Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 257
Filtrar
1.
Development ; 148(10)2021 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-33999994

RESUMO

It is well known that electrical signals are deeply associated with living entities. Much of our understanding of excitable tissues is derived from studies of specialized cells of neurons or myocytes. However, electric potential is present in all cell types and results from the differential partitioning of ions across membranes. This electrical potential correlates with cell behavior and tissue organization. In recent years, there has been exciting, and broadly unexpected, evidence linking the regulation of development to bioelectric signals. However, experimental modulation of electrical potential can have multifaceted and pleiotropic effects, which makes dissecting the role of electrical signals in development difficult. Here, I review evidence that bioelectric cues play defined instructional roles in orchestrating development and regeneration, and further outline key areas in which to refine our understanding of this signaling mechanism.


Assuntos
Comunicação Celular/fisiologia , Fenômenos Eletrofisiológicos/fisiologia , Desenvolvimento Embrionário/fisiologia , Potenciais da Membrana/fisiologia , Regeneração/fisiologia , Animais , Transporte Biológico/fisiologia , Padronização Corporal/fisiologia , Humanos , Canais Iônicos/fisiologia , Transdução de Sinais/fisiologia
2.
J Membr Biol ; 2024 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-39183198

RESUMO

Electrophysiology typically deals with the electrical properties of excitable cells like neurons and muscles. However, all other cells (non-excitable) also possess bioelectric membrane potentials for intracellular and extracellular communications. These membrane potentials are generated by different ions present in fluids available in and outside the cell, playing a vital role in communication and coordination between the cell and its organelles. Bioelectric membrane potential variations disturb cellular ionic homeostasis and are characteristic of many diseases, including cancers. A rapidly increasing interest has emerged in sorting out the electrophysiology of cancer cells. Compared to healthy cells, the distinct electrical properties exhibited by cancer cells offer a unique way of understanding cancer development, migration, and progression. Decoding the altered bioelectric signals influenced by fluctuating electric fields benefits understanding cancer more closely. While cancer research has predominantly focussed on genetic and molecular traits, the delicate area of electrophysiological characteristics has increasingly gained prominence. This review explores the historical exploration of electrophysiology in the context of cancer cells, shedding light on how alterations in bioelectric membrane potentials, mediated by ion channels and gap junctions, contribute to the pathophysiology of cancer.

3.
J Transl Med ; 21(1): 912, 2023 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-38102652

RESUMO

BACKGROUND: Bioelectrical impedance analysis (BIA) is a rapid and user-friendly technique for assessing body composition in sports. Currently, no sport-specific predictive equations are available, and the utilization of generalized formulas can introduce systematic bias. The objectives of this study were as follows: (i) to develop and validate new predictive models for estimating fat-free mass (FFM) components in male elite soccer players; (ii) to evaluate the accuracy of existing predictive equations. METHODS: A total of 102 male elite soccer players (mean age 24.7 ± 5.7 years), participating in the Italian first league, underwent assessments during the first half of the in-season period and were randomly divided into development and validation groups. Bioelectrical resistance (R) and reactance (Xc), representing the bioimpedance components, were measured using a foot-to-hand BIA device at a single frequency of 50 kHz. Dual-energy X-ray absorptiometry was employed to acquire reference data for FFM, lean soft tissue (LST), and appendicular lean soft tissue (ALST). The validation of the newly developed predictive equations was conducted through regression analysis, Bland-Altman tests, and the area under the curves (AUC) of regression receiver operating characteristic (RROC) curves. RESULTS: Developed models were: FFM = - 7.729 + (body mass × 0.686) + (stature2/R × 0.227) + (Xc × 0.086) + (age × 0.058), R2 = 0.97, Standard error of estimation (SEE) = 1.0 kg; LST = - 8.929 + (body mass × 0.635) + (stature2/R × 0.244) + (Xc × 0.093) + (age × 0.048), R2 = 0.96, SEE = 0.9 kg; ALST = - 24.068 + (body mass × 0.347) + (stature2/R × 0.308) + (Xc × 0.152), R2 = 0.88, SEE = 1.4 kg. Train-test validation, performed on the validation group, revealed that generalized formulas for athletes underestimated all the predicted FFM components (p < 0.01), while the new predictive models showed no mean bias (p > 0.05), with R2 values ranging from 0.83 to 0.91, and no trend (p > 0.05). The AUC scores of the RROC curves indicated an accuracy of 0.92, 0.92, and 0.74 for FFM, LST, and ALST, respectively. CONCLUSIONS: The utilization of generalized predictive equations leads to an underestimation of FFM and ALST in elite soccer players. The newly developed soccer-specific formulas enable valid estimations of body composition while preserving the portability of a field-based method.


Assuntos
Futebol , Humanos , Masculino , Adulto Jovem , Adulto , Impedância Elétrica , Composição Corporal , Análise de Regressão , Absorciometria de Fóton/métodos , Reprodutibilidade dos Testes
4.
Ecotoxicol Environ Saf ; 268: 115691, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37979359

RESUMO

The slow rate of electron transfer and the large consumption of carbon sources are technical bottlenecks in the biological treatment of wastewater. Here, we first proposed to domesticate aerobic denitrifying bacteria (ADB) from heterotrophic to autotrophic by electricity (0.6 V) under zero organic carbon source conditions, to accelerate electron transfer and shorten hydraulic retention time (HRT) while increasing the biodegradation rate. Then we investigated the extracellular electron transfer (EET) mechanism mediated by this process, and additionally examined the integrated nitrogen removal efficiency of this system with composite pollution. It was demonstrated that compared with the traditional membrane bioreactor (MBR), the BEC displayed higher nitrogen removal efficiency. Especially at C/N = 0, the BEC exhibited a NO3--N removal rate of 95.42 ± 2.71 % for 4 h, which was about 6.5 times higher than that of the MBR. Under the compound pollution condition, the BEC still maintained high NO3--N and tetracycline removal (94.52 ± 2.01 % and 91.50 ± 0.001 %), greatly superior to the MBR (10.64 ± 2.01 % and 12.00 ± 0.019 %). In addition, in-situ electrochemical tests showed that the nitrate in the BEC could be directly converted to N2 by reduction using electrons from the cathode, which was successfully demonstrated as a terminal electron acceptor.


Assuntos
Desnitrificação , Elétrons , Carbono , Processos Heterotróficos , Processos Autotróficos , Nitratos , Nitrogênio/metabolismo , Reatores Biológicos
5.
J Wound Care ; 32(Sup10a): S8-S14, 2023 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-37830843

RESUMO

There are many types of dressings available for the management of hard-to-heal (chronic) wounds. This case report illustrates the efficacy of bioelectric dressings in healing hard-to-heal wounds in five patients. Of the patients, four had diabetic foot ulcers (DFUs) and one had a surgical site infection. Wounds were examined using the TIMES concept and debridement was carried out if needed. Amorphous hydrogel was used as conduction fluid before the application of the bioelectric wound dressings. The wound was covered with foam dressing and crepe bandage. In this case report, among all five wounds, one wound healed completely while the other four reduced in size, with the presence of more granulation and re-epithelialisation. In this case report, bioelectric wound dressings were effective in managing infection and promoting wound healing.


Assuntos
Curativos Hidrocoloides , Pé Diabético , Humanos , Cicatrização , Pé Diabético/cirurgia , Hidrogéis , Reepitelização
6.
World J Microbiol Biotechnol ; 39(5): 130, 2023 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-36959310

RESUMO

Electrogens are very common in nature and becoming a contemporary theme for research as they can be exploited for extracellular electron transfer. Extracellular electron transfer is the key mechanism behind bioelectricity generation and bioremediation of pollutants via microbes. Extracellular electron transfer mechanisms for electrogens other than Shewanella and Geobacter are less explored. An efficient extracellular electron transfer system is crucial for the sustainable future of bioelectrochemical systems. At present, the poor extracellular electron transfer efficiency remains a decisive factor in limiting the development of efficient bioelectrochemical systems. In this review article, the EET mechanisms in different electrogens (bacteria and yeast) have been focused. Apart from the well-known electron transfer mechanisms of Shewanella oneidensis and Geobacter metallireducens, a brief introduction of the EET pathway in Rhodopseudomonas palustris TIE-1, Sideroxydans lithotrophicus ES-1, Thermincola potens JR, Lysinibacillus varians GY32, Carboxydothermus ferrireducens, Enterococcus faecalis and Saccharomyces cerevisiae have been included. In addition to this, the article discusses the several approaches to anode modification and genetic engineering that may be used in order to increase the rate of extracellular electron transfer. In the side lines, this review includes the engagement of the electrogens for different applications followed by the future perspective of efficient extracellular electron transfer.


Assuntos
Fontes de Energia Bioelétrica , Shewanella , Fontes de Energia Bioelétrica/microbiologia , Elétrons , Transporte de Elétrons , Biodegradação Ambiental , Shewanella/metabolismo , Engenharia Genética
7.
Sensors (Basel) ; 22(18)2022 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-36146180

RESUMO

(1) Background: The purpose of this study was to evaluate the analysis of measurements of bioelectric signals obtained from electromyographic sensors. A system that controls the speed and direction of rotation of a brushless DC motor (BLDC) was developed; (2) Methods: The system was designed and constructed for the acquisition and processing of differential muscle signals. Basic information for the development of the EMG signal processing system was also provided. A controller system implementing the algorithm necessary to control the speed and direction of rotation of the drive rotor was proposed; (3) Results: Using two muscle groups (biceps brachii and triceps), it was possible to control the direction and speed of rotation of the drive unit. The control system changed the rotational speed of the brushless motor with a delay of about 0.5 s in relation to the registered EMG signal amplitude change; (4) Conclusions: The prepared system meets all the design assumptions. In addition, it is scalable and allows users to adjust the signal level. Our designed system can be implemented for rehabilitation, and in exoskeletons or prostheses.


Assuntos
Exoesqueleto Energizado , Músculo Esquelético , Braço , Eletricidade , Eletromiografia , Músculo Esquelético/fisiologia , Processamento de Sinais Assistido por Computador
8.
Osteoporos Int ; 32(5): 939-949, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33128075

RESUMO

Low phase angle, a non-invasive bioimpedance marker, is associated with elevated odds of dysmobility syndrome and its components. Phase angle (estimated cutoffs: < 4.8° in men; < 4.5° in women) can be used to detect dysmobility syndrome in community-dwelling older adults as a simple, integrative screening tool. INTRODUCTION: Dysmobility syndrome uses a score-based approach to predict fracture risk that incorporates the concepts of osteoporosis, sarcopenia, and obesity. Low phase angle (PhA), a simple, non-invasive bioelectrical impedance marker, was associated with low lean mass, high fat mass, and poor muscle function. We aimed to investigate the association between PhA and dysmobility syndrome, with the exploration of the diagnostic cutoffs. METHODS: In a community-dwelling Korean older adult cohort, dysmobility syndrome was defined as the presence of ≥ 3 of the following components: osteoporosis, low lean mass, falls in the preceding year, low grip strength, high fat mass, and poor timed up and go performance. RESULTS: Among the 1825 participants (mean age 71.6, women 66.7%), subjects were classified into sex-stratified PhA tertiles. The prevalence of dysmobility syndrome increased from the highest PhA tertile group to the lowest (15.50 to 2.45% in men; 33.41 to 12.25% in women, P for trend < 0.001). The mean PhA values decreased as the dysmobility score increased (5.33° to 4.65° in men; 4.76° to 4.39° in women, P for trend < 0.001). Low PhA (cutoff: < 4.8° in men; < 4.5° in women) was associated with twofold elevated odds of dysmobility syndrome after adjusting for age, sex, and conventional risk factors. Low PhA improved the identification of individuals with dysmobility syndrome when added to the conventional risk model (area under the curve, 0.73 to 0.75, P = 0.002). CONCLUSION: Low PhA was associated with dysmobility syndrome and its components, independent of age, sex, body mass index, nutritional status, and inflammation.


Assuntos
Osteoporose , Sarcopenia , Idoso , Feminino , Humanos , Vida Independente , Masculino , Osteoporose/diagnóstico , Osteoporose/epidemiologia , República da Coreia/epidemiologia , Sarcopenia/diagnóstico , Sarcopenia/epidemiologia , Síndrome
9.
Exp Physiol ; 106(4): 1038-1060, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33512049

RESUMO

NEW FINDINGS: What is the central question of this study? Does peripheral non-invasive focused ultrasound targeted to the celiac plexus improve inflammatory bowel disease? What is the main finding and its importance? Peripheral non-invasive focused ultrasound targeted to the celiac plexus in a rat model of ulcerative colitis improved stool consistency and reduced stool bloodiness, which coincided with a longer and healthier colon than in animals without focused ultrasound treatment. The findings suggest that this novel neuromodulatory technology could serve as a plausible therapeutic approach for improving symptoms of inflammatory bowel disease. ABSTRACT: Individuals suffering from inflammatory bowel disease (IBD) experience significantly diminished quality of life. Here, we aim to stimulate the celiac plexus with non-invasive peripheral focused ultrasound (FUS) to modulate the enteric cholinergic anti-inflammatory pathway. This approach may have clinical utility as an efficacious IBD treatment given the non-invasive and targeted nature of this therapy. We employed the dextran sodium sulfate (DSS) model of colitis, administering lower (5%) and higher (7%) doses to rats in drinking water. FUS on the celiac plexus administered twice a day for 12 consecutive days to rats with severe IBD improved stool consistency scores from 2.2 ± 1 to 1.0 ± 0.0 with peak efficacy on day 5 and maximum reduction in gross bleeding scores from 1.8 ± 0.8 to 0.8 ± 0.8 on day 6. Similar improvements were seen in animals in the low dose DSS group, who received FUS only once daily for 12 days. Moreover, animals in the high dose DSS group receiving FUS twice daily maintained colon length (17.7 ± 2.5 cm), while rats drinking DSS without FUS exhibited marked damage and shortening of the colon (13.8 ± 0.6 cm) as expected. Inflammatory cytokines such as interleukin (IL)-1ß, IL-6, IL-17, tumour necrosis factor-α and interferon-γ were reduced with DSS but coincided with control levels after FUS, which is plausibly due to a loss of colon crypts in the former and healthier crypts in the latter. Lastly, overall, these results suggest non-invasive FUS of peripheral ganglion can deliver precision therapy to improve IBD symptomology.


Assuntos
Plexo Celíaco , Colite , Doenças Inflamatórias Intestinais , Animais , Plexo Celíaco/metabolismo , Plexo Celíaco/patologia , Colite/tratamento farmacológico , Colite/metabolismo , Colite/patologia , Colo/metabolismo , Citocinas/metabolismo , Sulfato de Dextrana/metabolismo , Sulfato de Dextrana/uso terapêutico , Modelos Animais de Doenças , Doenças Inflamatórias Intestinais/metabolismo , Doenças Inflamatórias Intestinais/terapia , Ratos
10.
Adv Gerontol ; 34(3): 466-471, 2021.
Artigo em Russo | MEDLINE | ID: mdl-34409828

RESUMO

For the first time, the research work offers a method of estimating human biological age based on the spectral analysis of the brain bioelectric activity. IDC decentralization index, which could consider summary degree of reduction of the background neurotrophic influences of the brain activating system on the peripheral tissues and organs, was developed. The close to linear dependence of the IDC index on the age of healthy people aged 10-90 as well as on the oncological patients' cancer G1-G4 cells differentiation was obtained. The cell disorders and mutations in relation with the age from 10 to 90 could be seen in growth of the IDC index from 100 to 900 units. The greater amount of the cell mutations in the oncological patients with the G1-G4 differentiation resulted in the IDC index growth up to the 3 000 units and more. All the obtained data allowed estimating the real biological age after a 10-minute registration of the human brain bioelectric activity. The accuracy increased with the averaging several surveys taken from one particular person. The technology will be highly efficient for scientific researches in the field of gerontology, monitoring of healthy people, revealing of risk groups, and for controlling of the cancer patients' medical treatment.


Assuntos
Envelhecimento , Encéfalo , Diferenciação Celular , Humanos , Fatores de Risco
11.
Bull Exp Biol Med ; 171(6): 732-735, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34705175

RESUMO

In primary dissociated hippocampal cell cultures from 18-day-old mouse embryos, streptozotocin in concentrations of 2-5 mM produced a dose-dependent cytotoxic effect on day 3 in vitro, whereas on day 11 of culturing, the neurons were resistant to streptozotocin. The neurons in the 3-day cultures were functionally immature, which was seen from their weak spontaneous bioelectric activity in the form of rare single action potentials; by day 11 of culturing, the neurons reached a high level of differentiation and their functional properties acquired a character of network burst activity. Thus, streptozotocin had the most pronounced cytotoxic effect on immature hippocampal neurons in vitro.


Assuntos
Antibióticos Antineoplásicos/toxicidade , Neurônios/efeitos dos fármacos , Estreptozocina/toxicidade , Potenciais de Ação/efeitos dos fármacos , Potenciais de Ação/fisiologia , Animais , Diferenciação Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Embrião de Mamíferos , Hipocampo/citologia , Hipocampo/efeitos dos fármacos , Hipocampo/fisiologia , Camundongos , Camundongos Endogâmicos BALB C , Neurônios/citologia , Neurônios/fisiologia , Cultura Primária de Células , Fatores de Tempo
12.
Development ; 144(15): 2771-2783, 2017 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-28684627

RESUMO

Loss of embryonic ion channel function leads to morphological defects, but the underlying reason for these defects remains elusive. Here, we show that inwardly rectifying potassium (Irk) channels regulate release of the Drosophila bone morphogenetic protein Dpp in the developing fly wing and that this is necessary for developmental signaling. Inhibition of Irk channels decreases the incidence of distinct Dpp-GFP release events above baseline fluorescence while leading to a broader distribution of Dpp-GFP. Work by others in different cell types has shown that Irk channels regulate peptide release by modulating membrane potential and calcium levels. We found calcium transients in the developing wing, and inhibition of Irk channels reduces the duration and amplitude of calcium transients. Depolarization with high extracellular potassium evokes Dpp release. Taken together, our data implicate Irk channels as a requirement for regulated release of Dpp, highlighting the importance of the temporal pattern of Dpp presentation for morphogenesis of the wing.


Assuntos
Proteínas de Drosophila/metabolismo , Drosophila/embriologia , Drosophila/metabolismo , Canais de Potássio Corretores do Fluxo de Internalização/metabolismo , Asas de Animais/embriologia , Asas de Animais/metabolismo , Animais , Cálcio/metabolismo , Proteínas de Drosophila/genética , Feminino , Regulação da Expressão Gênica no Desenvolvimento/genética , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Masculino , Potenciais da Membrana/genética , Potenciais da Membrana/fisiologia , Morfogênese/genética , Morfogênese/fisiologia , Potássio/metabolismo , Canais de Potássio Corretores do Fluxo de Internalização/genética , Transdução de Sinais/genética , Transdução de Sinais/fisiologia
13.
Br J Nutr ; 124(12): 1345-1352, 2020 12 28.
Artigo em Inglês | MEDLINE | ID: mdl-32616079

RESUMO

There is a need for accurate, inexpensive and field-friendly methods to assess body composition in children. Bioelectrical impedance analysis (BIA) is a promising approach; however, there have been limited validation and use among young children in resource-poor settings. We aim to develop and validate population-specific prediction equations for estimating total fat mass (FM), fat free-mass (FFM) and percentage body fat (PBF) in Vietnamese children (4-7 years) using reactance and resistance from BIA, anthropometric variables and demographic information. We conducted a cross-sectional survey of 120 children. Body composition was measured using dual-energy X-ray absorptiometry (DXA), BIA and anthropometry. To develop prediction equations, we split all data into development (70 %) and validation datasets (30 %). The model performance was evaluated using predicted residual error sum of squares, root mean squared error (RMSE), mean absolute error (MAE) and R2. We identified a top performing model with the least number of parameters (age, sex, weight and resistance index or resistance and height), low RMSE (FM 0·70, FFM 0·74, PBF 3·10), low MAE (FM 0·55, FFM 0·62, PBF 2·49), high R2 (FM 0·95, FFM 0·92, PBF 0·82) and the least difference between predicted values and actual values from DXA (FM 0·03 kg or 0·01 sd, FFM 0·06 kg or 0·02 sd, PBF 0·27 % or 0·04 sd). In conclusion, we developed the first valid and highly predictive equations to estimate FM, FFM and PBF in Vietnamese children using BIA. These findings have important implications for future research on the double burden of disease and risks associated with overweight and obesity in young children.


Assuntos
Povo Asiático/estatística & dados numéricos , Regras de Decisão Clínica , Impedância Elétrica , Saúde da População/estatística & dados numéricos , Absorciometria de Fóton/estatística & dados numéricos , Antropometria , Composição Corporal , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Valor Preditivo dos Testes , Vietnã
14.
Support Care Cancer ; 28(6): 2899-2910, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31758325

RESUMO

BACKGROUND: Sarcopenia is associated with physical disability, increased post-operative complications, poorer tolerance to chemotherapy, and reduced survival outcome. However, little is known about the changes in body composition during chemotherapy treatment. We aimed to determine whether adjuvant or palliative chemotherapy causes the development of sarcopenia in newly diagnosed cancer patients and to reveal the relationship of sarcopenia with the duration of chemotherapy. METHODS: The study included newly diagnosed cancer patients who underwent curative surgery for primary tumor and also cancer patients who were metastatic at diagnosis. Body composition and handgrip strength were assessed by bio-electric impedance analysis (BIA) and handgrip dynamometer tools, respectively. Measurement tests were performed prior to chemotherapy, in the third and sixth months of chemotherapy. RESULTS: The median age of a total of 276 patients was 57.5 years (range 18-83), and majority of them (55.8%) were women. Among the pre-chemotherapy factors that could be associated with sarcopenia, male gender ≥ 65 years of age, body mass index (BMI) < 25, and nutritional risk screening 2002 score < 3 were found to be positively associated with sarcopenia (p < 0.001, p = 0.036, p < 0.001, and p < 0.001, respectively). In the multivariate analysis, male gender (p < 0.001) and BMI < 25 (p = 0.047) were found to be significant. Of 276 patients, 14.5% were sarcopenic prior to chemotherapy. After chemotherapy, 21.4% of them were sarcopenic at the end of the third month and 23.9% were sarcopenic at the end of the sixth month. CONCLUSION: The incidence of sarcopenia was found to be increased with chemotherapy itself and its duration in both non-metastatic and metastatic cancer patients which has to be evaluated in detail in disease-specific prospective and randomized studies.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Neoplasias/tratamento farmacológico , Neoplasias/epidemiologia , Sarcopenia/induzido quimicamente , Sarcopenia/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Composição Corporal/efeitos dos fármacos , Índice de Massa Corporal , Feminino , Força da Mão/fisiologia , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Neoplasias/diagnóstico , Estudos Prospectivos , Fatores de Tempo , Turquia/epidemiologia , Adulto Jovem
15.
Support Care Cancer ; 28(2): 837-843, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31161438

RESUMO

INTRODUCTION: Sarcopenia is defined as the loss of muscle mass and muscular functioning. Although sarcopenia prevalence is highly variable in the literature, pre-chemotherapy sarcopenia prevalence was not well studied in newly diagnosed cancer patients. In this context, the present study aims to determine the prevalence of sarcopenia and its related factors in this population. MATERIAL AND METHODS: Prospectively, newly diagnosed cancer patients were evaluated for body composition measurement and muscle strength by employing the bioelectric impedance analysis method and handgrip dynamometer tool. RESULTS: A total of 461 patients were included in the study. The median age of patients was 59 years (range 18-83) and 258 patients (56%) were women. Sarcopenia was present in 77 patients (16.7%) and was at significantly higher frequencies in men (p = 0.015), advanced age (≥ 65 years, p = 0.014), lower body mass index (BMI < 25, p = < 0.001), and poor performance status (ECOG status > 0, p = 0.026). In multivariate analyses, advanced age (over 65 years), gender (men), and lower body mass index (BMI < 25) were significantly associated with sarcopenia (p values 0.033, < 0.001, and < 0.001, respectively). CONCLUSIONS: Our study is the first prevalence study conducted with bioelectric impedance analysis on Turkish cancer patients and sarcopenia was detected to be notably prevalent among our patients with newly diagnosed cancer. Given the likely negative outcomes of sarcopenia reported in the literature (treatment failure, increased complications, and impaired survival), it is important to know the presence of sarcopenia before treatment and take preventive precautions.


Assuntos
Neoplasias/complicações , Sarcopenia/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência
16.
Nutr Neurosci ; 23(1): 49-54, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29734917

RESUMO

Background: Spinocerebellar ataxias (SCAs) are a group of neurodegenerative genetic diseases characterized by movement disorders that can affect nutritional status and body composition. This study sought to assess body composition in SCA3 and SCA10 patients. Methods: Anthropometric assessments and bioelectric impedance analysis were performed in 46 SCA3 and SCA10 patients and 76 controls of both genders. Results: Of the patients, 69.6% had SCA3 and 58.7% were women. SCA3 patients had significantly lower percentages of body fat (%BF) than controls (15.0 ± 6.1 vs. 20.6 ± 7.1; p=0.014) and (22.4 ± 6.9 vs. 30.1 ± 6.0; p<0.001), respectively. Among the women, there was a statistically significant difference in %BF between SCA3 and SCA10 patients (22.4 ± 6.9 vs. 32.4 ± 4.9; p<0.001). Male and female SCA3 patients had significantly lower fat-free mass (FFM) than controls [50.6 kg (46.9-54.7) vs. 58.6 kg (52.6-63.9); p=0.001] and [38.2 kg (35.1-42.6) vs. 42.8 kg (39.7-46.1); p=0.004], respectively. Male SCA10 patients also had lower FFM than controls [51.2 kg (47.1-55.4) vs. (52.6-63.9); p=0.008]. Female SCA10 patients had significantly higher FFM than controls and SCA3 patients [45.0 kg (43.3-45.6) vs. 42.8 kg (39.7-46.1); p=0.004] and [45.0 kg (43.3-45.6) vs. 38.2 kg (35.1-42.6); p=0.004], respectively. There was moderate correlation (-0.42) between disease duration and muscle mass (MM), and weak (-0.38) between SARA (Scale for the Assessment and Rating of Ataxia) and MM in SCA3. In SCA10, there was no significant correlation between these variables. Conclusion: Female SCA3 patients had more body composition changes than female SCA10 patients, mainly in relation to FFM. SCA3 and SCA10 patients need nutritional follow-up to minimize body compartment changes.


Assuntos
Composição Corporal , Doença de Machado-Joseph/fisiopatologia , Ataxias Espinocerebelares/fisiopatologia , Adulto , Antropometria , Expansão das Repetições de DNA , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
17.
Sensors (Basel) ; 20(11)2020 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-32486477

RESUMO

One of the key challenges of the recent COVID-19 pandemic is the ability to accurately estimate the number of infected individuals, particularly asymptomatic and/or early-stage patients. We herewith report the proof-of-concept development of a biosensor able to detect the SARS-CoV-2 S1 spike protein expressed on the surface of the virus. The biosensor is based on membrane-engineered mammalian cells bearing the human chimeric spike S1 antibody. We demonstrate that the attachment of the protein to the membrane-bound antibodies resulted in a selective and considerable change in the cellular bioelectric properties measured by means of a Bioelectric Recognition Assay. The novel biosensor provided results in an ultra-rapid manner (3 min), with a detection limit of 1 fg/mL and a semi-linear range of response between 10 fg and 1 µg/mL. In addition, no cross-reactivity was observed against the SARS-CoV-2 nucleocapsid protein. Furthermore, the biosensor was configured as a ready-to-use platform, including a portable read-out device operated via smartphone/tablet. In this way, we demonstrate that the novel biosensor can be potentially applied for the mass screening of SARS-CoV-2 surface antigens without prior sample processing, therefore offering a possible solution for the timely monitoring and eventual control of the global coronavirus pandemic.


Assuntos
Betacoronavirus/isolamento & purificação , Técnicas Biossensoriais , Infecções por Coronavirus/diagnóstico , Pneumonia Viral/diagnóstico , Glicoproteína da Espícula de Coronavírus/isolamento & purificação , Anticorpos Antivirais/química , Anticorpos Antivirais/imunologia , Antígenos Virais/genética , Antígenos Virais/isolamento & purificação , Betacoronavirus/patogenicidade , COVID-19 , Infecções por Coronavirus/virologia , Humanos , Limite de Detecção , Pandemias , Pneumonia Viral/virologia , SARS-CoV-2 , Smartphone , Glicoproteína da Espícula de Coronavírus/química
18.
J Neurosci Res ; 97(5): 620-638, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30585651

RESUMO

Electrical stimulation of the brain has become a mainstay of fundamental neuroscience research and an increasingly prevalent clinical therapy. Despite decades of use in basic neuroscience research and the growing prevalence of neuromodulation therapies, gaps in knowledge regarding activation or inactivation of neural elements over time have limited its ability to adequately interpret evoked downstream responses or fine-tune stimulation parameters to focus on desired responses. In this work, in vivo two-photon microscopy was used to image neuronal calcium activity in layer 2/3 neurons of somatosensory cortex (S1) in male C57BL/6J-Tg(Thy1-GCaMP6s)GP4.3Dkim/J mice during 30 s of continuous electrical stimulation at varying frequencies. We show frequency-dependent differences in spatial and temporal somatic responses during continuous stimulation. Our results elucidate conflicting results from prior studies reporting either dense spherical activation of somas biased toward those near the electrode, or sparse activation of somas at a distance via axons near the electrode. These findings indicate that the neural element specific temporal response local to the stimulating electrode changes as a function of applied charge density and frequency. These temporal responses need to be considered to properly interpret downstream circuit responses or determining mechanisms of action in basic science experiments or clinical therapeutic applications.


Assuntos
Cálcio/metabolismo , Neurônios/fisiologia , Córtex Somatossensorial/fisiologia , Animais , Proteínas de Ligação ao Cálcio/metabolismo , Estimulação Elétrica , Proteínas de Fluorescência Verde/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Neurônios/metabolismo , Córtex Somatossensorial/citologia , Córtex Somatossensorial/metabolismo
19.
Neurosurg Rev ; 42(2): 227-241, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29063229

RESUMO

The aim of this study is to discuss the state of the art with regard to established or promising bioelectric therapies meant to alter or control neurologic function. We present recent reports on bioelectric technologies that interface with the nervous system at three potential sites-(1) the end organ, (2) the peripheral nervous system, and (3) the central nervous system-while exploring practical and clinical considerations. A literature search was executed on PubMed, IEEE, and Web of Science databases. A review of the current literature was conducted to examine functional and histomorphological effects of neuroprosthetic interfaces with a focus on end-organ, peripheral, and central nervous system interfaces. Innovations in bioelectric technologies are providing increasing selectivity in stimulating distinct nerve fiber populations in order to activate discrete muscles. Significant advances in electrode array design focus on increasing selectivity, stability, and functionality of implantable neuroprosthetics. The application of neuroprosthetics to paretic nerves or even directly stimulating or recording from the central nervous system holds great potential in advancing the field of nerve and tissue bioelectric engineering and contributing to clinical care. Although current physiotherapeutic and surgical treatments seek to restore function, structure, or comfort, they bear significant limitations in enabling cosmetic or functional recovery. Instead, the introduction of bioelectric technology may play a role in the restoration of function in patients with neurologic deficits.


Assuntos
Fontes de Energia Bioelétrica , Terapia por Estimulação Elétrica/instrumentação , Terapia por Estimulação Elétrica/métodos , Doenças do Sistema Nervoso/terapia , Eletrodos , Humanos , Próteses e Implantes
20.
Int J Mol Sci ; 20(14)2019 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-31340481

RESUMO

We employed dielectrophoresis to a yeast cell suspension containing amyloid-beta proteins (Aß) in a microfluidic environment. The Aß was separated from the cells and characterized using the gradual dissolution of Aß as a function of the applied dielectrophoretic parameters. We established the gradual dissolution of Aß under specific dielectrophoretic parameters. Further, Aß in the fibril form at the tip of the electrode dissolved at high frequency. This was perhaps due to the conductivity of the suspending medium changing according to the frequency, which resulted in a higher temperature at the tips of the electrodes, and consequently in the breakdown of the hydrogen bonds. However, those shaped as spheroidal monomers experienced a delay in the Aß fibril transformation process. Yeast cells exposed to relatively low temperatures at the base of the electrode did not experience a positive or negative change in viability. The DEP microfluidic platform incorporating the integrated microtip electrode array was able to selectively manipulate the yeast cells and dissolve the Aß to a controlled extent. We demonstrate suitable dielectrophoretic parameters to induce such manipulation, which is highly relevant for Aß-related colloidal microfluidic research and could be applied to Alzheimer's research in the future.


Assuntos
Peptídeos beta-Amiloides/isolamento & purificação , Eletroforese/métodos , Técnicas Analíticas Microfluídicas/instrumentação , Saccharomyces cerevisiae/química , Eletrodos , Eletroforese/instrumentação , Liofilização , Ligação de Hidrogênio , Cinética , Saccharomyces cerevisiae/citologia , Solubilidade , Temperatura
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa