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R J Sokol

Publications and source records attributed to R J Sokol.

At least 55 records · Page 3Linked to original sources
PubMed1999

Determining the human origin of fragments of burnt bone: a comparative study of histological, immunological and DNA techniques.

In situations where badly burnt fragments of bone are found, identification of their human or non-human origin may be impossible by gross morphology alone and other techniques have to be employed. In order to determine whether histological methods were redundant and should be superseded by biomolecular analyses, small fragments of artificially burnt bone (human and non-human) were examined by quantitative and standard light microscopy, and the findings compared with newer biomolecular analyses based on identifying specific human albumin by ELISA and amplifying human mitochondrial DNA by PCR. For quantitative microscopy, reference data were first created using burnt bones from 15 human and 20 common domestic and farm animals. Measured osteon and Haversian canal parameters were analysed using multivariate statistical methods. Highly significant differences were found between values for human and non-human bone, and a canonical discriminant function equation was derived, giving a predicted correct classification of 79%. For the main study, samples of cortical bone were taken from three fresh cadavers, six human skeletons and ten freshly slaughtered animals and burnt by exposure to temperatures ranging from 800 to 1200 degrees C; charred fragments of human cortical bone from two forensic cases were also tested. Quantitative microscopy and canonical discriminant function gave the correct origin of every sample. Standard microscopy falsely assigned burnt bone from one human skeleton and one forensic case to a non-human source, but otherwise gave correct results. Human albumin was identified in five individuals, including one of the forensic cases, but mitochondrial DNA could not be amplified from any of the human bone. No false positive test results were seen with either biomolecular method; and human albumin and mitochondrial DNA were correctly identified in all unburnt control specimens. It was concluded that histological methods were not redundant and that quantitative microscopy provided an accurate and consistent means of determining the human or non-human origin of burnt bone and was more reliable than standard microscopy or the newer immunological and DNA techniques tested here.

Animals↗
PubMed1999

Correction of hypozincemia following liver transplantation in children is associated with reduced urinary zinc loss.

Zinc deficiency is a relatively common problem in children with chronic liver disease. We have previously shown inappropriate urinary zinc excretion in children with chronic liver disease and hypozincemia. This study was designed to determine if zinc deficiency and inappropriate urinary zinc losses are corrected in children with liver disease by liver transplantation. Thirty-three patients (age 1-19 years) underwent 35 liver transplants for acute and chronic liver disease. At the time of transplant, 17 patients had low plasma zinc (hypozincemic) (plasma zinc, 45.4 +/- 1.8 microg/dL), whereas 18 had normal plasma zinc (75.7 +/- 3.8). Before transplant, patients with zinc deficiency had higher urinary zinc to creatinine ratio compared with those with normal zinc status (6.6 +/- 1.9 vs. 2.2 +/- 0.6; P =.03) and lower serum albumin concentrations (low: 2.8 +/- 0.1 vs. normal: 3.3 +/- 0.2; P =.02). After transplant, there was a significant reduction in urinary zinc losses in the hypozincemic group followed by normalization of plasma zinc levels by 7 days posttransplant. These data suggest that the abnormal renal zinc homeostasis that is present in approximately 50% of pediatric patients undergoing liver transplant is rapidly improved and biochemical zinc deficiency is reversed after liver transplantation.

Acute Disease↗
PubMed1999

Prospective, long-term study of fat-soluble vitamin status in children with cystic fibrosis identified by newborn screen.

OBJECTIVE: To prospectively evaluate the biochemical status of vitamins A, D, and E in children with cystic fibrosis (CF). SUBJECTS: A total of 127 infants identified by the Colorado CF newborn screening program. DESIGN: Vitamin status (serum retinol, 25-hydroxy vitamin D, ratio of alpha-tocopherol/total lipids) and serum albumin were assessed at diagnosis (4 to 8 weeks), ages 6 months, 12 months, and yearly thereafter, to age 10 years. RESULTS: Deficiency of 1 or more vitamins was present in 44 (45.8%) of 96 patients at age 4 to 8 weeks as follows: vitamin A 29.0%, vitamin D 22.5%, and vitamin E 22.8%. Of these patients with initial deficiency, the percent that was deficient at 1 or more subsequent time points, despite supplementation, was vitamin A 11.1%, vitamin D 12.5%, and vitamin E 57.1%. Of the initial patients with vitamin sufficiency, the percent who became deficient at any time during the 10-year period was as follows: vitamin A 4.5%, vitamin D 14.4%, and vitamin E 11.8%. The percent of patients deficient for 1 or more vitamins ranged from 4% to 45% for any given year. CONCLUSIONS: Despite supplementation with standard multivitamins and pancreatic enzymes, the sporadic occurrence of fat-soluble vitamin deficiency and persistent deficiency is relatively common. Frequent and serial monitoring of the serum concentrations of these vitamins is therefore essential in children with CF.

Child↗
PubMed1999

Liver disease in Navajo neuropathy.

OBJECTIVE: To describe clinical and histologic features of liver disease in infants and children with Navajo neuropathy (NN). METHODS: Physicians at Navajo Area Indian Health Service facilities and neurologists and gastroenterologists at regional referral hospitals were surveyed for identification of patients born between 1980 and 1994 with known or suspected NN. Clinical records and liver histologic findings were reviewed. RESULTS: Liver disease was present in all children with NN. Three clinical phenotypes of NN were observed, based on age at presentation and course: infantile NN presented in 5 infants before 6 months of age with jaundice and failure to thrive and progressed to liver failure before 2 years of age; childhood NN presented in 6 children between 1 and 5 years of age with liver dysfunction, which progressed to liver failure and death within 6 months; and classical NN presented in 9 children with variable onset of liver disease but progressive neurologic deterioration. Liver histologic findings were characterized by multinucleate giant cells, macrovesicular and microvesicular steatosis, pseudo-acini, inflammation, cholestasis, and bridging fibrosis and cirrhosis. Cases of all 3 phenotypes occurred within the same kindred. CONCLUSIONS: Liver disease is an important component of NN and may be the predominant feature in infants and young children. We propose changing the name of this disease to Navajo neurohepatopathy.

Age of Onset↗
PubMed1999

Mitochondria and childhood liver diseases.

The newly recognized mitochondrial hepatopathies should be considered in the differential diagnosis of acute and chronic liver disease in childhood. It may appear as neonatal liver failure, delayed onset liver failure in early childhood or as a multisystemic process. Comparison of features of several of the known primary mitochondrial hepatopathies is provided in Table 5. Secondary mitochondrial hepatopathies are examples of the critical importance of mitochondrial function in the pathogenesis of liver injury. Our improved understanding of the role of the mitochondria in cellular necrosis and apoptosis opens the way for development of new therapeutic approaches to several hepatic disorders. Primary mitochondrial hepatopathies (especially the respiratory chain defects) should be considered in any child with liver disease and neuromuscular involvement, multisystemic disease, lactic acidosis or rapidly progressive disease, and when hepatic steatosis is the dominant histologic finding on examination of a liver specimen. Current therapies are inadequate; improved therapeutic strategies are needed for these disorders. Some patients with respiratory chain defects limited to the liver have had successful liver transplantation. This field is in evolution and will undoubtedly provide new and important developments as the next millennium begins.

Child↗
PubMed1999

Use of rifampin for severe pruritus in children with chronic cholestasis.

BACKGROUND: Rifampin has been proposed to reduce pruritus in children and adults with chronic cholestasis; however, there is a paucity of published data regarding the use of rifampin in children. METHODS: In an open trial, 24 children were evaluated during a 6-year period. Diagnoses included 13 patients with extrahepatic biliary atresia (54%), six with Alagille's syndrome, three with Byler's disease, and one each with primary sclerosing cholangitis and alpha1-antitrypsin deficiency. All patients had severe pruritus that had not responded adequately to at least 2 months of therapy with ursodeoxycholic acid, diphenhydramine, or phenobarbital and local skin care measures. Treatment was initiated with rifampin, 10 mg/kg per day in two divided doses for 18+/-20 months, and the effect on the severity of pruritus was assessed by a clinical scoring system. RESULTS: Ten patients showed a complete response, 12 a partial response, and 2 no response. Complete response was more common in extrahepatic cholestasis (64% vs. 10%), whereas partial response was more common in intrahepatic cholestasis (80% vs. 29%). Treatment was associated with reduction of gamma-glutamyl transpeptidase. No clinical or biochemical toxicity of rifampin was observed. CONCLUSIONS: We conclude that for more than 90% of children with chronic cholestasis and severe pruritus unresponsive to other treatments, rifampin appears to be a safe and effective therapy.

Adolescent↗
PubMed1999

Prevalence of HIV and hepatitis C markers among a cadaver population in Milan.

AIMS: To examine the distribution of serological markers for HIV and hepatitis C virus (HCV) infection in a medicolegal population; to compare prevalence of HIV and HCV markers and cause of death; and to evaluate the risk of potential infection to personnel involved in medicolegal incidents and procedures. METHODS: Blood samples were collected at necropsy from 328 males and 69 females, aged 16 to 50 years at time of death, and tested for antibodies to HIV and HCV. The individuals were classified according to cause of death and whether there was known antemortem risk of infection. RESULTS: Overall, 134 subjects gave positive test results: 20 for anti-HIV, 69 for anti-HCV, and 45 for both. By cause of death, the total number of positives (and negatives) with the pairs of figures referring, respectively, to patients with and without known antemortem risks were: natural causes 3 (1), 8 (32); AIDS 2 (0), 0 (0); homicide 0 (2), 5 (24); suicide 3 (0), 9 (69); road traffic accidents 1 (0), 9 (81); other accidents 2 (3), 1 (12); drug overdose 74 (17), 7 (9); unknown causes 3 (2), 7 (11). CONCLUSIONS: The cases tested represented a predominantly young male population with a high prevalence of serological markers for HIV and HCV infection. The distribution of HIV and HCV positivity varied with the cause of death, probably reflecting the known association between high risk behaviour and infection. However, a substantial number of cases with no known risks also had markers for HIV and HCV, suggesting that there is a large unrecognised pool of potential infection in medicolegal practice.

Adolescent↗
PubMed1999

Paroxysmal cold haemoglobinuria caused by non-Hodgkin's lymphoma.

Paroxysmal cold haemoglobinuria is an autoimmune haemolytic anaemia characterized by a biphasic polyclonal IgG autoantibody, the Donath-Landsteiner (D-L) antibody. Although classically described in association with chronic syphilis, it is most commonly seen after acute viral infections in children. We describe a case of high-grade B-cell non-Hodgkin's lymphoma which presented with paroxysmal cold haemoglobinuria. The lymphoma responded promptly to combination chemotherapy whilst, at the same time, the haemolytic process rapidly resolved. Subsequent investigations showed that the D-L antibody originated from the lymphoma cells.

Aged↗
PubMed1998

Identification of a new inborn error in bile acid synthesis: mutation of the oxysterol 7alpha-hydroxylase gene causes severe neonatal liver disease.

We describe a metabolic defect in bile acid synthesis involving a deficiency in 7alpha-hydroxylation due to a mutation in the gene for the microsomal oxysterol 7alpha-hydroxylase enzyme, active in the acidic pathway for bile acid synthesis. The defect, identified in a 10-wk-old boy presenting with severe cholestasis, cirrhosis, and liver synthetic failure, was established by fast atom bombardment ionization-mass spectrometry, which revealed elevated urinary bile acid excretion, a mass spectrum with intense ions at m/z 453 and m/z 510 corresponding to sulfate and glycosulfate conjugates of unsaturated monohydroxy-cholenoic acids, and an absence of primary bile acids. Gas chromatography-mass spectrometric analysis confirmed the major products of hepatic synthesis to be 3beta-hydroxy-5-cholenoic and 3beta-hydroxy-5-cholestenoic acids, which accounted for 96% of the total serum bile acids. Levels of 27-hydroxycholesterol were > 4,500 times normal. The biochemical findings were consistent with a deficiency in 7alpha-hydroxylation, leading to the accumulation of hepatotoxic unsaturated monohydroxy bile acids. Hepatic microsomal oxysterol 7alpha-hydroxylase activity was undetectable in the patient. Gene analysis revealed a cytosine to thymidine transition mutation in exon 5 that converts an arginine codon at position 388 to a stop codon. The truncated protein was inactive when expressed in 293 cells. These findings indicate the quantitative importance of the acidic pathway in early life in humans and define a further inborn error in bile acid synthesis as a metabolic cause of severe cholestatic liver disease.

Amino Acid Sequence↗
PubMed1998

Detection of reovirus RNA in hepatobiliary tissues from patients with extrahepatic biliary atresia and choledochal cysts.

Extrahepatic biliary atresia (EHBA) and choledochal cysts (CDC) are important causes of obstructive jaundice in pediatric patients. Viruses in general, and reoviruses in particular, have long been considered as possible etiologic agents responsible for inciting the inflammatory process that leads to these infantile obstructive cholangiopathies. In an effort to determine whether reovirus infection is associated with these disorders, we used a sensitive and specific reverse-transcriptase polymerase chain reaction (RT-PCR) technique designed to amplify a portion of the reovirus L1 gene segment from extracts of liver and/or biliary tissues. These tissues were obtained at the time of liver biopsy or surgical procedures from 23 patients with EHBA, 9 patients with CDC, and 33 patients with other hepatobiliary diseases. Hepatic and biliary tissues obtained at autopsy from 17 patients who died without known liver or biliary disease were also analyzed. Reovirus RNA was detected in hepatic and/or biliary tissues from 55% of patients with EHBA and 78% of patients with CDC. Reovirus RNA was found also in extracts of hepatic and/or biliary tissue from 21% of patients with other hepatobiliary diseases and in 12% of autopsy cases. The prevalence of reovirus RNA in tissues from patients with EHBA and CDC was significantly greater than that in patients with other hepatobiliary diseases (chi2 P = .012 EHBA vs. OTHER, P = .001 CDC vs. OTHER), or AUTOPSY cases (chi2 P = .006 EHBA vs. AUTOPSY, P < .001 CDC vs. AUTOPSY).

Biliary Atresia↗
PubMed1998

Fulminant Epstein-Barr viral hepatitis: orthotopic liver transplantation and review of the literature.

Acute hepatic failure caused by primary Epstein-Barr virus (EBV) infection has been reported in the literature in 16 cases, with an overall mortality of 87%. We report a case of fulminant hepatic failure in an immunocompetent young girl caused by primary EBV infection that was treated by orthotopic liver transplantation. After transplantation she has been treated with low-dose immunosuppression, a pooled gammaglobulin preparation containing anti-EBV antibodies, and anti-viral therapy. The patient is presently doing well 2 years after transplantation without evidence of clinical EBV infection, primary immunodeficiency, or lymphoproliferative disease.

Antiviral Agents↗
PubMed1998

Variability of biochemical and clinical phenotype in X-linked liver glycogenosis with mutations in the phosphorylase kinase PHKA2 gene.

X-linked liver glycogenosis (XLG) resulting from phosphorylase kinase (Phk) deficiency is one of the most common forms of glycogen storage disease. It is caused by mutations in the gene encoding the liver isoform of the Phk alpha subunit (PHKA2). In the present study, we address the issue of phenotypic and allelic heterogeneity in XLG. We have identified mutations in seven male patients. One of these patients represents the variant biochemical phenotype, XLG subtype 2 (XLG2), where Phk activity is low in liver but normal or even elevated in erythrocytes. He carries a K189E missense mutation, which adds to the emerging evidence that XLG2 is associated with missense mutations clustering at a few sites. Two patients display clinical phenotypes unusual for liver Phk deficiency, with dysfunction of the kidneys (proximal renal tubular acidosis) or of the nervous system (seizures, delayed cognitive and speech abilities, peripheral sensory neuropathy), respectively, in addition to liver glycogenosis. In the patient with kidney involvement, we have identified a missense mutation (P399S) and a trinucleotide deletion (2858del3) leading to the replacement of two amino acids by one new residue (N953/L954I), and a missense mutation has also been found in the patient with neurological symptoms (G1207W). These two cases demonstrate that PHKA2 mutations can also be associated with uncommon clinical phenotypes. Finally, in four typical XLG cases, we have identified three truncating mutations (70insT, R352X, 567del22) and an in-frame deletion of eight well-conserved amino acids (2452del24). Together, this study adds eight new mutations to the previously known complement of sixteen PHKA2 mutations. All known PHKA2 mutations but one are distinct, indicating pronounced allelic heterogeneity of X-linked liver glycogenosis with mutations in the PHKA2 gene.

Amino Acid Sequence↗
PubMed1998

Vitamin E reduces oxidant injury to mitochondria and the hepatotoxicity of taurochenodeoxycholic acid in the rat.

BACKGROUND & AIMS: Hydrophobic bile acids have been implicated in the pathogenesis of cholestatic liver injury. The hypothesis that hydrophobic bile acid toxicity is mediated by oxidant stress in an in vivo rat model was tested in this study. METHODS: A dose-response study of bolus intravenous (i.v.) taurochenodeoxycholic acid (TCDC) in rats was conducted. Rats were then pretreated with parenteral alpha-tocopherol, and its effect on i.v. TCDC toxicity was evaluated by liver blood tests and by assessing mitochondrial lipid peroxidation. RESULTS: Four hours after an i.v. bolus of TCDC (10 mumol/100 g weight), serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels peaked, hepatic mitochondria showed evidence of increased lipid peroxidation, and serum bile acid analysis was consistent with a cholestatic injury. Liver histology at 4 hours showed hepatocellular necrosis and swelling and mild portal tract inflammation. Treatment with parenteral alpha-tocopherol was associated with a 60%-70% reduction in AST and ALT levels, improved histology, and a 60% reduction in mitochondrial lipid peroxidation in rats receiving TCDC. CONCLUSIONS: These data show that hepatocyte injury and oxidant damage to mitochondria caused by i.v. TCDC can be significantly reduced by pretreatment with the antioxidant vitamin E. These in vivo findings support the role for oxidant stress in the pathogenesis of bile acid hepatic toxicity.

Animals↗
PubMed1998

The effect of idebenone, a coenzyme Q analogue, on hydrophobic bile acid toxicity to isolated rat hepatocytes and hepatic mitochondria.

Oxidant stress induced by hydrophobic bile acids has been implicated in the pathogenesis of liver injury in cholestatic liver disorders. We evaluated the effect of idebenone, a coenzyme Q analogue, on taurochenodeoxycholic acid (TCDC)-induced cell injury and oxidant stress in isolated rat hepatocytes and on glycochenodeoxycholic acid (GCDC)-induced generation of hydroperoxides in fresh hepatic mitochondria. Isolated rat hepatocytes in suspension under 9% oxygen atmosphere were preincubated with 0, 50, and 100 micromol/l idebenone for 30 min and then exposed to 1000 micromol/l TCDC for 4 h. LDH release (cell injury) and thiobarbituric acid reactive substances (measure of lipid peroxidation) increased after TCDC exposure but were markedly suppressed by idebenone pretreatment. In a second set of experiments, the addition of 100 micromol/l idebenone up to 3 h after hepatocytes were exposed to 1000 micromol/l TCDC resulted in abrogation of subsequent cell injury and markedly reduced oxidant damage to hepatocytes. Chenodeoxycholic acid concentrations increased to 5.15 nmol/10(6) cells after 2 h and to 7.05 after 4 h of incubation of hepatocytes with 1000 micromol/l TCDC, and did not differ in the presence of idebenone. In freshly isolated rat hepatic mitochondria, when respiration was stimulated by succinate, 10 micromol/l idebenone abrogated the generation of hydroperoxides during a 90-minute exposure to 400 micromol/l GCDC. These data demonstrate that idebenone functions as a potent protective hepatocyte antioxidant during hydrophobic bile acid toxicity, perhaps by reducing generation of oxygen free radicals in mitochondria.

Animals↗