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https://www.readbyqxmd.com/read/28417297/regulation-of-the-glucose-supply-from-capillary-to-tissue-examined-by-developing-a-capillary-model
#1
Akitoshi Maeda, Yukiko Himeno, Masayuki Ikebuchi, Akinori Noma, Akira Amano
A new glucose transport model relying upon diffusion and convection across the capillary membrane was developed, and supplemented with tissue space and lymph flow. The rate of glucose utilization (J util) in the tissue space was described as a saturation function of glucose concentration in the interstitial fluid (C glu,isf), and was varied by applying a scaling factor f to J max. With f = 0, the glucose diffusion ceased within ~20 min. While, with increasing f, the diffusion was accelerated through a decrease in C glu,isf, but the convective flux remained close to resting level...
April 17, 2017: Journal of Physiological Sciences: JPS
https://www.readbyqxmd.com/read/28361852/epr-spectroscopy-studies-of-changes-in-erythrocyte-membranes-in-patients-with-laryngeal-cancer
#2
Y B Burlaka, O V Sukhoveev, N V Grin, O M Khilchevskyi, S V Verevka
AIM: To evaluate microviscosity and sorption capacity of erythrocyte membranes (SCEM) from patients with laryngeal cancer (LC). MATERIALS AND METHODS: Samples from 35 patients with LC of stages II and III and 20 healthy volunteers were investigated by electron paramagnetic resonance with Bis(1-oxyl-2,2,6,6-tetramethylpiperidinyl-4)-ester of 5,7-dimethyladamantane-1,3-dicarbonic acid (AdTEMPO) probe. SCEM was evaluated by amount of unabsorbed methylene blue. RESULTS: Microviscosity of erythrocyte membranes was determined by the effective rotational diffusion correlation times (τeff) and a decrease in radical spectrum signal intensity per hour...
March 2017: Experimental Oncology
https://www.readbyqxmd.com/read/28356732/angiopep-2-conjugated-poly-ethylene-glycol-co-poly-%C3%AE%C2%B5-caprolactone-polymersomes-for-dual-targeting-drug-delivery-to-glioma-in-rats
#3
Fei Lu, Zhiyong Pang, Jingjing Zhao, Kai Jin, Haichun Li, Qiang Pang, Long Zhang, Zhiqing Pang
The blood-brain barrier is a formidable obstacle for glioma chemotherapy due to its compact structure and drug efflux ability. In this study, a dual-targeting drug delivery system involving Angiopep-2-conjugated biodegradable polymersomes loaded with doxorubicin (Ang-PS-DOX) was developed to exploit transport by the low-density lipoprotein receptor-related protein 1 (LRP1), which is overexpressed in both blood-brain barrier and glioma cells. The polymersomes (PS) were prepared using a thin-film hydration method...
2017: International Journal of Nanomedicine
https://www.readbyqxmd.com/read/28350448/mechanism-exploration-of-ion-transport-in-nanocomposite-cation-exchange-membranes
#4
Xin Tong, Bopeng Zhang, Yilin Fan, Yongsheng Chen
The origin of property enhancement of nanocomposite ion exchange membranes (IEMs) is far from being fully understood. By combining experimental work and computational modeling analysis, we could determine the influence of nanomaterials on the ion transport properties of nanocomposite cation exchange membranes (CEMs). We synthesized and characterized a series of nanocomposite CEMs by using SPPO as polymer materials and silica nanoparticles (NPs) (unsulfonated or sulfonated) as nanomaterials. We found that with the increase of NP loading, measured CEM permselectivity and swelling degree first increased and then decreased...
April 5, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28336536/the-effect-of-aging-and-cardiorespiratory-fitness-on-the-lung-diffusing-capacity-response-to-exercise-in-healthy-humans
#5
Kirsten E Coffman, Alex R Carlson, Andrew D Miller, Bruce D Johnson, Bryan Joseph Taylor
Aging is associated with deterioration in the structure and function of the pulmonary circulation. We characterized the lung diffusing capacity for carbon monoxide (DLCO), alveolar-capillary membrane conductance (DmCO), and pulmonary-capillary blood volume (VC) response to discontinuous incremental exercise at 25, 50, 75, and 90% of peak work (Wpeak) in four groups: 1) Young [27 ± 3 y, maximal oxygen consumption (V̇O2max) 110 ± 18% age-predicted]; 2) Young Highly-Fit (27 ± 3 y, V̇O2max 147 ± 8% age-predicted); 3) Old (69 ± 5 y, V̇O2max 116 ± 13% age-predicted); and 4) Old Highly-Fit (65 ± 5 y, V̇O2max 162 ± 18% age-predicted)...
March 23, 2017: Journal of Applied Physiology
https://www.readbyqxmd.com/read/28303361/human-topoisomerase-inhibition-and-dna-bsa-binding-of-ru-ii-scar-complexes-as-potential-anticancer-candidates-for-oral-application
#6
Rone A De Grandis, Mariana S de Camargo, Monize M da Silva, Érica O Lopes, Elias C Padilha, Flávia A Resende, Rosângela G Peccinini, Fernando R Pavan, Alessandro Desideri, Alzir A Batista, Eliana A Varanda
Three ruthenium(II) phosphine/diimine/picolinate complexes were selected aimed at investigating anticancer activity against several cancer cell lines and the capacity of inhibiting the supercoiled DNA relaxation mediated by human topoisomerase IB (Top 1). The structure-lipophilicity relationship in membrane permeability using the Caco-2 cells have also been evaluated in this study. SCAR 5 was found to present 45 times more cytotoxicity against breast cancer cell when compared to cisplatin. SCAR 4 and 5 were both found to be capable of inhibiting the supercoiled DNA relaxation mediated by Top 1...
March 16, 2017: Biometals: An International Journal on the Role of Metal Ions in Biology, Biochemistry, and Medicine
https://www.readbyqxmd.com/read/28293753/cd16-positive-circulating-monocytes-and-fibrotic-manifestations-of-systemic-sclerosis
#7
Alain Lescoat, Valérie Lecureur, Mikael Roussel, Béatrice Ly Sunnaram, Alice Ballerie, Guillaume Coiffier, Stéphane Jouneau, Olivier Fardel, Thierry Fest, Patrick Jégo
The objective of this study is to assess the association of clinical manifestations of systemic sclerosis (SSc) with the absolute count of circulating blood monocyte subpopulations according to their membrane expression of CD16. Forty-eight consecutive patients fulfilling the 2013 ACR/EULAR classification criteria for SSc were included in this cross-sectional study. CD16+ monocyte absolute count was defined by flow cytometry and confronted to the clinical characteristics of SSc patients. Twenty-three healthy donors (HD) were randomly selected for comparison...
March 14, 2017: Clinical Rheumatology
https://www.readbyqxmd.com/read/28287506/assessment-of-pulmonary-capillary-blood-volume-membrane-diffusing-capacity-and-intrapulmonary-arteriovenous-anastomoses-during-exercise
#8
Vincent Tedjasaputra, Sean van Diepen, Sophie É Collins, Wade M Michaelchuk, Michael K Stickland
Exercise is a stress to the pulmonary vasculature. With incremental exercise, the pulmonary diffusing capacity (DLCO) must increase to meet the increased oxygen demand; otherwise, a diffusion limitation may occur. The increase in DLCO with exercise is due to increased capillary blood volume (Vc) and membrane diffusing capacity (Dm). Vc and Dm increase secondary to the recruitment and distension of pulmonary capillaries, increasing the surface area for gas exchange and decreasing pulmonary vascular resistance, thereby attenuating the increase in pulmonary arterial pressure...
February 20, 2017: Journal of Visualized Experiments: JoVE
https://www.readbyqxmd.com/read/28249804/hypothesis-why-%C3%AE-no-could-be-finite-in-vitro-but-infinite-in-vivo
#9
Colin Borland, Suhani Patel, Qingyu Zhu, Alain Vuylsteke
There is controversy as to whether the lung Diffusing Capacity for Nitric Oxide (DLNO) is a direct measure of DM in the Roughton-Forster equation or whether θNO is finite and DM is greater than DLNO. Despite in vitro evidence that θNO is finite, some groups believe that it is infinite in vivo and that DMNO/DMCO (α) is greater than predicted by the combined Fick/Graham law of Gas Diffusion through a membrane. We here present a hypothesis applying the fundamental rules of combined diffusion and chemical reaction to a red cell to explain (i) why θNO could be finite in vitro but effectively infinite in vivo and (ii) why ∝ could appear greater than predicted...
February 27, 2017: Respiratory Physiology & Neurobiology
https://www.readbyqxmd.com/read/28223209/langmuir-schaefer-film-deposition-onto-honeycomb-porous-films-for-retinal-tissue-engineering
#10
Maria Teresa Calejo, Tanja Ilmarinen, Elina Vuorimaa-Laukkanen, Elina Talvitie, Hanna M Hakola, Heli Skottman, Minna Kellomäki
Age-related macular degeneration (AMD) is the leading cause of vision loss in senior citizens in the developed world. The disease is characterised by the degeneration of a specific cell layer at the back of the eye - the retinal pigment epithelium (RPE), which is essential in retinal function. The most promising therapeutic option to restore the lost vision is considered to be RPE cell transplantation. This work focuses on the development of biodegradable biomaterials with similar properties to the native Bruch's membrane as carriers for RPE cells...
February 18, 2017: Acta Biomaterialia
https://www.readbyqxmd.com/read/28179436/standardisation-and-application-of-the-single-breath-determination-of-nitric-oxide-uptake-in-the-lung
#11
Gerald S Zavorsky, Connie C W Hsia, J Michael B Hughes, Colin D R Borland, Hervé Guénard, Ivo van der Lee, Irene Steenbruggen, Robert Naeije, Jiguo Cao, Anh Tuan Dinh-Xuan
Diffusing capacity of the lung for nitric oxide (DLNO), otherwise known as the transfer factor, was first measured in 1983. This document standardises the technique and application of single-breath DLNO This panel agrees that 1) pulmonary function systems should allow for mixing and measurement of both nitric oxide (NO) and carbon monoxide (CO) gases directly from an inspiratory reservoir just before use, with expired concentrations measured from an alveolar "collection" or continuously sampled via rapid gas analysers; 2) breath-hold time should be 10 s with chemiluminescence NO analysers, or 4-6 s to accommodate the smaller detection range of the NO electrochemical cell; 3) inspired NO and oxygen concentrations should be 40-60 ppm and close to 21%, respectively; 4) the alveolar oxygen tension (PAO2 ) should be measured by sampling the expired gas; 5) a finite specific conductance in the blood for NO (θNO) should be assumed as 4...
February 2017: European Respiratory Journal: Official Journal of the European Society for Clinical Respiratory Physiology
https://www.readbyqxmd.com/read/28161679/recovery-of-ammonia-from-domestic-wastewater-effluents-as-liquid-fertilizers-by-integration-of-natural-zeolites-and-hollow-fibre-membrane-contactors
#12
I Sancho, E Licon, C Valderrama, N de Arespacochaga, S López-Palau, J L Cortina
The integration of up-concentration processes to increase the efficiency of primary sedimentation, as a solution to achieve energy neutral wastewater treatment plants, requires further post-treatment due to the missing ammonium removal stage. This study evaluated the use of zeolites as a post-treatment step, an alternative to the biological removal process. A natural granular clinoptilolite zeolite was evaluated as a sorbent media to remove low levels (up to 100mg-N/L) of ammonium from treated wastewater using batch and fixed bed columns...
April 15, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28089275/microfluidic-membrane-suppressor-module-design-and-evaluation-for-capillary-ion-chromatography
#13
Sam Wouters, Cees Bruggink, Yury Agroskin, Christopher Pohl, Sebastiaan Eeltink
A microfluidic ion-suppression module for use in ion-exchange chromatography has been developed and evaluated. The device consists of an ion-exchange membrane clamped between two polymer chips featuring a 200×100μm (width×depth) eluent channel (l=60mm), and a 300×150μm regenerant channel (60mm), respectively. The suppression efficacy using a Nafion membrane was compared with that of a styrene-sulfonate grafted fluorinated ethylene propylene (FEP) membrane. The latter was found to outperform Nafion in terms of lowest attainable background signal (suppression efficacy) and dynamic suppression range...
February 10, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28088638/the-dlno-dlco-ratio-physiological-significance-and-clinical-implications
#14
J M B Hughes, A T Dinh-Xuan
DLNO/DLCO directly measures the ratio of the diffusing capacities of the lung for nitric oxide (NO) and carbon monoxide (CO). In terms of the Roughton and Forster (1957) equation, 1/DL=1/Dm+1/θVc, where Dm is the membrane (Dm) and θVc is the red cell component of the overall diffusing conductance (DL); DLNO mostly reflects the Dm component and DLCO the θVc red cell component. The DLNO/DLCO ratio is positively related to the DmCO/Vc ratio and the CO red cell resistance (1/θCOVc) as a percentage of the total resistance (1/DLCO), independent of the absolute values of DLNO or DLCO...
January 11, 2017: Respiratory Physiology & Neurobiology
https://www.readbyqxmd.com/read/28053522/do-nanoparticles-provide-a-new-opportunity-for-diagnosis-of-distal-airspace-disease
#15
Jakob Löndahl, Jonas Kf Jakobsson, David M Broday, H Laura Aaltonen, Per Wollmer
There is a need for efficient techniques to assess abnormalities in the peripheral regions of the lungs, for example, for diagnosis of pulmonary emphysema. Considerable scientific efforts have been directed toward measuring lung morphology by studying recovery of inhaled micron-sized aerosol particles (0.4-1.5 µm). In contrast, it is suggested that the recovery of inhaled airborne nanoparticles may be more useful for diagnosis. The objective of this work is to provide a theoretical background for the use of nanoparticles in measuring lung morphology and to assess their applicability based on a review of the literature...
2017: International Journal of Nanomedicine
https://www.readbyqxmd.com/read/28018177/heterocellular-contacts-with-mouse-brain-endothelial-cells-via-laminin-and-%C3%AE-6%C3%AE-1-integrin-sustain-subventricular-zone-svz-stem-progenitor-cells-properties
#16
Alexandra I Rosa, Sofia Grade, Sofia D Santos, Liliana Bernardino, Thomas C Chen, João Relvas, Florence M Hofman, Fabienne Agasse
Neurogenesis in the subventricular zone (SVZ) is regulated by diffusible factors and cell-cell contacts. In vivo, SVZ stem cells are associated with the abluminal surface of blood vessels and such interactions are thought to regulate their neurogenic capacity. SVZ neural stem cells (NSCs) have been described to contact endothelial-derived laminin via α6β1 integrin. To elucidate whether heterocellular contacts with brain endothelial cells (BEC) regulate SVZ cells neurogenic capacities, cocultures of SVZ neurospheres and primary BEC, both obtained from C57BL/6 mice, were performed...
2016: Frontiers in Cellular Neuroscience
https://www.readbyqxmd.com/read/28013060/the-blood-transfer-conductance-for-nitric-oxide-infinite-vs-finite-%C3%AE-no
#17
Kirsten E Coffman, Steven C Chase, Bryan J Taylor, Bruce D Johnson
Whether the specific blood transfer conductance for nitric oxide (NO) with hemoglobin (θNO) is finite or infinite is controversial but important in the calculation of alveolar capillary membrane conductance (DmCO) and pulmonary capillary blood volume (VC) from values of lung diffusing capacity for carbon monoxide (DLCO) and nitric oxide (DLNO). In this review, we discuss the background associated with θNO, explore the resulting values of DmCO and VC when applying either assumption, and investigate the mathematical underpinnings of DmCO and VC calculations...
December 21, 2016: Respiratory Physiology & Neurobiology
https://www.readbyqxmd.com/read/27976860/voltammetric-thin-layer-ionophore-based-films-part-2-semi-empirical-treatment
#18
Dajing Yuan, Maria Cuartero, Gaston A Crespo, Eric Bakker
This work reports on a semiempirical treatment that allows one to rationalize and predict experimental conditions for thin-layer ionophore-based films with cation-exchange capacity read out with cyclic voltammetry. The transition between diffusional mass transport and thin-layer regime is described with a parameter (α), which depends on membrane composition, diffusion coefficient, scan rate, and electrode rotating speed. Once the thin-layer regime is fulfilled (α = 1), the membrane behaves in some analogy to a potentiometric sensor with a second discrimination variable (the applied potential) that allows one to operate such electrodes in a multianalyte detection mode owing to the variable applied ion-transfer potentials...
December 15, 2016: Analytical Chemistry
https://www.readbyqxmd.com/read/27976858/voltammetric-thin-layer-ionophore-based-films-part-1-experimental-evidence-and-numerical-simulations
#19
Dajing Yuan, Maria Cuartero, Gaston A Crespo, Eric Bakker
Voltammetric thin layer (∼200 nm) ionophore-based polymeric films of defined ion-exchange capacity have recently emerged as a promising approach to acquire multi-ion information about the sample, in analogy to performing multiple potentiometric measurements with individual membranes. They behave under two different regimes that are dependent on the ion concentration. A thin layer control (no mass transport limitation of the polymer film or solution) is identified for ion concentrations of >10 μM, in which case the peak potential serves as the readout signal, in analogy to a potentiometric sensor...
December 15, 2016: Analytical Chemistry
https://www.readbyqxmd.com/read/27976398/pushing-it-to-the-limit-enhanced-diffusing-membrane-capacity-facilitates-greater-pulmonary-diffusing-capacity-in-athletes-during-exercise
#20
Leah Groves, Sara Brade, Stephen P Wright
No abstract text is available yet for this article.
December 15, 2016: Journal of Physiology
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