The effect of face inversion on activity in human neural systems for face and object perception.
The differential effect of stimulus inversion on face and object recognition suggests that inverted faces are processed by mechanisms for the perception of other objects rather than by face perception mechanisms. We investigated the face inversion using functional magnetic resonance imaging (fMRI). The principal effect of face inversion on was an increased response in ventral extrastriate regions that respond preferentially to another class of objects (houses). In contrast, house inversion did not produce a similar change in face-selective regions. Moreover, stimulus inversion had equivalent, minimal effects for faces in in face-selective regions and for houses in house-selective regions. The results suggest that the failure of face perception systems with inverted faces leads to the recruitment of processing resources in object perception systems, but this failure is not reflected by altered activity in face perception systems. (+info)
Microdeletion 22q11 and oesophageal atresia.
Oesophageal atresia (OA) is a congenital defect associated with additional malformations in 30-70% of the cases. In particular, OA is a component of the VACTERL association. Since some major features of the VACTERL association, including conotruncal heart defect, radial aplasia, and anal atresia, have been found in patients with microdeletion 22q11.2 (del(22q11.2)), we have screened for del(22q11.2) by fluorescent in situ hybridisation (FISH) in 15 syndromic patients with OA. Del(22q11.2) was detected in one of them, presenting with OA, tetralogy of Fallot, anal atresia, neonatal hypocalcaemia, and subtle facial anomalies resembling those of velocardiofacial syndrome. The occurrence of del(22q11.2) in our series of patients with OA is low (1/15), but this chromosomal anomaly should be included among causative factors of malformation complexes with OA. In addition, clinical variability of del(22q11.2) syndrome is further corroborated with inclusion of OA in the list of the findings associated with the deletion. (+info)
Hyper-IgE syndrome with recurrent infections--an autosomal dominant multisystem disorder.
BACKGROUND: The hyper-IgE syndrome with recurrent infections is a rare immunodeficiency characterized by recurrent skin and pulmonary abscesses and extremely elevated levels of IgE in serum. Associated facial and skeletal features have been recognized, but their frequency is unknown, and the genetic basis of the hyper-IgE syndrome is poorly understood. METHODS: We studied 30 patients with the hyper-IgE syndrome and 70 of their relatives. We took histories, reviewed records, performed physical and dental examinations, took anthropometric measurements, and conducted laboratory studies. RESULTS: Nonimmunologic features of the hyper-IgE syndrome were present in all patients older than eight years. Seventy-two percent had the previously unrecognized feature of failure or delay of shedding of the primary teeth owing to lack of root resorption. Common findings among patients were recurrent fractures (in 57 percent of patients), hyperextensible joints (in 68 percent), and scoliosis (in 76 percent of patients 16 years of age or older). The classic triad of abscesses, pneumonia, and an elevated IgE level was identified in 77 percent of all patients and in 85 percent of those older than eight. In 6 of 23 adults (26 percent), IgE levels declined over time and came closer to or fell within the normal range. Autosomal dominant transmission of the hyper-IgE syndrome was found, but with variable expressivity. Of the 27 relatives at risk for inheriting the hyper-IgE syndrome, 10 were fully affected, 11 were unaffected, and 6 had combinations of mild immunologic, dental, and skeletal features of the hyper-IgE syndrome. CONCLUSIONS: The hyper-IgE syndrome is a multisystem disorder that affects the dentition, the skeleton, connective tissue, and the immune system. It is inherited as a single-locus autosomal dominant trait with variable expressivity. (+info)
Larsen syndrome in two generations of an Italian family.
This paper describes a familial case of Larsen syndrome. Typical anomalies were present in the propositus and 2 of his 6 daughters. In addition, all patients had progressive deafness and the 2 daughters had cleft palate. The certain exclusion of any consanguinity between the couple, suggests, in this instance, the dominant mode of transmission of the syndrome. (+info)
The robust australopithecine face: a morphogenetic perspective.
The robust australopithecines were a side branch of human evolution. They share a number of unique craniodental features that suggest their monophyletic origin. However, virtually all of these traits appear to reflect a singular pattern of nasomaxillary modeling derived from their unusual dental proportions. Therefore, recent cladistic analyses have not resolved the phylogenetic history of these early hominids. Efforts to increase cladistic resolution by defining traits at greater levels of anatomical detail have instead introduced substantial phyletic error. (+info)
Expression of chick Barx-1 and its differential regulation by FGF-8 and BMP signaling in the maxillary primordia.
The vertebrate face develops from a series of primordia surrounding the primitive mouth and is thought to be patterned by the differential expression of homeobox-containing genes. Here we describe the isolation of the chick homologue of the homeobox-containing gene, Barx-1, and show its expression in the developing facial primordia, stomach, and appendicular skeleton. In the maxillary primordia, mesenchymal expression of Barx-1 is complementary to that of Msx-1, which correlate with overlying epithelial expression of Fgf-8 and Bmp-4, respectively. We show that epithelial signals are required to maintain Barx-1 expression and that FGF-8 can substitute for the epithelium. By contrast, BMPs reduce Barx-1 expression and can antagonize FGF-8 signaling. This suggests that in vivo, FGF-8/BMP signaling may regulate Barx-1 gene expression. This provides evidence that the differential expression of FGF-8 and BMPs may determine homeobox-containing gene expression and hence patterning of the facial primordia. (+info)
Alcohol promotes in vitro chondrogenesis in embryonic facial mesenchyme.
Ethanol is a well-recognized teratogen in vertebrates that can perturb the development of the facial primordia and various other embryonic structures. However,the mechanisms underlying alcohol's effects on embryogenesis are currently unclear. Recent evidence suggests that the cranial neural crest, which forms the entire facial skeleton, may be a particularly sensitive target of ethanol teratogenicity. In the present study we have examined the influence of in vitro ethanol exposure on cartilage differentiation in micromass cultures of mesenchymal cells isolated from the various facial primordia (maxillary, mandibular, frontonasal, and hyoid processes) of the stage 24 chick embryo. In all four populations of facial mesenchyme, exposure to 1-1.5% ethanol promoted marked increases in Alcian blue-positive cartilage matrix formation, a rise in 35SO4 accumulation into matrix glycosaminoglycans, and enhanced expression of cartilage-characteristic type II collagen and aggrecan gene transcripts. In frontonasal and mandibular mesenchyme cultures, which undergo extensive spontaneous cartilage formation, ethanol treatment quantitatively elevated both matrix production and cartilage-specific gene transcript expression. In cultures of maxillary process and hyoid arch mesenchyme, which form little or no cartilage spontaneously, ethanol exposure induced the formation of chondrogenic cell aggregates and the appearance of aggrecan and type II collagen mRNAs. These actions were not restricted to ethanol, since tertiary butanol treatment also enhanced cartilage differentiation in facial mesenchyme cultures. Our findings demonstrate a potent stimulatory effect of alcohol on the differentiation of prechondrogenic mesenchyme of the facial primordia. Further analysis of this phenomenon might yield insight into the developmental mechanisms underlying the facial dysmorphologies associated with embryonic ethanol exposure. (+info)
A rapid and dynamic regulation of GDNF-family ligands and receptors correlate with the developmental dependency of cutaneous sensory innervation.
Glial cell line-derived neurotrophic factor (GDNF) and neurturin (NTN) are members of the transforming growth factor-beta family and have been shown to elicit neurotrophic effects upon several classes of neurons including dopaminergic neurons, motoneurons, parasympathetic, sympathetic as well as primary sensory neurons. However, there is little information available on their roles in cutaneous innervation. Herein, we have studied the regulation of gdnf, ntn and the GDNF family receptors and examined their role in the development of facial cutaneous innervation in GDNF mutant mice. A dynamic spatial and temporal regulation of gdnf, ntn and their ligand binding receptors within the follicle-sinus complex correlate with development of distinct subclasses of sensory nerve endings. Furthermore, development of NGF-dependent myelinated mechanoreceptors, i.e. reticular and transverse lanceolate endings also require GDNF during ending formation and maintenance. In addition, ligand and receptor association seems to be intricately linked to a local Schwann cell-axon interaction essential for sensory terminal formation. Our results suggests that functionally specified nerve endings depend on different GDNF family members and that in contrast to neurotrophins, this family of neurotrophic factors may be acting at local sites of terminal Schwann cell-axon growth cone interactions and that they collaborate with neurotrophins by supporting the same populations of neurons but at different times in development. (+info)