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Biomedical subjects

O Bernard

Publications and source records attributed to O Bernard.

At least 235 records · Page 13Linked to original sources
PubMed1986

Influence of the embryo on the distribution of maternal immunoglobulins in the mouse uterus.

The effect of the embryo on the distribution of IgA, IgG and IgM was studied by an immunoperoxidase technique on mouse uterine sections, (1) during the first part of pregnancy and pseudopregnancy, and (2) in delayed implantation combined with different progesterone-oestradiol treatments designed to extend the delay or induce implantation, and in nonpregnant ovariectomized mice similarly treated. The number of glandular lumina containing IgA increased particularly from the implantation period, but in pseudopregnancy this number decreased from the morning of Day 4, and afterwards continued to decline. In delayed implantation, the number of glandular lumina containing IgA also rose considerably when implantation was induced by oestradiol, whereas under the same progesterone-oestradiol treatment, nonpregnant ovariectomized animals displayed no such increase. Significant staining for IgG in the stroma was observed on Day 4 of pregnancy and pseudopregnancy but prolonged staining for IgG was observed only during pregnancy. In addition, significant numbers of IgA-plasma cells in the stroma were observed mostly in uteri containing embryos. These results indicate that embryos might affect the process by which ovarian hormones regulate IgA and IgG distribution.

Animals↗
PubMed1986

[Serum DNA of hepatitis B virus in children with chronic infection].

Viral replication has been studied in 44 children with chronic infection induced by hepatitis B virus (HBV) investigating HBV-DNA by molecular hydridization technique, correlating its presence with immunological markers and activity of liver disease. HBV-DNA presence is correlated to HBe Ag detection, but this antigen was also found in absence of viral DNA (7 cases of 31). That can mean viral replication diminishes or disappears before the seroconversion. No differences were found in viral replication phases as for clinical manifestations in children. In presence of viral DNA, serum aminotransferases were higher (p less than 0,005) and active hepatic lesions more frequent. Therefore, more cytolysis an inflammation are found in presence of circulating virus. On the other, more developed lesions (inactive cirrhosis and hepatocellular carcinoma) have been found in viral replication absence.

Adolescent↗
PubMed1985

Anti-liver-kidney microsome antibody recognizes a 50,000 molecular weight protein of the endoplasmic reticulum.

Children with autoimmune chronic active hepatitis may have high titers of antibodies detected by immunofluorescence staining of hepatocytes and tubular cells in rat liver and kidney sections, respectively. These antibodies are directed against antigens contained in microsomal fractions prepared from these two organs. We have found that sera from these patients recognized a 50,000 mol wt protein present in higher concentration in smooth microsome subfractions compared with rough microsome subfractions. This protein is an integral membrane protein and is not glycosylated. It is exposed on the cytoplasmic face of the endoplasmic reticulum and is rather resistant to proteolysis with proteinase K. Since patients with liver disease of different etiology and similar severity of cell lysis do not give rise to liver-kidney microsome antibody (LKMA), lysis of hepatocytes is apparently not a sufficient condition for their development.

Animals↗
PubMed1985

Ultrasonic demonstration of porto-caval anastomosis in portal hypertension in children.

Seventy-one children with portal hypertension and a portocaval anastomosis were studied by ultrasound. The patency of the shunt may be inferred when it directly visualised. There are four indirect signs of patency: (1) decrease of the thickness of the lesser omentum; (2) decrease of the gastro-oesophageal collaterals; (3) decrease of the portal vein size; and (4) increase of the diameter of the inferior vena cava, as compared to pre-operative ultrasound.

Adolescent↗
PubMed1985

[Protein metabolism in the newborn lamb. I. Impact of the ingestion of colostrum on blood glucose, blood levels of gammaglobulin and free amino acids in tissues].

Ten newborn lambs were divided into two groups at birth. Five of them were fed hourly with cow colostrum; the others (unfed lambs) were given saline. Jugular blood levels of glucose, urea, free amino acids and IgG1 were measured during the 10-hour period following birth. The lambs were then exsanguinated under pentobarbital anaesthesia. Free amino acid levels were determined in liver, muscle (longissimus dorsi) and skin. The glycogen contents of the liver and whole body were measured. The IgG1 levels were determined in the intestinal wall and in the contents of the abomasum and small intestine. The blood glucose levels increased after birth in both groups and did not differ significantly in either group. After colostrum feeding, hepatic glycogen and blood urea concentrations were higher in fed than in unfed lambs. Blood free essential amino acid levels which increased after birth in the fed group, were higher in that group than in the unfed one. Nonessential free amino acid levels remained nearly constant throughout the experimental period and did not differ significantly in either group (fig. 2). Free threonine and valine in the liver, skin and muscle were higher in the colostrum-fed lambs than in the others. IgG1 levels increased after birth in the blood of the fed lambs and seemed to be closely related to the intestinal contents of these compounds (fig. 3). The amount of blood free essential amino acids provided by the hydrolysis of colostral proteins was estimated at about 43% of the amount entering the small intestine.

Aging↗
PubMed1985

[Results of portasystemic shunts in cirrhosis in children].

A surgical porto-systemic shunt was carried out in 37 children and adolescents (age: 2 yrs-18 yrs) who presented with cirrhosis and portal hypertension. All patients were classified "A" or "B" according to Child's criteria. Proof of the patency of the shunt was obtained by endoscopy and/or angiography in 31 children. Two children died in the early postoperative period. Thrombosis of the shunt occurred in 4 children. With a follow-up of 6 months to 11 years, none of the 31 children operated on successfully presented with gastro-intestinal bleeding due to portal hypertension. Nine presented with one or several episodes of porto-systemic encephalopathy. Five of these were transient allowing for a normal diet to be resumed later. These results indicate that porto-systemic shunts are effective to prevent gastro-intestinal bleeding, even in young children with cirrhosis. However, in addition to Child's criteria, indications for shunt surgery must take into account the degree of hemorrhage risk and the possible need for a liver transplantation later.

Brain Diseases↗
PubMed1985

Life-saving immunosuppressive treatment in severe autoimmune chronic active hepatitis.

A 13-year-old girl with a 1-year history of elevated serum alanine transferase was hospitalized because of liver failure. Low prothrombin time (12%) prevented needle liver biopsy. Because of a high titer of antismooth-muscle antibodies (1:500), a tentative diagnosis of "autoimmune" chronic active hepatitis was made and immunosuppressive therapy was started. Despite the severity of the liver disease, of her poor general condition, and of spontaneous bacterial peritonitis, she dramatically responded to treatment, prothrombin time returning to normal within 5 months. Diagnosis of chronic active hepatitis was later confirmed by liver biopsy. This report indicates that immuno-suppressive therapy can be life saving in children with severe chronic active hepatitis even when major signs of liver failure are present.

Adolescent↗
PubMed1985

[Familial Budd Chiari syndrome and glomerular involvement].

We report a case of a child with familial Budd-Chiari syndrome and proteinuria. Renal biopsy disclosed predominant arteriolo-capillary endothelial and mesangial lesions suggesting a microangiopathy. This may be due to hypoxemic damage with polycythemia and high venous pressure resulting from precapillary pulmonary arteriovenous shunts.

Budd-Chiari Syndrome↗
PubMed1985

[Protein metabolism in the newborn lamb. II. Influence of diet on protein synthesis and turnover].

Leucine turnover and protein fractional synthesis rates were measured in fed and unfed newborn lambs. The fed group (4 animals) was fed hourly with cow colostrum throughout the experiment which started at birth; the unfed group (5 animals) was given saline (NaCl 9 0/00). Two hours after birth, L-(1-14C) leucine was infused into the jugular vein at a constant rate for 8 h. Eight blood samples were taken during the infusion period; at the end of the experiment, the liver, skin and three muscles (supraspinatus, longissimus dorsi, tensor fasciae latae) were sampled. The specific activity of free and protein-bound leucine was measured in these samples and in the whole body (table 2). The specific activity of free leucine reached a quasi-steady state in the plasma within 2 h after the beginning of infusion (fig. 1). The irreversible loss rate of plasma leucine and the leucine catabolic rate were higher in fed than in unfed lambs. The highest fractional rates of protein synthesis occurred in the liver, skin and whole body (table 3). They were similar in both groups. In contrast, fractional rates of protein synthesis in muscles were higher in fed than in unfed animals. Thus, the proportion of whole body protein synthesis, accounted for by muscle protein synthesis, was higher in fed than in fasting newborn lambs (fig. 2). The leucine flux from whole body protein breakdown was unaffected by nutritional status (table 1). Feeding colostrum stimulated muscle protein synthesis, which was in keeping with body weight gain and protein accretion.

Animals↗
PubMed1984

Activation of immunoglobulin mu gene expression involves stepwise demethylation.

In an attempt to identify stages of mu gene activation subsequent to VHDHJH assembly, we investigated two pre-B cell lines (A1 and A8) that have both alleles of the JH locus rearranged but do not make mu polypeptides. The block in A1 reflects incorrect VHDHJH assembly on both alleles. In A8, although an out-of-phase VHDHJH-C mu allele is transcribed, the properly assembled allele is silent, despite having a normal VH promoter and mu enhancer. Thus, transcription can be restricted to a single mu allele. Low level mu transcription in both lines was associated with demethylation of the VHDHJH and enhancer regions but not of the C mu gene. Markedly elevated mu transcription ensued on lipopolysaccharide stimulation or fusion to a plasmacytoma, but only fusion induced C mu demethylation. Hence stepwise demethylation is implicated in mu gene regulation, but enhanced expression can also occur independently of, or prior to, demethylation.

Alleles↗
PubMed1984

Genes of the protozoan parasite Babesia bovis that rearrange to produce RNA species with different sequences.

We describe a highly polymorphic gene family from the protozoan parasite Babesia bovis that encodes a complex pattern of transcripts. Gene rearrangements at this locus (designated BabR ) have generated RNA species that differ in sequence. The naturally occurring virulent field isolate Kv expresses two different sized transcripts that are identical in sequence at their 5' ends but different at the 3' ends. An avirulent derivative of this isolate, Ka, expresses not only these two transcripts but a third, of intermediate size. Analysis of cloned genomic fragments from Ka identified genes encoding all three transcripts. Two fragments contained tandemly repeated copies of the BabR genes. The gene encoding the intermediate sized transcript has undergone a rearrangement, substituting a 5' region different to that shared by the other transcripts. These results suggest that sequence diversity may play an important role in the biological function of the BabR locus.

Amino Acid Sequence↗
PubMed1984

Maternal immunoglobulins G, A and M in mouse uterus and embryo during the postimplantation period.

The distribution of maternal IgG, IgA and IgM was studied by an immunoperoxidase technique on mouse uteri and embryo sections from 4.5 to 10 days of gestation. In the embryo, from day 5, IgG was found in the endoderm, and later in the trophoblast, distal and extraembryonic proximal endoderm, embryo cavity and early vitelline vessels. From day 6, IgA was found in the same areas but staining was less intense and was not seen in vitelline vessels. From day 8, small amounts of IgM were found in the same areas, but not in vitelline vessels. Between implantation sites, IgG and plasma cells containing IgA remained present in the stroma; most glands contained IgA, and the uterine lumen stained for IgA and IgG. IgG granules were found in the apical region of luminal epithelial cells in the implantation sites at 5 and 5.5 days; IgA granules were seen in the apical region of luminal epithelial cells between implantation sites from 4.5 to 6.5 days. These results suggest that IgA and some IgM are transmitted along with IgG to the early mouse embryo but do not reach the embryonic circulation, and that during the implantation period reabsorption of IgG and IgA from the uterine lumen into the epithelium differs, depending on the position of this epithelium in relation to the embryo. The persistent IgA and IgG secretion in the uterus after implantation suggests that during this period the mechanisms regulating immunoglobulin secretion may differ from those during the oestrous cycle.

Animals↗