ABSTRACT
Titanium is a relevant technological material due to its extraordinary mechanical and biocompatible properties, its nanopatterning being an increasingly important requirement in many applications. We report the successful nanopatterning of titanium by means of focused electron beam induced etching using XeF(2) as a precursor gas. Etch rates up to 1.25 × 10(-3) µm(3) s(-1) and minimum pattern sizes of 80 nm were obtained. Different etching parameters such as beam current, beam energy, dwell time and pixel spacing are systematically investigated, the etching process being optimized by decreasing both the beam current and the beam energy. The etching mechanism is investigated by transmission electron microscopy. Potential applications in nanotechnology are discussed.
ABSTRACT
We have investigated the internalization of magnetic nanoparticles (NPs) into dendritic cells (DCs) in order to assess both the final location of the particles and the viability of the cultured cells. The particles, consisting of a metallic iron core covered with carbon, showed no toxic effects on the DCs and had no effect in their viability. We found that mature DCs are able to incorporate magnetic nanoparticles in a range of size from 10 nm to ca. 200 nm, after 24 h of incubation. We describe a method to separate cells loaded with NPs, and analyze the resulting material by electron microscopy and magnetic measurements. It is found that NPs are internalized in lysosomes, providing a large magnetic signal. Our results suggest that loading DCs with properly functionalized magnetic NPs could be a promising strategy for improved vectorization in cancer diagnosis and treatment.
Subject(s)
Cell Separation/methods , Dendritic Cells/metabolism , Magnetics , Metal Nanoparticles , Dendritic Cells/ultrastructure , Humans , Lysosomes/metabolism , Microscopy, Electron, TransmissionABSTRACT
BACKGROUND AND AIMS: The great potential of using nanodevices as delivery systems to specific targets in living organisms was first explored for medical uses. In plants, the same principles can be applied for a broad range of uses, in particular to tackle infections. Nanoparticles tagged to agrochemicals or other substances could reduce the damage to other plant tissues and the amount of chemicals released into the environment. To explore the benefits of applying nanotechnology to agriculture, the first stage is to work out the correct penetration and transport of the nanoparticles into plants. This research is aimed (a) to put forward a number of tools for the detection and analysis of core-shell magnetic nanoparticles introduced into plants and (b) to assess the use of such magnetic nanoparticles for their concentration in selected plant tissues by magnetic field gradients. METHODS: Cucurbita pepo plants were cultivated in vitro and treated with carbon-coated Fe nanoparticles. Different microscopy techniques were used for the detection and analysis of these magnetic nanoparticles, ranging from conventional light microscopy to confocal and electron microscopy. KEY RESULTS: Penetration and translocation of magnetic nanoparticles in whole living plants and into plant cells were determined. The magnetic character allowed nanoparticles to be positioned in the desired plant tissue by applying a magnetic field gradient there; also the graphitic shell made good visualization possible using different microscopy techniques. CONCLUSIONS: The results open a wide range of possibilities for using magnetic nanoparticles in general plant research and agronomy. The nanoparticles can be charged with different substances, introduced within the plants and, if necessary, concentrated into localized areas by using magnets. Also simple or more complex microscopical techniques can be used in localization studies.
Subject(s)
Cucurbita/metabolism , Metal Nanoparticles/analysis , Microscopy, Confocal/methods , Microscopy, Electron, Transmission/methods , Microscopy, Fluorescence/methods , Biological Transport , Cucurbita/cytology , Cucurbita/ultrastructure , Iron/chemistry , MagneticsABSTRACT
No disponible
Subject(s)
Humans , Nanotechnology/trends , Nanostructures , Nanoparticles , Biomedical Engineering/trends , Biomedical Technology/trends , Biomedical Research/trendsABSTRACT
No disponible
Subject(s)
Humans , Neoplasms/therapy , Nanoparticles/therapeutic use , Cell- and Tissue-Based Therapy/methods , Drug Implants/therapeutic use , Chemotherapy, Cancer, Regional Perfusion/methodsABSTRACT
Se describe un caso de embarazo ectópico cervical, cuya presentación habitual es una metrorragia irregular durante el primer trimestre de gestación. La estrategia diagnóstica no difiere de los embarazos ectópicos de otra localización, donde un valor elevado de Beta -HCG y el estudio ecográfico resultan fundamentales. La imagen más frecuente es un útero vacío con anejos normales y una vesícula gestacional a escala cervical, en contadas ocasiones con polo embrionario y latido cardíaco positivo, como en nuestro caso. La importancia del diagnóstico temprano se basa en intentar un tratamiento lo más conservador posible y mantener la fertilidad de la paciente. El tratamiento médico con metotrexato sistémico e intrasacular resulta una alternativa terapéutica bastante eficaz y válida para conseguir una escasa morbilidad (AU)
Subject(s)
Adult , Pregnancy , Female , Humans , Methotrexate/administration & dosage , Pregnancy, Ectopic/diagnosis , Pregnancy, Ectopic/drug therapy , Pregnancy, Ectopic , Pregnancy Complications/diagnosis , Ultrasonography/methods , Ultrasonography/instrumentation , Angiography/methods , Metrorrhagia/complications , Metrorrhagia/diagnosis , Pregnancy, Ectopic/epidemiology , Pregnancy, Ectopic/physiopathology , Pregnancy, Ectopic , Hysterectomy/methods , Embolization, Therapeutic/methodsABSTRACT
OBJECTIVE: To identify a twin pregnancy consisting of a complete mole and coexistent fetus by means of molecular cytogenetics and DNA polymorphisms. STUDY DESIGN: Seven highly polymorphic DNA markers were used to establish the androgenetic origin of a complete hydatidiform mole that coexisted with a normal 46,XY fetus. Cytogenetic analysis of mole nuclei was performed with centromeric probes, demonstrating a 46,XX constitution. RESULTS: Molar tissue was diploid with two X chromosomes, possibly due to chromosome doubling after monospermic fertilization of an ovum with inactivated or absent nucleus. CONCLUSION: Although contamination with maternal tissue may be difficult to avoid, molecular markers provide the possibility of distinguishing between a complete hydatidiform mole and coexisting normal fetus versus a partial mole, with methods that can be performed antenatally. This distinction is important since in the first case up to 24% of fetuses described in the literature have been viable, and the risk of subsequent development of persistent trophoblastic tumor in patients with a complete mole and a coexisting fetus is considerably higher than in patients with a single, complete hydatidiform mole.
Subject(s)
Hydatidiform Mole/genetics , Polymorphism, Genetic , Twins, Dizygotic/genetics , Uterine Neoplasms/genetics , X Chromosome , Adult , DNA/analysis , Female , Genetic Markers , Humans , Hydatidiform Mole/pathology , Karyotyping , Polymerase Chain Reaction , Pregnancy , Uterine Neoplasms/pathologyABSTRACT
BACKGROUND: Formoterol is a highly effective therapeutic agent in the prevention of exercise-induced bronchospasm (EIB). Regular use of beta-adrenergic drugs may result in a reduction in the protective effect afforded by these bronchodilators against bronchoconstrictor stimuli. It is unknown whether this effect extends to formoterol and exercise. METHODS: We performed a randomized, double-blind, parallel clinical trial in 19 patients with EIB. Each patient received inhaled formoterol or placebo twice daily during 4 weeks. Patients performed two exercise tests in a cycle ergometer on the 1st, 14th, and 28th study days separated 3 hours from each other. A dose of formoterol was given 30 min prior to the 2nd test. RESULTS: There were significant differences in bronchoprotection between days 1 and 14 (p = .012) and between days 1 and 28 (p = .012) in the formoterol group. No differences were found in the placebo group. The evolution of the bronchoprotection index was also significantly different between the formoterol and the placebo group (p = .002) from day 1 to 28. CONCLUSIONS: Tachyphylaxis developed to the protective effect of formoterol against EIB after 4 weeks of regular dosing. Tolerance was already found on day 14, though not progressive. Formoterol should be recommended only as needed in EIB.
Subject(s)
Asthma, Exercise-Induced/drug therapy , Bronchodilator Agents/therapeutic use , Ethanolamines/therapeutic use , Tachyphylaxis , Adrenergic beta-Agonists/administration & dosage , Adrenergic beta-Agonists/adverse effects , Adrenergic beta-Agonists/therapeutic use , Adult , Asthma, Exercise-Induced/physiopathology , Bronchodilator Agents/administration & dosage , Bronchodilator Agents/adverse effects , Double-Blind Method , Ethanolamines/administration & dosage , Ethanolamines/adverse effects , Exercise Test , Female , Forced Expiratory Volume/drug effects , Formoterol Fumarate , Humans , Male , Time FactorsABSTRACT
Se estudia la conducta diagnóstica y terapeútica del quiste de ovario tanto en el feto como en el recién nacido a propósito de 10 casos habidos en nuestro departamento entre noviembre de 1996 y junio del 2000. La prevalencia fue de 1/1405 nacidos. La edad gestacional media en la que se realizó el diagnóstico fue 31.5 semanas, siendo el diagnóstico más precoz en la semana 28. El tamaño del quiste fue inferior a 40 mm en 4 casos. No se pudo identificar ningún factor materno que tuviera relación epidemiológica en su aparición y desarrollo. Tampoco se produjeron complicaciones fetales que obligasen a interrumpir la gestación antes del término. El único caso de finalización del embarazo mediante cesárea lo fue por indicación obstétrica. La evolución fue variable resolviéndose espontáneamente durante el período fetal en tres casos y en el neonatal en otros 3. Cuatro recién nacidos precisaron cirugía para extirpar el quiste, realizándose en 2 de ellos quistectomía y en otros dos anexectomía. A la vista de nuestros resultados, ante el diagnóstico ecográfico de quiste de ovario fetal se deberá adoptar una conducta expectante, tanto durante la gestación como en el período postnatal. En caso de precisar cirugía, ésta deberá ser lo más conservadora posible (AU)
Subject(s)
Pregnancy , Female , Humans , Infant, Newborn , Ovarian Cysts/embryology , Ovarian Cysts , Ultrasonography, Prenatal , Fetal Diseases , Ovarian Cysts/surgery , Retrospective StudiesSubject(s)
Abnormalities, Multiple , Chromosome Aberrations , Chromosome Disorders , Chromosomes, Human, Pair 22 , Polydactyly , Humans , Infant, Newborn , Male , SyndromeABSTRACT
Si bien la hidrocefalia constituye por lo general un defecto esporádico, existen unos síndromes infrecuentes pero bien definidos en los que cabe esperar la recurrencia. Se presenta un síndrome de Bickers-Adams de hidrocefalia ligada al sexo, producida por estenosis congénita del Acueducto de Silvio. Se describe un caso de este síndrome así como los aspectos referentes a la anamnesis, el diagnóstico, el árbol genético, los hallazgos necrópsicos y el manejo clínico. (AU)
Subject(s)
Female , Male , Humans , Infant, Newborn , Hydrocephalus/genetics , Pregnancy Outcome , Fetal Death , SyndromeABSTRACT
La incidencia de gemelos monocigóticos unidos oscila alrededor 1:600 embarazos gemelares. El método diagnóstico óptimo es la ecografía, que puede señalar dicha patología estructural alrededor de la 7ª-8ª semana de gestación. La ecografía resulta fundamental a la hora de definir el grado de anastómosis, los órganos compartidos y diversas malformaciones asociadas, principales condicionantes de la conducta obstétrica, del tratamiento quirúrgico posterior y en definitiva del pronóstico fetal, que suele ser desfavorable (AU)