Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.196
Filtrar
1.
Eur Rev Med Pharmacol Sci ; 27(22): 11103-11108, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38039041

RESUMO

OBJECTIVE: Methotrexate (MTX) is a folic acid antagonist used in chronic inflammatory diseases and various cancer treatments. Although the main mechanism of the toxic effect of MTX is not known, it is stated that it causes oxidative stress and inflammation. Alpha-linolenic acid (ALA) protects against oxidative stress, apoptosis, and inflammation. For this reason, we aimed to find out the useful effect of ALA on MTX-induced nephrotoxicity MATERIALS AND METHODS: The mice were divided into 4 groups randomly. The control group was treated with physiological saline solution; the ALA group was treated with ALA (200 mg/kg) by gavage; MTX-treated group received 20 mg/kg i.p. (intraperitoneal) MTX; and MTX+ALA treated group received 20 mg/kg i.p. MTX and ALA 200 mg/kg by gavage. All of the drugs were performed once a day for 9 days. RESULTS: Alpha-linolenic acid significantly decreased oxidative stress parameters and MTX-induced inflammatory and apoptotic mediators. Furthermore, histopathological examination showed that MTX induced significant edematous damage, and ALA treatment attenuated this damage in renal tissue. CONCLUSIONS: Our results revealed that ALA may be helpful against MTX-induced nephrotoxicity in mice via its antioxidant and anti-inflammatory properties.


Assuntos
Metotrexato , Ácido alfa-Linolênico , Camundongos , Animais , Metotrexato/toxicidade , Ácido alfa-Linolênico/farmacologia , Ácido alfa-Linolênico/metabolismo , Antioxidantes/metabolismo , Estresse Oxidativo , Inflamação/metabolismo , Rim/patologia
2.
Science ; 377(6603): 285-291, 2022 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-35857591

RESUMO

Carbonaceous asteroids, such as (101955) Bennu, preserve material from the early Solar System, including volatile compounds and organic molecules. We report spacecraft imaging and spectral data collected during and after retrieval of a sample from Bennu's surface. The sampling event mobilized rocks and dust into a debris plume, excavating a 9-meter-long elliptical crater. This exposed material is darker, spectrally redder, and more abundant in fine particulates than the original surface. The bulk density of the displaced subsurface material was 500 to 700 kilograms per cubic meter, which is about half that of the whole asteroid. Particulates that landed on instrument optics spectrally resemble aqueously altered carbonaceous meteorites. The spacecraft stored 250 ± 101 grams of material, which will be delivered to Earth in 2023.

3.
Bratisl Lek Listy ; 121(11): 801-804, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33164541

RESUMO

OBJECTIVES: Cutaneous squamous cell carcinoma (cSCC) is a common cancer in Caucasian populations. Treatments registered for high-risk cSCC are still undetermined. Experimental data have demonstrated possibly useful effects of a combined application of beta­blockers in cancer therapy. The goal of this study was to examine the efficacy of propranolol in the treatment of cSCC and its impact on apoptosis. Thus, we aimed to investigate the apoptotic pathway protein levels and activity in beta­blocker­treated cSCC cells. MATERIALS AND METHODS: The study was performed on human cSCC cancer cell line culture. One of the cSCC cell lines was treated with propranolol, whereas no treatment was given to the other group. Then, the levels of apoptotic pathway proteins were determined by ELISA test in both groups. RESULTS: The propranolol treatment group exhibited a remarkable difference as compared with the other group. It was found that propranolol treatment enhanced the activity of caspase-3 while the expression of bax, wee1, gadd153, grp78 and AIF decreased bcl-2 which is antiapoptotic protein in cSCC cell lines. CONCLUSION: Our results suggest that propranolol treatment has anti-cancer properties with an effect on various apoptotic pathways in cSCC. These data are important because propronalol may be involved in future cSCC treatment (Tab. 1, Fig. 3, Ref. 22).


Assuntos
Apoptose , Carcinoma de Células Escamosas/patologia , Propranolol/farmacologia , Neoplasias Cutâneas/patologia , Carcinoma de Células Escamosas/tratamento farmacológico , Linhagem Celular Tumoral , Proliferação de Células , Chaperona BiP do Retículo Endoplasmático , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Cutâneas/tratamento farmacológico
4.
Eur J Radiol ; 133: 109402, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33190102

RESUMO

INTRODUCTION: Computed Tomography is an essential diagnostic tool in the management of COVID-19. Considering the large amount of examinations in high case-load scenarios, an automated tool could facilitate and save critical time in the diagnosis and risk stratification of the disease. METHODS: A novel deep learning derived machine learning (ML) classifier was developed using a simplified programming approach and an open source dataset consisting of 6868 chest CT images from 418 patients which was split into training and validation subsets. The diagnostic performance was then evaluated and compared to experienced radiologists on an independent testing dataset. Diagnostic performance metrics were calculated using Receiver Operating Characteristics (ROC) analysis. Operating points with high positive (>10) and low negative (<0.01) likelihood ratios to stratify the risk of COVID-19 being present were identified and validated. RESULTS: The model achieved an overall accuracy of 0.956 (AUC) on an independent testing dataset of 90 patients. Both rule-in and rule out thresholds were identified and tested. At the rule-in operating point, sensitivity and specificity were 84.4 % and 93.3 % and did not differ from both radiologists (p > 0.05). At the rule-out threshold, sensitivity (100 %) and specificity (60 %) differed significantly from the radiologists (p < 0.05). Likelihood ratios and a Fagan nomogram provide prevalence independent test performance estimates. CONCLUSION: Accurate diagnosis of COVID-19 using a basic deep learning approach is feasible using open-source CT image data. In addition, the machine learning classifier provided validated rule-in and rule-out criteria could be used to stratify the risk of COVID-19 being present.


Assuntos
COVID-19/diagnóstico por imagem , Aprendizado Profundo , Pulmão/diagnóstico por imagem , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Tomografia Computadorizada por Raios X/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Curva ROC , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
5.
Sci Adv ; 6(41)2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33033037

RESUMO

Thermal inertia and surface roughness are proxies for the physical characteristics of planetary surfaces. Global maps of these two properties distinguish the boulder population on near-Earth asteroid (NEA) (101955) Bennu into two types that differ in strength, and both have lower thermal inertia than expected for boulders and meteorites. Neither has strongly temperature-dependent thermal properties. The weaker boulder type probably would not survive atmospheric entry and thus may not be represented in the meteorite collection. The maps also show a high-thermal inertia band at Bennu's equator, which might be explained by processes such as compaction or strength sorting during mass movement, but these explanations are not wholly consistent with other data. Our findings imply that other C-complex NEAs likely have boulders similar to those on Bennu rather than finer-particulate regoliths. A tentative correlation between albedo and thermal inertia of C-complex NEAs may be due to relative abundances of boulder types.

6.
Science ; 370(6517)2020 11 06.
Artigo em Inglês | MEDLINE | ID: mdl-33033155

RESUMO

The composition of asteroids and their connection to meteorites provide insight into geologic processes that occurred in the early Solar System. We present spectra of the Nightingale crater region on near-Earth asteroid Bennu with a distinct infrared absorption around 3.4 micrometers. Corresponding images of boulders show centimeters-thick, roughly meter-long bright veins. We interpret the veins as being composed of carbonates, similar to those found in aqueously altered carbonaceous chondrite meteorites. If the veins on Bennu are carbonates, fluid flow and hydrothermal deposition on Bennu's parent body would have occurred on kilometer scales for thousands to millions of years. This suggests large-scale, open-system hydrothermal alteration of carbonaceous asteroids in the early Solar System.

7.
Science ; 370(6517)2020 11 06.
Artigo em Inglês | MEDLINE | ID: mdl-33033157

RESUMO

Visible-wavelength color and reflectance provide information about the geologic history of planetary surfaces. Here we present multispectral images (0.44 to 0.89 micrometers) of near-Earth asteroid (101955) Bennu. The surface has variable colors overlain on a moderately blue global terrain. Two primary boulder types are distinguishable by their reflectance and texture. Space weathering of Bennu surface materials does not simply progress from red to blue (or vice versa). Instead, freshly exposed, redder surfaces initially brighten in the near-ultraviolet region (i.e., become bluer at shorter wavelengths), then brighten in the visible to near-infrared region, leading to Bennu's moderately blue average color. Craters indicate that the time scale of these color changes is ~105 years. We attribute the reflectance and color variation to a combination of primordial heterogeneity and varying exposure ages.

8.
Niger J Clin Pract ; 23(2): 252-257, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32031102

RESUMO

OBJECTIVE: Obstructive sleep apnea syndrome (OSAS) is a highly prevalent breathing disorder in sleep. The aim of this study was to evaluate the relationship between OSAS and prolidase activity, the oxidative stress index (OSI), total antioxidative capacity (TAC), total oxidative capacity (TOC) and the carotid intima media thickness (CIMT). METHOD: : After night polysomnography, 74 people were diagnosed with OSAS and simple snoring. Plasma prolidase activities, TAC and TOC were measured in blood samples taken in the morning after the sleep study. The patients' bilateral common carotid arteries were scanned. RESULTS: In total, 56 patients were in OSAS group [13 subjects 23.2% mild, 19 subjects 33.9% moderate, 24 subjects 42.8% severe] and 18 in simple snoring control group. The mean Prolidase, TOC, TAC and OSI levels were 744.7 ± 156.8, 59.2 ± 19.2, 2.12 ± 0.41, 3.12 ± 1.03, in the mild OSAS group, 761.6 ± 114.4, 57.9 ± 18.3, 2.03 ± 0.37, 3.15 ± 0.8, in the moderate OSAS group, 754.08 ± 133.9, 51.15 ± 12.1, 1.97 ± 0.27, 2.8 ± 0.82, in the severe OSAS group, and 711.9 ± 139, 52.3 ± 15.1, 1.83 ± 0.32, 3.06 ± 0.92 in the control group, respectively. Mean CIMT measurements were 0.71(±0,13) in the OSAS group and 0.76(±0.07) in the control group. CONCLUSION: There was no difference between the control and OSAS groups in terms of the parameters studied. Further studies should be undertaken in order to clarify the relation.


Assuntos
Antioxidantes/metabolismo , Artéria Carótida Primitiva/diagnóstico por imagem , Artéria Carótida Primitiva/fisiopatologia , Espessura Intima-Media Carotídea , Dipeptidases/sangue , Estresse Oxidativo/fisiologia , Apneia Obstrutiva do Sono/fisiopatologia , Sono/fisiologia , Ronco/fisiopatologia , Adulto , Biomarcadores/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Polissonografia , Apneia Obstrutiva do Sono/sangue , Apneia Obstrutiva do Sono/diagnóstico , Ronco/diagnóstico
9.
Nat Astron ; 3(4): 332-340, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31360777

RESUMO

Early spectral data from the Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) mission reveal evidence for abundant hydrated minerals on the surface of near-Earth asteroid (101955) Bennu in the form of a near-infrared absorption near 2.7 µm and thermal infrared spectral features that are most similar to those of aqueously altered CM carbonaceous chondrites. We observe these spectral features across the surface of Bennu, and there is no evidence of substantial rotational variability at the spatial scales of tens to hundreds of meters observed to date. In the visible and near-infrared (0.4 to 2.4 µm) Bennu's spectrum appears featureless and with a blue (negative) slope, confirming previous ground-based observations. Bennu may represent a class of objects that could have brought volatiles and organic chemistry to Earth.

10.
Appl Radiat Isot ; 149: 182-199, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31075563

RESUMO

We report the results of an experiment conducted near the High Flux Isotope Reactor of Oak Ridge National Laboratory, designed to address the question of whether a flux of reactor-generated electron antineutrinos (ν¯e) can alter the rates of weak nuclear interaction induced decays of 54Mn, 22Na, and 60Co. This experiment has small statistical errors but, when systematic uncertainties are included, has null results. Perturbations greater than one part in 104 are excluded at 95% confidence level in ß± decay and electron capture processes, in the presence of an antineutrino flux of 3 × 1012 cm-2s-1. The present experimental methods are applicable to a wide range of radionuclides. Improved sensitivity in future experiments can be anticipated as we continue to better understand and reduce the dominant systematic uncertainties.

11.
Nature ; 568(7750): 55-60, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30890786

RESUMO

NASA'S Origins, Spectral Interpretation, Resource Identification and Security-Regolith Explorer (OSIRIS-REx) spacecraft recently arrived at the near-Earth asteroid (101955) Bennu, a primitive body that represents the objects that may have brought prebiotic molecules and volatiles such as water to Earth1. Bennu is a low-albedo B-type asteroid2 that has been linked to organic-rich hydrated carbonaceous chondrites3. Such meteorites are altered by ejection from their parent body and contaminated by atmospheric entry and terrestrial microbes. Therefore, the primary mission objective is to return a sample of Bennu to Earth that is pristine-that is, not affected by these processes4. The OSIRIS-REx spacecraft carries a sophisticated suite of instruments to characterize Bennu's global properties, support the selection of a sampling site and document that site at a sub-centimetre scale5-11. Here we consider early OSIRIS-REx observations of Bennu to understand how the asteroid's properties compare to pre-encounter expectations and to assess the prospects for sample return. The bulk composition of Bennu appears to be hydrated and volatile-rich, as expected. However, in contrast to pre-encounter modelling of Bennu's thermal inertia12 and radar polarization ratios13-which indicated a generally smooth surface covered by centimetre-scale particles-resolved imaging reveals an unexpected surficial diversity. The albedo, texture, particle size and roughness are beyond the spacecraft design specifications. On the basis of our pre-encounter knowledge, we developed a sampling strategy to target 50-metre-diameter patches of loose regolith with grain sizes smaller than two centimetres4. We observe only a small number of apparently hazard-free regions, of the order of 5 to 20 metres in extent, the sampling of which poses a substantial challenge to mission success.


Assuntos
Meio Ambiente Extraterreno/química , Planetas Menores , Voo Espacial , Exobiologia , Origem da Vida , Voo Espacial/instrumentação , Propriedades de Superfície
12.
Nature ; 551(7682): 601-604, 2017 11 29.
Artigo em Inglês | MEDLINE | ID: mdl-29189781

RESUMO

A quantum simulator is a type of quantum computer that controls the interactions between quantum bits (or qubits) in a way that can be mapped to certain quantum many-body problems. As it becomes possible to exert more control over larger numbers of qubits, such simulators will be able to tackle a wider range of problems, such as materials design and molecular modelling, with the ultimate limit being a universal quantum computer that can solve general classes of hard problems. Here we use a quantum simulator composed of up to 53 qubits to study non-equilibrium dynamics in the transverse-field Ising model with long-range interactions. We observe a dynamical phase transition after a sudden change of the Hamiltonian, in a regime in which conventional statistical mechanics does not apply. The qubits are represented by the spins of trapped ions, which can be prepared in various initial pure states. We apply a global long-range Ising interaction with controllable strength and range, and measure each individual qubit with an efficiency of nearly 99 per cent. Such high efficiency means that arbitrary many-body correlations between qubits can be measured in a single shot, enabling the dynamical phase transition to be probed directly and revealing computationally intractable features that rely on the long-range interactions and high connectivity between qubits.

13.
Philos Trans A Math Phys Eng Sci ; 375(2108)2017 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-29084886

RESUMO

Linear arrays of trapped and laser-cooled atomic ions are a versatile platform for studying strongly interacting many-body quantum systems. Effective spins are encoded in long-lived electronic levels of each ion and made to interact through laser-mediated optical dipole forces. The advantages of experiments with cold trapped ions, including high spatio-temporal resolution, decoupling from the external environment and control over the system Hamiltonian, are used to measure quantum effects not always accessible in natural condensed matter samples. In this review, we highlight recent work using trapped ions to explore a variety of non-ergodic phenomena in long-range interacting spin models, effects that are heralded by the memory of out-of-equilibrium initial conditions. We observe long-lived memory in static magnetizations for quenched many-body localization and prethermalization, while memory is preserved in the periodic oscillations of a driven discrete time crystal state.This article is part of the themed issue 'Breakdown of ergodicity in quantum systems: from solids to synthetic matter'.

14.
Refuat Hapeh Vehashinayim (1993) ; 34(2): 79-83, 91, 2017 04.
Artigo em Hebraico | MEDLINE | ID: mdl-30699481

RESUMO

Oketz is a military special unit that operates different dog species for various missions. The dogs get routine medical and dental treatments in order to maintain their health and function. The dental treatment is based on the principles of contemporary dentistry for small animals. Furthermore, these working dogs need special care due to higher risk to trauma and attrition. The dogs go through routine dental examination and prophylactic dental cleaning. Each dental procedure is performed under general anesthesia; therefore it is well planned ahead including all the pre-operative workup needed. The article presents the current concepts of dental treatment of dogs especially in respect to their activity.


Assuntos
Assistência Odontológica/veterinária , Odontologia Militar/métodos , Serviço Veterinário Militar/métodos , Anestesia Geral/veterinária , Animais , Assistência Odontológica/métodos , Cães , Humanos , Israel , Odontologia Militar/organização & administração , Militares , Serviço Veterinário Militar/organização & administração
15.
Paediatr Int Child Health ; 35(3): 213-9, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26134488

RESUMO

BACKGROUND: At the time of the research, Dr Weiss was a clinical fellow in neonatal-perinatal medicine at Baylor College of Medicine, Texas Children's Hospital. Dr Profit was on faculty at Baylor College of Medicine, Texas Children's Hospital, Department of Pediatrics, Section of Neonatology. He held a secondary appointment in the Department of Medicine, Section of Health Services Research and conducted his research at the VA Health Services Research and Development Center of Excellence where he collaborated with Dr Kowalkowski.: Improving the quality of neonatal intensive care is an important health policy priority in Mexico. A formal assessment of barriers and priorities for quality improvement has not been undertaken. AIM: To provide guidance to providers and policy makers with regard to addressing opportunities for better care delivery in Mexican neonatal intensive care units. OBJECTIVE: To conduct a needs assessment regarding improvement of quality of neonatal intensive care delivery in Mexico. METHODS: Spanish-language survey administered to a volunteer sample of Mexican neonatal care providers attending a large paediatric conference in Mexico in June 2011. Survey domains included institutional context of quality improvement, barriers, priorities, safety culture, and respondents' characteristics. Results were analysed using descriptive analyses of frequencies, proportions and percentage positive response (PPR) rates. RESULTS: Of 91 respondents, the majority identified neonatology as their primary specialty (n = 48, 65%) and were physicians (n = 55, 73%). Generally, providers expressed a desire to improve quality of care (PPR 69%) but reported notable deterrents. Respondents (n, %) identified family inability to pay (38, 48%), overcrowded work areas (38, 44%), insufficient financial reimbursement (25, 36%), lack of availability of nurses (26, 30%), ancillary staff (25, 29%), and subspecialists (22, 25%) as the principal barriers. Respiratory care (27, 39%)--reduction of mechanical ventilation and initiation of nasal continuous positive airway pressure--and reduction in frequency of late-onset infections (19, 28%) were selected as top clinical priorities. There were substantial opportunities for improving safety (PPR 48%) and teamwork climate (PPR 58%). CONCLUSION: These findings may guide efforts to improving quality of care delivery in Mexican neonatal intensive care units.


Assuntos
Terapia Intensiva Neonatal/métodos , Terapia Intensiva Neonatal/organização & administração , Avaliação das Necessidades , Feminino , Humanos , Masculino , México , Qualidade da Assistência à Saúde
16.
Child Care Health Dev ; 41(3): 459-66, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-24865813

RESUMO

BACKGROUND: Previous research has demonstrated a relationship between prepubertal alcohol and tobacco use and delayed pubertal characteristics in girls. Although, laboratory research indicates that alcohol and tobacco use inhibits sexual maturation in male rats, human research in this area is lacking. To address this question among boys, we conducted a study to explore the association between early use of alcohol and tobacco and time to development of secondary sexual characteristics. METHODS: The study population included 3199 boys interviewed between the ages of 11 and 21. Participants reported the ages at which they first experienced body hair growth, deepening of the voice and facial hair growth. Early alcohol and tobacco use were defined as first use preceding the age of pubertal development among those reporting regular consumption patterns. Hazard ratios (HR) and 95% confidence intervals (CI) were calculated using Cox proportional hazard models. RESULTS: Early alcohol use was associated with longer time to body hair growth (HR 0.77; 95% CI 0.69-0.87), voice changes (HR 0.72; 95% CI 0.64-0.82) and facial hair growth (HR 0.77; 95% CI 0.68-0.86), after adjusting for tobacco use and age at interview. Tobacco use was not independently associated with the puberty indicators after controlling for alcohol use and age at interview. CONCLUSIONS: Our findings are consistent with the hypothesis that alcohol may inhibit puberty onset in boys, an association that has been previously observed among young girls. Thus, alcohol may be an exposure deserving more scrutiny as a disruptor to normal pubertal development.


Assuntos
Desenvolvimento do Adolescente/fisiologia , Consumo de Bebidas Alcoólicas/fisiopatologia , Puberdade Tardia/fisiopatologia , Uso de Tabaco/fisiopatologia , Adolescente , Fatores Etários , Consumo de Bebidas Alcoólicas/efeitos adversos , Criança , Estudos Transversais , Humanos , Estudos Longitudinais , Masculino , Puberdade Tardia/induzido quimicamente , Fatores de Risco , Texas , Uso de Tabaco/efeitos adversos , Adulto Jovem
17.
J Perinatol ; 34(11): 867-72, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24921412

RESUMO

OBJECTIVE: Neonatal abstinence syndrome (NAS) is a drug withdrawal syndrome experienced by opioid-exposed infants. There is no standard treatment for NAS and surveys suggest wide variation in pharmacotherapy for NAS. Our objective was to determine whether different pharmacotherapies for NAS are associated with differences in outcomes and to determine whether pharmacotherapy and outcome vary by hospital. STUDY DESIGN: We used the Pediatric Health Information System Database from 2004 to 2011 to identify a cohort of infants with NAS requiring pharmacotherapy. Mixed effects hierarchical negative binomial models evaluated the association between pharmacotherapy and hospital with length of stay (LOS), length of treatment (LOT) and hospital charges, after adjusting for socioeconomic variables and comorbid clinical conditions. RESULT: Our cohort included 1424 infants with NAS from 14 children's hospitals. Among hospitals in our sample, six used morphine, six used methadone and two used phenobarbital as primary initial treatment for NAS. In multivariate analysis, when compared with NAS patients initially treated with morphine, infants treated with methadone had shorter LOT (incidence rate ratio (IRR) = 0.55; P < 0.0001) and LOS (IRR = 0.60; P < 0.0001). Phenobarbital as a second-line agent was associated with increased LOT (IRR = 2.09; P<0.0001), LOS (IRR = 1.78; P < 0.0001) and higher hospital charges (IRR = 1.84; P < 0.0001). After controlling for case-mix, hospitals varied in LOT, LOS and hospital charges. CONCLUSION: We found variation in hospital in treatment for NAS among major US children's hospitals. In analyses controlling for possible confounders, methadone as initial treatment was associated with reduced LOT and hospital stay.


Assuntos
Síndrome de Abstinência Neonatal/tratamento farmacológico , Padrões de Prática Médica/estatística & dados numéricos , Comorbidade , Feminino , Preços Hospitalares , Hospitais Pediátricos , Humanos , Recém-Nascido , Tempo de Internação , Masculino , Análise Multivariada , Síndrome de Abstinência Neonatal/epidemiologia , Fenobarbital/uso terapêutico , Estudos Retrospectivos , Estados Unidos
18.
Surg Neurol Int ; 4: 74, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23776760

RESUMO

BACKGROUND: Thymomas are typically benign tumors of thymic epithelium. Metastases to distal sites, particularly intracranial locations, are extremely rare. Herein, we present the third case of thymoma and the second invasive thymoma to metastasize to the cavernous sinus, adjacent to the pituitary. CASE DESCRIPTION: A 41-year-old female patient presented with headaches, stuffy nose, and drooping of the right face. A magnetic resonance imaging scan revealed a complex, multilobulated mass centered upon the right cavernous sinus. The mass was removed via transsphenoidal surgery, and histopathological investigation confirmed the diagnosis of metastatic thymoma. A positron emission tomography-computed tomography scan demonstrated a large anterior mediastinal mass. A biopsy confirmed the diagnosis of invasive thymoma morphologically identical to the World Health Organization type B2 sellar region metastasis. CONCLUSION: Although rare, thymomas can metastasize to the central nervous system. Our case is the second invasive thymoma to metastasize to the cavernous sinus, adjacent to the pituitary.

19.
Stem Cells Int ; 2012: 263264, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22550501

RESUMO

To determine the effect of membrane brightness on multifocal electroretinograms (mfERGs), we implanted poly lactic-co-glycolic acid (PLGA) membranes in the subretinal space of 11 porcine eyes. We compared membranes with their native shiny white color with membranes that were stained with a blue dye (Brilliant Blue). Histological and electrophysiological evaluation of the overlying retina was carried out 6 weeks after implantation. Histologically, both white and blue membranes degraded in a spongiform manner leaving a disrupted outer retina with no preserved photoreceptor segments. Multifocal ERG revealed the white membranes to have a significantly higher P1-amplitude ratio than the blue (P = 0.027), and a correlation between brightness ratio and P1-amplitude ratio was found (r = 0.762). Based on our findings, we conclude that bright subretinal objects can produce normal mfERG amplitude ratios even when the adjacent photoreceptors are missing. Functional assessment with mfERG in scaffold implant studies should therefore be evaluated with care.

20.
Stem Cells Int ; 2012: 454295, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22550509

RESUMO

Biodegradable scaffolds play an important adjunct role in transplantation of retinal progenitor cells (RPCs) to the subretinal space. Poly(ε-Caprolactone) (PCL) scaffolds with different modifications were subretinally implanted in 28 porcine eyes and evaluated by multifocal electroretinography (mfERG) and histology after 6 weeks of observation. PCL Short Nanowire, PCL Electrospun, and PCL Smooth scaffolds were well tolerated in the subretinal space in pigs and caused no inflammation and limited tissue disruption. PCL Short Nanowire had an average rate of preserved overlying outer retina 17% higher than PCL Electrospun and 25% higher than PCL Smooth. Furthermore, PCL Short Nanowire was found to have the most suitable degree of stiffness for surgical delivery to the subretinal space. The membrane-induced photoreceptor damage could be shown on mfERG, but the reductions in P1 amplitude were only significant for the PCL Smooth. We conclude that of the tested scaffolds, PCL Short Nanowire is the best candidate for subretinal implantation.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...