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Biomedical subjects

D K Freese

Publications and source records attributed to D K Freese.

At least 19 recordsLinked to original sources

Pediatric "PSC-IBD": a descriptive report of associated inflammatory bowel disease among pediatric patients with psc.

BACKGROUND: Inflammatory bowel disease (IBD) in adults with primary sclerosing cholangitis (PSC) is characterized by pancolonic involvement, a high frequency of rectal sparing, and an increased risk of pouchitis and colorectal neoplasia. The clinical features of IBD in pediatric patients with PSC have not been well described. The aim of this study was to characterize the frequency, clinical features, and natural history of IBD in pediatric patients diagnosed with PSC. METHODS: A retrospective chart review was performed for all patients 18 years of age or younger diagnosed with PSC seen at the Mayo Clinic between 1975 and 1999. Endoscopic and histologic features and surgical and postsurgical outcomes were recorded. RESULTS: Fifty-two children with PSC were identified. Forty-three patients (84%) were also diagnosed with IBD. In 36 of 43 cases, there was a sufficient diagnostic evaluation to allow a detailed review. Thirty-two of 36 patients (89%) had ulcerative colitis and 4 of 36 patients (11%) had Crohn's disease. In 4 of 36 patients (11%), IBD was asymptomatic. Although the most frequent endoscopic presentation of IBD was universal colitis, endoscopic rectal sparing was frequently noted (27% of colonoscopic studies). Of the four patients diagnosed with Crohn disease, in none did perianal, fistulizing, or stricturing disease develop. Proctocolectomy was performed in six patients (17%); three operations were performed for dysplasia. Pouchitis complicated four of the five ileal pouch-anal anastomoses procedures. CONCLUSIONS: Among pediatric patients (1) PSC without IBD is uncommon; (2) asymptomatic IBD may be associated with PSC; (3) because the time to dysplasia may be accelerated, once the diagnosis of IBD is made in the setting of PSC, heightened endoscopic surveillance may be indicated; (4) pouchitis occurs frequently in these patients.

Adolescent↗

No evidence of hepatitis G virus in fulminant hepatic failure in children.

BACKGROUND: The cause of fulminant hepatic failure in children remains unknown, but a viral origin has been suspected in most cases. The recently discovered blood-borne virus, hepatitis G, has been suggested as a possible causative agent. METHOD: Six consecutive children who underwent liver transplantation for fulminant hepatic failure were studied. The children were tested for hepatitis G virus antibodies and hepatitis G virus RNA by polymerase chain reaction after excluding other causes of fulminant hepatic failure. RESULTS: No evidence of hepatitis G virus infection was found in these patients. CONCLUSION: Hepatitis G virus is unlikely to be a common cause of fulminant hepatic failure in pediatric patients from the upper midwestern United States.

Adolescent↗

Tacrolimus (FK506): the pros and cons of its use as an immunosuppressant in pediatric liver transplantation.

Tacrolimus (FK506) is a new immunosuppressive agent that has recently been given to recipients of liver transplants. Multicentre studies conducted in the United States and Europe have reported that tacrolimus is superior to cyclosporine in preventing allograft rejection. The absorption of tacrolimus is independent of bile, and, therefore, therapeutic blood levels are usually achieved by taking oral preparations within 72 hours of liver transplantation. Compared with the use of cyclosporine, this regimen has resulted in shorter hospital stays and reduced costs. Tacrolimus does not cause hirsutism or gingival hyperplasia, which are common disfiguring complications of cyclosporine. Serious neurological side effects, lymphoproliferative disorders and hypertrophic cardiomyopathy have recently been reported in children taking high doses of tacrolimus. When lower doses of tacrolimus are used in primary immunosuppressive therapy, the incidence of neurological side effects and lymphoproliferative disorders of tacrolimus and cyclosporine have been reported to be similar. Hence, tacrolimus is a potent immunosuppressant that has many advantages over cyclosporine but must be used cautiously, since high doses have been associated with an increased incidence of lymphoproliferative disorders and cardiomyopathy.

Child↗

Antibody response of pediatric solid organ transplant recipients to immunization against influenza virus.

We studied the immunogenicity of the 1992-1993 trivalent split-virus influenza vaccine in pediatric solid organ transplant recipients (PSOTRs) and their healthy siblings. One month after immunization, 41 (82%) of 50 subjects achieved protective titers of antibodies to influenza A, and 30 (60%) to influenza B, rates similar to those in healthy siblings. Achievement and persistence of protective titers occurred significantly more often in children with preexisting antibody. We recommend annual immunization of PSOTRs, their household contacts, and health care workers; immunologically naive PSOTRs may benefit from immunization before transplantation.

Antibody Formation↗

Histologic pathology of the liver in progressive familial intrahepatic cholestasis.

This work details the histologic findings in 84 liver biopsy specimens from 28 patients with progressive familial intrahepatic cholestasis (PFIC), who met the clinical criteria of early onset of chronic unremitting cholestasis, exclusion of any known metabolic or anatomic etiology, and low serum gamma-glutamyl transpeptidase (GGTP) values. Hepato-canalicular cholestasis and disruption of the liver cell plate arrangement were early, uniform findings, and giant cell transformation was found in 56% of initial biopsies. Duct loss was a prominent finding; 70% of patients had ductal paucity, and many had abnormal bile duct epithelium, suggesting degeneration. Fibrosis was seen in the samples from 16 patients, including bridging fibrosis in specimens obtained from six patients during the first 2 years of life. Proliferating ductules at the margins of portal tracts increased as fibrosis progressed and were especially prominent in end-stage histology. Cirrhosis developed in nine of these patients and had a characteristic histologic pattern, consisting of biliary cirrhosis with diffuse stellate lobular fibrosis associated with severe cholestasis and pseudoacinar transformation. Mallory hyalin and hepatocellular carcinoma were observed in materials from some patients with advanced cirrhosis. The constellation of histologic findings in PFIC forms a recognizable pattern, and the liver histology appears to have a predictable progression.

Adolescent↗

Clinical and biochemical findings in progressive familial intrahepatic cholestasis.

The clinical findings in 33 patients with progressive familial intrahepatic cholestasis (PFIC) are presented. Symptoms developed almost invariably before 6 months of age with severe pruritus and moderate jaundice. Other clinical findings included wheezing and nosebleeds, fat-soluble vitamin deficiency states, and cholelithiasis. Lower values for gamma-glutamyl transpeptidase, averaging 15 IU/L before the administration of phenobarbital, and cholesterol, which averaged 156 mg/dl, are helpful in distinguishing PFIC from other pediatric cholestatic liver diseases. Autosomal recessive inheritance is probable. Twenty-six patients are alive at 12.9 +/- 6.7 years of age, all having had successful surgical treatment, either partial biliary diversion (n = 17) or orthotopic liver transplantation (n = 10). Seven patients died at a mean age of 3.9 +/- 2.4 years, as a result of liver failure in two, hepatocellular carcinoma in two, and complications of liver transplantation in three.

Adolescent↗

Resolution of severe intrapulmonary shunting after liver transplantation.

A major complication of hepatic cirrhosis is arterial hypoxemia, often the result of intrapulmonary arteriovenous shunting. While previously such hypoxemia was thought to preclude successful hepatic transplantation, more recent studies have suggested that hepatic transplantation should be considered if the hypoxemia is corrected by supplemental oxygen. We report the findings in a cirrhotic patient with severe hypoxemia associated with intrapulmonary arteriovenous shunting. The patient did not respond to supplemental oxygen (PaO2 < 40 mm Hg on O2 at 4 L/min). The patient underwent successful hepatic transplantation, with complete resolution of intrapulmonary shunting. We believe that patients with cirrhosis-associated intrapulmonary shunting, even with hypoxemia resistant to supplemental oxygen, are acceptable candidates for hepatic transplantation.

Adolescent↗

Liver transplantation for hepatoblastoma. The American experience.

The current role of liver transplantation in treating malignant tumors of the liver is uncertain, except for select histologic types. Pooled data on the results of liver transplantation in 12 children with hepatoblastoma is presented here. One half of the children are alive 24 to 70 (44 +/- 19) months after transplantation with no evidence of recurrence. Three patients (25%) died of tumor recurrence and three (25%) died of other causes. Unifocal and intrahepatic tumors were associated with better prognosis compared to the multifocal tumors and tumors with extrahepatic spread (p = 0.04 and 0.13). Microscopically vascular invasion and the predominance of embryonal and/or anaplastic epithelium were associated with a poor prognosis compared to the tumors with no vascular invasion and with predominantly fetal epithelium (p = 0.08 and 0.1). It is concluded that continued efforts to treat unresectable hepatoblastomas by liver transplantation is justified and the role of adjuvant chemotherapy in improving the results needs to be better defined.

Carcinoma, Hepatocellular↗

Early liver transplantation is indicated for tyrosinemia type I.

Liver transplantation is now accepted as the treatment of choice for tyrosinemia type I (hereditary tyrosinemia). In an effort to determine whether any factors in these patients would aid in predicting optimal timing of the transplant procedure, we evaluated several clinical, biochemical, and radiographic parameters in five successive patients undergoing liver transplant for tyrosinemia type I at the University of Minnesota. All five patients evidenced prolonged periods of clinical and metabolic stability with dietary therapy and four of five remained stable at the time of evaluation for transplantation. Nevertheless, all five suffered significant and unexpected complications of tyrosinemia prior to the time of liver transplant. Four developed renal stones, two were in liver failure, and one developed a neurologic crisis that left him completely paralyzed. Hepatocellular carcinoma was found in one of the five at transplant. We could identify no clinical, biochemical, or radiographic study that was predictive of the likelihood of significant complications of the disorder. Survival from the transplant procedure itself was 100%. The inability to predict or prevent significant complications of tyrosinemia and the favorable outcome from transplantation lead us to recommend liver transplant for all patients with tyrosinemia type I by 12 months of age.

Amino Acid Metabolism, Inborn Errors↗

Chronic rejection after liver transplantation: a study of clinical, histopathological and immunological features.

In an effort to better understand chronic liver transplant rejection, we studied 110 children and adults who survived for at least 2 mo after the transplant procedure. Chronic rejection was defined using a combination of clinical and histopathological criteria and was diagnosed in 10 of the 110 patients for an incidence of 9.1%. All 10 patients were children with the mean age 3.4 yr vs. 21.7 yr for patients without chronic rejection (p less than .001). Males and females were equally represented, and nine received a liver from a gender-matched donor. Four patients were non-Caucasian, resulting in an incidence of 21.7% in non-Caucasian recipients vs. 6.6% in Caucasian recipients (p less than .05). All chronic rejection patients received a liver from an ABO-compatible donor. T-cell crossmatch was negative in all patients in whom it was assessed, and no significant disparity in either the class I or class II human leukocyte antigen loci was noted. Patients who had chronic rejection experienced acute rejection earlier, 11 days vs. 16 days (p less than .05), than patients who did not. In 8 of 10 patients, chronic rejection appeared to evolve directly from early episodes of acute rejection that were unresponsive to immunosuppressive therapy. Two distinct histological presentations were noted. One was progressive loss of bile ducts without hepatocellular injury (four patients), and the other was characterized by worsening ischemic hepatocellular damage and fibrosis (six patients) in addition to severe ductular injury. The first was associated with a more benign clinical course, the second with rapidly deteriorating hepatic function. Three patients recovered spontaneously 9 to 14 mo after transplant, one died awaiting a donor for retransplant, and five had retransplants. We conclude that chronic rejection after the operation is a relatively uncommon complication of liver transplantation with a variable clinical course and unpredictable outcome.

Adolescent↗

Plasma amino acids in long-term models for obstructive versus toxic liver injury in developing rats.

We evaluated plasma amino acid (AA) concentrations associated with a histologically defined lesion caused by bile duct ligation (BDL) in developing rats. Nineteen rats that underwent BDL at 14 days of age had marked bile duct proliferation with bridging fibrosis, multifocal lobular necrosis, and minimal polymorphonuclear periportal infiltrate in their livers at sacrifice (11-31 days after ligation). These were compared to two age-matched control groups: 21 nonoperated rats and 22 sham-operated rats; and eight rats with cirrhosis caused by carbon tetrachloride. Signs of liver damage including jaundice, growth failure, bleeding, and ascites were accompanied by elevated bilirubin, ammonia, aspartate aminotransferase (AST), and alkaline phosphatase levels in BDL rats compared to controls. They had higher concentrations of total AAs, phenylalanine, tyrosine, and cyst(c)ine when compared to controls and to CCl4-treated rats. Micronodular cirrhosis was present in CCL4-treated rats with elevated AST and alkaline phosphatase levels. Glutamine and glutamate levels were higher in them than in BDL rats or controls, and branched chain AA levels were lower. These two chronic lesions, one obstructive and one hepatotoxic, both result in fibrotic change, but their metabolic abnormalities as reflected in plasma AA levels are distinct. We found that BDL is an appropriate model with which to study metabolic changes and growth failure due to chronic biliary stasis during its progression to frank cirrhosis.

Amino Acids↗

Gastric bezoar after hepatic transplantation.

A gastric bezoar complicated the postoperative course of three children following successful hepatic transplantation. Two patients had evidence of extremely erratic absorption of the cyclosporine (CSA) used for immunosuppression. Gastric bezoars usually occur in patients with gastric dysmotility and/or patients ingesting poorly digestible material. Although several factors may contribute to bezoar formation after hepatic transplantation, a major predisposing factor may be the administration of the large quantities of olive oil required for solubilization of CSA.

Bezoars↗

Aplastic anemia complicating orthotopic liver transplantation for non-A, non-B hepatitis.

Aplastic anemia developed in 9 of 32 patients (28 percent) undergoing orthotopic liver transplantation for acute non-A, non-B hepatitis, at one to seven weeks after the procedure. No patient previously had evidence of hematologic dysfunction or conditions known to be associated with aplastic anemia. No other cases of aplastic anemia were identified among 1463 patients undergoing liver transplantation for all other indications at the four centers participating in the study (chi-square = 415, P less than 0.001; 95 percent confidence interval for the incidence of aplastic anemia after transplantation for non-A, non-B hepatitis, 13 to 44 percent, vs. 0.00 to 0.13 percent for all other indications). The operative and postoperative treatment of these patients was not otherwise different, indicating that the aplastic anemia was a complication of the hepatitis, not of the transplantation procedure. Four of the nine patients died of complications due to infections. Three of the surviving patients have been followed for less than six months, one for one year, and one for two years. The two patients followed the longest have recovered marrow function to an appreciable degree, and two of the others have evidence of early recovery. We conclude that patients undergoing orthotopic liver transplantation for non-A, non-B hepatitis are at a high risk for the development of aplastic anemia.

Adolescent↗