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1.
Behav Neurosci ; 136(5): 349-363, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35254840

RESUMEN

The ability to remember sequences of events is fundamental to episodic memory. While rodent studies have examined sex and estrous cycle in episodic-like spatial memory tasks, little is known about these biological variables in memory for sequences of events that depend on representations of temporal context. We investigated the role of sex and estrous cycle in rats during training and testing stages of a cross-species validated sequence memory task (Jayachandran et al., 2019). Rats were trained on a two four-odor sequence memory task delivered on opposite ends of a linear track. Training occurred in six successive stages starting with learning to poke in a nose-port for ≥ 1.2 s; eventually demonstrating sequence memory by holding their nose in the port ≥ 1 s for in-sequence odors and < 1 s for out-of-sequence odors. Performance was analyzed across sex and estrous cycle (proestrus, estrus, metestrus, and diestrus), the latter being determined by cellular composition of a daily vaginal lavage. We found no evidence of sex differences in asymptotic sequence memory performance, similar to humans performing an analogous task (Reeders et al., 2021). Likewise, no differences in sequence memory performance were found across the estrous cycle. Some caveats are that males acquired out-of-sequence trials faster during training with a 3-odor sequence, but this apparent advantage did not carry over to the 4-odor sequence. Additionally, males had shorter poke times overall which seem consistent with a decreased overall response inhibition because they occurred regardless of sequence demands. Together, these results suggest sex and estrous cycle are not major factors in sequence memory capacities. (PsycInfo Database Record (c) 2022 APA, all rights reserved).


Asunto(s)
Ciclo Estral , Estro , Animales , Ciclo Estral/fisiología , Estro/fisiología , Femenino , Humanos , Masculino , Metestro/fisiología , Proestro/fisiología , Ratas , Memoria Espacial
2.
Sci Rep ; 11(1): 17250, 2021 08 26.
Artículo en Inglés | MEDLINE | ID: mdl-34446798

RESUMEN

This paper presents a comprehensive review of advanced technologies with various control approaches in terms of their respective merits and outcomes for power grids. Distributed energy storage control is classified into automatic voltage regulator and load frequency control according to corresponding functionalities. These control strategies maintain a power balance between generation and demand. Besides, three basic electric vehicle charging technologies can be distinguished, i.e. stationary, quasi-dynamic and dynamic control. For realizing charge-sustaining operation at minimum cost quasi-dynamic and dynamic strategies are adopted for in-route charging, while stationary control can only be utilized when the electric vehicle is in stationary mode. Moreover, power system frequency stability and stabilization techniques in non-synchronous generator systems are reviewed in the paper. Specifically, a synchronverter can damp power system oscillations and ensure stability by providing virtual inertia. Furthermore, it is crucial to manage the massive information and ensure its security in the smart grid. Therefore, several attack detection and mitigation schemes against cyber-attacks are further presented to achieve reliable, resilient, and stable operation of the cyber-physical power system. Thus, bidirectional electrical power flows with two-way digital control and communication capabilities have poised the energy producers and utilities to restructure the conventional power system into a robust smart distribution grid. These new functionalities and applications provide a pathway for clean energy technology. Finally, future research trends on smart grids such as IoT-based communication infrastructure, distributed demand-response with artificial intelligence and machine learning solutions, and synchrophasor-based wide-area monitoring protection and control (WAMPC) are examined in the present study.

3.
J Nanosci Nanotechnol ; 19(6): 3511-3518, 2019 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-30744779

RESUMEN

Unadulterated and scorch stage In2SnO3 nanopowder is effectively arranged with the doping proportion of 80-20% (In2O3-Sn) by simple sol-gel combustion direction. The material is characterized by XRD measurements and their geometrical parameters are compared with calculated values. The FT-IR and NMR spectra are recorded in both bulk and nanophase and FT-Raman spectrum is recorded in bulk phase and the fundamental frequencies are assigned. The optimized parameters and the frequencies are calculated using HF and DFT (B3LYP, B3PW91 and MPW1PW91) theory in bulk phase of In2SnO3 and are compared with its nanophase. The vibrational frequency pattern in nanophase gets realigned and the frequencies are shifted up and down little bit to the region of spectra when compared with bulk phase. The UV-visible spectrum is simulated and analyzed. The frontier molecular orbital analysis has been carried out and the values of the HOMO-LUMO bandgap (Kubo gap) explore the optical and electronic characteristics of the In2SnO3. Structural studies by XRD showed the crystallite sizes of the particles. The atomic arrangement in the grain boundary seems to be somewhat different from regular periodic arrangement whereas inside the grain there is a good periodic arrangement of atoms. Above 10 mol% Sn ions, 15 mol% Sn ions, 20 mol% Sn ions to 50 mol% Sn ions form correlated clusters, 20 mol% Sn ions which lead to broadening. These EPR spectra were formed to contain two different components, one from the single isolated ions and the other from the clusters. The transition is observed for different composition increase with decreasing grain size.

4.
J Nanosci Nanotechnol ; 18(10): 6680-6707, 2018 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-29954484

RESUMEN

Telluride's and Selenides were assessed whether it is appropriate for thermoelectric effects. Previous researches showed that researchers strived to progress the performance of telluride based materials in creating structures where the entire dimensions are reduced, such as nanowires or thin films. Seebeck and Peltier coefficient was developed by means of Telluride thermoelectric devices. Epitaxial growth methods such as molecular beam epitaxy and metal organic chemical vapor deposition are some of the frequent methods of acquiring telluride thin films. Thermoelectric nano thin films and nanostructured materials should have the properties of insulation so that it can be used as energy storage devices and thermo electric generators. Conduction of electricity is usually convoyed by reversible and irreversible effects, such as electrical resistance and thermal conduction which is used to, Peltier refrigerators, generating electricity, renewable energies and its applications. Telluride films can be used in thermoelectric applications; these thermoelectric materials are mainly rare metals such as (Bi), (Te), (Pb) and (Sb). Thermal conductivity, figure of merit is advantageous factor of these energy storage devices. Thermoelectric cooler, thermoelectric generators are the powerful sources which can be eligible due to the use of telluride thin films. The thermal conductivity performance, figure of merit and Seebeck and Peltier coefficients of diverse materials were conferred.

5.
Climacteric ; 21(1): 53-59, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-29189095

RESUMEN

OBJECTIVE: This study examined relationships, by pregnancy histories, between bone mineral density (BMD) and coronary artery calcification (CAC) in postmenopausal women. METHODS: Forty women identified from their medical record as having pre-eclampsia (PE) were age/parity-matched with 40 women having a normotensive pregnancy (NP). Vertebral (T4-9) BMD and CAC were assessed by quantitative computed tomography in 73 (37 with PE and 36 with NP) of the 80 women. Analyses included linear regression using generalized estimating equations. RESULTS: Women averaged 59 years of age and 35 years from the index pregnancy. There were no significant differences in cortical, trabecular or central BMD between groups. CAC was significantly greater in the PE group (p = 0.026). In multivariable analysis, CAC was positively associated with cortical BMD (p = 0.001) and negatively associated with central BMD (p = 0.036). There was a borderline difference in the association between CAC and central BMD by pregnancy history (interaction, p = 0.057). CONCLUSIONS: Although CAC was greater in women with a history of PE, vertebral BMD did not differ between groups. However, both cortical and central BMD were associated with CAC. The central BMD association was marginally different by pregnancy history, suggesting perhaps differences in underlying mechanisms of soft tissue calcification.


Asunto(s)
Enfermedad de la Arteria Coronaria/complicaciones , Osteoporosis/complicaciones , Preeclampsia , Historia Reproductiva , Calcificación Vascular/diagnóstico por imagen , Absorciometría de Fotón , Densidad Ósea , Enfermedad de la Arteria Coronaria/epidemiología , Femenino , Humanos , Modelos Lineales , Menopausia , Persona de Mediana Edad , Minnesota/epidemiología , Análisis Multivariante , Osteoporosis/epidemiología , Embarazo , Factores de Riesgo , Tomografía Computarizada por Rayos X
6.
J Photochem Photobiol B ; 173: 50-60, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28564630

RESUMEN

Nanomaterials of CeO2 with A. vera were synthesized by using simple chemical method. Grapes drops are used as an oxidizing agent. Structural and morphological studies of nanomaterials of cerium oxide (CeO2), were studied for combustion method of preparation. The precursor solution was initialized by a hydrothermal reaction. Cerium hydroxyl carbonate precursors which involves cerium (III) nitrate Ce(NO3)3. 6 H2O with (1.0M) of seashell powder, 3% A. vera, extracts, grapes and pomegranate drops and this complex solution was used to produce the CeO2 powder particles. We have prepared another sample with 5% of Aloe vera extract and found that 3% Aloe vera extract has lesser grain size and enhanced band gap values, so the article explained the sample analysis of combination with 3% extract of Aloe vera. The product has the rod pattern which was the unusual features appear to originate from the unique crystal chemistry aspects. From the optical absorption spectrum, it has been shown that the CeO2 rods have 3.847eV of direct band gap energy. The minimum inhibitory concentration (MIC) values of the synthesized compounds exhibited activity towards various microbial pathogens such as B. subtilis (15µg/mL), S. aureus (50µg/mL), S. epidermidis (20µg/mL), E. faecalis (25µg/mL) and towards E. coli (100µg/mL), K. pneumoniae (50µg/mL) and P. aeruginosa (75µg/mL) respectively. The tests on bacterial activities confirmed that the CeO2 rods are suitable hand for the biological applications. The seashell structure and the phytochemical contents of A. vera might enhance its bacterial activities.


Asunto(s)
Exoesqueleto/química , Antibacterianos/química , Antibacterianos/síntesis química , Cerio/química , Nanopartículas del Metal/química , Animales , Antibacterianos/farmacología , Frutas/química , Frutas/metabolismo , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Grampositivas/efectos de los fármacos , Tecnología Química Verde , Pruebas de Sensibilidad Microbiana , Extractos Vegetales/química , Especies Reactivas de Oxígeno/metabolismo , Espectroscopía Infrarroja por Transformada de Fourier , Difracción de Rayos X
7.
Climacteric ; 19(1): 49-59, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26652904

RESUMEN

BACKGROUND: Serotonin (5-hydroxytryptamine, 5-HT) is modulated by sex steroid hormones and affects vascular function and mood. In the Kronos Early Estrogen Prevention Cognitive and Affective Ancillary Study (KEEPS-Cog), women randomized to oral conjugated equine estrogens (oCEE) showed greater benefit on affective mood states than women randomized to transdermal 17ß-estradiol (tE2) or placebo (PL). This study examined the effect of these treatments on the platelet content of 5-HT as a surrogate measure of 5-HT synthesis and uptake in the brain. METHODS: The following were measured in a subset (n = 79) of women enrolled in KEEPS-Cog: 5-HT by ELISA, carotid intima-medial thickness (CIMT) by ultrasound, endothelial function by reactive hyperemic index (RHI), and self-reported symptoms of affective mood states by the Profile of Mood States (POMS) questionnaire. RESULTS: Mean platelet content of 5-HT increased by 107.0%, 84.5% and 39.8%, in tE2, oCEE and PL groups, respectively. Platelet 5-HT positively correlated with estrone in the oCEE group and with 17ß- estradiol in the tE2 group. Platelet 5-HT showed a positive association with RHI, but not CIMT, in the PL and oCEE groups. Reduction in mood scores for depression-dejection and anger-hostility was associated with elevations in platelet 5-HT only in the oCEE group (r = -0.5, p = 0.02). CONCLUSIONS: Effects of oCEE compared to tE2 on RHI and mood may be related to mechanisms involving platelet, and perhaps neuronal, uptake and release of 5-HT and reflect conversion of estrone to bioavailable 17ß-estradiol in platelets and the brain.


Asunto(s)
Afecto/efectos de los fármacos , Endotelio Vascular/efectos de los fármacos , Estradiol/administración & dosificación , Terapia de Reemplazo de Estrógeno , Estrógenos Conjugados (USP)/administración & dosificación , Serotonina/sangre , Administración Cutánea , Femenino , Humanos , Persona de Mediana Edad , Posmenopausia
8.
Chem Sci ; 7(5): 3188-3205, 2016 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-29997811

RESUMEN

Seedless, surfactantless and support-free unprotected, metallic, interconnected nano-chain networks of ruthenium nanoparticles (NPs) were successfully synthesized via the reduction of ruthenium(iii) chloride (RuCl3) with sodium borohydride (NaBH4) at three different temperatures, viz. 30 °C, 45 °C and 60 °C. The molar ratio of RuCl3 solution and borohydride was optimized to be 1 : 1.5 to produce stable colloids with the optimum final solution pH of 9.7 ± 0.2. Average diameters of the interconnected nano-chain networks prepared at 30 °C (Ru-30), 45 °C (Ru-45) and 60 °C (Ru-60) were 3.5 ± 0.5 nm, 3.0 ± 0.2 nm and 2.6 ± 0.2 nm respectively. The morphology and composition dependent catalytic and electrocatalytic activities of these unprotected Ru nano-chain networks (Ru-30, Ru-45 and Ru-60) were studied in detail. The catalysis study was performed by investigating the transfer hydrogenation of several substituted aromatic nitro compounds. It was observed that Ru-60 was relatively more active compared to Ru-30 and Ru-45, which was reflected in their rate constant values. The electrocatalytic activities of Ru-30, Ru-45 and Ru-60 were screened for anodic water splitting in alkaline medium (0.1 M NaOH) and it was found that all of them showed almost the same activity which required an over-voltage of 308 ± 2 mV to obtain an anodic current density of 10 mA cm-2. The catalytic and electrocatalytic performances of these unprotected Ru0 networks were compared with Ru0 nanomaterials prepared under similar conditions with three different surfactants, viz. CTAB, SDS and TX-100, which revealed that unprotected Ru0 networks are better catalysts than those stabilized with surfactants. The superior catalytic and electrocatalytic performance is due to the availability of unprotected Ru0 surfaces. The present route may provide a new possibility of synthesizing other surfactant-free, unprotected metal colloids for enhanced catalytic and electrocatalytic applications.

9.
Spectrochim Acta A Mol Biomol Spectrosc ; 118: 1135-43, 2014 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-24184584

RESUMEN

In this work, pure and singe phase SnO2 Nano powder is successfully prepared by simple sol-gel combustion route. The photo luminescence and XRD measurements are made and compared the geometrical parameters with calculated values. The FT-IR and FT-Raman spectra are recorded and the fundamental frequencies are assigned. The optimized parameters and the frequencies are calculated using HF and DFT (LSDA, B3LYP and B3PW91) theory in bulk phase of SnO2 and are compared with its Nano phase. The vibrational frequency pattern in nano phase gets realigned and the frequencies are shifted up to higher region of spectra when compared with bulk phase. The NMR and UV-Visible spectra are simulated and analyzed. Transmittance studies showed that the HOMO-LUMO band gap (Kubo gap) is reduced from 3.47 eV to 3.04 eV while it is heated up to 800°C. The Photoluminescence spectra of SnO2 powder showed a peak shift towards lower energy side with the change of Kubo gap from 3.73 eV to 3.229 eV for as-prepared and heated up to 800°C.


Asunto(s)
Compuestos de Estaño/química , Luminiscencia , Espectroscopía de Resonancia Magnética , Modelos Moleculares , Polvos , Teoría Cuántica , Espectrofotometría Ultravioleta , Espectroscopía Infrarroja por Transformada de Fourier , Espectrometría Raman
10.
Neurology ; 80(10): 911-8, 2013 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-23408873

RESUMEN

OBJECTIVE: To determine the association of conventional cardiovascular risk factors, markers of platelet activation, and thrombogenic blood-borne microvesicles with white matter hyperintensity (WMH) load and progression in recently menopausal women. METHODS: Women (n = 95) enrolled in the Mayo Clinic Kronos Early Estrogen Prevention Study underwent MRI at baseline and at 18, 36, and 48 months after randomization to hormone treatments. Conventional cardiovascular risk factors, carotid intima-medial thickness, coronary arterial calcification, plasma lipids, markers of platelet activation, and thrombogenic microvesicles were measured at baseline. WMH volumes were calculated using a semiautomated segmentation algorithm based on fluid-attenuated inversion recovery MRI. Correlations of those parameters with baseline WMH and longitudinal change in WMH were adjusted for age, months past menopause, and APOE ε4 status in linear regression analysis. RESULTS: At baseline, WMH were present in all women. The WMH to white matter volume fraction at baseline was 0.88% (0.69%, 1.16%). WMH volume increased by 122.1 mm(3) (95% confidence interval: -164.3, 539.5) at 36 months (p = 0.003) and 155.4 mm(3) (95% confidence interval: -92.13, 599.4) at 48 months (p < 0.001). These increases correlated with numbers of platelet-derived and total thrombogenic microvesicles at baseline (p = 0.03). CONCLUSION: Associations of platelet-derived, thrombogenic microvesicles at baseline and increases in WMH suggest that in vivo platelet activation may contribute to a cascade of events leading to development of WMH in recently menopausal women.


Asunto(s)
Plaquetas/patología , Encéfalo/patología , Trombosis Intracraneal/patología , Fibras Nerviosas Mielínicas/patología , Posmenopausia , Adulto , Encéfalo/irrigación sanguínea , Enfermedades Cardiovasculares/patología , Femenino , Humanos , Persona de Mediana Edad , Ensayos Clínicos Controlados Aleatorios como Asunto , Factores de Riesgo
11.
J Mater Sci Mater Med ; 23(2): 329-38, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22113251

RESUMEN

Nanoscale multilayered TiN/VN coatings were developed by reactive dc magnetron sputtering on 316L stainless steel substrates. The coatings showed a polycrystalline cubic structure with (111) preferential growth. XPS analysis indicated the presence of peaks corresponding to Ti2p, V2p, N1s, O1s, and C1s. Raman spectra exhibited the characteristic peaks in the acoustic range of 160-320 cm(-1) and in the optic range between 480 and 695 cm(-1). Columnar structure of the coatings was observed from TEM analysis. The number of adherent platelets on the surface of the TiN/VN multilayer, VN, TiN single layer coating exhibit fewer aggregation and pseudopodium than on substrates. The wear resistance of the multilayer coatings increases obviously as a result of their high hardness. Tafel plots in simulated bodily fluid showed lower corrosion rate for the TiN/VN nanoscale multilayer coatings compared to single layer and bare 316L SS substrate.


Asunto(s)
Acero Inoxidable/química , Titanio/química , Vanadio/química , Acústica , Bacillus/metabolismo , Bacillus megaterium/metabolismo , Adhesión Bacteriana , Materiales Biocompatibles/química , Plaquetas/citología , Plaquetas/metabolismo , Líquidos Corporales/química , Corrosión , Cristalización , Electroquímica/métodos , Dureza , Microscopía Electrónica de Transmisión/métodos , Nanotecnología/métodos , Adhesividad Plaquetaria , Espectrometría Raman/métodos , Estrés Mecánico , Propiedades de Superficie , Difracción de Rayos X
12.
Climacteric ; 12(2): 177-84, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19051075

RESUMEN

BACKGROUND: Estrogen modulates antithrombotic characteristics of the vascular endothelium and the interaction of blood elements with the vascular surface. A marker of these modulatory activities is formation of cell-specific microparticles. This study examined the relationship between blood-borne microparticles and endogenous estrogen at menopause. METHODS: Platelet activation and plasma microparticles were characterized from women being screened (n = 146) for the Kronos Early Estrogen Prevention Study. Women were grouped according to serum estrogen (< 20 pg/ml; low estrogen, n = 21 or > 40 pg/ml; high estrogen, n = 11). RESULTS: Age, body mass index, blood pressure and blood chemistries were the same in both groups. No woman was hypertensive, diabetic or a current smoker. Platelet counts, basal and activated expression of P-selectin on platelet membranes were the same, but activated expression of glycoprotein IIb/IIIa was greater in the high-estrogen group. Numbers of endothelium-, platelet-, monocyte- and granulocyte-derived microparticles were greater in the low-estrogen group. Of the total numbers of microparticles, those positive for phosphatidylserine and tissue factor were also greater in the low-estrogen group. CONCLUSION: These results suggest that, with declines in endogenous estrogen at menopause, numbers of procoagulant microparticles increase and thus may provide a means to explore mechanisms for cardiovascular risk development in newly menopausal women.


Asunto(s)
Micropartículas Derivadas de Células , Estrógenos/sangre , Menopausia/sangre , Plaquetas/química , Plaquetas/ultraestructura , Enfermedades Cardiovasculares , Micropartículas Derivadas de Células/química , Estudios Transversales , Células Endoteliales/ultraestructura , Femenino , Granulocitos/ultraestructura , Humanos , Persona de Mediana Edad , Monocitos/ultraestructura , Fosfatidilserinas/sangre , Recuento de Plaquetas , Complejo GPIIb-IIIa de Glicoproteína Plaquetaria/análisis , Factores de Riesgo
13.
J Colloid Interface Sci ; 328(2): 396-401, 2008 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-18848331

RESUMEN

MgIn(2)O(4), which has an inverse spinel structure, has been adopted as the transparent material in optoelectronic device fabrication due to its high optical transparency and electrical conductivity. Such a technologically important material was prepared by the spray pyrolysis technique. Precursors prepared for the cationic ratio Mg/In=0.5 were thermally sprayed onto glass substrates at 400 and 450 degrees C. We report herein the preparation and characterization of the films by X-ray diffraction (XRD), energy-dispersive absorption X-ray spectroscopy (EDAX), and atomic force microscopy (AFM). The XRD results showed the single phase formation of the material that revealed the presence of Mg(2+) and In(3+) in the inverse spinel-related structure. The FTIR and EDAX results further confirmed that the nanocrystalline films were mainly composed of magnesium, indium, and oxygen, in agreement with XRD analysis. We surmised from the AFM micrographs that the atoms have enough diffusion activation energy to occupy the correct site in the crystal lattice. For the 423-nm-thick magnesium indium oxide films grown at 400 degrees C, the electrical conductivity was 5.63x10(-6) Scm(-1) and the average optical transmittance was 63% in the visible range (400-700 nm). Similar MgIn(2)O(4) films deposited at 450 degrees C have a conductivity value of 1.5x10(-5) Scm(-1) and an average transmittance of 75%. Hall coefficient observations showed n-type electrical conductivity and high electron carrier concentration of 2.7x10(19) cm(-3).

15.
J Phys Condens Matter ; 19(18): 186204, 2007 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-21690985

RESUMEN

In this paper, we report on modification of the structural, optical, vibrational, and surface morphological properties of 2 MeV N(+)-ion irradiated WO(3) thin films at different fluences (up to 1 × 10(15) ions cm(-2)). Although we observe irradiation induced grain growth, no structural phase transition takes place in the WO(3) films. These are accompanied by a systematic reduction in the optical band gap of the films. These observations are corroborated by our independent micro-Raman and optical absorption spectroscopy studies. We have made an attempt to correlate these results with MeV ion-matter interaction.

16.
Int J Clin Pract ; 59(8): 992-4, 2005 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-16033628

RESUMEN

Renal insufficiency because of obstruction may not always be represented by dilated pelvicalyceal system. This may make diagnosis and thence the management very difficult with the present available investigative armamentarium. Experience and clinical acumen may help with a decision of empirical treatment in the form of stenting or nephrostomy in these cases. This may be diagnostic as well as curative of the renal failure. We present herewith three such challenging cases managed by us. We also have reviewed the literature as to the diagnosis and management of such cases.


Asunto(s)
Pelvis Renal/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Obstrucción Ureteral/diagnóstico por imagen , Anciano de 80 o más Años , Diagnóstico Diferencial , Femenino , Humanos , Hidronefrosis/diagnóstico por imagen , Hidronefrosis/cirugía , Masculino , Persona de Mediana Edad , Nefrostomía Percutánea , Obstrucción Ureteral/cirugía
17.
J Obstet Gynaecol ; 25(2): 189-92, 2005 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-15814404

RESUMEN

A solitary fibrous tumour is an unusual spindle cell neoplasm that most frequently occurs in the pleura based intrathoracic region. In recent years attention has been drawn towards solitary fibrous tumours arising in extrathoracic sites. They are usually benign but malignant solitary fibrous tumours have also been reported (Nielson et al. 1997). There is far less information about the clinical behaviour of an extra thoracic solitary fibrous tumour unlike intrathoracic tumours which is well reported in many case series (England et al. 1989). Although solitary fibrous tumours are well described lesions, the occurrence of similar tumours in the pelvic retroperitoneum of women and presenting as pelvic mass have been reported only sporadically. Because of the rarity, unpredictable behaviour; lack of information available about the clinical behaviour (recurrence and metastasis) and lack of follow up protocol, we are reporting this case which we encountered along with the review of previously reported cases.


Asunto(s)
Fibroma/diagnóstico , Neoplasias Retroperitoneales/diagnóstico , Diagnóstico Diferencial , Femenino , Fibroma/diagnóstico por imagen , Fibroma/patología , Fibroma/cirugía , Humanos , Imagen por Resonancia Magnética , Persona de Mediana Edad , Pelvis , Posmenopausia , Neoplasias Retroperitoneales/diagnóstico por imagen , Neoplasias Retroperitoneales/patología , Neoplasias Retroperitoneales/cirugía , Ultrasonografía
18.
Am J Physiol Heart Circ Physiol ; 283(6): H2389-96, 2002 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-12388282

RESUMEN

Our experiments were designed to determine the acute effects of 17beta-estradiol on femoral veins from intact and ovariectomized female pigs. Rings of femoral veins with or without endothelium were suspended in organ chambers for measurement of isometric force. Concentration-response curves to 17beta-estradiol (10(-9) to 10(-5) M) were obtained in veins contracted with prostaglandin F(2alpha) in the absence and presence of inhibitors of either estrogen receptors (ICI-182780; 10(-5) M), nitric oxide synthase [N(G)-monomethyl-l-arginine (l-NMMA); 10(-4) M], soluble guanylate cyclase (1-H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one; 10(-5) M), or potassium channels (tetraethylammonium; 10(-2) M). Estrogen receptors were identified with the use of Western blotting and immunostaining in veins of both groups. 17beta-Estradiol caused acute endothelium-dependent relaxations in both groups. Relaxations to 17beta-estradiol were inhibited by l-NMMA and 1-H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one but not ICI-182780. Tetraethylammonium inhibited relaxations only in veins with endothelium from intact females. Results indicate that 17beta-estradiol causes acute endothelium-dependent relaxations in femoral veins. The relative contribution of nitric oxide and K(+) channels as mechanisms involved in relaxations to 17beta-estradiol in femoral veins is modulated by ovarian status.


Asunto(s)
Estradiol/análogos & derivados , Estradiol/farmacología , Vena Femoral/efectos de los fármacos , Vena Femoral/fisiología , Animales , Dinoprost/farmacología , Relación Dosis-Respuesta a Droga , Inhibidores Enzimáticos/farmacología , Femenino , Vena Femoral/citología , Fulvestrant , Inmunohistoquímica , Técnicas In Vitro , Ovariectomía , Bloqueadores de los Canales de Potasio/farmacología , Receptores de Estrógenos/antagonistas & inhibidores , Estereoisomerismo , Porcinos , Vasoconstricción/efectos de los fármacos , Vasoconstricción/fisiología , Vasodilatación/efectos de los fármacos , Vasodilatación/fisiología
19.
Life Sci ; 69(14): 1651-60, 2001 Aug 24.
Artículo en Inglés | MEDLINE | ID: mdl-11589505

RESUMEN

17beta-estradiol up-regulates endothelial nitric oxide synthase (eNOS) expression in cultured endothelial cells. To clarify the role of mRNA stabilization in upregulation of eNOS expression, endothelial cells were incubated with actinomycin D as transcriptional inhibitor. Up to 10 hours incubation with 17beta-estradiol alone did not affect significantly the stability of eNOS mRNA. As tumor necrosis factor-alpha (TNF-alpha) is associated with the progression of atherosclerosis, we examined the effect of 17beta-estradiol on eNOS mRNA destabilization with TNF-alpha. After 10 hours co-incubation with TNF-alpha, relative intensity of eNOS mRNA decreased to 50% of the intensity at the start time of incubation, however, it remained significantly 1.6 times in the presence of 17beta-estradiol. This inhibitory effect of 17beta-estradiol was abolished by the treatment of estrogen receptor antagonist, ICI 182,780. This is the first finding that 17beta-estradiol stabilizes eNOS mRNA destabilized by TNF-alpha through estrogen receptor mediated mechanism.


Asunto(s)
Estrógenos/fisiología , Óxido Nítrico Sintasa/genética , ARN Mensajero/genética , Receptores de Estrógenos/fisiología , Factor de Necrosis Tumoral alfa/fisiología , Animales , Aorta/citología , Aorta/efectos de los fármacos , Bovinos , Dactinomicina/farmacología , Endotelio Vascular/citología , Endotelio Vascular/efectos de los fármacos , Activación Enzimática , Estradiol/análogos & derivados , Estradiol/farmacología , Antagonistas de Estrógenos/farmacología , Fulvestrant , Óxido Nítrico Sintasa de Tipo III , ARN Mensajero/biosíntesis , Receptores de Estrógenos/antagonistas & inhibidores , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
20.
Am J Physiol Heart Circ Physiol ; 281(3): H1327-33, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11514304

RESUMEN

Endothelial nitric oxide synthase (eNOS) is regulated both by caveolin-1 and 17beta-estradiol (E(2)). Temporal relationships between effects of estrogen on caveolin-1 and nitric oxide (NO) are not known. Therefore, this study was designed to determine whether estrogen regulates caveolin-1 and, if so, whether such regulation corresponds to changes in nitrite/nitrate (NO(x)) production. Bovine aortic endothelial cells (BAECs) were cultured in the absence and presence of 17beta-estradiol or 17alpha-estradiol (10(-8) and 10(-10) M) for 12, 24, and 48 h. eNOS protein expression and NO(x) production increased significantly after 24 h but not after 12-h treatment with 17beta- and not 17alpha-estradiol. Both mRNA and protein for caveolin-1 were increased significantly only after 48-h treatment with E(2), but eNOS protein and NO(x) production were decreased compared with cells treated for 24 h. These increases in caveolin-1 were inhibited by the estrogen receptor antagonist ICI-182,780 (10(-6) M). Results of this study suggest that E(2) stimulates caveolin-1 transcription and translation through estrogen receptor-mediated mechanisms. The results further suggest that estrogen may indirectly regulate NO(x) through caveolin-1 expression, which inhibits eNOS catalytic activity.


Asunto(s)
Caveolinas/metabolismo , Endotelio Vascular/efectos de los fármacos , Endotelio Vascular/metabolismo , Estradiol/farmacología , ARN Mensajero/metabolismo , Animales , Aorta , Bovinos , Caveolina 1 , Caveolinas/genética , Caveolinas/farmacología , Células Cultivadas , Activación Enzimática/efectos de los fármacos , Estradiol/análogos & derivados , Antagonistas de Estrógenos/farmacología , Femenino , Fulvestrant , Expresión Génica/efectos de los fármacos , Masculino , Nitratos/metabolismo , Óxido Nítrico Sintasa/metabolismo , Óxido Nítrico Sintasa de Tipo III , Nitritos/metabolismo , Estereoisomerismo , Factores de Tiempo
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