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E Petit

Publications and source records attributed to E Petit.

84 records · Page 5Linked to original sources
PubMed1985

Interferon-induced enhancement of newborn pig natural killing (NK) activity.

The possible activation of Natural Killing (NK) activity by interferon (IFN) was studied in peripheral blood leukocytes of newborn piglets. It is reported that, although NK is very low during the first week of life, in vitro pretreatment of newborn leukocytes with semi-purified human alpha IFN induces a significant NK enhancement. These data suggest that piglets have pre-NK cells which become fully cytotoxic when exposed to IFN.

Animals↗
PubMed1983

Effects of intravenous injection of BCG or Freund's complete adjuvant on swine alveolar macrophages.

The intravenous injection of killed mycobacteria in oil (Freund's Complete Adjuvant) or BCG produces an accumulation of macrophages in swine alveolar airspaces. The collected alveolar macrophages were studied in vitro: expression of Fc and complement surface receptors, uptake of chicken red blood cells and in vitro spreading were not modified by either treatment, whereas the cytostatic activity of alveolar macrophages decreased following administration of high doses of BCG or Adjuvant. These "treated" cells have a lower thymidine incorporation rate, which suggests that cell accumulation is related to an influx of blood monocytes and not to an in situ cell multiplication.

Animals↗
PubMed1983

In vitro effects of lipopolysaccharides and mycobacterial cell wall components on swine alveolar macrophages.

The possible activation of swine alveolar macrophages (AM) by lipopolysaccharides (LPS) and mycobacterial cell wall components such as muramyl dipeptide (MDP) and interphase material (IPM) was investigated. Swine AM were harvested by post mortem lung washings and the following functions were assayed: adherence and spreading in cultures; phagocytosis of 51Cr-labelled chicken red cells; cytostatic activity against xenogeneic tumour cells (P815 mastocytoma cells); monokine synthesis; interferon and LAF (lymphocyte activating factor or interleukin-1). Incubation of swine AM with either MDP, LPS or IPM (0.1 micrograms to 100 micrograms/ml) for 24 hours did not affect the cell viability but increased their adherence and spreading slightly. Phagocytosis was not markedly modified. Under the same experimental conditions, the unstimulated AM cultures exhibited a strong cytostatic activity which was not modified by these components. No interferon synthesis could be observed in the normal or stimulated AM cultures. In contrast, LAF activity was consistently increased after 48 hours of incubation with LPS, whereas MDP produced this effect only in some experiments.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMedDate not supplied

Immunological approach to investigating membrane cell damages induced by lipoperoxidative stress. Application to far UV-irradiated erythrocytes.

Oxygen-reactive species are being described as agents responsible for cell degeneration mechanisms resulting from membrane, enzyme, and nuclear alterations. Lipid peroxidation on its own is considered to be one of the consequences of the free radicals attack, and among the different reactive aldehydes that can be formed from the decomposition of lipid peroxides, the most extensively assayed have been malondialdehyde (MDA). However, the different techniques currently used for MDA assay (HPLC, GLC) are barely sensitive enough to follow its production at the cellular level. In order to develop an immunofluorescent technique able to detect cellular damages provoked by lipoperoxidation, polyclonal antibodies against lysozyme modified by MDA treatment have been raised in rabbits. We show that this immunserum recognizes specifically all the MDA-treated proteins tested, but not the intact proteins or the proteins treated by other aldehydes. Moreover, we demonstrate using an ELISA technique that the amount of immunoreactive proteins in MDA-treated membrane erythrocytes is proportional to the concentration of MDA applied, suggesting that this assay may represent a quantitative method of determination of lipoperoxidative alterations. In addition, when coupled to an indirect fluorophore antibody (FITC), the immunserum allows a precise location of these modified proteins within the membranes of erythrocytes in which lipid peroxidation was initiated by far UV irradiation. In summary, the interest of this work is to provide an immunological probe that can precociously detect membrane damages induced by MDA, regardless of the cell type and pro-oxidant (physiological or pathological) conditions.

Animals↗
PubMedDate not supplied

Microsatellite variation in an introduced mouflon population.

As previous studies of genetic polymorphism in the mouflon (Ovis gmelini) have not provided any valuable markers for population studies, we tested the capacity of microsatellites to index the genetic diversity of a recently introduced mouflon population. Six pairs of bovine primer amplified microsatellites in mouflon, and all six were polymorphic. Furthermore, despite the low number of founders, five loci had a high gene diversity in this introduced population. Unlike other genetic markers, microsatellites could be powerful to study the genetic structure of mouflon populations.

Animals↗
PubMedDate not supplied

Construction and characterization of a bovine BAC library with four genome-equivalent coverage.

A bovine artificial chromosome (BAC) library of 105 984 clones has been constructed in the vector pBeloBAC11 and organized in 3-dimension pools and high density membranes for screening by PCR and hybridization. The average insert size, determined after analysis of 388 clones, was estimated at 120 kb corresponding to a four genome coverage. Given the fact that a male was used to construct the library, the probability of finding any given autosomal and X or Y locus is respectively 0.98 and 0.86. The library was screened for 164 microsatellite markers and an average of 3.9 superpools was positive for each PCR system. None of the 50 or so BAC clones analysed by FISH was chimeric. This BAC library increases the international genome coverage for cattle to around 28 genome equivalents and extends the coverage of the ruminant genomes available at the Inra resource center to 15 genome equivalents.

Animals↗
PubMedDate not supplied

Three novel point mutations in the keratinocyte transglutaminase (TGK) gene in lamellar ichthyosis: significance for mutant transcript level, TGK immunodetection and activity.

We have investigated 8 patients from 7 unrelated families with lamellar ichthyosis (LI) for defects in the keratinocyte transglutaminase (TGK) gene. We have characterized three novel homozygous mutations and a previously reported splice acceptor site mutation. One patient showed a C-to-T change in the binding site for the transcription factor Sp1 within the promoter region. Another patient had a Gly 143-to-Glu mutation in exon 3 and a third patient, affected with a particular form of LI sparing the four limbs, demonstrated a Val382-to-Met mutation within exon 7. These three patients exhibited drastically reduced transglutaminase activity and an absence of detectable TGK polypeptide, as assessed by immunofluorescence and immunoblotting. Northern blot analysis showed that the Sp1 site mutation was associated with profound reduction of TGK transcript levels whereas normal transcript levels were observed for the two missense mutations. We hypothesize that the Sp1 site mutation impairs transcription of the TGK gene, whereas the two missense mutations induce structural changes leading to protein instability. Linkage to TGK was excluded in another family and no evidence for TGK defect was found in 3 other patients. These results further support the involvement of TGK in some patients with LI. They identify a TGK mutation as a cause for non-generalized LI and further delineate the molecular mechanisms underlying TGK deficiency in LI.

Adult↗