Seminario de Vinculación
Martes 7 de diciembre, 2010
8:30-9:45 |
Autologous Hematopoietic Stem Cells Transplantation and a Novel Nanotechnological Approach for the Treatment of Fibrosis Gabriela Gutierrez, Tessy Lopez
In a study to be conducted in patients with advanced liver disease listed for liver transplantation we will carry out a three arm study: a) repeated mobilization of CD34+ stem cells stimulated by GCSF over a period of 12 months b) direct liver delivery (10) of CD 34+ stem cells c) direct liver delivery of nanostructures elements that encapsulated living cells.
The nanotechnology part of the project is designed mainly to develop nanosized devices that will allow treating fibrosis and cirrhosis in order to deliver the living stem cells into the liver to promote cell differentiation and tissue recovering. An alkaloid drug colchicine will be encapsulated into an inorganic matrix using functionalized nanoparticles of Titanium (IV) and Silicon. The encapsulation will be done by the sol-gel method, where the drug is directly added to the reactive mixture during the synthesis. Such a process allows us to obtain a material with high porosity and large specific surface area. The material morphology therefore allows releasing the drug slowly in a controlled way with the desired release kinetics- A small grain like reservoir may be made of this material and implanted in the liver for sustained drug liberation. The second direction is to prepare DNA functionalized nanocatalystic materials. A suspension of such particles injected into a liver tissue showed broke the C-C and C-N bonds to reduce the collagen fibers as it was shown in vivo previously by our group. The main idea is to infiltrate the particle NPt plus antifibrotic agent in the liver. Finally the third and the long run investigation is to design a nanostructured reservoir to encapsulated living cells. In case of a successful encapsulation the cells will be released in a controlled way inside the liver to restore liver damage. This could be a better alternative to a direct cell implantation because the cells will not be taken away by the blood stream. |
9:45-11:00 |
Determination of the Mechanism of HIV-1 Inhibition Associated to GB Virus Infection Gibran Horemheb
GB virus C (GBV-C) is a relative recently discovered Flavivirus associated with GBV-A and GBV-B that was found in tamarind monkeys, it is closely related with HCV, whit whom share 30% of their genome. GBV-C until today is not related with any pathogenesis, and the world prevalence is 1% – 5% in healthy blood donors, in Mexico 2.5% – 2.9%.
This virus has a 9.4kb genome length, and produces 8 proteins, 6 non structural and 2 structural, and is capable to replicate in lymphocytes T (CD4+ and CD8+) and B. The importance of this virus has gained relevance due to the discovery of a relationship between this virus infection and a better clinical course of HIV clinical cases (Tillman HL et al. N Engl J Med. 2001), as it has been demonstrated that GBV-C is capable to inhibit HIV replication at least in vitro experiments (Xiang J et al. N Engl J Med 2001). This inhibition has been demonstrated that at least in part is caused by downregulation of HIV coreceptors (CCR5 and CXCR4). The studies have also shown that to produce this inhibition it is necessary that the infection of GBCV-C takes place before HIV (Xiang J et al. N Engl J Med 2001). Another proposed mechanism is the downregulation of coreceptors CCR5 in the presence of E2 envelope glycoprotein of GBV-C, but this experiments have also demonstrated that GBV-C inhibits CXCR4 HIV tropism without downregulation of coreceptors, opening a new window to explore, while the receptors downregulation is just 40% and HIV inhibition is 78%-98% in both tropism(Jung S et al. AIDS. 2005 Aug 12;19(12):1267-72). In summary GBV-C infection generates better clinical progression and longer survival in HIV coinfected patients, in vitro studies have demonstrated the inhibition of HIV replication by GBV-C, proposing as a mechanism the stimulation of secretion by the cells of MIP 1 alfa, MIP 1 beta and RANTES, which are specific of CCR5 coreceptors, making downregulation of. And the inhibition of CXCR4 HIV tropism remains unexplained. In our project, we hypothesized that GBV-C is capable to inhibit HIV infection by 2 pathways
2 Indirect inhibition by immunoregulation Our General Objective is to describe the mechanism by which HIV is inhibited and its association with GBV-C. Our specific objectives are: |
11:00-12:15 |
Hypotalamic Deep Brain Stimulation in an Obesogenic Non-Human Primate Model Fiacro Jimenez Ponce , Juan Carlos Lopez Alvarenga
The electric stimulation in deep brain nuclei modifies mood behavior in humans. We have published human cases with improvement for major depression and obsessive compulsive disorders, both illnesses refractory to medical treatment and responders to electrode stimulation. It is well known that deep in brain there are different regions associated with satiety and hunger. Some of these zones are the lateral and ventromedial hypothalamic nuclei. The aim of our research is to sort out the basis for weight decrease in a non-human obesity model in primates (Rhesus – Macaca mulatta) using very tiny electrodes capable to be sited deep in brain for electrical stimulus with specific frequency and voltage.
Nowadays, obesity surgery is used for losing weight in morbid obese subjects, some of them with secondary local effects on the digestive track, like diarrhea and others can develop liver diseases. The use electrode stimulation can be easily manipulated by producing changes in the amplitude and even shutting down the stimulus if necessary. For the purpose of this investigation we will implement an experimental model based on a recent publication relating to the exquisite palatability of high fructose fat food in baboons. After two months of treatment with this type of diet they became obese and with metabolic abnormalities. We will look for the electrophysiology changes in the described nuclei (ventromedial and lateral) and the accumbens (center of pleasure) before and during the weight increase process. Then the experimental animals will go through to an electrode switch on where we expect to induce a decrease in weight despite the exposure to the same obesogenic diet. |
12:15-13:15 |
Lunch |
13:15-14:30 |
Laser Induced Photothermal Tomography Crescencio Garcia Segundo
Tomographic images are obtained from the optical absorption contrast in breast tissue. The contrast is due to the rate density of blood vessels around a cancer tumor and other non-pathological areas.
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14:30-15:45 |
Non-Controlled Environment Functional Thermography Cresencio Garcia Segundo
We present trial tests as proof of concept for the use of thermography in non-controlled environment areas, as an imagenology tool for monitoring health conditions such as: diabetic foot, bronchial and respiratory illnesses, or obesity.
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