347 research outputs found
tecnologías de información y comunicación para la enseñanza de la biotecnología
This study is framed in an investigation of descriptive field, the same was to describe the use of ITC for teaching biotechnology. This research is focused on the constructivist theory supported on technological theory .The subjects of this study were composed of thirty (30) teachers who teach the subject of Biology. . The phase of the study was conducted primarily by the diagnosis is performed by applying an instrument with its evaluation by experts in the subject proposed. In other reliability was performed by calculating the Alpha Cronbach coefficient to determine that the instrument is homogeneous, uniform, consistent and reliable. The analysis results indicate that there is very high need for incorporating ITC for teaching biotechnology.El presente estudio está enmarcado en una investigación de campo de tipo descriptiva, el mismo tuvo el fin de describir el uso del tic para la enseñanza de la Biotecnología. Esta investigación está enfocada en la teoría constructivista apoyada en la teoría tecnológica. Los sujetos del presente estudio estuvieron conformados por treinta (30) docentes que imparten la asignatura de Biología. La fase del estudio se desarrolló principalmente por el diagnosticó esta se realizó mediante la aplicación de un instrumento con su respectiva evaluación por expertos en la temática planteada. A demás la confiabilidad se realizó a través del cálculo del coeficiente Alpha Cronbach permite determinar que el instrumento es homogéneo, uniforme, consistente y confiable. El análisis de los resultados indica que existe muy alta necesidad de incorporar las TIC para la enseñanza de la Biotecnología
La inhibición de la síntesis de óxido nítrico durante la colestasis inducida experimentalmente reduce la lesión hepatocelular al facilitar la homeostasis de nitrosotioles
Comunicaciones a congreso
Phosphorus restriction does not prevent the increase in fibroblast growth factor 23 elicited by high fat diet
This
study
was
designed
to evaluate
the
influence
of phosphorus
(P)
restriction
on
the
dele-
terious
effects
of high
fat
diets
on
mineral
metabolism.
Twenty-four
rats
were
allotted
to 3
groups
(n = 8 each)
that
were
fed
different
diets
for
7 months.
Rats
in group
1 were
fed
nor-
mal
fat-normal
P (0.6%)
diet
(NF-NP),
rats
in group
2 were
fed
high
fat-
normal
P diet
(HF-
NP)
and
rats
in group
3 were
fed
high
fat-low
P (0.2%)
diet
(HF-LP).
Blood,
urine
and
tissues
were
collected
at the
end
of the
experiments.
When
compared
with
the
control
group
(NF-
NP),
rats
fed
HF
diets
showed
increases
in body
weight,
and
in plasma
concentrations
of tri-
glycerides
and
leptin,
and
decreased
plasma
calcitriol
concentrations.
In rats
fed
HF-NP
plasma
fibroblast
growth
factor
23
(FGF23)
was
higher
(279.6
±
39.4
pg/ml
vs
160.6
±
25.0
pg/ml,
p = 0.018)
and
renal
klotho
(ratio
klotho/GAPDH)
was
lower
(0.75
±
0.06
vs
1.06
±
0.08,
p
<
0.01)
than
in rats
fed
NF-NP.
Phosphorus
restriction
did
not
normalize
plasma
FGF23
or
renal
klotho;
in fact,
rats
fed
HF-LP,
that
only
ingested
an
average
of 22.9
mg/day
of P,
had
higher
FGF23
(214.7
±
32.4
pg/ml)
concentratio
ns
than
rats
fed
NF-NP
(160.6
±
25.
0 pg/ml),
that
ingested
and
average
of 74.4
mg/day
of P over
a 7 month
period.
In conclusion,
our
results
demonstrate
that
severe
P restriction
over
a prolonged
period
of time
(7 months)
does
not
normalize
the
increase
in circulating
FGF23
induced
by
HF
diets.
These
data
indi-
cate
that
the
deleterious
effects
of high
fat
diet
on
the
FGF23/klotho
axis
are
not
eliminated
by
reduced
P intake
Evaluación de sistemas de producción y alimentación bovina (Quindío-Colombia).
Se realizó una encuesta en 50 explotaciones ganaderas en el departamento de Quindio (Colombia) cubriendo aspectos: físicos (altura m.s.n.m.), socio-económicos (precio de leche, uso de mano de obra), manejo de forrajes (area de pastos mejorados), manejo animal (sistemas de crianza de terneros), alimentación (uso de concentrados, pasto de corte), parámetros de productividad (producción por vaca, carga animal). Los objetivos básicos del trabajo, fueron describir y caracterizar los sistemas de producción y evaluar técnicamente las formas de alimentación tradicional utilizadas. Para el primer objetivo se emplearon las técnicas para análisis multivariante de datos: análisis factorial y análisis de conglomerados ((cluster), de la cual se obtuvo la tipificación de los productores en 4 grupos de fincas con caractersticas productivas y socio-agroenonómicas diferentes. Para cada grupo se obtuvo un modelo esquemático del sistema de producción respectivo. La evaluación alimentaria se realizó con modelos sencillos para el cálculo de raciones en vacas en producción, vacas secas, novillas y terneros, empleando en el modelo dietas típicas utilizadas en los diferentes sistemas de producción. Al analizar las dietas se encontraton tendencias dentro de la muestra en estudio tales como: deficiencias de energía en el aporte nutricional de las dietas para las vacas en producción, bajos niveles de producción de leche/vaca y bajas ganancias de peso para animales en crecimiento. También se encontró en la zona de estudio costosos sistemas de crianza para terneros, manejo irracional del componente forrajero: praderas - pasto de corte y utilización ineficiente de subproductos y recursos no convencionales de alta disponibilidad para la alimentación de bovinos.;A partir del análisis integrado de los aspectos estudiados, se proponen recomendaciones prácticas dirigidas al asistente técnico e instituciones tendientes a solucionar los problemas encontrados y con el criterio de reducir costos de producción y aumentar productividad/ha en las finca
Klotho/FGF23 and Wnt Signaling as Important Players in the Comorbidities Associated with Chronic Kidney Disease
Fibroblast Growth Factor 23 (FGF23) and Klotho play an essential role in the regulation of mineral metabolism, and both are altered as a consequence of renal failure. FGF23 increases to augment phosphaturia, which prevents phosphate accumulation at the early stages of chronic kidney disease (CKD). This effect of FGF23 requires the presence of Klotho in the renal tubules. However, Klotho expression is reduced as soon as renal function is starting to fail to generate a state of FGF23 resistance. Changes in these proteins directly affect to other mineral metabolism parameters; they may affect renal function and can produce damage in other organs such as bone, heart, or vessels. Some of the mechanisms responsible for the changes in FGF23 and Klotho levels are related to modifications in the Wnt signaling. This review examines the link between FGF23/Klotho and Wnt/β-catenin in different organs: kidney, heart, and bone. Activation of the canonical Wnt signaling produces changes in FGF23 and Klotho and vice versa; therefore, this pathway emerges as a potential therapeutic target that may help to prevent CKD-associated complications
Energy-dense diets increase FGF23, lead to phosphorus retention and promote vascular calcifications in rats
Rats with normal renal function (Experiment 1, n = 12) and uninephrectomized (1/2Nx) rats
(Experiment 2, n = 12) were fed diets with normal P (NP) and either normal (NF) or high fat (HF).
Rats with intact renal function (Experiment 3, n = 12) were also fed NF or HF diets with high P (HP).
Additionally, uremic (5/6Nx) rats (n = 16) were fed HP diets with NF or HF. Feeding the HF diets resulted
in significant elevation of plasma FGF23 vs rats fed NF diets: Experiment 1, 593 ± 126 vs 157 ± 28 pg/
ml (p < 0.01); Experiment 2, 538 ± 105 vs 250 ± 18 pg/ml (p < 0.05); Experiment 3, 971 ± 118 vs
534 ± 40 pg/ml (p < 0.01). Rats fed HF diets showed P retention and decreased renal klotho (ratio
klotho/actin) vs rats fed NF diets: Experiment 1, 0.75 ± 0.06 vs 0.97 ± 0.02 (p < 0.01); Experiment 2,
0.69 ± 0.07 vs 1.12 ± 0.08 (p < 0.01); Experiment 3, 0.57 ± 0.19 vs 1.16 ± 0.15 (p < 0.05). Uremic rats
fed HF diet showed more severe vascular calcification (VC) than rats fed NF diet (aortic Ca = 6.3 ± 1.4
vs 1.4 ± 0.1 mg/g tissue, p < 0.001). In conclusion, energy-rich diets increased plasma levels of
FGF23, a known risk factor of cardiovascular morbidity and mortality. Even though FGF23 has major
phosphaturic actions, feeding HF diets resulted in P retention, likely secondary to decreased renal
klotho, and aggravated uremic V
Oral Acid Load Down-Regulates Fibroblast Growth Factor 23
Increased dietary acid load has a negative impact on health, particularly when renal function is compromised. Fibroblast growth factor 23 (FGF23) is a bone-derived hormone that is elevated during renal failure. The relationship between metabolic acidosis and FGF23 remains unclear. To investigate the effect of dietary acid load on circulating levels of FGF23, rats with normal renal function and with a graded reduction in renal mass (1/2 Nx and 5/6 Nx) received oral NH4Cl for 1 month. Acid intake resulted in a consistent decrease of plasma FGF23 concentrations in all study groups when compared with their non-acidotic control: 239.3 ± 13.5 vs. 295.0 ± 15.8 pg/mL (intact), 346.4 ± 19.7 vs. 522.6 ± 29.3 pg/mL (1/2 Nx) and 988.0 ± 125.5 vs. 2549.4 ± 469.7 pg/mL (5/6 Nx). Acidosis also decreased plasma PTH in all groups, 96.5 ± 22.3 vs. 107.3 ± 19.1 pg/mL, 113.1 ± 17.3 vs. 185.8 ± 22.2 pg/mL and 504.9 ± 75.7 vs. 1255.4 ± 181.1 pg/mL. FGF23 showed a strong positive correlation with PTH (r = 0.877, p < 0.0001) and further studies demonstrated that acidosis did not influence plasma FGF23 concentrations in parathyroidectomized rats, 190.0 ± 31.6 vs. 215 ± 25.6 pg/mL. In conclusion, plasma concentrations of FGF23 are consistently decreased in rats with metabolic acidosis secondary to increased acid intake, both in animals with intact renal function and with decreased renal function. The in vivo effect of metabolic acidosis on FGF23 appears to be related to the simultaneous decrease in PTH
Modelación numérica hidrodinámico-hidrológica en zonas de inundación con presencia de infraestructura
Se presenta la modelación numérica computacional de la hidrodinámica superficial e hidrológica de la zona de estudio donde se pretende construir infraestructura para la exploración de hidrocarburos en las márgenes del río Grijalva, México; para ello se muestra el análisis de la información meteorológica, determinando los valores de intensidad de precipitación, temperaturas, evaporación y una estimación de los gastos, correspondiente al año 2014; las zonas de inundación se estimaron con el uso de programas desarrollados en Fortran y Matlab, que resuelven las ecuaciones de Navier-Stokes-Reynolds para flujos a superficie libre y la intensidad de precipitación con la distribución de Gumbel, con parámetros estimados mediante el método de Momentos Ponderados con Probabilidad (MPP), con los cuales, mediante una malla numérica de la topografía, en conjunto con los valores meteorológicos, como condiciones iniciales y forzantes, se determina la magnitud de la inundación del área de estudio, así como la obtención de gastos, velocidades y el funcionamiento hidráulico de las obras de mitigación propuestas para preservar el balance hidrológico del sistema
Procaine Inhibits Osteo/Odontogenesis through Wnt/β-Catenin Inactivation
Introduction
Periodontitis is a complex pathology characterized by the loss of alveolar bone. The causes
and the mechanisms that promote this bone resorption still remain unknown. The knowledge
of the critical regulators involved in the alteration of alveolar bone homeostasis is of
great importance for developing molecular therapies. Procaine is an anesthetic drug with
demethylant properties, mainly used by dentists in oral surgeries. The inhibitor role of Wnt
signaling of procaine was described in vitro in colon cancer cells.
Methods
In this work we evaluated the role of procaine (1 uM) in osteo/odontogenesis of rat bone
marrow mesenchymal stem cells. Similarly, the mechanisms whereby procaine achieves
these effects were also studied.
Results
Procaine administration led to a drastic decrease of calcium content, alkaline phosphatase
activity, alizarin red staining and an increase in the expression of Matrix Gla Protein. With
respect to osteo/odontogenic markers, procaine decreased early and mature osteo/odontogenic
markers. In parallel, procaine inhibited canonical Wnt/β-catenin pathway, observing a
loss of nuclear β-catenin, a decrease in Lrp5 and Frizzled 3, a significant increase of sclerostin
and Gsk3β and an increase of phosphorylated β-catenin. The combination of osteo/
odontogenic stimuli and Lithium Chloride decreased mRNA expression of Gsk3β, recovered
by Procaine. Furthermore it was proved that Procaine alone dose dependently
increases the expression of Gsk3β and β-catenin phosphorylation. These effects of procaine
were also observed on mature osteoblast. Interestingly, at this concentration of procaine
no demethylant effects were observed.
PLO
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