We report on the occurrence of discrete patches of unusually long pigmented hair on the skin of three patients with Gorlin syndrome from two unrelated families with confirmed heterozygous mutations in the Patched (PTCH) gene. The PTCH protein is a negative regulator of Hedgehog signaling, and the Sonic Hedgehog (SHH)-PTCH pathway is known to play an important role in the formation and cycling of the hair follicle. We believe that the patches represent a genuine physical sign associated with Gorlin syndrome, and discuss molecular mechanisms by which they might arise.
[Show abstract][Hide abstract] ABSTRACT: INTRODUCTION: Basal cell carcinomas (BCC) are the most usual skin cancer that affects human beings. Sporadic BCCs are prevalent, often arising in people chronically exposed to UV radiation from the sun. Eventually BCCs may be associated to different syndroms like Bazex-Dupré-Christol, Rambo and Gorlin. Contrarily to syndromic BCCs, the cases of multiple familiar nonsydromic BCCs(MFNSBCC) have only few studies found in the literature. Only five families have been described to date with the disease. Since sporadic and Gorlin BCCs are associated to many mutations in the PTCH1 gene, we hypothesized that the multiple BCCs phenotype is also associated with mutations in this same gene. The PTCH1 tumor suppressor gene is located in the 9q22.3 chromosomal region, contains 23 exons, and has an important role in embryogenesis. OBJETIVE: To perform genetic analysis of PTCH1 exons 9, 11, 16, 17 e 23. METHODS: Eight individuals belonging to different generations from the same family were studied. Three of them bore multiple BCCs, and two of those were suspect to have MFNSBCC. DNA was extracted from blood leukocytes, submitted to PCR, and the PCR products were cloned (pGEM T Easy Vector, Promega) and sequenced (Big Dye Terminator Kit; ABI Prism 3100 sequencer; Applied Biosystems). The polymorphisms and mutations found were analyzed and compared to literature and PTCH1database (www.cybergene.se/PTCH/). RESULTS: In the patients suspect of MFNSBCC were found two new mutation: one frameshift nt4130(del C) and one missense nt4261(A->G). In the relatives were found five new mutation: Three missense nt1420(G->T); nt2873(C->T); nt4130(C->T); and two frameshift nt1443 (ins T) and nt1468 (ins T). In the introns 10,15,16 and 17 were found eighteen new mutations that were not previously reported. CONCLUSION: For the first time mutation in exons and introns of PTCH1 gene have been described in patients bore MFNSBCC and some of their relatives. INTRODUÇÃO: O carcinoma basocelular (CBC) é o tipo de câncer cutâneo mais comum no ser humano. O aparecimento de CBC na maioria das vezes se dá de forma esporádica em indivíduos que se expõem cronicamente ao sol. Eventualmente pode estar associado a síndromes, como: Bazex-Dupré- Christol, Rombo e Gorlin-Goltz. Diferente do que ocorre nas síndromes, os casos de CBCs múltiplos familiares não sindrômicos(CBCMFNS) são poucos estudados, tendo na literatura somente cinco relatos de famílias com a doença. O fenótipo é de múltiplos CBCs superficiais sem presença de outras anormalidades. Devido os CBCs esporádicos e os CBCs presentes na Síndrome de Gorlin-Goltz apresentarem mutações no gene PTCH1, possivelmente os CBCs múltiplos também estejam associados a alterações neste gene. Este gene esta localizado na região 9q22.3 possuindo 23 éxons, tem um papel importante na formação embrionária e de supressão tumoral. OBJETIVO: Análise genética dos éxons 9,11, 16, 17 e 23 do PTCH1 de oito componentes da mesma família, pertencentes a três diferentes gerações, sendo três portadores de CBCs múltiplos, e dentre estes dois suspeitos de CBCMFNS. MÉTODOS: Extração de DNA dos leucócitos do sangue periférico; PCR; clonagem dos produtos de amplificação (pGEM T Easy Vector) e seqüenciamento (Big Dye Terminator Kit). As mutações e polimorfismos encontrados foram comparados com a literatura e banco de dados de mutação do gene PTCH1 (www.cybergene.se/PATCH). RESULTADOS: Duas novas mutações foram encontradas nos pacientes suspeitos de CBCMFNS: uma frameshift nt4130(del C) e uma missense nt4261(A->G). Nos familiares foram encontradas cinco novas mutações: Em um primeiro indivíduo uma missense nt1420(G->T); em um segundo a mesma missense nt1420(G->T) e mais uma missense nt2873(C->T); em um terceiro duas frameshift nt1443 (ins T) e nt1468 (ins T), em dois outros indivíduos, irmãos, uma outra mutação missense nt4130(C->T). Foram encontradas ainda dezoito mutações, não descritas anteriormente, nos íntrons 10,15,16 e 17, algumas se repetindo em todos os indivíduos analisados. CONCLUSÃO: Pela primeira vez estão sendo descritas mutações em éxons e íntrons do gene PTCH1 em indivíduos portadores de CBCMFNS e em alguns de seus familiares.
[Show abstract][Hide abstract] ABSTRACT: A study is made of the nonlinear dynamical properties of a class
of recurrent artificial neural networks with time delay that have been
proposed in the literature to learn and recognize time-varying input
patterns. Their nonlinear dynamics are studied to see if they have the
potential to model nonlinear dynamical behavior of biological field
potentials such as the electroencephalogram (EEG). It is shown that
changing the value of the weights in a periodic fashion causes the
output of time-delay neural networks to show a correlation dimension in
the EEG range
Neural Networks, 1990., 1990 IJCNN International Joint Conference on; 07/1990
[Show abstract][Hide abstract] ABSTRACT: Skin tissue engineering emerged as an experimental regenerative therapy motivated primarily by the critical need for early permanent coverage of extensive burn injuries in patients with insufficient sources of autologous skin for grafting. With time, the approach evolved toward a wider range of applications including disease modeling. We have established a skin-humanized mouse model system consisting in bioengineered human-skin-engrafted immunodeficient mice. This new model allows to performing regenerative medicine, gene therapy, genomics, and pathology studies in a human context on homogeneous samples. Starting from skin cells (keratinocytes and fibroblasts) isolated from normal donor skin or patient's biopsies, we have been able to deconstruct-reconstruct several inherited skin disorders including genodermatoses and cancer-prone diseases in a large number of skin humanized mice. In addition, the model allows conducting studies in normal human skin to gain further insight into physiological processes such as wound healing or UV-responses.
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