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Dive into the research topics where Thierry Merrot is active.

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Featured researches published by Thierry Merrot.


Journal of Pediatric Surgery | 2013

Esophageal atresia: Data from a national cohort

Rony Sfeir; Arnaud Bonnard; Naziha Khen-Dunlop; Frédéric Auber; Thomas Gelas; Laurent Michaud; Guillaume Podevin; A. Breton; Virginie Fouquet; Christian Piolat; Jean Louis Lemelle; Thierry Petit; Frederic Lavrand; Francis Becmeur; Marie Laurence Polimerol; Jean Luc Michel; F. Elbaz; Eric Habonimana; Hassan Allal; Emmanuel Lopez; Hubert Lardy; Marianne Morineau; C. Pelatan; Thierry Merrot; P. Delagausie; Philline de Vries; Guillaume Levard; Phillippe Buisson; Emmanuel Sapin; Olivier Jaby

PURPOSE A prospective national register was established in 2008 to record all new cases of live-birth newborns with esophageal atresia (EA). This epidemiological survey was recommended as part of a national rare diseases plan. METHODS All 38 national centers treating EA participated by completing for each patient at first discharge a questionnaire validated by a national committee of experts. Data were centralized by the national reference center for esophageal anomalies. Quantitative and qualitative analyses were performed, with P-values of less than 0.05 considered statistically significant. Results of the 2008-2009 data collection are presented in this report. RESULTS Three hundred seven new living cases of EA were recorded between January 1, 2008, and December 31, 2009. The male/female sex ratio was 1.3, and the live-birth prevalence of EA was 1.8 per 10,000 births. Major characteristics were comparable to those reported in the literature. Survival was 95%, and no correlation with caseload was noted. CONCLUSIONS Epidemiologic surveys of congenital anomalies such as EA, which is a rare disease, provide valuable data for public health authorities and fulfill one important mission of reference centers. When compared with previous epidemiological data, this national population-based registry suggests that the incidence of EA remains stable.


European Urology | 2015

Is Hypospadias Associated with Prenatal Exposure to Endocrine Disruptors? A French Collaborative Controlled Study of a Cohort of 300 Consecutive Children Without Genetic Defect

Nicolas Kalfa; Françoise Paris; Pascal Philibert; Mattea Orsini; Sylvie Broussous; Nadège Fauconnet-Servant; Françoise Audran; Laura Gaspari; Hélène Lehors; Myriam Haddad; J.M. Guys; Rachel Reynaud; Pierre Alessandrini; Thierry Merrot; Kathy Wagner; Jean-Yves Kurzenne; Florence Bastiani; Jean Breaud; Jean-Stéphane Valla; Gérard Morisson Lacombe; Eric Dobremez; Amel Zahhaf; Jean-Pierre Daurès; Charles Sultan

BACKGROUND Numerous studies have focused on the association between endocrine-disrupting chemicals (EDCs) and hypospadias. Phenotype variability, the absence of representative comparison groups and concomitant genetic testing prevent any definitive conclusions. OBJECTIVE To identify the role of occupational and environmental exposures to EDCs in nongenetic isolated hypospadias. DESIGN, SETTING, AND PARTICIPANTS A total of 408 consecutive children with isolated hypospadias and 302 normal boys were prospectively included (2009-2014) in a multi-institutional study in the south of France, the area of the country with the highest prevalence of hypospadias surgery. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS In patients without AR, SRD5A2, and MAMLD1 mutations, parental occupational and professional exposures to EDCs were evaluated based on European questionnaire QLK4-1999-01422 and a validated job-exposure matrix for EDCs. Environmental exposure was estimated using the zip code, the type of surrounding hazards, and distance from these hazards. Multivariate analysis was performed. RESULTS Fetal exposure to EDCs around the window of genital differentiation was more frequent in the case of hypospadias (40.00% vs 17.55%, odds ratio 3.13, 95% confidence interval 2.11-4.65). The substances were paints/solvents/adhesives (16.0%), detergents (11.0%), pesticides (9.0%), cosmetics (5.6%), and industrial chemicals (4.0%). Jobs with exposure were more frequent in mothers of hypospadiac boys (19.73% vs 10.26%, p=0.0019), especially cleaners, hairdressers, beauticians, and laboratory workers. Paternal job exposure was more frequent in the cases of hypospadias (40.13% vs 27.48%, p=0.02). Industrial areas, incinerators, and waste areas were more frequent within a 3-km radius for mothers of hypospadiac boys (13.29% vs. 6.64%, p<0.00005). Association of occupational and environmental exposures increases this risk. CONCLUSIONS This multicenter prospective controlled study with a homogeneous cohort of hypospadiac boys without genetic defects strongly suggests that EDCs are a risk factor for hypospadias through occupational and environmental exposure during fetal life. The association of various types of exposures may increase this risk. PATIENT SUMMARY Our multi-institutional study showed that parental professional, occupational, and environmental exposures to chemical products increase the risk of hypospadias in children.


Experimental Dermatology | 2011

ATP signalling is crucial for the response of human keratinocytes to mechanical stimulation by hypo‐osmotic shock

Nathalie Azorin; Matthieu Raoux; Lise Rodat-Despoix; Thierry Merrot; Patrick Delmas; Marcel Crest

Abstract:  Touch is detected through receptors located in the skin and the activation of channels in sensory nerve fibres. Epidermal keratinocytes themselves, however, may sense mechanical stimulus and contribute to skin sensation. Here, we showed that the mechanical stimulation of human keratinocytes by hypo‐osmotic shock releases adenosine triphosphate (ATP) and increases intracellular calcium. We demonstrated that the release of ATP was found to be calcium independent because emptying the intracellular calcium stores did not cause ATP release; ATP release was still observed in the absence of external calcium and it persisted on chelating cytosolic calcium. On the other hand, the released ATP activated purinergic receptors and mobilized intracellular calcium stores. The resulting depletion of stored calcium led to the activation of capacitative calcium entry. Increase in cytosolic calcium concentration was blocked by the purinergic receptor blocker suramin, phospholipase C inhibitor and apyrase, which hydrolyses ATP. Collectively, our data demonstrate that human keratinocytes are mechanically activated by hypo‐osmotic shock, leading first to the release of ATP, which in turn stimulates purinergic receptors, resulting in the mobilization of intracellular calcium and capacitative calcium entry. These results emphasize the crucial role of ATP signalling in the transduction of mechanical stimuli in human keratinocytes.


Urology | 2003

Fetal bladder rupture due to anteriorurethral valves.

Thierry Merrot; Kathia Chaumoitre; Raha Shojai; Claude D’Ercole; Pierre Alessandrini

A rupture of the fetal bladder that resulted in urinary ascites has rarely been reported in published studies. We present the first case of a spontaneous rupture of the fetal bladder, due to an anterior urethral valve, in which the diagnosis was suspected prenatally by means of Doppler ultrasonography and was confirmed postnatally.


Histochemistry and Cell Biology | 2006

The distribution of PKC isoforms in enteric neurons, muscle and interstitial cells of the human intestine

John B. Furness; Anderson J. Hind; Katrina Ngui; Heather L. Robbins; Nadine Clerc; Thierry Merrot; Joseph J. Tjandra; Daniel P. Poole

In many organs, different protein kinase C (PKC) isoforms are expressed in specific cell types, suggesting that the different PKCs have cell-specific roles, and also that drugs acting on a particular PKC may have effects on the whole organ that are distinguishable from drugs that target other isoforms. Previous studies of the guinea-pig and mouse intestine indicate that there are cell-specific expressions of PKC isoforms in neurons, muscle and the interstitial cells of Cajal. In the present study we have investigated the expression of different PKCs in human intestine. Immunohistochemical studies showed that the forms that are prominent in human enteric neurons are PKCs γ and ε and in muscle the dominant form is PKCδ. Neurons were weakly stained for PKCβI. These observations parallel findings in guinea-pig and mouse, except that in human PKCγ-IR was not present in the same types of neurons that express it in the guinea-pig. Enteric glial cells were strongly immunoreactive for PKCα, which is also the major isoform in enteric glial cells of guinea-pig. In human and guinea-pig, glial cells also express PKCβI. Spindle-shaped cells in the mucosa were immunoreactive for PKCα and PKCγ and in the muscle layers similar cells had PKCγ-IR and PKCθ-IR. The spindle-shaped cells were similar in morphology to interstitial cells of Cajal. Western analysis and RT-PCR confirmed the presence of the PKC isoform proteins and mRNA in the tissue. We conclude that there is cell-type specific expression of different PKCs in enteric neurons and intestinal muscle in human tissue, and that there are strong similarities in patterns of expression between laboratory animals and human, but some clear differences are also observed.


Orphanet Journal of Rare Diseases | 2013

Health-related quality of life and its determinants in children with a congenital diaphragmatic hernia

Fabrice Michel; Karine Baumstarck; Agathe Gosselin; Pierre Le Coz; Thierry Merrot; Sophie Hassid; Kathia Chaumoitre; Julie Berbis; Claude Martin; Pascal Auquier

BackgroundThe development of new therapeutics has led to progress in the early management of congenital diaphragmatic hernia (CDH) in pediatric intensive care units (PICU). Little is known about the impact on the quality of life (QoL) of children and their family. The aim of this study was to assess the impact of CDH treated according to the most recent concepts and methods outlined above on child survivors’ QoL and their parents’ QoL.Patients and methodsThis study incorporated a cross-sectional design performed in two PICU (Marseille, France). Families of CDH survivors born between 1999 and 2008 were eligible. The following data were recorded: socio-demographics, antenatal history and delivery, initial hospitalization history. Self-reported data were collected by mail, including current clinical problems of the children (13-symptom list), children’s QoL (Kidscreen-27 questionnaire), and parents’ QoL (Short-Form 36 questionnaire). Children’s QoL score was compared with controls and QoL of survivors of childhood leukemia. Parent’s QoL was compared with controls. Non-parametric statistics were employed.ResultsForty-two families agreed to participate and questionnaires were completed by 32 of them. Twenty-one children had a current clinical problems related to CDH. All the QoL scores of CHD survivors were significantly lower compared with controls. The physical well-being dimension was significantly higher for CHD survivors compared with survivors of childhood leukemia. Gastro-esophageal reflux at discharge, antenatal diagnosis, length of stay in the PICU, and neuropsychological and respiratory issues significantly impacted QoL scores of children. The parents of CHD survivors had significantly poorer score in emotional role dimension compared with controls.ConclusionThe impact of CDH on QoL seems to be important and must be understood by clinicians who treat these children and their parents.


Journal of Pediatric Surgery | 2003

Small bowel obstruction caused by congenital mesocolic hernia: case report

Thierry Merrot; Robert Anastasescu; Taras Pankevych; Katia Chaumoı̂tre; Pierre Alessandrini

Transmesocolic hernias are extremely rare. Their exact incidence is still unknown. A strangulated hernia through a mesocolic opening is a rare operative finding. Preoperative diagnosis still is difficult in spite of imaging techniques currently available. This is the case of a 4-month-old boy with transmesocolic internal hernia and coincident intestinal malrotation and volvulus of small bowel.


Journal of Pediatric Surgery | 2011

Terlipressin as rescue therapy for refractory pulmonary hypertension in a neonate with a congenital diaphragmatic hernia

Lefteris Stathopoulos; Claire Nicaise; Fabrice Michel; Laurent Thomachot; Thierry Merrot; Pierre Lagier; Claude Martin

We report the case of a 38-week gestational age neonate, with isolated congenital diaphragmatic hernia presenting with refractory persistent pulmonary hypertension, systemic hypotension, and hypoxemia, resistant to usual therapeutics. Arginine vasopressin is responsible for systemic vasoconstriction and decreases pulmonary hypertension. We theorized that terlipressin, its long-acting analogue, could have the same properties. We used terlipressin as rescue therapy after parental and local ethics committee acceptance. After a bolus of terlipressin 20 μg/kg and continuous infusion at a rate of 5 μg/kg per hour, blood oxygen saturation improved from 75% to 98%, oxygen requirements fell from fraction of inspired oxygen 100% to 40%, and mean arterial pressure rose from 28 to 46 mm Hg, allowing a decrease of vasopressor infusion. Terlipressin may be useful in the management of neonates with congenital diaphragmatic hernia and refractory pulmonary hypertension.


Urology | 2010

Prenatal urinoma related to ureteropelvic junction obstruction: poor prognosis of the affected kidney.

Lefteris Stathopoulos; Thierry Merrot; Kathia Chaumoitre; Florence Bretelle; Fabrice Michel; Pierre Alessandrini

OBJECTIVES We evaluated functional outcome of kidneys with fetal urinoma associated to ureteropelvic junction obstruction. METHODS We retrospectively reviewed 5 cases of antenatally diagnosed urinoma associated to hydronephrosis. Prenatal imaging work-up consisted of ultrasound (US) and magnetic resonance (MR) examination. Differential renal function was assessed postnatally with renal scintigraphy. RESULTS Four male fetuses and 1 female fetuse presented with urinoma with hydronephrosis diagnosed by US at 24-25 weeks gestational age and confirmed by MRI examination at 28-29 weeks gestational age. On postnatal US, urinoma had disappeared in 4 cases. Parenchyma of the affected kidney was poorly differentiated in all cases. Ureteropelvic junction obstruction was confirmed in the 5 cases. Renal scintigraphy revealed poor functioning kidney (1%) in 2 cases, no function in 1 case, and impaired function in 2 cases (17%). CONCLUSIONS Association of upper urinary tract dilatation caused by ureteropelvic junction obstruction and prenatally diagnosed urinoma may suggest a poor ipsilateral functioning kidney.


Journal De Radiologie | 2004

Diagnostic prénatal d’atrésie de l’œsophage par IRM

Katia Chaumoitre; Zoubeir Amous; Florence Bretelle; Thierry Merrot; C. d’Ercole; Michel Panuel

Resume Le diagnostic prenatal d’atresie de l’œsophage est suspecte a l’echographie devant un estomac absent ou de petite taille, une dilatation de l’œsophage cervical et un hydramnios inexplique mais la valeur de ces signes n’est pas formelle. Deux observations sont rapportees ou l’IRM fœtale a permis le diagnostic de cette anomalie congenitale.

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Katia Chaumoitre

Centre national de la recherche scientifique

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Michel Panuel

Aix-Marseille University

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Alice Faure

Aix-Marseille University

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J.M. Guys

Aix-Marseille University

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Fabrice Michel

Centre national de la recherche scientifique

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