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Biomedical subjects

A Tzakis

Publications and source records attributed to A Tzakis.

At least 271 records · Page 15Linked to original sources
PubMedDate not supplied

Analysis of rejection episodes in over 100 pediatric intestinal transplant recipients.

Rejection after intestinal transplant is a significant source of morbidity and mortality. We analyzed number of rejections, severity, and duration of episodes in pediatric recipients of intestinal transplants. One hundred eighteen intestinal transplants were performed: intestine (n = 27), liver-intestine (n = 27), modified multivisceral (n = 7), and multivisceral (n = 57). A total of 186 rejections were classified: mild (n = 89), moderate (n = 70), severe (n = 27). Duration of episodes doubled for each increasing step in severity. Treatment of mild rejection was with steroids, moderate rejection was treated with OKT3, severe rejection required OKT3 and organ removal. Most rejections occurred during the first month posttransplant, with the incidence of all rejections declining after 6 months posttransplant. Intestine and liver-intestine recipients had significantly higher probability of developing severe rejections, as compared to MVT. In summary, recipients of MVT seemed to be protected from rejection as compared to intestine or liver-intestine recipients.

Adolescent↗
PubMedDate not supplied

Renal dysfunction following adult intestinal transplant under tacrolimus-based immunosuppression.

We analyzed data from the records of 24 adult patients who survived more than 2 years after intestinal transplantation performed between 1995 and 2002 under tacrolimus-based immunosuppression. Ages ranged from 19.3 to 59.2 years old (median 32.1 years). Tacrolimus cumulative level was defined as a sum of weekly average tacrolimus level over time. Kidney function was evaluated by the 6-month average serum creatinine level. Estimated creatinine clearance was calculated with the Cockcroft-Gault formula. Student's t test was used for analysis. Primary diseases were mesenteric thrombosis (n = 7), trauma (n = 4), Crohn's (n = 3), Gardner's (n = 5), and others (n = 7). Procedures were isolated intestinal transplant (n = 10), liver and intestine (n = 1), multivisceral transplant (n = 9), or modified multivisceral transplant (n = 4). Cumulative tacrolimus levels ranged between 1161 and 8623 ng*day/mL (median 4132 ng*day/mL) at 0 to 12 months. Pretransplant kidney function as mean creatinine clearance was 114 mL/min per 1.73 m(2) (n = 24). Creatinine clearance decreased to a mean of 49.6 mL/min per 1.73 m(2) (43.5% of pretransplant) at 2 years (P < .0001). The average creatinine clearance at 18 to 24 months in each patient with a cumulative tacrolimus level <4500 ng*day/mL was 63% +/- 25% of preoperative creatinine clearance. In patients with a cumulative tacrolimus level >4500 ng*day/mL, it was 34% +/- 17%. Cumulative tacrolimus level >4500 ng ng*day/mL was significantly associated with a decreased creatinine clearance at 2 years (P = .006). Renal function decreased significantly after intestinal transplantation in adults. Cumulative tacrolimus level in the first year affected renal function at 2 years.

Adult↗
PubMedDate not supplied

Percutaneous transluminal angioplasty of venous anastomotic stenoses complicating liver transplantation: intermediate-term results.

PURPOSE: The authors evaluated the safety and efficacy of percutaneous transluminal angioplasty (PTA) for the treatment of venous stenoses in liver transplant recipients. PATIENTS AND METHODS: Over a 5-year period, 15 venous stenoses were treated with PTA in 12 patients with liver transplants (seven children and five adults). PTA was performed for portal vein stenoses in five patients, inferior vena cava (IVC) stenoses (n = 6) in five patients, combined superior mesenteric vein-portal vein graft anastomosis and hepatic vein-IVC anastomosis in one patient, and combined IVC and hepatic vein-IVC anastomosis in one patient. PTA was repeated in three patients (five procedures) for recurrent IVC stenoses. RESULTS: Initial technical and clinical success of PTA was achieved in 11 patients (92%); failure occurred in one patient (8%) with a portal vein anastomotic stenosis. No complications occurred in the immediate post-procedure period (up to 7 days). Nine patients (75%) are clinically well, with follow-up ranging from 7 to 33 months (mean, 18 months). Two of them required one or more repeated PTA procedures to maintain vessel patency. One patient required retransplantation for chronic rejection at 3 months, and another died of gastrointestinal tract bleeding from a gastric ulcer at 2 months after initially successful IVC PTA. CONCLUSIONS: PTA is a safe procedure for the treatment of venous anastomotic stenoses in liver transplant recipients. PTA of portal vein anastomotic stenosis has favorable intermediate-term results. Repeat PTA may be necessary in some cases of IVC anastomotic stenoses to maintain vessel patency and avoid surgical revision or retransplantation.

Adolescent↗
PubMedDate not supplied

Aspergillosis of the CNS in a pediatric liver transplant recipient: case report and review.

A 2-month-old infant who had undergone orthotopic liver transplantation at the age of 2 weeks for carbamoyl phosphate synthetase deficiency developed infection of the CNS due to Aspergillus fumigatus. The patient was successfully treated with administration of a combination of antifungal agents (including intraventricular amphotericin B), drainage of the parietal lobe abscess, and cessation of immunosuppression. An intraventricular catheter was used both to obtain ventricular fluid for microbiologic testing and to deliver amphotericin B during nearly 4 months of treatment. We review literature on aspergillosis in solid-organ transplant recipients, especially those in whom the disease involves the CNS, and discuss in particular clinical presentation, diagnosis, treatment, and outcome.

Antifungal Agents↗
PubMedDate not supplied

Nutritional support after liver transplantation: a randomized prospective study.

Nutritional support in patients with advanced cirrhosis is difficult due to protein, fluid and salt restrictions. Successful liver transplantation should improve nutrient tolerance. We randomly assigned 28 hypoalbuminemic cirrhotic patients to receive, immediately after liver transplantation, one of three regimens: group 1, no nutritional support (n = 10); group 2, total parenteral nutrition (TPN) (35 kcal/kg/day) with standard amino acids (1.5 g/kg/day) (n = 8); or group 3, isocaloric isonitrogenous TPN with added branched-chain amino acids (n = 10). Therapy was continued for 7 days posttransplant. Jaundice resolution was unaffected by nutritional support. Nitrogen balance favored both TPN groups. Branched-chain amino acid (BCAA) aromatic amino acid ratios were highest in group 3. Coma scores and serum ammonia levels were similar in all groups. Both TPN groups achieved respirator independence earlier; this difference was not statistically significant. Group 1 patients stayed longest in ICU; the difference was statistically significant. TPN with either standard or BCAA- enriched amino acids is tolerated well immediately after successful liver transplant. Positive nitrogen balance is achieved; large protein loads do not worsen encephalopathy. Nutritional support may improve respiratory muscle function, allowing earlier weaning from ventilatory support. A shortened length of ICU stay justifies the expense of TPN.

Amino Acids, Branched-Chain↗
PubMedDate not supplied

A new technique for isolating and culturing human hepatocytes from whole or split livers not used for transplantation.

Large numbers of human hepatocytes were obtained from split and whole livers by using an adaptive form of the collagenase perfusion technique employed in rodent and human biopsies. In order to guarantee a homogenous distribution of the perfusate within the whole specimen, major hepatic veins were cannulated with large bore catheters. This technique allowed for the isolation of human hepatocytes on a large scale (up to 18.5 x 10(9) in one case) from normal and diseased liver specimens. The yield of isolated normal viable hepatocytes is inversely proportional to the donor age. In addition, it was noted that a short time between declared death and organ harvest (cross clamp time) results in higher viability of hepatocytes. In contrast, the time of cold organ preservation did not correlate with the viability or the yield of isolated hepatocytes. We conclude that the technique presented here allows isolation of large numbers of human hepatocytes from specimens unsuitable for transplantation but very valuable for biomedical research.

Animals↗