LIFE SCIENCES, 11

Author: VIVANCOS PRELLEZO ANA.
Year: 2005.
University: POMPEU FABRA.
Place of defense: DEPARTAMENTO DE CIENCIAS EXPERIMENTALES Y DE LA SALUD.
Place of preparation: DEPARTAMENTO DE CIENCIAS EXPERIMENTALES Y DE LA SALUD.

Summary: Life involves aerobic information derived reactive oxygen species (ROS), the hydroxyl radical (OH.), superoxide ion (O-) and hydrogen peroxide (H2O2). ROS These are highly toxic and can cause damage to virtually all biomolecules: lipids, proteins and DNA. cells, therefore, must have systems of detoxification of these ROS at the same time signaling systems in response to elevated levels of these toxic or ROS, which constitute the status of oxidative stress. yeast Schizosaccharomyces pombe, eucariota unicellular system, has two signaling pathways in response to oxidative stress: the transcription factor Pap1 (pombe AP-1) and MAPK (mitogen activated protein kinase) Sty1 specifically responding to stress oxidative, while the route of Sty1 responds to multiple stress situations, such as osmotic type, temperature, deprivation of carbon source or entry into stationary phase. activation by phosphorylation of Sty1 culminates in the phosphorylation and activation of factor transcription Atf1. While conducting this thesis, has been characterized, the response to stress by H2O2 of Pap1 and its relationship with Sty1. S.pombe there is a different response depending on the severity of stress by H2O2, low dose H2O2 in the extracellular caused by the activation of Pap1, while high doses of this oxidant causing activation late under the MAPK Sty1 of transcription factor. superexpresión gene target of the route Sty1-Atf1 as gpz1 or ctt1, encoding activity detoxificantes of H2O2, it is capable of advancing the activation of Pap1 after treatments of high dose H2O2. Moreover, the ectopic expression of gpx1 is able to reverse the phenotype of a strain Dsty1, allowing activation Pap1 after high-dose treatments oxidizer, but with kinetic later than the wild. Seeking more genes involved in the activation of Pap1 after high doses of H2O2, led to the characterization of peroxirredoxina (Prx) Tpx1 as sensor H2O2 and transducer signal to Pap1. Tpx1 is in a catalytic redox cycle of peroxides in a situation of low doses of them. catalytic activity of Tpx1 consists of the reaction of his two cisteínas, peroxidática (COP) and resolutiva (CR ), and oxidized to form a disulfide bridge in exchange for reducing H2O2. Under these conditions, Tpx1 is capable of activating Pap1. inactivation temporary high dose of H2O2 suffering Tpx1 explains the delay in activating Pa1 under these conditions . Reviving Tpx1 necessary for the signal to Pap1 is mediated by the sulflirredoxina Srx1, which reduces sulphydryl oxidase how to sulfínico of CP Tpx1. gene srx1 is target of the road Sty1-Atf1 and induction of specifically in response to high doses of H2O2, establishing the link between the activation of Pap1 and Sty1. Beginning in the studies that led to the characterization of Tpx1 as sensor oxidative stress, it was revealed its importance aerobically. wanted because , to determine whether its role detoxificante or other function unknown, was responsible for this essentiality. Beginning in studies "in vitro" We have found that their high affinity for H2O2 allows Tpx1 found detoxificando peroxides in the basal cell and it is vital his presence. We have also been able to determine the role of each of its two cisteínas redox, peroxidática and resolutiva aerobically. Amazing, the only cysteine essential for survival in the presence of oxygen is peroxidática, indicating that it is capable in the absence of the resolutive, found in a cycle detoxificante. Lastly, we have studied the implications in the system S.pombe the presence of a Prx not idle excess H2O2, a truncated form of Tpx1 in the extreme carboxyl terminal: Tpx1DCTD and Prx Escherichia coli, AhpC level resistance to oxidative stress and activation Pap1 and Sty1.

Author: BRUNET ROIG MAURICI.
Year: 2005.
University: POMPEU FABRA.
Place of defense: DEPARTAMENTO DE CIENCIAS EXPERIMENTALES Y DE LA SALUD.
Place of preparation: DEPARTAMENTO DE CIENCIAS EXPERIMENTALES Y DE LA SALUD.

Summary: The apoptosis, or programmed cell death, is an active process that mobilizes resources of the cell in order to maintain homeostasis of the body in exchange for the suicide of individual cells affected. Various studies have shown that there is an increase in the activity of certain proteins cdk, especially Cdk1 and Cdk2, in correlation with the progression of the early stages of apoptosis. In our laboratory study of this process in thymocytes, or cells arrested in G1 and without activity cdk due to cell cycle showed that the induction of the activity of Cdk2 after treatment with gamma radiation or glucocorticoids is necessary for the initiation of apoptosis . While none of the known ciclinas seems to be activating protein of Cdk2 in apoptosis, in our laboratory we have identified a new member of the family of ciclinas, called Ciclina Or, capable of activating kinase Cdk2 in vivo cell lines. The expression of this new ciclina in the thymus, and other tissues, is rapidly induced after treatment with gamma radiation and coincides with the emergence of apoptósis. These results positioned the Ciclina Or as the best candidate to be the activator of Cdk2 necessary to induce programmed cell death in time, and probably also in other organs.

Author: LAMARCA CASADO ROSA.
Year: 2005.
University: POMPEU FABRA.
Place of defense: DEPARTAMENTO DE CIENCIAS EXPERIMENTALES Y DE LA SALUD.
Place of preparation: DEPARTAMENTO DE CIENCIAS EXPERIMENTALES Y DE LA SALUD.

Author: ACOSTA ROJAS EMILIA RUTHY.
Year: 2005.
University: POMPEU FABRA.
Place of defense: DEPARTAMENTO DE CIENCIAS EXPERIMENTALES Y DE LA SALUD.
Place of preparation: DEPARTAMENTO DE CIENCIAS EXPERIMENTALES Y DE LA SALUD.

Summary: OBJECTIVE 1-evaluate the association between clinical measures (Sharpness Visual (AV), contrast sensitivity (CS) and stereopsis) and the rate of visual function (VF-14). 2-To assess the impact of AV and SC on esteropsis. METHODS We evaluated a cohort of 137 patients with bilateral cataract (CB), before and after the first and second cataract surgery. We calculated the correlation coefficients and partial regression models. RESULTS 1, AV - has a greater partnership with the VF-14 (r = -0.30, p = 0.003) in the CB and stereopsis in pseudofaquia monocular and binocular (r = 0.26 and -0.51, p = 0,001, respectively). 2, and AV-SC had a greater impact on the CB. The AV had a greater impact after the first surgery of the eye, and the SC after surgery in the second eye. CONCLUSIONS The identification of the visually impaired in patients with better visual level, it may be best detected through the esteropsis and SC, if worse eye level, the VA is the best identifies disability.

Author: Fuentes Enriquez de Salamanca Susana.
Year: 2005.
University: GRANADA.
Place of defense: Facultad de Farmacia.
Place of preparation: Universidad de Granada.

Summary: There are many properties assigned to the probiotic microorganisms, including those associated with the gastrointestinal tract, immune system (including the processes allergic), the cardiovascular system or the urogenital tract. Still unknown is the impact of probiotic microorganisms on the composition of the gastro-intestinal microbiota, and the relationships being established between the endogenous bacteria and the host. As for the molecular mechanisms of the so-called "effects probiotics" too little is known, which can vary from one strain probiótica to another, or be caused by a series of reactions. The previous state of the immune system or gastrointestinal tract of individuals who are treated with agents probiotics is a factor of great influence in the choice of strains and the results obtained. One of the potential applications of microorganisms probiotics is the restoration of the damaged immune functions by infections, and anti-tumor chemotherapy treatments among other immunosuppressants. Microorganisms Probiotics have also been proposed for application in the treatment of inflammatory bowel diseases. For all these applications is particularly important to consider the safety of these probiotics to be living microorganisms administered to subjects with immunocompromised or endogenous microbiota altered. The thesis of this work was performed within a project of Health Research Fund of the Ministry of Health, was intended to address the ability of probiotic bacteria to colonize the intestinal mucosa, communities interact with representatives of the endogenous microbiota and modify responsiveness of the immune system in murine models, evaluating also the safety of these bacteria. These models were carried out as approaches to clinical situations of immuno-and inflammatory bowel disease. For the development of this project were isolated and identified strains of Lactobacillus casei and Lactobacillus plantarum isolated from commercial products derived from milk. It is administered through cannula intragástrica a daily dose of 100 liters of a suspension in skim milk with 109 CFU of probiotic, during different periods of time, female mice BALB / c of 8-10 weeks of age. All tests were taken stool samples and biopsies from the gastrointestinal tract altogether. The initial tests were designed to establish the most effective dose of probiotic, and the appropriate conditions for the application of different analytical techniques of the intestinal microbiota and the effect of the administration of probiotic microorganisms and the various clinical situations tested on the endogenous bacteria. To determine changes in the gastro-intestinal microbiota of mice by the various treatments, a polifásico approach to the study of the evolution of major groups of fecal and intestinal microorganisms by classical techniques of stool culture and molecular biology techniques based on the study gene rRNA 16S (DGGE, T-RFLP, construction of libraries clones and quantification by real-time PCR of certain bacterial populations). Isolation of DNA and the PCR reactions were conducted under the same conditions for all samples. Universal oligonucleotides were used for the region V6-V8 gene rRNA 16S and primers specific lactobacilli for obtaining PCR products for the analysis of DGGE. In addition, it assessed the influence of the immune response and / or treatment on the probiotic group segmented filamentous bacteria present in the intestine of mice youth to the development of the immune system. The possible spread of probiotic bacteria testad 8 as by hemática v 814 would be investigated by molecular techniques for the evaluation of the safety of the strains, using oligonucleotides specific biopsies of mesenteric lymph nodes. The data obtained from the different techniques used were integrated using multivariate statistical analysis. The results of the analysis of different samples by DGGE and T-RFLP showed a great diversity in the profiles, without significant effect on the administration of probiotics on the composition of the intestinal microbiota. There were some effects on specific profiles of lactobacilli. It detected the strain probiótica erratically in the fecal samples and biopsies, possibly because low levels of probiotic compared to the rest of the community endogenous lactobacilli. The models analyzed immunosuppression no observed effect on the immune system determined by actual count of peripheral leukocytes by the administration of the strain probiótica, although neither was exacerbated by it. There was a clear effect of probiotic treatment on the removal of filamentous bacteria, bacteria associated with the development of the immune system. In the model of inflammatory bowel disease was observed an increase in the inflammatory response by the joint administration of probiotic microorganism.

Author: Navajas Pérez Rafael.
Year: 2005.
University: GRANADA.
Place of defense: Facultad de Ciencias.
Place of preparation: Departamento de Genética, Facultad de Ciencias, Universidad de Granada.

Summary: In this Doctoral Thesis we have analyzed in depth gender Rumex (Polygonaceae) in relation to the reproductive systems presented, as well as on their systems sex chromosomes. Gender Rumex is currently divided into four subgenera including hermaphroditic species, polygamous, ginodioicas, monoecious and dioicas. Also, species dioicas present systems sex chromosomes in different evolutionary stages, simple (XX / XY) and complex (XX/XY1Y2). In this classification, it was deduced that the emergence of dioecia and different systems of sex determination had appeared several times over the evolution of gender Rumex. In this report we compared the sequences ribosómicas STI, as well as the intrón gene trnL and spacer intergénico between this and the gene trnF from 31 species Rumex, and we used these sequences as markers for inferring phylogenetic relationships among them. Our classification supports a new sistemáti

Author: PARANTU SHAH.
Year: 2005.
University: AUTÓNOMA DE MADRID.
Place of defense: FACULTAD DE CIENCIAS BIOLÓGICAS.
Place of preparation: EUROPEAN MOLECULAR BIOLOGY LABORATORY HEIDELBERG.

Author: SOLÉ SERRA CARME.
Year: 2005.
University: LLEIDA.
Place of defense: FACULTAT DE MEDICINA.
Place of preparation: FACULTAT DE MEDICINA.

Summary: This paper is based on the study of two proteins identified as antagonists death induced by the death receptor Fas, FAIM and FLIP, in the nervous system. To that end, and despite the fact that they share the phenotype of promoting growth neurítico, there are differences mecanísticas that detail their separate ways. Initially, we characterize the protein FAIM (Fas Apoptosis Inhibitory Molecule), of which there are only two references in the literature. We have demonstrated that the expression forced FAIM does not protect neurons from the withdrawal of trophic support, but exerts a clear advocacy growth neurítico in different neural systems studied. On the one hand, the expression forced FAIM increases the length and extent of the arborización neuritas induced by nerve growth factor (NGF), in both cell line PC12 and in primary cultures of neurons in the cervical ganglion (SCG) higher. On the other hand, if reduced levels of endogenous FAIM by the technique of RNA interference, it decreases the growth neurítico in these cells. The expression forced FAIM promotes activation of the road NF-? B, while blocking the line through the transaction of a mutated form of l? B? Not degradable or using cortical neurons null mice lacking the subunit p65 of NF-? B prevents growth neurítico promoted by NGF. The stimulating effect of growth neurítico also can be blocked by inhibiting the route of Ras / ERK. Finally, we demonstrate that FAIM interacts with both the neurotrofina NGF receptor, p75NTR and TrkA, in a ligand-dependent manner. These results reveal a new role as a promoter of FAIM growth neurítico through a mechanism dependent NF-? B. In the case of FLIP, has been described his role as endogenous inhibitor of apoptosis mediated by Fas, but has also been implicated in promoting proliferation. The paper describes for the first time a role hitherto unknown, FLIP in the nervous system. FLIP is expressed in motoneuronas in neurons SCGs cells and PC12, but his expression forced only protects against cell death induced by the withdrawal of trophic factors in motoneuronas. Anyway, this phrase significant improvement growth neurítico in three models, after the stimulus neurotrophic appropriate. So interesting, and without exception, lower levels of endogenous FLIP inhibits neuritrogénesis in these models. The intracellular pathways regulated by FLIP involve both ERK as NF-B. The forced expression of FLIP promotes an increase in activity, while reducing its expression causes a diminishment of it, after an encouraging NGF cells PC12. Finally, we demonstrate that FLIP interacts with the NGF receptor, TrkA in a manner dependent stimulation. These results reveal a new role for FLIP, neuritogénesis, through a mechanism that involves the activation of Ras pathways / ERK yNF-B, and that is not related to its classic role antiapoptótica.

Author: PABLO LLAVALL YOLANDA DE.
Year: 2005.
University: LLEIDA.
Place of defense: FACULTAD DE MEDICINA.
Place of preparation: FACULTAD DE MEDICINA.

Summary: TrkA was discovered as an oncogene product of the merger of its domain tyrosine kinase (TK) with tropomiosina. Later, his interest grew after the discovery that the protein native was the recipient of nerve growth factor (NGF). It is well known events that occur after binding of ligand receptor and leading to the activation of the signaling pathways of the MAPK and Pl 3-K/Akt. It is known that in vivo receptor internalization and retrograde transport also play an important role in the long-term effect of NGF and that is a hallmark of other recipients of growth factors. The activation of the receptor also brings a transient increase in Ca2 + intracellular. Therefore we are exploring the link between activation of TrkA and calmodulina (CaM) as a sensor levels of Ca2 + intracellular. First we see a direct interaction and Ca2 +-dependent between CaM and half c-terminal the intracellular domain of TrkA. The first part of the work focuses on characterizing this interaction. To see the effect of marriage on Trk, we use inhibitors CaM. They do not prevent the phosphorylation of TrkA induced by NGF, but it carries the proteolysis receptor leading to a fragment with tyrosine kinase activity constituent. Given the ubiquity of CaM and its importance in life processes in the cell, the second objective was to seek the binding site to CaM of TrkA, so they can get a building Trk which lost the union to CaM. Based on a variety of evidence, we focused on the characterization of a region containing a Tyr fosforilable / Y701), which also forms part of a plea of internalization. The last part of the work is focused on describing the characteristics of that Tyr and function, beyond the relationship with CaM, can be a phosphorylation for the inhibitory activity of Trk and a place for negative regulation of its internalization.

Author: SEGURA GINARD MIGUEL FRANCISCO.
Year: 2005.
University: LLEIDA.
Place of defense: FACULTAD DE MEDICINA.
Place of preparation: FACULTAD DE MEDICINA. UNIVERSIDAD DE LLEIDA.

Summary: Apoptosis is a physiological mechanism that helps to regulate the number of cells of an organism so that those who perform functions transitional who are injured, or in excess, will be removed. This is a strictly regulated process during embryonic development and intimately linked with the onset or progression of certain diseases. Thus, the excessive apoptosis contributes to the development of neurodegenerative diseases while failing would be the origin of cancer. The chief regulator of apoptótico process is the activation of caspases, cisteína-proteasas with specificity for aspartate residues. The main mechanisms that activate caspases are out of the mitochondrial cytochrome C by an alteration in mitochondrial function, and the activation of membrane proteins called receptors death (DRs, Death Receptors). The latter have been extensively characterized in the immune system, whereas in the nervous system tissues as their functions are in the initial stages of characterization. The objective of this study is to elucidate the molecular mechanisms that regulate the activity of these receptors in the nervous system, through the functional characterization of two novel proteins, FAIM and Lifeguard, originally proposed as a receptor antagonists death CD95/Fas / APO-1. This has been used cell lines PC12 and SH-SY5Y widely used in models of differentiation and death CD95/Fas/APO-1. This has been used cell lines PC12 and SH-SY5Y widely used in models of differentiation and cell death, along with primary cultures of cortical neurons and granule neurons in the cerebellum. In the first part of this paper describes the cloning of ortólogo of mouse Lifeguard, and its characterization as a functional antagonist of CD95 in the nervous system. We have demonstrated that its overexpression is able to block the death induced CD95 on the model of neuroblastoma human SH-SY5Y well as in murine cortical neurons. We have also found that the decrease in endogenous levels sensitizes granule neurons and cortical mouse. In addition, it has been found that its molecular mechanism of action depends on its location exclusive microdominios membrane called Lipid Rafts, where you can interact with CD95 and inhibit the activation of initiator caspases. From the results obtained in the second part of the work shows that levels of the long isoform antagonist FAIM, FAIML, specifically the nervous system, increase during embryonic development. Its highest expression is in periods of development in which shape and adjust the neural structures that give rise to adult brain. Functionally, we have demonstrated that not participating in processes neuritogénesis (unlike the short isoform of FAIM, FAIMS), and it does not block the apoptotic death induced mitochondrial through incentives. However, FAIML is capable of antagonizing apoptosis induced by the DRs CD95 and TNFR1. Trials with RNA interference has allowed us to clarify that FAIML is at least partly responsible for blocking the activity of initiator caspases activated DRs. Therefore, this study provides clues about the molecular basis regulating the activity of DRs on the nervous system and that may constitute a basis for the development of therapeutic strategies neuropathology in which the DRs involved so relevant.

Author: VILELLA MITJANA FELIPE.
Year: 2005.
University: LLEIDA.
Place of defense: FACULTAD DE MEDICINA, DEPARTAMENTO DE CIENCIAS MÉDICAS BÁSICAS.
Place of preparation: FACULTAD DE MEDICINA DE LLEIDA.

Summary: The route of cellular integrity or via Pkc1-MAP kinase Saccharomyces cerevisiae has a central role in the cellular response mechanisms responding to different environmental stress, such as heat stress, stress hipoosmótico or any stress which affects the cell wall. In this dissertation demonstrates that this route of signal transduction is also involved in the survival and adaptation to the effects of oxidative stress. We noticed that the proteins Pkc1 and Rom2 are essential for cell survival compared to oxidative stress mediated by two agents (hydrogen peroxide and diamida). In addition, the actin cytoskeleton is one of the targets for action of hydrogen peroxide and the diamida, both agents mediate devaluation of the actin cytoskeleton with the consequent effect on morphogenesis and viability. This phenomenon occurs independently of proteins dela via cellular integrity. However, for the cytoskeletal actin repolarice in response to oxidizing agents are required to proteins Mtl1, Rom2 and Pkc1, all components of the path of cellular integrity. The diamida induces the formation of disulfide bridges proteins in the cell surface, leading to structural changes in the same, which ultimately caused the activation of the path of cellular integrity. Our studies have led to assign a function to the recipient cell wall Mtl1 as oxidative stress sensor surface, and an integral part of the road Pkc1-MAP kinase. The hydrogen peroxide affects essentially a cellular function related to the last stages of secretion and morphogenesis cellar. Also note two essential functions of the protein Pkc1 in response to treatment with hydrogen peroxide: 1-Pkc regulated biogenesis of ribosomes in response to the problems caused by the secretion oxidizing agent. In addition, inhibition of ribosomal gene transcription is done depending on a cytoskeletal polymerization active. 2-Pkc induces the restoration of actin cables and so on morphogenesis and cell polarity through the activation of the profilina Pfy1.

Author: RIBAS FORTUNY JUDIT.
Year: 2005.
University: LLEIDA.
Place of defense: FACULTAD DE MEDICINA.
Place of preparation: FACULTAT DE MEDICINA.

Summary: The olomoucina and roscovitina are two inhibitors of cinasas dependent ciclinas (CDKs), whose mechanism of action is competing with ATP for binding to the enzyme. They show a high selectivity in vitro before the CDK1, 2,5,7,9 and ERKs. This profile inhibitor confers broad prospects in anti-tumor therapy. In this paper, we have shown that the line of SH-SY5Y, derived from neuroblastoma, and the HL-60, derived from a promielocítica leukemia, died apoptoticamente in response to drugs masters. A characterization of the broader process apoptótico, showed that the forced expression of Bcl-2 or Bcl-XL did not confer resistance to any of our drugs. On the other hand, if made more resistant when he was partially covered with a general inhibitor of caspase (z-VAD-fmk). Therefore, neutral hypothesis was that we were facing a extrinsic pathway of apoptosis initiated by caspase 8 (CASP8) and / or caspase 10 (CASP10). Curiously, these caspases not expressed in SH-SY5Y due to a process of gene methylation, and we saw that the treatment also induced his re. In conclusion, ruling that SH-SY5Y initiate a canonical extrinsic pathway in response to our drugs. Furthermore, the inhibition of protein synthesis in our model inhibiting apoptosis. Moreover, the z-VAD-fmk together with, for example, cicloheximida exhibited synergy in the rescue. This suggested to our growing coexistence of different subpopulations able to start different apoptotic pathways. Treatment with PD98059 or UO126, two inhibitors towards Erk1 / 2, was safe at the time of inducing death, thus ruling out that the inhibition of Erk1 / 2 was responsible for apoptosis. Surprisingly, the study of the state of phosphorylation of Erk1 / 2, we were able to see that they are activated in response to the olomoucina and roscovitina. More surprising still, was the fact that the iso-olomoucina an inactive isomer of olomoucina, cause the same effects on Erk1 / 2. This allowed us to say that there was no correlation between the phosphorylation of Erk1 / 2 and inhibition of CDKs. Based primarily on the results of the iso-olomoucina, we affirm that the phosphorylation of ERKs and subsequent activation, it is not correlated with apoptosis, proliferation and differentiation of cells. Finally, we show that the SH-SY5Y differentiated became resistant to olomoucina and roscovitina done for the inhibition of CDKs outside the event originator dela apoptotic cascade. Alternatively, the olomoucina and roscovitina being increasingly studied in the context of combinatorial therapy against cancer. In my experiments, I used the R-roscovitina, one of the stereoisomers of the roscovitina. In combination with docetaxel (DTX), we did not see synergy. The case happened when it was administered along with the nutlina-3, a new and promising inducing p53. We saw how the R-roscovitina sensiblizaba the SH-SY% already apoptosis induced by nutlina-3.

Author: MOLINA NAVARRO MARIA MICAELA.
Year: 2005.
University: LLEIDA.
Place of defense: UNIVERSITAT DE LLEIDA.
Place of preparation: UNIVERSITAT DE LLEIDA.

Summary: The glutaredoxinas are thiol oxidoreductases governing the redox state of the groups sulfidrilo of proteins. In the yeast Saccharomyces cerevisiae Grx1 and Grx2 are glutaredoxinas ditiólicas located in the cytosol, while Grx3, Grx4 and Grx5 are monotiólicas. Grx5 is located in the mitochondrial matrix and is involved in the synthesis of centers iron / sulfur (Fe / S). In his absence, enzymes centers Fe / S as aconitasa are inactive, there was no growth in respiratory conditions, there is accumulation of intracellular iron and there is a constituent of protein oxidation. While Grx5 contains a dominioglutaredoxina simple Grx3 and Grx4 possess a kind tioredoxina merged domain to the domain glutaredoxina. The latter two proteins are localized in the nucleus, being the domain tioredoxina necessary for that location. It has been used mutant zero grx5 as a model of cells exhibiting a estréx oxidative endogenous establishing (as opposed to situations of stress caused by an external stimulus) to study the transcriptoma cell in those conditions. It has been observed that: 1-It is primarily induce genes regulón Aft1 involved in the uptake and utilization of iron. 2-It suppresses the expression of genes involved in metabolism respiratory dependent regulator Hap4. This latter effect is suppressed by the overexpression of HAP4, so that the inhibition of respiratory metabolism during moderately oxidizing conditions could provide a protective response by the cells of yeast. Using a building capable of internalizing proteins in the mitochondria through the mitochondrial localization signal of Grx5, it has been shown that glutaredoxinas ditiólicas of S.cerevisiae were unable to rescue the defects of a mutant grx5, while the monotiólicas Grx3 and Grx4 only when they are directed into the mitochondrial matrix. It shows that glutaredoxinas ditiólicas are functionally divergent from monotiólicas, but that the latter can switch between them when their biological activities beyond the barriers compartimentales. The conservation functions between glutaredoxinas monotiólicas extends throughout the evolutionary scale, as the shortcomings of mutant grx5 of S.cerevisiae are also terminated for other proteins from the same family as Grx4 Escherichia coli, GrxC of Synechocystis sp. , and the respective homologous proteins of chicken and human cells.

Author: AMO DE PAZ LUISA.
Year: 2005.
University: COMPLUTENSE DE MADRID.
Place of defense: FACULTAD DE CIENCIAS BIOLÓGICAS.
Place of preparation: FACULTAD DE CIENCIAS BIOLÓGICAS (UCM).

Summary: The risk of predation is considered one of the major selective force in the evolution numerous behavioral and morphological characteristics of the animals. To cope with an increase in the risk of predation, the animals showed behavioral changes that are known as strategies antidepredatorias. One of the first preventive strategies of dams to deal with the risk of predation s selection of safe habitats. However, human activity is causing drastic changes in the middle to a speed in relation to the evolutionary time, which may affect the perceived risk of predation by dams and strategies antidepredatorias. Because strategies antidepredatorias as adjustments exhaust or use of shelters with costly, in terms of lost time for other activities and in terms of loss of body condition, a change in the structure of the medium might affect the maintenance of reptile populations. Likewise, since the lizards respond to the presence of people like the predator, an increase in eco-zone could also affect the maintenance of these populations. The main objective of this thesis is to identify anthropogenic factors that may be affecting the maintenance of the populations of lizards in the Sierra de Guadarrama. The results show that the modification of the natural environment is an optimal habitat loss for some species, so that drastic changes of habitat, such as the drastic changes in habitat, such as stocking with pines at locations originally occupied by oak, involving the disappearance of some species and the colonization of others. Changes in the structure of vegetation also involve an increase in the perceived risk of predation by lizards as, for example, can be more easily detectable in degraded areas. The lizards respond to this increase in risk strategies antidepredatorias preventive as the selection of microhabitats insurance, and are able to change their patterns of movement to minimize the risk to scroll through unsafe areas. In addition, from attack by a predator, presented strategies exhaust commensurate with the level of risk. Ecotourism is an increase in the risk of predation for lizards. Before the simulated attack of a predator, the lizards respond well in areas with high or low levels of ecotourism. Therefore, in areas with high levels of ecotourism, the lizards need to make frequent strategies antidepredatorias. The behavior antidepredatorios are energetically costly, so an increase in the frequency of these behaviors because of the increased risk in degraded environments or with a high influx of tourists, leads with a loss of body condition. The loss of body condition in some cases appear to affect the ability of lizards to develop an immune response to adequate defense against parasites, which can enhance the negative effects of parasites and affect the biological effectiveness of individuals.

Author: ESTEBAN FRANCO ALEXANDRE.
Year: 2005.
University: AUTÓNOMA DE BARCELONA.
Place of defense: FACULTAD DE VETERINARIA.
Place of preparation: FACULTAD DE VETERINARIA.

Summary: This memory Doctoral Thesis, in the form of a compendium of publications, reflects the physiological and molecular study conducted with species of the genus Aspergillus section Nigiri producing Ochratoxin A (OTA). This mycotoxin is receiving special attention throughout the world because of its highly nephrotoxic. In addition, it is a carcinogen, teratogenic and inmunotóxica and from the year 2002, the EU has begun to establish maximum levels of this mycotoxin in some foods. Recent studies have highlighted the involvement of some species of the genus Aspergillus, section Nigri (A.carbonarius and included in the "aggregate A.niger") in the presence of OTE in foods such as grapes, raisins and wine, among others. However, it was not known until now the environmental conditions that favor the production of the mycotoxin in these species. In physiological models used have been included strains A.carbonarius and added A.niger selected on the basis of their different origins and ability ocratoxígena. It has studied the effect of substrate (CYA facilities and YES), temperature (5-45Â ° C), the water activity (aw) (0.78-0.99) and pH (2-10) in the growth and production of OTE. It has also analyzed the phylogenetic relationship of the strains studied by different techniques of molecular biology (RFLP, RAPD, sequencing, ERIC-PCR, microsatellites and AFLP). The results have identified the optimum conditions for producing strains in the OTA added A.niger (half YES to 20-25Â ° C in the range 0,96-0,99 aw and pH 5-10) and in the a.carbonarius (half CYA to 15-20Â ° C in the range 0,98-0,99 aw and pH 5-7). In relation to the molecular characterization of the strains studied the techniques of RAPD and sequencing confirmed the separation of adding A.niger into two groups that correspond to the patterns of RFLP (NyT) previously established. In the case of A.carbonarius these techniques have enabled molecular differentiation of the strains studied. This strain belongs to a new species within the proposed section Nigri, called "A.ibericus." Techniques ERIC-PCR, microsatellites and AFLP have proved useful for the molecular characterization of the species studied. The most significant results were obtained by AFLP analysis and microsatellites, allowing both the differentiation of the strains of adding A.niger into two groups that correspond to RFLP patterns Ny T. The results demonstrate the ability of the added strains of A. Niger and A.carbonarisu to grow and develop in OTE wide margins of temperature, pH and water activity. This capability helps to explain the role these species ocratoxígenas in the presence of estamicotoxina in foods and especially in those where they are the predominant mycobiota.

Author: SERRANO CÁNOVAS RAQUEL.
Year: 2005.
University: AUTÓNOMA DE BARCELONA.
Place of defense: UNIVERSIDAD AUTÓNOMA DE BARCELONA.
Place of preparation: UNIVERSIDAD AUTÓNOMA DE BARCELONA.

Summary: In this paper we have addressed the study of the response to stress alkaline s.cerevisiae using two main techniques as tools of analysis on a large scale. On the one hand, we have done an analysis of microarrays DAN of the transcriptional response to stress alkaline and, secondly, we used a library of over 4800 mutant to identify genes essential for the survival alkaline pH. All this has enabled us to identify new areas in the response and adaptation to stress that yeast alkaline. First, starting with the identification of ENA1 t PHO89 as alkaline pH regulated genes whose expression is dependent calcineurin have established a relationship between the response to alkaline pH and route signs of calcium / calcineurin. We demonstrate that the alcaliniación extracellular stimulates the transport of calcium from abroad resulting in an increase in cytoplasmic levels of this cation. This is the signal that triggers the activation of the fosfatas calcineurin, whose main action, though not the only one, is to activate the expression of a number of genes involved in resistance to alkaline pH. Moreover, the results indicate that microarrays of alkali stress induces the transcription of several genes involved in obtaining phosphate and in the metabolism of iron and copper. In turn, the analysis of mutants reveals that the integrity of both elements of regulón PHO as the transport of metals is essential for survival in an alkaline medium. All this suggests that alkalization environment creates a situation of scarcity of these ions. We have also shown that alkalization extracellular causes an increase in intracellular ROS (reactive oxygen species), which creates a situation of oxidative stress can trigger a set of genes through mechanisms specific response to oxidative stress. Finally, we have found a way of involving the integrity of the cell wall (CWI) in response to stress alkaline. We have described the absence of several elements involved in the route, such as the sensor Wsc1 or kinases Bck1 and Slt2, resulting in a phenotype of sensitivity to alkaline pH. In addition, we confirm that stress leads to activation of Slt2, MAPK of the road CWI, and the sensor via dela more relevant in that activation is Wsc1. On the other hand, the study of the transcriptional response to alkaline pH of a mutant slt2 suggests that this kinase is responsible for a portion of the transcriptional response and probably the alcalinizaicón extracellular effects on the structure of glucanos of the cell wall. The final conclusion to be drawn from our results is that alkalization environment leads to an adaptive response that is not the result of the activation of a single channel signaling specific alkaline pH, but it is the protocol to activate various channels ecaminadas various alterations to alleviate the stress caused by alkali.

Author: AULÍ CASACUBERTA MARIONA.
Year: 2005.
University: AUTÓNOMA DE BARCELONA.
Place of defense: FACULTAD DE VETERINARIA.
Place of preparation: FACULTAD DE VETERINARIA.

Summary: The model intestinal inflammation induced by the parasite Trichinella spiralis is a model widely used for studying and other intestinal disorders that occur during this infection. Moreover, the use of this parasite to induce inflammation in the colon has been little investigated. OBJECTIVES The goal of this study was to analyze the extent to which colitis induced T.spiralis rat shares similarities with ulcerative colitis and can be useful as a model of this human disease. MATERIALS AND METHODS The methods used in this work are the bath bodies for the study of the mechanical activity, the intracellular micro-electrodes to study the electrical activity and Immunohistochemical techniques and / or inmunofluorescéncia for marking some types of neurotransmitters and cell. RESULTS rats infected presented 2 periods of declining intake and weight. The first occurs between day 1 and 4 post-infection (PI) and the second occurs between days 11 and 15 Pl, from the day 15 rats recover without achieve the values observed in control animals. The infected rats also have leukocytosis and neutrophilia with eosinophilia from day 6 to 21 Pl. The consistency of stools down and the presence of mucus increases from day 2 to 20 Pl. The histological findings of this model include: atrophy epithelial ederma and hyperplasia of the mucosa, submucosa edema, the presence of larvae T.spiralis and infiltrated inflammatory type of acute level of mucosa and submucosa to day 2Pl: Micro -ulceras and larvae in the mucosa and edema sumbucoso severe with increased inflammatory infiltrate after day 6 Pl; by day 14 Pl observed regeneration of mucosal and presence of some larvae; by day 30 Pl not see any kind of inflammatory injury. The inflammatory infiltrate is mainly neutrofílico day 2 to 6 Pl while macrophages are more abundant around day 14 Pl. The number of cells inmunoreactivas to OX-6, which recognizes the antífeno's largest histocompatibility complex type II (MHCII) is dramatically increased in the plexus mientérico and submucoso of rats infected (6-14 Pl). Furthermore, the number of cells inmunorectivas to ED1, which is expressed in monocytes and macrophages rat is very grown in both plexuses enféricos, while the number of cells inmunoreactivas the PS2, which is expressed in a distinct subpopulation of resident macrophages Intestinal only is increased in the plexus submucoso of infected animals. The colonic inflammation induced T.spiralis is also characterized by an increased expression of iNOS in the epithelium and the inflammatory infiltrate in the mucosa and submucosa, and is associated with the decrease in colonic motility that can be seen in the rats infected. The circular strips of the colon in these rats also have a decreased response to acetylcholine and / or potassium chloride on the other hand, depletion of intracellular calcium decreases markedly more contraction induced by acetylcholine in rats infected not in control. This finding suggests that the use of extracellular calcium can be altered during the colonic inflammation by T.spiralis. The membrane potential of the smooth muscle cells of the colon is inflamed more hiperpolarizado than in control animals, this fact could also participate in the hipomotilidad colonic observed. The potential union-type inhibitory (IJPs) with a duration diminished in inflamed colon, suggesting a decrease in nitric oxide is released from montoneuronas inhibitory plexus mientérico. The decrease in the number of neurons inmunoreactivas to nNOS observed in the plexus mientérico rats infected, may explain the observed decrease in the duration of IJPs. During colitis induced T.spiralis we have also found a decrease in the density and intensity of the fibers inmunoreactivas to CGRP (calcitonine gene realted pepetide), which suggests an 8 greater l 553 iberación of this peptide during the inflammatory process. CONCLUSIONS The model of colitis induced by the administration of intra-rectal larvae T.spiralis shares similarities with ulcerative colitis, including among others: episodes of weight loss, decrease in the consistency of stools, hipomotilidad colonic and histological findings similar. The macrophages ED1 positive expressing MHC II could mediate the neural changes and alterations which are observed in this model on the other hand, it appears that the increase in the expression of iNOS is responsible for hipomotilitdad colonic observed during the inflammatory process induced with this parasite.

Author: PÉREZ MACHADO GISSELLE.
Year: 2005.
University: AUTÓNOMA DE BARCELONA.
Place of defense: FACULTAD DE CIENCIAS.
Place of preparation: AUTÓNOMA DE BARCELONA.

Summary: The carcinogenesis is a complex process based multigénico-ambiental; in which genes involved in cell cycle control, metabolism and repair of the DAN, among other functions of the body affected. The polymorphisms of these genes, either individually in combination, can alter the susceptiblidad to carcinogenesis. The thyroid cancer is the most common malignancy of the endocrine system and contributes more than 50% of samples for cancers of this origin. However, it is not clarified the molecular mechanism underlying its autosomal dominant inheritance, or what is the influence of different genetic polymorphisms on the risk. Therefore studied 14 SNPs genes affecting the mechanism of base excision repair (XRCC1 and OGG1), the mechanism for redress for homologous recombination (XRCC2 and XRCC3) gene own thyroid (TG and TSHR) gene and control cell cycle (PTPRJ). For genotipado techniques were used RFLP PCR, real-time PCR probes FRET and allele-specific PCR with primers NDE. It was studying the allelic association and analysis of multiple loci, in addition assessed interactions between polymorphisms of genes under study and modulation of risk through interaction genotipo - ambiente. The best markers susceptiblidad proved to be the SNPs gene TG, their variants analyzed alleles and in combination haplotípica increased susceptibility to risk. The SNP ARg28His of XRCC1 was associated with an increased risk of thyroid cancer, especially with papillary its option, for its part, the SNP of codon 194 of XRCC1 declined susceptiblidad for this carcinoma. The haplotypes 399Gln-280His-194Arg and 399ARg-280His-194Arg increased risk and indicated that the alleles 280His and 194ARg are in linkage disequilibrium. Also at HNS region intrónica IVS5-14 of XRCC3 and the codon 188 of XRCC2 had protective effect. The amino acid change that represents the polymorphism Thr241Met of XRCC3 is irrelevant on the risk of thyroid cancer, but the alleo Met in combination haplotípica with allele A-IVS5-14 increase the risk, possibly because they are in disequilibrium with a functional SNP and the susceptibility of thyroid cancer. The results in relation to PTPRJ, although not significant, suggesting that the substitution at codon 872 of PTPRJ might have a protective effect against the development of thyroid cancer. The combination of some genotypes XRCC1 and XRCC3, increase susceptibility to cancer and reveal the interaction between two enzymes repair mechanisms. The interactions of the genotypes of the GST with repair enzymes had no significant effect on the risk of developing thyroid cancer, while the susceptibility to thyroid cancer is increased by genotype NAT2 (notably by NAT2 * 5 + / + and NAT2 * 6) in the repair mechanisms where individuals are altered by plimorfismos at codons 280 and 399 * XRCC1 and IVS5-14 of XRCC3. The female makes it more susceptible to the carriers of genotypes and risk, on the other hand, the habit of consuming alcohol was related to a protective effect. We detected no significant interactions of the various genotypes with smoking and age.

Author: FERNÁNDEZ CADENAS ISRAEL.
Year: 2005.
University: AUTÓNOMA DE BARCELONA.
Place of defense: HOSPITAL VALL D'HEBRON.
Place of preparation: HOSPITAL VALL D'HEBRON.

Summary: The ischemic stroke is the most common type of stroke. The only treatment approved for use in this disease is the fibrinolytic therapy using the drug t-PA. The t-PA plasminogen endogenous and actively to this as the active plasmin active fibrinolytic cascade that degrades the thrombus causing arterial occlusion. Despite the enrome benefit of this treatment, between 30 and 40% of patients is not rechanneling blood and a 5 to about 10% of symptomatic patients suffer hemorrhagic transformation with high mortality rates. We intend to assess whether the presence of certain genetic polymorphisms in genes associated with inflammation and inhibition of fibrinolysis could predict rates rechanneling blood and the emergence of these transformations bleeding. We determined that the genetic background of each individual is associated with the indices of arterial and rechanneling predisposes him to suffer the onset of hemorrhagic transformation after the administration of t-PA.

Author: MIÑANO MOLINA ALFREDO JESÚS.
Year: 2005.
University: AUTÓNOMA DE BARCELONA.
Place of defense: FACULTAD DE MEDICINA.
Place of preparation: FACULTAD DE MEDICINA.

Summary: Over the past few years, due mainly to an increase in life expectancy of the population in developed societies and the impact of the rhythm of life in this population has increased the incidence and development of diseases neurodegnerativas. This situation has forced major efforts to expand the know about one of the great riddles of S. Century; the brain. Along with the development of neurodegenerative diseases neurons die. One of the most common consequences of the development of diseases neurodgenerativas is the trigger in most of them the program of cell death known as apoptosis. Comprehensive knowledge of this program apoptótico is key to addressing therapeutic strategies that can limit the spread of these diseases. Apoptosis is an important physiological process in the developed CNS maintaining homeóstasis cell. The cerebellum is one of the regions of the brain in which this phenomenon is particularly dramatic. During the development of granule neurons in the cerebellum (CGCs) almost half are lost during the process apoptótico. This phenomenon can minetizarse in vitro from a pure culture of these neurons. The primary culture of CGCs is a model widely used for the study of apoptosis, incudiendola by deprivation of potassium. This process can produce an increase in the concentrations of intracellular ceramide, involved in this process of death. The ceramide is a signaling molecule involved in various cellular processes including proliferation, senescence, differentiation and cell cycle meadow. During recent years it has been proposed that the ceramide could have a bigger role as a regulator of the apoptotic death. One of our goals was using this model, characterize the process of apoptotic death by ceramide. Over the past few years have accumulated evidence suggesting that exposure to estrogen reduces the risk and retasa the beginning and development of neurodegenerative diseases such as Alzheimer's and Parkinson's, as well as enhance recover from traumatic neurological damage such as cerebral ischemia. These hormones can play these roles involving different processes such as cell survival, regenerative responses, axonal growth, enhancing the signal and synaptic neurogenesis. They have been involved in many of these processes, from neuroprotection compared with apoptotic processes through plasticity and growth neurítico, to exercise a beneficial antioxidant effect to the body. So, we were interested in studying the potential impact that the 17-beta-estradil (E2) could have a model for our work, the cultivation of CGCs. The results of our research indicate that: 1 - The ceramide induced apoptosis in CGCs activating both caspase-9 and caspase-2, two ways to kill priori parallel and that this death apotótica. 2 - The inhibition of Akt and the activation of MAPKs are involved. 3, - E2 fails as a neuroprotective versus apoptosis fails as a neuroprotective off the apoptósis in CGCs and the absence of activation of Akt could be key in this lack of neuroprotection. 4 - The lack of neuroprotection could be because estrogen ER-alfa not receptor interacts with the IGF-I receptor. 5-ER-alfa is located in the plasma membrane of the CGCs and medium activation of ERK1 / 2 by E2. Activation of the classical pathway of MAPKs by E2 involves a different mechanism of action for E2 on the model of the CGCs. 6, - E2 exerts a neuroprotective effect in the CGCs because of its antioxidant properties as a molecule. 7 - The activation of the path Src / Ras / ERK / CREB be related phenomena of synaptic plasticity and maintaining connections between neurons of the CGCs but it will not be enough to protect the CGCs of apoptotic death. Although the E2 not just protecting the CGCs of apoptotic death, podrí 8 to take 5c6 great importance to the fact of knowing how the E2 can put in place mechanisms that would trigger phenomena keeping dendritic and decrease the potential vulnerability of the neurons compared to noxious stimuli, we would be able to influence a future model of neurodegenerative diseases such as Alzheimer's or ischemic processes, where you keeping dendritic existing connections and the generation of new synapses, in addition to maintaining its structure can be utility to cope with the fearsome consequences of the passage of time each day in a more aging society, with life expectancies greater, but with many more neurodegenerative diseases and more problems to face the future with assurance and quality of life more humane.