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Biomedical subjects

D K Freese

Publications and source records attributed to D K Freese.

29 records · Page 2Linked to original sources
PubMed1987

Direct hyperbilirubinemia and hepatic fibrosis: a new presentation of Jeune syndrome (asphyxiating thoracic dystrophy).

Jeune syndrome (asphyxiating thoracic dystrophy) is an autosomal recessive skeletal dysplasia with multisystem involvement. The disorder is usually considered lethal, with death resulting from respiratory insufficiency during infancy, or from renal failure during childhood. Hepatic dysfunction, diagnosed on the basis of direct hyperbilirubinemia and hepatic fibrosis, led to early diagnosis of Jeune syndrome in a newborn infant. Review of the literature indicates that the specific pathologic lesion (biliary dysgenesis with portal fibrosis and bile duct proliferation) has been observed as an incidental finding at autopsy, but that clinically significant liver dysfunction has not been appreciated as an important manifestation in this disorder. The characteristic histopathologic abnormality has been present in every patient studied, and may advance during infancy; in contrast, clinical liver dysfunction resolves over the first few months of life. Whereas many patients with Jeune syndrome die early, several have survived into adolescence, suggesting that aggressive treatment is appropriate, especially for those with minimal respiratory and renal involvement. Longitudinal evaluation of liver function and pathology in these survivors is needed to define the long-term prognosis.

Asphyxia Neonatorum↗
PubMed1987

Contribution of extrahepatic tissues to biochemical abnormalities in hereditary tyrosinemia type I: study of three patients after liver transplantation.

Three patients with hereditary tyrosinemia type I were examined before and after liver transplantation to assess the role of extrahepatic tissues in the biochemical disorders of this disease. Before transplantation the three patients excreted excessive amounts of succinylacetoacetate (SAA), succinylacetone (SA), tyrosyl acidic compounds, and 5-aminolevulinate (ALA). The activity of 5-aminolevulinate dehydratase (ALA-D) in red blood cells was markedly inhibited (1% to 5% of control) in the three patients. Successful liver transplantation resulted in decreased excretion of urinary SAA plus SA, tyrosyl acidic compounds, and ALA. Two of the patients continued to excrete significant amounts of SAA plus SA, whereas those compounds were undetectable in the urine of the third patient. Tyrosine loading resulted in increased excretion of SAA plus SA in two patients, but those compounds remained undetectable in the third. All three patients continued to excrete higher than normal amounts of ALA, but the activity of ALA-D in red blood cells returned to normal after transplantation, indicating marked clearance of SA from the blood. Liver transplantation may not totally correct the biochemical abnormalities of hereditary tyrosinemia. It is likely that the kidney is the source of persistent biochemical aberrations in the urine without significant effects on the blood. Our results suggest the existence of heterogeneity for renal involvement in hereditary tyrosinemia.

Acetoacetates↗
PubMed1987

Liver allograft rejection. An analysis of the use of biopsy in determining outcome of rejection.

Two-hundred-seventy biopsy specimens from 47 patients undergoing liver transplants at the University of Minnesota were analyzed to determine if histological features could predict the eventual outcome of rejection episodes. Thirty-six patients (76.6%) rejected the transplant. Of these, five either suffered acute liver failure due to rejection (two cases) or developed chronic rejection (three cases). Features of significance in predicting such a bad outcome were arteritis, bile duct paucity, or simultaneous hepatocellular ballooning and hepatocellular dropout and necrosis. Other features, such as type and intensity of infiltrate, degree of bile duct damage, or simple presence of hepatocellular necrosis, were not predictive of outcome. Our conclusion is that biopsy is useful in predicting outcome. Since many of the histologic findings of predictive value were not present in initial pretreatment biopsy specimens, follow-up biopsies of patients being treated for rejection are recommended to assess efficacy of therapy.

Adolescent↗
PubMed1985

Persistent succinylacetone excretion after liver transplantation in a patient with hereditary tyrosinaemia type I.

A liver transplant was performed on a 4-year-old female in liver failure caused by hereditary tyrosinaemia, with hepatocellular carcinoma following a negative evaluation for metastases. However, serum alpha-fetoprotein levels never returned to normal after the surgery. Urinary succinylacetone (SA) was detected in her urine prior to transplantation despite strict adherence to a low-tyrosine diet. Other patients with severe liver disease awaiting liver transplantation do not excrete SA in the urine. She continued to excrete SA during the postoperative period despite normal liver functions. Oral tyrosine loading resulted in significant elevation of SA excretion. Possible explanations for this observation and clinical and therapeutic relevance are discussed.

Carcinoma, Hepatocellular↗
PubMed1983

Disposition of sodium benzoate in newborn infants with hyperammonemia.

Sodium benzoate lowers serum ammonia concentrations by the activation of a non-urea cycle pathway of ammonia removal. The disposition of sodium benzoate was monitored in four hyperammonemic newborn infants, using a simple and newly developed assay for benzoate and hippurate, to assess (1) the metabolic capability of patients of this age to utilize this pathway for nitrogen removal, (2) the potential risks of benzoate toxicity at clinically achieved serum benzoate concentrations, and (3) the value of routine monitoring of serum benzoate concentrations in this patient population. In three of the four infants, more than half of the administered benzoate was converted to hippurate. Hippurate was effectively cleared by the neonatal kidney, although removal of unconjugated benzoate by peritoneal dialysis or urinary excretion was slow compared with the metabolic conversion to hippurate. There was a considerable interpatient variability in benzoate metabolism; consequently, an eight-fold range in serum benzoate concentrations (2.14 to 16.0 mM/L) was found after patients had received benzoate for longer than 24 hours. These serum benzoate concentrations were calculated to be capable of producing substantial (four to 25 times) increases in free bilirubin concentrations in jaundiced infants. Although sodium benzoate offers considerable promise for the treatment of hyperammonemia, toxicity appears likely in some infants receiving this drug in currently recommended doses. Monitoring of serum concentrations appears to be warranted. Dosage reduction in jaundiced infants and in those with demonstrated insufficiency of benzoate metabolism is recommended.

Ammonia↗
PubMed1983

Neonatal cholestatic syndromes associated with alterations in bile acid synthesis.

In summary, the conditions discussed above are examples of diseases that result in deficient bile acid synthesis and production of abnormal bile acids. Although the relationship between the production of these abnormal bile acids and the pathogenesis of these diseases remains unknown, they continue to provide us with a better understanding of normal pathways of bile acid production. Clearly, more studies are needed before these interesting metabolic defects and normal infantile bile acid metabolism itself are well understood.

Abnormalities, Multiple↗
PubMedDate not supplied

Orthotopic liver transplantation: a pathological study of 63 serial liver biopsies from 17 patients with special reference to the diagnostic features and natural history of rejection.

The histopathological features of orthotopic liver transplants were evaluated in 63 serial biopsy specimens from 17 patients. Biopsies were taken at the time of insertion of the liver (six biopsies), at the time of development of liver function abnormalities (11 biopsies) and as follow-up to previously abnormal biopsies (46 biopsies). The biopsies taken at the time of insertion all showed diffuse hepatocellular ballooning with confluent areas of necrosis in one case. Biopsies taken at the time of onset of rejection (nine cases) all showed a mixed portal inflammatory infiltrate, bile duct damage and central or portal vein endothelialitis (i.e., attachment of lymphocytes to the vein endothelium). Follow-up biopsies showed several patterns including: (i) resolution of changes of acute rejection with subsequent development of recurrent acute or chronic rejection (four cases); (ii) prolonged acute rejection simulating extrahepatic biliary obstruction (four cases); (iii) prolonged acute rejection with predominance of eosinophils simulating a drug reaction (one case); and (iv) rapidly progressive acute rejection leading to death (one case). Biopsy of the transplanted liver at the time of transplantation is useful to provide a baseline for comparison with later biopsies. Biopsy at the time of onset of changes in liver function is essential to confirm the presence of rejection prior to alteration of immunosuppression.

Adolescent↗
PubMedDate not supplied

Amino acid abnormalities in infants with extrahepatic biliary atresia and cirrhosis.

We measured fasting plasma amino acids in 26 children aged 6 months to 5 years with extrahepatic biliary atresia and cirrhosis and compared them with fasting values in 95 normal control children aged 4 months to 12 years. We found that the cirrhotic children had elevations of total free plasma amino acids implying reduced hepatic metabolism of amino acids and that the molar ratio of the branched chain amino acids (isoleucine, leucine, and valine) to the aromatic amino acids (phenylalanine and tyrosine) was significantly depressed. Methionine was also markedly elevated, and taurine concentrations were significantly decreased. Manipulation of the amino acid distribution in dietary protein to normalize plasma amino acids prior to orthotopic hepatic transplantation may be helpful in improving amino acid utilization.

Amino Acids↗
PubMedDate not supplied

A new hepato-pancreato-renal disorder resembling tyrosinemia involving neuropathy and abnormal metabolism of polyunsaturated acids.

This report describes a new disorder resembling hereditary tyrosinemia (HT) but differing from it in several respects. Similarities include failure to thrive with hypoproteinemia, micronodular cirrhosis, alpha-fetoprotein positive hepatocellular carcinoma, renal Fanconi syndrome with renal tubular ectasia, hypermethioninemia, and hypoglycemia associated with islet cell hyperplasia. However, the tyrosine metabolic pathway was intact. Unique findings include optic atrophy, cerebellar degeneration, and exocrine pancreatic hypoplasia. Polyunsaturated fatty acid (PUFA) status was evaluated in the serum and liver. Initial PUFA profile to serum phospholipids revealed grossly elevated linoleic acid and subnormal linolenic acid. All PUFAs derived from these precursors were absent suggesting gross abnormalities in the utilization of these two essential fatty acids for synthesis of longer chain highly unsaturated structural PUFA. Analysis of liver phospholipids indicated that linoleic acid was lower and w3 and monenoic acids were higher than in the liver specimens from two cases of HT. The gross abnormalities in PUFA pattern, although perhaps secondary to another cause, represent serious structural and functional abnormalities of essential membrane lipids and potentially of eicosanoids derived from them.

Amino Acid Metabolism, Inborn Errors↗