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Biomedical subjects

A Tzakis

Publications and source records attributed to A Tzakis.

At least 91 records · Page 5Linked to original sources
PubMed1995

Abdominal multivisceral transplantation.

Under FK506-based immunosuppression, 13 abdominal multivisceral transplantations were performed in 6 children and 7 adults. Of the 13 recipients, 7 (53.8%) are alive and well with functioning grafts after 9 to 31 months. Six recipients died: three from PTLD, one from rejection, one from sepsis, and one from respiratory failure. In addition to rejection, postoperative complications occurring in more than isolated cases included PTLD (n = 6), abdominal abscess formation (n = 5), pancreatitis (n = 3), and ampullary dysfunction (n = 2). In addition, infection by enteric microorganisms was common during the early postoperative period. Currently, all 7 survivors are on an oral diet and have normal liver function. Two recipients (one insulin-dependent) require antidiabetes treatment, in one case following distal pancreatectomy and in the other after two episodes of pancreatic rejection. Thus, abdominal multivisceral transplantation is a difficult but feasible operation that demands complex and prolonged posttransplantation management. It is not yet ready for application and awaits a better strategy of immune modulation.

Abdomen↗
PubMed1995

The association of Epstein-Barr virus with smooth-muscle tumors occurring after organ transplantation.

BACKGROUND: Epstein-Barr virus (EBV) has been associated with nasopharyngeal carcinoma, some lymphomas, and lymphoproliferative disease after organ transplantation. Many lymphoproliferative tumors that occur after transplantation are clonal, a property that classifies them as neoplastic. Clonality can be determined by analysis of the extrachromosomal circular DNA episomes produced by EBV infection. METHODS: We describe three young children in whom smooth-muscle tumors developed 18 months to 5 1/2 years after liver transplantation with immunosuppression. We examined the tumors by microscopy and with immunohistochemical studies and molecular genetic analyses of the EBV DNA: RESULTS: The tumors were composed of spindle cells with smooth-muscle features and resembled those described in patients with the acquired immunodeficiency syndrome. Immunohistochemical analysis was negative for EBV latent membrane protein and EBV receptor (CD21), but positive for EBV nuclear antigen 2. In situ hybridization revealed nuclear EBV sequences, and molecular genetic analysis showed the EBV genome to be clonal in all three patients. CONCLUSIONS: Smooth-muscle tumors that developed after organ transplantation contained clonal EBV, suggesting that the virus has a role in the development of these neoplastic lesions.

Colonic Neoplasms↗
PubMed1995

Acute pancreatitis after liver transplantation: incidence and contributing factors.

In order to assess the incidence and possible predisposing and contributing factors in the development of acute pancreatitis after liver transplantation, we reviewed the medical records of all 1832 adult patients who underwent 2161 orthotopic liver transplantation (OLTx) procedures in our center between January 1987 and September 1992. Of these patients, 55 (3% incidence) developed clinical pancreatitis and 247 (13.4% incidence) developed hyperamylasemia (biochemical pancratitis). Overall mortality in cases of clinical pancreatitis was 63.6%. The mortality in cases of hyperamylasemia was similar to that found in the general liver transplant population (i.e., 23%). A strong correlation was found between pancreatitis after liver transplantation and end-stage liver disease due to hepatitis B (30% of the cases, P = 0.00001). Extensive surgical dissection around the pancreas (P < 0.05), the type of biliary reconstruction following liver transplantation (P < 0.05), and the number of liver grafts received by the same patient (P = 0.00001) appeared to be possible contributing factors as did the duration of venovenous bypass and the quantity of IV calcium chloride administered intraoperatively.

Acute Disease↗
PubMed1995

Cloning and expression of canine interleukin-10.

We describe here the cloning of canine IL-10 cDNA (GenBank accession No. U33843) and the expression of recombinant IL-10 in a dog kidney cell line (DK6247) and Chinese hamster ovary cells (CHO). Canine IL-10 exhibits strong sequence homology to the known sequences of human, mouse, rat, and bovine genes at nucleotide and amino acid levels. The IL-10 gene, when introduced into DK and CHO cell lines, produces recombinant IL-10 that causes an inhibitory effect on allogeneic MHC-driven lymphoproliferative responses.

Amino Acid Sequence↗
PubMed1995

Outcome analysis of 71 clinical intestinal transplantations.

OBJECTIVE: The aim of the study was to determine risk factors associated with graft failure and mortality after transplantation of the intestine alone or as part of an organ complex. SUMMARY BACKGROUND DATA: Even with modern immunosuppressive therapies, clinical intestinal transplantation remains a difficult and unreliable procedure. Causes for this and solutions are needed. METHODS: Between May 1990 and February 1995, 71 intestinal transplantations were performed in 66 patients using tacrolimus and low-dose steroids. The first 63 patients, all but one treated 1 to 5 years ago, received either isolated grafts (n = 22), liver and intestinal grafts (n = 30), or multivisceral grafts (n = 11). Three more recipients of allografts who recently underwent surgery and one undergoing retransplantation were given unaltered donor bone marrow cells perioperatively as a biologic adjuvant. RESULTS: Of the first 63 recipients, 32 are alive: 28 have functioning primary grafts and 4 have resumed total parenteral nutrition after graft enterectomy. Thirty-five primary grafts were lost to technical and management errors (n = 10), rejection (n = 6), and infection (n = 19). Regression analysis revealed that duration of surgery, positive donor cytomegalovirus (CMV) serology, inclusion of graft colon, OKT3 use, steroid recycle, and high tacrolimus blood levels contributed to graft loss. All four intestine and bone marrow recipients are alive for 2-3 months without evidence of graft-versus-host disease. CONCLUSION: To improve outcome after intestinal transplantation with previous management protocols, it will be necessary to avoid predictably difficult patients, CMV seropositive donors, and inclusion of the graft colon. Bone marrow transplantation may further improve outcome by ameliorating the biologic barriers of rejection and infection and allowing less restrictive selection criteria.

Adult↗
PubMed1995

The use of interferon for the treatment of viral hepatitis in pediatric liver transplant recipients.

Between January 1990 and July 1992, 12 children with viral hepatitis occurring after liver transplantation (LTx) were treated with interferon alpha-2b. Seven were female and 5 were male; their ages ranged between 0.7 and 14.7 years (mean = 5.4 years). The indications for LTx included biliary atresia (n = 7), chronic active hepatitis (n = 2), and fulminant hepatitis (n = 3). Therapy was initiated at a dose of 1-3 million units (5 million units/1.73 m2) given 3 times per week and continued for more than six months. Six patients experienced a full response with normalization of their serum liver enzymes and a complete resolution of histologic hepatitis on liver biopsy. Two patients had a partial response with improvement in their liver enzyme values. Four patients required retransplantation for worsening hepatitis despite interferon (IFN) therapy. Three of these four were treated prophylactically with IFN therapy after their second transplant. Two of these four have shown no clinical or histologic evidence of hepatitis in their second liver after a follow-up of 20 and 4 months. IFN failed to prevent recurrent hepatitis in the other two children. One died at retransplant and the second developed recurrence of the giant cell hepatitis and rejection. Overall, IFN was well-tolerated by 11 of the 12 children; the 12th child required a dose reduction because of seizures. Based upon this preliminary uncontrolled experience, we conclude that the use of interferon alpha-2b is safe and effective in the treatment of viral hepatitis in children after liver transplantation.

Adolescent↗
PubMed1995

Assessment of five-year experience with abdominal organ cluster transplantation.

BACKGROUND: Upper abdominal exenteration (resection of the liver, stomach, spleen, pancreaticoduodenal complex, and part of the colon) for the treatment of otherwise unresectable tumors is one of the more radical operations in oncology. This study was done to analyze retrospectively a five-year experience with exenteration in 57 patients treated with variations of resectional and transplant reconstructive techniques. STUDY DESIGN: Sixty-one transplantations were performed upon 57 patients. Three different organ replacement techniques were used: liver-pancreas-duodenum en bloc (original procedure), liver only (modified procedure), and liver plus pancreatic islets. The diagnoses were cholangiocarcinoma (20 patients), hepatocellular carcinoma (12 patients), endocrine neoplasms (14 patients), sarcoma (six patients), and adenocarcinoma of the pancreas (two patients), colon (two patients), or gallbladder (one patient). Analyses of survival and tumor recurrence were stratified by procedure variations, type and extent of tumor, and immunosuppressive regimen. RESULTS: The three month and one, two, three, and five year actuarial patient survival rates were 82, 56, 38, 33, and 30 percent, respectively. Eighteen (31.5 percent) of the 57 patients are alive after 425 15 (standard deviation) months (range of 17 to 61 months) and 12 patients are tumor free. The actuarial survival rates stratified by transplantation procedure, immunosuppression, and tumor diagnosis and extent showed no statistically significant differences beyond the three different transplantation groups. Endocrine tumors had a better three-year survival rate (64 percent) than sarcoma (44 percent), hepatocellular carcinoma (25 percent), cholangiocarcinoma (20 percent), and the other adenocarcinomas (20 percent). Twenty-three patients (40 percent) died as a result of tumor recurrence. Patients with combined factors of no lymph node involvement, absence of vascular invasion, and metastases to the liver only (11 patients) had the lowest incidence of recurrence (27 compared to 73.5 percent, p = 0.006). CONCLUSIONS: Patients with unresectable endocrine neoplasms, fibrolamellar hepatocellular carcinoma, and selected cholangiocarcinoma confined to the liver can benefit from this radical operative approach. Patients with sarcoma can achieve long survival periods but have a high recurrence rate.

Abdominal Neoplasms↗
PubMed1994

Small intestinal transplantation in humans with or without the colon.

Under FK506-based immunosuppression, 16 cadaveric small bowel transplantations were performed in 15 recipients with (n = 5) or without (n = 11) the large bowel. Twelve (80%) patients are alive after 1.5 to 19 months, 11 bearing their grafts, of which 4 include colon. The actuarial one-year patient and graft survivals are 87.5% and 65.9%, respectively. Five grafts were lost to acute (n = 4) or chronic (n = 1) rejection, and 3 of these patients subsequently died after 376, 440, and 776 days total survival. Six recipients developed severe CMV infection that was strongly associated with seronegative status preoperatively and receipt of grafts from CMV positive donors; 3 died, and the other 3 required prolonged hospitalization. Currently, 9 patients are free from TPN 1-18 months postoperatively, 2 require partial TPN, and one has returned to TPN after graft removal. The results show the feasibility of small bowel transplantation but emphasize the difficulty of managing these recipients not only early but long after their operation.

Adult↗
PubMed1994

FK506 "rescue" for resistant rejection of renal allografts under primary cyclosporine immunosuppression.

Seventy-seven patients with ongoing acute rejection on initial CsA therapy were converted to FK506 to attempt graft salvage. Fifty-nine patients had undergone primary transplantation and 18 had been retransplanted; there were 52 cadaveric and 25 living-donor transplants. The indications for conversion to FK506 were ongoing, biopsy-confirmed rejection in all patients, including vascular rejection in 20. The median interval to rescue was 2 months (range 2 weeks to 36 months) after transplantation. Sixty-one of the 77 patients (79%) had already received one or more courses of an antilymphocyte preparation (OKT3: n = 33; ALG or ATG: n = 1; OKT3+ALG/ATG: n = 27). Of the 77 patients, 57 (74%) have been successfully rescued and still have functioning grafts with a mean follow-up of 14 months, with a mean serum creatinine of 2.35 +/- 0.97 mg/dl. Eighteen patients were already dialysis-dependent at the time of conversion to FK506; of these, 9 (50%) were successfully salvaged and have a mean serum creatinine of 2.3 mg/dl. Of the 61 patients previously treated with antilymphocyte preparations, 48 (79%) were rescued. In those salvaged, prednisone doses have been lowered from 22.2 +/- 7.2 mg/day preconversion to 7.5 +/- 5.6 mg/day postconversion, and 12 patients are on FK506 monotherapy. In nondiabetics, mean serum glucose was 101.4 +/- 20.5 mg/dl preconversion and 93.2 +/- 22 postconversion (P = 0.07), uric acid 7.3 +/- 2.3 and 7.1 +/- 1.5 mg/dl (P = 0.53), and triglycerides 199.2 +/- 101.6 and 167.2 +/- 106.4 mg/dl (P = 0.06). Cholesterol levels were significantly lower following FK conversion (207.7 +/- 46.5 mg/dl pre. vs. 188.3 +/- 39.7 post., P = 0.007). FK506 is capable of salvaging renal allografts with ongoing acute rejection on CsA therapy, even when antilymphocyte preparations have been ineffective.

Adolescent↗
PubMed1994

Disease gravity and urgency of need as guidelines for liver allocation.

One thousand one hundred and twenty-eight candidates for liver transplantation were stratified into five urgency-of-need categories by the United Network for Organ Sharing (UNOS) criteria. Most patients of low-risk UNOS 1 status remained alive after 1 yr without transplantation; the mortality while waiting was 3% after a median of 229.5 days. In contrast, only 3% of those entered at the highest risk UNOS 5 category survived without transplantation; 28% died while waiting, the deaths occurring at a median of 5.5 days. The UNOS categories in between showed the expected gradations, in which at each higher level fewer patients remained as candidates throughout the 1-yr duration of study while progressively more died at earlier and earlier times while waiting for an organ. In a separate study of posttransplantation survival during the same time period, the best postoperative results were in the lowest-risk UNOS 1 and 2 patients (88% combined), and the worst results were those in UNOS 5 (71%). However, a relative risk cross-analysis showed that a negative benefit of transplantation may have been the result in terms of 1-yr survival for the low-risk elective patients, but that a gain in life extension was achieved in the potentially lethal UNOS categories 3, 4 and 5 (greatest for UNOS 3). These findings and conclusions are discussed in terms of total care of patients with liver disease, and in the context of organ allocation policies of the United States and Europe.

Adult↗
PubMed1994

Liver transplantation for neonatal hepatitis as compared to the other two leading indications for liver transplantation in children.

Neonatal hepatitis is a syndrome of unknown etiology occurring in children with viral liver disease, as well as children with unidentified disorders of bile salt synthesis and other poorly understood metabolic diseases. It is characterized by jaundice, giant cell hepatitis and rare liver failure necessitating liver transplantation. In the present investigation, the outcome of liver transplantation performed in 16 children with neonatal hepatitis at the investigators' institution was determined from 1 January 1989 to 31 December 1991. The results were compared to those obtained in 288 children transplanted for biliary atresia and 66 children transplanted for recognized metabolic liver disease. The children transplanted for neonatal hepatitis (4.1 +/- 1.3 years) and metabolic liver disease (5.8 +/- 0.6 years) were older than those transplanted for biliary atresia (3.3 +/- 0.2 years) (p < 0.01), but did not differ in terms of sex, ABO type, UNOS status or year in which the transplant procedure was performed. Interestingly, first allograft survival was equal in the children with neonatal hepatitis (74%) and those with metabolic liver disease (74%), but was greater than that for children transplanted for biliary atresia (68%) (p < 0.01). Despite this significant difference in first graft survival, no differences in 5-year survival were seen for the three groups (81% for neonatal hepatitis, 68% for biliary atresia and 79% for metabolic liver disease).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

The incidence, timing, and management of biliary tract complications after orthotopic liver transplantation.

OBJECTIVE: This study analyzed the incidence and timing of biliary tract complications after orthotopic liver transplantation (OLTx) in 1792 consecutive patients. These results were then compared with those of previously reported series. Finally, recommendations were made on appropriate management strategies. SUMMARY BACKGROUND DATA: Technical complications after OLTx have a significant impact on patient and graft survival. One of the principal technical advances has been the standardization of techniques for biliary reconstruction. Nonetheless, biliary complications still occur. A 1983 report from the University of Pittsburgh reported biliary complications in 19% of all transplants, and an update in 1987 reported biliary complications in 13.2% of transplants. METHODS: The medical records of all patients who underwent liver transplantation and were hospitalized between January 1, 1988 and July 31, 1991 were reviewed. The case material consisted of the medical records of 217 patients treated for 245 biliary complications. RESULTS: Primary biliary continuity was established by either choledochocholedochostomy over a T-tube (C-C, n = 129) or a Roux-en-Y choledochojejunostomy with an internal stent (C-RY, n = 85). The overall incidence for biliary complication in this large series was 11.5%. Strictures (n = 93) and bile leak (n = 58) were the most common complications (69.6%). Most biliary complications (n = 143, 66%) occurred within the first 3 months after surgery. In general, leaks occurred early, and strictures developed later. Bile leaks were equally frequent in both C-C and C-RY (27.1% and 25.9%, respectively); strictures were more common after a C-RY type of reconstruction (36.4% and 52.9%, respectively). Twenty-one patients died, an incidence of 9.6%. Fifteen of the 21 biliary-related deaths were among patients treated for rejection before the recognition of biliary tract pathologic findings. CONCLUSIONS: Progress has been made on improving the results of biliary reconstruction after OLTx. Nonetheless, patients continue to experience biliary complications after OLTx, and these complications cause considerable loss of grafts and life. If significant additional improvement in patient and graft survival are to be obtained, the technical performance of OLTx must continue to improve.

Adult↗