La terapia celular con células madre, como estrategia para regenerar tejidos dañados, es una de las áreas más prometedoras en el tratamiento de enfermedades con escasas o nulas expectativas de ...curación. La insuficiencia cardíaca, principalmente de origen isquémico, es una de las enfermedades que más se pueden beneficiar de esta estrategia. El objetivo es regenerar el músculo, reducir la apoptosis, aumentar la expresión del colágeno intersticial e inducir la generación de nuevos vasos. la terapia celular cardíaca ha sido propuesta con una gran variedad de células angiogénicas y miogénicas: mioblastos esqueléticos, células mononucleares y mesenquimales de médula ósea, progenitores endoteliales circulantes, células derivadas del estroma de la grasa o del endometrio, células mesoteliales y pluripotenciales (induced pluripotent stem cells iPS). las indicaciones incluyen a pacientes con miocardiopatía isquémica o dilatada, enfermedad de Chagas, insuficiencia mitral isquémica y miocardiopatía diabética. Los abordajes son quirúrgicos, con inyección periinfarto, intracoronario y endoventricular percutáneo. Los mecanismos de acción propuestos son la reducción del tamaño de la cicatriz del infarto, el aumento de la viabilidad miocárdica, la limitación del remodelado ventricular y los efectos paracrinos. Sin embargo, los resultados clínicos muestran sólo mejoras muy limitadas de la función sistólica y del remodelado ventricular. El desarrollo de estrategias que mejoren la supervivencia y la diferenciación celular deben ser prioritarias, tales como el preacondicionamiento con electroestimulación o la ingeniería tisular con el objetivo de desarrollar un miocardio bioartificial.
A computational method is used to study processes for obtaining super-fragmented metallic materials and products made from them (strands or filaments reduced to nanometers). The article examines ...three problems concerning the super-fragmentation of long metallic bodies by electrostimulation rolling in grooves and passes. Super-fragmentation is used to obtain experimental metallic nanomaterials and products that could not be obtained by traditional methods of rolling.
Zusammenfassung
Bradyarrhythmien (BA) sind durch Sinusknotendysfunktionen (SKD), höhergradige AV-Blockierungen oder Schenkelblockbilder bedingt. SKD können als Sinusbradykardie, sinuatriale ...Blockierungen oder Sinusknotenstillstand imponieren. AV-Blockierungen I° sind Ausdruck einer Leitungsverzögerung in Vorhof, AV-Knoten, His-Bündel oder Tawara-System. AV-Blockierungen I. und II. Grades treten sehr häufig <24 h nach Infarktbeginn auf und dauern gewöhnlich nicht mehr als 72 h an. AV-Blockierungen III° sind bei vielen Patienten bei Hinterwandinfarkt (HWI) nur vorübergehend, bei Vorderwandinfarkt (VWI) dagegen oft dauerhaft. Zur Akuttherapie bradykarder Arrhythmien ist zunächst eine medikamentöse Behandlung sinnvoll (Atropin 1–3 mg i.v.), die bei 70–80% der Patienten zu einer ausreichenden Frequenzsteigerung führt. Die Indikation zur temporären Elektrotherapie unterscheidet sich bei Patienten mit HWI und solchen mit VWI: Während BA bei HWI oft nur passager sind und meistens keine dauerhafte Schrittmacherstimulation (SM) notwendig ist, sind BA bei VWI oft Zeichen einer septalen Nekrose und erfordern sehr häufig eine permanente SM. Notfallsituationen sind bei SM-Patienten relativ selten, können aber zu lebensbedrohlichen Situationen führen. Beim Nachweis einer BA und fehlender SM-Stimulation liegt entweder eine Störung des Schrittmachersystems vor oder externe elektrische Phänomene durch Muskelpotenziale oder technische Geräte führen zu einer Inhibierung der Schrittmacherstimulation. BA mit SM-Spikes werden vor allem durch „exit block“, „oversensing“ und SM-Syndrom hervorgerufen. In der Notfallsituation kann bei symptomatischer Bradykardie versucht werden, die Herzfrequenz durch Atropin (0,5 mg i.v.) oder Orciprenalin (0,25–0,5 mg i.v.) zu steigern. Bei Versagen dieser medikamentösen Maßnahmen kann eine transvenöse oder transkutane Elektrostimulation notwendig werden, bei Asystolie muss sofort eine kardiopulmonale Reanimation erfolgen.
SUMMARY
Low electric field cancer treatment − enhanced chemotherapy (LEFCT‐EC) is a new anticancer treatment which utilizes a combination of chemotherapeutic agents and a low electric field. We ...investigated the antitumour effectiveness of this technique in a model of murine colon carcinoma (CT‐26). The low electric field was applied to ∼ 65 mm3 intracutaneous tumours after intratumoral injection of 5FU, bleomycin or BCNU. We observed significant tumour size reduction and a prolongation of survival time. The complete cure of a significant fraction of animals treated by LEFCT‐EC with 5FU (33%), bleomycin (51%) or BCNU (83%) was observed. Mice cured by LEFCT‐EC developed resistance to a tumour challenge and their splenocytes had antitumour activity in vivo. Our results suggest that LEFCT‐EC is an effective method for treatment of solid tumours.
We studied reflection of artificially induced and amplifi ed food motivation in impulse activity of the masticatory muscles during electrostimulation of “hunger center” of the lateral hypothalamus in ...the absence and presence of food. The threshold stimulation of the lateral hypothalamus in hungry and satiated animals in the absence of food induced incessant food-procuring behavior paralleled by regular generation of spike bursts in masticatory muscles with biomodal distributions of intervals between pulses. This reaction of masticatory muscles during stimulation of the lateral hypothalamus in the absence of food was an example of the anticipatory reaction reflecting characteristics of the action result acceptor. Higher level of hunger motivation during threshold stimulation of the lateral hypothalamus in hungry and satiated rabbits in the course of effective food-procuring behavior increased the incidence of spike burst generation during the food capture phase, but did not modify this parameter during the chewing phase. Impulse activity of the masticatory muscles reflected convergent interactions of food motivation and support excitation on neurons of the central generator of chewing pattern.
Easy-to-Implement Configurable Multimodal Electrostimulator Santos, Matheus Cardoso; Bedenik, Graziella; Carvalho, Stephane ...
2021 5th International Symposium on Instrumentation Systems, Circuits and Transducers (INSCIT),
2021-Aug.-23
Conference Proceeding
The central nervous system controls all movements and muscle actions in our bodies through electrical signals. Electrical Stimulation is a recognized non-invasive modality of emulating these signals ...by sending electrical signals through electrodes placed on the skin. In this paper, we propose an easy-to-implement configurable multimodal ES system. The control of timing and intensity parameters allows therapists to configure stimuli characteristics through an intuitive communication interface. In our tests, we verified that the proposed device is more effective when compared to commercially available electrostimulators while still being safe for both patients and therapists.
The objective of the present study was to assess the spatiotemporal scenario of brain activity associated with sensory stimulation of the abductor pollicis brevis muscle. Spatiotemporal dipole ...models, using realistic individual boundary element head models, were built from somatosensory evoked potentials (SEPs; 64 Ch. EEG) to nonpainful and painful intramuscular electrostimulation (IMES) as well as to cutaneous electrostimulation delivered to the distal phalanx of the thumb. Nonpainful and painful muscle stimuli resulted in activation of the same brain regions. In temporal order, these were: the contralateral primary sensorimotor cortex, contralateral dorso-lateral premotor area (PM), bilateral operculo-insular cortices, caudal cingulate motor area (CMA), and posterior cingulate cortex/precuneus. Brain processing induced by muscle sensory input showed a characteristic pattern in contrast to cutaneous sensory input, namely: (1) no early SEP components to IMES; (2) an initial IMES component likely generated by proprioceptive input is not present for digit stimulation; (3) one source was located in the PM only for IMES. This source was unmasked by the lower stimulus intensity; (4) a source for IMES was located in the contralateral caudal CMA rather than being located in the cingulate gyrus. Cerebral sensory processing of input from the muscle involved several sensory and motor areas and likely occurs in two parallel streams subserving higher order somatosensory processing as well as sensory–motor integration. The two streams might on one hand involve sensory discrimination via SI and SII and on the other hand integration of sensory feedback for further motor processing via MI, lateral PM area, and caudal CMA.
Studies have investigated the influence of neuromuscular electrostimulation on the exercise/muscle capacity of patients with heart failure (HF), but the hemodynamic overload has never been ...investigated. The aim of our study was to evaluate the heart rate (HR), systolic and diastolic blood pressures in one session of strength exercises with and without neuromuscular electrostimulation (quadriceps) in HF patients and in healthy subjects.
Ten (50% male) HF patients and healthy subjects performed three sets of eight repetitions with and without neuromuscular electrostimulation randomly, with one week between sessions. Throughout, electromyography was performed to guarantee the electrostimulation was effective. The hemodynamic variables were measured at rest, again immediately after the end of each set of exercises, and during the recovery period.
Systolic and diastolic blood pressures did not change during each set of exercises among either the HF patients or the controls. Without electrostimulation: among the controls, the HR corresponding to the first (85 ± 13 bpm, p = 0.002), second (84 ± 10 bpm, p < 0.001), third (89 ± 17, p < 0.001) sets and recuperation (83 ± 16 bpm, p = 0.012) were different compared to the resting HR (77 bpm). Moreover, the recuperation was different to the third set (0.018). Among HF patients, the HR corresponding to the first (84 ± 9 bpm, p = 0.041) and third (84 ± 10 bpm, p = 0.036) sets were different compared to the resting HR (80 ± 7 bpm), but this increase of 4 bpm is clinically irrelevant to HF. With electrostimulation: among the controls, the HR corresponding to the third set (84 ± 9 bpm) was different compared to the resting HR (80 ± 7 bmp, p = 0.016). Among HF patients, there were no statistical differences between the sets. The procedure was well tolerated and no subjects reported muscle pain after 24 hours.
One session of strength exercises with and without neuromuscular electrostimulation does not promote a hemodynamic overload in HF patients.
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