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Biomedical subjects

O Bernard

Publications and source records attributed to O Bernard.

At least 217 records · Page 12Linked to original sources
PubMed1988

Budd-Chiari syndrome in children: report of 22 cases.

Clinical, radiologic, and histologic features in 22 children with Budd-Chiari syndrome are reported. Three children had acute refractory ascites; all the others had hepatomegaly, which was detected either fortuitously or because of abdominal pain or distention. Results of liver function tests were normal or only moderately abnormal. In most cases a combination of ultrasonography and needle liver biopsy pointed to the diagnosis of Budd-Chiari syndrome, which was confirmed by angiography. Eighteen children underwent surgery involving various techniques, depending on the degree of patency of the inferior vena cava. Five children died postoperatively. Histologic studies of the liver, carried out in 12 of the surviving children, showed disappearance or regression of centrilobular hemorrhagic infiltration. Half of the surviving surgical patients are now free of complications after a follow-up of 7 months to 7 years; the others have either secondary thrombosis of the inferior vena cava or stenosis of the shunt or have experienced late pulmonary complications. Our results suggest that (1) Budd-Chiari syndrome must be considered a possible diagnosis in children with firm hepatomegaly and normal or near normal liver function, (2) surgery provides good results in many instances, and (3) the possibility of late complications requires careful follow-up.

Budd-Chiari Syndrome↗
PubMed1988

Immortalization of mouse neural precursor cells by the c-myc oncogene.

Immortalized cell lines have been generated from embryonic mouse neuroepithelium by infection with a retrovirus containing the c-myc oncogene. The morphology and the antigenic phenotype of the cloned cell lines are characteristic of normal neuroepithelium. Although the cell lines are stable and do not spontaneously differentiate, morphological changes can be induced with both acidic and basic fibroblast growth factor. Fibroblast growth factor at 5 ng/ml stimulates differentiation of the neuroepithelial cells, and it has been shown that the cloned cell line 2.3D can differentiate into astrocytes, containing glial fibrillary acidic protein, and neurons, expressing the A2B5 marker and neurofilaments. This indicates that some cells in the neuroepithelium at embryonic day 10 are multipotent and are not restricted to either the glial or neuronal cell lineage. The cell lines also can be induced with interferon gamma to express class I and class II histocompatibility antigens. The response of the c-myc-immortalized cell lines to these two factors is similar to that observed with freshly isolated neuroepithelium and suggests that such immortalized precursor populations are representative of the cells found in the developing neuroepithelium.

Animals↗
PubMed1988

Short- and long-term vitamin A treatment in children with cholestasis.

Newborns have limited reserve supplies of vitamin A. Infants with chronic cholestasis are in a precarious nutritional state because of their limited ability to build these stores even though the vitamin is present in their diet. In this study, we investigated liver concentrations of vitamin A in 30 children with extrahepatic biliary atresia. We demonstrate that correction of the deficiency occurs after intramuscular administration of a water-miscible solution of retinyl palmitate (100,000 IU, or 30 mg retinol equivalent). Furthermore, we evaluated the effect of vitamin A injections on liver and blood concentrations in nine children with chronic cholestasis over a 1-y period. We conclude this treatment is efficient and is well tolerated.

Biliary Atresia↗
PubMed1988

[Practical aspects of surveillance after hepatic transplantation in children].

From a practical point of view, the care of a child after liver transplantation comprises 3 periods with decreasing severity: -the first one takes place in the intensive care unit: immunosuppression is started with steroids, azathioprine and cyclosporine and four major complications are sought for and treated: primary graft dysfunction, acute rejection, hepatic artery thrombosis and infection; -the second period takes place in conventional hospital settings: cyclosporine is progressively switched from IV to oral; rejection, cytomegalovirus infection and biliary complications are sought for and treated; -the third period takes place at home: the level of immunosuppression is progressively lowered under biochemical supervision; long-term complications (renal and malignancies) are detected.

Bacterial Infections↗
PubMed1988

Molecular mechanisms of a t(8;14)(q24;q11) translocation juxtaposing c-myc and TcR-alpha genes in a T-cell leukaemia: involvement of a V alpha internal heptamer.

We have recently described a t(8;14)(q24;q11) translocation which appeared secondarily in a non-established acute T-cell leukaemia and involved the 3' region of c-myc proto-oncogene and the alpha chain of the T-cell receptor gene (TcR-alpha). In order to elucidate the mechanism of the translocation, we have isolated breakpoint regions from normal and recombinant chromosomes. Our results show that the translocation occurred at the 3' end of a V alpha segment in the proximity of recombination signal sequences (5'-heptamer-23bp spacer-nonamer-3'). Interestingly, an inverted heptamer internal to the V alpha segment was found at two nucleotides 5' of the break. Nucleotide sequence analysis also revealed the presence of homologous signal sequences on chromosome 8, suggesting that the recombination enzymatic system played an important role in the generation of the translocation. This hypothesis is supported by the addition of N nucleotides and the loss of only three nucleotides during the rejoining process. These data established the involvement of a V alpha segment and its recombination signals in the mechanisms of t(8;14) translocations in T-cell leukaemias.

Amino Acid Sequence↗
PubMed1987

Human immunoglobulin variable region genes: a new VH sequence used to detect polymorphism.

A human heavy chain variable region subgroup III pseudogene (HV3.3) was isolated, characterized, and sequenced. When HV3.3 was hybridized to Southern blots of human DNA, two potentially informative polymorphic bands, resulting from 2.7 kb Hind III (HH2.7) and 7.3 kb Eco RI (HE7.3) fragments, were detected with frequencies of 0.553 and 0.606, respectively. These polymorphic bands showed Mendelian segregation in families and appeared to be in tight linkage disequilibrium with each other (chi 2(1) = 24.91, P less than 0.001). Evidence from sibling-pair data indicated linkage of the Hind III polymorphic band to constant region allotypic and restriction fragment length polymorphism markers. Bands representing alternative forms of the polymorphic restriction sites were not detected for either HH2.7 or HE7.3. This indicates either that the alternative fragments comigrate with homologous fragments resulting from conserved restriction sites, or that the polymorphism is due to a gene duplication or deletion. No band segregating with HH2.7 was found in separate digests using eight other enzymes. Although this indicates that a major deletion or unlikely, it does not exclude the possibility of a gene deletion or duplication affecting the intergenic region(s) of one or more homologous genes. Whatever the precise explanation, these findings support the hypothesis that there is polymorphic variation of VH gene repertoires in man.

Genes↗
PubMed1987

Bilio-pancreatic common channel in children. Clinical, biological and radiological findings in 12 children.

Twelve patients (11 girls and 1 boy) with dilated bile ducts and anomalous junction between the common bile duct and pancreatic duct are reported. All patients underwent preoperative opacification of the bile ducts either by transhepatic cholangiography or percutaneous cholecystography. Abdominal pain and jaundice were the main clinical symptoms. Reflux of pancreatic enzymes in the bile duct was proven by measuring amylase and lipase activity in the biliary system after IV injection of 1 IU/kg of cholecystokinin. All patients were operated upon. Bile ducts size returned to normal in all patients who are clinical well with a follow-up from 1 to 6 years.

Adolescent↗
PubMed1987

Sclerosing cholangitis with neonatal onset.

Sclerosing cholangitis is characterized by irregular narrowing of extrahepatic or intrahepatic bile ducts, and in adults is defined mainly by radiologic findings. We describe eight children with cholestasis from the first week of life, followed by early cirrhosis and portal hypertension. Histologic examination of the liver showed absence of interlobular bile ducts in the early cholestatic phase in two patients and biliary cirrhosis later in all patients. Radiologic examination by percutaneous cholecystography under ultrasound guidance, carried out at age 8 months to 9 years, disclosed abnormal intrahepatic bile ducts with rarefaction of segmental branches, stenosis, and focal dilation. The extrahepatic ducts were involved in six patients. No intestinal disease has been found in these patients.

Bile Ducts↗
PubMed1987

Bacterial cholangitis after surgery for biliary atresia.

We retrospectively studied the incidence of bacterial cholangitis in 129 infants operated on because of biliary atresia over 5 years. Forty-six of the 101 children who underwent hepatic portoenterostomy had a total of 105 episodes of cholangitis (range one to eight episodes per child). Most episodes occurred within 3 months of the operation. Factors associated with cholangitis included good or partial restoration of bile flow, abnormal intrahepatic bile ducts or cavities at the porta hepatis, and routine postoperative use of antibiotics. External jejunostomy was not effective in preventing cholangitis. In addition to fever and decreased bile flow, increased erythrocyte sedimentation rate and signs of shock were frequently observed. The responsible organisms, most often gram-negative bacteria, were identified in 79 (75%) episodes by blood or liver cultures. Most were susceptible to trimethoprim-sulfamethoxazole and third-generation cephalosporins during the first episode, but only to cephalosporins during later episodes. The incidence of signs of portal hypertension in children with normal serum bilirubin values at age 5 years was not higher in those who had previously experienced one or more episodes of cholangitis.

Biliary Atresia↗
PubMed1987

High-affinity interleukin 2 binding by an oncogenic hybrid interleukin 2-epidermal growth factor receptor molecule.

Both interleukin 2 (IL-2) and epidermal growth factor (EGF) receptors exist in two forms that differ with respect to affinity for their ligand. Only the high-affinity receptors appear to be responsible for the proliferation signal delivered upon binding of the growth factor. Fibroblasts transfected with IL-2 receptor cDNA generate only low-affinity receptors for IL-2, but fusion of membranes from these fibroblasts with T-cell membranes converts some receptors to high affinity, indicating the involvement of a T cell-specific factor in the generation of high-affinity receptors. We have constructed a chimeric cDNA molecule containing the extracellular IL-2-binding domain of the IL-2 receptor cDNA and the transmembrane and intracellular tyrosine kinase domains of the EGF receptor cDNA. When transfected into fibroblasts, this IL-2-EGF receptor cDNA generated high-affinity receptors for IL-2. Moreover, fibroblasts transfected with the chimeric molecule were morphologically transformed and produced rapidly growing tumors in nude mice.

Animals↗
PubMed1987

Plasma lipid peroxides in cholestatic children.

Plasma lipid peroxide levels were studied in 40 children with chronic cholestasis comprising 21 with syndromatic paucity of interlobular bile ducts (PILBD) and 19 with biliary atresia. Compared to the controls, mean lipid peroxide values were twice as high in children with biliary atresia (4.56 +/- 2.28 nmol/ml) and four times as high in those with PILBD (9.62 +/- 3.3 nmol/ml). These differences are highly significant. In patients with biliary atresia, the increase in lipid peroxide levels was clearly related to the bilirubin, cholesterol and phospholipid concentrations. In the PILBD group, however, there was little evidence of such a relationship. Vitamin E treatment seemed to have no effect on these increased lipid peroxide levels during the evolution of chronic cholestasis, and further investigations are necessary to clarify the pathological mechanisms involved.

Adolescent↗
PubMed1987

Murine c-myc retroviruses alter the growth requirements of myeloid cell lines.

Recombinant retroviruses encoding a murine c-myc gene were utilised to explore the consequences of constitutive c-myc expression for interleukin 3-dependent murine myeloid cell lines. The c-myc virus-infected cells exhibited a diminished requirement for growth factor and serum when grown in soft agar, but no factor-independent cells could be isolated and the cells were not tumorigenic. Thus deregulated expression of a c-myc gene at physiological levels apparently renders myeloid cells more responsive to growth factors but cannot abrogate this requirement or render the cells malignant.

Animals↗
PubMed1986

Liver disease associated with anti-liver-kidney microsome antibody in children.

In the past 10 years we have examined 20 children with inflammatory liver disease associated with high serum titers of anti-liver-kidney microsome antibody (anti-LKM). The first hepatic symptoms were progressive fatigue and jaundice, the fortuitous finding of hepatomegaly or splenomegaly with raised transaminase activity, or an acute hepatitis-like illness. At the time of diagnosis, hepatomegaly was present in 18 children, splenomegaly in 16, jaundice in nine, and ascites in two. Serum alanine transferase activities were elevated in all but two, who had already received steroids. Serum total gammaglobulin values were greater than 2.0 gm/dl in 16 children, prothrombin activity less than or equal to 60% in six, and serum titer of anti-LKM between 1:100 and 1:100,000. All children but one had cirrhosis, and histologic signs of aggressivity were present in 14. In 11 children one or more extrahepatic diseases were present, including type 1 diabetes, vitiligo, glomerulonephritis, autoimmune hemolytic anemia, hypoglycemia with hyperinsulinism, autoimmune thyroiditis, chronic mucocutaneous candidiasis with hypoparathyroidism, and multiple cutaneous and visceral telangiectasias. Treatment with prednisone and azathioprine improved the liver condition in 16 of the 18 patients given treatment. In eight of them discontinuation of treatment resulted in rapid relapse; 14 are still receiving treatment and have stable hepatic function with follow-up from 8 months to 6 1/2 years. Only two are free of treatment. Four children died, two in spite of immunosuppressive therapy, one during a relapse, and one of extrahepatic disease. These results indicate that this autoimmune inflammatory liver disease may have onset early in life, with several clinical patterns; is frequently associated with certain types of extrahepatic manifestations of autoimmune origin; and is a potentially fatal disease for which immunosuppressive treatment must be started early.

Adolescent↗