Craniofacial development is intrinsically related to segmentation along the primary body axis (Hunt and Krumlauf, 1991; Hunt et al., 1991a; Thorogood, 1993). In mammalian embryos, segmentally arranged cranial structures such as the branchial arches and nerve ganglia are built upon this primary metamerism (Keynes and Stern, 1984; Lumsden and Keynes, 1989; Puelles and Rubenstein, 1993). Like most...

STUDY OBJECTIVES Although gonorrhea may infect the cervix, rectum, or pharynx of women, culturing non-cervical sites is rare outside of sexually transmitted disease (STD) clinics. This study aims to compare rectal and pharyngeal gonorrhea prevalence in adolescent and adult women and to calculate the percentage of cases that would be missed with cervical culture alone. DESIGN Retrospective rev...

Three cases of pharyngeal gonorrhoea were misdiagnosed in patients harbouring meningococci which failed to utilise maltose in CTA medium. The microbiological identity of the isolates was established by other means. Although meningococci giving atypical reactions to carbohydrate utilisation tests occur only rarely, the possibility of a misdiagnosis of gonorrhea, and its social and legal repercus...

Acquisition of the lower jaw (mandible) was evolutionarily important for jawed vertebrates. In humans, syndromic craniofacial malformations often accompany jaw anomalies. The basic helix-loop-helix transcription factor Hand2, which is conserved among jawed vertebrates, is expressed in the neural crest in the mandibular process but not in the maxillary process of the first branchial arch. Here, ...

The origin of active predation in vertebrates is associated with the rise of three major, uniquely derived developmental characteristics of the head: (i) migratory cranial neural crest cells (CNCCs) giving rise to most skeletal skull elements; (ii) expression of Dlx genes by CNCCs in the Hox-free first pharyngeal arch (PA1); and (iii) muscularization of PA1 derivatives. Here we show that these ...

BACKGROUND Intake of retinoic acid (RA) or of its precursor, vitamin A, during early pregnancy is associated with increased incidence of craniofacial lesions. The origin of these teratogenic effects remains enigmatic as in cranial neural crest cells (CNCCs), which largely contribute to craniofacial structures, the RA-transduction pathway is not active. Recent results suggest that RA could act o...

Hedgehog (Hh) signaling plays multiple roles in the development of the anterior craniofacial skeleton. We show that the earliest function of Hh is indirect, regulating development of the stomodeum, or oral ectoderm. A subset of post-migratory neural crest cells, that gives rise to the cartilages of the anterior neurocranium and the pterygoid process of the palatoquadrate in the upper jaw, conde...