Biomedical subjects

Manuel Mazo

Publications and source records attributed to Manuel Mazo.

5 recordsLinked to original sources

PubMed2007

Plasticity and cardiovascular applications of multipotent adult progenitor cells.

Cardiovascular disease is the leading cause of death worldwide, which has encouraged the search for new therapies that enable the treatment of patients in palliative and curative ways. In the past decade, the potential benefit of transplantation of cells that are able to substitute for the injured tissue has been studied with several cell populations, such as stem cells. Some of these cell populations, such as myoblasts and bone marrow cells, are already being used in clinical trials. The laboratory of CM Verfaillie has studied primitive progenitors, termed multipotent adult progenitor cells, which can be isolated from adult bone marrow. These cells can differentiate in vitro at the single-cell level into functional cells that belong to the three germ layers and contribute to most, if not all, somatic cell types after blastocyst injection. This remarkably broad differentiation potential makes this particular cell population a candidate for transplantation in tissues in need of regeneration. Here, we focus on the regenerative capacity of multipotent adult progenitor cells in several ischemic mouse models, such as acute and chronic myocardial infarction and limb ischemia.

Adult Stem Cells↗

PubMed2006

Can bone marrow-derived multipotent adult progenitor cells regenerate infarcted myocardium?

OBJECTIVES: To assess the functional effects of multipotent adult progenitor cells (MAPCs) transplanted in a rat model of chronic myocardial infarction. METHODS: Forty-four rats underwent coronary ligation and, 14 days later, were randomly allocated to receive in-scar injections (5 x 10(6) cells/150 microL) of green fluorescent protein (eGFP)-transduced allogeneic MAPCs (n = 25) or culture medium (controls, n = 19). Nine of the MAPC-treated hearts were employed for functional studies while the remaining 16 received cells co-labeled with Resovist and were only used for serial histological assessments. Left ventricular (LV) function was assessed echocardiographically before transplantation and 1 month thereafter in a blinded manner. Immunohistochemistry, electron microscopy and PCR were used to detect grafted cells. All data were compared by nonparametric tests. RESULTS: Baseline ejection fractions (EF, median;[interquartile range]) did not differ significantly among the groups: 30% [0.23;0.37] and 37% [0.32;0.38] in control and rMAPC-transplanted hearts, respectively. One month later, LV function of control hearts was found to have deteriorated, as reflected by a decline in EF to 24% [0.21;0.30], and although EF tended to remain more stable after cell transplantation (37% [0.27;0.41]), the difference between the two groups failed to achieve statistical significance (p = 0.06). While MAPCs could be identified early post-transplant, no evidence of engraftment was further observed at 1 month by immunohistochemistry, electron microscopy or PCR. CONCLUSIONS: In this model, MAPCs did not improve global pump function, and although some of these cells expressed endothelial markers during the early post-transplant period, we could not detect any evidence for differentiation into cardiomyocytes and no engraftment was further identified beyond 2 weeks after cell injections.

Animals↗

PubMed2006

High reliability outdoor sonar prototype based on efficient signal coding.

Many mobile robots and autonomous vehicles designed for outdoor operation have incorporated ultrasonic sensors in their navigation systems, whose function is mainly to avoid possible collisions with very close obstacles. The use of these systems in more precise tasks requires signal encoding and the incorporation of pulse compression techniques that have already been used with success in the design of high-performance indoor sonars. However, the transmission of ultrasonic encoded signals outdoors entails a new challenge because of the effects of atmospheric turbulence. This phenomenon causes random fluctuations in the phase and amplitude of traveling acoustic waves, a fact that can make the encoded signal completely unrecognizable by its matched receiver. Atmospheric turbulence is investigated in this work, with the aim of determining the conditions under which it is possible to assure the reliable outdoor operation of an ultrasonic pulse compression system. As a result of this analysis, a novel sonar prototype based on complementary sequences coding is developed and experimentally tested. This encoding scheme provides the system with very useful additional features, namely, high robustness to noise, multi-mode operation capability (simultaneous emissions with minimum cross talk interference), and the possibility of applying an efficient detection algorithm that notably decreases the hardware resource requirements.

Data Compression↗

PubMed2004

Ultrasonic ranging sensor using simultaneous emissions from different transducers.

In recent applications based on ultrasound, several ultrasonic transducers have been geometrically and electronically associated to constitute a global sensor. There are several different methods used to process the ultrasonic signals obtained from these transducers. In this work, multimode techniques using Golay complementary sequences are proposed for processing the ultrasonic signal. The system increases scan rate, precision, and reliability. It is also capable of echo discrimination, allowing simultaneous measurements to be made and detection of the same obstacle by different transducers without cross-talk problems. The real-time implementation of the algorithm is presented on a field-programmable gate array (FPGA) device.

Algorithms↗

PubMed2002

System for assisted mobility using eye movements based on electrooculography.

This paper describes an eye-control method based on electrooculography (EOG) to develop a system for assisted mobility. One of its most important features is its modularity, making it adaptable to the particular needs of each user according to the type and degree of handicap involved. An eye model based on electroculographic signal is proposed and its validity is studied. Several human-machine interfaces (HMI) based on EOG are commented, focusing our study on guiding and controlling a wheelchair for disabled people, where the control is actually effected by eye movements within the socket. Different techniques and guidance strategies are then shown with comments on the advantages and disadvantages of each one. The system consists of a standard electric wheelchair with an on-board computer, sensors and a graphic user interface run by the computer. On the other hand, this eye-control method can be applied to handle graphical interfaces, where the eye is used as a mouse computer. Results obtained show that this control technique could be useful in multiple applications, such as mobility and communication aid for handicapped persons.

Activities of Daily Living↗