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Dive into the research topics where Jean Michel Prades is active.

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Featured researches published by Jean Michel Prades.


Virchows Archiv | 2005

Global DNA methylation evaluation: potential complementary marker in differential diagnosis of thyroid neoplasia

Bogdan Galusca; Jean Marc Dumollard; Sandrine Lassandre; Alain Niveleau; Jean Michel Prades; Bruno Estour; Michel Peoc’h

The implications of global DNA hypomethylation were recently reported in several models of tumorigenesis. Little is known about this epigenetic event in thyroid neoplasia. The study aimed to evaluate the status of global DNA methylation in several types of thyroid tumors using a monoclonal antibody specific for 5-methylcytidine (5-mc) and to define the diagnosis potential of this marker. 5-mc immunostaining scores were calculated in 17 papillary thyroid carcinomas (PTC), 6 follicular thyroid carcinomas (FTC), 16 follicular adenomas (FA), 19 nodular goiters (NG) and ten Hürthle cells adenomas (HCA). The expression of galectin-3 was also evaluated. Computerized image analysis showed a significant lower level of 5-mc immunostaining in thyroid carcinoma when compared with benign tumors or adjacent normal thyroid parenchyma (P<0.0001). Overall, 5-mc accuracy to distinguish malign from benign thyroid tumors was similar to that of galectin-3 (89% versus 87%, P>0.05). The combination of 5-mc with galectin-3 led to an excellent accuracy level of 96%. Among follicular neoplasia 5-mc accuracy to differentiate malign tumors trends to be higher than galectin-3 one (90% versus 66%, P=0.06). These data stress the necessity of epigenetic events evaluation among thyroid nodules and propose global DNA methylation assessment as a potential diagnostic tool to combine with other valuable markers.


Pathology | 2016

p16 and p53 expression status in head and neck squamous cell carcinoma: a correlation with histological, histoprognostic and clinical parameters

Georgia Karpathiou; Alessandra Monaya; Fabien Forest; Marios Froudarakis; François Casteillo; Jean Marc Dumollard; Jean Michel Prades; Michel Peoc'h

Different histopathology and prognosis characterise the human papillomavirus (HPV)-related oropharyngeal tumours, but squamous cell carcinomas (SCC) of other localisations have not been exhaustively studied. Tissues from 120 patients with a head and neck SCC were studied for the expression of p16 and p53, and the Brandwein-Gensler (BG) histological risk assessment model. p16 positivity and p53 normal expression were significantly correlated with non-smoking, an earlier T stage and a non-keratinising morphology. The BG risk score was not associated with p16 or p53 expression; p16 expression was associated with a lymphocytic T-cytotoxic response. BG risk score was significantly correlated with overall survival and progression-free survival, while neither p16 nor p53 expression were associated with prognosis. p16 and p53 expression are associated with the histological subtype and the T stage even in non-oropharyngeal-restricted tumours. The BG risk score is not correlated with p16 or p53 and retains its power in non-site-specific SCCs.


Oncotarget | 2017

Prognostic impact of immune microenvironment in laryngeal and pharyngeal squamous cell carcinoma: Immune cell subtypes, immuno-suppressive pathways and clinicopathologic characteristics

Georgia Karpathiou; François Casteillo; Jean-Baptiste Giroult; Fabien Forest; Pierre Fournel; Alessandra Monaya; Marios Froudarakis; Jean Marc Dumollard; Jean Michel Prades; Michel Peoc'h

Background Immune system affects prognosis of various malignancies. Anti-immune pathways like PD-L1 and CTLA4 are used by the tumor to overcome immune system and they serve as immunotherapy targets. The immune microenvironment of head-and-neck squamous cell carcinoma (SCCHN) has not been sufficiently studied. Patients and Methods 152 SCCHN were immunohistochemically studied for the expression of CD3, CD8, CD57, CD4, granzyme b, CD20, CD163, S100, PD-L1, CTLA4 and CXCR4. Results CD3, CD8, CD57 and stromal S100 higher density is a good prognostic factor (p=0.02, 0.01, 0.02, 0.03 respectively). CTLA4 tumor expression is a poor prognostic factor (p=0.05). The rest immune cells do not affect prognosis. CD3 and CD8 density does not correlate with clinicopathological factors or p16/p53 expression, while CD57 and CD4 higher density is associated with the absence of distant metastases (p=0.03 and 0.07, respectively). Higher CD20 and S100 density is associated with lower T stage (p=0.04 and 0.03, respectively). PD-L1 expression is higher in CD3, CD8, and CD163 infiltrated tumors and in histologically more aggressive tumors. Response to neoadjuvant chemotherapy is better in highly CD3 infiltrated tumors and in tumors with less intraepithelial macrophages. Conclusion Rich T-lympocytic and dendritic cell response is a good prognostic factor in SCCHN, whereas tumors expressing CTLA4 show poor prognosis. PDL1 expression does not affect prognosis, but it is expressed in histologically more aggressive tumors and in T-cells rich tumors. Response to induction chemotherapy is better in tumors less infiltrated by macrophages and mostly infiltrated by T cells.


American Journal of Clinical Pathology | 2016

Clinical and Histologic Predictive Factors of Response to Induction Chemotherapy in Head and Neck Squamous Cell Carcinoma.

Georgia Karpathiou; Jean-Baptiste Giroult; Fabien Forest; Pierre Fournel; Alessandra Monaya; Marios Froudarakis; Jean Marc Dumollard; Jean Michel Prades; Marie Gavid; Michel Peoc'h

Objectives Induction chemotherapy (IC) is occasionally used in head and neck cancer, leading to less extensive surgery and reduced need for irradiation. Factors predicting the response to IC have not been determined. In this study, we investigated the clinical and histopathologic factors that predict the response to IC. Methods Head and neck squamous cell carcinomas from 81 patients were analyzed; clinical factors, histologic parameters, and expression of p16 and p53 were correlated with response to chemotherapy and prognosis. Results Factors predicting a good response to IC were the nonoropharyngeal localization, a rich lymphocytic tissue response, and a low platelet-to-lymphocyte blood ratio before treatment. Response to IC did not correlate with prognosis, whereas a low neutrophil-to-lymphocyte ratio (NLR), the absence of a desmoplastic reaction, a rich lymphocytic tissue response, and the overexpression of p53 were associated with better prognosis. Conclusions Lymphocytic tissue response, NLR, and nonoropharyngeal localization are factors predictive of response to IC.


Experimental and Molecular Pathology | 2017

FOXA1 in HPV associated carcinomas: Its expression in carcinomas of the head and neck and of the uterine cervix

Georgia Karpathiou; Vanessa Da Cruz; François Casteillo; Mousa Mobarki; Jean Marc Dumollard; Céline Chauleur; Fabien Forest; Jean Michel Prades; Michel Peoc'h

BACKGROUND FOXA1 is a major transcription factor involved in the action of human papilloma virus (HPV). However, it has been never studied in HPV-associated tumors. AIM OF THE STUDY To investigate its expression in cervical and head and neck tumors. MATERIAL AND METHODS 63 cervical carcinomas/dysplasias and 152 head and neck squamous cell carcinomas (HNSCC) were immunohistochemically studied for the expression of FOXA1. RESULTS 63.1% of cervical SCC and 40.7% of endocervical adenocarcinomas strongly expressed FOXA1. Most (90%) pre-invasive lesions (CIN3 and in situ adenocarcinomas) strongly expressed FOXA1 and this difference from invasive lesions was statistically significant (p=0.005). No association with clinicopathological factors was found. 51.3% of HNSCC expressed FOXA1. In these tumors, FOXA1 expression was associated with the non-keratinizing morphology but not with the HPV/p16 status neither other clinicopathological features. Of normal structures, salivary glands, endocervical glands and basal/parabasal cell layer of squamous epithelium of both uterine cervix and head and neck mucosa, all strongly expressed FOXA1. CONCLUSION FOXA1 is expressed by basal cells of squamous epithelium, pre-invasion lesions of the uterine cervix and the head/neck and almost half invasive cervical and head/neck carcinomas, supporting its possible implication in HPV pathogenesis.


Knee | 2018

The anterolateral ligament is a distinct ligamentous structure: A histological explanation

Thomas Neri; Pierre Dalcol; Fabien Palpacuer; Florian Bergandi; Jean Michel Prades; Frederic Farizon; Rémi Philippot; Michel Peoc'h

BACKGROUND The aim was to determine whether the anterolateral ligament (ALL) had a histological structure that defined it as a real ligament. METHODS Histological examination of 30 ALL samples taken from fresh-frozen knees were performed. The ALL femoral insertion and its relationship with the lateral collateral ligament (LCL) were studied and the tibial insertion and its relationship with articular cartilage of the tibial joint surface were analyzed. For the ligamentous part, its histological structure and its differences with the articular capsule were studied. RESULTS This connective tissue is composed of a dense fibrous core constituted by a network of oriented collagenous fibers. The periphery of this dense connective center is made up of loose fibrocollagenous tissue with vascular structures and focal deposits of adipose tissue. This part was in contact but different to the joint capsule. With a perpendicular orientation of the collagen fibers relative to the bone, a fibrocartilaginous zone with an unmineralized hyalinized aspect, a mineralization front, its bone insertions presented a typical ligamentous insertion. With a cleavage plane between ALL and LCL femoral insertion, the ALL appeared to have a femoral insertion distinct from the LCL. ALL tibial insertion was less characteristic with less organized connective tissue and was at a distance from the articular cartilage. CONCLUSION From its bony insertion to its tissue composition and organization, the ALL has all the histological characteristics of a ligamentous structure. Our study confirms that ALL can be considered a real and distinct ligament.


Surgical and Radiologic Anatomy | 2017

The anterior commissure of the human larynx revisited

Jean Michel Prades; C. Petcu; Alexandre Karkas; Jean-Marc Dumollard; Marie Gavid

BackgroundThe anterior commissure (AC) of the human larynx is usually understood as an area of the glottis anteriorly situated between the two vocal folds inserting to the thyroid cartilage (TC). The pattern of spread of AC carcinoma could hypothesize that AC could include other structures of the ventral larynx as developmental anatomy could demonstrate.MethodsTen adult larynx specimens from donation program cadavers and 15 selected fetal specimens (from 11 to 34 weeks of amenorrhoea) were studied using microdissection and histological serial sections stained with hematoxylin–eosin and reticuline.ResultsIn adult specimens, internal perichondrium of the TC was easily detached from the entire lateral lamina but not from an intermediate lamina superiorly marked by the superior thyroid notch. On this median band of TC is inserted the ventral connective tissue of the three levels of the larynx: the ventral part of the vocal folds with the anterior macula flava, the Broyle’s epiglottic ligament, and the subglottic part of the conoid ligament. In young fetuses (11–12 weeks), intermediate lamina of TC joined at the glottic level but not at the supraglottic level; in fetuses at 22–25 weeks, a meshwork of bundles of connective fibers inserted to the intermediate lamina of TC. In fetuses at 33–34 weeks, organization is practically identical to adult specimens.ConclusionAccording to the adult anatomical features and the organogenesis, the AC of the human larynx could be anatomically defined ventrally as being made up of the intermediate lamina of TC beneath the superior thyroid notch and dorsally the ventral insertions of vocal folds with macula flava, supraglottic Broyle’s ligament, and subglottic conoid ligament leading to a “developmental” AC definition which could better explain specific spreading of AC carcinoma.


Anticancer Research | 2004

Peroxisome Proliferator Activated Receptor Gamma Immunohistochemical Expression in Human Papillary Thyroid Carcinoma Tissues. Possible Relationship to Lymph Node Metastasis

Bogdan Galusca; Jean Marc Dumollard; Marie Laure Chambonniere; Natacha Germain; Jean Michel Prades; Michel Peoc'h; Bruno Estour


Surgical and Radiologic Anatomy | 2015

Surgical anatomy of the ansa cervicalis nerve: which branch to use for laryngeal reinnervation in humans?

Jean Michel Prades; Marie Gavid; Marie-Dominique Dubois; Jean-Marc Dumollard; A.T. Timoshenko


Morphologie | 2015

Bases anatomiques de la ré-innervation laryngée sélective chez l’homme : résultats préliminaires sur le transfert du nerf phrénique et de l’anse cervicale sur les branches terminales du nerf laryngé inférieur

Jean Michel Prades; Marie Gavid; Marie Dominique Dubois; Jean Marc Dumollard; A.T. Timoshenko; Michel Peoc’h

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Georgia Karpathiou

Democritus University of Thrace

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Marios Froudarakis

Democritus University of Thrace

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Alain Niveleau

Joseph Fourier University

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