Jean-Yves Kurzenne

Isolation of a Highly Myogenic CD34-Negative Subset of Human Skeletal Muscle Cells Free of Adipogenic Potential†‡§

The differentiation of multipotent cells into undesirable lineages is a significant risk factor when performing cell therapy. In muscular diseases, myofiber loss can be associated with progressive fat accumulation that is one of the primary factors leading to decline of muscular strength. Therefore, to avoid any contribution of injected multipotent cells to fat deposition, we have searched for a highly myogenic but nonadipogenic muscle‐derived cell population. We show that the myogenic marker CD56, which is the gold standard for myoblast‐based therapy, was unable to separate muscle cells into myogenic and adipogenic fractions. Conversely, using the stem cell marker CD34, we were able to sort two distinct populations, CD34+ and CD34−, which have been thoroughly characterized in vitro and in vivo using an immunodeficient Rag2−/−γc−/− mouse model of muscle regeneration with or without adipose deposition. Our results demonstrate that both populations have equivalent capacities for in vitro amplification. The CD34+ cells and CD34− cells exhibit equivalent myogenic potential, but only the CD34− population fails to differentiate into adipocytes in vitro and in vivo after transplantation into regenerative fat muscle. These data indicate that the muscle‐derived cells constitute a heterogeneous population of cells with various differentiation potentials. The simple CD34 sorting allows isolation of myogenic cells with no adipogenic potential and therefore could be of high interest for cell therapy when fat is accumulated in diseased muscle. STEM CELLS 2010;28:753–764

ALK probe rearrangement in a t(2;11;2)(p23;p15;q31) translocation found in a prenatal myofibroblastic fibrous lesion: Toward a molecular definition of an inflammatory myofibroblastic tumor family?

A prenatal tumor located in the lumbar paravertebral area was discovered during a routine ultrasound examination at 32 weeks of pregnancy and surgically removed at 4 months of life. The histopathological diagnosis was first suggested to be an infantile desmoid fibromatosis. The tumor karyotype showed a three‐way translocation involving both chromosomes 2 and a chromosome 11, t(2;11;2)(p23;p15;q31). Fluorescence in situ hybridization with a probe flanking the ALK gene at 2p23 demonstrated a rearrangement, as previously described in inflammatory myofibroblastic tumors (IMTs). In light of the genetic analysis, the histopathological diagnosis was revised to IMT, although inflammatory cells were scarce. IMTs are pseudosarcomatous inflammatory lesions that primarily occur in the soft tissue and viscera of children and young adults. Our report describes for the first time the occurrence of IMT during prenatal life. The ALK rearrangement may represent the molecular definition of a subgroup of mesenchymal tumors, not always with complete morphological features of IMT, similar to the model of EWS rearrangement in the Ewing sarcoma family of tumors.

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

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.

Hierarchization of Myogenic and Adipogenic Progenitors Within Human Skeletal Muscle

Skeletal muscle cells constitute a heterogeneous population that maintains muscle integrity through a high myogenic regenerative capacity. More unexpectedly, this population is also endowed with an adipogenic potential, even in humans, and intramuscular adipocytes have been found to be present in several disorders. We tested the distribution of myogenic and adipogenic commitments in human muscle‐derived cells to decipher the cellular basis of the myoadipogenic balance. Clonal analysis showed that adipogenic progenitors can be separated from myogenic progenitors and, interestingly, from myoadipogenic bipotent progenitors. These progenitors were isolated in the CD34+ population on the basis of the expression of CD56 and CD15 cell surface markers. In vivo, these different cell types have been found in the interstitial compartment of human muscle. In vitro, we show that the proliferation of bipotent myoadipogenic CD56+CD15+ progenitors gives rise to myogenic CD56+CD15− progenitors and adipogenic CD56−CD15+ progenitors. A cellular hierarchy of muscle and fat progenitors thus occurs within human muscle. These results provide cellular bases for adipogenic differentiation in human skeletal muscle, which may explain the fat development encountered in different muscle pathological situations. STEM CELLS 2010;28:2182–2194

Molecular Diagnosis of 5α-Reductase Deficiency in 4 Elite Young Female Athletes Through Hormonal Screening for Hyperandrogenism

CONTEXT Although a rare occurrence, previously undiagnosed disorders of sex development (DSD) with hyperandrogenism are sometimes detected by hormonal screening during the international sports competitions. Identifying the cause of XY,DSD raises medical and ethical concerns, especially with regard to issues of the eligibility to compete. OBJECTIVE The aim of this study was to determine whether the detection of high plasma T in young elite female athletes during hormonal screening would reveal an unsuspected XY DSD. SETTING The study was performed in the Nice and Montpellier University Hospitals (France), which collaborate as reference centers for DSD in elite athletes on behalf of sports governing bodies. PATIENTS Four cases of elite young athletes with female phenotypes but high plasma T detected during hormonal screening were investigated for undiagnosed XY DSD. MAIN OUTCOME MEASURES Evaluation of clinical, biological, radiological (magnetic resonance imaging and dual-energy x-ray absorptiometry) and genetic characteristics was conducted. RESULTS The 4 athletes presented as tall, slim, muscular women with a male bone morphotype, no breast development, clitoromegaly, partial or complete labial fusion, and inguinal/intralabial testes. All reported primary amenorrhea. The hormonal analysis evidenced plasma T within the male range, the karyotype was 46, XY, and molecular analysis of the 5α-reductase type 2 (srd5A2) gene identified a homozygotic mutation in 2 cases, a heterozygotic compound in 1 case, and a deletion in 1 case. CONCLUSION 5α-Reductase deficiency should be investigated in elite young female athletes with primary amenorrhea and high male T levels detected during antidoping programs to identify undiagnosed XY DSD.

Blunt abdominal aortic trauma in paediatric patients.

BACKGROUND Blunt abdominal aortic trauma (BAAT) is a very rare occurrence in children, with significant morbidity and mortality. Varied clinical presentations and sparse literature evidence make it difficult to define the proper management policy for paediatric patients. METHOD We report our centres data on three consecutive children with BAAT managed between 2006 and 2010. A Medline search was also performed for relevant publications since 1966, together with a review of references in retrieved publications. RESULTS Forty children (range 1-16 years) were included in our final analysis. Motor vehicle crashes (MVC) were the leading cause of injury (65%). The in-hospital mortality rate was 7.5% (3/40). Nine patients (22.5%) ended up with residual sequelae. Main primary aortic lesions were complete wall rupture (12.5%), intimal transection (70%) and pseudoaneurysm (15%). Twenty-eight children underwent aortic surgical repair (70%). Among the 12 non-operatively managed patients, 41.6% had complications, including one death. CONCLUSION Symptomatic lesions and complete ruptures should undergo immediate surgical repair. Circumferential intimal transections are at high risk of complication and should also receive intervention. Partial intimal transections and delayed pseudoaneurysms can be initially observed by clinical examination and imaging. Patients with these latter pathologies should be operated on at any sign of deterioration.

MR features of isolated uterine relapse in an adolescent with acute lymphoblastic leukaemia

Relapses of lymphoblastic leukaemia traditionally involve the central nervous system and testes in boys. Involvement of the female pelvic organs is frequently found at autopsy; however, involvement of the cervical uterus is rare and even less commonly symptomatic. A 13-cm uterine mass was discovered in a 15-year-old adolescent with a history of lymphoblastic leukaemia during childhood. Pelvic MRI was the best tool to assess the size, characteristics and invasive nature of this lesion of the uterine cervix. To our knowledge, this is a unique case in that we describe the MRI appearance of a relapsing lymphoblastic leukaemic mass both before and after treatment.

Une tumeur de Castelman révélée chez une adolescente par une hypertension portale

La malade décrivait depuis un mois des douleurs abdominales susombilicales, intermittentes et spontanément résolutives. L’examen clinique ne révélait qu’une splénomégalie, sans autre signe clinique d’hypertension portale. L’examen abdominal par échographie montrait une splénomégalie homogène, de 17 cm de flèche, et un important réseau veineux collatéral le long du pédicule splénique. Ces éléments étaient associés à une structure tissulaire, un peu hétérogène, de 3 cm de diamètre, peu vascularisée, d’allure extrinsèque, qui comprimait le bord antérieur du tronc porte au dessus et en dehors du pancréas. De plus, il existait une petite calcification postérieure au dessus de l’artère hépatique. Le caractère extra-luminal et compressif de la masse sur le tronc porte, juste au dessus du niveau théorique du confluent splénomésaraique (figure 1) qu’elle interrompait, était confirmé par tomodensitométrie et par l’I.R.M. Aucune adénopathie associée n’était visible sur ces examens. Le bilan biologique (hémogramme, fonctions hépatiques et pancréatiques, marqueurs tumoraux) était normal. Il n’y avait pas de retentissement oesophagien ou gastrique visible en oesogastroscopie. A l’exploration chirurgicale, il existait une masse bien limitée, dure, homogène, non vasculaire, qui refoulait la veine porte et l’artère hépatique commune. Cette masse, très adhérente à l’artère hépatique, était associée à des remaniements fibreux au niveau du bord inférieur du foie et du bord supérieur du pancréas. Son exérèse, complète, emportait un petit fragment adhérent de capsule hépatique et de tissu pancréatique. L’examen anatomopathologique en extemporané affirmait le caractère bénin de la lésion et, après fixation au formol, concluait au diagnostic de maladie de Castelman avec importante fibrose d’aspect hyalin, correspondant à une maladie de Castelman localisée. A 1 an de l’intervention, la malade était asymptomatique. Le contrôle par échographie confirmait la diminution significative de la vascularisation collatérale et de la splénomégalie, avec une cinétique portale normale.