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1.
Faraday Discuss ; 240(0): 210-227, 2022 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-35861059

RESUMO

The number of maps deposited in public databases (Electron Microscopy Data Bank, EMDB) determined by cryo-electron microscopy has quickly grown in recent years. With this rapid growth, it is critical to guarantee their quality. So far, map validation has primarily focused on the agreement between maps and models. From the image processing perspective, the validation has been mostly restricted to using two half-maps and the measurement of their internal consistency. In this article, we suggest that map validation can be taken much further from the point of view of image processing if 2D classes, particles, angles, coordinates, defoci, and micrographs are also provided. We present a progressive validation scheme that qualifies a result validation status from 0 to 5 and offers three optional qualifiers (A, W, and O) that can be added. The simplest validation state is 0, while the most complete would be 5AWO. This scheme has been implemented in a website https://biocomp.cnb.csic.es/EMValidationService/ to which reconstructed maps and their ESI can be uploaded.


Assuntos
Processamento de Imagem Assistida por Computador , Microscopia Crioeletrônica/métodos , Microscopia Eletrônica
2.
J Mol Biol ; 434(11): 167556, 2022 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-35662471

RESUMO

Computational approaches for predicting protein-protein interfaces are extremely useful for understanding and modelling the quaternary structure of protein assemblies. In particular, partner-specific binding site prediction methods allow delineating the specific residues that compose the interface of protein complexes. In recent years, new machine learning and other algorithmic approaches have been proposed to solve this problem. However, little effort has been made in finding better training datasets to improve the performance of these methods. With the aim of vindicating the importance of the training set compilation procedure, in this work we present BIPSPI+, a new version of our original server trained on carefully curated datasets that outperforms our original predictor. We show how prediction performance can be improved by selecting specific datasets that better describe particular types of protein interactions and interfaces (e.g. homo/hetero). In addition, our upgraded web server offers a new set of functionalities such as the sequence-structure prediction mode, hetero- or homo-complex specialization and the guided docking tool that allows to compute 3D quaternary structure poses using the predicted interfaces. BIPSPI+ is freely available at https://bipspi.cnb.csic.es.


Assuntos
Uso da Internet , Aprendizado de Máquina , Mapeamento de Interação de Proteínas , Proteínas , Software , Sítios de Ligação , Conjuntos de Dados como Assunto , Ligação Proteica , Mapeamento de Interação de Proteínas/métodos , Proteínas/química
5.
J Vis Exp ; (171)2021 05 29.
Artigo em Inglês | MEDLINE | ID: mdl-34125107

RESUMO

Cryo-electron microscopy has become one of the most important tools in biological research to reveal the structural information of macromolecules at near-atomic resolution. In single-particle analysis, the vitrified sample is imaged by an electron beam and the detectors at the end of the microscope column produce movies of that sample. These movies contain thousands of images of identical particles in random orientations. The data need to go through an image processing workflow with multiple steps to obtain the final 3D reconstructed volume. The goal of the image processing workflow is to identify the acquisition parameters to be able to reconstruct the specimen under study. Scipion provides all the tools to create this workflow using several image processing packages in an integrative framework, also allowing the traceability of the results. In this article the whole image processing workflow in Scipion is presented and discussed with data coming from a real test case, giving all the details necessary to go from the movies obtained by the microscope to a high resolution final 3D reconstruction. Also, the power of using consensus tools that allow combining methods, and confirming results along every step of the workflow, improving the accuracy of the obtained results, is discussed.


Assuntos
Processamento de Imagem Assistida por Computador , Imagem Individual de Molécula , Microscopia Crioeletrônica , Substâncias Macromoleculares , Fluxo de Trabalho
6.
Clin Transl Oncol ; 21(9): 1280-1285, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30680609

RESUMO

PURPOSE: Autophagy has lately emerged as an important biological process with implications in several hematological pathologies. Recently, a growing body of evidence supports a putative role of autophagy in chronic lymphocytic leukemia; however, no definitive clue has been established so far. To elucidate this issue, we have developed a pilot study to measure autophagic flux in peripheral blood mononuclear cells from chronic lymphocytic leukemia patients, and explored its correlation with classical clinical/analytical parameters. METHODS/PATIENTS: Thirty-three chronic lymphocytic leukemia patients participated in the study. Autophagic flux in peripheral blood mononuclear cells was determined by western blot measuring the levels of the proteins p62 and lipidated LC3. Moreover, p62 mRNA levels were analyzed by RT-qPCR. RESULTS: Lymphocytosis and the percentage of tumoral lymphocytes in chronic lymphocytic leukemia patients statistically correlate with a blocked autophagic flux. CONCLUSION: Alterations in autophagic flux could play an important role in the physiopathology of chronic lymphocytic leukemia.


Assuntos
Autofagia , Biomarcadores Tumorais/metabolismo , Leucemia Linfocítica Crônica de Células B/patologia , Leucócitos Mononucleares/patologia , Linfocitose/patologia , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Humanos , Leucemia Linfocítica Crônica de Células B/metabolismo , Leucócitos Mononucleares/metabolismo , Linfocitose/metabolismo , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Prognóstico
7.
J Struct Biol ; 158(2): 205-13, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17400476

RESUMO

The increase of daily released bioinformatic data has generated new ways of organising and disseminating information. Specifically, in the field of sequence data, many efforts have been made not only to store information in databases, but also to annotate it and then share these annotations through a standard XML (eXtensible Markup Language) protocol and appropriate integration clients. This is the context in which the Distributed Annotation System (DAS) has emerged in genomics. Additionally, initiatives in the field of structural data, such as the extension of DAS to atomic resolution data, which generated the SPICE client, have also occurred. This paper presents 3D-EM DAS, a further extension of the DAS protocol that allows sharing annotations about hybrid models. This annotation system has been built on the basis of the EMDB, which stores Three-dimensional Electron Microscopy (3D-EM) volumes, PDB, which houses atomic coordinates, and UniProt (for protein sequences) databases. In this way, annotations for sequences, atomic coordinates, and 3D-EM volumes are collected and displayed through a single graphical visualization client. Thus, users have an integrated view of all the annotations together with the whole macromolecule (3D-EM map coming from EMDB), the atomic resolution structures fitted into it (coordinates coming from PDB) and the sequences corresponding to each of the structures (from UniProt).


Assuntos
Biologia Computacional/métodos , Redes de Comunicação de Computadores , Bases de Dados de Proteínas , Microscopia Eletrônica , Conformação Proteica
13.
Gene ; 198(1-2): 217-22, 1997 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-9370284

RESUMO

The Brevibacterium lactofermentum EF-P gene, encoding the elongation factor protein P, was cloned and sequenced. According to DNA sequence analysis of this gene, the B. lactofermentum EF-P protein consists of 187 amino acids with a calculated molecular weight of 20,584. Southern hybridization of an internal fragment of the EF-P gene from B. lactofermentum with chromosomal DNAs from different microorganisms reveals that it is a unique gene product in B. lactofermentum and Corynebacterium glutamicum. The EF-P gene was expressed in E. coli using the T7 expression system and the calculated molecular weight of the expressed protein was 23,000. Disruption experiments using an internal fragment of the EF-P gene or a disrupted EF-P gene in suicide plasmids always failed, suggesting that the gene is needed for cell viability.


Assuntos
Brevibacterium/genética , Corynebacterium/genética , Fatores de Alongamento de Peptídeos/genética , Sequência de Aminoácidos , Aminoácidos/biossíntese , Proteínas de Bactérias/genética , Sequência de Bases , Sequência Consenso , DNA Bacteriano/genética , Genes Bacterianos , Dados de Sequência Molecular , Mapeamento por Restrição , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos
14.
Medicina (B Aires) ; 56(4): 397-402, 1996.
Artigo em Espanhol | MEDLINE | ID: mdl-9138346

RESUMO

A case of lung Kaposi sarcoma (KS) in the absence of cutaneomucosal lesions was observed in a 30-year-old heterosexual male with AIDS and a history of intravenous drug addiction. Both chest X-ray and CT scanning disclosed a diffuse nodular pattern in lungs, whereas endoscopy failed to demonstrate endobronchial damage. Cytological examination of the sample taken by transthoracic lung puncture proved compatible with primary KS, a rare neoplasia in heterosexual male drug addicts with AIDS. A year following the diagnosis of KS, the patient died of respiratory failure.


Assuntos
Síndrome da Imunodeficiência Adquirida/complicações , Neoplasias Pulmonares/diagnóstico , Sarcoma de Kaposi/diagnóstico , Transtornos Relacionados ao Uso de Substâncias/complicações , Adulto , Humanos , Masculino
15.
Medicina (B Aires) ; 55(4): 334-6, 1995.
Artigo em Espanhol | MEDLINE | ID: mdl-8728874

RESUMO

Here we report a case of HIV infection in a lesbian lacking other risk factors. She had sought advice for asthenia and unexplained weight loss. The physical examination disclosed oropharyngeal candidiasis and generalized lymphoadenopathies. The patient defined herself as an active sexual partner and denied having any heterosexual intercourse whatsoever. Particle agglutination test proved positive for anti-HIV, as well as two consecutive ELISA assays, confirmed by Western blot. Since there was no history of blood transfusions or intravenous drug addiction, it may be concluded that HIV transmission was most likely due to female homosexual practices.


Assuntos
Síndrome da Imunodeficiência Adquirida/transmissão , Homossexualidade Feminina , Sorodiagnóstico da AIDS/métodos , Síndrome da Imunodeficiência Adquirida/diagnóstico , Adulto , Argentina , Western Blotting , Ensaio de Imunoadsorção Enzimática , Feminino , Soropositividade para HIV/diagnóstico , Humanos
16.
Medicina [B Aires] ; 55(4): 334-6, 1995.
Artigo em Espanhol | BINACIS | ID: bin-37103

RESUMO

Here we report a case of HIV infection in a lesbian lacking other risk factors. She had sought advice for asthenia and unexplained weight loss. The physical examination disclosed oropharyngeal candidiasis and generalized lymphoadenopathies. The patient defined herself as an active sexual partner and denied having any heterosexual intercourse whatsoever. Particle agglutination test proved positive for anti-HIV, as well as two consecutive ELISA assays, confirmed by Western blot. Since there was no history of blood transfusions or intravenous drug addiction, it may be concluded that HIV transmission was most likely due to female homosexual practices.

17.
Rev. argent. dermatol ; 75(3): 105-8, jul.-set. 1994. ilus
Artigo em Espanhol | LILACS | ID: lil-139691

RESUMO

Se relatan cinco casos de sarcoma de Kaposi Sida en pacientes de sexo femenino. Se destaca que todas tuvieron lesiones en las mucosas accesibles; que dichas lesiones a veces precedieron a las cutaneas, que en ningno de los casos el contagio de Sida fue transfusional o por inyeccion de productos de sangre, y que en la mayoria de los casos el sarcoma de Kaposi aparece cuando el deterioro inmunologico ya es muy marcado, preanunciando un rapido desenlace fatal. Esto ultimo, en contraste con lo que sucede en el sexo masculino


Assuntos
Sarcoma de Kaposi/complicações , Síndrome da Imunodeficiência Adquirida/etiologia
18.
Rev. argent. dermatol ; 75(3): 105-8, jul.-set. 1994. ilus
Artigo em Espanhol | BINACIS | ID: bin-24412

RESUMO

Se relatan cinco casos de sarcoma de Kaposi Sida en pacientes de sexo femenino. Se destaca que todas tuvieron lesiones en las mucosas accesibles; que dichas lesiones a veces precedieron a las cutaneas, que en ningno de los casos el contagio de Sida fue transfusional o por inyeccion de productos de sangre, y que en la mayoria de los casos el sarcoma de Kaposi aparece cuando el deterioro inmunologico ya es muy marcado, preanunciando un rapido desenlace fatal. Esto ultimo, en contraste con lo que sucede en el sexo masculino(AU)


Assuntos
Sarcoma de Kaposi/complicações , Síndrome da Imunodeficiência Adquirida/etiologia
19.
Sangre (Barc) ; 39(4): 293-5, 1994 Aug.
Artigo em Espanhol | MEDLINE | ID: mdl-7985060

RESUMO

The acute chest syndrome is a clinical entity appearing in patients suffering from sickle cell anaemia. It presents with pleuritic pain, fever, leucocytosis and pulmonary infiltrates in the thoracic radiology. The etiological diagnosis is difficult, and it is necessary to distinguish between pneumonia and pulmonary infarction. This syndrome is quite frequent among the patients at risk, and can be lethal according to the severity and the etiology of the event. A case of acute chest syndrome due to a S. pneumoniae sepsis is presented. The interest of the case lies in the rareness of this disease in our population and the peculiar evolutive clinical features of this case, with the development of intracranial hypertension and death.


Assuntos
Anemia Falciforme/complicações , Dor no Peito/etiologia , Pneumonia Pneumocócica/complicações , Adulto , Diagnóstico Diferencial , Coagulação Intravascular Disseminada/etiologia , Guiné Equatorial/etnologia , Evolução Fatal , Humanos , Masculino , Infarto do Miocárdio/diagnóstico , Pneumonia/diagnóstico , Pseudotumor Cerebral/etiologia , Espanha
20.
Acta Gastroenterol Latinoam ; 12(1): 61-74, 1982.
Artigo em Espanhol | MEDLINE | ID: mdl-7136455

RESUMO

A case of multiple lymphomatous polyposis of the gastrointestinal tract is presented. The recent literature on this type of lymphoma is reviewed. Also summarized are the clinical findings, diagnostic procedures, current methods of treatment and prognosis of these patients. Diarrhea upon admission, lead us to a complete work up finally to the correct diagnosis. The lack of symptoms of this patient was in contrast with most of the cases reviewed, so the diagnosis was mainly based on the endoscopic findings (colonoscopy and esofago-gastro-duodenoscopy). It is emphasized the importance of repeated biopsies in case of negative ones, as it occurs in this patient, in which an endoscopic "polypectomy" from the recto-sigmoid area, provided enough material to the pathologist, for the diagnosis, after several "non-diagnostic" biopsies taken previously. Finally the therapy for this entity is updated, with special reference to quemotherapy and a list of drugs combination is given.


Assuntos
Neoplasias Gastrointestinais/diagnóstico , Linfoma/diagnóstico , Adulto , Neoplasias Gastrointestinais/terapia , Humanos , Linfoma/terapia , Masculino , Prognóstico
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