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Biomedical subjects

A Imbert

Publications and source records attributed to A Imbert.

14 recordsLinked to original sources
PubMed2003

[Diagnostic strategy when confronted with a moderate and prolonged increase of transaminases].

TWO TYPES OF SITUATIONS: Measurement of transaminase serum activity is a common biological test. Although the etiological scope of acute and severe hyper-aminotransferase is codified and limited, that of prolonged and moderate hyper-aminotransferase is much broader. IN THE CASE OF PROLONGED AND MODERATE INCREASE IN TRANSAMINASE SERUM ACTIVITY: The discovery of this abnormality during systematic biological controls is a frequent situation, and its management is relatively well standardised. It requires a rigorous diagnostic strategy, which includes the search for consumption of alcohol, overweight, chronic hepatic disease of viral origin and the nature of the medicinal products ingested. FROM AN ETIOLOGICAL POINT OF VIEW: The most frequent causes of moderate and prolonged hyper-aminotransferase are alcohol abuse, overweight, non-insulin-dependent diabetes, dyslipaemia, viral hepatitis and medicinal products. However, less frequent hepatic or extra-hepatic causes must not be neglected.

Alcoholism↗
PubMed2001

Delta N89 beta-catenin induces precocious development, differentiation, and neoplasia in mammary gland.

To investigate the role of beta-catenin in mammary gland development and neoplasia, we expressed a stabilized, transcriptionally active form of beta-catenin lacking the NH(2)-terminal 89 amino acids (Delta N 89 beta-catenin) under the control of the mouse mammary tumor virus long terminal repeat. Our results show that Delta N 89 beta-catenin induces precocious lobuloalveolar development and differentiation in the mammary glands of both male and female mice. Virgin Delta N 89 beta-catenin mammary glands resemble those found in wild-type (wt) pregnant mice and inappropriately express cyclin D1 mRNA. In contrast to wt mammary glands, which resume a virgin appearance after cessation of lactation, transgenic mammary glands involute to a midpregnant status. All transgenic females develop multiple aggressive adenocarcinomas early in life. Surprisingly, the Delta N89 beta-catenin phenotype differs from those elicited by overexpression of Wnt genes in this gland. In particular, Delta N 89 beta-catenin has no effect on ductal side branching. This suggests that Wnt induction of ductal branching involves additional downstream effectors or modulators.

Adenocarcinoma↗
PubMed2001

[Hepatotoxicity of medications].

A TIMELY TOPIC: Liver toxicity remains a common problem despite adequate information for physicians and drug watch programs. The number of recent publications reporting severe drug-induced liver disease emphasizes the need for prudence. ACUTE AND CHRONIC HEPATOTOXICITY: Cases of acute drug-induced liver disease have been described for nearly all drug classes: a few examples concern hepatitis subsequent to administration of fluoxetin, acarbose, riluzole, coumarin, or orlistat. Fulminant hepatitis is fortunately an exceptional event but has been described after administration of ketoprofene, nimesulid, and clarithyromycin. Chronic liver disease has also resulted from the use of mesalazine, minocyclin or fibrates. Nevirapin prescribed for HIV infection can cause severe liver disease. OTHER AGENTS: Certain herbal agents, such as chelidoin for example, can cause cholestasis. Certain excipients can also be toxic for the liver. Ecstasy appears to be a frequent cause of sometimes severe liver disease in younger subjects.

Chemical and Drug Induced Liver Injury↗
PubMed2001

Giant cell arteritis localized to the colon associated with Crohn's disease.

AIMS: Intestinal vasculitis is uncommon and usually accompanies systemic vasculitis. Although intestinal vascular changes including vasculitis have been studied intensively, and are found regularly in Crohn's disease, giant cell arteritis is distinctly unusual. We describe a case of giant cell arteritis localized to the colon of an 18-year-old girl suffering from Crohn's disease. METHODS AND RESULTS: After three years of medical treatment, the patient underwent a proctocolectomy. The medium-sized arteries of the mesocolon demonstrated striking changes characterized by intimal fibrous thickening and an inflammatory infiltrate with giant cells, most predominant at the intima-media junction. Epithelioid cells and sarcoid-like granulomas were not observed. The internal elastic lamina was fragmented. Neither clinical symptoms nor laboratory findings showed evidence of systemic vasculitis. Neither the chest CT scan nor the echo-Doppler of the temporal arteries, supra-aortic and abdominal vessels revealed any abnormality. CONCLUSIONS: This case illustrates an extremely rare feature in the spectrum of vascular lesions in Crohn's disease which have to be differentiated from temporal and Takayasu's arteritis.

Adolescent↗
PubMed1999

Flow cytometric assessment of amphotericin B susceptibility in Leishmania infantum isolates from patients with visceral leishmaniasis.

Amphotericin B susceptibility was measured by a flow cytometric membrane potential assay in Leishmania infantum promastigotes isolated from 11 immunocompetent children treated with liposomal amphotericin B and 19 HIV-infected young adults treated with intralipid amphotericin B. Susceptibility levels were measured by the 90% inhibitory concentrations (IC90) representing the concentrations of drug that induced a 90% decrease in membrane potential compared with the control culture. In immunocompetent children, treatment was fully effective whatever the susceptibility of isolates to amphotericin B. In immunocompromised adults, on the contrary, unresponsiveness and relapses could be observed in all cases and IC90 increased in the course of successive treatments: a decrease of amphotericin B susceptibility in both promastigote and amastigote forms could be observed in a patient who had six relapses. These results suggest that the success of amphotericin B treatment depends greatly on patient immunity status, and indicate that successive relapses could enhance emergence of amphotericin B resistant isolates. The results demonstrate that the flow cytometric membrane potential assay can be used as an easy and reliable tool for studying the evolution of interactions between amphotericin B and the parasite membrane during long-term treatments.

Acquired Immunodeficiency Syndrome↗
PubMed1998

Chromosome region 8p11-p21: refined mapping and molecular alterations in breast cancer.

Several genes, most of them unknown, of the short arm of chromosome 8 are involved in malignant diseases. Numerous studies have implicated a portion of the 8p11-p21 region as the location of one or more tumor suppressor genes involved in a variety of human cancers, including breast cancer. We and others have reported linkage analyses suggesting the presence of a putative breast cancer susceptibility gene. Furthermore, several oncogenes of the 8p11-p12 region are involved in reciprocal translocations in myeloproliferative and myelodysplastic disorders and in amplification in breast cancer. To facilitate the analysis of the 8p11-p21 region and the cloning of candidate oncogenes and tumor suppressor genes, a high-resolution physical and transcriptional map was established with 39 yeast artificial chromosomes and 94 markers, including so-called sequence-tagged sites and expressed sequence-tagged sites derived from either known genes or expressed sequence tags corresponding to unidentified transcripts. In addition, four novel transcripts were identified and localized precisely within the map. This transcription map provides a detailed description of gene order for the 8p11-p21 region and will be helpful in the identification of candidate genes for diseases. From this basis, we refined the mapping of two types of molecular alterations that occur at 8p11-p21 in sporadic breast cancers, i.e., amplification and deletion.

Breast Neoplasms↗
PubMed1997

The ECG in pulmonary embolism. Predictive value of negative T waves in precordial leads--80 case reports.

BACKGROUND AND STUDY OBJECTIVE: The value of the ECG for the diagnosis of pulmonary embolism (PE) is debatable. Once the diagnosis of PE has been established, however, the ECG could allow the massive forms to be distinguished. The purpose of our study was to analyze the ECG signs in patients hospitalized for PE in a cardiology unit. DESIGN: Taking a series of 80 consecutive patients hospitalized for PE, we analyzed the ECGs on admission and then during hospitalization. We sought to evaluate changes in ECG signs compared with angiographic and hemodynamic changes in PE. RESULTS: T-wave inversion in the precordial leads is the most common abnormality (68%), and represents the ECG sign best correlated to the severity of the PE. Among those patients with anterior T-wave inversion, 90% had a Miller index over 50% (mean, 60 +/- 8%). Eighty-one percent had a mean pulmonary arterial pressure (PAP) over 30 mm Hg (mean, 37 +/- 8%). This subepicardial ischemic pattern is an even stronger marker of severity when it appears as early as the first day (p < 0.01). Its reversibility is correlated to the changes in PE. After thrombolysis in particular, normalization of repolarization systematically indicates mean Miller and PAP indexes of < 20% and < 20 mm Hg, respectively. CONCLUSIONS: The anterior subepicardial ischemic pattern is the most frequent ECG sign of massive PE. This parameter is easy to obtain and reflects the severity of PE. Its reversibility before the sixth day points to a good outcome or high level of therapeutic efficacy.

Adult↗
PubMed1996

Integrated map of the chromosome 8p12-p21 region, a region involved in human cancers and Werner syndrome.

Detailed physical maps of the human genome are important resources for the identification and isolation of disease genes and for studying the structure and function of the genome. To improve the definition of the 8p12-p21 chromosomal region, an integrated physical and genetic map was constructed extending from the genes. NEFL to FGFR1. The map comprises a series of contigs (the larger of these being around 9 Mb) of yeast artificial chromosomes (YACs) spanning the proximal region of deletion involved in a broad range of human cancers, including breast carcinomas, and in the Werner syndrome. In addition, losses of heterozygosity at 8p markers and linkage analysis of breast cancer families were also detailed. Finally, several genes potentially involved in 8p-associated diseases, namely GTF2E2, PPP2CB, and HGL, were precisely mapped within the YAC contigs. The reported map and contigs of YACs should facilitate the search for putative genes involved in sporadic and familial breast cancer as well as in the Werner syndrome.

Base Sequence↗
PubMed1996

A 3.1-Mb YAC contig within the Werner syndrome region, on the short arm of human chromosome 8.

The locus for Werner syndrome (WRN) has been localized to human chromosome 8p21 --> p12, close to the anonymous marker D8S339. A 3.1-Mb contig of yeast artificial chromosomes (YACs) was assembled around D8S339. Results from analyses of somatic cell hybrids, FISH, and physical mapping suggest the following loci order: tel-NEFL-D8S131-D8S339-[D8S540/GSR]-D8S124 -D8S259-D8S87-FGFR1-cen. Close physical linkage between D8S540 and GSR was established within a DNA fragment of 200 kb. These two loci are not more than 400 kb from D8S339. In addition, D8S339, D8S540, D8S124, and GSR are within 1.1 Mb. These data establish a primary physical map of the Werner syndrome region and identify useful YAC clones for the isolation of new markers and of the corresponding gene.

Chromosome Mapping↗
PubMed1995

Characterization of the region of the short arm of chromosome 8 amplified in breast carcinoma.

Chromosomal region 8p11.2-p12 is consistently amplified in human breast cancer. We have constructed a 2.8 Mb YAC contig of this region, centered on the human Fibroblast Growth Factor Receptor 1 (FGFR1) locus and encompassing the Adrenergic beta 3 Receptor (ADRB3) locus. A smaller centromeric YAC contig spanning 1.4 Mb was also assembled, and included the Ankyrin 1 (ANK1) and Tissue-type Plasminogen Activator (PLAT) genes. Results from mapping of the contigs showed physical linkage of the ADRB3 and FGFR1 genes, which were colocalized within the same YAC clone and separated by about 900 kb, FGFR1 being in centromeric position. It also showed physical linkage of ANK1 and PLAT genes, which appear to be separated by a maximum of 700 kb. In parallel, several loci were mapped according to their amplification status in a large panel of breast tumor samples. The overall amplification pattern suggested a continuous amplicon with a core around FGFR1. Data from both the detailed physical map and the amplification status allowed to establish the following gene order, from telomere to centromere: ADRB3-D8S105-FGFR1-ANK1-PLAT-POLB. The precise localization and YAC cloning of the core of the amplicon will allow to isolate a putative oncogene involved in mammary carcinogenesis.

Base Sequence↗
PubMed1994

Characterization of a yeast artificial chromosome from human chromosome band 13q12 containing the FLT1 and FLT3 receptor-type tyrosine kinase genes.

A yeast artificial chromosome containing the two receptor-type tyrosine kinase genes FLT1 and FLT3 was isolated, analyzed, and compared to a genomic map in order to establish their organization and linkage. FLT1 and FLT3 are physically linked in a head-to-tail configuration and separated by about 150 kb. The region contains three CpG islands. Two of them are likely to correspond to FLT1 and FLT3, whereas the third one is suggestive of another putative, unidentified RTK gene.

Base Sequence↗
PubMed1980

[Survey on the nitrate-nitrite content of various dairy products].

The laboratories charged with dairy product control have had to determine the nitrates and nitrites especially for the examination of products in view of export. The use of nitrates is prohibited in France. Some E.E.C. countries however authorize its use in cheese-making. The L.C.H.A. has carried for the last several years a systematic analysis of samples received for other studies in order to evaluate eventual contamination. The results can not be considered as representative of the whole French production, as they are samples from different composition and origins. The following have been examined during 1979: 729 dried milks (92,6% less than 30 mg/kg), 209 whey powders (56,5% less than 50 mg/kg), 133 milking feeds (82,7% less than 40 mg/kg), 1 039 cheeses (81,8% less than 5 mg/kg). The greater part of these analyses were realized by a Technicon autoanalyseur I and by manual cadmium reducing methods.

Autoanalysis↗