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Biomedical subjects

C Gérard

Publications and source records attributed to C Gérard.

At least 19 recordsLinked to original sources

[Heart failure patient management: evolution, organization, application on a local scale].

Heart failure is a severe disease which prevalence and incidence are steadily growing, with high morbidity and mortality rates, and responsible for significant financial cost. This evolution requires our therapeutic approach to be modified, by favouring multidisciplinary management and including patient education. The proof of the effectiveness of these measures is brought by many studies, and therapeutic education is now recommended by the European Society of Cardiology. This new approach of management is set out according to various procedures. In Le Creusot, the therapeutic unit of heart failure management was created in September 2004 and operate on a day hospital pattern. The results are satisfactory knowing that the average duration of spells fell by 33% after one year. Further local initiatives are spreading and need shall arise to pooling equipment and personnel as well as reinforcing collaboration between public and private professionals in order to improve heart failure patients' management. In the meantime a more sustained involvement of the authorities is to be hoped.

Ambulatory Care↗

[New approaches to prenatal diagnosis of rhesus incompatibility].

Despite generalisation of anti-D immunoprophylaxis, RhD allo-immunisation still remains the major cause of severe haemolytic disease of the fetus and of the newborn (HDFN). The routine follow up of pregnant women comprises: the ABO/D, Rh/Kell red cells typing and the search for irregular antibodies. In case of anti-D immunisation, the paternal Rh phenotype, when known, provides useful information regarding the probability for the fetus to have inherited the D antigen and thereby to be exposed to the risk of HDFN. The antibody titre, which is predictive of possible in vivo haemolysis, must be interpreted in the light of the previous obstetric history, and can lead to the decision of invasive amniocentesis. Then the measurement of the optical density (deltaOD450 nm) and the fetal RhD typing can be realised on amniotic fluid. New molecular techniques make it possible now to demonstrate the presence of fetal DNA in maternal plasma. These methods lying on non invasive procedures could advantageously be applied to the genotyping of fetal RHD during pregnancy. The present paper aims to discuss the predictive values of RHD fetal genotype in maternal plasma of RhD negative mothers. The ante-partum management of immunised pregnant women is reviewed in the light of this new molecular approach combined to Doppler ultrasonography of the fetal middle cerebral artery. This non invasive method for determining fetal RHD genotype could be systematically proposed to all RhD negative pregnant women for a better targeted prenatal follow-up and an increased efficacy of RhD prophylaxis.

Algorithms↗

[Hepatoid adenocarcinoma of the stomach. A case report].

Hepatoid adenocarcinoma of the stomach is a very rare tumor with a poor prognosis. Lymph nodes involvement and/or liver metastases are frequently observed. Diagnosis should be pointed out if elevated serum level of alpha-fetoprotein (AFP) is detected with gastric tumor. Histologically, the tumor is an adenocarcinoma of intestinal type including foci of hepatoïd differenciation. Immunohistochemistry is positive for alpha-1-antitrypsin and alpha-1-antichymotripsin, and for AFP. We report a case of a 66 year-old man presenting an advanced stage of hepatoid adenocarcinoma of the stomach, treated by gastrectomy followed by chemotherapy. The patient died four months after the surgery because of progressing liver metastatic disease.

Adenocarcinoma↗

Treatment of acute hepatitis C with interferon alpha-2b: early initiation of treatment is the most effective predictive factor of sustained viral response.

AIM: To evaluate the efficacy of early interferon alpha-2b in non-post-transfusion acute hepatitis C virus: a prospective study with historical comparison. PATIENTS: Group A: 28 patients prospectively treated for acute hepatitis C virus with daily regimen of interferon 5 million units for 2 months. Group B: historical series of 16 patients with untreated acute hepatitis C virus. RESULTS: There was no significant difference between the two groups with regard to gender, age, icterus, alanine aminotransferase, or genotypes. In group B, hepatitis spontaneously resolved in three of 16 (19%) patients (follow-up 1-7 years). In group A, 21 of 25 patients became sustained viral responders (75%; P = 0.0003 vs. group B). Factors include not predictive of sustained viral response: age, gender, sources of infection, presence of icterus, alanine aminotransferase peak, bilirubin peak, incubation period, presence of hepatitis C virus antibodies at presentation, or genotypes. The time from presentation to the start of therapy was, however, significantly shorter in sustained viral responders (43 +/- 31 days) than in relapsers or non-responders (88 +/- 52 days) (P = 0.016). CONCLUSIONS: Early treatment of acute hepatitis C virus with interferon prevents chronicity. A short waiting time from presentation to treatment appears as the most relevant predictive factor for sustained response.

Acute Disease↗

First occurrence of Schistosomatidae infecting Aplexa hypnorum (Gastropoda, Physidae) in France.

Due to the recrudescence of cercarial dermatitis in the world, larval Schistosomatidae have been researched during 20 months in gastropods of stagnant fresh waters in a wetland. Brevifurcate ocellate cercariae have been detected after crushing in a species of Physidae, Aplexa hypnorum, with a prevalence of 6.52%. Up to now, this species had never been found infected by larval trematodes. Lymnaeidae, Planorbidae and other Physidae didn't harbour schistosomatids. Cercariae of A. hypnorum present furcal fin-folds and the length of the tail stem is inferior to that of the body. Only cercariae of Heterobilharzia americana, Schistosomatidae of Carnivora in America, have also these two features. This species, not described in Physidae, is an agent of the human cercarial dermatitis. Schistosomatid cercariae in american species of Physidae have been compared with that of A. hypnorum. Brevifurcate ocellate cercariae of A. hypnorum, possible agent of the cercarial dematitis, probably belong to a new species with unknown genus.

Animals↗

BlaB, a protein involved in the regulation of Streptomyces cacaoi beta-lactamases, is a penicillin-binding protein.

Streptomyces cacaoi beta-lactamase genes are controlled by two regulators named blaA and blaB. Whereas BlaA has been identified as a LysR-type activator, the function of BlaB is still unknown. Its primary structure is similar to that of the serine penicillin-recognizing enzymes (PREs). Indeed, the SXXK and KTG motifs are perfectly conserved in BlaB, whereas the common SXN element found in PREs is replaced by a SDG motif. Site-directed mutations were introduced in these motifs and they all disturb beta-lactamase regulation. A water-soluble form of BlaB was also overexpressed in the Streptomyces lividans TK24 cytoplasm and purified. To elucidate the activity of BlaB, several compounds recognized by PREs were tested. BlaB could be acylated by some of them, and it can therefore be considered as a penicillin-binding protein. BlaB is devoid of beta-lactamase, D-aminopeptidase, DD-carboxypeptidase or thiolesterase activity.

Amino Acid Sequence↗

Prevalence of human erythrovirus B19 DNA in healthy Belgian blood donors and correlation with specific antibodies against structural and non-structural viral proteins.

BACKGROUND AND OBJECTIVES: Human parvovirus (erythrovirus) B19 is recognized as a major contaminant of blood and blood products. To reduce the risk of contamination, plasma-pool screening and exclusion of highly viraemic donations are recommended. The objectives of this study were to estimate the prevalence of B19 DNA in our blood-donor population, to determine the appropriate pool size to be tested (taking into account parameters such as prevalence, viral load, test sensitivity, and the efficacy of inactivation procedures), and to correlate viral loads with the serological status of donors as regards antibodies against different viral proteins. MATERIALS AND METHODS: Pools of different sizes were tested for B19, using a sensitive nested polymerase chain reaction (PCR) as well as an simple, un-nested, less sensitive PCR. Positive pools were resolved to the level of individual donations, and the viral load and serological markers were determined. RESULTS: Of 16,859 donations, 27 (one of 625) were found to be B19 DNA positive, with viral loads ranging from 10(2) to > 10(7) IU/ml. Twenty-five of the positive donations were tested for VP-specific anti-B19 antibodies, and eight (32%) were negative for both immunoglobulin (Ig)M and IgG. They were probably collected in the preseroconversion window period or from chronic carriers without detectable antibodies. We regarded the seven (28%) IgM-positive donors as being in the early phase of infection. The remaining 10 (40%) IgM-negative, IgG-positive donors were probably carriers of persistent infection (i.e. PCR positive despite the presence of IgG antibodies), as suggested by their low viral loads (< 10(4) IU/ml). Fifteen out of 36 major pools contained one or more contaminated donations. Among these, 12 tested positive by nested PCR and only three by un-nested PCR, this reflecting a viral load of > 10(4) IU/ml. CONCLUSIONS: By testing all donations as pools of 480 by un-nested PCR, and resolving positive pools to identify the responsible donations, it is possible to ensure that the viral load in fractionation pools (5000 donations) remains < 10(3) IU/ml, compatible with the efficacy of inactivation procedures and complying with Food and Drug Administration (FDA) recommendations.

Algorithms↗

[Spontaneous rupture of utero-ovarian vessels in postpartal period: a case report and review of the literature].

Spontaneous rupture of utero-ovarian veins occurring during pregnancy or the peripartal period is generally considered to be a medical curiosity (approximately 100 reported cases) rarely mentioned in obstetric textbooks. It is nevertheless a dramatic cause of maternal and /or fetal mortality. The available statistics are the following: 60% of the cases are directly related to labor and 50% occur in primiparas; when the rupture is associated with labor, mortality is 40%. Occurring outside of labor, mortality rate is approximatively 10%. The perinatal mortality remains high at 30%; in 75% of the cases, the broad ligament is the site of rupture (in many cases, the site of rupture is not found, at laparotomy or autopsy). We report the case of a patient who developed ovarian vein rupture on the 3rd postpartum day.

Adult↗

[Analysis of 516 reports of reactions after the transfusion of labile blood products].

BACKGROUND: In order to assess the implemented preventive measures of transfusion reactions (TR) and to make a study of residual reactions, we analyzed 516 TR reports from 14 hospitals, for three years since 1996 to 1998. METHODS: Clinical signs were classified according to seven etiologic categories. Systematic anti-erythrocyte and anti-leucocyte detection, as well as bacterial control of the returned bag were performed. RESULTS: The TR incidence is 3.7 per 1.000 products. Platelet concentrates (PC) provoke 7.4 TR per 1.000 transfusions, and red cell concentrates (RCC) 3.8. There are as many TR with apheresis platelets (AP), pre-storage leuco-depleted, as with random platelets, post-storage leuco-depleted, and as many with leuco-depleted RCC as with non leuco-depleted RCC. Leuco-depleted AP provoke more allergic reactions than other blood components. TR with AP are much more frequent in children than in adults. Plasma removal from AP before transfusion decreases reaction frequency. CONCLUSIONS: The lack in efficacy failure of pre-storage deleucocytation in TR prevention should be due to related patient factors. Etiology of AP allergic reactions deserves further study. PC suspension in synthetic medium before transfusion is an efficient means for RT decreasing. Hemovigilance system has to be improved so that all TR be reported.

Belgium↗

Structure and temporal variation of trematode and gastropod communities in a freshwater ecosystem.

The infro- and component community dynamics of digenetic trematodes in a freshwater gastropod community were examined over a 33-month period. The gastropod and trematode communities were composed of 17 and 10 species respectively. A total of 9,831 snails was collected; among them, 192 belonging to 14 species were infected by larval trematodes. The size of infected snails was significantly greater than that of healthy ones, and the increase of prevalence with size/age was interpreted as related to the increased probability of ultimately becoming parasitized. The trematode community was rich in allogenic species, but the most frequent trematode (cercariaeum) was autogenic and generalist (a range of 12 snail host species). There was a significantly positive relationship between the frequency of trematode species in the community and the number of first intermediate host species. A great temporal heterogeneity occurred in the prevalence of the snails, mainly attributed to the great temporal fluctuations of snail host populations and the variability of freshwater ecological conditions. The data on the occurrence of larval trematodes in 14 host species over the 33-month study allowed indicate a significant negative correlation between the abundance of gastropods and the prevalence of trematodes.

Age Factors↗

RXR-alpha ablation in skin keratinocytes results in alopecia and epidermal alterations.

RXR-alpha is the most abundant of the three retinoid X receptors (RXRs) in the epidermis. In this study, we have used Cre-mediated recombination to selectively disrupt the mouse gene for RXR-alpha in epidermal and hair follicle keratinocytes. We show that RXR-alpha is apparently dispensable for prenatal epidermal development, while it is involved in postnatal skin maturation. After the first hair pelage, mutant mice develop a progressive alopecia, histologically characterised by the destruction of hair follicle architecture and the formation of utriculi and dermal cysts in adult mice. Our results demonstrate that RXR-alpha plays a key role in anagen initiation during the hair follicle cycle. In addition, RXR-alpha ablation results in epidermal interfollicular hyperplasia with keratinocyte hyperproliferation and aberrant terminal differentiation, accompanied by an inflammatory reaction of the skin. Our data not only provide genetic evidence that RXR-alpha/VDR heterodimers play a major role in controlling hair cycling, but also suggest that additional signalling pathways mediated by RXR-alpha heterodimerised with other nuclear receptors are involved in postnatal hair follicle growth, and homeostasis of proliferation/differentiation of epidermal keratinocytes and of the skin's immune system.

Alopecia↗

Relationship between branching density and crystalline structure of A- and B-type maize mutant starches.

Amylopectin from two double maize mutant starches of A-crystalline (wxdu) and B-crystalline type (aewx) was subjected successively to hydrolysis involving alpha and beta amylases, which isolated clusters and all branching zones of clusters (BZC). Enzymatic analysis together with ionic and size-exclusion chromatography revealed the structural features of the clusters and BZC and their role in starch crystallization. A-type clusters were larger (dp(n) > 80) and contained more (but shorter) chains than B-type clusters. The BZC of A-type starch was also larger, but with a shorter distance between the branching points than in B-type BZC. A-type clusters had a densely packed structure and B-type a poorly branched structure. Models for the structure of A- and B-type clusters are presented, and a hypothesis for the influence of cluster geometry on crystallization is proposed.

Amylopectin↗

Germline transformation of the silkworm Bombyx mori L. using a piggyBac transposon-derived vector.

We have developed a system for stable germline transformation in the silkworm Bombyx mori L. using piggyBac, a transposon discovered in the lepidopteran Trichoplusia ni. The transformation constructs consist of the piggyBac inverted terminal repeats flanking a fusion of the B. mori cytoplasmic actin gene BmA3 promoter and the green fluorescent protein (GFP). A nonautonomous helper plasmid encodes the piggyBac transposase. The reporter gene construct was coinjected into preblastoderm eggs of two strains of B. mori. Approximately 2% of the individuals in the G1 broods expressed GFP. DNA analyses of GFP-positive G1 silkworms revealed that multiple independent insertions occurred frequently. The transgene was stably transferred to the next generation through normal Mendelian inheritance. The presence of the inverted terminal repeats of piggyBac and the characteristic TTAA sequence at the borders of all the analyzed inserts confirmed that transformation resulted from precise transposition events. This efficient method of stable gene transfer in a lepidopteran insect opens the way for promising basic research and biotechnological applications.

Actins↗

Targeted somatic mutagenesis in mouse epidermis.

Gene targeting in the mouse is a powerful tool to study mammalian gene function. The possibility to efficiently introduce somatic mutations in a given gene, at a chosen time and/or in a given cell type will further improve such studies, and will facilitate the generation of animal models for human diseases. To create targeted somatic mutations in the epidermis, we established transgenic mice expressing the bacteriophage P1 Cre recombinase or the tamoxifen-dependent Cre-ER(T2) recombinase under the control of the human keratin 14 (K14) promoter. We show that LoxP flanked (floxed) DNA segments were efficiently excised in epidermal keratinocytes of K14-Cre transgenic mice. Furthermore, Tamoxifen administration to adult K14-Cre-ER(T2) mice efficiently induced recombination in the basal keratinocytes, whereas no background recombination was detected in the absence of ligand treatment. These two transgenic lines should be very useful to analyse the functional role of a number of genes expressed in keratinocytes.

Animals↗

Vasoactive intestinal polypeptide and pituitary adenylate cyclase-activating polypeptides stimulate mitogen-activated protein kinase in the pituitary cell line GH4C1 by a 3',5'-cyclic adenosine monophosphate pathway.

Vasoactive intestinal polypeptide (VIP) and pituitary adenylate cyclase-activating polypeptide (PACAP38) regulate anterior pituitary cell secretion and proliferation. In the somatolactotrope GH4C1 cell line, these effects are mediated through the type-II-like PACAP receptor (VPAC2) coupled to the cAMP pathway. In this study, the control of the extracellularly responsive kinases (ERKs) by VIP and PACAP38 was investigated in GH4C1 cells. VIP and PACAP38 increased ERK1 and ERK2 phosphorylation and were equipotent stimulators of both kinases. ERK activation was mimicked by cholera toxin, forskolin and 8bromo-cAMP. VIP and PACAP38 activation of ERK2 was blocked by the protein kinase A inhibitor H89, whereas the protein kinase C inhibitor GF109203X, or prior PMA-induced depletion of the protein kinases C, failed to inhibit VIP and PACAP38 activation of ERK2. In contrast, thyrotropin-releasing hormone (TRH) elicited ERK activation by a PKC-dependent process. ERK activation by VIP or PACAP38 and TRH were additive and both sensitive to the MEK inhibitors PD98059 and U0126. In parallel, U0126 reduced prolactin (PRL) mRNA levels induced by VIP. These results demonstrate for the first time that VIP and PACAP38 activate ERK in GH4C1 cells. Cyclic AMP increase is sufficient to elicit ERK activation in these cells and thus likely to represent the transduction pathway underlying VIP- and PACAP38-dependent ERK activation. This mechanism seems to be involved in VIP-induced PRL gene regulation.

8-Bromo Cyclic Adenosine Monophosphate↗