EXPERIMENTAL SURGERY

Author: MOLTÓ AGUADO MARIO VICENTE.
Year: 2003.
University: MIGUEL HERNÁNDEZ DE ELCHE [More theses of this university] [www.umh.es].
Place of defense: MEDICINA.
Place of preparation: FACULTAD DE MEDICINA.

Summary: In the pancreas of mammals, birds, reptiles and amphibians, there is a multitude of morphological evidence showing an interconnection between tracks exocrina and endocrine. From this evidence, emphasizes the "system portal insulo-acinar", which is the anatomic substrate of the so-called "axis insulo-acinar", which was important for the physiology of the pancreatic secretion, through which the secretion of the blocks could acting on pancreatic acini of the gland. In this context it is proposed to carry out a study on the effects of insulin and glucagon exerted on pancreatic secretion exocrina, baseline, in a model of isolated pancreas and prefundido with a control system perfusion pressure. It has employed a dose range of stimulation submáximas and highest (physiological) and suparmáximas (drug) insulin and glucagon. It has a control group and 6 subgroups of stimulation. It incorporates the pancreatic juice every 20 minutes to determine the volume and the activities and productions amylase and lipase. From the results obtained, the largest response to insulin was obtained with maximum doses (physiological). With these dose insulin increases the partial volumes and total pancreatic juice, as well as productions partial enzyme amylase and lipase. Also dose submáxima occurs umento of amylase production. Therefore, the influence on insulin secretion of pancreatic exocrina physiological dose. With regard to gucagón, this hormone has no effect on basal conditions on the volume of pancreatic juice. Moreover, there are disparate effects on the secretion enzyme amylase and lipase, as dose submáxima output increases amylase and maximum dose decreases the activity of lipase. It shows that as a physiological dose, insulin and glucagon secretion exocrina alter pancreatic could say that in basal conditions exist in the pancreas of rats and isolated perfused action of the hormone insulin and glucagon on vertiene exocrina pancreatic in limits range physiological stimulation.

Author: CRISÓSTOMO AYALA VERÓNICA.
Year: 2003.
University: EXTREMADURA [More theses of this university] [www.unex.es].
Place of defense: FACULTAD DE VETERINARIA.
Place of preparation: FACULTAD DE VETERINARIA.

Summary: The aneurysm of aortic abduminal (ASA) is a trastomo vascular whose incidence and prevalence is increasing in developed countries as lengthening life expectancies. The new therapies minimally invasive pem1iten treatment of this condition in many cases where, otherwise foma, it would not be possible to intervene because of the high morbidity and mortality associated with surgery AAA. However, it is imperative to have expertise in these new technologies, given the inherent complexity of this disease. There are currently has an animal model that pem1ita learning these techniques in vivo. Moreover, it is also necessary to have a successful model for testing new therapies and evaluation precJínica of endoprostheses. The main objective of this research project is to compare the two models AAA made using different autologous tissue, to assess which of them is more representative of the phenomena taking place in the human disease, as it relates primarily to dilation and trend the breakdown of Aneurysmal sack. We used it for ten pigs, divided into two grupOS five animals each. Both groups took out a AAA medÍante suturing of a patch of autologous tissue at the front of the abdominal aorta. In group A, the patch was composed of parietal peritoneum, and in Group B serous stomach. To follow up on these mock-ups know angiographic studies conducted in two projections (dorsoventral and lateral) immediately before and after the creation of the model, as well as the 7; 14,30,45,60 and 90 days. From the day 7 of postopatorio was also carried out in each track ultrasonographic examination of AAA. After three months of follow up, the animals were sacrificed for histological study of the samples. Both models exhibit similar behavior postoperative increasing diameter of the first third of postoperative to stabilize later. We believe that its utility in development, learning and assessment predinicade new techniques lies in the evaluation of the same in acute phase. The results show that the model established by the AAA patch peritoneum was technically easier, sencilIo and reproducible model made with the serous gastric letting a higher postoperative recovery which, combined with increased postoperative dilation, makes it potentially the most useful of the two experimental aneurysms object of this work.

Author: GIMENO BENITEZ RUFINO.
Year: 2003.
University: EXTREMADURA [More theses of this university] [www.unex.es].
Place of defense: FACULTAD DE MEDICINA.

Summary: The unilateral testicular torsion may cause alterations in the contralateral testis. It performs an experimental model of unilateral testicular torsion and considers evocativamente its impact on the contralateral testis. In studies feivndiad, fertility, PA, immunological and esperniograficos, is checked injuries in the short term are improving gradually until reaching normalcy to more time of evolution.

Author: GARCÍA TORRALBO EVA M..
Year: 2004.
University: AUTÓNOMA DE BARCELONA [More theses of this university] [www.uab.es].
Place of defense: FACULTAD DE MEDICINA.
Place of preparation: FAC. MEDICINA, UAB HOSPITAL DEL MAR BARCELONA.

Summary: Because of the progress made in recent years in the care of sick critics, has suggested a new type of patient, the patient with chronic or critical Syndrome dysfunction Multiorgánica (MODS). About 30% of patients politraumáticos develop a MODS, the main cause of death on them after the first 24 hours after the attack. The sequential organ dysfunction occurred after a period of days or weeks of the original insult. Usually begins with a failure, respiratory failure followed by bowel, liver, kidney, heart and blood. The exact order of appearance varies depending on pre-existing illness and the nature of the causal insult. The mortality correlates with the number of bodies concerned and with the age and duration of organ dysfunction. For three decades, research has focused on finding a specific agent as a cause of MODS. Initially, it was believed that it was an infection that the uncontrolled and out multiorgánica dysfunction. Subsequently it became clear that the infection was encouraging starter only half of the patients with MODS, in another 50% this syndrome occurs without identifying a source of infection. Thus, the studies focused on the response of the host face of aggression. A localized inflammatory reaction is a physiological response that is protective controlled by the body at the scene of the attack. The loss of local control or an excessive activation of this response leads to excessive systemic response clinically identified as SIRS. Faced with this situation compensating mechanisms are activated and the end result (resolution, or death MODS), depends on the balance between SIRS and their compensating mechanisms (CARS). It develops a MODS when inflammatory responses or anti-inflamatoria host to the aggression (or both) are excessive. The discovery of multiple inflammatory mediators its way to new theories about the pathogenesis of MODS included in the answer "hyperactive" to aggression: theory of ischemia, theory and theory of the mediators in the gut. The theory of the intestine as "engine" of MODS is that the endotoxins and bacteria translocadas reach macrophages shaft hepato-esplénico that to be activated started the synthesis and uncontrolled release of cytokines into the systemic circulation leading to a SIRS and thereafter the multi dysfunction. The inflammatory mediators are considered responsible for a widespread, persistent and exaggerated inflammatory response of the host. Therapies anti-mediadores emerged in an attempt to attenuate the inflammatory response to aggression; despite numerous clinical studies in this field, the results have been disappointing. Because we know that act on the inflammatory cascade once begun is doomed to fail, we make an assumption based on preventing the activation of this in the same home. A literature review made us know that there is the possibility of selectively eliminate macrophages shaft hepato-esplénico through the administration of clodronate in liposomes. Despite the depletion macrophagic increases bacterial translocation (bacteria are not fagocitadas and move into the systemic circulation), prevents the activation of macrophages and the release of the inflammatory cascade of meters. Applying this assumption to a model of experimental polytraumatism have shown an increased incidence of bacterial translocation following the depletion macrophagic trauma in a low intensity. In assessing the impact of the elimination macrophagic on systemic toxicity, we have witnessed a toxic effect of clodronate (increasing signs of systemic toxicity) has not been described previously. At 8 despite 37b this we have demonstrated a modulation of the inflammatory response based on more mobile and less weight loss of the animals subjected to macrophagic depletion. However, despite being described, we have not observed differences in mortality or not to administer clodronate. All these findings lead us to conclude that the depletion macrophagic a model of polytraumatism does not improve mortality, but it modulates, in part, the inflammatory response.

Author: RUIZ RABELO JUAN FRANCISCO.
Year: 2005.
University: CÓRDOBA [More theses of this university] [www.uco.es].
Place of defense: FACULTAD DE MEDICINA.
Place of preparation: FACULTAD DE MEDICINCA.

Summary: Oxidative stress involves a factor in triggering the natural history of cancer. The case of the pancreas is no different given the impact on the molecular biology of this disease has the disbalance of OFR, particularly on groups of oncogenes and tumor suppressor genes. On the other parties melatonin is the most potent endogenous antioxidant known, it could raise if the application thereof can modify the natural history of pancreatic cancer trial. The inhibridores of cox-2 have shown its effectiveness in gastrointestinal tumors (esophagus, stomach and colon) on a pilot basis and in turn are used in clinical practice. OBJECTIVES. Analyzing the role of oxidative stress and the action of antioxidant therapy in pancreatic cancer trial. MATERIALS AND METHODS. 80 animals (Hámster Syrian) were divided into 8 groups of animals being treated in different periods both melatonin com with celecoxib. The tumor induction was performed using the carcinogen BOP (N-nitrosobis2oxopropilamina) during the first 12 weeks. They were sacrificed at week 24. RESULTS AND CONCLUSION: Animals treated with melatonin had a lower incidence of pancreatic tumors than those treated with celecoxib. Those animals treated with either celecoxib with melatonin had a better defense against oxidative stress compared to control groups sick. Animals treated with melatonin in perído induction as a treatment presented the best answer on the parameters of oxidative stress as well as the lower incidence of pancreatic tumors.

Author: VILAR ALEJO JAIME DAVID.
Year: 2005.
University: LAS PALMAS DE GRAN CANARIA [More theses of this university] [www.ulpgc.es].
Place of defense: CENTRO SUPERIOR DE CIENCIAS DE LA SALUD.
Place of preparation: CENTRO SUPERIOR DE CIENCIAS DE LA SALUD.

Summary: The replacement of a body that has failed to irreversibly in its role has been one of the priority objectives of Medicine. This dream has become a reality and has become a special development in the second half of last century, and it seems likely that we are at the beginning of a new era of science. At present, the transplant is a valid therapeutic alternative processes not reversible bodies such as kidney, liver, cornea, bone marrow, corazónâ | .. The lung transplant is the treatment of choice for certain lung diseases that do not have effective medical and therapeutic condicionarían within a short time of the death of the patient. Advances in surgical technique, d preservation of the body and postoperative management, have resulted in a survival acceptable and good lung function, while chronic rejection, and its most common form: bronchiolitis obiterante determines a negative evolution a significant percentage of patients transplanted lung, not available at present an effective immunosuppressive regimen in its prevention and treatment. The fundamental objective in the management of rejection in organ transplantation, is to determine the importance of the mechanisms involved in it to run a specific treatment. The response observed over the rejection is influenced by the characteristics of the transplanted organ by the host's immune status and by the time the graft has been present. The purpose of this work is to study the morphological changes secondary to the rejection in transplanted airway, according to an experimental protocol validated heterotopic transplant airway revascularizada with epiplon mayor, to create a model in which to evaluate the effects the immunosuppressive drugs. This continuity of a research project initiated by our group just a little more than a decade.

Author: Garcia Barreiro Juan Javier.
Year: 2005.
University: A CORUÑA [More theses of this university] [www.udc.es].
Place of defense: Facultade de Ciencias de la Salud.
Place of preparation: Facultad de Ciencias de la Salud.

Summary: Introduction: This raises the need for an alternative to autologous vein graft (VAT) in Microsurgery, extending this kind of intervention and increases the number of complications. Given the clinical experience with cryopreserved arterial grafts higher caliber, these are raised as an alternative in Microsurgery. Objectives: Get a protocol for cryopreservation arteries small arms and the application of these as allografts on the femoral artery in Wistar rats, comparing their results with the conventional technique of VAT. We evaluate the histological and functional changes result of the cripreservación and graft. Materials and methods: We designed a pilot study on the femoral artery of Wistar rats into two phases: phase control cryopreservation, which designed the protocol cryopreservation, and experimental phase in which they compare the results of VAT Graft versus autologous blood on the one hand and arterial graft criopreservado secondly, in terms of permeability, while surgical complications, and clinical monitoring changes hispatológicos after explantación to four weeks. Results: The protocol allows cryopreservation designed obtain arterial segments viable, but with significant structural damage in the loss of endothelium and thinning of the muscular layer. The group of arterial graft criopreservado get higher results than the VAT in terms of: surgical time, but not in terms of permeability to four weeks or presence of complications. The structural changes produced on the arterial graft criopreservado after explantación to four weeks are important and include: reendotelización, intimal hyperplasia, thinning of the muscular layer and infiltrating lymphocyte periadventicial. Conclusions: The proposed protocol cryopreservation allows obtaining arterial grafts viable, but with major changes on its structure. The arterial graft criopreservado does not improve the outcome of VAT in terms of permeability and surgical complications but in terms of surgical time. The process of cryopreservation and immune rejection produce significant structural damage on the arterial wall to four weeks.

Author: GARCÍA REIJA MARÍA FE.
Year: 2005.
University: VALLADOLID [More theses of this university] [www.uva.es].
Place of defense: FACULTAD DE MEDICINA.
Place of preparation: FACULTAD DE MEDICINA.

Summary: In this experimental work, we have studied the interaction of a material osteoinductivo (lyophilized collagen) techniques with guided bone regeneration (GBR) Membrane reabsorbobles. For this we have the following scenario: "Techniques of WBG through membranes osteorregenerativas collagen, to improve the ability oteoinductiva collagen liofilizao when used in conjunction with the repair of bone defects jaw size critic (not autorreparativos) of the rat." To carry out this study, we used 56 adult rats Wistar race. Bone Defects of 4-5 mm diameter in the right angle of the mandible of these animals were treated with collagen lyophilized (group osteoinducción), covered with collagen membrane (group ROG), filled with freeze-dried and coated with collagen membrane (combined group ) or untreated (control group). Each group consisted of 14 animals. In addition, an assessment evolving over time, so that half the animals in each group were sacrificed to 21 days and the other for 42. We analyzed macroscopic, radiological and histological data obtained. For further analysis Statistical rating scales were used as numerical models set out. The results showed that: 1 - The lyophilized collagen was able to induce the formation of bone defects in critical mandibularesm whose histological characteristics and structural differed from the original bone tissue. However, aunqque in no case was found outside the displacement of collagen implant site, were found varying degrees of pockets of bone formation outside the original defect. 2 - The application of lyophilized collagen is able to accelerate bone regeneration early. 3-membranes resorbable collagen acted as a barrier preventing the invasion and proliferation of connective tissue and muscle inside defects and improving the amount of bone regeneration with respect to the controls. However, due to the trend to the collapse of the membranes in the central portion, there was no case in the complete repair of the defect, which led to the failure of the technique at this level. 4 - The combined use of lyophilized collagen membrane resorbable collagen permits the regeneration of not autorreparativos jaw defects in rats, with a fairly predictable structure and maintaining the original contour jawbone. The membranes not only acted as a barrier entee the bone defect and surrounding soft tissue, but also as a containment system and molding of lyophilized collagen, avoiding migration out of this defect and contributing to a more uniform bone repair. The lyophilized collagen, in turn, had the necessary space that averted the collapse of the membranes in your poprción Central.

Author: MIÑO FARIÑA NATALIA.
Year: 2005.
University: SANTIAGO DE COMPOSTELA [More theses of this university] [www.usc.es].
Place of defense: FACULTAD DE VETERINARIA.
Place of preparation: FACULTAD DE VETERINARIA - CAMPUS LUGO.

Summary: The aim of this study was to compare the in vivo behavior of two formulations of calcium phosphate cement, a dense and porous another, and a glass bioactivo with a defect cavitario vacuum to demonstrate its potential application as a bone substitute in the many fields includes trauma and reconstructive surgery. To that end, a pilot study was conducted in 36 rabbits breed in New Zealand who are practiced defects cavitarios of 6 mm in the femoral condyle of each, implementing a different material in each: 18 rabbits were in one of a cement cóndilos tricalcium phosphate to dense and the other a cement to tricalcium phosphate porous. For the other 18 were implanted in one of the few cylinders cóndilos a glass phosphate system P2O5-CaO-Na2O-TiO2 and the other was left defect cavitario empty. The radiological survey revealed a gradual resorption and bone remodeling in the case of bone cements and no further developments in the glass; also found the biocompatibility of materials. The same results were apparent in the qualitative study by scanning microscopy, which also noted macroporosity achieved by blowing agent used in the development of porous concrete. The quantitative study by scanning microscopy determined the ratio Ca / P, very similar to the bone in the case of bone cements and well below the glass bioactivo, which together with the presence of titanium in the latter explains the slow biorreabsorción generated in the glass, the presence of magnesium from the curta week provided information on the process of bone mineralization appears in the cement. The study showed a correct histological osseointegration of the three biomaterials phenomena exist without inflammatory reaction or foreign body and histomorphometric study revealed that the bone neoformación achieved at four and twelve weeks was higher, with statistically significant differences in the two bone cement with regarding the glass and the default cavitario empty. These results show that the three biomaterials are osteoconductivos, biocompatible and biodegradable, and they behave as a replacement bone defects in cavitarios created in rabbits as animal experimentation.

Author: RIBAS BLASCO YOLANDA.
Year: 2005.
University: BARCELONA [More theses of this university] [www.ub.es].
Place of defense: FACULTAD DE MEDICINA.
Place of preparation: FACULTAD DE MEDICINA.

Summary: INTRODUCTION The rejection xenogénico is a humoral rejection, mediated by antibodies (C) directed against antigens of endothelial cells from the donor, which triggered the snap and coagulation. In the model of cardiac xenotransplantation to Hamster rats, the association of cyclosporine or tacrolimus, a drug antiproliferative a short time to get permits indefinite survival of xenoinjerto. OBJECTIVES 1-Ac Describe levels and histological pattern of rejection in xenotransplantation without immunosuppression. 2-Demonstrate that can be achieved by associating a drug Survival indefinite antiproliferative a short time to tacrolimus at low doses (0.2 mg / kg / d). 3-To study the effectiveness of combining two patterns immunosuppressive drug antiproliferative to tacrolimus. 4-Establish the consequences of the withdrawal of immunosuppression and studying the rejection late xenoinjerto (LXR, late xenograft rejection). 5-To assess the effect of a pretreatment to the receiver. 6-c study whether epa rat used influences the evolution of transplantation. MATERIALS AND METHODS were performed heart transplants heterotópicos hamster to rats. Immunosuppression was withdrawn the day 30 post and the rats were sacrificed at the time of rejection. In two groups, immunosuppression was maintained until day 50 post. It identified 89 study groups who received different patterns of mycophenolate mofetil (MM) or cyclophosphamide (CP) associated with tacrolimus at low doses. Protocol I: Study of the evolution of C levels and histological pattern of rejection without immunosuppression. Protocol II: Demonstrate that can be achieved by associating a drug Survival indefinite antiproliferative to tacrolimus at low doses, to analyze the effectiveness of two patterns of immunosuppression, to study the consequences of the withdrawal of immunosuppression, LXR, and evaluate the groups treated with tracrolimus to low dose indefinitely. Protocol III: To evaluate whether the administration of a pretreatment to the receiver translates into lower Ac after transplantation and if that correlates with an increase in graft survival. Protocol IV: Studying whether the rat strain used influence on the evolution of xenotransplantation in their level of antibodies and graft survival. CONCLUSIONS 1 - The rat has low levels of Ac preformed against hamster, which increased to rejection in 3-4 days. Liabilities IgM and complement in the endothelium demonstrate that it is mediated by Ac. 2 - The low dose tacrolimus associated with GM or COP a short time, it produces prolonged survival of xenoinjerto. The withdrawal of immunosuppression translates into an increase of Ac and rejection. 3, - The combination of CP and tacrolimus have the greatest effect and that the immunosuppressant tacrolimus, but this does not translate into a survival of the graft. Injuries histólogas are subjectively less severe grafts receiving COP. 4 - Despite the presence of serum C, grafts maintained with tacrolimus show no notable injuries in histological study. 5 - The pretreatment results in a decrease in C, but after transplantation developments is the same as the other groups, so that this difference does not translate into increased graft survival. The grafts receiving pretreatment are less fibrosis, probably due to the delay in early myocardial injury. 6 - The strain of rat used affects you hamster model to rat xenotransplantation. 7 - In the model of cardiac xenotransplantation to Hamster rats, the acute rejection of xenoinjerto, rejection delayed xenoinjerto and chronic rejection have a common mechanism humoral although their histopathologic patterns are different. The pattern 8 No histop 1d2 atológico depends on the length of immunosuppressive treatment.

Author: GALVAN PEREZ ANTONIO.
Year: 2005.
University: LA LAGUNA [More theses of this university] [www.ull.es].
Place of defense: FACULTAD DE MEDICINA.
Place of preparation: FACULTAD DE MEDICINA.

Summary: There are two working hypotheses: Check whether the elongation is capable of producing artery intimal thickening (proliferation and migration of vascular smooth muscle cells) and then if these smooth muscle cells stimulated and are capable of producing nerve collateralization in peripheral nerve healthy made contact with artery elongated. This series using rats, conducted elongation of the femoral artery in the rat using a simple and readily reproducible in the first group of animals, and then doing the same elongation and subsequent adventicectomía of the artery and adosamiento traumatic for a branch of nerve Cruris not injured. Check both working hypotheses, recreating a new method to produce physical intimal thickening and later that the smooth muscle cells stimulated are capable of producing colateraliación nervous.

Author: TORRES GARCÍA-DENCHE JESÚS.
Year: 2005.
University: REY JUAN CARLOS [More theses of this university] [www.urjc.es].
Place of defense: FACULTAD DE CIENCIAS DE LA SALUD.
Place of preparation: FACULTAD DE ODONTOLOGÍA.

Summary: The purpose of this study was to evaluate the influence of platelet rich plasma (PRP) in bone regeneration when combined with a hidroxiapatila bovine calota of osteoporotic rabbits by densitometry and histomorfometría. It stabilized in the calota of animals around cylinders tidanio of 4mm in height and 10 mm in diameter to stabilize various biomaterials graft: PRP + Bio-Oss, PRP and control. After 4 weeks are performed bone mineral density (BMD), the percentage of bone neformado as well as unwinding of biomaterial. Statistical analysis was performed by analysis of variance (ANOVA). The results of the study found a similar BMD in the group PRP + Bio-Oss as in the Bio-Oss although significant differences with respect to the control groups and PRP. The percentage of bone neoformado presented significant differences in favor of PRP + Bio-Oss with regard to all groups, concluding that the application of PRP to a hydroxyapatite greatest bovine bone regeneration that the use of hydroxyapatite coil isolation.

Author: PÉREZ-AGOTE ITURRIOZ JOSÉ.
Year: 2006.
University: PAÍS VASCO [More theses of this university] [www.ehu.es].
Place of defense: FACULTAD DE MEDICINA Y ODONTOLOGÍA.
Place of preparation: FACULTAD DE MEDICINA Y ODONTOLOGÍA.

Summary: The tissue reperfusion injury is attributed mainly to attack leukocyte on endothelial cells. The drugs have antioxidant shown to improve survival and reduce the damage, but it was not clear its effect on capillary circulation. This Doctoral thesis addresses the problem quantifying through láser-doppler the capillary flow in three different sections of the intestine reperfundido after two different periods of ischemia and treated with folic acid, superoxide dismutase, alfa-tocoferol or ocreótido. The experiments are carried out in rats WAG. A mere two cc administration of normal saline improves reperfusion capillary level, data is taken as controls for the drugs tested. Folic acid worsens the effect of normal saline where ischemia is less intense, namely jejunal level, but it is clearly effective when conditions are intense ischemia (ileum), over thirty minutes ischemia of 60 minutes and only effective in the initial ischemia reperfusion of 120 minutes. SOD has little effect on the microcirculation uniforms after ischemia of 60 minutes, but there was a definite improvement in all the results obtained with 120 minutes of ischemia. The AFT shows a paradoxical effect. After ischemia of 60 minutes on the ATF has overall effects on the microcirculation counterproductive. However, after ischemia of 2 hours, it provides clear benefits in the jejunum and ileum terminal, which is not in keeping with the discreet improvement, not statistically significant, mortality found at the time, although í s with the ability to decrease the harmfulness in the ileum. The octeotrído has beneficial effects stable, except in the ischemia of 60 minutes over jejunum and ischemia two hours on the ileum.