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Bernard J Moxham - One of the best experts on this subject based on the ideXlab platform.
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Ultrastructural characterization of the mesenchyme of the facial processes during development of the rat Intermaxillary Segment.
Connective tissue research, 2020Co-Authors: D Symons, Bernard J MoxhamAbstract:This study quantifies ultrastructural changes within the mesenchyme of the maxillary and medial/lateral nasal processes before and after formation of the Intermaxillary Segment. At both day 11 and day 13 of development, 4 fetal rat heads were fixed with 3% glutaraldehyde and processed for electron microscopy. Differences between cells within the facial processes were discerned at day 11 of gestation. Significantly more rough endoplasmic reticulum was present in the cells of the maxillary processes than in the lateral nasal processes (p < .05), and a greater number of cell projections was found in the maxillary processes than in the medial nasal processes (p < .05). At day 13, no significant differences were found in the facial processes. Of particular note, a consistent increase in the number of cell projections within all the facial processes was found on day 13 when compared with day 11 (p < .05). This change may be related to intercellular signaling between the mesenchymal cells at the time of onset of major histogenic changes.
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ultrastructural characterization of the mesenchyme of the facial processes during development of the rat Intermaxillary Segment
Connective Tissue Research, 2002Co-Authors: D Symons, Bernard J MoxhamAbstract:This study quantifies ultrastructural changes within the mesenchyme of the maxillary and medial/lateral nasal processes before and after formation of the Intermaxillary Segment. At both day 11 and day 13 of development, 4 fetal rat heads were fixed with 3% glutaraldehyde and processed for electron microscopy. Differences between cells within the facial processes were discerned at day 11 of gestation. Significantly more rough endoplasmic reticulum was present in the cells of the maxillary processes than in the lateral nasal processes ( p < .05), and a greater number of cell projections was found in the maxillary processes than in the medial nasal processes ( p < .05). At day 13, no significant differences were found in the facial processes. Of particular note, a consistent increase in the number of cell projections within all the facial processes was found on day 13 when compared with day 11 ( p < .05). This change may be related to intercellular signaling between the mesenchymal cells at the time of onset...
D Symons - One of the best experts on this subject based on the ideXlab platform.
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Ultrastructural characterization of the mesenchyme of the facial processes during development of the rat Intermaxillary Segment.
Connective tissue research, 2020Co-Authors: D Symons, Bernard J MoxhamAbstract:This study quantifies ultrastructural changes within the mesenchyme of the maxillary and medial/lateral nasal processes before and after formation of the Intermaxillary Segment. At both day 11 and day 13 of development, 4 fetal rat heads were fixed with 3% glutaraldehyde and processed for electron microscopy. Differences between cells within the facial processes were discerned at day 11 of gestation. Significantly more rough endoplasmic reticulum was present in the cells of the maxillary processes than in the lateral nasal processes (p < .05), and a greater number of cell projections was found in the maxillary processes than in the medial nasal processes (p < .05). At day 13, no significant differences were found in the facial processes. Of particular note, a consistent increase in the number of cell projections within all the facial processes was found on day 13 when compared with day 11 (p < .05). This change may be related to intercellular signaling between the mesenchymal cells at the time of onset of major histogenic changes.
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ultrastructural characterization of the mesenchyme of the facial processes during development of the rat Intermaxillary Segment
Connective Tissue Research, 2002Co-Authors: D Symons, Bernard J MoxhamAbstract:This study quantifies ultrastructural changes within the mesenchyme of the maxillary and medial/lateral nasal processes before and after formation of the Intermaxillary Segment. At both day 11 and day 13 of development, 4 fetal rat heads were fixed with 3% glutaraldehyde and processed for electron microscopy. Differences between cells within the facial processes were discerned at day 11 of gestation. Significantly more rough endoplasmic reticulum was present in the cells of the maxillary processes than in the lateral nasal processes ( p < .05), and a greater number of cell projections was found in the maxillary processes than in the medial nasal processes ( p < .05). At day 13, no significant differences were found in the facial processes. Of particular note, a consistent increase in the number of cell projections within all the facial processes was found on day 13 when compared with day 11 ( p < .05). This change may be related to intercellular signaling between the mesenchymal cells at the time of onset...
Scott T. Baur - One of the best experts on this subject based on the ideXlab platform.
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Epithelial–Mesenchymal Transformation Is the Mechanism for Fusion of the Craniofacial Primordia Involved in Morphogenesis of the Chicken Lip
Developmental Biology, 2000Co-Authors: Scott T. BaurAbstract:Abstract We have previously demonstrated that epithelial–mesenchymal transformation (EMT) brings about TGFβ3-induced confluence of craniofacial primordia that derive from the maxillary processes and give rise to the avian palate. The upper lip of the chick embryo forms by confluence of primordia also derived from the maxillary processes, but in this case, they fuse with the Intermaxillary Segment of the nasofrontal process. Here, we ask whether the bilateral epithelial seams formed when these primordia contact each other in vivo are removed by apoptosis (as formerly was believed to occur in developing palate) or by EMT. We found that, as is the case in the palate, the periderm of the two-layered embryonic epithelium begins to slough shortly before these primordia fuse, bringing the basal epithelial cells into close contact. We show by TUNEL staining and confirm by TEM that apoptosis occurs only in periderm. TEM reveals that basal epithelial cells contacting each other to form the midline seam produce numerous desmosomes with each other. Then, basement membrane begins to disappear, numerous filopodia extend from the basal surfaces of epithelial cells, the space between them enlarges, and the seam breaks apart, leaving mesenchymal cells in its wake. Transformation of the carboxyfluorescein (CCFSE)-labeled epithelial seam is demonstrated in vivo by detection of CCFSE bodies in mesenchymal cells that replace it. This demonstration of EMT in avian lip development lays important groundwork for understanding the causes of human cleft lip and analyzing the mechanism of action of growth factors, such as SHH and BMPs, that have been shown (J. A. Helms et al., 1997, Dev. Biol. 187, 25–35) to be involved in avian lip confluence.
Prashanth Adiga - One of the best experts on this subject based on the ideXlab platform.
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Unusual facial cleft in Fryns syndrome: defect of stomodeum?
Genetic Counseling, 2020Co-Authors: Katta M. Girisha, Pv Bhat, Prashanth AdigaAbstract:Summary: Unusual facial cleft in Fryns syndrome: defect of stomodeum?: We report on a fetus with Fryns syndrome. The facial cleft was unusual. There was bilateral cleft lip with cleft palate. The Intermaxillary Segment was connected through the base of a mound in the midline to the lower lip. We believe this is an atypical facial cleft in Fryns syndrome and likely represents a defective stomodeum. Key-words: Fryns syndrome - Facial cleft. INTRODUCTION Fryns syndrome (OMIM 229850) is an autosomal recessive condition with congenital diaphragmatic hernia, pulmonary hypoplasia, craniofacial anomalies, distal limb hypoplasia and other malformations (1). Cleft palate and cleft lip are common findings and rarely pseudo cleft of upper lip and high arched palate may be observed (3). We found an unusual orofacial cleft in a fetus with Fryns syndrome and postulate on the developmental defect. CASE REPORT A 25-year-old primigravida with non-consanguineous marriage was detected to have Dandy-Walker malformation, cleft lip and congenital diaphragmatic hernia in the fetus at about 20 weeks of gestation on antenatal sonogram. Polyhydramnios was not observed. Pregnancy was terminated and the fetus was sent for autopsy. The male fetus showed cloudy corneae, broad nasal bridge, macrostomia, low set ears, micrognathia, and bilateral cleft lip-palate with the triangular philtral Segment in continuity with the lower lip (distorted mouth and lips) (Figs 1 and 2). Lower lip showed a groove adjacent to this almost spherical tissue probably due to pressure effect. There was a globoid tissue attached to the lower lip in the midline the base of which was connected to the philtral Segment of the upper lip and premaxilla through a band of tissue lined by mucosa. Tongue was normal and separate from these tissues. Nails had mild hypoplasia. Thorax was slightly small and short. There was congenital diaphragmatic hernia on the left side with left lobe of liver and intestines as its contents and shift of mediastinum to the right. The left lung was hypoplastic. Brain could not be evaluated in view of autolysis. No heart defect was observed. Abdominal contents were normal except for the herniation of liver and kidneys. The observations were limited by partial maceration of the fetus. Karyotype was not possible. Radiograph of the fetus was normal. There was no convincing shortening of terminal phalanges. DISCUSSION Congenital diaphragmatic hernia, lung hypoplasia, cloudy corneae, broad nasal bridge, cleft lip, cleft palate, hypoplastic nails and DandyWalker malformation in the fetus suggest the diagnosis of Fryns syndrome. …
Byung-jai Choi - One of the best experts on this subject based on the ideXlab platform.
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EARLY DEVELOPMENT OF THE TOOTH IN THE STAGED HUMAN EMBRYOS AND FETUSES
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, 1998Co-Authors: Hyoung-woo Park, Hyeon-joo Oh, Byung-jai ChoiAbstract:Tooth development is usually described in four stages such as bud stage, cap stage, bell stage and crown stage. Exact time of appearance of tooth primordia is different among reports, and up to now there is no timetable regarding initial tooth development. To understand the congenital malformations and other disorders of the orofacial region, there is a need to establish a standard timetable on early tooth development. Till now, studies on the tooth development were mainly on later fetuses, and only few reports on early stage. Also, there were no reports on the time when bud stage turns to cap stage, and cap stage to bell stage. In this study, external morphology of face and the early development of the tooth, and transition of bud stage to cap stage, cap stage to bell stage were studied using 27 staged human embryos and 9 serially sectioned human fetuses. The results are as follows: 1. Mandibular region was formed by union of both mandibular arch at stage 15, and maxillary region by union of maxillary arch, medial nasal prominence, and Intermaxillary Segment at stage 19. 2. Ectodermal thickening which represents the primordia of tooth appeared in mandibular region at stage 13, and maxillary region at stage 15. 3. Bud stage began from mandibular primary central incisor at stage 17, and maxillary primary central incisor at stage 18. And the sequence of appearance was in the mandibular primary lateral incisor at stage 19, maxillary primary lateral incisor at stage 20, mandibular primary canine at stage 22, maxillary primary canine and primary first molar at stage 23, madibular primary first molar and maxillary primary second molar at 9th week, and mandibular primary second molar at 10th week of development. 4. Cap stage began from the primary anterior teeth at 9th week, and primary second molar still had the characteristics of cap stage at 12th week of development. 5. Transition to bell stage started from the primary anterior teeth at 12th week, and primary second molar started at 16th week of development. 6. Trnasition to crown stage started from primary anterior teeth at 16th week, and primary second molar at 26th week of development.