Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “ECTODERM”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 811 records · Page 45Linked to original sources
PubMedDate not supplied

Autosomal recessive neurodegenerative disorder with trichorrhexis invaginata and ectodermal dysplasia.

Two siblings are reported with an autosomal recessive syndrome characterized by hair and skin abnormalities, hypoplastic nails, generalized hypotonia, absent reflexes, and progressive neurologic deterioration. Although this disorder shares clinical features with an ectodermal dysplasia syndrome with neurodegenerative changes, no specific neuropathologic findings were present. Instead, trichorrhexis invaginata was found in some hair shafts. Hair analysis may be helpful in classifying clinically confusing neurologic conditions.

Abnormalities, Multiple↗
PubMed1994

Differential expression of a Distal-less homeobox gene Xdll-2 in ectodermal cell lineages.

Neural induction in Xenopus requires the activation of new sets of genes that are necessary for cellular and regional specification of the neural tube. It has been reported earlier that members of the Distal-less homeobox gene family are specifically activated in distinct regions of the central nervous system (CNS) of Xenopus embryos (Dirksen et al., 1993; Papalopulu and Kintner, 1993). In this paper we describe in detail a Xenopus homeobox containing gene Xdll-2, which belongs to the Distal-less gene family. In contrast to other previously described Xenopus family members, Xdll-2 is expressed in the embryonic ectoderm and is specifically repressed in the CNS. This repression can be mimicked in isolated animal caps by treatment with activin. Expression of Xdll-2 persists in the epidermis and some neural crest cells. Because of its spatial and temporal expression pattern this gene is a good candidate to have a regulatory function in the initial formation of the epidermis. Its high level of expression in adult skin indicates that its function is continuously required in this tissue.

Activins↗
PubMed1994

Localization of PDGF A and PDGFR alpha mRNA in Xenopus embryos suggests signalling from neural ectoderm and pharyngeal endoderm to neural crest cells.

In situ hybridization analysis of Xenopus laevis embryos reveals that mRNA encoding the platelet-derived growth factor alpha receptor (PDGFR alpha) is expressed in cephalic neural crest masses prior to migration from the future neural tube and during their migration into the visceral arches. The analysis of fluorescently labeled neural crest tissue transplanted to unlabeled host embryos demonstrates that neural crest cells are the only detectable source of PDGFR alpha mRNA within visceral arches. Transcripts encoding PDGF A are present in neural ectoderm, otic vesicle and pharyngeal endoderm. Their location suggests that PDGF A provides a signal, first from the neural epithelium and later from the otic vesicle and pharyngeal endoderm, to cephalic neural crest cells during their migration in the arch region.

Animals↗
PubMed1995

The expression pattern of the Distal-less homeobox-containing gene Dlx-5 in the developing chick limb bud suggests its involvement in apical ectodermal ridge activity, pattern formation, and cartilage differentiation.

Here we report the isolation from a chick limb bud cDNA library of a cDNA that contains the full coding sequence of chicken Dlx-5, a member of the Distal-less (Dlx) family of homeobox-containing genes that encode homeodomains highly similar to that of the Drosophila Distal-less gene, a gene that is required for limb development in the Drosophila embryo. The expression pattern of Dlx-5 in the developing chick limb bud suggests that it may be involved in several aspects of limb morphogenesis. Dlx-5 is expressed in the apical ectodermal ridge (AER) which directs the outgrowth and patterning of underlying limb mesoderm. During early limb development Dlx-5 is also expressed in the mesoderm at the anterior margin of the limb bud and in a discrete group of mesodermal cells at the mid-proximal posterior margin that corresponds to the posterior necrotic zone. These mesodermal domains of Dlx-5 expression roughly correspond to the anterior and posterior boundaries of the progress zone, the group of highly proliferating undifferentiated mesodermal cells underneath the AER that will give rise to the skeletal elements of the limb and associated structures. The AER and anterior and posterior mesodermal domains of Dlx-5 expression are regions in which the homeobox-containing gene Msx-2 is also highly expressed, suggesting that Dlx-5 and Msx-2 might be involved in regulatory networks that control AER activity and demarcate the progress zone. In addition, Dlx-5 is expressed in high amounts by the differentiating cartilaginous skeletal elements of the limb, suggesting it may be involved in regulating the onset of limb cartilage differentiation.

Amino Acid Sequence↗
PubMed2004

EGF receptor signaling regulates pulses of cell delamination from the Drosophila ectoderm.

Many different intercellular signaling pathways are known but, for most, it is unclear whether they can generate oscillating cell behaviors. Here we use time-lapse analysis of Drosophila embryogenesis to show that oenocytes delaminate from the ectoderm in discrete bursts of three. This pulsatile process has a 1 hour period, occurs without cell division, and requires a localized EGF receptor (EGFR) response. High-threshold EGFR targets are sequentially activated in rings of three cells, prefiguring the temporal pattern of delamination. Surprisingly, widespread misexpression of the relevant activating ligand, Spitz, is compatible with robust delamination pulses. Moreover, although Spitz ligand becomes limiting after only two pulses, artificially prolonging its secretion generates up to six additional cycles, revealing a rhythmic underlying mechanism. These findings illustrate how intercellular signaling and cell movements can generate multiple cycles of a cell behavior, despite individual cells experiencing only one cycle of receptor activation.

Animals↗
PubMed2004

Characteristics of mycobacterial infection in patients with immunodeficiency and nuclear factor-kappaB essential modulator mutation, with or without ectodermal dysplasia.

Hypomorphic mutations of the nuclear factor kappaB essential modulator gene cause ectodermal dysplasia and immunodeficiency. Affected patients have increased susceptibility to mycobacterial disease including cutaneous manifestations. We describe clinical and histopathologic characteristics of 5 patients with nuclear factor kappaB essential modulator gene mutations and mycobacterial infections, two of whom had mycobacterial cutaneous infections.

Adolescent↗
PubMed2005

Focal palmoplantar and gingival keratosis: a distinct palmoplantar ectodermal dysplasia with epidermolytic alterations but lack of mutations in known keratins.

Focal palmoplantar and gingival keratosis is a rare autosomal dominant disease whose clinical features, and in particular, pathologic alterations and molecular etiology remain to be well defined. Recently we observed a German family affected by the disease in at least 3 consecutive generations. The 4 patients examined showed circumscribed and painful hyperkeratosis at the weight-bearing plantar skin since infancy, rather mild palmar hyperkeratosis, and continuous leukokeratosis confined to the maxillary and mandibulary attached gingiva. There were no nail changes, subungeal keratoses, or follicular hyperkeratosis. Light and electron microscopy of the plantar and gingival lesions revealed alterations of epidermolytic hyperkeratosis. Mutations in the known keratin genes were excluded by linkage analysis using microsatellite markers. We conclude that focal palmoplantar and gingival keratosis is a clinically distinct palmoplantar ectodermal dysplasia that is pathologically characterized by epidermolytic alterations, but is most probably not caused by a mutation in a keratin gene.

Adult↗
PubMed2006

Bilateral congenital lacrimal sac fistulae in a patient with ectrodactyly-ectodermal dysplasia-clefting syndrome.

We describe a case of bilateral congenital lacrimal sac fistulas, associated with ectrodactyly-ectodermal dysplasia-clefting syndrome. The embryologic basis for this condition is discussed, as well as the epidemiology, typical presentation, and possible treatment modalities. After we excised the fistulas and intubated the nasolacrimal ducts in this patient, he experienced improvement in symptoms by report.

Abnormalities, Multiple↗
PubMed2004

Nuclear factor kappaB essential modulator-deficient child with immunodeficiency yet without anhidrotic ectodermal dysplasia.

BACKGROUND: Amorphic mutations in the X-linked nuclear factor kappaB essential modulator ( NEMO ) gene cause Incontinentia pigmenti, which is lethal in hemizygous male patients. Hypomorphic NEMO mutations in male patients lead to anhidrotic ectodermal dysplasia (EDA) with immunodeficiency. OBJECTIVE: To report the clinical features of a child bearing a NEMO mutation who displayed an immunodeficiency without EDA. METHODS: Documentation of clinical care, chart review, standard immunologic and microbiological laboratory techniques, mutation analysis of the NEMO gene. RESULTS: Since the age of 15 months, the patient had Mycobacterium avium disease, beginning with multiple adenitis, later followed by disseminated osteomyelitis and dermatitis. In addition, Haemophilus influenzae and Streptococcus pneumoniae infections led to bronchiectasis. An immunologic work-up revealed a low production of IFN-gamma by PBMCs associated with a hyper-IgM phenotype. Despite treatment using repeated cycles of a 4-drug antimycobacterial regimen, continuous subcutaneous IFN-gamma, repeated antibiotic treatment, and intravenous immunoglobulin substitution, the boy remained chronically ill. At the age of 12 years, the disease was complicated by severe autoimmune hemolytic anemia and eventually fatal herpes simplex virus 1 encephalitis despite high-dose acyclovir therapy. Although he did not present any sign of EDA, a novel type of disease-causing hypomorphic NEMO mutation (110-111insC in exon 2) was identified. CONCLUSION: This case demonstrates that patients hemizygous for NEMO mutations can present with an immunodeficiency without EDA. An investigation of NEMO should thus be undertaken in selected children with immunodeficiency despite the lack of EDA.

Carrier Proteins↗
PubMed2005

Notch signaling modulates the nuclear localization of carboxy-terminal-phosphorylated smad2 and controls the competence of ectodermal cells for activin A.

Loss of mesodermal competence (LMC) during Xenopus development is a well known but little understood phenomenon that prospective ectodermal cells (animal caps) lose their competence for inductive signals, such as activin A, to induce mesodermal genes and tissues after the start of gastrulation. Notch signaling can delay the onset of LMC for activin A in animal caps [Coffman, C.R., Skoglund, P., Harris, W.A., Kintner, C.R., 1993. Expression of an extracellular deletion of Xotch diverts cell fate in Xenopus embryos. Cell 73, 659-671], although the mechanism by which this modulation occurs remains unknown. Here, we show that Notch signaling also delays the onset of LMC in whole embryos, as it did in animal caps. To better understand this effect and the mechanism of LMC itself, we investigated at which step of activin signal transduction pathway the Notch signaling act to affect the timing of the LMC. In our system, ALK4 (activin type I receptor) maintained the ability to phosphorylate the C-terminal region of smad2 upon activin A stimulus after the onset of LMC in both control- and Notch-activated animal caps. However, C-terminal-phosphorylated smad2 could bind to smad4 and accumulate in the nucleus only in Notch-activated animal caps. We conclude that LMC was induced because C-terminal-phosphorylated smad2 lost its ability to bind to smad4, and consequently could not accumulate in the nucleus. Notch signal activation restored the ability of C-terminal-phosphorylated smad2 to bind to smad4, resulting in a delay in the onset of LMC.

Activin Receptors↗
PubMed2006

Regionalised signalling within the extraembryonic ectoderm regulates anterior visceral endoderm positioning in the mouse embryo.

The development of the anterior-posterior (AP) axis in the mammalian embryo is controlled by interactions between embryonic and extraembryonic tissues. It is well established that one of these extraembryonic tissues, the anterior visceral endoderm (AVE), can repress posterior cell fate and that signalling from the other, the extraembryonic ectoderm (ExE), is required for posterior patterning. Here, we show that signals from the prospective posterior ExE repress AVE gene expression and affect the distribution of the AVE cells. Surgical ablation of the prospective posterior, but not the anterior, extraembryonic region at 5.5 days of development (E5.5) perturbs the characteristic distal-to-anterior distribution of AVE cells and leads to a dramatic expansion of the AVE domain. Time-lapse imaging studies show that this increase is due to the ectopic expression of an AVE marker, which results in a symmetrical positioning of the AVE. Surgical ablation of this same ExE region after the distal-to-anterior migration has already commenced, at E5.75, does not affect the localisation of the AVE, indicating that this effect takes place within a short time window. Conversely, transplanting the prospective posterior, but not the anterior, extraembryonic region onto isolated E5.5 embryonic explants drastically reduces the AVE domain. Further, transplantation experiments demonstrate that the signalling regulating AVE gene expression originates from the posterior ExE, rather than its surrounding VE. Together, our results show that signals emanating from the future posterior ExE within a temporal window both restrict the AVE domain and promote its specific positioning. This indicates for the first time that the ExE is already regionalised a day before the onset of gastrulation in order to correctly set the orientation of the AP axis of the mouse embryo. We propose a reciprocal function of the posterior ExE and the AVE in establishing a balance between the antagonistic activities of these two tissues, essential for AP patterning.

Animals↗
PubMed2004

Simultaneous functional and fixed appliance therapy for growth modification and dental alignment prior to prosthetic habilitation in hypohidrotic ectodermal dysplasia: a clinical report.

This clinical report describes the simultaneous use of functional and fixed appliances to modify the pattern of dentofacial development and align teeth in preparation for prosthodontic habilitation of a growing child with hypohidrotic ectodermal dysplasia. The treatment objective was to create a more favorable starting point for the prosthodontic phase of habilitation by improving the sagittal and vertical skeletal relationships and facial esthetics. This was accomplished through growth modification with functional appliances conducted simultaneously with eruption of maxillary and mandibular molars, dental arch expansion, alignment, and space management using fixed orthodontic appliances. Orthodontic retention was accomplished by means of removable partial dentures. A second phase of orthodontics conducted closer to the age of skeletal maturation will aim at definitive tooth alignment in preparation for dental implant-supported restorations.

Bone Development↗
PubMed2005

Frequent respiratory tract infections in the canine model of X-linked ectodermal dysplasia are not caused by an immune deficiency.

As in many human patients with X-linked hypohidrotic ectodermal dysplasia (XHED), XHED dogs are at an increased risk for pulmonary disorders. Localized immune system defects had been suspected previously in affected dogs because of frequent infections and unexpected deaths due to opportunistic respiratory tract infections. Experiments were designed to examine systemic and localized humoral and cellular responses, development and function of T cells, and thymic morphology. All dogs used in these experiments were clinically healthy at the time of examination and their immune responses were compared to normal littermates. Serum immunoglobulin concentrations differed somewhat between normal dogs and dogs affected with XHED but they were all within normal ranges. The XHED dogs responded appropriately to vaccination with tetanus toxoid suggesting normal systemic B and plasma cell function. Thymic morphology was compared between normal and affected dogs and T cells were assessed for functionality. Numbers and phenotypes of T and B cells in blood and thymus of affected dogs were within normal limits suggesting normal development of T cells. Cytotoxic and phagocytic ability of macrophages and neutrophils was also normal in affected dogs. In contrast, the secretory IgA concentrations found in affected dogs were significantly higher than in normal dogs, while lacrimal secretions were significantly decreased. These results suggest a compensatory mechanism for secretory IgA, so that the total amount equals that in normal dogs. The results presented in this study indicate that the XHED dogs have a relatively intact immune system and suggest that the same is true for humans with the homologous form of XHED.

Animals↗
PubMed2004

Expression of an NK2 homeodomain gene in the apical ectoderm defines a new territory in the early sea urchin embryo.

We have identified an NK2 family homeodomain transcription factor, SpNK2.1, in the sea urchin Strongylocentrotus purpuratus whose transcripts are initially detected within the apical plate ectoderm of the hatching blastula and are confined to the apical organ at least through 2 weeks of development. Protein localization studies demonstrate that SpNK2.1 is restricted to the apical plate epithelium, but is excluded from the nucleus of serotonergic neurons. The expression profile of SpNK2.1 is dictated via two separate regulatory systems. Initially, SpNK2.1 is restricted to the apical pole domain by beta-catenin-dependent processes operating along the animal-vegetal axis, as evidenced by an expansion of SpNK2.1 expression upon cadherin overexpression. Starting at gastrulation, expression in the apical plate is maintained by SpDri, the sea urchin orthologue of dead ringer. Abrogation of SpDri results in the downregulation of SpNK2.1 after gastrulation, but SpDri is not necessary for the initial activation of SpNK2.1. Loss of function experiments using SpNK2.1-specific morpholino antisense oligonucleotides and SpNK2.1 overexpression experiments do not disrupt embryonic development and have no effect upon the development of neuronal components of the apical organ. Nonetheless, SpNK2.1 defines a new early territory of the sea urchin embryo.

Animals↗
PubMed2004

Zebrafish gcm2 is required for gill filament budding from pharyngeal ectoderm.

The pharyngeal arches give rise to multiple organs critical for diverse processes, including the thymus, thyroid and parathyroids. Several molecular regulators of thymus and thyroid organogenesis are strikingly conserved between mammals and zebrafish. However, land animals have parathyroids whereas fish have gills. The murine transcription factor Glial cells missing 2 (Gcm2) is expressed specifically in the parathyroid primordium in the endodermal epithelium of the third pharyngeal pouch, and in both mice and humans is required for normal development of parathyroid glands. The molecular regulation of fish gill organogenesis remains to be described. We report the expression of gcm2 in the zebrafish pharyngeal epithelium and a requirement for Hox group 3 paralogs for gcm2 expression. Strikingly, zebrafish gcm2 is expressed in the ectodermal portion of the pharyngeal epithelium and is required for the development of the gill filament buds, precursors of fish-specific gill filaments. This study identifies yet another role for a GCM gene in embryonic development and indicates a role for gcm2 during the evolution of divergent pharyngeal morphologies.

Amino Acid Sequence↗
PubMed1984

Absent meibomian glands in the ectrodactyly, ectodermal dysplasia, cleft lip-palate syndrome.

A 27-year-old woman with the syndrome characterized by ectrodactyly, ectodermal dysplasia, and cleft lip-palate had an absent lacrimal punctum in each eye, with signs and symptoms of nasolacrimal obstruction during childhood. Examination disclosed bilateral corneal vascularization and opacification, with diffuse superficial punctate staining of the ocular surface epithelium by fluorescein, an instantaneous tear film break-up time, and normal Schirmer tear measurements. A full-thickness biopsy specimen of the eyelid confirmed the absence of meibomian glands that had been suspected because of absent meibomian gland orifices and secretions. The total absence of meibomian gland secretions in this patient may be a primary feature of this case and may contribute to a lipid-deficient and unstable tear film with resultant desiccation and destruction of the ocular surface epithelium. Breakdown of the corneal epithelium in association with obstruction and infection of the nasolacrimal system may be a particularly disastrous combination for the cornea that resulted in the recurrent, severe bacterial corneal ulcers found in our patient.

Adult↗
PubMed2000

Bilateral sequential lung transplant for ectodermal dysplasia.

A case of bilateral sequential lung transplantation for anhidrotic ectodermal dysplasia is presented. The patient was a 16-year-old male with end-stage lung disease secondary to chronic severe respiratory infection. Although a relatively rare disease, the common association of fatal pulmonary compromise in those affected with this disorder warrants consideration of lung transplantation as a viable therapeutic option.

Adolescent↗
PubMed1980

A new familial syndrome of 46,XY gonadal dysgenesis with anomalies of ectodermal and mesodermal structures.

Two 46,XY phenotypic female siblings, aged 1 1/2 and 8 1/2 years, have peculiar facies, cardiac, renal, musculoskeletal, and ectodermal anomalies, short stature, streak gonads, and mild developmental delay. Previous reported cases of 46,XY gonadal dysgenesis have not had major associated malformations. These children present a new constellation of anomalies unlike those seen in other types of gonadal dysgenesis and represent a new familial syndrome of 46,XY gonadal dysgenesis.

Abnormalities, Multiple↗