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International Journal of Surgery... Nov 2016Diabetes mellitus may cause degeneration in the myelin and/or axonal structures of peripheral nerves. The aim of this study was to investigate the effects of diabetic...
BACKGROUND
Diabetes mellitus may cause degeneration in the myelin and/or axonal structures of peripheral nerves. The aim of this study was to investigate the effects of diabetic neuropathy on intraoperative neuromonitoring findings such as latency and amplitude values of the recurrent laryngeal nerves during thyroidectomy. To our knowledge this is the first study to report comparison of the electrophysiologic features of diabetic and non-diabetic patients.
MATERIALS AND METHODS
One-hundred-and-eleven consecutive patients who received neuromonitoring during thyroidectomy between 2013 and 2015 were included to study. The patients were divided into two groups according to the presence of diabetes mellitus. Pre-thyroidectomy and post thyroidectomy motor response latency and amplitude values of recurrent laryngeal nerves were compared between groups. Neuromonitoring findings, demographic data and postoperative complications were evaluated.
RESULTS
The diabetic group consisted of 29 (26.1%) patients while 82 (73.9%) patients were in non-diabetic group. The mean post-thyroidectomy amplitude values (millivolts-mV) of the recurrent laryngeal nerve were significantly lower in diabetic group (0.51 ± 0.26 mV vs. 0,70 ± 0,46 mV, p < 0.05), whereas the latency values were significantly higher (2.50 ± 0.86 ms vs. 1.85 ± 0.59 ms, p < 0.01) compared to non-diabetic group. Additionally, post-thyroidectomy latency values were significantly increased compared to the pre-thyroidectomy latency values (2.50 ± 0.86 ms vs. 2.02 ± 0.43 ms) in diabetic group patients (p < 0.05). Although postoperative complication rates were higher in diabetic group (10.3% vs. 5.9%), there were no statistical significance differences.
CONCLUSIONS
Prolonged latency and decreased amplitude values in recurrent laryngeal nerves of diabetic patients show that diabetic neuropathy of the recurrent laryngeal nerves develop similarly to the peripheral nerves. Increased post-thyroidectomy latency values reveal that the recurrent laryngeal nerve is more susceptible to surgical trauma in diabetic patients.
Topics: Adult; Aged; Aged, 80 and over; Diabetic Neuropathies; Electrophysiological Phenomena; Female; Humans; Male; Middle Aged; Monitoring, Intraoperative; Prospective Studies; Recurrent Laryngeal Nerve; Recurrent Laryngeal Nerve Injuries; Thyroid Diseases; Thyroidectomy; Vocal Cord Paralysis; Young Adult
PubMed: 27720825
DOI: 10.1016/j.ijsu.2016.10.001 -
Medical Devices (Auckland, N.Z.) 2016Reliable detection of pacemaker pulses is getting more and more important in electrocardiography (ECG) diagnosis. Many studies recommend ECG amplifiers with higher...
Reliable detection of pacemaker pulses is getting more and more important in electrocardiography (ECG) diagnosis. Many studies recommend ECG amplifiers with higher bandwidth to prevent errors. In the past, few pilot studies showed that analysis of pacemaker pulses waveform can enhance diagnosis (eg, lead failure and fractured wire), but they were carried out with inadequate instrumentations for clinical practice. Typically, pacemaker pulses last hundreds of microseconds, edges of pulses elapse in few microseconds, and amplitude may exhibit large variations from few millivolts to volts. Pulse waveforms change often and depend on pacemaker type and programming. A simple, biopotential amplifier made of a few off-the-shelf components is proposed. The circuit fulfills specifications for biopotential amplifiers and offers a large bandwidth (~1 MHz). Therefore, it is able to accurately record time course of pacemaker pulses and allows highly accurate pulse detection and timing. Signals can be easily displayed and acquired by means of a standard, battery-powered oscilloscope. Pacemaker pulse vectorcardiography can be obtained by using two or more, wideband channels. Some exemplificative waveforms recorded during patient's periodic medical examination are reported. The proposed circuit offers simultaneous conventional ECG signal as an additional output.
PubMed: 27695369
DOI: 10.2147/MDER.S97902 -
The Journal of Neuroscience : the... Jul 2016Pathways arising from the periphery that target the inferior olive [spino-olivocerebellar pathways (SOCPs)] are a vital source of information to the cerebellum and are...
UNLABELLED
Pathways arising from the periphery that target the inferior olive [spino-olivocerebellar pathways (SOCPs)] are a vital source of information to the cerebellum and are modulated (gated) during active movements. This limits their ability to forward signals to climbing fibers in the cerebellar cortex. We tested the hypothesis that the temporal pattern of gating is related to the predictability of a sensory signal. Low-intensity electrical stimulation of the ipsilateral hindlimb in awake rats evoked field potentials in the C1 zone in the copula pyramidis of the cerebellar cortex. Responses had an onset latency of 12.5 ± 0.3 ms and were either short or long duration (8.7 ± 0.1 vs 31.2 ± 0.3 ms, respectively). Both types of response were shown to be mainly climbing fiber in origin and therefore evoked by transmission in hindlimb SOCPs. Changes in response size (area of field, millivolts per millisecond) were used to monitor differences in transmission during rest and three phases of rearing: phase 1, rearing up; phase 2, upright; and phase 3, rearing down. Responses evoked during phase 2 were similar in size to rest but were smaller during phases 1 and 3, i.e., transmission was reduced during active movement when self-generated (predictable) sensory signals from the hindlimbs are likely to occur. To test whether the pattern of gating was related to the predictability of the sensory signal, some animals received the hindlimb stimulation only during phase 2. Over ∼10 d, the responses became progressively smaller in size, consistent with gating-out transmission of predictable sensory signals relayed via SOCPs.
SIGNIFICANCE STATEMENT
A major route for peripheral information to gain access to the cerebellum is via ascending climbing fiber pathways. During active movements, gating of transmission in these pathways controls when climbing fiber signals can modify cerebellar activity. We investigated this phenomenon in rats during their exploratory behavior of rearing. During rearing up and down, transmission was reduced at a time when self-generated, behaviorally irrelevant (predictable) signals occur. However, during the upright phase of rearing, transmission was increased when behaviorally relevant (unpredictable) signals may occur. When the peripheral stimulation was delivered only during the upright phase, so its occurrence became predictable over time, transmission was reduced. Therefore, the results indicate that the gating is related to the level of predictability of a sensory signal.
Topics: Afferent Pathways; Animals; Cerebellum; Exploratory Behavior; Feedback, Physiological; Male; Neural Inhibition; Neural Pathways; Neurons, Afferent; Olivary Nucleus; Rats; Rats, Wistar; Sensation
PubMed: 27466330
DOI: 10.1523/JNEUROSCI.0439-16.2016 -
Oncology Letters Aug 2016The aim of the present study was to report the case of a patient with recurrent myoepithelial carcinoma of the submandibular gland without progression for five years...
The aim of the present study was to report the case of a patient with recurrent myoepithelial carcinoma of the submandibular gland without progression for five years following treatment. A 71-year-old male patient presented to hospital with a painless swelling in the region of the right submandibular gland, and received a radical neck dissection on January 29, 2008. A nodule of ~7×4×2 cm was identified at the site of the right submandibular gland, and the pathological results revealed a diagnosis of myoepithelial carcinoma of the right submandibular gland with no lymph node metastasis. However, this case developed local recurrence with wide-spread metastasis in the lungs. Between April and October 2008, the patient underwent several treatment regimens and demonstrated no improvement following 6 cycles of chemotherapy. From then on, the patient was treated with recombinant adenoviral-p53 (rAd-p53) combined with radiotherapy using a 6 millivolt medical linear accelerator. The foci were relieved and the cancer demonstrated no signs of progression during the 5-year follow-up. rAd-p53 combined with radiotherapy was useful for treating myoepithelial carcinoma of the submandibular gland.
PubMed: 27446369
DOI: 10.3892/ol.2016.4746 -
Cardio-oncology (London, England) Jul 2016Electrocardiographic changes may manifest in patients with pericardial effusions. PR segment changes are frequently overlooked, but when present, can provide diagnostic...
BACKGROUND
Electrocardiographic changes may manifest in patients with pericardial effusions. PR segment changes are frequently overlooked, but when present, can provide diagnostic significance. The diagnostic value of PR segment changes in determining benign versus malignant pericardial disease in cancer patients with pericardial effusions has not been investigated. We aimed to determine the relationship between PR segment changes and malignant pericardial disease in cancer patients presenting with pericardial effusions.
METHODS
Consecutive patients with active malignancy who underwent surgical subxiphoid pericardial window by a single thoracic surgeon between 2011 and 2014 were included in this study. A total of 104 pre- and post-operative ECGs were reviewed, and PR depression or elevation was defined by deviation of at least 0.5 millivolts from the TP segment using a magnifying glass. Pericardial fluid cytology, flow cytometry and tissue biopsy were evaluated. Baseline characteristics and co-morbidities were compared between cancer patients with benign and malignant pericardial effusions.
RESULTS
A total of 26 patients with active malignancy and pericardial effusion who underwent pericardial window over the study period were included. Eighteen (69 %) patients had isoelectric PR segments, of whom none (0 %) had evidence of malignant pericardial disease (100 % negative predictive value). Eight (31 %) patients had significant ECG findings (PR segment depression in leads II, III and/or aVF as well as PR elevation in aVR/V1), all 8 (100 %) of whom had pathologically confirmed malignant pericardial disease (100 % positive predictive value). PR segment changes in all 8 patients persisted (up to 11 months) on post-operative serial ECGs. The PR segment changes had no relationship to heart rate or the time of atrial-ventricular conduction.
CONCLUSIONS
In patients with active cancer presenting with pericardial effusion, the presence of PR segment changes is highly predictive of active malignant pericardial disease. When present, PR changes typically persist on serial ECGs even after pericardial window.
PubMed: 33530138
DOI: 10.1186/s40959-016-0015-1 -
Journal of Cerebral Blood Flow and... May 2017We examined in live coronal slices from rat and mouse which brain regions generate potassium-triggered spreading depolarization (SD). This technique simulates cortical...
We examined in live coronal slices from rat and mouse which brain regions generate potassium-triggered spreading depolarization (SD). This technique simulates cortical spreading depression, which underlies migraine aura in the intact brain. An SD episode was evoked by increasing bath [K] and recorded as a propagating front of elevated light transmittance representing transient neuronal swelling in gray matter of neocortex, hippocampus, striatum, and thalamus. In contrast, SD was not imaged in hypothalamic nuclei or brainstem with exception of those nuclei near the dorsal brainstem surface. In rat slices, single neurons were whole-cell current clamped during SD. "Higher" neurons depolarized to near zero millivolts indicating SD generation. In contrast, seven types of neurons in hypothalamus and brainstem only slowly depolarized without generating SD, supporting our imaging findings. Therefore, SD is not a default of CNS neurons but rather displays a region-specific susceptibility, similar to anoxic depolarization, which we have proposed is correlated with a region's vulnerability to traumatic brain injury. In the higher brain, SD may be a vestigial spreading depolarization that originally evolved to shut down and vasoconstrict gray matter regions more exposed to impact and contusion.
Topics: Animals; Brain; Brain Stem; Cortical Spreading Depression; Culture Media; Hypothalamus; In Vitro Techniques; Male; Membrane Potentials; Mice; Mice, Inbred C57BL; Neurons; Optical Imaging; Patch-Clamp Techniques; Potassium Chloride; Rats; Rats, Sprague-Dawley
PubMed: 27381828
DOI: 10.1177/0271678X16657344 -
Sensors (Basel, Switzerland) Jun 2016This paper focuses on the design and fabrication of a high-temperature piezoresistive pressure sensor with an integrated signal-conditioning circuit, which consists of...
This paper focuses on the design and fabrication of a high-temperature piezoresistive pressure sensor with an integrated signal-conditioning circuit, which consists of an encapsulated pressure-sensitive chip, a temperature compensation circuit and a signal-conditioning circuit. A silicon on insulation (SOI) material and a standard MEMS process are used in the pressure-sensitive chip fabrication, and high-temperature electronic components are adopted in the temperature-compensation and signal-conditioning circuits. The entire pressure sensor achieves a hermetic seal and can be operated long-term in the range of -50 °C to 220 °C. Unlike traditional pressure sensor output voltage ranges (in the dozens to hundreds of millivolts), the output voltage of this sensor is from 0 V to 5 V, which can significantly improve the signal-to-noise ratio and measurement accuracy in practical applications of long-term transmission based on experimental verification. Furthermore, because this flexible sensor's output voltage is adjustable, general follow-up pressure transmitter devices for voltage converters need not be used, which greatly reduces the cost of the test system. Thus, the proposed high-temperature piezoresistive pressure sensor with an integrated signal-conditioning circuit is expected to be highly applicable to pressure measurements in harsh environments.
PubMed: 27322288
DOI: 10.3390/s16060913 -
Journal of Neurophysiology Apr 2016The ongoing activity of neurons generates a spatially and time-varying field of extracellular voltage (Ve). This Ve field reflects population-level neural activity, but...
The ongoing activity of neurons generates a spatially and time-varying field of extracellular voltage (Ve). This Ve field reflects population-level neural activity, but does it modulate neural dynamics and the function of neural circuits? We provide a cable theory framework to study how a bundle of model neurons generates Ve and how this Ve feeds back and influences membrane potential (Vm). We find that these "ephaptic interactions" are small but not negligible. The model neural population can generate Ve with millivolt-scale amplitude, and this Ve perturbs the Vm of "nearby" cables and effectively increases their electrotonic length. After using passive cable theory to systematically study ephaptic coupling, we explore a test case: the medial superior olive (MSO) in the auditory brain stem. The MSO is a possible locus of ephaptic interactions: sounds evoke large (millivolt scale)Vein vivo in this nucleus. The Ve response is thought to be generated by MSO neurons that perform a known neuronal computation with submillisecond temporal precision (coincidence detection to encode sound source location). Using a biophysically based model of MSO neurons, we find millivolt-scale ephaptic interactions consistent with the passive cable theory results. These subtle membrane potential perturbations induce changes in spike initiation threshold, spike time synchrony, and time difference sensitivity. These results suggest that ephaptic coupling may influence MSO function.
Topics: Animals; Humans; Membrane Potentials; Models, Neurological; Neurons; Superior Olivary Complex
PubMed: 26823512
DOI: 10.1152/jn.00780.2015 -
Beilstein Journal of Nanotechnology 2015The electroviscous effect has been widely studied to investigate the effect of surface charge-induced electric double layers (EDL) on the pressure-driven flow in a...
The electroviscous effect has been widely studied to investigate the effect of surface charge-induced electric double layers (EDL) on the pressure-driven flow in a micro/nano channel. EDL has been reported to reduce the velocity of fluid flow and increase the fluid drag. Nevertheless, the study on the combined effect of EDL with large zeta potential up to several hundred millivolts and surface charge depenedent-slip on the micro/nano flow is still needed. In this paper, the nonlinear Poisson-Boltzmann equation for electrical potential and ion distribution in non-overlapping EDL is first analytically solved. Then, the modified Navier-Stokes equation for the flow considering the effect of surface charge on the electrical conductivity of the electrolyte and slip length is analytically solved. This analysis is used to study the effect of non-overlapping EDL with large zeta potential on the pressure-driven flow in a microchannel with no-slip and charge-dependent slip conditions. The results show that the EDL leads to an increase in the fluid drag, but that slip can reduce the fluid drag. When the zeta potential is large enough, the electroviscous effect disappears for flow in the microchannel under a no-slip condition. However, the retardation of EDL on the flow and the enhancement of slip on the flow counteract each other under a slip condition. The underlying mechanisms of the effect of EDL with large zeta potential on fluid drag are the high net ionic concentration near the channel wall and the fast decay of electrical potential in the EDL when the zeta potential is large enough.
PubMed: 26734512
DOI: 10.3762/bjnano.6.226 -
Journal of Neuroscience Methods Mar 2016Computationally efficient spike recognition methods are required for real-time analysis of extracellular neural recordings. The enteric nervous system (ENS) is important...
BACKGROUND
Computationally efficient spike recognition methods are required for real-time analysis of extracellular neural recordings. The enteric nervous system (ENS) is important to human health but less well-understood with few appropriate spike recognition algorithms due to large waveform variability.
NEW METHOD
Here we present a method based on dynamic time warping (DTW) with high tolerance to variability in time and magnitude. Adaptive temporal gridding for "fastDTW" in similarity calculation significantly reduces the computational cost. The automated threshold selection allows for real-time classification for extracellular recordings.
RESULTS
Our method is first evaluated on synthesized data at different noise levels, improving both classification accuracy and computational complexity over the conventional cross-correlation based template-matching method (CCTM) and PCA+k-means clustering without time warping. Our method is then applied to analyze the mouse enteric neural recording with mechanical and chemical stimuli. Successful classification of biphasic and monophasic spikes is achieved even when the spike variability is larger than millisecond in width and millivolt in magnitude.
COMPARISON WITH EXISTING METHOD(S)
In comparison with conventional template matching and clustering methods, the fastDTW method is computationally efficient with high tolerance to waveform variability.
CONCLUSIONS
We have developed an adaptive fastDTW algorithm for real-time spike classification of ENS recording with large waveform variability against colony motility, ambient changes and cellular heterogeneity.
Topics: Action Potentials; Algorithms; Animals; Cluster Analysis; Mice, Inbred C57BL; Microelectrodes; Muscle, Smooth; Myenteric Plexus; Neurons; Pattern Recognition, Automated; Physical Stimulation; Principal Component Analysis; Signal Processing, Computer-Assisted; Time Factors; Tissue Culture Techniques; Wavelet Analysis
PubMed: 26719239
DOI: 10.1016/j.jneumeth.2015.12.006