Blog, para el estudio, la publicación, la investigación, la asesoría y la consulta médica,prevención, diagnóstico, tratamiento de las enfermedades alergicas, el asma, la inmunología y la pediatría global en niños y adultos. En Venezuela e internacionalmente.
Blog for the study, publication, research, assesment and the consultancy of medical prevention, diagnosis, treatment of the allergic diseases: asthma,immunology and pediatrics in children and adults in Venezuela and world-wide.
Wheat Allergy as treated by Carlos E Mijares MD, former fellow in Allergy / Immunology, pediatrics at University of Kansas, USA.
Currently, practicing at www.centromedicodecaracas.com,ve
carlosmixares@gmail.com
Insights and opinion from BioMed Central on the latest biology research and developments in the field. About this blog »
Durum roll please: updated genome a huge milestone for designing high-yield sustainable wheat
The updated wheat genome sequence, released today, is a new step toward generating improved wheat varieties. Here, Genome Biology's Dominique Morneau outlines the challenges and opportunities that accompany the sequencing of the wheat genome.
Bread wheat (Triticum aestivum)
is the second most highly produced cereal worldwide, grown on more than
215 million hectares, and the leading source of vegetable protein in
human food. It was first domesticated in western Asia around 11,700
years ago, after which it spread to North Africa, Europe, and East Asia.
Scientists are currently trying to figure out how to feed a growing
population; in the next 50 years, we will need to grow more wheat than
has been produced since the dawn of agriculture.
The key to improving wheat lies in identifying genes that can be
exploited to meet the increased demand for high quality food.
Unfortunately, sequencing the wheat genome is proving to be quite
difficult.
The complexity of the wheat genome
Bread wheat is an allohexaploid, meaning that it has six sets of
seven chromosomes derived from three different progenitor species (Triticum uratru, Aegilops speltoides, and Aegilops tauschii). The wheat genome is divided into three subgenomes: A, B, and D, each of which is almost twice as large as the human genome.
The wheat genome itself isn’t any harder to sequence than smaller
genomes. What researchers have been struggling with is putting all the
letters together in the right order. The wheat genome contains 17
gigabases (compared to the 3 gigabase human genome), and 80% of it is
repetitive sequences. Using whole-genome shotgun sequencing methods thus
becomes unattractive, since they generate reads of 500-1000 bases.
To understand why this problem is so complex, imagine a jigsaw puzzle
with 17 million small pieces, 80% of which are very similar to each
other. An international consortium of 1,100 researchers from 55
countries has been working on sequencing and assembling the wheat genome
for the last 10 years!
The wheat genome – spelt out here
The wheat genome is currently being sequenced chromosome by
chromosome. In July 2014, a draft of the full genome was published in
the journal Science along with a reference sequence for
chromosome 3B. Because of the complexity of the genome, the draft genome
has lower accuracy, with segments either missing or in the wrong order
or orientation.
Since then, work has focused on producing reference-quality
assemblies for the remaining chromosomes – filling in the gaps with high
accuracy and removing ambiguity in the order of segments – and mapping
specific genes and genomic features. Other researchers have used the
draft genome to study the evolution of wheat and other cereals, and to
find variability in loci encoding agronomically important traits.
Today, The Genome Analysis Centre (TGAC) in Norwich, UK, has made a more complete and accurate wheat genome
assembly available to the research community. The updated genome is now
assembled into fewer, larger sections of DNA covering regions that were
previously not sequenced. These regions include many of the large and
complex groups of genes in wheat that contribute to the nutritional and
bread-making quality of the grain.
The updated wheat genome is another step toward a chromosome-based
complete genome in this important crop species. With this information,
plant breeders will have high quality tools at their disposal to
identify specific genes affecting agronomically important traits, such
as yield, grain size and weight, nutritional quality, and stress
tolerance. This will enable farmers and breeders to produce new wheat
varieties better adapted to increasing demand in a changing climate.
El asma es una enfermedad crónica que
afecta las vías respiratorias. Las vías respiratorias son los tubos que
trasladan el aire hacia dentro y fuera de los pulmones. Cuando una
persona tiene asma, las paredes internas de estas vías se sensibilizan y
se hinchan.
En los Estados Unidos, aproximadamente 20 millones de personas padecen asma
y casi nueve millones de ellos son niños. Ellos tienen vías
respiratorias más pequeñas que los adultos, lo que hace que el asma sea
especialmente serio en ellos. Los niños con asma pueden respirar con un
silbido, tos, presión en el pecho y dificultad, especialmente temprano
en la mañana o en la noche.
Muchas cosas pueden desencadenar el asma, entre ellas:
Alergenos: moho, polen, animales
Irritantes: humo del cigarrillo, contaminación del aire
Clima: aire frío, cambios climáticos
Ejercicio
Infecciones: gripe, resfrío común
Cuando los síntomas de asma empeoran, se produce una crisis de asma.
El asma se trata con dos tipos de medicinas: unas para el alivio rápido y
detener los síntomas y otras para controlarlo a largo plazo y que
previenen la aparición de los síntomas.
Instituto Nacional del Corazón, los Pulmones y la Sangre
Comience aquí
Asma / Asthma (Hospitales y Clínicas de Niños)
- PDF - En inglés y español
