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Biomedical subjects

M Vignal

Publications and source records attributed to M Vignal.

At least 19 recordsLinked to original sources
PubMed2004

HLA antibodies and neonatal alloimmune thrombocytopenia.

A female baby with a severe thrombocytopenia at 18 x 10(9)/l was born to a 29-year-old (gestation 2/partum 2) mother. Scattered petechiae were present on her legs, arms, chest and face, but there was no bleeding, infection, fever or hepatosplenomegaly. A platelet antibody screening immunocapture test was positive, which was performed on the mother's serum 3, 12 and 38 days after delivery, but no platelet-specific antibodies were found by the monoclonal-antibody-specific immobilization of platelet antigen assay. The baby's platelets and lymphocytes and the father's platelets reacted strongly with the HLA antibodies present in the mother's serum. The neonate was treated with intravenous human immunoglobulin (Tegeline), 1 g/kg per day) 1, 2 and 3 days after delivery. The platelet count rose from 18 x 10(9)/l on day 0 to 37 x 10(9)/l on day 3 and to 227 x 10(9)/l on day 12. No platelet transfusion was needed. Several factors which developed hereafter lead us to think that this neonatal alloimmune thrombocytopenia is due to the transplacental passage of maternal HLA antibodies to the baby.

Adult↗
PubMed1997

Synergism between multiple virus-induced factor-binding elements involved in the differential expression of interferon A genes.

Comparative transfection analysis of murine interferon A4 and interferon A11 promoter constructs transiently transfected in mouse L929 and human HeLa S3 cells infected with Newcastle disease virus showed that the second positive regulatory domain I-like domain (D motif), located between nucleotides -57 and -46 upstream of the transcription start site, contributes to the activation of virus-induced transcription of the interferon (IFN)-A4 gene promoter by cooperating with the positive regulatory domain I-like and TG-like domains previously described. Electrophoretic mobility shift assay performed with the virus-inducible fragments containing these motifs indicated that the binding activity that we have denoted as virus-induced factor (Génin, P., Bragança, J., Darracq, N., Doly, J., and Civas, A. (1995) Nucleic Acids Res. 23, 5055-5063) is different from interferon-stimulated gene factor 3. It binds to the D motif but not to the virus-unresponsive form of the D motif disrupted by a G-57 --> C substitution. We show that the low levels of IFN-A11 gene expression are caused essentially by the lack of two inducible enhancer domains disrupted by the A-78 --> G and the G-57 --> C substitutions. These data suggest a model taking account of the differential regulation of IFN-A gene family members. They also suggest that virus-induced factor may correspond to the primary transcription factor directly activated by virus that is involved in the initiation of IFN-A gene transcription.

Animals↗
PubMed1997

Localization and structure of v-mos in transformed mouse fibroblasts reverted by long-term interferon treatment to nonmalignancy.

We have reported previously that Moloney virus-transformed cells, when treated for over 200 passages in the presence of low concentrations of mouse interferon-alpha/beta, can be reverted to a stable nonmalignant status. The cells recover full contact inhibition and are unable to raise tumors when grafted in nude mice. In the present report, we show that whether reverted or malignant, these cells contain deleted v-mos oncogenes, which have lost 392 nucleotides. The truncated oncogenes contain a reduced and modified open reading frame but are able, however, to induce tumors when transfected in mouse 3T3 cells. As there is no difference either in the location or in the structure of this modified v-mos, whether yielded by reverted or malignant cells, we postulate that both cell lines derive from the same population and this modification does not play any role in the reversion process obtained through prolonged IFN-dependent selection. We suggest that reversion could be an epigenetic phenomenon, involving the constitutive synthesis of IFN-beta only in the reverted and not in the malignant cells. The continued persistence of such noncancerous cells could result at least partly from a balance involving the expression of v-mos, IFN-beta, and an IFN antagonist, sarcolectin. These reverted cells can undergo an unlimited number of passages, but they must be trypsinized before day 5 in confluent cultures. Thereafter, the cells stop dividing, cannot proliferate anymore, progressively show signs of apoptosis, and die.

Amino Acid Sequence↗
PubMed1996

Identification of distal silencing elements in the murine interferon-A11 gene promoter.

The murine interferon-A11 (Mu IFN-A11) gene is a member of the IFN-A multigenic family. In mouse L929 cells, the weak response of the gene's promoter to viral induction is due to a combination of both a point mutation in the virus responsive element (VRE) and the presence of negatively regulating sequences surrounding the VRE. In the distal part of the promoter, the negatively acting E1E2 sequence was delimited. This sequence displays an inhibitory effect in either orientation or position on the inducibility of a virus-responsive heterologous promoter. It selectively represses VRE-dependent transcription but is not able to reduce the transcriptional activity of a VRE-lacking promoter. In a transient transfection assay, an E1E2-containing DNA competitor was able to derepress the native Mu IFN-A11 promoter. Specific nuclear factors bind to this sequence; thus the binding of trans-regulators participates in the repression of the Mu IFN-A11 gene. The E1E2 sequence contains an IFN regulatory factor (IRF)-binding site. Recombinant IRF2 binds this sequence and anti-IRF2 antibodies supershift a major complex formed with nuclear extracts. The protein composing the complex is 50 kDa in size, indicating the presence of IRF2 or antigenically related proteins in the complex. The Mu IFN-A11 gene is the first example within the murine IFN-A family, in which a distal promoter element has been identified that can negatively modulate the transcriptional response to viral induction.

Animals↗
PubMed1995

[Fresh frozen plasma: a pilot study of the context of utilization and the indications].

The aim of this pilot study was to assess the feasibility of a tolerance study of qualified (secured by quarantine or solvent-detergent-treated) fresh frozen plasma (FFP) in real conditions of use. We included all patients receiving qualified FFP during a one-month observation period in three french hospitals (Besançon, Brest, Lyon). The 192 FFP transfusion episodes corresponded to 111 patients. Only two thirds of all prescriptions corresponded to indications mentioned in the ministerial order of december 1991. Forty-two episodes consisted of FFP only; in the 150 remaining episodes, at least one product (mostly labile blood products) had been injected within 24 hours before or after the plasma injection. The free interval between FFP transfusion and the nearest associated product was usually less than three hours. Only one side effect was notified. This pilot study points out the difficulties of a tolerance study of qualified FFP in real conditions of use. It also raises the necessity to clarify current indications of FFP.

Adolescent↗
PubMed1995

Induction of interferon-beta gene expression by dexamethasone in murine L929 cells.

Glucocorticoids bind to their receptors and trigger the transcriptional activation or repression of target genes by binding to DNA sequences, the glucocorticoid responsive element (GRE). The murine interferon-beta (Mu-IFN beta) gene in L929 cells can be induced by dexamethasone to give both transcription and translation products specific to murine IFN beta. The 3'-noncoding region of the Mu-IFN beta gene was found to contain a GRE very similar to the consensus GRE sequence involved in glucocorticoid-regulated genes. Gel retardation assays showed that the oligonucleotide corresponding to that GRE competed with the MMTV GRE oligonucleotide for glucocorticoid receptor binding and was supershifted by human antiglucocorticoid receptor antibodies. Transiently transfected murine cells (L929) with the GRE-IFN beta 3' sequence inserted upstream of the thymidine kinase promoter and the chloramphenicol acetyl transferase gene treated with dexamethasone with or without the antiglucocorticoid RU486 and their chloramphenicol acetyl transferase activity assayed, show that this GRE is efficient. We conclude that the Mu-IFN beta gene in L929 murine cells can be induced by dexamethasone, and that the hormone effect may be mediated by the 3'-GRE sequence.

Animals↗
PubMed1993

[Clinical study of 12 cases of malignant non-Hodgkin's lymphoma of the orbital region].

Over an 8-year period in the Departments of Hematology, Ophthalmology and Internal Medicine of our hospital, 12 cases of orbital and adnexal malignant non-Hodgkin's lymphoma were reported. Diagnostic elements varied, including local tumefaction, watering eyes, uveitis, and unexplained, long-term fever. Nine patients had primary paraocular lymphomas involving either orbital structures, the lacrimal gland or the eyeball, but after appropriate staging, the disease was found to be disseminated in 5; the 3 other cases were secondary orbital lymphomas. Intermediate or high grade histological types were predominant (9 patients) in our series. Radiation therapy, alone or combined (5 patients) with chemotherapy, was administered in 8 cases; other treatments consisted of chemotherapy (2 cases) or steroids (2 cases). Evolution was poor, with only 4 patients surviving at 34-180 months of follow-up. The main prognostic factors were tumor stage and histological grade. The clinical characteristics of this group are compared to those reported in the literature.

Adult↗
PubMed1991

Haemolytic disease of the newborn infant. Long term efficiency of the screening and the prevention of alloimmunization in the mother: thirty years of experience.

During the last thirty years, the diagnosis, management and prevention of haemolytic disease of the newborn infant (HDN) have improved. From 1959 to 1988, 3004 HDN (ABO excluded) have been collected. The percentage of HDN with anti-D alloimmunization decreased significantly (98.4% from 1959 to 1968, 93.5% from 1969 to 1978 and 68.1% from 1979 to 1988). The anti-D HDN with exchange transfusion (ET) fell significantly between the first and second periods (577 versus 970; chi 2 = 19.92; P less than 0.001). On the other hand, the number of HDN other than anti-D increased during these three periods, but the percentage of these HDN which needed ET decreased. Our study shows the long term efficiency of the prevention of anti-D alloimmunization (since 1970) and of the irregular antibodies screening among all pregnant women (since 1979).

Antibodies, Anti-Idiotypic↗
PubMed1991

A case of hemolytic disease of the newborn infant due to anti-K (Cellano).

Hemolytic disease of the newborn infant (HDN) due to anti-K (Cellano) is very uncommon in Caucasians. We report here a case of anti-K HDN. The anti-K alloimmunization appeared in the mother during her fifth pregnancy. This HDN needed an exchange transfusion immediately after delivery. The clinical outcome of the newborn infant was good.

Adult↗
PubMed1989

[Systematic detection of anti-erythrocyte alloimmunization during pregnancy. Experience at the Lyon Regional Blood Transfusion Center].

In France, relative increases in hemolytic disease of the newborn (HDN) due to non anti-D maternal alloimmunization is linked to a systematic search and prevention of an anti-D alloimmunization in Rh negative women during and after pregnancy. In May 1985, detection of anti-red blood cell alloantibodies in all pregnant women has been ordered by a new law. We have observed the efficiency of this law by studying the number of HDN with anti-D and non anti-D maternal alloimmunization detected before and after delivery during the years 1984 and 1986. Our results show that this law is well used. Nevertheless, this work demonstrates that often clinicians omit to set cord blood aside for hemoglobin and bilirubinemia concentration determinations. Because these two parameters are very important in establishing the severity of HDN and therapeutic management, improvements are necessary.

Adult↗
PubMed1980

Investigations on the chromosomal localizations of the human and chimpanzee interferon genes: possible role of chromosomes 9 and 13.

Analysis of a great number of independent hamster-human and mouse-chimpanzee somatic cell hybrid clones confirms the role of chromosome 9 as carrying one or more primate beta interferon genes. The presence of chromosome 13 in producing hybrids and its absence in all non producing clones must be kept in mind for future studies. The strong negative regulation of interferon production in the parental hamster cells also affects the human gene product. The UV irradiation target for these regulatory genes is significantly greater than the structural genes responsible for interferon production.

Animals↗