Read by QxMD icon Read

in vivo facilitated diffusion

Qian Zhao, Xueqi Chen, Yun Zhou
Alzheimer's disease (AD) is a progressive neurodegenerative disorder, causing changes in memory, thinking, and other dysfunction of brain functions. More and more people are suffering from the disease. Early neuroimaging techniques of AD are needed to develop. This review provides a preliminary summary of the various neuroimaging techniques that have been explored for in vivo imaging of AD. Recent advances in magnetic resonance (MR) techniques, such as functional MR imaging (fMRI) and diffusion MRI, give opportunities to display not only anatomy and atrophy of the medial temporal lobe, but also at microstructural alterations or perfusion disturbance within the AD lesions...
March 2016: Brain Informatics
Richard A Hawkins, Juan R Viña
A facilitative transport system exists on the blood-brain barrier (BBB) that has been tacitly assumed to be a path for glutamate entry to the brain. However, glutamate is a non-essential amino acid whose brain content is much greater than plasma, and studies in vivo show that glutamate does not enter the brain in appreciable quantities except in those small regions with fenestrated capillaries (circumventricular organs). The situation became understandable when luminal (blood facing) and abluminal (brain facing) membranes were isolated and studied separately...
October 8, 2016: Biology
Benjamin L Timney, Barak Raveh, Roxana Mironska, Jill M Trivedi, Seung Joong Kim, Daniel Russel, Susan R Wente, Andrej Sali, Michael P Rout
Passive macromolecular diffusion through nuclear pore complexes (NPCs) is thought to decrease dramatically beyond a 30-60-kD size threshold. Using thousands of independent time-resolved fluorescence microscopy measurements in vivo, we show that the NPC lacks such a firm size threshold; instead, it forms a soft barrier to passive diffusion that intensifies gradually with increasing molecular mass in both the wild-type and mutant strains with various subsets of phenylalanine-glycine (FG) domains and different levels of baseline passive permeability...
October 10, 2016: Journal of Cell Biology
Emil Meng-Lund, Jette Jacobsen, Anette Müllertz, Erling B Jørgensen, René Holm
Buccal delivery may be clinically beneficial for compounds with a high gastrointestinal and hepatic first pass metabolism or in situations where a fast systemic absorption is desired. The delivery of a crystalline low soluble compounds, e.g. diazepam, may be limited due to the low volume of saliva available to facilitate solvation in order to drive the permeation of drug through the buccal mucosa. Therefore, the present study investigated the potential benefits of administering diazepam either as an amorphous or as a crystalline form in mucoadhesive tablets to conscious Göttingen mini-pigs...
September 30, 2016: International Journal of Pharmaceutics
Xi Chen, Shizhu Bai, Bei Li, Huan Liu, Guofeng Wu, Sha Liu, Yimin Zhao
INTRODUCTION: Periodontitis is a chronic infectious disease and is the major cause of tooth loss and other oral health issues around the world. Periodontal tissue regeneration has therefore always been the ultimate goal of dentists and researchers. Existing fabrication methods mainly focused on a top-down tissue engineering strategy in which several drawbacks remain, including low throughput and limited diffusion properties resulting from a large sample size. Gelatin methacrylate (GelMA) is a kind of photocrosslinkable and biocompatible hydrogel, with the capacities of enabling cell encapsulation and regeneration of functional tissues...
2016: International Journal of Nanomedicine
Metin Uz, Anup D Sharma, Pratish Adhikari, Donald S Sakaguchi, Surya K Mallapragada
: In this study, a poly(lactic acid) (PLLA) porous film with longitudinal surface micropatterns was fabricated by a dry phase inversion technique to be used as potential conduit material for peripheral nerve regeneration applications. The presence of a nerve growth factor (NGF) gradient on the patterned film surface and protein loaded, surface-eroding, biodegradable, and amphiphilic polyanhydride (PA) microparticles within the film matrix, enabled co-delivery of neurotrophic factors with controlled release properties and enhanced neurite outgrowth from PC12 cells...
September 29, 2016: Acta Biomaterialia
Yifat Sarda, Elad Bergman, Inbar Hillel, Itzhak Binderman, Uri Nevo
PURPOSE: Osteoporosis is characterized by a decrease in bone mineral density (BMD). A preliminary stage of the disease is progressive bone marrow adiposity, caused by imbalance between osteogenesis and adipogenesis in the marrow. Detection of osteoporosis relies on the quantification of BMD with techniques such as dual-energy X-ray absorptiometry. This work aimed to detect bone marrow changes in an experimental model of osteopenia using a low-field tabletop NMR scanner. METHODS: An experiment was performed on 32 female rats, 3 months old, 16 of which were ovariectomized (OVX) and 16 were sham-operated (sham)...
September 30, 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Birgit R Plantinga, Yasin Temel, Yuval Duchin, Kâmil Uludağ, Rémi Patriat, Alard Roebroeck, Mark Kuijf, Ali Jahanshahi, Bart Ter Haar Romenij, Jerrold Vitek, Noam Harel
Deep brain stimulation of the subthalamic nucleus (STN) is a widely performed surgical treatment for patients with Parkinson's disease. The goal of the surgery is to place an electrode centered in the motor region of the STN while lowering the effects of electrical stimulation on the non-motor regions. However, distinguishing the motor region from the neighboring associative and limbic areas in individual patients using imaging modalities was until recently difficult to obtain in vivo. Here, using ultra-high field MR imaging, we have performed a dissection of the subdivisions of the STN of individual Parkinson's disease patients...
September 26, 2016: NeuroImage
Shan Liu, Wei Wei, Bo Xie, Hua Yue, Dezhi Ni, Yali Bao, Guanghui Ma, Zhiguo G Su
In contrast to traditional strategies based on external driving forces, an internal path for intratumoral delivery is explored by degrading the tumor microenvironment component hyaluronan. Natural hyaluronidase PH20 and constructed long-acting PH20-Fc have been used to achieve this objective. It has been then evaluated how these agents facilitate the diffusion of the following typical therapeutic agents varying in nanoscales: doxorubicin (≈1.5 × 1.0 × 0.7 nm) chemotherapy, trastuzumab (10-15 nm) biotherapy, and gold nanorod (≈100 × 35 nm) thermotherapy...
September 27, 2016: Advanced Healthcare Materials
Yi Zhang, Mei Long, Peng Huang, Huaming Yang, Shi Chang, Yuehua Hu, Aidong Tang, Linfeng Mao
Nanoclay can be incorporated into emerging dual functional drug delivery systems (DDSs) to promote efficiency in drug delivery and reduce the toxicity of doxorubicin (DOX) used for thyroid cancer treatment. This paper reports the expansion of the basal spacing of kaolinite nanoclay was expanded from 0.72 nm to 0.85 nm, which could provide sufficiently spacious site for hosting doxorubicin molecules and controlling the diffusion rate. A targeted design for papillary thyroid cancer cells was achieved by introducing KI, which is consumed by the sodium-iodide symporter (NIS)...
2016: Scientific Reports
Xiaoqing Feng, Anpu Chen, Juan Wang, Nanrong Zhao, Zhonghuai Hou
Understanding the diffusion of proteins in polymer solutions is of ubiquitous importance for modeling processes in vivo. Here, we present a theoretical framework to analyze the decoupling of translational and rotational diffusion of globular proteins in semidilute polymer solutions. The protein is modeled as a spherical particle with an effective hydrodynamic radius, enveloped by a depletion layer. Based on the scaling formula of macroscopic viscosity for polymer solutions as well as the mean-field theory for the depletion effect, we specify the space-dependent viscosity profile in the depletion zone...
September 6, 2016: Journal of Physical Chemistry. B
Anna R Arnold, Andy Zhou, Jacqueline K Barton
Dps proteins are bacterial ferritins that protect DNA from oxidative stress and have been implicated in bacterial survival and virulence. In addition to direct oxidation of the Dps iron sites by diffusing oxidants, oxidation from a distance via DNA charge transport (CT), where electrons and electron holes are rapidly transported through the base-pair π-stack, could represent an efficient DNA protection mechanism utilized by Dps. Here, we spectroscopically characterize the DNA-mediated oxidation of ferrous iron-loaded Dps...
September 7, 2016: Journal of the American Chemical Society
Shiran Barber-Zucker, René Uebe, Geula Davidov, Yotam Navon, Dror Sherf, Jordan H Chill, Itamar Kass, Ronit Bitton, Dirk Schüler, Raz Zarivach
Cation diffusion facilitators (CDF) are highly conserved, metal ion efflux transporters that maintain divalent transition metal cation homeostasis. Most CDF proteins contain two domains, the cation transporting transmembrane domain and the regulatory cytoplasmic C-terminal domain (CTD). MamM is a magnetosome-associated CDF protein essential for the biomineralization of magnetic iron-oxide particles in magnetotactic bacteria. To investigate the structure-function relationship of CDF cytoplasmic domains, we characterized a MamM M250P mutation that is synonymous with the disease-related mutation L349P of the human CDF protein ZnT-10...
2016: Scientific Reports
Yipei Chen, Yuzhuo Li, Wenjia Shen, Kun Li, Lin Yu, Qinghua Chen, Jiandong Ding
In treatment of diabetes, it is much desired in clinics and challenging in pharmaceutics and material science to set up a long-acting drug delivery system. This study was aimed at constructing a new delivery system using thermogelling PEG/polyester copolymers. Liraglutide, a fatty acid-modified antidiabetic polypeptide, was selected as the model drug. The thermogelling polymers were presented by poly(ε-caprolactone-co-glycolic acid)-poly(ethylene glycol)-poly(ε-caprolactone-co-glycolic acid) (PCGA-PEG-PCGA) and poly(lactic acid-co-glycolic acid)-poly(ethylene glycol)-poly(lactic acid-co-glycolic acid) (PLGA-PEG-PLGA)...
2016: Scientific Reports
Alexandra Badea, Lauren Kane, Robert J Anderson, Yi Qi, Mark Foster, Gary P Cofer, Neil Medvitz, Anne F Buckley, Andreas K Badea, William C Wetsel, Carol A Colton
Multivariate biomarkers are needed for detecting Alzheimer's disease (AD), understanding its etiology, and quantifying the effect of therapies. Mouse models provide opportunities to study characteristics of AD in well-controlled environments that can help facilitate development of early interventions. The CVN-AD mouse model replicates multiple AD hallmark pathologies, and we identified multivariate biomarkers characterizing a brain circuit disruption predictive of cognitive decline. In vivo and ex vivo magnetic resonance imaging (MRI) revealed that CVN-AD mice replicate the hippocampal atrophy (6%), characteristic of humans with AD, and also present changes in subcortical areas...
August 10, 2016: NeuroImage
Moussa Chehade, Amit K Srivastava, Jeff W M Bulte
We present a practical approach for co-registration of bioluminescence tomography (BLT), computed tomography (CT), and magnetic resonance (MR) images. To this end, we developed a customized animal shuttle composed of non-fluorescent, MR-compatible Delrin plastic that fits a commercially available MR surface coil. Mouse embryonic stem cells (mESCs) were transfected with the luciferase gene and labeled with superparamagnetic iron oxide (SPIO) nanoparticles. Cells were stereotaxically implanted in mouse brain and imaged weekly for 4 weeks with BLI (IVIS Spectrum CT scanner) and MRI (11...
June 2016: Tomography: a Journal for Imaging Research
Elias Pambou, Zongyi Li, Mario Campana, Arwel Hughes, Luke Clifton, Philipp Gutfreund, Jill Foundling, Gordon Bell, Jian R Lu
Cuticular waxes are essential for the well-being of all plants, from controlling the transport of water and nutrients across the plant surface to protecting them against external environmental attacks. Despite their significance, our current understanding regarding the structure and function of the wax film is limited. In this work, we have formed representative reconstituted wax film models of controlled thicknesses that facilitated an ex vivo study of plant cuticular wax film properties by neutron reflection (NR)...
July 2016: Journal of the Royal Society, Interface
Irvin Teh, Darryl McClymont, Rebecca A B Burton, Mahon L Maguire, Hannah J Whittington, Craig A Lygate, Peter Kohl, Jürgen E Schneider
Cardiac architecture is fundamental to cardiac function and can be assessed non-invasively with diffusion tensor imaging (DTI). Here, we aimed to overcome technical challenges in ex vivo DTI in order to extract fine anatomical details and to provide novel insights in the 3D structure of the heart. An integrated set of methods was implemented in ex vivo rat hearts, including dynamic receiver gain adjustment, gradient system scaling calibration, prospective adjustment of diffusion gradients, and interleaving of diffusion-weighted and non-diffusion-weighted scans...
2016: Scientific Reports
Samreen Jatana, Linda M Callahan, Alice P Pentland, Lisa A DeLouise
Understanding the interactions of nanoparticles (NPs) with skin is important from a consumer and occupational health and safety perspective, as well as for the design of effective NP-based transdermal therapeutics. Despite intense efforts to elucidate the conditions that permit NP penetration, there remains a lack of translatable results from animal models to human skin. The objectives of this study are to investigate the impact of common skin lotions on NP penetration and to quantify penetration differences of quantum dot (QD) NPs between freshly excised human and mouse skin...
March 2016: Cosmetics
Joseph C Masdeu, Belen Pascual
Neuroimaging comprises a powerful set of instruments to diagnose the different causes of dementia, clarify their neurobiology, and monitor their treatment. Magnetic resonance imaging (MRI) depicts volume changes with neurodegeneration and inflammation, as well as abnormalities in functional and structural connectivity. MRI arterial spin labeling allows for the quantification of regional cerebral blood flow, characteristically altered in Alzheimer's disease, diffuse Lewy-body disease, and the frontotemporal dementias...
2016: Handbook of Clinical Neurology
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"