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1.
Cell ; 185(4): 654-671.e22, 2022 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-35065713

RESUMO

Sex hormones exert a profound influence on gendered behaviors. How individual sex hormone-responsive neuronal populations regulate diverse sex-typical behaviors is unclear. We performed orthogonal, genetically targeted sequencing of four estrogen receptor 1-expressing (Esr1+) populations and identified 1,415 genes expressed differentially between sexes or estrous states. Unique subsets of these genes were distributed across all 137 transcriptomically defined Esr1+ cell types, including estrous stage-specific ones, that comprise the four populations. We used differentially expressed genes labeling single Esr1+ cell types as entry points to functionally characterize two such cell types, BNSTprTac1/Esr1 and VMHvlCckar/Esr1. We observed that these two cell types, but not the other Esr1+ cell types in these populations, are essential for sex recognition in males and mating in females, respectively. Furthermore, VMHvlCckar/Esr1 cell type projections are distinct from those of other VMHvlEsr1 cell types. Together, projection and functional specialization of dimorphic cell types enables sex hormone-responsive populations to regulate diverse social behaviors.


Assuntos
Ciclo Estral/genética , Regulação da Expressão Gênica , Caracteres Sexuais , Comportamento Sexual Animal/fisiologia , Agressão , Animais , Aromatase/metabolismo , Transtorno Autístico/genética , Receptor alfa de Estrogênio/genética , Receptor alfa de Estrogênio/metabolismo , Feminino , Perfilação da Expressão Gênica , Células HEK293 , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Neurônios/metabolismo , Comportamento Social
3.
Am J Occup Ther ; 77(6)2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-38051265

RESUMO

IMPORTANCE: Currently, no self-report instruments exist for assessing satisfaction with performing instrumental activities of daily living and occupations for people with disabilities using internet-connected assistive devices like accessible smartphones, tablets, laptops, and apps. OBJECTIVE: To assess the test-retest reliability and internal consistency of the Electronic Instrumental activities of daily living Satisfaction Assessment (EISA) self-report outcome tool. DESIGN: Repeated-measures cohort study with a time frame of 7 to 21 days. SETTING: Multicity online recruitment at assistive technology clinics, nongovernmental organizations, advocacy and peer support groups for people with disabilities, and higher education institutions. PARTICIPANTS: Eighty-four participants with disabilities, age 18 yr or older, with a mean age of 43.3 yr (range = 19-75 yr), and 57% female. INTERVENTION: Not applicable. OUTCOMES AND MEASURES: The a priori study hypotheses were that the EISA test-retest reliability scores would be above the minimum acceptable level (Rs > .80) and that internal consistency would be good (Cronbach's α = .70-.90). RESULTS: On the basis of the study data, the EISA, Version 1.0, demonstrated good test-retest reliability (Rs = .81) and excellent internal consistency (Cronbach's α = .88). CONCLUSIONS AND RELEVANCE: The results of the test-retest reliability and internal consistency analyses provide good support for the EISA to be used in clinical settings. What This Article Adds: This article documents the reliability and internal consistency of, to our knowledge, the first-ever self-report instrument for assessing satisfaction with performance of everyday occupations for people with disabilities using internet-connected assistive devices such as smartphones, tablets, laptops, and apps.


Assuntos
Atividades Cotidianas , Pessoas com Deficiência , Humanos , Feminino , Adulto , Adolescente , Masculino , Estudos de Coortes , Reprodutibilidade dos Testes , Satisfação Pessoal , Inquéritos e Questionários , Psicometria
4.
J Cutan Pathol ; 49(7): 618-622, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35302653

RESUMO

Arterial tortuosity syndrome (ATS) is a rare autosomal recessive disease characterized by elongation and tortuosity of the large- and medium-sized arteries. ATS patients display features that are also found in Ehlers-Danlos syndrome (EDS) patients. ATS is caused by pathogenic mutations in the SLC2A10 gene, which encodes for the glucose transporter, GLUT10. This study aimed at examining the ultrastructure of skin for abnormalities that can explain the loose skin and arterial phenotypes of Arab patients with the p.S81R mutation in SLC2A10. Forty-eight patients with SLC2A10 mutation were recruited for this study. Skin biopsy specimens from three children with ATS and a healthy child were examined by electron microscopy to determine the ultrastructure of collagen and elastin. Histopathologic staining of sections from tissue biopsy specimens was also performed. Large spaces were observed among the collagen fibrils in the skin biopsy specimens obtained from ATS patients, suggesting disorganization of the collagen structures. Furthermore, elastin fiber contents and their thickness are reduced in the skin. In small muscular arteries in the skin from ATS patients, discontinuous internal elastic lamina, lack of myofilaments, and disorganized medial smooth muscle cells with vacuolated cytoplasm are present. The disorganization of collagen fibrils and reduced elastin contents in the skin may explain the loose skin phenotype of ATS patients similar to the EDS patients. The lack of elastin in small muscular arteries may have contributed to the development of arterial tortuosity in these patients.


Assuntos
Artérias , Colágeno , Elastina , Instabilidade Articular , Dermatopatias Genéticas , Malformações Vasculares , Árabes , Artérias/anormalidades , Artérias/patologia , Colágeno/ultraestrutura , Síndrome de Ehlers-Danlos/genética , Síndrome de Ehlers-Danlos/patologia , Elastina/ultraestrutura , Humanos
5.
ScientificWorldJournal ; 2022: 2864485, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35431665

RESUMO

A diagnosis of carpal tunnel syndrome (CTS) in a human often contains more than one test. Calcification of the traverse carpal ligament (TCL) is the common reason why patients seek CTS surgery. However, the determination of calcium (Ca) concentration in the TCL has not been studied. The results of environmental toxicity studies assessing the relationship between Ca and elemental deposition in the TCL are inconsistent. The purpose of this paper was to verify this hypothesis by conducting a chemical analysis of a portion of the released TCL to assess whether there is a relationship between CTS and Ca, measured as the total concentration of Ca, and to measure the precipitation of elements; the most closely related elements associated with Ca are cadmium and lead, which are also toxic. Surgical release of TCL was performed on forty patients. Total concentrations of Ca, Cd, and Pb in the extracted portion of TCL were digested and determined using inductively coupled plasma mass spectrometry (ICP-MS) and the possibility of using X-ray spectroscopy (XRF) for direct elemental analysis. Ca mineralisation was revealed in some TCLs. In assessing patients' environmental pollution, it was observed that the Cd and Pb concentrations were significant with a higher Ca concentration, and XRF was useful for direct detection of the elements in samples of the human body. These results indicate that TCL mineralisation by Ca does not characterise CTS, which has important concerns in improving patients' therapeutic strategies, and Cd and Pb concentrations varied due to different factors.


Assuntos
Cálcio , Síndrome do Túnel Carpal , Cádmio , Síndrome do Túnel Carpal/diagnóstico , Síndrome do Túnel Carpal/cirurgia , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Chumbo , Ligamentos Articulares/cirurgia
6.
West Afr J Med ; 39(5): 497-500, 2022 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-35633629

RESUMO

BACKGROUND: Acute leukaemias are very aggressive diseases that run a rapidly fatal course if not promptly diagnosed and appropriately treated. The clinical presentations range from bone marrow failure such as anaemia, neutropenia or thrombocytopenia to features of organ infiltrations such as lymphadenopathy, splenomegaly, etc, but presentations may be non-specific. Misdiagnosis is very common with delay in diagnosis and prompt treatment being the causes of high morbidity and mortality in acute leukaemias. This study aims to determine the pattern of presentation and various clinical entities of acute leukaemias in Bauchi State, North-Eastern Nigeria. SUBJECTS, MATERIALS AND METHODS: This was a three year retrospective study in which records of cases of acute leukaemias diagnosed in the Haematology Department of Abubakar Tafawa Balewa University Teaching Hospital (ATBUTH) Bauchi from the bone marrow aspiration cytology register from 1st January, 2018 to 31st December, 2020 were collected. Data on socio-demographic characteristics of the patients that include age, gender, diagnosis as well as subtypes of some of the malignancies diagnosed were also collated. The collated data were analyzed using SPSS Version 20.0. A p-value of < 0.05 was considered significant. RESULTS: Twenty-nine cases of acute leukaemias were diagnosed during the period under review. Majority of cases had acute lymphoblastic leukaemia (ALL) 19/29 (65.5%) while acute myeloid leukaemia (AML) was seen in 10/29 (34.5%). The mean ± SD age of the patients was 22.2±9.2 years with a range 6 months to 60 years. Males constituted 75.9% (22/29) of the cases of acute leukaemias diagnosed. The male to female ratios for AML and ALL were 2:1 and 2.6:1 respectively. The mean±SD ages for AML and ALL were 27±9.2years and 17.3±11.3 years respectively. The most common form of presentation of acute leukaemia in this study is recurrent anaemia necessitating blood transfusion while proptosis and epistaxis were the least forms of presentation. CONCLUSION: Acute lymphoblastic leukaemia is the commonest form of acute leukaemias while recurrent anaemia is the commonest form of clinical presentations in our setting. Early referral of patients with clinical features suggestive of acute leukaemias is recommended.


CONTEXTE: Les leucémies aiguës sont des maladies très agressives qui exécuter un cours rapidement mortel s'il n'est pas diagnostiqué rapidement et de manière appropriée Traités. Les présentations cliniques vont de l'insuffisance médullaire tels que l'anémie, la neutropénie ou la thrombocytopénie aux caractéristiques d'infiltrations d'organes telles que lymphadénopathie, splénomégalie, etc., mais les présentations peuvent être non spécifiques. Les erreurs de diagnostic sont très courantes le retard dans le diagnostic et le traitement rapide étant les causes demorbidité et mortalité élevées dans les leucémies aiguës. Cette étude vise à :déterminer le modèle de présentation et les diverses entités cliniques de leucémies aiguës dans l'État de Bauchi, au nord-est du Nigéria. SUBJETS, MATÉRIAUX ET MÉTHODES: Il s'agissait d'une étude rétrospective de trois ans dans laquelle des enregistrements de cas de leucémies aiguës diagnostiqués dans le département d'hématologie d'Abubakar Tafawa Balewa University Teaching Hospital (ATBUTH) Bauchi du registre de cytologie par aspiration de la moelle osseuse du 1er janvier 2018 au31 décembre 2020 ont été collectés. Données sociodémographiques caractéristiques des patients qui incluent l'âge, le sexe, le diagnostic comme ainsi que des sous-types de certaines des tumeurs malignes diagnostiquées ont également été rassemblé. Les données rassemblées ont été analysées à l'aide de SPSS version 20.0. Une valeur de p < 0,05 a été jugée significative. RÉSULTATS: Vingt-neuf cas de leucémies aiguës ont été diagnostiqués au cours de la période considérée. La majorité des cas avaient des cas aigus leucémie lymphoblastique (LAL) 19/29 (65,5 %) en myéloïde aiguëune leucémie (LAM) a été observée chez 10/29 (34,5 %). L'âge moyen ± du DS deles patients étaient âgés de 22,2 ±9,2 ans avec une fourchette de 6 mois à 60 ans.Les hommes constituaient 75,9 % (22/29) des cas de leucémies aiguës diagnostiqué. Les ratios hommesfemmes pour la LAM et la LAL étaient de 2:1 et2.6:1 respectivement. Les âges moyens ±SD pour la LAM et la LAL étaient les suivants:27±9,2 ans et 17,3±11,3 ans respectivement. Le plus commun la forme de présentation de la leucémie aiguë dans cette étude est récurrente anémie nécessitant une transfusion sanguine pendant la proptose et l'épistaxis étaient les formes les moins présentes. CONCLUSION: La leucémie lymphoblastique aiguë est la plus courante forme de leucémies aiguës tandis que l'anémie récurrente est la plus courante forme de présentations cliniques dans notre cadre. Orientation précoce des patients avec des caractéristiques cliniques suggérant des leucémies aiguës est recommandé. Mots-clés: Leucémie aiguë, Modèle de présentation, État de Bauchi.


Assuntos
Anemia , Leucemia Mieloide Aguda , Leucemia-Linfoma Linfoblástico de Células Precursoras , Doença Aguda , Adolescente , Adulto , Feminino , Humanos , Lactente , Masculino , Nigéria/epidemiologia , Estudos Retrospectivos , Adulto Jovem
7.
J Rehabil ; 88(1): 32-42, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-38528880

RESUMO

This scoping review mapped the pertinent extant published and grey literature and policy to assess factors that promote positive community living outcomes among people of color with disabilities and concomitant opioid use disorder (OUD) in the United States (U.S.). Forty-three publications covering OUD and people of color with disabilities and people of color with disabilities and community living content were reviewed. Select community living barriers and potential interventions were identified for people of color with disabilities in general; however, the review failed to classify such factors for those with OUD. Authors offered recommendations for practice, research, and policy.

8.
Helminthologia ; 59(4): 377-384, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36875675

RESUMO

The present study reports the prevalence of Paramphistomum spp. in small and large ruminants and their association with the histopathology of the infected rumens. A total of 384 animals were screened for Paramphistomum spp. The animals found positive for Paramphistomum spp. were divided into three groups according to the worm load/5 cm2 (G1: 10 - 20 worms/5 cm2 = Low, G2: 20 - 40 worms/5 cm2 = Medium, and G3: >41 worms/5 cm2 = High). Tissue slides were prepared from samples of the rumen (1 cm2) taken from animals positive for ruminal fluke to determine the histological parameters, including epithelial length or thickness, length and width of the ruminal papilla, and thickness of tunica submucosa and mucularis externae. The overall prevalence of Paramphistomum spp. in the ruminant population of district Narowal was 56.25 % with a significant (P < 0.05) variation among different species of ruminants. The highest prevalence was in cattle, followed in order by buffalo, goat, and sheep. Epithelium thickness was significantly correlated with parasite load in large ruminants and the most significant (P < 0.05) decrease in epithelium thickness was in Group B (31.12 ± 1.82 µm) and Group C (31.07 ± 1.68 µm) and a same trend was recorded in small ruminants. Histopathological changes due to Paramphistomum spp. are reported for the first time, which explained the histomorphological and physiological changes in Paramphistomum-infected rumens which might be associated with lowered feed efficiency and productivity in ruminants.

9.
Niger J Clin Pract ; 24(10): 1492-1498, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34657015

RESUMO

BACKGROUND: Pulpal involvement, secondary to dental caries, is not uncommon and is a challenging task for pediatric dentists. Morphological differences in root canal of deciduous teeth increases the complexity of management. The aim of this study was to compare two rotary file systems and hand instrumentation for root canal preparation in regard to canal transportation, centering ability ratio, and dentin thickness using cone-beam computed tomography (CBCT). METHODS: A total of 72 canals from 24 freshly extracted mandibular deciduous second molars were divided into a set of 8 teeth, then prepared using 2 rotary files systems: the Kedo-S pediatric file system (Group A) and Pro AF Baby Gold file system (Group B) were compared to hand instrumentation (Group C). CBCT scans before and after root canal preparation were used to evaluate tested parameters. Instrumentation time for all three techniques was also measured using a chronometer. RESULTS: Although rotary file systems have shown superior results in root canal preparation as compared to hand instrumentation, no significant differences were observed between all the groups for canal transportation and dentin thickness at all three levels of prepared canals. A comparison of centering ability ratio between all the groups was found to be statistically significant only at the cervical level. A significant difference was observed between hand instrumentation using K-files (117.3 s) and both rotary systems (Kedo-S (81 s) and Pro AF Baby Gold (81.5 s)) in terms of canal preparation time (P < 0.001). CONCLUSIONS: Both tested rotary systems and hand instrumentation demonstrated comparable canal preparation results, with differences that were statistically non-significant in most tested parameters, without shaping errors. However, both the rotary systems were more efficient and faster than hand instrumentation.


Assuntos
Cárie Dentária , Criança , Tomografia Computadorizada de Feixe Cônico , Cavidade Pulpar/diagnóstico por imagem , Cavidade Pulpar/cirurgia , Desenho de Equipamento , Humanos , Dente Molar/diagnóstico por imagem , Dente Molar/cirurgia , Preparo de Canal Radicular , Dente Decíduo
10.
Chembiochem ; 21(3): 392-400, 2020 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-31287209

RESUMO

Biomedicinally important histone lysine methyltransferases (KMTs) catalyze the transfer of a methyl group from S-adenosylmethionine (AdoMet) cosubstrate to lysine residues in histones and other proteins. Herein, experimental and computational investigations on human KMT-catalyzed ethylation of histone peptides by using S-adenosylethionine (AdoEth) and Se-adenosylselenoethionine (AdoSeEth) cosubstrates are reported. MALDI-TOF MS experiments reveal that, unlike monomethyltransferases SETD7 and SETD8, methyltransferases G9a and G9a-like protein (GLP) do have the capacity to ethylate lysine residues in histone peptides, and that cosubstrates follow the efficiency trend AdoMet>AdoSeEth>AdoEth. G9a and GLP can also catalyze AdoSeEth-mediated ethylation of ornithine and produce histone peptides bearing lysine residues with different alkyl groups, such as H3K9meet and H3K9me2et. Molecular dynamics and free energy simulations based on quantum mechanics/molecular mechanics potential supported the experimental findings by providing an insight into the geometry and energetics of the enzymatic methyl/ethyl transfer process.


Assuntos
Histona-Lisina N-Metiltransferase/metabolismo , Lisina/metabolismo , Biocatálise , Teoria da Densidade Funcional , Histona-Lisina N-Metiltransferase/química , Humanos , Lisina/química , Conformação Molecular , Simulação de Dinâmica Molecular
11.
Biochem J ; 476(7): 1109-1119, 2019 04 10.
Artigo em Inglês | MEDLINE | ID: mdl-30898847

RESUMO

The biologically important carnitine biosynthesis pathway in humans proceeds via four enzymatic steps. The first step in carnitine biosynthesis is catalyzed by trimethyllysine hydroxylase (TMLH), a non-heme Fe(II) and 2-oxoglutarate (2OG)-dependent oxygenase, which catalyzes the stereospecific hydroxylation of (2S)-Nε-trimethyllysine to (2S,3S)-3-hydroxy-Nε-trimethyllysine. Here, we report biocatalytic studies on human TMLH and its 19 variants introduced through site-directed mutagenesis. Amino acid substitutions at the sites involved in binding of the Fe(II) cofactor, 2OG cosubstrate and (2S)-Nε-trimethyllysine substrate provide a basic insight into the binding requirements that determine an efficient TMLH-catalyzed conversion of (2S)-Nε-trimethyllysine to (2S,3S)-3-hydroxy-Nε-trimethyllysine. This work demonstrates the importance of the recognition sites that contribute to the enzymatic activity of TMLH: the Fe(II)-binding H242-D244-H389 residues, R391-R398 involved in 2OG binding and several residues (D231, N334 and the aromatic cage comprised of W221, Y217 and Y234) associated with binding of (2S)-Nε-trimethyllysine.


Assuntos
Oxigenases de Função Mista/química , Sequência de Aminoácidos , Substituição de Aminoácidos , Biocatálise , Carnitina/biossíntese , Domínio Catalítico/genética , Humanos , Cinética , Oxigenases de Função Mista/genética , Oxigenases de Função Mista/metabolismo , Modelos Moleculares , Mutagênese Sítio-Dirigida , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Homologia de Sequência de Aminoácidos , Especificidade por Substrato , gama-Butirobetaína Dioxigenase/química , gama-Butirobetaína Dioxigenase/genética , gama-Butirobetaína Dioxigenase/metabolismo
12.
Ecotoxicol Environ Saf ; 196: 110518, 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32224367

RESUMO

Nano-sized Fe2Zr2-xWxO7 system was prepared using the Pacini method where x = 0, 0.05, 0.1 and 0.15. All the samples were characterized using chemical analysis, X-ray diffraction (XRD), Fourier-transform infrared (FT-IR), transmission electron microscopy (TEM), UV-vis diffuse reflectance measurements (DRS) and surface area measurements. The undoped Fe2Zr2O7 was crystallised in the cubic fluorite phase as a major phase in addition to rhombohedral phase of Fe2O3 and monoclinic phase of ZrO2 as the minor phases. Meanwhile, single cubic fluorite phase was defined for Fe2Zr0.85W0.15O7 sample. The last has the lowest band gap (1.69 eV) and the highest surface area (106 m2/g). From TEM, the average particle size of the prepared samples was in the range of (3-7 nm). The photocatalytic efficiency of the prepared Fe2Zr2-xWxO7 system was manifested by the degradation of methylene blue and real textile wastewater of blue colour. Ascending degradation efficiency was exhibited with increasing tungsten concentration which is in accordance with their band gap as well as their surface area values. The degradation rate using Fe2Zr0.85W0.15O7 sample obeys the pseudo-first order kinetic at the optimum degradation conditions (1.5 g/L catalyst and pH11). Fe2Zr0.85W0.15O7 showed promising photocatalytic activity for real textile wastewater where the 69% COD removal was obtained under the same conditions used for methylene blue degradation.


Assuntos
Compostos Férricos/química , Luz , Azul de Metileno/análise , Nanopartículas/química , Óxidos/química , Tungstênio/química , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Zircônio/química , Catálise , Azul de Metileno/química , Azul de Metileno/efeitos da radiação , Tamanho da Partícula , Águas Residuárias/química , Poluentes Químicos da Água/química , Poluentes Químicos da Água/efeitos da radiação , Difração de Raios X
13.
Molecules ; 25(8)2020 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-32326252

RESUMO

Gaining a fundamental insight into the biomolecular recognition of posttranslationally modified histones by epigenetic reader proteins is of crucial importance to understanding the regulation of the activity of human genes. Here, we seek to establish whether trimethylthialysine, a simple trimethyllysine analogue generated through cysteine alkylation, is a good trimethyllysine mimic for studies on molecular recognition by reader proteins. Histone peptides bearing trimethylthialysine and trimethyllysine were examined for binding with five human reader proteins employing a combination of thermodynamic analyses, molecular dynamics simulations and quantum chemical analyses. Collectively, our experimental and computational findings reveal that trimethylthialysine and trimethyllysine exhibit very similar binding characteristics for the association with human reader proteins, thereby justifying the use of trimethylthialysine for studies aimed at dissecting the origin of biomolecular recognition in epigenetic processes that play important roles in human health and disease.


Assuntos
Cisteína/análogos & derivados , Histonas/química , Lisina/análogos & derivados , Sítios de Ligação , Cisteína/síntese química , Cisteína/química , Epigênese Genética , Histonas/metabolismo , Humanos , Lisina/síntese química , Lisina/química , Metilação , Modelos Moleculares , Conformação Molecular , Ligação Proteica , Técnicas de Síntese em Fase Sólida , Relação Estrutura-Atividade , Termodinâmica
14.
Bioconjug Chem ; 30(6): 1798-1804, 2019 06 19.
Artigo em Inglês | MEDLINE | ID: mdl-31117351

RESUMO

Biomedicinally important histone lysine methyltransferases (KMTs) transfer a methyl group from S-adenosylmethionine to lysine residues in histones and other proteins. Here, we report comparative studies on epigenetic methylation of lysine and γ-thialysine, the simplest cysteine-derived lysine analog, which can be introduced to histone peptides and histone proteins via site-specific bioconjugation-based cysteine alkylation. Enzyme assays and computational studies demonstrate that human KMTs catalyze efficient methylation of histones that possess γ-thialysine. This work provides a molecular basis for the application of γ-thialysine for biomolecular studies of intact histones and the nucleosome assembly.


Assuntos
Cisteína/análogos & derivados , Histona-Lisina N-Metiltransferase/metabolismo , Histonas/metabolismo , Lisina/metabolismo , Cisteína/análise , Cisteína/metabolismo , Histonas/química , Humanos , Cinética , Lisina/análise , Metilação , Modelos Moleculares , Especificidade por Substrato
15.
Bioconjug Chem ; 30(3): 952-958, 2019 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-30794748

RESUMO

Site-specific incorporation of post-translationally modified amino acids into proteins, including histones, has been a subject of great interest for chemical and biochemical communities. Here, we describe a site-specific incorporation of structurally simplest trimethyllysine analogs into position 4 of the intact histone H3 protein. An efficient alkylation of cysteine 4 of the recombinantly expressed histone H3 provides a panel of trimethyllysine analogs that differ in charge, charge density, sterics, and chain length. We demonstrate that H3 histone that bears trimethyllysine analogs can be further assembled into the octameric histone complex that constitutes the nucleosome. Binding studies showed that H3 histone that possesses trimethyllysine analogs is well recognized by a PHD3 reader domain of human JARID1A. This work provides important (bio)chemical tools for fundamental biomolecular studies aimed at unravelling the molecular basis of the higher order nucleosome and chromatin assemblies.


Assuntos
Cisteína/química , Histonas/química , Lisina/análogos & derivados , Alquilação , Animais , Eletroforese em Gel de Poliacrilamida , Histonas/metabolismo , Humanos , Lisina/química , Processamento de Proteína Pós-Traducional , Proteína 2 de Ligação ao Retinoblastoma/metabolismo , Espectrometria de Massas por Ionização por Electrospray , Xenopus laevis
16.
Org Biomol Chem ; 17(23): 5693-5697, 2019 06 12.
Artigo em Inglês | MEDLINE | ID: mdl-31134245

RESUMO

Histone lysine methyltransferases (KMTs) are biomedicinally important class of epigenetic enzymes that catalyse methylation of lysine residues in histones and other proteins. Enzymatic and computational studies on the simplest lysine analogues that possess a modified main chain demonstrate that the lysine's backbone contributes significantly to functional KMT binding and catalysis.


Assuntos
Histona-Lisina N-Metiltransferase/metabolismo , Histonas/química , Histonas/metabolismo , Lisina/química , Lisina/metabolismo , Histona-Lisina N-Metiltransferase/genética , Modelos Moleculares , Estrutura Molecular , Termodinâmica
17.
Bioorg Med Chem Lett ; 28(7): 1234-1238, 2018 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-29519735

RESUMO

Histone lysine methyltransferases G9a and GLP are validated targets for the development of new epigenetic drugs. Most, if not all, inhibitors of G9a and GLP target the histone substrate binding site or/and the S-adenosylmethionine cosubstrate binding site. Here, we report an alternative approach for inhibiting the methyltransferase activity of G9a and GLP. For proper folding and enzymatic activity, G9a and GLP contain structural zinc fingers, one of them being adjacent to the S-adenosylmethionine binding site. Our work demonstrates that targeting these labile zinc fingers with electrophilic small molecules results in ejection of structural zinc ions, and consequently inhibition of the methyltransferase activity. Very effective Zn(II) ejection and inhibition of G9a and GLP was observed with clinically used ebselen, disulfiram and cisplatin.


Assuntos
Inibidores Enzimáticos/farmacologia , Histona-Lisina N-Metiltransferase/antagonistas & inibidores , Bibliotecas de Moléculas Pequenas/farmacologia , Dedos de Zinco/efeitos dos fármacos , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Antígenos de Histocompatibilidade/química , Antígenos de Histocompatibilidade/metabolismo , Histona-Lisina N-Metiltransferase/química , Histona-Lisina N-Metiltransferase/metabolismo , Humanos , Estrutura Molecular , Bibliotecas de Moléculas Pequenas/síntese química , Bibliotecas de Moléculas Pequenas/química , Relação Estrutura-Atividade
18.
Ecotoxicol Environ Saf ; 163: 620-628, 2018 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-30096663

RESUMO

Nanosized BaFe1-xCuxO3 powders were prepared using the Pechini method. To limit grain growth and agglomeration, the temperature of calcination was limited to 800 °C. For all samples, the cubic form of BaFeO2.75 was predominant with minor additional phases. Cu doping was found to have a remarkable effect on the structural cubic unit cell parameter as the Cu concentration increased. As shown by XRD,the samples were in the nanometer size range (17-63 nm). However, as the Cu concentration increases, the agglomeration increases with the highest surface area for the BaFe0.95Cu0.05O3 composition, which also displays the highest photocatalytic atrazine degradation. For this sample, more than 90% degradation of atrazine was obtained at the optimum conditions (120 min irradiation under visible light at pH 11 using 0.75 mg of the catalyst). The Atrazine degradation was found to follow the pseudo-order kinetics. GC/MS was used to detect the intermediates and the reaction pathways. All the prepared samples and produced waters at the end of the experiment were found to be nontoxic.


Assuntos
Atrazina/efeitos da radiação , Herbicidas/efeitos da radiação , Luz , Óxidos/química , Atrazina/química , Catálise , Herbicidas/química , Cinética , Óxidos/efeitos da radiação , Fotólise , Temperatura
19.
Ann Pharm Fr ; 76(2): 97-106, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29145995

RESUMO

To avoid frequent drug administration, PLGA-based monolithic filament-shaped implants were prepared. In this study, the effect of different formulation variables was studied, namely: type of PLGA (PLGA 502 and PLGA 503), type of drug (the lipophilic Prednisolone acetate, PA and the hydrophilic Propranolol Hydrochloride, PH) and drug loading (10 and 30% w/w). PLGA 503-based implants showed a lower water uptake, lower mass loss and erosion, slower drug release, and better mechanical properties and elasticity (P<0.05) compared to the corresponding PLGA 502-based implants. PH-loaded implants showed a faster swelling and degradation as well as drug release (P<0.05) compared to PA-loaded implants; the former attained almost complete drug release after about 18 days, while the latter attained it after about 30 days. All the implants followed a zero-order kinetic pattern suitable for a controlled drug release. Characterization was done using SEM and DSC. This study proved the potential tailoring of the properties of PLGA-implants, prepared by hot-melt extrusion (HME), based on some formulation variables.


Assuntos
Implantes de Medicamento , Ácido Láctico/química , Ácido Poliglicólico/química , Varredura Diferencial de Calorimetria , Química Farmacêutica , Portadores de Fármacos , Composição de Medicamentos , Excipientes , Temperatura Alta , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Prednisolona/administração & dosagem , Propranolol/administração & dosagem , Água/química
20.
Bioconjug Chem ; 28(8): 2160-2166, 2017 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-28697600

RESUMO

A novel synthetic methodology, employing a combination of the strain-promoted azide-alkyne cycloaddition and maleimide-thiol reactions, for the preparation of permethylated ß-cyclodextrin-linker-peptidyl conjugates is reported. Two different bifunctional maleimide cross-linking probes, the polyethylene glycol containing hydrophilic linker bicyclo[6.1.0] nonyne-maleimide and the hydrophobic 5'-dibenzoazacyclooctyne-maleimide, were attached to azide-appended permethylated ß-cyclodextrin. The successfully introduced maleimide function was exploited to covalently graft a cysteine-containing peptide (Ac-Tyr-Arg-Cys-Amide) to produce the target conjugates. The final target compounds were isolated in high purity after purification by isocratic preparative reverse-phase high-performance liquid chromatography. This novel synthetic approach is expected to give access to many different cyclodextrin-linker peptides.


Assuntos
Interações Hidrofóbicas e Hidrofílicas , Oligopeptídeos/química , beta-Ciclodextrinas/química , Alcinos/química , Sequência de Aminoácidos , Azidas/química , Maleimidas/química , Metilação , Compostos de Sulfidrila/química
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