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1.
New Phytol ; 209(2): 855-70, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26350789

RESUMO

Despite progress based on multilocus, phylogenetic studies of the palms (order Arecales, family Arecaceae), uncertainty remains in resolution/support among major clades and for the placement of the palms among the commelinid monocots. Palms and related commelinids represent a classic case of substitution rate heterogeneity that has not been investigated in the genomic era. To address questions of relationships, support and rate variation among palms and commelinid relatives, 39 plastomes representing the palms and related family Dasypogonaceae were generated via genome skimming and integrated within a monocot-wide matrix for phylogenetic and molecular evolutionary analyses. Support was strong for 'deep' relationships among the commelinid orders, among the five palm subfamilies, and among tribes of the subfamily Coryphoideae. Additionally, there was extreme heterogeneity in the plastid substitution rates across the commelinid orders indicated by model based analyses, with c. 22 rate shifts, and significant departure from a global clock. To date, this study represents the most comprehensively sampled matrix of plastomes assembled for monocot angiosperms, providing genome-scale support for phylogenetic relationships of monocot angiosperms, and lays the phylogenetic groundwork for comparative analyses of the drivers and correlates of such drastic differences in substitution rates across a diverse and significant clade.


Assuntos
Arecaceae/genética , Genomas de Plastídeos , Filogenia , Evolução Molecular , Magnoliopsida/genética , Proteínas de Plantas/genética
2.
Mol Biol Evol ; 31(12): 3095-112, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25172958

RESUMO

Parasitic organisms exemplify morphological and genomic reduction. Some heterotrophic, parasitic plants harbor drastically reduced and degraded plastid genomes resulting from relaxed selective pressure on photosynthetic function. However, few studies have addressed the initial stages of plastome degradation in groups containing both photosynthetic and nonphotosynthetic species. Corallorhiza is a genus of leafless, heterotrophic orchids that contains both green, photosynthetic species and nongreen, putatively nonphotosynthetic species, and represents an ideal system in which to assess the beginning of the transition to a "minimal plastome." Complete plastomes were generated for nine taxa of Corallorhiza using Illumina paired-end sequencing of genomic DNA to assess the degree of degradation among taxa, and for comparison with a general model of degradation among angiosperms. Quantification of total chlorophyll suggests that nongreen Corallorhiza still produce chlorophyll, but at 10-fold lower concentrations than green congeners. Complete plastomes and partial nuclear rDNA cistrons yielded a fully resolved tree for Corallorhiza, with at least two independent losses of photosynthesis, evidenced by gene deletions and pseudogenes in Co. striata and nongreen Co. maculata. All Corallorhiza show some evidence of degradation in genes of the NAD(P)H dehydrogenase complex. Among genes with open reading frames, photosynthesis-related genes displayed evidence of neutral evolution in nongreen Corallorhiza, whereas genes of the ATP synthase complex displayed some evidence of positive selection in these same groups, though for reasons unknown. Corallorhiza spans the early stages of a general model of plastome degradation and has added critical insight for understanding the process of plastome evolution in heterotrophic angiosperms.


Assuntos
Genomas de Plastídeos , Orchidaceae/genética , Clorofila/metabolismo , Evolução Molecular , Genes de Plantas , Processos Heterotróficos/genética , Dados de Sequência Molecular , Orchidaceae/metabolismo , Filogenia , Análise de Sequência de DNA
3.
Rev. Hosp. Clin. Fac. Med. Univ. Säo Paulo ; 57(6): 257-264, Nov.-Dec. 2002. ilus, tab
Artigo em Inglês | LILACS | ID: lil-336458

RESUMO

INTRODUCTION: Traumatic spinal cord injury is one of the most disabling conditions occurring in man and thus stimulates a strong interest in its histopathological, biochemical, and functional changes, primarily as we search for preventive and therapeutic methods. PURPOSE: To develop an experimental model for transplantation of cells from the fetal rat central nervous system to the site of an injured spinal cord of an adult rat in which the transplanted cells survive and become integrated. This experimental model will facilitate investigations of factors that promote regeneration and functional recovery after spinal cord trauma. MATERIAL AND METHODS: Fifteen adult Wistar rats underwent laminectomy, and an spinal cord lesion was made with microdissection. Fetal spinal cord tissue was then transplanted to the site of the injury. The rats were monitored over a 48-hour period, and then their vertebral column was completely removed for histological analysis. RESULTS: In 60 percent of transplanted rats, the fetal tissue at the injured site remained viable in the site of the lesion


Assuntos
Animais , Masculino , Feminino , Ratos , Transplante de Tecido Fetal , Medula Espinal , Traumatismos da Medula Espinal , Transplante de Células-Tronco , Modelos Animais de Doenças , Tecido Nervoso , Ratos Wistar , Medula Espinal
4.
Rev Hosp Clin Fac Med Sao Paulo ; 57(6): 257-64, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12612757

RESUMO

INTRODUCTION: Traumatic spinal cord injury is one of the most disabling conditions occurring in man and thus stimulates a strong interest in its histopathological, biochemical, and functional changes, primarily as we search for preventive and therapeutic methods. PURPOSE: To develop an experimental model for transplantation of cells from the fetal rat central nervous system to the site of an injured spinal cord of an adult rat in which the transplanted cells survive and become integrated. This experimental model will facilitate investigations of factors that promote regeneration and functional recovery after spinal cord trauma. MATERIAL AND METHODS: Fifteen adult Wistar rats underwent laminectomy, and an spinal cord lesion was made with microdissection. Fetal spinal cord tissue was then transplanted to the site of the injury. The rats were monitored over a 48-hour period, and then their vertebral column was completely removed for histological analysis. RESULTS: In 60% of transplanted rats, the fetal tissue at the injured site remained viable in the site of the lesion.


Assuntos
Transplante de Tecido Fetal/métodos , Traumatismos da Medula Espinal/cirurgia , Medula Espinal/transplante , Transplante de Células-Tronco , Animais , Modelos Animais de Doenças , Feminino , Masculino , Tecido Nervoso , Ratos , Ratos Wistar , Medula Espinal/citologia , Medula Espinal/embriologia
5.
Rev. med. (Säo Paulo) ; 77(2): 124-35, mar.-abr. 1998. ilus, tab
Artigo em Português | LILACS | ID: lil-224968

RESUMO

Dada a relevancia que o tromboembolismo pulmonar (TEP) vem adquirindo nos ultimos tempos, realizamos um estudo epidemiologico retrospectivo (caso-controle) embasado na analise de 1290 laudos de necropsias consecutivas realizadas em 1993 e 1994, no HCFMUSP, com posterior analise estatistica dos dados obtidos atraves dos programas Multlr e SPSS for Windows. Notamos que a incidencia de TEP foi de 12 por cento e que alguns fatores de risco como TVP (O.R.=13,98), trombose mural (O.R.=10,23), cirurgia ortopedica (O.R.=2,71), cirurgia neurologica (O.R.=4,16), doenca arterial obstrutiva periferica (O.R.=3,12) e ICC (O.R.=2,43) contribuem para o seu desenvolvimento. A insuficiencia hepatica apareceu como fator protetor (O.R.=0,77). Desta forma, achamos que a profilaxia nestes casos e necessaria para prevenir o TEP


Assuntos
Humanos , Feminino , Masculino , Embolia Pulmonar/epidemiologia , Fatores de Risco , Tromboembolia/epidemiologia , Autopsia , Causas de Morte , Pacientes Internados , Estudos Retrospectivos
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