Publications by authors named "Antonio Vilches"

Telomere shortening with age has been documented in many organisms, but few studies have reported telomere length measurements in amphibians, and no information is available for growth after metamorphosis, nor in wild populations. We provide both cross-sectional and longitudinal evidence of net telomere attrition with age in a wild amphibian population of natterjack toads (). Based on age-estimation by skeletochronology and qPCR telomere length measurements in the framework of an individual-based monitoring programme, we confirmed telomere attrition in recaptured males.

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Cochlear hair cells are critical for the conversion of acoustic into electrical signals and their dysfunction is a primary cause of acquired hearing impairments, which worsen with aging. Piezoelectric materials can reproduce the acoustic-electrical transduction properties of the cochlea and represent promising candidates for future cochlear prostheses. The majority of piezoelectric hearing devices so far developed are based on thin films, which have not managed to simultaneously provide the desired flexibility, high sensitivity, wide frequency selectivity, and biocompatibility.

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Background: In incident hemodialysis (HD) patients, the use of catheters is associated with a worse prognosis when compared with those with an arteriovenous fistula, but the role of vascular access (VA) type in the morbidity and mortality of patients returning to HD with a failing renal allograft is unknown. We aimed to determine the associations between the type of VA and mortality in this population.

Methods: This was a retrospective observational cohort study of 138 patients who initiated dialysis after kidney transplant failure between 1995 and 2014.

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Article Synopsis
  • Travel for transplantation has sparked intense discussions in medical, legal, and ethical fields, particularly about patients receiving kidney transplants in other countries.
  • A study from 1971 to 2008 evaluated 58 patients who underwent kidney transplants abroad, mostly in the USA and Bolivia, and compared their outcomes with patients transplanted domestically.
  • Findings indicated that there were no significant differences in kidney function and graft survival between travelers and local patients, and travelers spent less time on dialysis before their transplants.
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We report the development of a novel multi-tier interface which enables the wireless, noninvasive transfer of sufficient amounts of power as well as the collection and transmission of data from low-power, deeply implantable analog sensors. The interface consists of an inductive coupling subsystem and an ultrasonic subsystem. The designed and experimentally verified inductive subsystem ensures that 5 W of power is transferred across 10 mm of air gap between a single pair of PCB spiral coils with an efficiency of 83% using our prototype CMOS logic gate-based driver circuit.

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To investigate how depth and bottom color affect prey selectivity in Common kingfisher (Alcedo atthis), we developed several experimental procedures using captive birds. We used 20 young kingfishers to test depth (25 or 50cm) and color (natural gravel or white) effects on foraging behavior. Live freshwater fish were used as target prey.

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Rapidly progressive glomerulonephritis (RPGN) is a syndrome characterized by glomerular lesions giving rise to acute renal injury that develops within a brief period of time, usually days or a few months. It is classified according to the underlying mechanism of injury and the immunofluorescence findings into four main disorders. In the last decade, nephrologists have witnessed a steady rise in the mean age of the patients diagnosed with RPGN.

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The tumor lysis syndrome (TLS) is a metabolic disorder resulting from a massive tumor breakdown. It is characterized by hyperuricemia, hyperphosphatemia, hypocalcemia and hyperkalemia and predisposes to acute renal failure. TLS usually occurs after the initiation of cytotoxic therapy and is more frequent in the case of neoplasias with a high proliferative rate or that are highly chemo-sensitive.

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Introduction: Liver disease related to chronic viral hepatitis is a major cause of morbidity and mortality in renal transplant patients. There is no agreement upon the influence of chronic hepatitis B (HBV) and hepatitis C (HCV) infection in patient and graft survival.

Aims: The aim of the study was to evaluate the influence of HBV and HCV on patient and graft short and long term survival, in the patients transplanted at our institution.

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Background: The potential risk for transmission of hepatitis C virus (HCV) by peritoneal dialysis (PD) has been studied previously, with conflicting results.

Methods: To assess whether HCV crosses the peritoneal membrane, the following determinations were performed in 16 patients (7 males, 9 females; mean age 41.8 years; mean time on PD 14 +/- 15 months) undergoing PD: serum anti-HCV using second-generation enzyme-linked immunosorbent assay (ELISA), serum and PD fluid HCV RNA by nested polymerase chain reaction, HCV genotyping by restriction fragment length polymorphism, and serum HCV load by branched DNA assay.

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Chronic liver infections related to hepatitis B and C viruses are a common problem in renal transplant patients with a prevalence of 1.5 to 50% in different countries. There is no uniform agreement regarding their influence on the incidence of acute rejection, graft outcome and survival of renal transplant patients.

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Angiotensin converting enzyme inhibitors have been shown to be useful in the treatment of essential hypertension while anti-platelet agents improve the overall cardiovascular risk profile in this population. Our aim was to assess the interaction of two different aspirin (ASA) doses--81 and 325 mg/day--with the antihypertensive effect of enalapril as well as their impact upon the urinary sodium excretion (Na(u)). A total of 22 patients between 35 and 65 years of age were included in a prospective double blind trial with a partial cross-over design.

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Membranous nephropathy is the most common histologic phenotype associated with the primary nephrotic syndrome in adults and the second most common etiological diagnosis in over sixteen hundred renal biopsies on native kidneys processed at our institution over a 30 year period. Renal survival at 10 years is about 70%, but the course of the disease is related to a series of factors which have constituted the basis for mathematical models developed to predict the natural history in a given individual. These factors are gender, age, renal function at the time of diagnosis, presence of the nephrotic syndrome, high blood pressure and the degree of structural damage.

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Thyrotoxicosis may present with a variety of cardiovascular symptoms. Sinus tachycardia is the most frequently encountered electrocardiographic abnormality and conduction disturbances are extremely uncommon. We present a case of first degree atrio-ventricular block in a patient with newly diagnosed hyperthyroidism and discuss the underlying pathophysiological mechanisms and the clinical implications from the internist's standpoint.

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