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1.
J Hand Surg Eur Vol ; : 17531934241246479, 2024 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-38641940

RESUMO

We investigated whether ChatGPT was able to increase the Flesch reading ease and the Flesch-Kincaid reading level of elective clinic letters written by hand surgeons. ChatGPT could not reliably simplify the hand clinic letters any further.

2.
J Anat ; 236(6): 1154-1159, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32064616

RESUMO

Spiracles are a general character of gnathostomes (jawed fishes), being present in antiarch placoderms, commonly regarded as the most basal gnathostome group. The presence of spiracular tubes in acanthodians has been deduced from grooves on the neurocranium of the derived acanthodiform Acanthodes bronni from the Permian of Germany, but until now these tubes were presumed to lack an external opening, rendering them non-functional. Here we describe the external spiracular elements in specimens of the Middle Devonian acanthodiforms Cheiracanthus murchisoni, Cheiracanthus latus and Mesacanthus pusillus from northern Scotland, and the internal structure of these elements in C. murchisoni, demonstrating that the spiracle in acanthodiforms differed from all known extant and extinct fishes in having paired cartilage-pseudobranch structures. This arrangement represents a transitional state between the presumed basal gnathostome condition with an unconstricted first gill slit (as yet not identified in any fossil) and the derived condition with a spiracle and a single pseudobranch derived from the posterior hemibranch of the mandibular arch. We identify the main tissue forming the pseudobranch as elastic cartilage, a tissue previously unrecorded in fossils.


Assuntos
Evolução Biológica , Cartilagem Elástica/anatomia & histologia , Peixes/anatomia & histologia , Arcada Osseodentária/anatomia & histologia , Crânio/anatomia & histologia , Animais , Fósseis , Filogenia
3.
Sci Technol Adv Mater ; 19(1): 194-202, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29511397

RESUMO

Solution-processed organic small molecule solar cells (SMSCs) have achieved efficiency over 11%. However, very few studies have focused on their stability under illumination and the origin of the degradation during the so-called burn-in period. Here, we studied the burn-in period of a solution-processed SMSC using benzodithiophene terthiophene rhodamine:[6,6]-phenyl C71 butyric acid methyl ester (BTR:PC71BM) with increasing solvent vapour annealing time applied to the active layer, controlling the crystallisation of the BTR phase. We find that the burn-in behaviour is strongly correlated to the crystallinity of BTR. To look at the possible degradation mechanisms, we studied the fresh and photo-aged blend films with grazing incidence X-ray diffraction, UV-vis absorbance, Raman spectroscopy and photoluminescence (PL) spectroscopy. Although the crystallinity of BTR affects the performance drop during the burn-in period, the degradation is found not to originate from the crystallinity changes of the BTR phase, but correlates with changes in molecular conformation - rotation of the thiophene side chains, as resolved by Raman spectroscopy which could be correlated to slight photobleaching and changes in PL spectra.

4.
Cancer Chemother Pharmacol ; 69(4): 901-9, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22080169

RESUMO

PURPOSE: Chidamide (CS055/HBI-8000) is a new histone deacetylase (HDAC) inhibitor of the benzamide class currently under clinical development in cancer indications. This study reports the in vitro and in vivo antitumor characteristics of the compound. METHODS: Selectivity and potency of chidamide in inhibition of HDAC isotypes were analyzed by using a panel of human recombinant HDAC proteins. Tumor cell lines either in culture or inoculated in nude mice were used for the evaluation of the compound's antitumor activity. To investigate the immune cell-mediated antitumor effect, isolated peripheral blood mononuclear cells from healthy donors were treated with chidamide, and cytotoxicity and expression of relevant surface proteins were analyzed. Microarray gene expression studies were performed on peripheral white blood cells from two T-cell lymphoma patients treated with chidamide. RESULTS: Chidamide was found to be a low nanomolar inhibitor of HDAC1, 2, 3, and 10, the HDAC isotypes well documented to be associated with the malignant phenotype. Significant and broad spectrum in vitro and in vivo antitumor activity, including a wide therapeutic index, was observed. Chidamide was also shown to enhance the cytotoxic effect of human peripheral mononuclear cells ex vivo on K562 target cells, accompanied by the upregulation of proteins involved in NK cell functions. Furthermore, the expression of a number of genes involved in immune cell-mediated antitumor activity was observed to be upregulated in peripheral white blood cells from two T-cell lymphoma patients who responded to chidamide administration. CONCLUSIONS: The results presented in this study provide evidence that chidamide has potential applicability for the treatment of a variety of tumor types, either as a single agent or in combination therapies.


Assuntos
Aminopiridinas/farmacologia , Benzamidas/farmacologia , Inibidores de Histona Desacetilases/farmacologia , Neoplasias/tratamento farmacológico , Acetilação/efeitos dos fármacos , Animais , Processos de Crescimento Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Citotoxicidade Imunológica/efeitos dos fármacos , Feminino , Expressão Gênica/efeitos dos fármacos , Histona Desacetilases/metabolismo , Histonas/metabolismo , Humanos , Imunidade Celular/efeitos dos fármacos , Isoenzimas , Células K562 , Células Matadoras Naturais/efeitos dos fármacos , Células Matadoras Naturais/imunologia , Linfoma de Células T/tratamento farmacológico , Linfoma de Células T/enzimologia , Linfoma de Células T/imunologia , Linfoma de Células T/patologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Neoplasias/enzimologia , Neoplasias/imunologia , Neoplasias/patologia , Ensaios Antitumorais Modelo de Xenoenxerto
5.
Bioorg Med Chem Lett ; 16(19): 5194-8, 2006 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-16870428

RESUMO

In the present work, we explore the possibility of introducing selectivity to existing chemotherapeutics via the design of non-pro-drug, bi-functional molecules comprising a microtubule-binding agent and a substrate for a disease-associated kinase. The design, synthesis, and in vitro biological evaluation of paclitaxel-thymidine and vinblastine-thymidine bi-functional conjugates are reported here. This work provides the first account of 'kinase-mediated trapping' of cancer therapeutics.


Assuntos
Antineoplásicos/síntese química , Sistemas de Liberação de Medicamentos/métodos , Proteínas de Neoplasias/metabolismo , Neoplasias/patologia , Paclitaxel/administração & dosagem , Proteínas Quinases/metabolismo , Timidina/administração & dosagem , Vimblastina/administração & dosagem , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Desenho de Fármacos , Humanos , Microtúbulos/metabolismo , Neoplasias/tratamento farmacológico , Relação Estrutura-Atividade , Especificidade por Substrato
6.
Invest New Drugs ; 23(4): 311-5, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16012790

RESUMO

BACKGROUND: ONT-093 is an orally bioavailable inhibitor of P-glycoprotein (P-gp). In pre-clinical studies, ONT-093 could inhibit P-gp and reverse multidrug resistance at nM concentrations with no effect on paclitaxel pharmacokinetics. Phase I trials of ONT-093 in normal human volunteers showed no dose-limiting toxicities at serum concentrations associated with biologic activity achieved with doses ranging from 300 to 500 mg. METHODS: Phase I pharmacokinetic trial of ONT-093 in doses from 300 to 500 mg administered before and after intravenous paclitaxel doses of 150 to 175 mg/m(2) repeated every 21 days. All patients received paclitaxel alone on cycle 1. RESULTS: 18 patients were enrolled onto 4 dose levels. Toxicity of the combination included neutropenia, arthralgia, myalgia, and peripheral neuropathy. Four of 6 patients receiving 500 mg doses of ONT-093 and paclitaxel at 175 mg/m(2) (dose level 4) had higher-grade neutropenia with cycle 2, with 1 patient experiencing febrile neutropenia. Plasma pharmacokinetic parameters of paclitaxel were unchanged between cycle 1 and 2 for dose levels 1 to 3, but at dose level 4, 45-65% increases in paclitaxel AUC were observed in 4 of the 6 patients. Mean C(max) of ONT-093 was 9 microM (range 5-15 microM) which were 3- to 5-fold higher than in single agent studies of ONT-093. CONCLUSIONS: Doses of ONT-093 achieving serum concentrations associated with biological activity were well tolerated in combination with standard doses of paclitaxel. Toxicities of the combination in this schedule were mainly attributable to paclitaxel and dose-limiting toxicity was limited to febrile neutropenia. There was an apparent pharmacokinetic interaction between paclitaxel and ONT-093, possibly related in part to the excipient, Cremophor, present in the paclitaxel formulation.


Assuntos
Antineoplásicos Fitogênicos/farmacocinética , Antineoplásicos/farmacocinética , Imidazóis/farmacocinética , Neoplasias/tratamento farmacológico , Paclitaxel/farmacocinética , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/antagonistas & inibidores , Adulto , Idoso , Alopecia/induzido quimicamente , Antineoplásicos/administração & dosagem , Antineoplásicos/efeitos adversos , Antineoplásicos Fitogênicos/administração & dosagem , Antineoplásicos Fitogênicos/efeitos adversos , Artralgia/induzido quimicamente , Relação Dose-Resposta a Droga , Quimioterapia Combinada , Feminino , Humanos , Imidazóis/administração & dosagem , Masculino , Pessoa de Meia-Idade , Neutropenia/induzido quimicamente , Paclitaxel/administração & dosagem , Polietilenoglicóis/administração & dosagem , Polietilenoglicóis/efeitos adversos
7.
J Biol Chem ; 279(23): 24226-35, 2004 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-15024017

RESUMO

Protein-tyrosine phosphatases (PTPs) are considered important therapeutic targets because of their pivotal role as regulators of signal transduction and thus their implication in several human diseases such as diabetes, cancer, and autoimmunity. In particular, PTP1B has been the focus of many academic and industrial laboratories because it was found to be an important negative regulator of insulin and leptin signaling, and hence a potential therapeutic target in diabetes and obesity. As a result, significant progress has been achieved in the design of highly selective and potent PTP1B inhibitors. In contrast, little attention has been given to other potential drug targets within the PTP family. Guided by x-ray crystallography, molecular modeling, and enzyme kinetic analyses with wild type and mutant PTPs, we describe the development of a general, low molecular weight, non-peptide, non-phosphorus PTP inhibitor into an inhibitor that displays more than 100-fold selectivity for PTPbeta over PTP1B. Of note, our structure-based design principles, which are based on extensive bioinformatics analyses of the PTP family, are general in nature. Therefore, we anticipate that this strategy, here applied to PTPbeta, in principle can be used in the design and development of selective inhibitors of many, if not most PTPs.


Assuntos
Inibidores Enzimáticos/farmacologia , Proteínas Tirosina Fosfatases/antagonistas & inibidores , Clonagem Molecular , Cristalografia por Raios X , Desenho de Fármacos , Inibidores Enzimáticos/química , Ligação de Hidrogênio , Insulina/metabolismo , Cinética , Leptina/metabolismo , Ligantes , Modelos Químicos , Modelos Moleculares , Mutação , Ftalimidas/química , Conformação Proteica , Proteína Tirosina Fosfatase não Receptora Tipo 1 , Proteínas Tirosina Fosfatases/química , Transdução de Sinais , Relação Estrutura-Atividade , Temperatura
8.
J Biol Chem ; 278(51): 51176-83, 2003 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-14530289

RESUMO

A highly constrained pseudo-tetrapeptide (OC252-324) further defines a new allosteric binding site located near the center of fructose-1,6-bisphosphatase. In a crystal structure, pairs of inhibitory molecules bind to opposite faces of the enzyme tetramer. Each ligand molecule is in contact with three of four subunits of the tetramer, hydrogen bonding with the side chain of Asp187 and the backbone carbonyl of residue 71, and electrostatically interacting with the backbone carbonyl of residue 51. The ligated complex adopts a quaternary structure between the canonical R- and T-states of fructose-1,6-bisphosphatase, and yet a dynamic loop essential for catalysis (residues 52-72) is in a conformation identical to that of the T-state enzyme. Inhibition by the pseudo-tetrapeptide is cooperative (Hill coefficient of 2), synergistic with both AMP and fructose 2,6-bisphosphate, noncompetitive with respect to Mg2+, and uncompetitive with respect to fructose 1,6-bisphosphate. The ligand dramatically lowers the concentration at which substrate inhibition dominates the kinetics of fructose-1,6-bisphosphatase. Elevated substrate concentrations employed in kinetic screens may have facilitated the discovery of this uncompetitive inhibitor. Moreover, the inhibitor could mimic an unknown natural effector of fructose-1,6-bisphosphatase, as it interacts strongly with a conserved residue of undetermined functional significance.


Assuntos
Regulação Alostérica , Frutose-Bifosfatase/química , Monofosfato de Adenosina/química , Monofosfato de Adenosina/farmacologia , Sítio Alostérico , Sequência de Aminoácidos , Cristalografia por Raios X , Sinergismo Farmacológico , Escherichia coli/genética , Frutose-Bifosfatase/antagonistas & inibidores , Frutosedifosfatos/química , Frutosedifosfatos/farmacologia , Cinética , Magnésio/química , Magnésio/farmacologia , Modelos Moleculares , Dados de Sequência Molecular , Oligopeptídeos/química , Oligopeptídeos/farmacologia
9.
J Med Chem ; 46(7): 1120-2, 2003 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-12646020

RESUMO

The regulation of lipid metabolism and it's effect on glucose control and diabetes has received intense interest. Hormone-sensitive lipase (HSL) is a vital enzyme in lipid metabolism. A series of novel pyrrolopyrazinediones has been discovered that demonstrate submicromolar activity both in the enzyme assay and in a (14)C-emulsion assay employing cholesteryl oleate as a substrate as a secondary measure of HSL activity. These compounds represent novel inhibitors of the human HSL enzyme.


Assuntos
Inibidores Enzimáticos/síntese química , Pirazinas/síntese química , Esterol Esterase/antagonistas & inibidores , Animais , Linhagem Celular , Bases de Dados Factuais , Avaliação Pré-Clínica de Medicamentos , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Humanos , Insetos/citologia , Pirazinas/química , Pirazinas/farmacologia , Relação Estrutura-Atividade
10.
J Med Chem ; 45(20): 4443-59, 2002 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-12238924

RESUMO

Reversible phosphorylation and dephosphorylation of key proteins on tyrosine residues are important parts of intracellular signaling triggered by hormones and other agents. Recent knock-out studies in mice have identified PTP1B as a potential target for the treatment of diabetes and obesity. As a consequence, a number of academic and industrial groups are aggressively pursuing the development of selective PTP1B inhibitors. In addition, other protein-tyrosine phosphatases (PTPs) appear to be critically involved in major diseases such as cancer and autoimmunity. Given the diversity of PTPs and their potential as drug targets in different diseases, we have taken a broad approach to develop active site-directed selective inhibitors of specific members of this family of enzymes. Using a high throughput screening, we have previously identified 2-(oxalylamino)benzoic acid 3a as a relatively weak but classical competitive inhibitor of several PTPs.(4) On the basis of our early studies, indicating that 3a might be used as a starting point for the synthesis of selective PTP inhibitors, we now present our efforts in expansion of this concept and provide here a number of new chemical scaffolds for the development of inhibitors of different members of the PTP family. Although the core structure of these inhibitors is charged, good oral bioavailability has been observed in rat for some compounds. Furthermore, we have observed enhancement of 2-deoxy-glucose accumulation in C2C12 cells with prodrug analogues.


Assuntos
Inibidores Enzimáticos/síntese química , Proteínas Tirosina Fosfatases/antagonistas & inibidores , Piridinas/síntese química , Tiofenos/síntese química , Administração Oral , Animais , Disponibilidade Biológica , Linhagem Celular , Cristalografia por Raios X , Desoxiglucose/metabolismo , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Camundongos , Modelos Moleculares , Proteína Tirosina Fosfatase não Receptora Tipo 1 , Piridinas/química , Piridinas/farmacologia , Ratos , Relação Estrutura-Atividade , Tiofenos/química , Tiofenos/farmacologia
11.
Novartis Found Symp ; 243: 213-26; discussion 226-30, 231-5, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-11990779

RESUMO

Inhibitors of P gLycoprotein (Pgp) may be useful for the enhancement of blood-brain barrier penetration of anti-epileptic drugs (AEDs). Due to polypharmacy and the need for chronic treatment, Pgp inhibitors used in epilepsy should be highly specific and non-toxic. In particular, it may be essential to use compounds that produce minimal inhibition of enzymes involved in metabolism of AEDs and other drugs used by epilepsy patients. OC144-093 is a novel substituted diarylimidazole generated using the OntoBLOCK system, a solid-phase combinatorial chemistry technology, in combination with high-throughput cell-based screening. The compound is an extremely potent inhibitor of Pgp-mediated multidrug resistance (MDR) in cancer with an average FC50 of 32 nM, but does not inhibit multidrug resistance-associated protein (MRP1). OC144-093 is the least non-specifically toxic Pgp inhibitor described to date, with an average cytostatic IC50 of >60 microM in 15 cell types. It is not metabolized by cytochrome P450s CYP3A4, 2C8 or 2C9 enzymes involved in AED metabolism. OC144-093 does not produce a pharmacokinetic (PK) interaction with paclitaxel and has exhibited an excellent PK and safety profile in phase I clinical trials. Our results suggest that OC144-093 may represent an ideal candidate for use in enhancement of AED blood-brain barrier penetration.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/antagonistas & inibidores , Anticonvulsivantes/farmacocinética , Barreira Hematoencefálica/efeitos dos fármacos , Resistência a Múltiplos Medicamentos , Inibidores Enzimáticos/farmacologia , Epilepsia/tratamento farmacológico , Imidazóis/farmacologia , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/fisiologia , Animais , Antineoplásicos/metabolismo , Barreira Hematoencefálica/fisiologia , Ensaios Clínicos Fase I como Assunto , Técnicas de Química Combinatória , Cães , Desenho de Fármacos , Avaliação Pré-Clínica de Medicamentos , Resistencia a Medicamentos Antineoplásicos , Inibidores Enzimáticos/efeitos adversos , Inibidores Enzimáticos/farmacocinética , Epilepsia/metabolismo , Feminino , Humanos , Imidazóis/efeitos adversos , Imidazóis/farmacocinética , Masculino , Estrutura Molecular , Proteínas de Neoplasias/antagonistas & inibidores , Proteínas de Neoplasias/fisiologia , Proteínas do Tecido Nervoso/antagonistas & inibidores , Proteínas do Tecido Nervoso/fisiologia , Ratos , Células Tumorais Cultivadas/efeitos dos fármacos , Células Tumorais Cultivadas/metabolismo
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