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1.
J Pharm Sci ; 112(1): 91-99, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-35605689

RESUMO

The reported inconsistencies between calorimetry and the van't Hoff equation hinder the utility of thermodynamics in pharmaceutical research. In ligand binding or adsorption assays, it is believed that the van't Hoff equation falls short because of the lack of stoichiometric treatment in the equilibrium constant. A new modified Langmuir-Like equation that accounts for the stoichiometry of solute adsorption and solvent displacement is proposed in this work. The performance of the model was evaluated by studying the adsorption of phenobarbital from aqueous solutions by commercial activated carbon. The amount of water occupying the adsorption sites was estimated by graphical analysis of the 'knee point' of water-vapor adsorption isotherms and was found to correlate well with the relative percentage of hydroxyl and carbonyl surface groups. It was found that one phenobarbital molecule displaces 2-6 water molecules from the adsorption site. It is shown that adsorption enthalpy was not affected by the adjustment for stoichiometry, supporting the notion that the van't Hoff enthalpy is intrinsic and is independent of the stoichiometry of solvent displacement in Langmuir-based binding. The widely reported disparities between the van't Hoff and calorimetric enthalpies are unlikely to be from a stoichiometric origin.


Assuntos
Fenobarbital , Água , Solventes/química , Adsorção , Temperatura , Termodinâmica , Calorimetria , Fenobarbital/química
2.
Nat Chem Biol ; 17(8): 888-895, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33941924

RESUMO

The uniquely hollow structure of microtubules (MTs) confers characteristic mechanical and biological properties. Although most regulatory processes take place at the outer surface, molecular events inside MTs, such as α-tubulin acetylation, also play a critical role. However, how regulatory proteins reach the site of action remains obscure. To assess luminal accessibility, we first identified luminally positioned residues of ß-tubulin that can be fused to a protein of interest. We then developed a chemically inducible technique with which cytosolic proteins can be rapidly trapped at the lumen of intact MTs in cells. A luminal trapping assay revealed that soluble proteins of moderate size can enter the lumen via diffusion through openings at the MT ends and sides. Additionally, proteins forming a complex with tubulins can be incorporated to the lumen through the plus ends. Our approach may not only illuminate this understudied territory, but may also help understand its roles in MT-mediated functions.


Assuntos
Microtúbulos/metabolismo , Fenobarbital/metabolismo , Tubulina (Proteína)/metabolismo , Células Cultivadas , Humanos , Microtúbulos/química , Fenobarbital/química , Solubilidade , Tubulina (Proteína)/química
3.
Nature ; 585(7824): 303-308, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32879488

RESUMO

Most general anaesthetics and classical benzodiazepine drugs act through positive modulation of γ-aminobutyric acid type A (GABAA) receptors to dampen neuronal activity in the brain1-5. However, direct structural information on the mechanisms of general anaesthetics at their physiological receptor sites is lacking. Here we present cryo-electron microscopy structures of GABAA receptors bound to intravenous anaesthetics, benzodiazepines and inhibitory modulators. These structures were solved in a lipidic environment and are complemented by electrophysiology and molecular dynamics simulations. Structures of GABAA receptors in complex with the anaesthetics phenobarbital, etomidate and propofol reveal both distinct and common transmembrane binding sites, which are shared in part by the benzodiazepine drug diazepam. Structures in which GABAA receptors are bound by benzodiazepine-site ligands identify an additional membrane binding site for diazepam and suggest an allosteric mechanism for anaesthetic reversal by flumazenil. This study provides a foundation for understanding how pharmacologically diverse and clinically essential drugs act through overlapping and distinct mechanisms to potentiate inhibitory signalling in the brain.


Assuntos
Anestésicos Gerais/química , Anestésicos Gerais/farmacologia , Barbitúricos/química , Barbitúricos/farmacologia , Benzodiazepinas/química , Benzodiazepinas/farmacologia , Microscopia Crioeletrônica , Receptores de GABA-A/química , Regulação Alostérica/efeitos dos fármacos , Anestésicos Gerais/metabolismo , Barbitúricos/metabolismo , Benzodiazepinas/metabolismo , Bicuculina/química , Bicuculina/metabolismo , Bicuculina/farmacologia , Sítios de Ligação , Ligação Competitiva/efeitos dos fármacos , Diazepam/química , Diazepam/metabolismo , Diazepam/farmacologia , Eletrofisiologia , Etomidato/química , Etomidato/metabolismo , Etomidato/farmacologia , Flumazenil/farmacologia , Antagonistas de Receptores de GABA-A/química , Antagonistas de Receptores de GABA-A/metabolismo , Antagonistas de Receptores de GABA-A/farmacologia , Humanos , Ligantes , Modelos Moleculares , Conformação Molecular , Simulação de Dinâmica Molecular , Fenobarbital/química , Fenobarbital/metabolismo , Fenobarbital/farmacologia , Picrotoxina/química , Picrotoxina/metabolismo , Picrotoxina/farmacologia , Propofol/química , Propofol/metabolismo , Propofol/farmacologia , Receptores de GABA-A/metabolismo , Receptores de GABA-A/ultraestrutura , Ácido gama-Aminobutírico/química , Ácido gama-Aminobutírico/metabolismo , Ácido gama-Aminobutírico/farmacologia
4.
Molecules ; 25(14)2020 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-32650603

RESUMO

Ibuprofen is one of the most widely used pharmaceuticals, and due to its inefficient removal by conventional wastewater treatment, it can be found in natural surface waters at high concentrations. Recently, we demonstrated that the TpBD-(CF3)2 covalent organic framework (COF) can adsorb ibuprofen from ultrapure water with high efficiency. Here, we investigate the performance of the COF for the extraction of ibuprofen from natural water samples from a lake, river, and estuary. In general, the complexity of the natural water matrix induced a reduction in the adsorption efficiency of ibuprofen as compared to ultrapure water. The best performance, with over 70% adsorption efficiency, was found in lake water, the sample which featured the lowest pH. According to the theoretical calculations, ibuprofen more favorably interacts with the COF pores in the protonated form, which could partially account for the enhanced adsorption efficiency found in lake water. In addition, we explored the effect of the presence of competing pharmaceuticals, namely, acetaminophen and phenobarbital, on the ibuprofen adsorption as binary mixtures. Acetaminophen and phenobarbital were adsorbed by TpBD-(CF3)2 with low efficiency and their presence led to an increase in ibuprofen adsorption in the binary mixtures. Overall, this study demonstrates that TpBD-(CF3)2 is an efficient adsorbent for the extraction of ibuprofen from natural waters as well.


Assuntos
Ibuprofeno/isolamento & purificação , Estruturas Metalorgânicas/química , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água , Adsorção , Ibuprofeno/química , Fenobarbital/química , Fenobarbital/isolamento & purificação , Poluentes Químicos da Água/química
5.
Talanta ; 216: 120959, 2020 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-32456893

RESUMO

An analytical procedure using low-cost instrumentation (fluorescence/phosphorescence spectrophotometer) has been developed to assess total mercury in fishery products. Determinations were based on the room temperature phosphorescence (RTP) quenching of a composite Ph-QDs consisting of phenobarbital-containing polymer/silica coated Mn-doped ZnS quantum dots. Under optimum conditions (fish extract pH of 8.0, Ph-QDs concentration of 20 mg L-1, and an interaction time of 12 min), the material offers high selectivity for inorganic mercury and methyl-mercury over other common ions present in the fish matrix. Moreover, good linearity was obtained for mercury concentrations within the 0-100 µg L-1 range, and the obtained limit of detection (68.2 µg kg-1) is low enough for a reliable assessment of total mercury in fish and seafood samples. The developed method was found to be free of matrix effects, and offers the advantage that the fish extracts can be directly analysed even at a 1:10 dilution. The method was found to be accurate after analysing a fish certified reference material, and after comparing total mercury levels in a set of fish samples analysed by the proposed chemosensor probe and by inductively coupled plasma mass spectrometry after an acid decomposition sample pre-treatment.


Assuntos
Contaminação de Alimentos/análise , Mercúrio/análise , Fenobarbital/química , Polímeros/química , Pontos Quânticos/química , Dióxido de Silício/química , Animais , Peixes , Medições Luminescentes , Estrutura Molecular , Temperatura
6.
J Cell Biol ; 219(4)2020 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-32328632

RESUMO

Epithelial cell physiology critically depends on the asymmetric distribution of channels and transporters. However, the mechanisms targeting membrane proteins to the apical surface are still poorly understood. Here, we performed a visual forward genetic screen in the zebrafish intestine and identified mutants with defective apical targeting of membrane proteins. One of these mutants, affecting the vacuolar H+-ATPase gene atp6ap1b, revealed specific requirements for luminal acidification in apical, but not basolateral, membrane protein sorting and transport. Using a low temperature block assay combined with genetic and pharmacologic perturbation of luminal pH, we monitored transport of newly synthesized membrane proteins from the TGN to apical membrane in live zebrafish. We show that vacuolar H+-ATPase activity regulates sorting of O-glycosylated proteins at the TGN, as well as Rab8-dependent post-Golgi trafficking of different classes of apical membrane proteins. Thus, luminal acidification plays distinct and specific roles in apical membrane biogenesis.


Assuntos
Proteínas de Membrana/metabolismo , Fenobarbital/metabolismo , ATPases Translocadoras de Prótons/metabolismo , Proteínas de Peixe-Zebra/metabolismo , Peixe-Zebra/metabolismo , Animais , Concentração de Íons de Hidrogênio , Proteínas de Membrana/genética , Mutação , Fenobarbital/química , Transporte Proteico , ATPases Translocadoras de Prótons/genética , Proteínas de Peixe-Zebra/genética
7.
Histol Histopathol ; 35(1): 83-96, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31250425

RESUMO

Breast cancer has different molecular subtypes, which determine the prognosis and response to the treatment. CD133 is a marker for cancer stem cells in tumor microenvironment with diagnostic/therapeutic importance. The tumor associated macrophages (TAMs) interact with the cancer stem cells through the CXCR1 receptor. In this study, we wanted to investigate the expression of these markers in patients with different molecular subtypes, in order to detect pathophysiological mechanisms and new molecular targets for the prospective targeted therapies. In this study we hypothesized a difference in expression of these antigens among different subtypes. We investigated expression of antigens in breast cancer patients with luminal A (LA), luminal B (LB), HER2 overexpressing (HER2OE), triple negative (TN) subtypes (n=70) and control patients (n=10) without cancer diagnosis. We applied indirect immunohistochemistry and evaluated immunostaining. CD133 expression was at the periphery and CXCR1 expression was at the central area of the tumor. The cytoplasmic CXCR1, CD133 expressions and nuclear CD133 expression, which is prominent in the TN subtype, were observed in patients. There was a statistically significant difference between the groups for CD133 (p=0.004), CXCR1 (p=0.002) H-Score values and M2 macrophages/whole TAM ratios (p=0.022). Between the CD133 and CXCR1 H-scores, there was a weak positive correlation (r=0.249, p=0.035). This study showed the compartment specific expression of the CD133 and CXCR1 antigens in neoplastic cells. The use of CD133 as a stem cell marker may be limited to TN subtype, due to its heterogeneous expression.


Assuntos
Antígeno AC133/metabolismo , Neoplasias da Mama/metabolismo , Macrófagos/metabolismo , Células-Tronco Neoplásicas/metabolismo , Receptores de Interleucina-8A/metabolismo , Idoso , Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/diagnóstico , Linhagem Celular Tumoral , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Interleucina-1alfa/metabolismo , Masculino , Pessoa de Meia-Idade , Fenobarbital/química , Receptor ErbB-2/metabolismo , Estudos Retrospectivos , Células-Tronco/metabolismo , Microambiente Tumoral
8.
J Mol Model ; 25(7): 181, 2019 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-31175465

RESUMO

In order to reveal the essence of the pharmaceutical incompatibility, the cooperativity effects of the drug-drug intermolecular π∙∙∙π and H∙∙∙O H-bonding interactions involving hydration were evaluated in the phenobarbital∙∙∙paracetamol∙∙∙H2O complex at the M06-2X/6-311++G** and MP2/6-311++G** levels. The thermodynamic cooperativity effects were also investigated by the statistical thermodynamic method. The results show that the π∙∙∙π stacking ternary complexes with the moderate anti-cooperativity effects are dominant in controling the aggregation process of phenobarbital, paracetamol, and H2O, as is confirmed by the atoms-in-molecules (AIM) and reduced density gradient (RDG) analyses. Therefore, it can be inferred that the anti-cooperativity effect plays an important role in forming the pharmaceutical incompatibility, and thus a deduction on the formation process of the pharmaceutical incompatibility between phenobarbital and paracetamol, with the hydration effect, is given. Several valuable models that relate the features of molecular surface electrostatic potentials or their statistical parameters, such as the surface areas, average values ([Formula: see text]), variances ([Formula: see text], [Formula: see text] and [Formula: see text]), and product of [Formula: see text] and electrostatic balance parameter (ν) ([Formula: see text]ν), to the values of the cooperativity effects were predicted. The formation of the pharmaceutical incompatibility is a thermodynamic cooperativity process driven by the enthalpy change. Graphical abstract Anti-cooperativity effect plays an important role in forming the pharmaceutical incompatibility.


Assuntos
Acetaminofen/química , Incompatibilidade de Medicamentos , Interações Medicamentosas , Modelos Teóricos , Fenobarbital/química , Água/química , Acetaminofen/farmacologia , Algoritmos , Humanos , Ligação de Hidrogênio , Modelos Moleculares , Conformação Molecular , Fenobarbital/farmacologia , Eletricidade Estática , Relação Estrutura-Atividade
9.
Interdiscip Sci ; 11(4): 711-722, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31187432

RESUMO

Circular RNAs (circRNAs) possess valuable characteristics for both diagnosis and treatment of several human cancers including breast cancer (BC). In this study, we combined several systems, biology tools and approaches to identify influential BC circRNAs, miRNAs, and related mRNAs as the members of competing endogenous RNAs (ceRNAs) networks and related RNA binding proteins (RBPs) to study and decipher the BC-triggering biological processes and pathways. Rooting from the identified total of 25 co-differentially expressed circRNAs (DECs) between triple negative (TN) and luminal A subtypes of BC from microarray analysis, five hub DECs (hsa_circ_0003227, hsa_circ_0001955, hsa_circ_0020080, hsa_circ_0001666, and hsa_circ_0065173) and top eleven RBPs (AGO1, AGO2, EIF4A3, FMRP, HuR (ELAVL1), IGF2BP1, IGF2BP2, IGF2BP3, EWSR1, FUS, and PTB) were explored to form the upper stream regulatory elements. All the hub circRNAs were regarded as a super sponge having multiple miRNA response elements (MREs). Then, three BC leading miRNAs (hsa-miR-149, hsa-miR-182, and hsa-miR-383) were also introduced from merging several established ceRNAs networks. The predicted 7- and 8-mer MREs matches between hub circRNAs and leading miRNAs ensured their enduring regulatory capability. The mined downstream mRNAs of the circRNAs-miRNAs network then were presented to STRING database to form the PPI network and to decipher the issue from another point of view. The BC interconnected enriched pathways and processes guarantee the merits of the ceRNAs network's members as targetable therapeutic elements. This study suggested extensive panels of novel therapeutic targets that are in charge of BC progression, hence their impressive role cannot be excluded and needs deeper empirical laboratory designs.


Assuntos
Neoplasias da Mama/genética , Redes Reguladoras de Genes , MicroRNAs/genética , RNA Circular/genética , Proteínas de Ligação a RNA/metabolismo , Biologia Computacional , Bases de Dados Genéticas , Progressão da Doença , Feminino , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Análise de Sequência com Séries de Oligonucleotídeos , Fenobarbital/química , Análise de Sequência de RNA
10.
Chem Biol Interact ; 305: 12-20, 2019 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-30926317

RESUMO

Human dehydrogenase/reductase SDR family member 11 (DHRS11) has been recently reported to be an NADP+-dependent 3(17)ß-hydroxysteroid dehydrogenase, and its orthologs are predicted in genomic analyses of various animals. Among them, the amino acid sequence of predicted rabbit DHRS11 shares 92% identity with that of human DHRS11 and matches peptide sequences (composed of total 87 amino acids) of rabbit heart acetohexamide reductase (RHAR) previously reported. However, the physiological role of RHAR remains unknown, because its known substrates are only acetohexamide and 1,4-naphthoquinone. To elucidate whether the two rabbit enzymes are identical, we have isolated the cDNA for rabbit DHRS11, which was abundantly detected in the brain, heart, kidney and intestine by RT-PCR. The recombinant rabbit DHRS11 reduced acetohexamide and 1,4-naphthoquinone, and was inhibited by tolbutamide and phenobarbital (RHAR-specific inhibitors), demonstrating its identity with RHAR. Rabbit DHRS11 also reduced α-dicarbonyl compounds, aldehydes and aromatic ketones (acetylbenzenes and acetylpyridines), and exhibited 3(17)ß-hydroxysteroid dehydrogenase activity. It was competitively inhibited not only by tolbutamide and phenobarbital, but also more potently by several non-steroidal anti-inflammatory drugs such as diclofenac and sulindac. The broad substrate specificity and inhibitor sensitivity were different from those of human DHRS11, which did not reduce aliphatic aldehydes and aromatic ketones despite its higher 3(17)ß-hydroxysteroid dehydrogenase activity, and was insensitive to tolbutamide, phenobarbital and diclofenac. The site-directed mutagenesis of Thr163 and Val200 in human DHRS11 to the corresponding residues (Gly and Leu, respectively) in rabbit DHRS11 suggested that these residues are pertinent to the differences in properties of rabbit and human DHRS11s.


Assuntos
17-Hidroxiesteroide Desidrogenases/metabolismo , Oxirredutases do Álcool/metabolismo , 17-Hidroxiesteroide Desidrogenases/antagonistas & inibidores , 17-Hidroxiesteroide Desidrogenases/genética , Acetoexamida/metabolismo , Oxirredutases do Álcool/antagonistas & inibidores , Oxirredutases do Álcool/química , Sequência de Aminoácidos , Animais , Domínio Catalítico , Diclofenaco/química , Diclofenaco/metabolismo , Humanos , Cinética , Masculino , Mutagênese , Miocárdio/enzimologia , Fenobarbital/química , Fenobarbital/metabolismo , Coelhos , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Alinhamento de Sequência , Especificidade por Substrato , Tolbutamida/química , Tolbutamida/metabolismo
11.
Talanta ; 194: 143-149, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30609514

RESUMO

Herein, a selective and sensitive fluorescence sensor was developed for the detection of phenobarbital, an epilepsy drug, using molecularly imprinted polymers (MIPs) coated on the surface of green source carbon dots (GSCDs). First, GSCDs were synthesized through a hydrothermal method using Cedrus as a carbon source. Then, a MIPs-GSCDs as a fluorescence probe was obtained by coating a thin film of silica on the surface of the GSCDs using a reverse micro emulsion method. In this step, phenobarbital, 3-aminopropyltriethoxysilane (APTES) and tetraethoxysilane (TEOS) were applied as a template, a functional monomer, and cross linker, respectively. The fluorescence signal of MIPs-GSCDs was selectively quenched by phenobarbital rebinding with MIP cavities. The fluorescence quenching signal was applied for phenobarbital sensing at the pH = 8 without the interference of other materials. After optimizing the factors affecting the sensor's response, a linear range between 0.4 and 34.5 nmol L-1 with a detection limit of 0.1 nmol L-1 was obtained. The sensor's capability in the real sample analysis was investigated by phenobarbital determination in a human blood plasma samples.


Assuntos
Carbono/química , Limite de Detecção , Impressão Molecular , Fenobarbital/análise , Polímeros/síntese química , Pontos Quânticos/química , Dióxido de Silício/química , Calibragem , Corantes Fluorescentes/química , Concentração de Íons de Hidrogênio , Fenobarbital/química , Polímeros/química , Espectrometria de Fluorescência , Temperatura , Fatores de Tempo
12.
J Pharm Sci ; 108(1): 173-177, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29940180

RESUMO

In the present study, the interaction between phenobarbital and activated carbons which is driven by hydrophobic bonding was evaluated. The Two-Mechanism Langmuir-Like Equation was proposed to describe the isotherms for phenobarbital adsorbing to activated carbons. The parameters in the Two-Mechanism Langmuir-Like Equation obtained from the nonlinear fitting of isotherms were used in the calculations of the differential Gibbs free energy for the hydrophobic bonding-driven interaction. Two thermodynamic models, the Modified Crisp Model and the van't Hoff Equation, were adopted to estimate the differential Gibbs free energy. And, comparing the differential Gibbs free energy obtained from the 2 thermodynamic relationships, it can be determined that an adsorbing phenobarbital molecule displaces 12 water molecules on the hydrocarbon surfaces of the activated carbons (hydrophobic bonding case). The difference between the estimates of the differential Gibbs free energy obtained by the Modified Crisp Model and by the van't Hoff Equation provides a new experimental method to calculate the number of solvent molecules displaced by an adsorbing solute molecule. This is a completely general technique for the hydrophobic bonding-driven interaction and is not limited to the systems studied. The calculated positive differential entropy confirmed that the adsorption process was entropy driven.


Assuntos
Carvão Vegetal/química , Fenobarbital/química , Soluções/química , Água/química , Adsorção , Entropia , Interações Hidrofóbicas e Hidrofílicas , Solventes/química , Temperatura , Termodinâmica
13.
Int J Pharm Compd ; 22(6): 516-526, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30384353

RESUMO

Compounded liquid medication is frequently required in children to allow easy dose adjustment and overcome swallowing difficulties. The objective of this study was to evaluate the stability of oral suspensions compounded with SyrSpend SF PH4 and the commonly used active pharmaceutical ingredients baclofen 2.0 mg/mL, carvedilol 5.0 mg/mL, hydrochlorothiazide 2.0 mg/mL, mercaptopurine 10.0 mg/mL, methadone hydrochloride 10.0 mg/mL, oseltamivir phosphate 6.0 mg/mL, phenobarbital 9.0 mg/mL and 15.0 mg/mL, propranolol hydrochloride 0.5 mg/mL and 5.0 mg/mL, pyrazinamide 100.0 mg/mL, spironolactone 2.0 mg/mL and 2.5 mg/mL, sotalol hydrochloride 5.0 mg/mL, tacrolimus monohydrate 0.5 mg/mL, ursodeoxycholic acid 20.0 mg/mL, and vancomycin hydrochloride 25.0 mg/mL. Suspensions were compounded with raw powders, except for mercaptopurine, pyrazinamide, and sotalol hydrochloride, which were made from commercial tablets. Stability was assessed by measuring the percentage recovery at 0 (baseline), 60 days, and 90 days after compounding for suspensions made with raw powders, which were stored at 2ÅãC to 8ÅãC. The stability of tablets, which were stored at 2ÅãC to 8ÅãC and 20ÅãC to 25ÅãC, was assessed by measuring the percentage recovery at 0 (baseline), 7 days, 14 days, 30 days, 60 days, and 90 days. Active pharmaceutical ingredients quantification was performed by ultraviolet high-performance liquid chromatography via a stability-indicating method. Given the percentage of recovery of the active pharmaceutical ingredients within the suspensions, the beyond-use date of the final products (active pharmaceutical ingredients + vehicle) was at least 90 days for all suspensions in the conditions tested. This suggests that SyrSpend SF PH4 is suitable for compounding active pharmaceutical ingredients from different pharmacological classes.


Assuntos
Baclofeno/química , Carvedilol/química , Hidroclorotiazida/química , Mercaptopurina/química , Metadona/química , Oseltamivir/química , Veículos Farmacêuticos/química , Fenobarbital/química , Propranolol/química , Sotalol/química , Espironolactona/química , Amido/química , Tacrolimo/química , Ácido Ursodesoxicólico/química , Vancomicina/química , Administração Oral , Baclofeno/administração & dosagem , Carvedilol/administração & dosagem , Composição de Medicamentos , Estabilidade de Medicamentos , Hidroclorotiazida/administração & dosagem , Concentração de Íons de Hidrogênio , Mercaptopurina/administração & dosagem , Metadona/administração & dosagem , Oseltamivir/administração & dosagem , Soluções Farmacêuticas , Fenobarbital/administração & dosagem , Propranolol/administração & dosagem , Pirazinamida/administração & dosagem , Sotalol/administração & dosagem , Espironolactona/administração & dosagem , Suspensões , Tacrolimo/administração & dosagem , Temperatura , Fatores de Tempo , Ácido Ursodesoxicólico/administração & dosagem , Vancomicina/administração & dosagem
14.
J Pharm Sci ; 107(4): 1055-1062, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29191760

RESUMO

A Modified Crisp Equation, describing the differential Gibbs free energy of the adsorption process, is being proposed, which considers multiple sites available on the surface for adsorption and their relative fractions. The differential Gibbs free energy can be calculated by the van't Hoff Equation, which depends on the affinity constant in the Langmuir-like equation. To consider the number of solvent molecules displaced by a solute molecule in the adsorption process, a new derivative of the Langmuir-like equation is being proposed as well. By comparing the differential Gibbs free energies obtained from the 2 thermodynamic relationships, it can be determined that a phenobarbital molecule displaces 5 water molecules on the activated carbon surface for site-specific adsorption from solution. For the series of experimental conditions studied, including 4 activated carbons, pH effects, temperature effects, and solvent effects, the corrected differential Gibbs free energies using n1 = 5 for site-specific adsorption are quite consistent between the 2 thermodynamic relationships. The difference between the estimates of the differential Gibbs free energies by the Modified Crisp Equation and the van't Hoff Equation provides a new experimental method to calculate the number of solvent molecules displaced by an adsorbing solute molecule.


Assuntos
Carbono/química , Fenobarbital/química , Soluções/química , Solventes/química , Adsorção/efeitos dos fármacos , Concentração de Íons de Hidrogênio , Temperatura , Termodinâmica
15.
Adv Healthc Mater ; 6(24)2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28975768

RESUMO

Clinically available hollow nerve guidance conduits (NGCs) have had limited success in treating large peripheral nerve injuries. This study aims to develop a biphasic NGC combining a physicochemically optimized collagen outer conduit to bridge the transected nerve, and a neuroconductive hyaluronic acid-based luminal filler to support regeneration. The outer conduit is mechanically optimized by manipulating crosslinking and collagen density, allowing the engineering of a high wall permeability to mitigate the risk of neuroma formation, while also maintaining physiologically relevant stiffness and enzymatic degradation tuned to coincide with regeneration rates. Freeze-drying is used to seamlessly integrate the luminal filler into the conduit, creating a longitudinally aligned pore microarchitecture. The luminal stiffness is modulated to support Schwann cells, with laminin incorporation further enhancing bioactivity by improving cell attachment and metabolic activity. Additionally, this biphasic NGC is shown to support neurogenesis and gliogenesis of neural progenitor cells and axonal outgrowth from dorsal root ganglia. These findings highlight the paradigm that a successful NGC requires the concerted optimization of both a mechanical support phase capable of bridging a nerve defect and a neuroconductive phase with an architecture capable of supporting both Schwann cells and neurons in order to achieve functional regenerative outcome.


Assuntos
Regeneração Nervosa , Nervos Periféricos/cirurgia , Próteses e Implantes , Animais , Materiais Biocompatíveis/química , Linhagem Celular , Colágeno/química , Gânglios Espinais/metabolismo , Laminina/metabolismo , Masculino , Neurogênese , Fenobarbital/química , Ratos , Ratos Endogâmicos Lew , Células de Schwann/metabolismo , Engenharia Tecidual
17.
Environ Toxicol Pharmacol ; 52: 214-220, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28445845

RESUMO

The aim of the study was to compare the adsorption ability of two adsorbent materials, namely diosmectite and activated charcoal towards selected model compounds that are most commonly involved in acute intoxication. Eleven model compounds were selected: acetylsalicylic acid, α-amanitin, amlodipine, digoxin, phenobarbital, ibuprofen, imipramine, carbamazepine, oxazepam, promethazine, and theophylline. Of the tested compounds, promethazine and imipramine were the most effectively adsorbed to diosmectite. Their adsorption to diosmectite (0.356±0.029mg promethazine/mg diosmectite and 0.354±0.019mg imipramine/mg diosmectite, respectively) was significantly higher than their adsorption to activated charcoal. The effect of temperature and pH on the adsorption efficiencies was also evaluated. In the case of experiments with mixture of both adsorbents, they mostly behaved in a solution independently or in a slightly antagonistic way. Using various methods such as N2 adsorption and thermogravimetric analysis, the structure and texture of diosmectite and activated charcoal were attained.


Assuntos
Antídotos/química , Carvão Vegetal/química , Intoxicação/prevenção & controle , Silicatos/química , Adsorção , Alfa-Amanitina/química , Anlodipino/química , Aspirina/química , Carbamazepina/química , Digoxina/química , Ibuprofeno/química , Imipramina/química , Oxazepam/química , Fenobarbital/química , Prometazina/química , Teofilina/química
18.
Int J Cancer ; 140(7): 1633-1644, 2017 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-28006839

RESUMO

The aim of our study was to examine the relationship between tumour IKKα expression and breast cancer recurrence and survival. Immunohistochemistry was employed in a discovery and a validation tissue microarray to assess the association of tumour IKKα expression and clinico-pathological characteristics. After siRNA-mediated silencing of IKKα, cell viability and apoptosis were assessed in MCF7 and MDA-MB-231 breast cancer cells. In both the discovery and validation cohorts, associations observed between IKKα and clinical outcome measures were potentiated in oestrogen receptor (ER) positive Luminal A tumours. In the discovery cohort, cytoplasmic IKKα was associated with disease-free survival (p = 0.029) and recurrence-free survival on tamoxifen (p < 0.001) in Luminal A tumours. Nuclear IKKα and a combination of cytoplasmic and nuclear IKKα (total tumour cell IKKα) were associated with cancer-specific survival (p = 0.012 and p = 0.007, respectively) and recurrence-free survival on tamoxifen (p = 0.013 and p < 0.001, respectively) in Luminal A tumours. In the validation cohort, cytoplasmic IKKα was associated with cancer-specific survival (p = 0.023), disease-free survival (p = 0.002) and recurrence-free survival on tamoxifen (p = 0.009) in Luminal A tumours. Parallel experiment with breast cancer cells in vitro demonstrated the non-canonical NF-κB pathway was inducible by exposure to lymphotoxin in ER-positive MCF7 cells and not in ER-negative MDA-MB-231 cells. Reduction in IKKα expression by siRNA transfection increased levels of apoptosis and reduced cell viability in MCF7 but not in MDA-MB-231 cells. IKKα is an important determinant of poor outcome in patients with ER-positive invasive ductal breast cancer and thus may represent a potential therapeutic target.


Assuntos
Neoplasias da Mama/metabolismo , Receptor alfa de Estrogênio/metabolismo , Regulação Neoplásica da Expressão Gênica , Quinase I-kappa B/metabolismo , Recidiva Local de Neoplasia/metabolismo , Idoso , Linhagem Celular Tumoral , Núcleo Celular/metabolismo , Sobrevivência Celular , Citoplasma/metabolismo , Intervalo Livre de Doença , Feminino , Perfilação da Expressão Gênica , Inativação Gênica , Humanos , Imuno-Histoquímica , Ligantes , Células MCF-7 , Pessoa de Meia-Idade , Fenobarbital/química , Prognóstico , RNA Interferente Pequeno/metabolismo , Estudos Retrospectivos , Tamoxifeno/química , Resultado do Tratamento
19.
Oncotarget ; 7(26): 40252-40265, 2016 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-27259233

RESUMO

The Rab GTPases regulate vesicular trafficking machinery that transports and delivers a diverse pool of cargo, including growth factor receptors, integrins, nutrient receptors and junction proteins to specific intracellular sites. The trafficking machinery is indeed a major posttranslational modifier and is critical for cellular homeostasis. Deregulation of this stringently controlled system leads to a wide spectrum of disorders including cancer. Herein we demonstrate that Rab25, a key GTPase, mostly decorating the apical recycling endosome, is a dichotomous variable in breast cancer cell lines with higher mRNA and protein expression in Estrogen Receptor positive (ER+ve) lines. Rab25 and its effector, Rab Coupling Protein (RCP) are frequently coamplified and coordinately elevated in ER+ve breast cancers. In contrast, Rab25 levels are decreased in basal-like and almost completely lost in claudin-low tumors. This dichotomy exists despite the presence of the 1q amplicon that hosts Rab25 across breast cancer subtypes and is likely due to differential methylation of the Rab25 promoter. Functionally, elevated levels of Rab25 drive major hallmarks of cancer including indefinite growth and metastasis but in case of luminal B breast cancer only. Importantly, in such ER+ve tumors, coexpression of Rab25 and its effector, RCP is significantly associated with a markedly worsened clinical outcome. Importantly, in claudin-low cell lines, exogenous Rab25 markedly inhibits cell migration. Similarly, during Snail-induced epithelial to mesenchymal transition (EMT) exogenous Rab25 potently reverses Snail-driven invasion. Overall, this study substantiates a striking context dependent role of Rab25 in breast cancer where Rab25 is amplified and enhances aggressiveness in luminal B cancers while in claudin-low tumors, Rab25 is lost indicating possible anti-tumor functions.


Assuntos
Neoplasias da Mama/metabolismo , Transição Epitelial-Mesenquimal , Fatores de Transcrição da Família Snail/metabolismo , Proteínas rab de Ligação ao GTP/metabolismo , Animais , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Claudina-1/metabolismo , Feminino , Perfilação da Expressão Gênica , Humanos , Células MCF-7 , Camundongos , Oncogenes , Fenobarbital/química , Regiões Promotoras Genéticas , Cicatrização , Proteínas rab de Ligação ao GTP/genética
20.
Anticancer Agents Med Chem ; 16(11): 1445-1454, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27087163

RESUMO

PURPOSE: Phenobarbital is a commonly employed antidepressant and anti-epileptic drug. The cancer promoting activity of this genotoxic xenobiotic is often ignored. It is responsible for oxidative stress leading to modulation in xenobiotic and antioxidative enzymes. Glucosinolates and more specifically their hydrolytic products are known for their antioxidative and anticancer activities. The present study involves the analysis of hepatoprotective effect of erucin (isolated from Eruca sativa (Mill.) Thell.) against phenobarbital mediated hepatic damage in male wistar rats. METHODS: The liver homogenate was analyzed for oxidative stress (superoxide dismutase, catalase, guaiacol peroxidase, ascorbate peroxidase, glutathione reductase and lactate dehydrogenase), other oxidative parameters (thiobarbituric acid reactive species, conjugated dienes and lipid hydroperoxide), phase I enzymes (NADPH-cytochrome P450 reductase, NADH-cytochrome b5 reductase, cytochrome P420, cytochrome P450 and cytochrome b5), phase II enzymes (γ-glutamyl transpeptidase, DT-diaphorase and glutathione-S-transferase), serum parameters (alkaline phosphatase, serum glutamic oxaloacetic transaminase, serum glutamic pyruvic transaminase, direct bilirubin and total bilirubin) and certain histological parameters. RESULTS: Erucin accorded protection from phenobarbital induced hepatic damage by normalizing antioxidative enzymes, other oxidative parameters, phase I, II, and serum parameters. CONCLUSIONS: Erucin, an analogue of sulforaphane has the potential to act as an anticancer agent by regulating various biochemical parameters.


Assuntos
Antioxidantes/farmacologia , Fígado/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Fenobarbital/farmacologia , Sulfetos/farmacologia , Tiocianatos/farmacologia , Animais , Antioxidantes/química , Antioxidantes/isolamento & purificação , Brassicaceae/química , Humanos , Fígado/metabolismo , Fígado/patologia , Masculino , Estrutura Molecular , Fenobarbital/química , Ratos , Ratos Wistar , Sulfetos/química , Sulfetos/isolamento & purificação , Tiocianatos/química , Tiocianatos/isolamento & purificação
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