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Dopamine and Norepinephrine Transporter Inhibition in Cocaine Addiction: Using Mice Expressing Cocaine-Insensitive TransportersMartin, Bradley J. 26 September 2011 (has links)
No description available.
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Interaction of hepatic uptake transporters with antineoplastic compounds and regulation of the expression of organic cation transporter 3 in renal carcinoma cellsMarada, Venkata 15 January 2015 (has links)
No description available.
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Hållbarhetsarbete för transportföretag : En fallstudie utförd hos företag i Gävleborg / How logistics service providers can be more sustainable.Wiklund, Emma, Eriksson, Johan January 2016 (has links)
Introduktion: Ökade transporter på den globala marknaden påverkar miljön negativt. Detta har lett till ett ökat intresse för mer hållbara logistiklösningar. Transportföretagen spelar en stor roll för att uppnå de satta miljömålen. Syfte: Syftet med studien är att undersöka hur transportföretag arbetar med hållbarhetsfrågor idag och vilka faktorer som kommer vara viktiga i framtiden. Metod: För att kunna svara mot syftet antogs ett angreppssätt i två steg. Litteratur samlades in och användes som grund för kunskap inom området. Samtidigt som intervjuer genomfördes med tre transportföretag. Deras svar jämfördes med varandra och ställdes mot den insamlade teorin i en analys. Utifrån denna analys drogs en slutsats. Resultat: De två mindre företagen hade inga kundkrav på sig angående hållbarhet, deras arbete kom främst inifrån. För alla deltagande företag innebär hållbarhet mest miljödimensionen. Fokus för alla ligger på att minska koldioxidutsläppen, främst genom val av miljöklassade fordon, val av drivmedel samt minskning av bränsleåtgången. Transportföretagen är miljöcertifierade och arbetar kontinuerligt med att bli bättre i sitt miljöarbete. De har utbildat sina chaufförer och satt in IT-system för direkt återkoppling, detta gör att förarna lättare kan tänka på miljön i sin körning. För att uppnå en hög fyllnadsgrad gäller det att utnyttja lastkapaciteten till max och undvika tomma körningar. Därför samarbetar företagen med konkurrenter och hämtar gods åt varandra. Slutsats: Det finns hjälpmedel att tillämpa för att erhålla hållbarare transporter. Dessa är val av fordon, val av bränsle, utbildning, IT-system, packningslösningar och samkörning. De viktigaste faktorerna för transportföretagen är idag val av fordon, drivmedel och bränsleåtgången. Inför framtiden händer det mycket på bränslefronten, bland annat en utveckling gällande elfordon och elvägar samt biobränslen. Även en attitydförändring gällande hållbarhet för uppköparna av transporttjänster behövs då det i dagsläget fokuseras för mycket på priset. / Introduction: Increased transports on the global market is effecting the environment negatively, which has led to an increased interest in sustainable logistics. The logistics service providers (LSPs) play a major role in achieving the set environmental goals. Purpose: The purpose of this study is to examine how LSPs can be more sustainable today and in the future. Methodology: In order to answer the purpose of the paper two phases were used. Literature was collected and used as the basis of knowledge in the field. At the same time interviews were conducted with three LSPs. Their answers were compared with each other and with the literature. From the analysis a conclusion was drawn. Results: The two smaller companies had no demands from customers regarding their work with sustainability. For all the involved LSPs sustainability mostly meant the environmental aspect. Their focus is on reducing carbon dioxide emissions, this is achieved by using environmentally certified vehicles, choice of fuels and reducing the fuel consumption. The three LSPs all have an environmental management system and work continuously to be more sustainable. They have trained their drivers and have set up an IT-system for direct feedback. This helps the drivers to see the impact their driving has on the environment. To achieve a high fill ratio the companies avoid empty runs and try to maximize the cargo capacity. The LSPs collaborate with competitors and pick up cargo for each other. Conclusion: There are tools to apply to obtain more sustainable transports. These are the choice of vehicle, the choice of fuel, fuel consumption, training, IT-systems, packaging solutions and collaboration. The most important factors for the LSPs today are the choice of vehicles, the choice of fuel and fuel consumptions. A lot is happening in the area of alternative fuels including the development of biofuels, electric vehicles and electric roads. Also a change of attitude from the transport buyers regarding the sustainability is needed because today they mainly focus on the price.
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Mechanism and Functional Consequence of MRP2 Mislocalization in Nonalcoholic SteatohepatitisDzierlenga, Anika L. January 2016 (has links)
Adverse drug reactions (ADRs) are a pervasive complication in the realm of pharmacotherapy. At the root of ADRs lies interindividual variability in drug response, which can range from allergic reactions, to genetic variability, to any factors that influence the pharmacokinetics of a drug. Nonalcoholic steatohepatitis (NASH) is the late-stage of non-alcoholic fatty liver disease (NAFLD), characterized by fat deposition, oxidative stress, inflammation, and fibrosis. Over the last several years, alterations in drug metabolizing enzymes and transporters have been broadly characterized through NAFLD progression. Multidrug resistance-associated protein 2 (MRP2) is a canalicular efflux transporter that directs the biliary elimination of a wide variety of xenobiotics and metabolites. In NASH, MRP2 is mislocalized away from the canalicular membrane in a post-translational event. The mechanism and extent of this mislocalization has yet to be elucidated. While transporter misregulation has been shown to influence the disposition of a variety of substrates, the direct impact of MRP2 mislocalization on its overall transport capacity, and pharmacologic consequence of this change, is unknown. The purpose of this study was to elucidate the mechanism behind, and functional consequence of, MRP2/Mrp2 mislocalization in NASH, predominantly using the rodent methionine-and-choline-deficient (MCD) dietary model.To identify the mechanism of MRP2/Mrp2 mislocalization, a comparison of the activation status of various mediators of MRP2/Mrp2 retrieval was conducted between healthy and NASH livers. Results in rat samples and human NASH samples indicate that activation changes of these mediators, including radixin, PKCα, PKCδ, and PKA, are consistent with a shift toward active retrieval of MRP2/Mrp2 from the membrane, and some evidence of impaired membrane insertion is also present. Measurement of Mrp2 transport capacity was completed using pemetrexed, a novel Mrp2 probe substrate. Comparison of biliary excretion of pemetrexed between wild-type and Mrp2^(-/-) rats shows a 100% decrease, confirming that it relies upon Mrp2 for biliary excretion. NASH rats exhibited a 60% decrease in pemetrexed levels in the bile compared to their control counterparts, indicating that Mrp2 transport capacity is severely impaired in NASH rats. Finally, to ascertain the pharmacologic consequence of impaired Mrp2 transport, a study was conducted measuring the effects of the active morphine glucuronide on control and NASH rats. NASH rats exhibited a decreased biliary excretion, and increased systemic retention, of M3G. While they did also exhibit increased antinociception of M6G, the definitive impact of altered disposition on pharmacologic response was masked due to the interference of an MCD dietary effect on antinociception. Overall, the data reported herein identify active membrane retrieval as a mechanism of MRP2/Mrp2 mislocalization in NASH, and that mislocalization results in a 60% decrease in overall Mrp2 transport capacity. This decrease significantly hinders biliary excretion of Mrp2 substrates, and may result in ADRs by contributing to interindividual variability in drug response.
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Characterization of Centrally Expressed Solute Carriers : Histological and Functional Studies with Transgenic Mice / : HisRoshanbin, Sahar January 2016 (has links)
The Solute Carrier (SLC) superfamily is the largest group of membrane-bound transporters, currently with 456 transporters in 52 families. Much remains unknown about the tissue distribution and function of many of these transporters. The aim of this thesis was to characterize select SLCs with emphasis on tissue distribution, cellular localization, and function. In paper I, we studied the leucine transporter B0AT2 (Slc6a15). Localization of B0AT2 and Slc6a15 in mouse brain was determined using in situ hybridization (ISH) and immunohistochemistry (IHC), localizing it to neurons, epithelial cells, and astrocytes. Furthermore, we observed a lower reduction of food intake in Slc6a15 knockout mice (KO) upon intraperitoneal injections with leucine, suggesting B0AT2 is involved in mediating the anorexigenic effects of leucine. In paper II, we studied the postnatal, forebrain-specific deletion of Slcz1, belonging to the SLC18 family, in conditional KO mice (cKO). We observed a decreased response to diazepam and a higher neuronal activity in cortex and hippocampus of cKO mice, as well as an impairment in short-term recognition memory. Intracellular expression was found in neurons but not astrocytes with IHC, indicating SLCZ1 is implicated in neuronal regulation of locomotion and memory. In paper III, we performed the first detailed histological analysis of PAT4, a transporter belonging to the SLC36 family, involved in the activation of mTOR complex 1 on lysosomes. We found abundant Slc36a4 mRNA and PAT4 expression in mouse brain, using ISH and IHC. We used IHC to localize PAT4 to both inhibitory and excitatory neurons and epithelial cells. We also found both intracellular- and plasmalemmal expression and partial colocalization of PAT4 with lysosomal markers. Lastly, in paper IV, we provided the first tissue mapping of orphan transporter MCT14 (SLC16A14). Using qPCR, we detected moderate to high Slc16a14 mRNA in the central nervous system and kidney. We found widespread Slc16a14 and MCT14 in mouse brain using ISH and IHC. We also found MCT14 to have intracellular and plasmalemmal expression in mainly excitatory but also inhibitory neurons, as well as epithelial cells. We found MCT14 to be most closely related to MCT8, MCT2 and MCT9, suggesting a similar role for this transporter.
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Steered Molecular Dynamics Simulations of Biological MoleculesBaker, Joseph Lee January 2011 (has links)
Molecular dynamics (MD) simulation, which employs an empirical potential energy function to describe the interactions between the atoms in a system, is used to investigate atomistic motions of proteins. However, the timescale of many biological processes exceeds the reach of standard MD due to computational limitations. To circumvent these limitations, steered molecular dynamics (SMD), which applies external forces to the simulated system, can be used.Dynamical properties of the gonococcal type IV pilus (GC-T4P) from the bacteria Neisseria gonorrhoeae are first considered. T4 pili are long, filamentous proteins constructed from a subunit (pilin) found to emanate from the surface of pathogenic bacteria. They can withstand large forces (~100 pN), and are implicated in infection. SMD simulations are performed to study the response of the filament to an applied force. Our simulations reveal that stability of the pilus likely results from hydrophobic contacts between pilin domains buried within the filament core. Along the filament surface, gaps are formed between pilin globular head domains. These gaps reveal an amino acid sequence that was also observed to become exposed in the experimentally stretched filament. We propose two other regions initially hidden in the native filament that might become exposed upon stretching.The multidrug resistance transporter EmrD, found in the inner membrane of Escherichia coli is also the target of our studies. EmrD removes harmful drugs from the bacterial cell. We use MD to explore equilibrium dynamics of the protein, and MD/SMD to study drug interactions and transport along its central cavity. Motions supporting a previously proposed lateral diffusion pathway for substrate from the cytoplasmic membrane leaflet into the central cavity were observed. Additionally, interactions of a few specific residues with CCCP have been identified.Finally, we describe network analysis as an approach for analyzing conformational sampling by MD simulations. We demonstrate for several model systems that networks can be used to visualize both the dominant conformational substates of a trajectory and the connectivity between them. Specifically, we compare the results of various clustering algorithms to the network layouts and show how information from both methods can be combined.
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Förutsättningar för intermodala transporter : Fallstudie i Kronobergs län / Conditions for intermodal transportsKarlsson, Erik, Lindström, Jeppe January 2017 (has links)
Magisteruppsats (30 HP) i logistik för Civilekonomprogrammet Linnéuniversitetet, 4FE19E, VT 17 Författare: Erik Karlsson & Jeppe Lindström Handledare: Petra Andersson Examinator: Helena Forslund Titel: Förutsättningar för intermodala transporter Bakgrund: Ett av de vanligaste alternativen för företag att göra positiva åtgärder för miljön är att använda sig av intermodala transporter, vilket är en transport där lastbäraren överförs minst en gång från ett transportmedel till ett annat mellan avsändning och mottagning. Bytet av transportslag sker i en kombi- och omlastningsterminal. En sådan terminal finns i Alvesta, som drivs och arrenderas av Alwex Intermodal AB. Syfte: Syftet är identifiera vilka förutsättningar som krävs för att företag ska kunna använda sig av intermodala transporter genom att skapa en teoretisk modell samt jämföra modellen med befintliga och potentiella kunder för Alwex intermodala tjänster. Metodval: Studien utgår ifrån en kvalitativ fallstudie, där datainsamling har genomförts i form av semi-strukturerade intervjuer. Först samlades teori in i form av litteratur och artiklar vilket sedan skapade en teoretisk modell. Denna modell jämfördes med nuvarande och potentiella kunder till Alwex Intermodal. Slutsatser: Författarna kan efter genomförd studie visa en teoretisk modell som visar förutsättningarna för intermodala transporter. Denna modell utgår från fem olika kategorier, geografiskt läge, tekniska förutsättningar, miljökrav, gods- och flödesegenskaper samt ekonomiska förutsättningar. Denna modell har jämförts med nuvarande och potentiella kunder till Alwex Intermodal där många likheter mellan den teoretiska modellen och nuvarande kunder kan påvisas, men även för de potentiella kunderna. Nyckelord: Intermodala transporter, järnväg, kombiterminal, omlastningsterminal, förutsättningar / Master thesis, Progam of Master of science in Business and Economics, Logistics Linnaeus University, 4FE19E, Spring 17 Authors: Erik Karlsson & Jeppe Lindström Supervisor: Petra Andersson Examiner: Helena Forslund Title: Conditions for intermodal transports Background: One of the most common alternatives for companies to improve the environment emissions is to use intermodal transports, which is a transport where the load carrier is transfered at least once from one transport to another between consignment and pickup. The exchange of transport takes place in a combi terminal or a transshipment terminal. This type of terminal is located in Alvesta, which is operated and leased by Alwex Intermodal AB. Purpose: The purpose is to identify which conditions which are required for companies to use intermodal transports by creating a theoretical model and also comparing the model with current and potential customers of Alwex Intermodal AB. Methodology: The study applies a qualitative case study, where collecting of data was conducted by interviews. First the theory was collected through litterature and scientic articles which created a theoretic model. This theoretical model was compared with current and potentail customers of Alwex Intermodal AB. Conclusions: The authors can after concluded study present a theoretical model which presents the conditions for intermodala transports. This model proceeds five different categories, geographical location, technical conditions, environmental requirements, goods- and flow qualities and also economical conditions. This model has been compared to current and potential customers of Alwex Intermodal where many similarities between the theoretical model and current customers have been detected, but also for the potential customers. Keywords: Intermodal transports, railway, combi terminal, transshipment terminal, conditions
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SYSTEMATIC ANALYSIS OF ABC TRANSPORTERS IN STREPTOCOCCUS SANGUINISAtia, Sawsan 16 April 2013 (has links)
The bacterium Streptococcus sanguinis is a primary member of the human oral microflora and also has been recognized as a key player in the bacterial colonization of the mouth. It is considered the most common viridians streptococcal species implicated in infective endocarditis. In all kingdoms of life, ATP binding cassette (ABC) transporters are essential to many cellular functions. Sequencing of the SK36 genome provided the opportunity to study ABC transporter mutants and their relationship with acidity of the oral environment. Despite numerous studies that have focused on carbohydrate uptake systems in closely related streptococcal species such as S. mutans, S. pneumonia and S. pyogenes, the mechanism of the response of these ABC transporters to acidic conditions in S. sanguinis is still unknown. The capability of S. sanguinis to adapt in these harsh environments suggests this bacterium is capable of responding to various environmental stimuli. The purpose of this study was to examine ABC mutants to identify functions that contribute to acid tolerance in S. sanguinis. This study demonstrates that two acid-sensitive mutant genes, SSA_1507 and SSA_1508, identify genes involved in acid tolerance. The two mutants grew on different sugars and none of them showed a defect in sugar utilization at acid pH. We couldn’t recognize any significant differences in sugar uptake for the two acid sensitive mutants or in mutants of their neighboring genes. Thus, the observed acid sensitivity is not due to a failure to take up any of the common sugars tested. The cytoplasmic pH of S. sanguinis was studied with the fluorescent pH indicator (BCECF) and SK36 was observed to have a wider pH range than either of the two acid-sensitive mutants SSA_1507 or SSA_1508. In these two mutants, intracellular pH was not as well maintained. At all pH values tested, the mutants displayed a lower intracellular pH than the wild type. These observations indicate that the cell membrane of these two mutants is unable to protect the interior components from adverse effects of higher pH values and lower pH values, and prove that these two mutant genes SSA_1507 and SSA_1508 are unable to grow in lower pH values. These results support a role for these ABC transporters in proton pump or export and indicate that the mutants are less able to pump out protons.
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THE SLC22 TRANSPORTER FAMILY: NOVEL INSIGHTS TO ROLES IN DRUG EFFICACY, DRUG-DRUG INTERACTIONS AND MOOD DISORDERSPan, Xiaolei 01 January 2015 (has links)
Numerous studies have demonstrated the impact of organic cation (OCTs; SLC22 family) and anion transporters (OATs; SLC22 family) on the efficacy and safety of clinically important therapeutics. To be specific, OCTs and OATs have been identified as determinants for uptake into and secretion from enterocytes, hepatocytes and renal proximal tubular cells, and are frequent sites of drug-drug interaction (DDI). In addition, OCTs expressed in brain are components of the low-affinity, high capacity clearance pathway (uptake-2) for biogenic monoamine neurotransmitters. As a result, OCTs may represent novel targets for mood disorders.
The inhibitory effects of several therapeutic agents, designed drugs and novel compounds were assessed on the function of OCTs/Octs and OATs/Oats. Among these compounds, the anthraquinone rhein showed significant inhibition on hOATs. While the antituberculosis drug ethambutol, the herbal products matrine and oxymatrine, synthetic cathinones, and all quinazoline and guanidine compounds produced significant inhibition on hOCT activity with most IC50 values in the micro- and even nanomolar ranges.
Considering the clinically relevant unbound concentrations in biofluids, significant DDI potentials were found for rhein, ethambutol, matrine, oxymatrine and several synthetic cathinones affecting enterocytes, hepatocytes and/or proximal tubules. As hOCT2 and hOCT3 may participate in modulating neurotransmitter homeostasis in the CNS, these findings also suggested that the CNS pharmacological effects of synthetic cathinones, quinazoline and guanidine compounds might be due to their inhibitory effects on OCTs; although their impact may be limited solely to clearance of these compounds. Based upon their in vitro OCT/Oct inhibition profiles, three lead quinazoline and guanidine compounds were chosen for in vivo studies. Potent antidepressant-like effects of one lead hOCT-interacting compound (KEO-099) were re-confirmed in the tail suspension test. While in vivo results of the two newly identified hOCT-interacting lead compounds were somewhat less clear.
Finally, homology modeling and docking studies for hOCT3 identified key amino acid residues that might be involved in interaction between hOCT3 and small molecules. Subsequent experiments confirmed a competitive mode of interaction between MPP+ and lead compounds on hOCT3. Thus, preliminary analysis indicates our hOCT3 homology model can be used to support rational drug design and high-throughput screening of novel hOCT substrates/inhibitors.
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Enhancement of the Placental Transmission of Lopinavir Using a Transporter Targeted Prodrug StrategyWang, Meng 01 January 2015 (has links)
Lopinavir (LPV) is a potent protease inhibitor specific for HIV-1. However, LPV has poor placental penetration due to substrate activity for efflux transporter by P-glycoprotein (P-gp). Since fatty acid transporters are highly expressed in the placenta during pregnancy, we designed fatty acid ester prodrug of lopinavir as substrates of fatty acid transporter in order to improve their uptake into placenta. Seven dicarboxylic acid esters of lopinavir have been made in our lab. The structures were characterized by 1H-NMR, 13C-NMR, LC-MS/MS, HRMS, IR and melting points. After making the prodrugs, an LC-MS/MS method with high specificity and sensitivity, as well as simultaneous quantitative analyses of lopinavir and SLPV, GLPV and DLPV in the BeWo cells methanol extraction was established and validated. The uptake of prodrugs (SLPV, GLPV and DLPV) in the BeWo cells was then determined. GLPV has the highest uptake followed by SLPV and then DLPV. The results suggest that the carbon length of the promoiety may have a positive relationship with the uptake. Ideal prodrugs should be stable before they reach placenta and can be hydrolyzed in the placenta and/or in fetal plasma. We did a series of stability and hydrolysis studies in human tissue fractions. The results showed that GLPV and SLPV were very stable in HIC, HLC and human adult plasma. DLPV was stable in HIC, HLC, but can be hydrolyzed in human adult plasma. GLPV and SLPV cannot be hydrolyzed in either human placenta or fetal plasma, while DLPV can be hydrolyzed in both human placenta and fetal plasma. Anti-HIV activities study of prodrugs was also conducted. The results showed that the EC50 of three prodrugs (GLPV, SLPV and DLPV) are 0.86 μM, 0.84 μM and 0.05 μM, which are much lower than 50 μM (The active drug criteria for this assay). It suggests that prodrugs have apparently anti-HIV activity. DLPV has comparable apparent anti-HIV activity to LPV (<0.02 μM). After incubation with CEM-SS cells for 6 days, almost half of DLPV was hydrolyzed into LPV. Therefore, the high anti-HIV potent of DLPV may be due to the anti-HIV activity of generated LPV.
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