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Search Results: 1 - 10 of 11398 matches for " Rafael Lasierra "
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3D Reconstruction with Spiral Computed Tomography in Choroidal Osteoma  [PDF]
Francisco Javier Ascaso, Laura Herrera, Laura Villén, Rafael Lasierra, Juan Iba?ez, Diana Pérez, José Angel Cristóbal
Open Journal of Ophthalmology (OJOph) , 2013, DOI: 10.4236/ojoph.2013.31002
Abstract:

Choroidal osteoma (CO) is a rare, ossifying benign tumor originated in the choroid that typically occurs in otherwise healthy young women (1,2). It is characterized by a yellowish, well demarcated lesion in the juxtapapillary or macular area. The diagnosis is clinical and can be confirmed with the use of fluorescein or indocyanine angiography, optical coherence tomography, computed tomography or magnetic resonance imaging. Choroidal neovascularization or subretinal fluid, the main causes for vision loss, can be treated with laser therapy, photodynamic therapy or intravitreal antivascular endothelial growth factor therapy. We present a case of choroidal osteoma, showing the role of the high resolution 3D spiral computed tomography.

Aging: Thromboembolic Disease, Metabolic Syndrome, Type 2 Diabetes Mellitus, and Alzheimer’s Disease  [PDF]
Joaquín Lasierra-Cirujeda, María José Aza Pascual-Salcedo, Alicia Lasierra-Iba?ez, Carmen Lasala Aza, María Mercedes Aza Pascual-Salcedo
Journal of Biosciences and Medicines (JBM) , 2016, DOI: 10.4236/jbm.2016.45001
Abstract: Aging can be interpreted as an unavoidable process whose end point is the death. Aging entails, in the hemostasis field, some changes that favour blood hypercoagulability. Both the plasminogen activator inhibitor (PAI-1), specific inhibitor of the tissue plasminogen activator (t-PA), accompanied by the oxidative stress and the marked decrease of the main antioxidant—glutathione are fundamental in the bases of elderly pathologies which can cause death. There is some scientific evidence of the relationship between aging, neuro-degenerative diseases, an excessive production of reactive oxygen species and the decrease of proteolysis in brain. The cerebral plasminogen/plasmin system represents the essential proteolytic mechanism that degrades amyloid peptides (β-amyloidosis) for action of plasmin with effectiveness. This physiologic process is being considered as a preventive neurodegenerative mechanism. At the same time, the decrease of glutathione levels in aging entails a decrease of cerebral plasmin activity and a progressive descent of t-PA activity due to a descent in t-PA expression and an increase in PAI production. All of them entail an increment of amyloid beta peptides (Aβ) production and a lower level of their clearance. Both mechanisms, oxidative stress, direct consequence of the oxygenate metabolism of aerobics cells, and changes in the systemic fibrinolysis and cerebral b-amyloidolytic activity, play a very important role in thromboembolic disease, metabolic syndrome—obesity, insulin resistance, hyperglycemia—, type 2 Diabetes Mellitus and Alzheimer’s disease, clinical processes that accompany the aging. In this revision we show the importance of the interaction between glutathione, proteolytic t-PA/plasminogen/plasmin system, and the inhibitor PAI-1 in aging physiopathology, whose results suggest the hypothesis of the importance of a therapeutic strategy using the inhibition of PAI-1 as a goal, because it is increased in the different aging pathologic processes.
Sulodexide and Alzheimer’s Disease: A Preliminary Prospective Study  [PDF]
Joaquín Lasierra-Cirujeda, María José Aza Pascual-Salcedo, María Mercedes Aza Pascual-Salcedo
World Journal of Cardiovascular Diseases (WJCD) , 2016, DOI: 10.4236/wjcd.2016.62007
Abstract: The purpose of this prospective study is to determine the relative incidence of Alzheimer’s disease in patients treated for at least three years, with sulodexide (n = 46, 76.48 ± 7.02 years old) or acenocoumarol (n = 47, 78.21 ± 6.66 years old) in order to prevent primary and secondary venous thromboembolism and atherothrombotic disease. In the sulodexide group, there was an apparent prevention of cognitive and behavioural impairment (relative incidence: 2.02) compared with acenocoumarol group (relative incidence: 4.86). The favourable results in sulodexide group may be related to their pharmacodynamic actions of inhibition of PAI-1, which may interfere with the pathogenesis of Alzheimer’s disease, and to the role of glutathione and PAI-1 in the β-amyloid system in the brain.
Use of sulodexide in patients with peripheral vascular disease
J Lasierra-Cirujeda, P Coronel, MJ Aza, et al
Journal of Blood Medicine , 2010, DOI: http://dx.doi.org/10.2147/JBM.S10558
Abstract: e of sulodexide in patients with peripheral vascular disease Review (9194) Total Article Views Authors: J Lasierra-Cirujeda, P Coronel, MJ Aza, et al Published Date June 2010 Volume 2010:1 Pages 105 - 114 DOI: http://dx.doi.org/10.2147/JBM.S10558 J Lasierra-Cirujeda1, P Coronel2, MJ Aza3, M Gimeno2 1CM Hematológico SC, Logro o, La Rioja; 2Tedec-Meiji Farma, SA, Alcalá de Henares, Madrid; 3Pharmaceutical Act, Ministry of Health, La Rioja Regional Government, Spain Abstract: Sulodexide is a highly purified glycosaminoglycan containing a combination of heparan sulfate with affinity for antithrombin III and dermatan sulfate with affinity for heparin cofactor II. This antithrombotic and antithrombin activity is of great pharmacologic interest and makes sulodexide a suitable drug for the prophylaxis and treatment of arterial and venous peripheral diseases. In arterial pathology, changes in the Winsor Index, improvement in peripheral blood flow, and reduction in pain-free walking distance confirm that treatment with oral sulodexide is effective. Lipid components linked to the genesis of peripheral vascular processes, including triglycerides, total cholesterol, and low-density lipoprotein fractions, as well as plasma and blood viscosity, are reduced by the administration of sulodexide, whereas the high-density lipoprotein fraction increases. Sulodexide inhibits aggregation and adhesion of platelets at the level of the vascular wall, reduces plasma fibrinogen concentrations, reduces plasminogen activator inhibitor-1, and increases tissue plasminogen activator, as well as systemic fibrinolytic and thrombolytic activity, thereby demonstrating efficacy in the treatment of thromboembolic disease. There is no interaction between sulodexide and other drugs used as long-term treatment for peripheral vascular disease. It is well tolerated, and the adverse reactions described after oral administration are related mainly to transient gastrointestinal intolerance, ie, nausea, dyspepsia, and minor bowel symptoms. Sulodexide may become the treatment of choice when dealing with vascular diseases and their complications, as well as for the prevention of venous thromboembolic disease, being particularly indicated in elderly patients, due to its good tolerability and ease of management.
Beta-amyloidolysis and glutathione in Alzheimer's disease
Lasierra-Cirujeda J,Coronel P,Aza MJ,Gimeno M
Journal of Blood Medicine , 2013,
Abstract: J Lasierra-Cirujeda,1 P Coronel,2 MJ Aza,3 M Gimeno2 1CM Hematológico SC, Logro o, La Rioja, Spain; 2Tedec-Meiji Farma, SA, Alcalá de Henares, Madrid, Spain; 3Pharmaceutical Act, Ministry of Health, Regional Government, La Rioja, Spain Abstract: In this review, we hypothesized the importance of the interaction between the brain glutathione (GSH) system, the proteolytic tissue plasminogen activator (t-PA)/plasminogen/plasmin system, regulated by plasminogen activator inhibitor (PAI-1), and neuroserpin in the pathogenesis of Alzheimer's disease. The histopathological characteristic hallmark that gives personality to the diagnosis of Alzheimer's disease is the accumulation of neurofibroid tangles located intracellularly in the brain, such as the protein tau and extracellular senile plaques made primarily of amyloidal substance. These formations of complex etiology are intimately related to GSH, brain protective antioxidants, and the proteolytic system, in which t-PA plays a key role. There is scientific evidence that suggests a relationship between aging, a number of neurodegenerative disorders, and the excessive production of reactive oxygen species and accompanying decreased brain proteolysis. The plasminogen system in the brain is an essential proteolytic mechanism that effectively degrades amyloid peptides ("beta-amyloidolysis") through action of the plasmin, and this physiologic process may be considered to be a means of prevention of neurodegenerative disorders. In parallel to the decrease in GSH levels seen in aging, there is also a decrease in plasmin brain activity and a progressive decrease of t-PA activity, caused by a decrease in the expression of the t-PA together with an increase of the PAI-1 levels, which rise to an increment in the production of amyloid peptides and a lesser clearance of them. Better knowledge of the GSH mechanism and cerebral proteolysis will allow us to hypothesize about therapeutic practices. Keywords: glutathione, Alzheimer's disease, t-PA, PAI-1, plasminogen
The Physiopathological Crossroads of Aging  [PDF]
J. Lasierra-Cirujeda, P. Coronel, M. J. Aza Pascual-Salcedo, M. Gimeno, M. M. Aza Pascual Salcedo, A. Lasierra-Iba?ez, C. Lasala-Aza
Journal of Biosciences and Medicines (JBM) , 2019, DOI: 10.4236/jbm.2019.76007
Abstract: Stress, inflammation and Plasminogen activator inhibitor 1 (PAI-1) are key mechanisms throughout the development of aging, constituting a crossroad in the most frequent pathologies that accompany it. Among metabolic processes, obesity, metabolic syndrome and type 2 diabetes mellitus are included and Alzheimer’s disease among the neurodegenerative processes. Stress is a mechanism of defense of the organism against exogenous and endogenous actions called stressors. In the case of low intensity stimuli, the organism responds with actions aimed at a physiological adaptation (Homeostasis). On the other hand, when a high intensity (experimental level) or chronic stimulus (oxidative stress) is repeated, structural and functional changes are observed in different organs with activation of the hypothalamus-pituitary-adrenal axis, the renin angiotensin system and the sympathetic nervous system, stimulating the production of hormones that release cytokines with proin-flammatory/antiinflammatory properties that play an important role in the previously mentioned pathologies, as well as a marked increase in PAI-1, a gene regulated by stress and by cytokines, with manifest action at the origin of thromboembolic disease, so frequent in aging. The objective of this review is to highlight the importance of the binomial stress and PAI-1 in aging and in the pathologies that accompany it. Because PAI-1 is part of the pathology and complications in aging, some authors suggest the study of PAI-1 inhibitors to achieve its physiological levels, as part of the treatment of these diseases.
Prognostic value of quantitative immune alterations in melanoma patients
Andrés,R.; Mayordomo,J. I.; Isla,D.; Lasierra,P.; Godino,J.; Marcos,I.; Saenz,A.; Escudero,P.; Lambea,J.; Aguirre,E.; Millastre,E.; Larrad,L.; Tres,A.;
Oncología (Barcelona) , 2006, DOI: 10.4321/S0378-48352006000100004
Abstract: purpose: the immune response is altered in patients with neoplasms. immunosuppression has important consequences in patients with melanoma. the aim of this study was to assess quantitative immune alterations in melanoma patients.. material and methods: we obtained a peripheral blood sample in edta from 86 melanoma patients (63 of them disease-free and 23 with distant disease). total leukocytes and lymphocytes, b lymphocytes (cd19), types cd3, cd4, cd8 lymphocytes, and nk lymphocytes (cd56) were counted by determining the surface markers by flow cytometry, using a coulter epics elite (coulter corp.). iga, igg, ige and igm were assayed by nephelometric methods employing a hyland pdq laser nephelometer. results: we found significant differences between disease-free patients and those with active disease with regard to lymphocytes total count (median: 2251.57 vs. 1783.04/mm3, p=0.010), nk lymphocytes (cd56) (149.54 vs. 115.2/mm3, p=0.016), and iga levels (241.59 vs. 300.55 mg/dl, p=0.044), when taken as continuous variables. when considering each parameter as a discontinuous variable, only changes in absolute lymphocyte count retained an statistical difference depending on the presence or absence of active disease, 73.9% of the patients with active metastatic disease having a lymphocyte count below 2000 cells/mm3 versus only 36.5% of the disease-free patients (c2 pearson=9.476, df=1, p=0.002). the median survival for the 46 patients with absolute lymphocyte count above 2000 cells/mm3 was 965 days (df=65.03, ic 95%=792.72-1090.30) versus 441 days (df=75.61, ic 95%=292.81-589.19) for the 40 patients with absolute lymphocyte count below 2000 cells/mm3 (log rank=4.54, df=1, p=0.0331). conclusions: there are significant differences in some lymphocyte populations and iga levels between patients with metastases and disease-free patients. melanoma patients with absolute lymphocyte levels above 2000 cells/mm3 have a longer survival than those with a lymphocyte count below 2000 c
Sustainable and Economic Alternative for the Electric Supply of Isolated Communities in the Brazilian Off-Grid Systems  [PDF]
Rebeca Doctors, Rafael Kelman
Journal of Power and Energy Engineering (JPEE) , 2017, DOI: 10.4236/jpee.2017.59012
Abstract: Roughly 99% of the demand for electricity in Brazil is supplied by a national interconnected grid. The remaining 1% is spread in several “isolated systems” of the Amazon region—mini-grids that rely on expensive diesel gensets due to high commodity and transportation costs. The isolated systems also have remote communities disconnected altogether from the mini-grids with inadequate health, education and leisure services. These communities are precariously supplied by small inefficient diesel gensets that run for a few hours per day. In this article, we propose a sustainable and economic alternative for the electric supply of the remote communities of isolated systems through a combination of photovoltaic solar generation and storage. The objective is to improve access to electricity with savings for the communities. The present paper outlines a public policy to meet this objective.
The Difference in Calcium Levels in Aspergillus nidulans Grown on Glucose or Pectin  [PDF]
Janice Aparecida Rafael, Suraia Said
Advances in Microbiology (AiM) , 2012, DOI: 10.4236/aim.2012.22016
Abstract: Understanding the growth regulatory mechanisms in filamentous fungi is very important for the production of medicines for antifungal therapies. It is well established that Ca2+ gradient is essential for hyphal growth and that one mechanism responsible for the Ca2+ cellular concentration starts with the hydrolysis of phosphatidylinositol 4,5-bisphosphate (PIP2) by receptor-regulated forms of phosphoinositide-specific phospholipase C (PI-PLC). In the present study the levels of calcium in Aspergillus nidulans wild type (A26) and plcA-deficient mutant (AP27) growing in a carbon source readily assimilated, as glucose or pectin a non-readily assimilated carbon source was investigated. Intracellular calcium levels in A26 were higher in the presence of glucose than in pectin, but lower in AP27 independently of the carbon source and in AP27 the vesicular calcium distribution occurred mainly at the apex of the hyphae. Delay in nuclear division was also observed if A26 and AP27 were grown in pectin presence when compared with growth in glucose. For the first time, it is demonstrated that the levels of intracellular Ca2+ were higher when A. nidulans was growing in glucose than in a non readily assimilated carbon source as pectin. Further, it also showed that the plcA gene, although not essential, may be responsible for high-molecular weight carbon source recongnation, for the intracellular Ca2+ levels maintenance and consequently by the nuclear division in A. nidulans.
Evaluation of Inherent Uncertainties of the Homogeneous Effective Thermal Conductivity Approach in Modeling of Printed Circuit Boards for Space Applications  [PDF]
Rafael Lopes Costa, Valeri Vlassov
Journal of Electronics Cooling and Thermal Control (JECTC) , 2013, DOI: 10.4236/jectc.2013.31005
Abstract:

Electronic components are normally assembled to printed circuit boards (PCBs). Such components generate heat in operation which must be conducted away efficiently from the small mounting areas to frames where the PCB is fixed. The temperature of the component depends on heat dissipation rate, technology and parameters of mounting, component placement and finally effective thermal conductivity (keff) of the board. The temperature of some components may reach significant magnitudes over 100°C while the PCB frame is kept at near-ambient temperature. The reliability of electronic components is directly related to operating temperature; so the thermal project should be able to provide a correct temperature prediction of all PCB components under the hottest operational condition. In space applications, the main way to spread and reject heat of electronic equipment is by thermal conduction once there is no air available to apply convection-based cooling techniques. The PCB keff is an important parameter for the electronics thermal analysis when the PCB is modeled as a simplified homogeneous board with a unique thermal conductivity. In this paper, an intrinsic uncertainty of such approach is firstly reveled and its magnitude is evaluated for a real space use PCB. The simulation uses SINDA/FLUINT Thermal Desktop and aims to determine the keff of the PCB by comparison between a detailed multi-layered anisotropic model and an

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