Home About us Contact
|
Home About us Contact | ||
|
|
||
MMF
Terms modified by MMF Selected AbstractsThe application of modified lapped transform domain median filter to narrow,band interference excision in DSSS systemsEUROPEAN TRANSACTIONS ON TELECOMMUNICATIONS, Issue 4 2001Chongni Li Guangruihu A novel communication receiver which uses lapped transform (LT) incorporating modified median filter (MMF) algorithm is designed for narrow,band interference (NB1) excision. Comparing to traditional Fourier Transform, LT has longer basis vectors, less spectral leakage, thus better frequency resolution. The LT domain MMF algorithm takes full advantages of the direct sequence spread spectrum signal, as well as the characteristics of LT, performs the transform domain filtering twice. The first filtering locates the position of interference and mitigates most of them. The second filtering was performed in a small neighborhood of the located interference. So LT domain MMF algorithm can completely mitigate the interference without distorting the desired signal. Simulation results demonstrated the improved BER performance and increased robustness of our approach. [source] The immunosuppressant mycophenolate mofetil improves preservation of the perforant path in organotypic hippocampal slice cultures: A retrograde tracing studyHIPPOCAMPUS, Issue 5 2006Tilman M. Oest Abstract Previous studies with excitotoxically lesioned organotypic hippocampal slice cultures (OHSC) have revealed that the immunosuppressant mycophenolate mofetil (MMF) inhibits microglial activation and suppresses neuronal injury in the dentate gyrus. We here investigate whether MMF also has beneficial effects on axon survival in a long-range projection, the perforant path. Complex OHSC including the entorhinal cortex were obtained from Wistar rats (p8); the plane of section ensuring that perforant path integrity was preserved. These preparations were cultured for 9 days in vitro with or without MMF (100 ,g/ml). After fixation, the perforant path was retrogradely labeled by application of the fluorescent dye DiI (1,1,-dioctadecyl-3,3,3,,3,-tetramethylindo-carbocyanine) in the hilus of the dentate gyrus, and neuronal perikarya were immunohistochemically stained by the neuron-specific marker NeuN. Analysis of DiI-labeled and NeuN-stained OHSC by confocal laser scanning microscopy revealed double-labeled neurons in the entorhinal cortex, which projected to the dentate gyrus via the perforant path. Quantitative analysis showed that the number of these double-labeled neurons was 19-fold higher in OHSC treated with MMF than in control cultures (P < 0.05). Our findings indicate that MMF treatment improves preservation of the perforant path and encourage further studies on development and regeneration of long-range projections under the influence of immunosuppressants. © 2006 Wiley-Liss, Inc. [source] Treatment of a Myasthenic Dog with Mycophenolate MofetilJOURNAL OF VETERINARY EMERGENCY AND CRITICAL CARE, Issue 3 2000C.W. Dewey DVM, DACVIM (Neurology), DACVS Summary A ten-year-old, male castrated Springer Spaniel was presented for dysphagia, ptyalism, and regurgitation. Evidence of megaesophagus and mild aspiration pneumonia were apparent on thoracic radiographs. A diagnosis of focal acquired myasthenia gravis was suspected and subsequently confirmed with a positive serum acetylcholine (ACh) receptor antibody concentration (3.87 nM/L). A gastrostomy tube was placed shortly after presentation; food and drugs (including azathioprine) were administered through the tube. After transient improvement, the dog suddenly deteriorated clinically, experiencing frequent episodes of regurgitation and developing severe aspiration pneumonia. Mycophenolate mofetil (MMF), a novel immunosuppressive drug with relative specificity for lymphocytes, was instituted every twelve hours via the gastrostomy tube. Within four days of beginning MMF therapy, both clinical evidence of pharyngeal/esophageal dysfunction and radiographic evidence of megaesophagus had resolved. Initially, clinical side-effects of combined MMF/AZA administration were not apparent, but the patient experienced several vomiting episodes during the third week of treatment. The vomiting resolved after decreasing the dose of both drugs. The patient made a full recovery, and a one-month follow-up ACh receptor antibody concentration was normal (0.26 nM/L). After one month of combination therapy, the patient was weaned off of AZA and maintained on MMF as the sole immunosuppressive drug. The dog was subsequently weaned off of MMF on two occasions. Mycophenolate mofetil was reinstituted after the first discontinuation due to the development of profound appendicular muscle weakness two days after stopping MMF; the weakness resolved within 24 hours of reinstituting MMF. A positive ACh receptor antibody concentration (0.89 nM/L) after the second MMF weaning prompted the second reinstitution of MMF. Two months following this second MMF reinstitution, the dog was again serologically negative (0.51 nM/L) for myasthenia gravis. At the time of last followup, the dog remained in clinical remission eight months after initial presentation. The use of MMF to treat acquired myasthenia gravis in dogs has not been reported previously. The literature concerning MMF and its potential use in treating patients with autoimmune diseases is discussed. [source] Validation of limited sampling strategy for the estimation of mycophenolic acid exposure in Chinese adult liver transplant recipientsLIVER TRANSPLANTATION, Issue 12 2007Chen Hao Mycophenolate mofetil (MMF) is indicated as immunosuppressive therapy in liver transplantation. The abbreviated models for the estimation of mycophenolic acid (MPA) area under the concentration-time curve (AUC) have been established by limited sampling strategies (LSSs) in adult liver transplant recipients. In the current study, the performance of the abbreviated models to predict MPA exposure was validated in an independent group of patients. A total of 30 MPA pharmacokinetic profiles from 30 liver transplant recipients receiving MMF in combination with tacrolimus were used to compare 8 models' performance with a full 10 time-point MPA-AUC. Linear regression analysis and Bland-Altman analysis were used to compare the estimated MPA-AUC0-12h from each model against the measured MPA-AUC0-12h. A wide range of agreement was shown when estimated MPA-AUC0-12h was compared with measured MPA-AUC0-12h, and the range of coefficient of determination (r2) was from 0.479 to 0.936. The model based on MPA pharmacokinetic parameters C1h, C2h, C6h, and C8h had the best ability to predict measured MPA-AUC0-12h, with the best coefficient of determination (r2 = 0.936), the excellent prediction bias (2.18%), the best prediction precision (5.11%), and the best prediction variation (2SD = ±7.88 mg · h/L). However, the model based on MPA pharmacokinetic sampling time points C1h, C2h, and C4h was more suitable when concerned with clinical convenience, which had shorter sampling interval, an excellent coefficient of determination (r2 = 0.795), an excellent prediction bias (3.48%), an acceptable prediction precision (14.37%), and a good prediction variation (2SD = ±13.23 mg · h/L). Measured MPA-AUC0-12h could be best predicted by using MPA pharmacokinetic parameters C1h, C2h, C6h, and C8h. The model based on MPA pharmacokinetic parameters C1h, C2h, and C4h was more feasible in clinical application. Liver Transpl 13:1684,1693, 2007. © 2007 AASLD. [source] Corticosteroid-free immunosuppression with daclizumab in HCV+ liver transplant recipients: 1-year interim results of the HCV-3 study,LIVER TRANSPLANTATION, Issue 11 2007Goran B.G. Klintmalm This work is a 1-yr interim analysis of a prospective, randomized, multicenter trial evaluating the effect of corticosteroid-free immunosuppression on hepatitis C virus,positive (HCV+) liver transplant recipients following liver transplantation (LT). Patients received tacrolimus and corticosteroids (Arm 1; n = 80); tacrolimus, corticosteroids, and mycophenolate mofetil (MMF) (Arm 2; n = 79); or daclizumab induction, tacrolimus, and MMF (Arm 3; n = 153). At 1 yr, 64.1%, 63.4%, and 69.4% of patients achieved the composite primary endpoint of freedom from rejection, freedom from HCV recurrence, and freedom from treatment failure, respectively. Excellent patient and graft survival did not differ significantly among treatment arms. Freedom from HCV recurrence at 1 yr was 61.8 ± 6.2%, 60.1 ± 6.1%, and 67.0 ± 4.3% in Arms 1, 2, and 3, respectively (P = not significant). Freedom from rejection was significantly higher in Arm 3 compared to Arm 1 (93.0 ± 2.2% vs. 81.9 ± 4.4%; P = 0.011). Multivariate analysis identified acute rejection (hazard ratio = 2.692; P = 0.001) and donor age (hazard ratio = 1.015; P = 0.001) as significant risk factors for HCV recurrence. HCV recurrence was not influenced by recipient demographics, HCV genotype, or immunosuppression. In conclusion, these results suggest that a corticosteroid-free regimen of tacrolimus and MMF following daclizumab induction is safe and effective in HCV+ liver transplant recipients. Liver Transpl 13:1521,1531, 2007. © 2007 AASLD. [source] Conversion to sirolimus-based immunosuppression in maintenance liver transplantation patientsLIVER TRANSPLANTATION, Issue 5 2007Isabelle Morard Sirolimus (SRL) has been proposed to replace calcineurin inhibitors (CNI) in case of CNI-induced toxicity. The aim of this study was to evaluate the efficacy and safety of conversion from CNI to SRL in maintenance liver transplantation (LT) patients. Between 2002 and 2006, conversion was performed in 48 patients (17 female, 31 male; mean age 57 ± 10 yr) after a median delay of 19.4 months (range 0.2,173 months) after LT. Indication for conversion was renal impairment (RI) (78%), CNI neurotoxicity (13%), or post-LT cancer (9%). Median follow-up was 22.6 ± 11 months. Median SRL dosage and trough levels were 2.4 ± 1.3 mg and 8.1 ± 2.7 ,g/L. Immunosuppression consisted of SRL alone (33%), or SRL + mycophenolate mofetil (MMF) (39%), SRL + prednisone (15%), SRL + CNI (4%), or SRL + MMF + prednisone (8%). Mean glomerular filtration rate (GFR) improved from 33 to 48 mL/minute in patients with severe RI (P = 0.022) and from 56 to 74 mL/minute in patients with moderate RI (P = 0.0001). After conversion, main complications were albuminuria (36%), hyperlipidemia (49%), dermatitis (14%), edema (14%), oral ulcers (12%), joint pain (4%), infection (2%), and pneumonia (2%). Acute rejection (AR) occurred in 17% of the patients. SRL was withdrawn in 17% of the patients. In conclusion, conversion from CNI to SRL is safe and is associated with significant renal function improvement. Liver Transpl 13:658,664, 2007. © 2007 AASLD. [source] MMF to EC-MPS conversion: What makes the difference?LIVER TRANSPLANTATION, Issue 5 2007Hartmut Schmidt [source] Mycophenolate mofetil in combination with reduction of calcineurin inhibitors for chronic renal dysfunction after liver transplantation,LIVER TRANSPLANTATION, Issue 12 2006Georges-Philippe Pageaux The purpose of the study was to introduce mycophenolate mofetil (MMF) in liver transplant recipients with renal dysfunction to decrease calcineurin inhibitor (CNI) dosages without increasing rejection risk. In this prospective, multicenter, randomized study, chronic CNI-related renal dysfunction was defined by an increase in serum creatinine with values >140 ,mol/L and <300 ,mol/L. Patients were randomized in 2 groups. Study group: combination of MMF (2 to 3 g/day) and reduced dose of CNI ,50% of initial dose; control group: no MMF, but with the ability to reduce CNI doses, but not below 75% of initial dose. Fifty-six patients were included, 27 in the study group and 29 in the control group. In the study group, there was a significant decrease in serum creatinine values, from 171.7 ± 24.2 ,mol/L at day 0 to 143.4 ± 19 ,mol/L at month 12 and a significant increase in creatinine clearance, from 42.6 ± 10.9 mL/min to 51.7 ± 13.8 mL/min. No rejection episode was observed in the study group. In the control group, there was no improvement of renal function, assessed by the changes in serum creatinine values, from 175.4 ± 23.4 ,mol/L at day 0 to 181.6 ± 63 ,mol/L at month 12, and in creatinine clearance, from 42.8 ± 12.8 mL/min to 44.8 ± 19.7 mL/min. The differences between the 2 groups were significant: P = 0.001 for serum creatinine, and P = 0.04 for creatinine clearance. In conclusion, the introduction of MMF combined with the reduction of at least 50% of CNI dose allowed the renal function of liver transplant recipients to significantly improve at 1 year, without any rejection episode and without significant secondary effects. Liver Transpl 12:1755,1760, 2006. © 2006 AASLD. [source] Conversion from mycophenolate mofetil to enteric-coated mycophenolate sodium in liver transplant patients presenting gastrointestinal disorders: A pilot studyLIVER TRANSPLANTATION, Issue 9 2006Jérôme Dumortier Gastrointestinal (GI) disorders are one of the main adverse events in patients treated by mycophenolic acid (MPA). The aim of this prospective study was to evaluate the effect of conversion from mycophenolate mofetil (MMF) to enteric-coated mycophenolate sodium (EC-MPS) in liver transplant patients presenting GI side-effects Since January 2003, stable liver transplant patients receiving MMF and presenting GI disorders, without evidence of other origin than MMF were enrolled. Conversion was performed without a washout period at an equimolar daily dosage. Thirty-six patients were included after a median delay of 45 months after liver transplantation (LT) (16 women and 20 men, median age of 47 years). Diarrhoea was the main clinical symptom (n = 28, 77.7%). At the time of inclusion, patients were treated with MMF since 18 months (range 3-28) and GI disorders were known for 9 months (range 3-12). After a median follow-up of 12 months after conversion, GI disorders were resolved in 20 patients (55%), improved in 6 patients (17%) and not modified or worsened in 10 patients (28%). Our results strongly suggest that conversion from MMF to EC-MPS in liver transplant patients can improve gastrointestinal disorders in a majority of the patients, and therefore might be considered as the best therapeutic option. Liver Transpl 12:1342-1346, 2006. © 2006 AASLD. [source] Comparison of plume structures of carbon dioxide emitted from different mosquito trapsMEDICAL AND VETERINARY ENTOMOLOGY, Issue 1 2006Miriam F. Cooperband Abstract., A large field wind tunnel was used to compare four types of CO2 -baited mosquito traps. This study compared the plume structure and concentration of CO2 emitted by each trap, flow of suction into the trapping systems, flow of CO2 being released, trap shape and configuration, differences in visual appearance, and differences in temperature and humidity of emissions at the source of CO2 compared to ambient air. The structure of the CO2 plumes emitted by each trap differed considerably. All four plumes were turbulent, causing the concentration of CO2 within several metres of the source to attenuate to between 375 and 875 p.p.m. The Encephalitis Virus Surveillance (EVS) trap emitted concentrations of CO2 exceeding 20 000 p.p.m., the detection limits of our equipment, whereas the Mosquito Magnet® Freedom (MMF), Mosquito Magnet® Liberty (MML) and Mosquito Magnet® X (MMX) traps released CO2 at peaks of about 3500, 7200 and 8700 p.p.m., respectively. The MMX trap produced the greatest air velocity at both the suction inlet and CO2 outlet, followed by the MMF, MML and the EVS traps, respectively. [source] Orientation of Culex mosquitoes to carbon dioxide-baited traps: flight manoeuvres and trapping efficiencyMEDICAL AND VETERINARY ENTOMOLOGY, Issue 1 2006M. F. Cooperband Abstract., Females of Culex quinquefasciatus Say and Culex tarsalis Coquillet (Diptera: Culicidae) in the host-seeking stage were released and video recorded in three dimensions in a large field wind tunnel as they flew to four kinds of CO2 -baited mosquito traps. The trapping efficiency (number of mosquitoes approaching compared to the number caught) was determined for each trap type. The Encephalitis Virus Surveillance (EVS), Mosquito Magnet Freedom (MMF) and Mosquito Magnet Liberty (MML) traps captured only 13,16% of approaching Cx. quinquefasciatus females, whereas the Mosquito Magnet-X (MMX) trap captured 58%. Similar results were obtained for Cx. tarsalis. Orientation behaviour and flight parameters of mosquitoes approaching the four traps were compared. Mosquitoes spent the most time orienting to the EVS trap. Flight speed decreased as mosquitoes entered the vicinity of each trap and a large portion of their time was spent within 30 cm downwind of the traps. Flights became highly tortuous downwind of the poorly performing traps and just upwind of the MMX trap. Differences between traps and possible explanations for the superior performance of the MMX trap are considered. [source] Refractive-index sensor based on tilted fiber Bragg grating interacting with multimode fiberMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 6 2010Yongxing Jin Abstract A simple refractive-index fiber sensor based on a tilted Bragg fiber grating (TFBG) interacting with multimode fiber (MMF) is described. The sensor structure is formed by insertion of a small section of MMF between the single-mode fiber and the TFBG. The average reflective power in the cladding modes of the TFBG reflected a different power as the surrounding refractive index changes, while the power of the reflected Bragg mode keeps unchanged. Therefore, the power of the reflected Bragg mode can be used as a reference to compensate any possible fluctuation of the light source power. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1375,1377, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25178 [source] Less is more, or almost as much: A 15-item quality-of-life instrument for myasthenia gravisMUSCLE AND NERVE, Issue 2 2008Ted M. Burns MD Abstract We describe the process whereby a recently developed myasthenia gravis (MG)-specific quality-of-life (QOL) instrument was reduced from 60 items to 15 items while maintaining potential usefulness in the clinic and in prospective treatment trials. In data from a recently completed prospective trial of mycophenolate mofetil (MMF) in MG, the MG-QOL15 correlated as highly as the 60-item MG-QOL for physical and social domains of the 36-item health survey of the Medical Outcomes Study Short Form (SF-36). Correlation coefficients for the MG-QOL15 were similar to the 60-item MG-QOL for the Quantitative Myasthenia Gravis (QMG), MG-specific Manual Muscle Testing (MG-MMT), and the MG-specific Activities of Daily Living (MG-ADL) scores at week 0 and for change in scores from week 0 to week 12 in the MMF trial. Using the physician global impression at week 12 of the trial as the "gold standard," the MG-QOL15 demonstrated high sensitivity. Because the MG-QOL15 instrument can be quickly and easily administered and interpreted, it is a potential QOL measure for treatment trials and the clinical evaluation of patients with MG. Muscle Nerve, 2008 [source] Prevention of diabetes: effect of mycophenolate mofetil and anti-CD25 on onset of diabetes in the DRBB ratPEDIATRIC DIABETES, Issue 6 2008Figen Ugrasbul Background:, Anti-CD25 and mycophenolate mofetil (MMF) treatment of patients with new-onset diabetes is currently being tested as one of the trials in TrialNet. We tested the effectiveness of MMF and anti-CD25 in preventing autoimmune diabetes in the diabetes-resistant biobreeding (DRBB) rat. Methods:, Autoimmune diabetes in the DRBB rat was induced with a Treg cell depletion regimen starting at 24,26 d of age. Treatment was started on the first day of the depletion regimen in the following groups: (i) control (vehicle); (ii) MMF 25 mg/kg/d intramuscularly daily for 8 wk; (iii) anti-CD25 0.8 mg/kg/d intraperitoneally 5 d/wk for 3 wk; and (iv) combination of MMF and anti-CD25. In a second set of experiments, treatments were started on day 5 of the depletion regimen (delayed treatment) with groups 1, 3, and 4. Rats that had diabetes-free survival for at least 30 d after the treatment was stopped underwent a second Treg depletion (redepletion). Results:, In each of the three treatment groups (n = 10/group), onset of diabetes was delayed or prevented in 20, 40 and 80% in groups 2, 3, and 4, respectively. After redepletion, diabetes-free survival was unchanged in group 2 and decreased to 10 and 30% in groups 3 and 4, respectively. With delayed treatment, groups 3 and 4 had 33 and 50% diabetes-free survival that decreased to 0 and 33% after redepletion. Summary:, MMF and anti-CD25 alone or in combination are effective in delaying and preventing diabetes in the DRBB rat especially if treatment is started before stimulation and expansion of the autoreactive T cells. [source] Efficacy and safety of conversion of mycophenolate mofetil to enteric-coated mycophenolate sodium in Mexican renal transplant childrenPEDIATRIC TRANSPLANTATION, Issue 6 2010H. Reyes Reyes H, Hernández AM, Valverde S, Cataneo A, Mendoza A, Barrera I, Ortíz L, García-Roca P, Lopéz-Martínez B, Castańeda-Hernández G, Medeiros M. Efficacy and safety of conversion of mycophenolate mofetil to enteric-coated mycophenolate sodium in Mexican renal transplant children. Pediatr Transplantation 2010: 14:746,752. © 2010 John Wiley & Sons A/S. Abstract:, The aim of the study was to evaluate the efficacy and safety of the conversion of MMF to EC-MPS in pediatric renal transplant recipients. We included 12 patients with stable graft function who were receiving MMF treatment. In the first visit, a complete medical examination was performed, which included a GSRS, a nine-point pharmacokinetic profile, samples for renal, liver and hematological tests and evaluation of IMPDH2 gene expression. The patients were transferred to an equimolar dose of EC-MPS. Two wk later, a clinical evaluation and blood collection, as in the first visit were performed. There was no change in serum creatinine, leukocyte count, serum albumin, or transaminase levels, but we found a statistically significant reduction of hemoglobin after conversion (13.2 ± 1.6 g/dL with MMF vs. 12.5 ± 1.3 g/dL when receiving EC-MPS). The GSRS total mean score was 16 ± 12 with MMF vs. 8 ± 5 with EC-MPA (p < 0.05). There was no statistically significant difference between formulations in the gene expression of IMPDH 2, in the AUC0-12h or in Cmax. However, peak concentration occurred later with EC-MPS. [source] Steroid avoidance using sirolimus and cyclosporine in pediatric renal transplantation: One year analysisPEDIATRIC TRANSPLANTATION, Issue 1 2010Franca M. Iorember Iorember FM, Patel HP, Ohana A, Hayes JR, Mahan JD, Baker PB, Rajab A. Steroid avoidance using sirolimus and cyclosporine in pediatric renal transplantation: One year analysis. Pediatr Transplantation 2010: 14: 93,99. © 2009 John Wiley & Sons A/S. Abstract:, Steroids are commonly used in pediatric renal transplantation, but have numerous adverse effects. This retrospective study compares one-yr outcomes in 22 pediatric renal transplant recipients receiving SRL and CSA as primary immunosuppression (steroid-avoidance group) to age- and gender-matched historical controls receiving CSA, MMF, and prednisone (steroid group). At one yr, both groups had similar graft survival, acute rejection, and estimated GFR. Subjects in the steroid-avoidance group had better linear growth, less excessive weight gain and were less likely to have an increase in antihypertensive medication use. Subjects in the steroid-avoidance group were more likely to be started on lipid lowering medications and erythropoiesis stimulating agents. Despite having a greater proportion of living donors, the steroid-avoidance group had a similar GFR compared to the steroid group at one month. The steroid-avoidance group was also more likely to have a biopsy for elevated Cr that was not because of rejection and had more interstitial fibrosis noted. We conclude that using a steroid-avoidance immunosuppression regimen of SRL and CSA results in comparable rejection rates and short-term graft function with less steroid-associated morbidity. However, early findings also suggest possible potentiation of CSA nephrotoxicity by SRL in some children. [source] Benefits of conversion from mycophenolate mofetil to enteric-coated mycophenolate sodium in pediatric renal transplant patients with stable graft functionPEDIATRIC TRANSPLANTATION, Issue 2 2009Rejane De Paula Meneses Abstract:, Conversion from MMF to EC-MPS may reduce GI complications and permit increased MPA dosing with a concomitant reduction in CNI dose. In a prospective trial, paediatric renal transplant patients with stable graft function were converted from MMF to EC-MPS and followed-up for 12 months. Data from 28 patients (mean age 13.9 ± 3.1 yr) were available for analysis. Mean EC-MPS dose increased significantly from conversion to month 12 (668 ± 81 mg/m2/day vs. 747 ± 98 mg/m2/day, p < 0.001). CsA-ME dose (n = 23) decreased from 5.3 ± 1.7 mg/kg/day at conversion to 4.6 ± 1.4 mg/kg/day at month 12 (p = 0.010). cGFR increased from 69.5 ± 23.3 mL/min/1.73 m2 at the time of conversion to 80.7 ± 30.7 mL/min/1.73 m2 at month 12 (p = 0.007). The number of patients reporting at least one GI event during six months prior to conversion was 15/28 (53.6%), declining to 8/28 (28.6%) at month 6 post-conversion and 5/28 (17.8%) at month 12. This single-arm study suggests that conversion of paediatric renal transplant patients from MMF to EC-MPS does not compromise efficacy and leads to improved GI tolerability. MPA dose increased and CsA-ME dose decreased significantly, with an associated improvement in calculated GFR. A large-scale controlled trial is required to confirm these promising findings. [source] Tacrolimus withdrawal and conversion to sirolimus at three months post-pediatric renal transplantationPEDIATRIC TRANSPLANTATION, Issue 7 2008Leonard C. Hymes Abstract:, Nephrotoxicity caused by CNI may adversely affect long-term graft outcomes. For this reason, we have adopted a protocol for withdrawing TAC and converting to SRL at three months post-renal transplantation. All recipients received basiliximab induction and TAC, MMF, and prednisone. Patients without acute rejection by surveillance biopsy at three months were eligible for SRL conversion. Results: From August 2004 to September 2006, TAC was withdrawn and replaced by SRL in 30 first transplant recipients, who were followed for six to 39 months (mean 18 ± 8). Renal function did not improve significantly after SRL conversion (p = 0.25). Acute rejection occurred in three patients (10%) at five to 12 months after CNI withdrawal. There were no occurrences of wound healing problems, pneumonitis or post-transplant lymphoproliferative disease. Thrombocytopenia and diabetes each occurred in one patient. Four patients received treatment for hypercholesterolemia. CNI withdrawal and replacement with SRL was an effective regimen in children who did not display biopsy evidence of acute rejection at three months post-transplant. While these early results are promising, the ultimate benefit of this protocol to enhance the long-term renal function and graft survival requires ongoing follow-up. [source] Renal Fanconi syndrome and myopathy after liver transplantation: Drug-related mitochondrial cytopathy?PEDIATRIC TRANSPLANTATION, Issue 1 2008Umut Selda Bayrakci Abstract:, Advances in the field of transplantation provide a better quality of life and allow more favorable conditions for growth and development in children. However, combinations of different therapeutic regimens require consideration of potential adverse reactions. We describe a 15-yr-old girl who had orthotopic liver transplantation because of Wilson's disease. Tacrolimus, MMF, and steroids were given as immunosuppressant. Lamivudine was added because of de nova hepatitis B infection during her follow-up. Three yr after transplantation she developed renal Fanconi syndrome with severe metabolic acidosis, hypophosphatemia, glycosuria, and aminoaciduria. Although tacrolimus was suspected to be the cause of late post-transplant renal acidosis and was replaced by sirolimus, acidosis, and electrolyte imbalance got worse. Proximal muscle weakness has developed during her follow-up. Fanconi syndrome, as well as myopathy, is well recognized in patients with mitochondrial disorders and caused by depletion of mtDNA. We suggest that our patient's tubular dysfunction and myopathy may have resulted from mitochondrial dysfunction which is triggered by tacrolimus and augmented by lamivudine. [source] Rapid steroid discontinuation for pediatric renal transplantation: A single center experiencePEDIATRIC TRANSPLANTATION, Issue 5 2007Keith K. Lau Abstract:, To determine the outcomes of pediatric renal transplant recipients who received immunosuppression consisting of early withdrawal of corticosteroids at a single Northern California center. Protocols using minimal steroid exposure have been recently reported in adult transplant recipients with successful results. We examined the outcomes of pediatric renal transplant recipients who were managed at our center using a protocol with very early discontinuation of steroids after renal transplantation. We retrospectively studied the medical records of all renal transplant recipients followed at the Children's Hospital at the University of California, Davis Medical Center from 01/2004 to 12/2005. All patients were less than 18 yr of age at the time of transplantation. The immunosuppressive protocol included three tapering daily doses of methylprednisolone, together with five doses of thymoglobulin followed by maintenance therapy with tacrolimus and MMF. Eight patients with equal numbers of males and females were transplanted during this time period. There were equal numbers of Caucasians, African-Americans, Hispanics, and Asians. A total of 37.5% (3/8) of the subjects received preemptive transplantation, 25% (2/8) received peritoneal, and 37.5% (3/8) received hemodialysis before transplantation. The median (range) age at transplantation was 12.3 (3.1,16.0) year with a follow-up of 1.7 (0.9,2.8) year. At one yr post-transplantation, 57% (4/7) of patients still required anti-hypertensives. Three children required erythropoietin supplementation after transplantation. The mean delta height standard deviation score at 12 months was 0.20 ± 0.56. There were no episodes of clinical acute rejection. One patient switched from tacrolimus to sirolimus due to biopsy-proven CAN. No patient became diabetic or required hypoglycemic agents. Surveillance biopsies showed no subclinical acute rejection in any patient. Steroid-free immunosuppression is safe in children after renal transplantation. Larger number of patients and longer follow-up are required to further confirm the effectiveness and safety of immunosuppression with rapid steroid discontinuation. [source] First experiences of pediatric kidney transplantation in Sri LankaPEDIATRIC TRANSPLANTATION, Issue 4 2007C. K. Abeysekera Abstract:, KT is the most effective therapeutic option for ESRF. We present our first experiences in a developing country. All children who underwent kidney transplantation since the inception of this program in July 2004 until 30 September 2005 were studied. Their demographic data, operative and peri-operative details, graft and host survival, and drug compliance are described here. Data were collected from patient records and nursing observation records. Eleven children were transplanted during this period (median recipient age 10.75 yr, range: 8,16). The median age of the donors was 41 yr (range: 38,45) and was the mother in eight, father in two and uncle in one. The median (range) follow-up period following transplantation was 12.5 months (7,12). The vascular anastomotic site was aorta and inferior vena cava in nine patients and the cold ischemia time was mean (s.d.) 1.9 h (0.96). All patients received steroids, cyclosporine and MMF for immunosuppression. Hypotension, heart failure and septicemia were common medical complications. Four were treated for acute rejection. Vascular anastomotic leak, burst abdomen, intestinal obstruction, intra-abdominal leak of supra pubic catheter and vesico-ureteric junction obstruction were surgical complications. There were no graft losses or deaths. Despite limited resources good outcomes are possible following renal transplantation in children in developing countries. [source] Sirolimus is not always responsible for new-onset proteinuria after conversion for chronic allograft nephropathyPEDIATRIC TRANSPLANTATION, Issue 3 2007Zainab Abdurrahman Abstract:, An eight-yr-old combined liver and kidney transplant recipient for hyperoxaluria type I developed significant proteinuria and hypertension after conversion of a Tacrolimus, MMF, and corticosteroids-based immunosuppression to Sirolimus, low-dose Tacrolimus, and corticosteroids six and a half yr after the transplant for chronic allograft nephropathy. There was only one class I HLA match and the recipient had multiple blood exposures prior to transplantation. The patient was treated with combined hemodialysis and peritoneal dialysis while awaiting transplantation to reduce the oxalate load. A renal biopsy revealed a de novo transplant glomerulopathy that was associated with specific HLA antibodies unrelated to the donor (HLA DR 17 and 18). After reintroduction of MMF, these antibodies became undetectable and the proteinuria completely resolved. We hypothesize that HLA antibodies may cause transplant glomerulopathy even if they are not donor-specific. Their production appears more susceptible to MMF therapy. A thorough work-up of new-onset proteinuria after conversion to Sirolimus should be performed, including an immunological work-up and a renal biopsy. [source] Mycophenolate mofetil introduction stabilizes and subsequent cyclosporine A reduction slightly improves kidney function in pediatric renal transplant patients: A retrospective analysisPEDIATRIC TRANSPLANTATION, Issue 3 2006Kerstin Benz Abstract: Chronic allograft nephropathy (CAN) is the major cause of late graft loss. Among others, chronic calcineurin inhibitor toxicity (CNI) contributes to the development of CAN. Therefore, reduction in CNI dosage may delay the development of CAN, leading to longer graft survival. It was the aim of the present retrospective analysis to investigate the effect of mycophenolate mofetil (MMF) addition with subsequent cyclosporine A (CSA) reduction on renal function in pediatric kidney allograft recipients. Seventeen patients (aged 8.3,17.6 yr) with monotherapy with CSA and progressive loss of renal function at a median of 3.4 yr after kidney transplantation were enrolled. After at least three months of MMF treatment, CSA dosage was stepwise reduced to trough levels of 100, 80, and 60 ng/mL. In all patients, introduction of MMF prevented a further decrease of glomerular filtration rate (GFR). The mean GFR 12 months before study enrollment was 96.1±24.5 and 71.0±21.0 mL/min/1.73 m2 at start of MMF. After introduction of MMF and unchanged CSA dosage GFR was stabilized to 71.1±23.8 mL/min/1.73 m2. After CSA reduction to trough levels of 60 ng/mL, GFR was slightly ameliorated up to 76.3±24.1 mL/min/1.73 m2. Within the follow-up period, one borderline rejection occurred in a patient in whom the CSA trough level was 60 ng/mL since seven months. In pediatric kidney allograft recipients with progressive loss of renal function reduction of CSA after introduction of MMF may stabilize and even slightly ameliorate renal function. [source] Anemia in children after transplantation: etiology and the effect of immunosuppressive therapy on erythropoiesisPEDIATRIC TRANSPLANTATION, Issue 4 2003Amira Al-Uzri Abstract: Anemia in children after renal transplantation is more common than previously appreciated. Multiple factors appear to play roles in the development of post-transplant anemia, the most common of which is absolute and/or functional iron deficiency anemia. Most experts recommend that iron limited anemias in transplant patients should be diagnosed using the same criteria as for chronic renal failure patients. Serum erythropoietin (EPO) levels are expected to normalize after a successful renal transplantation with a normal kidney function, yet both EPO deficiency and resistance have been reported. While no large controlled trials comparing the effect of different immunosuppressive agents on erythropoiesis after transplantation have been performed, generalized bone marrow suppression attributable to azathioprine (AZA), mycophenolate mofetil (MMF), tacrolimus, antithymocyte preparations has been reported. Pure red cell aplasia (PRCA) occurs rarely after transplantation and is characterized by the selective suppression of erythroid cells in the bone marrow. PRCA has been reported with the use of AZA, MMF, tacrolimus, angiotensin converting enzyme inhibitors (ACEI), but not with cyclosporine (CSA) use. Post-transplant hemolytic uremic syndrome has been reported with orthoclone anti T-cell antibody (OKT3), CSA and tacrolimus therapy. Viral infections including cytomegalovirus, Epstein,Barr virus and human parvovirus B19 have been reported to cause generalized marrow suppression. Management of severe anemia associated with immunosuppressive drugs generally requires lowering the dose, drug substitution or, when possible, discontinuation of the drug. Because this topic has been incompletely studied, our recommendation as to the best immunosuppressive protocol after renal transplantation remains largely dependent on the clinical response of the individual patient. [source] Mycophenolate mofetil without antibody induction in cadaver vs. living donor pediatric renal transplantationPEDIATRIC TRANSPLANTATION, Issue 2 2003O. Ojogho Abstract: Mycophenolate mofetil (MMF) is a new immunosuppressive agent that blocks de novo purine synthesis in T and B lymphocytes via a potent selective inhibition of inosine monophosphate dehydrogenase. MMF has been shown to significantly reduce the incidence of acute rejection in both adult and pediatric renal transplantation. The impact of MMF on routine antibody induction therapy in pediatric renal transplantation has not been defined. Remarkably, a recent North American Pediatric Transplant Cooperative Study concluded that T-cell antibody induction therapy was deleterious for patients who received MMF. Our study examines the use of MMF in an evolving immunosuppressive strategy to avoid antibody induction in both living (LD) and cadaver (CAD) donor pediatric renal transplantation. We retrospectively analyzed the records of 43 pediatric renal transplants that received MMF-based triple therapy without antibody induction therapy between November 1996 and April 2000. We compared CAD (n = 17) with LD (n = 26). The two groups were similar demographically except that CAD had significantly younger donors than LD, 26.1 ± 13.7 vs. 36.2 ± 9.2 yr (p = 0.006). All the patients received MMF at 600 mg/m2/b.i.d. (maximum dose of 2 g/d) and prednisone with cyclosporine (86%) or tacrolimus (14%). Mean follow-up was >36 months for each group. Acute rejection rate at 6 months was 11.8% (CAD) vs. 15.4% (LD) (p = 0.999) and at 1 yr was 23.5% (CAD) vs. 26.9% (LD) (p = 0.999). Mean estimated glomerular filtration rate (ml/min/1.73 m2) at 6 months was 73.3 ± 15.3 (CAD) vs. 87.6 ± 24.2 (LD) (p = 0.068). Patient survival at 1, 2, and 3 yr was 100, 100, and 100% for CAD vs. 100, 96, and 96% for LD, respectively. Graft survival at 1, 2, and 3 yr was 100, 100, and 94% for CAD vs. 96, 88, and 71% for LD, respectively. Graft loss in CAD was because of chronic rejection (n = 2) while in LD it was because of non-compliance (n = 6), post-transplant lymphoproliferative disorder (n = 1), and sepsis (n = 1). In conclusion, MMF without antibody induction in both CAD and LD pediatric renal transplantation provides statistically similar and effective prophylaxis against acute rejection at 6 months and 1 yr post-transplant. The short-term patient and graft survival rates are excellent, however, non-compliance remains a serious challenge to long-term graft survival. Additional controlled studies are needed to define the role of MMF without antibody induction therapy in pediatric renal transplantation. [source] Visceral Kaposi's sarcoma with intracranial metastasis: A rare complication of renal transplantationPEDIATRIC TRANSPLANTATION, Issue 6 2002Elif Bahat Abstract: The incidence of Kaposi's sarcoma (KS) has increased in solid organ transplantation recipients. This type of KS tends to be aggressive, involving lymph nodes, mucosa and visceral organs in about half of patients, sometimes in the absence of skin lesions. Brain involvement of KS has rarely been reported. A 16-yr-old Turkish boy underwent renal transplantation from his mother. The immunosuppressive regimen included prednisolone, cyclosporin A and azathioprine. Fourteen months later the azathioprine was changed to cyclophosphamide (3 mg/kg/day) because of the development of a nephrotic syndrome. After 12 weeks, the cyclophosphamide was changed to mycophenolate mofetil (MMF) to control the nephrotic syndrome. At this time his serum creatinine level rose to 2.1 mg/dL. Polyclonal or monoclonal antibodies were never given. Multiple intra-abdominal lymphadenopathy was detected on abdominal tomography at the 32nd month after renal transplantation. Kaposi's sarcoma was diagnosed via laparotomy and biopsy. He had a generalized tonic and clonic seizure and contrast enhanced cranial tomography showed two intracranial masses which had an abundant vascular component which caused a mild shift. One of the masses was removed via a burr-hole with the aim of diagnosis and treatment of the shift. A pathologic examination of the intracranial lesion was also reported as Kaposi's sarcoma. Herpes virus-8 DNA was detected by PCR in the intracranial lesion. [source] Single-center experience with mycophenolate mofetil in pediatric renal transplant recipientsPEDIATRIC TRANSPLANTATION, Issue 4 2001Mumtaz Virji Abstract: Mycophenolate mofetil (MMF), a potent and specific inhibitor of guanosine nucleotide synthesis, is a new immunosuppressive drug used to prevent rejection in transplant patients. Extensive data on its utility and efficacy exists in adult patients but there is limited experience in pediatrics. Twenty-four children (14 male, 10 female; 2,19 yr of age), eight of whom had received living-related donor (LRD) transplants and 16 of whom had received cadaveric donor (CD) transplants, have been treated with MMF in our institution since September 1996. MMF was administered for a duration ranging from 13 weeks to 38 months, at an average dose of 600 mg/m2 (range: 200,1,000 mg/dose) every 12 h, for a total experience of 304 patient months. MMF capsules were used in 16 patients and/or pediatric suspension in eight. Five patients were switched to MMF from azathioprine as a result of rejection episodes or inability to taper prednisone, between 5 weeks and 3.5 yr post-transplant. All patients received prednisone, cyclosporin A (CsA), and induction therapy with anti-lymphocyte globulin (19 patients), anti-thymocyte globulin (one patient) or daclizumab (four patients). In 12 patients started on MMF at the time of CD transplant, five (42%) had an acute rejection episode. In seven who received a LRD transplant, one (14%) had an acute rejection episode. No patients who were converted to MMF were treated for acute rejection following conversion to MMF. One LRD graft was lost at 19 days following injury to the donor artery at the time of retrieval. At the last follow-up, the average creatinine level was 93 µmol/L and average urea level was 8.6 mmol/L. One patient developed epigastric distress. Three patients developed diarrhea/abdominal pain requiring dose adjustment. Five episodes of leukopenia and one episode of thrombocytopenia required dose adjustment. Two patients developed symptomatic cytomegalovirus (CMV) infection, one while on acyclovir prophylaxis. No malignancy has been encountered to date. Hence, MMF can be administered safely to children with good effect and with an acceptable side-effect profile. [source] B-cell dysfunction and depletion using mycophenolate mofetil in a pediatric combined liver and kidney graft recipientPEDIATRIC TRANSPLANTATION, Issue 1 2001R. Ganschow Abstract: The use of mycophenolate mofetil (MMF) in combination with cyclosporin A (CsA) and steroids is well established after kidney transplantation (Tx) in children. A 9-yr-old girl with primary hyperoxaluria type 1 and systemic oxalosis underwent a combined kidney and liver Tx at our institution. The post-operative immunosuppression consisted of CsA, prednisolone, and MMF. Four weeks post-transplant the girl suffered from a severe urinary tract infection caused by Pseudomonas aeruginosa, when the serum immunoglobulin G (IgG) concentration was found to be critically low (< 1.53 g/L). Additionally, there was an isolated B-cell depletion (240/µL) at that time. In the following course, the B-cell count was significantly diminished until the MMF was stopped 13 weeks post-transplant. As a result of the very low serum IgG concentration, intravenous immunoglobulin (IVIG) substitution was necessary. There was no significant loss of immunoglobulins in the ascites and urine and no other medication with possible side-effects on B cells was given. We suggest that MMF can lead to suppressed IgG production by B cells and can cause a defective differentiation into mature B cells. In vitro studies demonstrated these effects of MMF on B cells, but no in vivo cases of this phenomenon have been reported. B-cell counts and serum IgG concentrations returned to normal values after discontinuing the MMF. As we can assume that the observed B-cell dysfunction and depletion were MMF related, we suggest that serum IgG concentrations should be monitored when MMF is used after solid-organ Tx. [source] Investigation of Lymphocyte Depletion and Repopulation Using Alemtuzumab (Campath-1H) in Cynomolgus MonkeysAMERICAN JOURNAL OF TRANSPLANTATION, Issue 4 2010D. J. Van Der Windt As the target CD52 molecule is expressed on erythrocytes of most nonhuman primate strains, using alemtuzumab in these species would cause massive hemolysis. Six cynomolgus monkeys of Indonesian origin, screened by agglutination assay for absence of CD52 on erythrocytes, were administered alemtuzumab in a cumulative dose to a maximum of 60 mg/kg. In two monkeys, mycophenolate mofetil (MMF) was added as maintenance therapy. Complete depletion of T and B lymphocytes (>99.5%) was achieved with 20 mg/kg alemtuzumab and was more profound than in monkeys treated with antithymocyte globulin (n = 5), as quantified by flow cytometry. Repopulation was suppressed by weekly injections of 10 mg/kg. Without MMF, repopulation of CD20+B cells and CD8+T cells was complete within 2 and 3 months, respectively, and repopulation of CD4+T cells was 67% after 1 year. MMF significantly delayed CD4+T-cell repopulation. Among repopulating CD4+ and CD8+ T cells, a phenotypic shift was observed from CD45RAhiCD62Lhi naďve cells toward CD45RAloCD62Llo effector memory cells. In lymph nodes, the depletion of naďve cells was more profound than of memory cells, which may have initiated a proliferation of memory cells. This model offers opportunities to investigate lymphocyte depletion/repopulation phenomena, as well as the efficacy of alemtuzumab in preclinical transplantation models. [source] A Randomized Trial to Assess the Impact of Early Steroid Withdrawal on Growth in Pediatric Renal Transplantation: The TWIST StudyAMERICAN JOURNAL OF TRANSPLANTATION, Issue 4 2010R. Grenda Minimizing steroid exposure in pediatric renal transplant recipients can improve linear growth and reduce metabolic disorders. This randomized multicenter study investigated the impact of early steroid withdrawal on mean change in height standard deviation score (SDS) and the safety and efficacy of two immunosuppressive regimens during the first 6 months after transplantation. Children received tacrolimus, MMF, two doses of daclizumab and steroids until day 4 (TAC/MMF/DAC, n=98) or tacrolimus, MMF and standard-dose steroids (TAC/MMF/STR, n=98). Mean change in height SDS was 0.16 ± 0.32 with TAC/MMF/DAC and 0.03 ± 0.32 with TAC/MMF/STR. The mean treatment group difference was 0.13 (p < 0.005 [95% CI 0.04,0.22]), 0.21 in prepubertal (p = 0.009 [95% CI 0.05,0.36]) and 0.05 in pubertal children (p = ns). Frequency of biopsy-proven acute rejection was 10.2%, TAC/MMF/DAC, and 7.1%, TAC/MMF/STR. Patient and graft survival and renal function were similar. Significantly greater reductions in total cholesterol and triglycerides but significantly higher incidences of infection and anemia were found with TAC/MMF/DAC (p < 0.05 all comparisons). Early steroid withdrawal significantly aided growth at 6 months more so in prepubertal than pubertal children. This was accompanied by significantly better lipid and glucose metabolism profiles without increases in graft rejection or loss. [source] | ||||||||||||||||||||||||||||