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At least 1,135 records · Page 63Linked to original sources
PubMed1997

Cerebral primitive neuro-ectodermal tumour following treatment of a unilateral retinoblastoma.

Cerebral primitive neuro-ectodermal tumour (PNET) occurring as a second primary malignancy in childhood is exceedingly rare. We present a 7-year-old boy who developed a proven supratentorial PNET five years after enucleation and radio-/chemotherapy for a sporadic, unilateral retinoblastoma with optic nerve invasion. The association with this malignant eye disease as well as the effect of irradiation and multi-agent chemotherapy on second tumour induction are evaluated.

Chemotherapy, Adjuvant↗
PubMed1994

Experimental induction of primitive neuro-ectodermal tumours in rats: a re-appraisement of the ENU-model of neurocarcinogenesis.

A series of 122 experimental brain tumours, induced in the Wistar rat by means of prenatal exposition to ethyl-nitrosourea, were studied with histological, immunohistochemical and ultrastructural techniques. Although with conventional histological techniques, most of the induced tumours showed morphological features suggesting their classification as malignant schwannomas or oligodendroglioma-like neoplasms, their study by means of immunohistochemistry and electron microscopy suggested that they are, in fact, primitive neuroectodermal tumours, with a tendency toward neuronal differentiation. This finding obliges us to re-appraise the ethyl-nitrosourea model of neurocarcinogenesis and to consider its possible usefulness for the experimental study of therapeutic approaches with potential applications in human neuro-ectodermal neoplasms.

Animals↗
PubMed2002

Autoimmune regulator (AIRE) gene on chromosome 21: implications for autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) any more common manifestations of endocrine autoimmunity.

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is a rare, but well-defined monogenic disorder that is caused by mutations in the autoimmune regulator (AIRE) gene on chromosome 21q22.3. Patients most often suffer from loss of endocrine function in the parathyroid and adrenal glands but may also develop Type 1 diabetes, thyroid disease or hypogonadism. The disease may therefore serve as a model for sporadic endocrine autoimmunity and help to develop new screening and prevention methods. To date at least 46 mutations of AIRE have been identified in affected individuals. Little is known about heterozygosity states but patients with the more prevalent isolated autoimmune endocrinopathies such as Type 1 diabetes, Hashimoto's thyroiditis, Graves' or Addison's disease do not have any of the common mutations. This does not rule out AIRE to be affected either by so far unknown or regulatory variants. The recent characterization of AIRE knockout mice with similar immune pathological findings compared to the human setting will help to elucidate endocrine autoimmunity.

Animals↗
PubMed2002

Expression of hunchback protein in a subset of ectodermal teloblasts of the oligochaete annelid Tubifex.

The early expression patterns of hunchback protein (T-hb protein) were examined in the oligochaete Tubifex, using an antibody raised to the LZF2 protein in leech. This antibody recognizes a 60-kDa polypeptide in the Tubifex embryo. Before teloblastogenesis, T-hb protein is expressed in every cleavage-stage blastomere. At the completion of teloblastogenesis, the only cells expressing T-hb are a fraction of the micromere-derived epithelial cells. During gastrulation, nuclear T-hb is seen in spreading micromere-derived epithelial cells and also in a subset of ectodermal teloblasts. Comparisons of these results with those from other annelids suggest that hb expression in the early cleavage blastomeres and the micromere-derived epithelium are features highly conserved among annelids. In contrast, hb expression in teloblasts appears to be an innovation evolved in the oligochaetes.

Animals↗
PubMed2004

Primary primitive neuro-ectodermal tumor of cauda equina with intracranial seeding.

Primitive neuro-ectodermal tumor (PNET) of the cauda equina is a rare entity. 18 cases have been reported in the literature so far, including 4 cases with intracranial seeding. Moreover parenchymal involvement of brain has never been reported as a form of intracranial seeding from PNET of the cauda equina. A 31 year-old female patient, with PNET of cauda equina showing intracranial seeding 6 months after surgery, is presented in this report. To our knowledge, this is the first adult case of spinal cord PNET with parenchymal involvement of brain. The histopathological, clinical and radiological findings as well as treatment of the patient were evaluated.

Adult↗
PubMed2006

Local recurrence and distant metastasis of supratentorial primitive neuro-ectodermal tumor in an adult patient successfully treated with intensive induction chemotherapy and maintenance temozolomide.

Supratentorial primitive neuro-ectodermal tumors (PNET) in adults are very rare. Extraneural metastasis are unusual and the optimal palliative chemotherapy regimen is not established. We present a 26-year-old patient with local recurrence and distant metastasis of supratentorial PNET successfully treated with intensive induction chemotherapy and maintenance temozolomide.

Adult↗
PubMed1988

Epidermolysis bullosa letalis: an immunogenetic disease of extraembryonic ectoderm?

A newborn male infant with epidermolysis bullosa letalis died at age 6 weeks of septicemia. He had many congenital ectodermal abnormalities and a rudimentary thymus. The spleen had no germinal centers and the lymph nodes lacked follicles. Cytotrophoblast of the amniochorion was sparse and the amniotic epithelium was distorted. Immunohistologic studies of amniotic epithelium revealed the unprecedented presence of trophoblast antigens. Before birth of the patient, the parents had a 5-year history of infertility; after death of the patient, the mother sustained a ruptured tubal pregnancy that necessitated blood transfusions and surgical removal of the tube. She subsequently became pregnant a third time and was delivered of a normal child. The wife shared four major histocompatibility (HLA) antigens with her husband. The parents' immunogenetic characteristics and the immunopathologic features and extraembryonic membranes of the child are considered in terms of maternal responses to trophoblast antigens.

Amnion↗
PubMed1988

Spec2 genes of Strongylocentrotus purpuratus. Structure and differential expression in embryonic aboral ectoderm cells.

Members of the Spec gene family are expressed during embryonic development of the sea urchin, Strongylocentrotus purpuratus. The family encodes proteins related to the calmodulin/troponin C/myosin light chain group of calcium binding proteins and one gene, Spec1, has been studied extensively in our laboratory. In this paper, we analyze other members of the family, collectively termed Spec2 genes. We make use of several hybridization probes derived from Spec1 and Spec2 cDNA clones, which recognize different members of the family. Genomic DNA gel blot and slot blot analyses show that there are approximately eight Spec genes in the S. purpuratus genome. The structures of three Spec2 genes, Spec2a, Spec2c and Spec2d, are described. A 60 kb (kb = 10(3) bases or base-pairs) region of the genome contains the linked Spec1-Spec2c genes and two separate 20 kb regions contain the Spec2a and Spec2d genes. Six members of a repetitive sequence family are dispersed at various locations among the genes. The transcriptional initiation sites of the three Spec2 genes are mapped, and 400 to 500 base-pairs of 5'-flanking DNA sequenced. All three Spec2 genes initiate transcription approximately 120 base-pairs upstream from the 3' end of the first exon. In contrast, the 5' end of the Spec1 transcript begins about 107 base-pairs farther upstream, so it contains 5' untranslated sequences that correspond to non-transcribed 5'-flanking sequences of the Spec2 genes. There is little similarity among the sequences upstream from the CAP site of the Spec2 genes except the TATA consensus sequence and a repeating trinucleotide, AAC. Measurements of Spec mRNA levels during embryogenesis show that Spec1 mRNA begins to accumulate at the early blastula stage and is the most abundant; Spec2a/Spec2c mRNAs begin accumulating several hours later at the late blastula-early gastrula stage and reach about 40 to 60% the levels of Spec1; and Spec2d mRNAs accumulate mostly during the gastrula and pluteus stages with levels reaching only 2% those of Spec1. In situ hybridization with probes that recognize either all Spec2 mRNAs or only Spec2d mRNAs show that, like Spec1, these mRNAs are restricted to aboral ectoderm cells and their precursors. The Spec gene family represents a group of related genes whose mRNAs all accumulate in the same cell type but at different times and to different levels during embryogenesis.

Animals↗
PubMed2004

Ectodermal odontogenic tumours: analysis of 197 Nigerian cases.

This article presents a clinico-pathologic analysis of 197 cases of ectodermal odontogenic tumours archived in the Lagos University Teaching Hospital, Lagos Nigeria over a 21-year period. They were categorized according to the WHO classification of odontogenic tumours. Of the 197 cases, 182 (92.3%) were benign while 15 (7.6%) were malignant. Central ameloblastoma, which accounted for 88.3% in this series, was the most common benign neoplasm demonstrating predilection for males (58.6%) and the mandible (83.3%). The mean age of occurrence (+/-SD) was 31.00 +/- 13.9 (range 9-82 years). Similarly ameloblastic carcinoma was the most prevalent malignant tumour (5.6%) with a predilection for females (63.6%) and the mandible (81.8%). The mean age of occurrence (+/-SD) was 30.1+/- 20.7 (range 16-85) years. Follicular ameloblastoma was found to be the commonest histologic subtype seen in Nigeria.

Adolescent↗
PubMed2026

Mammalian DNA methyltransferases in DNA methylation and imprinted gene expression in extraembryonic ectoderm of post-implantation embryos.

DNA methylation in mammals is mainly catalyzed by three DNA methyltransferases (DNMTs). Conventionally, DNMT1 is considered the primary DNMT protein for maintenance DNA methylation, whereas DNMT3A and DNMT3B function in de novo DNA methylation. In two previous studies, we demonstrated that DNMT3A and DNMT3B maintain genome-wide DNA methylation in embryonic stem (ES) cells and in the epiblast of post-implantation embryos. Interestingly, DNMT3A and DNMT3B also sustain genome-wide DNA methylation in the extraembryonic ectoderm (EXE) of post-implantation embryos, including repeats, genic and intergenic regions. Although DNMT1 plays a major role in maintaining DNA methylation at the imprinting control regions (ICRs) in the imprinted regions, DNMT3A and DNMT3B are required for preserving DNA methylation at the ICRs of a subset of imprinted regions in EXE, similar to the observations in ES cells and epiblast. Surprisingly, de novo DNA methylation mediated by DNMT3A and DNMT3B leads to increased DNA methylation at a large subset of imprinted regions. These results are consistent with what we previously elucidated in the epiblast of post-implantation embryos. Importantly, loss of DNA methylation at the ICR of an imprinted region, resulting from the absence of DNMT1 or two DNMT3 proteins, causes allelic expression switch of the corresponding imprinted genes in that imprinted region. This study provides further evidence that DNMT3A and DNMT3B exert both maintenance and de novo DNA methylation functions across the genome in post-implantation embryos. It also validates some previous findings for DNA methylation-dependent allelic expression switch of imprinted genes.

DNA methylation↗
PubMed2006

Oral and oesophageal squamous cell carcinoma--a complication or component of autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED, APS-I).

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is an autosomal recessive disease exceptionally common in Finland. It is associated with a limited T lymphocyte defect, an autoimmune response to various tissues, particularly endocrine glands. Most patients have chronic oral candidosis, which has been suggested to be carcinogenic. In Finland 92 patients have been diagnosed with APECED and 66 of them are alive. Our aim was to study the possible association of APECED with oral and oesophageal carcinoma. We evaluated the medical histories of all 92 patients for morbidity, causes of death, and known risk factors for oral cancer. We invited all current patients for a clinical examination of their oral mucosa. Six of the 92 had developed oral or oesophageal squamous cell carcinoma (SCC) by the mean age of 37 (29-44years) and four of them had died from it. The six represent 10% of the patients older than 25years. Five of the six patients had long-lasting oral candidosis. Four of the six had smoked regularly for 15years or more. One patient had been on immunosuppressive therapy for 6years following kidney transplantation when SCC in her mouth occurred. The partial T cell defect of APECED seems to favour the growth of Candida albicans and predispose to chronic mucositis and SCC. Aggressive control of oral candidosis and close follow-up of oral mucosa is a necessity in patients with APECED.

Adolescent↗
PubMed1983

Melanotic neuro-ectodermal tumour of infancy. A case report.

A case of melanotic neuro-ectodermal tumour of infancy (retinal anlage tumour, melanotic ameloblastoma) is described. Although a well recognized entity, the biological origin of this tumour is still disputed. A confusing array of names has been awarded to this tumour which characteristically occurs in infants under one year of age, commonly arising from the maxilla but also from the mandible, frontal bone, mediastinum, shoulder and cerebellum. While the origin of the tumour remains unclear, the ultra-structural evidence of Haywood et al. (1969) supports a neural crest origin. Consistent with this are the findings by Borello and Gorlin (1966) of high urinary vanillylmandelic acid excretion in one case and the correlation of tumour enzyme patterns with those of paragangliomas, neuroblastomas and phaeochromocytomas.

Humans↗
PubMed1993

Melanotic neuro-ectodermal tumour of infancy arising from the squamous and occipital bone.

The melanotic neuro-ectodermal tumour of infancy is an uncommon benign tumour of neural crest origin occurring in infants with a predilection for the anterior maxilla. This lesion shows a good response to conservative surgical excision with few recurrences but it should be followed up for long periods of time because of the rare malignant change possible in the tumour.

Humans↗
PubMed2000

Chronic bilateral keratitis in autoimmune polyendocrinopathy-candidiadis-ectodermal dystrophy (APECED). A long-term follow-up and visual prognosis.

PURPOSE: To report the outcome of chronic bilateral keratitis and other ocular manifestations in autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED). MATERIAL AND METHODS: The material consists of 69 patients with APECED, who were examined by the senior author as referrals from the pediatricians. The patients were seen at the Helsinki University Eye Hospital a total of 370 times and the follow-up periods range from 2 to 25 years. RESULTS: 25% of the patients had chronic bilateral keratitis with symptoms of intense photophobia, blepharospasm and lacrimation. On 13 patients the first symptoms appeared before the age of 4 years. Keratitis was the first presenting sign before any evidence of systemic disease in three patients, and in all patients keratitis was among the first three manifestations of the syndrome. The clinical picture from the acute to the chronic cicatricial stage is described. The best corrected visual acuity at the end of the follow-up was 0.6 or better in six patients only. Of the total material 12 patients had lenticular opacities as the manifestation of hypoparathyroidism. CONCLUSIONS: Chronic bilateral keratitis is an ocular manifestation of APECED and in its etiology both hypoparathyroidism and candidiasis may be ruled out as single causes. When an ophthalmologist is confronted with a young child with bilateral chronic keratitis with symptoms of intense photophobia, blepharospasm, lacrimation and either with mucocutaneous candidiasis or hypoparathyroidism, the patient should be referred to a pediatric endocrinological consultation for the possibility of underlying APECED.

Age of Onset↗
PubMed2001

Corneal pathology and outcome of keratoplasty in autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED).

BACKGROUND: Disabling, chronic, persistent keratoconjunctivitis is an essential ocular manifestation in autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED). PURPOSE: Because of the paucity of previous studies our aim is to describe the main histopathological features of the keratopathy and to report the long-term outcome of corneal grafting. MATERIAL: Four corneal buttons obtained at keratoplasties. Two patients with clinical follow-up data of 30 years. RESULTS: The corneal epithelium showed a severe atrophy with even areas of incipient epidermalization. The Bowman's membrane was destroyed. The anterior corneal stroma was replaced by vascularized scar tissue with areas of chronic inflammatory cell infiltration consisting mainly of lymphocytes and plasma cells. The posterior corneal stroma, the Descemet's membrane and the endothelium were normal. Rejection occurred after each keratoplasty. The last visual acuity of the first patient was finger counting of the right eye and 0.3 of the left eye and of the second patient 0.08 of both eyes. CONCLUSION: In chronic keratopathy of APECED the anterior corneal layers, the epithelium, the Bowman's membrane and the anterior corneal stroma are affected while the posterior cornea appears normal. As after keratoplasty rejection may be expected, its prevention and management need intensive attention.

Adult↗
PubMed2001

Hepatic autoantigens in patients with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy.

BACKGROUND & AIMS: Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is caused by mutations of both copies of the autoimmune regulator (AIRE) gene. It is characterized by susceptibility to mucocutaneous candidiasis and multiple autoimmune lesions. A serious disease component is hepatitis. To identify diagnostic autoantibodies for APECED hepatitis, sera from 64 patients with APECED were screened for autoantibodies established in the diagnosis of idiopathic autoimmune hepatitis, and for autoantibodies against 10 cytochrome P450s. METHODS: Screening methods were indirect immunofluorescence, Western blot, Ouchterlony gel diffusion, enzyme-linked immunosorbent assay, and immunoprecipitation. RESULTS: Anti-liver microsomal antibodies were detected in 50% of the patients with APECED hepatitis and 11% of those without hepatitis. Prevalences of antinuclear, smooth muscle, anti-liver cytosol, anti-soluble liver protein/liver pancreas, and anti-CYP2D6 autoantibodies were 9%, 6%, 3%, 0%, and 0%, respectively. CYP1A1, CYP2B6, CYP1A2, and CYP2A6 were identified as autoantigens. Thirty percent of patients with anti-CYP2A6 and 100% of patients with anti-CYP1A2 were affected by hepatitis. Despite the high specificity of anti-CYP1A2 for APECED hepatitis, its sensitivity was low (50%). Anti-CYP2A6 and anti-CYP1A2 were not detected in patients with autoimmune hepatitis (N = 68) or nonhepatitic controls (N = 81). CONCLUSIONS: Anti-CYP1A2 is a highly specific but insensitive marker for APECED hepatitis. No clinical correlation was observed for anti-CYP2A6. Autoimmune hepatitis and APECED hepatitis are characterized by different molecular targets of autoantibodies with no overlap.

Adolescent↗
PubMed2001

[Chronic keratitis and autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy syndrome - a case report].

BACKGROUND: The autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy syndrome (APECED) is a rare disease which can be associated with severe keratitis leading to blindness. Besides conjunctivitis and keratitis uveitis anterior, cataract, retinitis pigmentosa, atrophy of the optical nerve, loss of lashes and eye-brows have been described. CASE REPORT: We report on an 11-year-old girl with the history of APECED syndrom. For 6.5 years she has suffered from chronic keratoconjunctivitis including corneal infiltrates, peripheral epithelial and subepithelial scarring and peripheral neovascularisation of the cornea. Most of all she complained of recurrent conjunctivitis, photophobia and epiphora. The best therapy consisted in local application of dexamethasone and gentamycine three times daily. Under this therapy the corneal infiltration remained stable and the patient felt most comfortable. No side effects appeared by now. CONCLUSIONS: Inspite of the bad prognosis of the keratitis we managed to keep the cornea infiltrates stable. Nevertheless the search for a more effective treatment with less side effects like secondary glaucoma or cataracts will go on.

Child↗
PubMed1996

Autoimmune polyendocrinopathy--candidiasis--ectodermal dystrophy (APECED).

APECED, an autosomal recessive disease manifests itself as a widely variable combination of three groups of components: 1) autoimmune destruction of tissues, predominantly endocrine glands, 2) chronic superficial candidiasis, and 3) ectodermal dystrophy. Clinical and basic information obtained from Finnish series of 72 patients is reviewed.

Addison Disease↗