Louise Devisme

Mucin gene expression in human embryonic and fetal intestine

Background—The intestinal epithelium is covered by a continuous layer of mucus which is secreted by well differentiated epithelial cells. Disregulation of the expression of mucins has been reported to have possible implications in the neoplastic process which affects intestinal mucosae. It is well known that preneoplastic and neoplastic tissues can express fetal phenotypic characteristics. Aims—To assess whether the expression of mucin genes in the intestinal tract is linked to the stage of cellular differentiation and tissue development, by studying the expression of six mucin genes in human fetal small intestine and colon, and also adult tissues. Methods—In situ hybridisation was used to study mRNA expression of MUC2, MUC3, MUC4, MUC5B, MUC5AC, and MUC6 in 32 human embryos and fetuses (6.5–27 weeks gestation). Normal adult mucosae were used as controls. Results—Three mucin genes, MUC2, MUC4, and MUC5AC, were differently expressed in fetal intestine compared with expression in normal adults. Conclusion—These differences in mucin gene expression suggest a possible regulatory role for these products in intestinal epithelial cell differentiation.

From normal respiratory mucosa to epidermoid carcinoma: Expression of human mucin genes

Mucous cells in the respiratory tract contribute to the maintenance of the normal epithelial cell population via mechanisms of cell proliferation and differentiation. Mucous cell hyperplasia often occurs as a basic response to injury in the tracheobronchial epithelium. These cells are also thought to be involved in the histogenesis of epidermoid metaplasia. A typical biochemical feature of these cells is mucus secretion. Aberrant glycosylation or under‐glycosylation of mucins is well known in cancer; however, the specific role played by mucin genes is at present unclear. To provide information regarding the expression of these genes in squamous metaplasia and squamous cell carcinoma, we analyzed and compared the expression of MUC1‐MUC7 genes by in situ hybridization in control respiratory mucosa and lesions associated with neoplasia (hyperplasia, metaplasia and dysplasia) and squamous cell carcinomas. MUC4 was expressed independently of mucus secretion since it was expressed weakly by basal cells and probably by ciliated cells as well as collecting ducts, epidermoid metaplasia with complete squamous cell differentiation, and most of epidermoid carcinomas even well differentiated and keratinized. In squamous metaplasia and dysplasia, MUC4 gene expression was diffuse and less intense than in normal epithelium. MUC5AC was overexpressed in dysplasia as well as in mucous cell and basal cell hyperplasia and undetectable when squamous differentiation was achieved. Int. J. Cancer 86:162–168, 2000.

Expression of human mucin genes in normal kidney and renal cell carcinoma

Expression of human mucin genes in normal kidney and renal cell carcinoma

Prenatal and early postnatal morphogenesis and growth of human laryngotracheal structures

Advances in neonatal medicine have resulted in increased care of fetal and neonatal airways. These advances have required an exhaustive knowledge of fetal airway anatomy and development. The aim of this study was to determine the anatomical development of laryngotracheal structures during the fetal and immediate postnatal period and to correlate these observations with other fetal biometric parameters to estimate developmental particularities of the fetal airway. An anatomical prospective study was based on examination of larynx and trachea from 300 routine autopsies of fetuses and infants, free of malformation and never intubated. Anatomical measurements of cricoid cartilage, thyroid cartilage, glottis, arytenoid cartilage and trachea were performed using a precision calliper and precision divider. Statistical analysis was performed to represent the growth of anatomical structures and to evaluate the correlation with biometric data. Raw data and 10th and 90th percentile curves were fitted satisfactorily with a linear model for gestational age. A linear relationship between laryngotracheal measurement and body weight and height was observed except for glottis length, interarytenoid distance and anterior cricoid height. The diameter of the cricoid lumen was significantly less than that of the trachea and glottis lumen. A sexual dysmorphism was noted for thyroid cartilage measurements and interarytenoid distance, with measurements significantly smaller in females. This study reports the anatomical development of normal laryngotracheal structures during the fetal period. Despite the fact that this study was performed during postmortem examination, these observations can be useful to develop criteria, materials and surgical procedures adapted to fetal and neonatal airways as well as for the purposes of early diagnosis and management of laryngotracheal malformations.

Neonatal tracheal changes following in utero fetoscopic balloon tracheal occlusion in severe congenital diaphragmatic hernia

OBJECTIVE To report postnatal tracheal changes after in utero fetoscopic balloon tracheal occlusion in severe congenital diaphragmatic hernia (CDH). DESIGN Case series. SETTING Tertiary care center, CDH National Reference Center. PATIENTS Seven consecutive newborn infants with severe CDH who underwent fetoscopic balloon tracheal occlusion. INTERVENTIONS Flexible laryngotracheoscopy and histological aspect observed at necropsy in 2 nonsurvivors. RESULTS All infants displayed elongation and relaxation of the posterior tracheal wall, intermittently obstructing the lumen during tidal breathing. Whereas the cartilage displayed adequate rigidity, the pars membranacea appeared both flaccid and loose. Tracheal widening (tracheomegaly) was seen in all cases. Histology (n = 2) pointed to structural modifications throughout the pars membranacea, that is, loss of epithelial folding and of longitudinal elastic network and focal muscular disruption. The cartilage displayed no visible or histologic changes. The above tracheal changes were not symptomatic, except for a barking cough during increased respiratory efforts. CONCLUSIONS Tracheal widening and intermittent collapse of the posterior wall of the trachea during tidal breathing was found in 7 consecutive newborns who underwent fetoscopic balloon tracheal occlusion, causing mild clinical symptoms. Endoscopic tracheal assessment might provide useful information in children with CDH, in particular, when they underwent in utero fetoscopic balloon tracheal occlusion.

A case–control study of placental lesions associated with pre-eclampsia

To investigate gross and microscopic placental lesions associated with pre‐eclampsia and to determine which lesions are most strongly linked to serious pregnancy complications.

Determination of endotracheal tube size in a perinatal population: an anatomical and experimental study.

Background:This study aimed at correlating anatomical dimensions of the larynx and trachea to age and weight in a prenatal population. Endotracheal tube size determination was then proposed according to these considerations. Methods:Anatomical measurements were obtained during 150 fetal and infant postmortem examinations. The optimal endotracheal tube size was determined by three methods: clinically, by a pressure method using calibrated inextensible balloons, and anatomically by comparing the laryngotracheal perimeter to the tube perimeters. Based on these results, recommended tube sizes were calculated. Results:In premature babies before 37 weeks gestation, the optimal tube size according to pressure estimation was significantly greater than that determined by anatomical measurement alone. This difference was no longer valid after 40 weeks gestation. Conclusions:This study identified the elasticity of laryngeal structures in premature babies, allowing intubation with tube sizes greater than predicted by anatomical measurements with an increasing injury risk located in the posterior part of the glottic plane. This elasticity disappears near 40 weeks gestation, and the injury risk then predominates in the subglottic region. These results lead the authors to recommend that the size of the endotracheal tube used in the perinatal population should be based on anatomical and experimental data to limit the injury risks.

SALL4 is a marker of the embryonal subtype of hepatoblastoma

SALL4 is a marker of germ cell tumours. The aim of this study was to investigate SALL4 expression in blastemal tumours, particularly in hepatoblastoma.

Histologic Structure and Development of the Laryngeal Macula Flava

The laryngeal maculae flavae (MF) have been previously described as cellular condensations at the extremities of the vocal cords, but the exact nature and role of the MF are unknown. The purpose of this study is a histomorphological analysis of the nature and development of the MF in human vocal cords, from the beginning of fetal life to adulthood. Eighty-six larynges, from the fetus at 12 weeks of amenorrhea (WA) to adulthood, were collected from autopsies and studied by light microscopy with hematoxylin and eosin, orcein, and Alcian blue staining and pS 100 immunostaining. Our observations allowed us to separate the fetal development of the MF into 4 periods. The first corresponds to the appearance of the posterior MF between 13 and 15 WA. In the second period, the anterior MF appeared between 16 and 18 WA, allowing definition of the intermacular space. Fibrous structures, composed of collagen and elastic fibers, of the MF and intermacular space developed between 20 and 33 WA. The last period, from 33 WA to birth, corresponded to a maturation of these structures. In adults, the histologic structure of the MF presented a concentric peripheral fibrous layer associated with a central cellular component. Structural analysis of the MF concludes in favor of the chondroid nature of the macular cell. These observations bring into question the current knowledge on the MF. From these observations, the role of the MF in the developing vocal cord is discussed.

Un tératome mature médiastinal vieux de 1 800 ans

La paleopathologie, c’est-a-dire l’etude medicale des restes humains provenant des fouilles archeologiques, permet d’identifier certaines maladies, parfois rarissimes, principalement sur des squelettes. Nous presentons ici le cas d’un teratome mature identifie sur le squelette d’une esclave de 25-45 ans provenant d’une necropole antique proche de Rome (2 e – 3 e siecle ap. J.-C.). De topographie mediastinale, il etait constitue d’une coque osseuse mesurant 4 cm de grand axe. A l’interieur de cette formation ont ete retrouves cinq bourgeons dentaires. Il s’agit du premier cas decrit d’une telle tumeur sur des restes humains anciens.