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1.
Nature ; 616(7958): 686-690, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-37100940

RESUMO

The nearby radio galaxy M87 is a prime target for studying black hole accretion and jet formation1,2. Event Horizon Telescope observations of M87 in 2017, at a wavelength of 1.3 mm, revealed a ring-like structure, which was interpreted as gravitationally lensed emission around a central black hole3. Here we report images of M87 obtained in 2018, at a wavelength of 3.5 mm, showing that the compact radio core is spatially resolved. High-resolution imaging shows a ring-like structure of [Formula: see text] Schwarzschild radii in diameter, approximately 50% larger than that seen at 1.3 mm. The outer edge at 3.5 mm is also larger than that at 1.3 mm. This larger and thicker ring indicates a substantial contribution from the accretion flow with absorption effects, in addition to the gravitationally lensed ring-like emission. The images show that the edge-brightened jet connects to the accretion flow of the black hole. Close to the black hole, the emission profile of the jet-launching region is wider than the expected profile of a black-hole-driven jet, suggesting the possible presence of a wind associated with the accretion flow.

2.
Molecules ; 29(8)2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38675653

RESUMO

Leishmaniasis, an infectious disease caused by pathogenic Leishmania parasites, affects millions of people in developing countries, and its re-emergence in developed countries, particularly in Europe, poses a growing public health concern. The limitations of current treatments and the absence of effective vaccines necessitate the development of novel therapeutics. In this study, we focused on identifying small molecule inhibitors which prevents the interaction between peroxin 5 (PEX5) and peroxisomal targeting signal 1 (PTS1), pivotal for kinetoplastid parasite survival. The Leishmania donovani PEX5, containing a C-terminal tetratricopeptide repeat (TPR) domain, was expressed and purified, followed by the quantification of kinetic parameters of PEX5-PTS1 interactions. A fluorescence polarization-based high-throughput screening assay was developed and small molecules inhibiting the LdPEX5-PTS1 interaction were discovered through the screening of a library of 51,406 compounds. Based on the confirmatory assay, nine compounds showed half maximal inhibitory concentration (IC50) values ranging from 3.89 to 24.50 µM. In silico docking using a homology model of LdPEX5 elucidated that the molecular interactions between LdPEX5 and the inhibitors share amino acids critical for PTS1 binding. Notably, compound P20 showed potent activity against the growth of L. donovani promastigotes, L. major promastigotes, and Trypanosoma brucei blood stream form, with IC50 values of 12.16, 19.21, and 3.06 µM, respectively. The findings underscore the potential of targeting LdPEX5-PTS1 interactions with small molecule inhibitors as a promising strategy for the discovery of new anti-parasitic compounds.


Assuntos
Ensaios de Triagem em Larga Escala , Leishmania donovani , Simulação de Acoplamento Molecular , Receptor 1 de Sinal de Orientação para Peroxissomos , Proteínas de Protozoários , Leishmania donovani/efeitos dos fármacos , Leishmania donovani/metabolismo , Ensaios de Triagem em Larga Escala/métodos , Receptor 1 de Sinal de Orientação para Peroxissomos/metabolismo , Receptor 1 de Sinal de Orientação para Peroxissomos/química , Proteínas de Protozoários/antagonistas & inibidores , Proteínas de Protozoários/metabolismo , Proteínas de Protozoários/química , Polarização de Fluorescência/métodos , Ligação Proteica , Bibliotecas de Moléculas Pequenas/farmacologia , Bibliotecas de Moléculas Pequenas/química , Antiprotozoários/farmacologia , Antiprotozoários/química , Humanos
3.
J Econom ; 232(1): 70-86, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33519026

RESUMO

We estimate a panel model with endogenously time-varying parameters for COVID-19 cases and deaths in U.S. states. The functional form for infections incorporates important features of epidemiological models but is flexibly parameterized to capture different trajectories of the pandemic. Daily deaths are modeled as a spike-and-slab regression on lagged cases. Our Bayesian estimation reveals that social distancing and testing have significant effects on the parameters. For example, a 10 percentage point increase in the positive test rate is associated with a 2 percentage point increase in the death rate among reported cases. The model forecasts perform well, even relative to models from epidemiology and statistics.

4.
Molecules ; 28(23)2023 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-38067553

RESUMO

Seahorse is a valuable marine-animal drug widely used in traditional Chinese medicine (TCM), and which was first documented in the "Ben Cao Jing Ji Zhu" during the Liang Dynasty. Hippocampus kelloggi (HK) is the most common seahorse species in the medicinal material market and is one of the genuine sources of medicinal seahorse documented in the Chinese pharmacopeia. It is mainly cultivated in the Shandong, Fujian, and Guangxi Provinces in China. However, pseudo-HK, represented by Hippocampus ingens (HI) due to its similar appearance and traits, is often found in the market, compromising the safety and efficacy of clinical use. Currently, there is a lack of reliable methods for identifying these species based on their chemical composition. In this study, we employed, for the first time, a strategy combining gas chromatography-mass spectrometry (GC-MS) fingerprints and chemical patterns in order to identify HK and HI; it is also the first metabolomic study to date of HI as to chemical components. The obtained results revealed remarkable similarities in the chemical fingerprints, while significant differences were also observed. By employing hierarchical cluster analysis (HCA) and principal component analysis (PCA), based on the relative contents of their characteristic peaks, all 34 samples were successfully differentiated according to their species of origin, with samples from the same species forming distinct clusters. Moreover, nonadecanoic acid and behenic acid were exclusively detected in HK samples, further distinguishing them from HI samples. Additionally, the relative contents of lauric acid, tetradecanoic acid, pentadecanoic acid, n-hexadecanoic acid, palmitoleic acid, margaric acid, oleic acid, fenozan acid, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) exhibited significant differences between HK and HI (p < 0.0001), as determined by an unpaired t-test. Orthogonal partial least squares discriminant analysis (OPLS-DA) identified seven components (DHA, EPA, n-hexadecanoic acid, tetradecanoic acid, palmitoleic acid, octadecanoic acid, and margaric acid) with high discriminatory value (VIP value > 1). Thus, nonadecanoic acid, behenic acid, and these seven compounds can be utilized as chemical markers for distinguishing HK from HI. In conclusion, our study successfully developed a combined strategy of GC-MS fingerprinting and chemical pattern recognition for the identification of HK and HI, and we also discovered chemical markers that can directly differentiate between the two species. This study can provide a foundation for the authentication of Hippocampus and holds significant importance for the conservation of wild seahorse resources.


Assuntos
Smegmamorpha , Animais , Cromatografia Gasosa-Espectrometria de Massas , Ácido Mirístico , China , Análise por Conglomerados , Cromatografia Líquida de Alta Pressão/métodos , Análise de Componente Principal
5.
Int J Mol Sci ; 23(13)2022 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-35806086

RESUMO

The immediate and delayed metabolic changes in rats treated with valproate (VPA), a drug used for the treatment of epilepsy, were profiled. An established approach using dried blood spots (DBS) as sample matrices for gas chromatography/mass spectrometry-based metabolomics profiling was modified using double solvents in the extraction of analytes. With the modified method, some of the previously undetectable metabolites were recovered and subtle differences in the metabolic changes upon exposure to a single dose of VPA between males and female rats were identified. In male rats, changes in 2-hydroxybutyric acid, pipecolic acid, tetratriacontane and stearic acid were found between the control and treatment groups at various time points from 2.5 h up to 24 h. In contrast, such differences were not observed in female rats, which could be caused by the vast inter-individual variations in metabolite levels within the female group. Based on the measured DBS drug concentrations, clearance and apparent volume of distribution of VPA were estimated and the values were found to be comparable to those estimated previously from full blood drug concentrations. The current study indicated that DBS is a powerful tool to monitor drug levels and metabolic changes in response to drug treatment.


Assuntos
Epilepsia , Ácido Valproico , Animais , Teste em Amostras de Sangue Seco/métodos , Epilepsia/tratamento farmacológico , Feminino , Cromatografia Gasosa-Espectrometria de Massas/métodos , Masculino , Metabolômica , Ratos
6.
Int J Mol Sci ; 22(4)2021 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-33670029

RESUMO

Hair follicle morphogenesis is heavily dependent on reciprocal, sequential, and epithelial-mesenchymal interaction (EMI) between epidermal stem cells and the specialized cells of the underlying mesenchyme, which aggregate to form the dermal condensate (DC) and will later become the dermal papilla (DP). Similar models were developed with a co-culture of keratinocytes and DP cells. Previous studies have demonstrated that co-culture with keratinocytes maintains the in vivo characteristics of the DP. However, it is often challenging to develop three-dimensional (3D) DP and keratinocyte co-culture models for long term in vitro studies, due to the poor intercellular adherence between keratinocytes. Keratinocytes exhibit exfoliative behavior, and the integrity of the DP and keratinocyte co-cultured spheroids cannot be maintained over prolonged culture. Short durations of culture are unable to sufficiently allow the differentiation and re-programming of the keratinocytes into hair follicular fate by the DP. In this study, we explored a microgel array approach fabricated with two different hydrogel systems. Using poly (ethylene glycol) diacrylate (PEGDA) and gelatin methacrylate (GelMA), we compare their effects on maintaining the integrity of the cultures and their expression of important genes responsible for hair follicle morphogenesis, namely Wnt10A, Wnt10B, and Shh, over prolonged duration. We discovered that low attachment surfaces such as PEGDA result in the exfoliation of keratinocytes and were not suitable for long-term culture. GelMA, on the hand, was able to sustain the integrity of co-cultures and showed higher expression of the morphogens overtime.


Assuntos
Derme/citologia , Queratinócitos/citologia , Microgéis/química , Polietilenoglicóis/farmacologia , Adesão Celular/efeitos dos fármacos , Agregação Celular/efeitos dos fármacos , Linhagem Celular , Técnicas de Cocultura , Proteínas de Fluorescência Verde/metabolismo , Células HaCaT/citologia , Células HaCaT/efeitos dos fármacos , Humanos , Hidrogéis/farmacologia , Proteínas Luminescentes/metabolismo , Esferoides Celulares/citologia , Esferoides Celulares/efeitos dos fármacos , Proteínas Wnt/metabolismo , Proteína Vermelha Fluorescente
7.
Mol Pharm ; 17(11): 4256-4269, 2020 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-33084343

RESUMO

Curcumin (CUR) has antioxidant and anti-inflammatory effects that are beneficial to Alzheimer's disease (AD). However, the poor solubility and high instability of CUR compromise its application greatly. In this study, CUR-encapsulated chitosan-coated poly (lactic-co-glycolic acid) nanoparticles (CUR-CS-PLGA-NPs) and hydroxypropyl-ß-cyclodextrin-encapsulated CUR complexes (CUR/HP-ß-CD inclusion complexes) were developed and compared through intranasal administration. In vitro studies indicated that CUR in CUR/HP-ß-CD inclusion complexes was stable under physiological conditions over 72 h with 95.41 ± 0.01% remaining, which was higher than 49.66 ± 3.91% remaining in CUR-CS-PLGA-NPs. Meanwhile, CUR/HP-ß-CD inclusion complexes showed a higher cellular uptake level of CUR than CUR-CS-PLGA-NPs in SH-SY5Y cells. Both formulations could reduce CUR's cellular cytotoxicity and showed a comparable antioxidant effect. Both formulations displayed the anti-inflammatory effect at 20 µM CUR in BV-2 cells, which decreased TNF-α and IL-6 levels to approximately 70 and 40%, respectively, when compared to the positive control, respectively. In vivo pharmacokinetic studies indicated that after intranasal administration, the AUC values of CUR in the plasma and brain of the CUR/HP-ß-CD inclusion complex group were 2.57-fold and 1.12-fold higher than those in the CUR-CS-PLGA-NP group at the same dose of 2 mg/kg, respectively. In conclusion, CUR/HP-ß-CD inclusion complexes displayed better properties than CUR-CS-PLGA-NPs as a carrier for intranasal delivery of CUR for application in AD.


Assuntos
2-Hidroxipropil-beta-Ciclodextrina/química , Doença de Alzheimer/tratamento farmacológico , Anti-Inflamatórios/administração & dosagem , Antioxidantes/administração & dosagem , Quitosana/química , Curcumina/administração & dosagem , Portadores de Fármacos/química , Nanopartículas/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Administração Intranasal , Animais , Anti-Inflamatórios/farmacocinética , Antioxidantes/farmacocinética , Linhagem Celular Tumoral , Curcumina/farmacocinética , Composição de Medicamentos/métodos , Estabilidade de Medicamentos , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Solubilidade
8.
J Hepatol ; 71(2): 289-300, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31077792

RESUMO

BACKGROUND & AIMS: As hepatitis B virus (HBV) spreads through the infected liver it is simultaneously secreted into the blood. HBV-susceptible in vitro infection models do not efficiently amplify viral progeny or support cell-to-cell spread. We sought to establish a cell culture system for the amplification of infectious HBV from clinical specimens. METHODS: An HBV-susceptible sodium-taurocholate cotransporting polypeptide-overexpressing HepG2 cell clone (HepG2-NTCPsec+) producing high titers of infectious progeny was selected. Secreted HBV progeny were characterized by native gel electrophoresis and electron microscopy. Comparative RNA-seq transcriptomics was performed to quantify the expression of host proviral and restriction factors. Viral spread routes were evaluated using HBV entry- or replication inhibitors, visualization of viral cell-to-cell spread in reporter cells, and nearest neighbor infection determination. Amplification kinetics of HBV genotypes B-D were analyzed. RESULTS: Infected HepG2-NTCPsec+ secreted high levels of large HBV surface protein-enveloped infectious HBV progeny with typical appearance under electron microscopy. RNA-seq transcriptomics revealed that HBV does not induce significant gene expression changes in HepG2-NTCPsec+, however, transcription factors favoring HBV amplification were more strongly expressed than in less permissive HepG2-NTCPsec-. Upon inoculation with HBV-containing patient sera, rates of infected cells increased from 10% initially to 70% by viral spread to adjacent cells, and viral progeny and antigens were efficiently secreted. HepG2-NTCPsec+ supported up to 1,300-fold net amplification of HBV genomes depending on the source of virus. Viral spread and amplification were abolished by entry and replication inhibitors; viral rebound was observed after inhibitor discontinuation. CONCLUSIONS: The novel HepG2-NTCPsec+ cells efficiently support the complete HBV life cycle, long-term viral spread and amplification of HBV derived from patients or cell culture, resembling relevant features of HBV-infected patients. LAY SUMMARY: Currently available laboratory systems are unable to reproduce the dynamics of hepatitis B virus (HBV) spread through the infected liver and release into the blood. We developed a slowly dividing liver-derived cell line which multiplies infectious viral particles upon inoculation with patient- or cell culture-derived HBV. This new infection model can improve therapy by measuring, in advance, the sensitivity of a patient's HBV strain to specific antiviral drugs.


Assuntos
Proliferação de Células , Vírus da Hepatite B/genética , Hepatite B/metabolismo , Hepatócitos/virologia , Transportadores de Ânions Orgânicos Dependentes de Sódio/metabolismo , Simportadores/metabolismo , Replicação Viral/efeitos dos fármacos , Antivirais/farmacologia , Técnicas de Cultura de Células/métodos , DNA Viral/metabolismo , Regulação Viral da Expressão Gênica , Genótipo , Células Hep G2 , Hepatite B/virologia , Vírus da Hepatite B/efeitos dos fármacos , Hepatócitos/metabolismo , Humanos , RNA-Seq , Receptores Virais/metabolismo , Transcriptoma , Internalização do Vírus/efeitos dos fármacos
9.
Artigo em Inglês | MEDLINE | ID: mdl-29358290

RESUMO

Bacterial sepsis is a major cause of morbidity and mortality in neonates, especially those involving methicillin-resistant Staphylococcus aureus (MRSA). Guidelines by the Infectious Diseases Society of America recommend the vancomycin 24-h area under the concentration-time curve to MIC ratio (AUC24/MIC) of >400 as the best predictor of successful treatment against MRSA infections when the MIC is ≤1 mg/liter. The relationship between steady-state vancomycin trough concentrations and AUC24 values (mg·h/liter) has not been studied in an Asian neonatal population. We conducted a retrospective chart review in Singapore hospitals and collected patient characteristics and therapeutic drug monitoring data from neonates on vancomycin therapy over a 5-year period. A one-compartment population pharmacokinetic model was built from the collected data, internally validated, and then used to assess the relationship between steady-state trough concentrations and AUC24 A Monte Carlo simulation sensitivity analysis was also conducted. A total of 76 neonates with 429 vancomycin concentrations were included for analysis. Median (interquartile range) was 30 weeks (28 to 36 weeks) for postmenstrual age (PMA) and 1,043 g (811 to 1,919 g) for weight at the initiation of treatment. Vancomycin clearance was predicted by weight, PMA, and serum creatinine. For MRSA isolates with a vancomycin MIC of ≤1, our major finding was that the minimum steady-state trough concentration range predictive of achieving an AUC24/MIC of >400 was 8 to 8.9 mg/liter. Steady-state troughs within 15 to 20 mg/liter are unlikely to be necessary to achieve an AUC24/MIC of >400, whereas troughs within 10 to 14.9 mg/liter may be more appropriate.


Assuntos
Antibacterianos/farmacologia , Vancomicina/farmacologia , Feminino , Humanos , Recém-Nascido , Masculino , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Método de Monte Carlo , Estudos Retrospectivos , Sepse/microbiologia , Sepse/prevenção & controle
10.
Environ Sci Technol ; 52(23): 13747-13755, 2018 12 04.
Artigo em Inglês | MEDLINE | ID: mdl-30394724

RESUMO

Bench-scale experiments were performed on natural sediments to assess abiotic dechlorination of trichloroethene (TCE) under both aerobic and anaerobic conditions. In the absence of oxygen (<26 µM), TCE dechlorination proceeded via a reductive pathway generating acetylene and/or ethene. Reductive dechlorination rate constants up to 3.1 × 10-5 d-1 were measured, after scaling to in situ solid:water ratios. In the presence of oxygen greater than 120 µM, TCE dechlorination proceeded via an oxidative pathway generating formic/glyoxylic and glycolic/acetic acids, and oxidative dechlorination rate constants (again scaled to in situ conditions) up to 7.4 × 10-3 d-1 were measured. These rates correspond to half-lives of 60 and 0.25 years for abiotic TCE dechlorination under anaerobic and aerobic conditions, respectively, indicating the potentially large impact of aerobic TCE oxidation in the field. For both reductive and oxidative TCE dechlorination pathways, measured first-order rate constants increased with increasing ferrous iron content, suggesting the role of iron oxidation. Hydroxyl radical formation was measured and increased with increasing oxygen and ferrous iron content. Rate constants associated with TCE oxidation products increased with increasing hydroxyl radical generation rates, and were zero in the presence of a hydroxyl radical scavenger, suggesting that oxidative TCE dechlorination is a hydroxyl radical driven process.


Assuntos
Tricloroetileno , Halogenação , Ferro , Minerais , Oxirredução
11.
Nature ; 530(7589): 169-70, 2016 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-26863979

Assuntos
Planetas
12.
J Proteome Res ; 14(2): 587-602, 2015 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-25388527

RESUMO

Early diagnosis and life-long surveillance are clinically important to improve the long-term survival of bladder cancer patients. Currently, a noninvasive biomarker that is as sensitive and specific as cystoscopy in detecting bladder tumors is lacking. Metabonomics is a complementary approach for identifying perturbed metabolic pathways in bladder cancer. Significant progress has been made using modern metabonomic techniques to characterize and distinguish bladder cancer patients from control subjects, identify marker metabolites, and shed insights on the disease biology and potential therapeutic targets. With its rapid development, metabonomics has the potential to impact the clinical management of bladder cancer patients in the future by revolutionizing the diagnosis and life-long surveillance strategies and stratifying patients for diagnostic, surgical, and therapeutic clinical trials. An introduction to metabonomics, typical metabonomic workflow, and critical evaluation of metabonomic investigations in identifying biomarkers for the diagnosis of bladder cancer are presented.


Assuntos
Metabolômica , Neoplasias da Bexiga Urinária/metabolismo , Humanos , Neoplasias da Bexiga Urinária/patologia
13.
Antimicrob Agents Chemother ; 59(2): 1200-10, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25487807

RESUMO

Limited information is available on the pharmacokinetic (PK) and pharmacodynamic (PD) parameters driving the efficacy of antimalarial drugs. Our objective in this study was to determine dose-response relationships of a panel of related spiroindolone analogs and identify the PK-PD index that correlates best with the efficacy of KAE609, a selected class representative. The dose-response efficacy studies were conducted in the Plasmodium berghei murine malaria model, and the relationship between dose and efficacy (i.e., reduction in parasitemia) was examined. All spiroindolone analogs studied displayed a maximum reduction in parasitemia, with 90% effective dose (ED90) values ranging between 6 and 38 mg/kg of body weight. Further, dose fractionation studies were conducted for KAE609, and the relationship between PK-PD indices and efficacy was analyzed. The PK-PD indices were calculated using the in vitro potency against P. berghei (2× the 99% inhibitory concentration [IC99]) as a threshold (TRE). The percentage of the time in which KAE609 plasma concentrations remained at >2× the IC99 within 48 h (%T>TRE) and the area under the concentration-time curve from 0 to 48 h (AUC0-48)/TRE ratio correlated well with parasite reduction (R2=0.97 and 0.95, respectively) but less so for the maximum concentration of drug in serum (Cmax)/TRE ratio (R2=0.88). The present results suggest that for KAE609 and, supposedly, for its analogs, the dosing regimens covering a T>TRE of 100%, AUC0-48/TRE ratio of 587, and a Cmax/TRE ratio of 30 are likely to result in the maximum reduction in parasitemia in the P. berghei malaria mouse model. This information could be used to prioritize analogs within the same class of compounds and contribute to the design of efficacy studies, thereby facilitating early drug discovery and lead optimization programs.


Assuntos
Antimaláricos/farmacocinética , Antimaláricos/uso terapêutico , Malária/tratamento farmacológico , Plasmodium berghei/efeitos dos fármacos , Plasmodium berghei/patogenicidade , Animais , Modelos Animais de Doenças , Feminino , Malária/sangue , Camundongos
14.
J Antimicrob Chemother ; 70(3): 857-67, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25587994

RESUMO

OBJECTIVES: The discovery and development of TB drugs has met limited success, with two new drugs approved over the last 40 years. Part of the difficulty resides in the lack of well-established in vitro or in vivo targets of potency and physicochemical and pharmacokinetic parameters. In an attempt to benchmark and compare such properties for anti-TB agents, we have experimentally determined and compiled these parameters for 36 anti-TB compounds, using standardized and centralized assays, thus ensuring direct comparability across drugs and drug classes. METHODS: Potency parameters included growth inhibition, cidal activity against growing and non-growing bacteria and activity against intracellular mycobacteria. Pharmacokinetic parameters included basic physicochemical properties, solubility, permeability and metabolic stability. We then attempted to establish correlations between physicochemical, in vitro and in vivo pharmacokinetic and pharmacodynamic indices to tentatively inform future drug discovery efforts. RESULTS: Two-thirds of the compounds tested showed bactericidal and intramacrophage activity. Most compounds exhibited favourable solubility, permeability and metabolic stability in standard in vitro pharmacokinetic assays. An analysis of human pharmacokinetic parameters revealed associations between lipophilicity and volume of distribution, clearance, plasma protein binding and oral bioavailability. Not surprisingly, most compounds with favourable pharmacokinetic properties complied with Lipinski's rule of five. CONCLUSIONS: However, most attempts to detect in vitro-in vivo correlations were unsuccessful, emphasizing the challenges of anti-TB drug discovery. The objective of this work is to provide a reference dataset for the TB drug discovery community with a focus on comparative in vitro potency and pharmacokinetics.


Assuntos
Antituberculosos/farmacologia , Antituberculosos/farmacocinética , Mycobacterium tuberculosis/efeitos dos fármacos , Animais , Antituberculosos/química , Linhagem Celular , Fenômenos Químicos , Estabilidade de Medicamentos , Macrófagos/microbiologia , Camundongos , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos dos fármacos , Permeabilidade , Solubilidade
15.
J Pers Assess ; 97(2): 200-8, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25101907

RESUMO

Feelings of pleasure felt in the moment of goal attainment (consummatory pleasure) are thought to be dissociable from feelings of desire connected with the motivated approach of goals (anticipatory pleasure). The Temporal Experience of Pleasure Scales (TEPS; Gard, Gard, Kring, & John, 2006) was developed to assess individual differences in these distinct processes. Recently, an independent evaluation of the psychometric characteristics of a Chinese-translated TEPS suggested a more complex factor structure (Chan et al., 2012). This study aimed to reexamine the factor structure and convergent and divergent validity of the TEPS in two previously unexamined multiethnic samples. University students in the United Kingdom (N = 294) completed the TEPS and university students in Australia (N = 295) completed the TEPS as well as a battery of conceptually related questionnaires. A confirmatory factor analysis of Gard et al.'s (2006) 2-factor model produced inadequate fit, which model-modification indexes suggested might be due to item cross-loadings. This issue was examined further using an exploratory factor analysis, which revealed a clear 2-factor solution despite cross-loadings among some items. Finally, mixed evidence for convergent-divergent validity was obtained, in terms of relationships between the TEPS and measures of anhedonia, approach-motivation, and positive emotion.


Assuntos
Emoções , Motivação , Prazer , Adolescente , Adulto , Austrália , Análise Fatorial , Feminino , Humanos , Masculino , Psicometria , Reprodutibilidade dos Testes , Estudantes , Inquéritos e Questionários , Reino Unido , Universidades , Adulto Jovem
16.
Int J Pharm ; 654: 123945, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38403088

RESUMO

This study aimed to develop an innovative dosage form for 10-hydroxycamptothecin (HCPT), a chemotherapeutic agent with limited aqueous solubility and stability, to enhance its parenteral delivery and targeting to hepatic cancer. We formulated HCPT into a nanoemulsion using tributyrin, a dietary component with histone deacetylase inhibitor activity. The resulting HCPT-loaded tributyrin nanoemulsion (Tri-HCPT-E) underwent extensive evaluations. Tri-HCPT-E significantly improved the aqueous solubility, stability, and anti-cancer activities in HepG2 cells. Pharmacokinetic studies confirmed the increased stability and hepatic targeting, with Tri-HCPT-E leading to a 120-fold increase in plasma exposure of intact HCPT and a 10-fold increase in hepatic exposure compared to the commercial free solution. Co-administration of 17α-ethynylestradiol, an up-regulator of low-density lipoprotein (LDL) receptor, further enhanced the distribution and metabolism of HCPT, demonstrating an association between the LDL receptor pathway and hepatic targeting. Most importantly, Tri-HCPT-E exhibited superior in vivo anti-cancer efficacy in a mouse xenograft model compared to the commercial formulation, without causing escalated hepatic or renal toxicity. In conclusion, formulating HCPT into a nanoemulsion with tributyrin has proven to be an innovative and effective strategy for targeted hepatic cancer chemotherapy while tributyrin, a pharmacologically active dietary component, has emerged as a promising functional excipient for drug delivery.


Assuntos
Antineoplásicos Fitogênicos , Camptotecina/análogos & derivados , Neoplasias Hepáticas , Triglicerídeos , Humanos , Camundongos , Animais , Excipientes , Linhagem Celular Tumoral , Neoplasias Hepáticas/tratamento farmacológico
17.
Sci Rep ; 14(1): 4932, 2024 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-38418847

RESUMO

One potential approach for treating obesity is to increase energy expenditure in brown and white adipose tissue. Here we aimed to achieve this outcome by targeting mitochondrial uncoupler compounds selectively to adipose tissue, thus avoiding side effects from uncoupling in other tissues. Selective drug accumulation in adipose tissue has been observed with many lipophilic compounds and dyes. Hence, we explored the feasibility of conjugating uncoupler compounds with a lipophilic C8-hydrocarbon chain via an ether bond. We found that substituting the trifluoromethoxy group in the uncoupler FCCP with a C8-hydrocarbon chain resulted in potent uncoupling activity. Nonetheless, the compound did not elicit therapeutic effects in mice, likely as a consequence of metabolic instability resulting from rapid ether bond cleavage. A lipophilic analog of the uncoupler compound 2,6-dinitrophenol, in which a C8-hydrocarbon chain was conjugated via an ether bond in the para-position (2,6-dinitro-4-(octyloxy)phenol), exhibited increased uncoupling activity compared to the parent compound. However, in vivo pharmacokinetics studies suggested that 2,6-dinitro-4-(octyloxy)phenol was also metabolically unstable. In conclusion, conjugation of a hydrophobic hydrocarbon chain to uncoupler compounds resulted in sustained or improved uncoupling activity. However, an ether bond linkage led to metabolic instability, indicating the need to conjugate lipophilic groups via other chemical bonds.


Assuntos
Tecido Adiposo Marrom , Tecido Adiposo , Camundongos , Animais , Tecido Adiposo Marrom/metabolismo , Tecido Adiposo/metabolismo , Obesidade/metabolismo , Metabolismo Energético , Tecido Adiposo Branco/metabolismo , Éteres , Fenóis/farmacologia , Proteína Desacopladora 1/metabolismo
18.
J Proteome Res ; 12(9): 3865-73, 2013 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-23885889

RESUMO

Cystoscopy is the gold standard clinical diagnosis of human bladder cancer (BC). As cystoscopy is expensive and invasive, it compromises patients' compliance toward surveillance screening and challenges the detection of recurrent BC. Therefore, the development of a noninvasive method for the diagnosis and surveillance of BC and the elucidation of BC progression become pertinent. In this study, urine samples from 38 BC patients and 61 non-BC controls were subjected to urinary metabotyping using two-dimensional gas chromatography time-of-flight mass spectrometry (GC×GC-TOFMS). Subsequent to data preprocessing and chemometric analysis, the orthogonal partial least-squares discriminant analysis (OPLS-DA, R2X=0.278, R2Y=0.904 and Q2Y (cumulative)=0.398) model was validated using permutation tests and receiver operating characteristic (ROC) analysis. Marker metabolites were further screened from the OPLS-DA model using statistical tests. GC×GC-TOFMS urinary metabotyping demonstrated 100% specificity and 71% sensitivity in detecting BC, while 100% specificity and 46% sensitivity were observed via cytology. In addition, the model revealed 46 metabolites that characterize human BC. Among the perturbed metabolic pathways, our clinical finding on the alteration of the tryptophan-quinolinic metabolic axis in BC suggested the potential roles of kynurenine in the malignancy and therapy of BC. In conclusion, global urinary metabotyping holds potential for the noninvasive diagnosis and surveillance of BC in clinics. In addition, perturbed metabolic pathways gleaned from urinary metabotyping shed new and established insights on the biology of human BC.


Assuntos
Biomarcadores Tumorais/urina , Cromatografia Gasosa-Espectrometria de Massas , Neoplasias da Bexiga Urinária/urina , Idoso , Estudos de Casos e Controles , Creatinina/urina , Feminino , Humanos , Masculino , Metabolômica , Pessoa de Meia-Idade , Triptofano/urina , Neoplasias da Bexiga Urinária/diagnóstico
19.
Epilepsia ; 54(6): 1020-7, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23448146

RESUMO

PURPOSE: To evaluate adherence to prescribed antiepileptic drugs (AEDs) in children with epilepsy using a combination of adherence-assessment methods. METHODS: A total of 100 children with epilepsy (≤17 years old) were recruited. Medication adherence was determined via parental and child self-reporting (≥9 years old), medication refill data from general practitioner (GP) prescribing records, and via AED concentrations in dried blood spot (DBS) samples obtained from children at the clinic and via self- or parental-led sampling in children's own homes. The latter were assessed using population pharmacokinetic modeling. Patients were deemed nonadherent if any of these measures were indicative of nonadherence with the prescribed treatment. In addition, beliefs about medicines, parental confidence in seizure management, and the presence of depressed mood in parents were evaluated to examine their association with nonadherence in the participating children. KEY FINDINGS: The overall rate of nonadherence in children with epilepsy was 33%. Logistic regression analysis indicated that children with generalized epilepsy (vs. focal epilepsy) were more likely (odds ratio [OR] 4.7, 95% confidence interval [CI] 1.37-15.81) to be classified as nonadherent as were children whose parents have depressed mood (OR 3.6, 95% CI 1.16-11.41). SIGNIFICANCE: This is the first study to apply the novel methodology of determining adherence via AED concentrations in clinic and home DBS samples. The present findings show that the latter, with further development, could be a useful approach to adherence assessment when combined with other measures including parent and child self-reporting. Seizure type and parental depressed mood were strongly predictive of nonadherence.


Assuntos
Anticonvulsivantes/uso terapêutico , Epilepsia/tratamento farmacológico , Adesão à Medicação , Adolescente , Anticonvulsivantes/sangue , Criança , Pré-Escolar , Depressão/psicologia , Epilepsia/psicologia , Epilepsia Generalizada/tratamento farmacológico , Epilepsia Generalizada/psicologia , Feminino , Humanos , Lactente , Modelos Logísticos , Masculino , Adesão à Medicação/estatística & dados numéricos , Pais , Escalas de Graduação Psiquiátrica , Testes Psicológicos , Autorrelato
20.
Analyst ; 138(10): 2883-9, 2013 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-23529371

RESUMO

A fully automated and computationally efficient Pearson's correlation change classification (APC3) approach is proposed and shown to have overall comparable performance with both an average accuracy and an average AUC of 0.89 ± 0.08 but is 3.9 to 7 times faster, easier to use and have low outlier susceptibility in contrast to other dimensional reduction and classification combinations using only the total ion chromatogram (TIC) intensities of GC/MS data. The use of only the TIC permits the possible application of APC3 to other metabonomic data such as LC/MS TICs or NMR spectra. A RapidMiner implementation is available for download at http://padel.nus.edu.sg/software/padelapc3.


Assuntos
Automação , Simulação por Computador , Algoritmos , Cromatografia Gasosa-Espectrometria de Massas
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