeared also positive for class II Ab. These results indicate that: (i) a large proportion of patients, waiting for a kidney retransplantation, display in their sera alloantibodies specific for graft mismatched HLA class I (80.6%) and class II antigens (54.2); (ii) the immunogenic determinants, mainly involved in HLA class I and II specific Ab production, were, in a significant rate, private specificities of mismatched HLA antigens (70% for class I and 59.4% for class II), and in a lesser percentage by public (CREG) epitopes (24% for class I and 34.3% for class II). In a few patients only no HLA class I and class II Ab specificities could be determined, as they displayed multispecific antibodies (6% for class I and 6.2% for class II). These findings may have important implications to improve donor-recipient matching in dialysis recipients waiting for a subsequent renal transplantation.
Collapse
|
31
|
Abstract
The pathogenesis of immunological and nonimmunological components that cause chronic kidney allograft nephropathy (CAN), is not yet completely understood. To explore the possible contribution of alloreactive cytotoxic T cells, we analyzed the transcription of cytotoxic molecules such as granzyme B and perforin using semiquantitative RT-PCR on surgically removed grafts obtained from two groups: group 1 (n = 10) were cases of CAN; group 2 (n = 3) had no CAN. Among group 1 kidneys, granzyme-B was expressed in 7 of 10, whereas perforin was detectable in 9 of 10 cases; their detection was not related to the presence of superimposed signs of acute graft lesions. Cytotoxic molecules were never found in group 2 kidneys. These results show that explanted chronically rejected grafts display cytotoxic molecule transcripts in addition to Th2 type cytokines, such as IL-10, IL-3, and IL-6, suggesting that both cellular and humoral alloreactive mechanisms may play important roles in CAN pathogenesis.
Collapse
|
32
|
Treatment of EBV-related post-renal transplant lymphoproliferative disease with a tailored regimen including EBV-specific T cells. Am J Transplant 2005; 5:1415-22. [PMID: 15888049 DOI: 10.1111/j.1600-6143.2005.00854.x] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The treatment of EBV-associated post-transplant lymphoproliferative disease (PTLD) poses a considerable challenge. Efforts have been made to define regimens based on combination of the available therapeutic agents, chosen and tailored on a patient-by-patient basis, with the aim of augmenting event-free patient and graft survival. Recently, autologous EBV-specific cytotoxic T-lymphocytes (CTL) have proved effective in enhancing EBV-specific immune responses and reducing viral load in organ transplant recipients with active infection. We investigated the use of a tailored combined approach including autologous EBV-specific CTL for the treatment of EBV-related PTLD developing after pediatric kidney transplantation. Five patients with disseminated monoclonal (n = 3) or localized polyclonal (n = 2) PTLD unresponsive to reduction of immunosuppression were enrolled. The patients with disseminated PTLD received 4-5 courses of reduced-dosage polychemotherapy, accompanied by rituximab on the first day of each course, while localized disease was removed surgically. At treatment completion, autologous EBV-specific CTL were infused. All patients showed a complete response to treatment, without therapy-related toxicity or rejection, and persist in remission with good renal function at a median follow-up of 31 months. These preliminary results suggest that a combined chemoimmunotherapy regimen including virus-specific T-cells is well tolerated and potentially effective as first-line treatment of EBV-related PTLD.
Collapse
|
33
|
[Renal transplantation in the North Italy Transplant program (NITp): Organ allocation and results]. GIORNALE ITALIANO DI NEFROLOGIA : ORGANO UFFICIALE DELLA SOCIETA ITALIANA DI NEFROLOGIA 2005; 22 Suppl 31:S30-5. [PMID: 15786399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Renal transplantation is an effective therapeutic tool for patients with end-stage renal diseases (ESRDs). Data reported in this article summarize the results obtained from 30 years' activity in the North Italy Transplant program (NITp), the first transplant organization in Italy that implemented a donor procurement and organ transplantation network. In the NITp kidney allocation is governed by a computerized algorithm, NITK3, put in place in 1997, aimed at ensuring equity, transparency and traceability during the stages of the allocation decision-making process. The NITp working group has recognized the NITK3 criteria and they are periodically reviewed following the results of the analysis of patients' transplantation odds. The results obtained with the use of the NITK3 algorithm have been very satisfactory: after 6 yrs, a significantly higher percentage of patients at immunological risk (sensitized or waiting for re-transplant), of patients waiting for >3 yrs and of patients with 0-1 HLA A,B,DR mismatches have been transplanted. Moreover, a higher percentage of kidneys were used locally (in a hospital within the procurement area), and this is known to stimulate donor procurement. Finally, we performed a preliminary statistical analysis of transplants carried out from 1998-2002 in 5/16 centers of the NITp area, demonstrating the quality of the NITp program in terms of patient and graft survival, and that donor and recipient age are the variables significantly impacting on transplant results.
Collapse
|
34
|
Renal transplantation. Strategies to prevent organ rejection--the role of an inter-regional reference center. CONTRIBUTIONS TO NEPHROLOGY 2004; 146:1-10. [PMID: 15567915 DOI: 10.1159/000082056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
This paper summarizes the role of the Inter-Regional Reference Center (RC) of the North Italy Transplant program (NITp), in coordinating a donor procurement and organ transplantation network, with a special focus on the strategies to minimize immunological risk and complications after transplantation. In the NITp, patients enrolled on the renal transplantation (RT) waiting list are typed for HLA-A,B,DRB1 antigens with a genomic method. They are periodically screened for the presence of lymphocytotoxic antibodies in their serum by the RC and their suitability to receive the transplant is checked periodically. Cadaver kidney allocation is ruled by a computerized algorithm, named NITK3, established in 1997, which aims at ensuring quality, equity, transparency and traceability during all the phases of the allocation decision-making process. NITK3 has been set up by the NITp Working Group on the basis of biological, medical and administrative criteria and it is periodically reviewed after the analysis of transplant results. In this paper, we show the results of a preliminary analysis of RTs performed from 1998 to 2002 in nine out of sixteen centers of the NITp area, which demonstrates the general quality of the NITp program in terms of patients and graft survival and the special attention to the patients at higher immunological risk.
Collapse
|
35
|
Abstract
Although both immunologic and non-immunologic components may cause kidney allograft chronic rejection (KGCR), also referred to as chronic allograft nephropathy (CAN), its pathogenesis is largely not yet understood. To explore relevant immunologic mechanisms occurring in KGCR, we have analyzed in surgically removed KG the transcription of the following cytokine and apoptotic molecule genes: interleukin (IL)-2, IL-3, IL-4, IL-5, IL-6, IL-10, tumor necrosis factor (TNF)-alpha, IFN-gamma, FAS, and FAS-L. Semiquantitative RT-PCR was used and KG explants were obtained from two groups of transplanted patients. Group 1 was represented by CR/CAN KG, removed for: (a) superimposed symptoms of acute lesions (SAL) due to tapering or suspension of immunosuppression (subgroup 1a, eight cases); (b) causes other than SAL (two cases, subgroup 1b). Group 2 comprised explanted kidneys with no CR/CAN (three cases--vascular thrombosis, intrarenal hemorrhage and vascular thrombosis). The results showed that in group 1 IL- 6 was detectable in seven of 10, IL-10 in six of 10, IFN-gamma in five of 10, and IL-3 in four of 10 cases with a variable pattern of reciprocal association. IL-2 and TNF-alpha were represented in one of 10 cases only. Particularly, in the subgroup 1b IL-10 was never detected. Among the most represented cytokines of group 1, IL-10 as well as IL-3 were never found in group 2. The peculiar expression of IL-10 and IL-3 and partially IL-6 seems to support the hypothesis that a Th2 pattern predominantly characterizes KGCR, thus indicating that Th2 cytokines, likely produced by different intragraft cell types including T cells, macrophages and natural killer (NK) cells, may represent an important component in the pathogenesis of this process. Moreover, IL-10 seems to exquisitely characterize a group of CR/CAN kidney grafts more prone to immunologic assaults.
Collapse
|
36
|
Dendritic cells pulsed with polyomavirus BK antigen induce ex vivo polyoma BK virus-specific cytotoxic T-cell lines in seropositive healthy individuals and renal transplant recipients. J Am Soc Nephrol 2004; 14:3197-204. [PMID: 14638918 DOI: 10.1097/01.asn.0000096374.08473.e3] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Polyoma BK virus (BKV)-associated interstitial nephritis has emerged as a relevant complication of immunocompromise after kidney transplantation, leading to reduced survival of the renal allograft. The limitations of current antiviral treatment and the high probability of rejection in kidney graft recipients when control of viral replication is attempted by reduction of immunosuppression warrant further efforts to develop alternative therapeutic tools. Cellular immunotherapy has proved to be a successful approach for prevention and/or treatment of other viral complications in the immunocompromised host. For assessing the feasibility of translating this strategy to the prevention of BKV-associated disease, a procedure for ex vivo reactivation of BKV-specific cytotoxic T cells (CTL) was developed from BKV-seropositive healthy donors and allograft recipients through stimulation with dendritic cells pulsed with inactivated BKV. The CTL lines thus obtained showed BKV specificity, as an efficient lysis of BKV-infected targets was accompanied by little or no reactivity against mock-infected autologous or allogeneic targets. In vitro killing of allogeneic BKV-infected targets, likely as a result of populations of TCRgammadelta+/CD3+ displaying MHC class I unrestricted cytotoxicity, was also displayed. Application of this culture system may allow a preemptive therapy approach to BKV-related complications in transplant recipients, based on CTL treatment guided by BKV DNA levels.
Collapse
|
37
|
Abstract
Alport syndrome (AS) is a genetic disease of type IV collagen involving non-homogeneous patterns of inheritance characterized clinically by the presence of progressive haematuric nephritis leading to end-stage renal disease (ESRD), hearing loss and/or ophthalmologic abnormalities. The aim of this study was to investigate, in a cohort of AS patients who had undergone a kidney graft (KG) or who were still on a waiting list for a KG, (a) whether there is a correlation between AS and HLA antigen expression, and (b) long-term graft outcome in transplant patients. The AS cohort was represented by 34 ESRD patients, of whom 25 received a KG and the remaining nine were still on a waiting list. AS transplant patients represented 2.78% of 899 first KGs performed at our centre (Transplantation Department at S. Martino Hospital, Genoa) between 1983 and 2002. Grafts were procured from cadaveric donors in 18 cases and from living, related donors in seven cases. All AS transplant patients had a post-transplant follow-up period of at least 12 months. Results showed that: (i) the frequency of the HLA-DRB1*16 antigen was significantly increased in the whole AS cohort as compared to 128 healthy subjects (HS) (corrected P-value 0.0026; relative risk 7.20) as well as to 232 non-AS ESRD patients on a waiting list for KG (corrected P-values 0.0156; relative risk 4.67); (ii) 5- and 10-year graft survivals in the AS transplant patients were 80 and 73%, respectively, and did not differ from those of a control group represented by 25 non-AS KG recipients matched for sex, age, number of HLA mismatches and immunosuppressive treatment. Increased frequency of HLA-DRB1*16 in AS patients may reflect a linkage disequilibrium with genes coding for collagen synthesis.
Collapse
|
38
|
Adoptive transfer of allogeneic Epstein-Barr virus (EBV)-specific cytotoxic T cells with in vitro antitumor activity boosts LMP2-specific immune response in a patient with EBV-related nasopharyngeal carcinoma. Ann Oncol 2004; 15:113-7. [PMID: 14679129 DOI: 10.1093/annonc/mdh027] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND The outcome of patients with nasopharyngeal carcinoma (NPC) presenting as advanced-stage disease or failing conventional radio-chemotherapy is poor. Thus, additional forms of effective, low-toxicity treatment are warranted to improve NPC prognosis. Since NPC is almost universally associated with Epstein-Barr virus (EBV), cellular immunotherapy with EBV-specific cytotoxic T lymphocytes (CTLs) may prove a successful treatment strategy. Patient and methods A patient with relapsed NPC, refractory to conventional treatments, received salvage adoptive immunotherapy with EBV-specific CTLs reactivated ex vivo from a human leukocyte antigen-identical sibling. EBV-specific immunity, as well as T-cell repertoire in the tumor, before and after immunotherapy, was evaluated. RESULTS CTL transfer was well tolerated, and a temporary stabilization of disease was obtained. Moreover, notwithstanding the short in-vivo duration of allogeneic CTLs, immunotherapy induced a marked increase of endogenous tumor-infiltrating CD8+ T lymphocytes, and a long-term increase of latent membrane protein 2-specific immunity. CONCLUSIONS Preliminary data obtained in this patient indicate that EBV-specific CTLs are safe, may exert specific killing of NPC tumor cells in vitro, and induce antitumor effect in vivo.
Collapse
MESH Headings
- Adult
- Antigens, Viral/immunology
- Herpesvirus 4, Human/immunology
- Humans
- Immunohistochemistry
- Immunotherapy, Adoptive
- Male
- Nasopharyngeal Neoplasms/immunology
- Nasopharyngeal Neoplasms/pathology
- Nasopharyngeal Neoplasms/therapy
- Neoplasms, Glandular and Epithelial/immunology
- Neoplasms, Glandular and Epithelial/pathology
- Neoplasms, Glandular and Epithelial/therapy
- Neoplasms, Glandular and Epithelial/virology
- T-Lymphocytes, Cytotoxic/immunology
- T-Lymphocytes, Cytotoxic/transplantation
- Transplantation, Homologous
- Viral Matrix Proteins/immunology
- Virus Latency
Collapse
|
39
|
Polyomavirus BK infection in pediatric kidney-allograft recipients: a single-center analysis of incidence, risk factors, and novel therapeutic approaches. Transplantation 2003; 75:1266-70. [PMID: 12717214 DOI: 10.1097/01.tp.0000061767.32870.72] [Citation(s) in RCA: 139] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
BACKGROUND Although a growing body of literature regarding polyoma BK virus (BKV) infection and associated interstitial nephritis in kidney-allograft recipients is becoming available, the impact of BKV infection in the pediatric population has not been fully evaluated. METHODS In a retrospective analysis, we performed polymerase chain reaction (PCR) assays for BKV DNA in serum and urine samples from 100 pediatric kidney-allograft recipients referred to our institution in the last 5 years. RESULTS BKV viruria was observed in 26 of 100 patients, whereas BKV viremia was demonstrated in 5 patients. Serum creatinine was significantly higher in recipients with positive BK viremia compared with BKV DNA-negative patients (mean 2.66 vs. 1.14 mg/100 mL). Renal biopsy performed in 3 of 5 patients showed graft damage consistent with interstitial nephropathy. In the univariate analysis, negative antibody status of the recipient and the presence of mycophenolate mofetil in baseline immunosuppression were the two factors predictive of active BKV infection. CONCLUSIONS Our study shows that BKV-associated nephropathy is a relevant complication in the pediatric kidney transplantation setting also. Identification of patients at risk of developing virus-associated nephropathy, through prospective quantification of viral load, could improve clinical outcome by allowing the use of timely preemptive therapy guided by BKV DNA levels.
Collapse
|
40
|
|
41
|
'Sieve', 'sort' or START. EMERGENCY MEDICINE (FREMANTLE, W.A.) 2001; 13:477;author reply 477-8. [PMID: 11903440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
|
42
|
Abstract
BACKGROUND A standardized major incident nomenclature has practical applications for medical communication and audit of the medical response to incidents. METHODS A telephone and fax survey of major incident nomenclature in State and Territory health service emergency management plans and 'disaster' legislation was carried out on 13 August 1999. RESULTS Within Australia there were a total of 13 different terms to describe incidents that could produce casualties: there were four definitions of the word 'disaster', eight definitions of the word 'emergency' and one definition of the word 'incident'. CONCLUSION Australia lacks a uniform system of classifying and recording mass casualty incidents. This prevents both the independent clinical audit of the medical response to an incident and the cross-border comparison of the effectiveness of trauma systems to deal with multiple casualties. Australia's geography highlights the need to develop a nomenclature that allows medical practitioners, in isolated environments, to accurately describe an incident and the medical support that is required. The Potential Injury-Creating Event (PICE) nomenclature is a simple system to describe the functional impact of an event upon a community and the level of medical support required. It can be used to provide the basis for the uniform reporting of the medical management of major incidents within Australia.
Collapse
|
43
|
|
44
|
Late Epstein-Barr virus infection of a hepatosplenic gamma delta T-cell lymphoma arising in a kidney transplant recipient. Haematologica 2000; 85:256-62. [PMID: 10702813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023] Open
Abstract
BACKGROUND AND OBJECTIVE gd T-cell lymphomas are only exceptionally observed in transplanted patients. Aim of this study was the detailed characterization of one such case. DESIGN AND METHODS The patient developed spontaneous splenic rupture six years after kidney transplantation. The splenic red pulp was infiltrated by medium-sized and large lymphoid cells with two or more nucleoli. At autopsy, similar lymphoid cells infiltrated the hepatic sinusoids. Histologic, immunologic and molecular studies were carried out. RESULTS By immunohistochemistry, the atypical lymphoid cells were found to express CD3, CD45 and CD43, indicating their T-lineage origin. Approximately 99% of spleen mononuclear cells (MNC) were CD3(+), gammadelta TcR+, CD4-, CD8-, alphabeta TcR-. A clonal gammadelta TcR rearrangement (Vgamma1-Jgamma1.3/2.3-Cgamma2; Vdelta1-Ddelta2-Jdelta1) was detected. The final diagnosis was peripheral T-cell lymphoma, hepato-splenic gammadelta-type. EBV infection of spleen MNC was documented by molecular studies. However, in situ hybridization for EBER-1 (EBV-RNA) showed that only a minority of malignant lymphoid cells (5-7%) were EBV-infected. INTERPRETATION AND CONCLUSIONS It is concluded that EBV infection was as a late event involving an already transformed gd T-cell clone.
Collapse
|
45
|
Abstract
Disasters and mass casualty incidents are traumatic events that are followed by a predictable media response. Managing the media response appropriately can avoid problems in a hospital's security, command, control and communications structures and mitigate the stress of hospital staff attempting to deal with the incident.
Collapse
|
46
|
De novo cancers in paediatric renal transplant recipients: a multicentre analysis within the North Italy Transplant programme (NITp), Italy. Eur J Cancer 2000; 36:80-6. [PMID: 10741299 DOI: 10.1016/s0959-8049(99)00234-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The purpose of this study was to determine the frequency and the outcome of de novo malignancies in a cohort of renal transplant paediatric patients. The records of 493 kidney transplants, carried out in 454 paediatric recipients at the three paediatric transplant centres of the North Italy Transplant programme (NITp, Italy) were reviewed. 10 cases of malignancies (2.2%) comprising both PTLD (post-transplant lymphoproliferative disorders) (6 cases, 1.3%) and non-PTLD malignancies (4 cases, 0.88%) were reported. Non-PTLD included one urothelial carcinoma and one Wilms' tumour of the recipient's left native kidney, one abdominal dysgerminoma and one optic nerve glioma of the left eye. The PTLD consisted of localised or disseminated Epstein-Barr virus (EBV)--associated B-lymphocyte monoclonal (5 cases) and polyclonal (1 case) proliferations. All patients suffering from PTLD had been EBV-negative at the time of transplantation, but developed EBV primary infection after transplantation. All PTLD patient donors were EBV-positive. In addition, all but 1 patient received, before and/or after transplantation, a range of immunosuppressive drugs in addition to the baseline prophylactic immunosuppressive regimen. Moreover, 3 patients suffered from syndromes associated with a genetic predisposition to cancer. Finally, the malignancies reported here were associated with 20% graft failure and 20% mortality rates.
Collapse
|
47
|
Prior planning to avoid responders becoming "victims" during disasters. Prehosp Disaster Med 2000; 15:46-8. [PMID: 11066841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
Prior planning to meet the physical and mental needs of medical and emergency services responder, is a practical measure to reduce staff stress. This has the potential to improve both the operational efficiency of a disaster response and reduce the incidence of post-traumatic stress disorders in responders. Research is needed to define which interventions provide the greatest benefits to local responders.
Collapse
|
48
|
Coexistence of two functioning T-cell repertoires in healthy ex-thalassemics bearing a persistent mixed chimerism years after bone marrow transplantation. Blood 1999; 94:3432-8. [PMID: 10552953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023] Open
Abstract
Bone marrow transplantation (BMT) from an HLA-identical donor is an established therapy to cure homozygous beta-thalassemia. Approximately 10% of thalassemic patients developed a persistent mixed chimerism (PMC) after BMT characterized by stable coexistence of host and donor cells in all hematopoietic compartments. Interestingly, in the erythrocytic lineage, close to normal levels of hemoglobin can be observed in the absence of complete donor engraftment. In the lymphocytic lineage, the striking feature is the coexistence of immune cells. This implies a state of tolerance or anergy, raising the issue of immunocompetence of the host. To understand the state of the T cells in PMC, repertoire analysis and functional studies were performed on cells from 3 ex-thalassemics. Repertoire analysis showed a profound skewing. This was due to an expansion of some T cells and not to a collapse of the repertoire, because phytohemagglutinin stimulation showed the presence of a complex repertoire. The immunocompetence of the chimeric immune systems was further established by showing responses to alloantigens and recall antigens in vitro. Both host and donor lymphocytes were observed in the cultures. These data suggest that the expanded T cells play a role in specific tolerance while allowing a normal immune status in these patients.
Collapse
|
49
|
Should New South Wales hospital disaster teams be sent to major incident sites? THE AUSTRALIAN AND NEW ZEALAND JOURNAL OF SURGERY 1999; 69:702-6. [PMID: 10527345 DOI: 10.1046/j.1440-1622.1999.01672.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND The aim of the present review was to assess the suitability of hospital disaster medical teams' training, personal safety and medical equipment for site casualty work at multiple casualty incidents (MCI), and to compare this with retrieval teams who routinely provide pre-hospital trauma care. The options for the provision of a site medical response based upon international and Australian disaster planning guidelines are also reviewed. METHODS A questionnaire was mailed to all doctors dispatched to the 1997 Thredbo disaster as part of trauma service (TS) hospital medical teams, medical commanders or Helicopter Emergency Medical Service (HEMS) crew. Doctors with Sydney retrieval services (SRS) experience were compared with those without SRS experience in regard to the reported level of relevant training and experience as defined by current Australian guidelines and the Education and Training in Disaster Medicine Curriculum, Scientific Committee of the International Society of Disaster Medicine. Familiarity with medical equipment was assessed, as was level of compliance with Australian guidelines for personal protective clothing and equipment. RESULTS Responses were obtained from all 25 doctors. Nine had SRS experience. None of the 16 doctors without SRS experience met the criteria of the Education and Training Curriculum, compared with four of nine doctors with SRS experience (44%). All six SRS doctors using SRS equipment had personally used or checked their equipment within 2 weeks prior to dispatch to Thredbo, compared with none of the 19 doctors using hospital equipment. Of the 11 areas of personal safety equipment and clothing assessed, all SRS doctors using SRS equipment complied with the guidelines in five areas (45%). There was no area assessed in which all the doctors using hospital equipment complied. CONCLUSION Hospital medical teams suffer from the same problems of inadequate training, experience and personal safety equipment that are identified in previous reports from disasters overseas. The continued focus on hospital medical teams in counter-disaster planning as the primary source of on-site medical services is inappropriate because, with the exception of retrieval doctors who routinely provide pre-hospital trauma care, appropriately trained and experienced doctors are unlikely to be available from within the hospital system.
Collapse
|
50
|
Cadaver kidney allocation in the north Italy transplant program on the eve of the new millennium. CLINICAL TRANSPLANTS 1999:133-45. [PMID: 10503092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
The identification of parameters impacting on cadaver kidney graft outcome is of paramount importance to ensure proper organ allocation, a process that must take into account ethical, biological, social and administrative factors. This is particularly critical in countries where organ procurement is largely insufficient. In the present chapter we report the results of studies carried out to determine the impact of 17 factors on graft survival and function at 4 years posttransplant in 2,917 recipients transplanted from January 1990-September 1997 in the North Italy Transplant program (NITp). Patient and graft survival rates at 4 years (+/- SEM) were 93.5 +/- 0.5% and 81.4 +/- 0.8%, respectively. Excellent graft function at 4 years was shown by 69.8% of recipients. Younger donor age, absence of pretransplant transfusions, patient dialysis center in the NITp area and level of HLA match showed a statistically significant positive association with graft survival. Younger donor age and male donor gender showed a statistically significant association with excellent graft function at 4 years. These global outcomes were confirmed when the analysis was limited to the subset of the 2,617 adult recipients and to the subset of 1,211 cases for whom both donor and recipient HLA-DRB1 types were available before transplant. The results were used to develop a computer-assisted, refined version of the NITp adult kidney allocation algorithm that was named NITK3. A preliminary evaluation of 472 transplants allocated in 12 months with NITK3 compared with 459 transplants allocated in the preceding 12 months according to the previous algorithm (NITK2) showed a significantly higher proportion of recipients who had been on the waiting list for more than 3 years (33.1% vs 21.1%). The use of NITK3 was also associated with a significantly increased ability to transplant alloimmunized patients (17.7% vs 9.5% with NITK2) and recipients with 0-1 HLA mismatches (21.2% vs 13.5% with NITK2). Differences in 6-month graft survival rates and in the percentage of patients with excellent function at 6 months were not statistically significant in recipients transplanted with NITK3 versus NITK2. Survival rates were 96.9% and 92.4%, respectively. Percentages of patients with excellent renal function were 68.3% and 70.5%, respectively. These preliminary data suggest that NITK3 improves HLA match and reduces the number of patients on the waiting list for 3 or more years without determining significant modifications of 6-month graft survival and function. Moreover, it facilitates the achievement of a fair local balance between organs retrieved and transplanted, the compliance of operators with objective allocation rules and the documentation of the whole allocation process.
Collapse
|