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1.
Semina cienc. biol. saude ; 43(1): 129-152, jan./jun. 2022. ilus, tab
Article in English | LILACS | ID: biblio-1354470

ABSTRACT

This macro-level scientometrics study aimed to analyze the similarities and differences in the scientific communication patterns of the Brazilian postgraduate programs (BPPs) belonging to the Biological Sciences II field (BS2), as defined by Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES). Also, it was identified the most researched diseases and it was discussed their relationship with the needs of Brazilian public health considering the burden of disease (Disability-Adjusted Life Year - DALY, Brazil) estimated by the World Health Organization (WHO). Thus, the scientific production of the BS2's sub-areas Biophysics, Biochemistry, Pharmacology, Physiology, and Morphology was evaluated from 2013 to 2016, through considering the citation impact, Impact Factor (Journal Citation Reports), and scientific collaboration. Data collected included formal information provided to CAPES by all BPPs through the Plataforma Sucupira as well as metadata from Web of Science documents. In addition, were employed the standardized Medical Subject Headings (PubMed) for the analysis of researched diseases. We concluded that the patterns of scientific communication in Biophysics, Biochemistry, Pharmacology, Physiology, and Morphology were predominantly different. Thus, there is a need to consider specificities among the five sub-areas in the evaluation process performed by CAPES. Different approaches are revealed by identifying the most frequently researched diseases and explaining the contributions of each sub-area for Brazilian public health.


Este estudo cientométrico de nível macro teve como objetivo analisar as semelhanças e as diferenças nos padrões de comunicação científica dos programas de pós-graduação brasileiros (PPGs) da área de Ciências Biológicas II, avaliados pela Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES). Além disso, foram identificadas as doenças mais pesquisadas e foi discutido sua relação com as necessidades de saúde pública brasileira, considerando a carga de doenças (Disability-Adjusted Life Year - DALY, Brasil) estimada pela Organização Mundial da Saúde (OMS). Assim, a produção científica das subáreas Biofísica, Bioquímica, Farmacologia, Fisiologia e Morfologia da área de Ciências Biológicas II foi avaliada de 2013 a 2016, considerando o impacto de citações, o Fator de Impacto (Journal Citation Reports) e a colaboração científica. Os dados coletados incluíram informações declaradas à CAPES por todos os PPGs por meio da Plataforma Sucupira, bem como metadados de documentos da Web of Science. Além disso, foram utilizados os cabeçalhos de Medical Subject Headings (PubMed) para a análise das doenças pesquisadas. Concluímos que os padrões de comunicação científica entre as subáreas Biofísica, Bioquímica, Farmacologia, Fisiologia e Morfologia foram predominantemente diferentes. Assim, é necessário considerar as especificidades entre as cinco subáreas no processo de avaliação realizado pela CAPES. Diferentes abordagens são reveladas a partir da identificação das doenças mais pesquisadas e da explicação das contribuições de cada subárea para a saúde pública brasileira.


Subject(s)
Humans , World Health Organization , Biological Science Disciplines , Medical Subject Headings , Impact Factor , Metadata , Powders , Biochemistry , Biophysics , Public Health , PubMed
2.
Acta Physiologica Sinica ; (6): 160-174, 2021.
Article in Chinese | WPRIM | ID: wpr-878245

ABSTRACT

Vascular smooth muscle cell (vSMC) is the predominant cell type in the blood vessel wall and is constantly subjected to a complex extracellular microenvironment. Mechanical forces that are conveyed by changes in stiffness/elasticity, geometry and topology of the extracellular matrix have been indicated by experimental studies to affect the phenotype and function of vSMCs. vSMCs perceive the mechanical stimuli from matrix via specialized mechanosensors, translate these stimuli into biochemical signals controlling gene expression and activation, with the consequent modulation in controlling various aspects of SMC behaviors. Changes in vSMC behaviors may further cause disruption of vascular homeostasis and then lead to vascular remodeling. A better understanding of how SMC senses and transduces mechanical forces and how the extracellular mechano-microenvironments regulate SMC phenotype and function may contribute to the development of new therapeutics for vascular diseases.


Subject(s)
Biophysics , Cells, Cultured , Extracellular Matrix , Humans , Muscle, Smooth, Vascular , Myocytes, Smooth Muscle , Phenotype , Vascular Remodeling
3.
Biomedical Engineering Letters ; (4): 425-434, 2019.
Article in English | WPRIM | ID: wpr-785531

ABSTRACT

Heart rate variability (HRV) is governed by the autonomic nervous system (ANS) and is routinely used to estimate the state of body and mind. At the same time, recorded HRV features can vary substantially between people. A model for HRV that (1) correctly simulates observed HRV, (2) reliably functions for multiple scenarios, and (3) can be personalised using a manageable set of parameters, would be a significant step forward toward understanding individual responses to external influences, such as physical and physiological stress. Current HRV models attempt to reproduce HRV characteristics by mimicking the statistical properties of measured HRV signals. The model presented here for the simulation of HRV follows a radically different approach, as it is based on an approximation of the physiology behind the triggering of a heart beat and the biophysics mechanisms of how the triggering process—and thereby the HRV—is governed by the ANS. The model takes into account the metabolisation rates of neurotransmitters and the change in membrane potential depending on transmitter and ion concentrations. It produces an HRV time series that not only exhibits the features observed in real data, but also explains a reduction of low frequency band-power for physically or psychologically high intensity scenarios. Furthermore, the proposed model enables the personalisation of input parameters to the physiology of different people, a unique feature not present in existing methods. All these aspects are crucial for the understanding and application of future wearable health.


Subject(s)
Autonomic Nervous System , Biophysics , Heart Rate , Heart , Membrane Potentials , Neurotransmitter Agents , Physiology , Stress, Physiological , Vital Signs
4.
Rio de Janeiro; s.n; 2019. xi, 79 p. ilus.
Thesis in Portuguese | LILACS | ID: biblio-1049934

ABSTRACT

A hepatite B é um problema de saúde global: só no ano de 2015 foram quase 900 mil óbitos decorrentes de complicações relacionadas à infecção com o vírus HBV. No Brasil, a situação também é grave: no ano de 2000 até o ano de 2015 o número de óbitos atingiu 13 mil. O diagnóstico da doença e o tratamento dos pacientes crônicos podem ser feitos através do uso de imunoglobulinas que tem afinidade pelo antígeno de superfície do vírus, HBsAg. Portanto, estratégias que busquem diminuir os custos de produção de imunoglobulinas anti-HBsAg ou aumentar sua afinidade frente a este antígeno são desejáveis em âmbitos nacional e global. O estudo de biomoléculas através de técnicas computacionais tem produzido bons resultados, capazes de orientar estudos experimentais, economizando tempo e recursos e, frequentemente, resolvendo problemas biológicos. Dentre estas técnicas computacionais, destaca-se o cálculo de energia livre. A aplicação do cálculo de energia livre a complexos anticorpo-antígeno pode fornecer informações detalhadas sobre a afinidade do anticorpo frente ao antígeno. Neste trabalho, estudamos a interação do anticorpo 19CC6CG2, desenvolvido no Laboratório de Tecnologia de Anticorpos Monoclonais de Bio-Manguinhos, com o HBsAg através de duas técnicas de cálculo de energia livre: MM-PBSA e Adaptive Biasing Force


Embora a primeira técnica tenha fornecido um valor de ΔG de ligação de -12 kcal/mol, a análise mais robusta através do segundo método mostrou um ΔG de dissociação de -7,6 kcal/mol. Adicionalmente, foram propostas mutações na estrutura do anticorpo visando ao aumento da sua afinidade pelo antígeno. O anticorpo mutante foi então modelado in silico e a sua afinidade frente ao HBsAg foi mensurada através da técnica de ABF. Resultados preliminares mostraram um valor de ΔG de ligação de -4,2 kcal/mol. As mutações na estrutura do anticorpo favoreceram a formação de ligações hidrogênio e pontes salinas intermoleculares mais estáveis nas simulações de dinâmica molecular. No entanto, simulações mais longas e/ou o aumento da dimensionalidade do espaço através de variáveis coletivas no cálculo de ABF, podem melhorar a convergência do método, tornando evidente se as mutações aqui propostas são favoráveis à afinidade do anticorpo 19CC6CG2 contra o HBsAg. (AU)


Subject(s)
Humans , Biophysics , Immunoglobulins/administration & dosage , Hepatitis B , Antibodies
5.
Rev. Paul. Enferm. (Online) ; 29(1/3): 136-145, nov. 14, 2018. quadros
Article in Portuguese | LILACS, BDENF | ID: biblio-970778

ABSTRACT

O presente estudo, fundado no relato de experiência, expõe a elaboração de um plano de aula voltado\r\npara a disciplina Biofísica Aplicada à Enfermagem. Os objetivos visam explicitar as bases normativas que\r\nestruturam a prática docente em cursos de Graduação em Enfermagem, bem como apresentar as etapas\r\nnecessárias ao trabalho de planejamento de aula. A metodologia utilizada reside no estudo de caso,\r\ndesenvolvido a partir das propostas do Programa de Capacitação e Atualização Didático-Pedagógico para\r\nEnfermeiros Docentes ­ Pro-CAD, promovido pela Associação Brasileira de Enfermagem ­ ABEn-SP em\r\nparceria com o Conselho Regional de Enfermagem de São Paulo COREN-SP. Os resultados desvelam o\r\npotencial do planejamento da prática docente, bem como a função do enfermeiro/docente no processo\r\nde formação e orientação profissional


The present study based on a case report exposes the elaboration of a lesson plan of Biophysics for\r\nNursing. The objectives aim to explain the normative bases which form the faculty hands-on approach\r\nfor graduation courses in Nursing, as well as to present the necessary steps for lesson planning. The\r\nmethodology used focuses on a case report developed from proposals made by The Programa de\r\nCapacitação e Atualização Didático-pedagógico para Enfermeiros Docentes ­ Pro-CAD ( Professional\r\nUpgrading and Updating for Faculty Nurses), promoted by the Associação Brasileira de Enfermagem de\r\nSão Paulo ­ ABEn-SP together with the Conselho Regional de Enfermagem de São Paulo ­ COREN-SP.The results sheds a light to the potential of faculty hands-on planning and also the role of the nurse/\r\nfaculty member in the process of professional education and orientation.


El presente estudio, fundado en el relato de experiencia, expone la elaboración de un plan de aula direccionado a la disciplina Biofísica Aplicada a Enfermería. Los objetivos visan explicitar las bases normativas que estructuran la práctica docente en los cursos de Graduación en Enfermería, bien como presentar las etapas necesarias en el trabajo de planeamiento de aula. La metodología utilizada reside en el estudio de caso, desarrollado a partir de las propuestas del Programa de Capacitación e Actualización\r\nDidáctico-Pedagógico para Enfermeros Docentes ­ Pro-CAD, organizado por la Asociación Brasileña de\r\nEnfermería ­ ABEn-SP en pacería con el Consejo Regional de Enfermería de Sao Paulo ­ COREN-SP. El\r\nresultado debela lo potencial del planeamiento de la práctica docente, bien como la función del enfermero/docente en el proceso de formación y orientación profesional


Subject(s)
Humans , Biophysics , Case Reports , Planning Techniques , Competency-Based Education , Education, Nursing , Planning
6.
Korean Circulation Journal ; : 114-123, 2018.
Article in English | WPRIM | ID: wpr-738682

ABSTRACT

The cryoballoon was invented to achieve circumferential pulmonary vein isolation more efficiently to compliment the shortcomings of point-by-point ablation by radiofrequency ablation (RFA). Its efficacy and safety were shown to be comparable to those of RFA, and the clinical outcomes have improved with the second-generation cryoballoon. The basic biophysics, implemental techniques, procedural recommendations, clinical outcomes, and complications of the cryoballoon are presented in this practical and systematic review.


Subject(s)
Atrial Fibrillation , Biophysics , Catheter Ablation , Cryosurgery , Pulmonary Veins
7.
Article in English | WPRIM | ID: wpr-740099

ABSTRACT

BACKGROUND: The mechanical deformability of cancer cells has attracted particular attention as an emerging biomarker for the prediction of anti-cancer drug sensitivity. Nevertheless, it has not been possible to establish a general rubric for the identification of drug susceptibility in breast cancer cells from a mechanical perspective. In the present study, we investigated the mechanical alteration associated with resistance to adjuvant therapy in breast cancer cells. METHODS: We performed an ‘atomic force microscopy (AFM)-based nanomechanical study’ on ‘drug-sensitive (MCF-7)’ and ‘drug-resistant (MCF-7/ADR)’ breast cancer cells. We also conducted cell viability tests to evaluate the difference in doxorubicin responsiveness between two breast cancer cell lines. We carried out a wound closure experiment to investigate the motility changes associated with chemotherapeutic resistance. To elucidate the changes in molecular alteration that accompany chemotherapeutic resistance, we investigated the expression of vinculin and integrin-linked kinase-1–which are proteins involved in substrate adhesion and the actin cytoskeleton–using Western blotting analysis. RESULTS: A MTT assay confirmed that the dose-dependent efficacy of doxorubicin was reduced in MCF-7/ADR cells compared to that in MCF-7 cells. The wound assay revealed enhanced two-dimensional motility in the MCF-7/ADR cells. The AFM mechanical assay showed evidence that the drug-resistant breast cancer cells exhibited a significant decrease in mechanical deformability compared to their drug-sensitive counterparts. The mechanical alteration in the MCF-7/ADR cells was accompanied by upregulated vinculin expression. CONCLUSIONS: The obtained results manifestly showed that the altered mechanical signatures–including mechanical deformability and motility–were closely related with drug resistance in the breast cancer cells. We believe that this investigation has improved our understanding of the chemotherapeutic susceptibility of breast cancer cells.


Subject(s)
Actins , Biophysics , Blotting, Western , Breast Neoplasms , Breast , Cell Line , Cell Survival , Doxorubicin , Drug Resistance , Drug Resistance, Multiple , Elastic Modulus , MCF-7 Cells , Microscopy, Atomic Force , Vinculin , Wounds and Injuries
8.
Article in English | WPRIM | ID: wpr-122239

ABSTRACT

The extracellular matrix (ECM) is a heterogeneous, connective network composed of fibrous glycoproteins that coordinate in vivo to provide the physical scaffolding, mechanical stability, and biochemical cues necessary for tissue morphogenesis and homeostasis. This review highlights some of the recently raised aspects of the roles of the ECM as related to the fields of biophysics and biomedical engineering. Fundamental aspects of focus include the role of the ECM as a basic cellular structure, for novel spontaneous network formation, as an ideal scaffold in tissue engineering, and its essential contribution to cell sheet technology. As these technologies move from the laboratory to clinical practice, they are bound to shape the vast field of tissue engineering for medical transplantations.


Subject(s)
Biomedical Engineering , Biophysics , Cellular Structures , Collagen , Cues , Elastin , Extracellular Matrix , Fibronectins , Glycoproteins , Homeostasis , Morphogenesis , Tissue Engineering
9.
Arq. bras. cardiol ; 104(5): 417-425, 05/2015. tab, graf
Article in English | LILACS | ID: lil-748154

ABSTRACT

Introduction: Although diuretics are mainly used for the treatment of acute decompensated heart failure (ADHF), inadequate responses and complications have led to the use of extracorporeal ultrafiltration (UF) as an alternative strategy for reducing volume overloads in patients with ADHF. Objective: The aim of our study is to perform meta-analysis of the results obtained from studies on extracorporeal venous ultrafiltration and compare them with those of standard diuretic treatment for overload volume reduction in acute decompensated heart failure. Methods: MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials databases were systematically searched using a pre‑specified criterion. Pooled estimates of outcomes after 48 h (weight change, serum creatinine level, and all-cause mortality) were computed using random effect models. Pooled weighted mean differences were calculated for weight loss and change in creatinine level, whereas a pooled risk ratio was used for the analysis of binary all-cause mortality outcome. Results: A total of nine studies, involving 613 patients, met the eligibility criteria. The mean weight loss in patients who underwent UF therapy was 1.78 kg [95% Confidence Interval (CI): −2.65 to −0.91 kg; p < 0.001) more than those who received standard diuretic therapy. The post-intervention creatinine level, however, was not significantly different (mean change = −0.25 mg/dL; 95% CI: −0.56 to 0.06 mg/dL; p = 0.112). The risk of all-cause mortality persisted in patients treated with UF compared with patients treated with standard diuretics (Pooled RR = 1.00; 95% CI: 0.64–1.56; p = 0.993). Conclusion: Compared with standard diuretic therapy, UF treatment for overload volume reduction in individuals suffering from ADHF, resulted in significant reduction of body weight within 48 h. However, no significant decrease of serum creatinine level or reduction of all-cause mortality ...


Introdução: Embora os diuréticos sejam utilizados como o principal tratamento na insuficiência cardíaca aguda descompensada, sua significativa taxa de complicações e respostas inadequadas levou ao uso de ultrafiltração extracorpórea como uma alternativa. Objetivo: Realizar uma meta-análise de estudos de ultrafiltração venosa extracorpórea e diuréticos no tratamento de sobrecarga hídrica na insuficiência cardíaca aguda descompensada. Métodos: MEDLINE, EMBASE e o banco de dados do Cochrane Central Register of Controlled Trials foram pesquisados sistematicamente usando um critério pré-estabelecido. Estimativas combinadas para os resultados na alteração de peso em 48 horas, creatinina sérica e mortalidade por todas as causas foram calculados utilizando modelos de efeitos aleatórios. As diferenças entre as médias ponderadas combinadas foram calculadas para a perda de peso e alteração nos níveis de creatinina e relação risco partilhado foi utilizada para o resultado binário de todas as causas de mortalidade. Resultados: Nove estudos foram considerados elegíveis para a análise, com inclusão de 613 pacientes. Pacientes submetidos a ultrafiltração perderam em média 1,78kg (intervalo de confiança [IC] 95% -2,65 a 0,91kg, p < 0,001) quando comparados com pacientes submetidos à terapia diurética padrão. Os níveis de creatinina pós-intervenção, no entanto, não diferiram entre os grupos (diferença média de -0,25 mg/dL CI 95% -0,56 a 0,06mg/dL p = 0,112). Não observamos evidências de redução de risco de mortalidade por todas as causas em pacientes submetidos à UF quando comparados àqueles tratados com terapia diurética padrão (RR combinado = 1,00 CI 95% 0,64 1,56, p = 0,993). Conclusão: Quando comparado à terapia diurética padrão, o uso de UF no tratamento de sobrecarga hídrica em ICAD resultou em uma redução significativa de peso em 48 horas. No entanto, não foi observada melhoria significativa na redução dos níveis de creatinina ou na taxa de ...


Subject(s)
Aged , Female , Humans , Male , Middle Aged , Diabetic Foot/etiology , Diabetic Neuropathies/physiopathology , Foot/physiopathology , Pressure , Walking/physiology , Analysis of Variance , Awards and Prizes , Biophysics , Case-Control Studies , Forefoot, Human/physiopathology , Societies, Scientific
10.
Salud colect ; 11(1): 115-128, ene.-mar. 2015.
Article in Spanish | LILACS | ID: lil-746688

ABSTRACT

Los antipsicóticos no parecen revertir las causas de la esquizofrenia y, aunque son fármacos que pueden aliviar los síntomas a corto y mediano plazo, a largo plazo pueden no ser beneficiosos e incluso ser contraproducentes. Su empleo debería limitarse a situaciones agudas con agitación y tensión incapacitante. Presentan considerables efectos adversos y, ante la negativa de una persona a seguir tomándolos, adoptar una estrategia de reducción de daños apoyando y supervisando la retirada puede ser preferible a la coerción. Existen alternativas a los neurolépticos. Los prescriptores deberían estar más atentos y considerar las valoraciones que los usuarios hacen de sus efectos. El apego a las guías de tratamiento es escaso, seguramente por basarse en ensayos clinicos de calidad deficente, que deben mejorar y prolongarse en el tiempo. La raíz del problema probablemente se encuentra en la tautología sobre la etiología y naturaleza biológica de lo que llaman esquizofrenia, que realmente no parece ser más que un constructo ideológico-comercial.


Antipsychotic drugs do not appear to reverse the causes of schizophrenia, and although they can relieve symptoms in the short to medium term, in the long term they may not be beneficial and could even be counterproductive. Their use should be limited to acute situations in which agitation and tension is disabling. The drugs have significant adverse effects, and given the refusal of a person to continue taking them, a harm reduction strategy to support and monitor the withdrawal may be preferable to coercion. There are alternatives to neuroleptics. Prescribers should be more vigilant and consider the assessments of users regarding the drugs' effects. Adherence to treatment guidelines is low, probably because the guidelines are based on clinical trials of deficient quality which consequently should be improved and extended over a greater period of time. The root of the problem is likely the tautology on the etiology and biological nature of what is known as schizophrenia, which in fact does not seem to be more than a commercial and ideological construct.


Subject(s)
Bacterial Proteins/chemistry , Biophysics/methods , DNA-Binding Proteins/chemistry , Microscopy, Atomic Force/methods , Hydrogen Bonding , Kinetics , Models, Molecular , Models, Statistical , Monte Carlo Method , Protein Conformation , Protein Denaturation , Protein Folding , Protein Structure, Secondary , Protein Structure, Tertiary , Peptostreptococcus/metabolism , Proteins/chemistry , Stress, Mechanical , Temperature , Time Factors , Ubiquitin/chemistry
11.
Ciênc. saúde coletiva ; 20(2): 515-524, 02/2015. tab, graf
Article in Portuguese | LILACS | ID: lil-742222

ABSTRACT

O presente estudo identificou as características demográficas dos indivíduos e assistenciais do tratamento odontológico sob sedação e/ou anestesia geral em ambiente hospitalar no SUS-MG. Foram avaliadas todas as Autorizações de Internações Hospitalares (AIH) para o procedimento Tratamento Odontológico para Pacientes com Necessidades Especiais, de julho de 2011 a junho de 2012. Foram mensuradas variáveis demográficas e assistenciais dos atendimentos. Foram calculadas as taxas de internações por 10.000 habitantes e a cobertura assistencial realizada no estado de Minas Gerais e em cada uma das Regiões Ampliadas de Saúde. A análise descritiva das variáveis foi feita por meio de cálculo da frequência e medidas de tendência central e variabilidade. Foram avaliadas todas as 1.063 AIH pagas no período estudado, que representaram uma taxa de 0,54 internações por 10.000 habitantes. A maioria dos indivíduos era adulta, do sexo masculino, com diagnóstico de transtornos mentais ou comportamentais e residente em 27,7% dos municípios de Minas Gerais. Os procedimentos foram realizados em 39 municípios e a cobertura assistencial foi igual a 1,58%. O estudo revelou um perfil clássico do paciente atendido. Dificuldades em se estabelecer uma rede de atenção à saúde bucal foram identificadas.


This study identified the demographic characteristics of individuals and dental treatment care under sedation/general anesthesia in a hospital environment in the Unified Health System in the State of Minas Gerais (SUS-MG). All Hospitalization Authorizations (AIHs) for Dental Treatment for Patients with Special Needs procedures were evaluated between July 2011 and June 2012. Demographic and health care variables for treatment were also assessed. Hospitalization rates per 10,000 inhabitants, and health care coverage provided in the state of Minas Gerais and in each of the Broader Health Regions were calculated. Descriptive analysis of data was carried out by calculating the central trend and variability frequency and measurements. All 1,063 AIHs paid during the study period were evaluated, which is equivalent to a rate of 0.54 hospitalizations per 10,000 individuals. The majority of the patients were adult, male, diagnosed with mental or behavioral disorders and resident in 27.7% of the municipalities in Minas Gerais. The procedures were performed in 39 municipalities and the care coverage was equal to 1.58%. The study reveals a classic demographic and clinical profile of patient attendance. Difficulties in establishing a network of dental care were identified.


Subject(s)
Humans , Biophysics , Causality , Data Interpretation, Statistical , Models, Neurological , Models, Statistical , Bayes Theorem , Brain Mapping/methods , Brain Mapping/statistics & numerical data , Electroencephalography/statistics & numerical data , Image Processing, Computer-Assisted , Magnetoencephalography , Magnetic Resonance Imaging/statistics & numerical data , Reproducibility of Results
12.
Ciênc. saúde coletiva ; 20(1): 139-144, 01/2015.
Article in English | LILACS | ID: lil-733133

ABSTRACT

This paper analyses some aspects of the trajectory of the Argentinian physician and sociologist Juan César García (1932-1984) in the field of Latin American Social Medicine. Three dimensions constituting his basic orientations are highlighted: the elaboration of systematic and reflective social thought; a critical attitude in questioning teaching and professional practices; a commitment to the institutionalization and dissemination of health knowledge.


O artigo analisa aspectos da trajetória de Juan César García (1932-1984), médico e sociólogo argentino, no campo da medicina social latino-americana. Destaca três dimensões que constituem as suas orientações básicas no campo da saúde: a elaboração de um pensamento sobre o social, sistemático e reflexivo; uma atitude crítica na problematização do ensino e das práticas profissionais; um compromisso com a institucionalização e divulgação do saber sanitário.


Subject(s)
Animals , Anesthetics, General/pharmacology , Luciferases, Firefly/antagonists & inhibitors , Anisotropy , Binding Sites , Biophysical Phenomena , Biophysics , Crystallography, X-Ray , Fatty Alcohols/pharmacology , Halothane/pharmacology , In Vitro Techniques , Luciferases, Firefly/chemistry , Models, Molecular , Protein Conformation , Protein Structure, Tertiary , Thermodynamics
14.
Indian J Exp Biol ; 2013 Mar; 51(3): 187-200
Article in English | IMSEAR | ID: sea-147582

ABSTRACT

Wireless technologies are ubiquitous today and the mobile phones are one of the prodigious output of this technology. Although the familiarization and dependency of mobile phones is growing at an alarming pace, the biological effects due to the exposure of radiations have become a subject of intense debate. The present evidence on mobile phone radiation exposure is based on scientific research and public policy initiative to give an overview of what is known of biological effects that occur at radiofrequency (RF)/ electromagnetic fields (EMFs) exposure. The conflict in conclusions is mainly because of difficulty in controlling the affecting parameters. Biological effects are dependent not only on the distance and size of the object (with respect to the object) but also on the environmental parameters. Health endpoints reported to be associated with RF include childhood leukemia, brain tumors, genotoxic effects, neurological effects and neurodegenerative diseases, immune system deregulation, allergic and inflammatory responses, infertility and some cardiovascular effects. Most of the reports conclude a reasonable suspicion of mobile phone risk that exists based on clear evidence of bio-effects which with prolonged exposures may reasonably be presumed to result in health impacts. The present study summarizes the public issue based on mobile phone radiation exposure and their biological effects. This review concludes that the regular and long term use of microwave devices (mobile phone, microwave oven) at domestic level can have negative impact upon biological system especially on brain. It also suggests that increased reactive oxygen species (ROS) play an important role by enhancing the effect of microwave radiations which may cause neurodegenerative diseases.


Subject(s)
Animals , Apoptosis , Biophysics/methods , Brain/radiation effects , Brain Neoplasms/etiology , Cell Cycle , Cell Line, Tumor , Cell Phone , Central Nervous System/radiation effects , DNA Damage/radiation effects , Electromagnetic Fields , Environmental Exposure , Free Radicals , Humans , Mice , Models, Biological , Mutagens , Neoplasms, Radiation-Induced/diagnosis , Radiometry , Rats , Reactive Oxygen Species
15.
Indian J Exp Biol ; 2013 Jan; 51(1): 5-22
Article in English | IMSEAR | ID: sea-147532

ABSTRACT

Surfactant is an agent that decreases the surface tension between two media. The surface tension between gaseous-aqueous interphase in the lungs is decreased by the presence of a thin layer of fluid known as pulmonary surfactant. The pulmonary surfactant is produced by the alveolar type-II (AT-II) cells of the lungs. It is essential for efficient exchange of gases and for maintaining the structural integrity of alveoli. Surfactant is a secretory product, composed of lipids and proteins. Phosphatidylcholine and phosphatidylglycerol are the major lipid constituents and SP-A, SP-B, SP-C, SP-D are four types of surfactant associated proteins. The lipid and protein components are synthesized separately and are packaged into the lamellar bodies in the AT-II cells. Lamellar bodies are the main organelle for the synthesis and metabolism of surfactants. The synthesis, secretion and recycling of the surfactant lipids and proteins is regulated by complex genetic and metabolic mechanisms. The lipid-protein interaction is very important for the structural organization of surfactant monolayer and its functioning. Alterations in surfactant homeostasis or biophysical properties can result in surfactant insufficiency which may be responsible for diseases like respiratory distress syndrome, lung proteinosis, interstitial lung diseases and chronic lung diseases. The biochemical, physiological, developmental and clinical aspects of pulmonary surfactant are presented in this article to understand the pathophysiological mechanisms of these diseases.


Subject(s)
Animals , Biophysics/methods , Homeostasis , Humans , Lipids/chemistry , Lung/metabolism , Lung Diseases/physiopathology , Models, Biological , Models, Genetic , Phosphatidylcholines/metabolism , Phosphatidylglycerols/metabolism , Pulmonary Surfactants/metabolism
16.
Tehran University Medical Journal [TUMJ]. 2013; 71 (2): 79-89
in Persian | IMEMR | ID: emr-133003

ABSTRACT

Widespread of telecommunication systems in recent years, have raised the concerns on the possible danger of cell phone radiations on human body. Thus, the study of the electromagnetic fields on proteins, particularly the membrane nano channel forming proteins is of great importance. These proteins are responsible for keeping certain physic-chemical condition within cells and managing cell communication. Here, the effects of cell phones radiation on the activity of a single nanopore ion channel forming protein, OmpF, have been studied biophysically. Planar lipid bilayers were made based on Montal and Muller technique, and the activity of single OmpF channel reconstituted by electrical shock was recorded and analyzed by means of voltage-clamp technique at 20[degree]C. The planar lipid bilayers were formed from the monolayers made on a 60 micro m diameter aperture in the 20 micro m thick Teflon film that separated two [cis and trans] compartments of the glass chamber. In this practical approach we were able to analyze characteristics of an individual channel at different chemical and physical experimental conditions. The voltage clamp was used to measure the channel's conductance, voltage sensitivity, gating patterns in time scales as low as microseconds in real time. Our results showed that exposure of single voltage dependent channel, OmpF, to EMF of cell phone at high-frequency has a significant influence on the voltage sensitivity, gating properties and substate numbers of the single channel but has no effect on single-channel conductance. Regarding to the relaxation time, the channel also recovers in the millisecond time range when the field is removed. We observed an increase in the voltage sensitivity of the OmpF single channel while it had no effect on the single-channel conductance, which is remained to be further elucidated.


Subject(s)
Electromagnetic Fields , Porins , Nanopores , Biophysics , Ion Channel Gating , Patch-Clamp Techniques
17.
Immune Network ; : 71-83, 2012.
Article in English | WPRIM | ID: wpr-216360

ABSTRACT

T cell activation and function require physical contact with antigen presenting cells at a specialized junctional structure known as the immunological synapse. Once formed, the immunological synapse leads to sustained T cell receptor-mediated signalling and stabilized adhesion. High resolution microscopy indeed had a great impact in understanding the function and dynamic structure of immunological synapse. Trends of recent research are now moving towards understanding the mechanical part of immune system, expanding our knowledge in mechanosensitivity, force generation, and biophysics of cell-cell interaction. Actin cytoskeleton plays inevitable role in adaptive immune system, allowing it to bear dynamic and precise characteristics at the same time. The regulation of mechanical engine seems very complicated and overlapping, but it enables cells to be very sensitive to external signals such as surface rigidity. In this review, we focus on actin regulators and how immune cells regulate dynamic actin rearrangement process to drive the formation of immunological synapse.


Subject(s)
Actin Cytoskeleton , Actins , Antigen-Presenting Cells , Biophysics , Immune System , Immunological Synapses , Microscopy , T-Lymphocytes , Ursidae
18.
Rev. bras. odontol ; 67(1): 97-100, jul.-dez. 2010. ilus, tab
Article in Portuguese | LILACS, BBO | ID: lil-563845

ABSTRACT

O propósito deste estudo foi avaliar a formação de microtrincas na raiz durante o preparo da rosca considerando a influência do design dos retentores e a força imposta. Foram avaliados os sistemas Screw Post (SSW/Duflex Artigos Dentários) e Flexi Post (Essential Dental Systems). Os testes foram realizados em 28 incisivos inferiores humanos, divididos em quatro grupos, sendo dois grupos testados em movimento manual até encontrar resistência e dois com calibração de 10N. As raízes foram fotografadas por microscópio óptico. As imagens foram observadas por dois avaliadores de maneira cega, que relataram não existir trincas em nenhum dos espécimes. Concluiu-se que o design e as forças aplicadas não contribuíram para a formação de microtrincas.


Subject(s)
Biophysics , Microscopy , Post and Core Technique , Tooth Root
19.
Indian J Biochem Biophys ; 2010 Aug; 47(4): 197-202
Article in English | IMSEAR | ID: sea-135266

ABSTRACT

Familial amyloidotic polyneuropathy (FAP) is strictly associated with point mutations of transthyretin (TTR) protein. The Tyr116->Ser (Y116S) mutant TTR is an important amyloidogenic variant responsible for FAP. Structural dynamics of monomeric TTR and its mutant (Y116S) may give some clue relating to amyloid formation. In this study, molecular dynamic simulation at 310 K has been performed on wild-type and mutant (Y116S) TTR monomer, which can provide the molecular insight of structural transition in the inner and outer strand of the protein. Results show that mutation in the H-strand (Tyr116->Ser) leads to disruption of secondary structure and H-bonding pattern of some important parts of the inner DAGH-sheet of the protein. Especially, the residues T106, A108, L110 of G-strand, S117 and T119 of H-strand are affected, which are involved in the binding of thyroxin hormone. This unfolding of mutant structure during dynamics may cause instability in the protein and thus induce amyloidgenesis.


Subject(s)
Amyloid/chemistry , Biophysics/methods , Computer Simulation , Humans , Hydrogen Bonding , Molecular Conformation , Mutation , Prealbumin/chemistry , Prealbumin/genetics , Protein Binding , Protein Structure, Secondary , Protein Structure, Tertiary , Solvents/chemistry , Thermodynamics , Thyroxine/chemistry , Time Factors
20.
Rio de Janeiro; Fiocruz; 2010. 295 p. ilus.
Monography in Portuguese | LILACS | ID: lil-600482

ABSTRACT

Este livro integra as iniciativas empreendidas pela Fundação Oswaldo Cruz (Fiocruz), em 2010, para a comemoração do centenário de nascimento de Carlos Chagas Filho, que legou uma contribuição de grande relevo para a ciência: o Instituto de Biofísica. O instituto surgiu em 1946 na Universidade do Brasil (atual Universidade Federal do Rio de Janeiro), substituindo o Laboratório de Biofísica, que fora implantado por Chagas Filho na Faculdade de Medicina do Rio de Janeiro em 1938, quando assumiu - aos 27 anos de idade - a cátedra de Física biológica. Não seria exagero afirmar que Chagas Filho conseguiu realizar uma notável façanha: sua atuação contribuiu para criar as condições que deram estabilidade às Instituições científicas brasileiras a partir dos 1950, de que é emblemático o instituto que criou. O personagem e sua obra confundiram-se por longo período, quando certamente, o prestígio e a autoridade de Chagas Filho garantiram a continuidade da instiuição. Mas no momento em que se afastou de sua direção pela primeira vez, em 1964, e após o curto período em que novamento a dirigiu, entre 1970 e 1973, esse laço se desfez - embora não inteiramente, porque ali esteve até sua morte no ano 2000 -, sem que por isso a institucionalidade adquirida pelo centro de pesquisas tenha sew debilitado ou se interrompido. Por quê? Méritos de um genuíno institucional builder? Sim, mas um institucional builderafinado com os rumos dos acontecimentos de seu tempo. Nesse sentido, é notável a oreintação que Carlos Chagas Filho deu à sua carreira científica, aproximando-se da tendência em voga a partir dos anos 1930, quando biólogos e físicos forjaram inovadoras análises dos fenômenos da vida, perscrutando a dimensão físico-química das interações celulares.


Subject(s)
Biophysics , Science/history , Governmental Research Institutes , History of Medicine , Brazil
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