Your browser doesn't support javascript.
loading
Montrer: 20 | 50 | 100
Résultats 1 - 20 de 97
Filtrer
1.
Pathol Res Pract ; 248: 154623, 2023 Aug.
Article de Anglais | MEDLINE | ID: mdl-37331184

RÉSUMÉ

Neuroendocrine neoplasms represent a heterogeneous group of rare tumors, more frequently arising from gastroenteropancreatic tract and lungs. At the time of diagnosis, 20% of cases are metastatic, and 10% of cases are considered as cancer of unknown primary origin. Several immunohistochemical markers are routinely used to confirm the neuroendocrine differentiation, first among all Synaptophysin and Chromogranin-A; on the other hand, different immunohistochemical markers are used to establish primary anatomical site, as TTF1, CDX2, Islet-1 and Calcitonin, but no marker is available in order to distinguish among different sites of the digestive tract. DOG1 (discovered on GIST-1) is a gene normally expressed in interstitial cells of Cajal and, in routine practice, DOG1 immunostaining is used in diagnosis of GIST (gastrointestinal stromal tumor). DOG1 expression has been described in several neoplasms other than GIST, both in mesenchymal and epithelial neoplasms. In the present study, DOG1 immunostaining has been performed in a large cohort of neuroendocrine neoplasms, including neuroendocrine tumors and neuroendocrine carcinomas, in order to evaluate frequency, intensity and pattern of expression in different anatomical site and in different tumor grade. DOG1 expression was detected in a large percentage of neuroendocrine tumors, with statistically significant association between DOG1 expression and gastrointestinal tract neuroendocrine tumors. As a consequence, DOG1 could be included in marker panel for the identification of primary site in neuroendocrine metastases of unknown primary origin; moreover, these results recommend careful evaluation of DOG1 expression in gastrointestinal neoplasms, in particular in differential diagnosis between epithelioid GIST and neuroendocrine tumors.

2.
Ann Diagn Pathol ; 48: 151562, 2020 Oct.
Article de Anglais | MEDLINE | ID: mdl-32653819

RÉSUMÉ

A new viral disease named COVID-19 has recently turned into a pandemic. Compared to a common viral pneumonia it may evolve in an atypical way, causing the rapid death of the patient. For over two centuries, autopsy has been recognized as a fundamental diagnostic technique, particularly for new or little-known diseases. To date, it is often considered obsolete giving the inadequacy to provide samples of a quality appropriate to the sophisticated diagnostic techniques available today. This is probably one of the reasons why during this pandemic autopsies were often requested only in few cases, late and discouraged, if not prohibited, by more than one nation. This is in contrast with our firm conviction: to understand the unknown we must look at it directly and with our own eyes. This has led us to implement an autopsy procedure that allows the beginning of the autopsy shortly after death (within 1-2 h) and its rapid execution, also including sampling for ultrastructural and molecular investigations. In our experience, the tissue sample collected for diagnosis and research were of quality similar to biopsy or surgical resections. This procedure was performed ensuring staff and environmental safety. We want to propose our experience, our main qualitative results and a few general considerations, hoping that they can be an incentive to use autopsy with a new procedure adjusted to match the diagnostic challenges of the third millennium.


Sujet(s)
Autopsie/méthodes , Infections à coronavirus/anatomopathologie , Prévention des infections/méthodes , Pneumopathie virale/anatomopathologie , Manipulation d'échantillons/méthodes , Betacoronavirus , COVID-19 , Humains , Pandémies , SARS-CoV-2 , Facteurs temps
3.
Mycopathologia ; 184(1): 147-150, 2019 Feb.
Article de Anglais | MEDLINE | ID: mdl-29967970

RÉSUMÉ

We analyze the prognostic potential of (1 → 3)-ß-D-glucan (BG) levels in predicting clinical outcomes in patients with invasive fungal infections, on a population undergoing 253 episodes (177 with positive and 76 with negative outcome). Using linear regression analysis, we assessed the prognostic potential of kinetically evaluated BG levels and we found an overall sensitivity and specificity of 68 and 82%, respectively. Moreover, using an interpretative algorithm based on two distinct cutoff values, we were able to predict the outcome in 84% of the studied population with a diagnostic accuracy of 82%.


Sujet(s)
Tests diagnostiques courants/méthodes , Infections fongiques invasives/diagnostic , bêta-Glucanes/sang , Humains , Pronostic , Études prospectives , Protéoglycanes , Études rétrospectives , Sensibilité et spécificité
4.
Eur J Clin Microbiol Infect Dis ; 34(1): 131-136, 2015 Jan.
Article de Anglais | MEDLINE | ID: mdl-25082186

RÉSUMÉ

We investigated the clinical performance of a polymerase chain reaction (PCR)-based commercial platform, the Myconostica MycAssay™ Aspergillus (MAP), for fungal DNA detection in the serum of patients at risk of invasive aspergillosis (IA). Sixty-four hospitalized patients were prospectively enrolled and a total of 71 different episodes were investigated (30 episodes were clinically/microbiologically classified as IA and 41 as control episodes). When MAP was compared to the galactomannan (GM) assay, no significant differences were found in terms of sensitivity (46.7% vs. 50.0%), specificity (97.6% vs. 95.1%), positive predictive value (PPV) (93.3% vs. 88.2%), and negative predictive value (NPV) (71.4% vs. 72.2%). The corresponding areas under the curve (AUC) of the receiver operating characteristic (ROC) curves were also superimposable. Overall, because of the good agreement between the two assays and considering the high specificity and PPV of the MAP, we suggest the use of this PCR-based platform as a second-level examination for the evaluation of clinically undefined cases where culture or GM have provided positive results.


Sujet(s)
Aspergillose/diagnostic , Aspergillus/génétique , ADN fongique/sang , Techniques de diagnostic moléculaire/méthodes , Réaction de polymérisation en chaine en temps réel/méthodes , Adulte , Sujet âgé , Sujet âgé de 80 ans ou plus , Femelle , Fongémie/diagnostic , Galactose/analogues et dérivés , Humains , Techniques immunoenzymatiques , Mâle , Mannanes/sang , Adulte d'âge moyen , Valeur prédictive des tests , Études prospectives , Courbe ROC , Sensibilité et spécificité , Jeune adulte
5.
Int J Immunopathol Pharmacol ; 27(3): 403-12, 2014.
Article de Anglais | MEDLINE | ID: mdl-25280031

RÉSUMÉ

The increased incidence of invasive candidiasis and of patients at risk requires early diagnosis and treatment to improve prognosis and survival. The aim of this study was to set up a ten-protein array-based immunoassay to assess the IgG antibody responses against ten well-known immunogenic C. albicans proteins (Bgl2, Eno1, Pgk1, Pdc11, Fba1, Adh1, Als3, Hwp1, Hsp90 and Grp2) in 51 patients with invasive candidiasis (IC) and in 38 culture-negative controls (non-IC). Antibody levels were higher against Bgl2, Eno1, Pgk1, Als3, Hwp1 and Grp2, than against Adh1, Pdc11, Fba1 and Hsp90, irrespectively of the patient group considered. Moreover, the IgG levels against Bgl2, Eno1, Pgk1 and Grp2 were significantly higher in IC than in non-IC patients. Furthermore, the ROC curves generated by the analysis of the antibody responses against Bgl2, Grp2 and Pgk1 displayed AUC values above 0.7, thus discriminating IC and non-IC patients. According to these results, the employment of the microarray immunoassay (a rapid, sensitive and multiparametric system), in parallel with conventional diagnostics, can help to spot IC patients. This ultimately will allow to initiate an early, focused and optimized antifungal therapy.


Sujet(s)
Anticorps antifongiques/sang , Candidose invasive/diagnostic , Analyse par réseau de protéines/méthodes , Protéines fongiques/immunologie , Humains , Dosage immunologique , Immunoglobuline G/sang , Protéines recombinantes/immunologie
6.
J Biol Regul Homeost Agents ; 28(4): 743-52, 2014.
Article de Anglais | MEDLINE | ID: mdl-25620183

RÉSUMÉ

The aim of this study was to investigate the effects of different species of Lactobacilli on hyphal formation and biofilm development by the opportunistic fungal pathogen Candida albicans. We employed 4 different Lactobacillus species, namely L. rhamnosus, L. acidophilus, L. plantarum and L. reuteri, and 2 C. albicans strains, the reference DAY286 and its isogenic hwp1/hwp1 mutant, the FJS24 strain. As assessed by morphological analysis and quantitative colorimetric assays, Lactobacillus crude filtrate supernatant fluids (CFSF) affected Candida, impairing both hyphal formation and biofilm production. The CFSF-mediated phenomenon occurred in a dilution- and time-dependent manner and was consistently observed, irrespective of the C. albicans HWP1 genotype.


Sujet(s)
Biofilms/croissance et développement , Candida albicans/physiologie , Hyphae/croissance et développement , Lactobacillus
7.
Int J Immunopathol Pharmacol ; 27(4): 661-8, 2014.
Article de Anglais | MEDLINE | ID: mdl-25572748

RÉSUMÉ

The detection of Aspergillus antigen (galactomannan) is considered a reliable marker for the diagnosis of invasive aspergillosis (IA), yet the sensibility and specificity of the assays commonly employed in routine are not optimal. The aim of the present study was to investigate whether the detection of another panfungal antigen, the (1,3)-b-D-glucan could have an auxiliary role in the identification of patients with IA. The study was carried out on 63 sera belonging to patients who had been screened for galactomannan, according to the clinical suspect of IA. Our data show that the positive galactomannan results were not confirmed by positive (1,3)-b-D-glucan results in patients receiving therapy with beta-lactam antibiotics associated with tazobactam, whereas in all the other cases, with the exception of four, the results of the (1,3)-b-D-glucan test were confirmatory of the galactomannan results.


Sujet(s)
Aspergillose/diagnostic , Colorimétrie/méthodes , bêta-Glucanes/sang , Adulte , Sujet âgé , Aspergillose/sang , Proenzymes/composition chimique , Femelle , Galactose/analogues et dérivés , Humains , Mâle , Mannanes/sang , Adulte d'âge moyen , Peptide hydrolases/composition chimique , Protéoglycanes
8.
Int J Immunopathol Pharmacol ; 25(4): 1029-40, 2012.
Article de Anglais | MEDLINE | ID: mdl-23298493

RÉSUMÉ

Novel technologies that allow simultaneous assessment of multiple biomarkers provide new and promising diagnostic/prognostic approaches. By protein microarrays, here we analyzed amniotic fluids (AF) from 50 women with preterm delivery (PTD) and 50 control women, who delivered at term. In detail, cytokines, chemokines, matrix metalloproteinases and antigen-specific antibodies were assessed. The AF analysis showed significant differences between women with preterm and term delivery in the levels of IL-1alpha, IL-1beta, IL-4, IL-6, IL-8, MCP-1, IFN-gamma and anti-HSV2 IgG. No significant differences were observed in the levels of TNF-alpha, MMP-2, MMP-9 and specific IgG for seven vertically transmitted pathogens. In conclusion, we demonstrated the feasibility of protein microarrays in the diagnosis of early intrauterine inflammation. The significant association between the increased levels of certain cytokines and preterm delivery argues on their relevance as early pathogenetic markers for identification of risk patients.


Sujet(s)
Liquide amniotique/composition chimique , Chorioamnionite/diagnostic , Naissance prématurée/étiologie , Analyse par réseau de protéines/méthodes , Adulte , Cytokines/analyse , Femelle , Humains , Grossesse , Deuxième trimestre de grossesse
9.
Cardiovasc Ther ; 30(5): 287-94, 2012 Oct.
Article de Anglais | MEDLINE | ID: mdl-21884012

RÉSUMÉ

BACKGROUND: Sunitinib, a multi-tyrosine kinase inhibitor has demonstrated clinical activity in advanced renal cell carcinoma and imatinib-resistant/intolerant gastrointestinal stromal tumor. It has been associated with manageable hypertension and other unique toxicities. AIMS: Two nonclinical studies were conducted to determine if sunitinib has direct/indirect effects on cardiac structure/function that may be related to hypertension at clinically relevant exposures. MATERIALS & METHODS: Rats received once-daily vehicle or sunitinib 1 or 10 mg/kg/day (n = 10/group) orally for 4 weeks, followed by 2 weeks off treatment then a 2-week rechallenge. Blood pressure (BP) and heart rate (HR) were continuously acquired and echocardiograms were obtained weekly. Effects of sunitinib and its metabolite (0.003-0.3 µM) were also evaluated in guinea pig isolated Langendorff-perfused hearts (n = 4-6 hearts/group). RESULTS: Sunitinib 10 mg/kg/day produced significant (P < 0.05) hemodynamic changes: 24 h average BP increased during initial dosing/rechallenge, with rebound hypotension during the off-treatment period; 24 h average HR increased during the off-treatment period, and decreased during rechallenge; no changes in cardiac structure/function were observed. In guinea pig isolated hearts, neither sunitinib nor its metabolite had direct effects on contractility, HR or left ventricular pressure. DISCUSSION & CONCLUSION: These studies demonstrate that sunitinib/metabolite had no direct effects on cardiac function ex vivo, and that therapeutically relevant concentrations of sunitinib dosed on a "clinical schedule" increased BP in rats without adverse changes in cardiac structure/function.


Sujet(s)
Inhibiteurs de l'angiogenèse/pharmacologie , Pression sanguine/effets des médicaments et des substances chimiques , Antienzymes/usage thérapeutique , Coeur/effets des médicaments et des substances chimiques , Indoles/pharmacologie , Pyrroles/pharmacologie , Récepteurs à activité tyrosine kinase/antagonistes et inhibiteurs , Inhibiteurs de l'angiogenèse/pharmacocinétique , Animaux , Hémogramme , Analyse chimique du sang , Échocardiographie , Cochons d'Inde , Coeur/anatomie et histologie , Coeur/physiologie , Rythme cardiaque/effets des médicaments et des substances chimiques , Techniques in vitro , Indoles/métabolisme , Indoles/pharmacocinétique , Mâle , Pyrroles/métabolisme , Pyrroles/pharmacocinétique , Rats , Rat Sprague-Dawley , Sunitinib , Télémétrie
11.
Eur J Clin Microbiol Infect Dis ; 28(9): 1067-75, 2009 Sep.
Article de Anglais | MEDLINE | ID: mdl-19415353

RÉSUMÉ

The detection of specific serum antibodies is mainly achieved by enzyme-linked immunosorbent assay (ELISA). Here, we describe the setting up of a microarray-based serological assay to screen for IgG and IgM against vertically transmitted pathogens (Toxoplasma gondii, rubella virus, cytomegalovirus, herpes simplex virus types 1 and 2, varicella zoster virus, Chlamydia trachomatis). The test, accommodated onto a restricted area of a microscope slide, consists of: (a) the immobilization of antigens and human IgG and IgM antibody dilution curves, laid down in an orderly manner; (b) addition of serum samples; (c) detection of antigen-serum antibodies complexes by indirect immunofluorescence. The IgG and IgM curves provide an internal calibration system for the interpolation of the signals from the single antigens. The test was optimized in terms of spotting conditions and processing protocol. The detection limit was 400 fg for the IgG assay and 40 fg for the IgM assay; the analytical specificity was >98%. The clinical sensitivity returned an average value of 78%, the clinical specificity was >96%, the predictive values were >73%, and the efficiency was >88%. The results obtained make this test a promising tool, suitable for introduction in the clinical diagnostic routine of vertically transmitted infections, in parallel (and in future as an alternative) to ELISA.


Sujet(s)
Anticorps antibactériens/sang , Anticorps antiprotozoaires/sang , Anticorps antiviraux/sang , Maladies transmissibles/diagnostic , Maladies transmissibles/immunologie , Transmission verticale de maladie infectieuse , Analyse par réseau de protéines/méthodes , Femelle , Humains , Immunoglobuline G/sang , Immunoglobuline M/sang , Grossesse , Sensibilité et spécificité
12.
J Neuroimmunol ; 210(1-2): 80-6, 2009 May 29.
Article de Anglais | MEDLINE | ID: mdl-19329191

RÉSUMÉ

This cross-sectional study investigated with two-dimensional gel electrophoresis coupled to MALDI-TOF and MRI the relationship between PBMCs protein expression profile and whole-brain atrophy in 16 unselected RR-MS IFN-treated patients compared with 6 RR IFN-untreated and 12 matched healthy control subjects. Grey/white matter fraction, T1/T2 lesion load and clinical variables were considered too. Twenty six proteins showed significant differential expression among RR IFN-treated patients and control samples. Four of these (IN35, GANAB, PP1B, SEPT2) resulted correlated with clinical and MRI findings in RR IFN-treated MS patients. Future clinical applications remain to be validated by other techniques and confirmed by a larger study.


Sujet(s)
Atrophie/anatomopathologie , Encéphale/anatomopathologie , Agranulocytes/métabolisme , Sclérose en plaques récurrente-rémittente/métabolisme , Sclérose en plaques récurrente-rémittente/anatomopathologie , Adulte , Sujet âgé , Atrophie/physiopathologie , Encéphale/physiopathologie , Études transversales , Évolution de la maladie , Électrophorèse bidimensionnelle sur gel , Femelle , Humains , Agranulocytes/immunologie , Imagerie par résonance magnétique , Mâle , Adulte d'âge moyen , Sclérose en plaques récurrente-rémittente/immunologie , Neurofibres myélinisées/anatomopathologie , Phosphoric monoester hydrolases/analyse , Phosphoric monoester hydrolases/métabolisme , Projets pilotes , Valeur prédictive des tests , Protéomique/méthodes , Spectrométrie de masse MALDI , Jeune adulte
13.
Folia Morphol (Warsz) ; 67(4): 261-6, 2008 Nov.
Article de Anglais | MEDLINE | ID: mdl-19085866

RÉSUMÉ

The axillary arch is the main variation of the axillary muscle. It was first described by Ramsay in 1795. In its classical form, it arises from the latissimus dorsi muscle and extends from this towards the pectoralis major, crossing the base of the axilla and creating a close relationship with the elements of the axillary neurovascular bundle. We describe the finding of 9 axillary arches, including one case of a bilateral arrangement. We develop a searching and finding technique for the axillary arch, essential for the safe and successful development of surgical procedures in the axillary region. Knowledge of this muscle variation and the possibility of finding it during axillary procedures is crucial for lymph node staging and lymphadenectomy and is also important for differential diagnosis in compressive pathologies of the axillary vessels and brachial plexus.


Sujet(s)
Aisselle/anatomie et histologie , Muscles squelettiques/anatomie et histologie , Adulte , Cadavre , Dissection/méthodes , Latéralité fonctionnelle , Humains
14.
Cell Mol Neurobiol ; 27(4): 517-28, 2007 Jun.
Article de Anglais | MEDLINE | ID: mdl-17380379

RÉSUMÉ

1. Microglial cell activation occurs during brain injury, ischemia, and in several neurologic disorders. Recently, we isolated a transmissible cytotoxic activity (TCA) from the cerebrospinal fluid of a patient with brain ischemia. Such a TCA, associated with one or more protein(s) that supposedly had undergone in vivo misfolding, causes apoptosis in vitro in different cell lines, including microglial cells. The TCA producing cells and the potential in vivo role of such cytotoxic activity remains to be elucidated. Here, we investigated the in vitro effects of TCA on microglial cell immune functions.2. The murine microglial cell line RR4 was exposed to TCA, and then its response was evaluated as: (a) phagocytosis and antifungal activity against Candida albicans; (b) secretory pattern; and (c) levels of p38 phosphorylation.3. Unlike mock-treated controls, microglial cells exposed to TCA showed an increase in phagocytic activity. Unexpectedly, their capability to kill the ingested fungi significantly diminished. Moreover, TCA-treated cells produced amounts of macrophage inflammatory protein 1-alpha, tumor necrosis factor-alpha, and nitric oxide significantly higher than mock-treated cells. Finally, phosphorylation of p38 mitogen-activated protein kinase (MAPK) was detected in TCA-treated but not in mock-treated controls as early as 30 min after treatment.4. Overall, these results indicate that TCA causes a rapid molecular response in microglial cells, by the time, leading to an intriguing effector and secretory dysfunction.


Sujet(s)
Encéphalopathie ischémique/anatomopathologie , Cytotoxicité immunologique , Hypoxie cérébrale/liquide cérébrospinal , Microglie/effets des médicaments et des substances chimiques , Microglie/anatomopathologie , Lignée cellulaire , Survie cellulaire , Cytokines/métabolisme , Formazanes/pharmacologie , Humains , Microglie/métabolisme , Monoxyde d'azote/métabolisme , Phagocytose , Sels de tétrazolium/pharmacologie , p38 Mitogen-Activated Protein Kinases/métabolisme
15.
Methods Inf Med ; 44(2): 233-8, 2005.
Article de Anglais | MEDLINE | ID: mdl-15924182

RÉSUMÉ

BACKGROUND: In health applications, and elsewhere, 3D data sets are increasingly accessed through the Internet. To reduce the transfer time while maintaining an unaltered 3D model, adequate compression and decompression techniques are needed. Recently, Grid technologies have been integrated with Web Services technologies to provide a framework for interoperable application-to-application interaction. OBJECTIVES: The paper describes an implementation of the Edgebreaker compression technique exploiting web services technology and presents a novel approach for using such services in a Grid Portal. The Grid portal, developed at the CACT/ISUFI of the University of Lecce, allows the processing and delivery of biomedical images (CT--computerized tomography--and MRI--magnetic resonance images) in a distributed environment, using the power and security of computational Grids. METHODS: The Edgebreaker Compression Web Service has been deployed on a Grid portal and allows compressing and decompressing 3D data sets using the Globus toolkit GSI (Globus Security Infrastructure) protocol. Moreover, the classical algorithm has been modified extending the compression to files containing more than one object. RESULTS AND CONCLUSIONS: An implementation of the Edgebreaker compression technique and related experimental results are presented. A novel approach for using the compression web service in a Grid portal allowing storing and preprocessing of huge 3D data sets, and subsequent efficient transmission of results for remote visualization is also described.


Sujet(s)
Imagerie tridimensionnelle/instrumentation , Internet/instrumentation , Systèmes informatisés de dossiers médicaux , Systèmes d'information de radiologie/instrumentation , Intégration de systèmes , Téléradiologie/instrumentation , Algorithmes , Systèmes de gestion de bases de données , Bases de données factuelles , Humains , Mémorisation et recherche des informations , Italie , Mise au point de programmes
16.
Eur J Clin Microbiol Infect Dis ; 20(8): 535-43, 2001 Aug.
Article de Anglais | MEDLINE | ID: mdl-11681432

RÉSUMÉ

The aim of this study was to examine three serial isolates of Cryptococcus neoformans from a patient with AIDS for genotypical and phenotypical characteristics. The isolates were obtained during a first episode of cryptococcosis (simultaneous sampling of blood and cerebrospinal fluid) and after a relapse 3 years later (sampling of cerebrospinal fluid). Pulsed-field gel electrophoresis and random amplification of polymorphic DNA revealed that the blood isolate 1525 (first episode) was different from the two cerebrospinal fluid isolates (1526, first episode; 1782, relapse), yet the cerebrospinal fluid isolates were indistinguishable from each other regardless of the analysis performed. Phenotypical studies showed that isolate 1782 had significantly improved resistance to phagocytosis and killing by monocytes and polymorphonuclear cells and an altered efficacy in evoking cytokine response (augmentation of tumour necrosis factor-alpha, interleukin [IL]-1beta, IL-10, and interferon-gamma, decrease of IL-12). Interestingly, capsule size and antifungal drug resistance remained unchanged, while production of phospholipase and protease was consistently enhanced in the 1782 isolate with respect to the 1525 and 1526 isolates. In conclusion, in serial Cryptococcus neoformans isolates from a patient with AIDS, phenotypical changes but not molecular changes were documented, thus supporting the role of microevolution as a pathogenetic mechanism(s) for persistence/reactivation of fungal organisms.


Sujet(s)
Infections opportunistes liées au SIDA/microbiologie , Cryptococcose/microbiologie , Cryptococcus neoformans/classification , Cryptococcus neoformans/génétique , Méningoencéphalite/microbiologie , Adulte , Techniques de typage bactérien , Liquide cérébrospinal/microbiologie , Cryptococcose/sang , Cryptococcus neoformans/immunologie , Cryptococcus neoformans/isolement et purification , Cytokines/biosynthèse , Humains , Mâle , Phagocytose/immunologie , Phénotype , Récidive
17.
Med Microbiol Immunol ; 189(4): 209-16, 2001 Sep.
Article de Anglais | MEDLINE | ID: mdl-11599791

RÉSUMÉ

Cryptococcus neoformans is an opportunistic fungus responsible for severe and often recurrent meningoencephalitis in immunodepressed patients. Initial evidence suggests that C. neoformans is a facultative intracellular pathogen; however, the strategies by which C. neoformans undergoes survival and eventually proliferation have not been elucidated. We investigated the role of Nrampl gene in macrophage-mediated anti-cryptococcal defense. Using cell lines expressing the functional, mutated or knockout gene, it was established that Nramp1 (1) is not involved in the phagocytic event, (2) influences anti-cryptococcal activity in the early steps but not at later times, and (3) is unrelated to the biomolecular pathways through which C. neoformans impairs macrophage secretory response. Although the functional role of Nramp1 is still far from being elucidated, the present data add insight into its involvement in macrophage-mediated antimicrobial defense, particularly in the initial steps allowing C. neoformans growth inhibition.


Sujet(s)
Transporteurs de cations/génétique , Cryptococcose/immunologie , Cryptococcus neoformans/immunologie , Macrophages/immunologie , Macrophages/microbiologie , Animaux , Transporteurs de cations/métabolisme , Lignée cellulaire , Cryptococcose/microbiologie , Souris , Phagocytose
19.
Glia ; 33(2): 131-42, 2001 Feb.
Article de Anglais | MEDLINE | ID: mdl-11180510

RÉSUMÉ

We evaluated the intracellular and extracellular biological role of S100B protein with respect to microglia. S100B, which belongs to the multigenic family of Ca2+-binding proteins, is abundant in astrocytes where it is found diffusely in the cytoplasm and is associated with membranes and cytoskeleton constituents. S100B protein is also secreted by astrocytes and acts on these cells to stimulate nitric oxide secretion in an autocrine manner. However, little is known about the relationship between S100B and microglia. To address this issue, we used primary microglia from newborn rat cortex and the BV-2 microglial cell line, a well-established cell model for the study of microglial properties. S100B expression was assessed by immunofluorescence in primary microglia and by RT-PCR, Western blotting, and immunofluorescence in BV-2 cells. S100B was found in microglia in the form of a filamentous network as well as diffusely in the cytoplasm and associated with intracellular membranes. S100B relocated around phagosomes during BV-2 phagocytosis of opsonized Cryptococcus neoformans. Furthermore, interferon-gamma (IFN-gamma) treatment caused cell shape changes and redistribution of S100B, and downregulation of S100B mRNA expression in BV-2 cells. Treatment of BV-2 cells with nanomolar to micromolar amounts of S100B resulted in increased IFN-gamma-induced expression of inducible nitric oxide synthase mRNA as well as nitric oxide secretion. Taken together, these data suggest a possible role for S100B in the accomplishment/regulation of microglial cell functions.


Sujet(s)
Protéines de liaison au calcium/métabolisme , Microglie/métabolisme , Facteurs de croissance nerveuse/métabolisme , Protéines S100 , Animaux , Protéines de liaison au calcium/génétique , Protéines de liaison au calcium/pharmacologie , Lignée cellulaire/cytologie , Lignée cellulaire/effets des médicaments et des substances chimiques , Lignée cellulaire/métabolisme , Infections fongiques du système nerveux central/métabolisme , Infections fongiques du système nerveux central/anatomopathologie , Infections fongiques du système nerveux central/physiopathologie , Cortex cérébral/cytologie , Cortex cérébral/effets des médicaments et des substances chimiques , Cortex cérébral/métabolisme , Cryptococcus neoformans/métabolisme , Cytosquelette/métabolisme , Régulation négative/effets des médicaments et des substances chimiques , Régulation négative/physiologie , Technique d'immunofluorescence , Interféron gamma/pharmacologie , Souris , Souris de lignée C57BL , Microglie/cytologie , Microglie/effets des médicaments et des substances chimiques , Facteurs de croissance nerveuse/génétique , Facteurs de croissance nerveuse/pharmacologie , Monoxyde d'azote/métabolisme , Nitric oxide synthase/effets des médicaments et des substances chimiques , Nitric oxide synthase/génétique , Nitric oxide synthase/métabolisme , Phagocytose/effets des médicaments et des substances chimiques , Phagocytose/physiologie , ARN messager/métabolisme , Sous-unité bêta de la protéine liant le calcium S100
SÉLECTION CITATIONS
DÉTAIL DE RECHERCHE
...