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1.
J Phys Chem Lett ; 15(6): 1734-1740, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38323906

RESUMO

Optical pump-probe techniques allow for an in-depth study of dark excited states. Here, we utilize them to map and gain insights into the excited states involved in the thermally activated delayed fluorescence (TADF) mechanism of a benchmark TADF emitter DMAC-TRZ. The results identify different electronic excited states involved in the key TADF transitions and their nature by combining pump-probe and photoluminescence measurements. The photoinduced absorption signals are highly dependent on polarity, affecting the transition oscillator strength but not their relative energy positions. In methylcyclohexane, a strong and vibronically structured local triplet excited state absorption (3LE → 3LEn) is observed, which is quenched in higher polarity solvents as 3CT becomes the lowest triplet state. Furthermore, ultrafast transient absorption (fsTA) confirms the presence of two stable conformers of DMAC-TRZ: (1) quasi-axial (QA) interconverting within 20 ps into (2) quasi-equatorial (QE) in the excited state. Moreover, fsTA highlights how sensitive excited state couplings are to the environment and the molecular conformation.

2.
Inorg Chem ; 62(45): 18465-18473, 2023 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-37905928

RESUMO

In this work, we introduce a spiro-fluorene unit into a phenylpyridine (CN)-type ligand as a simple way to deplanarize the structure and increase the solubility of the final platinum(II)···complex. Using a spiro-fluorene unit, orthogonal to the main coordination plane of the complex, reduces intermolecular interactions, leading to increased solubility but without significantly affecting the ability of the complex to form Pt···Pt dimers and excimers. This approach is highly important in the design of platinum(II) complexes, which often suffer from low solubility due to their mainly planar structure, and offers an alternative to the use of bulky alkyl groups. The nonplanar structure is also beneficial for vacuum-deposition techniques as it lowers the sublimation temperature. Importantly, there are no sp3 hybridized carbon atoms in the cyclometalating ligand that contain hydrogens, the undesired feature that is associated with the low stability of the materials in OLEDs. The complex displays high solubility in toluene, ∼10 mg mL-1, at room temperature, which allows producing solution-processed OLEDs in a wide range of doping concentrations, 5-100%, and EQE up to 5.9%, with a maximum luminance of 7400 cd m-2. Concurrently, we have also produced vacuum-deposited OLEDs, which display luminance up to 32 500 cd m-2 and a maximum EQE of 11.8%.

3.
Inorg Chem ; 62(14): 5772-5779, 2023 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-36996164

RESUMO

Alkylation of one of the phenolic hydroxyl groups in a salen-type tetradentate ligand changes the coordination mode from O^N^N^O to the cyclometallating C^N^N^O type. The ligand was used to synthesize a new cyclometalated luminescent Pt(II) complex 2. While in solution the complex is poorly luminescent, in the solid state the emission is reinstated, which allowed one to evaluate complex 2 as a phosphorescent emitter in organic light-emitting diodes. 2 displays external quantum efficiency (EQE) = 9.1% and a maximum luminance of 9000 cd m-2 in a vacuum-deposited device. We carried out comparative analysis of photo- and electroluminescence of complex 2 with O^N^N^O complex 1 and demonstrated that the similar luminescent properties of the O^N^N^O and C^N^N^O complexes are rather coincidental because they display different excited-state landscapes. Surprisingly, the two complexes display a dramatically different electrochemical behavior, with O^N^N^O coordination leading to the formation of a stable electropolymer but C^N^N^O coordination fully preventing electropolymerization.

4.
J Phys Chem Lett ; 14(11): 2764-2771, 2023 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-36897796

RESUMO

The molecular photophysics in the thermally activated delayed fluorescence (TADF) spiro-acridine-anthracenone compound, ACRSA, is dominated by the rigid orthogonal spirocarbon bridging bond between the donor and acceptor. This critically decouples the donor and acceptor units, yielding photophysics, which includes (dual) phosphorescence and the molecular charge transfer (CT) states giving rise to TADF, that are dependent upon the excitation wavelength. The molecular singlet CT state can be directly excited, and we propose that supposed "spiro-conjugation" between acridine and anthracenone is more accurately an example of intramolecular through-space charge transfer. In addition, we show that the lowest local and CT triplet states are highly dependent upon spontaneous polarization of the environment, leading to energy reorganization of the triplet states, with the CT triplet becoming lowest in energy, profoundly affecting phosphorescence and TADF, as evident by a (thermally controlled) competition between reverse intersystem crossing and reverse internal conversion, i.e., dual delayed fluorescence (DF) mechanisms.

5.
Chemistry ; 29(23): e202203800, 2023 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-36648938

RESUMO

Most organic room-temperature phosphorescence (RTP) emitters do not show their RTP in solution. Here, we incorporated sulfur-containing thiophene bridges between the donor and acceptor moieties in D3 A-type tristriazolotriazines (TTTs). The thiophene inclusion increased the spin-orbit coupling associated with the radiative T1 →S0 pathway, allowing RTP to be observed in solution for all compounds, likely assisted by protection of the emissive TTT-thiophene core from the environment by the bulky peripheral donors.

6.
Psicol. ciênc. prof ; 43: e251711, 2023. tab
Artigo em Português | LILACS, Index Psicologia - Periódicos | ID: biblio-1448945

RESUMO

As resoluções emitidas pelo Sistema Conselhos são instrumentos essenciais de orientação e promoção de práticas éticas que denotem qualidade técnica no exercício profissional da Psicologia. Dada a complexidade que envolve a elaboração de documentos psicológicos, esta pesquisa teve como objetivo identificar as principais mudanças observadas no texto da recém-publicada Resolução CFP n.º 006/2019 quando comparada à Resolução CFP n.º 007/2003, ambas referidas à elaboração de documentos psicológicos. Trata-se de uma pesquisa descritiva-comparativa de abordagem qualitativa, que utilizou da análise de conteúdo no tratamento e interpretação dos dados oriundos de fonte exclusivamente documental. Os resultados indicaram poucas diferenças qualitativas entre os marcos resolutivos, embora se vislumbre altamente relevante o ganho adquirido com a proibição de escritos descritivos, a exigência de referencial teórico para fundamentar o raciocínio profissional e a obrigatoriedade da devolutiva documental. Entre os achados que ganham notoriedade consta a preocupação com os princípios que regem a elaboração de documentos, cuja apresentação tautológica responde a um cenário político de retrocessos que tem favorecido o desrespeito aos direitos humanos e às minorias.(AU)


Resolutions issued by Sistema Conselhos are essential tools to guide and promote ethical and quality psychology practices. Given the complexity involved in elaborating such documents, this descriptive, qualitative research outlines the main changes in the text of the recently published CFP Resolution no. 006/2019 when compared with CFP Resolution no. 007/2003, both addressing the elaboration of psychological documents. Documentary data was investigated by content analysis. Results indicated few qualitative differences between the analyzed Resolutions, among them the prohibition of descriptive writing, the requirement for a theoretical framework to support professional reasoning, and the obligation to return documents. Concern with the principles that guide document elaboration stands out, responding to a political scenario of major setbacks regarding respect for human rights and minorities.(AU)


Las resoluciones que expide el Sistema Conselhos consisten en instrumentos fundamentales que guían y promueven prácticas éticas respecto a la calidad técnica en el ejercicio profesional de la Psicología. Dada la complejidad que implica la elaboración de documentos psicológicos, esta investigación tuvo como objetivo identificar los principales cambios observados en la Resolución CFP n.º 006/2019, de reciente publicación, en comparación con la Resolución CFP n.º 007/2003, ambas abordan la elaboración de documentos psicológicos. Se trata de una investigación descriptiva-comparativa con enfoque cualitativo, que utilizó el análisis de contenido en el tratamiento e interpretación de datos de fuente exclusivamente documental. Los resultados indicaron pocas diferencias cualitativas entre los marcos resolutivos (aunque el logro de prohibir los escritos descriptivos es muy relevante), la exigencia de un marco teórico para sostener el razonamiento profesional y la devolución obligatoria de los documentos. Entre los hallazgos que cobran notoriedad está la preocupación por los principios que rigen la elaboración de documentos, cuya presentación tautológica responde a un escenario político de retrocesos que ha favorecido la falta de respeto a los derechos humanos y las minorías.(AU)


Assuntos
Humanos , Masculino , Feminino , Guias como Assunto , Diagnóstico , Prova Pericial , Organização e Administração , Equipe de Assistência ao Paciente , Satisfação Pessoal , Fenômenos Psicológicos , Psicologia , Publicações , Qualidade da Assistência à Saúde , Qualidade de Vida , Comportamento Sexual , Classe Social , Valores Sociais , Transexualidade , Revelação da Verdade , Orientação Vocacional , Trabalho , Redação , Comportamento e Mecanismos Comportamentais , Políticas, Planejamento e Administração em Saúde , Cooperação Técnica , Atestado de Saúde , Atitude do Pessoal de Saúde , Registros , Classificação Internacional de Doenças , Diretório , Carga de Trabalho , Direitos Civis , Negociação , Comunicação , Artigo de Jornal , Vocabulário Controlado , Declarações , Publicação Governamental , Má Conduta Profissional , Autonomia Pessoal , Normas Jurídicas , Conselhos de Saúde , Denúncia de Irregularidades , Códigos de Ética , Manual Diagnóstico e Estatístico de Transtornos Mentais , Grupos Raciais , Documentação , Acordos de Cooperação Científica e Tecnológica , Domínios Científicos , Ética na Publicação Científica , Publicações Científicas e Técnicas , Publicações de Divulgação Científica , Humanização da Assistência , Acolhimento , Ética Profissional , Prazo de Validade de Produtos , Relatório de Pesquisa , Participação Social , Escrita Médica , Confiabilidade dos Dados , Profissionalismo , Controle de Formulários e Registros , Ciência na Literatura , Estratégias de eSaúde , Sociedade Civil , Angústia Psicológica , Assistência de Saúde Universal , Intervenção Psicossocial , Cidadania , Análise Documental , Condições de Trabalho , Escrita Manual , Ciências Humanas , Idioma
7.
ACS Appl Electron Mater ; 4(7): 3486-3494, 2022 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-35910938

RESUMO

Delayed fluorescence (DF) by triplet-triplet annihilation (TTA) is observed in solutions of a benzoperylene-imidoester mesogen that shows a hexagonal columnar mesophase at room temperature in the neat state. A similar benzoperylene-imide with a slightly smaller HOMO-LUMO gap, that also is hexagonal columnar liquid crystalline at room temperature, does not show DF in solution, and mixtures of the two mesogens show no DF in solution either, because of collisional quenching of the excited triplet states on the imidoester by the imide. In contrast, DF by TTA from the imide but not from the imidoester is observed in condensed films of such mixtures, even though neat films of either single material are not displaying DF. In contrast to the DF from the monomeric imidoester in solution, DF of the imide occurs from dimeric aggregates in the blend films, assisted by the imidoester. Thus, the close contact of intimately stacked molecules of the two different species in the columnar mesophase leads to a unique mesophase-assisted aggregate DF. This constitutes the first observation of DF by TTA from the columnar liquid crystalline state. If the imide is dispersed in films of polybromostyrene, which provides an external heavy-atom effect facilitating triplet formation, DF is also observed. Organic light-emitting diodes (OLEDs) devices incorporating these liquid crystal molecules demonstrated high external quantum efficiency (EQE). On the basis of the literature and to the best of our knowledge, the EQE reported is the highest among nondoped solution-processed OLED devices using a columnar liquid crystal molecule as the emitting layer.

8.
J Am Chem Soc ; 144(33): 15211-15222, 2022 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-35944182

RESUMO

We present a detailed and comprehensive picture of the photophysics of thermally activated delayed fluorescence (TADF). The approach relies on a few-state model, parametrized ab initio on a prototypical TADF dye, that explicitly accounts for the nonadiabatic coupling between electrons and vibrational and conformational motion, crucial to properly address (reverse) intersystem crossing rates. The Onsager model is exploited to account for the medium polarity and polarizability, with careful consideration of the different time scales of relevant degrees of freedom. TADF photophysics is then quantitatively addressed in a coherent and exhaustive approach that accurately reproduces the complex temporal evolution of emission spectra in liquid solvents as well as in solid organic matrices. The different rigidity of the two environments is responsible for the appearance in matrices of important inhomogeneous broadening phenomena that are ascribed to the intertwined contribution from (quasi)static conformational and dielectric disorder.


Assuntos
Elétrons , Corantes Fluorescentes , Solventes , Espectrometria de Fluorescência , Temperatura
9.
J Phys Chem Lett ; 13(30): 6981-6986, 2022 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-35881847

RESUMO

Donor-acceptor (D-A) thermally activated delayed fluorescence (TADF) molecules are exquisitely sensitive to D-A dihedral angle. Although commonly simplified to an average value, these D-A angles nonetheless exist as distributions across the individual molecules embedded in films. The presence of these angle distributions translates to distributions in the rates of reverse intersystem crossing (krISC), observed as time dependent spectral shifts and multiexponential components in the emission decay, which are difficult to directly quantify. Here we apply inverse Laplace transform fitting of delayed fluorescence to directly reveal these distributions. Rather than a single average value, the crucial krISC rate is instead extracted as a density of rates. The modes and widths of these distributions vary with temperature, host environment, and intrinsic D-A torsional rigidity of different TADF molecules. This method gives new insights and deeper understanding of TADF host-guest interactions, as well as verifies future design strategies that target D-A bond rigidity.

10.
Anticancer Agents Med Chem ; 22(5): 968-977, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34170812

RESUMO

BACKGROUND: Target treatment using site-specific nanosystems is a hot topic for treating several diseases, especially cancer. OBJECTIVE: The study was set out to develop site-specific liposomes using ConcanavalinA (ConA) to target ß- lapachone(ß-lap) to human breast cancer cells. METHODS: Liposomes were prepared and characterized according to diameter size, zeta potential, ConA conjugation(%) and ß-lap encapsulation efficiency (%). Isothermal Titration Calorimetry evaluated the binding energy between the biomolecules, which compose of the liposomes. ConA avidity was assessed before and after conjugation. Cytotoxicity was evaluated, and fluorescence microscopy was performed to investigate the influence of ConA influenced on MCF-7 uptake. RESULTS: Uncoated and ConA-coated liposomes presented size, and zeta potential values from 97.46 ± 2.01 to 152.23 ± 2.73 nm, and -6.83 ± 0.28 to -17.23 ±0.64 mV, respectively. Both ConA conjugation and ß-lap encapsulation efficiency were approximately 100%. The favorable and spontaneous process confirmed the binding between ConA and the lipid. Hemagglutination assay confirmed ConA avidity once Lipo-ConA and Lipo-PEG-ConA were able to hemagglutinate the red blood cells at 128-1 and 256-1, respectively. Lipo-ConA was not cytotoxic, and the site-specific liposomes presented the highest toxicity. ConA-coated liposomes were more internalized by MCF7 than uncoated-liposomes. CONCLUSION: Therefore, the presence of ConA on the surface of liposomes influenced MCF7 uptake, in that way could be used as a promising site-specific system to target ß-lap to cancer cells.


Assuntos
Neoplasias da Mama , Naftoquinonas , Neoplasias da Mama/tratamento farmacológico , Concanavalina A , Feminino , Humanos , Lipossomos/química , Naftoquinonas/química
11.
Psicol. USP ; 33: e190174, 2022. tab
Artigo em Português | LILACS, Index Psicologia - Periódicos | ID: biblio-1406388

RESUMO

Resumo Este trabalho teve como objetivo analisar os conteúdos de psicanálise ensinados nos cursos de psicologia do Acre por meio das ementas das disciplinas e bibliografias correspondentes, registradas nos projetos pedagógicos curriculares dos quatro cursos existentes no estado. Trata-se de um estudo descritivo de abordagem qualitativa e fonte do tipo documental, que recorreu à análise de conteúdo para conduzir a interpretação dos dados. Os resultados indicaram ementas com ênfase no ensino freudiano e privilégio de publicações nacionais. Entre as lacunas identificadas, destaca-se a carência de conteúdos a respeito da pesquisa psicanalítica e da clínica para além do modelo clássico, o que convoca a implementação de mudanças que possam subsidiar as investigações e as práticas no contexto amazônico, além de fomentar o desenvolvimento desta abordagem tendo como horizonte o percurso formativo que a disciplina freudiana exige.


Abstract This paper analyzes the psychoanalysis subjects taught in psychology programs in the state of Acre by the syllabus and bibliographies of the corresponding disciplines, available on the curricular pedagogical projects of the four existing programs. A descriptive and qualitative study was conducted based on documentary sources investigated by content analysis. The results indicated syllabuses that emphasize Freudian teachings and a preference for national publications. Lack of classes on psychoanalytic research and clinic beyond the classic model stands out amidst the identified gaps, calling for changes that may subsidize investigations and practices in the Amazon context, fomenting the development of this approach aiming at the formative journey that the Freudian discipline requires.


Résumé Ce article analyse les contenus de psychanalyse enseignés dans les programmes de psychologie dans l'état d'Acre par les syllabus et les bibliographies des disciplines correspondantes, disponibles sur les projets pédagogiques curriculaires des quatre programmes existant. Une étude descriptive et qualitative a été menée sur la base de sources documentaires étudiée par analyse de contenu. Les résultats indiquent des syllabus qui mettent l'accent sur les enseignements freudiens et une préférence pour les publications nationales. L'absence de cours concernant la recherche et la clinique psychanalytiques au-delà du modèle classique ressort parmi les lacunes identifiées, appelant à des changements qui pourraient subventionner les investigations et les pratiques dans le contexte amazonien, favorisant le développement de cette approche visant le parcours formateur que la discipline freudienne exige.


Resumen El presente trabajo tuvo como objetivo analizar los contenidos de psicoanálisis impartidos en los cursos de psicología en el estado de Acre, a través de los roles de las disciplinas y bibliografías correspondientes, registrados en los proyectos pedagógicos curriculares de los cuatro cursos existentes en el estado. Se trata de un estudio descriptivo, con enfoque cualitativo, y con una fuente documental que utilizó el análisis de contenido para dirigir la interpretación de los datos. Los resultados indicaron roles con énfasis en la enseñanza freudiana y el privilegio de las publicaciones nacionales. Entre los vacíos identificados, se encuentra una falta de contenido en materia de investigación psicoanalítica y clínica más allá del modelo clásico, lo que requiere la implementación de cambios que puedan subvencionar las investigaciones y prácticas en el contexto amazónico, además de potenciar el desarrollo de este enfoque teniendo como horizonte el camino formativo que demanda la disciplina freudiana.


Assuntos
Psicanálise/educação , Psicologia/educação , Universidades , Brasil
12.
J Phys Chem Lett ; 12(11): 2820-2830, 2021 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-33719455

RESUMO

Commonly, thermally activated delayed fluorescence (TADF) emitters present a twisted donor-acceptor structure. Here, electronic communication is mediated through-bond via π-conjugation between donor and acceptor groups. A second class of TADF emitters are those where electronic communication between donor and acceptor moieties is mediated through-space. In these through-space charge-transfer (TSCT) architectures, the donor and acceptor groups are disposed in a pseudocofacial orientation and linked via a bridging group that is typically an arene (or heteroarene). In most of these systems, there is no direct evidence that the TSCT is the dominant contributor to the communication between the donor and acceptor. Herein we investigate the interplay between through-bond localized excited (LE) and charge-transfer (CT) states and the TSCT in a rationally designed emitter, TPA-ace-TRZ, and a family of model compounds. From our photophysical studies, TSCT TADF in TPA-ace-TRZ is unambiguously confirmed and supported by theoretical modeling.

13.
J Phys Chem Lett ; 12(5): 1490-1500, 2021 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-33533617

RESUMO

The molecular photophysics and thermally activated delayed fluorescence (TADF) in spiro compounds are distinct because of the rigid orthogonal C-C bridging bond between donor and acceptor. The photophysics is found to be highly complex, with unprecedented multiple anti-Kasha emissions from three different singlet states, two of which are one-photon forbidden. The TADF mechanism is critically controlled by local acceptor nπ* states; the singlet nπ* state undergoes rapid intersystem crossing populating an energetically close acceptor ππ* triplet state. The acceptor triplet nπ* state couples nonadiabatically to a CT triplet state mediating reverse intersystem crossing. When the nπ* and CT states are energetically close, TADF is greatly enhanced with rISC rate reaching 107 s-1. We observe neither DF from the singlet nπ* state nor electron transfer (ET) to form the 1CT because there is no ET driving force; however, ET from the higher-energy donor singlet ππ* state readily occurs along with donor emission.

14.
ACS Appl Electron Mater ; 2(9): 2868-2881, 2020 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-32984822

RESUMO

The thermally activated delayed fluorescence (TADF) donor-acceptor (D-A) molecule, DMAC-TRZ, is used as a TADF emitter "probe" to distinguish the environmental effects of a range of solid-state host materials in guest-host systems. Using the guest's photophysical behavior in solution as a benchmark, a comprehensive study using a variety of typical TADF organic light-emitting diode hosts with different characteristics provides a clearer understanding of guest-host interactions and what affects emitter performance in solid state. We investigate which are the key host characteristics that directly affect charge-transfer (CT) state energy and singlet triplet energy gaps. Using time-resolved photoluminescence measurements, we use the CT state energy distribution obtained from the full width at half-maximum (fwhm) of the emission band and correlate this with other photophysical properties such as the apparent dynamic red shift of CT emission on-set to estimate the disorder-induced heterogeneity of D-A dihedral angles and singlet triplet gaps. Further, the delayed emission stabilization energy value and time-dependent CT band fwhm are shown to be related to a combination of host's rigidity, emitter molecule packing, and the energy difference between guest and host lowest energy triplet states. Concentration dependence studies show that emitter dimerization/aggregation can improve as well as reduce emission efficiency depending on the characteristics of the host. Two similar host materials, mCPCN and mCBPCN, with optimum host characteristics show completely different behaviors, and their hosting potential is extensively explored. We demonstrate that type I and type III TADF emitters behave differently in the same host and that the materials with intrinsic small ΔE ST have the smallest disorder-induced CT energy and reverse intersystem crossing rate dispersion. We also present an optimized method to define the actual triplet energy of a guest-host system, a crucial parameter in understanding the overall mechanism of the TADF efficiency of the system.

15.
Rev. Ciênc. Méd. Biol. (Impr.) ; 16(1): 5-9, jul 14, 2017. fig
Artigo em Inglês | LILACS | ID: biblio-1348194

RESUMO

Introduction: vitiligo is a multifactorial acquired depigmenting disorder, characterized by a spontaneous loss of functional melanocytes from the epidermis. Vitiligo and Hashimoto's thyroiditis (HT) often occur in association and seem to be characterized by an autoimmune process. The vitiligo associated with HT suggests genetic homologies between them. Objective: to identify protein sequence homology between melanocyte protein (Pmel) and thyroid peroxidase (TPO), using bioinformatics tools, to propose an initial mechanism which could explain the production of cross-reacting autoantibodies to melanocyte and TPO. Methods: we performed a comparison between Pmel and TPO amino acids (AA) sequences, available on the National Center for Biotechnology Information (NCBI) database by BLAST (Basic Local Alignment Search Tool) in order to find local homology regions between the AA sequences. Results: the homology sequence between the Pmel and TPO ranged from 21.0 % (19 identical residues out of 90 AA in the sequence) to 55.0% (6 identical residues out of 11 AA in the sequence). The identical alignments presented relatively high E values due to presence of short alignment. Conclusion: bioinformatics data suggest a possible pathological link between Pmel and TPO. Sequence homology between Pmel and TPO may present a molecular mimicry suggesting the possibility of antigen crossover between Pmel and TPO that might represent an immunological basis for vitiligo associated with HT.


Introdução: o vitiligo é uma doença de despimentação adquirida multifatorial, caracterizada por uma perda espontânea de melanócitos funcionais da epiderme. Vitiligo e tiroidite de Hashimoto (TH) ocorrem frequentemente em associação e parecem ser caracterizados por um processo autoimune. O vitiligo associado à TH sugere homologias genéticas entre eles. Objetivo: identificar homologia das sequências de proteína entre a proteína do melanócito (Pmel) e peroxidase da tiróide (TPO), usando ferramentas de bioinformática, para propor um mecanismo inicial que poderia explicar a produção de autoanticorpos de reação cruzada entre o melanócito e a TPO. Metodologia: foi realizada uma comparação entre a sequência de aminoácidos (AA) da Pmel e da TPO, disponível no banco de dados Basic Local Alignment Search Tool (BLAST) do National Center for Biotechnology Information (NCBI), a fim de encontrar regiões de homologia locais entre as sequências de AA. Resultados: a sequência de homologia entre a Pmel e a TPO variou de 21,0% (19 resíduos idênticos na sequência de cada 90 AA na sequência) a 55,0% (6 resíduos idênticos na sequência de 11 AA). Os alinhamentos idênticos apresentaram valores relativamente altos (E) devido à presença de alinhamentos curtos. Conclusão: os dados de Bioinformática sugerem uma possível ligação patológica entre Pmel e a TPO. A sequência de homologia entre Pmel e a TPO pode apresentar um mimetismo molecular sugerindo a possibilidade de cruzamento entre antígeno da Pmel e da TPO que pode representar uma base imunológica para a associação entre o vitiligo e a TH.


Assuntos
Humanos , Vitiligo , Sequência de Aminoácidos , Homologia de Sequência de Aminoácidos , Biologia Computacional , Doença de Hashimoto , Estudo Comparativo , Peroxidase , Base de Dados
16.
Arq. bras. endocrinol. metab ; 58(9): 953-957, 12/2014. tab, graf
Artigo em Inglês | LILACS | ID: lil-732187

RESUMO

Atypical presentation forms of hyperthyroidism are always a challenge to the clinician. We present a female patient with the typical symptoms of thyrotoxicosis, without any thionamides treatment before, associated with pancytopenia, which recovered after euthyroidism state was achieved. Although the major cases of pancytopenia in Grave’s disease are seen as a complication of antithyroid drugs (thioamides), in this case report the alteration in blood tests was associated with untreated hyperthyroidism. In the literature review, we found 19 case reports between 1981 to 2012, but it has been related to a hypercellular bone marrow with periferic destruction. Our case, however, is about a hypocellular bone marrow without fibrosis or fat tissue replacement, which proceeded with a periferic improvement following thyroid treatment. Although rare, pancytopenia, when present, may develop as an unusual and severe manifestation in untreated subjects.


Formas atípicas de apresentação do hipertireoidismo são sempre um desafio para o clínico. Apresentamos uma paciente do sexo feminino, com sintomas típicos de tireotoxicose associado a um quadro de pancitopenia sem nenhum tratamento prévio com tionamidas. A melhora da alteração hematológica ocorreu após recuperação do eutireoidismo. Embora a maioria dos casos de pancitopenia na doença de Graves seja uma complicação das drogas antitireoidianas (tionamidas), neste caso a alteração hematológica foi associada ao quadro de hipertireoidismo não tratado. Após uma revisão na literatura, encontramos 19 relatos de caso descritos no período de 1981 a 2012, nos quais o quadro de pancitopenia estava relacionado à hipercelularidade medular com destruição periférica das células sanguíneas. Nosso caso, entretanto, trata-se de uma pancitopenia com medula óssea hipocelular, sem infiltração por tecido adiposo ou fibrose, que evoluiu com melhora dos elementos do sangue periférico após tratamento do hipertireoidismo. Embora rara, a pancitopenia, quando presente, pode se manifestar como uma severa manifestação se não tratada a condição desencadeadora.


Assuntos
Feminino , Humanos , Pessoa de Meia-Idade , Doenças da Medula Óssea/patologia , Medula Óssea/patologia , Doença de Graves/complicações , Pancitopenia/sangue , Anticorpos Monoclonais/uso terapêutico , Biópsia por Agulha , Contagem de Células Sanguíneas , Doenças da Medula Óssea/complicações , Doenças da Medula Óssea/tratamento farmacológico , Medula Óssea/anormalidades , Fator Estimulador de Colônias de Granulócitos/uso terapêutico , Doença de Graves/tratamento farmacológico , Compostos de Lítio/uso terapêutico , Pancitopenia/tratamento farmacológico , Pancitopenia/etiologia , Receptores da Tireotropina/sangue , Resultado do Tratamento
17.
J. vasc. bras ; 13(3): 192-197, Jul-Sep/2014. tab
Artigo em Inglês | LILACS | ID: lil-727123

RESUMO

Prescription of a drug outside of the indications for which it was originally approved by regulators is internationally known as "off-label" prescription. We describe off-label treatments for the diabetic foot reported in international scientific literature. This is a qualitative and descriptive bibliographical review based on the results of a search of the Medline international database. The criteria for review were publication between January 1985 and November 2013, and the MeSH (Medical Subject Heading) keywords "off-label use" OR "off-label" OR "off-label prescribing" plus "diabetic foot" were input on the search form. Nine studies were selected that contained information about off-label treatments for the diabetic foot. We conclude that the practice of off-label prescribing has potential benefits. In some situations an off-label prescription is the only treatment available for patients, either because a more targeted drug does not exist, or because other methods of treatment are ineffective or unavailable due to patient intolerance...


A prescrição de um medicamento sem as indicações para as quais a droga foi originalmente aprovada por órgãos reguladores é internacionalmente conhecida como prescrição off-label. Descrevemos a terapia off-label em pé diabético, relatada na literatura científica internacional, por meio de uma revisão bibliográfica qualitativa, descritiva, através de pesquisa na base de dados internacional Medline, para seleção dos artigos. Os critérios para revisão foram publicações entre janeiro de 1985 e novembro de 2013, sendo as palavras-chave MeSH "off-label use" OR "off-label" OR "off-label prescribing" plus "diabetic foot" – colocadas no formulário de busca. Foram selecionados nove artigos com informações sobre a terapia off-label em pé diabético. Conclui-se que a prática de prescrição off-label possui benefícios potenciais em muitas situações. Em algumas circunstâncias, uma prescrição off-label é o único tratamento disponível, seja por não existir uma droga específica, seja porque outros métodos de tratamento são ineficazes ou não disponíveis por intolerância...


Assuntos
Humanos , Diabetes Mellitus/terapia , Pé Diabético/reabilitação , Uso Off-Label/história , Bases de Dados Bibliográficas
18.
Arq Bras Endocrinol Metabol ; 58(9): 953-7, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25627052

RESUMO

Atypical presentation forms of hyperthyroidism are always a challenge to the clinician. We present a female patient with the typical symptoms of thyrotoxicosis, without any thionamides treatment before, associated with pancytopenia, which recovered after euthyroidism state was achieved. Although the major cases of pancytopenia in Grave's disease are seen as a complication of antithyroid drugs (thioamides), in this case report the alteration in blood tests was associated with untreated hyperthyroidism. In the literature review, we found 19 case reports between 1981 to 2012, but it has been related to a hypercellular bone marrow with periferic destruction. Our case, however, is about a hypocellular bone marrow without fibrosis or fat tissue replacement, which proceeded with a periferic improvement following thyroid treatment. Although rare, pancytopenia, when present, may develop as an unusual and severe manifestation in untreated subjects.


Assuntos
Doenças da Medula Óssea/patologia , Medula Óssea/patologia , Doença de Graves/complicações , Pancitopenia/sangue , Anticorpos Monoclonais/uso terapêutico , Biópsia por Agulha , Contagem de Células Sanguíneas , Medula Óssea/anormalidades , Doenças da Medula Óssea/complicações , Doenças da Medula Óssea/tratamento farmacológico , Feminino , Fator Estimulador de Colônias de Granulócitos/uso terapêutico , Doença de Graves/tratamento farmacológico , Humanos , Compostos de Lítio/uso terapêutico , Pessoa de Meia-Idade , Pancitopenia/tratamento farmacológico , Pancitopenia/etiologia , Receptores da Tireotropina/sangue , Resultado do Tratamento
19.
J. vasc. bras ; 11(3): 232-235, jul.-set. 2012. ilus
Artigo em Inglês | LILACS | ID: lil-653564

RESUMO

Hepatic artery aneurysm (HAA) was first reported at autopsy in 1809, represents one fifth of visceral aneurysms and the mortality from spontaneous rupture is high in most of cases. We are reporting a case of an asymptomatic 48-year-old woman with an extrahepatic HAA, diagnosed initially and incidentally with abdominal ultrasonography, confirmed by a three-dimensional contrast-enhanced magnetic resonance imaging and angiography. Endovascular treatment was considered feasible and was successfully treated with coil embolization.


Aneurisma da artéria hepática (AAH) foi relatado pela primeira vez através de autópsia em 1809, representa um quinto dos aneurismas viscerais, e a mortalidade por ruptura espontânea é alta na maioria dos casos. Relatamos o caso de uma mulher de 48 anos de idade com um AAH extra-hepático assintomático, diagnosticado inicialmente, e incidentalmente, com ultrassonografia abdominal e confirmado através de angiorressonância tridimensional e angiografia contrastada. O tratamento endovascular foi considerado viável, sendo tratada com sucesso através de embolização com molas.


Assuntos
Humanos , Feminino , Adulto , Aneurisma/diagnóstico , Artéria Hepática/patologia , Doenças Vasculares/terapia , Embolização Terapêutica , Angiografia , Abdome
20.
Acta Gastroenterol Latinoam ; 41(2): 104-10, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21894723

RESUMO

OBJECTIVE: In order to analyze the effect on autoimmune thyroiditis (AT) of current anti-hepatitis C virus (HCV) treatment in HCV-infected patients, we performed a systematic review with meta-analysis of the available literature. The present meta-analysis was conducted to evaluate the strength and the consistency of the association between treatments with interferon-alpha (IFN-alpha) for HCV infection and AT. MATERIAL AND METHODS: A search in Medline, PubMed, and EMBASE was conducted with a systematic review of clinical studies in English and other languages. Only studies in HCV subjects compared to a control group with hepatitis B (positive HBsAg) were considered. The relative risk (RR) of AT was regarded as the most reliable outcome end-point. The pooled odds ratio (OR) and 95% confidence intervals (95% CI) were calculated from the raw study data using the Mantel-Haenszel methods. We used a statistical evaluation of heterogeneity by the chi2-test to assess whether the variation in treatment effect within trials of the same group was greater than it might be expected. RESULTS: We identified 35 clinical trials with a total of 6.403 patients. Five trials were selected for analysis involving a total of 625 patients with hepatitis C treatment with IFN-alpha and 456 HBsAg-positive controls. These studies yielded a combined adjusted OR of 4.98 (95% IC 1.56-15.91). The test for heterogeneity was significant (P = 0.0008), and the test for overall effect was Z statistic 2.71 (P = 0.007). CONCLUSION: Our meta-analysis indicates that treatment with IFN-alpha for HCV infection has an increased risk of AT.


Assuntos
Antivirais/efeitos adversos , Hepatite C Crônica/tratamento farmacológico , Interferon-alfa/efeitos adversos , Tireoidite Autoimune/induzido quimicamente , Adulto , Idoso , Antivirais/uso terapêutico , Estudos de Casos e Controles , Feminino , Humanos , Interferon-alfa/uso terapêutico , Masculino , Pessoa de Meia-Idade , Fatores de Risco
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