Francisco López-hernández - Academia.edu (original) (raw)

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Papers by Francisco López-hernández

Cardiovascular drugs and therapy / sponsored by the International Society of Cardiovascular Pharmacotherapy, 2000

Unilateral nephrectomy in the spontaneously hypertensive rat (SHR) does not produce any change in... more Unilateral nephrectomy in the spontaneously hypertensive rat (SHR) does not produce any change in blood pressure but does induce humoral alterations that might influence the antihypertensive action of some drugs. In this study, the antihypertensive effect of treatment (5 weeks) with placebo (control), verapamil, trandolapril, or their combination (verapamil plus trandolapril) was investigated in SHRs with half renal mass ablation, regarding the structure and function of small mesenteric arteries. Arterial pressure was followed during the period of treatment. Trandolapril and veratran returned pressure to normal, while verapamil was ineffective. Statistically significant differences in the parameters of vessel structure were not observed among groups; thus, the alterations in functionality cannot be attributed to morphologic changes. The noradrenaline-induced contraction was reduced similarly by the three treatments as compared to controls. This difference involved a higher participa...

CCNC IEEE Consumer Communications and Networking Conference, 2011

ABSTRACT An infrared optical wireless system is presented, consisting on autonomous remote nodes ... more ABSTRACT An infrared optical wireless system is presented, consisting on autonomous remote nodes communicating with a central node. The network is designed for telecommand/telemetry purposes, comprising a large number of nodes at a low data rate . Simultaneous access is granted by using CDMA techniques, and an appropriate selection of the code family can also keep power consumption to a minimum.

2008 IEEE 10th International Symposium on Spread Spectrum Techniques and Applications (ISSSTA), 2008

A novel method to be used in OCDMA systems is exhaustively described in this paper. It uses Algor... more A novel method to be used in OCDMA systems is exhaustively described in this paper. It uses Algorithmic Optical Codes (AOCs). They are based on the signature sequence idea. However patterns are constantly changing. A common seed for pseudo-random sequence is the signature element.

Vertical-Cavity Surface-Emitting Lasers Xv, 2011

We present results on the electrical characterization of commercial fiber pigtailed 1. 55 μm 2.5 ... more We present results on the electrical characterization of commercial fiber pigtailed 1. 55 μm 2.5 Gb/s VCSEL based on InAlGaAs active region, tunnel junction (TJ), air-gap aperture and InAlGaAs/InAlAs mirrors. The current-voltage (I-V) characteristics were measured and the results were fitted to the analytical expressions of an equivalent circuit considering the TJ in series with the active junction and a series resistance. Carrier capture/escape effects were considered in order to account for the reduced value of the drop in the measured differential resistance at threshold. The electrical parameters of both junctions were determined, showing that the TJ was responsible for most of the voltage drop at threshold. High frequency electrical impedance measurements were used to determine internal parameters as well as the role of external parasitics. The results were analyzed using a small signal equivalent circuit which includes the TJ, carrier capture/escape effects, the cavity parasitics, and the electrical access. A good agreement between the experimental and the equivalent circuit impedances at different bias was obtained by considering the differential resistances of the active and tunnel junctions extracted from the I-V characteristics, yielding reasonable values of the dynamic time constants and of the recombination coefficients.

Toxicology Letters, 2011

Iron-chelating therapy results in a significant improvement in the life expectancy of patients wi... more Iron-chelating therapy results in a significant improvement in the life expectancy of patients with transfusional iron overload. However, alterations of renal function have been observed in some patients undergoing chelation therapy. In the present study we evaluated the effect of treatment with deferasirox iron chelator on the renal function in normal Wistar rats and in mouse and human cultured tubular cell lines.

Kidney International, 2009

Acute renal failure induced by renal ischemia or drugs continues to be a relevant clinical proble... more Acute renal failure induced by renal ischemia or drugs continues to be a relevant clinical problem. Li et al. have demonstrated that proximal tubule-restricted peroxisome proliferator-activated receptor-alpha (PPARalpha) expression in transgenic mice reduced cisplatin- and ischemia/reperfusion-induced acute renal injury. Their article suggests a role for the maintenance of free fatty acid oxidation in the proximal tubule as a mechanism of nephroprotection, as well as a potential clinical utility of PPARalpha activators in the prevention of acute renal failure.

Journal of Translational Medicine, 2011

Chronic kidney disease (CKD) comprises a group of pathologies in which the renal excretory functi... more Chronic kidney disease (CKD) comprises a group of pathologies in which the renal excretory function is chronically compromised. Most, but not all, forms of CKD are progressive and irreversible, pathological syndromes that start silently (i.e. no functional alterations are evident), continue through renal dysfunction and ends up in renal failure. At this point, kidney transplant or dialysis (renal replacement therapy, RRT) becomes necessary to prevent death derived from the inability of the kidneys to cleanse the blood and achieve hydroelectrolytic balance. Worldwide, nearly 1.5 million people need RRT, and the incidence of CKD has increased significantly over the last decades. Diabetes and hypertension are among the leading causes of end stage renal disease, although autoimmunity, renal atherosclerosis, certain infections, drugs and toxins, obstruction of the urinary tract, genetic alterations, and other insults may initiate the disease by damaging the glomerular, tubular, vascular or interstitial compartments of the kidneys. In all cases, CKD eventually compromises all these structures and gives rise to a similar phenotype regardless of etiology. This review describes with an integrative approach the pathophysiological process of tubulointerstitial, glomerular and renovascular diseases, and makes emphasis on the key cellular and molecular events involved. It further analyses the key mechanisms leading to a merging phenotype and pathophysiological scenario as etiologically distinct diseases progress. Finally clinical implications and future experimental and therapeutic perspectives are discussed.

Cell and Tissue Research, 2012

Transforming growth factor beta (TGF-β) has been recognized as an important mediator in the genes... more Transforming growth factor beta (TGF-β) has been recognized as an important mediator in the genesis of chronic kidney diseases (CKD), which are characterized by the accumulation of extracellular matrix (ECM) components in the glomeruli (glomerular fibrosis, glomerulosclerosis) and the tubular interstitium (tubulointerstitial fibrosis). Glomerulosclerosis is a major cause of glomerular filtration rate reduction in CKD and all three major glomerular cell types (podocytes or visceral epithelial cells, mesangial cells and endothelial cells) participate in the fibrotic process. TGF-β induces (1) podocytopenia caused by podocyte apoptosis and detachment from the glomerular basement membrane; (2) mesangial expansion caused by mesangial cell hypertrophy, proliferation (and eventually apoptosis) and ECM synthesis; (3) endothelial to mesenchymal transition giving rise to glomerular myofibroblasts, a major source of ECM. TGF-β has been shown to mediate several key tubular pathological events during CKD progression, namely fibroblast proliferation, epithelial to mesenchymal transition, tubular and fibroblast ECM production and epithelial cell death leading to tubular cell deletion and interstitial fibrosis. In this review, we re-examine the mechanisms involved in glomerulosclerosis and tubulointerstitial fibrosis and the way that TGF-β participates in renal fibrosis, renal parenchyma degeneration and loss of function associated with CKD.

Pharmacology and Toxicology, 2002

The antihypertensive efficacy of the angiotensin-converting enzyme inhibitor trandolapril was eva... more The antihypertensive efficacy of the angiotensin-converting enzyme inhibitor trandolapril was evaluated in uninephrectomized spontaneously hypertensive rats. After 5 weeks of treatment, blood pressure, cardiac and aortic mass, as well as the functional status of the aortic endothelium, and the role played by the cyclooxygenase pathway were investigated. In addition, the effect of a sub-antihypertensive dose of the calcium antagonist verapamil, in combination with trandolapril, was also investigated. As compared to placebo, trandolapril returned blood pressure and aortic lamina media cross sectional area to normotensive values, significantly reduced the heart-to-body weight, and improved the acetylcholine-induced relaxation of aortic rings. This latter effect is thought to be mediated by the elimination of a substance derived from the cyclooxygenase pathway. Verapamil, in single therapy, did not reduce blood pressure, or heart-to-body weight, increased aortic lamina media cross sectional area and impaired acetylcholine-induced relaxation. When combined with trandolapril in dual therapy, some of the beneficial effects of trandolapril remained, whereas others were counterbalanced by verapamil. In conclusion, trandolapril proved to be an effective therapeutic drug in this animal model of hypertension. Combination of trandolapril with a sub-antihypertensive dose of verapamil did not show any positive synergistic effect; on the contrary, it outweighed some of the beneficial effects of trandolapril.