The Effects of Testosterone and Transcutaneous Muscle Stimulation on Strength and Muscle Mass in Myotonic Dystrophy

         In myotonic dystrophy type 1 (DM1) quadriceps weakness often results in severe functional limitations and genu recurvatum. To improve quadriceps strength the effects of isometric tetanic contractions using transcutaneous muscle stimulation (TMS) and testosterone enanthate (TE) were assessed. Ten DM1 subjects underwent unilateral TMS 6 hours per day for 14 days. The stimulated leg was randomly assigned and sham stimulation was done on the opposite leg by transcutaneous nerve stimulation. Muscle mass was estimated by cross-sectional area computed tomography and strength was measured by Cybex ergometry. Following the initial TMS period, 8 of 10 subjects were given a 12-week course of TE (3 mg/kg/wk) followed by 14 days of TMS. Neither TMS nor TE improved strength.  Following 12 weeks of TE, there was an average increase in muscle mass of at least 8.7 +/- 1.6 cm2. These findings are consistent with the TE—increased muscle mass in DM1 as measured by creatinine clearance and total body potassium. The dissociation of mass and strength following TE and the failure of exercise to improve strength may have significance in characterizing the muscle defect in DM1

The Effects of Testosterone and Transcutaneous Muscle Stimulation on Strength and Muscle Mass in Myotonic Dystrophy

         In myotonic dystrophy type 1 (DM1) quadriceps weakness often results in severe functional limitations and genu recurvatum. To improve quadriceps strength the effects of isometric tetanic contractions using transcutaneous muscle stimulation (TMS) and testosterone enanthate (TE) were assessed. Ten DM1 subjects underwent unilateral TMS 6 hours per day for 14 days. The stimulated leg was randomly assigned and sham stimulation was done on the opposite leg by transcutaneous nerve stimulation. Muscle mass was estimated by cross-sectional area computed tomography and strength was measured by Cybex ergometry. Following the initial TMS period, 8 of 10 subjects were given a 12-week course of TE (3 mg/kg/wk) followed by 14 days of TMS. Neither TMS nor TE improved strength.  Following 12 weeks of TE, there was an average increase in muscle mass of at least 8.7 +/- 1.6 cm2. These findings are consistent with the TE—increased muscle mass in DM1 as measured by creatinine clearance and total body potassium. The dissociation of mass and strength following TE and the failure of exercise to improve strength may have significance in characterizing the muscle defect in DM1

A Method to Shorten Signals in SM-OFDM

Spatial modulation (SM) added to traditional OFDM communications has been intensively studied as a candidate transmission method to convey high-speed, low-delay, powerefficient and high-mobility 5G communications in a reliable basis. This approach implies the use of multiple antennas at the transmitter. Then, the fundamental aspect revised in this work takes into account that in a single-carrier SM system, the selection of the active transmit antenna according to (part of) the information bits makes it possible to use a single power amplifier (PA) that is switched among the available antennas. On the other hand, in a conventional SM-OFDM system, every antenna needs to be continuously active as the index information is typically different for each subcarrier. Consequently, we propose a transmission scheme that precodes the information symbols in frequency domain, such that the global symbol period is split into partitions that enable a sequential operation of antennas which can be fed by a single PA. In addition, it is possible to establish that the proposed approach tends to be more robust against disturbances observed in high mobility environments.Sociedad Argentina de Informática e Investigación Operativa (SADIO

A Method to Shorten Signals in SM-OFDM

Spatial modulation (SM) added to traditional OFDM communications has been intensively studied as a candidate transmission method to convey high-speed, low-delay, powerefficient and high-mobility 5G communications in a reliable basis. This approach implies the use of multiple antennas at the transmitter. Then, the fundamental aspect revised in this work takes into account that in a single-carrier SM system, the selection of the active transmit antenna according to (part of) the information bits makes it possible to use a single power amplifier (PA) that is switched among the available antennas. On the other hand, in a conventional SM-OFDM system, every antenna needs to be continuously active as the index information is typically different for each subcarrier. Consequently, we propose a transmission scheme that precodes the information symbols in frequency domain, such that the global symbol period is split into partitions that enable a sequential operation of antennas which can be fed by a single PA. In addition, it is possible to establish that the proposed approach tends to be more robust against disturbances observed in high mobility environments.Sociedad Argentina de Informática e Investigación Operativa (SADIO

Quantitative sensory testing in a large cohort of neuropathy patients: QST in Neuropathy

Background: Quantitative sensory testing (QST) is a subjective but reliable and quantifiable method to detect patient thresholds to different sensory stimuli. QST is used to measure small- and large-fiber nerve function and can be used in conjunction with other diagnostic modalities in the evaluation of peripheral neuropathy (PN). The utility of QST to distinguish among different types of PN, however, has not been explored. The objective of the study was to evaluate if different patterns of QST abnormalities could distinguish between PN types. Methods: This single-center retrospective cohort study evaluated the frequency of QST abnormalities to vibratory, cold and heat detection thresholds in a large population of PN cases evaluated at the University of Texas Southwestern Medical Center peripheral neuropathy clinic between 1995-2000. PN was categorized by etiology. Results: A total of 559 QST studies were performed in this study. The average age of patients (n=557) was 60 years with a male-to-female ratio of 1:1. The most common diagnosis was cryptogenic sensory polyneuropathy (CSPN, n=294), followed by Charcot–Marie–Tooth disease (n=84)). Meta-regression of vibration and cold indicate that the expected proportion of abnormal responses is less for the vibration test (p = 0.0002), relative to the cold test. However, no differences were observed between diagnoses. Conclusions: Though abnormal QST thresholds were seen in most patients with PN, patterns of QST abnormalities do not distinguish between different types of PN. The routine clinical utility of QST is likely limited

A Method to Shorten Signals in SM-OFDM

Spatial modulation (SM) added to traditional OFDM communications has been intensively studied as a candidate transmission method to convey high-speed, low-delay, powerefficient and high-mobility 5G communications in a reliable basis. This approach implies the use of multiple antennas at the transmitter. Then, the fundamental aspect revised in this work takes into account that in a single-carrier SM system, the selection of the active transmit antenna according to (part of) the information bits makes it possible to use a single power amplifier (PA) that is switched among the available antennas. On the other hand, in a conventional SM-OFDM system, every antenna needs to be continuously active as the index information is typically different for each subcarrier. Consequently, we propose a transmission scheme that precodes the information symbols in frequency domain, such that the global symbol period is split into partitions that enable a sequential operation of antennas which can be fed by a single PA. In addition, it is possible to establish that the proposed approach tends to be more robust against disturbances observed in high mobility environments.Sociedad Argentina de Informática e Investigación Operativa (SADIO

Getting Rid of Weakness in the ICU: An Updated Approach to the Acute Management of Myasthenia Gravis and Guillain-Barré Syndrome

Abstract After prompt diagnosis, severe myasthenia gravis and Guillain-Barré syndrome (GBS) usually require management in the intensive care unit. In the myasthenic patient, recognition of precipitating factors is paramount, and frequent monitoring of bulbar, upper airway, and/or respiratory muscle strength is needed to identify impending myasthenic crisis. Noninvasive ventilation can be attempted prior to intubation and mechanical ventilation in the setting of respiratory failure. Cholinesterase inhibitors should be discontinued, but resumed prior to extubation, and steroid dosage could be increased once the airway is secured. In GBS, hemodynamic and respiratory monitoring are essential; however, respiratory failure can develop rapidly and intubation with mechanical ventilation is often required and can be prolonged. Guillain-Barré syndrome can also be complicated by dysautonomia necessitating specific therapies. Prompt recognition and initiation of immunotherapy including intravenous immunoglobulin or plasmapheresis, together with supportive care including treatment of underlying infections and physical therapy, can improve outcomes in both myasthenic crisis and GBS

Deep reinforcement learning for hybrid beamforming in multi-user millimeter wave wireless systems

Publisher Copyright: © 2021 IEEE.This paper proposes a Machine Learning (ML) algorithm for hybrid beamforming in millimeter-wave wireless systems with multiple users. The time-varying nature of the wireless channels is taken into account when training the ML agent, which identifies the most convenient hybrid beamforming matrix with the aid of an algorithm that keeps the amount of signaling information low, avoids sudden changes in the analog beamformers radiation patterns when scheduling different users (flashlight interference), and simplifies the hybrid beamformer update decisions by adjusting the phases of specific analog beamforming vectors. The proposed hybrid beamforming algorithm relies on Deep Reinforcement Learning (DRL), which represents a practical approach to embed the online adaptation feature of the hybrid beamforming matrix into the channel states of continuous nature in which the multiuser MIMO system can be. Achievable data rate curves are used to analyze performance results, which validate the advantages of DRL algorithms with respect to solutions relying on conventional/deterministic optimization tools.Peer reviewe