Dengue protease inhibition activity of selected Malaysian medicinal herbs.

Dengue fever is one of major health problem around the world including Malaysia. It is caused by the arthropode-borne flavivirus and transmitted by the bite of the Aedes aegypti or Aedes albopictus mosquito infected with one of the four dengue virus serotypes (DENV-1, DENV-2, DENV-3, or DENV-4). In this study, a screening exercise of various Malaysian medicinal plants showed that the extracts of Lawsonia inermis, Dryobalanops aromatica, Punica granatum, Zizyphus jujuba Lam. and Zingiber zerumbet exhibited potent inhibitory activity against NS2B-NS3 serine protease. The methanol extracts of Dryobalanops aromatica showed inhibition of 99.70 % at concentration of 200 µg/mL with IC50 value of 0.30 ± 0.16 µg/mL.

Dengue protease inhibition activity of selected Malaysian medicinal herbs

@#Dengue fever is one of major health problem around the world including Malaysia. It is caused by the arthropode-borne flavivirus and transmitted by the bite of the Aedes aegypti or Aedes albopictus mosquito infected with one of the four dengue virus serotypes (DENV-1, DENV-2, DENV-3, or DENV-4). In this study, a screening exercise of various Malaysian medicinal plants showed that the extracts of Lawsonia inermis, Dryobalanops aromatica, Punica granatum, Zizyphus jujuba Lam. and Zingiber zerumbet exhibited potent inhibitory activity against NS2B-NS3 serine protease. The methanol extracts of Dryobalanops aromatica showed inhibition of 99.70 % at concentration of 200 μg/mL with IC50 value of 0.30 ± 0.16 μg/mL.

Effect of cervicolumbar coupling on spinal reflexes during cycling after incomplete spinal cord injury.

Spinal networks in the cervical and lumbar cord are actively coupled during locomotion to coordinate arm and leg activity. The goals of this project were to investigate the intersegmental cervicolumbar connectivity during cycling after incomplete spinal cord injury (iSCI) and to assess the effect of rehabilitation training on improving reflex modulation mediated by cervicolumbar pathways. Two studies were conducted. In the first, 22 neurologically intact (NI) people and 10 people with chronic iSCI were recruited. The change in H-reflex amplitude in flexor carpi radialis (FCR) during leg cycling and H-reflex amplitude in soleus (SOL) during arm cycling were investigated. In the second study, two groups of participants with chronic iSCI underwent 12 wk of cycling training: one performed combined arm and leg cycling (A&L) and the other legs only cycling (Leg). The effect of training paradigm on the amplitude of the SOL H-reflex was assessed. Significant reduction in the amplitude of both FCR and SOL H-reflexes during dynamic cycling of the opposite limbs was found in NI participants but not in participants with iSCI. Nonetheless, there was a significant reduction in the SOL H-reflex during dynamic arm cycling in iSCI participants after training. Substantial improvements in SOL H-reflex properties were found in the A&L group after training. The results demonstrate that cervicolumbar modulation during rhythmic movements is disrupted in people with chronic iSCI; however, this modulation is restored after cycling training. Furthermore, involvement of the arms simultaneously with the legs during training may better regulate the leg spinal reflexes. NEW & NOTEWORTHY This work systematically demonstrates the disruptive effect of incomplete spinal cord injury on cervicolumbar coupling during rhythmic locomotor movements. It also shows that the impaired cervicolumbar coupling could be significantly restored after cycling training. Actively engaging the arms in rehabilitation paradigms for the improvement of walking substantially regulates the excitability of the lumbar spinal networks. The resulting regulation may be better than that obtained by interventions that focus on training of the legs only.

Global resuscitation alliance utstein recommendations for developing emergency care systems to improve cardiac arrest survival.

INTRODUCTION: The Global Resuscitation Alliance (GRA) was established in 2015 to improve survival for Out- of-Hospital Cardiac Arrest (OHCA) using the best practices developed by the Seattle Resuscitation Academy. However, these 10 programs were recommended in the context of developed Emergency Care Systems (ECS). Implementing these programs can be challenging for ECS at earlier stages of development. We aimed to explore barriers faced by developing ECS and to establish pre-requisites needed. We also developed a framework by which developing ECS may use to build their emergency response capability. METHOD: A consensus meeting was held in Singapore on 1st-2nd August 2017. The 74 participants were key stakeholders from 26 countries, including Emergency Medical Services (EMS) directors, physicians and academics, and two Physicians who sit on the World Health Organisation (WHO) panel for development of Emergency Care Systems. Five discussion groups examined the chain of survival: community, dispatch, ambulance and hospital; a separate group considered perinatal resuscitation. Discussion points were voted upon to reach a consensus. RESULTS: The answers and discussion points from each groupwere classified into a table adapted from WHO's framework of development for Emergency Services. After which, it was used to construct the modified survival framework with the chain of survival as the backbone. Eleven key statements were then derived to describe the pre-requisites for achieving the GRA 10 programs. The participants eventually voted on the importance and feasibility of these 11 statements as well as the GRA 10 programs using a matrix that is used by organisations to prioritise their action steps. CONCLUSION: In this paper, we propose a modified framework of survival for developing ECS systems. There are barriers for developing ECS systems to improve OHCA survival rates. These barriers may be overcome by systematic prioritisation and cost-effective innovative solutions.

Intravenous regional anaesthesia (Bier's block) for pediatric forearm fractures in a pediatric emergency department-Experience from 2003 to 2014.

STUDY OBJECTIVES: To evaluate the efficacy (length of stay in the emergency department and failure rate of Bier's block) and safety profile (death and major complications) of Bier's block in its use for manipulation and reduction of paediatric forearm fractures. METHODS: This is a retrospective cohort study of pediatric patients in KKWomen's and Children's Hospital Children's Emergency Department with forearm fractures between Jan 2003 and Dec 2014 who underwent manipulation and reduction using Bier's block. Demographic data, time from registration to discharge, major complications and success rate were collated in a standardized data collection form. A subanalysis of the Bier's block group from 2009 to 2014 was performed and compared to a corresponding data set of paediatric patients who underwent manipulation and reduction of forearm fractures using ketamine for procedural sedation from 2009 to 2014. RESULTS: 1781 cases of paediatric forearm fractures were analysed. The mean age of patients in the Bier's block group was 12.0 years (range 5.5-17.8 years old). Of all patients undergoing Bier's block, 1471 out of 1781 patients were male (82.7%). The mean length of stay (LOS) in the department was 168±72min, measured from time of registration till departure. From our subanalysis of data from 2009 to 2014, the mean LOS for the Bier's block group was shorter - 170min compared to 238min for the ketamine group (P <0.0001). 2 patients had failed Bier's block which required a repeat procedural sedation using ketamine. 96% of patients who underwent Bier's block were discharged with an outpatient orthopaedic appointment. There were no deaths or major complications identified in our study. CONCLUSION: Bier's block is a safe technique for reduction of fractures when used in the appropriate population and fracture types, with a low failure rate and no major complications including death. Compared to the ketamine group, it has a shorter length of stay in the emergency department. We recommend the adoption of this practice for manipulation and reduction of pediatric forearm fractures in the Emergency Department with a formalised protocol to reduce and prevent any human errors that can potentially result in complications.

Modulation of corticospinal input to the legs by arm and leg cycling in people with incomplete spinal cord injury.

The spinal cervico-lumbar interaction during rhythmic movements in humans has recently been studied; however, the role of arm movements in modulating the corticospinal drive to the legs is not well understood. The goals of this study were to investigate the effect of active rhythmic arm movements on the corticospinal drive to the legs (study 1) and assess the effect of simultaneous arm and leg training on the corticospinal pathway after incomplete spinal cord injury (iSCI) (study 2). In study 1, neurologically intact (NI) participants or participants with iSCI performed combinations of stationary and rhythmic cycling of the arms and legs while motor evoked potentials (MEPs) were recorded from the vastus lateralis (VL) muscle. In the NI group, arm cycling alone could facilitate the VL MEP amplitude, suggesting that dynamic arm movements strongly modulate the corticospinal pathway to the legs. No significant difference in VL MEP between conditions was found in participants with iSCI. In study 2, participants with iSCI underwent 12 wk of electrical stimulation-assisted cycling training: one group performed simultaneous arm and leg (A&L) cycling and the other legs-only cycling. MEPs in the tibialis anterior (TA) muscle were compared before and after training. After training, only the A&L group had a significantly larger TA MEP, suggesting increased excitability in the corticospinal pathway. The findings demonstrate the importance of arm movements in modulating the corticospinal drive to the legs and suggest that active engagement of the arms in lower limb rehabilitation may produce better neural regulation and restoration of function.NEW & NOTEWORTHY This study aimed to demonstrate the importance of arm movements in modulating the corticospinal drive to the legs. It provides direct evidence in humans that active movement of the arms could facilitate corticospinal transmission to the legs and, for the first time, shows that facilitation is absent after spinal cord injury. Active engagement of the arms in lower limb rehabilitation increased the excitability of the corticospinal pathway and may produce more effective improvement in leg function.

Moderate to severe obstructive sleep apnoea patients is associated with a higher incidence of visual field defect.

PURPOSE: To compare the visual fields (VFs) and optic nerve head changes between obstructive sleep apnoea (OSA) in normotensive patients and an age-matched non-OSA population. DESIGN: Case-control study. PARTICIPANTS: A total of 41 ethnic Chinese patients diagnosed with moderate to severe OSA referred from the Sleep Laboratory, ENT Department, Tuen Mun Hospital. A total of 35 age-matched non-OSA subjects recruited from the Ophthalmology Department, North District Hospital. METHODS: Comprehensive ophthalmological and systemic history, complete ophthalmological examination, including central-30 computerized perimetry for all studied patients. MAIN OUTCOME MEASURES: Polysomnographic data, VF indices, optic disc changes. RESULTS: In the OSA arm, VF indices were significantly subnormal and the incidence of suspicious glaucomatous disc changes was four times higher than that of the control arm. None of the studied patients suffered from any form of anterior segment complications. CONCLUSIONS: Moderate to severe OSA is associated with a higher incidence of VF defect and glaucomatous optic nerve changes.

Functional electrical stimulation using microstimulators to correct foot drop: a case study.

This paper presents a case study that tested the feasibility and efficacy of using injectable microstimulators (BIONs) in a functional electrical stimulation (FES) device to correct foot drop. Compared with surface stimulation of the common peroneal nerve, stimulation with BIONs provides more selective activation of specific muscles. For example, stimulation of the tibialis anterior (TA) and extensor digitorum longus (EDL) muscles with BIONs produces ankle flexion without excessive inversion or eversion of the foot (i.e., balanced flexion). Efficacy was assessed using a 3-dimensional motion analysis of the ankle and foot trajectories during walking with and without stimulation. Without stimulation, the toe on the affected leg drags across the ground. BION stimulation of the TA muscle and deep peroneal nerve (which innervates TA and EDL) elevates the foot such that the toe clears the ground by 3 cm, which is equivalent to the toe clearance in the less affected leg. The physiological cost index (PCI) measured effort during walking. The PCI equals the change in heart rate (from rest to activity) divided by the walking speed; units are beats per metre. The PCI is high without stimulation (2.29 +/- 0.37, mean +/- SD) and greatly reduced with surface (1.29 +/- 0.10) and BIONic stimulation (1.46 +/- 0.24). Also, walking speed increased from 9.4 +/- 0.4 m/min without stimulation to 19.6 +/- 2.0 m/min with surface and 17.8 +/- 0.7 m/min with BIONic stimulation. These results suggest that FES delivered by a BION is an alternative to surface stimulation and provides selective control of muscle activation.

BIONic WalkAide for correcting foot drop.

The goal of this study was to test the feasibility and efficacy of using microstimulators (BIONs) to correct foot drop, the first human application of BIONs in functional electrical stimulation (FES). A prototype BIONic foot drop stimulator was developed by modifying a WalkAide2 stimulator to control BION stimulation of the ankle dorsiflexor muscles. BION stimulation was compared with surface stimulation of the common peroneal nerve provided by a normal WalkAide2 foot drop stimulator. Compared to surface stimulation, we found that BION stimulation of the deep peroneal nerve produces a more balanced ankle flexion movement without everting the foot. A 3-D motion analysis was performed to measure the ankle and foot kinematics with and without stimulation. Without stimulation, the toe on the affected leg drags across the ground. The BIONic WalkAide elevates the foot such that the toe clears the ground by 3 cm, which is equivalent to the toe clearance in the unaffected leg. The physiological cost index (PCI) was used to measure effort during walking. The PCI is high without stimulation (2.29 +/- 0.37; mean +/- S.D.) and greatly reduced with surface (1.29 +/- 0.10) and BION stimulation (1.46 +/- 0.24). Also, walking speed is increased from 9.4 +/- 0.4 m/min. without stimulation to 19.6 +/- 2.0 m/min. with surface and 17.8 +/- 0.7 m/min. with BION stimulation. We conclude that functional electrical stimulation with BIONs is a practical alternative to surface stimulation and provides more selective control of muscle activation.

A wheelchair modified for leg propulsion using voluntary activity or electrical stimulation.

A commercially available wheelchair has been modified for propulsion by movements of the lower legs. The feet are attached securely to a foot rest that can rotate around the knee joint. Movement is generated either with residual voluntary activation of the quadriceps (knee extensor) and hamstring (knee flexor) muscles, or with electrical stimulation of these muscles, if voluntary control is absent. Either a chain or a lever can couple the movements through a gearbox to the wheel to propel the wheelchair forward. Control of a wheelchair with the legs is more efficient than using the arms and has the potential to increase the mobility and whole-body fitness of many wheelchair users, but there is considerable variability between subjects. To address this variability, we measured for individual subjects the passive properties of the legs and foot at rest (effective stiffness and viscosity), the length-tension (torque-angle) properties of the active muscle groups, as well as their force-velocity curve and their activation and fatigue rates. The measured values were then inserted into a model of the leg-propelled wheelchair. The purpose of this paper is to test whether the model could predict the performance of individual subjects accurately and could be used, for example, to optimize the speed of the wheelchair for a given subject.

Improved efficiency with a wheelchair propelled by the legs using voluntary activity or electric stimulation.

OBJECTIVE: To determine whether a new leg-propelled wheelchair provides enhanced efficiency and mobility to wheelchair users. DESIGN: Observational; subjects were tested while wheeling with the arms and legs and while walking (where possible) for 4-minute periods in random order with approximately 10-minute rest periods between exercise sets. SETTING: Tests were done on an indoor 200-meter track. PATIENTS: Group 1, 13 controls; group 2, 9 persons with complete spinal cord injury (SCI); group 3, 13 persons with other motor disorders (retaining some voluntary control of the legs). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Physiological Cost Index (PCI), (computed as change in heart rate divided by velocity of movement) and oxygen consumption (VO(2)) RESULTS: Arm wheeling took significantly more effort (mean PCI =.52 beats/m) than walking (.33 beats/m) in control subjects. Leg wheeling was most efficient (.23), requiring less than half the effort of arm wheeling and 30% less effort than walking. For SCI subjects, leg wheeling with functional electric stimulation (FES) required less than half the effort (.18) of arm wheeling (.40). The FES group could not walk. Subjects in group 3 could walk, but with substantial effort (1.81) compared with arm (.76) or leg wheeling (.64). Results for VO(2) were similar. CONCLUSIONS: Better wheelchair efficiency can be obtained for many disabled individuals, by moving the leg muscles voluntarily or with FES.

Effect of various infection-control methods for light-cure units on the cure of composite resins.

This study (1) compared the curing-light intensity with various barrier infection-control methods used to prevent cross contamination, (2) compared the Knoop hardness value of cured composite resin when various barrier control methods were used, and (3) correlated the hardness of the composite resin with the light-intensity output when different infection-control methods were used. The light-cure unit tips were covered with barriers, such as cellophane wrap, plastic gloves, Steri-shields, and finger cots. The control group had no barrier. Composite resins were then cured for each of the five groups, and their Knoop hardness values recorded. The results showed that there was significant statistical difference in the light-intensity output among the five groups. However, there was no significant statistical difference in the Knoop hardness values among any of the groups. There was also no correlation between the Knoop hardness value of the composite resin with the light-intensity output and the different infection-control methods. Therefore, any of the five infection-control methods could be used as barriers for preventing cross-contamination of the light-cure unit tip, for the light-intensity output for all five groups exceeded the recommended value of 300 W/m2. However, to allow a greater margin of error in clinical situations, the authors recommend that the plastic glove or the cellophane wrap be used to wrap the light-cure tip, since these barriers allowed the highest light-intensity output.

Sol-gel coating technology for the preparation of solid-phase microextraction fibers of enhanced thermal stability.

A novel sol-gel method is described for the preparation of solid-phase microextraction (SPME) fibers. The protective polyimide coating was removed from a 1-cm end segment of a 200 µm o.d. fused-silica fiber, and the exposed outer surface was coated with a bonded sol-gel layer of poly(dimethylsiloxane) (PDMS). The chemistry behind this coating technique is presented. Efficient SPME-GC analyses of polycyclic aromatic hydrocarbons, alkanes, aniline derivatives, alcohols, and phenolic compounds in dilute aqueous solutions were achieved using sol-gel-coated PDMS fibers. The extracted analytes were transferred to a GC injector using an in-house-designed SPME syringe that also allowed for easy change of SPME fibers. Electron microscopy experiments suggested a porous structure for the sol-gel coating with a thickness of ∼10 µm. The coating porosity provided higher surface area and allowed for the use of thinner coatings (compared with 100-µm-thick coatings for conventional SPME fibers) to achieve acceptable stationary-phase loadings and sample capacities. Enhanced surface area of sol-gel coatings, in turn, provided efficient analyte extraction rates from solution. Experimental results on thermal stability of sol-gel PDMS fibers were compared with those for commercial 100-µm PDMS fibers. Our findings suggest that sol-gel PDMS fibers possess significantly higher thermal stability (>320 °C) than conventionally coated PDMS fibers that often start bleeding at 200 °C. This is due, in part, to the strong chemical bonding between the sol-gel-generated organic-inorganic composite coating and the silica surface. Enhanced thermal stability allowed the use of higher injection port temperatures for efficient desorption of less-volatile analytes and should translate into extended range of analytes that can be handled by SPME-GC techniques. Experimental evidence is provided that supports the operational advantages of sol-gel coatings in SPME-GC analysis.