Search PubMed⌕ Search

Biomedical subjects

A Petit

Publications and source records attributed to A Petit.

At least 55 records · Page 3Linked to original sources
PubMed1998

Epidermodysplasia verruciformis-like eruption complicating human immunodeficiency virus infection.

Three human immunodeficiency virus (HIV)-infected patients presented with disseminated pityriasis versicolor-like skin lesions. Histological examination showed features characteristic of epidermodysplasia verruciformis (EV). Hybridization studies demonstrated the presence of human papillomavirus (HPV) type 5 (HPV5) DNA in two patients and HPV20 in one. A relative increase in CD8+, CD57+ cells, which are known to inhibit cell-mediated cytolysis, was observed in all patients. HLA-DQB 0301 haplotype, which has been associated with EV, was detected in two patients. The findings suggest that infection with EV-associated HPV types can complicate HIV infection. Both cellular immune defects and a hitherto unknown genetic background might explain the occurrence of EV in HIV-infected patients.

AIDS-Related Opportunistic Infections↗
PubMed1998

Auxin production is a common feature of most pathovars of Pseudomonas syringae.

We investigated indole-3-acetic acid (IAA) production by 57 pathovars of Pseudomonas syringae and related species. Most of those analyzed produced IAA, especially in the presence of tryptophan. Eight strains produced high IAA concentrations in the absence of Trp. The iaaM and iaaH genes of P. savastanoi pv. savastanoi were detected in a limited number of strains only, including the eight above-mentioned strains. Thus, IAA synthesis in most assayed strains of P. syringae and related species does not involve genes highly similar to iaaM and iaaH. In contrast, the iaaL gene encoding an IAA-lysine synthase was detected in most pathovars, and was often found on plasmids.

Indoleacetic Acids↗
PubMed1998

[Result and outcome of prenatal detection of congenital cardiopathies at the Côte-d'Or over a period of 9 years].

Antenatal echocardiographic diagnosis of congenital heart disease in 699 women living in the department of the Côte d'Or between 1988 and 1996 revealed 39 cardiac abnormalities which were later confirmed by anatomical examination or echocardiography. During the same period, 157 cardiac malformations which could have been detected in the antenatal period were diagnosed after birth. The detection rate of congenital heart disease was 19.8% over the whole study period, and 33.3% in the last three years. The malformations which were most easily diagnosed were hypoplastic left ventricle, single ventricle, atriventricular canal and severe obstruction of the ventricular outflow tracts. Twenty-one abortions (53.8%) were undertaken because of the severity of the cardiac lesion or of a genetic abnormality. Seventeen children were live born (43.5%) but, globally, they had severe malformations and the mortality rate was 84.5% whereas in the children diagnosed post-partum, the lesions were generally less severe and the mortality was 19.7%. The detection rate of congenital heart disease depends on the screening of first intention. Thus, 90% of the lesions diagnosed in this series were referred because of a foetal heart abnormality and, in this indication, echographic expertise was by far the most accurate with 33% of confirmation. As other workers have reported, teaching programmes and regional collaboration between physicians implicated in antenatal care are essential.

Echocardiography↗
PubMed1997

Expression of G proteins in human placentas from pregnancies complicated by gestational hypertension.

Preeclampsia (gestational hypertension) is accompanied by decreased hPL and increased hCG levels in maternal serum. The expression of these peptides as well as the endocrine mechanisms responsible for their regulation in preeclampsia are unknown. We have demonstrated that regulatory GTP-binding proteins (G proteins) are implicated in the modulation of hPL production by placentas from normal pregnancies. In order to extend our knowledge on placental endocrinology, we analyzed in this study the expression of hPL and beta-hCG mRNAs as well as placental G protein alpha-subunits in pregnancies complicated by gestational hypertension. Western and Northern blot analyses were respectively performed on membrane protein and total mRNA preparations from human placentas of preeclamptic (n = 7) and normal pregnancies (n = 4). The levels of hPL and beta-hCG mRNAs were respectively 108% and 105% of those from normal placentas, suggesting that the altered circulating levels of hPL and beta-hCG are not related to dysfunctional mRNA expression of these peptides. The autoradiographs for G proteins and their mRNAs showed no difference in G protein expression between preeclamptic and normal tissues. Specifically, G alpha i2, G alpha i3, G alpha o, G alpha s, and G alpha q/11 levels reached 87%, 81%, 91%, 99%, and 103% respectively of those from normal placentas. In parallel with the protein levels, their mRNAs expression were respectively 93%, 89%, 113%, 104%, and 94% of normal values for G alpha i2, G alpha i3, G alpha o, G alpha s, and G alpha q/11. These results suggest that neither a change in hPL and beta-hCG expression nor a change in signal transduction machinery is implicated in the altered circulating levels of hPL and beta-hCG in preeclampsia.

Chorionic Gonadotropin↗
PubMed1997

Interaction of D2-dopamine receptor with two pertussis toxin sensitive G proteins in human placenta.

We have demonstrated the presence in human placenta of D2 dopamine receptors (D2R) which inhibit human placental lactogen (hPL) release. This inhibitory effect of dopamine (DA) was sensitive to pertussis toxin (PTX) indicating that it may be mediated by the Gi/Go family of G proteins. However, nothing is known on this G proteins/D2R interaction in human placenta. In this study, we demonstrate that DA (10(-4) M) inhibits by 39% the ADP-ribosylation by PTX of two G proteins of 40 and 41 kDa. This inhibition is receptor specific since it is reversed by spiperone, a D2R antagonist. Moreover we show that bromocriptine, a D2 agonist, inhibited the labeling of these two proteins in a dose-dependent manner with a maximal inhibition of 37% at a concentration of 10(-6) M. In order to understand the role of D2R in placental endocrinology, we have analyzed the interactions of these two PTX-sensitive G proteins with D2R in normal and abnormal pregnancies. The autoradiographs of both PTX ADP-ribosylated placental proteins of 40 and 41 kDa showed differential labeling during normal pregnancy. Thus, the relative levels of ADP-ribosylation by PTX of both proteins were 2.5 and 3.0 fold lower at term than those observed during first and second trimester whereas no difference was observed between the first and second trimester. Also, no significant change in the level of inhibition by DA was observed between 7-9 weeks and 18-40 weeks of pregnancies (35-45% inhibition). However, we observed a maximal inhibition between 10 to 17 weeks of pregnancy (64% inhibition). In placentas from preeclamptic pregnancies, the levels of ADP-ribosylation were similar to those observed in normal pregnancy, while the DA inhibition was increased by 24%. The levels of ADP-ribosylation in molar placentas reached 20% of normal values, while no difference in DA inhibition was observed. This study demonstrates that two distinct PTX-sensitive G proteins are coupled to human placental D2R. The physiological significance of the variations in these ADP-ribosylated-G proteins/D2R interaction during normal and preeclamptic pregnancies remains to be investigated.

Adenosine Diphosphate↗
PubMed1997

Genetically engineered plants producing opines alter their biological environment.

Little is known about the consequences of releasing genetically engineered plants (GEP) into the environment. Using opine-producing GEP, we show that transgenic plants alter their biological environment, more precisely the root-associated bacterial populations. The alterations were both transgene-specific and target population-specific. Therefore, assessment studies on the introduction of a given transgene into a GEP will be valid on the given transgene. Evidence of any transgene-associated biological effect will depend on the determination of the pertinent target populations, the identification of which is a key step of such studies.

Bacteria↗
PubMed1997

Somatic excision of the Ac transposable element in transgenic Arabidopsis thaliana after 5-azacytidine treatment.

We have introduced the maize Ac transposable element in Arabidopsis thaliana and found that after three selfing generations, the element is immobile and extensively methylated. Moreover, the nopaline synthase (nos) gene present on the same transferred T-DNA, was active early after transformation and regeneration, but inactive in most of the S1 progeny. We used 5-azacytidine (5AzaC) to determine whether a reduction in the methylation would affect both Ac transposition and expression of the nos gene. After treatment with 5AzaC doses from 0.3 mM to 1.0 mM, approximately 25% of the plants produced detectable amounts of nopaline, indicating that the nos gene was reactivated. Using the polymerase chain reaction (PCR) to detect the empty donor site left by Ac transposition, we demonstrated that 5AzaC also activates Ac excision in the transgenic plants. Approximately 13% of the 5AzaC treated plants (doses from 0.1 mM to 1.0 mM) were shown to have empty donor sites due to Ac excision. None of the plants cultivated in the absence of 5AzaC showed evidence for Ac transposition or reactivation of the nos gene. Further analysis using Southern blot indicate that some demethylation occurred in the genome of individual plants. These results may represent demethylation in few cells during development which may be sufficient to reactivate in these cells the expression of the nos and Ac transposase transgenes, the latter promoting Ac transposition in somatic cells.

Amino Acid Oxidoreductases↗
PubMed1997

[Disproportion in diameter of the cardiac chambers and great arteries in the fetus. Contribution to the prenatal diagnosis of coarctation of the aorta].

The aim of this study was to identify simple echocardiographic criteria suggesting the presence of coarctation of the aorta in the antenatal period. This was a retrospective cooperative study of 43 cases of foetal echocardiography referred to a paediatric cardiologist for abnormal dimensions of the left cardiac chambers and vessels compared with 102 control foetus. Eighteen (41.8%) had abnormalities of the aortic arch at birth. Thirteen of the 18 (72%) neonates had aortic arch abnormalities when disequilibrium with a small left heart was observed before 25 weeks amenorrhea. The ratio between the right and left ventricular dimensions was abnormally high in foetus with functional disequilibrium similar to the foetus with coarctation: the difference between the two groups was not significant. The ratio of pulmonary artery to aortic dimension was higher in the foetus with coarctation of the aorta than with functional disequilibrium. The difference was significant: p < 0.0001. The diameter of the aortic arch in foetus with a future coarctation was much smaller than the mean of the controls, except in 4 cases. The majority of the foetus without left-sided obstacles at birth had normal aortic arches. An early disequilibrium, a high pulmonary artery/aortic ratio and the small size of the aortic ischmus were the main elements suggestive of abnormalities of the aortic arch, especially in the early prenatal period.

Aorta, Thoracic↗
PubMed1996

[Contact photoallergic eczema caused by ketoprofen].

INTRODUCTION: Since 1983, several cases of allergy and photoallergic contact dermatitis to ketoprofen gel have been reported in Italy and Spain. In France, this drug has been available for topic applications since 1989 and no cases of photoallergy have been reported. CASE REPORT: We observed two cases of photoallergic contact dermatitis to ketoprofen (Profenid gel, Ketum gel). Imputability was suggested by clinical history and proven by patch-tests showing evidence of crossed photoallergy with fenofibrate in both cases. Photoallergic dermatitis to oxybenzone was associated in one case. COMMENTS: Ketoprofen is the predominant nonsteroid anti-inflammatory drug responsible for allergic and/or photoallergic contact dermatitis resulting from topic applications. Its prevalence is probably underestimated in France in light of the number of cases reported in certain Mediterranean countries. Cross reactive photoallergy to ketoprofen and fenofibrate can be explained by the common benzoly-ketone structure of these compounds. In case of skin reaction, the other drug should not be prescribed and benzophenone-containing cosmetics discouraged.

Adult↗
PubMed1996

Synthesis of putative metabolites and investigation of the metabolic fate of gliclazide, [1-(3-azabicyclo(3,3,0)oct-3-yl)-3-(4-methylphenylsulfonyl) urea], in diabetic patients.

Synthesis of postulated hydroxylated metabolites of gliclazide is described together with their detailed structural analysis using 1H-NMR, two-dimensional 1H-NMR, and MS to characterize the products. Metabolism of gliclazide has been investigated in the urine of nine patients of different ethnic origins receiving gliclazide therapy for the treatment of diabetes. Urine extracts were analyzed by GC/MS to quantify and identify the metabolites excreted in urine and the metabolites compared with the synthesized products. Metabolic profiles in all diabetic patients were very similar and comparable with those reported for healthy human volunteers. In addition to the expected metabolites arising from oxidation of the 4-methylphenyl ring, four isomeric hydroxylated products of the azabicyclooctyl ring were identified and the structure of a fifth isomer postulated.

Adult↗
PubMed1995

Prolonged impairment of hematopoiesis after high-dose therapy followed by autologous bone marrow transplantation.

Hematopoietic reconstitution has been studied in 180 patients after autologous bone marrow transplantation based on peripheral blood cell (PBC) recovery time and marrow progenitor counts sequentially tested for up to 4 years. Several factors that could influence hematopoietic reconstitution have been analyzed including sex, age, diagnosis, disease status, conditioning regimen, graft progenitor content, graft in vitro purging, and postgrafting administration of growth factors. Before transplantation, marrow progenitor values were normal only for colony-forming unit granulocyte macrophage (CFU-GM) in contrast to colony-forming unit-erythroid (CFU-E), burst-forming unit-erythroid (BFU-E), and colony-forming unit-megakaryocyte (CFU-Meg). After transplantation, as described with allogenic grafts, these values remained low for several years, although PBC counts were nearly normalized within a few weeks. Pregraft values were reached after 2 years for CFU-GM and BFU-E, and after 4 years for CFU-E, while CFU-Meg failed to reach pregraft values after this time. Normal levels were reached after 4 years only by CFU-GM. On univariate and multivariate analysis, the following factors appeared to delay both PBC and marrow progenitor reconstitution: underlying disease (particularly acute myeloid leukemias), graft characteristics such as low stem cell content and in vitro purging, conditioning regimens with total body irradiation or busulfan, and lack of postgraft administration of growth factors. In conclusion, high-dose therapy followed by bone marrow transplantation induces a deep and prolonged impairment of hematopoiesis irrespective of any alloimmune reaction or postgraft immunosuppressive therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗