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1.
Proc Natl Acad Sci U S A ; 120(38): e2301518120, 2023 09 19.
Artigo em Inglês | MEDLINE | ID: mdl-37695910

RESUMO

SARS-CoV-2 spike harbors glycans which function as ligands for lectins. Therefore, it should be possible to exploit lectins to target SARS-CoV-2 and inhibit cellular entry by binding glycans on the spike protein. Burkholderia oklahomensis agglutinin (BOA) is an antiviral lectin that interacts with viral glycoproteins via N-linked high mannose glycans. Here, we show that BOA binds to the spike protein and is a potent inhibitor of SARS-CoV-2 viral entry at nanomolar concentrations. Using a variety of biophysical approaches, we demonstrate that the interaction is avidity driven and that BOA cross-links the spike protein into soluble aggregates. Furthermore, using virus neutralization assays, we demonstrate that BOA effectively inhibits all tested variants of concern as well as SARS-CoV 2003, establishing that multivalent glycan-targeting molecules have the potential to act as pan-coronavirus inhibitors.


Assuntos
COVID-19 , Humanos , RNA Viral , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus , Internalização do Vírus , Aglutininas , Lectinas , Polissacarídeos/farmacologia
2.
Rev. méd. Chile ; 151(5)mayo 2023.
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1560213

RESUMO

Background: The largest growth in cases of COVID-19 worldwide during 2020 was in the Americas, and Chile was one of the most affected countries. Aim: To describe, characterize, and evaluate the use of drugs as treatment for COVID-19 in hospitalized patients in Chile during the first wave of the pandemic. Methods: We performed a multicenter, observational study that included 442 patients with confirmed SARS-CoV-2 infection admitted in Chilean hospitals between March 21 and September 22, 2020. The analysis included demographics, comorbidities, specific drug therapy, and outcomes over a 28-day follow-up period. Results: The median age of patients was 68 years (IQR 55-73), and 38.9% were women. The most common comorbidities were hypertension (57.7%) and diabetes (36.9%). Fifty-seven (12.9%) patients died. Hypertension (HR 2.99; CI 95% 1.43-6.26) and age ≥ 65 (2.14; CI 95% 1.10- 4.17) were the main predictors of mortality. Primary drugs were azithromycin (58.8%) and corticosteroids (51.1%). In this sample, azithromycin was a protective factor regarding mortality (HR 0.53; CI 95% 0.31-0.90), increasing clinical improvement and avoiding progression. Conclusions: The patterns of use of drugs to treat COVID-19 in Chile during the first wave of the pandemic were very dynamic and followed the international, evidence-based guidelines. The low mortality rate indicates that the clinical management of hospitalized patients was adequate.


Antecedentes: Durante 2020, el mayor incremento de casos de COVID-19 se observó en el continente americano, donde Chile fue uno de los países más afectados. Objetivos: Describir, caracterizar y evaluar el uso de fármacos indicados para tratar el COVID-19 en pacientes hospitalizados en Chile durante la primera ola de pandemia. Pacientes y Métodos: Un estudio multicéntrico observacional incorporó a 442 pacientes con infección confirmada por SARS- CoV-2 admitidos en hospitales chilenos entre el 21 de marzo y el 22 de septiembre de 2020. Se analizaron variables demográficas, comorbilidades, terapia farmacológica específica y desenlaces clínicos para un período de seguimiento de 28 días. Resultados: La mediana de la edad fue de 68 años (RIC 55-73), y un 38,9% fueron mujeres. Las comorbilidades más comunes fueron hipertensión (57,7%) y diabetes (36,9%). Cincuenta y siete (12,9%) de los pacientes murieron. Los principales predictores de mortalidad fueron la hipertensión (HR 2,99; IC 95% 1,43-6,26) y la edad ≥ 65 años (2,14; IC 95% 1,10- 4,17). Los fármacos más utilizados fueron azitromicina (58,8%) y corticosteroides (51,1%). En esta muestra, la azitromicina fue un factor de protección respecto a la mortalidad (HR 0,53; IC 95% 0,31-0,90), incrementando igualmente la mejoría y evitando la progresión. Conclusiones: Los patrones de uso de fármacos para tatar COVID-19 en Chile durante la primera ola de pandemia fueron muy dinámicos y siguieron las directrices internacionales basadas en la evidencia. La baja mortalidad sugiere que el manejo de los pacientes hospitalizados fue adecuado.

3.
bioRxiv ; 2023 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-38187617

RESUMO

Reverse transcription of the retroviral single-stranded RNA into double-stranded DNA is an integral step during HIV-1 replication, and reverse transcriptase (RT) is a primary target for antiviral therapy. Despite a wealth of structural information on RT, we lack critical insight into the intermediate kinetic states of DNA synthesis. Using catalytically active substrates, and a novel blot/diffusion cryo-electron microscopy approach, we captured 11 structures that define the substrate binding, reactant, transition and product states of dATP addition by RT at 1.9 to 2.4 Å resolution in the active site. Initial dATP binding to RT-template/primer complex involves a single Mg 2+ (site B), and promotes partial closure of the active site pocket by a large conformational change in the ß3-ß4 loop in the Fingers domain, and formation of a negatively charged pocket where a second "drifting" Mg 2+ can bind (site A). During the transition state, the α-phosphate oxygen from a previously unobserved dATP conformer aligns with the site A Mg 2+ and the primer 3'-OH for nucleophilic attack. In the product state, we captured two substrate conformations in the active site: 1) dATP that had yet to be incorporated into the nascent DNA, and 2) an incorporated dAMP with the pyrophosphate leaving group coordinated by metal B and stabilized through H- bonds in the active site of RT. This study provides insights into a fundamental chemical reaction that impacts polymerase fidelity, nucleoside inhibitor drug design, and mechanisms of drug resistance.

4.
Rev Med Chil ; 151(5): 541-550, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-38687535

RESUMO

BACKGROUND: The largest growth in cases of COVID-19 worldwide during 2020 was in the Americas, and Chile was one of the most affected countries. AIM: To describe, characterize, and evaluate the use of drugs as treatment for COVID-19 in hospitalized patients in Chile during the first wave of the pandemic. METHODS: We performed a multicenter, observational study that included 442 patients with confirmed SARS-CoV-2 infection admitted in Chilean hospitals between March 21 and September 22, 2020. The analysis included demographics, comorbidities, specific drug therapy, and outcomes over a 28-day follow-up period. RESULTS: The median age of patients was 68 years (IQR 55-73), and 38.9% were women. The most common comorbidities were hypertension (57.7%) and diabetes (36.9%). Fifty-seven (12.9%) patients died. Hypertension (HR 2.99; CI 95% 1.43-6.26) and age ≥ 65 (2.14; CI 95% 1.10- 4.17) were the main predictors of mortality. Primary drugs were azithromycin (58.8%) and corticosteroids (51.1%). In this sample, azithromycin was a protective factor regarding mortality (HR 0.53; CI 95% 0.31-0.90), increasing clinical improvement and avoiding progression. CONCLUSIONS: The patterns of use of drugs to treat COVID-19 in Chile during the first wave of the pandemic were very dynamic and followed the international, evidence-based guidelines. The low mortality rate indicates that the clinical management of hospitalized patients was adequate.


Assuntos
Tratamento Farmacológico da COVID-19 , COVID-19 , Hospitalização , Humanos , Chile/epidemiologia , Feminino , Masculino , Pessoa de Meia-Idade , Idoso , COVID-19/epidemiologia , COVID-19/mortalidade , Hospitalização/estatística & dados numéricos , SARS-CoV-2 , Resultado do Tratamento , Comorbidade , Pandemias , Azitromicina/uso terapêutico , Antivirais/uso terapêutico , Hipertensão/tratamento farmacológico , Hipertensão/epidemiologia
5.
Invest. educ. enferm ; 40(3): 161-174, 15 octubre de 2022. tab, ilus
Artigo em Inglês | LILACS, BDENF - Enfermagem, COLNAL | ID: biblio-1401306

RESUMO

Objective. This work sought to describe the adaptation process by men to the nurse role. Methods.Secondary analysis of data from a collective case study that had as participants 12 male nurses working in the city of Medellín, with ages between 28 and 47 years and average time of professional experience of 11 years. Information collection was carried out through in-depth interviews. The analysis was conducted through Roy's Adaptation Model (RAM), reading of the interviews, identification of RAM's components, grouping of fragments, assignment of tags, construction of a matrix and classification. Results. The analysis performed accounts for the coping processes and adaptation by male nurses and the ineffective responses (control of emotions and emotional silencing) when practicing a role considered feminine. Conclusion.In this study, it was possible to establish that, to achieve adaptation within nursing, men use strategies related with changes in bodily appearance, management of physical strength, and management of emotions.


Objetivo. Describir el proceso de adaptación de los hombres al rol enfermero. Métodos. Análisis secundario de los datos de un estudio de casos colectivo que tuvo como participantes a 12 enfermeros que trabajan en la ciudad de Medellín, con edades entre los 28 y los 47 años y un tiempo de experiencia profesional promedio de 11 años. La recolección de la información se realizó mediante entrevistas en profundidad. El análisis se realizó a partir del Modelo de Adaptación de Roy (RAM), lectura de las entrevistas, identificación de los componentes del RAM, agrupación de fragmentos, asignación de etiquetas, construcción de una matriz y clasificación. Resultados. El análisis realizado da cuenta de los procesos de afrontamiento y adaptación de los enfermeros y las respuestas inefectivas (control de emociones y silenciamiento emocional) al ejercer un rol considerado femenino. Conclusión. En este estudio fue posible establecer que, para alcanzar una adaptación dentro de la enfermería, los hombres utilizan estrategias relacionadas con cambios en la apariencia corporal, el manejo de la fuerza física y el manejo de las emociones.


Objetivo. Descrever o processo de adaptação do homem à função de enfermagem. Métodos.Análise secundária de dados de um estudo de caso coletivo que teve como participantes 12 enfermeiros que atuam na cidade de Medellín, com idade entre 28 e 47 anos e tempo de experiência profissional média 11 anos. As informações foram coletadas por meio de entrevistas em profundidade. A análise foi realizada por meio do Modelo de Adaptação de Roy (RAM), leitura das entrevistas, identificação dos componentes do RAM, agrupamento de fragmentos, atribuição de rótulos, construção de matriz e classificação. Resultados. A análise realizada dá conta dos processos de enfrentamento e adaptação das enfermeiras e das respostas ineficazes (controle das emoções e silenciamento emocional) ao exercer um papel considerado feminino. Conclusão.Neste estudo foi possível constatar que, para conseguir uma adaptação dentro da enfermagem, os homens utilizam estratégias relacionadas a mudanças na aparência corporal, manejo da força física e manejo emocional


Assuntos
Humanos , Masculino , Masculinidade , Identidade de Gênero , Homens , Enfermeiros , Prática Profissional , Educação em Enfermagem
6.
Invest Educ Enferm ; 40(3)2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36867785

RESUMO

OBJECTIVES: This work sought to describe the adaptation process by men to the nurse role. METHODS: Secondary analysis of data from a collective case study that had as participants 12 male nurses working in the city of Medellín, with ages between 28 and 47 years and average time of professional experience of 11 years. Information collection was carried out through in-depth interviews. The analysis was conducted through Roy s Adaptation Model (RAM), reading of the interviews, identification of RAMs components, grouping of fragments, assignment of tags, construction of a matrix and classification. RESULTS: The analysis performed accounts for the coping processes and adaptation by male nurses and the ineffective responses (control of emotions and emotional silencing) when practicing a role considered feminine. CONCLUSIONS: In this study, it was possible to establish that, to achieve adaptation within nursing, men use strategies related with changes in bodily appearance, management of physical strength, and management of emotions.


Assuntos
Adaptação Psicológica , Papel do Profissional de Enfermagem , Masculino , Humanos , Emoções
7.
Cancer Lett ; 525: 97-107, 2022 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-34740610

RESUMO

Neuro-endocrine prostate cancer (NEPC) accounts for about 20% of lethal metastatic castration-resistant prostate cancer (CRPC). NEPC has the most aggressive biologic behavior of all prostate cancers and is associated with poor patient outcome. Effective treatment for NEPC is not available because NEPC exhibit distinct cell-surface expression profiles compared to other types of prostate cancer. Recently, the carcinoembryonic antigen-related cell adhesion molecule 5 (CEACAM5) (known as CEA or CD66e) was suggested to be a specific surface protein marker for NEPC. Therefore, we identified a new, fully-human anti-CEACAM5 monoclonal antibody, 1G9, which bound to the most proximal membrane domains, A3 and B3, of CEACAM5 with high affinity and specificity. It shows no off-target binding to other CEACAM family members, membrane distal domains of CEACAM5, or 5800 human membrane proteins. IgG1 1G9 exhibited CEACAM5-specific ADCC activity toward CEACAM5-positive prostate cancer cells in vitro and in vivo. Chimeric antigen receptor T cells (CAR-T) based on scFv 1G9 induced specific and strong antitumor activity in a mouse model of prostate cancer. Our results suggest that IgG1 and CAR-T cells based on 1G9 are promising candidate therapeutics for CEACAM5-positive NEPC and other cancers.


Assuntos
Antígeno Carcinoembrionário/genética , Tumores Neuroendócrinos/terapia , Neoplasias de Próstata Resistentes à Castração/terapia , Neoplasias da Próstata/terapia , Receptores de Antígenos Quiméricos/imunologia , Animais , Anticorpos Anti-Idiotípicos/imunologia , Anticorpos Anti-Idiotípicos/farmacologia , Anticorpos Monoclonais/farmacologia , Antineoplásicos/imunologia , Antígeno Carcinoembrionário/imunologia , Antígeno Carcinoembrionário/uso terapêutico , Proliferação de Células/efeitos dos fármacos , Proteínas Ligadas por GPI/genética , Proteínas Ligadas por GPI/imunologia , Proteínas Ligadas por GPI/uso terapêutico , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Imunoglobulina G/imunologia , Imunoterapia Adotiva/tendências , Masculino , Camundongos , Tumores Neuroendócrinos/imunologia , Tumores Neuroendócrinos/patologia , Próstata/patologia , Próstata/cirurgia , Neoplasias da Próstata/imunologia , Neoplasias da Próstata/patologia , Neoplasias de Próstata Resistentes à Castração/imunologia , Neoplasias de Próstata Resistentes à Castração/patologia , Receptores de Antígenos Quiméricos/genética , Receptores de Antígenos Quiméricos/uso terapêutico
8.
bioRxiv ; 2022 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-36597530

RESUMO

SARS-CoV-2 Spike harbors glycans which function as ligands for lectins. Therefore, it should be possible to exploit lectins to target SARS-CoV-2 and inhibit cellular entry by binding glycans on the Spike protein. Burkholderia oklahomensis agglutinin (BOA) is an antiviral lectin that interacts with viral glycoproteins via N-linked high mannose glycans. Here, we show that BOA binds to the Spike protein and is a potent inhibitor of SARS-CoV-2 viral entry at nanomolar concentrations. Using a variety of biophysical tools, we demonstrate that the interaction is avidity driven and that BOA crosslinks the Spike protein into soluble aggregates. Furthermore, using virus neutralization assays, we demonstrate that BOA effectively inhibits all tested variants of concern as well as SARS-CoV 2003, establishing that glycan-targeting molecules have the potential to be pan-coronavirus inhibitors.

9.
Medellín; s.n; 2022.
Tese em Espanhol | LILACS, BDENF - Enfermagem, COLNAL | ID: biblio-1443569

RESUMO

Objetivo: comprender el rol de los hombres en enfermería, teniendo en cuenta su reconocimiento y las emociones que subyacen en el ejercicio de su práctica profesional. Metodología: esta tesis fue realizada desde la metodología de estudio de casos colectivo propuesta por Robert E. Stake. Se entrevistaron 12 enfermeros con desempeño en diferentes escenarios laborales empleando entrevistas en profundidad, notas de campo y memorando analíticos para registrar las experiencias emotivas de los participantes. El análisis se realizó por medio de agrupamiento y reducción de los fragmentos de las entrevistas y la construcción de un mapa conceptual. Resultados: los roles de género son producto de una construcción social, y en este sentido, se moldean y cambian con el devenir histórico y cultural, prueba de esto es el ingreso de los hombres a la enfermería. Sin embargo, a nivel social persiste una naturalización de la enfermería como un oficio femenino que se traduce en una imagen estereotipada del papel de los enfermeros que dificulta su reconocimiento. Conclusiones: los hombres desde el momento en que manifiestan su intención de convertirse en enfermeros, inician un proceso de adaptación en diferentes esferas, donde no solo deben negociar sus emociones, sino emprender una lucha permanente por el reconocimiento como un motor para el desarrollo y el cambio en diferentes aspectos de su vida. (Tomado del repositorio institucional)


Objective: to understand the role of men in nursing, taking into account their recognition and the emotions that underlie their professional practice. Methodology: This thesis was conducted using the collective case study methodology proposed by Robert E. Stake. Twelve nurses with performance in different work scenarios were interviewed using in-depth interviews, field notes, and analytical memorandum to record the emotional experiences of the participants. The analysis was carried out by grouping and reducing the fragments of the interviews and constructing a conceptual map. Results: gender roles are the product of a social construction, and in this sense, they are molded and change with historical and cultural evolution, proof of which is the entry of men into nursing. However, at the social level, a naturalization of nursing as a female profession persists, which translates into a stereotyped image of the role of female patients that hinders its recognition. Conclusions: men, from the moment they express their intention to become nurses, begin a process of adaptation in different areas, where they must, in addition to negotiating their emotions, constantly fight for recognition as the engine of change and development in different aspects of their lives. (Tomado del repositorio institucional)


Assuntos
Humanos , Masculino , Papel do Doente , Prática Profissional , Conhecimentos, Atitudes e Prática em Saúde , Enfermeiros
10.
Animals (Basel) ; 11(9)2021 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-34573620

RESUMO

Canine bites are an important public health problem, with consequences such as physical injuries, psychological trauma, transmission of zoonoses, infections and they can even cause death. To avoid deaths caused by this type of bite, multiple factors related to this issue must be considered. The objective of this review was to search and analyze the indexed scientific literature on canine bites resulting in death, published during the period 2013-2017. A search was carried out in various databases of indexed literature, in Spanish and English. After selecting and excluding items using PRISMA, they were classified according to SIGN guidelines to filter out the level of evidence and potential biases. Thirty-three scientific articles were retrieved and analyzed. In most of these, victims between 50 and 64 years of age (28.6%, 8/28) were registered. Additionally, in most of the articles, only one animal participated (80%, 16/20). The highest number of events occurred in public spaces (58.5%, 7/12). In conclusion, most of the scientific articles that report incidents of dog bites resulting in death, provide details about the victims, their injuries and the treatment received; however, few articles provide background information on the context of the attack and the biting animal.

11.
iScience ; 24(9): 103014, 2021 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-34522857

RESUMO

Therapeutic and diagnostic efficacies of small biomolecules and chemical compounds are hampered by suboptimal pharmacokinetics. Here, we developed a repertoire of robust and high-affinity antihuman serum albumin nanobodies (NbHSA) that can be readily fused to small biologics for half-life extension. We characterized the thermostability, binding kinetics, and cross-species reactivity of NbHSAs, mapped their epitopes, and structurally resolved a tetrameric HSA-Nb complex. We parallelly determined the half-lives of a cohort of selected NbHSAs in an HSA mouse model by quantitative proteomics. Compared to short-lived control nanobodies, the half-lives of NbHSAs were drastically prolonged by 771-fold. NbHSAs have distinct and diverse pharmacokinetics, positively correlating with their albumin binding affinities at the endosomal pH. We then generated stable and highly bioactive NbHSA-cytokine fusion constructs "Duraleukin" and demonstrated Duraleukin's high preclinical efficacy for cancer treatment in a melanoma model. This high-quality and versatile Nb toolkit will help tailor drug half-life to specific medical needs.

12.
rev. cuid. (Bucaramanga. 2010) ; 12(1): e1336, ene-2021.
Artigo em Espanhol | LILACS, BDENF - Enfermagem, COLNAL | ID: biblio-1177856

RESUMO

De manera sorpresiva el COVID-19 detuvo al mundo, o puntualmente frenó el acelerado ritmo en que confluía la actividad humana, pues los capullos siguen brotando en primavera, las ballenas continúan sus largas migraciones por el océano, la temporada de sequía volvió para quemar la tierra y el planeta continuó su incesante danza de rotación y traslación. Es decir, todos los seres vivos continuaron con normalidad su existencia, excepto los seres humanos, aterrados por una muerte invisible y un enemigo despiadado que hasta este momento parece infranqueable.


Assuntos
Humanos , Infecções por Coronavirus , Educação , Pandemias
13.
Methods Mol Biol ; 2215: 299-307, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33368010

RESUMO

Here, we present a strategy to identify microcrystals from initial protein crystallization screen experiments and to optimize diffraction quality of those crystals using negative stain transmission electron microscopy (TEM) as a guiding technique. The use of negative stain TEM allows visualization along the process and thus enables optimization of crystal diffraction by monitoring the lattice quality of crystallization conditions. Nanocrystals bearing perfect lattices are seeded and can be used for MicroED as well as growing larger crystals for X-ray and free electron laser (FEL) data collection.


Assuntos
Microscopia Crioeletrônica/métodos , Microscopia Eletrônica de Transmissão/métodos , Nanopartículas/química , Conformação Proteica , Cristalização/métodos , Nanopartículas/ultraestrutura
14.
Methods ; 159-160: 23-28, 2019 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-31029767

RESUMO

Well-diffracting crystals are essential to obtain relevant structural data that will lead to understanding of RNA Polymerase II (Pol II) transcriptional processes at a molecular level. Here we present a strategy to study Pol II crystals using negative stain transmission electron microscopy (TEM) and a methodology to optimize radiation damage free data collection using free electron laser (FEL) at the Linac Coherent Light Source (LCLS). The use of negative stain TEM allowed visualization and optimization of crystal diffraction by monitoring the lattice quality of crystallization conditions. Nano crystals bearing perfect lattices were seeded and used to grow larger crystals for FEL data collection. Moreover, the use of in house designed crystal loops together with ultra-violet (UV) microscopy for crystal detection facilitated data collection. Such strategy permitted collection of multiple crystals of radiation-free-damage data, resulting in the highest resolution of wild type (WT) Pol II crystals ever observed.


Assuntos
Cristalografia/métodos , Lasers , Microscopia Eletrônica de Transmissão/métodos , RNA Polimerase II/metabolismo , Humanos , Modelos Moleculares , Nanoestruturas , Conformação Proteica , RNA Polimerase II/química
15.
mBio ; 9(5)2018 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-30228242

RESUMO

Iron is an indispensable micronutrient for all eukaryotic organisms due to its participation as a redox cofactor in many metabolic pathways. Iron imbalance leads to the most frequent human nutritional deficiency in the world. Adaptation to iron limitation requires a global reorganization of the cellular metabolism directed to prioritize iron utilization for essential processes. In response to iron scarcity, the conserved Saccharomyces cerevisiae mRNA-binding protein Cth2, which belongs to the tristetraprolin family of tandem zinc finger proteins, coordinates a global remodeling of the cellular metabolism by promoting the degradation of multiple mRNAs encoding highly iron-consuming proteins. In this work, we identify a critical mechanism for the degradation of Cth2 protein during the adaptation to iron deficiency. Phosphorylation of a patch of Cth2 serine residues within its amino-terminal region facilitates recognition by the SCFGrr1 ubiquitin ligase complex, accelerating Cth2 turnover by the proteasome. When Cth2 degradation is impaired by either mutagenesis of the Cth2 serine residues or deletion of GRR1, the levels of Cth2 rise and abrogate growth in iron-depleted conditions. Finally, we uncover that the casein kinase Hrr25 phosphorylates and promotes Cth2 destabilization. These results reveal a sophisticated posttranslational regulatory pathway necessary for the adaptation to iron depletion.IMPORTANCE Iron is a vital element for many metabolic pathways, including the synthesis of DNA and proteins, and the generation of energy via oxidative phosphorylation. Therefore, living organisms have developed tightly controlled mechanisms to properly distribute iron, since imbalances lead to nutritional deficiencies, multiple diseases, and vulnerability against pathogens. Saccharomyces cerevisiae Cth2 is a conserved mRNA-binding protein that coordinates a global reprogramming of iron metabolism in response to iron deficiency in order to optimize its utilization. Here we report that the phosphorylation of Cth2 at specific serine residues is essential to regulate the stability of the protein and adaptation to iron depletion. We identify the kinase and ubiquitination machinery implicated in this process to establish a posttranscriptional regulatory model. These results and recent findings for both mammals and plants reinforce the privileged position of E3 ubiquitin ligases and phosphorylation events in the regulation of eukaryotic iron homeostasis.


Assuntos
Adaptação Fisiológica , Complexo de Endopeptidases do Proteassoma/metabolismo , RNA Mensageiro/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/fisiologia , Tristetraprolina/metabolismo , Regulação Fúngica da Expressão Gênica , Ferro/metabolismo , Mutagênese , Fosforilação , Complexo de Endopeptidases do Proteassoma/genética , Processamento de Proteína Pós-Traducional , Estabilidade Proteica , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética , Serina/genética , Tristetraprolina/genética
16.
J Phys Chem Lett ; 8(22): 5523-5530, 2017 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-29072840

RESUMO

Solving the atomic structure of metallic clusters is fundamental to understanding their optical, electronic, and chemical properties. Herein we present the structure of the largest aqueous gold cluster, Au146(p-MBA)57 (p-MBA: para-mercaptobenzoic acid), solved by electron micro-diffraction (MicroED) to subatomic resolution (0.85 Å) and by X-ray diffraction at atomic resolution (1.3 Å). The 146 gold atoms may be decomposed into two constituent sets consisting of 119 core and 27 peripheral atoms. The core atoms are organized in a twinned FCC structure, whereas the surface gold atoms follow a C2 rotational symmetry about an axis bisecting the twinning plane. The protective layer of 57 p-MBAs fully encloses the cluster and comprises bridging, monomeric, and dimeric staple motifs. Au146(p-MBA)57 is the largest cluster observed exhibiting a bulk-like FCC structure as well as the smallest gold particle exhibiting a stacking fault.

17.
Microsc Res Tech ; 80(12): 1249-1255, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28799676

RESUMO

In the current work, irregular morphology of Staphylococcus aureus bacteria has been visualized by phase retrieval employing off-axis electron holography (EH) and 3D reconstruction electron tomography using high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM). Bacteria interacting with gold nanoparticles (AuNP) acquired a shrunken or irregular shape due to air dehydration processing. STEM imaging shows the attachment of AuNP on the surface of cells and suggests an irregular 3D morphology of the specimen. The phase reconstruction demonstrates that off-axis electron holography can reveal with a single hologram the morphology of the specimen and the distribution of the functionalized AuNPs. In addition, EH reduces significantly the acquisition time and the cumulative radiation damage (in three orders of magnitude) over biological samples in comparison with multiple tilted electron expositions intrinsic to electron tomography, as well as the processing time and the reconstruction artifacts that may arise during tomogram reconstruction.


Assuntos
Tomografia com Microscopia Eletrônica/métodos , Holografia/métodos , Imageamento Tridimensional/métodos , Staphylococcus aureus/ultraestrutura , Elétrons , Ouro , Nanopartículas Metálicas/química , Microscopia Eletrônica de Transmissão e Varredura
18.
Aquichan ; 16(2): 205-218, Apr.-June 2016.
Artigo em Espanhol | LILACS, BDENF - Enfermagem, COLNAL | ID: lil-791091

RESUMO

Objetivo: describir las vivencias de los familiares en sala de espera de trabajo de parto. Materiales y métodos: estudio cualitativo etnográfico. Se entrevistaron diez participantes y cuatro grupos focales; la saturación se logró cuando los investigadores no encontraron más explicación, interpretación o descripción de la experiencia. Para el análisis, se usó el método de Spradley, se construyeron categorías y dominios, y se realizó análisis taxonómico. Se desarrollaron notas de campo y observación participante. Se utilizó el software Atlas ti. Resultados: los familiares experimentan necesidades de información oportuna y eficiente. El lenguaje verbal y no verbal y el contenido de la información les produjo ansiedad e incertidumbre. Los familiares sienten la necesidad de acompañar a la gestante durante el trabajo de parto para brindarle apoyo. El ambiente en la sala de espera depende de los factores internos del familiar y los factores externos de la sala. La educación en la sala de espera representó una excelente oportunidad para aprovechar el tiempo. Emergieron los dominios: comunicación terapéutica, acompañamiento, ambiente y educación. Conclusión: el significado cultural de esperar es un acontecimiento de la vida altamente significativo, atravesado por cuatro circunstancias: la comunicación, el acompañamiento, el ambiente de la sala y la educación, situaciones que cambiaron la experiencia del nacimiento.


Objective: Describe the experiences of family members in the labor room. Materials and Methods: This is a qualitative ethnographic study in which ten participants and four focus groups were interviewed; Saturation was achieved when the researchers found no further explanation, interpretation or description of the experience. Spradley's method was used for the analysis. Categories and domains were constructed and a taxonomic analysis was done. Field notes and participant observation were developed. Atlas ti software was used. Results: Family members want and feel they need timely and efficient information. Verbal and non-verbal language and the content of the information provided can cause them anxiety and uncertainty. Family members want to accompany and support the expectant mother during labor prior to childbirth. The atmosphere in the labor room depends on the internal factors of the family member and the external factors of the room. Education in the waiting room proved to be an excellent opportunity to take advantage of the time. Several domains emerged; namely, therapeutic communication, accompaniment, environment and education. Conclusion: The cultural significance of waiting for birth to occur is a highly meaningful event in life and is marked by four factors: communication, accompaniment, the environment in the room and education. These are situations that changed the birth experience.


Objetivo: descrever as vivências dos familiares na sala de espera de trabalho de parto. Materiais e métodos: estudo qualitativo etnográfico. Foram entrevistados dez participantes e quatro grupos focais. A saturação foi atingida quando os pesquisadores não encontraram mais explicação, interpretação ou descrição da experiência. Para a análise, usou-se o método de Spradley e foram construídos categorias e domínios, além de realizada análise taxonómica. Desenvolveram-se anotações de campo e observação participante. Utilizouse o software Atlas ti. Resultados: os familiares experimentaram necessidades de informação oportuna e eficiente. A linguagem verbal e não verbal, e o conteúdo da informação lhes produziram ansiedade e incerteza. Os familiares sentem a necessidade de acompanhar a gestante durante o trabalho de parto para oferecer-lhe apoio. O ambiente na sala de espera depende dos fatores internos do familiar e dos fatores externos da sala. A educação na sala de espera representou uma excelente oportunidade para aproveitar o tempo. Emergiram os domínios: comunicação terapêutica, acompanhamento, ambiente e educação. Conclusão: o significado cultural de esperar é um acontecimento da vida altamente significativo, permeado por quatro circunstâncias: a comunicação, o acompanhamento, o ambiente da sala e a educação, situações que mudaram a experiência do nascimento.


Assuntos
Relações Profissional-Família , Trabalho de Parto , Educação em Saúde , Pesquisa Qualitativa
19.
Arch. med ; 15(2): 241-249, July-Dec.2015.
Artigo em Espanhol | LILACS | ID: lil-785579

RESUMO

Determinar la frecuencia de infecciones vaginales y lesiones intraepiteliales en los resultados de laboratorio de las usuarias de los laboratorios clínicos de Dinámica IPS de la ciudad de Medellín, atendidas entre el 2005 y el 2010. Materiales y métodos:estudio descriptivo transversal con fuentes secundarias de los resultados de pruebas realizadas a usuarias de Dinámica IPS atendidas en el periodo de estudio, en el que se evaluaron variables como la edad y los resultados de citología vaginal (n= 261 789),Gram (n= 70 447) y directo de flujo vaginal (n= 89 527). Se excluyeron registros con información incompleta. Se realizó análisis estadístico con medianas y proporciones.Resultados: del total de muestras analizadas por citología vaginal (n=261 789), el 1,99% correspondían a lesiones escamosas, de éstas el 0,038% corresponde a muestras positivas de cáncer de cuello uterino confirmada por patólogo; el 8,01% corresponde a lesiones intraepiteliales de alto grado y el 36,13% a lesiones escamosas de bajo grado.En el examen de flujo vaginal por directo se encontraron 14 803 pruebas positivas(16,51%) para vaginitis por hongos, 19 079 (21,31%) para vaginosis bacteriana y 414(0,46%) para vaginitis por Trichomona; en el Gram se observó que el desequilibrio de la flora normal generado por Gardnerella ocupan la mayor frecuencia con 19 186 resultados positivos (27,23%). Conclusiones: los datos encontrados con relación a las frecuencias de lesiones escamosas intraepiteliales y de infecciones vaginales guardan relación con lo reportado en la literatura nacional; sin embargo, para los casos de atipia en células escamosas de significado no determinado se encuentra variación, probablemente por las características mismas de este tipo de atipias...


Assuntos
Humanos , Gardnerella , Papiloma , Prevalência , Vaginose Bacteriana
20.
Mol Cell Biol ; 33(11): 2178-87, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23530061

RESUMO

Iron (Fe) is an essential element for all eukaryotic organisms because it functions as a cofactor in a wide range of biochemical processes. Cells have developed sophisticated mechanisms to tightly control Fe utilization in response to alterations in cellular demands and bioavailability. In response to Fe deficiency, the yeast Saccharomyces cerevisiae activates transcription of the CTH1 and CTH2 genes, which encode proteins that bind to AU-rich elements (AREs) within the 3' untranslated regions (3'UTRs) of many mRNAs, leading to metabolic reprogramming of Fe-dependent pathways and decreased Fe storage. The precise mechanisms underlying Cth1 and Cth2 function and regulation are incompletely understood. We report here that the Cth1 and Cth2 proteins specifically bind in vivo to AREs located at the 3'UTRs of their own transcripts in an auto- and cross-regulated mechanism that limits their expression. By mutagenesis of the AREs within the CTH2 transcript, we demonstrate that a Cth2 negative-feedback loop is required for the efficient decline in Cth2 protein levels observed upon a rapid rise in Fe availability. Importantly, Cth2 autoregulation is critical for the appropriate recovery of Fe-dependent processes and resumption of growth in response to a change from Fe deficiency to Fe supplementation.


Assuntos
Adaptação Fisiológica , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Ferro/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Tristetraprolina/metabolismo , Regiões 3' não Traduzidas , Elementos Ricos em Adenilato e Uridilato , Sequência de Bases , Regulação Fúngica da Expressão Gênica , Ferro/farmacologia , Dados de Sequência Molecular , Estabilidade de RNA , RNA Mensageiro/metabolismo , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/genética , Tristetraprolina/genética
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