ABSTRACT
This work aimed to characterize the molecular structure and functional properties of starches isolated from wild Dioscorea yams grown at the Amazons, using conventional and up-to-date methodologies. Among the high purity starches isolated (≥99%), the chain lengths were similar, whereas variations in gelatinization profile were observed. Starches have shown varied-shaped granules with monomodal distribution, and B-type crystallinity. Variations in amylose contents found by three analyses were hypothesized being related to intermediate material. Linear chain lengths were similar, and their amylopectins showed a dense, spherical conformation and similar molecular characteristics. The average molar mass and the radius of gyration of the chromatograms of the yam amylopectin, M¯W and R¯G were ranging between 174×10(6) g mol(-1) and 237×10(6) g mol(-1), and 201 nm and 233 nm, respectively. The white yams starches were more sensible to enzymes than the other two. All starches have shown a wide range of functional and nutritional properties.
Subject(s)
Dioscorea/chemistry , Dioscorea/growth & development , Starch/chemistry , Starch/isolation & purification , Amylose/chemistry , Chemical Phenomena , Dioscorea/genetics , Dioscorea/metabolism , Genotype , Rheology , Starch/metabolism , Temperature , VenezuelaABSTRACT
A preliminary analysis of the sequence alignment of the chloroplast intergene atp beta-rbcL in tribe Valerianeae reveals that insertion-deletion evolutionary events ('indels'), combined with nucleotide substitutions, have occurred in large zones in some of the studied taxa. Due to the frequent occurrence and large size of indels within this tribe, intergene length varies from 531 to 788 base pairs within the studied species. This situation poses gap coding problems that we had to tackle before phylogenetic analysis. Four methods of gap coding were used: elimination of gapped sites ('complete omission'), 'missing data', 'fifth base' and Barriel's coding method, which translates indels into new multistate characters in the data matrix. After application of these four methods of data treatment, phylogenetic analyses (maximum parsimony) did not lead to very different results. Three robust clades emerged in each case, corresponding to the Centranthinae subtribe (genus Centranthus), the Fediinae subtribe (genera Fedia and Valerianella), and the American species of Valeriana. The theoretical basis and biological significance of these four methods are discussed in order to apply the best ones in future studies.
Subject(s)
Chloroplasts/genetics , DNA, Intergenic/genetics , DNA, Plant/genetics , Valerianaceae/genetics , Base Pairing , Base Sequence , Chloroplast Proton-Translocating ATPases/genetics , Consensus Sequence , Evolution, Molecular , Genes, Plant , Genetic Markers , Molecular Sequence Data , Mutagenesis, Insertional , Phylogeny , Plant Proteins/genetics , Ribulose-Bisphosphate Carboxylase/genetics , Sequence Alignment , Sequence Deletion , Sequence Homology, Nucleic Acid , Species Specificity , Valerianaceae/classificationABSTRACT
Con la finalidad de estudiar la asociación de fibrosis quística y reflujo gastroesofágico en nuestro medio, se revisaron 65 historias de pacientes con diagnóstico de fibrosis quística, controlados en el Servicio de Gastroenterología del Hospital de Niños J.M. de los Rios, en los cuales se había realizado al menos uno de los siguientes estudios: radiología convencional de esófago-estómago-duodeno, endoscopia digestiva superior, estudio histológico y pHmetría. Las edades oscilaron entre 2 meses y 15 años, predominando el sexo masculino (63 por ciento). En 56 pacientes (86,1 por ciento) se realizó estudio radiológico, evidenciándose en 38 (67,8 por ciento), reflujo gastroesofágico. La endoscopia digestiva superior se llevó a cabo en 45 casos (69,2 por ciento), encontrándose en 44 (97,7 por ciento), algún grado de esofagitis. El estudio histológico realizado en 36 pacientes (55,3 por ciento), reportó variados grado de esofagitis en 35 (97,2 por ciento), resaltando en 2 de ellos (5,7 por ciento) el hallazgo de esófago de Barrett. En 2 pacientes (3 por ciento) se practicó pHmetría, cuyo resultado fue patológico. Se realizaron estudios radiológicos, endoscópicos e histológicos en 27 pacientes (41,5 por ciento), evidenciandose en 21 (77,7 por ciento) reflujo gastroesofágico en la radiología y variados grados de esofagitis en los restantes estudios. Se concluye que el reflujo gastroesofágico es una patología frecuentemente asociada a la fibrosis quística y que el estudio radiológico, endoscópico, histológico así como la pHmetría, son métodos útiles en el diagnóstico del mismo
