Biomedical subjects

E Faure

Publications and source records attributed to E Faure.

At least 37 records · Page 2Linked to original sources

PubMed2000

Safe and effective placement of two bipolar silicone leads in the cephalic vein using a hydrophilic guidewire and a split introducer.

The cephalic vein (CV) is preferable to the subclavian vein for implanting permanent pacing leads because of fewer complications. Unfortunately, this access is unusable in a substantial number of patients. This prospective study evaluates a technique to increase CV access for the placement of two silicone bipolar leads used in DDD pulse generator implants. A standard cephalic cutdown was performed under local anesthesia and a hydrophilic guidewire (HGW) threaded in the CV. The first (ventricular) bipolar lead was then introduced and positioned. When possible, introduction of the second (atrial) lead followed the same direct access. A failed introduction led to a modified procedure (MP) relying on a "split" introducer (8-9 Fr Plastimed) advanced with a circular motion over the HGW, then removal of the dilator, removal of the HGW, insertion of the pacing lead into the sheath with placement in the right atrium, followed by sheath withdrawal. Over an 18-month period, 90 consecutive patients had DDD pacemakers implanted. The CV was accessible in 76 (84.5%) of 90 patients and the direct introduction of the ventricular lead was obtained in 74 (97.4%) of these. Atrialization proceeded as follows: direct access CV in 14 (18%) of 76 patients, MP access in 54 (71%) of 76 patients, and MP failure in 8 (11%) of 76 patients. Overall, this approach allowed cephalic dual insertion in 68 (89%) of 76 patients. In conclusion, the modified procedure presented in this study allows a dual catheterization with bipolar leads in 89% of patients when a CV is available. This significantly improves the success rate for dual bipolar lead implants in this configuration.

Adult↗

PubMed2000

[Malignant mediastinal lymph node tumors with unknown primary cancers].

PURPOSE: Malignant mediastinal lymph nodes with unknown primary tumor is a rare occurrence. The purpose of this study is to specify some characteristics of the patients presenting with this disease and to define an adequate therapeutic approach. MATERIAL AND METHODS: Between 1985 and 1997, we have operated on 54 patients with isolated non-small cell malignancy to mediastinal lymph nodes. Forty-nine patients underwent surgical biopsy of the mediastinal mass, generally followed by radiation therapy and/or chemotherapy. A mediastinal lymph node resection was performed in 5 patients. RESULTS: Five patients were lost to follow-up (9.3%). The 5-year survival rate and the median survival were 12.4 +/- 5% and 7 months respectively. Four of the 7 patients who were still alive after follow-ups ranging from 10 to 68 months had undergone a lymph node resection. During the follow-up, a primary tumor was discovered in only 5 patients (11.4%). CONCLUSIONS: Patients with isolated malignant lymph nodes of the mediastinum have a poor prognosis. In order to improve their survival, we recommend a more aggressive therapeutic approach comprising a chemotherapy and a mediastinal lymph node resection, associated in some cases with a lung resection. Radiation therapy of the mediastinum can be administered, principally in case of incomplete resection.

Actuarial Analysis↗

PubMed1999

Bacterial lipopolysaccharide activates nuclear factor-kappaB through interleukin-1 signaling mediators in cultured human dermal endothelial cells and mononuclear phagocytes.

Bacterial lipopolysaccharide (LPS)-mediated immune responses, including activation of monocytes, macrophages, and endothelial cells, play an important role in the pathogenesis of Gram-negative bacteria-induced sepsis syndrome. Activation of NF-kappaB is thought to be required for cytokine release from LPS-responsive cells, a critical step for endotoxic effects. Here we investigated the role and involvement of interleukin-1 (IL-1) and tumor necrosis factor (TNF-alpha) signal transducer molecules in LPS signaling in human dermal microvessel endothelial cells (HDMEC) and THP-1 monocytic cells. LPS stimulation of HDMEC and THP-1 cells initiated an IL-1 receptor-like NF-kappaB signaling cascade. In transient cotransfection experiments, dominant negative mutants of the IL-1 signaling pathway, including MyD88, IRAK, IRAK2, and TRAF6 inhibited both IL-1- and LPS-induced NF-kappaB-luciferase activity. LPS-induced NF-kappaB activation was not inhibited by a dominant negative mutant of TRAF2 that is involved in TNF signaling. LPS-induced activation of NF-kappaB-responsive reporter gene was not inhibited by IL-1 receptor antagonist. TLR2 and TLR4 were expressed on the cell surface of HDMEC and THP-1 cells. These findings suggest that a signal transduction molecule in the LPS receptor complex may belong to the IL-1 receptor/toll-like receptor (TLR) super family, and the LPS signaling cascade uses an analogous molecular framework for signaling as IL-1 in mononuclear phagocytes and endothelial cells.

Adaptor Proteins, Signal Transducing↗

PubMed1999

A sequence of the U5 region of Drosophila 1731 retrotransposon long terminal repeat (LTR) trans-represses the LTR-directed transcription.

Transcription of retrotransposons is modulated by various upstream and downstream regulatory sites and, as in retroviruses, the majority of these sites are in long terminal repeats (LTRs). Also, various mechanisms of positive or negative regulation have been shown in the LTR of 1731, a Drosophila melanogaster retrotransposon. Here we describe experiments investigating the possible mechanism of action of a region localized in the U5 region of the 1731-LTR, which has been considered as a silencer. Using cotransfection experiments, we have been able to show that this region is implicated in trans-transcriptional repression of the 1731 promoter in Schneider's Drosophila cells (S2). However, cotransfections have no effect on the UV-B upregulation of the 1731-LTR. Also, in spite of the fact that previous experiments have shown that UV-B irradiation activation of the 1731-LTR requires the same short sequence of U3 region both in drosophila cells and in a human colonic carcinoma cell line (HT29), cotransfection experiments showed that the silencer of the U5 region has no significant effect in human cells. Analysis of the U5 region shows the presence of a short open reading frame which could encode a 26 amino acid polypeptide. Furthermore, computer assisted sequence comparisons suggest a possible role for this putative peptide in the repression of transcription since this peptide has sequence similarities with some of the members of a family of inhibitors of transcriptional factor (Rox and Mnt proteins). Interestingly, the 1731-LTR contains the sequence CACGCG that is identical to the non-canonical E-box recognized by the Rox--Max heterodimer.

Amino Acid Sequence↗

PubMed1999

[Empirical treatment of urinary infections in urologic surgery].

Emergency prescription of empirical antibiotic therapy is justified in a context of febrile urinary tract infection, or to shorten the preoperative period in a hospitalised infected patient. The severity of the infection, its origin (community or nosocomial), morphological characteristics of the bacteria on direct examination, and urinary dip-stick data must be taken into account to select the most appropriate antibiotic while waiting for the antibiotic susceptibility test results.

Antibiotic Prophylaxis↗

PubMed1998

Secretion of extracellular factor(s) induced by X-irradiation activates the HIV type 1 long terminal repeat through its kappaB motif.

X-irradiation has been used in the treatment of several human diseases, including AIDS-related-malignancies. X-irradiation might induce the transcription and the replication of human immunodeficiency virus type 1 (HIV-1) and enhance nuclear factor kappa B (NF-kappaB). In the present article we show that the activation of the HIV-1 long terminal repeat (LTR) by direct X-irradiation can be mimicked by coculture of transfected cells with X-irradiated nontransfected (HIV-1-negative) cells. In the human colonic carcinoma cell line HT29, the activation seems to depend on an extracellular factor(s) released by a cell line treated with X-rays. The HIV-1 LTR cis-acting element conferring X-indirect responsiveness was identified as the kappaB tandem motif. The two main nuclear HIV-1 kappaB-binding complexes activated by X-direct and -indirect irradiation were the NF-kappaB p50/p65 and c-Rel/p65 heterodimers. Nuclear NF-kappaB activation was dependent on protein neosynthesis. It was partially inhibited by 100 microM pyrrolidine dithiocarbamate, a potent antioxidant drug, but was not correlated with a significant decrease in cellular IkappaBalpha. Furthermore, X-irradiation induces the expression of several cytokine genes generally associated with stress response and antibodies against interleukin 6 and TNF-alpha partially inhibited the X-indirect activation of the HIV-1 LTR. The use of protein kinase C (PKC)-specific inhibitor and of forskolin, an adenylate cyclase activator, suggests that a PKC-dependent pathway and the cAMP intracellular concentration could play a role in the X-indirect enhancement of HIV-1 LTR transcription in the HT29 cell line. In addition, supernatants of an X-irradiated HT29 cell culture activated the HIV-1 stimulation in infected peripheral blood monocytes.

Antioxidants↗

PubMed1998

Mitochondrial phylogeny of the European cyprinids: implications for their systematics, reticulate evolution, and colonization time.

Two different mitochondrial genes, the cytochrome b and the 16S rDNA, support the same European cyprinid molecular phylogeny: the most basal subfamily is the paraphyletic Rasborinae, the Cyprininae are monophyletic, the Tincinae and Gobioninae are close to the Cyprininae or more basal lineages but not close to Leuciscinae or Alburninae, and the Leuciscinae are paraphyletic but can become monophyletic if we include the biphyletic alburninae and exclude the Phoxinini. The relationship of the Acheilognathinae remains obscure. Natural intergeneric and interspecific hybridizations are clearly demonstrated within the Leuciscinae, both from high bootstrap proportions and intermediate morphological features: Chondrostoma toxostoma and Rutilus rutilus, Scardinius erythrophthalmus and R. rutilus, and Leuciscus multicellus and Leuciscus soufia. Finally, the use of the nonsaturated and clockwise 16S mtDNA sequences have been used to infer from nonintrogressive taxa the time of the first European cyprinid cladogeneses. The estimation confirms the hypothesis of Almaça and Banarescu that European cyprinid subfamilies started to diversify 35 mya and confirms the hypothesis of Bianco on the diversification of European leuciscines in the Mediterranean area during the late Messinian (6.5 to 5.3 mya).

Animals↗

PubMed1998

Cold abscess of the chest wall: a surgical entity?

BACKGROUND: Cold abscesses of the chest wall are rare tuberculous locations. Because of the resurgence of tuberculosis, this diagnosis must be considered more frequently. METHODS: During a 15-year period (1980 to 1995), 18 patients with one or more cold abscesses of the chest wall were managed in our department. Epidemiologic characteristics, indications, methods and results of operation, and pathogenesis of the abscesses were considered in this retrospective study. RESULTS: Most of the patients were immigrant men. A previous history of tuberculosis was noted in 15 cases (83%). Six patients had concomitant active pulmonary tuberculosis. There was mostly a solitary lesion in the chest wall, the most frequent location being the rib shaft (60%). Before operation the diagnosis was confirmed only in 4 patients (by needle aspiration of the abscess) and presumed in 4 others: an antituberculous chemotherapy was therefore given preoperatively to 8 patients. One patient did not undergo operation after a favorable response to medical treatment. In the other patients, an operation was indicated because of lack of response in 5 patients and the absence of diagnosis in 12 patients. Adequate debridement and a postoperative antituberculous regimen were performed with recurrence prevention in mind. A follow-up was obtained in 11 of the 17 patients undergoing operation. The only patient who required a second operation because of a recurrence at the same location had refused the antituberculous therapy after the first surgical procedure. Locations of the abscesses, computed tomographic scan results, and histologic examinations are in favor of a lymph-borne dissemination of tubercle bacilli. CONCLUSIONS: Because fine-needle aspiration remains an inaccurate diagnostic tool and antituberculous medical treatment is not always efficient, chest wall tuberculous cold abscesses remain in most cases a surgical entity.

Abscess↗

PubMed1998

Ultrastructural and immunohistochemical observations concerning laminin in B16 melanoma. Is an amorphous form of laminin promoting a non hematogenous migration of tumor cells?

The gravity of cancer is related to the propensity of tumor cells to migrate from a primary site to distant organs. It is generally accepted that tumor migration occurs in the vascular stream, via the endothelial basement membrane or lamina. A recent study identified in human malignant melanomas an angio-tumoral association (termed the angio-tumoral complex) characterized by an amorphous material juxtaposed between endothelial cells and tumor cells that contained laminin. The absence of any sign of intravasation and the pericytic location of tumor cells in this typical image raised the question of the role of these complexes in promoting tumorigenesis. Using the mouse B16 melanoma model, we observed an increase of angio-tumoral complexes with tumor progression, again without any evidence of intravasation. Given the role of laminin in migration and metastasis, we discuss a non hematogenous mechanism of tumor migration along the abluminal surface of endothelium.

Animals↗

PubMed1998

Angio-tumoral laminin in murine tumors derived from human melanoma cell lines. Immunohistochemical and ultrastructural observations.

Cells in tissues interact with each other and with the extracellular matrix as part of a structural and informational unit. During cancer progression, tumor cells participate in the formation of a neotissue involving other cells and matrix. We recently observed in melanoma an association between tumor and endothelial cells via an amorphous matrix containing free laminin. The pericytic location of melanoma cells in this angio-tumoral complex raised the question of an intramesenchymal migration of metastatic melanoma cells promoted by free laminin along the endothelium. However the respective roles of melanoma cells and endothelial cells in laminin secretion were not clear. In an attempt to clarify the latter issue, we injected into mice three human melanoma cells lines, one secreting laminin and two that did not, in order to identify the source of laminin secretion in the subsequent interactions between tumor cells and vascular endothelium. Using immunohistochemistry and electron microscopy we observed in all three cases an amorphous matrix containing laminin between tumor and endothelial cells. The fact that two cell lines did not secrete laminin suggests that the periendothelial/peritumoral laminin could be of endothelial origin. Given the presence of laminin alone during intramesenchymal angiogenesis and embryogenesis, we propose an analogous role for endothelial laminin in facilitating the migration of melanoma cells along the abluminal surface of the endothelium.

Animals↗

PubMed1998

Activation of transcription from the human immunodeficiency virus type 1 (HIV-1) long terminal repeat by the vasoactive intestinal peptide (VIP).

The ability of the human immunodeficiency virus type 1 (HIV-1) to persist and replicate in human CD4+ cells is under the control of both virally encoded proteins and a variety of host-related factors. Transcription of human immunodeficienty virus type 1 (HIV-1) is regulated by multiple cis-acting regulatory elements located in the viral long terminal repeats (LTRs). Here we report that the human vasoactive intestinal peptide (VIP) can activate the HIV-1-LTR. The activity of VIP is dose-dependent and specific. The effective concentration of VIP is within the physiological range suggesting that VIP release may modulate the activity of HIV-1 in vivo. A sequence in U3 region could be involved in VIP and in various VIP-related peptides' activation of HIV-1-LTR. This cis-acting element conferring VIP responsiveness is indistinguishable from HIV NF-kappa B tandem repeat binding sites (HIV-1 kappa B).

Enhancer Elements, Genetic↗

PubMed1998

X-rays-induced secretion of cellular factor(s) that enhance(s) HIV-1 promoter transcription in various non-irradiated transfected cell lines.

Various cellular stress agents like ionizing radiation exposure could activate human immunodeficiency virus type 1 (HIV- 1) replication or reporter gene expression. In addition, extracellular factor(s) released by X-ray-treated human colonic carcinoma cell line (HT29) might activate the long terminal repeat (LTR) of HIV-1 in non-irradiated HT29 cells. In the present report we show that in various transiently or stably transfected cell lines, X-ray irradiation up-regulates HIV-1 LTR transcription through the kappaB regulatory elements. A factor(s), which is processed by and acts upon a variety of cell types, was detected by addition to non-irradiated cells of either X-ray-treated cells or a conditioned medium taken from irradiated cultures. The magnitude of responsiveness is cell type dependent. In addition, X-ray activation of HIV-1 LTR in transiently or stably transfected cell lines is inhibited by a potent antioxidant drug, pyrrolidine dithiocarbamate and by another drug, known for its role in the trapping of growth factors, suramin. The importance of these observations in the pathophysiology of patients with AIDS-related cancers treated by radiotherapy remains to be established.

3T3 Cells↗

PubMed1997

Cell-to-cell contact activates the long terminal repeat of human immunodeficiency virus 1 through its kappaB motif.

Cell-to-cell contact between peripheral blood lymphocytes and transfected human colonic carcinoma cell line HT29 activates transcription of the long terminal repeats (LTR) of human immunodeficiency virus. HIV-1 LTR transcription is controlled by a complex array of virus-encoded and cellular proteins. Using various constructs expressing a lacZ reporter gene under the control of the intact or three deleted forms of HIV-1 LTR, we obtained evidence that the kappaB regulatory elements located in the U3 region are involved in cell-to-cell activation of HIV-1 LTR. Cell-to-cell contact activates in vitro binding of the nuclear factor kappaB (NF-kappaB) p50/p65 heterodimer to an HIV-1 kappaB oligonucleotide. Cell-to-cell contact activation of NF-kappaB was only partially inhibited by 100 microM pyrrolidine dithiocarbamate and was not correlated with a significant decrease of cellular inhibitor kappaB alpha. NF-kappaB nuclear activation was not detectable before 1 h after cell contact and was dependent on protein synthesis.

Base Sequence↗

PubMed1997

Efficacy of preoperative diagnostic imaging localization of technetium 99m-sestamibi scintigraphy in hyperparathyroidism.

BACKGROUND: Until now, preoperative parathyroid imaging has been considered unnecessary because currently available techniques do not provide any better results than an expert surgeon. We conducted a multicenter prospective study evaluating the capability of technetium 99m sestamibi scintigraphy in the preoperative identification of pathologic glands. METHODS: Ninety-three patients with hyperparathyroidism, seven of them reoperative cases, were studied. In addition, 20 age-matched normocalcemic control subjects were also studied. RESULTS: Surgical confirmation of scintigraphic images was obtained in 91 of 93 cases (sensitivity, 97.8%). In all reoperative cases (n = 7), in all cases of ectopic glands (whether operated or not; n = 6), and in all patients with a single-gland disease (n = 70), topographic identification of the pathologic gland was correct in 100%. In multiple-gland disease (n = 23), involvement of more than one gland was visualized in only 61% of the patients; however, in 91% of patients, at least one gland was localized. Surgical success-defined as postoperative normocalcemia-with this approach was 100%. All scans of normocalcemic control subjects were negative. Of 31 patients in whom a multinodular goiter coexisted, seven presented a significant radionuclide background at 120 minutes' scan. False-positive images were found together with those corresponding to the pathologic glands in only three cases. CONCLUSIONS: 99mTc-sestamibi is a highly reliable, sensitive, and specific technique for imaging of pathologic glands in hyperparathyroidism, especially in single-gland disease. It may be considered as a first line single-procedure when a preoperative topographic diagnosis is required.

Adult↗

PubMed1997

Induction of transcription from the long terminal repeat of the intracysternal particles type A (IAP) by X-irradiation.

Intracisternal A particles (IAPs) are retrovirus-like entities that are present in many embryonic and transformed cells of Mus musculus. They present long terminal repeats (LTRs) which control the promotion and regulation of their transcription. Using a construction expressing a reporter gene under the control of the entire long terminal repeat (LTR) of IAP in transfected murine fibroblast BALB/c 3T3 cells clone D152, we were able to show that the IAP-LTR is activated by X-irradiation in a time-dependent manner. The relative CAT activity increased with increasing X-irradiation doses, reaching a maximum at 75-150 cGy, followed by a drop in activation. In addition, X-induced D152 mouse cells produced extracellular factor(s), in response to X-irradiation, which activated the IAP-LTR in non-irradiated cells. This factor(s) was detected both when transfected cells were cocultured with inducing cells and when conditioned medium from irradiated cultures was added to the cell cultures. The use of suramin, a strong polyanonic molecule which has been reported to trap growth factors, induces a high reduction of the indirect activation.

3T3 Cells↗

PubMed1996

Mutant isoforms of the anti-Müllerian hormone type II receptor are not expressed at the cell membrane.

Anti-Müllerian hormone, a member of the transforming growth factor beta superfamily, produces early regression of Müllerian ducts in the male fetus through binding to a serine/threonine kinase receptor, homologous to type II receptors of the transforming growth factor beta (TGF-beta) family. A splice mutation of this receptor, described in a patient with abnormal retention of Müllerian derivatives, generates two mutant isoforms, one lacking the second exon and the other bearing an insertion of 12 bases between exons 2 and 3. Using hemagglutinin-tagged recombinant receptors, we have visualized wild type and mutant receptors in COS cells by Western blotting and immunoprecipitation. The 82-kDa, endoglycosidase H-insensitive, mature form of the wild type receptor is reduced to 68 kDa by N-glycosidase F treatment. Mutant receptor isoforms, 73 and 63 kDa for the long and short form, respectively, are sensitive to endoglycosidase H, suggesting that they are retained in the endoplasmic reticulum. Indeed, only the wild type receptor was expressed on the cell surface and bound iodinated anti-Müllerian hormone. These results provide a biological explanation for the failure of the mutant receptor to induce Müllerian regression.

Alternative Splicing↗

PubMed1996

Activation of the HIV type 1 long terminal repeat by X-irradiation involves two main Re1/NF-kappa B DNA-binding complexes.

Transcription of human immunodeficiency virus type 1 (HIV-1) is regulated by multiple cis-acting regulatory elements located in the viral long terminal repeats (LTRs). HIV-1 LTR enhancer is activated by a variety of heterologous viral, chemical, and physical agents. Studies have demonstrated that irradiation by X-rays induces transcription under the control of the HIV-1 LTR and that ionizing radiations activate DNA binding of the nuclear transcription factor NF-kappa B. Using various constructs expressing a reporter gene under the control of complete or deleted LTRs of HIV-1, we evidenced that a sequence located in the U3 region was involved in X-ray activation of the HIV-1 LTR in the human colonic carcinoma cell line HT29. The cis-acting element conferring X-ray responsiveness is indistinguishable from HIV NF-kappa B tandem repeat binding sites (HIV-1, kappa B). The present work has examined the effects of X-irradiation on the NF-kappa B transcription factor. Furthermore, we characterized the subunit composition of the two major nuclear NF-kappa B complexes that bind HIV-1 kappa B after X-ray irradiation.

Antioxidants↗

PubMed1996

Upregulation of the Drosophila 1731 retrotransposon long-terminal repeat by UV-B irradiation requires a short sequence in the U3 region.

A 1731 is a Drosophila melanogaster retrotransposon, the transcripts of which decrease in Drosophila cells after treatment by the 20-hydroxyecdysone (20-OH), the steroid-molting hormone of insects. In order to analyze the regulation of the long terminal repeat (LTR) directed transcription by UV-B, S2 Drosophila cells were transfected with various chimeric constructs carrying the LTR of 1731 linked to the bacterial chloramphenicol acetyltransferase (CAT) reporter gene and then subjected to UV-B irradiation. The results demonstrated that the 1731 LTR is activated by UV-B irradiation in a dose- and time-dependent manner. Using constructions expressing the reporter gene under the control of either the entire or deleted LTRs of 1731, we established that a sequence located in the U3 region was required for the retrotransposon to respond to UV-B. The cis-acting element is identical to the binding sequence of the dorsal transcription factors. In addition, the S2 Drosophila cell produced extracellular factor(s) in response to UV-B irradiation which activated the 1731 LTR in nonirradiated cells. This factor(s) was detected when responding cells were cocultured with inducing cells and when conditioned medium from irradiated cultures was added to the cell cultures.

Animals↗