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Biomedical subjects

F Forestier

Publications and source records attributed to F Forestier.

At least 55 records · Page 3Linked to original sources
PubMed1996

Blood smears and prenatal diagnosis.

Fetal blood sampling is a widely used technique for both diagnostic and therapeutic purposes. However, despite the fact that examination of blood smears is a critical step in the study of a large variety of disorders, the place of fetal blood smears analysis has been overshadowed by more sophisticated diagnostic tools such as those offered by molecular biology. Nevertheless, as highlighted by four cases presented in this paper, the role of fetal blood smears examination must be re-emphasized. The recognition of abnormal cytological findings limits the number of possible aetiologies, thus elegantly contributing to the diagnosis without multiplying unnecessary test techniques.

Fetal Blood↗
PubMed1996

Fetal gammaglutamyl transferase activity: clinical implication in fetal medicine.

In a retrospective study of 3,129 fetal blood samples, we first determined normal values for gammaglutamyl transferase (GGT) activity and found 33 cases with a mean GGT level of 961.8 U/l (prevalence 1.05%) corresponding to more than 10-fold normal values. In such extreme cases, elevations of GGT activity in fetal blood have been poorly studied. The goal of this work was to correlate this highly abnormal biological finding with pathological fetal conditions and try to better understand the pathophysiological mechanisms. The most frequent underlying disorders were infections (n = 11), renal or bowel malformations (n = 12) and genetic abnormalities (n = 5). Two cases of cystic fibrosis and one case of fetal alcohol syndrome were also encountered. In another 2 cases, no explanation was found.

Chromosome Aberrations↗
PubMed1995

The influence of E. coli implantation in axenic mice on cytokine production by peritoneal and bone marrow-derived macrophages.

To assess the involvement of bacterial microflora in the development of host defenses, we compared in vitro LPS-induced cytokine production by macrophages in germ-free and E. coli monoxenic mice. E. coli implantation significantly increased IL-1 and IL-6 and, to a lesser extent, TNF activities of peritoneal and bone marrow-derived macrophages. These results suggest that exposure to microflora primes macrophages for an enhanced cytokine production, which may contribute to the activation of the antiinfectious defense. The priming was not restricted to peritoneal macrophages but was associated with a more general effect of the flora since the enhanced response of bone marrow-derived macrophages indicates an effect on macrophage precursors. Furthermore, a higher ability of peritoneal macrophages to produce IL-1 in axenic and monoxenic mice was observed as compared to bone marrow-derived macrophages. In contrast, bone marrow-derived macrophages demonstrated a higher ability to produce IL-6 and TNF but only 3 weeks after bacterial administration.

Animals↗
PubMed1994

Prenatal diagnosis of congenital toxoplasmosis with a polymerase-chain-reaction test on amniotic fluid.

BACKGROUND: Congenital infection with Toxoplasma gondii can produce serious sequelae. However, there is little consensus about screening during pregnancy, and the tests used to establish a prenatal diagnosis of toxoplasmosis are complex and slow. We evaluated a simpler approach that is based on a polymerase-chain-reaction (PCR) test. METHODS: Prenatal diagnostic tests, including ultrasonography, amniocentesis, and fetal-blood sampling, were performed in 2632 women with T. gondii infection acquired during pregnancy. In 339 consecutive women, a competitive PCR test for T. gondii was performed on amniotic fluid, and its results were compared with those of conventional diagnostic tests. The PCR test targets the B1 gene of T. gondii, uses an internal control, and can be completed in a day. Positive tests were confirmed by serologic testing of newborns or by autopsy in terminated pregnancies. RESULTS: Overall, the risk of fetal infection was 7.4 percent, but it increased sharply with gestational age. Congenital infection was demonstrated in 34 of 339 fetuses by conventional methods, and the PCR test was positive in all 34. In three other fetuses, only the PCR test gave positive results, and follow-up testing confirmed the presence of congenital toxoplasmosis. The PCR test gave one false negative result but no false positive results. The PCR test performed better than conventional parasitologic methods (sensitivity, 97.4 vs. 89.5 percent; negative predictive value, 99.7 vs. 98.7 percent). CONCLUSIONS: For the prenatal diagnosis of congenital T. gondii infection, an approach based on a PCR test performed on amniotic fluid is rapid, safe, and accurate.

Amniotic Fluid↗
PubMed1994

Fetal thrombocytopenia: a retrospective survey of 5,194 fetal blood samplings.

Fetal platelet counts were retrospectively studied in a series of 5,194 consecutive fetal blood samplings (FBS). The mean value was 245 +/- 65 x 10(9)/L, without significant variation between 17 and 41 weeks' gestation. After exclusion of false thrombocytopenia due to contamination with amniotic fluid, 247 fetuses had platelet counts less than 150 x 10(9)/L. In 70 cases, thrombocytopenia was due to congenital infectious diseases (toxoplasmosis, rubella, and cytomegalovirus). It was related to immune causes in 45 cases: anti-HPA-1a (n = 23), anti-HPA-5b (n = 2) or possible anti-HLA (n = 2) alloimmunizations, and immune thrombocytopenic purpura (n = 18). Chromosomal abnormality was the etiology in 43 cases (trisomy 13, 18, and 21, Turner's syndrome, triploidy), and other disorders (multiple birth defects, intrauterine growth retardation, rhesus disease, and gestational thrombocytopenia) in 62 cases. No specific cause for the low platelet count could be established in 27 fetuses (range, 115 to 149 x 10(9)/L). Severe thrombocytopenia (< or = 50 x 10(9)/L) occurred mainly in immune cases (16%), congenital infectious diseases (7%), and chromosomal abnormalities (1%). Diagnosis, prognosis, and management of fetal thrombocytopenia are presented in the different clinical situations. In this series, FBS was never associated with serious bleeding, and no fetal exsanguination was observed.

Chromosome Aberrations↗
PubMed1994

Tumour-associated antigens in maternal and fetal blood.

Normal levels of cancer-associated antigen (CA) 19-9, neurone-specific enolase (NSE), cancer-associated antigen (CA) 125, and mucin-like carcinoma-associated antigen (MCA) during pregnancy were determined in 87 mothers and fetuses, using a solid-phase sandwich enzyme immunoassay. CA 19-9 concentrations were higher in the fetuses, whereas the other three tumour-associated antigen levels were higher in the mothers. Only fetal NSE and MCA levels were positively correlated with those in maternal serum. Contrary to adult samples, no difference was demonstrated between male and female fetal levels of CA 125. MCA was the only maternal marker that increased significantly with gestational age between 20 and 34 weeks' pregnancy.

Antigens, Tumor-Associated, Carbohydrate↗
PubMed1994

[Fetal-neonatal thrombocytopenia of immunologic origin: current aspects].

Fetal/neonatal immune thrombocytopenias result from increased platelet destruction by maternal antiplatelet antibodies. There is a risk of intracerebral haemorrhage and therefore of neurological impairment or death during the thrombocytopenic period, especially if a defective platelet function co-exists. As no maternal parameter is predictive of the fetal platelet count, the only reliable assessment of the fetal status depends on the fetal blood sampling. Only in case of materno-fetal alloimmunisation the therapy initiated to reverse fetal thrombocytopenia was shown to be effective, but the optimal mode of antenatal treatment is currently under study. As the neonatal therapy and the management of subsequent pregnancies are somehow different it is mandatory to make the distinction between the auto or allo-origin of the fetal thrombocytopenia. The definition of high risk pregnancies will be of help for the development of a routine screening program.

Antigens, Human Platelet↗
PubMed1993

Effect of acute oral administration of alcohol on superoxide anion production from mouse alveolar macrophages.

The production of superoxide anions (superoxide) from alveolar macrophages stimulated or not with opsonized zymosan was investigated in the mouse after acute oral administration of alcohol (6.5 g/kg). Superoxide production was assayed using a nitroblue tetrazolium (NBT) reduction and chemiluminescence assay. In the absence of opsonized zymosan, superoxide concentration was not affected 1 h after ethanol treatment but was significantly increased 15 and 24 h after treatment. In the presence of opsonized zymosan, a biphasic response was observed. Superoxide production was significantly reduced 1 and 3 h after administration but was increased 15 and 24 h after treatment. One hour after treatment, the percentage of cells that phagocytized opsonized zymosan and reduced NBT was significantly decreased, whereas 24 h after alcohol treatment, phagocytosis was normal and the percentage of cells reducing NBT was significantly increased. The activity of cytosolic superoxide dismutase from alveolar macrophages was not altered 1 h after administration but was significantly reduced 24 h later. Considering the functions of alveolar macrophages in the defense of the lung, these alterations in the production of reactive oxygen species after ingestion of alcohol could explain why alcoholics are more sensitive to pulmonary infections.

Animals↗
PubMed1993

Diagnosis and management of foetal thrombocytopenia.

Platelet counts remain stable during intrauterine life (245 +/- 65 x 10(9)/litre, mean +/- SD). Before diagnosing thrombocytopenia (< 150 x 10(9)/litre), a foetal blood sample must be checked for contamination with amniotic fluid, since even slight contamination can activate coagulation and lead to a false positive result. In this paper, we review the major causes of thrombocytopenia and discuss their pathogenesis and management. Foetal thrombocytopenia can be caused by maternal complications (immune thrombocytopenic purpura, neonatal alloimmune thrombocytopenia, gestational thrombocytopenia, preeclampsia, alloimmune haemolytic disease) or infectious diseases (toxoplasmosis, cytomegalovirus, rubella) or be of true foetal origin (chromosomal abnormalities, malformations, congenital thrombocytopenia, intrauterine growth retardation.

Female↗
PubMed1993

Separation of red blood cells by field flow fractionation.

Field flow fractionation (FFF) is a new methodology described as being well-suited for the separation and characterization of biopolymers and particles. On theoretical grounds, cells may be separated with FFF if they differ in size, density or deformability. In the present study, we first tried to determine optimal separation conditions for red blood cells; thereafter we used FFF to examine red cell changes during a phenylhydrazine-induced hemolytic anemia. It has been shown that in less than 30 minutes, FFF is able to separate normal red blood cells from Heinz body-rich cells or reticulocytes that differ in size or density. The successive steps of hemolysis and regeneration appear clearly on the fractograms. Advantages and drawbacks of the method are discussed.

Anemia, Hemolytic↗
PubMed1993

Plasma/serum protein patterns in human fetuses and infants: a study by high-resolution two-dimensional polyacrylamide gel electrophoresis.

Plasma/serum proteins of fetal blood samples (N = 88) obtained under ultrasound guidance between the 18th and the 39th week of pregnancy, of blood samples collected from premature infants (N = 19), newborns at term (N = 20) and children of less than 5 years of age (N = 55) were analysed by high-resolution two-dimensional polyacrylamide gel electrophoresis. By comparison with adult 'reference' protein maps, tens of different proteins (and some of their genetic variants) were identified on the electrophoretograms. After the 18th week of gestation, albumin, transferrin, Factor B, glu- and lys-plasminogen, antithrombin III, Gc-globulin, alpha 1-antitrypsin, alpha 2-HS-glycoprotein, several apolipoproteins (apo A-I, A-II, A-IV, C-II, C-III, D, E, J), retinol-binding protein, transthyretin and alpha-fetoprotein could be observed. During intrauterine life, the size of the spots corresponding to alpha-fetoprotein progressively decreased, whereas the protein pattern globally showed an increase in the number and in the size of the spots. These modifications were particularly apparent in the regions of the electrophoretograms restricted to the heavy and light chains of IgG and to alpha 1-antichymotrypsin. In addition, we observed an unidentified fetal polypeptide characterized by an apparent molecular weight (M(r)) of 46 kDa (P46) and a pI of 5.0. P46 was present in all fetuses and all infants of less than 2 years of age.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗