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K B Schwarz

Publications and source records attributed to K B Schwarz.

At least 19 recordsLinked to original sources
PubMed2002

Two siblings with a new Aicardi-Goutières-like syndrome.

We present two siblings (male and female) with very similar characteristics comprising dysmorphic features, severe developmental delay, progressive microcephaly, tonic seizures, and hypothyroidism. The male also had micropenis and cryptorchidism. Both children developed pericardial effusions which caused the death of the female at age 16 months. The male's cardiac function was stable at last follow-up at the age of 15 months. Cerebral imaging showed widespread intracranial calcifications, delay in myelination, hypoplasia of the corpus callosum, and cerebral atrophy. CSF examination showed normal CSF white-cell count and was negative for interferon, although a cytotoxic antibody was thought to be present. Other causes of a neurodegenerative condition and congenital infection were excluded. The combination of these features has not been described before. We believe that these patients represent a new syndrome which has some of the features of Aicardi-Goutières syndrome but is distinct from it.

Abnormalities, Multiple↗
PubMed2001

Increased hepatic oxidative DNA damage in patients with hepatocellular carcinoma.

Since oxidative DNA damage plays a role in experimental carcinogen-induced cancers, the purpose of the present study was to determine if hepatic oxidative DNA damage was increased in patients with HCC compared to patients with benign hepatic tumors or hepatic metastases (non-HCC) or to patients with end-stage alcoholic liver disease undergoing liver transplantation. Oxidative DNA damage was assessed by 8-hydroxy-2'-deoxyguanosine (8-OH-dG). Results showed that peritumoral 8-OH-dG was markedly increased in HCC (N= 51) (180 +/- 74 vs 32 +/- 58-OH-dG/10(6)dG for tumor, P < 0.005) in contrast to patients with non-HCC (N = 17), in whom the peritumoral 8-OH-dG did not differ from that in tumor (39 +/- 7 vs. 31 +/- 108-OH-dG/10(6)dG). Oxidative DNA damage can be both mutagenic and carcinogenic; our data suggested it will be important in future studies to determine the chronology of this type of liver injury relative to hepatocarcinogenesis.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed1999

Utility of liver biopsy culture in pediatric liver transplant recipients.

The purpose of our study was to determine the utility of the practice of culturing percutaneous liver biopsy specimens obtained from pediatric LT recipients for evaluation of fever and/or elevated serum aminotransferases. Accordingly, a retrospective analysis was done of the 101 liver biopsies obtained during an eight-year period which had been submitted for bacterial, fungal and/or viral culture (out of a total of 174 biopsies in 38 patients). The purpose of the analysis was to ask three questions. (1) What organisms were cultured? (2) Were there clinical profiles that were characteristic of the type of organism? (3) Was the practice cost-effective? The analysis indicated that 34/86 biopsy cultures were positive for bacteria, 4/75 for fungus and 2/81 for virus. Clinical and laboratory data for children with cultures positive for enteric flora (n = 9) were compared to those with cultures positive for Gram-positive organisms (n = 17), laboratory contaminants (n = 8), and those with negative cultures (n = 52). Children with biopsies positive for enteric flora had a 'cholestatic profile': mean direct bilirubin 7 mg/dl, ALT 78 IU/l, direct bilirubin/ALT 0.09, in comparison to children with biopsies positive for Gram-positive flora. These children had a 'hepatocellular profile': mean direct bilirubin 4 mg/dl, ALT 332 IU/l, direct bilirubin/ALT 0.01 (p = 0.04 versus the enteric flora values) and a high percentage of polymorphonuclear leukocytes (mean 69% versus 38% for those with negative cultures, p = 0.001.) The charge for performing each bacterial culture was $28 (total $28 x 86 = $2408: $268 per enteric flora-positive biopsy; $93 per biopsy positive for either enteric flora or Gram-positive flora). The charge for each fungal culture was also $28 (total $28 x 75 = $2100: $525 per positive culture), while the cost for each viral culture was $140 (total $140 x 81 = $11,340: $5670 per positive culture). Thus, discounting the eight cultures positive for laboratory contaminants, a total of $15,848 was spent for 32 positive cultures. Given the high cost of liver transplantation, this information suggests that discretion should be used in submission of liver biopsy samples for culture in pediatric transplant patients. We recommend that when liver biopsies are performed for evaluation of elevated serum aminotransferases and/or fever, culture of biopsy specimens for bacteria should be considered in children with a 'cholestatic profile': direct bilirubin > or = 7 mg/dl and direct bilirubin/ALT > 0.08, or a 'hepatocellular profile': direct bilirubin < or = 4 mg/dl and direct bilirubin/ALT < 0.05, together with polymorphonuclear leukocytes > 70%. Following these guidelines might provide valuable information pertinent to patient management (especially since Gram-negative organisms can sometimes be cultured from the liver and not from blood) while reducing costs. Fungal cultures should be restricted to critically ill children. However, our data suggest that the practice of obtaining fungal and viral cultures of the liver in most pediatric transplant patients has an unacceptably high cost/benefit ratio, particularly since recovery of the organism from the peripheral blood is likely.

Bacterial Infections↗
PubMed1999

High viral load and mild liver injury in children with hemophilia compared with other children with chronic hepatitis C virus infection.

BACKGROUND: In adults with hepatitis C virus (HCV) infection, the severity of liver disease may be influenced by the mode of transmission. The purpose of this study was to evaluate whether the mode of transmission affects liver injury and viral load in children with chronic HCV infection, independent of duration of infection and/or HCV genotype. METHODS: Thirty-nine anti-HCV (EIA-2) positive patients, were divided into three groups: group 1, children with a history of blood transfusion (n = 9; age, 13.3+/-1.3 years), group 2, children with hemophilia (n = 19; age, 11.6+/-0.8 years); and group 3, children with maternal-fetal transmitted disease (n = 10; age, 4.7+/-1.1 years). Serum alanine aminotransferase, HCV viral load, HCV genotype, and liver histology were assessed. RESULTS: Serum HCV viral load was higher in group 2 (4.27+/-1.0x10(6) copies/ml; p = 0.006) than in group 1 (0.73+/-0.3x10(6) copies/ml) and in group 3 (0.83+/-0.2x10(6) copies/ml). Conversely, group 2 had less severe liver injury compared with children of similar age in group 1 (p = 0.022). Despite a shorter duration of infection, group 3 had liver injury similar to that in group 1. Hepatitis C virus genotype did not influence the level of viremia or liver injury. CONCLUSIONS: Although children with hemophilia exhibited a high HCV viral load, liver histopathology was less severe than in children who had acquired HCV by blood transfusion or maternal-fetal transmission. These observations support the need to investigate the role of host immune response rather than the virus per se in the pathogenesis of HCV infection in children.

Adolescent↗
PubMed1998

Transforming growth factor-beta1 in plasma and liver of children with liver disease.

Although several liver diseases of childhood, particularly biliary atresia (BA) and cystic fibrosis (CF) liver disease (CFLD) are characterized by hepatic fibrosis, the pathogenesis of this process is incompletely understood. The cytokine transforming growth factor-beta1 (TGF-beta1) has been implicated in hepatic fibrosis in experimental animals, in which both the hepatic expression and plasma concentration of this cytokine are increased. The objective of our study was to determine whether there are similar alterations of TGF-beta1 in patients with hepatic fibrosis secondary to either BA and/or CFLD. The study design was as follows. In study 1, plasma TGF-beta1 was assessed by ELISA in 9 children with BA undergoing liver transplantation, 11 patients with CFLD, and appropriate control subjects. In study 2, hepatic expression of TGF-beta1 protein (assessed immunohistochemically) and hepatic fibrosis were scored semiquantitatively, on a 1-3 scale, by blinded investigators, in archival liver biopsy specimens from 10 children with BA, 10 with CFLD, and from 10 older children with normal hepatic histology, as well as in 4 patients with liver diseases of various etiologies. Simultaneous plasma and liver TGF-beta1 studies were performed in 8 patients with liver disease. Results were as follows. Plasma TGF-beta1 values were inversely correlated with age in healthy subjects (r=-0.54, p < 0.0001). The plasma TGF-beta1 protein of children with BA was decreased (13+/-2 ng/mL) compared with values for healthy children (42+/-6 ng/mL, n=10, p < 0.005). Similarly, the plasma TGF-beta1 concentration in patients with CFLD was also decreased compared with values for children with CF and normal serum liver profiles (n=14) (2+/-1 ng/mL versus 12+/-1, p < 0.05). However, the plasma TGF-beta1 concentration was increased in two patients with other types of liver disease. The hepatic expression of TGF-beta1 was increased in the presence of hepatic fibrosis in all types of liver diseases studied. Forty-six percent of patients had both marked hepatic fibrosis and marked TGF-beta1 labeling; 86% of samples without fibrosis showed no TGF-beta1 labeling, p=0.007. In conclusion, these studies have established the association of hepatic TGF-beta1 protein and hepatic fibrosis in several common liver diseases of childhood. Our data also suggest that, in children, plasma TGF-beta1 does not appear to be a useful marker of hepatic expression of this cytokine.

Adult↗
PubMed1997

Hepatic basolateral sodium-dependent-bile acid transporter expression in two unusual cases of hypercholanemia and in extrahepatic biliary atresia.

The recent cloning of a human sodium-dependent bile acid transporter (NTCP) permits analysis of its expression in human liver disease and investigation of potential primary defects in its expression. NTCP from normal human liver (NHL) was first characterized in detail. Northern blotting of RNA from NHL revealed a 1.8-kb NTCP transcript. Western blotting of crude NHL plasma membranes using a carboxyterminal antipeptide antibody showed that NTCP is a 39-kd polypeptide that is N-glycosylated to a final molecular weight of 56 kd. Indirect immunofluorescent analysis of NHL sections indicated that the NTCP protein is expressed on the basolateral surface of hepatocytes. We hypothesized that the clinical phenotype of a defect in NTCP might be hypercholanemia in the relative absence of liver disease. Accordingly, the coding region of the NTCP gene of two children with this phenotype was sequenced after reverse transcription/polymerase chain reaction (RT/PCR) amplification. No primary defects in the deduced NTCP amino acid sequence were found. Despite the extremely high serum bile salt levels (235 and 126 micromol/L) in these two patients, NTCP messenger RNA (mRNA) and protein expression were quantitatively normal, in contrast to the published observations in a rat model of cholestasis secondary to common bile duct ligation. Hepatic steady-state NTCP mRNA levels in a group of 23 pre- and postportoenterostomy biliary atresia patients were inversely related to total bilirubin, indicating that extrahepatic bile duct obstruction leads to down-regulation of NTCP mRNA levels, similar to that observed in rat common bile duct ligation. Therefore the lack of down-regulation in the two patients with hypercholanemia indicates that elevated serum bile salts are not sufficient to down-regulate NTCP expression, these two patients have abnormal responses to hypercholanemia, or these two patients have a defect in a gene other than NTCP that influences hepatic clearance of bile salts.

Animals↗
PubMed1997

Kaposi's sarcoma presenting as a protracted multisystem illness in an adolescent liver transplant recipient.

Kaposi's sarcoma (KS) is a common malignancy in patients with acquired immunodeficiency syndrome (AIDS), classically appearing as red to purple plaques containing small papules and nodules. We report our experience with an adolescent orthotopic liver transplant recipient who presented with an unusual presentation of KS. The patient had a protracted multisystem illness that began with hemolytic anemia, fevers, and fatigue and progressed to pancreatitis, sinusitis, lymphadenopathy, and mouth ulcers. The diagnosis was made by a lymph node biopsy that was performed to evaluate for Epstein-Barr virus. The classical subcutaneous nodules characteristic of KS did not become evident until shortly before the patient died. We present this case to emphasize that KS in pediatric liver transplant patients can present as a multisystem disease that progresses to disseminated organ involvement before the characteristic subcutaneous manifestations are evident.

Adolescent↗
PubMed1997

Nutritional considerations and management of the child with liver disease.

Nutritional management of the infant and child with liver disease is highly dependent upon the type of liver disease. Acute liver disease, such as that secondary to viral hepatitis, requires no specific nutritional therapy with the exception that branched-chain amino acid supplements may be indicated in the management of hepatic encephalopathy. Nutritional management of the child with chronic liver disease depends upon whether or not cholestasis is present, since in that condition, large amounts of fat-soluble vitamin supplements and medium-chain triglycerides are usually required for optimum growth. However, anicteric cirrhotic liver disease also presents nutritional challenges because of hypermetabolism, enteropathy, and increased protein oxidation. Certain inborn errors of metabolism that result in liver disease (including galactosemia, hepatorenal tyrosinemia, hereditary fructose intolerance, and Wilson's disease) have specific nutritional requirements. And, finally, the advent of pediatric liver transplantation has placed new emphasis on the importance of optimum nutritional management of the child with chronic liver disease, since improvement of nutritional status in the pretransplant period maximizes success of the transplant. This review will focus on the pathogenesis of malnutrition in childhood liver disease and will provide recommendations for nutritional assessment and monitoring as well as nutritional management of cholestatic liver disease, anicteric cirrhotic liver disease, and the inborn errors of metabolism enumerated above. Specific recommendations for nutritional management of the child awaiting liver transplantation will be provided.

Child↗
PubMed1997

Prooxidant effects of maternal smoking and formula in newborn infants.

BACKGROUND: The purpose of this study was to use the breath ethane test to determine if either maternal cigarette smoking, formula, and/or deficiency of the antioxidant nutrients vitamins A and E was associated with oxidant stress in newborn infants. The rationale for this study was: (1) our observation that cigarette smoking was a source of oxidant stress in pregnant women, suggesting that it could be a source of oxidant stress for infants exposed in utero; (2) formula was predicted to be prooxidant compared to colostrum, which contains several compounds with antioxidant activity in vitro; and (3) deficiencies of vitamins A and E have been shown to promote oxidant stress in experimental animals. METHODS: Breath ethane, a volatile alkane produced by peroxide of n-3 fatty acids, was utilized as an index of oxidant stress status. Forty-five healthy full-term infants of the women mentioned above were studied at 18-24 h of age, after four to six feedings of breast milk (colostrum) or caseinbased infant formula. Relationships between infant breath ethane, maternal smoking, mode of infant nutrition, and serum concentrations of the antioxidant vitamins A and E of infants were examined. RESULTS: The breath ethane of the entire group of infants whose mothers smoked (n = 19) was increased compared to values of infants whose mothers did not smoke (n = 26): 97 +/- 16 versus 43 +/- 9 pmol/kg/min, p < 0.03. When infants of mothers who smoked were eliminated from the analysis in order to study effects of nutrition alone, formula appeared to be prooxidant compared to breast milk. Breath ethane of formula-fed infants (n = 16) was 62 +/- 13 versus 13 +/- 4 pmol/kg/min for breast-fed infants (n = 10), p < 0.04. For the group as a whole, there was no correlation between infant breath ethane and serum concentrations of vitamins A and E. CONCLUSIONS: Exposure to maternal smoking in utero is prooxidant in newborn infants. Formula also has a prooxidant effect compared to colostrum in newborn infants not exposed to maternal smoking in utero. Further investigations will be necessary to explore the clinical consequences of these observations.

Antioxidants↗
PubMed1997

Possible antioxidant effect of vitamin A supplementation in premature infants.

BACKGROUND: Increased lipid peroxidation caused by oxygen free radicals is thought to be one of the common pathogenetic mechanisms for the so-called oxygen radical diseases of prematurity. Since in vitro studies have shown that various forms of vitamin A can exert antioxidant effects that are more potent than those of vitamin E (treatment with which has been ineffective in these diseases), the purpose of this prospective, controlled study was to determine whether administration of supplemental vitamin A to premature infants deficient in this vitamin would have an antioxidant effect in vivo. METHODS: Fourteen infants (1181 +/- 35 g; gestational age 29 +/- 0.04 weeks) with a serum retinol concentration at 7 +/- 2 days of age in the deficient range, lower than 0.7 mumol/l (< 20 micrograms/dl), were enrolled in the study. Infants were randomized to receive the standard amount of vitamin A or standard plus supplemental (2.6 mumol/l [2500 IU] orally each day) vitamin A, beginning at 1 week of age. Antioxidant effects of supplementation were assessed by a decrease in lipid peroxidation, quantified by the ethane content of expired air. RESULTS: Three weeks after study enrollment, total daily vitamin A intake in the infants receiving supplements was 4.565 +/- 0.236 mumol (4354 +/- 225 IU) versus 1.879 +/- 0.317 mumol/l (1792 +/- 302 IU) in infants receiving standard amounts of the vitamin. In spite of the difference in intake of vitamin A, 3 weeks after study enrollment, serum retinol concentrations did not differ between the infants given supplements and those receiving standard amounts of vitamin A, 0.70 +/- 0.21 versus 0.66 +/- 0.07 mumol/l (20 +/- 6 micrograms/dl versus 19 +/- 2 micrograms/dl, respectively). In the infants receiving supplemental vitamin A, breath ethane values declined from baseline values. There was an inverse correlation between the number of weeks of supplementation and breath ethane values, whereas there was no significant correlation between the duration of the study and breath ethane values in the infants not given supplements. CONCLUSIONS: Our data suggest that supplementation with vitamin A in a small group of vitamin A-deficient preterm infants was associated with an antioxidant effect. Although no immediate clinical benefits were associated with supplementation, the data provide the rationale for future investigations of possible antioxidant effects of (larger amounts?) of vitamin A in higher risk premature infants born with subnormal serum retinol concentrations.

Administration, Oral↗
PubMed1997

Positive MIBG scanning at the time of relapse in neuroblastoma which was MIBG negative at diagnosis.

Metaiodobenzylguanidine (MIBG) labelled with iodine-123 (123I) or 131I has become a well established tool with high sensitivity and specificity in the diagnosis and staging of neuroblastoma in children. However, some neuroblastomas do not take up MIBG at the time of diagnosis. The reasons for this are unclear but may be related to uptake mechanisms. Follow-up MIBG scans have not been reported in these patients. We present a case where an initial 123I-MIBG-scan was negative at diagnosis but became positive when the patient relapsed. This unusual occurrence may have implications for patients with a negative MIBG-scan at presentation. These patients should be re-evaluated by MIBG-scan at the time of relapse as a positive scan then offers the possibility of additional treatment with MIBG therapy.

3-Iodobenzylguanidine↗
PubMed1996

Oxidative stress during viral infection: a review.

The purpose of this review is to analyze the role of reactive oxygen species (ROS) in the pathogenesis of viral infections, an area of research that has recently gained momentum given the accumulation of evidence regarding the role of ROS in the pathogenesis of infection with the human immunodeficiency virus (HIV). Attention will be focussed on three classes of viruses: (1) RNA viruses, (2) DNA viruses, and (3) retroviruses, with particular attention to influenza viruses, hepatitis B virus, and HIV as representative examples of these three classes, respectively. For each type of virus, evidence for the following will be analyzed: (1) the effect of the virus on activation of phagocytic cells to release ROS and pro-oxidant cytokines such as tumor necrosis factor; (2) the effect of the virus on the pro-/antioxidant balance in host cells, including virally induced inhibition of antioxidant enzymes such as superoxide dismutase and virally induced increases in pro-oxidants such as nitric oxide; (3) effects of the redox state of the cell on the genetic composition of the virus as well as ROS-mediated release of host cell nuclear transcription factor-kappa-B, resulting in increased viral replication; and (4) efficacy of antioxidants as therapeutic agents in viral diseases of both animal models and patients.

Animals↗
PubMed1995

Proximal renal tubular acidosis secondary to FK506 in pediatric liver transplant patients.

We hereby report our experience with an index case of a pediatric liver transplant patient in whom FK506 administration was associated with the development of proximal renal tubular acidosis (RTA), as well the prevalence of acidosis and renal dysfunction in all pediatric liver transplant patients in our institution followed long term during a 6-year period. Data were grouped according to immunosuppressant regime: cyclosporine (CsA) only, FK506 only, or CsA with conversion to FK506. A 23-month-old female treated with FK506 after orthotopic liver transplantation (OLT) performed 15 months earlier presented with a 1-wk history of fever, watery diarrhea and metabolic acidosis. Although the acidosis did not improve following correction of her hydration status, administration of oral bicarbonate was effective. Discontinuation of this therapy resulted in acidosis. Since other indirect measurements of renal tubular function were normal, the patient was judged to have an isolated proximal RTA. In our group of pediatric liver transplant patients converted from CsA to FK506, FK506 administration was associated with a decline in serum bicarbonate (19 +/- 1 vs. 16 +/- 1 mEq/l, p < 0.02); neither blood urea nitrogen nor serum creatinine differed between the two groups. The number of rejection episodes/patient/month was comparable, allowing clinically relevant comparison of relative drug nephrotoxicities. We conclude that proximal RTA may be a relatively common treatable complication of FK506 administration in children.

Acidosis, Renal Tubular↗
PubMed1994

Activated THP-1 cells depress mitochondrial respiration in Hep G2 cells infected with influenza B virus.

Influenza B virus has been aetiologically linked to Reye Syndrome (RS), but the mechanism(s) by which this pathogen could disrupt liver metabolism and produce the hepatic mitochondrial injury characteristic of the syndrome are unknown. In this study, two mechanisms by which infection of hepatocytes with influenza B virus could disrupt cellular metabolism were investigated. (1) virus-induced increase in pro-oxidant iron with subsequent iron-induced lipid peroxidation (LP) and (2) increased membrane permeability. Hep G2 cells, a well-differentiated continuous human liver cell line derived from a hepatoblastoma, were infected with allantoic-fluid derived influenza B Lee/40 virus (AFDV) at a multiplicity of infection of 10 for 24 h; productive infection was confirmed by both haemagglutination of chick erythrocytes and by plaque assay. Infection of Hep G2 cells preloaded with 59Fe-transferrin resulted in increased release of 59Fe (153 +/- 17% of controls, P < 0.03). However, the iron released did not result in increased LP (assessed by thiobarituric acid reactive substances; TBARS). To confirm that this lack of of increase in TBARS was not due to insensitivity of the cell line to pro-oxidant iron, cells were exposed to 15 microM iron ascorbate for 60 min. Production of TBARS was increased (122 +/- 4% of controls, P < 0.0003). Release of 51Cr from infected cells was also increased (128 +/- 12% of controls, P < 0.05); thus the infected cells exhibited a generalized increase in membrane permeability. However, infection did not depress mitochondrial respiration (as assessed by the formation of MTT-f3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide-formazan. To determine if the combination of viral infection and soluble products of activated macrophages would affect mitochondrial respiration, infected hepatocytes were exposed to the supernatant fluid from THP-1 cells which had previously been incubated with lipopolysaccharide at 100 ng ml-1 for 18 h. This supernate did depress the formation of MTT-f (81 +/- 5% of controls, P < 0.03). We conclude that influenza B virus does productively infect Hep G2 cells, and does increase hepatocyte membrane permeability. This effect does not impair mitochondrial respiration directly. However, infection does act in concert with soluble products of activated macrophages to depress hepatic mitochondrial respiration. Whether this interaction can be explained by virus-induced permeability changes and/or other effects of infection deserves further investigation.

Animals↗