Solid dispersions: formulation, characterisation, permeability and genomic evaluation

Poor water solubility is characterised by low dissolution rate and consequently reduced bioavailability. Formulation of solid dispersion of the drug has attracted considerable interest as a means of improving dissolution process of a range of poorly water soluble drugs. This current study investigates the formulation of solid dispersion for a range of poorly water soluble drugs with varying physicochemical properties including paracetamol, sulphamethoxazole, phenacetin, indomethacin, chloramphenicol, phenylbutazone and succinylsulphathiazole. Solid dispersions were prepared using various drugs to polymer ratios. PEG 8000 was selected as a carrier in the solid dispersions. The study revealed that inclusion of drug within the polymeric matrix, ratio of drug to polymer and physicochemical properties of the drug molecules enhance the dissolution rate. Characterisations of the solid dispersions were performed using DSC, FTIR and SEM. These studies revealed that all seven drugs were present in the amorphous form within the solid dispersions and there was a lack of interaction between the PEG 8000 and drug. Stability studies for solid dispersions showed that all seven drugs studied were unstable at accelerated conditions (40°C±2°C/75%RH±5%RH) whereas, they were found to be stable for 12 months at room conditions. Permeability of indomethacin, phenacetin, phenylbutazone and paracetamol were higher for solid dispersions as compared to drug alone across Caco-2 cell monolayers. From the cell uptake studies it was shown that PEG 8000 enhanced rhodamine123 uptake which suggested that PEG 8000 may increase the permeability of these drugs in solid dispersions. Gene expression profiles analyzing the expression changes in the ABC and solute carrier transporter during permeability studies.ABCA10, ABCB4, ABCC12, SLC12A6, MCT13, SLC22A12 and SLC6A6 gene expression were increased by indomethacin alone whereas solid dispersion of indomethacin resulted in a slight increase in expression. ABCC12 and SAMC gene expression was increased in case of paracetamol alone but slightly increased when exposed to solid dispersion of paracetamol.

Multiple roles of charged amino acids in cytoplasmic loop 7 for expression and function of the multidrug and organic anion transporter MRP1 (ABCC1)

Multidrug resistance protein MRP1 mediates the ATP-dependent efflux of many chemotherapeutic agents and organic anions. MRP1 has two nucleotide binding sites (NBSs) and three membrane spanning domains (MSDs) containing 17 transmembrane helices linked by extracellular and cytoplasmic loops (CL). Homology models suggest that CL7 (amino acids 1141-1195) is in a position where it could participate in signaling between the MSDs and NBSs during the transport process. We have individually replaced eight charged residues in CL7 with Ala, and in some cases, an amino acid with the same charge, and then investigated the effects on MRP1 expression, transport activity, and nucleotide and substrate interactions. A triple mutant in which Glu(1169), Glu(1170), and Glu(1172) were all replaced with Ala was also examined. The properties of R1173A and E1184A were comparable with those of wild-type MRP1, whereas the remaining mutants were either poorly expressed (R1166A, D1183A) or exhibited reduced transport of one or more organic anions (E1144A, D1179A, K1181A, (1169)AAQA). Same charge mutant D1183E was also not expressed, whereas expression and activity of R1166K were similar to wild-type MRP1. The moderate substrate-selective changes in transport activity displayed by mutants E1144A, D1179A, K1181A, and (1169)AAQA were accompanied by changes in orthovanadate-induced trapping of [alpha-(32)P]azidoADP by NBS2 indicating changes in ATP hydrolysis or release of ADP. In the case of E1144A, estradiol glucuronide no longer inhibited trapping of azidoADP. Together, our results demonstrate the extreme sensitivity of CL7 to mutation, consistent with its critical and complex dual role in both the proper folding and transport activity of MRP1.

Astrocytic GABA transporter GAT-1 dysfunction in experimental absence seizures

An enhanced tonic GABA-A inhibition in the thalamus plays a crucial role in experimental absence seizures, and has been attributed, on the basis of indirect evidence, to a dysfunction of the astrocytic GABA transporter-1 (GAT-1). Here, the GABA transporter current was directly investigated in thalamic astrocytes from a well-established genetic model of absence seizures, the Genetic Absence Epilepsy Rats from Strasbourg (GAERS), and its non-epileptic control (NEC) strain. We also characterized the novel form of GABAergic and glutamatergic astrocyte-to-neuron signalling by recording slow outward currents (SOCs) and slow inward currents (SICs), respectively, in thalamocortical (TC) neurons of both strains. In patch-clamped astrocytes, the GABA transporter current was abolished by combined application of the selective GAT-1 and GAT-3 blocker, NO711 (30µM) and SNAP5114 (60µM), respectively, to GAERS and NEC thalamic slices. NO711 alone significantly reduced (41%) the transporter current in NEC, but had no effect in GAERS. SNAP5114 alone reduced by half the GABA transporter current in NEC, whilst it abolished it in GAERS. SIC properties did not differ between GAERS and NEC TC neurons, whilst moderate changes in SOC amplitude and kinetics were observed. These data provide the first direct demonstration of a malfunction of the astrocytic thalamic GAT-1 transporter in absence epilepsy and support an abnormal astrocytic modulation of thalamic ambient GABA levels. Moreover, while the glutamatergic astrocyte-neuron signalling is unaltered in the GAERS thalamus, the changes in some properties of the GABAergic astrocyte-neuron signaling in this epileptic strain may contribute to the generation of absence seizures.

Detergent-free purification of ABC (ATP-binding-cassette) transporters

ABC (ATP-binding-cassette) transporters carry out many vital functions and are involved in numerous diseases, but study of the structure and function of these proteins is often hampered by their large size and membrane location. Membrane protein purification usually utilizes detergents to solubilize the protein from the membrane, effectively removing it from its native lipid environment. Subsequently, lipids have to be added back and detergent removed to reconstitute the protein into a lipid bilayer. In the present study, we present the application of a new methodology for the extraction and purification of ABC transporters without the use of detergent, instead, using a copolymer, SMA (polystyrene-co-maleic acid). SMA inserts into a bilayer and assembles into discrete particles, essentially solubilizing the membrane into small discs of bilayer encircled by a polymer, termed SMALPs (SMA lipid particles). We show that this polymer can extract several eukaryotic ABC transporters, P-glycoprotein (ABCB1), MRP1 (multidrug-resistance protein 1; ABCC1), MRP4 (ABCC4), ABCG2 and CFTR (cystic fibrosis transmembrane conductance regulator; ABCC7), from a range of different expression systems. The SMALP-encapsulated ABC transporters can be purified by affinity chromatography, and are able to bind ligands comparably with those in native membranes or detergent micelles. A greater degree of purity and enhanced stability is seen compared with detergent solubilization. The present study demonstrates that eukaryotic ABC transporters can be extracted and purified without ever being removed from their lipid bilayer environment, opening up awide range of possibilities for the future study of their structure and function. © The Authors Journal compilation © 2014 Biochemical Society.

Transporter associated with antigen processing preselection of peptides binding to the MHC:a bioinformatic evaluation

TAP is responsible for the transit of peptides from the cytosol to the lumen of the endoplasmic reticulum. In an immunological context, this event is followed by the binding of peptides to MHC molecules before export to the cell surface and recognition by T cells. Because TAP transport precedes MHC binding, TAP preferences may make a significant contribution to epitope selection. To assess the impact of this preselection, we have developed a scoring function for TAP affinity prediction using the additive method, have used it to analyze and extend the TAP binding motif, and have evaluated how well this model acts as a preselection step in predicting MHC binding peptides. To distinguish between MHC alleles that are exclusively dependent on TAP and those exhibiting only a partial dependence on TAP, two sets of MHC binding peptides were examined: HLA-A*0201 was selected as a representative of partially TAP-dependent HLA alleles, and HLA-A*0301 represented fully TAP-dependent HLA alleles. TAP preselection has a greater impact on TAP-dependent alleles than on TAP-independent alleles. The reduction in the number of nonbinders varied from 10% (TAP-independent) to 33% (TAP-dependent), suggesting that TAP preselection is an important component in the successful in silico prediction of T cell epitopes.

Under the ABC Umbrella: Orphanages, Rights, and Education in Mexico

The National System for the Integral Development of the Family (DIF) in Mexico assists children in orphanages. This paper provides an overview of its current practices, and advocates a holistic educational/social model for “alternative orphanages,” integrating Maslow’s Hierarchy of Needs and the rights-based approach. The model complements DIF’s social efforts.

PÓS-GRADUAÇÃO, PRODUÇÃO ACADÊMICA, INTERDISCIPLINARIDADE E SOCIALIZAÇÃO DO CONHECIMENTO: A PRODUÇÃO CIENTÍFICA DO GRANDE ABC À LUZ DO PNPG 2011-2020

O objetivo desta investigação foi verificar se, diante da autonomia e vocação que possuem, bem como da possibilidade de receber amparo e incentivos governamentais, as universidades pertencentes à região do Grande ABC atenderam as recomendações feitas pelo PNPG vigente. Para tanto, foram analisadas cinquenta e sete dissertações e duas teses da área de ciências sociais aplicadas, publicadas no período entre 2011 e 2014, pelas seguintes instituições: Universidade Metodista de São Paulo (UMESP); Universidade Municipal de São Caetano do Sul (USCS); Universidade Federal do ABC (UFABC) e Faculdade de Engenharia Industrial (FEI). Essa averiguação se deu ao redor de dois eixos organizadores do PNPG 2011-2014: o terceiro eixo – o aperfeiçoamento da avaliação e sua expansão para outros segmentos do sistema de CT&I (formação de pós-graduados voltados para atividades extra-acadêmicas/setor empresarial) e o quarto eixo – a multi e a interdisciplinaridade entre as principais características da pós-graduação e importantes temas da pesquisa (promover, por meio de programas, áreas de concentração e linhas de pesquisa, a convergência de temas e compartilhamento de problemas em oposição à sua mera associação ou sobreposição). Este estudo – qualitativo, bibliográfico, documental, exploratório, descritivo, tipo estado do conhecimento – se desenvolveu por meio de pesquisa documental e de análise de conteúdo temático categorial. A coleta de dados foi feita por meio dos repositórios digitais de teses e dissertações mantidos na internet pelas Universidades, cuja produção científica foi investigada. Após a análise dos dados ficou demonstrado que aproximadamente 68,96% da produção científica da área de ciências sociais aplicadas, publicada pelas universidades do Grande ABC, no período entre 2011 e 2014, corresponde às expectativas do PNPG atual no que diz respeito às recomendações constantes no terceiro eixo. Em relação às recomendações feitas no texto do quarto eixo, vemos que aproximadamente 31,03% dos trabalhos selecionados atendem às expectativas do Plano, apresentando em sua estrutura, segundo a fundamentação teórica utilizada neste trabalho, características de interdisciplinaridade.

Análisis del mercado laboral de los medios de comunicación a través de los diarios "ABC" y "El País" entre los años 2000 y 2006

En el D.E.A.se examina como en los dos de los principales periódicos españoles, uno de tendencia progresista, "El País", y otro de tendencia conservadora, "ABC", se publican, cuantitativa y cualitativamente, las noticias sobre el mercado laboral de los medios de comunicación en un lapso temporal, 2000 a 2006, en el que acaecieron dos legislaturas con gobiernos estatales de diversa ideología política: Partido Popular, (P.P.), y Partido Socialista Obrero Español, (P.S.O.E.). El objeto del trabajo de investigación ha sido analizar la situación laboral en aquéllos, con especial incidencia en los periodistas, y cómo la misma tiene cabida en las noticias de los dos diarios; es decir, cómo se transmite a la sociedad, en su caso, a través de dos periódicos de tendencias ideológicas muy diferentes. La finalidad del trabajo investigador es la comprobación de si los dos diarios han reflejado la preocupación expresada por los colectivos profesionales de periodistas o si realmente estas preocupaciones expuestas anteriormente no transcienden socialmente más allá del ámbito de las redacciones.

Drug Transporter Gene Expression in Human Colorectal Tissue and Cell Lines : Modulation with Antiretrovirals for Microbicide Optimization

This work was supported by the European Union's Seventh Programme for research, technological development and demonstration under grant agreement No 305316 as part of the MOTIF (Microbicides Formulation Through Innovative Formulation for Vaginal and Rectal Delivery) project.

Drug Transporter Gene Expression in Human Colorectal Tissue and Cell Lines : Modulation with Antiretrovirals for Microbicide Optimization

This work was supported by the European Union's Seventh Programme for research, technological development and demonstration under grant agreement No 305316 as part of the MOTIF (Microbicides Formulation Through Innovative Formulation for Vaginal and Rectal Delivery) project.

Demonstration against Tex Antoine at ABC-TV

General note: Title and date provided by Bettye Lane.

Umpire Bernice Gera holds press conference at ABC-TV NY

General note: Title and date provided by Bettye Lane.

Demonstration against rape and Tex Antoine at ABC-TV

General note: Title and date provided by Bettye Lane.

Umpire Bernice Gera holds press conference at ABC-TV NY

General note: Title and date provided by Bettye Lane.

ABC-TV sound technician at OP Sail

General note: Title and date provided by Bettye Lane.