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1.
Elife ; 122024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38941139

RESUMO

Homeostatic plasticity represents a set of mechanisms that are thought to recover some aspect of neural function. One such mechanism called AMPAergic scaling was thought to be a likely candidate to homeostatically control spiking activity. However, recent findings have forced us to reconsider this idea as several studies suggest AMPAergic scaling is not directly triggered by changes in spiking. Moreover, studies examining homeostatic perturbations in vivo have suggested that GABAergic synapses may be more critical in terms of spiking homeostasis. Here, we show results that GABAergic scaling can act to homeostatically control spiking levels. We found that perturbations which increased or decreased spiking in cortical cultures triggered multiplicative GABAergic upscaling and downscaling, respectively. In contrast, we found that changes in AMPA receptor (AMPAR) or GABAR transmission only influence GABAergic scaling through their indirect effect on spiking. We propose that GABAergic scaling represents a stronger candidate for spike rate homeostat than AMPAergic scaling.


Assuntos
Potenciais de Ação , Receptores de AMPA , Receptores de AMPA/metabolismo , Animais , Potenciais de Ação/fisiologia , Sinapses/fisiologia , Sinapses/metabolismo , Plasticidade Neuronal/fisiologia , Neurônios GABAérgicos/fisiologia , Neurônios GABAérgicos/metabolismo , Transmissão Sináptica/fisiologia , Células Cultivadas , Ácido gama-Aminobutírico/metabolismo , Homeostase
2.
Elife ; 122024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38376907

RESUMO

Basal forebrain cholinergic neurons modulate how organisms process and respond to environmental stimuli through impacts on arousal, attention, and memory. It is unknown, however, whether basal forebrain cholinergic neurons are directly involved in conditioned behavior, independent of secondary roles in the processing of external stimuli. Using fluorescent imaging, we found that cholinergic neurons are active during behavioral responding for a reward - even prior to reward delivery and in the absence of discrete stimuli. Photostimulation of basal forebrain cholinergic neurons, or their terminals in the basolateral amygdala (BLA), selectively promoted conditioned responding (licking), but not unconditioned behavior nor innate motor outputs. In vivo electrophysiological recordings during cholinergic photostimulation revealed reward-contingency-dependent suppression of BLA neural activity, but not prefrontal cortex. Finally, ex vivo experiments demonstrated that photostimulation of cholinergic terminals suppressed BLA projection neuron activity via monosynaptic muscarinic receptor signaling, while also facilitating firing in BLA GABAergic interneurons. Taken together, we show that the neural and behavioral effects of basal forebrain cholinergic activation are modulated by reward contingency in a target-specific manner.


Assuntos
Tonsila do Cerebelo , Complexo Nuclear Basolateral da Amígdala , Neurônios Colinérgicos , Interneurônios , Recompensa
3.
Front Neurosci ; 17: 1167007, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37409104

RESUMO

Introduction: Deprivation of normal vision early in postnatal development elicits modifications of neural circuitry within the primary visual pathway that can cause a severe and intractable vision impairment (amblyopia). In cats, amblyopia is often modeled with monocular deprivation (MD), a procedure that involves temporarily closing the lids of one eye. Following long-term MD, brief inactivation of the dominant eye's retina can promote recovery from the anatomical and physiological effects of MD. In consideration of retinal inactivation as a viable treatment for amblyopia it is imperative to compare its efficacy against conventional therapy, as well as assess the safety of its administration. Methods: In the current study we compared the respective efficacies of retinal inactivation and occlusion of the dominant eye (reverse occlusion) to elicit physiological recovery from a prior long-term MD in cats. Because deprivation of form vision has been associated with development of myopia, we also examined whether ocular axial length or refractive error were altered by a period of retinal inactivation. Results: The results of this study demonstrate that after a period of MD, inactivation of the dominant eye for up to 10 days elicited significant recovery of visually-evoked potentials that was superior to the recovery measured after a comparable duration of reverse occlusion. After monocular retinal inactivation, measurements of ocular axial length and refractive error were not significantly altered from their pre-inactivation values. The rate of body weight gain also was not changed during the period of inactivation, indicating that general well-being was not affected. Discussion: These results provide evidence that inactivation of the dominant eye after a period of amblyogenic rearing promotes better recovery than eye occlusion, and this recovery was achieved without development of form-deprivation myopia.

4.
Biomedicines ; 11(3)2023 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-36979841

RESUMO

Preeclampsia (PE) occurs in women pregnant for more than 20 weeks with de novo hypertension and proteinuria, and is a devastating disease in maternal-fetal medicine. Cytokine tumor necrosis factor (TNF)-α may play a key role in the pathogenesis of PE. We conducted this study to investigate the regulatory regions of the TNF genes, by investigating two promoter polymorphisms, TNFA-308G/A (rs1800629) and -238G/A (rs361525), known to influence TNF expression, and their relationship to PE. An observational, monocentric, case-control study was conducted. We retrospectively collected 74 cases of severe PE and 119 pregnant women without PE as control. Polymerase chain reaction (PCR) was carried out for allele analysis. Higher A allele in women with PE was found in rs1800629 but not rs361525. In this study, we first found that polymorphism at the position -308, but not -238, in the promoter region of the TNF-α gene can contribute to severe PE in Taiwanese Han populations. The results of our study are totally different to previous Iranian studies, but have some similarity to a previous UK study. Further studies are required to confirm the roles of rs1800629 and rs361525 in PE with circulating TNF-α in PE.

5.
BMC Med Genomics ; 14(Suppl 3): 212, 2021 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-34789231

RESUMO

BACKGROUND: Skeletal dysplasia (SD) is one of the most common inherited neonatal disorders worldwide, where the recurrent pathogenic mutations in the FGFR2, FGFR3, COL1A1, COL1A2 and COL2A1 genes are frequently reported in both non-lethal and lethal SD. The traditional prenatal diagnosis of SD using ultrasonography suffers from lower accuracy and performed at latter gestational stage. Therefore, it remains in desperate need of precise and accurate prenatal diagnosis of SD in early pregnancy. With the advancements of next-generation sequencing (NGS) technology and bioinformatics analysis, it is feasible to develop a NGS-based assay to detect genetic defects in association with SD in the early pregnancy. METHODS: An ampliseq-based targeted sequencing panel was designed to cover 87 recurrent hotspots reported in 11 common dominant SD and run on both Ion Proton and NextSeq550 instruments. Thirty-six cell-free and 23 genomic DNAs were used for assay developed. Spike-in DNA prepared from standard sample harboring known mutation and normal sample were also employed to validate the established SD workflow. Overall performances of coverage, uniformity, and on-target rate, and the detecting limitations on percentage of fetal fraction and read depth were evaluated. RESULTS: The established targeted-seq workflow enables a single-tube multiplex PCR for library construction and shows high amplification efficiency and robust reproducibility on both Ion Proton and NextSeq550 platforms. The workflow reaches 100% coverage and both uniformity and on-target rate are > 96%, indicating a high quality assay. Using spike-in DNA with different percentage of known FGFR3 mutation (c.1138 G > A), the targeted-seq workflow demonstrated the ability to detect low-frequency variant of 2.5% accurately. Finally, we obtained 100% sensitivity and 100% specificity in detecting target mutations using established SD panel. CONCLUSIONS: An expanded panel for rapid and cost-effective genetic detection of SD has been developed. The established targeted-seq workflow shows high accuracy to detect both germline and low-frequency variants. In addition, the workflow is flexible to be conducted in the majority of the NGS instruments and ready for routine clinical application. Taken together, we believe the established panel provides a promising diagnostic or therapeutic strategy for prenatal genetic testing of SD in routine clinical practice.


Assuntos
Testes Genéticos , Sequenciamento de Nucleotídeos em Larga Escala , Feminino , Humanos , Mutação , Gravidez , Diagnóstico Pré-Natal , Reprodutibilidade dos Testes , Análise de Sequência de DNA
6.
Elife ; 102021 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-34464258

RESUMO

Monocular deprivation early in development causes amblyopia, a severe visual impairment. Prognosis is poor if therapy is initiated after an early critical period. However, clinical observations have shown that recovery from amblyopia can occur later in life when the non-deprived (fellow) eye is removed. The traditional interpretation of this finding is that vision is improved simply by the elimination of interocular suppression in primary visual cortex, revealing responses to previously subthreshold input. However, an alternative explanation is that silencing activity in the fellow eye establishes conditions in visual cortex that enable the weak connections from the amblyopic eye to gain strength, in which case the recovery would persist even if vision is restored in the fellow eye. Consistent with this idea, we show here in cats and mice that temporary inactivation of the fellow eye is sufficient to promote a full and enduring recovery from amblyopia at ages when conventional treatments fail. Thus, connections serving the amblyopic eye are capable of substantial plasticity beyond the critical period, and this potential is unleashed by reversibly silencing the fellow eye.


Assuntos
Ambliopia/veterinária , Visão Binocular/fisiologia , Animais , Gatos , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Privação Sensorial , Acuidade Visual
7.
Int J Nanomedicine ; 16: 8103-8115, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34992362

RESUMO

INTRODUCTION: Although the preparation of lipid nanoparticles (LNPs) achieves great success, their retention of highly hydrophobic drugs is still problematic. METHODS: Herein, we report a novel strategy for efficiently loading hydrophobic drugs to LNPs for stroke therapy. Oleoylethanolamide (OEA), an endogenous highly hydrophobic molecule with outstanding neuroprotective effect, was successfully loaded to OEA-SPC&DSPE-PEG lipid nanoparticles (OSDP LNPs) with a drug loading of 15.9 ± 1.2 wt%. Efficient retention in OSDP LNPs greatly improved the pharmaceutical property and enhanced the neuroprotective effect of OEA. RESULTS: Through the data of positron emission tomography (PET) and TTC-stained brain slices, it could be clearly visualized that the acute ischemic brain tissues were preserved as penumbral tissues and bounced back with reperfusion. The in vivo experiments stated that OSDP LNPs could significantly improve the survival rate, the behavioral score, the cerebral infarct volume, the edema degree, the spatial learning and memory ability of the MCAO (middle cerebral artery occlusion) rats. DISCUSSION: These results suggest that the OSDP LNPs have a great chance to develop hydrophobic OEA into a potential anti-stroke formulation.


Assuntos
Nanopartículas , Acidente Vascular Cerebral , Animais , Endocanabinoides , Lipossomos , Ácidos Oleicos , Ratos , Acidente Vascular Cerebral/tratamento farmacológico
8.
J Neurosci ; 40(21): 4090-4102, 2020 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-32312887

RESUMO

Neurons can respond to decreased network activity with a homeostatic increase in the amplitudes of miniature EPSCs (mEPSCs). The prevailing view is that mEPSC amplitudes are uniformly multiplied by a single factor, termed "synaptic scaling." Deviations from purely multiplicative scaling have been attributed to biological differences, or to a distortion imposed by a detection threshold limit. Here, we demonstrate in neurons dissociated from cortices of male and female mice that the shift in mEPSC amplitudes observed in the experimental data cannot be reproduced by simulation of uniform multiplicative scaling, with or without the distortion caused by applying a detection threshold. Furthermore, we demonstrate explicitly that the scaling factor is not uniform but is close to 1 for small mEPSCs, and increases with increasing mEPSC amplitude across a substantial portion of the data. This pattern was also observed for previously published data from dissociated mouse hippocampal neurons and dissociated rat cortical neurons. The finding of "divergent scaling" shifts the current view of homeostatic plasticity as a process that alters all synapses on a neuron equally to one that must accommodate the differential effect observed for small versus large mEPSCs. Divergent scaling still accomplishes the essential homeostatic task of modifying synaptic strengths in the opposite direction of the activity change, but the consequences are greatest for those synapses which individually are more likely to bring a neuron to threshold.SIGNIFICANCE STATEMENT In homeostatic plasticity, the responses to chronic increases or decreases in network activity act in the opposite direction to restore normal activity levels. Homeostatic plasticity is likely to play a role in diseases associated with long-term changes in brain function, such as epilepsy and neuropsychiatric illnesses. One homeostatic response is the increase in synaptic strength following a chronic block of activity. Research is focused on finding a globally expressed signaling pathway, because it has been proposed that the plasticity is uniformly expressed across all synapses. Here, we show that the plasticity is not uniform. Our work suggests that homeostatic signaling molecules are likely to be differentially expressed across synapses.


Assuntos
Córtex Cerebral/fisiologia , Potenciais Pós-Sinápticos Excitadores/fisiologia , Potenciais Pós-Sinápticos em Miniatura/fisiologia , Plasticidade Neuronal/fisiologia , Neurônios/fisiologia , Animais , Células Cultivadas , Camundongos , Técnicas de Patch-Clamp , Sinapses/fisiologia , Transmissão Sináptica/fisiologia
9.
Cereb Cortex ; 30(4): 2555-2572, 2020 04 14.
Artigo em Inglês | MEDLINE | ID: mdl-31832634

RESUMO

Primary visual cortex (V1) is the locus of numerous forms of experience-dependent plasticity. Restricting visual stimulation to one eye at a time has revealed that many such forms of plasticity are eye-specific, indicating that synaptic modification occurs prior to binocular integration of thalamocortical inputs. A common feature of these forms of plasticity is the requirement for NMDA receptor (NMDAR) activation in V1. We therefore hypothesized that NMDARs in cortical layer 4 (L4), which receives the densest thalamocortical input, would be necessary for all forms of NMDAR-dependent and input-specific V1 plasticity. We tested this hypothesis in awake mice using a genetic approach to selectively delete NMDARs from L4 principal cells. We found, unexpectedly, that both stimulus-selective response potentiation and potentiation of open-eye responses following monocular deprivation (MD) persist in the absence of L4 NMDARs. In contrast, MD-driven depression of deprived-eye responses was impaired in mice lacking L4 NMDARs, as was L4 long-term depression in V1 slices. Our findings reveal a crucial requirement for L4 NMDARs in visual cortical synaptic depression, and a surprisingly negligible role for them in cortical response potentiation. These results demonstrate that NMDARs within distinct cellular subpopulations support different forms of experience-dependent plasticity.


Assuntos
Potenciais Evocados Visuais/fisiologia , Plasticidade Neuronal/fisiologia , Estimulação Luminosa/métodos , Receptores de N-Metil-D-Aspartato/deficiência , Privação Sensorial/fisiologia , Córtex Visual/fisiologia , Animais , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Receptores de N-Metil-D-Aspartato/genética
10.
J Cancer ; 9(16): 2834-2843, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30123352

RESUMO

Through bioinformatics analysis, a novel lncRNA, LINC00460, was implicated in the development of multiple cancers. However, the precise expression pattern, clinical significance and biological function of LINC00460 in colorectal cancer (CRC) remain unknown. Network databases were used to investigate the correlation between LINC00460 and CRC. In situ hybridization was performed to verify the precise expression pattern and clinical significance of LINC00460 in a CRC tissue microarray, which included 92 pairs of CRC and adjacent normal tissues. The effect of LINC00460 on proliferation was evaluated by MTT, colony formation assays and flow cytometry employing SW620 and HCT116 cell lines. Cell migration and matrigel invasion assays were performed to investigate whether LINC00460 is involved in the metastasis of CRC. The expression of LINC00460 was significantly upregulated in CRC tissues and cells, associated with early stage CRC and low disease-free survival. The downregulated of LINC00460 expression increased cell proliferation by regulating the cell cycles of SW620 and HCT116 cells. LINC00460 knockdown did not affect cell migration or invasion in vitro. These findings suggest that LINC00460 may be an interesting target for the development of CRC.

11.
Oncotarget ; 9(36): 24514-24524, 2018 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-29849957

RESUMO

BACKGROUND: Quantitative analyses of circulating cell-free DNA (cfDNA) are suggested to be a promising method for the detection of colorectal cancer, validated clinical relevance of cfDNA has not been published so far. Though some of the inconsistent results were published. This study is the first meta-analysis to systematically evaluate the diagnostic accuracy of circulating cfDNA as non-invasive biomarkers for colorectal cancer. RESULTS: Fourteen studies concerning a quantitative analysis of circulating cfDNA for the diagnosis of colorectal cancer met the inclusion criteria. Data includes 1,258 patients with colorectal cancer and 803 healthy individuals as control was analyzed. The summary estimates were as follow: sensitivity, 0.735 (95% CI 0.713-0.757); specificity, 0.918 (95% CI, 0.900-0.934); positive likelihood ratio, 8.295 (95% CI, 5.037-13.659); negative likelihood ratio, 0.300 (95% CI, 0.231-0.391); diagnostic odds ratio, 30.783 (95% CI, 16.965-55.856); and area under the curve, 0.8818 (95% CI, 0.88-0.93), respectively. Publication bias was not evident with Deeks' funnel plot asymmetry test (p = 0.197). MATERIALS AND METHODS: A systematic literature was searched in PubMed, EMBASE, Cochrane Library and Chinese National Knowledge Infrastructure from their inception to August 07, 2017. Analyses were conducted by Meta-DiSc 1.4 and Stata 12.0. Diagnostic accuracy in sensitivity, specificity and aspects were pooled. Subgroup analyses and meta-regression were performed to identify the sources of heterogeneity. Clinical utility of the cfDNA was evaluated by Fagan nomogram. CONCLUSIONS: Our meta-analysis suggested that the diagnostic accuracy of circulating cfDNA has unsatisfactory sensitivity but acceptable specificity for diagnosis of colorectal cancer. Furthermore, the integrity index (ALU247/ALU115) is better than absolute DNA concentration in diagnostic accuracy of colorectal cancer.

12.
Strahlenther Onkol ; 194(9): 843-854, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29802435

RESUMO

PURPOSE: To investigate the quality of treatment plans of spinal radiosurgery derived from different planning and delivery systems. The comparisons include robotic delivery and intensity modulated arc therapy (IMAT) approaches. Multiple centers with equal systems were used to reduce a bias based on individual's planning abilities. The study used a series of three complex spine lesions to maximize the difference in plan quality among the various approaches. METHODS: Internationally recognized experts in the field of treatment planning and spinal radiosurgery from 12 centers with various treatment planning systems participated. For a complex spinal lesion, the results were compared against a previously published benchmark plan derived for CyberKnife radiosurgery (CKRS) using circular cones only. For two additional cases, one with multiple small lesions infiltrating three vertebrae and a single vertebra lesion treated with integrated boost, the results were compared against a benchmark plan generated using a best practice guideline for CKRS. All plans were rated based on a previously established ranking system. RESULTS: All 12 centers could reach equality (n = 4) or outperform (n = 8) the benchmark plan. For the multiple lesions and the single vertebra lesion plan only 5 and 3 of the 12 centers, respectively, reached equality or outperformed the best practice benchmark plan. However, the absolute differences in target and critical structure dosimetry were small and strongly planner-dependent rather than system-dependent. Overall, gantry-based IMAT with simple planning techniques (two coplanar arcs) produced faster treatments and significantly outperformed static gantry intensity modulated radiation therapy (IMRT) and multileaf collimator (MLC) or non-MLC CKRS treatment plan quality regardless of the system (mean rank out of 4 was 1.2 vs. 3.1, p = 0.002). CONCLUSIONS: High plan quality for complex spinal radiosurgery was achieved among all systems and all participating centers in this planning challenge. This study concludes that simple IMAT techniques can generate significantly better plan quality compared to previous established CKRS benchmarks.


Assuntos
Benchmarking , Radiocirurgia/métodos , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia de Intensidade Modulada/métodos , Neoplasias da Coluna Vertebral , Vértebras Torácicas , Idoso , Algoritmos , Fracionamento da Dose de Radiação , Humanos , Recidiva Local de Neoplasia/radioterapia , Órgãos em Risco , Radiocirurgia/instrumentação , Dosagem Radioterapêutica , Radioterapia de Intensidade Modulada/instrumentação , Reirradiação , Procedimentos Cirúrgicos Robóticos/instrumentação , Neoplasias da Coluna Vertebral/radioterapia , Neoplasias da Coluna Vertebral/secundário , Vértebras Torácicas/cirurgia
13.
Ultrasonics ; 88: 174-184, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29674228

RESUMO

We have investigated limited angle transmission tomography to estimate speed of sound (SOS) distributions for breast cancer detection. That requires both accurate delineations of major tissues, in this case by segmentation of prior B-mode images, and calibration of the relative positions of the opposed transducers. Experimental sensitivity evaluation of the reconstructions with respect to segmentation and calibration errors is difficult with our current system. Therefore, parametric studies of SOS errors in our bent-ray reconstructions were simulated. They included mis-segmentation of an object of interest or a nearby object, and miscalibration of relative transducer positions in 3D. Close correspondence of reconstruction accuracy was verified in the simplest case, a cylindrical object in homogeneous background with induced segmentation and calibration inaccuracies. Simulated mis-segmentation in object size and lateral location produced maximum SOS errors of 6.3% within 10 mm diameter change and 9.1% within 5 mm shift, respectively. Modest errors in assumed transducer separation produced the maximum SOS error from miscalibrations (57.3% within 5 mm shift), still, correction of this type of error can easily be achieved in the clinic. This study should aid in designing adequate transducer mounts and calibration procedures, and in specification of B-mode image quality and segmentation algorithms for limited angle transmission tomography relying on ray tracing algorithms.


Assuntos
Neoplasias da Mama/diagnóstico por imagem , Imagem Multimodal , Tomografia por Raios X/métodos , Ultrassonografia Mamária/métodos , Algoritmos , Calibragem , Simulação por Computador , Desenho de Equipamento , Humanos , Aumento da Imagem/métodos , Interpretação de Imagem Assistida por Computador/métodos , Imagens de Fantasmas , Sensibilidade e Especificidade , Transdutores
14.
J Comp Neurol ; 526(2): 310-323, 2018 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-29023717

RESUMO

Monocular deprivation (MD) imposed early in postnatal life elicits profound structural and functional abnormalities throughout the primary visual pathway. The ability of MD to modify neurons within the visual system is restricted to a so-called critical period that, for cats, peaks at about one postnatal month and declines thereafter so that by about 3 months of age MD has little effect. Recovery from the consequences of MD likewise adheres to a critical period that ends by about 3 months of age, after which the effects of deprivation are thought to be permanent and without capacity for reversal. The attenuation of plasticity beyond early development is a formidable obstacle for conventional therapies to stimulate recovery from protracted visual deprivation. In the current study we examined the efficacy of dark exposure and retinal inactivation with tetrodotoxin to promote anatomical recovery in the dorsal lateral geniculate nuclues (dLGN) from long-term MD started at the peak of the critical period. Whereas 10 days of dark exposure or binocular retinal inactivation were not better at promoting recovery than conventional treatment with reverse occlusion, inactivation of only the non-deprived (fellow) eye for 10 days produced a complete restoration of neuron soma size, and also reversed the significant loss of neurofilament protein within originally deprived dLGN layers. These results reveal a capacity for neural plasticity and recovery that is larger than anything previously observed following protracted MD in cat, and they highlight a possibility for alternative therapies applied at ages thought to be recalcitrant to recovery.


Assuntos
Lateralidade Funcional/fisiologia , Corpos Geniculados/anatomia & histologia , Corpos Geniculados/fisiologia , Recuperação de Função Fisiológica/fisiologia , Privação Sensorial/fisiologia , Vias Visuais/fisiologia , Fatores Etários , Análise de Variância , Anestésicos Locais/farmacologia , Animais , Animais Recém-Nascidos , Gatos , Escuridão , Proteínas de Neurofilamentos/metabolismo , Tetrodotoxina/farmacologia , Vias Visuais/efeitos dos fármacos
15.
Ultrasound Med Biol ; 44(1): 199-213, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29074273

RESUMO

The ability to control high-intensity focused ultrasound (HIFU) thermal ablation using echo decorrelation imaging feedback was evaluated in ex vivo bovine liver. Sonications were automatically ceased when the minimum cumulative echo decorrelation within the region of interest exceeded an ablation control threshold, determined from preliminary experiments as -2.7 (log-scaled decorrelation per millisecond), corresponding to 90% specificity for local ablation prediction. Controlled HIFU thermal ablation experiments were compared with uncontrolled experiments employing two, five or nine sonication cycles. Means and standard errors of the lesion width, area and depth, as well as receiver operating characteristic curves testing ablation prediction performance, were computed for each group. Controlled trials exhibited significantly smaller average lesion area, width and treatment time than five-cycle or nine-cycle uncontrolled trials and also had significantly greater prediction capability than two-cycle uncontrolled trials. These results suggest echo decorrelation imaging is an effective approach to real-time HIFU ablation control.


Assuntos
Ablação por Ultrassom Focalizado de Alta Intensidade/métodos , Interpretação de Imagem Assistida por Computador/métodos , Fígado/cirurgia , Animais , Bovinos
16.
Ultrasound Med Biol ; 43(1): 176-186, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27712923

RESUMO

In open surgical procedures, image-ablate ultrasound arrays performed thermal ablation and imaging on rabbit liver lobes with implanted VX2 tumor. Treatments included unfocused (bulk ultrasound ablation, N = 10) and focused (high-intensity focused ultrasound ablation, N = 13) exposure conditions. Echo decorrelation and integrated backscatter images were formed from pulse-echo data recorded during rest periods after each therapy pulse. Echo decorrelation images were corrected for artifacts using decorrelation measured prior to ablation. Ablation prediction performance was assessed using receiver operating characteristic curves. Results revealed significantly increased echo decorrelation and integrated backscatter in both ablated liver and ablated tumor relative to unablated tissue, with larger differences observed in liver than in tumor. For receiver operating characteristic curves computed from all ablation exposures, both echo decorrelation and integrated backscatter predicted liver and tumor ablation with statistically significant success, and echo decorrelation was significantly better as a predictor of liver ablation. These results indicate echo decorrelation imaging is a successful predictor of local thermal ablation in both normal liver and tumor tissue, with potential for real-time therapy monitoring.


Assuntos
Ablação por Ultrassom Focalizado de Alta Intensidade/métodos , Neoplasias Hepáticas Experimentais/diagnóstico por imagem , Neoplasias Hepáticas Experimentais/cirurgia , Fígado/diagnóstico por imagem , Fígado/cirurgia , Ultrassonografia/métodos , Animais , Modelos Animais de Doenças , Coelhos
17.
J Acoust Soc Am ; 140(3): 2113, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27914403

RESUMO

Attenuation of ultrasound waves traversing a medium is not only a result of absorption and scattering within a given tissue, but also of coherent scattering, including diffraction, refraction, and reflection of the acoustic wave at tissue boundaries. This leads to edge enhancement and other artifacts in most reconstruction algorithms, other than 3D wave migration with currently impractical, implementations. The presented approach accounts for energy loss at tissue boundaries by normalizing data based on variable sound speed, and potential density, of the medium using a k-space wave solver. Coupled with a priori knowledge of major sound speed distributions, physical attenuation values within broad ranges, and the assumption of homogeneity within segmented regions, an attenuation image representative of region bulk properties is constructed by solving a penalized weighted least squares optimization problem. This is in contradistinction to absorption or to conventional attenuation coefficient based on overall insertion loss with strong dependence on sound speed and impedance mismatches at tissue boundaries. This imaged property will be referred to as the bulk attenuation coefficient. The algorithm is demonstrated on an opposed array setup, with mean-squared-error improvements from 0.6269 to 0.0424 (dB/cm/MHz)2 for a cylindrical phantom, and 0.1622 to 0.0256 (dB/cm/MHz)2 for a windowed phantom.


Assuntos
Acústica , Algoritmos , Imagens de Fantasmas , Som , Ondas Ultrassônicas
18.
Proc Natl Acad Sci U S A ; 113(49): 14139-14144, 2016 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-27856748

RESUMO

A half-century of research on the consequences of monocular deprivation (MD) in animals has revealed a great deal about the pathophysiology of amblyopia. MD initiates synaptic changes in the visual cortex that reduce acuity and binocular vision by causing neurons to lose responsiveness to the deprived eye. However, much less is known about how deprivation-induced synaptic modifications can be reversed to restore normal visual function. One theoretically motivated hypothesis is that a period of inactivity can reduce the threshold for synaptic potentiation such that subsequent visual experience promotes synaptic strengthening and increased responsiveness in the visual cortex. Here we have reduced this idea to practice in two species. In young mice, we show that the otherwise stable loss of cortical responsiveness caused by MD is reversed when binocular visual experience follows temporary anesthetic inactivation of the retinas. In 3-mo-old kittens, we show that a severe impairment of visual acuity is also fully reversed by binocular experience following treatment and, further, that prolonged retinal inactivation alone can erase anatomical consequences of MD. We conclude that temporary retinal inactivation represents a highly efficacious means to promote recovery of function.


Assuntos
Ambliopia/terapia , Potenciais Evocados Visuais , Visão Monocular , Animais , Gatos , Feminino , Masculino , Camundongos , Modelos Animais , Recuperação de Função Fisiológica , Acuidade Visual
19.
J Tradit Chin Med ; 36(6): 701-5, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-29949329

RESUMO

OBJECTIVE: To investigate the therapeutic and preventive effects of Rorrico on influenza, especially influenza A viral infection, including swine flu (H1N1) in humans. METHODS: Eighty-nine subjects were recruited in Hong Kong and Macau, and divided into treatment group (TG) and prevention group (PG) based on their influenza A and swine flu symptoms. All subjects were prescribed Rorrico or placebo, and monitored by a Chinese medicine practitioner. Blood samples were collected before and after 7-day Rorrico or placebo treatment for laboratory investigations. RESULTS: After treatment, there were some full recoveries and obvious relief of onset symptoms in the TG. Blood test results showed that Rorrico produced (a) no adverse effects on subjects' renal and liver functions, muscle enzyme and hematological status, (b) no up-regulation of pro-inflammatory cytokines tumour necrosis factor-a and interleukin-18 in both TG and PG, (c) mild yet statistically significant elevation of plasma mannose-binding lectin (MBL) in PG. CONCLUSION: Rorrico has no up-regulating effect on the participants' immune response, or, equally likely, the immuno-modulatory effects of Rorrico do not non-specifically or unnecessarily promote inflammation when not required. It is possible that oral administration of Rorrico can promote hepatic synthesis of MBL in healthy PG subjects, thereby conferring increased protection against infection.


Assuntos
Medicamentos de Ervas Chinesas/administração & dosagem , Vírus da Influenza A Subtipo H1N1/efeitos dos fármacos , Influenza Humana/tratamento farmacológico , Animais , Citocinas/genética , Citocinas/imunologia , Humanos , Vírus da Influenza A Subtipo H1N1/fisiologia , Influenza Humana/genética , Influenza Humana/imunologia , Influenza Humana/virologia , Suínos , Doenças dos Suínos/virologia , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/imunologia
20.
Taiwan J Obstet Gynecol ; 54(4): 385-9, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26384055

RESUMO

OBJECTIVES: The research was designed to examine the impact of the previous diagnoses of depression, menopause status, vasomotor symptoms, and neuroticism on depressive symptoms among menopausal women in Taiwan over a 30-month follow-up. MATERIALS AND METHODS: A community-based sample of 190 middle-aged women was enrolled. The Menopausal Symptoms Scale, Neuroticism Extraversion Openness Five Factor Inventory-Chinese version, and Ko's Depression Inventory were applied, and results were assessed. In addition, each woman underwent a semistructured diagnostic interview with the Chinese version of the Modified Schedule of Affective Disorders and Schizophrenia-Lifetime to obtain her lifetime psychiatric history. After 30 months, 111 participants completed follow-up questionnaires. RESULTS: Results of the hierarchical multiple regression analyses showed that depressive symptoms during the menopause transition predicted depressive symptoms over 30 months. After controlling for depressive symptoms during the menopause transition, the previous diagnoses of depression, menopause status, and vasomotor symptoms could not predict depressive symptoms over 30 months, whereas neuroticism still predicted depressive symptoms over 30 months. CONCLUSION: The research suggested that neuroticism plays an important role in the persistence of depression among climacteric women after 30 months.


Assuntos
Transtornos de Ansiedade/diagnóstico , Depressão/diagnóstico , Transtorno Depressivo/diagnóstico , Fogachos/diagnóstico , Menopausa/psicologia , Transtornos de Ansiedade/epidemiologia , Climatério/fisiologia , Climatério/psicologia , Estudos de Coortes , Depressão/epidemiologia , Transtorno Depressivo/epidemiologia , Feminino , Seguimentos , Fogachos/epidemiologia , Humanos , Incidência , Modelos Lineares , Menopausa/fisiologia , Pessoa de Meia-Idade , Análise Multivariada , Testes Neuropsicológicos , Neuroticismo , Estudos de Amostragem , Índice de Gravidade de Doença , Taiwan , Fatores de Tempo , Sistema Vasomotor/fisiopatologia
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