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Biomedical subjects

N Delorme

Publications and source records attributed to N Delorme.

At least 19 recordsLinked to original sources
PubMed2007

Prosaposin is a novel androgen-regulated gene in prostate cancer cell line LNCaP.

Androgen-regulated genes (ARG) are implicated in normal and neoplastic growth of the prostate. Recently, we reported genomic amplification and/or overexpression of a previously known neurotrophic factor, prosaposin, in androgen-independent (AI) or metastatic prostate cancer (PCa) cells and tissues. Prosaposin and/or its known active molecular derivatives (e.g., saposin C) function as a pluripotent growth factor with diverse biological activities that favor malignant phenotypes in PCa cells. In addition, prosaposin or saposin C upregulates androgen receptor (AR) and AR-target genes (i.e., prostate-specific antigen, Probasin) expression and activity in LNCaP cells. Here, we examined prosaposin as an ARG. We report that DHT treatment of LNCaP cells increases prosaposin expression. In addition, we demonstrate androgen-responsiveness of prosaposin promoter and AR occupancy to a hormone-responsive element located in the proximal region of the prosaposin promoter. Our data for the first time identify prosaposin as an ARG. This observation, together with the pleiotropic growth factor activity of prosaposin, might suggest a role for this molecule in AR-dependent progression of prostate cancer at its early or late AI-state.

Androgens↗
PubMed2006

Direct method to study membrane rigidity of small vesicles based on atomic force microscope force spectroscopy.

Mechanical properties of lipidic membranes such as their bending rigidity are governing liposome morphology and play an important role in processes like membrane fusion and adhesion. Force versus deformation measurements are the most direct means to determine this, but so far experimental data is scarce and mainly stems from techniques that are limited to giant vesicles. We present atomic force microscope force spectroscopy as a method allowing force-deformation measurements of submicron vesicles. Bending rigidities of small unilamellar dipalmitoylphosphatidylcholine (DPPC) liposomes (R<200 nm) can be derived from the force-deformation data using analytical models based on shell theory and are in good agreement with independent measurements.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed2005

Azobenzene-containing monolayer with photoswitchable wettability.

A compact monolayer containing azobenzene has been prepared on silicon substrates. The elaboration route consisted of covalent grafting of freshly synthesized azobenzene moieties onto an isocyanate-functionalized self-assembled monolayer (SAM). The highly packed and ordered isocyanate-functionalized SAM and the azobenzene-functionalized SAM were monitored and characterized by contact angle measurements and X-ray reflectivity (XR). Photoswitching of the wettability of the film induced by the reversible cis-trans isomerization of the azobenzene chromophores is experimentally shown from water and olive oil contact angle measurements.

Journal Article↗
PubMed2005

Interleukin-1beta (IL-1beta) induces a crosstalk between cAMP and ceramide signaling pathways in thyroid epithelial cells.

Interleukin-1 beta (IL-1beta) is an important regulator of the thyroid cell function. This cytokine has been largely described to trigger an important biological signaling cascade: the sphingomyelin/ceramide pathway. In this report, we show that IL-1beta induces the transient activation of a neutral sphingomyelinase in porcine thyroid cells. Moreover, IL-1beta and ceramides are demonstrated to inhibit the TSH-induced cAMP production via the implication of alphaGi subunit of the adenylyl cyclase system. This crosstalk between cAMP and ceramide pathways constitutes a preponderant process in the TSH-controlled differentiation state of thyrocytes. All these results argue for the involvement of ceramides and IL-1beta in the thyroid function regulation, leading to a cell dedifferentiated state.

Animals↗
PubMed2005

[Unusual presentation of infantile myofibromatosis with an ulcered plaque].

INTRODUCTION: Infantile myofibromatosis is a rare fibrovascular-like, isolated or multicentric tumor, occasionally of the bone or an organ and appearing before the age of 2. We report a case of infantile myofibromatosis in a child in an atypical form with a single, ulcerated plaque and having developed after the onset of clusters of papular nodules. OBSERVATION: An infant was seen in consultation because of asymptomatic papules that had developed on the back. The histological examination of a partial biopsy revealed a histiocytofibromatus aspect and led to the diagnosis of clusters of multiple histiocytofibromatous. One year later, the papular nodules had converged, forming a large plaque with ulcerated center. The progressive extension and the absence of healing prompted surgical exeresis and the final diagnosis of myofibromatosis. DISCUSSION: Diagnosis of infantile myofibromatosis is difficult histologically and clinically and relies on a clear anatomoclinical confrontation. The clinical aspects are varied. To our knowledge, myofibromatosis with a single ulcerated plaque has never been reported in the literature before.

Humans↗
PubMed2004

Thrombospondin 1: a multifunctional protein implicated in the regulation of tumor growth.

Thrombospondins belong to a family of extracellular matrix (ECM) proteins widely found from embryonic to adult tissues. The modular structure of thrombospondins contains a series of peptide sequences implicated in a multiplicity of biological functions. Extracellular matrix undergoes important alterations under proteolysis that occurs in pathological processes like tumorigenesis. An elevated secretion of thrombospondin 1 (TSP1) is often observed in tumors and is sometimes considered as a predictive factor. However, the role of TSP1 in cancer progression remains controversial and must be carefully apprehended. The regulation of cell adhesion, proliferation, apoptosis by TSP1 is examined in the present review and it is clear from the literature and from our investigations that TSP1 presents both stimulatory and inhibitory effects. The exposition of cryptic sites upon conformational changes can partially explain this contradiction. More interestingly, the analysis of TSP1-directed intracellular signaling pathways activated through specific receptors or supramolecular receptors docking systems may be useful to discriminate the precise function of TSP1 in tumor progression. The central role played by TSP1 in the control of matrix-degrading enzyme activation and catabolism reveals attractive tracks of research and highlights the involvement of the lipoprotein receptor-related protein (LRP) receptor in these events. Therefore, TSP1-derived peptides constitute a source of potentially active matrikins which could provide essential tools in cancer therapy.

Apoptosis↗
PubMed2004

[Pseudolymphomatous folliculitis].

INTRODUCTION: A case of a rare variety of cutaneous pseudo-lymphoma is reported. CASE REPORT: A 13 Year-old boy presented with a nodule on the nose groove which corresponded histologically to a dense, peri follicular lymphocyte infiltration penetrating the hair. Following partial biopsy, the lesion disappeared within a fortnight. COMMENTS: Our case report corresponds to the entity described in 1999 in the Japanese. Our case occurred in a Caucasian French adolescent. The papulonodule, usually unique, is composed histologically of a dense, peripilary infiltrate that penetrates and disrupt the hair. The majority of cases have been removed surgically. Those that have not usually disappear following partial biopsy. The individualization of this entity is debatable: the involvement of the hair follicles by the infiltration of pseudolymphomas on the face is frequent and non-specific.

Adolescent↗
PubMed2002

TGFbeta1 effects on functional activity of porcine thyroid cells cultured in suspension.

Thyrotropin (TSH) and transforming growth factor beta 1 (TGFbeta1) have major roles in the regulation of folliculogenesis and differentiation in thyroid cells. Isolated porcine thyroid cells cultured in the presence of TSH on a plastic surface recover a follicular architecture and exhibit normal functional properties. The addition of TGFbeta1 to the culture medium induces important morphological changes and extracellular matrix remodelling. Similarly, thyroid cells lose their ability to organify iodine and their responsiveness to adenylate cyclase. The aim of this study was to analyse the influence of TGFbeta1 on the functional activity of thyrocytes in suspension culture, independent of follicle disruption. In this system, we demonstrate that TGFbeta1 inhibits expression of thyroperoxidase, NADPH oxidase activity, iodine uptake and, consequently, iodine organification. Moreover, TGFbeta1 decreases basal and TSH-stimulated cAMP production and TSH receptor expression. Taken together, these data converge to demonstrate an essential role of TGFbeta1 in the regulation of the thyroid cell function.

Animals↗
PubMed2002

[Cold-induced urticaria].

Cold urticaria is characterized by the development of urticaria, usually superficial and/or angioedematous reaction after cold contact. It was found predominantly in young women. The diagnosis is based on the history and ice cube test. Patients with a negative ice cube test may have represented systemic cold urticaria (atypical acquired cold urticaria) induced by general body cooling. The pathogenesis is poorly understood. Cold urticaria can be classified into acquired and familial disorders, with an autosomal dominant inheritance. Idiopathic cold urticaria is most common type but the research of a cryopathy is necessary. Therapy is often difficult. It is essential that the patient be warned of the dangers of swimming in cold water because systemic hypotension can occur. H1 antihistamines can be used for treatment of cold urticaria but the clinical responses are highly variable. The combination with an H2 antagonists is more effective. Doxepin may be useful in the treatment. Leukotriene receptor antagonists may be a novel, promising drug entity. In patients who do not respond to previous treatments, induction of cold tolerance may be tried.

Acetates↗
PubMed2001

Interleukin 1 beta (IL-1 beta) action in porcine thyroid cells involves the ceramide signalling pathway.

Interleukin 1 beta (IL-1beta) is often associated with thyroidal autoimmune diseases. This cytokine has been largely described to trigger an important biological signalling pathway: the sphingomyelin/ceramide pathway. In this report we show that IL-1beta induces ceramide formation and sphingomyelin degradation in porcine thyroid cells via the activation of a neutral sphingomyelinase. Among the potential targets of IL-1beta and ceramides action, we have investigated the role of an atypical protein kinase C (PKC), the PKC zeta. We show that both IL-1beta and ceramides lead to an increase of PKCzeta activity. All these results suggest an important role for ceramides and IL-1beta in regulation of thyroid function, leading to cell survival or to apoptosis.

Animals↗
PubMed2000

Involvement of the ceramide signaling pathway in modulating the differentiated state of porcine thyroid cells.

Neutral sphingomyelinase (Smase) is a cell membrane-associated phospholipase that hydrolyzes sphingomyelin to phosphocholine and ceramide, a lipid second messenger involved in cell differentiation and/or apoptosis. We first evidenced that porcine cultured thyroid cells could express neutral Smase activity even if thyrotropin (TStH), an essential hormone in thyroid cell differentiation, was found to induce a 1.7-fold decrease in Smase activity. Triggering the ceramide pathway by exogenous addition of neutral bacterial Smase (0.1 U/mL for 48 h), which transiently increased ceramide level by fourfold, drastically modified thyroid cell morphology. The follicle-like structures generated by TSH were disrupted, and the Smase-induced cell spreading was accompanied by a parallel loss of cell ability to iodinate proteins as well as a decrease of the adenylate cyclase system response. These inhibitory effects have been reproduced using short-chain exogenous ceramide analogs (C2-ceramides). Overall these data showed that ceramides emerged as potential mediators of dedifferentiation in thyroid cells.

Animals↗
PubMed1998

[Prevention of venous thromboembolism. Survey of in-hospital medical practice].

OBJECTIVES: In an effort to improve the prevention of venous thromboembolism, the Nancy University Hospitals conducted a survey of medical practice concerning indications for preventive therapy and surveillance of platelet counts and anti Xa activity. METHODS: The survey involved 163 medical files. Questionnaires were filled out in 6 units (3 medical wards and 3 intensive care units). RESULTS: Indications for preventive therapy were found to be quite variable with the exception of very low risk of thromboembolism where the treat/do not treat ratio was 0.1/1, indicating a clear tendency for abstention. This ratio was 0.77/1 and 0.38/1 respectively for low and moderate risk and 2/1 for high risk. There was undoubtedly a ward effect. The attitudes in practice tended toward non-prevention in patients without limited mobility. For platelet counts, an initial count was performed in 95% of the cases and during treatment in 38% although the specific rates were not the same for different types of units. Anti-Xa activity, which according to prevention recommendations need not to be determined, was not monitored in 88% of the cases. In accordance with prevention recommendations, anti-Xa activity was not determined in 88% of the cases. CONCLUSION: Further progress is needed in the prevention of venous thromboembolism and should be based on wider use of existing methods.

France↗
PubMed1996

[Fibrosing pneumopathy caused by labetalol].

A diffuse interstitial pulmonary fibrosis occurred in a 74-year-old woman treated for ten years with labetalol for systemic hypertension. Bronchoalveolar lavage (BAL) revealed lymphocytic and neutrophilic alveolitis. The lack of another etiologic factor and the spontaneously favorable course after withdrawal of the drug support the hypothesis of a labetalol induced pulmonary fibrosis.

Adrenergic beta-Antagonists↗
PubMed1995

Effect of acute hypercapnia on alpha atrial natriuretic peptide, renin, angiotensin II, aldosterone, and vasopressin plasma levels in patients with COPD.

Disturbances in hormonal systems involved in sodium and water homeostasis are common during respiratory insufficiency. To investigate the role of hypercapnia, we designed a study to examine the hormonal response to acute hypercapnia induced at constant cardiac filling pressures and without hypoxemia. Seven sedated patients with COPD receiving mechanical ventilation were studied during five successive periods. Hemodynamics, arterial blood gases, and plasma hormone levels (atrial natriuretic peptide, renin, angiotensin II, aldosterone, vasopressin) were measured three times during 60 min of acute hypercapnia (52 +/- 5 mm Hg) and at control periods, before (36 +/- 4 mm Hg) and after (42 +/- 3 mm Hg) acute hypercapnia. During acute hypercapnia, mean pulmonary arterial pressure and cardiac output were increased without variation of other measured cardiorespiratory data and hormonal levels when compared with control values. After acute hypercapnia, cardiorespiratory variables returned to control values without variations of hormonal levels. Our results show that moderate acute hypercapnia does not significantly influence the hormonal levels when cardiac filling pressures and sympathetic tone remain stable. We suggest that changes in those plasma hormones involved in salt and water homeostasis during acute hypercapnia are secondary to hemodynamic changes induced by acute respiratory failure and not to acute hypercapnia per se.

Aged↗
PubMed1995

[Methotrexate pneumonitis arising during the treatment of non-Hodgkin's lymphomas with the m-BACOD protocol].

We retrospectively studied 32 patients treated with the m-BACOD regimen in a single institution between January 1988 and December 1991. After four to seven courses, four patients presented severe acute pneumonitis (PaO2 < 55 mmHg in room air), with diffuse bilateral interstitial syndrome. Broncho-alveolar lavage displayed increased lymphocyte count (> 45%) with inversion of CD4/CD8 in two cases and no evidence of parasitic, bacterial or viral infection. All patients received methyl-prednisolone (0.5 to 1 mg/kg/d x 1 week) with both complete clinical and radiological recovery within a week. The m-BACOD regimen was continued without bleomycine for four patients and without bleomycine plus methotrexate for two patients, until the completion of eight courses, without recurrence of pneumonitis. Drug-exclusion decisions were made empirically because the exact nature of the pneumonitis was not recognized at the time of diagnostic. Because of the regular administration in the m-BACOD regimen, methotrexate leads to an increased risk of pneumonitis. We concluded that the use of the m-BACOD regimen should henceforth be discontinued.

Adult↗
PubMed1995

[Contribution of bronchoalveolar lavage and transbronchial biopsy to diagnosis and prognosis of drug-induced pneumopathies].

This survey reports on 10 case-studies of drug-induced pneumonitis. The drugs under consideration are amiodarone, methotrexate, chlorambucil, sulindac, nilutamide-leuproreline, cyclothiazide, with the possible addition of bleomycin. In each case, one or more bronchoalveolar lavage were carried out and in most cases it was also possible to perform a transbronchoscopic lung biopsy. The results of these tests are analysed in order to ascertain their contribution to diagnosis and prognosis. Regarding diagnosis, bronchoalveolar lavage does not evidence a typical cellular configuration characterizing drug-induced alveolitis. Moreover, transbronchoscopic lung biopsy plays no part in diagnosing this pathology. Both these tests, however, help to eliminate other hypotheses. Regarding prognosis, transbronchoscopic lung biopsy provides no information, unlike bronchoalveolar lavage in which a high rate of neutrophils in the lavage fluid is sometimes associated with the development of pulmonary fibrosis.

Acute Disease↗
PubMed1992

[Drug-induced pulmonary diseases: diagnostic, therapeutic and prognostic aspects. Apropos of 10 personal case reports].

The authors report ten cases of drug induced lung diseases, complicated by respiratory failure of whom five were attributed to cytotoxic drugs and five to non cytotoxic drugs. The drug induced lung disease presented as acute respiratory distress syndrome in two cases, alveolar interstitial lung disease in three cases, purely interstitial in five cases. There was acute respiratory failure (ARF) in eight cases and chronic respiratory failure (CRF) in two cases. Among the five patients admitted for cytotoxic drug induced lung disease and ARF, four recovered and one died of diffuse destructive pulmonary fibrosis. Among the five patients having non cytotoxic drug induced lung disease, three were in ARF and recovered. The other two had CRF and died of diffuse pulmonary fibrosis. The diagnostic of drug induced lung disease was established in each case with the chronology of the clinical events, the exclusion of other possible causes of the lung disease and the evolution after removal of the incriminated drug. Broncho-alveolar lavage (BAL) had a major diagnostic value. It was contraindicated by respiratory failure in five cases. The predominant alveolar cell type was lymphocyte (four cases), eosinophil (three cases) and neutrophil (one case), BAL was realized with a provocation test and demonstrated the pathogenic role of cyclothiazide in one case. No specific information was given by histology. The prognosis did not seem to be linked to the severity of the initial clinical picture, or to the nature of the underlying neoplastic disorder, but to the degree and evolution of the pulmonary fibrosis.

Adrenal Cortex Hormones↗