RESUMEN
Stroke results in local neural disconnection and brain-wide neuronal network dysfunction leading to neurological deficits. Beyond the hyper-acute phase of ischaemic stroke, there is no clinically-approved pharmacological treatment that alleviates sensorimotor impairments. Functional recovery after stroke involves the formation of new or alternative neuronal circuits including existing neural connections. The type-5 metabotropic glutamate receptor (mGluR5) has been shown to modulate brain plasticity and function and is a therapeutic target in neurological diseases outside of stroke. We investigated whether mGluR5 influences functional recovery and network reorganization rodent models of focal ischaemia. Using multiple behavioural tests, we observed that treatment with negative allosteric modulators (NAMs) of mGluR5 (MTEP, fenobam and AFQ056) for 12 days, starting 2 or 10 days after stroke, restored lost sensorimotor functions, without diminishing infarct size. Recovery was evident within hours after initiation of treatment and progressed over the subsequent 12 days. Recovery was prevented by activation of mGluR5 with the positive allosteric modulator VU0360172 and accelerated in mGluR5 knock-out mice compared with wild-type mice. After stroke, multisensory stimulation by enriched environments enhanced recovery, a result prevented by VU0360172, implying a role of mGluR5 in enriched environment-mediated recovery. Additionally, MTEP treatment in conjunction with enriched environment housing provided an additive recovery enhancement compared to either MTEP or enriched environment alone. Using optical intrinsic signal imaging, we observed brain-wide disruptions in resting-state functional connectivity after stroke that were prevented by mGluR5 inhibition in distinct areas of contralesional sensorimotor and bilateral visual cortices. The levels of mGluR5 protein in mice and in tissue samples of stroke patients were unchanged after stroke. We conclude that neuronal circuitry subserving sensorimotor function after stroke is depressed by a mGluR5-dependent maladaptive plasticity mechanism that can be restored by mGluR5 inhibition. Post-acute stroke treatment with mGluR5 NAMs combined with rehabilitative training may represent a novel post-acute stroke therapy.
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Isquemia Encefálica , Enfermedades del Sistema Nervioso , Accidente Cerebrovascular , Animales , Humanos , Ratones , Encéfalo/metabolismo , Isquemia Encefálica/tratamiento farmacológico , Ratones Noqueados , Enfermedades del Sistema Nervioso/metabolismo , Receptor del Glutamato Metabotropico 5/metabolismoRESUMEN
Polyhydroxyalkanoate (PHA) is an environmental alternative to petroleum-based plastics because of its biodegradability. The polymer properties of PHA have been improved by the incorporation of different monomers. Traditionally, the monomer composition of PHA has been analyzed using gas chromatography (GC) and nuclear magnetic resonance (NMR), providing accurate monomer composition. However, sequential analysis of the thermal properties of PHA using differential scanning calorimetry (DSC) remains necessary, providing crucial insights into its thermal characteristics. To shorten the monomer composition and thermal property analysis, we directly applied DSC to the analysis of the obtained PHA film and observed a high correlation (r2 = 0.98) between melting enthalpy and the 3-hydroxyhexanoate (3-HHx) mole fraction in the polymer. A higher 3-HHx fraction resulted in a lower melting enthalpy as 3-HHx provided the polymer with higher flexibility. Based on this, we selected the poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (P(3HB-co-3HHx)) producing strain from Cupriavidus strains that newly screened and transformed with vectors containing P(3HB-co-3HHx) biosynthetic genes, achieving an average error rate below 1.8% between GC and DSC results. Cupriavidus sp. BK2 showed a high 3-HHx mole fraction, up to 10.38 mol%, with Tm (â) = 171.5 and ΔH of Tm (J/g) = 48.0, simultaneously detected via DSC. This study is an example of the expansion of DSC for PHA analysis from polymer science to microbial engineering.
RESUMEN
Normal aging is associated with a variety of neurologic changes including declines in cognition, memory, and motor activity. These declines correlate with neuronal changes in synaptic structure and function. Degradation of brain network activity and connectivity represents a likely mediator of age-related functional deterioration resulting from these neuronal changes. Human studies have demonstrated both general decreases in spontaneous cortical activity and disruption of cortical networks with aging. Current techniques used to study cerebral network activity are hampered either by limited spatial resolution (e.g. electroencephalography, EEG) or limited temporal resolution (e.g., functional magnetic resonance imaging, fMRI). Here we utilize mesoscale imaging of neuronal activity in Thy1-GCaMP6f mice to characterize neuronal network changes in aging with high spatial resolution across a wide frequency range. We show that while evoked activity is unchanged with aging, spontaneous neuronal activity decreases across a wide frequency range (0.01-4 Hz) involving all regions of the cortex. In contrast to this global reduction in cortical power, we found that aging is associated with functional connectivity (FC) deterioration of select networks including somatomotor, cingulate, and retrosplenial nodes. These changes are corroborated by reductions in homotopic FC and node degree within somatomotor and visual cortices. Finally, we found that whole-cortex delta power and delta band node degree correlate with exploratory activity in young but not aged animals. Together these data suggest that aging is associated with global declines in spontaneous cortical activity and focal deterioration of network connectivity, and that these reductions may be associated with age-related behavioral declines.
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Envejecimiento , Electroencefalografía , Anciano , Envejecimiento/fisiología , Animales , Mapeo Encefálico , Cognición , Humanos , Imagen por Resonancia Magnética/métodos , RatonesRESUMEN
Polyhydroxybutyrate (PHB) is a bio-based, biodegradable and biocompatible plastic that has the potential to replace petroleum-based plastics. Lignocellulosic biomass is a promising feedstock for industrial fermentation to produce bioproducts such as polyhydroxybutyrate (PHB). However, the pretreatment processes of lignocellulosic biomass lead to the generation of toxic byproducts, such as furfural, 5-HMF, vanillin, and acetate, which affect microbial growth and productivity. In this study, to reduce furfural toxicity during PHB production from lignocellulosic hydrolysates, we genetically engineered Cupriavidus necator NCIMB 11599, by inserting the nicotine amide salvage pathway genes pncB and nadE to increase the NAD(P)H pool. We found that the expression of pncB was the most effective in improving tolerance to inhibitors, cell growth, PHB production and sugar consumption rate. In addition, the engineered strain harboring pncB showed higher PHB production using lignocellulosic hydrolysates than the wild-type strain. Therefore, the application of NAD salvage pathway genes improves the tolerance of Cupriavidus necator to lignocellulosic-derived inhibitors and should be used to optimize PHB production.
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Cupriavidus necator , Petróleo , Amidas/metabolismo , Cupriavidus necator/genética , Cupriavidus necator/metabolismo , Azúcares de la Dieta/metabolismo , Azúcares de la Dieta/farmacología , Furaldehído/farmacología , Inhibidores de Crecimiento/metabolismo , Inhibidores de Crecimiento/farmacología , Hidroxibutiratos/metabolismo , Lignina , NAD/metabolismo , NAD/farmacología , Nicotina/metabolismo , Nicotina/farmacología , Nitrobencenos , Petróleo/metabolismo , PlásticosRESUMEN
INTRODUCTION: The Arc of Buhler is a rare vascular variant describing a persistent remnant of the embryologic ventral anastomosis between the celiac trunk (CT) and superior mesenteric artery (SMA), invariably reported in the context of CT stenosis. PURPOSE: To report a case of (1) a large and tortuous pancreaticoduodenal arcade and (2) a large and tortuous Arc of Buhler in the absence of celiac axis stenosis. METHODS: The variant was discovered during routine cadaver dissection. We acquired transverse biopsies of variant vessels and evaluated their wall thickness. RESULTS: The donor's anterior PDA, posterior PDA, and Arc of Buhler had larger diameters, and the common hepatic artery had a smaller diameter than the literature-reported values of a standard human body. The posterior PDA had significantly increased wall thickness compared to the other investigated vessels. CONCLUSIONS: The Arc of Buhler is a rare remnant of the embryologic ventral anastomosis that is estimated to be hemodynamically active in only half of cases. Previous reports have documented hemodynamically active Arcs of Buhler only in cases of CT stenosis. To the best of the authors' knowledge, this is a unique case of a persistent and hemodynamically active Arc of Buhler in the absence of CT stenosis. Clinicians should be aware of this variant as its abnormal position may increase risk of herniation and surgical complications, and its tortuosity may increase risk of clot formation.
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Arteria Celíaca , Arteria Mesentérica Superior , Humanos , Constricción Patológica/etiología , Arteria Celíaca/diagnóstico por imagen , Arteria Mesentérica Superior/diagnóstico por imagen , Arteria Hepática/diagnóstico por imagen , Páncreas/diagnóstico por imagen , Páncreas/irrigación sanguíneaRESUMEN
Kidney cancer is one of the most difficult cancers to treat by targeted and radiation therapy. Therefore, identifying key regulators in this cancer is especially important for finding new drugs. We focused on androgen receptor (AR) regulation by its epigenetic co-regulator lysine-specific histone demethylase 1 (LSD1) in kidney cancer development. LSD1 knock-down in kidney cancer cells decreased expression of AR target genes. Moreover, the binding of AR to target gene promoters was reduced and histone methylation status was changed in LSD1 knock-down kidney cancer cells. LSD1 knock-down also slowed growth and decreased the migration ability of kidney cancer cells. We found that pargyline, known as a LSD1 inhibitor, can reduce AR activity in kidney cancer cells. The treatment of kidney cancer cells with pargyline delayed growth and repressed epithelial-mesenchymal transition (EMT) markers. These effects were additively enhanced by co-treatment with the AR inhibitor enzalutamide. Down-regulation of LSD1 in renal cancer cells (RCC) attenuated in vivo tumor growth in a xenograft mouse model. These results provide evidence that LSD1 can regulate kidney cancer cell growth via epigenetic control of AR transcription factors and that LSD1 inhibitors may be good candidate drugs for treating kidney cancer.
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Carcinoma de Células Renales/patología , Histona Demetilasas/fisiología , Neoplasias Renales/patología , Receptores Androgénicos/metabolismo , Animales , Carcinoma de Células Renales/genética , Carcinoma de Células Renales/metabolismo , Línea Celular Tumoral , Células Cultivadas , Progresión de la Enfermedad , Regulación Neoplásica de la Expresión Génica , Células HEK293 , Histona Demetilasas/genética , Humanos , Neoplasias Renales/genética , Neoplasias Renales/metabolismo , Masculino , Ratones , Ratones Endogámicos NOD , Ratones SCID , Receptores Androgénicos/genética , Transducción de Señal/genéticaRESUMEN
Histone demethylase KDM7A regulates many biological processes, including differentiation, development, and the growth of several cancer cells. Here, we have focused on the role of KDM7A in bladder cancer cells, especially under drug-resistant conditions. When the KDM7A gene was knocked down, bladder cancer cell lines showed impaired cell growth, increased cell death, and reduced rates of cell migration. Biochemical studies revealed that KDM7A knockdown in the bladder cancer cells repressed the activity of androgen receptor (AR) through epigenetic regulation. When we developed a cisplatin-resistant bladder cancer cell line, we found that AR expression was highly elevated. Upon treatment with TC-E 5002, a chemical inhibitor of KDM7A, the cisplatin-resistant bladder cancer cells, showed decreased cell proliferation. In the mouse xenograft model, KDM7A knockdown or treatment with its inhibitor reduced the growth of the bladder tumor. We also observed the upregulation of KDM7A expression in patients with bladder cancer. The findings suggest that histone demethylase KDM7A mediates the growth of bladder cancer. Moreover, our findings highlight the therapeutic potential of the KMD7A inhibitor, TC-E 5002, in patients with cisplatin-resistant bladder cancer.
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Cisplatino/farmacología , Resistencia a Antineoplásicos/efectos de los fármacos , Histona Demetilasas con Dominio de Jumonji/metabolismo , Receptores Androgénicos/metabolismo , Neoplasias de la Vejiga Urinaria/metabolismo , Anciano , Anciano de 80 o más Años , Animales , Apoptosis/efectos de los fármacos , Apoptosis/genética , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Movimiento Celular/genética , Núcleo Celular/efectos de los fármacos , Núcleo Celular/metabolismo , Proliferación Celular/efectos de los fármacos , Proliferación Celular/genética , Cisplatino/uso terapéutico , Resistencia a Antineoplásicos/genética , Epigénesis Genética/efectos de los fármacos , Transición Epitelial-Mesenquimal/efectos de los fármacos , Transición Epitelial-Mesenquimal/genética , Femenino , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Masculino , Metilación , Ratones Endogámicos NOD , Persona de Mediana Edad , Invasividad Neoplásica , Regiones Promotoras Genéticas/genética , ARN Mensajero/genética , ARN Mensajero/metabolismo , Receptores Androgénicos/genética , Transcripción Genética/efectos de los fármacos , Carga Tumoral/efectos de los fármacos , Regulación hacia Arriba/efectos de los fármacos , Regulación hacia Arriba/genética , Neoplasias de la Vejiga Urinaria/tratamiento farmacológico , Neoplasias de la Vejiga Urinaria/genética , Neoplasias de la Vejiga Urinaria/patología , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Spatial attention is the cognitive function that coordinates the selection of visual stimuli with appropriate behavioral responses. Recent studies have reported that phase-amplitude coupling (PAC) of low and high frequencies covaries with spatial attention, but differ on the direction of covariation and the frequency ranges involved. We hypothesized that distinct phase-amplitude frequency pairs have differentiable contributions during tasks that manipulate spatial attention. We investigated this hypothesis with electrocorticography (ECoG) recordings from participants who engaged in a cued spatial attention task. To understand the contribution of PAC to spatial attention we classified cortical sites by their relationship to spatial variables or behavioral performance. Local neural activity in spatial sites was sensitive to spatial variables in the task, while local neural activity in behavioral sites correlated with reaction time. We found two PAC frequency clusters that covaried with different aspects of the task. During a period of cued attention, delta-phase/high-gamma (DH) PAC was sensitive to cue direction in spatial sites. In contrast, theta-alpha-phase/beta-low-gamma-amplitude (TABL) PAC robustly correlated with future reaction times in behavioral sites. Finally, we investigated the origins of TABL PAC and found it corresponded to behaviorally relevant, sharp waveforms, which were also coupled to a low frequency rhythm. We conclude that TABL and DH PAC correspond to distinct mechanisms during spatial attention tasks and that sharp waveforms are elements of a coupled dynamical process.
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Atención/fisiología , Ondas Encefálicas/fisiología , Corteza Cerebral/fisiología , Señales (Psicología) , Electrocorticografía/métodos , Desempeño Psicomotor/fisiología , Tiempo de Reacción/fisiología , Procesamiento de Señales Asistido por Computador , Percepción Espacial/fisiología , Percepción Visual/fisiología , Adulto , Corteza Cerebral/fisiopatología , Epilepsia/fisiopatología , Humanos , Tiempo de Reacción/inmunologíaRESUMEN
Designing tight-binding ligands is a primary objective of small-molecule drug discovery. Over the past few decades, free-energy calculations have benefited from improved force fields and sampling algorithms, as well as the advent of low-cost parallel computing. However, it has proven to be challenging to reliably achieve the level of accuracy that would be needed to guide lead optimization (â¼5× in binding affinity) for a wide range of ligands and protein targets. Not surprisingly, widespread commercial application of free-energy simulations has been limited due to the lack of large-scale validation coupled with the technical challenges traditionally associated with running these types of calculations. Here, we report an approach that achieves an unprecedented level of accuracy across a broad range of target classes and ligands, with retrospective results encompassing 200 ligands and a wide variety of chemical perturbations, many of which involve significant changes in ligand chemical structures. In addition, we have applied the method in prospective drug discovery projects and found a significant improvement in the quality of the compounds synthesized that have been predicted to be potent. Compounds predicted to be potent by this approach have a substantial reduction in false positives relative to compounds synthesized on the basis of other computational or medicinal chemistry approaches. Furthermore, the results are consistent with those obtained from our retrospective studies, demonstrating the robustness and broad range of applicability of this approach, which can be used to drive decisions in lead optimization.
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Biología Computacional , Descubrimiento de Drogas , Proteínas/metabolismo , Diseño de Fármacos , Ligandos , Modelos Moleculares , Unión Proteica , Conformación Proteica , Proteínas/química , TermodinámicaRESUMEN
A Gram-stain-negative, non-motile, aerobic and coccoid, ovoid or rod-shaped bacterial strain, designated BS-W9(T), was isolated from a tidal flat of the South Sea, South Korea. Strain BS-W9(T) grew optimally at 25-30 °C, at pH 7.0-8.0 and in the presence of approximately 2.0% (w/v) NaCl. Phylogenetic trees, based on 16S rRNA gene sequences, revealed that strain BS-W9(T) clustered with the type strain of Halocynthiibacter namhaensis , showing a highest sequence similarity of 97.3%. It exhibited sequence similarity values of less than 95.6% to the type strains of other species with validly published names. Strain BS-W9(T) contained Q-10 as the predominant ubiquinone and C18:1ω7c as the predominant fatty acid. The major polar lipids of strain BS-W9(T) were phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, one unidentified lipid and one unidentified aminolipid. The fatty acid and polar lipid profiles of strain BS-W9(T) were distinguished from those of the type strains of H. namhaensis and other phylogenetically related genera. The DNA G+C content of strain BS-W9(T) was 53.2 mol% and its mean DNA-DNA relatedness value with H. namhaensis RA2-3(T) was 14%. On the basis of the phylogenetic, chemotaxonomic and other phenotypic properties, strain BS-W9(T) is considered to represent a novel genus and species within the family Rhodobacteraceae , for which the name Pseudohalocyntiibacter aestuariivivens gen. nov., sp. nov. is proposed. The type strain of Pseudohalocyntiibacter aestuariivivens is BS-W9(T) (â=KCTC 42348(T)â=CECT 8726(T)).
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Sedimentos Geológicos/microbiología , Filogenia , Rhodobacteraceae/clasificación , Agua de Mar/microbiología , Técnicas de Tipificación Bacteriana , Composición de Base , ADN Bacteriano/genética , Ácidos Grasos/química , Datos de Secuencia Molecular , Hibridación de Ácido Nucleico , Fosfolípidos/química , ARN Ribosómico 16S/genética , República de Corea , Rhodobacteraceae/genética , Rhodobacteraceae/aislamiento & purificación , Análisis de Secuencia de ADN , Ubiquinona/análogos & derivados , Ubiquinona/químicaRESUMEN
A Gram-stain-negative, aerobic, non-spore-forming, non-flagellated and coccoid, ovoid or rod-shaped bacterial strain, DSSK2-12T, was isolated from the place where the ocean and a freshwater spring meet at Jeju island, South Korea. Strain DSSK2-12T grew optimally at 30 °C, at pH 7.08.0 and in the presence of 2.0 % (w/v) NaCl. The neighbour-joining phylogenetic tree based on 16S rRNA gene sequences revealed that strain DSSK2-12T fell within the clade comprising the type strains of species of the genus Alteromonas. Strain DSSK2-12T exhibited 16S rRNA gene sequence similarity values of 97.298.1 % to the type strains of Alteromonas litorea, Alteromonas marina, Alteromonas hispanica and Alteromonas genovensis and of 95.3996.98 % to those of other species of the genus Alteromonas. Strain DSSK2-12T contained Q-8 as the predominant ubiquinone and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), C16 : 0 and C18 : 1ω7c as the major fatty acids. The major polar lipids of strain DSSK2-12T were phosphatidylethanolamine, phosphatidylglycerol and one unidentified aminolipid. The DNA G+C content of strain DSSK2-12T was 48.6âmol% and its mean DNADNA relatedness values with the type strains of A. litorea, A. marina, A. hispanica and A. genovensis were 921 %. The differential phenotypic properties, together with phylogenetic and genetic distinctiveness, revealed that strain DSSK2-12T is separated from other species of the genus Alteromonas. On the basis of the data presented, strain DSSK2-12T is considered to represent a novel species of the genus Alteromonas, for which the name Alteromonas confluentis sp. nov. is proposed. The type strain is DSSK2-12T ( = KCTC 42603T = CECT 8870T).
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Alteromonas/clasificación , Agua Dulce/microbiología , Filogenia , Agua de Mar/microbiología , Alteromonas/genética , Alteromonas/aislamiento & purificación , Técnicas de Tipificación Bacteriana , Composición de Base , ADN Bacteriano/genética , Ácidos Grasos/química , Datos de Secuencia Molecular , Hibridación de Ácido Nucleico , Fosfatidiletanolaminas/química , ARN Ribosómico 16S/genética , República de Corea , Análisis de Secuencia de ADNRESUMEN
A highly sensitive immunosensor based on scanning tunneling microscopy (STM) was developed for the first time to detect living material such as HIV-1 virus by gold (Au) nanoparticle and fragmented antibody complex. Fragmented antibodies were pre-immobilized on the Au surface, then HIV-1 virus like particles (HIV-1 VLPs) and Au-nanoparticle and fragmented antibody complexes were applied to develop sandwich assay. The developed surface morphology and the current profile of fabricated immunosensing element were characterized by Raman spectroscopy and investigated with STM. The power spectrum derived from the current profile was found to be related with concentrations of HIV-1 VLPs. Using the electrical detection method based on current mapping profile of STM, living material such as virus, HIV-1 VLPs, was able to be detected successfully. The proposed technique can be a promising method to construct the highly sensitive and efficient sensor for detecting viruses and other living materials.
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Oro/química , VIH-1/aislamiento & purificación , Inmunoensayo/instrumentación , Nanopartículas del Metal/química , Microscopía de Túnel de Rastreo/instrumentación , Carga Viral/instrumentación , Anticuerpos Antivirales/química , Anticuerpos Antivirales/inmunología , Técnicas Biosensibles/instrumentación , Conductometría/instrumentación , Diseño de Equipo , Análisis de Falla de Equipo , VIH-1/inmunología , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
The box tree moth (BTM), Cydalima perspectalis Walker, is a pest that infests various plants within the Buxus genus. Although a specific parasitoid wasp species associated with the BTM has been observed in the Republic of Korea, no research on this species has been published. Here, we describe the fundamental morphological and biological characteristics of this parasitoid. We have identified the wasp as belonging to the genus Eriborus (Hymenoptera: Ichneumonidae: Campopleginae). Eriborus sp. parasitizes within the living host body, with 1 wasp emerging from each host. The parasitism rate observed in collected BTM populations was 33.1%. The emergence rate was 87.1%, with all emerging adults being females, resulting in a sex ratio of 0. The pupal period avg 9.5 days, and the adult lifespan avg 10.5 days. Eriborus sp. parasitized BTM larvae from the first to the fourth instar and reproduced by thelytokous parthenogenesis. Eriborus sp. exhibited morphological differences compared with previously reported Eriborus species in Korea, particularly in the length of the ovipositor sheath. Additionally, the proportion of the highest similarity in nucleotide sequences of mitochondrial cytochrome oxidase I DNA was only 94.53%, rendering species identification using GenBank's mt cytochrome c oxidase 1 DNA sequences unfeasible. These data suggest that Eriborus sp. could be used as a biological control agent for managing BTM infestations.
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Mariposas Nocturnas , Avispas , Animales , Avispas/fisiología , Mariposas Nocturnas/parasitología , Femenino , Masculino , República de Corea , Larva/crecimiento & desarrollo , Larva/parasitología , Pupa/parasitología , Pupa/crecimiento & desarrollo , Interacciones Huésped-Parásitos , Complejo IV de Transporte de Electrones/análisisRESUMEN
Significance: The non-invasive measurement of cerebral blood flow based on diffuse optical techniques has seen increased interest as a research tool for cerebral perfusion monitoring in critical care and functional brain imaging. Diffuse correlation spectroscopy (DCS) and speckle contrast optical spectroscopy (SCOS) are two such techniques that measure complementary aspects of the fluctuating intensity signal, with DCS quantifying the temporal fluctuations of the signal and SCOS quantifying the spatial blurring of a speckle pattern. With the increasing interest in the use of these techniques, a thorough comparison would inform new adopters of the benefits of each technique. Aim: We systematically evaluate the performance of DCS and SCOS for the measurement of cerebral blood flow. Approach: Monte Carlo simulations of dynamic light scattering in an MRI-derived head model were performed. For both DCS and SCOS, estimates of sensitivity to cerebral blood flow changes, coefficient of variation of the measured blood flow, and the contrast-to-noise ratio of the measurement to the cerebral perfusion signal were calculated. By varying complementary aspects of data collection between the two methods, we investigated the performance benefits of different measurement strategies, including altering the number of modes per optical detector, the integration time/fitting time of the speckle measurement, and the laser source delivery strategy. Results: Through comparison across these metrics with simulated detectors having realistic noise properties, we determine several guiding principles for the optimization of these techniques and report the performance comparison between the two over a range of measurement properties and tissue geometries. We find that SCOS outperforms DCS in terms of contrast-to-noise ratio for the cerebral blood flow signal in the ideal case simulated here but note that SCOS requires careful experimental calibrations to ensure accurate measurements of cerebral blood flow. Conclusion: We provide design principles by which to evaluate the development of DCS and SCOS systems for their use in the measurement of cerebral blood flow.
RESUMEN
Speckle contrast optical spectroscopy (SCOS) is an emerging camera-based technique that can measure human cerebral blood flow (CBF) with high signal-to-noise ratio (SNR). At low photon flux levels typically encountered in human CBF measurements, camera noise and nonidealities could significantly impact SCOS measurement SNR and accuracy. Thus, a guide for characterizing, selecting, and optimizing a camera for SCOS measurements is crucial for the development of next-generation optical devices for monitoring human CBF and brain function. Here, we provide such a guide and illustrate it by evaluating three commercially available complementary metal-oxide-semiconductor cameras, considering a variety of factors including linearity, read noise, and quantization distortion. We show that some cameras that are well-suited for general intensity imaging could be challenged in accurately quantifying spatial contrast for SCOS. We then determine the optimal operating parameters for the preferred camera among the three and demonstrate measurement of human CBF with this selected low-cost camera. This work establishes a guideline for characterizing and selecting cameras as well as for determining optimal parameters for SCOS systems.
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Circulación Cerebrovascular , Relación Señal-Ruido , Análisis Espectral , Humanos , Circulación Cerebrovascular/fisiología , Análisis Espectral/métodos , Análisis Espectral/instrumentación , Encéfalo/diagnóstico por imagen , Encéfalo/fisiología , Encéfalo/irrigación sanguíneaRESUMEN
5-hydroxyvaleric acid (5-HV) is a versatile C5 intermediate of bio-based high-value chemical synthesis pathways. However, 5-HV production faces a few shortcomings involving the supply of cofactors, especially α-ketoglutaric acid (α-KG). Herein, we established a two-cell biotransformation system by introducing L-glutamate oxidase (GOX) to regenerate α-KG. Additionally, the catalase KatE was adapted to inhibit α-KG degradation by the H2O2 produced during GOX reaction. We searched for the best combination of genes and vectors and optimized the biotransformation conditions to maximize GOX effectiveness. Under the optimized conditions, 5-HV pathway with GOX showed 1.60-fold higher productivity than that of without GOX, showing 11.3â¯g/L titer. Further, the two-cell system with GOX and KatE was expanded to produce poly(5-hydroxyvaleric acid) (P(5HV)), and it reached at 412â¯mg/L of P(5HV) production and 20.5% PHA contents when using the biotransformation supernatant. Thus, the two-cell biotransformation system with GOX can potentially give the practical and economic alternative of 5-HV production using bio-based methods. We also propose direct utilization of 5-HV from bioconversion for P(5HV) production.
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Aminoácido Oxidorreductasas , Biotransformación , Ácidos Cetoglutáricos , Azúcares Ácidos , Ácidos Cetoglutáricos/metabolismo , L-Aminoácido Oxidasa/metabolismo , L-Aminoácido Oxidasa/genética , Peróxido de Hidrógeno/metabolismo , Catalasa/metabolismo , Catalasa/genética , Valeratos/metabolismoRESUMEN
A highly sensitive label-free immunosensor for the detection of HIV-1 is newly developed based on localized surface plasmon resonance (LSPR) method. Uniform nanopattern of circular Au-dots (10-20nm) was fabricated on indium tin oxide (ITO) coated glass substrate by simple electrochemical deposition method. The surface of Au nanopattern was modified with HIV-1 neutralizing gp120 monoclonal antibody fragments. The modified substrate was employed to measure various concentrations of HIV-1 particles quantitatively based on the shift of longitudinal wavelength in the UV-Vis spectrum which results from the changes of local refractive index induced by specific antigen-antibody recognition events. The detection limit of the HIV-1 particles was estimated to be 200fg/mL, which is 10 fold higher than that of previously reported virus detection method based on LSPR. Since fabricated LSPR immunosensor has high sensitivity and selectivity, it is a promising approach for biological/medical sample analysis and various kinds of virus detection. FROM THE CLINICAL EDITOR: A localized surface plasmon resonance-based virus detection method is shown to have an order of magnitude improvement in detectable concentration of HIV-1 particles. Similar approaches may be used for screening other viral particles as well.
Asunto(s)
VIH-1/inmunología , VIH-1/aislamiento & purificación , Coloración y Etiquetado , Resonancia por Plasmón de Superficie/instrumentación , Resonancia por Plasmón de Superficie/métodos , Ensayo de Inmunoadsorción Enzimática , Genoma Viral/genética , Oro , Células HEK293 , VIH-1/genética , Humanos , Inmunoensayo , Límite de Detección , Nanopartículas/ultraestructura , Fenómenos Ópticos , ARN Viral/genética , Reproducibilidad de los Resultados , Virión/metabolismoRESUMEN
Cerebral blood flow (CBF) is crucial for brain health. Speckle contrast optical spectroscopy (SCOS) is a technique that has been recently developed to measure CBF, but the use of SCOS to measure human brain function at large source-detector separations with comparable or greater sensitivity to cerebral rather than extracerebral blood flow has not been demonstrated. We describe a fiber-based SCOS system capable of measuring human brain activation induced CBF changes at 33 mm source detector separations using CMOS detectors. The system implements a pulsing strategy to improve the photon flux and uses a data processing pipeline to improve measurement accuracy. We show that SCOS outperforms the current leading optical modality for measuring CBF, i.e. diffuse correlation spectroscopy (DCS), achieving more than 10x SNR improvement at a similar financial cost. Fiber-based SCOS provides an alternative approach to functional neuroimaging for cognitive neuroscience and health science applications.
Asunto(s)
Isquemia Encefálica , Encéfalo , Humanos , Análisis Espectral , Circulación Cerebrovascular/fisiología , HemodinámicaRESUMEN
Non-invasive continuous blood pressure monitoring remains elusive. There has been extensive research using the photoplethysmographic (PPG) waveform for blood pressure estimation, but improvements in accuracy are still needed before clinical use. Here we explored the use of an emerging technique, speckle contrast optical spectroscopy (SCOS), for blood pressure estimation. SCOS provides measurements of both blood volume changes (PPG) and blood flow index (BFi) changes during the cardiac cycle, and thus provides a richer set of parameters compared to traditional PPG. SCOS measurements were taken on the finger and wrists of 13 subjects. We investigated the correlations between features extracted from both the PPG and BFi waveforms with blood pressure. Features from the BFi waveforms were more significantly correlated with blood pressure than PPG features ( R = - 0.55, p = 1.1 × 10-4 for the top BFi feature versus R = - 0.53, p = 8.4 × 10-4 for the top PPG feature). Importantly, we also found that features combining BFi and PPG data were highly correlated with changes in blood pressure ( R = - 0.59, p = 1.7 × 10-4 ). These results suggest that the incorporation of BFi measurements should be further explored as a means to improve blood pressure estimation using non-invasive optical techniques.
RESUMEN
Medical and economic developments have allowed the human lifespan to extend and, as a result, the elderly population has increased worldwide. Osteoporosis is a common geriatric disease that has no symptoms and even a small impact can cause fractures in patients, leading to a serious deterioration in the quality of life. Osteoporosis treatment typically involves bisphosphonates and selective estrogen receptor modulators. However, these treatments are known to cause severe side effects, such as mandibular osteonecrosis and breast cancer, if used for an extended period of time. Therefore, it is essential to develop therapeutic agents from natural products that have fewer side effects. Gleditsiae fructus (GF) is a dried or immature fruit of Gleditsia sinensis Lam. and is composed of various triterpenoid saponins. The antiinflammatory effect of GF has been confirmed in various diseases, and since the antiinflammatory effect plays a major role in inhibiting osteoclast differentiation, GF was expected to be effective in osteoclast differentiation and menopausal osteoporosis; however, to the best of our knowledge, it has not yet been studied. Therefore, the present study was designed to examine the effect of GF on osteoclastogenesis and to investigate the mechanism underlying inhibition of osteoclast differentiation. The effects of GF on osteoclastogenesis were determined in vitro by tartrateresistant acid phosphatase (TRAP) staining, pit formation assays, filamentous actin (Factin) ring formation assays, western blotting and reverse transcriptionquantitative PCR analyses. Furthermore, the administration of GF to an animal model exhibiting menopausal osteoporosis allowed for the analysis of alterations in the bone microstructure of the femur using microCT. Additionally, assessments of femoral tissue and serum were conducted. The present study revealed that the administration of GF resulted in a reduction in osteoclast levels, Factin rings, TRAP activity and pit area. Furthermore, GF showed a dosedependent suppression of nuclear factor of activated Tcells cytoplasmic, cFos and other osteoclastogenesisrelated markers.