Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 37
Filtrar
Más filtros













Base de datos
Intervalo de año de publicación
1.
Brain Stimul ; 16(5): 1486-1500, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37778456

RESUMEN

Cochlear implants (CIs) restore activity in the deafened auditory system via electrical stimulation of the auditory nerve. As the spread of electric current in biological tissues is rather broad, the spectral information provided by electrical CIs is limited. Optogenetic stimulation of the auditory nerve has been suggested for artificial sound coding with improved spectral selectivity, as light can be conveniently confined in space. Yet, the foundations for optogenetic sound coding strategies remain to be established. Here, we parametrized stimulus-response-relationships of the auditory pathway in gerbils for optogenetic stimulation. Upon activation of the auditory pathway by waveguide-based optogenetic stimulation of the spiral ganglion, we recorded neuronal activity of the auditory midbrain, in which neural representations of spectral, temporal, and intensity information can be found. Screening a wide range of optical stimuli and taking the properties of optical CI emitters into account, we aimed to optimize stimulus paradigms for potent and energy-efficient activation of the auditory pathway. We report that efficient optogenetic coding builds on neural integration of millisecond stimuli built from microsecond light pulses, which optimally accommodate power-efficient laser diode operation. Moreover, we performed an activity-level-dependent comparison of optogenetic and acoustic stimulation in order to estimate the dynamic range and the maximal stimulation intensity amenable to single channel optogenetic sound encoding, and indicate that it complies well with speech comprehension in a typical conversation (65 dB). Our results provide a first framework for the development of coding strategies for future optogenetic hearing restoration.


Asunto(s)
Implantación Coclear , Implantes Cocleares , Vías Auditivas/fisiología , Optogenética/métodos , Mesencéfalo , Estimulación Acústica , Estimulación Eléctrica
2.
Food Res Int ; 165: 112472, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36869485

RESUMEN

Chloroplasts are abundant organelles in a diverse range of plant materials; they are predominantly composed of multicomponent thylakoid membranes which are lipid and protein rich. Intact or unravelled thylakoid membranes should, in principle, have interfacial activity, but little has been published on their activity in oil-in-water systems, and nothing on their performance on an oil continuous system. In this work different physical methods were used to produce a range of chloroplast/thylakoid suspensions with varying degrees of membrane integrity. Transmission electron microscopy revealed that pressure homogenisation led to the greatest extent of membrane and organelle disruption compared to less energy intensive preparation methods The ability of the derived materials to modulate the flow behaviour of a chocolate model system (65% (w/w) sugar/ sunflower oil (natural amphiphiles removed) suspension) was investigated by acquiring rheological parameters. All chloroplast/thylakoid preparations reduced yield stress, apparent viscosity, tangent flow point and cross over point in a concentration-dependent fashion, although not as significantly as polyglycerol polyricinoleate applied at a commercially relevant concentration in the same chocolate model system. Confocal laser scanning microscopy confirmed presence of the alternative flow enhancer material at the sugar surfaces. This research reveals that low-energy processing methods that do not extensively disrupt thylakoid membranes are applicable to generating materials with marked capacity to affect the flow behaviour of a chocolate model system. In conclusion, chloroplast/thylakoid materials hold strong potential as natural alternatives to synthetic rheology modifiers for lipid-based systems such as PGPR.


Asunto(s)
Cacao , Tilacoides , Cloroplastos , Ácidos Ricinoleicos , Azúcares
3.
Front Neurosci ; 17: 1105562, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36755736

RESUMEN

Background: The electrical cochlear implant (eCI) partially restores hearing in individuals affected by profound hearing impairment (HI) or deafness. However, the limited resolution of sound frequency coding with eCIs limits hearing in daily situations such as group conversations. Current research promises future improvements in hearing restoration which may involve gene therapy and optical stimulation of the auditory nerve, using optogenetics. Prior to the potential clinical translation of these technologies, it is critical that patients are engaged in order to align future research agendas and technological advancements with their needs. Methods: Here, we performed a survey study with hearing impaired, using an eCI as a means of hearing rehabilitation. We distributed a questionnaire to 180 adult patients from the University Medical Center Göttingen's Department of Otolaryngology who were actively using an eCI for 6 months or more during the time of the survey period. Questions revolved around patients needs, and willingness to accept hypothetical risks or drawbacks associated with an optical CI (oCI). Results: Eighty-one participants responded to the questionnaire; 68% were greater than 60 years of age and 26% had bilateral eCIs. Participants expressed a need for improving the performance beyond that experienced with their current eCI. Primarily, they desired improved speech comprehension in background noise, greater ability to appreciate music, and more natural sound impression. They expressed a willingness for engaging with new technologies for improved hearing restoration. Notably, participants were least concerned about hypothetically receiving a gene therapy necessary for the oCI implant; but expressed greater reluctance to hypothetically receiving an implant that had yet to be evaluated in a human clinical trial. Conclusion: This work provides a preliminary step in engaging patients in the development of a new technology that has the potential to address the limitations of electrical hearing rehabilitation.

4.
Bioresour Technol ; 372: 128680, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36706816

RESUMEN

Lignin is the second most abundant natural polymer after cellulose, and valorisation of lignin-rich streams has attracted increasing attention recently. This paper presents a novel and sustainable method to recover lignin from Cocoa Bean Shells (CBS) using Deep Eutectic Solvents (DES) and microwaves. A DES containing p-toluenesulfonic acid, choline chloride and glycerol (2:1:1 M ratio) was selected based on its dielectric properties. Under 200 W microwave power, the optimum yield of 95.5 % lignin was achieved at 130 °C and 30 min. DES-extracted lignin exhibited unique structural characteristics including larger particle sizes (242.5 µm D50 size), structural diversity (410.4 µm D90-D10 size) and H/G sub-unit ratio (71.9 %) compared with commercial Kraft lignin (77.2 µm, 157.9 µm and 0.1 % respectively), indicating the potential of DES in the modification and upgrading of lignin for novel value-added products.


Asunto(s)
Lignina , Microondas , Lignina/química , Disolventes Eutécticos Profundos , Solventes/química , Celulosa , Biomasa
5.
Biomacromolecules ; 24(1): 150-165, 2023 01 09.
Artículo en Inglés | MEDLINE | ID: mdl-36542545

RESUMEN

The increasing demand for tissue replacement has encouraged scientists worldwide to focus on developing new biofabrication technologies. Multimaterials/cells printed with stringent resolutions are necessary to address the high complexity of tissues. Advanced inkjet 3D printing can use multimaterials and attain high resolution and complexity of printed structures. However, a decisive yet limiting aspect of translational 3D bioprinting is selecting the befitting material to be used as bioink; there is a complete lack of cytoactive bioinks with adequate rheological, mechanical, and reactive properties. This work strives to achieve the right balance between resolution and cell support through methacrylamide functionalization of a psychrophilic gelatin and new fluorosurfactants used to engineer a photo-cross-linkable and immunoevasive bioink. The syntonized parameters following optimal formulation conditions allow proficient printability in a PolyJet 3D printer comparable in resolution to a commercial synthetic ink (∼150 µm). The bioink formulation achieved the desired viability (∼80%) and proliferation of co-printed cells while demonstrating in vivo immune tolerance of printed structures. The practical usage of existing high-resolution 3D printing systems using a novel bioink is shown here, allowing 3D bioprinted structures with potentially unprecedented complexity.


Asunto(s)
Bioimpresión , Bioimpresión/métodos , Impresión Tridimensional , Gelatina/química , Reología , Andamios del Tejido/química , Ingeniería de Tejidos/métodos
6.
Food Res Int ; 162(Pt B): 112064, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-36461320

RESUMEN

Consumers are increasingly looking for new plant-based alternatives to substitute animal proteins in their diets but for some applications it can be difficult to achieve the desired product microstructure using only plant proteins. One approach to facilitate structuring is to mix these plant-based ingredients with a polysaccharide. Here, the phase behaviour and microstructure of quinoa protein isolate (QPI) in mixture with maltodextrin (MD) of two dextrose equivalents (DE 7 and 2) were investigated. The binodals of both QPI-MD phase diagrams showed an atypical shape, where the concentration of MD in the QPI-rich phase and of QPI in the MD-rich phase increased with overall biopolymer concentration. Molecular weight distribution and microstructure analyses revealed that both maltodextrins fractionated between the phases and were probably entrapped within the volume-spanning protein network in the QPI-rich phase, indicating a depletion flocculation mechanism of phase separation. The pre-heating of QPI and the removal of salt from the systems resulted in similarly atypical phase diagrams. The approach presented contributes to our understanding of the phase behaviour of mixtures between plant proteins and polysaccharides, while the results suggest that the formulation of plant-based products of predictable properties may be more challenging than anticipated.


Asunto(s)
Chenopodium quinoa , Animales , Polisacáridos , Proteínas de Plantas , Peso Molecular
7.
Basic Res Cardiol ; 117(1): 52, 2022 10 24.
Artículo en Inglés | MEDLINE | ID: mdl-36279013

RESUMEN

Ischemic stroke imparts elevated risk of heart failure though the underlying mechanisms remain poorly described. We aimed to characterize the influence of cerebral ischemic injury on cardiac function using multimodality molecular imaging to investigate brain and cardiac morphology and tissue inflammation in two mouse models of variable stroke severity. Transient middle cerebral artery occlusion (MCAo) generated extensive stroke damage (56.31 ± 40.39 mm3). Positron emission tomography imaging of inflammation targeting the mitochondrial translocator protein (TSPO) revealed localized neuroinflammation at 7 days after stroke compared to sham (3.8 ± 0.8 vs 2.6 ± 0.7 %ID/g max, p < 0.001). By contrast, parenchyma topical application of vasoconstrictor endothelin-1 did not generate significant stroke damage or neuroinflammatory cell activity. MCAo evoked a modest reduction in left ventricle ejection fraction at both 1 weeks and 3 weeks after stroke (LVEF at 3 weeks: 54.3 ± 5.7 vs 66.1 ± 3.5%, p < 0.001). This contractile impairment was paralleled by elevated cardiac TSPO PET signal compared to sham (8.6 ± 2.4 vs 5.8 ± 0.7%ID/g, p = 0.022), but was independent of leukocyte infiltration defined by flow cytometry. Stroke size correlated with severity of cardiac dysfunction (r = 0.590, p = 0.008). Statistical parametric mapping identified a direct association between neuroinflammation at 7 days in a cluster of voxels including the insular cortex and reduced ejection fraction (ρ = - 0.396, p = 0.027). Suppression of microglia led to lower TSPO signal at 7 days which correlated with spared late cardiac function after MCAo (r = - 0.759, p = 0.029). Regional neuroinflammation early after cerebral ischemia influences subsequent cardiac dysfunction. Total body TSPO PET enables monitoring of neuroinflammation, providing insights into brain-heart inter-organ communication and may guide therapeutic intervention to spare cardiac function post-stroke.


Asunto(s)
Isquemia Encefálica , Cardiopatías , Accidente Cerebrovascular , Animales , Ratones , Encéfalo/diagnóstico por imagen , Encéfalo/metabolismo , Isquemia Encefálica/metabolismo , Endotelina-1/metabolismo , Cardiopatías/metabolismo , Infarto de la Arteria Cerebral Media/complicaciones , Infarto de la Arteria Cerebral Media/diagnóstico por imagen , Inflamación/metabolismo , Imagen Molecular/métodos , Tomografía de Emisión de Positrones/métodos , Accidente Cerebrovascular/metabolismo , Vasoconstrictores
8.
EMBO Mol Med ; 14(8): e15798, 2022 08 08.
Artículo en Inglés | MEDLINE | ID: mdl-35833443

RESUMEN

Hearing impairment, the most prevalent sensory deficit, affects more than 466 million people worldwide (WHO). We presently lack causative treatment for the most common form, sensorineural hearing impairment; hearing aids and cochlear implants (CI) remain the only means of hearing restoration. We engaged with CI users to learn about their expectations and their willingness to collaborate with health care professionals on establishing novel therapies. We summarize upcoming CI innovations, gene therapies, and regenerative approaches and evaluate the chances for clinical translation of these novel strategies. We conclude that there remains an unmet medical need for improving hearing restoration and that we are likely to witness the clinical translation of gene therapy and major CI innovations within this decade.


Asunto(s)
Implantación Coclear , Implantes Cocleares , Audífonos , Pérdida Auditiva Sensorineural , Pérdida Auditiva , Audición , Pérdida Auditiva/genética , Pérdida Auditiva/terapia , Pérdida Auditiva Sensorineural/genética , Pérdida Auditiva Sensorineural/terapia , Humanos
9.
Materials (Basel) ; 16(1)2022 Dec 22.
Artículo en Inglés | MEDLINE | ID: mdl-36614443

RESUMEN

Improved hearing restoration by cochlear implants (CI) is expected by optical cochlear implants (oCI) exciting optogenetically modified spiral ganglion neurons (SGNs) via an optical pulse generated outside the cochlea. The pulse is guided to the SGNs inside the cochlea via flexible polymer-based waveguide probes. The fabrication of these waveguide probes is realized by using 6" wafer-level micromachining processes, including lithography processes such as spin-coating cladding layers and a waveguide layer in between and etch processes for structuring the waveguide layer. Further adhesion layers and metal layers for laser diode (LD) bonding and light-outcoupling structures are also integrated in this waveguide process flow. Optical microscope and SEM images revealed that the majority of the waveguides are sufficiently smooth to guide light with low intensity loss. By coupling light into the waveguides and detecting the outcoupled light from the waveguide, we distinguished intensity losses caused by bending the waveguide and outcoupling. The probes were used in first modules called single-beam guides (SBGs) based on a waveguide probe, a ball lens and an LD. Finally, these SBGs were tested in animal models for proof-of-concept implantation experiments.

10.
Metab Brain Dis ; 36(8): 2597-2602, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34570340

RESUMEN

Status epilepticus (SE) is a clinical emergency with high mortality. SE can trigger neuronal death or injury and alteration of neuronal networks resulting in long-term cognitive decline or epilepsy. Among the multiple factors contributing to this damage, imbalance between oxygen and glucose requirements and brain perfusion during SE has been proposed. Herein, we aimed to quantify by neuroimaging the spatiotemporal course of brain perfusion during and after lithium-pilocarpine-induced SE in rats. To this purpose, animals underwent 99mTc-HMPAO SPECT imaging at different time points during and after SE using a small animal SPECT/CT system. 99mTc-HMPAO regional uptake was normalized to the injected dose. In addition, voxel-based statistical parametric mapping was performed. SPECT imaging showed an increase of cortical perfusion before clinical seizure activity onset followed by regional hypo-perfusion starting with the first convulsive seizure and during SE. Twenty-four hours after SE, brain 99mTc-HMPAO uptake was widely decreased. Finally, chronic epileptic animals showed regionally decreased perfusion affecting hippocampus and cortical sub-regions. Despite elevated energy and oxygen requirements, brain hypo-perfusion is present during SE. Our results suggest that insufficient compensation of required blood flow might contribute to neuronal damage and neuroinflammation, and ultimately to chronic epilepsy generated by SE.


Asunto(s)
Estado Epiléptico , Tomografía Computarizada de Emisión de Fotón Único , Animales , Encéfalo/irrigación sanguínea , Encéfalo/diagnóstico por imagen , Circulación Cerebrovascular/fisiología , Neuroimagen , Ratas , Estado Epiléptico/inducido químicamente , Estado Epiléptico/diagnóstico por imagen , Exametazima de Tecnecio Tc 99m , Tomografía Computarizada de Emisión de Fotón Único/métodos
11.
Foods ; 10(3)2021 Mar 17.
Artículo en Inglés | MEDLINE | ID: mdl-33802694

RESUMEN

Equal parts of sugar beet pectin and sodium caseinate were interacted through electrostatic attraction, enzymatic crosslinking, and the Maillard reaction to prepare three oil-in-water emulsifier systems. Oil-in-water emulsions (10%) were processed via high shear overhead mixing at the natural pH of the emulsifier systems, followed by pH adjustment to pH 4.5 and pH 7. The emulsions were stable against coalescence, except for a slight increase in the mean droplet size for the enzymatic cross-liked emulsion at pH 4.5 over a 14-day storage period. This emulsion also showed the lowest absolute zeta (ζ)-potential value of near 30 mV. The Maillard interaction emulsifier system resulted in larger droplet sizes compared to the other two emulsifier systems. Small deformation oscillatory shear rheology assessment of the emulsion cream phases revealed an impact of the emulsifier system design at pH 4.5.

12.
Foods ; 10(2)2021 Feb 09.
Artículo en Inglés | MEDLINE | ID: mdl-33572134

RESUMEN

This study concerns the preparation and functionality testing of a new class of Pickering particles for food emulsion stabilization: colloidal lignin-rich particles (CLRPs) derived from ethanol-soluble extract of cocoa shell. A further goal was to achieve Pickering functionality without the need to add co-emulsifying surfactants during emulsion processing. Cocoa shell is a co-product of the food manufacturing industry. As such it is anticipated that the particles would be accepted as a natural food ingredient, provided no harmful solvents are used in any step of their processing. The cocoa shell particles were milled, dispersed in water and exposed to 250 °C for 1 h in a stainless-steel tubular reactor followed by ethanol extraction to obtain a lignin-rich extract (46% (w/w) lignin with the remainder predominantly lipids). CLRPs were then fabricated by the precipitation of ethanol-dissolved extract into water (antisolvent). By employing an agitated process and droplet dosing into a non-agitated process, four particle suspensions of a range of submicron diameters were obtained. All particle suspensions contained the same mass fraction of extract and were surface active, with surface tension decreasing with increasing particle size. The smallest particles were obtained when lipids were removed from the extract prior to particle processing. In contrast to the other four particle suspensions, this one failed to stabilize a 10% (w/w) sunflower oil-in-water emulsion. We hypothesize that the phospholipids indigenously present in these CLRP formulations are a critical component for Pickering functionality. It can be concluded that we have successfully introduced a new class of Pickering particles, fabricated from an industry co-product and anticipated to be food grade.

13.
Geroscience ; 43(2): 673-690, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33517527

RESUMEN

Ageing provokes a plethora of molecular, cellular and physiological deteriorations, including heart failure, neurodegeneration, metabolic maladaptation, telomere attrition and hair loss. Interestingly, on the molecular level, the capacity to induce autophagy, a cellular recycling and cleaning process, declines with age across a large spectrum of model organisms and is thought to be responsible for a subset of age-induced changes. Here, we show that a 6-month administration of the natural autophagy inducer spermidine in the drinking water to aged mice is sufficient to significantly attenuate distinct age-associated phenotypes. These include modulation of brain glucose metabolism, suppression of distinct cardiac inflammation parameters, decreased number of pathological sights in kidney and liver and decrease of age-induced hair loss. Interestingly, spermidine-mediated age protection was associated with decreased telomere attrition, arguing in favour of a novel cellular mechanism behind the anti-ageing effects of spermidine administration.


Asunto(s)
Espermidina , Telómero , Envejecimiento , Animales , Autofagia , Suplementos Dietéticos , Ratones , Espermidina/farmacología
14.
Sci Transl Med ; 12(553)2020 07 22.
Artículo en Inglés | MEDLINE | ID: mdl-32718992

RESUMEN

When hearing fails, electrical cochlear implants (eCIs) provide the brain with auditory information. One important bottleneck of CIs is the poor spectral selectivity that results from the wide current spread from each of the electrode contacts. Optical CIs (oCIs) promise to make better use of the tonotopic order of spiral ganglion neurons (SGNs) inside the cochlea by spatially confined stimulation. Here, we established multichannel oCIs based on light-emitting diode (LED) arrays and used them for optical stimulation of channelrhodopsin (ChR)-expressing SGNs in rodents. Power-efficient blue LED chips were integrated onto microfabricated 15-µm-thin polyimide-based carriers comprising interconnecting lines to address individual LEDs by a stationary or mobile driver circuitry. We extensively characterized the optoelectronic, thermal, and mechanical properties of the oCIs and demonstrated stability over weeks in vitro. We then implanted the oCIs into ChR-expressing rats and gerbils, and characterized multichannel optogenetic SGN stimulation by electrophysiological and behavioral experiments. Improved spectral selectivity was directly demonstrated by recordings from the auditory midbrain. Long-term experiments in deafened ChR-expressing rats and in nontreated control animals demonstrated specificity of optogenetic stimulation. Behavioral studies on animals carrying a wireless oCI sound processor revealed auditory percepts. This study demonstrates hearing restoration with improved spectral selectivity by an LED-based multichannel oCI system.


Asunto(s)
Implantación Coclear , Implantes Cocleares , Animales , Vías Auditivas , Estimulación Eléctrica , Optogenética , Ratas , Ganglio Espiral de la Cóclea
15.
Food Res Int ; 133: 109193, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-32466904

RESUMEN

In this study the possibility of replacing current surfactants in chocolate formulations with natural lipids extracted from spinach leaf (SPLIP) or spinach chloroplast (CH.SPLIP) was evaluated. SPLIP and CH.SPLIP were extracted with chloroform/methanol following enzyme deactivation with hot isopropanol. Results showed a higher extraction yield for SPLIP while glycolipids were more concentrated in CH.SPLIP. Sugar/oil suspensions with dispersed volume fractions of 0.28, 0.33 and 0.37 containing 0.1% to 0.7% (w/w) surfactant (SPLIP, CH.SPLIP, lecithin and PGPR as commercial references) based on oil phase were prepared and analyzed in shear rheology. Apparent viscosity at 40 s-1 was significantly lower for the natural surfactants compared to lecithin at 0.5-0.7% (w/w) addition. With regard to yield stress, taken as the shear stress at 5 s-1, both natural surfactants showed comparable performance to PGPR at 0.3% to 0.7% addition. As SPLIP and CH.SPLIP behaved similar (p > 0.05), SPLIP, due to higher extraction yield, would be the preferred choice for application in chocolate matrices.


Asunto(s)
Chocolate , Spinacia oleracea , Cloroplastos , Emulsiones , Lípidos , Hojas de la Planta , Reología
16.
Food Hydrocoll ; 101: 105446, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32255886

RESUMEN

Scleroglucan, a neutral ß(1-3) glucan with ß(1-6) glucan branches every third residue, is being considered as an alternative rod-like, shear thinning high molecular weight ß-glucan based polysaccharide to xanthan gum for the management of patients with oropharyngeal dysphagia. It is therefore important to understand more fully its hydrodynamic properties in solution, in particular heterogeneity, molecular weight distribution and its behaviour in the presence of mucin glycoproteins. A commercially purified scleroglucan preparation produced by fermentation of the filamentous fungus Sclerotium rolfsii was analysed in deionised distilled water with 0.02% added azide. Sedimentation velocity in the analytical ultracentrifuge showed the scleroglucan preparation to be unimodal at concentrations >0.75 mg/ml which resolved into two components at lower concentration and with partial reversibility between the components. Sedimentation coefficient versus concentration plots showed significant hydrodynamic non-ideality. Self-association behaviour was confirmed by sedimentation equilibrium experiments with molecular weights between ~3 × 106 g/mol to ~5 × 106 g/mol after correcting for thermodynamic non-ideality. SEC-MALS-viscosity experiments showed a transition between a rod-shape at lower molar masses to a more flexible structure at higher masses consistent with previous observations. Sedimentation velocity experiments also showed no evidence for potentially problematic interactions with submaxillary mucin.

17.
Neurotherapeutics ; 17(3): 1228-1238, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-31970667

RESUMEN

Epileptogenesis-associated brain inflammation might be a promising target to prevent or attenuate epileptogenesis. Positron emission tomography (PET) imaging targeting the translocator protein (TSPO) was applied here to quantify effects of different dosing regimens of the anti-inflammatory drug minocycline during the latent phase in two rodent models of epileptogenesis. After induction of epileptogenesis by status epilepticus (SE), rats were treated with minocycline for 7 days (25 or 50 mg/kg) and mice for 5 or 10 days (50 or 100 mg/kg). All animals were subjected to scans at 1 and 2 weeks post-SE. Radiotracer distribution was analyzed and statistical parametric mapping (SPM) was performed, as well as histological analysis of astroglial activation and neuronal cell loss. Atlas-based analysis of [18F]GE180 PET in rats revealed a dose-dependent regional decrease of TSPO expression at 2 weeks post-SE. Results of SPM analysis depicted a treatment effect already at 1 week post-SE in rats treated with the higher minocycline dose. In mice, TSPO PET imaging did not reveal any treatment effects whereas histology identified only a treatment-related reduction in dispersion of dentate gyrus neurons. TSPO PET served as an auspicious tool for temporal monitoring and quantification of anti-inflammatory effects during epileptogenesis. Importantly, the findings underline the need to applying more than one animal model to avoid missing treatment effects. For future studies, the setup is ready to be applied in combination with seizure monitoring to investigate the relationship between individual early treatment response and disease outcome.


Asunto(s)
Antiinflamatorios/metabolismo , Proteínas Portadoras/metabolismo , Epilepsia/metabolismo , Minociclina/metabolismo , Tomografía de Emisión de Positrones/métodos , Radiofármacos/metabolismo , Receptores de GABA-A/metabolismo , Animales , Antiinflamatorios/uso terapéutico , Encéfalo/diagnóstico por imagen , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Modelos Animales de Enfermedad , Epilepsia/diagnóstico por imagen , Epilepsia/tratamiento farmacológico , Femenino , Masculino , Ratones , Minociclina/uso terapéutico , Ratas , Ratas Sprague-Dawley , Resultado del Tratamiento
18.
J Agric Food Chem ; 67(33): 9325-9334, 2019 Aug 21.
Artículo en Inglés | MEDLINE | ID: mdl-31318196

RESUMEN

In vitro dynamic aroma release over oil-in-water (o/w) and water-in-oil-in-water (w/o/w) emulsions stabilized with Tween 20 or octenyl succinic anhydride (OSA) starch as a hydrophilic emulsifier and polyglycerol polyricinoleate (PGPR) as a hydrophobic emulsifier was investigated. The equal-molecular-weight hydrophilic aroma diacetyl (2,3-butanedione) or relatively more-hydrophobic 3-pentanone was added to the emulsions prepared by high speed mixing, or membrane emulsification followed by thickened with xanthan gum removing droplet size distribution and creaming as variables affecting dynamic release. Results showed the differences of w/o/w emulsions in the dynamic release compared to o/w emulsions mainly depended on aroma hydrophobicity, emulsion type, emulsifier-aroma interactions, and creaming. Xanthan led to a reduced headspace replenishment. Interfacially adsorbed OSA starch and xanthan-OSA starch interaction influenced on diacetyl release over emulsions. OSA starch alone interacted with 3-pentanone. This study demonstrates the potential impact of emulsifying and thickening systems on aroma release systems and highlights that specific interactions may compromise product quality.


Asunto(s)
Emulsionantes/química , Odorantes/análisis , Almidón/química , Emulsiones/química , Glicerol/análogos & derivados , Glicerol/química , Interacciones Hidrofóbicas e Hidrofílicas , Polisacáridos Bacterianos/química , Polisorbatos/química , Ácidos Ricinoleicos/química , Anhídridos Succínicos/química , Agua/química
19.
Food Funct ; 10(7): 4242-4255, 2019 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-31259325

RESUMEN

Water-in-oil-in-water emulsions containing an internalised salt solution were stabilised with non-chemically modified waxy rice starch (WRS), and octinyl succinic anhydride (OSA) as reference, to release salt during oral processing due to amylase-induced destabilisation. Salt levels were 1.5 g salt and 0.47 g salt per 100 g external and internal aqueous phases, respectively. Variables were the starch content (2, 3, 4 g per 100 g emulsion; 20 g oil per 100 g emulsion), level of polyglycerol polyricinoleate (PGPR) as a lipophilic emulsifier (0.29, 0.57 g per 100 g emulsion) and ambient-pressure processing temperature for WRS gelatinisation, the non-chemical modification process, (75 ± 3, 88 ± 5 °C). OSA starch was used under previously applied conditions (2, 3, 4 g starch, 0.57 g PGPR per 100 g emulsion, 25 ± 5 °C). Emulsions were stable for three months, except OSA and lower level PGPR low temperature processed WRS emulsions lost salt into the external emulsion phase. One day after processing, encapsulation efficiency (EE) was as predicted from the composition for OSA emulsions, while at the same PGPR content an external aqueous phase was incorporated into the oil droplets of the WRS emulsion increasing EE. Salt release was assessed in vitro and through sensory evaluation using paired comparison testing. The results revealed that the efficacy of this salt reduction approach was enhanced for gelatinised WRS compared to OSA starch stabilised emulsions. Consumer tests on a tomato soup, to validate this salt reduction approach for a real food, revealed a possible 25% salt reduction, compared to current UK products.


Asunto(s)
Oryza/química , Cloruro de Sodio/análisis , Almidón/química , Adulto , Anciano , Comportamiento del Consumidor , Emulsionantes/química , Emulsiones , Femenino , Aditivos Alimentarios/análisis , Glicerol/análogos & derivados , Glicerol/química , Humanos , Masculino , Persona de Mediana Edad , Tamaño de la Partícula , Ácidos Ricinoleicos/química , Anhídridos Succínicos/análisis , Gusto , Viscosidad , Agua/química , Adulto Joven
20.
Foods ; 8(6)2019 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-31163639

RESUMEN

Polysaccharides and proteins are frequently conjugated through electrostatic attraction, enzymatic cross-linking, and heat treatment (Maillard reaction) to obtain food structuring ingredients, mostly for their application as emulsifiers. The conjugate partners and their interaction type affect performance at acidic or neutral pH and during thermal processing, thus requiring careful selection. Here, the aggregate properties (particle size, conjugate charge, shear viscosity) of three types of sugar beet pectin (SBP)-sodium caseinate (SC) 1:1 conjugates, at acidic and neutral pH (4.5; 7), as well as their thermal processing stability (80 °C), were investigated. The enzymatically cross-linked SBP:SC was more acid tolerant than the electrostatically interacting conjugates. Maillard cross-linked conjugates aggregated at pH 4.5, suggesting poor emulsifier performance in acidic conditions. At pH 7, the three conjugate types showed similar aggregate properties. The results are discussed in terms of structural re-arrangement.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA