Biomedical subjects

N Bilgin

Publications and source records attributed to N Bilgin.

At least 19 recordsLinked to original sources

PubMed2005

Long-term results of pediatric renal transplantation at one center in Turkey.

Kidney transplantation is more frequently indicated in children than in adults because growth retardation is an additional problem associated with chronic kidney disease in the pediatric age group. This study retrospectively analyzed the data from 75 kidney transplantations performed on 73 children (38 male and 35 female) at a center in Turkey from late 1975 through 2003. The aim of the study was to investigate the case characteristics and the long-term outcomes in this patient group. Patient ages ranged from 8 to 16 years (mean, 14.9 +/- 2.2 years). Sixty (82.1%) children were on hemodialysis, and 12 (16.4%) on peritoneal dialysis prior to transplantation. Pre-emptive transplantation was performed for one (1.4%) patient. Fifty-nine transplantations used organs from live donors (78.7%) and 16 cadaver transplants (21.3%). The mean cold ischemia time for the cadaveric transplantations was 38.6 hours (range, 23-56 hours). All recipients were placed on a low-dose immunosuppressive regimen. One graft was lost due to hyperacute rejection. Twenty-one patients (28.8%) experienced a total of 24 acute rejection episodes. The follow-up period ranged from 1 to 190 months (mean, 44.1 +/- 31.8 months). Concerning postoperative complications, four patients (5.5%) developed a lymphocele; there were two cases each (2.7% each) of distal ureteral stricture, perirenal hematoma, or renovascular stenosis; and one patient (1.4%) developed a urine leakage. Two patients (2.7%) developed Kaposi's sarcoma at 17 and 3 months after transplantation. Six recipients died (mortality 8%), four of whom had a functioning graft. Two patients (2.7%) underwent retransplantation at 4 and 2 years after the initial operation. The 1-, 3-, and 5-year graft survival rates for living-related transplantations were 92%, 81%, and 70%, and the corresponding patient survival rates were 98%, 93%, and 92%, respectively. The 1-, 3-, and 5-year graft survival rates for cadaveric transplantations were 90%, 78%, and 68%, and patient survival rates 98%, 91%, and 90%, respectively. These results indicate that kidney transplantation is successful in pediatric end-stage renal disease patients particularly from living-related donors.

Adolescent↗

PubMed2005

Living-related liver transplantation in pediatric patients.

INTRODUCTION: Many developments in surgical technique, immunosuppression, and patient selection criteria have led to improved long-term patient and graft survival in pediatric patients receiving liver transplants. In this study, we examined the early results of 26 pediatric recipients who underwent 26 liver transplantations between January 2003 and December 2004 at our institution. MATERIALS AND METHODS: The most common indications for liver transplantation were cholestasis in 10 patients (38.5%) and Wilson's disease in 8 (30.8%). Other indications were fulminant hepatic failure (4 patients, 15.4%), tyrosinemia (2 patients, 7.7%), Caroli disease (1 patient, 3.8%), and cryptogenic cirrhosis (1 patient, 3.8%). One recipient with Byler disease and two with tyrosinemia also had incidental hepatocellular carcinoma. RESULTS: Of 26 patients, 24 (92.3%) underwent living-related liver transplantation and 2 (7.7%) underwent cadaveric transplantation. The medical records of all patients were retrospectively reviewed. Twenty-two of 26 survived with excellent graft function, showing 91.2%, 86.4%, and 81.6% at 3, 12, and 24 months graft and patient survival rates, respectively. Sixteen patients (61.5%) developed various morbidities with biliary and vascular complications being the most common. Four patients (15.3%) developed bile leaks. Four patients (15.3%) developed hepatic artery thromboses. Five patients (19.2%) developed life-threatening infections. Four patients (15.4%) died during the study period, three owing to infectious complications. The other patient died due to acute respiratory distress syndrome. CONCLUSION: Despite technical difficulties and a donor organ shortage, the results of liver transplantation in pediatric patients with end-stage liver disease have demonstrated promising results at our institution.

Adolescent↗

PubMed2005

Switchability of neoral and equoral according to Food and Drug Administration rules and regulations.

According to the US Food and Drug Administration (FDA), if a drug product contains a drug substance that is chemically identical and is delivered to the site of action at the same rate and extent as another drug product, then it is equivalent and can be substituted (switchable) for that drug product. Methods used to define bioequivalence as stated by the FDA rules (FDA 21 CFR 320, 24) are (1) pharmacokinetic (PK) studies in healthy volunteers, (2) comparative clinical trials, and (3) pharmacodynamic (PD) studies (bioactivity). We evaluated the switchability of Equoral (IVAX-USA) with Neoral (Novartis Switzerland using all FDA rules. In a single oral dose, we undertook a comparative bioavailability study of Equoral (IVAX, USA) Neoral (Novartis, USA), and Neoral (Novartis UK). The pharmacokinetics of Equoral and Neoral were determined with blood levels at 0, 0.25, 0.5, 0.75, 1, 1.25, 1.5, 1.75, 2, 2.5, 3, 3.5, 4, 5, 6, 8, 10, 12, 16, 24, 30, 36, 42, and 48 hours. The area under curve (AUC), AUC extrapolated to infinity (AUC0-inf), rate of absorption (Tmax), extent of absorption (Cmax), half time (t1/2) of Equoral and Neoral were all within the 90% confidence interval of 80% to 125% boundaries. A comparative multinational multicenter clinical trial in stable renal transplant patients included 70 patients (22 women and 48 men) of mean age of 33 years (range, 26 to 43) was performed in Turkey, Lebanon, and Pakistan. In this study the ratios of LSM and the 90% confidence intervals for the Nontransformed/Parameters (AUC0-t, AUCinf, Tmax, and Cmax) of Equoral and Neoral SGC were 98% and 95%, respectively, which are within the 80% to 125% FDA acceptance range. For immunosuppressive drugs, the site of action is the lymphocyte and the measurable response is the decrease in lymphocyte count caused by the relative concentration of the drug in the lymphocyte. In a controlled switch, fixed-dose study, both Equoral and Neoral achieved the same concentration in the lymphocytes and caused the same degree of lymphocyte count reduction. The results of the testing (bioavailability-bioequivalence, clinical studies, and pharmacodynamic-bioactivity) required by FDA for interchangeability ("switchability") of immunosuppressive agents suggests that Neoral and Equoral are switchable.

Adult↗

PubMed2005

Long-term results of pediatric kidney transplantation at one center in Turkey.

Kidney transplantation is considered the treatment of choice for children with end-stage renal disease (ESRD). From November 1975 to June 2004, 80 of a total of 1477 kidney transplantations were performed in 78 pediatric patients. We retrospectively reviewed the records of 42 boys and 36 girls. Patient age ranged from 8 to 16 years (mean, 14.9 +/- 2.2). Sixty-three (78.7) grafts were from living donors and 17 (21.3%) from deceased donors. Two patients (2.6%) underwent preemptive transplantation, while 76 had preoperative renal replacement therapy with either hemodialysis in 62 (79.5%) or peritoneal dialysis in 14 (17.9%). Although the cause of ESRD could not be established in 30 cases, the other 48 showed the most common etiologies to be reflux nephropathy and glomerulonephritis. In conclusion, despite relatively poor socioeconomic conditions and health care problems in our country, the overall outcomes for pediatric patients at our transplantation center are good. We seek to perform more preemptive kidney transplantations in children with ESRD, and to increase our efforts to educate the Turkish public about organ transplantation and donation.

Adolescent↗

PubMed2005

Duct-to-duct biliary anastomosis with a "corner-saving suture" technique in living-related liver transplantation.

OBJECTIVES: Biliary complications after living-related liver transplantation (LRLT) remain a major source of morbidity for recipients. We describe our technique and early results with 32 recipients who underwent LRLT with duct-to-duct anastomoses during the last 2 years. METHODS: Between January 2003 and December 2004, 50 patients underwent liver transplantation in our center with overall patient and graft survival rate of 86.4% and 86.4%. Of 50 patients, 41 (82.0%; 17 adult and 24 pediatric) underwent LRLT, 32 (78.0%) of whom had duct-to-duct biliary anastomoses with a "corner-saving suture" technique. RESULTS: Of 32 patients in whom duct-to-duct biliary anastomoses were performed, 4 (12.5%) had an anastomotic leak with 2 eventually developing bile duct strictures within 3 months. One patient required reoperation for a bile leak. All other anastomotic leaks and strictures were treated with percutaneous drainage and balloon dilatation with excellent outcomes. There was no long-term morbidity and no graft loss owing to biliary complications. Seven patients died during follow-up (0.5 to 25 months); 43 are doing well with optimal liver function in the early posttransplantation period. CONCLUSION: According to our early results, we recommend duct-to-duct anastomosis in LRLT when calibration of the ducts show suitable results and when there is no tension on the anastomosis site. Otherwise, Roux-en-Y hepaticojejunostomy should be performed to decrease risk of biliary complications.

Anastomosis, Surgical↗

PubMed2004

The impact of cyclosporine on the development of immunosuppressive therapy.

The first immunosuppressive regimens based on glucocorticoids and azathioprine were introduced in the early 1960s. However, many patients developed acute rejection, which required treatment with high doses of prednisolone. Leading to a high mortality due to opportunistic infection. Prior to 1985, our center used a regimen of prednisolone and azathioprine for 352 renal transplantations with 1-year graft and patient survival rates of 63.9% and 82.4%, respectively. Cyclosporine was introduced into clinical practice in 1978, enabling more effective control of acute rejection. In 1985, our center adopted a protocol consisting of prednisolone, azathioprine, and cyclosporine producing significantly increased 1-, 3-, and 5-year patient and graft survival rates for living-related and cadaveric renal transplants. Newer drug combinations, which are less toxic and more potent than cyclosporine based protocols, have further decreased acute rejection rates from 60% to approximately 10%. Still, graft loss continues to be a problem. We believe that the most recent strategy of combining monoclonal antibodies with less toxic agents, such as sirolimus and mycophenolate mofetil, may eventually replace calcineurin inhibitors. Such protocols would eliminate the side effects of calcineurin inhibitors, and possibly permit steroid-free maintenance therapy. The immunosuppressive therapy that is currently available is not ideal; the ability to convert patients to a state of permanent immunologic tolerance would minimize the need for these drugs. The new generation of agents that includes FTY 20, anti-sense oligonucleotides, and agents capable of blocking the costimulatory pathway of allorecognition may improve host tolerance.

Cyclosporine↗

PubMed2003