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1.
Biomed Opt Express ; 14(12): 6521-6541, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-38420323

RESUMO

Optical biometers are routinely used to measure intraocular distances in ophthalmic applications such as cataract surgery planning or myopia monitoring. However, due to their high cost and reduced transportability, access to them for screening and surgical planning is still limited in low-resource and remote settings. To increase patients' access to optical biometry we propose a novel low-cost frequency-domain optical delay line (FD-ODL) based on an inexpensive stepper motor spinning a tilted mirror, for integration into a time-domain (TD)-biometer, amenable to a compact footprint. In the proposed FD-ODL, the axial scan range and the A-scan rate are decoupled from one another, as the former only depends on the spinning mirror tilt angle, while the A-scan rate only depends on the motor shaft rotational speed. We characterized the scanning performance and specifications for two spinning mirror tilt angles, and compared them to those of the standard, more expensive FD-ODL implementation, employing a galvanometric scanner for group delay generation. A prototype of the low-cost FD-ODL with a 1.5 deg tilt angle, resulting in an axial scan range of 6.61 mm and an A-scan rate of 10 Hz was experimentally implemented and integrated in a dual sample beam optical low-coherence reflectometry (OLCR) setup with a detour unit to replicate the measurement window around the anterior segment and the retina. The intraocular distances of a model eye were measured with the proposed low-cost biometer and found to be in good agreement with those acquired by a custom swept-source optical coherence tomography (SS-OCT) system and two commercial biometers, validating our novel design.

2.
MethodsX ; 9: 101802, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36034524

RESUMO

Partial evaluation (PE) is a branch of computer science that achieves code optimization via specialization. This article describes a PE methodology for optimizing rewrite theories that encode concurrent as well as nondeterministic systems by means of the Maude language. The main advantages of the proposed methodology can be summarized as follows:•An automatic program optimization technique for rewrite theories featuring several PE criteria that support the specialization of a broad class of rewrite theories.•An incremental partial evaluation modality that allows the key specialization components to be encapsulated at the desired granularity level to facilitate progressive refinements of the specialization.•All executability theory requirements are preserved by the PE transformation. Also the transformation ensures the semantic equivalence between the original rewrite theory and the specialized theory under rather mild conditions.

3.
Front Oncol ; 11: 740782, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34868937

RESUMO

Human WHO grade 1 meningiomas are generally considered benign tumors; despite this, they account for ≈50% of all recurrent meningiomas. Currently, limited data exist about the mutational profiles of grade 1 meningiomas and patient outcome. We investigated the genetic variants present in 32 WHO grade 1 meningiomas using whole exome sequencing, and correlated gene mutational profiles with tumor cytogenetics and patient outcome. Overall, WHO grade 1 meningiomas harbored numerous and heterogeneous genetic variants, which most frequently affected the NF2 (47%) gene and to a less extent the PNMA6A (22%), TIGD1 (16%), SMO (13%), PTEN (13%), CREG2 (9%), EEF1A1 (6%), POLR2A (6%), ARID1B (3%), and FAIM3 (3%) genes. Notably, non-synonymous genetic variants of SMO and POLR2A were restricted to diploid meningiomas, whereas NF2 mutations were only found among tumors that showed -22/22q─ (with or without a complex karyotype). Based on NF2 mutations and tumor cytogenetics, four genetic profiles were defined with an impact on patient recurrence-free survival (RFS). These included (1) two good-prognosis tumor subgroups-diploid meningiomas (n=9) and isolated -22/22q─ associated with NF2 mutation (n=7)-with RFS rates at 10 y of 100%; and (2) two subgroups of poor-prognosis meningiomas-isolated -22/22q─ without NF2 mutation (n=3) and tumors with complex karyotypes (n=11)-with a RFS rate at 10 y of 48% (p=0.003). Our results point out the existence of recurrent but heterogeneous mutational profiles in WHO grade 1 meningiomas which have an impact on patient outcome.

4.
Biomed Opt Express ; 11(11): 6337-6355, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-33282494

RESUMO

Corneal biomechanics play a fundamental role in the genesis and progression of corneal pathologies, such as keratoconus; in corneal remodeling after corneal surgery; and in affecting the measurement accuracy of glaucoma biomarkers, such as the intraocular pressure (IOP). Air-puff induced corneal deformation imaging reveals information highlighting normal and pathological corneal response to a non-contact mechanical excitation. However, current commercial systems are limited to monitoring corneal deformation only on one corneal meridian. Here, we present a novel custom-developed swept-source optical coherence tomography (SSOCT) system, coupled with a collinear air-puff excitation, capable of acquiring dynamic corneal deformation on multiple meridians. Backed by numerical simulations of corneal deformations, we propose two different scan patterns, aided by low coil impedance galvanometric scan mirrors that permit an appropriate compromise between temporal and spatial sampling of the corneal deformation profiles. We customized the air-puff module to provide an unobstructed SSOCT field of view and different peak pressures, air-puff durations, and distances to the eye. We acquired multi-meridian corneal deformation profiles (a) in healthy human eyes in vivo, (b) in porcine eyes ex vivo under varying controlled IOP, and (c) in a keratoconus-mimicking porcine eye ex vivo. We detected deformation asymmetries, as predicted by numerical simulations, otherwise missed on a single meridian that will substantially aid in corneal biomechanics diagnostics and pathology screening.

5.
Sci Total Environ ; 749: 141480, 2020 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-32836124

RESUMO

Based on the analysis of a large set of remote images, bathymetric studies and acoustic profiles, we studied the causes of erosion of a small island inside a ria of the NW coast of Spain. The island consists of a rocky sector to the south and a trailing, or comet-tail, spit to the north, which, until 1980, was in an equilibrium between the waves of the open ocean propagated inside the ria and the local wind waves. The development, in the 1970s, of a large park of floating rafts for mussel farming was identified as the factor triggering a period of disequilibrium and severe erosion on the island. The area covered by the floating rafts was the cause of the attenuation of local wind waves and the reinforcement of waves propagated from the open ocean. The spit underwent a period of approximately 38 years of disequilibrium characterized by a rotation movement with several phases. During the first period (1980-1989), a submarine lobe was formed, sequestering approximately 9000 m3 of sediment. Between 1989 and 2015, the spit maintained a rotation of 24° of amplitude and a phase of severe erosion, with rates of up to 6.6 m/yr, began in 2000. Since 2015, the spit has entered a new phase of stabilization, reducing the rotation to a small amplitude of 5°. The rates of erosion have also decreased, although they are still active.

6.
Cancers (Basel) ; 12(1)2020 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-31963499

RESUMO

BACKGROUND: The prognostic impact of the expression profile of genes recurrently amplified in glioblastoma multiforme (GBM) remains controversial. METHODS: We investigated the RNA gene expression profile of epidermal growth factor receptor (EGFR), cyclin-dependent kinase 4 (CDK4), murine doble minute 4 (MDM4), and platelet derived growth factor receptor alpha (PDGFRA) in 83 primary GBM tumors vs. 42 normal brain tissue samples. Interphase FISH (iFISH) analysis for the four genes, together with analysis of intragenic deletions in EGFR and PDGFRA, were evaluated in parallel at the DNA level. As validation cohort, publicly available RNA gene expression data on 293 samples from 10 different GBM patient series were also studied. RESULTS: At the RNA level, CDK4 was the most frequently overexpressed gene (90%) followed by EGFR (58%) and PDGFRA (58%). Chromosome 7 copy number alterations, i.e., trisomy (49%) and polysomy (44%), showed no clear association with EGFR gene expression levels. In turn, intragenic EGFR deletions were found in 39 patients (47%), including EGFRvIII (46%) in association with EGFRvIVa (4%), EGFRvII (2%) or other EGFR deletions (3%) and PDGFRA deletion of exons 8-9 was found in only two tumors (2%). CONCLUSIONS: Overall, none of the gene expression profiles and/or intragenic EGFR deletions showed a significant impact on overall survival of GBM supporting the notion that other still unraveled features of the disease might play a more relevant prognostic role in GBM.

7.
Vision Res ; 165: 143-151, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31751899

RESUMO

We investigated the effect of induced astigmatism on subjective best focus and on visual acuity in 28 subjects of different ages (pre-presbyopic and presbyopic) and with different refractive profiles (emmetropes and astigmats). Measurements were performed using a custom-developed Adaptive Optics system, which allowed correction of high order aberrations and induction of astigmatism (0.5, 1, 1.5 and 2.0 D; axis: 180°, 45° and 22.5°). Upon induction of astigmatism, best focus shifted towards negative values in pre-presbyopic emmetropic eyes (by -0.14 D for 0.5 D and by -0.33 D for 2.0 D), while it shifted towards positive values in presbyopes, both in emmetropic presbyopes (by +0.04 D for 0.50 D and by +0.16 D for 2.0 D) and in astigmatic presbyopes (by +0.23 D for 0.50 D and by +0.40 D for 2.0 D). Also, visual acuity was most sensitive to astigmatism induction in pre-presbyopic emmetropes and least sensitive in presbyopes, particularly when high order aberrations were corrected: visual acuity ratio with/without astigmatism was: 0.74/0.85/0.98 (for astigmatism induced at 180°) and 0.68/0.73/0.86 at 45°, for pre-presbyopic emmetropes/presbyopic emmetropes/presbyopic astigmats. These findings may be connected to long term exposure to astigmatism in astigmats and corrected presbyopes.


Assuntos
Astigmatismo/fisiopatologia , Presbiopia/fisiopatologia , Refração Ocular/fisiologia , Acuidade Visual , Percepção Visual/fisiologia , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Testes Visuais , Adulto Jovem
8.
Electron. j. biotechnol ; 41: 48-55, sept. 2019. tab, ilus, graf
Artigo em Inglês | LILACS | ID: biblio-1087162

RESUMO

Background: Plant gene homologs that control cell differentiation can be used as biotechnological tools to study the in vitro cell proliferation competence of tissue culture-recalcitrant species such as peppers. It has been demonstrated that SERK1 homologs enhance embryogenic competence when overexpressed in transformed tissues; therefore, cloning of a pepper SERK1 homolog was performed to further evaluate its biotechnological potential. Results: A Capsicum chinense SERK full-length cDNA (CchSERK1) was cloned and characterized at the molecular level. Its deduced amino acid sequence exhibits high identity with sequences annotated as SERK1 and predicted-SERK2 homologs in the genomes of the Capsicum annuum CM-334 and Zunla-1 varieties, respectively, and with SERK1 homologs from members of the Solanaceae family. Transcription of CchSERK1 in plant tissues, measured by quantitative RT-PCR, was higher in stems, flowers, and roots but lower in leaves and floral primordia. During seed development, CchSERK1 was transcribed in all zygotic stages, with higher expression at 14 days post anthesis. During somatic embryogenesis, CchSERK1 was transcribed at all differentiation stages, with a high increment in the heart stage and lower levels at the torpedo/cotyledonal stages. Conclusion: DNA sequence alignments and gene expression patterns suggest that CchSERK1 is the C. chinense SERK1 homolog. Significant levels of CchSERK1 transcripts were found in tissues with cell differentiation activities such as vascular axes and during the development of zygotic and somatic embryos. These results suggest that CchSERK1 might have regulatory functions in cell differentiation and could be used as a biotechnological tool to study the recalcitrance of peppers to proliferate in vitro.


Assuntos
Capsicum/genética , Clonagem Molecular , Técnicas In Vitro , Biotecnologia , Expressão Gênica , Diferenciação Celular , Genes de Plantas , DNA Complementar/genética , Solanaceae/genética , Proteínas de Arabidopsis , Proliferação de Células , Desenvolvimento Embrionário , Reação em Cadeia da Polimerase em Tempo Real
9.
PLoS One ; 14(8): e0221144, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31430328

RESUMO

Presbyopes can choose today among different corrections to provide them with functional vision at far and near, and the outcomes and patient satisfaction depend on the selection. In this study, we present a binocular and portable vision simulator, based on temporal multiplexing of two synchronized tunable lenses allowing see-through and programmable visual simulations of presbyopic corrections. Seventeen binocular corrections were tested: 3 Monofocal (Far, Intermediate, Near), 4 Simultaneous Vision (bifocal, trifocal), 2 Monovision (far and near in either eye) and 8 Modified Monovision corrections (Simultaneous vision in one eye, Monofocal in the other eye). Perceived visual quality was assessed through the simulated corrections in 8 cyclopleged subjects who viewed a composite realistic visual scene with high contrast letters and a landscape at far (4 m) and a high contrast text at intermediate (66 cm) and near (33 cm) distances. Perceptual scores were obtained on a scale of 0 to 5 (low to high perceived quality). Perceptual preference was assessed by judging 36 random image pairs (6 repetitions) viewed through 9 binocular presbyopic corrections using two-interval forced choice procedures. The average score, across far and near distances, was the highest for Monovision (4.4±0.3), followed by Modified Monovision (3.4±0.1), Simultaneous Vision (3.0±0.1) and Monofocal corrections (2.9±0.2). However, the mean difference between far and near was lower for Simultaneous Vision and Monovision (0.4±0.1 PS) than Modified Monovision (1.8±0.7) or monofocal corrections (3.3±1.5). A strong significant correlation was found between the perceptual scores and the percentages of energy in focus, for each correction and distance (R = 0.64, p<0.0001). Multivariate ANOVA revealed significant influence of observation distances (p<10-9) and patients (p = 0.01) on Perceptual Score. In conclusion, we have developed a binocular portable vision simulator that can simulate rapidly and non-invasively different combinations of presbyopic corrections. This tool has applications in systematic clinical evaluation of presbyopia corrections.


Assuntos
Presbiopia/diagnóstico , Telescópios , Testes Visuais/instrumentação , Adulto , Humanos , Masculino , Pessoa de Meia-Idade , Presbiopia/terapia , Adulto Jovem
10.
Sensors (Basel) ; 19(5)2019 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-30818880

RESUMO

This manuscript describes the Microwave Interferometric Reflectometer (MIR) instrument, a multi-beam dual-band GNSS-Reflectometer with beam-steering capabilities built to assess the performance of a PAssive Reflectrometry and Interferometry System-In Orbit Demonstrator (PARIS-IoD) like instrument and to compare the performance of different GNSS-R techniques and signals. The instrument is capable of tracking up to 4 different GNSS satellites, two at L1/E1 band, and two at L5/E5 band. The calibration procedure of the up- and down-looking arrays is presented, the calibration performance is evaluated, and the results of the validation experiments carried out before the field experiments are shown in this paper.

11.
Sci Rep ; 9(1): 1539, 2019 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-30733540

RESUMO

Adaptive optics (AO) visual simulators based on deformable mirrors, spatial light modulators or optotunable lenses are increasingly used to simulate vision through different multifocal lens designs. However, the correspondence of this simulation with that obtained through real intraocular lenses (IOLs) tested on the same eyes has not been, to our knowledge, demonstrated. We compare through-focus (TF) optical and visual quality produced by real multifocal IOLs (M-IOLs) -bifocal refractive and trifocal diffractive- projected on the subiect's eye with those same designs simulated with a spatial light modulator (SLM) or an optotunable lens working in temporal multiplexing mode (SimVis technology). Measurements were performed on 7 cyclopleged subjects using a custom-made multichannel 3-active-optical-elements polychromatic AO Visual Simulator in monochromatic light. The same system was used to demonstrate performance of the real IOLs, SLM and SimVis technology simulations on bench using double-pass imaging on an artificial eye. Results show a general good correspondence between the TF performance with the real and simulated M-IOLs, both optically (on bench) and visually (measured visual acuity in patients). We demonstrate that visual simulations in an AO environment capture to a large extent the individual optical and visual performance obtained with real M-IOLs, both in absolute values and in the shape of through-focus curves.


Assuntos
Óculos , Testes Visuais/métodos , Humanos , Estimulação Luminosa , Refração Ocular , Acuidade Visual
12.
Electron. j. biotechnol ; 36: 34-46, nov. 2018. tab, ilus
Artigo em Inglês | LILACS | ID: biblio-1048187

RESUMO

Background: Somatic embryogenesis receptor-like kinase 1 (SERK1) is a cell membrane receptor active in different plant tissues and involved in cell differentiation activities including somatic embryogenesis. The identification of promoter elements responsible for SERK1 expression during the onset of somatic embryogenesis can be useful to understand the molecular regulation of the cell-to embryo transition, and these promoter elements represent biotechnological tools in plant organ tissue culture. Results: A −1,620 bp DNA sequence located upstream of the Coffea canephora SERK1 gene homologue (CcSERK1) was isolated, and then, different segments containing key response elements (REs) for somatic embryogenesis onset and development were fused to the uidA (encoding a ß-glucuronidase, GUS) reporter gene to evaluate its expression in transgenic leaf explants. DNA segments of −1,620 and −1048 bp in length directed uidA expression with patterns in leaf explants similar to those occurring during somatic embryogenesis. When a −792-bp fragment was used, uidA expression disappeared only in leaf explants and pro-embryogenic mass but persisted in developing embryos. No uidA expression was detected in any embryogenic stage when a −618-bp fragment was used. Conclusion: DNA deletions showed that a −1048-bp sequence located upstream of the CcSERK1 gene is sufficient to direct gene expression during the onset and the development of C. canephora somatic embryogenesis. The DNA segment located between −1048 and −792 bp (containing BBM and WUS REs) is needed for gene expression before embryogenesis onset but not during embryo development. The promoter segment between −792 and −618 bp (including GATA, ARR1AT, and ANT REs) regulates gene expression in developing embryos.


Assuntos
Proteínas de Plantas/genética , Proteínas Quinases/genética , Coffea/genética , Biotecnologia , Expressão Gênica , Regiões Promotoras Genéticas , Plantas Geneticamente Modificadas , Clonagem Molecular , Genes Reporter , Regulação da Expressão Gênica de Plantas , Desenvolvimento Embrionário
13.
Physiol Plant ; 163(4): 530-551, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29607503

RESUMO

Somatic embryogenesis receptor-like kinase 1 (SERK1) is a membrane receptor that might serve as common co-regulator of plant cell differentiation processes by forming heterodimers with specific receptor-like kinases. The Coffea canephora SERK1 homolog (CcSERK1) was cloned in this work, and its early function in the transcription of embryogenesis master genes and of genes encoding proteins involved in auxin metabolism was investigated by externally manipulating its expression in embryogenic leaf explants, before the appearance of embryogenic structures. Overexpression of CcSERK1 early during embryogenesis caused an increase in the number of somatic embryos when the 55-day process was completed. Suppression of CcSERK1 expression by RNA interference almost abolished somatic embryogenesis. Real time-PCR experiments revealed that the transcription of the CcAGL15, CcWUS, CcBBM, CcPKL, CcYUC1, CcPIN1 and CcPIN4 homologs was modified in direct proportion to the expression of CcSERK1 and that only CcLEC1 was inversely affected by the expression levels of CcSERK1. The expression of the CcYUC4 homolog was induced to more than 80-fold under CcSERK1 overexpression conditions, but it was also induced when CcSERK1 expression was silenced. The level of CcTIR1 was not affected by CcSERK1 overexpression but was almost abolished during CcSERK1 silencing. These results suggest that CcSERK1 co-regulates the induction of somatic embryogenesis in Coffea canephora by early activation of YUC-dependent auxin biosynthesis, auxin transport mediated by PIN1 and PIN4, and probably auxin perception by the TIR1 receptor, leading to the induction of early-stage homeotic genes (CcAGL15, CcWUS, CcPKL and CcBBM) and repression of late-stage homeotic genes (CcLec1).


Assuntos
Coffea/genética , Coffea/metabolismo , Ácidos Indolacéticos/metabolismo , Proteínas Quinases/genética , Sementes/genética , Clonagem Molecular , Expressão Ectópica do Gene , Regulação da Expressão Gênica de Plantas , Família Multigênica , Filogenia , Folhas de Planta/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Proteínas Quinases/metabolismo , Sementes/crescimento & desenvolvimento , Transcrição Gênica
14.
Neurocir.-Soc. Luso-Esp. Neurocir ; 28(4): 176-182, jul.-ago. 2017. graf, tab
Artigo em Espanhol | IBECS | ID: ibc-164411

RESUMO

Objetivo: Evaluar si las tasas de recurrencia y las supervivencias libres de recurrencia/progresión (RFS) son diferentes en meningiomas de grado I de la Organización Mundial de la Salud (OMS) sometidos a resecciones grado I, II, III y IV de la escala de Simpson. Materiales y métodos: Revisamos de manera retrospectiva los datos de los pacientes que se sometieron a tratamiento quirúrgico de meningiomas de grado I de la OMS localizados en la convexidad, hoz/parasagital y base de cráneo entre junio de 1991 y diciembre de 2011. En el caso de las resecciones grado IV de Simpson la cirugía se complementó con radiocirugía o radioterapia sobre el resto tumoral. Comparamos las tasas de recurrencia y las RFS de los diferentes grados de Simpson tanto de manera global como por localización. Resultados: En el estudio se incluyeron 208 meningiomas. No existieron diferencias significativas en las tasas de recurrencia y en las RFS entre los diferentes grados de Simpson. Por localización, tampoco detectamos diferencias entre los grados de resección. En meningiomas de convexidad, las tasas de recurrencia en los grados I y III fueron del 7 y del 33%, respectivamente (p=0,131). Conclusiones: Este estudio sugiere que las tasas de control tumoral son independientes de los grados de Simpson. En meningiomas de hoz/parasagital y de base de cráneo debe valorarse la agresividad quirúrgica frente a los riesgos de lesionar estructuras neurovasculares. En meningiomas de convexidad, el objetivo inicial debería ser una resección grado I


Object: The aim of this study is to assess if the recurrence rates and recurrence/progression-free survivals (RFS) are different after Simpson's grades I, II, III and IV resections in World Health Organization (WHO) grade I meningiomas. Material and methods: A retrospective review was conducted on the data of patients who underwent surgical treatment of WHO grade I meningiomas located in convexity, falx/parasagittal, and skull base (anterior/media/posterior) between June 1991 and December 2011. In Simpson's grade IV resections, surgical treatment was supplemented with radiotherapy/radiosurgery on the tumour remains. A comparison was made on the recurrence rates and RFSs between Simpson's grades I, II, III, and IV resections, both overall and in tumour subsets according to their location. Results: A total of 208 meningiomas were included in this study. There were no significant differences in recurrence rates and RFSs between Simpson's grades I, II, III, and IV. No significant differences were noted between the different degrees of Simpson in any of the location groups. In convexity meningiomas, the recurrence rates were 7% and 33% in Simpson's grades I and III resections, respectively (P=.131). Conclusions: It has been shown that the rates of tumour control in meningiomas are not related to Simpson grades. In falx/parasagittal and skull base meningiomas, more aggressive attempts of tumour resection must be balanced against the risks of damaging critical neurovascular structures. In convexity meningiomas, a Simpson's grade I resection should be attempted first


Assuntos
Humanos , Meningioma/cirurgia , Neoplasias Meníngeas/cirurgia , Recidiva Local de Neoplasia/epidemiologia , Estadiamento de Neoplasias , Resultado do Tratamento , Complicações Pós-Operatórias/epidemiologia , Intervalo Livre de Doença , Meningioma/classificação , Estudos Retrospectivos
15.
Neurocirugia (Astur) ; 28(4): 176-182, 2017.
Artigo em Espanhol | MEDLINE | ID: mdl-28242156

RESUMO

OBJECT: The aim of this study is to assess if the recurrence rates and recurrence/progression-free survivals (RFS) are different after Simpson's grades I, II, III and IV resections in World Health Organization (WHO) grade I meningiomas. MATERIAL AND METHODS: A retrospective review was conducted on the data of patients who underwent surgical treatment of WHO grade I meningiomas located in convexity, falx/parasagittal, and skull base (anterior/media/posterior) between June 1991 and December 2011. In Simpson's grade IV resections, surgical treatment was supplemented with radiotherapy/radiosurgery on the tumour remains. A comparison was made on the recurrence rates and RFSs between Simpson's grades I, II, III, and IV resections, both overall and in tumour subsets according to their location. RESULTS: A total of 208 meningiomas were included in this study. There were no significant differences in recurrence rates and RFSs between Simpson's grades I, II, III, and IV. No significant differences were noted between the different degrees of Simpson in any of the location groups. In convexity meningiomas, the recurrence rates were 7% and 33% in Simpson's grades I and III resections, respectively (P=.131). CONCLUSIONS: It has been shown that the rates of tumour control in meningiomas are not related to Simpson grades. In falx/parasagittal and skull base meningiomas, more aggressive attempts of tumour resection must be balanced against the risks of damaging critical neurovascular structures. In convexity meningiomas, a Simpson's grade I resection should be attempted first.


Assuntos
Neoplasias Meníngeas/cirurgia , Meningioma/cirurgia , Gradação de Tumores/métodos , Adulto , Idoso , Intervalo Livre de Doença , Feminino , Humanos , Masculino , Neoplasias Meníngeas/patologia , Meningioma/patologia , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/cirurgia , Estudos Retrospectivos
16.
Sensors (Basel) ; 17(1)2017 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-28106825

RESUMO

This work addresses the accuracy of the Global Navigation Satellite Systems (GNSS)-Reflectometry (GNSS-R) scatterometric measurements considering the presence of both coherent and incoherent scattered components, for both conventional GNSS-R (cGNSS-R) and interferometric GNSS-R (iGNSS-R) techniques. The coherent component is present for some type of surfaces, and it has been neglected until now because it vanishes for the sea surface scattering case. Taking into account the presence of both scattering components, the estimated Signal-to-Noise Ratio (SNR) for both techniques is computed based on the detectability criterion, as it is done in conventional GNSS applications. The non-coherent averaging operation is considered from a general point of view, taking into account that thermal noise contributions can be reduced by an extra factor of 0.88 dB when using partially overlapped or partially correlated samples. After the SNRs are derived, the received waveform's peak variability is computed, which determines the system's capability to measure geophysical parameters. This theoretical derivations are applied to the United Kingdom (UK) TechDemoSat-1 (UK TDS-1) and to the future GNSS REflectometry, Radio Occultation and Scatterometry on board the International Space Station (ISS) (GEROS-ISS) scenarios, in order to estimate the expected scatterometric performance of both missions.

17.
Brain Behav Immun ; 53: 1-15, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26216710

RESUMO

Tumor-infiltrating immune cells are part of a complex microenvironment that promotes and/or regulates tumor development and growth. Depending on the type of cells and their functional interactions, immune cells may play a key role in suppressing the tumor or in providing support for tumor growth, with relevant effects on patient behavior. In recent years, important advances have been achieved in the characterization of immune cell infiltrates in central nervous system (CNS) tumors, but their role in tumorigenesis and patient behavior still remain poorly understood. Overall, these studies have shown significant but variable levels of infiltration of CNS tumors by macrophage/microglial cells (TAM) and to a less extent also lymphocytes (particularly T-cells and NK cells, and less frequently also B-cells). Of note, TAM infiltrate gliomas at moderate numbers where they frequently show an immune suppressive phenotype and functional behavior; in contrast, infiltration by TAM may be very pronounced in meningiomas, particularly in cases that carry isolated monosomy 22, where the immune infiltrates also contain greater numbers of cytotoxic T and NK-cells associated with an enhanced anti-tumoral immune response. In line with this, the presence of regulatory T cells, is usually limited to a small fraction of all meningiomas, while frequently found in gliomas. Despite these differences between gliomas and meningiomas, both tumors show heterogeneous levels of infiltration by immune cells with variable functionality. In this review we summarize current knowledge about tumor-infiltrating immune cells in the two most common types of CNS tumors-gliomas and meningiomas-, as well as the role that such immune cells may play in the tumor microenvironment in controlling and/or promoting tumor development, growth and control.


Assuntos
Neoplasias Encefálicas/imunologia , Glioma/imunologia , Neoplasias Meníngeas/imunologia , Meningioma/imunologia , Animais , Linfócitos B/imunologia , Linfócitos B/patologia , Neoplasias Encefálicas/patologia , Citometria de Fluxo , Glioma/metabolismo , Glioma/patologia , Humanos , Linfócitos/imunologia , Linfócitos/patologia , Macrófagos/imunologia , Macrófagos/patologia , Neoplasias Meníngeas/metabolismo , Meningioma/metabolismo , Meningioma/patologia , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/patologia
19.
Oncotarget ; 6(13): 10671-88, 2015 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-25965831

RESUMO

Meningiomas are usually considered to be benign central nervous system tumors; however, they show heterogenous clinical, histolopathological and cytogenetic features associated with a variable outcome. In recent years important advances have been achieved in the identification of the genetic/molecular alterations of meningiomas and the signaling pathways involved. Thus, monosomy 22, which is often associated with mutations of the NF2 gene, has emerged as the most frequent alteration of meningiomas; in addition, several other genes (e.g., AKT1, KLF4, TRAF7, SMO) and chromosomes have been found to be recurrently altered often in association with more complex karyotypes and involvement of multiple signaling pathways. Here we review the current knowledge about the most relevant genes involved and the signaling pathways targeted by such alterations. In addition, we summarize those proposals that have been made so far for classification and prognostic stratification of meningiomas based on their genetic/genomic features.


Assuntos
Predisposição Genética para Doença/genética , Neoplasias Meníngeas/genética , Meningioma/genética , Neurofibromina 2/genética , Transdução de Sinais/genética , Cromossomos Humanos Par 22/genética , Humanos , Fator 4 Semelhante a Kruppel , Neoplasias Meníngeas/patologia , Meningioma/patologia , Modelos Genéticos , Monossomia
20.
Biomed Opt Express ; 6(3): 948-62, 2015 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-25798317

RESUMO

Longitudinal Chromatic Aberration (LCA) influences the optical quality of the eye. However, the reported LCA varies across studies, likely associated to differences in the measurement techniques. We present LCA measured in subjects using wavefront sensing, double-pass retinal images, and psychophysical methods with a custom-developed polychromatic Adaptive Optics system in a wide spectral range (450-950 nm), with control of subjects' natural aberrations. LCA measured psychophysically was significantly higher than that from reflectometric techniques (1.51 D vs 1.00 D in the 488-700 nm range). Ours results indicate that the presence of natural aberrations is not the cause for the discrepancies across techniques.

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