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1.
Conserv Biol ; 34(1): 103-112, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31257646

RESUMO

More than half of the world's 18 penguin species are declining. We, the Steering Committee of the International Union for Conservation of Nature Species Survival Commission Penguin Specialist Group, determined that the penguin species in most critical need of conservation action are African penguin (Spheniscus demersus), Galápagos penguin (Spheniscus mendiculus), and Yellow-eyed penguin (Megadyptes antipodes). Due to small or rapidly declining populations, these species require immediate scientific collaboration and policy intervention. We also used a pairwise-ranking approach to prioritize research and conservation needs for all penguins. Among the 12 cross-taxa research areas we identified, we ranked quantifying population trends, estimating demographic rates, forecasting environmental patterns of change, and improving the knowledge of fisheries interactions as the highest priorities. The highest ranked conservation needs were to enhance marine spatial planning, improve stakeholder engagement, and develop disaster-management and species-specific action plans. We concurred that, to improve the translation of science into effective conservation for penguins, the scientific community and funding bodies must recognize the importance of and support long-term research; research on and conservation of penguins must expand its focus to include the nonbreeding season and juvenile stage; marine reserves must be designed at ecologically appropriate spatial and temporal scales; and communication between scientists and decision makers must be improved with the help of individual scientists and interdisciplinary working groups.


Aplicación de Ciencia en las Necesidades de Conservación Urgentes para los Pingüinos. Resumen Más de la mitad de las 18 especies de pingüinos del mundo están disminuyendo. Nosotros, el Comité Directivo de la Unión Internacional para la Conservación de la Naturaleza, Grupo de Especialistas en Pingüinos, determinamos que las especies de pingüinos con necesidades críticas de conservación son el pingüino africano (Spheniscus demersus), el pingüino de las Galápagos (Spheniscus mendiculus) y el pingüino de ojos amarillos (Megadyptes antipodes). Debido a que sus poblaciones son pequeñas o están declinando rápidamente, estos pingüinos requieren colaboración científica e intervención política inmediatas. También utilizamos un método de clasificación por pares para priorizar las necesidades de investigación y conservación para todas las especies de pingüinos. Entre las 12 áreas de investigación que identificamos, las más prioritarias fueron: cuantificación de las tendencias poblacionales, estimación de las tasas demográficas, predicción de las patrones de cambio ambiental y mejora del conocimiento de las interacciones con pesquerías. Las mayores necesidades de conservación fueron: optimizar la planificación marina espacial, mejorar la colaboración de las partes interesadas y desarrollar planes de manejo de desastres y de acción para cada especie. Coincidimos en que, para mejorar la traducción de la ciencia en la conservación efectiva de los pingüinos, la comunidad científica y los organismos financiadores deben reconocer la importancia de la investigación a largo plazo y apoyarla; la investigación sobre pingüinos y su conservación debe expandir su enfoque para incluir la época no reproductiva y la etapa juvenil; las reservas marinas deben ser diseñadas a escalas espaciotemporales ecológicamente apropiadas; y la comunicación entre científicos y tomadores de decisiones debe mejorar con la ayuda de científicos individuales y grupos de trabajo interdisciplinario.


Assuntos
Spheniscidae , Animais , Conservação dos Recursos Naturais , Pesqueiros , Especificidade da Espécie
2.
Mol Psychiatry ; 22(5): 680-688, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28194008

RESUMO

Accumulation of non-cell autonomous Otx2 homeoprotein in postnatal mouse visual cortex (V1) has been implicated in both the onset and closure of critical period (CP) plasticity. Here, we show that a genetic point mutation in the glycosaminoglycan recognition motif of Otx2 broadly delays the maturation of pivotal parvalbumin-positive (PV+) interneurons not only in V1 but also in the primary auditory (A1) and medial prefrontal cortex (mPFC). Consequently, not only visual, but also auditory plasticity is delayed, including the experience-dependent expansion of tonotopic maps in A1 and the acquisition of acoustic preferences in mPFC, which mitigates anxious behavior. In addition, Otx2 mis-localization leads to dynamic turnover of selected perineuronal net (PNN) components well beyond the normal CP in V1 and mPFC. These findings reveal widespread actions of Otx2 signaling in the postnatal cortex controlling the maturational trajectory across modalities. Disrupted PV+ network function and deficits in PNN integrity are implicated in a variety of psychiatric illnesses, suggesting a potential global role for Otx2 function in establishing mental health.


Assuntos
Córtex Auditivo/fisiologia , Plasticidade Neuronal/genética , Fatores de Transcrição Otx/genética , Córtex Pré-Frontal/fisiologia , Animais , Córtex Auditivo/metabolismo , Linhagem Celular , Matriz Extracelular/metabolismo , Técnicas de Introdução de Genes , Glicosaminoglicanos/metabolismo , Interneurônios/fisiologia , Camundongos , Camundongos Endogâmicos , Plasticidade Neuronal/fisiologia , Fatores de Transcrição Otx/metabolismo , Parvalbuminas/metabolismo , Mutação Puntual , Córtex Pré-Frontal/metabolismo , Domínios Proteicos , Córtex Visual/metabolismo
3.
Scand J Rheumatol ; 44(5): 389-98, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26099251

RESUMO

OBJECTIVES: Systemic sclerosis (SSc) patients in the early stages of pulmonary fibrosis (PF) often have few or no symptoms, normal to borderline pulmonary function tests, and negative chest X-ray (CXR); high-resolution computed tomography (HRCT) is the only reliable means of detecting the early signs of PF. However, thoracic ultrasound (TUS) enables detection of pleural thickening, pleural/subpleural nodules, and other subpleural lung abnormalities across 70% of the subpleural surface. We reassessed concordance between TUS abnormalities and HRCT findings in SSc patients, to see whether TUS pleural line thickness (normally <3.0 mm) could be used to earmark those with asymptomatic PF for timely HRCT assessment. METHOD: In total, 175 SSc patients (nine males, 166 females), aged 46.46±15.33 years, were given CXR, TUS, HRCT, echocardiography, and pulmonary function tests. RESULTS: In the 26 patients without HRCT signs of PF, pleural line thickness was ≤3.0 mm. In diffuse SSc, 97/137 patients showed pleural line thickening (between 3.0 and 5 mm) and subpleural nodules in 32/97; and 35/137 showed major pleural line thickening (≥5.0 mm) with nodules, with good concordance with HRCT patterns indicating lung fibrosis severity. HRCT was normal in 5/137, with pleural line thickness≤3.0 mm. CONCLUSIONS: TUS imaging of pleural/subpleural structures can detect ultrasonographic signs of initial PF prior to the onset of respiratory symptoms and function test abnormalities and, together with current criteria, could thereby enable exclusion of PF in SSc patients. Indicating some patients for selective referral to HRCT can thereby delay unwarranted procedures, provided that pulmonary function and TUS images are stable.


Assuntos
Fibrose Pulmonar/diagnóstico por imagem , Fibrose Pulmonar/etiologia , Radiografia Torácica , Escleroderma Sistêmico/complicações , Adulto , Ecocardiografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fibrose Pulmonar/diagnóstico , Testes de Função Respiratória , Estudos Retrospectivos , Escleroderma Sistêmico/fisiopatologia , Índice de Gravidade de Doença , Tomografia Computadorizada por Raios X , Ultrassonografia
6.
Nat Genet ; 14(2): 218-22, 1996 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8841200

RESUMO

The morphogenesis of the brain and the differentiation of the neural structures are highly complex processes. A series of temporally and spatially regulated morphogenetic events gives rise to smaller areas that are phylogenetically, functionally and often morphogenetically different. Candidate genes for positional information and differentiation during morphogenesis have been isolated. Both in vivo inactivation in mice and impairment in human diseases revealed, that they are required in regional specification and/or correct cell-type induction. We have previously cloned and characterized the murine Otx1 gene, which is related to orthodenticle (otd), a homeobox-containing gene required for Drosophila head development. Expression data during murine embryogenesis and postnatal brain development support the idea that Otx1 could be required for correct brain and sense organs development. To decipher its role in vivo we produced null mice by replacing Otx1 with the lacZ gene. Otx1-/- mice showed spontaneous epileptic behaviour and multiple abnormalities affecting mainly the telencephalic temporal and perirhinal areas, the hippocampus, the mesencephalon and the cerebellum, as well as the acoustic and visual sense organs. Our findings indicate that the Otx1 gene product is required for proper brain functions.


Assuntos
Encéfalo/anormalidades , Encéfalo/crescimento & desenvolvimento , Epilepsia/genética , Proteínas de Homeodomínio , Proteínas do Tecido Nervoso/fisiologia , Fatores de Transcrição , Animais , Encéfalo/embriologia , Encéfalo/fisiopatologia , Córtex Cerebral/patologia , Quimera , Orelha Interna/anormalidades , Orelha Interna/química , Epilepsia/fisiopatologia , Olho/química , Anormalidades do Olho/genética , Feminino , Genes/fisiologia , Glândula de Harder , Aparelho Lacrimal , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Camundongos Mutantes , Morfogênese , Proteínas do Tecido Nervoso/genética , Tamanho do Órgão , Fatores de Transcrição Otx , beta-Galactosidase/análise , beta-Galactosidase/genética
7.
Minerva Ginecol ; 63(3): 219-25, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21654607

RESUMO

AIM: The aim of this paper was to evaluate the feasibility, morbidity, and reproductive performance of fertile women undergoing minilaparotomic myomectomy for large uterine myomas. METHODS: Ninety-nine consecutive women with symptomatic myomas underwent myomectomy through a skin incision ≤8 cm. Operative, postoperative and reproductive data were prospectively collected. RESULTS: Median (range) age and Body Mass Index (BMI) were 37 years (23-44) and 23 (18-43), respectively. Median (range) myoma diameter was 7 cm (4-20), and the median number of myomas removed was 1 (range 1-31). Myomas were intramural in 76 (76%) cases. Median incision length was 7 cm (range 4-13) and median duration of surgery was 70 min (range 40-180). Operative time and length of skin incision were not correlated with the progressive number of interventions. An incision larger than 8 cm was necessary in 7 (7%) patients and the length of incision was significantly correlated with the diameter of the largest myoma (P<0.01). The feasibility of minilaparotomy was significantly reduced when the diameter of the largest myoma was >12 cm (P<0.05). Operative time was significantly longer in patients having >1 myoma (P<0.05). Three (3%) patients underwent blood transfusion. Median (range) postoperative stay was 2 days (range 2-12). Fever occurred in 8 (8%) patients, and wound complications in 5 (5%). CONCLUSION: Myomectomy by minilaparotomy is a feasible procedure in more than 90% of unselected patients with large symptomatic myomas. Feasibility is questionable when the myoma is >12 cm. This technique is a mini-invasive option to treat patients with large and multiple myomas.


Assuntos
Laparotomia , Leiomioma/cirurgia , Neoplasias Uterinas/cirurgia , Adulto , Feminino , Procedimentos Cirúrgicos em Ginecologia/métodos , Humanos , Leiomioma/patologia , Estudos Prospectivos , Neoplasias Uterinas/patologia , Adulto Jovem
8.
Eur Rev Med Pharmacol Sci ; 25(8): 3221-3225, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33928607

RESUMO

Due to early metastasis and delayed diagnosis, lung cancer is the leading cause of cancer-related deaths. Although the most common metastasis sites are brain, bone, lung, adrenal glands, liver, and extra-thoracic lymph node, soft tissues, such as skeletal muscles, skin, and subcutaneous tissues, can also be undermined. This article aims to report the first case of an asymptomatic radial extensor muscle metastasis generating from a lung adenocarcinoma that was diagnosed by ultrasound-guided fine-needle aspiration biopsy (FNAB).


Assuntos
Adenocarcinoma de Pulmão/diagnóstico , Aspiração por Agulha Fina Guiada por Ultrassom Endoscópico , Neoplasias Pulmonares/diagnóstico , Extremidade Superior/patologia , Idoso , Humanos , Masculino
9.
Eur Rev Med Pharmacol Sci ; 25(18): 5781-5789, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34604969

RESUMO

OBJECTIVE: The aim of the present study was to systematically assess the value of contrast-enhanced ultrasound (CEUS) vs. conventional transthoracic ultrasound (TUS) in improving diagnostic accuracy of percutaneous needle biopsy (PTNB) for subpleural lung lesions. PATIENTS AND METHODS: 232 patients with subpleural lesions were 1:1 randomly assigned to a group were CEUS was performed (n=116, mean age=65.5±5.6, M=69) or not (n=116, mean age=66.0±5.3, M=70). For CEUS study was used an injection of 4.8 mL of SonoVue (Bracco, Italy). For PTNB was employed a Menghini-modified technique with a semi-automatic 18-gauge needle. RESULTS: The mean diameter of subpleural lesions was 2.85±0.7 cm in the CEUS+ group and 2.95±0.6cm in the CEUS- group. Only 3 lesions, 1 in the CEUS+ group and 2 in the CEUS- group measured >5 cm. CEUS showed no superiority in terms of diagnostic accuracy compared to conventional TUS (p=0.34). Similar results were obtained in the sub-analysis of lesions sized between 1-2 cm (p=1.00) and 2-5 cm (p=0.08). As the lesion size increased, the detection rate of necrosis in lesions increased by CEUS (from 8% to 31%). CEUS showed no superiority in terms of diagnostic accuracy in the sub-analysis of necrotic lesions at CECT (p=0.38). AUC values for both the groups assessed an excellent diagnostic yield for TUS-PTNB (≥0.80). CONCLUSIONS: CEUS study does not improve the diagnostic accuracy of TUS-guided PTNB for peripheral lung lesions <5 cm of diameter. Further studies evaluating CEUS guidance for larger (>5 cm) and necrotic lesions are needed prior that its potential can be clarified.


Assuntos
Biópsia por Agulha/métodos , Aumento da Imagem/métodos , Pneumopatias/diagnóstico por imagem , Pneumopatias/patologia , Pulmão/diagnóstico por imagem , Pulmão/patologia , Ultrassonografia/métodos , Idoso , Meios de Contraste , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Sensibilidade e Especificidade
10.
Abdom Imaging ; 35(1): 106-14, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19444500

RESUMO

Endovascular repair (EVAR) is playing an increasingly role in the treatment of abdominal aortic aneurysm. A successful procedure depends on the complete sealing of the aneurysm sac from blood flow to achieve general pressure relief and avoid aneurysm rupture, with a shrinkage of the aneurysm sac. The most common complication of EVAR is endoleak that is the persistence of perigraft flow within the aneurysm sac, which has to be considered the major cause of enlargement and rupture of the aneurysm, and the main indication for surgical late conversion. For this reason, strict surveillance of these patients is mandatory for the early detection of endoleaks and the preferred method of follow-up is represented by CT angiography. However, CTA has limitations. The investigation is repeated several times, making radiation exposure a necessary concern. Therefore, it would be useful to have another reliable diagnostic examination during follow-up. Color duplex ultrasound is non-invasive, does not use radiation or contrast medium, is less expensive, easy to perform and widely available. However, this technique obtained poor results in terms of sensitivity in the detection of endoleaks. In the last years, the introduction of ultrasound contrast agents and contrast-specific imaging has, however, rekindled interest in this modality and its potential for replacing of CTA in routine surveillance. The purpose of this review is to highlight the diagnostic value of CEUS in the post-EVAR endoleaks detection.


Assuntos
Aneurisma da Aorta Abdominal/diagnóstico por imagem , Implante de Prótese Vascular , Meios de Contraste , Complicações Pós-Operatórias/diagnóstico por imagem , Stents , Idoso , Idoso de 80 Anos ou mais , Aneurisma da Aorta Abdominal/cirurgia , Feminino , Humanos , Masculino , Fosfolipídeos , Hexafluoreto de Enxofre , Ultrassonografia
11.
J Cell Biol ; 127(6 Pt 1): 1743-54, 1994 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-7528222

RESUMO

Hepatocyte growth factor (HGF) is a mesenchymal derived growth factor known to induce proliferation and "scattering" of epithelial and endothelial cells. Its receptor is the tyrosine kinase encoded by the c-MET protooncogene. Here we show that highly purified recombinant HGF stimulates hemopoietic progenitors to form colonies in vitro. In the presence of erythropoietin, picomolar concentrations of HGF induced the formation of erythroid burst-forming unit colonies from CD34-positive cells purified from human bone marrow, peripheral blood, or umbilical cord blood. The growth stimulatory activity was restricted to the erythroid lineage. HGF also stimulated the formation of multipotent CFU-GEMM colonies. This effect is synergized by stem cell factor, the ligand of the tyrosine kinase receptor encoded by the c-KIT protooncogene, which is active on early hemopoietic progenitors. By flow cytometry analysis, the receptor for HGF was found to be expressed on the cell surface in a fraction of CD34+ progenitors. Moreover, in situ hybridization experiments showed that HGF receptor mRNA is highly expressed in embryonic erythroid cells (megaloblasts). HGF mRNA was also found to be produced in the embryonal liver. These data show that HGF plays a direct role in the control of proliferation and differentiation of erythroid progenitors, and they suggest that it may be one of the long-sought mediators of paracrine interactions between stromal and hemopoietic cells within the hemopoietic microenvironment.


Assuntos
Células Precursoras Eritroides/efeitos dos fármacos , Fator de Crescimento de Hepatócito/farmacologia , Animais , Antígenos CD , Antígenos CD34 , Baculoviridae/genética , Medula Óssea/embriologia , Diferenciação Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Fatores de Crescimento de Células Hematopoéticas/farmacologia , Células-Tronco Hematopoéticas/efeitos dos fármacos , Fator de Crescimento de Hepatócito/genética , Humanos , Hibridização In Situ , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-kit , Proteínas Proto-Oncogênicas c-met , RNA Mensageiro/análise , Receptores Proteína Tirosina Quinases/metabolismo , Receptores de Fator Estimulador de Colônias/metabolismo , Proteínas Recombinantes/farmacologia , Spodoptera/citologia , Fator de Células-Tronco
12.
Neuron ; 13(1): 83-101, 1994 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-7913821

RESUMO

A novel homeobox-containing gene has been identified. Its name, Orthopedia (Otp), exemplifies the homology shared by both the orthodenticle and Antennapedia homeodomains. Otp is highly conserved in evolution. In mouse, Otp is expressed only in restricted domains of the developing forebrain, hindbrain, and spinal cord. In Drosophila, otp first appears at gastrulation in the ectodermal proctodeum and later in the hindgut, anal plate, and along the CNS. Here, we compare the Otp-, Distal-less homeobox 1-(DIx1-), Orthodenticle homolog 1-(Otx1-), Otx2-, and Empty spiracles homolog 2-expressing domains. Our results indicate that Otp is expressed along the CNS both in mouse and Drosophila; Otp could specify regional identities in the development of the forebrain and spinal cord; transcription of Otp and DIx1 takes place in alternating hypothalamic regions reminiscent of a segment-like pattern; and the structural and functional conservation could correspond to a conserved function maintained in evolution.


Assuntos
Encéfalo/embriologia , Proteínas de Drosophila , Drosophila/genética , Expressão Gênica , Genes Homeobox , Proteínas de Homeodomínio , Medula Espinal/embriologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Evolução Biológica , Encéfalo/metabolismo , Sequência Conservada , Gástrula/metabolismo , Globinas/genética , Células HeLa , Humanos , Camundongos , Dados de Sequência Molecular , Proteínas do Tecido Nervoso/química , Proteínas Recombinantes de Fusão , Medula Espinal/metabolismo , Transcrição Gênica , Transfecção
14.
Trends Genet ; 16(6): 237-40, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10827447

RESUMO

Regional diversity along the anterior-posterior axis of the central nervous system is established during gastrulation and is subsequently refined by local organizing centres that are located at genetically defined positions. The isthmic organizer possesses midbrain- and cerebellum-inducing properties, and its positioning at the midbrain-hindbrain boundary is a crucial event that controls midbrain and cerebellum development. Recent work has shown that two transcription factors, Otx2 and Gbx2, are instrumental in positioning the isthmic organizer at the midbrain-hindbrain boundary.


Assuntos
Encéfalo/embriologia , Regulação da Expressão Gênica no Desenvolvimento , Proteínas de Homeodomínio/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Transativadores/metabolismo , Proteínas de Peixe-Zebra , Animais , Padronização Corporal , Encéfalo/metabolismo , Fator 8 de Crescimento de Fibroblasto , Fatores de Crescimento de Fibroblastos/genética , Fatores de Crescimento de Fibroblastos/metabolismo , Proteínas de Homeodomínio/genética , Proteínas do Tecido Nervoso/genética , Fatores de Transcrição Otx , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , Transativadores/genética , Proteínas Wnt
15.
Trends Genet ; 7(10): 329-34, 1991 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-1685814

RESUMO

Vertebrate homeobox genes of the Hox family are, like Drosophila homeotic genes, organized in gene clusters and show a strict correspondence, or collinearity, between the order of the genes (3' to 5') within the chromosomal cluster and that of their expression domains (anterior to posterior) in the embryo. Recent data obtained from embryonal carcinoma cells induced to differentiate by retinoic acid cast some light on the molecular mechanisms underlying the collinear expression of the Hox genes.


Assuntos
Regulação da Expressão Gênica , Genes Homeobox , Tretinoína/farmacologia , Sequência de Aminoácidos , Animais , Humanos , Dados de Sequência Molecular , Ativação Transcricional
16.
Trends Neurosci ; 22(3): 116-22, 1999 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10199636

RESUMO

The murine homologs of the orthodenticle (otd) gene of Drosophila, Otx1 and Otx2, have an important role in brain morphogenesis. Analysis of Otx1 and Otx2 null mice reveals that Otx1 is required primarily for corticogenesis and sense-organ development,while Otx2 is necessary for specification and maintenance of anterior neural plate as well as for proper gastrulation. Cross-phylum recoveries of Otx1 abnormalities by Drosophila otd, and vice versa, indicate that genetic functions required in mammalian-brain development evolved in a primitive ancestor of flies and mice. Knock-in mouse models in which Otx2 was replaced with Otx1, and vice versa, provide evidence that the existence of Otx1-/- and Otx2-/- divergent phenotypes largely reflects differences in expression patterns rather than in the biochemical activity of OTX1 and OTX2. In evolutionary terms, some of these findings lead us to hypothesize a fascinating and crucial role for Otx genes that contributes to the genetic program required for the specification of the development of the vertebrate head.


Assuntos
Encéfalo/embriologia , Proteínas Fetais/fisiologia , Proteínas do Tecido Nervoso/fisiologia , Transativadores/fisiologia , Fatores de Transcrição , Animais , Córtex Cerebral/embriologia , Embrião de Galinha , Proteínas de Drosophila , Drosophila melanogaster/embriologia , Drosophila melanogaster/genética , Drosophila melanogaster/fisiologia , Orelha/anormalidades , Orelha/embriologia , Endoderma/metabolismo , Evolução Molecular , Olho/embriologia , Anormalidades do Olho/embriologia , Anormalidades do Olho/genética , Gástrula/fisiologia , Regulação da Expressão Gênica no Desenvolvimento , Cabeça/anormalidades , Cabeça/embriologia , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/fisiologia , Camundongos , Camundongos Knockout , Morfogênese/genética , Proteínas do Tecido Nervoso/deficiência , Proteínas do Tecido Nervoso/genética , Fatores de Transcrição Otx , Fenótipo , Processamento de Proteína Pós-Traducional , Proteínas Recombinantes de Fusão/biossíntese , Homologia de Sequência de Aminoácidos , Maturidade Sexual/genética , Especificidade da Espécie , Transativadores/deficiência , Transativadores/genética
17.
Curr Opin Neurobiol ; 9(5): 589-95, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10508733

RESUMO

The homeotic and cephalic gap genes play central roles in the specification of the anteroposterior animal body axis. Genetic studies carried out in Drosophila and mouse now demonstrate that these genes are also involved in embryonic brain development. The homeotic genes act in posterior brain patterning, and the cephalic gap genes act in anterior brain patterning. Moreover, striking cross-phylum gene replacement experiments show that invertebrate and vertebrate members of the orthodenticle gene family can functionally replace each other. These findings indicate that the genetic mechanisms involved in embryonic brain development are conserved and suggest a common evolutionary origin of the insect and vertebrate brain.


Assuntos
Encéfalo/embriologia , Sequência Conservada/fisiologia , Proteínas de Drosophila , Genes Homeobox/fisiologia , Proteínas de Homeodomínio/genética , Família Multigênica/fisiologia , Animais , Evolução Molecular
18.
Prog Neurobiol ; 64(1): 69-95, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11250063

RESUMO

Most of the gene candidates for the control of developmental programmes that underlie brain morphogenesis in vertebrates are the homologues of Drosophila genes coding for signalling molecules or transcription factors. Among these, the orthodenticle group includes the Drosophila orthodenticle (otd) and the vertebrate Otx1 and Otx2 genes, which are mostly involved in fundamental processes of anterior neural patterning. These genes encode transcription factors that recognise specific target sequences through the DNA binding properties of the homeodomain. In Drosophila, mutations of otd cause the loss of the anteriormost head neuromere where the gene is transcribed, suggesting that it may act as a segmentation "gap" gene. In mouse embryos, the expression patterns of Otx1 and Otx2 have shown a remarkable similarity with the Drosophila counterpart. This suggested that they could be part of a conserved control system operating in the brain and different from that coded by the HOX complexes controlling the hindbrain and spinal cord. To verify this hypothesis a series of mouse models have been generated in which the functions of the murine genes were: (i) fully inactivated, (ii) replaced with each others, (iii) replaced with the Drosophila otd gene. Otx1-/- mutants suffer from epilepsy and are affected by neurological, hormonal, and sense organ defects. Otx2-/- mice are embryonically lethal, they show gastrulation impairments and fail in specifying anterior neural plate. Analysis of the Otx1-/-; Otx2+/- double mutants has shown that a minimal threshold level of the proteins they encode is required for the correct positioning of the midbrain-hindbrain boundary (MHB). In vivo otd/Otx reciprocal gene replacement experiments have provided evidence of a general functional equivalence among otd, Otx1 and Otx2 in fly and mouse. Altogether these data highlight a crucial role for the Otx genes in specification, regionalization and terminal differentiation of rostral central nervous system (CNS) and lead to hypothesize that modification of their regulatory control may have influenced morphogenesis and evolution of the brain.


Assuntos
Encéfalo/fisiologia , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Proteínas de Homeodomínio/genética , Proteínas do Tecido Nervoso/genética , Transativadores/genética , Fatores de Transcrição , Animais , Evolução Biológica , Encéfalo/metabolismo , Proteínas de Drosophila , Humanos , Fatores de Transcrição Otx
19.
Oncogene ; 11(6): 1191-8, 1995 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-7566980

RESUMO

Receptor tyrosine kinases (RTKs) control proliferation and differentiation through their ability to bind and/or phosphorylate intracellular substrates. The repertoire of substrates recruited by different RTK is largely overlapping. It is not clear, therefore, how a cell distinguishes among signals originating from different RTKs. One possibility is that selective availability of substrates participates in the regulation of this process. To gain insight into this issue, we studied the expression pattern, during mouse embryogenesis, of the eps8 and eps15 genes, which encode two recently identified RTK substrates. Both genes are expressed from E 10 in a restricted fashion. eps8 is first expressed in frontonasal neural crest-derived cells, in the mesenchyme of branchial arches and in the liver primordium. At E 12.5-E 14, eps8 is additionally expressed in the central nervous system (CNS) in a regional restricted pattern at the met-mesencephalic transition area and in the developing submandibular salivary glands. eps15 is expressed at E 10 in the liver primordium, in the spinal ganglia and in the encephalic ganglia derived from the hindbrain neural crest. In addition, at E 12.5-E 14, eps15 is expressed, along all the CNS, in the ventricular zone where undifferentiated neuroblasts are located. The regional pattern of developmental expression of these two substrates sharply contrasts with their ubiquitous expression in adults, raising the possibility that their expression during embryogenesis is linked to selective proliferative and/or differentiative responses of specific neuroectodermal regions and body organs.


Assuntos
Proteínas de Ligação ao Cálcio/genética , Embrião de Mamíferos/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Fosfoproteínas/genética , Proteínas/genética , Proteínas de Peixe-Zebra , Proteínas Adaptadoras de Transdução de Sinal , Animais , Proteínas do Citoesqueleto , Feminino , Peptídeos e Proteínas de Sinalização Intracelular , Camundongos , Gravidez , Proteínas Proto-Oncogênicas/genética , Proteínas Wnt
20.
Oncogene ; 11(12): 2627-37, 1995 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-8545120

RESUMO

We previously showed that the proto-oncogene RON encodes the tyrosine kinase receptor for Macrophage Stimulating Protein (MSP), originally isolated as a chemotactic factor for peritoneal macrophages. To elucidate the biological role of MSP we studied the expression of the Ron receptor in vivo, and the response to the factor in vitro. RON specific transcripts were detectable in mouse liver from early embryonal life (day 12.5 p.c.) through adult life. Adrenal gland, spinal ganglia, skin, lung and--unexpectedly--ossification centers of developing mandible, clavicle and ribs were also positive at later stages (day 13.5-16.5 p.c.). From day 17.5 RON was expressed in the gut epithelium and in a specific area of the central nervous system, corresponding to the nucleus of the hypoglossus. In adult mouse tissues RON transcripts were observed in brain, adrenal glands, gastro-intestinal tract, testis and kidney. Epithelial, osteoclast-like and neuroendocrine cells express the Ron receptor and respond to MSP in vitro. In the neuroendocrine PC12 cell line, while NGF induced growth arrest and morphological differentiation, MSP behaved as a strong mitogen. These findings show that the Ron receptor and its ligand are involved in the development of epithelial tissues, bones, and neuroendocrine derivatives driving cells towards the proliferation program.


Assuntos
Desenvolvimento Ósseo , Sistemas Neurossecretores/embriologia , Proto-Oncogenes/fisiologia , Receptores Proteína Tirosina Quinases/genética , Receptores de Superfície Celular/genética , Animais , Sequência de Bases , Clonagem Molecular , Epitélio/embriologia , Feminino , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Dados de Sequência Molecular , Proto-Oncogene Mas , Proteínas Proto-Oncogênicas c-met , RNA Mensageiro/análise , Transcrição Gênica
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