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1.
Rev. Pesqui. (Univ. Fed. Estado Rio J., Online) ; 13: 1205-1210, jan.-dez. 2021. ilus
Artigo em Inglês, Português | BDENF - Enfermagem, LILACS | ID: biblio-1253510

RESUMO

Objective: To synthesize the evidence in the literature on the applicability of the Ryodoraku system in the energy diagnosis based on the precepts of Traditional Chinese Medicine. Method: integrative review, carried out by independent reviewers in databases. Results: we found 324 studies. After exclusion, eight were analyzed, with a predominance of descriptive studies. There was agreement about the 24 points selected for the application of Ryodoraku; however, there is disagreement as to their location. Conclusions: Ryodoraku still does not present consistent evidence on its use, limiting the evaluation of its applicability


Objetivo: Sintetizar as evidências disponíveis na literatura sobre a aplicabilidade do sistema Ryodoraku no diagnóstico energético baseado nos preceitos da Medicina Tradicional Chinesa. Método: revisão integrativa, realizada por revisores independentes em bases de dados. Resultados: encontrou-se 324 estudos. Após exclusões, oito foram analisados, com predomínio de estudos descritivos. Houve concordância acerca dos 24 pontos selecionados para a aplicação do Ryodoraku; entretanto, há divergência quanto à localização dos mesmos. Conclusões: o Ryodoraku ainda não apresenta evidências consistentes sobre sua utilização, limitando a avaliação de sua aplicabilidade.


Objetivo: Sintetizar las evidencias de la literatura sobre la aplicabilidad del sistema Ryodoraku en el diagnóstico energético basado en los preceptos de la Medicina Tradicional China. Método: revisión integrativa, realizada por revisores independientes en bases de datos. Resultados: se han encontrado 324 estudios. Después de exclusiones, ocho fueron analizados, con predominio de estudios descriptivos. Hubo concordancia sobre los 24 puntos seleccionados para la aplicación del Ryodoraku; sin embargo, hay divergencia en cuanto a la localización de los mismos. Conclusión: el Ryodoraku todavía no presenta evidencias consistentes sobre su utilización, limitando la evaluación de su aplicabilidad


Assuntos
Humanos , Masculino , Feminino , Pontos de Acupuntura/classificação , Eletrodiagnóstico/métodos , Medicina Tradicional Chinesa/métodos , Diagnóstico Diferencial , Condutividade Elétrica/uso terapêutico
2.
Sci Rep ; 10(1): 5824, 2020 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-32242027

RESUMO

Tissue engineering allows to combine biomaterials and seeded cells to experimentally replace urinary bladder wall. The normal bladder wall however, includes branched neuronal network propagating signals which regulate urine storage and voiding. In this study we introduced a novel biocomposite built from amniotic membrane (Am) and graphene which created interface between cells and external stimuli replacing neuronal network. Graphene layers were transferred without modifying Am surface. Applied method allowed to preserve the unique bioactive characteristic of Am. Tissue engineered constructs composed from biocomposite seeded with smooth muscle cells (SMC) derived from porcine detrusor and porcine urothelial cells (UC) were used to evaluate properties of developed biomaterial. The presence of graphene layer significantly increased electrical conductivity of biocomposite. UCs and SMCs showed an organized growth pattern on graphene covered surfaces. Electrical filed stimulation (EFS) applied in vitro led additionally to increased SMCs growth and linear arrangement. 3D printed chamber equipped with 3D printed graphene based electrodes was fabricated to deliver EFS and record pressure changes caused by contracting SMCs seeded biocomposite. Observed contractile response indicated on effective SMCs stimulation mediated by graphene layer which constituted efficient cell to biomaterial interface.


Assuntos
Âmnio/citologia , Materiais Biocompatíveis/administração & dosagem , Grafite/administração & dosagem , Reimplante/métodos , Engenharia Tecidual/métodos , Bexiga Urinária/efeitos dos fármacos , Bexiga Urinária/fisiologia , Animais , Proliferação de Células/efeitos dos fármacos , Condutividade Elétrica/uso terapêutico , Masculino , Contração Muscular/efeitos dos fármacos , Miócitos de Músculo Liso/efeitos dos fármacos , Suínos , Tecidos Suporte , Urotélio/efeitos dos fármacos
3.
Theranostics ; 10(5): 2047-2066, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32104499

RESUMO

Rationale: Researches on conductive engineering cardiac patch (ECP) for myocardial infarction (MI) treatment have achieved some progress in the animal while the availability of traditional conductive materials in ECP is still limited because of their controversial cytotoxicity. Here we aim to introduce a novel hydrophilic biocompatible conductive material: MXene Ti2C and mussel-inspired dopamine into PEGDA-GelMA cryogel to construct a bio-functional ECP of which the property closes to natural heart for the repair of MI. Method: MXene Ti2C was etched from MAX Ti2AlC, then uniformly dispersed into the prepolymer composed with dopamine-N', N'-methylene-bisacrylamide, methacrylate-gelatin, and poly (ethylene glycol) diacrylate by simple water bath sonication. The resilient conductive Ti2C-cryogel was fabricated by chemical cryogelation. The conductive ECP was evaluated in vitro and transplanted to the MI rat model for MI treatment. Results: In vitro, the 3D vessels-shape framework was observed in Ti2C-8-cryogel which was seeded with rats aortic endothelial cells. When the Ti2C-cryogels were cocultured with CMs, remarkably aligned sarcomere and the primitive intercalated disc between the mature CMs were formed on day 7. The as-prepared Ti2C-8-cryogel ECP also demonstrated rapid calcium transients and synchronous tissue-like beating. When transplanted into the infarcted heart of the MI rat model, the Ti2C-8-cryogel ECP could improve the cardiac function, reduce the infarct size, and inhibit the inflammatory response. Obvious vasculation especially newly formed arteriole was also found. Conclusion: A novel conductive Ti2C-embedded cardiac patch with suitable conductivity and the mechanical property was developed and could be served as an ideal candidate for MI repair.


Assuntos
Materiais Biocompatíveis/química , Criogéis/química , Condutividade Elétrica/efeitos adversos , Infarto do Miocárdio/terapia , Miócitos Cardíacos/transplante , Animais , Dopamina/química , Condutividade Elétrica/uso terapêutico , Células Endoteliais/metabolismo , Gelatina/química , Humanos , Masculino , Modelos Animais , Miocárdio/citologia , Miócitos Cardíacos/química , Polietilenoglicóis/química , Ratos , Ratos Sprague-Dawley , Sonicação/métodos
5.
J Vis Exp ; (141)2018 11 03.
Artigo em Inglês | MEDLINE | ID: mdl-30451241

RESUMO

Material corrosion can be a limiting factor for different materials in many applications. Thus, it is necessary to better understand corrosion processes, prevent them and minimize the damages associated with them. One of the most important characteristics of corrosion processes is the corrosion rate. The measurement of corrosion rates is often very difficult or even impossible especially in less conductive, non-aqueous environments such as biofuels. Here, we present five different methods for the determination of corrosion rates and the efficiency of anti-corrosion protection in biofuels: (i) a static test, (ii) a dynamic test, (iii) a static test with a reflux cooler and electrochemical measurements (iv) in a two-electrode arrangement and (v) in a three-electrode arrangement. The static test is advantageous due to its low demands on material and instrumental equipment. The dynamic test allows for the testing of corrosion rates of metallic materials at more severe conditions. The static test with a reflux cooler allows for the testing in environments with higher viscosity (e.g., engine oils) at higher temperatures in the presence of oxidation or an inert atmosphere. The electrochemical measurements provide a more comprehensive view on corrosion processes. The presented cell geometries and arrangements (the two-electrode and three-electrode systems) make it possible to perform measurements in biofuel environments without base electrolytes that could have a negative impact on the results and load them with measurement errors. The presented methods make it possible to study the corrosion aggressiveness of an environment, the corrosion resistance of metallic materials, and the efficiency of corrosion inhibitors with representative and reproducible results. The results obtained using these methods can help to understand corrosion processes in more detail to minimize the damages caused by corrosion.


Assuntos
Corrosão , Condutividade Elétrica/uso terapêutico , Metais/química , Humanos
6.
J Vis Exp ; (134)2018 04 13.
Artigo em Inglês | MEDLINE | ID: mdl-29708538

RESUMO

Stem cell therapy has emerged as an exciting stroke therapeutic, but the optimal delivery method remains unclear. While the technique of microinjection has been used for decades to deliver stem cells in stroke models, this technique is limited by the lack of ability to manipulate the stem cells prior to injection. This paper details a method of using an electrically conductive polymer scaffold for stem cell delivery. Electrical stimulation of stem cells using a conductive polymer scaffold alters the stem cell's genes involved in cell survival, inflammatory response, and synaptic remodeling. After electrical preconditioning, the stem cells on the scaffold are transplanted intracranially in a distal middle cerebral artery occlusion rat model. This protocol describes a powerful technique to manipulate stem cells via a conductive polymer scaffold and creates a new tool to further develop stem cell-based therapy.


Assuntos
Condutividade Elétrica/uso terapêutico , Estimulação Elétrica/métodos , Tecidos Suporte/estatística & dados numéricos , Animais , Humanos , Ratos , Acidente Vascular Cerebral/terapia
7.
Clinics (Sao Paulo) ; 72(4): 254-257, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28492726

RESUMO

OBJECTIVES:: The Meridian Energy Analysis Device is currently a popular tool in the scientific research of meridian electrophysiology. In this field, it is generally believed that measuring the electrical conductivity of meridians provides information about the balance of bioenergy or Qi-blood in the body. METHODS AND RESULTS:: PubMed database based on some original articles from 1956 to 2014 and the authors clinical experience. In this short communication, we provide clinical examples of Meridian Energy Analysis Device application, especially in the field of traditional Chinese medicine, discuss the reliability of the measurements, and put the values obtained into context by considering items of considerable variability and by estimating sample size. CONCLUSION:: The Meridian Energy Analysis Device is making a valuable contribution to the diagnosis of Qi-blood dysfunction. It can be assessed from short-term and long-term meridian bioenergy recordings. It is one of the few methods that allow outpatient traditional Chinese medicine diagnosis, monitoring the progress, therapeutic effect and evaluation of patient prognosis. The holistic approaches underlying the practice of traditional Chinese medicine and new trends in modern medicine toward the use of objective instruments require in-depth knowledge of the mechanisms of meridian energy, and the Meridian Energy Analysis Device can feasibly be used for understanding and interpreting traditional Chinese medicine theory, especially in view of its expansion in Western countries.


Assuntos
Medicina Tradicional Chinesa/instrumentação , Meridianos , Qi , Pontos de Acupuntura , Sangue , Condutividade Elétrica/uso terapêutico , Humanos , Medicina Tradicional Chinesa/métodos , Reprodutibilidade dos Testes , Tamanho da Amostra
8.
Clinics ; 72(4): 254-257, Apr. 2017. graf
Artigo em Inglês | LILACS | ID: biblio-840069

RESUMO

OBJECTIVES: The Meridian Energy Analysis Device is currently a popular tool in the scientific research of meridian electrophysiology. In this field, it is generally believed that measuring the electrical conductivity of meridians provides information about the balance of bioenergy or Qi-blood in the body. METHODS AND RESULTS: PubMed database based on some original articles from 1956 to 2014 and the authoŕs clinical experience. In this short communication, we provide clinical examples of Meridian Energy Analysis Device application, especially in the field of traditional Chinese medicine, discuss the reliability of the measurements, and put the values obtained into context by considering items of considerable variability and by estimating sample size. CONCLUSION: The Meridian Energy Analysis Device is making a valuable contribution to the diagnosis of Qi-blood dysfunction. It can be assessed from short-term and long-term meridian bioenergy recordings. It is one of the few methods that allow outpatient traditional Chinese medicine diagnosis, monitoring the progress, therapeutic effect and evaluation of patient prognosis. The holistic approaches underlying the practice of traditional Chinese medicine and new trends in modern medicine toward the use of objective instruments require in-depth knowledge of the mechanisms of meridian energy, and the Meridian Energy Analysis Device can feasibly be used for understanding and interpreting traditional Chinese medicine theory, especially in view of its expansion in Western countries.


Assuntos
Humanos , Meridianos , Qi , Medicina Tradicional Chinesa/instrumentação , Sangue , Pontos de Acupuntura , Reprodutibilidade dos Testes , Tamanho da Amostra , Condutividade Elétrica/uso terapêutico , Medicina Tradicional Chinesa/métodos
9.
Circulation ; 132(8): 772-84, 2015 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-26304669

RESUMO

BACKGROUND: Efficient cardiac function requires synchronous ventricular contraction. After myocardial infarction, the nonconductive nature of scar tissue contributes to ventricular dysfunction by electrically uncoupling viable cardiomyocytes in the infarct region. Injection of a conductive biomaterial polymer that restores impulse propagation could synchronize contraction and restore ventricular function by electrically connecting isolated cardiomyocytes to intact tissue, allowing them to contribute to global heart function. METHODS AND RESULTS: We created a conductive polymer by grafting pyrrole to the clinically tested biomaterial chitosan to create a polypyrrole (PPy)-chitosan hydrogel. Cyclic voltammetry showed that PPy-chitosan had semiconductive properties lacking in chitosan alone. PPy-chitosan did not reduce cell attachment, metabolism, or proliferation in vitro. Neonatal rat cardiomyocytes plated on PPy-chitosan showed enhanced Ca(2+) signal conduction in comparison with chitosan alone. PPy-chitosan plating also improved electric coupling between skeletal muscles placed 25 mm apart in comparison with chitosan alone, demonstrating that PPy-chitosan can electrically connect contracting cells at a distance. In rats, injection of PPy-chitosan 1 week after myocardial infarction decreased the QRS interval and increased the transverse activation velocity in comparison with saline or chitosan, suggesting improved electric conduction. Optical mapping showed increased activation in the border zone of PPy-chitosan-treated rats. Echocardiography and pressure-volume analysis showed improvement in load-dependent (ejection fraction, fractional shortening) and load-independent (preload recruitable stroke work) indices of heart function 8 weeks after injection. CONCLUSIONS: We synthesized a biocompatible conductive biomaterial (PPy-chitosan) that enhances biological conduction in vitro and in vivo. Injection of PPy-chitosan better maintained heart function after myocardial infarction than a nonconductive polymer.


Assuntos
Materiais Biocompatíveis/administração & dosagem , Condutividade Elétrica , Hidrogel de Polietilenoglicol-Dimetacrilato/administração & dosagem , Infarto do Miocárdio/terapia , Polímeros/administração & dosagem , Animais , Animais Recém-Nascidos , Materiais Biocompatíveis/química , Células Cultivadas , Quitosana/administração & dosagem , Quitosana/química , Condutividade Elétrica/uso terapêutico , Hidrogel de Polietilenoglicol-Dimetacrilato/química , Infarto do Miocárdio/fisiopatologia , Polímeros/química , Pirróis/administração & dosagem , Pirróis/química , Ratos , Ratos Sprague-Dawley
10.
Heart Rhythm ; 12(3): 574-579, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25485777

RESUMO

BACKGROUND: Cable externalization and insulation abrasion are known to occur with the St Jude Medical Riata leads under advisory. The distribution of these abnormalities and how they relate to clinical presentation have not been well described. OBJECTIVE: In this study, we sought to determine the relationship between structural lead failure and clinical presentation by using the analysis of returned Riata products in Canada. METHODS: The analyses of returned Riata products in Canada were obtained from St Jude Medical, Sylmar, CA. These data were correlated with the clinical presentation of patients just before lead removal from service. RESULTS: As of May 1, 2013, there were 263 returned Riata leads in Canada. Of these, 43 (16.8%) were found to have insulation abrasion that was due to either lead-can or lead-other device interaction (70%) or inside-out abrasion (27.9%). The predilection of lead-to-can abrasion was seen in the Riata 7-F leads (84.2% vs 58.4%; P = .07), while inside-out abrasion was more common in the Riata 8-F leads (37.5% vs 15.8%; P = .12). Electrical abnormalities were frequent (20 of 31 [65.4%]) and most often due to electrical noise (45.2%), although inappropriate shocks were present (25.8%). Death occurred in 1 of 43 (2.3%) of those patients with an insulation defect in the lead-can abrasion group. CONCLUSION: Lead-can abrasion is the most common form of insulation defect in the Riata group of leads under advisory. Management of this group of leads under advisory should not neglect the issue of lead-can abrasion, in addition to detection of cable externalization.


Assuntos
Desfibriladores Implantáveis/efeitos adversos , Condutividade Elétrica/efeitos adversos , Eletrodos Implantados/efeitos adversos , Desenho de Equipamento/efeitos adversos , Análise de Falha de Equipamento/instrumentação , Falha de Equipamento/estatística & dados numéricos , Idoso , Canadá , Condutividade Elétrica/uso terapêutico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Vigilância de Produtos Comercializados
11.
Neuroreport ; 22(16): 819-23, 2011 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-21915075

RESUMO

Direct current stimulation (DCS) has been known as a noninvasive method for modulating neural activity. We estimated the effects of noninvasive cutaneous DCS applied to the cervical region on corticospinal excitability and segmental sensorimotor excitability. The motor-evoked potential amplitudes and the parameters of the Hoffmann reflex were measured before, immediately after, 1 h after, and 2 h after DCS. In this study, we found that noninvasive cervical application of DCS could increase the motor-evoked potential amplitudes which reflected corticospinal tract excitability. This effect of DCS remained for 2 h after stimulation had ceased. These findings suggest DCS might be a noninvasive and effective tool for corticospinal tract excitation.


Assuntos
Eletricidade , Potencial Evocado Motor/fisiologia , Pescoço/fisiologia , Estimulação Elétrica Nervosa Transcutânea/métodos , Adulto , Condutividade Elétrica/uso terapêutico , Feminino , Humanos , Masculino , Condução Nervosa/fisiologia , Tratos Piramidais/fisiologia , Tempo de Reação/fisiologia , Medula Espinal/fisiologia , Adulto Jovem
12.
Bioelectromagnetics ; 32(2): 120-30, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21225889

RESUMO

Electrotherapy with direct current delivered through implanted electrodes is used for local control of solid tumors in both preclinical and clinical studies. The aim of this research is to develop a solution method for obtaining a three-dimensional analytical expression for potential and electric current density as functions of direct electric current intensity, differences in conductivities between the tumor and the surrounding healthy tissue, and length, number and polarity of electrodes. The influence of these parameters on electric current density in both media is analyzed. The results show that the electric current density in the tumor is higher than that in the surrounding healthy tissue for any value of these parameters. The conclusion is that the solution method presented in this study is of practical interest because it provides, in a few minutes, a convenient way to visualize in 3D the electric current densities generated by a radial electrode array by means of the adequate selection of direct current intensity, length, number, and polarity of electrodes, and the difference in conductivity between the solid tumor and its surrounding healthy tissue.


Assuntos
Condutividade Elétrica/uso terapêutico , Terapia por Estimulação Elétrica/métodos , Modelos Biológicos , Neoplasias/terapia , Eletrodos
13.
Neuroscientist ; 16(3): 285-307, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20040569

RESUMO

Transcranial stimulation with weak direct current (DC) has been valuable in exploring the effect of cortical modulation on various neural networks. Less attention has been given, however, to cranial stimulation with low-intensity alternating current (AC). Reviewing and discussing these methods simultaneously with special attention to what is known about their mechanisms of action may provide new insights for the field of noninvasive brain stimulation. Direct current appears to modulate spontaneous neuronal activity in a polarity-dependent fashion with site-specific effects that are perpetuated throughout the brain via networks of interneuronal circuits, inducing significant effects on high-order cortical processes implicated in decision making, language, memory, sensory perception, and pain. AC stimulation has also been associated with a significant behavioral and clinical impact, but the mechanism of AC stimulation has been underinvestigated in comparison with DC stimulation. Even so, preliminary studies show that although AC stimulation has only modest effects on cortical excitability, it has been shown to induce synchronous changes in brain activity as measured by EEG activity. Thus, cranial AC stimulation may render its effects not by polarizing brain tissue, but rather via rhythmic stimulation that synchronizes and enhances the efficacy of endogenous neurophysiologic activity. Alternatively, secondary nonspecific central and peripheral effects may explain the clinical outcomes of DC or AC stimulation. Here the authors review what is known about DC and AC stimulation, and they discuss features that remain to be investigated.


Assuntos
Córtex Cerebral/fisiologia , Sincronização Cortical/fisiologia , Condutividade Elétrica , Terapia por Estimulação Elétrica/métodos , Eletroencefalografia/métodos , Crânio/fisiologia , Condutividade Elétrica/uso terapêutico , Terapia por Estimulação Elétrica/tendências , Humanos , Rede Nervosa/fisiologia
14.
Georgian Med News ; (169): 48-51, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19430044

RESUMO

Measurement of osmolality of biological liquids is particular importance for value osmoregulation. The aim of our research was measuring osmolality of blood serum and urine by using fundamentally new measuring method of osmolality; method allows decreasing the quantitative data of osmolar gap. The study was conducted on 44 patients with cardiac insufficiency and 77 women in the III term of pregnancy under the test of Zimnicki. Osmolality of biological liquids - blood serum and urine was measured by using fundamentally new method - new conductance-measuring method of osmolality. The method is based on the total specific electroconductivity of available electrolytes in the liquid to be measured. The electrical scheme and methodical rule of this method is based on the two patents about measurement osmolality, those patents are received by G. Gelbakhiani (#1521039 and #4719485/14). This method implies to measure the total sum of electrolytes all dissolved salts in the biological liquids. By this way this method allows to measure blood and urine osmolality with high precision, which reduces osmolar gap.


Assuntos
Condutividade Elétrica/uso terapêutico , Insuficiência Cardíaca/sangue , Insuficiência Cardíaca/urina , Terceiro Trimestre da Gravidez/sangue , Terceiro Trimestre da Gravidez/urina , Feminino , Humanos , Métodos , Concentração Osmolar , Gravidez
15.
IEEE Trans Biomed Eng ; 55(12): 2823-6, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19126463

RESUMO

Mapping the myocardial electric field during a defibrillation pulse requires the recording of potential differences between electrodes. The field is then calculated from these quantities and the corresponding calibration matrix. One straightforward calibration technique involves alignment of a known electric field along each of the orthogonal axes of an electrode array and recording the resulting potential differences. However, no results have been reported to support the efficacy of this technique. This study performs a detailed error analysis including a one-to-one comparison to a precision calibration technique, and quantitatively establishes the efficacy of the orthogonal field technique.


Assuntos
Campos Eletromagnéticos , Técnicas Eletrofisiológicas Cardíacas/normas , Coração/fisiopatologia , Calibragem/normas , Condutividade Elétrica/uso terapêutico , Cardioversão Elétrica/métodos , Cardioversão Elétrica/normas , Eletrodos , Técnicas Eletrofisiológicas Cardíacas/métodos , Humanos , Valores de Referência , Projetos de Pesquisa
16.
BMC Complement Altern Med ; 5: 10, 2005 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-15882468

RESUMO

BACKGROUND: Acupuncture points and meridians are commonly believed to possess unique electrical properties. The experimental support for this claim is limited given the technical and methodological shortcomings of prior studies. Recent studies indicate a correspondence between acupuncture meridians and connective tissue planes. We hypothesized that segments of acupuncture meridians that are associated with loose connective tissue planes (between muscles or between muscle and bone) visible by ultrasound have greater electrical conductance (less electrical impedance) than non-meridian, parallel control segments. METHODS: We used a four-electrode method to measure the electrical impedance along segments of the Pericardium and Spleen meridians and corresponding parallel control segments in 23 human subjects. Meridian segments were determined by palpation and proportional measurements. Connective tissue planes underlying those segments were imaged with an ultrasound scanner. Along each meridian segment, four gold-plated needles were inserted along a straight line and used as electrodes. A parallel series of four control needles were placed 0.8 cm medial to the meridian needles. For each set of four needles, a 3.3 kHz alternating (AC) constant amplitude current was introduced at three different amplitudes (20, 40, and 80 microAmps) to the outer two needles, while the voltage was measured between the inner two needles. Tissue impedance between the two inner needles was calculated based on Ohm's law (ratio of voltage to current intensity). RESULTS: At the Pericardium location, mean tissue impedance was significantly lower at meridian segments (70.4 +/- 5.7 Omega) compared with control segments (75.0 +/- 5.9 Omega) (p = 0.0003). At the Spleen location, mean impedance for meridian (67.8 +/- 6.8 Omega) and control segments (68.5 +/- 7.5 Omega) were not significantly different (p = 0.70). CONCLUSION: Tissue impedance was on average lower along the Pericardium meridian, but not along the Spleen meridian, compared with their respective controls. Ultrasound imaging of meridian and control segments suggested that contact of the needle with connective tissue may explain the decrease in electrical impedance noted at the Pericardium meridian. Further studies are needed to determine whether tissue impedance is lower in (1) connective tissue in general compared with muscle and (2) meridian-associated vs. non meridian-associated connective tissue.


Assuntos
Tecido Conjuntivo/diagnóstico por imagem , Impedância Elétrica/classificação , Meridianos/classificação , Adulto , Condutividade Elétrica/uso terapêutico , Feminino , Humanos , Masculino , Pericárdio , Baço , Ultrassonografia
20.
J Biomed Mater Res ; 59(3): 499-506, 2002 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-11774308

RESUMO

The present study demonstrates that novel nanocomposites consisting of blends of polylactic acid and carbon nanotubes effectively can be used to expose cells to electrical stimulation. When osteoblasts cultured on the surfaces of these nanocomposites were exposed to electric stimulation (10 microA at 10 Hz) for 6 h/day for various periods of time, there was a 46% increase in cell proliferation after 2 days, a 307% increase in the concentration of extracellular calcium after 21 consecutive days, and upregulation of mRNA expression for collagen type-I after both 1 and 21 consecutive days. These results provide evidence that electrical stimulation delivered through novel, current-conducting polymer/nanophase composites promotes osteoblast functions that are responsible for the chemical composition of the organic and inorganic phases of bone. Furthermore, this evidence elucidates aspects of the cellular/molecular-level mechanisms involved in new bone formation under electrical stimulation.


Assuntos
Resinas Compostas/química , Condutividade Elétrica/uso terapêutico , Estimulação Elétrica/métodos , Osteoblastos/fisiologia , Animais , Matriz Óssea/metabolismo , Cálcio/metabolismo , Compostos Inorgânicos de Carbono , Divisão Celular/efeitos dos fármacos , Resinas Compostas/farmacologia , Matriz Extracelular/metabolismo , Expressão Gênica/efeitos dos fármacos , Ácido Láctico , Osteoblastos/citologia , Osteoblastos/metabolismo , Osteogênese/efeitos dos fármacos , Polímeros , Próteses e Implantes , Ratos , Ratos Sprague-Dawley
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