217 research outputs found
A native whole blood test for the evaluation of blood surface interaction: determination of thromboxane production
No full textThe method developed to evaluate the hemocompatibility of artificial materials involves the determination of thromboxane production during the clotting of rabbit blood, in test tubes of different materials. The concentration of serum TXB2 obtained after incubation of whole blood in glass test tubes, for 40 min at 37 degrees C, averaged 416.8 +/- 23.3 ng/ml (mean +/- SE). Polymethylpentene, recognised as having a relatively poor blood compatibility, elicited 309.5 +/- 17.2 ng/ml of serum TXB2, while silicone and Avcothane, considered of better hemocompatibility, showed thromboxane levels of 276.2 +/- 28.2 and 222.9 +/- 31.5 ng/ml, respectively. These values validate the usefulness of the proposed method as a preliminary in vitro screening test of artificial materials intended for biomedical application
Platelet responsiveness and biosynthesis of thromboxane and prostacyclin in response to in vitro cocaine treatment
No full textPreincubation of rabbit platelet-rich plasma with cocaine hydrochloride, at low and high concentrations, increased the platelet responsiveness to arachidonic acid, in terms of the aggregating response and the thromboxane production. The thromboxane levels released by collagen-stimulated platelets were increased after incubation with low concentrations of cocaine, while marked decreases were observed after incubation with high doses of cocaine. No effects on platelet aggregation induced by collagen and ADP were observed when low concentrations of cocaine were added; on the other hand, high doses of the anaesthetic were found to block the aggregating effects of these two agents. Specific studies showed cocaine to have an inhibitory activity on prostacyclin release when the aortic tissue was mechanically and thermically stimulated. By contrast, the prostacyclin synthesis by 'exhausted' aortic rings incubated with arachidonic acid appeared to be enhanced after addition of cocaine. These results lead us to believe that cocaine modifies both the Ca++ membrane binding and the extent of Ca++ influx, thereby increasing the permeability to arachidonic acid and altering the affinity of the membrane binding sites for the aggregating agents
Utilización de la torta de palmiste en piensos de cebo de conejos
No full textEn este trabajo se ha estudiado la inclusión de un 20% de torta de palmiste en 11 piensos equilibrados de cebo de conejos. Para ello se han realizado dos ensayos de 12 alimentación con 480 gazapos en cada uno, para controlar parámetros de crecimiento, 13 eficacia alimenticia y mortalidad a lo largo del periodo de cebo (35-63 días de edad). 14 Los resultados de los ensayos de alimentación muestran que la torta de palmiste es un 15 ingrediente palatable que permite sostener niveles altos de consumo y rendimientos en 16 el periodo de cebo, aunque su valor energético neto podría ser inferior al expresado por 17 su concentración en energía digestible. Por otra parte, su inclusión permitió reducir la 18 mortalidad en el periodo de cebo, lo que podría estar relacionado con su alto contenido 19 en ácidos grasos de cadena media y/o con su baja concentración de almidó
In vitro effects of mercury on platelet aggregation, thromboxane and vascular prostacyclin production.
No full textMercuric chloride [25-50 micrograms/ml platelet-rich plasma (PRP)] lowers the threshold concentration of arachidonic acid (AA) required for triggering rabbit platelet aggregation and causes a marked increase of thromboxane production. The metal, added as HgCl2, does not modify (50 micrograms/ml PRP) or block (100 micrograms/ml PRP) the platelet aggregation wave induced by a normal aggregating dose of AA. Whether or not AA-induced platelet aggregation takes place, a large increase in thromboxane production is observed. Methyl mercury, assayed as reference drug, induces platelet aggregation and a significant increase of thromboxane levels. Finally, HgCl2 and methyl mercury, in a concentration range of 0.125-0.5 micrograms/microliters in the incubation liquid, induce an increased prostacyclin release from rat aortic tissue
Efecto de una restricción alimenticia después del destete sobre la mortalidad y los rendimientos productivos de conejos en cebo
No full textEn este trabajo se ha estudiado el efecto de una restricción alimenticia moderada 15 y gradual después del destete (alrededor de 35 d de edad) sobre los rendimientos 16 productivos y la eficiencia alimenticia global del cebo. La restricción consistió en 17 suministrar una cantidad limitada de alimento (80, 100 y 120 g/d) en las tres semanas 18 siguientes al destete. Se han realizado seis ensayos, con 480 animales cada uno, 19 utilizando seis piensos comerciales que diferían en el tipo de medicación. En estos 20 ensayos se controlaron los parámetros de crecimiento, eficacia alimenticia global y 21 mortalidad durante el periodo de restricción y en el conjunto del cebo (destete a 63-67 d 22 de edad). El número de ooquistes y de Clostridium perfringens en heces duras fue 23 también evaluado en cada tratamiento. En ninguno de los ensayos se detectaron 24 problemas de elevada mortalidad causada por ERE. En estas condiciones, la mortalidad 25 de los gazapos restringidos se redujo un 33% (P=0,02) en el periodo de restricción y 26 tendió a disminuir en el conjunto del periodo de cebo. Los resultados obtenidos 27 muestran además que una restricción alimenticia moderada mejora en un 4% (Pmenor que0,001) 28 la eficiencia alimenticia global del cebo, sin afectar al peso total de animales enviado a 29 matadero. Además, la adopción de medidas que disminuyan la proliferación de 30 coccidios y C. perfringens en el contenido digestivo pueden resultar útiles para reducir 31 la mortalidad de conejos durante el ceb
Prognosis in traumatic brain injury
No full textIntroduction:
The
general
purpose
of
this
thesis
was
to
study
prognosis
in
traumatic
brain
injury
(TBI)
patients,
with
the
aim
of
providing
useful
and
practical
information
in
clinical
practice
and
clinical
research.
The
specific
objectives
were:
to
develop
and
validate
practical
prognostic
models
for
TBI
patients
and
to
assess
the
validity
of
the
Modified
Oxford
Handicap
Scale
(mOHS)
for
predicting
disability
at
six
months.
Methods:
A
survey
was
first
conducted
to
understand
the
importance
of
prognostic
information
among
physicians.
A
systematic
review
of
prognostic
models
for
TBI
patients
was
then
carried
out.
Prognostic
models
were
developed
using
data
from
a
cohort
of
10,008
TBI
patients
(CRASH
trial)
and
validated
in
a
cohort
of
8,509
TBI
patients
(IMPACT
study).
Two
focus
groups
and
a
survey
were
conducted
to
develop
a
paper-based
prognostic
score
card.
The
correlation
between
the
mOHS
and
the
Glasgow
Outcome
Scale
(GOS)
was
assessed,
the
validity
of
different
mOHS
dichotomies
was
assessed,
and
the
discriminative
ability
of
the
mOHS
to
predict
GOS
was
evaluated.
Results:
Doctors
considered
prognostic
information
to
be
very important
in
the
clinical
management
of
TBI
patients,
and
believed
that
an
accurate
prognostic
model
would
change
their
current
clinical
practice.
Many
prognostic
models
for
TBI
have
been
published,
but
they
have
many
methodological
flaws
which
limit
their
validity.
Valid
prognostic
models
for
patients
from
high
income
countries
and
low
&
middle
income
.countries
were
developed
and
made
available
as
a
web
calculator,
and
as
a
paper
based
score
card.
The
mOHS
was
strongly
correlated
with
and
was
predictive
of
GOS
at
six
months.
Conclusion:
The
prognostic
models
developed
are
valid
and
practical
to
use
in
the
clinical
setting.
The
association
between
mOHS
and
GOS
suggest
that
the
mOHS
could
be
used
for
interim
analysis
in
randomised
clinical
trials
in
TBI
patients,
for
dealing
with
loss
to
follow-up,
or
could
be
used
as
simple
tool
to
inform
patients
and
relatives
about
their
prognosis
at
hospital
discharg
Preventing smoking relapse using text messages: analysis of data from the txt2stop trial.
No full textINTRODUCTION: Interactive text message-based technologies which operate in real time have the potential to be especially effective for delivery of relapse prevention interventions. We examined predictors of use of a text message system for providing support for lapses and cravings, describe the natural history of requests for support, and predictors of time to requests for support. METHODS: Data were collected prospectively from participants in the intervention arm of txt2stop, a large randomized controlled trial of an automated, text message-based smoking cessation intervention. Txt2stop included 2,915 men and women aged 16-78, recruited from London, United Kingdom from 2009 to 2010. Participants could text "crave" or "lapse" when they experienced either; an automated system registered the time of the text message to the nearest second. RESULTS: One thousand one hundred and twenty one (38.5%) participants sent a lapse or crave message to request support. Women were more likely to lapse at some point during the trial. Of those who lapsed, being female, younger age, and setting a Saturday quit date were predictors of sending a lapse text requesting support. Half of all crave texts arrived within 106 hr of quitting. Half of all lapse texts arrived between 4 and 17 days after the quit date. Sending a crave text, being female, younger, and setting a quit date on a Saturday were associated with shorter time to sending a first lapse text. CONCLUSIONS: Text-based lapse support should be developed and evaluated, especially for women. Smokers may benefit from additional support to prevent lapses on days 4-17 postquit attempt
Resultados de predicción de varios métodos analíticos propuestos para determinar la alimentación recibida en la etapa de cebo por cerdos Ibéricos
No full textThe reliability of several analytical methods proposed to predict the feeding system received by Iberian pigs during the fattening period has been contrasted. Samples of subcutaneous adipose tissue were analyzed from 38 batches of pigs fattened in three seasons of montanera (acorn and pastures feeding). They corresponded to the four categories described in the Quality Standard for Iberian pig products: 251 samples of bellota, 164 of recebo, 197 of cebo de campo and 137 of cebo. To perform the study, the following analytical methods were used: fatty acid quantification, NIR, alpha and gamma tocopherol, chemical sensor, triacilglycerides, stable isotopes and neophytadiene. The laboratories received the samples without any information about the fattening system to which they belonged and remitted their predictions with respect to the above categories. The results showed a high percentage of accurate predictions of the methods when the fattening type corresponds to the extreme categories (bellota and cebo), however, the methods had difficulty in discerning between samples from a mixed feeding regime with acorn and feed (recebo) and problems when pigs are fattened with compound feeds including vegetable fats with high levels of oleic acid. Although a simplification into only two categories (cebo/campo and recebo/bellota) results in a success rate higher than 90% for some methods, the combination of two or three techniques with problematic samples allows for differentiating among the four categories with the same accuracy.Se ha contrastado la fiabilidad de varios métodos analíticos para determinar el tipo de alimentación recibida durante el cebo por cerdos Ibéricos a partir de muestras de tejido adiposo subcutáneo, procedentes de 38 partidas de cerdos de tres campañas de montanera. Las muestras correspondieron con las categorías de alimentación contempladas en la Norma de Calidad: 251 fueron de bellota, 164 de recebo, 197 de campo y 137 de cebo. Los métodos contrastados han sido ácidos grasos, NIR, alfa y gamma tocoferol, sensor químico, triacilglicéridos, isótopos estables y neofitadieno. Los distintos laboratorios recibieron las muestras sin información sobre el tipo de alimentación y remitieron sus predicciones respecto a las categorías previamente mencionadas. Los resultados obtenidos mostraron un elevado porcentaje de aciertos de los métodos cuando la alimentación se corresponde con las categorías extremas (bellota y cebo), sin embargo existía una dificultad en clasificar correctamente las muestras de cerdos de alimentación mixta con bellota y pienso (recebo) y confusión de algunos métodos cuando los cerdos son cebados con piensos que incluyen grasas vegetales con altos niveles de ácido oleico. Aunque la consideración de sólo dos categorías (cebo/campo y recebo/bellota) eleva el nivel de acierto por encima del 90% en algunos métodos, la combinación de dos o tres técnicas para muestras problemáticas permitiría diferenciar las cuatro categorías con el mismo porcentaje de éxito
Patrones corporales y conductuales del pulpo Octopus vulgaris frente a nasas con cebo: estudio de la primera captura
No full textThis study highlights for the first time individual differences in ethology and vulnerability of Octopus vulgaris (i.e. body postures, movements and skin displays) facing passive baited traps. Common octopus exposed to a baited trap during three consecutive first-capture tests exhibited diverse behavioural and body pattern sequences resembling when the octopus searches for and hunts its wild prey. Overall, they first visually recognized new objects or potential preys and rapidly moved out of the den, exploring, grabbing and approaching the trap with the arms (chemotactile exploration), and capturing the bait with the arms and feeding on top over long periods inside the trap. Simultaneously, O. vulgaris displayed diverse skin textural and chromatic signs, the regular pattern being the most frequent and long-lasting, followed by broad mottle, passing cloud and dark patterns. All individuals (n=8) caught the bait at least once, although only five octopuses (62.5%) entered the trap in all three tests. In addition, high variability among individuals was observed regarding behaviour and body patterns during the first-capture tests, which might evidence different individual temperaments or life-history traits. Differences in behavioural responses at individual level might have population consequences due to fisheries-induced selection, although there is a high necessity to assess how behavioural traits might play an important role in life-history traits of this species harvested by small-scale trap fisheries.Este estudio muestra por primera vez las diferencias individuales en cuanto al comportamiento y la vulnerabilidad del pulpo Octopus vulgaris (posturas corporales, movimientos, patrones de piel) frente a las trampas con cebo (nasas). Los pulpos fueron expuestos a una trampa con cebo durante tres pruebas consecutivas para estudiar la primera captura, y exhibieron secuencias comportamentales y patrones corporales que se asemejan a cuando el pulpo busca y caza sus presas en el medio natural. En general, primero reconocen visualmente nuevos objetos o potenciales presas, y rápidamente salen de su refugio, explorando el entorno y acercándose a la trampa, agarrando con los brazos (exploración quimiotáctil), y capturando el cebo con los brazos y alimentándose durante largos períodos dentro de la trampa. Simultáneamente, O. vulgaris mostró diversos patrones cromáticos y de textura de la piel, siendo el patrón “regular” el más frecuente y duradero, seguido de amplios patrones moteados, dinámicos y oscuros. Todos los individuos (n=8) capturaron el cebo al menos una vez, aunque sólo cinco pulpos (62.5%) entraron en la trampa en las tres pruebas. Además, se observó una gran variabilidad entre los individuos en cuanto al comportamiento y los patrones corporales durante las pruebas de primera captura, lo que podría evidenciar diferentes temperamentos individuales o rasgos de la historia de la vida. Las diferencias en las respuestas conductuales a nivel individual podrían tener consecuencias para la población debido a una selección inducida por la pesca, aunque es necesario evaluar cómo los rasgos conductuales podrían desempeñar un papel importante en el ciclo vital de esta especie, capturada por pescadores artesanales con trampas o nasas
Effect of toxic baits for fruit flies on Apis mellifera
No full text2 ilus. 4 tab. 33 referencias bibliográficasSe comparó el impacto que tienen los cebos tóxicos para moscas de la fruta sobre las abejas, Apis mellifera. Para el análisis estadístico, se utilizó un diseño bifactorial con cuatro niveles por cada factor. En el factor cebo, el cebo con malatión mató el 30,93 por ciento y 38,13 por ciento de las abejas a las 24 y 48 h, respectivamente el cebo con el colorante floxina B mató el 0,94 por ciento y 7,5 por ciento en los mismos períodos de tiempo. En el factor tiempo residual, a los cero minutos de residualidad la mortalidad de las abejas fue de 25,63 por ciento y 29,38 por ciento a las 24 y 48 h. Cuando las abejas se expusieron 60 minutos después de aplicar los cebos, la mortalidad disminuyó a 0,32 por ciento y 3,13 por ciento a las 24 y 48 h, respectivamente. La combinación de los factores anteriores que mató el 100 por ciento de las abejas fue el cebo con malatión y cero minutos de residualidad. El cebo con el colorante floxina B más tóxico fue a los cero minutos, con una mortalidad de 17,5 por ciento a las 48 h. De acuerdo con estos resultados, los cebos con malatión tienen un efecto tóxico mayor que el cebo con floxina B sobre las poblaciones de abejas, por lo que es posible sustituir el malatión como ingrediente activo por el colorante floxina B en la mezcla de cebos tóxicos para el combate de moscas de la fruta. This paper evaluates the effect of toxic baits used to control fruit flies on honey bees. A factorial design was used with two factors (toxic bait and time), of four levels each. The malathion bait killed up to 30.93 percent and 38.13 percent of honey bees at 24 and 48 hours, respectively phloxine B bait killed 0.94 percent and 7.5 percent during the same periods. Exposure of bees to phloxine B bait at 0 minutes caused 25.63 percent and 29.38 percent mortality at 24 and 48 hours, and at and at 60 minutes mortality declined to 0.32 percent and 3.13 percent at 24 and 48 hours, respectively. The combination of factors that killed 100 percent of honey bees was exposure to malathion bait at 0 minutes. Exposure to phloxine B bait at 0 minutes caused 17.5 percent of mortality in 48 hours. According to these results, malathion baits have a more toxic effect than phloxine B baits on bee populations therefore, it is possible to replace the malathion active ingredient for the dye phloxine B in the mixture of toxic baits for fruit fly control
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