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Biomedical subjects

B Charpentier

Publications and source records attributed to B Charpentier.

At least 19 recordsLinked to original sources
PubMed2006

Tolerability of enteric-coated mycophenolate sodium to 1 year in combination with cyclosporine and corticosteroids in renal transplant recipients.

Enteric-coated mycophenolate sodium (EC-MPS) is therapeutically equivalent to mycophenolate mofetil, but delays release of mycophenolic acid until it reaches the small intestine. De novo renal transplant patients taking part in a 12-month, multicenter, randomized study received cyclosporine microemulsion (CsA-ME, early or delayed to day 6), EC-MPS, steroids, and interleukin-2 antagonist induction. Tolerability data relating to EC-MPS are reported. Ninety-seven patients were randomized to early CsA-ME and 100 patients to delayed CsA-ME. Median daily dose of EC-MPS was 1440 mg at all time points throughout the 12-month period. The most frequently reported adverse events were constipation, anemia, urinary tract infection, abdominal pain, leukopenia, and cytomegalovirus infection; there were four malignancies. Fifty patients (24.6%) discontinued EC-MPS prematurely by 12 months, including 42 patients (84%) who discontinued owing to adverse events. No patient discontinued treatment because of gastrointestinal adverse events. Two-thirds of patients (137 [67.5%]) maintained full EC-MPS dose throughout the 12-month study and did not require any dose reduction or dose interruption. EC-MPS is well tolerated in de novo renal transplant recipients when administered in combination with CsA-ME and steroids, with low rates of dose reductions or interruptions. Gastrointestinal adverse events were responsible for dose reduction or interruption in only 5% of patients.

Adrenal Cortex Hormones↗
PubMed2006

Long-term results (10 years) of a prospective trial comparing Lo-tact-1 monoclonal antibody and anti-thymocyte globulin induction therapy in kidney transplantation.

To evaluate long-term patient and graft survival, and the incidence of acute and chronic rejection, infectious diseases and malignancies following induction therapy with a rat monoclonal interleukin 2 receptor antibody, Lo-Tact-1, or anti-thymocyte globulin (ATG). Forty first-time kidney transplant patients were prospectively randomized to two groups between May 1990 and June 1991. Twenty recipients were treated with Lo-Tact-1 (group 1) and the other 20, with ATG (group 2) during the first 14 days of the transplantation protocol. All patients were treated with azathioprine, steroids and cyclosporin A. Data were collected over 10 years. Median age was 42.1 years in group 1 and 39.3 years in group 2. Six recipients died during the 10 years of follow-up. All had functioning grafts. Death-censored graft survival was 35% in group 1 and 45% in group 2 after 10 years (P = NS). The number of acute rejection was similar in the two groups. Chronic allograft rejection was significantly more frequent in group 2 (n = 9) than in group 1 (n = 3), P < 0.05. Viral and bacterial infections were more frequent in group 2 than in group 1 (respectively 8 vs. 2 and 16 vs. 10, P < 0.05). Three patients had cancer. Although both Lo-tact-1 and ATG effectively prevented acute renal rejection, fewer bacterial and viral infections and cases of chronic allograft rejection were observed in Lo-tact-1-treated patients after 10 years of follow-up, demonstrating the potential value of this treatment for kidney transplantation.

Adult↗
PubMed2006

Risk factors and long-term outcome of transplant renal artery stenosis in adult recipients after treatment by percutaneous transluminal angioplasty.

Transplant renal artery stenosis (TRAS) is a common complication of kidney transplantation but attempts to identify predisposing risk factors for TRAS have yielded conflicting results. In order to determine the predisposing factors for transplant (TRAS), we retrospectively reviewed the records of 29 renal allograft recipients with TRAS treated with percutaneous transluminal angioplasty (PTA). The TRAS group was compared with a case-control group of 58 patients. Predisposing factors for TRAS included CMV infection (41.4% vs. 12.1% p = 0.0018) and initial delayed graft function (DGF) (48.3% vs. 15.5% p = 0.0018), respectively in the TRAS and the control group. Acute rejection occurred more frequently in patients from the TRAS group (48.3%) compared with the control group (27.6%), although the difference was not significant (p = 0.06). In a multivariate analysis, only CMV infection (p = 0.005) and DGF (p = 0.009) appear to be significantly and independently associated with TRAS. The long-term graft survival was significantly higher in the control group, compared with the TRAS group (p = 0.03). Our study suggests that CMV infection and DGF are two reliable risk factors for TRAS. Despite treatment by PTA with primary successful results, TRAS significantly affects long-term graft outcome.

Adult↗
PubMed2006

Impact of early or delayed cyclosporine on delayed graft function in renal transplant recipients: a randomized, multicenter study.

The benefit of delayed cyclosporine in reducing risk of delayed graft function (DGF) is not clearly established. This study compared early vs. delayed cyclosporine microemulsion (CsA-ME) inde novorenal transplant patients. Patients were randomized to early (day 0, n=97) or delayed (day 6, n=100) CsA-ME at an initial dose of 8 mg/kg/day with dose adjusted according to C2 level. All patients received enteric-coated mycophenolate sodium (EC-MPS), steroids and an anti-interleukin-2 receptor antibody. In both groups, 33% of patients were at high risk of DGF; 26 patients (26.8%) in the early CsA-ME group and 23 patients (23.0%) in the delayed CsA-ME group experienced DGF (n.s.). Renal function at 3 months was comparable (creatinine clearance 51.1 mL/min with early CsA-ME and 53.8 mL/min with delayed CsA-ME), and remained similar to 12 months. Treatment failure, defined as biopsy-proven acute rejection, graft loss or death, did not differ significantly at 12 months (23.7% with early CsA-ME vs. 29.0% with delayed CsA-ME). Biopsy-proven acute rejection occurred in 15.5% of early CsA-ME and 26.5% of delayed CsA-ME patients (n.s.). Both regimens were well tolerated. These data suggest that early or delayed introduction of CsA-ME results in similar renal function in renal transplant patients regardless of DGF risk level.

Adult↗
PubMed2006

Impact of cyclosporine reduction with MMF: a randomized trial in chronic allograft dysfunction. The 'reference' study.

Long-term use of calcineurine inhibitors (CNIs) may contribute to the development of chronic allograft dysfunction (CAD). We investigate the impact of the introduction of MMF combined with cyclosporine (CsA) 50% dose reduction. An open, randomized, controlled, multicenter, prospective study was conducted in 103 patients, receiving a CsA-based therapy with a serum creatinine between 1.7-3.4 mg/dL, more than 1 year after transplantation. They were randomized to receive MMF with half dose of CsA (MMF group) or to continue their maintenance CsA dose (control group). A total of 96 weeks after randomization, the evolution of renal function assessed by regression line analysis of 1/SeCr improved in the MMF group (positive slope) vs. the control group (negative slope), 4.2 x 10(-4) vs. -3.0 x 10(-4), respectively (p < 0.001). Concurrently, the absolute renal function improved significantly in the MMF group. No episode of biopsy-proven acute rejection occurred. One patient in each group lost his graft because of biopsy-proven chronic allograft nephropathy. There was a significant decrease of triglycerides level in the MMF group. Anemia and diarrhea were statistically more frequent in the MMF group. In CAD, the reduction of CsA in the presence of MMF results in significant improvement in renal function during a 2-year follow-up.

Adult↗
PubMed2006

FTY720 versus MMF with cyclosporine in de novo renal transplantation: a 1-year, randomized controlled trial in Europe and Australasia.

FTY720 is a novel immunomodulator investigated in de novo renal transplantation and other therapeutic areas including multiple sclerosis. This 1-year multicenter, randomized, phase III study in 668 de novo renal transplant patients compared FTY720 2.5 mg plus full-dose cyclosporine (FDC) or FTY720 5.0 mg plus reduced-dose cyclosporine (RDC), with mycophenolate mofetil (MMF) plus FDC. The primary efficacy endpoint was the composite incidence of first treated biopsy-proven acute rejection (BPAR), graft loss, death or premature study discontinuation at month 12. Primary efficacy with FTY720 2.5 mg and MMF (32.4% and 30.2%; p = NS), plus mortality and BPAR incidence, were comparable. Patients receiving FTY720 5.0 mg plus RDC were discontinued from treatment due to increased risk of acute rejection (primary endpoint incidence 47.3%). FTY720 was associated with lower creatinine clearance (month 12: 53.1, 56.0 vs. 65.1 mL/min; p < 0.001) and more macular edema cases (2.2% and 1.3% vs. 0%), whereas cytomegalovirus infections were higher with MMF (6.2% and 10.6% vs. 18.1% p < 0.0001 and p = 0.0139, respectively). FTY720 2.5 mg provided comparable rejection prophylaxis over 12 months versus MMF; however, FTY720 5.0 mg did not support a 50% reduction in cyclosporine exposure. The cause of macular edema cases and lower creatinine clearance with FTY720 in de novo transplantation needs further investigation.

Adult↗
PubMed2004

The archaeal sRNA binding protein L7Ae has a 3D structure very similar to that of its eukaryal counterpart while having a broader RNA-binding specificity.

The ribosomal L7Ae protein of archaea has the peculiarity to be a component of the C/D and H/ACA snRNPs, that guide rRNA post-transcriptional modifications. Its yeast (Snu13p) and human (15.5kDa protein) homologs are only found in C/D snoRNPs and the (U4/U6, U5) spliceosomal tri-snRNP. By using a large variety of RNAs, we compared the RNA-binding specificities of the recombinant Pyrococcus abyssi L7Ae and Saccharomyces cerevisiae Snu13 proteins. Unlike Snu13p, protein L7Ae binds terminal loops closed by two A:G and G:A pairs and canonical K-turn structures with similar efficiencies, provided that the terminal loop contains at least 5nt. In contrast to Snu13p, binding of protein L7Ae to canonical K-turn structures is not dependent on the identity of the residue at position 2 in the bulge. The peculiar KT-15 motif of P. abyssi 23S rRNA, that is recognized by L7Ae, does not associate with Snu13p. To get more information on the P. abyssi L7Ae protein, we solved its X-ray structure at 1.9A resolution. In spite of their sequence divergence, the free P. abyssi and bound H. marismortui proteins were found to have highly similar structures. Only a limited number of side-chain conformational changes occur at the protein-RNA interface upon RNA binding. In particular, one ion pair that is formed by residues Glu43 and Lys46 in the free protein is disrupted in the ribosomal 50S subunit, so that, residue Glu43 can interact with the RNA residue G264. The Glu43-Lys46 ion pair of protein L7Ae belongs to a complex network of ion pairs that may participate to protein thermostability.

Amino Acid Sequence↗
PubMed2004

Single-center experience with cyclosporine therapy for kidney transplantation: analysis of a twenty-year period in 1200 patients.

Since the introduction of cyclosporine (CyA) in our center in February 1983, 1267 kidney transplant patients have received an immunosuppressive regimen based on CyA, usually in association with azathioprine and steroids and following an induction therapy in three quarters of patients. The aim of this study was to retrospectively analyze our 20-year experience with CyA and examine the evolution of therapy during this period. Induction treatment has been less commonly used during the past 5 years. Even in the early years of our experience, CyA doses were low (under 6 mg/kg per day at 3 months after transplantation). Acute tubular necrosis was observed in 39.4% of patients. The incidence of acute rejection episodes has dramatically decreased since 1984, but the frequency of steroid-resistant rejection has remained constant (around 20%). The first year of transplantation, 32.7% of patients had arterial hypertension. De novo diabetes mellitus occurred in 2.5% of patients. An incidence of 11.8% of malignancies was observed. Skin cancer and lymphomas accounted for 50% and 12% of neoplasms. Five-year graft and patient survivals were 70% and 87%, respectively. Renal function remained remarkably constant during the first 10 years of follow-up with a mean creatinine of 150 micromol/L. Chronic allograft nephropathy resulted in 43% graft losses. In conclusion, CyA has been well tolerated in our patients. However, the occurrence of chronic allograft nephropathy was a major concern in our cohort.

Adult↗
PubMed2003

Potentiation of tumour apoptosis by human growth hormone via glutathione production and decreased NF-kappaB activity.

In addition to its primary role as growth factor, human growth hormone (hGH) can also participate in cell survival, as already documented by its protective effect on human monocytes or human promyelocytic leukaemia U937 cells exposed to a Fas-mediated cell death signal. However, despite similarities in the molecular events following Fas and TNF-alpha receptor engagement, we report that U937 cells, genetically engineered to constitutively produce hGH, were made more sensitive to TNF-alpha-induced apoptosis than parental cells. This was due to overproduction of the antioxidant glutathione, which decreased the nuclear factor (NF)-kappaB activity known to control the expression of survival genes. These findings were confirmed in vivo, in nude mice bearing U937 tumours coinjected with recombinant hGH and the NF-kappaB -inducing anticancer drug daunorubicin, to avoid the in vivo toxicity of TNF-alpha. This study therefore highlights one of the various properties of hGH that may have potential clinical implications.

Animals↗
PubMed2003

Bicêtre hospital experience with sirolimus-based therapy in human renal transplantation: the Sirolimus European Renal Transplant Study.

In 11 European centers, first cadaveric renal allograft recipients were randomized to CsA (n = 42) or sirolimus (n = 41). Dosing of these agents was concentration-controlled and open-labeled. All patients received corticosteroids and azathioprine. At 12 months, graft survival (98% sirolimus vs 93% CsA), patient survival (100% vs 98%), and incidence of biopsy-confirmed acute rejection (41% vs 38%) were similar. Serum creatinine was lower with sirolimus, significantly (P </=.05) so at 3 and 4 months, and serum uric acid and magnesium were normal. Laboratory abnormalities were reported significantly more often with sirolimus, which included hypertriglyceridemia (51% vs 12%), hypercholesterolemia (44% vs 14%), thrombocytopenia (37% vs 0%), leukopenia (39% vs 14%), and, of lesser importance, increased liver enzymes and hypokalemia. These abnormalities improved 2 months after transplantation when the sirolimus target trough level was lowered from 30 to 15 ng/mL. Occurrence of cytomegalovirus was comparable (14% vs 12%), but incidence of herpes simplex (24% vs 10%, P =.08) and pneumonia (17% vs 2%, P =.03) were higher with sirolimus. No gingival hyperplasia was seen with sirolimus, tremor was rare, and hypertension was less frequent (17% vs 33%). Two malignancies were observed with CsA, none with sirolimus. Results at 12 months suggest that sirolimus can be used as base therapy in the prophylaxis of acute renal transplant rejection, and has a safety profile that differs from that of CsA.

Adrenal Cortex Hormones↗
PubMed2003

Tacrolimus in renal transplantation. A review of recent data.

This overview will cover the main development of the use of Tacrolimus in organ transplantation. It summarizes the large amount of data which have recently appeared in the literature, especially in comparison with Cyclosporine, with recent controlled conversion experience, combination therapies, withdrawal of corticosteroids, the use of Tacrolimus in monotherapy and in paediatric renal transplant patients. Finally cardiovascular risk factors are discussed in the light of the other main risk factors in this particular population of transplant patients.

Cardiovascular Diseases↗
PubMed2003

[HLA-G: immunoregulatory molecule involved in allograft acceptance].

The Human Leucocyte Antigen-G (HLA-G) is a non-classical MHC class I molecule of low polymorphism, restricted tissue distribution and tolerogeneic functions. It is clearly demonstrated that HLA-G contributes to fetal graft tolerance by the maternal immune system. The tolerogeneic properties of HLA-G act via specific inhibitory receptors present on immunocompetents cells: HLA-G inhibits natural killer cells (NK) and CD8+ T cell cytotoxicity, suppresses CD4+ T cell proliferation in response to allogeneic stimulation and promotes T helper 2 (Th2) type responses. The soluble HLA-G protein is spontaneously secreted by allo-sensitized CD4+ T cells during mixed lymphocyte reactions (MLR), and inhibits their proliferative response. Finally, inhibition of dendritic cell maturation has been observed in HLA-G transgenic mice. In human organ transplantation, our group has reported in cardiac and liver-kidney transplanted patients, a positive correlation between the de novo ectopic expression of HLA-G in both patient's serum and graft biopsies, and a lower rate of acute rejection episodes of the grafts. Moreover no chronic graft rejection has been detected in those populations. These results support the involvement of HLA-G in regulatory mechanisms that may occur during human allotransplantation.

Cytokines↗