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1.
Ann Ig ; 34(6): 627-634, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35107122

RESUMO

Background: The International Standardization Organization operates the world's most widely recognized quality management system standard, the ISO 9001:2015. In the healthcare sector, the adoption of this standard within an organization helps to improve the overall performance and provides a foundation for development and continuous progress. Our study aims to describe the implementation process of a quality management system according to the ISO 9001:2015 standards in an Angiology Unit of an Italian Univer-sity hospital. Methods: The project was structured in 5 operational phases, which were carried out during a time frame of 14 months (March 2018-May 2019) and entailed several improvement actions associated with quality and safety outputs such as clinical management, clinical practice, safety, and patient-centeredness. Results: Implementation of the quality management system led to the improvement of many aspects of the processes performed in the Angiology Unit, both in the outpatient and day hospital setting. Overall, the project positively impacted on systems for patient safety, particularly in communication and data transmis-sion, and clinical leadership. Conclusions: The implementation of the ISO 9001 certification is a process that apparently may seem ex-pensive in terms of resources used, commitment, work, comparison, but it leads to substantial and always progressive improvements in the offer of Services to the user, safety both for the users and for the healthcare personnel involved, in addition to the care processes that translate into significant benefits in terms of quality of care for patients, as well as management savings for the organization.


Assuntos
Cardiologia , Hospitais , Certificação , Humanos , Segurança do Paciente , Padrões de Referência
2.
Arch Virol ; 159(1): 39-49, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23881084

RESUMO

Bovine noroviruses are enteric pathogens that are detected in stool samples from cattle. Five genogroups are currently described in the genus Norovirus (family Caliciviridae), and within the genogroups, sequences are further divided into genotypes according to genetic homology and phylogenetic relationships. In this study, stool specimens from Belgian cattle were screened by RT-PCR. All of the sequences that were detected were phylogenetically related to genogroup III genotype 2 bovine noroviruses, confirming their higher prevalence in comparison with strains from genotype 1. When other sequences from around the world were introduced, phylogenetic inferences allowed neither the determination of phylogenetic lineages over time nor the deduction of topotypes for genotype 2 bovine noroviruses. Three complete genotype 2 bovine norovirus sequences were also compared genetically (Newbury2/1976 /UK, Dumfries/1994/UK and B309/2003/BE). Interestingly, the genetic divergence of the complete genomes of these three strains was relatively low, but a region of the N-terminal protein encoded by ORF1, the hypervariable region of the capsid gene encoded by ORF2, and a region of the minor structural protein encoded by ORF3 seem to be the most exposed to genetic evolution. Bayesian inference also showed that genetic evolution of genogroup III, genotype 2 bovine noroviruses over a 30-year period seemed to be lower than that already reported for noroviruses from the genotypes 3 and 4 in genogroup II.


Assuntos
Infecções por Caliciviridae/veterinária , Doenças dos Bovinos/virologia , Evolução Molecular , Norovirus/genética , Norovirus/isolamento & purificação , Animais , Infecções por Caliciviridae/virologia , Proteínas do Capsídeo/genética , Bovinos , Fezes/virologia , Gastroenterite/veterinária , Gastroenterite/virologia , Genótipo , Dados de Sequência Molecular , Norovirus/classificação , Filogenia
3.
Chem Phys Lipids ; 165(8): 838-44, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23194898

RESUMO

Previous investigations showed that the extent of DNA condensation and the efficiency in the transfection of liposomes formulated with 1,2-dimyristoyl-sn-glycero-phosphocholine and cationic stereomeric gemini surfactants depend heavily on the stereochemistry of the gemini. The influence of the stereochemistry on the interaction of lipoplexes with zwitterionic and anionic cell membrane models was investigated by differential scanning calorimetry to rationalize their different biological behavior. Further, the thermotropic behavior of the corresponding liposomes and of the spontaneous self-assemblies of gemini surfactants in the presence and in the absence of DNA was evaluated to correlate the physicochemical properties of lipoplexes and the stereochemistry of the cationic component. The obtained results show that the stereochemistry of the gemini surfactant controls lipoplexes organization and their mode and kinetic of interaction with different cell membrane models.


Assuntos
Calcitriol/análogos & derivados , Lipossomos/química , Modelos Químicos , Tensoativos/química , Calcitriol/química , Varredura Diferencial de Calorimetria , Cátions/química , DNA/química , Dimiristoilfosfatidilcolina/química , Estereoisomerismo , Temperatura de Transição
4.
J Virol ; 86(22): 12449-50, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23087113

RESUMO

A new genogroup III genotype 2 bovine norovirus, B309/2003/BE, was entirely sequenced and genetically compared to the original Newbury2/1976/UK strain and to Dumfries/1994/UK, detected in 1976 and 1994, respectively. Interestingly, except in well-defined coding regions (N-terminal protein, 3A-like protease, hypervariable region of the capsid protein, and C-terminal part of the minor structural protein), very low genetic differences were noted between the entire genomes of these three strains along a 30-year-long period. It allowed some hypotheses of hotspots of genetic evolution through a low genetic evolution background in genotype 2 genogroup III bovine noroviruses.


Assuntos
Genoma Viral , Norovirus/genética , Animais , Bovinos , DNA Viral , Bases de Dados Genéticas , Evolução Molecular , Genes Virais , Genótipo , Dados de Sequência Molecular , Fases de Leitura Aberta , Análise de Sequência de DNA
5.
Nanotechnology ; 23(39): 395703, 2012 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-22972390

RESUMO

Regular configurationally alternating amino acid sequences generate cyclic and linear helical peptides with a local ß-conformation able to self-assemble in nanowires and nanoscaffolds directed and stabilized by hydrogen bonds. The possibility of modulating the chemical profile of the various amino acid residues containing reactive side chains means that peptides could be flexible templates for creating various building blocks. A method for the design of molecules with potential spintronic properties is described. Peptides containing lysine residues, the side chains of which are bridged through the formation of metal chelates via Schiff bases, could provide stable molecular channels. When metal chelates with high electron spin states are used, their coupling could generate materials that are interesting due to their magnetic properties as well as for the patterning of nanometric lattices driven by their orientation under a magnetic field. With this aim, three alternating D- and L-lysine-containing octapeptides are synthesized and the formation of their bis(pyridoxalaldimine) copper(II) chelate derivatives is shown by absorption and circular dichroism spectroscopies.


Assuntos
Quelantes/química , Cobre/química , Lisina/química , Nanotecnologia/métodos , Oligopeptídeos/química , Dicroísmo Circular , Modelos Moleculares , Análise Espectral , Estereoisomerismo
6.
J Endocrinol Invest ; 33(1): 2-6, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19794300

RESUMO

BACKGROUND: Agents capable of increasing radioiodine concentration by stimulating the sodium/iodide symporter (NIS) expression have been extensively investigated for the treatment of certain well-differentiated breast cancers. AIM: In this study, we analyzed the regulation of the NIS and lactoperoxidase (LPO) gene expression in 4 different human breast cancer cell lines, representative of different histotypes of breast cancer. METHODS: MCF-7, T-47D, MDA-MB231, and HCC-1937 (the latter carrying the BRCA-1 mutation) were exposed to different stimulators and the levels of NIS and LPO mRNA measured by a quantitative RT-PCR. RESULTS: All-trans-Retinoic Acid (RA), Dexamethasone (DEX), Trichostatin A (TSA), and Sodium Butyrate (NaB) induced the expression of NIS mRNA in MCF-7 and T-47D cell lines, whereas HCC-1937 and MBA-MB231 were slightly responsive only to the histone-deacetylase inhibitors TSA and NaB. Minor stimulatory effects were detected on LPO mRNA in MCF-7 and T-47D treated with TSA and NaB or RA only in MCF-7, while no effect was detectable in the other two cell lines. CONCLUSIONS: These data indicate that retinoic acid, alone or in combination with DEX, as well as HDAC-inhibitors are very promising agents for a radioiodine- based therapy in a large spectrum of breast cancers, including neoplasms from both basal and ductal cells, especially for the well-differentiated estrogen-dependent tumors. Other molecules or other drug combinations should be tested to extend the same strategy to the less differentiated and more aggressive tumor cells, including those carrying the BRCA mutation.


Assuntos
Neoplasias da Mama/metabolismo , Lactoperoxidase/genética , Simportadores/genética , Butiratos/farmacologia , Linhagem Celular Tumoral , Dexametasona/farmacologia , Inibidores de Histona Desacetilases/farmacologia , Humanos , Ácidos Hidroxâmicos/farmacologia , Lactoperoxidase/biossíntese , RNA Mensageiro/metabolismo , Simportadores/biossíntese , Tretinoína/farmacologia
7.
Waste Manag ; 29(9): 2462-74, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19450963

RESUMO

At international level LCA is being increasingly used to objectively evaluate the performances of different Municipal Solid Waste (MSW) management solutions. One of the more important waste management options concerns MSW incineration. LCA is usually applied to existing incineration plants. In this study LCA methodology was applied to a new Italian incineration line, to facilitate the prediction, during the design phase, of its potential environmental impacts in terms of damage to human health, ecosystem quality and consumption of resources. The aim of the study was to analyse three different design alternatives: an incineration system with dry flue gas cleaning (without- and with-energy recovery) and one with wet flue gas cleaning. The last two technological solutions both incorporating facilities for energy recovery were compared. From the results of the study, the system with energy recovery and dry flue gas cleaning revealed lower environmental impacts in relation to the ecosystem quality. As LCA results are greatly affected by uncertainties of different types, the second part of the work provides for an uncertainty analysis aimed at detecting the extent output data from life cycle analysis are influenced by uncertainty of input data, and employs both qualitative (pedigree matrix) and quantitative methods (Monte Carlo analysis).


Assuntos
Meio Ambiente , Incineração/métodos , Poluentes Atmosféricos/análise , Carbono/química , Carcinógenos/análise , Cinza de Carvão , Conservação de Recursos Energéticos , Eletricidade , Poluição Ambiental/análise , Eutrofização , Combustíveis Fósseis/economia , Incineração/economia , Itália , Minerais/análise , Minerais/economia , Ozônio/análise , Material Particulado/química , Radiação , Resíduos/economia
8.
J Clin Endocrinol Metab ; 93(10): 4080-7, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18664540

RESUMO

CONTEXT: Notch genes encode receptors for a signaling pathway that regulates cell growth and differentiation in various contexts, but the role of Notch signaling in thyroid follicular cells has never been fully published. OBJECTIVE: The objective of the study was to characterize the expression of Notch pathway components in thyroid follicular cells and Notch signaling activities in normal and transformed thyrocytes. DESIGN/SETTING AND PATIENTS: Expression of Notch pathway components and key markers of thyrocyte differentiation was analyzed in murine and human thyroid tissues (normal and tumoral) by quantitative RT-PCR and immunohistochemistry. The effects of Notch overexpression in human thyroid cancer cells and FTRL-5 cells were explored with analysis of gene expression, proliferation assays, and experiments involving transfection of a luciferase reporter construct containing human NIS promoter regions. RESULTS: Notch receptors are expressed during the development of murine thyrocytes, and their expression levels parallel those of thyroid differentiation markers. Notch signaling characterized also normal adult thyrocytes and is regulated by TSH. Notch pathway components are variably expressed in human normal thyroid tissue and thyroid tumors, but expression levels are clearly reduced in undifferentiated tumors. Overexpression of Notch-1 in thyroid cancer cells restores differentiation, reduces cell growth rates, and stimulates NIS expression via a direct action on the NIS promoter. CONCLUSION: Notch signaling is involved in the determination of thyroid cell fate and is a direct regulator of thyroid-specific gene expression. Its deregulation may contribute to the loss of differentiation associated with thyroid tumorigenesis.


Assuntos
Biomarcadores/metabolismo , Carcinoma Papilar/genética , Diferenciação Celular/genética , Receptores Notch/fisiologia , Glândula Tireoide/metabolismo , Neoplasias da Glândula Tireoide/genética , Adenocarcinoma Folicular/genética , Adenocarcinoma Folicular/metabolismo , Animais , Carcinoma Papilar/metabolismo , Desdiferenciação Celular/genética , Células Cultivadas , Regulação para Baixo , Regulação Neoplásica da Expressão Gênica , Humanos , Camundongos , Especificidade de Órgãos/genética , Receptores Notch/genética , Transdução de Sinais/genética , Transdução de Sinais/fisiologia , Simportadores/genética , Simportadores/metabolismo , Glândula Tireoide/citologia , Glândula Tireoide/embriologia , Neoplasias da Glândula Tireoide/metabolismo
9.
Vet J ; 178(1): 32-45, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18294883

RESUMO

Among enteric caliciviruses, noroviruses belong to the genus Norovirus, one of the four accepted genera in the family Caliciviridae. These single-stranded, positive-sense RNA viruses are highly variable both genetically and antigenically. Several animal enteric caliciviruses that are morphologically indistinguishable and genetically closely related to human noroviruses have been identified. The first bovine enteric noroviruses were described in Great Britain and are known as Newbury Agent 2. At least three genetic clusters of porcine noroviruses join together within genogroup II noroviruses. Human noroviruses are the most important cause of acute gastroenteritis illness in people of all ages. In the USA, they are associated with approximately 30-50% of all food-borne outbreaks. Until now, noroviruses have not been associated with gastroenteritis outbreaks in immunocompetent animals. Neither bovine nor porcine noroviruses can replicate in cell culture, although human norovirus can grow in a complex 3D culture system. However, the recently discovered murine noroviruses can replicate in cell culture and are therefore used as model viruses to study human noroviruses. This review focusses on virus classification, virion structure, pathogenesis, epidemiology, immune response and diagnosis of animal noroviruses in comparison with human noroviruses. The classification of animal enteric caliciviruses within the Norovirus genus raises the question of whether transmission from an animal reservoir to humans could occur. Answering this question is important in determining the risk of cross-species infections affecting the epidemiology and evolution of these viruses and so complicating the control of human norovirus infections.


Assuntos
Infecções por Caliciviridae/veterinária , Doenças dos Bovinos/virologia , Norovirus/isolamento & purificação , Doenças dos Suínos/virologia , Animais , Infecções por Caliciviridae/virologia , Bovinos , Suínos
10.
J Clin Endocrinol Metab ; 92(7): 2840-3, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17488796

RESUMO

CONTEXT: BRAF mutations are common in papillary thyroid carcinomas (PTCs). By affecting the expression of genes critically related to the development and differentiation of thyroid cancer, they may influence the prognosis of these tumors. OBJECTIVE: Our objective was to characterize the expression of thyroid-specific genes associated with BRAF mutation in PTCs. DESIGN/SETTING AND PATIENTS: We examined the expression of key markers of thyrocyte differentiation in 56 PTCs with BRAF mutations (BRAF-mut) and 37 with wild-type BRAF (BRAF-wt). Eight samples of normal thyroid tissue were analyzed as controls. Quantitative PCR was used to measure mRNA levels for the sodium/iodide symporter (NIS), apical iodide transporter (AIT-B), thyroglobulin (Tg), thyroperoxidase (TPO), TSH receptor (TSH-R), the transcription factor PAX8, and glucose transporter type 1 (Glut1). NIS protein expression and localization was also analyzed by immunohistochemistry. RESULTS: mRNA levels for all thyroid-specific genes were reduced in all PTCs vs. normal thyroid tissues. NIS, AIT-B, Tg, and TPO expression was significantly lower in BRAF-mut tumors than in the BRAF-wt group. Glut-1 transcript levels were increased in all PTCs, and additional increases were noted in BRAF-mut tumors. In both tumor subsets, the NIS protein that was expressed was abnormally retained in the cytoplasm. CONCLUSION: BRAF V600E mutation in PTCs is associated with reduced expression of key genes involved in iodine metabolism. This effect may alter the effectiveness of diagnostic and/or therapeutic use of radioiodine in BRAF-mut PTCs.


Assuntos
Carcinoma Papilar/genética , Regulação Neoplásica da Expressão Gênica , Iodo/metabolismo , Proteínas Proto-Oncogênicas B-raf/genética , Neoplasias da Glândula Tireoide/genética , Adulto , Idoso , Carcinoma Papilar/metabolismo , Diferenciação Celular , Feminino , Marcadores Genéticos , Humanos , Masculino , Pessoa de Meia-Idade , Mutação Puntual , RNA Mensageiro/metabolismo , Neoplasias da Glândula Tireoide/metabolismo
11.
J Endocrinol Invest ; 28(2): 137-44, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15887859

RESUMO

Differential protein arrays between nuclear extracts of human thyroid cell lines obtained from tumors with different degree of differentiation were exploited to define molecular alterations occurring during thyroid tumor progression. Nuclear extracts from the well differentiated TPC-1 (from papillary carcinoma) and the poorly differentiated ARO (from anaplastic carcinoma) cells showed an overall similar pattern of protein expression as revealed by two-dimensional gel electrophoresis analysis. However, manganese-superoxide dismutase (Mn-SOD) was clearly identified by mass spectrometry procedures as significantly less expressed in ARO compared to TPC-1 cells. A reduced expression of Mn-SOD in the nuclear compartment was confirmed by Western blot and immunofluorescence analysis. A similar expression pattern of nuclear Mn-SOD was detected by immunohistochemistry in human thyroid tumors, with the lowest or absent detection in anaplastic carcinomas. Moreover, the levels of nuclear Mn-SOD in tumor cells were lower than in the normal thyrocytes. These data indicate that an altered nuclear expression of Mn-SOD parallels, together with changes in other elements of the antioxidant protective system, the loss of differentiation occurring during the progression of thyroid tumors.


Assuntos
Carcinoma/enzimologia , Núcleo Celular/enzimologia , Proteômica , Superóxido Dismutase/metabolismo , Neoplasias da Glândula Tireoide/enzimologia , Neoplasias da Glândula Tireoide/patologia , Adenocarcinoma Folicular/enzimologia , Adenocarcinoma Folicular/patologia , Western Blotting , Carcinoma/patologia , Carcinoma Papilar/enzimologia , Carcinoma Papilar/patologia , Linhagem Celular Tumoral , Imunofluorescência , Humanos , Imuno-Histoquímica , Técnicas In Vitro , Distribuição Tecidual
12.
Acta Clin Belg ; 59(1): 30-3, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15065694

RESUMO

We report an outbreak of gastroenteritis due to Norovirus in a care unit in a Belgian hospital involving thirty-three people. The origin of the outbreak was traced to one nursing assistant. The virus strain identified by reverse transcription polymerase chain reaction and electron microscopy belonged to the genogroup II.


Assuntos
Infecções por Caliciviridae/epidemiologia , Infecções por Caliciviridae/virologia , Surtos de Doenças , Gastroenterite/epidemiologia , Gastroenterite/virologia , Hospitais , Norovirus , Bélgica/epidemiologia , Infecções por Caliciviridae/transmissão , Busca de Comunicante , Infecção Hospitalar/epidemiologia , Infecção Hospitalar/transmissão , Infecção Hospitalar/virologia , Humanos , Norovirus/classificação , Reação em Cadeia da Polimerase Via Transcriptase Reversa
13.
Biophys Chem ; 95(1): 23-47, 2002 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-11880171

RESUMO

A theoretical model for predicting intrinsic and induced DNA superstructures as well as their thermodynamic properties is presented. Intrinsic sequence-dependent superstructures are evaluated by integrating local deviations from the canonical B-DNA of the different dinucleotide steps. Induced superstructures are obtained by adopting the principle of minimum deformation free energy, evaluated in the Fourier space, in the framework of first-order elasticity. Finally dinucleotide stacking energies and melting temperatures are considered to account for local flexibility. In fact the two scales are strongly correlated. The model works very satisfactorily in predicting the sequence-dependent effects on the DNA experimental behavior, such as the gel electrophoresis retardation, the writhe transitions in topologically constrained domains, the thermodynamic constants of circularization reactions as well as the nucleosome thermodynamic stability constants.


Assuntos
DNA/química , Algoritmos , DNA/ultraestrutura , Elasticidade , Microscopia de Força Atômica , Modelos Químicos , Conformação de Ácido Nucleico , Nucleossomos , Termodinâmica
14.
Arq Bras Cardiol ; 77(1): 30-6, 2001 Jul.
Artigo em Inglês, Português | MEDLINE | ID: mdl-11500745

RESUMO

OBJECTIVE: To verify whether the guidelines for the treatment of heart failure have been adopted at a university hospital. The guidelines recommend the following: use of angiotensin-converting enzyme inhibitors for all patients with systolic ventricular dysfunction, use of digitalis and diuretics for symptomatic patients, use of beta-blockers for patients in functional classes II or III, use of spironolactone for patients in functional classes III or IV. METHODS: We analyzed the prescriptions of 199 patients. All these patients had ejection fraction (EF)

Assuntos
Baixo Débito Cardíaco/tratamento farmacológico , Cardiologia/normas , Fidelidade a Diretrizes , Guias de Prática Clínica como Assunto , Adulto , Idoso , Idoso de 80 Anos ou mais , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Cardiomiopatias/tratamento farmacológico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Isquemia Miocárdica/tratamento farmacológico , Volume Sistólico , Disfunção Ventricular/tratamento farmacológico
15.
Proc Natl Acad Sci U S A ; 98(6): 3074-9, 2001 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-11248034

RESUMO

The energy of DNA deformation plays a crucial and active role in its packaging and its function in the cell. Considerable effort has gone into developing methodologies capable of evaluating the local sequence-directed curvature and flexibility of a DNA chain. These studies thus far have focused on DNA constructs expressly tailored either with anomalous flexibility or curvature tracts. Here we demonstrate that these two structural properties can be mapped also along the chain of a "natural" DNA with any sequence on the basis of its scanning force microscope (SFM) images. To know the orientation of the sequence of the investigated DNA molecules in their SFM images, we prepared a palindromic dimer of the long DNA molecule under study. The palindromic symmetry also acted as an internal gauge of the statistical significance of the analysis carried out on the SFM images of the dimer molecules. It was found that although the curvature modulus is not efficient in separating static and dynamic contributions to the curvature of the population of molecules, the curvature taken with its direction (its sign in two dimensions) permits the direct separation of the intrinsic curvature from the flexibility contributions. The sequence-dependent flexibility seems to vary monotonically with the chain's intrinsic curvature; the chain rigidity was found to modulate as its local thermodynamic stability and does not correlate with the dinucleotide chain rigidities evaluation made from x-ray data by other authors.


Assuntos
DNA Bacteriano/química , Conformação de Ácido Nucleico , Plasmídeos/química , Microscopia de Força Atômica/métodos
16.
Biopolymers ; 58(2): 218-29, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11093120

RESUMO

A theoretical method is proposed to identify structural domains in proteins of known structures. It is based on the distribution of the local axes of the polypeptide chain. In particular, a statistical analysis is applied to the contributions of the local axes to the absolute writhing number, a topological property of a space curve resulting from the number of self-crossings in the curve projections onto a unit sphere. This finding supports the hypothesis that topological requirements should be satisfied in the process of protein folding and in the final organization of the tertiary structures.


Assuntos
Proteínas/química , Bases de Dados Factuais , Modelos Moleculares , Dobramento de Proteína , Estrutura Terciária de Proteína
17.
Arq Bras Cardiol ; 74(4): 324-8, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10967584

RESUMO

OBJECTIVE: We analyzed the frequency of peripheral embolisms, the underlying heart disease,triggering factors, the sites of the emboli, and evolution of the patients. METHODS: We analyzed 29 cases of peripheral arterial embolism out of a total of 20,211 hospitalizations in a cardiology center in the city of São Paulo. The age was 51.89+/-18.66 years, and 15 were males. RESULTS: Embolism in the right lower limb occurred in 18 patients (62.0%),in the left lower 11(37.9%) and right upper 3 (10.3%) limbs, and in the left arm (1). Four patients had embolism in two limbs. The heart disease, mitral valvar heart disease (9 patients - 31.0%); infective endocarditis (7- 24.1%); dilated cardiomyopathy (6 - 20.6%); ischemic coronary heart disease (6 patients - 20.6%); and one patient with cor pulmonale. Atrial fibrillation was observed in 20 patients (68.9%), chronic in 12 patients (41.3% ) and acute in 8 (27. 5%). All patients with mitral valvar heart disease had atrial fibrillation, chronic in 8 patients (88.8%); patients with cardiomyopathy and coronary heart disease, 4 in each group had atrial fibrillation, acute in 60% of the patients. Patients with infective endocarditis, 3 had staphylococcus and 2 Gram-negative bacteria. In the follow-up, 2 patients (6.8%) required limbs amputation, and 5 (17.2%) died due to embolism. CONCLUSION: Most of the time, embolism does not cause permanent complications. Our data highlight the importance of anticoagulation for patients acute atrial fibrillation in myocardial dysfunction and for patients with chronic atrial fibrillation in cases of mitral valvar heart disease to prevent peripheral embolism.


Assuntos
Embolia/etiologia , Cardiopatias/complicações , Doenças Vasculares Periféricas/etiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Brasil/epidemiologia , Criança , Ecocardiografia , Embolia/epidemiologia , Feminino , Hospitais Universitários , Humanos , Masculino , Pessoa de Meia-Idade , Doenças Vasculares Periféricas/epidemiologia , Fatores de Risco , Fatores de Tempo
18.
Biophys J ; 79(2): 601-13, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10919995

RESUMO

A theoretical model for predicting nucleosome thermodynamic stability in terms of DNA sequence is advanced. The model is based on a statistical mechanical approach, which allows the calculation of the canonical ensemble free energy involved in the competitive nucleosome reconstitution. It is based on the hypothesis that nucleosome stability mainly depends on the bending and twisting elastic energy to transform the DNA intrinsic superstructure into the nucleosomal structure. The ensemble average free energy is calculated starting from the intrinsic curvature, obtained by integrating the dinucleotide step deviations from the canonical B-DNA and expressed in terms of a Fourier series, in the framework of first-order elasticity. The sequence-dependent DNA flexibility is evaluated from the differential double helix thermodynamic stability. A large number of free-energy experimental data, obtained in different laboratories by competitive nucleosome reconstitution assays, are successfully compared to the theoretical results. They support the hypothesis that the stacking energies are the major factor in DNA rigidity and could be a measure of DNA stiffness. A dual role of DNA intrinsic curvature and flexibility emerges in the determination of nucleosome stability. The difference between the experimental and theoretical (elastic) nucleosome-reconstitution free energy for the whole pool of investigated DNAs suggests a significant role for the curvature-dependent DNA hydration and counterion interactions, which appear to destabilize nucleosomes in highly curved DNAs. This model represents an attempt to clarify the main features of the nucleosome thermodynamic stability in terms of physical-chemical parameters and suggests that in molecular systems with a large degree of complexity, the average molecular properties dominate over the local features, as in a statistical ensemble.


Assuntos
DNA/química , DNA/ultraestrutura , Modelos Teóricos , Nucleossomos/ultraestrutura , Sequência de Bases , Elasticidade , Conformação de Ácido Nucleico , Termodinâmica
20.
J Mol Biol ; 286(5): 1293-301, 1999 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-10064697

RESUMO

A statistical mechanistic approach to evaluate the sequence-dependent thermodynamic stability of nucleosomes is proposed. The model is based on the calculation of the DNA intrinsic curvature, obtained by integrating the nucleotide step deviations from the canonical B-DNA structure, and on the evaluation of the first order elastic distortion energy to reach the nucleosomal superstructure. Literature data on the free energy of nucleosome formation as obtained by competitive nucleosome reconstitution of a significant pool of different DNA sequences were compared with the theoretical results, and a satisfactorily good correlation was found. A striking result of the comparison is the emergence of two opposite roles of the DNA intrinsic curvature and flexibility in determining nucleosome stability. Finally, the obtained results suggest that the curvature-dependent DNA hydration should play a relevant role in the sequence-dependent nucleosome stability.


Assuntos
DNA/química , Conformação de Ácido Nucleico , Nucleossomos/metabolismo , Sequência de Bases , Ligação Competitiva , DNA/genética , DNA/metabolismo , Elasticidade , Modelos Químicos , Nucleossomos/química , Nucleossomos/genética , Ligação Proteica , Termodinâmica
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