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1.
Sensors (Basel) ; 24(9)2024 Apr 26.
Artículo en Inglés | MEDLINE | ID: mdl-38732871

RESUMEN

Myoelectric hands are beneficial tools in the daily activities of people with upper-limb deficiencies. Because traditional myoelectric hands rely on detecting muscle activity in residual limbs, they are not suitable for individuals with short stumps or paralyzed limbs. Therefore, we developed a novel electric prosthetic hand that functions without myoelectricity, utilizing wearable wireless sensor technology for control. As a preliminary evaluation, our prototype hand with wireless button sensors was compared with a conventional myoelectric hand (Ottobock). Ten healthy therapists were enrolled in this study. The hands were fixed to their forearms, myoelectric hand muscle activity sensors were attached to the wrist extensor and flexor muscles, and wireless button sensors for the prostheses were attached to each user's trunk. Clinical evaluations were performed using the Simple Test for Evaluating Hand Function and the Action Research Arm Test. The fatigue degree was evaluated using the modified Borg scale before and after the tests. While no statistically significant differences were observed between the two hands across the tests, the change in the Borg scale was notably smaller for our prosthetic hand (p = 0.045). Compared with the Ottobock hand, the proposed hand prosthesis has potential for widespread applications in people with upper-limb deficiencies.


Asunto(s)
Miembros Artificiales , Mano , Dispositivos Electrónicos Vestibles , Tecnología Inalámbrica , Humanos , Mano/fisiología , Proyectos Piloto , Tecnología Inalámbrica/instrumentación , Masculino , Adulto , Femenino , Electromiografía/instrumentación , Diseño de Prótesis
2.
Small ; 19(38): e2302193, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37224803

RESUMEN

In this study, a one-step method is discussed for producing uniform cell-sized microgels using glass capillaries filled with a binary polymer blend of polyethylene glycol (PEG) and gelatin. Upon decreasing temperature, phase separation of the PEG/gelatin blends and gelation of gelatin occur, and then the polymer blend forms linearly aligned, uniformly sized gelatin microgels in the glass capillary. When DNA is added to the polymer solution, gelatin microgels entrapping DNA are spontaneously formed, and the DNA prevents the coalescence of the microdroplets even at temperatures above the melting point. This novel method to form uniform cell-sized microgels may be applicable to other biopolymers. This method is expected to contribute to diverse materials science via biopolymer microgels and biophysics and synthetic biology through cellular models containing biopolymer gels.


Asunto(s)
Microgeles , Gelatina , Agua , Polietilenglicoles , Polímeros , Biopolímeros , Geles , ADN
3.
Int J Mol Sci ; 24(7)2023 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-37047603

RESUMEN

Daunomycin (DM), an anthracycline antibiotic, is frequently used to treat various cancers, but the direct effects of DM on gene expression and DNA structure are unclear. We used an in vitro cell-free system, optimized with spermine (SP), to study the effect of DM on gene expression. A bimodal effect of DM on gene expression, weak promotion followed by inhibition, was observed with increasing concentration of DM. We also performed atomic force microscopy observation to measure how DM affects the higher-order structure of DNA induced with SP. DM destroyed SP-induced flower-like conformations of DNA by generating double-strand breaks, and this destructive conformational change of DNA corresponded to the inhibitory effect on gene expression. Interestingly, the weakly enhanced cell-free gene expression occurred as DNA conformations were elongated or relaxed at lower DM concentrations. We expect these newly unveiled DM effects on gene expression and the higher-order structure of DNA will contribute further to the development and refinement of useful anticancer therapy chemicals.


Asunto(s)
ADN , Daunorrubicina , Daunorrubicina/farmacología , ADN/química , Antibióticos Antineoplásicos/farmacología , Espermina/farmacología , Conformación de Ácido Nucleico , Expresión Génica
4.
Int J Mol Sci ; 24(3)2023 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-36769000

RESUMEN

Complex functioning of the genome in the cell nucleus is controlled at different levels: (a) the DNA base sequence containing all relevant inherited information; (b) epigenetic pathways consisting of protein interactions and feedback loops; (c) the genome architecture and organization activating or suppressing genetic interactions between different parts of the genome. Most research so far has shed light on the puzzle pieces at these levels. This article, however, attempts an integrative approach to genome expression regulation incorporating these different layers. Under environmental stress or during cell development, differentiation towards specialized cell types, or to dysfunctional tumor, the cell nucleus seems to react as a whole through coordinated changes at all levels of control. This implies the need for a framework in which biological, chemical, and physical manifestations can serve as a basis for a coherent theory of gene self-organization. An international symposium held at the Biomedical Research and Study Center in Riga, Latvia, on 25 July 2022 addressed novel aspects of the abovementioned topic. The present article reviews the most recent results and conclusions of the state-of-the-art research in this multidisciplinary field of science, which were delivered and discussed by scholars at the Riga symposium.


Asunto(s)
Núcleo Celular , Genoma , Núcleo Celular/metabolismo , Diferenciación Celular/genética
5.
Chembiochem ; 23(17): e202200240, 2022 09 05.
Artículo en Inglés | MEDLINE | ID: mdl-35686962

RESUMEN

DNA is an excellent material for constructing self-assembled nano/microstructures. Owing to the widespread use of DNA as a building block in laboratories and industry, it is desirable to increase the efficiency of all steps involved in producing self-assembled DNA structures. One of the bottlenecks is the purification required to separate the excess components from the target structures. This paper describes a purification method based on the fractionation by water-in-water (W/W) droplets composed of phase-separated dextran-rich droplets in a polyethylene glycol (PEG)-rich continuous phase. The dextran-rich droplets facilitate the selective uptake of self-assembled DNA nano/microstructures and allow the separation of the target structure. This study investigates the ability to purify DNA origami, DNA hydrogels, and DNA microtubes. The W/W-droplet fractionation allows the purification of structures of a broad size spectrum without changes to the protocol. By quantifying the activity of deoxyribozyme-modified DNA origami after W/W-droplet purification, this study demonstrates that this method sufficiently preserves the accessibility to the surface of a functional DNA nanostructure. It is considered that the W/W-droplet fractionation could become one of the standard methods for the purification of self-assembled DNA nano/microstructures for biomedical and nanotechnology applications owing to its low cost and simplicity.


Asunto(s)
Nanoestructuras , Agua , ADN/química , Dextranos , Nanoestructuras/química , Nanotecnología/métodos , Agua/química
6.
J Gastroenterol Hepatol ; 36(9): 2523-2530, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-33783040

RESUMEN

BACKGROUND AND AIM: The small intestine plays a central role in gut immunity, and enhanced lymphocyte migration is involved in the pathophysiology of various enteropathy. Bile acid (BA) is closely related to lipid metabolism and gut microbiota and essential for gut homeostasis. However, the effects of BA on gut immunity have not been studied in detail, especially on the small intestine and lymphocyte migration. Therefore, we aimed to investigate the effect of BA on small intestinal lymphocyte microcirculation. METHODS: The effect of deoxycholic acid (DCA), taurocholic acid (tCA), or cholic acid (CA) on the indomethacin (IND)-induced small intestinal enteropathy in mice was investigated. Lymphocyte movements were evaluated after exposure to BA using intravital microscopy. The effects of BA on surface expression of adhesion molecules on the vascular endothelium and lymphocytes through BA receptors were examined in vitro. RESULTS: IND-induced small intestinal enteropathy was histologically aggravated by DCA treatment alone. The expression of adhesion molecules ICAM-1 and VCAM-1 was significantly enhanced by DCA. Exposure to DCA increased lymphocyte adhesion in the microvessels of the ileum, which was partially blocked by anti-α4ß1 integrin antibody in vivo. The expression of ICAM-1 and VCAM-1 was significantly enhanced by DCA in vitro, which was partially suppressed by the sphingosine-1-phosphate receptor 2 (S1PR2) antagonist. The S1PR2 antagonist significantly ameliorated IND-induced and DCA-exaggerated small intestinal injury. CONCLUSION: DCA exacerbated IND-induced small intestinal enteropathy. DCA directly acts on the vascular endothelium and enhances the expression levels of adhesion molecules partially via S1PR2, leading to enhanced small intestinal lymphocyte migration.


Asunto(s)
Movimiento Celular , Ácido Desoxicólico , Endotelio Vascular , Ileítis , Intestino Delgado , Linfocitos , Animales , Ácidos y Sales Biliares/efectos adversos , Ácidos y Sales Biliares/farmacología , Movimiento Celular/efectos de los fármacos , Movimiento Celular/inmunología , Ácidos Cólicos/efectos adversos , Ácidos Cólicos/farmacología , Ácido Desoxicólico/efectos adversos , Ácido Desoxicólico/farmacología , Modelos Animales de Enfermedad , Endotelio Vascular/efectos de los fármacos , Endotelio Vascular/inmunología , Endotelio Vascular/fisiopatología , Ileítis/inducido químicamente , Ileítis/inmunología , Ileítis/fisiopatología , Íleon/irrigación sanguínea , Íleon/efectos de los fármacos , Íleon/inmunología , Íleon/fisiopatología , Molécula 1 de Adhesión Intercelular/biosíntesis , Molécula 1 de Adhesión Intercelular/inmunología , Intestino Delgado/irrigación sanguínea , Intestino Delgado/efectos de los fármacos , Intestino Delgado/inmunología , Intestino Delgado/fisiopatología , Microscopía Intravital , Linfocitos/efectos de los fármacos , Linfocitos/inmunología , Masculino , Ratones , Ratones Endogámicos C57BL , Microvasos/efectos de los fármacos , Microvasos/inmunología , Ratas , Ratas Wistar , Receptores de Esfingosina-1-Fosfato/antagonistas & inhibidores , Circulación Esplácnica/inmunología , Molécula 1 de Adhesión Celular Vascular/biosíntesis , Molécula 1 de Adhesión Celular Vascular/inmunología
7.
Eur J Clin Pharmacol ; 77(4): 527-537, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33125516

RESUMEN

PURPOSE: To characterize the safety, pharmacodynamics, and pharmacokinetics (PK) of vericiguat in healthy males. METHODS: Six phase I studies were conducted in European, Chinese, and Japanese males. Subjects received oral vericiguat as a single dose (0.5-15.0 mg solution [for first-in-human study] or 1.25-10.0 mg immediate release [IR tablets]) or multiple doses (1.25-10.0 mg IR tablets once daily [QD] or 5.0 mg IR tablets twice daily for 7 consecutive days). Bioavailability and food effects on vericiguat PK (IR tablets) were also studied in European subjects. RESULTS: Overall, 255 of 265 randomized subjects completed their respective studies. There were no deaths or serious adverse events. Vericiguat was generally well tolerated at doses ≤ 10.0 mg. In the first-in-human study, the most frequent drug-related adverse events were headache and postural dizziness (experienced by five subjects each [7.2%]). Three of four subjects who received vericiguat 15.0 mg (oral solution, fasted) experienced orthostatic reactions. Vericiguat (≤ 10.0 mg, IR tablets) was rapidly absorbed (median time to reach maximum plasma concentration ≤ 2.5 h [fasted]) with a mean half-life of about 22.0 h (range 17.9-27.0 h for single and multiple doses). No evidence for deviation from dose proportionality or unexpected accumulation was observed. Administration of vericiguat 5.0 mg IR tablets with food increased bioavailability by 19% (estimated ratio 119% [90% confidence interval]: 108; 131]), reduced PK variability, and prolonged vericiguat absorption relative to the fasted state. CONCLUSION: In general, vericiguat was well tolerated. These results supported further clinical evaluation of vericiguat QD in patients with heart failure. REGISTRY NUMBERS: EudraCT: 2011-001627-21; EudraCT: 2012-000953-30.


Asunto(s)
Compuestos Heterocíclicos con 2 Anillos , Pirimidinas , Guanilil Ciclasa Soluble , Administración Oral , Adulto , Disponibilidad Biológica , Presión Sanguínea/efectos de los fármacos , Gasto Cardíaco/efectos de los fármacos , GMP Cíclico/sangre , GMP Cíclico/orina , Preparaciones de Acción Retardada/administración & dosificación , Preparaciones de Acción Retardada/efectos adversos , Preparaciones de Acción Retardada/farmacocinética , Método Doble Ciego , Esquema de Medicación , Epinefrina/sangre , Interacciones Alimento-Droga , Voluntarios Sanos , Frecuencia Cardíaca/efectos de los fármacos , Compuestos Heterocíclicos con 2 Anillos/administración & dosificación , Compuestos Heterocíclicos con 2 Anillos/efectos adversos , Compuestos Heterocíclicos con 2 Anillos/sangre , Compuestos Heterocíclicos con 2 Anillos/farmacocinética , Humanos , Masculino , Norepinefrina/sangre , Pirimidinas/administración & dosificación , Pirimidinas/efectos adversos , Pirimidinas/sangre , Pirimidinas/farmacocinética , Método Simple Ciego , Resistencia Vascular/efectos de los fármacos
8.
J Chem Phys ; 155(7): 075101, 2021 Aug 21.
Artículo en Inglés | MEDLINE | ID: mdl-34418942

RESUMEN

Intercellular fluids in living organisms contain high concentrations of macromolecules such as nucleic acid and protein. Over the past few decades, several studies have examined membraneless organelles in terms of liquid-liquid phase separation. These studies have investigated aggregation/attraction among a rich variety of biomolecules. Here, we studied the association between the polymerization/depolymerization of actin, interconversion between monomeric (G-actin) and filamentous states (F-actin), and water/water phase separation in a binary polymer solution using polyethylene glycol (PEG) and dextran (DEX). We found that actin, which is a representative cytoskeleton, changes its distribution in a PEG/DEX binary solution depending on its polymerization state: monomeric G-actin is distributed homogeneously throughout the solution, whereas polymerized F-actin is localized only within the DEX-rich phase. We extended our study by using fragmin, which is a representative actin-severing and -depolymerizing factor. It took hours to restore a homogeneous actin distribution from localization within the DEX-rich phase, even with the addition of fragmin in an amount that causes complete depolymerization. In contrast, when actin that had been depolymerized by fragmin in advance was added to a solution with microphase-separation, F-actin was found in DEX-rich phase droplets. The micro-droplets tended to deform into a non-spherical morphology under conditions where they contained F-actin. These findings suggest that microphase-separation is associated with the dynamics of polymerization and localization of the actin cytoskeleton. We discuss our observations by taking into consideration the polymer depletion effect.


Asunto(s)
Actinas/química , Multimerización de Proteína , Dextranos/química , Modelos Moleculares , Polietilenglicoles/química , Estructura Cuaternaria de Proteína , Soluciones , Agua/química
9.
J Acoust Soc Am ; 150(1): 241, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-34340483

RESUMEN

Double-strand breaks (DSBs) of giant DNA molecules after exposure to 1.0 MHz pulsed-wave ultrasound were quantitatively evaluated by single-molecule observation of giant DNA (T4 GT7 DNA; 166 kbp) through fluorescence microscopy. Aqueous solutions of DNA were exposed to ultrasonic waves with different sound pressures, repetition periods (1, 2, 5 ms), and pulse durations (5, 10, 50 µs). Below a threshold value of sound pressure, almost no double-strand breaks were generated, and above the threshold, the degree of damage increased in an accelerated manner as the pressure increased. DNA damage was much more severe for exposure to ultrasound with a shorter pulse duration. In addition, a longer pulse repetition period caused worse damage in DNA molecules. The effect of microbubbles on the damage induced by exposure to ultrasound had also been studied. While a result showed that a very small amount of microbubbles increased DSBs of DNA, this effect of microbubbles only weakly depended on their concentrations.


Asunto(s)
ADN , Ondas Ultrasónicas , Microburbujas , Ultrasonografía
10.
Int J Mol Sci ; 22(5)2021 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-33652986

RESUMEN

Polyamines are involved in various biological functions, including cell proliferation, differentiation, gene regulation, etc. Recently, it was found that polyamines exhibit biphasic effects on gene expression: promotion and inhibition at low and high concentrations, respectively. Here, we compared the effects of three naturally occurring tetravalent polyamines, spermine (SPM), thermospermine (TSPM), and N4-aminopropylspermidine (BSPD). Based on the single DNA observation with fluorescence microscopy together with measurements by atomic force microscopy revealed that these polyamines induce shrinkage and then compaction of DNA molecules, at low and high concentrations, respectively. We also performed the observation to evaluate the effects of these polyamine isomers on the activity of gene expression by adapting a cell-free luciferase assay. Interestingly, the potency of their effects on the DNA conformation and also on the inhibition of gene expression activity indicates the highest for TSPM among spermine isomers. A numerical evaluation of the strength of the interaction of these polyamines with negatively charged double-strand DNA revealed that this ordering of the potency corresponds to the order of the strength of the attractive interaction between phosphate groups of DNA and positively charged amino groups of the polyamines.


Asunto(s)
Bacteriófago T4/genética , Regulación Viral de la Expresión Génica , Espermina/análogos & derivados , Espermina/metabolismo , Bacteriófago T4/química , Bacteriófago T4/metabolismo , ADN Viral/química , ADN Viral/genética , ADN Viral/metabolismo , Isomerismo , Modelos Moleculares , Conformación de Ácido Nucleico , Espermina/química
11.
J Phys Ther Sci ; 33(6): 499-504, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-34177115

RESUMEN

[Purpose] Hybrid Assistive Limb® (HAL; Cyberdyne, Tsukuba, Japan) is a wearable robot that assists patients based on their voluntary movements. We report gait training with HAL after botulinum toxin treatment for spasticity of the lower limb in cerebral palsy (CP). [Participant and Methods] The participant was a 36 year-old male with spastic diplegia due to periventricular leukomalacia, with Gross Motor Function Classification System (GMFCS) level II. HAL training was performed in 20-minute sessions (3 sessions/week for 4 weeks). The outcome measures were range of motion, spasticity, walking ability, muscle strength, gross motor function measure (GMFM), Canadian Occupational Performance Measure (COPM), and Pediatric Evaluation of Disability Inventory measured before, immediately after, and one, two, and three months after HAL training. [Results] No adverse events were observed during training. After the HAL intervention, gait speed, step length, cadence, 6-min walking distance (6MD), knee extension strength, GMFM, and COPM increased, and Physiological Cost Index declined. Three months post-intervention, gait speed, step length, cadence, 6MD, and GMFM remained higher than those observed within the first two months. [Conclusion] Gait training with HAL can be a safe and feasible method for patients with CP who undergo botulinum toxin treatment to improve walking ability and motor function.

12.
Chembiochem ; 21(23): 3323-3328, 2020 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-32667694

RESUMEN

Recently, liquid-liquid phase separation (LLPS) has attracted considerable attention among researchers in the life sciences as a plausible mechanism for the generation of microstructures inside cells. LLPS occurs through multiple nonspecific interactions and does not always require a lock-and-key interaction with a binary macromolecular solution. The remarkable features of LLPS include the non-uniform localization and concentration of solutes, resulting in the ability to isolate certain chemical systems and thereby parallelize multiple chemical reactions within the limited space of a living cell. We report that, by using the macromolecules, poly(ethylene glycol) (PEG) and dextran, that exhibit LLPS in an aqueous solution, cell-sized liposomes are spontaneously formed therein in the presence of phospholipids. In this system, LLPS is generated through the depletion effect of macromolecules. The results showed that cell-like microdroplets entrapping DNA wrapped by a phospholipid layer emerge in a self-organized manner.


Asunto(s)
Dextranos/química , Gotas Lipídicas/química , Polietilenglicoles/química , ADN/química , Sustancias Macromoleculares/química , Tamaño de la Partícula , Fosfolípidos/química , Soluciones , Agua/química
13.
Int J Mol Sci ; 21(13)2020 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-32605138

RESUMEN

Elucidation of the genomic mechanism that guides the cell-fate change is one of the fundamental issues of biology. We previously demonstrated that whole genome expression is coordinated by the emergence of a critical point at both the cell-population and single-cell levels through the physical principle of self-organized criticality. In this paper, we further examine the genomic mechanism that determines the cell-fate changes from embryo to cancer development. The state of the critical point, acting as the organizing center of the cell fate, determines whether the genome resides in a super- or sub-critical state. In the super-critical state, a specific stochastic perturbation can spread over the entire system through the "genome engine", an autonomous critical-control genomic system, whereas in the sub-critical state, the perturbation remains at a local level. The cell-fate changes when the genome becomes super-critical. We provide a consistent framework to develop a time-evolutional transition theory for the biological regulation of the cell-fate change.


Asunto(s)
Biomarcadores de Tumor/genética , Diferenciación Celular , Embrión de Mamíferos/citología , Regulación del Desarrollo de la Expresión Génica , Regulación Neoplásica de la Expresión Génica , Genómica/métodos , Neoplasias/patología , Biomarcadores de Tumor/metabolismo , Linaje de la Célula , Embrión de Mamíferos/metabolismo , Humanos , Neoplasias/genética , Neoplasias/metabolismo , Análisis de la Célula Individual
14.
Medicina (Kaunas) ; 56(12)2020 Dec 07.
Artículo en Inglés | MEDLINE | ID: mdl-33297300

RESUMEN

Background and objectives: Cerebral palsy (CP) is the most frequent childhood motor disability. Achieving ambulation or standing in children with CP has been a major goal of physical therapy. Recently, robot-assisted gait training using the Hybrid Assistive Limb® (HAL) has been effective in improving walking ability in patients with CP. However, previous studies have not examined in detail the changes in gait pattern after HAL training for patients with spastic CP, including gait symmetry. This study aimed to evaluate the immediate effect of HAL training on the walking ability and the changes in gait pattern and gait symmetry in patients with spastic CP. Materials and Methods: We recruited 19 patients with spastic CP (13 male and six female; mean age, 15.7 years). Functional ambulation was assessed using the 10-Meter Walk Test and gait analysis in the sagittal plane before and after a single 20-min HAL intervention session. Results: The walking speed and stride length significantly increased after HAL intervention compared to the pre-intervention values. Two-dimensional gait analysis showed improvement in equinus gait, increase in the flexion angle of the swing phase in the knee and hip joints, and improvement in gait symmetry. Immediate improvements in the walking ability and gait pattern were noted after HAL training in patients with spastic CP. Conclusions: The symmetry of the joint angle of the lower limb, including the trunk, accounts for the improvement in walking ability after HAL therapy.


Asunto(s)
Parálisis Cerebral , Personas con Discapacidad , Trastornos Motores , Robótica , Adolescente , Niño , Femenino , Marcha , Humanos , Masculino
15.
Biophys J ; 116(10): 1836-1844, 2019 05 21.
Artículo en Inglés | MEDLINE | ID: mdl-31076102

RESUMEN

Compaction of T4 phage DNA (166 kbp) by short oligopeptide octamers composed of two types of amino acids, four cationic lysine (K), and four polar nonionic serine (S) having different sequence order was studied by single-molecule fluorescent microscopy. We found that efficient DNA compaction by oligopeptide octamers depends on the geometrical match between phosphate groups of DNA and cationic amines. The amino acid sequence order in octamers dramatically affects the mechanism of DNA compaction, which changes from a discrete all-or-nothing coil-globule transition induced by a less efficient (K4S4) octamer to a continuous compaction transition induced by a (KS)4 octamer with a stronger DNA-binding character. This difference in the DNA compaction mechanism dramatically changes the packaging density, and the morphology of T4 DNA condensates: DNA is folded into ordered toroidal or rod morphologies during all-or-nothing compaction, whereas disordered DNA condensates are formed as a result of the continuous DNA compaction. Furthermore, the difference in DNA compaction mechanism has a certain effect on the inhibition scenario of the DNA transcription activity, which is gradual for the continuous DNA compaction and abrupt for the all-or-nothing DNA collapse.


Asunto(s)
ADN Viral/química , ADN Viral/genética , Conformación de Ácido Nucleico , Oligopéptidos/química , Oligopéptidos/metabolismo , Transcripción Genética , Secuencia de Aminoácidos , Bacteriófago T4/genética , ADN Viral/metabolismo , Modelos Moleculares , Conformación Proteica
16.
J Chem Phys ; 150(1): 014901, 2019 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-30621421

RESUMEN

The direct current (DC) motor is a rotary device that converts DC electrical energy into mechanical energy. However, it is known that, in downsizing the currently available macromotor, rotary motion of DC micromotors cannot work well due to the larger viscous effect. Here, we report simple DC micromotors working under a new principle. We previously revealed that in an oil phase containing an ionic surfactant, non-spherical particles exhibit various types of regular motions such as spinning and circular orbital motions. In this study, we found that a microhelix exhibits a new type of periodic motion, namely, the cork-screw-type rotation, in a specific direction depending on the material of the helix, metal or non-metallic organics. The results show that a left-handed nickel helix rotates in the clockwise direction when viewed from the positive electrode, whereas an organic one rotates in the opposite direction (anti-clockwise) under the same electrode arrangement with stationary constant DC voltage. In addition, we demonstrate that the cork-screw rotation is switched to opposite direction by changing the handedness (chirality). It is to be noted that the micromotors reported here maintain their stable motion without any mechanical support such as rotational axes or electronic switching devices. The invented DC micromotor would be applicable for mechanical and fluidic devices, being useful as a smart device in microrobots and microfluidics.

17.
Int J Mol Sci ; 21(1)2019 Dec 19.
Artículo en Inglés | MEDLINE | ID: mdl-31861648

RESUMEN

Despite the effectiveness of cisplatin as an anticancer agent, its trans-isomer, transplatin, is clinically ineffective. Although both isomers target nuclear DNA, there is a large difference in the magnitude of their biological effects. Here, we compared their effects on gene expression in an in vitro luciferase assay and quantified their effects on the higher-order structure of DNA using fluorescence microscopy (FM) and atomic force microscopy (AFM). The inhibitory effect of cisplatin on gene expression was about 7 times that of transplatin. Analysis of the fluctuation autocorrelation function of the intrachain Brownian motion of individual DNA molecules showed that cisplatin increases the spring and damping constants of DNA by one order of magnitude and these visco-elastic characteristics tend to increase gradually over several hours. Transplatin had a weaker effect, which tended to decrease with time. These results agree with a stronger inhibitory effect of cisplatin on gene expression. We discussed the characteristic effects of the two compounds on the higher-order DNA structure and gene expression in terms of the differences in their binding to DNA.


Asunto(s)
Cisplatino/farmacología , ADN/química , Bacteriófago T4/química , Bacteriófago T4/genética , ADN/efectos de los fármacos , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Microscopía de Fuerza Atómica , Microscopía Fluorescente , Conformación de Ácido Nucleico , Plásmidos/química , Plásmidos/genética
18.
Medicina (Kaunas) ; 55(11)2019 Nov 18.
Artículo en Inglés | MEDLINE | ID: mdl-31752225

RESUMEN

Background and Objectives: In this study, we examined the effect of a consecutive 25-week gait training program, consisting of 5-week alternating phases of Hybrid Assistive Limb (HAL)-assisted robot gait training and conventional gait training, on the walking ability of a 50-year-old man with a chronic thoracic spinal cord injury (SCI). Materials and Methods: Clinical features of this patient's paraplegia were as follows: neurological level, T7; American Spinal Cord Injury Association Impairment Scale Score, C; Lower Extremity Motor Score, 20 points; Berg Balance Scale score, 15 points; and Walking Index for Spinal Cord Injury, 6 points. The patient completed a 100 m walk, under close supervision, using a walker and bilateral ankle-foot orthoses. The intervention included two phases: phase A, conventional walking practice and physical therapy for 5 weeks, and phase B, walking using the HAL robot (3 d/week, 30 min/session), combined with conventional physical therapy, for 5 weeks. A consecutive A-B-A-B-A sequence was used, with a 5-week duration for each phase. Results: The gait training intervention increased the maximum walking speed, cadence, and 2-min walking distance, as well as the Berg Balance and Walking Index for Spinal Cord Injury from 15 to 17 and 6 to 7, respectively. Walking speed, stride length, and cadence improved after phase A (but not B). Improved standing balance was associated with measured improvements in measured gait parameters. Conclusion: The walking ability of patients with a chronic SCI may be improved, over a short period by combining gait training, using HAL-assisted and conventional gait training and physical therapy.


Asunto(s)
Ejercicio Físico/fisiología , Marcha/fisiología , Modalidades de Fisioterapia/normas , Traumatismos de la Médula Espinal/terapia , Humanos , Masculino , Persona de Mediana Edad , Modalidades de Fisioterapia/estadística & datos numéricos , Resultado del Tratamiento , Caminata/fisiología , Caminata/estadística & datos numéricos
19.
Medicina (Kaunas) ; 55(8)2019 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-31344963

RESUMEN

Limited evidence is available on optimal patient effort and degree of assistance to achieve preferable changes during robot-assisted training (RAT) for spinal cord injury (SCI) patients with spasticity. To investigate the relationship between patient effort and robotic assistance, we performed training using an electromyography-based robotic assistance device (HAL-SJ) in an SCI patient at multiple settings adjusted to patient effort. In this exploratory study, we report immediate change in muscle contraction patterns, patient effort, and spasticity in a 64-year-old man, diagnosed with cervical SCI and with American Spinal Injury Association Impairment Scale C level and C4 neurological level, who underwent RAT using HAL-SJ from post-injury day 403. Three patient effort conditions (comfortable, somewhat hard, and no-effort) by adjusting HAL-SJ's assists were set for each training session. Degree of effort during flexion and extension exercise was assessed by visual analog scale, muscle contraction pattern by electromyography, modified Ashworth scale, and maximum elbow extension and flexion torques, immediately before and after each training session, without HAL-SJ. The amount of effort during training with the HAL-SJ at each session was evaluated. The degree of effort during training can be set to three effort conditions as we intended by adjusting HAL-SJ. In sessions other than the no-effort setting, spasticity improved, and the level of effort was reduced immediately after training. Spasticity did not decrease in the training session using HAL-SJ with the no-effort setting, but co-contraction further increased during extension after training. Extension torque was unchanged in all sessions, and flexion torque decreased in all sessions. When performing upper-limb training with HAL-SJ in this SCI patient, the level of assistance with some effort may reduce spasticity and too strong assistance may increase co-contraction. Sometimes, a patient's effort may be seemingly unmeasurable; hence, the degree of patient effort should be further measured.


Asunto(s)
Espasticidad Muscular/terapia , Entrenamiento de Fuerza/normas , Procedimientos Quirúrgicos Robotizados/normas , Extremidad Superior/fisiopatología , Médula Cervical/fisiopatología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Esfuerzo Físico/fisiología , Rango del Movimiento Articular/fisiología , Entrenamiento de Fuerza/métodos , Procedimientos Quirúrgicos Robotizados/métodos , Procedimientos Quirúrgicos Robotizados/rehabilitación
20.
Medicina (Kaunas) ; 55(3)2019 Mar 14.
Artículo en Inglés | MEDLINE | ID: mdl-30875846

RESUMEN

BACKGROUND AND OBJECTIVES: The Honda Walking Assistive device® (HWA) is a light and easywearable robot device for gait training, which assists patients' hip flexion and extension movementsto guide hip joint movements during gait. However, the safety and feasibility of robot-assisted gaittraining after total hip arthroplasty (THA) remains unclear. Thus, we aimed to evaluate the safetyand feasibility of this gait training intervention using HWA in a patient who underwent THA. MATERIALS AND METHODS: The patient was a 76-year-old woman with right hip osteoarthritis. Gaittraining using HWA was implemented for 20 sessions in total, five times per week from 1 week to5 weeks after THA. Self-selected walking speed (SWS), step length (SL), cadence, timed up and go(TUG), range of motion (ROM) of hip extension, and hip abduction and extension torque weremeasured preoperatively, and at 1 (pre-HWA), 2, 3, 4, 5 (post-HWA), and 10 weeks (follow-up) afterTHA. The gait patterns at SWS without HWA were measured by using three-dimensional (3D) gaitanalysis and an integrated electromyogram (iEMG). RESULTS: The patient completed 20 gait trainingsessions with no adverse event. Hip abduction torque at the operative side, hip extension torque,SWS, SL, and cadence were higher at post-HWA than at pre-HWA. In particular, SWS, TUG, andhip torque were remarkably increased 3 weeks after THA and improved to almost the same levelsat follow-up. Maximum hip extension angle and hip ROM during gait were higher at post-HWAthan at pre-HWA. Maximum and minimum anterior pelvic tilt angles were lower at post-HWA thanat pre-HWA. The iEMG of the gluteus maximus and gluteus medius in the stance phase were lowerat post-HWA than preoperatively and at pre-HWA. CONCLUSIONS: In this case, the gait training usingHWA was safe and feasible, and could be effective for the early improvement of gait ability, hipfunction, and gait pattern after THA.


Asunto(s)
Artroplastia de Reemplazo de Cadera/rehabilitación , Marcha/fisiología , Osteoartritis de la Cadera/cirugía , Dispositivos de Autoayuda/efectos adversos , Caminata/educación , Dispositivos Electrónicos Vestibles/efectos adversos , Actividades Cotidianas , Anciano , Estudios de Factibilidad , Femenino , Análisis de la Marcha , Articulación de la Cadera/fisiopatología , Humanos , Movimiento , Fuerza Muscular/fisiología , Ejercicios de Estiramiento Muscular , Dolor Postoperatorio/rehabilitación , Rango del Movimiento Articular
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