A multimodal, implantable sensor array and measurement system to investigate the suppression of focal epileptic seizure using hypothermia.

Local cooling of the brain as a therapeutic intervention is a promising alternative for patients with epilepsy who do not respond to medication.andstudies have demonstrated the seizure-suppressing effect of local cooling in various animal models. In our work, focal brain cooling in a bicuculline induced epilepsy model in rats is demonstrated and evaluated using a multimodal micro-electrocorticography (microECoG) device.

Recent antiepileptic and neuroprotective applications of brain cooling.

Hypothermia is a widely used clinical practice for neuroprotection and is a well-established method to mitigate the adverse effects of some clinical conditions such as reperfusion injury after cardiac arrest and hypoxic ischemic encephalopathy in newborns. The discovery, that lowering the core temperature has a therapeutic potential dates back to the early 20th century, but the underlying mechanisms are actively researched, even today. Especially, in the area of neural disorders such as epilepsy and traumatic brain injury, cooling has promising prospects.

The neural tissue around SU-8 implants: A quantitative in vivo biocompatibility study.

The use of SU-8 material in the production of neural sensors has grown recently. Despite its widespread application, a detailed systematic quantitative analysis concerning its biocompatibility in the central nervous system is lacking. In this immunohistochemical study, we quantified the neuronal preservation and the severity of astrogliosis around SU-8 devices implanted in the neocortex of rats, after a 2 months survival.

Comparing the effects of uncoated nanostructured surfaces on primary neurons and astrocytes.

The long-term application of central nervous system implants is currently limited by the negative response of the brain tissue, affecting both the performance of the device and the survival of nearby cells. Topographical modification of implant surfaces mimicking the structure and dimensions of the extracellular matrix may provide a solution to this negative tissue response and has been shown to affect the attachment and behavior of both neurons and astrocytes. In our study, commonly used neural implant materials, silicon, and platinum were tested with or without nanoscale surface modifications.

International survey of neuromuscular monitoring in two European countries: a questionnaire study among Hungarian and Romanian anaesthesiologists.

Background: Accumulating evidence indicates that objective neuromuscular monitoring and pharmacological reversal of neuromuscular block reduces the occurrence of residual muscle paralysis in the acute postoperative phase. However, objective neuromuscular monitoring is not a routine habit in anaesthesia. In order to change this situation, we wished to find out, as a first step to improvement, the current use of neuromuscular monitors and the custom of anaesthetists for reversal of neuromuscular block before tracheal extubation.

A softening laminar electrode for recording single unit activity from the rat hippocampus.

Softening neural implants that change their elastic modulus under physiological conditions are promising candidates to mitigate neuroinflammatory response due to the reduced mechanical mismatch between the artificial interface and the brain tissue. Intracortical neural probes have been used to demonstrate the viability of this material engineering approach. In our paper, we present a robust technology of softening neural microelectrode and demonstrate its recording performance in the hippocampus of rat subjects.

Reversal of Deep Pipecuronium-Induced Neuromuscular Block With Moderate Versus Standard Dose of Sugammadex: A Randomized, Double-Blind, Noninferiority Trial.

Background: Certain surgical interventions may require a deep neuromuscular block (NMB). Reversal of such a block before tracheal extubation is challenging. Because anticholinesterases are ineffective in deep block, sugammadex 4 mg/kg has been recommended for the reversal of rocuronium- or vecuronium-induced deep NMB.

Effect of nanostructures on anchoring stem cell-derived neural tissue to artificial surfaces.

Objective: Chronic application of brain implants monitoring or modulating neuronal activity are hindered by the foreign body response of the tissue. Topographical modification of implant surfaces may reduce negative tissue response by imitating the structure of the extracellular matrix and therefore affecting the attachment and behavior of neural cells.

Approach: In our in vitro study, the effect of nanostructuring was investigated on two commercially used neural implant materials: silicon and platinum.

Reversal of Vecuronium-induced Neuromuscular Blockade with Low-dose Sugammadex at Train-of-four Count of Four: A Randomized Controlled Trial.

Background: Rocuronium-induced neuromuscular block that spontaneously recovered to a train-of-four count of four can be reversed with sugammadex 0.5 or 1.0 mg/kg.

Simultaneous in vivo recording of local brain temperature and electrophysiological signals with a novel neural probe.

Objective: Temperature is an important factor for neural function both in normal and pathological states, nevertheless, simultaneous monitoring of local brain temperature and neuronal activity has not yet been undertaken.

Approach: In our work, we propose an implantable, calibrated multimodal biosensor that facilitates the complex investigation of thermal changes in both cortical and deep brain regions, which records multiunit activity of neuronal populations in mice. The fabricated neural probe contains four electrical recording sites and a platinum temperature sensor filament integrated on the same probe shaft within a distance of 30 µm from the closest recording site.

Impact of reversal strategies on the incidence of postoperative residual paralysis after rocuronium relaxation without neuromuscular monitoring: A partially randomised placebo controlled trial.

Background: Electronic neuromuscular monitoring is not widely used to determine either the reversal requirements for neuromuscular block before extubation of the trachea, or to determine if there is any subsequent postoperative residual neuromuscular block (PORNB).

Objectives: To investigate the incidence of PORNB using acceleromyography after spontaneous recovery of rocuronium-induced block and to compare this with the administration of sugammadex, neostigmine or a placebo.

Design: Partially randomised, partially randomised, placebo-controlled, double-blind, four-group parallel-arm study.

Neurobiochemical changes in the vicinity of a nanostructured neural implant.

Neural interface technologies including recording and stimulation electrodes are currently in the early phase of clinical trials aiming to help patients with spinal cord injuries, degenerative disorders, strokes interrupting descending motor pathways, or limb amputations. Their lifetime is of key importance; however, it is limited by the foreign body response of the tissue causing the loss of neurons and a reactive astrogliosis around the implant surface. Improving the biocompatibility of implant surfaces, especially promoting neuronal attachment and regeneration is therefore essential.

A silicon-based microelectrode array with a microdrive for monitoring brainstem regions of freely moving rats.

Objective: Exploring neural activity behind synchronization and time locking in brain circuits is one of the most important tasks in neuroscience. Our goal was to design and characterize a microelectrode array (MEA) system specifically for obtaining in vivo extracellular recordings from three deep-brain areas of freely moving rats, simultaneously. The target areas, the deep mesencephalic reticular-, pedunculopontine tegmental-and pontine reticular nuclei are related to the regulation of sleep-wake cycles.

A Multimodal, SU-8 - Platinum - Polyimide Microelectrode Array for Chronic In Vivo Neurophysiology.

Utilization of polymers as insulator and bulk materials of microelectrode arrays (MEAs) makes the realization of flexible, biocompatible sensors possible, which are suitable for various neurophysiological experiments such as in vivo detection of local field potential changes on the surface of the neocortex or unit activities within the brain tissue. In this paper the microfabrication of a novel, all-flexible, polymer-based MEA is presented. The device consists of a three dimensional sensor configuration with an implantable depth electrode array and brain surface electrodes, allowing the recording of electrocorticographic (ECoG) signals with laminar ones, simultaneously.

Reversal of Pipecuronium-Induced Moderate Neuromuscular Block with Sugammadex in the Presence of a Sevoflurane Anesthetic: A Randomized Trial.

Background: Pipecuronium is a steroidal neuromuscular blocking agent. Sugammadex, a relaxant binding γ-cyclodextrin derivative, reverses the effect of rocuronium, vecuronium, and pancuronium. We investigated whether sugammadex reverses moderate pipecuronium-induced neuromuscular blockade (NMB) and the doses required to achieve reversal.

Experimental study on the mechanical interaction between silicon neural microprobes and rat dura mater during insertion.

In vivo insertion experiments are essential to optimize novel neural implants. Our work focuses on the interaction between intact dura mater of rats and as-fabricated single-shaft silicon microprobes realized by deep reactive ion etching. Implantation parameters like penetration force and dimpling through intact dura mater were studied as a function of insertion speed, microprobe cross-section, tip angle and animal age.

Durability of high surface area platinum deposits on microelectrode arrays for acute neural recordings.

The durability of high surface area platinum electrodes during acute intracerebral measurements was investigated. Electrode sites with extremely rough surfaces were realized using electrochemical deposition of platinum onto silicon-based microelectrode arrays from a lead-free platinizing solution. The close to 1000-fold increase in effective surface area lowered impedance, its absolute value at 1 kHz became about 7 and 18 % of the original Pt electrodes in vitro and in vivo, respectively.

Reversal of neuromuscular blockade with sugammadex at the reappearance of four twitches to train-of-four stimulation.

Background: Doses of sugammadex required to reverse deep, moderate, and shallow rocuronium-induced neuromuscular blockade have been established. However, no adequate doses for the reversal of reappearance of four twitches of train-of-four (TOF) stimulation (threshold TOF-count-four) have been established.

Methods: This single-center, randomized, controlled, double-blind, four-groups parallel-arm study included 80 patients undergoing general anesthesia with propofol, sevoflurane, fentanyl, and rocuronium.

Testing rocuronium-induced neuromuscular blockade at the stapedius muscle using stapedius reflex measurements.

Background: Neuromuscular monitoring prior to emergence from anaesthesia has been shown to be necessary to achieve adequate airway protection in order to decrease postoperative pulmonary complications. In the present study we hypothesized that stapedius reflex measurement allows the detection of residual neuromuscular blockade using the stapedius muscle following the administration of rocuronium.

Patients And Methods: Parallel stapedius and acceleromyographic measurements were performed on 20 patients undergoing cholecystectomy.

Study of the toxic effects of an insecticide and copper sulphate on chicken embryos.

The toxic effects of the BI 58 EC insecticide (38% dimethoate) applied alone or in combination with copper sulphate were studied on chicken embryo in the early phase of development. The test materials were injected in 0.1-0.

Eye irritation study of some pesticides on chorioallantoic membrane of the egg.

The chorioallantoic membrane of chick embryo has been used extensively for many years in various fields of biological research, including virology, bacteriology and toxicology. The chorioallantoic membrane (CAM) is a complete tissue that responds to injury with a complete inflammatory reaction, this process similar to that induced by chemicals in the conjunctival tissue of the rabbit eye. A possible model for assessing the irritation potential of a chemical or product to such a vascularised tissue is the choriallantoic membrane of the embryonated hen's egg, as this is a highly vascular, thin membrane with relatively easy access for both treatment and assessment.

Toxicity of a dichlorvos containing insecticide formulation and an atrazine containing herbicide formulation in chicken embryos after individual administration.

A 50% dichlorvos containing insecticide formulation (Unifosz 50 EC) and a 50% atrazine containing herbicide formulation (Hungazin PK 50 WP) were studied in chicken embryos after administration as single compounds. Applied concentrations of dichlorvos were 0.1% (corresponding to the plant protection practice), 0.

Irritative effects of some pesticides and a technical component on tissue structure of the chorioallantoic membrane.

The chorioallantoic membrane (CAM) is a complete tissue that responds to injury with a complete inflammatory reaction, this process similar to that induced by chemicals in the conjunctival tissue of the rabbit eye. During the study chemicals are placed directly onto the chorioallantoic membrane and the occurrence of vascular injury or coagulation in response to a compound is as an indication of the potential of a chemical to damage mucous membranes. In our study irritant pesticides (Fusilade S, Karathane LC) and a technical pesticide component (Trend) were tested and their effects on the tissue structures of CAM were examined.