Maternal Folic Acid Deficiency Is Associated to Developing Nasal and Palate Malformations in Mice.

Craniofacial development requires extremely fine-tuned developmental coordination of multiple specialized tissues. It has been evidenced that a folate deficiency (vitamin B9), or its synthetic form, folic acid (FA), in maternal diet could trigger multiple craniofacial malformations as oral clefts, tongue, or mandible abnormalities. In this study, a folic acid-deficient (FAD) diet was administered to eight-week-old C57/BL/6J female mouse for 2-16 weeks. The head symmetry, palate and nasal region were studied in 24 control and 260 experimental fetuses. Our results showed a significant reduction in the mean number of fetuses per litter according to maternal weeks on FAD diet (p < 0.01). Fetuses were affected by cleft palate (3.8%) as well as other severe congenital abnormalities, for the first time related to maternal FAD diet, as head asymmetries (4.6%), high arched palate (3.5%), nasal septum malformed (7.3%), nasopharynx duct shape (15%), and cilia and epithelium abnormalities (11.2% and 5.8%). Dysmorphologies of the nasal region were the most frequent, appearing at just four weeks following a maternal FAD diet. This is the first time that nasal region development is experimentally related to this vitamin deficiency. In conclusion, our report offers novel discoveries about the importance of maternal folate intake on midface craniofacial development of the embryos. Moreover, the longer the deficit lasts, the more serious the consequent effects appear to be.

Early Transient Prenatal Ultrasound Features of Choanal Atresia.

We present a case series of early second-trimester prenatal ultrasound (US) features in 4 fetuses with a confirmed diagnosis of choanal atresia. The clinical characteristics and outcomes evaluated included prenatal US findings, genetic analyses, postmortem autopsies (2 cases), and computed tomographic findings. A transient large nasal cavity was detected by US in all 4 fetuses. This finding disappeared a few weeks later. Three cases were unilateral choanal atresia, and 1 was bilateral. Transient enlargement of the nasal cavity in early pregnancy appears to be a US sign of choanal atresia.

Choanal Atresia and Craniosynostosis: Development and Disease.

A number of textbooks, review articles, and case reports highlight the potential comorbidity of choanal atresia in craniosynostosis patients. However, the lack of a precise definition of choanal atresia within the current craniosynostosis literature and widely varying methods of detection and diagnosis have produced uncertainty regarding the true coincidence of these conditions. The authors review the anatomy and embryologic basis of the human choanae, provide an overview of choanal atresia, and analyze the available literature that links choanal atresia and craniosynostosis. Review of over 50 case reports that describe patients diagnosed with both conditions reveals inconsistent descriptions of choanal atresia and limited use of definitive diagnostic methodologies. The authors further present preliminary analysis of three-dimensional medical head computed tomographic scans of children diagnosed with craniosynostosis syndromes (e.g., Apert, Pfeiffer, Muenke, and Crouzon) and typically developing children and, although finding no evidence of choanal atresia, report the potentially reduced nasal airway volumes in children diagnosed with Apert and Pfeiffer syndromes. A recent study of the Fgfr2c Crouzon/Pfeiffer syndrome mouse model similarly found a significant reduction in nasal airway volumes in littermates carrying this FGFR2 mutation relative to unaffected littermates, without detection of choanal atresia. The significant correlation between specific craniosynostosis syndromes and reduced nasal airway volume in mouse models for craniosynostosis and human pediatric patients indicates comorbidity of choanal and nasopharyngeal dysmorphologies and craniosynostosis conditions. Genetic, developmental, and epidemiologic sources of these interactions are areas particularly worthy of further research.

[MR imaging of the Tornwaldt's cyst: retrospective study of 1300 patients]. / Imaging di RM della cisti di Tornwaldt: uno studio retrospettivo di 1300 pazienti.

Tornwaldt's cyst is a benign developmental lesion of the nasopharynx, most of all midline located, originating from an outpouching of the pharyngeal mucosa caused by notocord retraction. Usually, the cyst represents an incidental finding of magnetic resonance study. The purpose of this study is to investigate the differential diagnostic aspects of Tornwaldt's cysts, making a comparison with other diseases of nasopharynx on the basis of morphological characteristics and signal, contributing to the previous statistical works.

A rudimentary tragus in the nasopharynx: case report, literature review, and discussion of embryologic development.

We describe the rare case of a nine year-old girl with a several month history of mouth breathing and nasal obstruction due to a rudimentary tragus in the nasopharynx. We focus on the accessory tragus and its origins by describing the embryologic development of the external ear. Based on our review of the medical literature, this is the first report of a nasopharyngeal mass with a pathologic diagnosis of a rudimentary tragus.

Protein tyrosine phosphatase PTPN14 is a regulator of lymphatic function and choanal development in humans.

The lymphatic vasculature is essential for the recirculation of extracellular fluid, fat absorption, and immune function and as a route of tumor metastasis. The dissection of molecular mechanisms underlying lymphangiogenesis has been accelerated by the identification of tissue-specific lymphatic endothelial markers and the study of congenital lymphedema syndromes. We report the results of genetic analyses of a kindred inheriting a unique autosomal-recessive lymphedema-choanal atresia syndrome. These studies establish linkage of the trait to chromosome 1q32-q41 and identify a loss-of-function mutation in PTPN14, which encodes a nonreceptor tyrosine phosphatase. The causal role of PTPN14 deficiency was confirmed by the generation of a murine Ptpn14 gene trap model that manifested lymphatic hyperplasia with lymphedema. Biochemical studies revealed a potential interaction between PTPN14 and the vascular endothelial growth factor receptor 3 (VEGFR3), a receptor tyrosine kinase essential for lymphangiogenesis. These results suggest a unique and conserved role for PTPN14 in the regulation of lymphatic development in mammals and a nonconserved role in choanal development in humans.

The origin and early development of the nasal septum in human embryos.

Based on scanning electron microscopic dissections of human embryos and fetuses of the sixth to the twelfth week (Carnegie stages 16-23 and early fetus), the origin of the nasal septum was studied. The findings show that the nasal septum does not grow downwards. It is derived from the tissue between the primary choanae: as such, its anlage is present from the very beginning. Its contact and fusion with the palatal shelves is made possible by the elevation of the palatal shelves from the vertical into the horizontal position, as the tongue descends.

Expression of CYP2E1 in human nasopharynx and its metabolic effect in vitro.

It was evident that nitrosamines can act directly on target tissue and result in carcinogenesis. As has been shown, the carcinogenic activity of nitrosamines relied on its bioactivation by Cytochrome P450 2E1 (CYP2E1). In this study, we investigated the expression of CYP2E1 in Nasopharyngeal carcinoma (NPC) cells, embryonic nasopharyngeal epithelial tissue (ENET) specimens, and NPC biopsies by RT-PCR analysis. CYP2E1 was expressed in all NPC cell lines (6/6, including 7429) and ENET (6/6), and 80% of NPC biopsie (8/10). The fact that Human nasopharynx expresses CYP2E1 suggests that CYP2E1 may play an important role in the course of NPC by indirect carcinogens nitrosamines. To further evaluate the function of CYP2E1, the CYP2E1 was stably expressed in the cell line NIH 3T3/rtTA under a tetracycline-controlled transactivator. The expression of CYP2E1 was tightly regulated in a dose-dependent manner by Doxycycline (Dox) When the catalytic activity of CYP2E1 was assayed, the result showed that the generation of 6-hydroxychlorzoxazone (6-OH-CZ) from chlorzoxazone (CZ) was dose- and time-dependent on Dox addition to the medium. In the presence of 1 microg/ml Dox, the CZ 6-hydroxylase activity of the cell line was found to be 0.986 +/- 0.034 nmol/10(6) cells/h. The metabolic activation of Tet/3T3/2E1-6 cells was also assayed by N,N'-dinitrosopiperazine (DNP) cytotoxicity, and the viability of Tet/3T3/2E1-6 cells treated with Dox was lower than that of untreated cells with a significant difference between them in 80 and 160 microg/ml DNP (P ( 0.05, t test. This cell line will be useful not only to assess the metabolic characteristics of CYP2E1, but also will be useful to investigate the role of CYP2E1 in metabolic activation of carcinogenic nitrosamines in vitro.

A rare expression of neural crest disorders: an intrasphenoidal development of the anterior pituitary gland.

Congenital abnormalities of the pituitary gland are rare and may be associated with midline cranial, orbital, and facial anomalies and with hormonal insufficiency. Here we report a case of asymptomatic, abnormal migration of the adenohypophysis. The normally developed adenohypophysis was located in the sphenoid bone and developed on the intersphenoidal septum, extending from the superior pharyngeal wall to the floor of the sella turcica (craniopharyngeal canal). The abnormal migration of the pituitary gland was isolated without hormonal deficit, brain, or facial developmental anomalies.

Congenital pharyngolaryngeal band: report of an unusual case of respiratory distress.

Congenital pharyngolaryngeal band (PLB) is an extremely rare congenital abnormality, characterized by a fibrous web extending from the nasopharynx to the epiglottis. We report a case of unilateral pharyngolaryngeal band in a new-born who presented severe airway obstruction and feeding difficulties. The band extended from the right postero-inferior part of the nasopharynx to the right lateral margin of the larynx. Faucial pillars and tonsil were absent on this side. Endoscopic and radiological assessments excluded associated cervicofacial abnormality. Two endoscopic laser resection procedures were necessary to liberate the larynx from PLB. Clinical and radiological assessment advocated a second pharyngeal pouch development failure as the origin to PLB.

[Expression of human cytochrome P450 2E1 gene in embryonic nasopharynx, nasopharyngeal cancer cell lines and tissue].

BACKGROUND & OBJECTIVE: Research results in the past suggested that nitrosamines(chemicals) can induce nasopharyngeal carcinogenesis in vivo and in vitro. As the indirect carcinogens, their activation are mainly dependent on cytochrome P450 2E1. The study here was to investigate the roles of human cytochrome P450 2E1 (hCYP 2E1) gene in chemical cancinogen-induced nasopharyngeal carcinogenesis, and to provide new evidence about etiology and pathogenesis of nasopharyngeal carcinoma(NPC). METHODS: RT-PCR were used to detect the expression of CYP2E1 in 8 embryonic nasopharyngeal epithelial tissues(ENET), 10 NPC biopsys, 5 NPC cell lines(CNE-1, CNE-2, HNE-1, HNE-2, and HNE-3), 1 transformed nasopharyngeal cell line(7429) and 3 human embryonic nasopharyngeal epithelial(HENE) cell lines treated with 200, 250, and 300 micrograms/ml of chemical carcinogen N, N'-dinitrosopiperazine(DNP) in vitro for 24 h, respectively. RESULTS: (1) All of ENET(8/8), NPC cell lines(6/6, including 7429 cell line) and 80% of NPC biopsys(8/10) showed expression of hCYP2E1; (2) The hCYP 2E1 expression in HENE cell lines was elevated after treatment with different concentration of DNP. CONCLUSION: Human nasopharynx exist inducible CYP2E1 expression, suggesting that hCYP2E1 may play an important role in the course of nasopharyngeal carcinogenesis caused by indirect carcinogens nitrosamines(such as DNP).

[Fetal ventilation and craniomaxillary development]. / Ventilation foetale et développement cranio-maxillaire.

Data acquired by means of color Doppler ultrasound very explicitly suggest what the role of the fetal ventilation and nasal capsules in the morphogenesis of the maxillary prognathism, turbinates, nasal valves and nasopharynx could be. Furthermore, the dysmorphologies observed in Apert or Crouzon craniosynostosis, achondroplasia or unilateral cleft lip would also testify that the influence of the fetal ventilatory dynamics goes beyond the limits of the face and extends to the cranial base and the cranium. The wealth of raised hypothesis thanks to the contribution of this imaging system could question the validity of some conceptions of the fetal craniomaxillary morphogenesis.

Development and maturation of taste buds of the palatal epithelium of the rat: histological and immunohistochemical study.

Palatal taste buds are intriguing partners in the mediation of taste behavior and their spatial distribution is functionally important for suckling behavior, especially in the neonatal life. Their prenatal development has not been previously elucidated in the rat, and the onset of their maturation remains rather controversial. We delineated the development and frequency distribution of the taste buds as well as the immunohistochemical expression of alpha-gustducin, a G protein closely related to the transduction of taste stimuli, in the nasoincisor papilla (NIP) and soft palate (SP) from the embryonic day 17 (E17) till the postnatal day 70 (PN70). The main findings in the present study were the development of a substantial number of taste pores in the SP of fetal rats (60.3 +/- 1.7 out of 122.8 +/- 5.5; mean +/- SD/animal at E19) and NIP of neonatal rats (9.8 +/- 1.0 out of 44.8 +/- 2.2 at PN4). alpha-gustducin-like immunoreactivity (-LI) was not expressed in the pored taste buds of either prenatal or newborn rats. The earliest expression of alpha-gustducin-LI was demonstrated at PN1 in the SP (1.5 +/- 0.5 cells/taste bud; mean +/- SD) and at PN4 in the NIP (1.4 +/- 0.5). By age the total counts of pored taste buds continuously increased and their morphological features became quite discernible. They became pear in shape, characterized by distinct pores, long subporal space, and longitudinally oriented cells. Around the second week, a remarkable transient decrease in the total number of taste buds was recorded in the oral epithelium of NIP and SP, which might be correlated with the changes of ingestive behaviors. The total counts of cells showing alpha-gustducin-LI per taste bud gradually increased till the end of our investigation (14.1 +/- 2.7 in NIP and 12.4 +/- 2.5 in SP at PN70). We conclude that substantial development of taste buds began prenatally in the SP, whereas most developed entirely postnatal in the NIP. The present study provides evidence that the existence of a taste pore which is considered an important criterion for the morphological maturation of taste buds is not enough for the onset of the taste transduction, which necessitates also mature taste cells. Moreover, the earlier maturation of palatal taste buds compared with the contiguous populations in the oral cavity evokes an evidence of their significant role in the transmission of gustatory information, especially in the early life of rat.

Genomic organization of the mouse plunc gene and expression in the developing airways and thymus.

Few genes have been isolated which display specific expression in the proximal airways. A recently identified mouse cDNA, plunc, appears to be confined to the upper airways and nasopharyngeal epithelium, and may prove a useful marker for these regions. We now report the genomic cloning and characterization of the mouse plunc gene as well as its developmental expression in the nasal and airway epithelium. We also report the novel finding that plunc is also expressed in the medullary compartment of the murine thymus. The mouse gene contains nine exons and the intron-exon boundaries are conserved with those in the human homologue. At e14.5 plunc is expressed in the nasal epithelium and several days later is seen in the thymic lobes, but not in the lining of the tracheobronchial tree. Expression in the trachea and main-stem bronchi first appears at 1--2 days after birth. Tracheobronchial expression persists at high levels throughout adulthood, as do regional areas of nasal and thymic expression. Finally, we show that the human homologue is expressed in bronchial epithelium, suggesting a transcript that is evolutionarily conserved in the mammalian airway.

Assessment of fetal breathing movements using three different ultrasound modalities.

Twenty-five consecutive women in the third trimester of pregnancy were studied to determine the presence or absence of fetal breathing movements using three different ultrasound imaging techniques. Using real-time B-mode observation of the fetal trunk as the standard, image-directed pulsed wave Doppler insonation of the umbilical vein confirmed the presence of breathing movements with a sensitivity of 100% and the absence of breathing movements with a specificity of 100%. The sensitivity and specificity of color Doppler imaging of the fetal naso- and oropharynx for the presence or absence of fetal breathing movements were 96% and 100%, respectively. In the current study, the detection of fetal breathing movements by three different ultrasound modalities was virtually interchangeable.

The epipharynx in normo- and pathogenesis.

We studied the development of the epipharynx in normal human ontogeny comparing findings in fetuses with severe CNS malformations with those of normal fetuses of a comparable stage of development. Normally, the epipharynx forms a tube and bends at a right angle, whereas, in the fetuses with CNS malformations, the epipharynx develops as a balloon-like form of slightly triangular shape. In hydrocephaly, it formed a narrow tube that was nearly vertical. We concluded that the early formation of the epipharynx is influenced by the separation of the notochord and the formation of the basicranium, by ascendant processes during vertebrogenesis, and by the neotenic development of the maxillomandibular complex.

The human larynx at the end of the embryonic period proper. 2. The laryngeal cavity and the innervation of its lining.

The laryngeal cavity was studied in eight serially sectioned embryos of stage 23 and in three early fetuses, and graphic reconstructions were prepared. After the isolation of the tracheal from the pharyngeal cavity during stages 16 through 22, a communication (not necessarily the pharyngotracheal duct) appears again during stage 23. At this time (8 postovulatory weeks) the laryngeal cavity comprises 1) the coronal and parts of the sagittal clefts of the vestibule (uniting later at the laryngeal inlet); 2) the ventricles, which are not yet completely formed; and 3) the subglottic cavity, which appeared already in earlier stages. The characteristic events of stage 23 are the dissolution of the epithelial lamina and the development of the ventricles. The disruption of the epithelial lamina is an active process that comprises rearrangement and growth, but not loss of cells. The ventricles, which begin as solid outgrowths in stage 20, do not represent fifth pharyngeal pouches. They now point toward the middle of the still paired thyroid laminae and are not at the level of the future glottis, which lies more caudally. In the absence of the median part of the soft palate, the nasopharynx communicates widely with the oral cavity. The epithelium of the respiratory tube, including the larynx, resembles that of the pharynx and esophagus in being pseudostratified columnar and showing a clear basement membrane. It is ciliated over that part of the epiglottis that surmounts the arytenoid swellings, and also over the tip and back of the latter. The transitional area between the laryngopharynx and the esophagus is already innervated by the recurrent laryngeal nerve. Nerve fibers have not yet reached the epithelium of the coronal cleft and the ventricles, but fibers are present near the sagittal cleft of the vestibule. The sensory innervation of the pharynx and larynx has been followed and plotted for the first time in an embryo, and previously unrecorded silver-impregnated receptors have been observed.

Tornwaldt's bursa.

Tornwaldt's bursa results from the embryological relationship of the notochord to the developing foregut. Its embryology and anatomical location is separate from Rathke's pouch which is the primordial anterior hypophysis. Trauma and subsequent inflammation of the defect leads to a complex of symptoms known as 'Tornwaldt's disease' which may be quite confusing to the clinician. Appropriate therapy which includes excision or marsupialization of the cyst will provide complete relief of the symptoms. The embryology, anatomy and therapy of this entity are discussed in detail. Other abnormalities which may mimic Tornwaldt's disease are described along with an embryological and histological differentiation.