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A Ortiz

Publications and source records attributed to A Ortiz.

At least 19 recordsLinked to original sources
PubMed2006

Cytokine cooperation in renal tubular cell injury: the role of TWEAK.

Tumor necrosis factor (TNF)-like weak inducer of apoptosis (TWEAK, TNFSF12) is a member of the TNF superfamily. TWEAK activates the Fn14 receptor, and may regulate apoptosis, proliferation, and inflammation, processes that play a significant role in pathological conditions. However, there is little information on the function and regulation of this system in the kidney. Therefore, TWEAK and Fn14 expression were studied in cultured murine tubular epithelial MCT cells and in mice in vivo. The effect of TWEAK on cell death was determined. We found that TWEAK and Fn14 expression was increased in experimental acute renal failure induced by folic acid. Cultured tubular cells express both TWEAK and the Fn14 receptor. TWEAK did not induce cell death in non-stimulated tubular cells. However, in cells costimulated with TNFalpha/interferon-gamma, TWEAK induced apoptosis through the activation of the Fn14 receptor. Apoptosis was associated with activation of caspase-8, caspase-9, and caspase-3, Bid cleavage, and evidence of mitochondrial injury. There was no evidence of endoplasmic reticulum stress. A pan-caspase inhibitor benzyloxycarbonyl-Val-Ala-DL-Asp prevented TWEAK-induced apoptosis, but it sensitized cells to necrosis via generation of reactive oxygen species. In conclusion, cooperation between inflammatory cytokines results in tubular cell death. TWEAK and Fn14 may play a role in renal tubular cell injury.

Acute Kidney Injury↗
PubMed2006

Lethal activity of FADD death domain in renal tubular epithelial cells.

Fas-associated death domain (FADD) is an adaptor protein that is required for the transmission of the death signal from lethal receptors of the tumor necrosis factor superfamily. FADD contains a death domain (DD) and a death effector domain (DED). As death receptors contribute to renal tubular injury and tubular cell FADD increases in acute renal failure, we have studied the function of FADD in tubular epithelium. FADD expression was studied in kidney samples from mice. In order to study the contribution of FADD to renal tubular cell survival, FADD or FADD-DD were overexpressed in murine tubular epithelium. FADD is expressed in renal tubules of the healthy kidney. Both FADD and FADD-DD induce apoptosis in primary cultures of murine tubular epithelium and in the murine cortical tubular cell line. Death induced by FADD-DD has apoptotic morphology, but differs from death receptor-induced apoptosis in that it is not blocked by inhibitors of caspases. Neither an inhibitor of serine proteases nor overexpression of antiapoptotic BclxL prevented cell death. However, the combination of caspase and serine protease inhibition was protective. FADD and FADD-DD overexpression decreased nuclear factor kappa B activity. These data suggest that FADD has a death regulatory function in renal tubular cells that is independent of death receptors. FADD-DD is sufficient to induce apoptosis in these cells. This information is relevant to understanding the role of FADD in tubular injury.

Acute Kidney Injury↗
PubMed2006

Electrical and optical properties of C46H22N8O4KM (M=Co, Fe, Pb) molecular-material thin films prepared by the vacuum thermal evaporation technique.

In this work, the synthesis of new materials formed from metallic phthalocyanines (Pcs) and double potassium salt from 1,8-dihydroxianthraquinone is reported. The newly synthesized materials were characterized by scanning electron microscope (SEM), atomic force microscopy (AFM), infrared (IR) and Ultraviolet-visible (UV-vis) spectroscopy. The powder and thin-film samples of the synthesized materials, deposited by vacuum thermal evaporation, show the same intra-molecular bonds as in the IR spectroscopy studies, which suggests that the thermal evaporation process does not alter these bonds. The effect of temperature on conductivity and electrical conduction mechanism was measured in the thin films (approximately 137 nm thickness). They showed a semiconductor-like behaviour with an optical activation energy arising from indirect transitions of 2.15, 2.13 and 3.6eV for the C(46)H(22)N(8)O(4)KFe, C(46)H(22)N(8)O(4)KPb and C(46)H(22)N(8)O(4)KCo thin films.

Cobalt↗
PubMed2006

Clinical significance and epidemiology of non-pigmented rapidly growing mycobacteria in a university hospital.

OBJECTIVES: To study the clinical significance and epidemiology of Non-pigmented rapidly growing mycobacteria (NPRGM) during a 13-year period. METHODS: We performed a retrospective study of patients with isolates of NPRGM to evaluate their clinical significance. We also analyzed the strains using Randomly Amplified Polymorphic DNA (RAPD) analysis to evaluate the relationship between strains. RESULTS: Between 1990 and 2003, 65 patients had an isolate of NPRGM. Twenty of them were considered significant (19 cases) or doubtful (1 case). Many cases were skin and soft tissue infections. Six cases were foreign-body related. All the patients recovered with antibiotic therapy and removal of the foreign body. All the patients were apparently unrelated, despite 56.9% of the isolates were detected between 1995 and 1997. RAPD analysis was performed on 43 strains, and showed only a cluster of two Mycobacterium chelonae isolates. Both of them were related with contamination of a laboratory reactive, and were considered non-significant. CONCLUSION: In our hospital, almost one-third of the isolates of NPRGM were significant, being this percentage higher for skin and soft tissue isolates. Patients were cured with antibiotic therapy, but the removal of foreign bodies appeared to be necessary for a good outcome. A minor pseudo-outbreak was detected. No predominant strain was detected.

Adult↗
PubMed2006

Unusual perforated appendicitis within umbilical hernia: CT findings.

We present the first imaging report of perforated appendicitis in an umbilical hernia. Computed tomography demonstrated a gas-forming abscess within an umbilical hernia and the cecum was found inside the hernial sac, with an inner relation to the abscess. Computed tomographic findings suggested appendicitis as possible diagnosis, which was confirmed at surgery. Physicians must consider appendicitis within the differential diagnosis of an abdominal abscess located near to the cecum, even at an unexpected location.

Appendicitis↗
PubMed2006

Pseudo-outbreak of Mycobacterium gordonae: usefulness of randomly amplified polymorphic DNA analysis to assess the clonality of the isolates.

Mycobacterium gordonae was detected in 18 of 21 clinical samples processed during the same day from patients with clinical suspicion of tuberculosis. Randomly amplified polymorphic DNA (RAPD) analysis revealed that all the isolates generated an identical pattern with each of the five primers used, and that these patterns were different from those of epidemiologically non-related isolates of M. gordonae. M. gordonae was not detected in the distilled water used for the procedures, and following replacement of the commercial products and sterilisation of home-made reagents, no more isolates belonging to the same clone of M. gordonae were detected.

Disease Outbreaks↗
PubMed2006

Modulation of renal tubular cell survival: where is the evidence?

Tubular cell loss is prominent both in acute and chronic renal failure. Apoptosis and its regulatory mechanisms contribute to cell number regulation in the kidney. The potential role of apoptosis ranges from induction and progression to repair of renal injury. However, therapeutic interest has focused in preventing the apoptotic loss of tubular cells that leads to acute and chronic renal failure. Death ligands and receptors, such as tumor necrosis factor and Fas ligand, proapoptotic and antiapoptotic Bcl2 family members and caspases have all been shown to participate in apoptosis regulation in the course of renal cell injury. Nevertheless, the precise role of these proteins is unclear, and the participation of most known apoptosis regulatory proteins has not been studied. We now review the role of apoptosis in renal injury, the potential molecular targets of therapeutic intervention, the therapeutic weapons to modulate the activity of these targets and the few examples of therapeutic intervention on apoptosis, with emphasis in acute renal failure.

Acute Kidney Injury↗
PubMed2006

Recurrent acute postinfectious glomerulonephritis.

Recurrent acute postinfectious glomerulonephritis is infrequent in childhood and exceptional in adults. The factors that determine recurrence are poorly understood. Selective IgA deficiency is characterized by an increased incidence of gastrointestinal and respiratory infections. The case of a 33-year-old man with a history of repetitive sinopulmonary infections and diagnosed with selective IgA deficiency is described. He suffered 2 episodes of postinfectious glomerulonephritis within a 15-year period. Selective IgA deficiency may have predisposed to the development of recurrent postinfectious glomerulonephritis

Acute Disease↗
PubMed2005

Evolution of the activity of UGT1A1 throughout the development and adult life in a rat.

Biliary excretion is the main route of disposal of bilirubin and impaired excretion results in jaundice, a well recognisable symptom of liver disease. Conjugation of bilirubin in the liver is essential for its clearance. The glucuronidation of bilirubin is catalysed by the microsomal UDP-glucuronosyltransferase UGT1A1. Patients with Crigler-Najjar syndrome type 1 and Gunn rats, mutant strain of the Wistar rats, bear an autosomal recessive disorder resulting in hyperbilirubinemia. The aim of this work is to add new data about activity of UGT1A1 during the perinatal period and adult life. The results showed that activity of UGT1A1 is detectable from day 22 of the gestation. After birth, activity of UGT1A1 gradually increases and reaches the levels of adult life. Furthermore, bilirubin azopigments have been separated and characterized by thin layer chromatography. We have found that concentration of samples by evaporation and ulterior storing at -20 degrees C seemed to be suitable for the maintenance of samples.

Aging↗
PubMed2005

Synthesis and study of molecular interactions between phosphatidyl choline and two laminin derived peptides hydrophobically modified.

Two peptides based on the active SIKVAV sequence were synthesized and hydrophobically modified through attachment of a myristoyl residue to the amino terminal group. A comparative study was carried out on the physicochemical properties of both parent and hydrophobically modified structures. Properties studied were hydrophobicity, surface activity, spreadability on aqueous surfaces, penetration in lipid monolayers, aggregation and haemolytic activity. Results obtained indicate that myristoyl containing peptides form micelles at 10(-6) M concentration, whereas parent peptides start to aggregate at 10(-5) M. All of them are able to spread on aqueous surfaces forming stable monolayers. Concerning their haemolytic activity only one of the sequences promotes a partial lysis of erythrocytes after 30 min incubation at 37 degrees C and 10(-5) M concentration in the media.

Chromatography, High Pressure Liquid↗
PubMed2005

The behavior of single crystals of NaCl: Ca2+, Mn2+ exposed to gamma rays.

The behavior of single crystals of NaCl: Ca(2+), Mn(2+) exposed to gamma rays was explored for its potential usage as a dosimeter. The study was focused to the effect of dose and dose rate. The crystals were analyzed using thermoluminescence (TL). The productions of irradiation defects in the solid were correlated with the glow curve. F-centers were measured as function of the dose. The bleaching of the F-centers produced a decrease of the peak of the glow curve. The results showed that the response is linear in an interval up to 60 Gy.

Calcium↗
PubMed2005

First results from the CERN axion solar telescope.

Hypothetical axionlike particles with a two-photon interaction would be produced in the sun by the Primakoff process. In a laboratory magnetic field ("axion helioscope"), they would be transformed into x-rays with energies of a few keV. Using a decommissioned Large Hadron Collider test magnet, the CERN Axion Solar Telescope ran for about 6 months during 2003. The first results from the analysis of these data are presented here. No signal above background was observed, implying an upper limit to the axion-photon coupling g(agamma)<1.16x10(-10) GeV-1 at 95% C.L. for m(a) less, similar 0.02 eV. This limit, assumption-free, is comparable to the limit from stellar energy-loss arguments and considerably more restrictive than any previous experiment over a broad range of axion masses.

Journal Article↗
PubMed2005

Methodological optimization of polyethylenimine (PEI)-based gene delivery to the lungs of mice via aerosol application.

BACKGROUND: Polyethylenimine (PEI) has been successfully used for gene delivery to the lungs of mice via aerosol application using a whole body nebulization device. In this report we optimized the design of such an aerosol device. METHODS: Aerosol devices were constructed as either serial inhalation apparatus or as a whole body nebulization chamber connected to an aerosol spacer placed in a horizontal or vertical position. PEI-based gene vectors were nebulized using a standard jet nebulizer and luciferase gene expression of various tissues was examined. RESULTS: Using a whole body aerosol device resulted in luciferase gene expression in the lungs of mice at the same level as compared with a serial inhalation apparatus. Whereas gene expression was enhanced in the presence of 5% CO(2)-in-air, anesthesia of mice strongly decreased gene expression even when mice were intubated with an intravascular cannula. Reduction of the median mass aerodynamic diameter (MMAD) of the aerosol from 3.4 to 0.27 microm by interposition of an aerosol spacer increased gene expression significantly 3-fold. Drying of the aerosol by silica gel additionally increased gene delivery significantly 3-fold. Reporter gene expression mediated by branched PEI 25 kDa was 9- and 15-fold higher as compared with linear PEIs of 22 and 25 kDa, respectively, and was dependent on the DNA concentration. Gene expression was detectable as soon as 6 h after gene vector application and reached a maximum after 72 h but was still detectable after 14 days. The presence of Zn(2+) did not increase gene expression. CONCLUSION: We propose aerosol drying as a novel and simple method of optimizing PEI-based gene delivery to the lungs.

Aerosols↗
PubMed2005

[Cochlear implants in Aragón].

Cochlear implants are, actually, one of the major advances in the treatment for profound deafness. His use is, already, a routine in the daily practice of our specialty. Due to its special aspects, cochlear implants have to be done following a protocol that organizes and coordinates the different aspects of the diagnoses and treatment of profound deafness, in the different administrative and geographical fields. The health system in our country and the smale dimension of our area, has taken us to create and follow a special program in which all the available resources are used. Following this protocol, we have performed 63 cochlear implants, in the last 10 years. We show here the results and complications.

Adolescent↗
PubMed2005

Hepatic proliferation in Gunn rats transplanted with hepatocytes: effect of retrorsine and tri-iodothyronine.

Hepatocyte transplantation would offer an attractive alternative to liver transplantation in the treatment of inborn errors of liver metabolism. However, a major problem in most transplantation studies to date has been the limited growth of transplanted cells in the recipient organ. We performed a strategy for selective proliferation of transplanted cells by interfering with the proliferative capacity of resident hepatocytes, using the pyrrolizidine alkaloid retrorsine and then transplanting liver cells in conjunction with repeated administration of triiodothyronine, an inducer of hepatocyte proliferation in rats. In the present study, foetal and adult syngeneic hepatocyte transplantation into spleen was performed in retrorsine-treated hyperbilirubinemic Gunn rats. In parallel, repeated injections of triiodothyronine were given to recipients. Rats were sacrificed at 1, 7, 30 and 90 days after transplantation and blood and bile samples were taken to assess the functionality of transplanted cells. The proliferative activity of transplanted hepatocytes was evaluated using proliferating cell nuclear antigen labelling index. In summary, both adult and foetal hepatocyte transplantation were effective in correcting a metabolic abnormality in Gunn rats for as long as 3 months. The RS/T3 model, as a measure to increase graft function, could represent an important advance to future clinical application of hepatocyte transplantation.

Animals↗
PubMed2005

Retinoic acid increases tissue and plasma contents of nerve growth factor and prevents neuropathy in diabetic mice.

BACKGROUND: Decreased production of nerve growth factor (NGF) may contribute to diabetic neuropathy; however, exogenous administration of NGF induces only a modest benefit. Retinoic acid (RA) promotes the endogenous expression of nerve growth factor and its receptor. We studied the effects of RA on diabetic neuropathy in mice with streptozotocin-induced diabetes. MATERIAL AND METHODS: One hundred and twenty National Institutes of Health (NIH) albino mice randomly separated into three groups (A, n = 30; B, n = 30; C, n = 60). Diabetes mellitus was induced with streptozotocin in groups A and B. Animals from group A received a subcutaneous injection of 25 microl of mineral oil daily for 90 days, while those from group B received a subcutaneous injection of 20 mg kg(-1) of all trans RA. Animals from group C were taken as controls. At the end of the experiment, blood glucose and NGF levels (both in serum and sciatic nerve) were measured. Two behavioural tests were conducted in a blind fashion to detect abnormalities of thermal and nociceptive thresholds. RESULTS: Contents of NGF in healthy untreated mice were 1490 +/- 190 pg mg(-1) in nerve and 113 +/- 67 pg mg(-1) in serum; in diabetic untreated mice the values were 697 +/- 219 pg mL(-1) in nerve and 55 +/- 41 pg mL(-1) in serum; and in diabetic mice treated with RA the values were 2432 +/- 80 pg mL(-1) in nerve and 235 +/- 133 pg mg(-1) in serum (P < 0.002). Ultrastructural evidence of nerve regeneration and sensitivity tests improved in diabetic mice treated with RA as compared with nontreated diabetic mice. CONCLUSION: Our findings indicate that administration of RA increases serum and nerve contents of NGF in diabetic mice and suggest a potential therapeutic role for retinoic acid in diabetic patients.

Animals↗