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Biomedical subjects

O Bernard

Publications and source records attributed to O Bernard.

At least 253 records · Page 14Linked to original sources
PubMed1984

Treatment of autoimmune chronic active hepatitis in childhood.

Seventeen children with chronic active hepatitis and high serum titers of smooth-muscle or liver-kidney microsomal antibodies were given prednisone and azathioprine. Clinical and biochemical remission was obtained in all but two, who died of progressive liver failure. Evaluations in 14 children after a mean period of 22 months of treatment showed normal transaminase activity and gammaglobulin levels in 12, and serum autoantibody titers of less than 1: 100 in 10; liver histologic findings showed absence of inflammation in seven children, moderate portal or lobular inflammation in five, and minor features of aggressivity in two. Cessation of therapy was then attempted in nine children. Relapse occurred in all but one and could not be attributed to any previously recorded biologic or histologic feature. After follow-up of 18 months to 7 years, all but two patients are still receiving maintenance therapy with prednisone and azathioprine. Cirrhosis was present before treatment in 13 children and is now present in all but one. These results suggest that in most children with autoimmune chronic active hepatitis, immunosuppressive therapy can prevent further deterioration of liver function but must be pursued for several years before discontinuation is attempted.

Adolescent↗
PubMed1984

[Choleperitonitis after hepatoportocholecystostomy for atresia of the biliary tract].

The gallbladder, the cystic and the choledocal ducts are patent in one fifth of biliary atresia cases, and can be used for the corrective operation. The main interest of this hepatoportocholecystostomy (HPC) is to prevent the cholangitis episodes which are the most severe complication of successful hepatoportoenterostomies (HPE). However a singular complication of HPC has been noticed by previous authors: the choleperitonitis. We report a recent case in which this complication was diagnosed by a routine ultrasonography at the 3rd week of the uneventful postoperative course of a HPC performed in an 1 1/2 month old infant. An early reoperation (HPE) had a good result with restoration of a satisfactory bile flow. The child is anicteric with a follow-up of one year. In our experience with 208 corrective operations between 1969 and 1981, HPC was used in 38 cases, with restoration of bile flow in 17 cases. A choleperitonitis was noticed in 4 cases in this series, and in a 5th additional recent case. Three children were not suitable for reoperation because of very poor condition and died within 3 to 17 months after HPC. Two children were reoperated upon early with a good result. We advocate the HPC procedure despite the risk of choleperitonitis and emphasize the interest of early postoperative routine ultrasonography, especially when stools remain acholic at the 4th postoperative week.

Bile↗
PubMed1983

Sequence of the murine and human cellular myc oncogenes and two modes of myc transcription resulting from chromosome translocation in B lymphoid tumours.

The 15;12 chromosome translocation in murine plasmacytomas and the 8;14 in human Burkitt lymphomas often link the cellular myc oncogene to the locus for constant regions of immunoglobulin heavy chains (CH locus). To clarify how and why c-myc translocation occurs, we have sequenced the mouse and human c-myc genes and correlated c-myc transcription with c-myc rearrangement. Both genes comprise three exons; the second and third encode the myc polypeptide, which is conserved between mammals and birds, particularly in its more basic C-terminal half. Southern blots showed that four of 12 Burkitt lines have c-myc linked near CH switch regions and two near the joining region (JH) locus. Hence, immunoglobulin recombination machinery may participate in translocation, although the common myc breakpoint region around exon 1 does not resemble a switch region. Tumours with breakpoints just 5' to exon 1, or distant from c-myc, had normal c-myc mRNAs of 2.25 and 2.4 kb, which differ at their 5' ends, while tumours with breakpoints within exon 1 or intron 1 had altered c-myc mRNAs (2.1-2.7 kb in Burkitt lines), initiated within intron 1. Both types of mRNAs probably yield the same polypeptide. Since the untranslocated c-myc allele was generally silent, translocation to the CH locus must induce constitutive c-myc expression. The presence of c-myc mRNA in immortal but non-tumorigenic lymphoblastoid cell lines may implicate c-myc in an immortalization step.

Amino Acid Sequence↗
PubMed1983

Portal obstruction in children. I. Clinical investigation and hemorrhage risk.

We examined 108 children with obstruction of the portal vein. Symptoms included splenomegaly and gastrointestinal tract hemorrhage. Obstruction was secondary to portal vein injury in 44 children and was combined with congenital malformations in 17 others. Ultrasonography provided the correct diagnosis in 36 of the 37 children in whom it was performed. Angiography, performed in 101 children, showed that the obstruction extended to the superior mesenteric vein in 14 children and to the entire portal venous system in seven; intrahepatic branches were involved in half the cases. Natural splenorenal shunts were visible in 19 children but were not clearly associated with a lower risk of gastrointestinal tract bleeding; in five of 30 children, cavography displayed abnormalities of the inferior vena cava. Spontaneous gastrointestinal tract hemorrhage occurred in 78 children. Fiberoptic endoscopy showed esophageal varices in 79 of the 81 children studied. The presence of tense varices and congestion of esophageal mucosa clearly augmented the risk of bleeding. These results suggest a simple method of investigation based on ultrasonography for diagnosis and on endoscopy for prognosis. Angiography should be limited to children with a history of gastrointestinal tract bleeding for whom a surgical portosystemic shunt is being considered.

Adolescent↗
PubMed1983

Portal obstruction in children. II. Results of surgical portosystemic shunts.

Seventy-six children with portal vein obstruction underwent surgical portosystemic shunt, for severe gastrointestinal tract bleeding in 64 and for prophylactic purposes in 12. Endoscopy and angiography or both showed shunt patency in 70 children; thrombosis occurred in the remaining six. The mean age at successful shunt surgery was 6 years 10 months. Early postoperative assessment of shunt patency was judged from regression of splenomegaly and thrombocytopenia when splenectomy was not performed; when done, early postoperative ultrasonography correctly indicated the result. Significant regression of endoscopy was most often delayed postoperatively for up to six months. Children with a proved patent shunt did not have any further episodes of gastrointestinal tract bleeding, displayed no clinical signs of encephalopathy, and often exhibited a striking increase in growth velocity. These results strongly support the contention that a portosystemic shunt is the best treatment for portal vein obstruction after the first spontaneous bleeding episode, even in young children.

Adolescent↗
PubMed1983

Hepatitis B virus DNA in children's liver diseases: detection by blot hybridisation in liver and serum.

Molecular hybridisation using cloned hepatitis B virus DNA (HBV DNA) was applied to liver and serum samples from 46 children (39 with liver diseases and seven controls) for detection of HBV DNA sequences, free and integrated into the liver cell genome. HBV DNA integration was observed in 10 children. The young age of some of these cases indicates that such integration can occur early in liver disease and is not related to the duration of viral infection. Thirteen children exhibited serological evidence of active viral multiplication. All but one had free HBV DNA in liver tissue and integrated HBV DNA sequences were found in four cases. Integrated HBV DNA sequences alone were also detected in three children with neither HBV-antigens nor HBV DNA in serum. One had inactive cirrhosis, and the two others, chronic active hepatitis. Consequently DNA hybridisation may be useful for diagnosis, in the absence of serological signs of HBV infection; its specificity was enhanced in the present investigation by negative results in six children with autoimmune chronic active hepatitis. Taken together, the above results imply that HBV-DNA integration can occur in both active and inactive liver disease. Integrated HBV DNA was also observed in the liver of three children with fatal hepatic failure who presented with antibodies to HBsAg and/or to hepatitis B core antigen in the serum. This finding raises the question of the relationship between the host immune factors and the state of HBV DNA.

Adolescent↗
PubMed1983

Immunoglobulins in the mouse uterus during the oestrous cycle.

The distribution of IgA, IgG and IgM was studied by an immunoperoxidase technique on sections of mouse uteri at each stage of the oestrous cycle. Staining for IgG and IgA was highest at pro-oestrus, declined at oestrus and was very low during the other stages. At pro-oestrus IgG was found throughout the stroma, in the uterine lumen, and in 10% of glandular lumina; very few IgG-containing plasma cells were present. At pro-oestrus, IgA was found in the uterine lumen, and in most of the uterine glands, both in the lumen and in the epithelium; little IgA was present in the stroma. IgA-plasma cells were detected at each stage of the cycle and were particularly numerous at pro-oestrus and oestrus. These results suggest that IgA is secreted locally from plasma cells into the uterine gland through the glandular epithelium, but that IgG enters the stroma from the local capillaries. The obvious increase in IgG and IgA secretion at pro-oestrus, when plasma oestradiol levels are highest, supports the hypothesis that, during the oestrous cycle, the humoral immune response is regulated in the uterus by ovarian hormones.

Animals↗
PubMed1982

Latent chronic cholangitis in congenital hepatic fibrosis.

In a five-year-old girl with congenital hepatic fibrosis raised erythrocyte sedimentation rate and serum gammaglobulins were noted for 3 years. Needle liver biopsy showed histological features of cholangitis and Klebsiella oxytoca was cultured from a liver biopsy specimen. Antibiotic treatment resulted in normalization of erythrocyte sedimentation rate and serum gammaglobulins. This suggest that cholangitis can be clinically latent in congenital hepatic fibrosis and should be investigated and treated when unexplained inflammatory signs are present.

Child, Preschool↗
PubMed1982

Transcriptionally active DNA region that rearranges frequently in murine lymphoid tumors.

A DNA region not associated with conventional immunoglobulin gene rearrangement is rearranged in many lymphoid tumors. This region, designated here as lymphoid rearranging (LyR) DNA, was cloned from plasmacytoma J558 in which it had recombined 5' to a constant (C) region of the alpha heavy (H) chain gene, C alpha, within a switch (S) region, S alpha, involved in the switching of CH genes. Sequence determination established that LyR DNA had recombined within a S alpha recombination unit. LyR DNA does not originate from the H chain locus, and discordance between LyR DNA and CH copy number in certain lines suggests that LyR DNA probably derives from another chromosome. LyR DNA rearrangement is a characteristic of tumors of mature B cells; it was detected in 24 of 28 plasmacytomas and B-cell lymphomas, usually as LyR-S alpha, but not in 11 Abelson retrovirus-induced lymphomas of B-cell precursors nor detectably in normal B cells. In contrast, rearrangement was observed in only 3 of 18 T-cell lymphomas, and none of seven nonlymphoid lines. Most tumor lines (49 of 52), whether lymphoid or not, contained a low level of polyadenylylated LyR transcript(s), but several new RNA species with differences in their 5' regions appeared in B-cell lines in which LyR DNA was rearranged, suggesting that rearrangement may activate a new promoter or mode of splicing. The results suggest that the LyR-S alpha rearrangement represents a translocation to chromosome 12 that alters expression of LyR-encoded genes; hence, it may have participated in lymphoid tumor oncogenesis.

Animals↗
PubMed1982

mRNA for surface immunoglobulin gamma chains encodes a highly conserved transmembrane sequence and a 28-residue intracellular domain.

To probe the structure of the gamma heavy chain of membrane IgG and the mRNA and gene segments that encode it, we have analyzed cDNA clones derived from a gamma 1 membrane RNA of B lymphoma 2PK-3. The nucleotide sequence of the clones indicated that membrane gamma 1 chains bear a COOH-terminal 71-residue segment that is absent from secretory gamma 1 chains. This terminus includes a 26-residue hydrophobic transmembrane region homologous to that of membrane mu chains and, significantly, a 28-residue intracellular domain found only on gamma chains. The extra domain suggests that receptor IgG, on memory B cells, may generate a different signal on binding antigen than does receptor IgM, on virgin B cells. The gamma 1 membrane terminus is encoded by two gene segments 1.5 and 2.4 kilobase pairs downstream from the C gamma 1 gene, and homologous segments occur 3' to the C gamma 2a and C gamma 3 genes. Small amounts of membrane gamma mRNAs persist in plasmacytomas secreting IgG1, IgG2a, or IgG2b, suggesting that competition between alternative RNA processing pathways governs the synthesis of membrane and secretory gamma chain mRNAs.

Animals↗
PubMed1982

[HB virus antigens in the liver during chronic hepatitis in children].

An immunoperoxidase study of HBsAg and HBcAg was carried out on liver biopsies of 30 children with chronic hepatitis or idiopathic cirrhosis. Presence of HBsAg and HBcAg occurred only in children who were HBsAg positive in their serum. The number of cytoplasmic HBsAg positive hepatocytes appears higher in children whose liver disease is histologically less severe. The number of hepatocytes with nuclear HBcAg seems directly related to the presence or absence of HBeAg in the serum. Those results are in agreement with previously published observations suggesting that the host's immune response is an important factor of the severity of the liver disease in hepatitis B infections.

Autoimmune Diseases↗
PubMed1981

Immunological studies of mouse decidual cells. II. Studies of cells in artificially induced decidua.

Cells from artificially induced decidual tissue (deciduoma) in the mouse were examined for Thy-1 surface antigen and receptors for the Fc portion of immunoglobulin G (FcR) and compared with cells of the normal decidua from 6 to day 9 of pregnancy. It was shown that (1) Thy-1 antigen is present on the same proportion of cells in decidua and deciduoma on day 6 and day 7, (2) FcR-bearing cells can be detected in similar numbers on day 6 and day 7 but this does not increase on day 8 in deciduoma as it does in decidua, and (3) progesterone treatment after induction of decidualization allowed further increase of FcR-bearing cells in deciduoma. These results present further evidence of the similarity between deciduoma and decidua in the mouse. They indicate that these two membrane markers are present in the early decidua, regardless of the presence of an embryo, and suggest that progesterone may play a part in the increase of FcR-bearing cells in the decidua during pregnancy.

Animals↗
PubMed1981

Congenital hepatic fibrosis in children.

Twenty-seven children with congenital hepatic fibrosis were followed for three months to 12 years. Hepatosplenomegaly, normal liver function tests, and kidney abnormalities were present in most patients, indicating that a correct diagnosis of congenital hepatic fibrosis could be made using simple clinical, biologic, and radiologic criteria. Esophageal endoscopy showed varices in 21 patients. Sixteen children underwent portal-systemic shunt surgery. Follow-up examinations did not show any impairment of liver function or any sign of hepatic encephalopathy. Cholangitis was present in only three children.

Adolescent↗
PubMed1981

Severe giant cell hepatitis with autoimmune hemolytic anemia in early childhood.

Four children, aged 6 1/2 months to 2 years, presented with liver disease and autoimmune hemolytic anemia. Clinical signs included fever, jaundice, firm or hard hepatomegaly, and splenomegaly. Direct Coombs test results were of the mixed (IgG + C) type. Liver function tests showed high direct bilirubin transaminase, and serum gamma globulin values, and a prolonged prothrombin time. The liver histology was characterized by marked lobular fibrosis and giant cell transformation. The course of the disease was severe, resulting in the death of three patients from liver failure. However, the liver disease seemed responsive to corticosteroid treatment, which in one patient was clearly beneficial.

Anemia, Hemolytic, Autoimmune↗
PubMed1981

Fasting hypoglycemia resulting from hepatic carnitine palmitoyl transferase deficiency.

Two sisters developed severe hypoglycemia at 8 months of age, resulting in death in one of them. Metabolic studies of the second revealed decline of blood glucose concentration and low plasma ketone body values during a 20-hour fast, both reversed by administration of medium-chain triglycerides. Carnitine palmitoyl transferase activity was absent in the liver extract of the patient; lack of this enzyme impairs long-chain fatty acid oxidation and ketogenesis. Failure of gluconeogenesis could result from decreased production of acetyl-CoA and NADH.

Acyltransferases↗
PubMed1981

Sequences of the joining region genes for immunoglobulin heavy chains and their role in generation of antibody diversity.

To assess the contribution to immunoglobulin heavy chain diversity made by recombination between variable region (VH) genes and joining region (JH) genes, we have determined the sequence of about 2000 nucleotides spanning the rearranged JH gene cluster associated with the VH gene expressed in plasmacytoma HPC76. The active VH76 gene has recombined with the second germ-line JH gene. The region we have studied contains two other JH genes, designated JH3 and JH4. No other JH gene was found within the region 1000 nucleotides downstream from JH4. Between JH3 and JH4 there is a pseudo-JH sequence with substantial homology to the authentic JH genes. The four JH genes whose sequences now are known can account for all known JH amino acid sequences. The JH genes are more divergent than the Jk genes and vary in length, encoding either 15 or 17 amino acid residues. Because JH regions comprise part of the third hypervariable region (HV3), combinatorial VH--JH joining substantially augments VH diversity. Moreover, a VH gene can recombine with each JH gene at several positions, and either one or two germ-line JH codons can be excised. This JH truncation markedly reduces the length of HV3 and hence must alter antigen-binding specificity. We have also determined the sequence of the JH4 region in two different gamma 2a mRNAs and have found that each has suffered a point mutation (aspartate to asparagine) which would alter the charge of the antigen-binding site.

Amino Acid Sequence↗
PubMed1981

Plasmacytomas with more than one immunoglobulin kappa mRNA: implications for allelic exclusion.

Although only one allele of an immunoglobulin gene is thought to be expressed as a polypeptide by a given lymphocyte ("allelic exclusion"), three murine plasmacytomas were found to contain more than one kappa light chain mRNA species, as evidenced by the sequences of distinct kappa cDNA clones. Two different kappa cDNA sequences were cloned from BFPC 61 microsomal mRNA, two from MOPC 173, and three from S107. One cDNA sequence from each tumor matches the known secreted polypeptide, while the variant sequences differ in the variable (V) region. Hence fusion of a V kappa gene to a joining (J kappa) gene has occurred independently on separate homologous chromosomes and each allele is transcriptionally competent. The BFPC 61 variant sequence contained a normal V kappa sequence linked out of phase to J kappa 2; hence allelic exclusion in this line is accounted for by an error in DNA rearrangement. One S107 variant cDNA has an untranslatable sequence linked to J kappa--C kappa and may derive from a non-V kappa or pseudo-V kappa gene fused to J kappa. Another S107 variant cDNA, however, has a proper V kappa linked in phase to J kappa (albeit missing the first two germ-line J kappa codons) and the MOPC 173 variant sequence also contains a proper V kappa--J kappa join, although it does not encode a tryptophan residue common to all immunoglobulin chains. The presence of two potentially expressible kappa mRNAs in both S107 and MOPC 173 suggests that allelic exclusion does not hold in all lymphocytes, or that it sometimes reflects events subsequent to mRNA production, such as inability of certain kappa chains to assemble properly with the heavy chain. These observations are compatible with a stochastic model for allelic exclusion in which productive and nonproductive V--J recombination events occur at a certain frequency for each allele.

Alleles↗