Focal vibration of the plantarflexor and dorsiflexor muscles improves poststroke spasticity: a randomized single-blind controlled trial.

BACKGROUND: Post-stroke spasticity is a cause of gait dysfunction and disability. Focal vibration (FV) of agonist-antagonist upper limb muscle pairs reduces flexor spasticity; however, its effects on ankle plantarflexor spasticity are uncertain. OBJECTIVE: To assess the effects of focal vibration administered by a trained operator to the ankle plantarflexor and dorsiflexor muscles on post-stroke lower limb spasticity. METHODS: A randomized, single-blind controlled trial of 64 participants with stroke and plantarflexor spasticity assigned to 3 groups by centralized, computer-generated randomization (1:1:1): 1) physiotherapy alone (CON), 2) physiotherapy+gastrocnemius vibration (FV_GM) and 3) physiotherapy+tibialis anterior vibration (FV_TA). Physiotherapists and assessors were blinded to group assignment. The experimental groups underwent 15, 20-min vibration sessions at 40 Hz. We performed evaluations at baseline and after the final treatment: Modified Ashworth Scale (MAS), Clonus scale, Functional Ambulation Categories (FAC), Fugl-Meyer Assessment - Lower Extremity (FMA_LE), Modified Barthel Index (MBI), and electromyography and ultrasound elastography. Primary outcome was remission rate (number and proportion of participants) of the MAS. RESULTS: MAS remission rate was higher in FV_GM and FV_TA than CON groups (CON vs. FV_GM: p=0.009, odds ratio 0.15 [95% confidence interval 0.03-0.67]; CON vs. FV_TA: p=0.002, 0.12 [0.03-0.51]). Remission rate was higher in the experimental than CON groups for the Clonus scale (CON vs. FV_GM: p<0.001, OR 0.07 [95% CI 0.01-0.31]; CON vs. FV_TA: p=0.006, 0.14 [95% CI 0.03-0.61]). FAC remission rate was higher in the FV_TA than the CON (p=0.009, 0.18 [0.05-0.68]) and FV_GM (p=0.014, 0.27 [0.07-0.99]) groups. Ultrasound variables of the paretic medial gastrocnemius decreased more in FV_GM than CON and FV_TA groups (shear modulus: p=0.006; shear wave velocity: p=0.008). CONCLUSIONS: Focal vibration reduced post-stroke spasticity of the plantarflexor muscles. Vibration of the tibialis anterior improved ambulation more than vibration of the gastrocnemius or physiotherapy alone. Gastrocnemius vibration may reduce spasticity by changing muscle stiffness.

Bio-Scaffolds as Cell or Exosome Carriers for Nerve Injury Repair.

Central and peripheral nerve injuries can lead to permanent paralysis and organ dysfunction. In recent years, many cell and exosome implantation techniques have been developed in an attempt to restore function after nerve injury with promising but generally unsatisfactory clinical results. Clinical outcome may be enhanced by bio-scaffolds specifically fabricated to provide the appropriate three-dimensional (3D) conduit, growth-permissive substrate, and trophic factor support required for cell survival and regeneration. In rodents, these scaffolds have been shown to promote axonal regrowth and restore limb motor function following experimental spinal cord or sciatic nerve injury. Combining the appropriate cell/exosome and scaffold type may thus achieve tissue repair and regeneration with safety and efficacy sufficient for routine clinical application. In this review, we describe the efficacies of bio-scaffolds composed of various natural polysaccharides (alginate, chitin, chitosan, and hyaluronic acid), protein polymers (gelatin, collagen, silk fibroin, fibrin, and keratin), and self-assembling peptides for repair of nerve injury. In addition, we review the capacities of these constructs for supporting in vitro cell-adhesion, mechano-transduction, proliferation, and differentiation as well as the in vivo properties critical for a successful clinical outcome, including controlled degradation and re-absorption. Finally, we describe recent advances in 3D bio-printing for nerve regeneration.

Hydrogen Sulfide Modulates the S-Nitrosoproteome and the Mitochondrial Morphology in Endothelial Cells.

BACKGROUND: Hydrogen sulfide (H2S) is one of the endogenous gaseous molecules promoting the production of nitric oxide (NO) which has cardioprotective functions. However, the role of the H2S-mediated protein S-nitrosoproteome and its subsequent physiological response remains unclear. METHODS: Endothelial cells EAhy 926 were treated with 50 µM of H2S for 2 hours. The NO bound S-nitrosoproteins were purified by a biotin-switch and then digested by trypsin. Resulting peptides from control and H2S treatment were separately labeled by isobaric tag for relative and absolute quantitation 114/115, quantified by liquid chromatography tandem-mass spectrometry and analyzed by ingenuity pathway analysis (IPA) software. The microP software was applied to analyze the morphological changes of mitochondria. RESULTS: With the treatment of H2S, 416 S-nitrosylated proteins were identified. IPA analysis showed that these proteins were involved in five signaling pathways. The NO-bound cysteine residues and the S-nitrosylation levels (115/114) were shown for ten S-nitrosoproteins. Western blot further verified the S-nitrosylation of thioredoxin-dependant peroxide reductase, cytochrome c oxidase and cytochrome b-c1 complex that are involved in the mitochondrial signaling pathway. H2O2-induced mitochondrial swelling can be reduced by the pretreatment of H2S. CONCLUSIONS: The H2S-mediated endothelial S-nitrosoproteome has been confirmed. In the present study, we have proposed the cardioprotective role of H2S via maintaining mitochondrial homeostasis.

An Efficient VLSI Architecture for Multi-Channel Spike Sorting Using a Generalized Hebbian Algorithm.

A novel VLSI architecture for multi-channel online spike sorting is presented in this paper. In the architecture, the spike detection is based on nonlinear energy operator (NEO), and the feature extraction is carried out by the generalized Hebbian algorithm (GHA). To lower the power consumption and area costs of the circuits, all of the channels share the same core for spike detection and feature extraction operations. Each channel has dedicated buffers for storing the detected spikes and the principal components of that channel. The proposed circuit also contains a clock gating system supplying the clock to only the buffers of channels currently using the computation core to further reduce the power consumption. The architecture has been implemented by an application-specific integrated circuit (ASIC) with 90-nm technology. Comparisons to the existing works show that the proposed architecture has lower power consumption and hardware area costs for real-time multi-channel spike detection and feature extraction.

Arsenic modulates posttranslational S-nitrosylation and translational proteome in keratinocytes.

Arsenic is a class I human carcinogen (such as inducing skin cancer) by its prominent chemical interaction with protein thio (-SH) group. Therefore, arsenic may compromise protein S-nitrosylation by competing the -SH binding activity. In the present study, we aimed to understand the influence of arsenic on protein S-nitrosylation and the following proteomic changes. By using primary human skin keratinocyte, we found that arsenic treatment decreased the level of protein S-nitrosylation. This was coincident to the decent expressions of endothelial nitric oxide synthase (eNOS) and inducible nitric oxide synthase (iNOS). By using LC-MS/MS, around twenty S-nitrosoproteins were detected in the biotin-switched eluent. With the interest that arsenic not only regulates posttranslational S-nitrosylation but also separately affects protein's translation expression, we performed two-dimensional gel electrophoresis and found that 8 proteins were significantly decreased during arsenic treatment. Whether these decreased proteins are the consequence of protein S-nitrosylation will be further investigated. Taken together, these results provide a finding that arsenic can deplete the binding activity of NO and therefore reduce protein S-nitrosylation.

Agreement of cardiac output measurement between pulse contour analysis and thermodilution in various body positions: a porcine study.

BACKGROUND: We elucidated the effects of various body positions on the agreement of cardiac output (CO) measurement between pulse contour analysis with the PiCCO monitor and thermodilution with pulmonary artery catheterization. METHODS: Fifteen anesthetized and mechanically ventilated pigs (40 ± 2 kg) were sequentially placed in various positions to facilitate simultaneous CO measurement. Between-methods agreement was assessed using the Bland-Altman method. Trending ability was assessed using Pearson product-moment correlation coefficient analysis. RESULTS: In supine, reverse Trendelenburg, Trendelenburg, and left lateral decubitus (lateral) positions, CO measured by these two methods was comparable (4.9 ± 1.5 versus 4.6 ± 1.6 L/min, 4.6 ± 2.2 versus 4.8 ± 1.8 L/min, 5.1 ± 2.1 versus 4.9 ± 2.1 L/min, and 5.4 ± 1.8 versus 5.0 ± 1.6 L/min; all P > 0.05). Mean bias between methods and limits of agreement (percentage error) were 0.3 ± 2.9 L/min (61%), -0.3 ± 3.3 L/min (71%), 0.1 ± 4.1 L/min (77%), and 0.5 ± 3.7 L/min (71%). Directional changes of paired CO revealed 66% (reverse Trendelenburg), 57% (Trendelenburg), and 66% (lateral) concordance. The correlation coefficient (r(2)) was 0.199, 0.127, and 0.108. For paired CO ≤6 L/min, mean bias between methods and limits of agreement (percentage error) were 0.2 ± 1.0 L/min (25%), -0.1 ± 1.0 L/min (28%), 0.2 ± 1.1 L/min (29%), and 0.5 ± 0.9 L/min (23%). Directional changes of paired CO revealed 84% (reverse Trendelenburg), 76% (Trendelenburg), and 65% (lateral) concordance. The correlation coefficient (r2) was 0.583, 0.626, and 0.213. CONCLUSIONS: The mean CO measured by pulse contour analysis and thermodilution did not agree well in various body positions. Moreover, the measurements tended to trend differently in response to positional changes. For paired CO ≤6 L/min, however, the between-methods agreement and the trending ability improved significantly.

Airway management of patients with craniofacial abnormalities: 10-year experience at a teaching hospital in Taiwan.

BACKGROUND: Airway management for patients with craniofacial abnormalities poses many challenges. It potentially has a high rate of morbidity and even mortality. METHODS: We reviewed our experience in administering anesthesia to patients with a diagnosis of mucopolysaccharidosis or Pierre Robin sequence in the past 10 years (July 1998 to October 2008). The anesthetic procedures, methods of airway management, and events of morbidity and mortality were evaluated. RESULTS: Thirty patients with mucopolysaccharidosis and 53 patients with Pierre Robin sequence were placed under general anesthesia. Although the anesthesiologists always encountered difficulties in managing the airway, most of the anesthetic procedures were performed safely except for 1 case that resulted in mortality. CONCLUSION: Managing the airway of patients with craniofacial abnormalities can potentially be difficult. It should be carried out by experienced anesthesiologists, with assistance from an otolaryngologist when necessary. A variety of different airway devices should be available if needed.

Intermittent small doses of propofol for sedation of pediatric patients undergoing magnetic resonance imaging.

BACKGROUND: Sedation of children is always necessary for magnetic resonance imaging (MRI). General anesthesia may be recommended for infants and small children to protect the airway or in children who have previously failed sedation. Our practice has been to use intermittent administration of small doses of propofol. METHODS: We retrospectively reviewed the anesthesia records of all children who underwent sedation for MRI between March 2004 and March 2007. RESULTS: A total of 120 children underwent sedation for MRI. Few adverse events (respiratory 3%, movement 8%) and no complications occurred during sedation. Almost all of the procedures (99%) were completed successfully. CONCLUSIONS: Our experience demonstrates that intermittent administration of small doses of propofol by experienced personnel for MRI can be used safely and effectively in pediatric patients.

Delayed tension pneumothorax during surgery.

Tension pneumothorax is a life-threatening emergency that rapidly results in cardiopulmonary arrest. It requires prompt diagnosis and treatment. We present 2 cases from our practice, 1 caused by blunt chest trauma and the other resulting from laparoscopic surgery. Both were successfully treated by insertion of a chest tube. The diagnosis and treatment of intraoperative pneumothorax is discussed together with a review of the literature.