1,018 research outputs found
Utilización de células madre para la regeneración miocárdica en la insuficiencia cardíaca
La terapia celular en la reparación miocárdica se vislumbra
como una de las estrategias terapéuticas con
mayor futuro en el tratamiento de la insuficiencia cardíaca.
Numerosos estudios in vitro recientes apoyan la potencialidad
de distintos tipos de células madre de diferenciarse
hacia los tejidos necesarios para regenerar el
tejido miocárdico dañado, mientras que estudios en animales
de experimentación sugieren que células madre
de músculo (mioblastos), médula ósea (progenitores mesenquimales,
endoteliales o hematopoyéticos) e incluso
del propio corazón pueden contribuir in vivo a mejorar la
contractilidad cardíaca. Estos trabajos han conducido a
que diversos grupos hayan iniciado estudios en pacientes
con infarto de miocardio. Sin embargo, la utilización
de la terapia celular en ensayos clínicos no está desprovista
de controversia, fundamentalmente relacionada con
la necesidad de aumentar nuestro conocimiento antes
de pasar a la aplicación clínica de estas estrategias terapéuticas.
Aunque es fundamental aumentar significativamente
el conocimiento de los procesos, no consideramos
irrazonable iniciar ensayos clínicos en los que se
identifiquen preguntas concretas cuya respuesta nos
permita avanzar en esta dirección
Insecurity for compact surfaces of positive genus
A pair of points in a riemannian manifold is secure if the geodesics
between the points can be blocked by a finite number of point obstacles;
otherwise the pair of points is insecure. A manifold is secure if all pairs of
points in are secure. A manifold is insecure if there exists an insecure
point pair, and totally insecure if all point pairs are insecure.
Compact, flat manifolds are secure. A standing conjecture says that these are
the only secure, compact riemannian manifolds. We prove this for surfaces of
genus greater than zero. We also prove that a closed surface of genus greater
than one with any riemannian metric and a closed surface of genus one with
generic metric are totally insecure.Comment: 37 pages, 11 figure
Stem Cells to Regenerate Cardiac Tissue in Heart Failure
Myocardial regeneration is one of the most promising
therapeutic strategies for heart failure patients. Many experimental
studies have demonstrated that different types
of stem cell can differentiate into myocardial cells and tissues
necessary for regeneration of the damaged myocardium,
while studies in experimental animals suggest that
muscle (myoblast), bone marrow (mesenchymal, endothelial
or hematopoietic progenitors) and even heart cells
can help to improve heart contractility in vivo. These findings
have led several groups to undertake studies in patients
with myocardial infarction. However, the use of cellular
therapy in clinical trials is not without controversy,
mainly related with the need for better knowledge before
these therapeutic strategies are used in clinical practice.
Although significant enhancement of our knowledge of
the processes involved is fundamental, we do not consider
it unreasonable to initiate clinical trials in which specific
questions are posed, whose answers will allow us to
make further progress
Fibroma desmoplásico del hueso: aportación de un nuevo caso
Se presenta un caso de Fibroma Desmoplásico localizado en cuello femoral en
un paciente adulto joven de 34 años, al cual se le practicó una resección amplia de la lesión
y una reconstrucción por medio de un compuesto de aloinjerto intercalar proximal y prótesis
total de cadera (aloprótesis). Un año después de la intervención no hay recidiva local de la
lesión y se objetiva una buena incorporación del aloinjerto al huésped; con buena función de
la cadera. Se revisa la literatura y se discuten algunas consideraciones diagnósticas y terapéuticas
de la lesión.A case of Desmoplastic Fibroma of the Bone, located in the femoral neck, in
a 34 year old male patient is reported. The tumor was treated by wide resection, the reconstruction
beem performed with an allograft-prostheses composite. One year after surgery, there was
no local recurrence and a good is incorporation of the allograft to the host was observed. The
patient showed a good hip function. The literature is reviewed and diagnostic and therapeutic
considerations are discussed
Study of particulate matter and gaseous emissions in gasoline direct injection engine using on-board exhaust gas fuel reforming
Impact of exhaust gas fuel reforming and exhaust gas recirculation on particulate matter morphology in Gasoline Direct Injection Engine
Autologous human serum for cell culture avoids the implantation of cardioverter-defibrillators in cellular cardiomyoplasty
Background: Current clinical experience with cellular cardiomyoplasty (using serum bovine-cultivated myoblasts) has demonstrated
significant malignant ventricular arrhythmias and sudden deaths in patients. In some ongoing clinical trials the implantation of cardioverterdefibrillator
is mandatory. We have hypothesized that contact of human cells with fetal bovine serum results after 3-week fixation of animal
proteins on the cell surface, representing an antigenic substrate for immunological and inflammatory adverse events.
Methods and Results: Autologous myoblasts were transplanted into infarcted LV in 20 patients (90% males, mean age 62±8 years).
Cells were cultivated in a complete human medium during 3 weeks, using the patients' own serum obtained from a blood sample or from
plasmapheresis. Injections were performed during CABG (2.1 grafts/pt).
All patients had an uneventful recovery. At a mean follow-up of 14±5 months without mortality, no malignant cardiac arrhythmias are
reported. LV ejection fraction improved from 28±3% to 52:k4.7% (p = 0.03), and regional wall motion score index (WMSI) from 3.1 to
1.4 (p = 0.04) in the cell-treated segments. Myocardial viability tests showed areas of regeneration. Patients moved from mean NYHA
class 2.5 to class 1.2.
Conclusions: A total autologous cell culture procedure was used in cellular cardiomyoplasty reducing the risk of arrhythmia.
Human-autologous-serum cell expansion avoids the risk of prion, viral or zoonoses contamination. Since patients treated with noncultivated
bone marrow cells are free of arrhythmia, the bovine-culture medium seems to be responsible for this complication. Cellular
cardiomyoplasty may be efficient to avoid progression of ventricular remodeling and subsequent heart failure in ischemic heart disease
Prospective of Innovative Technologies for Quality Supervision and Classification of Roasted Coffee Beans
Color sorting is the major procedure employed for establish roast degree of coffee beans. However, color-based procedures have been proven to be ineffective, since coffee beans roasted to different degrees can present the same average readings in light reflectance measurements with significant quality variations. Besides to color, other major changes in beans are volume (swell), mass, form, bean pop and density. Eight samples of arabica coffee from Colombia and Guatemala have been roasted under slightly different conditions of time and temperature in order to obtain the same color classification. Sample analysis of data from nuclear magnetic resonance relaxometry show differences between samples in T1 and T2 parameters at cellular and subcellular level, and image analysis carried out on X-ray μCT leading to microestruture images corroborate differences in porosity and fissures presence among them, proving the potentiality of these technological solutions for sensing the microstructure of coffee to provide tools to enhance the roasting process
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