Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where L. Machet is active.

Publication


Featured researches published by L. Machet.


American Journal of Clinical Pathology | 2005

Blastic NK-cell lymphomas (agranular CD4+CD56+ hematodermic neoplasms): a review.

Tony Petrella; Martine Bagot; Rein Willemze; M. Beylot-Barry; Béatrice Vergier; Michèle Delaunay; Chris J. L. M. Meijer; Philippe Courville; Pascal Joly; F. Grange; Anne de Muret; L. Machet; Anne Dompmartin; Jacques Bosq; Anne Durlach; Philippe Bernard; Sophie Dalac; Pierre Dechelotte; M. D’Incan; Janine Wechsler; Michael A. Teitell

Blastic natural killer (NK) cell lymphoma (also termed CD4+CD56+ hematodermic neoplasm) is a recently described entity, with the first case reported in 1994. It was suggested initially that the disease originates from NK cells. Since 1994, single cases and a few small series have been published. In this review, data from the literature and a series of 30 cases from the French and Dutch study groups on cutaneous lymphomas are discussed. The major clinical, histopathologic, and phenotypic aspects of the disease and diagnostic criteria and data suggesting a plasmacytoid dendritic cell origin for the tumor cells are provided.


International Journal of Cancer | 2000

Delays in diagnosis and melanoma prognosis (I): The role of patients

Marie Aleth Richard; Jean Jacques Grob; Marie Françoise Avril; Michèle Delaunay; Johany Gouvernet; Pierre Wolkenstein; Pierre Souteyrand; Brigitte Dreno; Jean Jacques Bonerandi; Sophie Dalac; L. Machet; Jean Claude Guillaume; J. Chevrant-Breton; Catherine Vilmer; F. Aubin; Bernard Guillot; M. Beylot-Barry; C. Lok; Nadia Raison-Peyron; Philippe Chemaly

A prospective survey was conducted to assess the role of patients in the melanoma prognosis. Consecutive patients with primary melanoma were interviewed and examined using a comprehensive questionnaire including a psychological instrument. Main outcome measures were the delay before medical intervention and the tumor thickness. Of 590 melanomas, 70.8% were detected by patients and this proportion was higher in females. Relatives were involved in the detection of half of the cases. Median delays before the patient realized he had a suspicious lesion, before this lesion was seen by a doctor, and before the melanoma was removed were 4 months, 2 months, and 1 week, respectively. Delays up to several years were observed in some cases. The rate of self‐detection tended to be lower, the delays before seeking medical advice to be longer, and the tumor thickness to be higher in old people, in males, in lower‐educated individuals, in those living out of towns, and in people with a low awareness about melanocytic tumors than in other cases. Conversely, individuals with a high number of atypical nevi, those who were aware to be at risk, and those who regularly visited a dermatologist tended to detect their melanoma more rapidly. No specific psychological traits were associated with a late reaction, although negligence and anxiety tended to prolong the delays. Knowledge about melanoma was poor in many patients, especially in males, and wrong beliefs were widespread. This study provides the targets of future education programs. Int. J. Cancer 89:271–279, 2000.


British Journal of Dermatology | 2010

Blastic plasmacytoid dendritic cell neoplasm: is transplantation the treatment of choice?

Stéphane Dalle; M. Beylot-Barry; Martine Bagot; D. Lipsker; L. Machet; Pascal Joly; Anne Dompmartin; d'Incan M; Eve Maubec; F. Grange; O. Dereure; S. Prey; S. Barete; Wetterwald M; Sylvie Fraitag; T. Petrella

Background  Blastic plasmacytoid dendritic cell neoplasm (BPDCN) represents the malignant counterpart derived from plasmacytoid dendritic cells. This rare entity is usually revealed and diagnosed on cutaneous lesions associated or not with a leukaemic component. The prognosis associated with BPDCN is very poor.


Journal of Controlled Release | 2002

Effect of sonication parameters on transdermal delivery of insulin to hairless rats

Alain Boucaud; Marie Ange Garrigue; L. Machet; Loı̈c Vaillant; F. Patat

Application of low-frequency ultrasound has been shown to enhance transdermal drug transport of large molecules such as insulin. In this study, we investigated the dependence of ultrasound-induced transdermal delivery of insulin on ultrasound parameters. Insulin was delivered in vivo to hairless rats using 20 kHz ultrasound applied over a range of ultrasound intensity, application time and pulse length. Change in blood glucose levels of the animals was monitored to assess insulin transport. The results showed a threshold below which no detectable changes in blood glucose level was observed for each ultrasound parameter. Moreover, our findings indicated that sonophoretic enhancement is dependent on energy dose and length of ultrasound pulse that is consistent with a cavitation-based mechanism. The more significant effect of lowering glycemia was obtained with application of less than 15 min ultrasound and was similar to subcutaneous injection of 0.5 U of insulin. Pretreatment of hairless rat skin with ultrasound followed by application of insulin resulted in no significant modification in blood glucose level, indicating that transdermal transport of insulin mainly occurred during sonication. Sonophoresis may therefore potentially be applied for non-invasive and painless delivery of insulin in the treatment of insulin-dependent diabetes.


American Journal of Clinical Pathology | 2004

TCL1 and CLA Expression in Agranular CD4/CD56 Hematodermic Neoplasms (Blastic NK-Cell Lymphomas) and Leukemia Cutis

Tony Petrella; Chris J. L. M. Meijer; Sophie Dalac; Rein Willemze; Marc Maynadié; L. Machet; Olivier Casasnovas; Béatrice Vergier; Michael A. Teitell

Agranular CD4/CD56 hematodermic neoplasm (CD4/CD56 HN), also termed blastic natural killer cell lymphoma, is characterized by a peculiar immunophenotype and high skin tropism. The lineage of origin is not known, and a plasmacytoid dendritic cell derivation has been proposed. CD4/CD56 HN generally is diagnosed by using tumor skin biopsy, with the most important differential diagnosis being myelomonocytic leukemia cutis. We evaluated the expression of 2 plasmacytoid dendritic cell antigens, T-cell leukemia 1 (TCL1) and cutaneous lymphocyte-associated antigen (CLA), in 29 cases of CD4/CD56 HN and 18 cases of myelomonocytic leukemia cutis. TCL1 and CLA were expressed in 26 (90%) of 29 CD4/CD56 HN cases vs TCL1 expression in 3 (17%) and CLA expression in 14 (78%) of 18 leukemia cutis cases. Furthermore, CLA antiserum displays a peculiar small-dot staining pattern in CD4/CD56 HN. These results suggest that TCL1 and CLA are good markers for CD4/CD56 HN tumor cells and add support for a plasmacytoid dendritic cell origin. The high skin tropism of CD4/CD56 HN might be related to the skin-homing property of CLA.


International Journal of Cancer | 2000

Delays in diagnosis and melanoma prognosis (II): The role of doctors

Marie Aleth Richard; Jean Jacques Grob; Marie Françoise Avril; Michèle Delaunay; Johany Gouvernet; Pierre Wolkenstein; Pierre Souteyrand; Brigitte Dreno; Jean Jacques Bonerandi; Sophie Dalac; L. Machet; Jean Claude Guillaume; J. Chevrant-Breton; Catherine Vilmer; F. Aubin; Bernard Guillot; M. Beylot-Barry; C. Lok; Nadia Raison-Peyron; Philippe Chemaly

A prospective survey was conducted to assess physician responsibility in melanoma prognosis. Consecutive patients with primary melanoma were interviewed and examined using a standardized questionnaire. Main outcome measures were medical components of the delay before tumor resection and tumor thickness. Of 590 melanomas, 29.1% were coincidentally detected by physicians and their tumor depth was lower than in melanomas detected by patients (p < 0.001). Physician sensitivity for melanoma diagnosis was evaluated at 86%. Median time intervals to propose resection and to perform removal of melanoma were short: 0 (mean 103) and 7 (mean 68) days, respectively. Melanomas were managed in an inappropriate way in 14.2% of cases. Location on acral areas and absence of pigmentation were associated with longer medical delays and more frequent inappropriate medical attitudes. Melanomas located on hardly visible areas were less frequently detected by physicians than those on visible areas. Medical delays were shorter, doctors attitude was more frequently appropriate, and melanoma thickness was lower (p < 0.001) when the patient visited a dermatologist (54.7%) than when he or she visited a general practitioner (33.4%). Our study shows that doctor responsibility accounts for only a small part of the total delay before melanoma removal. However, systematic total examination and better training of doctors, especially about unusual forms of melanoma, could still improve melanoma detection. Int. J. Cancer 89:280–285, 2000.


British Journal of Dermatology | 2013

Blastic plasmacytoid dendritic cell neoplasm: clinical features in 90 patients

F. Julia; T. Petrella; M. Beylot-Barry; M. Bagot; Dan Lipsker; L. Machet; P. Joly; O. Dereure; Wetterwald M; d'Incan M; F. Grange; J. Cornillon; G. Tertian; Eve Maubec; Philippe Saiag; S. Barete; I. Templier; F. Aubin; Stéphane Dalle

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare disease characterized by malignant proliferation of a contingent blastic plasmacytoid dendritic cell. This rare entity is recognized mostly by cutaneous spreading, or not having a leukaemic component. The prognosis is very poor.


European Journal of Dermatology | 2010

A three-year-analysis of fixed drug eruptions in hospital settings in France

Nesrine Brahimi; Emilie Routier; Nadia Raison-Peyron; Anne-Fleur Tronquoy; Caroline Pouget-Jasson; Stéphanie Amarger; L. Machet; Emmanuelle Amsler; Antoine Claeys; Bruno Sassolas; Dominique Leroy; Anne Grange; Alain Dupuy; Nadège Cordel; Jean-Marie Bonnetblanc; B. Milpied; M.-S. Doutre; Marie-Thérèse Guinnepain; Annick Barbaud; Olivier Chosidow; Jean-Claude Roujeau; Bénédicte Lebrun-Vignes; Vincent Descamps

Fixed drug eruption (FDE) is one of the most typical cutaneous drug adverse reactions. This localized drug-induced reaction is characterized by its relapse at the same sites. Few large series of FDE are reported. The aim of this study was to retrospectively collect and analyse well informed cases observed in a hospital setting. This study involved 17 academic clinical centers. A French nation-wide retrospective multicentric study was carried out on a 3-year-period from 2005 to 2007 by collecting data in seventeen departments of dermatology in France. Diagnosis of FDE was based essentially on clinical findings, at times confirmed by pathological data and patch-testing. Records were reviewed for demographics, causative drugs, localization, severity, and patch-tests, when available. Fifty nine cases were analysed. Patients were 59-years-old on average, with a female predilection. The most common drug was paracetamol, followed by the non-steroidal anti inflammatory drugs. The time between drug intake and skin symptoms was, on average, two days. Beside these classical characteristics, some original findings were found including, a frequent non pigmentation course and a sex-dependent pattern of distribution. Women often had lesions on the hands and feet, and men on the genitalia. Given the fact that skin pigmentation is an inconstant feature of FDE, its French name (erythème pigmenté fixe) should be reconsidered. The sex-dependent distribution could help our understanding of the pathophysiology of fixed drug eruption.


The Lancet | 2017

First-line rituximab combined with short-term prednisone versus prednisone alone for the treatment of pemphigus (Ritux 3): a prospective, multicentre, parallel-group, open-label randomised trial

Pascal Joly; Maud Maho-Vaillant; Catherine Prost-Squarcioni; Vivien Hebert; Estelle Houivet; Sébastien Calbo; Frédérique Caillot; Marie Laure Golinski; B. Labeille; C. Picard-Dahan; C. Paul; M.-A. Richard; Jean David Bouaziz; Sophie Duvert-Lehembre; Philippe Bernard; F. Caux; M. Alexandre; Saskia Ingen-Housz-Oro; Pierre Vabres; E. Delaporte; Gaelle Quereux; Alain Dupuy; S. Debarbieux; M. Avenel-Audran; Michel D'Incan; C. Bedane; N. Beneton; D. Jullien; Nicolas Dupin; L. Misery

BACKGROUND High doses of corticosteroids are considered the standard treatment for pemphigus. Because long-term corticosteroid treatment can cause severe and even life-threatening side-effects in patients with this disease, we assessed whether first-line use of rituximab as adjuvant therapy could improve the proportion of patients achieving complete remission off-therapy, compared with corticosteroid treatment alone, while decreasing treatment side-effects of corticosteroids. METHODS We did a prospective, multicentre, parallel-group, open-label, randomised trial in 25 dermatology hospital departments in France (Ritux 3). Eligible participants were patients with newly diagnosed pemphigus aged 18-80 years being treated for the first time (not at the time of a relapse). We randomly assigned participants (1:1) to receive either oral prednisone alone, 1·0 or 1·5 mg/kg per day tapered over 12 or 18 months (prednisone alone group), or 1000 mg of intravenous rituximab on days 0 and 14, and 500 mg at months 12 and 18, combined with a short-term prednisone regimen, 0·5 or 1·0 mg/kg per day tapered over 3 or 6 months (rituximab plus short-term prednisone group). Follow-up was for 3 years (study visits were scheduled weekly during the first month of the study, then monthly until month 24, then an additional visit at month 36). Treatment was assigned through central computer-generated randomisation, with stratification according to disease-severity (severe or moderate, based on Harmans criteria). The primary endpoint was the proportion of patients who achieved complete remission off-therapy at month 24 (intention-to-treat analysis). This study is registered with ClinicalTrials.gov, number NCT00784589. FINDINGS Between May 10, 2010, and Dec 7, 2012, we enrolled 91 patients and randomly assigned 90 to treatment (90 were analysed; 1 patient withdrew consent before the random assignment). At month 24, 41 (89%) of 46 patients assigned to rituximab plus short-term prednisone were in complete remission off-therapy versus 15 (34%) of 44 assigned to prednisone alone (absolute difference 55 percentage points, 95% CI 38·4-71·7; p<0·0001. This difference corresponded to a relative risk of success of 2·61 (95% CI 1·71-3·99, p<0·0001), corresponding to 1·82 patients (95% CI 1·39-2·60) who would need to be treated with rituximab plus prednisone (rather than prednisone alone) for one additional success. No patient died during the study. More severe adverse events of grade 3-4 were reported in the prednisone-alone group (53 events in 29 patients; mean 1·20 [SD 1·25]) than in the rituximab plus prednisone group (27 events in 16 patients; mean 0·59 [1·15]; p=0·0021). The most common of these events in both groups were diabetes and endocrine disorder (11 [21%] with prednisone alone vs six [22%] with rituximab plus prednisone), myopathy (ten [19%] vs three [11%]), and bone disorders (five [9%] vs five [19%]). INTERPRETATION Data from our trial suggest that first-line use of rituximab plus short-term prednisone for patients with pemphigus is more effective than using prednisone alone, with fewer adverse events. FUNDING French Ministry of Health, French Society of Dermatology, Roche.


International Journal of Cancer | 2002

The kinetics of the visible growth of a primary melanoma reflects the tumor aggressiveness and is an independent prognostic marker: a prospective study.

Jean Jacques Grob; Marie Aleth Richard; Johany Gouvernet; Marie Françoise Avril; Michèle Delaunay; Pierre Wolkenstein; Pierre Souteyrand; Jean Jacques Bonerandi; L. Machet; Jean Claude Guillaume; J. Chevrant-Breton; Catherine Vilmer; F. Aubin; Bernard Guillot; M. Beylot-Barry; C. Lok; Nadia Raison-Peyron; Philippe Chemaly

Primary melanoma (MM) could be a good model to test an intuitive concept: a cancer that is growing fast in its early phase is likely to have a high aggressiveness. Since MMs are visible tumors, many patients can provide information to indirectly assess the kinetics of their lesion. A prospective study was designed to assess if the kinetics of the visible growth of a primary MM, as described by the patient, could be a noninvasive prognostic marker. The ratio of MM thickness to delay between MM appearance and MM removal was used as a surrogate value for the kinetics of the MM growth. To assess the delay between MM appearance and removal, 362 patients with self‐detected invasive MM fulfilled a detailed questionnaire, which provided 2 types of estimations of this delay and thus 2 melanoma kinetics indexes (MKI and MKI*). After a median follow‐up of 4 years, univariate and multivariate analyses assessed whether relapse‐free survival was linked to MKI or MKI*. MKI was significantly predictive of relapse‐free survival (HR = 1.84 [1.51–2.25]) and relapse at 1 year (RR = 2.93 [1.84–4.69]), independently from Breslow thickness. MKI was retained in multivariate prognostic models, just after thickness and before other usual markers. MKI* was also a significant independent risk marker, although less predictive. In this model, the initial growth kinetics of a cancer reflects its aggressiveness and a high index predicts a short‐term relapse. The “subjective” data obtained from patients about their MM history, although usually neglected, can thus provide a better prognostic marker than many “objective” tests.

Collaboration


Dive into the L. Machet's collaboration.

Top Co-Authors

Avatar

Annabel Maruani

François Rabelais University

View shared research outputs
Top Co-Authors

Avatar

L. Vaillant

François Rabelais University

View shared research outputs
Top Co-Authors

Avatar

M. Samimi

François Rabelais University

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

G. Lorette

François Rabelais University

View shared research outputs
Top Co-Authors

Avatar

Sophie Dalac

John Radcliffe Hospital

View shared research outputs
Top Co-Authors

Avatar

A. Perrinaud

François Rabelais University

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge