Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
ACS Chem Biol ; 19(4): 855-860, 2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38452396

RESUMO

Triceptides are cyclophane-containing ribosomally synthesized and post-translationally modified peptides. The characteristic cross-links are formed between an aromatic ring to Cß on three-residue Ω1X2X3 motifs (Ω1 = aromatic). Here, we explored the promiscuity of the XYE family triceptide maturase, XncB from Xenorhabdus nematophila DSM 3370. Single amino acid variants were coexpressed with XncB in vivo in Escherichia coli, and we show that a variety of amino acids can be incorporated into the Phe-Gly-Asn cyclophane. Aromatic amino acids at the X3 position were accepted by the enzyme but yielded hydroxylated, rather than the typical cyclophane, products. These studies show that oxygen can be inserted but diverges in the final product formed relative to daropeptide maturases. Finally, truncations of the leader peptide showed that it is necessary for complete modification by XncB.


Assuntos
Aminoácidos , Peptídeos , Xenorhabdus , Aminoácidos/metabolismo , Peptídeos/química , Sinais Direcionadores de Proteínas , Xenorhabdus/química , Xenorhabdus/enzimologia , Xenorhabdus/genética , Xenorhabdus/metabolismo , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Especificidade por Substrato
2.
Mar Drugs ; 22(3)2024 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-38535455

RESUMO

Extensive research has been conducted on the isolation and study of bioactive compounds derived from marine sources. Several natural products have demonstrated potential as inducers of apoptosis and are currently under investigation in clinical trials. These marine-derived compounds selectively interact with extrinsic and intrinsic apoptotic pathways using a variety of molecular mechanisms, resulting in cell shrinkage, chromatin condensation, cytoplasmic blebs, apoptotic bodies, and phagocytosis by adjacent parenchymal cells, neoplastic cells, or macrophages. Numerous marine-derived compounds are currently undergoing rigorous examination for their potential application in cancer therapy. This review examines a total of 21 marine-derived compounds, along with their synthetic derivatives, sourced from marine organisms such as sponges, corals, tunicates, mollusks, ascidians, algae, cyanobacteria, fungi, and actinobacteria. These compounds are currently undergoing preclinical and clinical trials to evaluate their potential as apoptosis inducers for the treatment of different types of cancer. This review further examined the compound's properties and mode of action, preclinical investigations, clinical trial studies on single or combination therapy, and the prospective development of marine-derived anticancer therapies.


Assuntos
Actinobacteria , Antozoários , Antineoplásicos , Neoplasias , Animais , Estudos Prospectivos , Ensaios Clínicos como Assunto
3.
ACS Chem Biol ; 19(3): 774-783, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38417140

RESUMO

Enzymes catalyzing peptide macrocyclization are important biochemical tools in drug discovery. The three-residue cyclophane-forming enzymes (3-CyFEs) are an emerging family of post-translational modifying enzymes that catalyze the formation of three-residue peptide cyclophanes. In this report, we introduce three additional 3-CyFEs, including ChlB, WnsB, and FnnB, that catalyze cyclophane formation on Tyr, Trp, and Phe, respectively. To understand the promiscuity of these enzymes and those previously reported (MscB, HaaB, and YxdB), we tested single amino acid substitutions at the three-residue motif of modification (Ω1X2X3, Ω1 = aromatic). Collectively, we observe that substrate promiscuity is observed at the Ω1 and X2 positions, but a greater specificity is observed for the X3 residue. Two nonnative cyclophane products were characterized showing a Phe-C3 to Arg-Cß and His-C2 to Pro-Cß cross-links, respectively. We also tested the leader dependence of selected 3-CyFEs and show that a predicted helix region is important for cyclophane formation. These results demonstrate the biocatalytic potential of these maturases and allow rational design of substrates to obtain a diverse array of genetically encoded 3-residue cyclophanes.


Assuntos
Ciclofanos , Peptídeos , Sequência de Aminoácidos , Ciclização , Peptídeos/química , Processamento de Proteína Pós-Traducional
4.
Med. U.P.B ; 42(2): 17-25, jul.-dic. 2023. tab, ilus
Artigo em Espanhol | LILACS, COLNAL | ID: biblio-1443360

RESUMO

Objetivo: el estiramiento muscular se aplica con el propósito de aumentar el arco de movimiento. Para este propósito se usan diferentes técnicas, entre ellas: la facilitación neuromuscular propioceptiva (FNP) y el estiramiento dinámico, pero aún no se conoce cuál de ellas es más efectiva. El objetivo de esta investigación fue estimar la eficacia de la técnica sostener relajar en comparación con el estiramiento dinámico sobre la flexibilidad de los isquiotibiales en adultos jóvenes sanos. Metodología: ensayo clínico controlado aleatorizado, con enmascaramiento de dos brazos. En el estudio participaron un total de 32 voluntarios adultos jóvenes con edades entre los 18 y 30 años y fueron aleatorizados a dos grupos de intervención FNP (n = 16), dinámico (n = 16). La flexibilidad de la articulación de la rodilla se evaluó mediante el ángulo poplíteo a través de la goniometría. Resultados: los resultados de las medias edad, peso, talla e índice masa corporal son equivalentes, lo que indica grupos comparables entre sí. No se hallaron diferencias entre los grupos de estiramiento en los promedios ajustados -2.09 (IC95% -7.05 a 2.87). Conclusiones: tanto la técnica dinámica como la FNP aumentaron el arco de movimiento de rodilla, ambas técnicas de estiramiento mostraron diferencias con la línea de base. No se encontraron diferencias entre los grupos de estiramiento.


Objective: Muscle stretching is applied with the purpose of increasing range of motion. Different techniques are used for this purpose, including proprioceptive neuromuscular facilitation (PNF) and dynamic stretching, but it is still unclear which one is more effective. The objective of this research was to estimate the efficacy of the hold-relax technique compared to dynamic stretching on hamstring flexibility in healthy young adults. Methodology: Randomized controlled trial with blinding, consisting of two intervention arms. The study included a total of 32 young adult volunteers aged 18 to 30 years, who were randomized into two intervention groups: PNF (n = 16) and dynamic stretching (n = 16). Knee joint flexibility was assessed using the popliteal angle measured with a goniometer. Results: The mean age, weight, height, and body mass index were found to be equivalent, indicating comparable groups. No significant differences were found between the stretching groups in the adjusted means, with a mean difference of -2.09 (95 % CI -7.05 to 2.87). Conclusions: Both dynamic stretching and PNF demonstrated an increase in knee range of motion, with both stretching techniques showing differences from the baseline. No significant differences were found between the stretching groups.


Finalidade: O alongamento muscular é aplicado com a finalidade de aumentar a ampli-tude de movimento. Para tanto, diversas técnicas são utilizadas, dentre elas: facilitação neuromuscular proprioceptiva (FNP) e alongamento dinâmico, mas ainda não se sabe qual delas é mais eficaz. O objetivo desta investigação foi estimar a eficáciada técnica segurar-relaxar em comparação com o alongamento dinâmico na flexibilidade dos isquiotibiais em adultos jovens saudáveis. Metodologia: Ensaio clínico randomizado, cego, controlado por dois braços. Um total de 32 voluntários adultos jovens com idades entre 18 e 30 anos participaram do estudo e foram randomizados para dois grupos de intervenção FNP (n = 16), dinâmico (n = 16). A flexibilidade da articulação do joelho foi avaliada por meio do ângulo poplíteo por goniometria. Resultados: os resultados das médias de idade, peso, altura e índice de massa corporal são equivalentes, o que indica grupos comparáveis entre si. Não foram encontradas dife-renças entre os grupos de alongamento nas médias ajustadas - 2,09 (IC 95 % -7,05 a 2,87). Conclusões: tanto a técnica dinâmica quanto o PNF aumentaram a amplitude de mo-vimento do joelho, ambas as técnicas de alongamento apresentaram diferenças com a linha de base. Não foram encontradas diferenças entre os grupos de alongamento.


Assuntos
Humanos
5.
J Surg Case Rep ; 2023(1): rjac626, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36636660

RESUMO

Obesity is a chronic disease with pandemic levels of prevalence worldwide. The most often performed bariatric procedure is sleeve gastrectomy. Although the patient's history may not indicate preoperative imaging studies, coincidental findings of unexpected pathology are not uncommon, such as leiomyoma. A 41-year-old female was scheduled to laparoscopic gastric sleeve with no contraindications for surgery. A tumor-like mass was identified on the left lateral face of the distal third of the esophagus. Trans-surgical endoscopy and pneumatic test were performed to rule out any type of communication. The surgeon managed to remove the tumor mass, that was sent to histopathological study, and concluded the procedure without complications. Benign tumors of the esophagus are rarely found lesions. Occasionally unexpected findings may occur during surgery, and they should be resolved intraoperatively when possible to allow the completion of the originally planned surgical procedure.

6.
J Am Chem Soc ; 144(26): 11580-11593, 2022 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-35729768

RESUMO

Peptide-derived cyclophanes inhabit a unique niche in the chemical space of macrocyclic peptides with several examples of pharmaceutical importance. Although both synthetic and biocatalytic methods are available for constructing these macrocycles, versatile (bio)catalysts able to incorporate a variety of amino acids that compose the macrocycle would be useful for the creation of diverse peptide cyclophanes. In this report, we synergized the use of bioinformatic tools to map the biosynthetic landscape of radical SAM enzymes (3-CyFEs) that catalyze three-residue cyclophane formation in the biosynthesis of a new family of RiPP natural products, the triceptides. This analysis revealed 3940 (3113 unique) putative precursor sequences predicted to be modified by 3-CyFEs. Several uncharacterized maturase systems were identified that encode unique precursor types. Functional studies were carried out in vivo in Escherichia coli to identify modified precursors containing His and Tyr residues. NMR analysis of the products revealed that Tyr and His can also be incorporated into cyclophane macrocycles by 3-CyFEs. Collectively, all aromatic amino acids can be incorporated by 3-CyFEs, and the cyclophane formation strictly occurs via a C(sp2)-C(sp3) cross-link between the (hetero)aromatic ring to Cß. In addition to 3-CyFEs, we functionally validated an Fe(II)/α-ketoglutarate-dependent hydroxylase, resulting in ß-hydroxylated residues within the cyclophane rings. This study reveals the potential breadth of triceptide precursors and a systematic approach for studying these enzymes to broaden the diversity of peptide macrocycles.


Assuntos
Biologia Computacional , Peptídeos , Catálise , Biologia Computacional/métodos , Escherichia coli/metabolismo , Peptídeos/química
7.
Molecules ; 26(6)2021 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-33802916

RESUMO

Honey exhibits antibacterial and antioxidant activities that are ascribed to its diverse secondary metabolites. In the Philippines, the antibacterial and antioxidant activities, as well as the bioactive metabolite contents of the honey, have not been thoroughly described. In this report, we investigated the in vitro antibacterial and antioxidant activities of honey from Apis mellifera and Tetragonula biroi, identified the compound responsible for the antibacterial activity, and compared the observed bioactivities and metabolite profiles to that of Manuka honey, which is recognized for its antibacterial and antioxidant properties. The secondary metabolite contents of honey were extracted using a nonionic polymeric resin followed by antibacterial and antioxidant assays, and then spectroscopic analyses of the phenolic and flavonoid contents. Results showed that honey extracts produced by T. biroi exhibits antibiotic activity against Staphylococcal pathogens as well as high antioxidant activity, which are correlated to its high flavonoid and phenolic content as compared to honey produced by A. mellifera. The bioassay-guided fractionation paired with Liquid Chromatography Mass Spectrometry (LCMS) and tandem MS analyses found the presence of the flavonoid isorhamnetin (3-methylquercetin) in T. biroi honey extract, which was demonstrated as one of the compounds with inhibitory activity against multidrug-resistant Staphylococcus aureus ATCC BAA-44. Our findings suggest that Philippine honey produced by T. biroi is a potential nutraceutical that possesses antibiotic and antioxidant activities.


Assuntos
Antibacterianos/farmacologia , Abelhas/química , Mel/análise , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Quercetina/análogos & derivados , Animais , Antibacterianos/isolamento & purificação , Antioxidantes/análise , Antioxidantes/farmacologia , Abelhas/metabolismo , Cromatografia Líquida , Flavonoides/análise , Flavonoides/farmacologia , Testes de Sensibilidade Microbiana , Fenóis/análise , Fenóis/farmacologia , Filipinas , Quercetina/farmacologia , Análise Espectral , Staphylococcus aureus/efeitos dos fármacos , Espectrometria de Massas em Tandem
8.
Front Microbiol ; 11: 743, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32390983

RESUMO

The rise of antibiotic resistance (ABR) and the drying up of the pipeline for the development of new antibiotics demands an urgent search for new antibiotic leads. While the majority of clinically available antibiotics were discovered from terrestrial Streptomyces, related species from marine sediments as a source of antibiotics remain underexplored. Here, we utilized culture-dependent isolation of thirty-five marine sediment-derived actinobacterial isolates followed by a screening of their antibacterial activity against multidrug-resistant S. aureus ATCC BAA-44. Our results revealed that the crude extract of Streptomyces griseorubens strain DSD069 isolated from marine sediments collected in Romblon, Philippines displays the highest antibacterial activity, with 96.4% growth inhibition. The S. aureus ATCC BAA-44 cells treated with crude extract of Streptomyces griseorubens strain DSD069 showed cell membrane damage as demonstrated by (a) leakage and loss of vital cell constituents, including DNA and proteins, (b) irregular shrinkage of cells, and (c) increase membrane permeability. The antibiotic compounds were identified as Bisanhydroaklavinone and 1-Hydroxybisanhydroaklavinone with MIC value of 6.25 µg/mL and 50.00 µg/mL, respectively. Bisanhydroaklavinone and 1-Hydroxybisanhydroaklavinone are shunt metabolites in the biosynthesis of anticancer anthracycline derivatives namely doxorubicin, daunorubicin, and cinerubins. It is rare, however, that shunt metabolites are accumulated during fermentation of marine sediment-derived Streptomyces strain without genetic modification. Thus, our study provides evidence that natural bacterial strain can produce Bisanhydroaklavinone and 1-Hydroxybisanhydroaklavinone as antibiotic leads to combat ABR.

9.
Rev. cuba. med. gen. integr ; 36(1): e1089, ene.-mar. 2020. tab
Artigo em Espanhol | LILACS, CUMED | ID: biblio-1099073

RESUMO

Introducción: La medición del Fracture Risk Assessment Tool - FRAX® es útil en Atención Primaria de Salud para evaluar el riesgo de fractura. Objetivo: Determinar el riesgo de fractura osteoporótica en adultos mayores. Métodos: Se realizó un estudio descriptivo de corte transversal, con una muestra de 54 adultos pertenecientes al grupo Club Nueva Vida de la Ciudad de Tunja, primer semestre de 2018, seleccionados por medio de un muestreo no probabilístico a conveniencia. Se empleó la herramienta FRAX®, propuesta por la Organización Mundial de la Salud y se realizó un análisis estadístico con el Chi2 de Pearson y la Razón de Prevalencia. Resultados: El factor de riesgo con mayor presencia fue la osteoporosis secundaria en 51,9 por ciento, donde 13 por ciento reporta FRAX®+ para probabilidad a 10 años de fractura mayor osteoporótica y 14,8 por ciento obtuvo FRAX®+ para probabilidad a 10 años de fractura de cadera sin densitometría ósea. Conclusiones: El FRAX®, es una herramienta útil en la prevención de problemas de salud resultado de fracturas que conllevan a alteraciones en la capacidad funcional y el movimiento(AU)


Introduction: The measurement of the Fracture Risk Assessment Tool - FRAX® is useful in primary healthcare for assessing the risk of fracture. Objective: To determine the risk of osteoporotic fracture in older adults. Methods: A descriptive and cross-sectional study was carried out, with a sample of 54 adults belonging to the Club Nueva Vida group of the City of Tunja, first semester of 2018, selected by means of a nonprobabilistic sampling at convenience. The FRAX® tool, proposed by the World Health Organization, was used, and statistical analysis was performed with Pearson's Chi2 and the prevalence ratio. Results: The risk factor with the highest presence was secondary osteoporosis in 51.9 percent, where 13 percent reported FRAX® + for a 10-year probability of major osteoporotic fracture and 14.8 percent obtained FRAX®+ for a 10-year probability of hip fracture without bone densitometry. Conclusions: FRAX® is a useful tool in the prevention of health problems resulting from fractures that lead to alterations in functional capacity and movement(AU)


Assuntos
Humanos , Masculino , Feminino , Idoso , Idoso de 80 Anos ou mais , Índice de Massa Corporal , Saúde do Idoso , Fatores de Risco , Densitometria/métodos , Fraturas por Osteoporose/epidemiologia , Epidemiologia Descritiva , Estudos Transversais
10.
Microbiologyopen ; 8(4): e00572, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30851083

RESUMO

The vast microbial diversity on the planet represents an invaluable source for identifying novel activities with potential industrial and therapeutic application. In this regard, metagenomics has emerged as a group of strategies that have significantly facilitated the analysis of DNA from multiple environments and has expanded the limits of known microbial diversity. However, the functional characterization of enzymes, metabolites, and products encoded by diverse microbial genomes is limited by the inefficient heterologous expression of foreign genes. We have implemented a pipeline that combines NGS and Sanger sequencing as a way to identify fosmids within metagenomic libraries. This strategy facilitated the identification of putative proteins, subcloning of targeted genes and preliminary characterization of selected proteins. Overall, the in silico approach followed by the experimental validation allowed us to efficiently recover the activity of previously hidden enzymes derived from agricultural soil samples. Therefore, the methodology workflow described herein can be applied to recover activities encoded by environmental DNA from multiple sources.


Assuntos
Bactérias/enzimologia , Proteínas de Bactérias/genética , Enzimas/genética , Biblioteca Gênica , Metagenômica/métodos , Solo/química , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Proteínas de Bactérias/metabolismo , Enzimas/metabolismo , Sequenciamento de Nucleotídeos em Larga Escala , Microbiologia do Solo
11.
Rev. MVZ Córdoba ; 21(3): 5535-5546, Dec. 2016. tab, graf
Artigo em Inglês | LILACS | ID: biblio-957318

RESUMO

ABSTRACT Objective . To characterize and identify yeasts of the genus Malassezia by phenotypic features. Materials and methods. First, the macroscopic and microscopic morphological characteristics were described. In addition we performed biochemical and physiological assays as Tweens and Cremophor, including more. Results. Our results evidenced of 105 isolates obtained from dogs diagnosed with external otitis, it was possible to identify two distinct species from 46 isolates within the Malassezia genus: 36.19% (n=38) were identified as M. pachydermatis and 7.62% (n=8) as M. furfur. According to phenotypic patterns the remaining 56.19% (n=59) were reported as Malassezia spp., possibly corresponding to M. furfur and/or M. pachydermatis. Conclusions. Results emphasize the necessity to characterize according to species. It is not feasible to define Malassezia by species based on morphological, biochemical, and physiological findings. Therefore, molecular genotyping should be performed to identify markers allowing a more precise isolate identification. This would broaden our epidemiological knowledge regarding different species involved in canine otitis pathologies.


RESUMEN Objetivo . Caracterizar e identificar levaduras del género Malassezia, mediante características fenotípicas. Materiales y métodos . Inicialmente se describieron las características morfológicas macroscópicas y microscópicas, adicionalmente se realizaron pruebas bioquímicas y fisiológicas como Tween y Cremophor, entre otras. Resultados . De 105 aislamientos de caninos diagnosticados previamente con otitis, 46 fueron caracterizados hasta especie, así: El 36.19% (n=38) correspondió a M. pachydermatis, el 7.2% (n=8) a M. furfur; y 56.19% (n=59) restante fueron reportados como Malassezia spp., debido a los patrones fenotípicos atípicos que presentaron, y que podrían corresponder a variantes de M. furfur y/o M. pachydermatis. Conclusión. Estos resultados enfatizan la necesidad de hacer una caracterización a nivel de especie y/o genotipos mediante marcadores moleculares que permitan una identificación más precisa de los aislamientos. Con el presente estudio, se contribuye al conocimiento de las diferentes especies involucradas en patologías óticas en caninos.

12.
Rev. Hosp. Psiquiátr. La Habana ; 25(1): 1-8, ene.-mar. 1984.
Artigo em Espanhol | LILACS | ID: lil-33334

RESUMO

El estudio de los mayores de 15 años en una muestra probabilística de conglomerados familiares en un área de salur evidenció una mayor proporción de consumo de tabaco, café y alcohol en el sexo masculino; proporciones importantes de consumidores de tabaco y café en que se reportaron síntomas de abstinencia ante la supresión brusca del tóxico; y cifras de 2,4% y 1,7% de sujetos reportados como bebedores abusivos entre el subtotal de consumidores y el total de integrantes de la muestra respectivamente, cifras muy inferiores a las reportadas en otras latitudes. Los autores recomiendan realizar estudios de mayor casuística o incrementar la divulgación de los riesgos del consumo de café y alcohol, de forma excesiva


Assuntos
Adolescente , Humanos , Masculino , Feminino , Alcoolismo , Café , Nicotiana , Cuba
13.
Rev. Hosp. Psiquiátr. La Habana ; 25(1): 1-8, ene.-mar. 1984.
Artigo em Espanhol | CUMED | ID: cum-5063

RESUMO

El estudio de los mayores de 15 años en una muestra probabilística de conglomerados familiares en un área de salur evidenció una mayor proporción de consumo de tabaco, café y alcohol en el sexo masculino; proporciones importantes de consumidores de tabaco y café en que se reportaron síntomas de abstinencia ante la supresión brusca del tóxico; y cifras de 2,4% y 1,7% de sujetos reportados como bebedores abusivos entre el subtotal de consumidores y el total de integrantes de la muestra respectivamente, cifras muy inferiores a las reportadas en otras latitudes. Los autores recomiendan realizar estudios de mayor casuística o incrementar la divulgación de los riesgos del consumo de café y alcohol, de forma excesiva (AU)


Assuntos
Adolescente , Humanos , Masculino , Feminino , Alcoolismo , Café , Nicotiana , Cuba
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...