Consulta: subjectFacets:"Calcium oxalate"
Registros recuperados: 6
Data/hora: 10/06/2024 01:10:16

Distribución ecológica del subgénero Neodawsonia Backeb. del género Cephalocereus Pfeiff. (Cactaceae), en el Itsmo de Tehuantepec, México.
Provedor de dados: Depósito Institucional Abierto de Documentos Digitales del Colegio de Postgraduados (COLPOS DIGITAL )
Autores: Bárcenas Argüello, María Luisa.
Cephalocereus es un género monofilético, cuya distribución es alopátrica y está restringida a la Barranca de Metztitlán (C. senilis), al Valle de Tehuacán-Cuicatlán (C. columna-trajani) y a la cuenca del río Tehuantepec (subgénero Neodawsonia, C. apicicephalium, C. nizandensis, C. totolapensis). Se desconoce qué factores condicionan este patrón de distribución endémico. El objetivo de este trabajo fue el proponer una hipótesis que explique el endemismo de sus especies, a partir de relaciones específicas entre la fisiología de los oxalatos de calcio y las propiedades de las rocas y de los suelos en los que habitan. En cada población se tomaron muestras del material parental (roca) del suelo, se removió tejido vegetal y se recolectaron semillas; estas...
Palavras-chave: Endemismo; Material Parental; Oxalato de calcio; Germinación; Filogenia; Endemism; Parent material; Calcium oxalate; Germination; Phylogeny; Doctorado; Botánica.
Ano: 2011
URL: http://hdl.handle.net/10521/458

Distribución ecológica del subgénero Neodawsonia Backeb. del género Cephalocereus Pfeiff. (Cactaceae), en el Itsmo de Tehuantepec, México.
Provedor de dados: Depósito Institucional Abierto de Documentos Digitales del Colegio de Postgraduados (COLPOS DIGITAL )
Autores: Bárcenas Argüello, María Luisa.
Cephalocereus es un género monofilético, cuya distribución es alopátrica y está restringida a la Barranca de Metztitlán (C. senilis), al Valle de Tehuacán-Cuicatlán (C. columna-trajani) y a la cuenca del río Tehuantepec (subgénero Neodawsonia, C. apicicephalium, C. nizandensis, C. totolapensis). Se desconoce qué factores condicionan este patrón de distribución endémico. El objetivo de este trabajo fue el proponer una hipótesis que explique el endemismo de sus especies, a partir de relaciones específicas entre la fisiología de los oxalatos de calcio y las propiedades de las rocas y de los suelos en los que habitan. En cada población se tomaron muestras del material parental (roca) del suelo, se removió tejido vegetal y se recolectaron semillas; estas...
Palavras-chave: Endemismo; Material Parental; Oxalato de calcio; Germinación; Filogenia; Endemism; Parent material; Calcium oxalate; Germination; Phylogeny; Doctorado; Botánica.
Ano: 2011
URL: http://hdl.handle.net/10521/458

IR - spectroscopic characterization of biominerals in marattiaceaeus ferns
Provedor de dados: Revista Brasileira de Botânica
Autores: Baran,Enrique J.; Rolleri,Cristina H.
(IR - spectroscopic characterization of biominerals in marattiaceaeus ferns). Frond samples of the eusporangiate ferns Marattiaceae genera Angiopteris, Christensenia, Danaea and Marattia were investigated by infrared spectroscopy, under different experimental conditions. The results confirmed the previously reported accumulation of biogenic silica (SiO2) in tissues of these ferns and also showed, for the first time, the presence of calcium oxalate in this group of plants, probably as weddellite. The ability to biomineralize SiO2, to produce and accumulate biogenic silica, is suggested now to be a general family trait of the Marattiaceae.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Biogenic silica; Calcium oxalate; Marattiaceae.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-84042010000300014

Role of intermediary cells in Peltodon radicans (Lamiaceae) in the transfer of calcium and formation of calcium oxalate crystals
Provedor de dados: Brazilian Archives of Biology and Technology
Autores: Paiva,Elder Antônio Sousa; Machado,Silvia Rodrigues.
With the objective of studying the connection between calcium oxalate crystals formation and the phloem, fragments of leaves of Peltodon radicans Pohl (Lamiaceae) were fixed and processed, for light and electron-transmission microscopes. It was observed that the crystals occurred in the cells of the bundle sheath, juxtaposed in relation to the phloem. Intermediary cells established a connection between the sieve element and crystal-bearing sheath cells. Calcium was present abundantly in the cytoplasm of sheath cells as calcium oxalate crystals. The presence of calcium was also detected in the intermediary cells, but in the sieve elements it was not detected. There was, therefore, an increasing concentration gradient of calcium in the sieve elements from...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Calcium oxalate; Calcium metabolism; Companion cells; Crystals; Peltodon radicans; Phloem.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132005000100019

Mechanisms involved in calcium oxalate endocytosis by Madin-Darby canine kidney cells
Provedor de dados: Brazilian Journal of Medical and Biological Research
Autores: Campos,A.H.; Schor,N.
Calcium oxalate (CaOx) crystals adhere to and are internalized by tubular renal cells and it seems that this interaction is related (positively or negatively) to the appearance of urinary calculi. The present study analyzes a series of mechanisms possibly involved in CaOx uptake by Madin-Darby canine kidney (MDCK) cells. CaOx crystals were added to MDCK cell cultures and endocytosis was evaluated by polarized light microscopy. This process was inhibited by an increase in intracellular calcium by means of ionomycin (100 nM; N = 6; 43.9% inhibition; P&amp;lt;0.001) or thapsigargin (1 µM; N = 6; 33.3% inhibition; P&amp;lt;0.005) administration, and via blockade of cytoskeleton assembly by the addition of colchicine (10 µM; N = 8; 46.1% inhibition;...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Calcium oxalate; DCK cells; Mechanisms of endocytosis; Renal stone.
Ano: 2000
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2000000100015

Role of Tamm-Horsfall protein and uromodulin in calcium oxalate crystallization
Provedor de dados: Brazilian Journal of Medical and Biological Research
Autores: Carvalho,M.; Mulinari,R.A.; Nakagawa,Y.
One of the defenses against nephrolithiasis is provided by macromolecules that modulate the nucleation, growth, aggregation and retention of crystals in the kidneys. The aim of the present study was to determine the behavior of two of these proteins, Tamm-Horsfall and uromodulin, in calcium oxalate crystallization in vitro. We studied a group of 10 male stone formers who had formed at least one kidney stone composed of calcium oxalate. They were classified as having idiopathic nephrolithiasis and had no well-known metabolic risk factors involved in kidney stone pathogenesis. Ten normal men were used as controls, as was a group consisting of five normal women and another consisting of five pregnant women. Crystallization was induced by a fixed...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Tamm-Horsfall protein; Uromodulin; Calcium oxalate; Nephrolithiasis.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2002001000009