Mason C.P. Leung
Hong Kong Polytechnic University
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Mason C.P. Leung.
Journal of Alternative and Complementary Medicine | 2003
M. M. L. Ng; Mason C.P. Leung; Dora My Poon
OBJECTIVES To examine the relative effectiveness of electro-acupuncture (EA) and transcutaneous electrical nerve stimulation (TENS) in alleviating osteoarthritic (OA)-induced knee pain. DESIGN Single-blinded, randomized controlled study. SUBJECTS Twenty-four (24) subjects (23 women and 1 man), mean age 85, were recruited from eight subsidized Care & Attention Homes for the elderly. INTERVENTIONS Subjects were randomly assigned to the EA, TENS, or control groups. Subjects in the EA group (n = 8) received low-frequency EA (2 Hz) on two acupuncture points (ST-35, Dubi and EX-LE-4, Neixiyan) of the painful knee for 20 minutes. Subjects in the TENS group (n = 8) received low-frequency TENS of 2 Hz and pulse width of 200 micros on the same acupuncture points for 20 minutes. In both treatment groups, electrical treatment was carried out for a total of eight sessions in 2 weeks. Eight subjects received osteoarthritic knee care and education only in a control group. All subjects were evaluated before the first treatment, after the last treatment, and at 2-week follow-up periods. RESULTS After eight sessions of treatment, there was significant reduction of knee pain in both EA group and TENS group, as measured by the Numeric Rating Scale (NRS) of pain (p < 0.01). Prolonged analgesic effect was maintained in the EA and the TENS groups at a 2-week follow-up evaluation. The Timed Up-and-Go Test (TUGT) score of the EA group was significantly lower than that of the control group (p < 0.05), but such change was not observed in the TENS group. CONCLUSIONS Both EA and TENS treatments were effective in reducing OA-induced knee pain. EA had the additional advantage of enhancing the TUGT results as opposed to TENS treatment or no treatment, which did not produce such corollary effect.
Ultrasound in Medicine and Biology | 2003
Christine O.Y Ng; Gabriel Y.F. Ng; Edwina K.N See; Mason C.P. Leung
The purpose of this study was to evaluate the effects of therapeutic ultrasound on structural properties and functional performance of Achilles tendon healing. Thirty Sprague-Dawley rats with surgical hemitransected Achilles tendon were studied. Ten were treated daily with 1 MHz continuous ultrasound at 1.0 W/cm2 for 4 min, 11 at 2.0 W/cm2 for 4 min and nine served as control without treatment. Achilles functional index (AFI) was recorded preoperatively and on postoperative days 3, 10 and 30. On day 30, the rats were sacrificed and Achilles tendons were tested for load-relaxation, stiffness and ultimate tensile strength (UTS). Results showed that UTS of both low-dose (p=0.023) and high-dose (p=0.002) groups was significantly greater than in controls. No significant differences in AFI (p=0.179), load-relaxation (p=0.205) and stiffness (p=0.842) were found among groups. These findings suggested that both low- and high-dose therapeutic ultrasound accelerate the healing process of ruptured tendon.
Journal of Alternative and Complementary Medicine | 2003
Cecilia K.N. Yeung; Mason C.P. Leung; Daniel H. K. Chow
OBJECTIVES To determine the effect of a series of electro-acupuncture (EA) treatment in conjunction with exercise on the pain, disability, and functional improvement scores of patients with chronic low-back pain (LBP). DESIGN A blinded prospective randomized controlled study. SUBJECTS AND INTERVENTIONS A total of 52 patients were randomly allocated to an exercise group (n = 26) or an exercise plus EA group (n = 26) and treated for 12 sessions. OUTCOME MEASURES Numerical Rating Scale (NRS), Aberdeen LBP scale, lumbar spinal active range of movement (AROM), and the isokinetic strength were assessed by a blinded observer. Repeated measures analysis of variance (R-ANOVA) with factors of group and time was used to compare the outcomes between the two groups at baseline (before treatment), immediately after treatment, 1-month follow-up, and 3-month follow-up. The level of significance was set at p = 0.05. RESULTS Significantly better scores in the NRS and Aberdeen LBP scale were found in the exercise plus EA group immediately after treatment and at 1-month follow-up. Higher scores were also seen at 3-month follow-up. No significant differences were observed in spinal AROM and isokinetic trunk concentric strength between the two groups at any stage of follow-up. CONCLUSIONS This study provides additional data on the potential role of EA in the treatment of LBP, and indicates that the combination of EA and back exercise might be an effective option in the treatment of pain and disability associated with chronic LBP.
Proteomics | 2002
John Hon-Kei Lum; Ka-Lee Fung; Pik-Yuen Cheung; Man-Sau Wong; Chi-Ho Lee; Francis Kwok; Mason C.P. Leung; Pak-Kwan Hui; Samuel Chun-Lap Lo
Oriental ginseng (Panax ginseng C. A. Meyer) and American ginseng (Panax quinquefolius) are two widely used valuable traditional Chinese medicines (TCM). Previously, the identification of ginseng was mainly performed by analyzing the ginsengnosides using high performance liquid chromatography and amplification of polymorphic DNA using polymerase chain reaction. However, these methods cannot be used to distinguish TCM samples which are from different parts (main root, lateral roots, rhizome head and skin) of ginseng and ginseng culture cells from wild‐grown ginseng. The present study aimed to identify different species of ginseng, different parts of the same ginseng and cultured cells of ginseng using a proteomic approach. Two‐dimensional electrophoresis (2‐DE) maps were established from the American ginseng main root, different parts (main root, lateral roots, rhizome head and skins) of Oriental ginseng and Oriental ginseng culture cells. Our results show that the 2‐DE maps of different ginseng samples contain sufficient differences to permit easy discrimination. We have also identified common and specific protein spots in the 2‐DE maps of different ginseng samples. The use of these “marker proteins” may help to speed up the identification process.
Molecular and Cellular Neuroscience | 2004
Zelda H. Cheung; Yuen-Man Chan; Flora K.W. Siu; Henry K. Yip; Wutian Wu; Mason C.P. Leung; Kf So
Transection of the optic nerve initiates massive death of retinal ganglion cells (RGCs). Interestingly, despite the severity of the injury, RGC loss was not observed until several days after axotomy. The mechanisms responsible for this initial lack of RGC death remained unknown. In the current study, immunohistochemical analysis revealed that caspases-3 and -9 activation in the RGCs were not detected until day 3 post-axotomy, coinciding with the onset of axotomy-induced RGC loss. Interestingly, elevated Akt phosphorylation was observed in axotomized retinas during the absence of caspase activation. Inhibiting the increase in Akt phosphorylation by intravitreal injection of wortmannin and LY294002, inhibitors of PI3K, resulted in premature nuclear fragmentation, caspases-3 and -9 activation in the ganglion cell layer. Our findings thus indicate that the PI3K/Akt pathway may serve as an endogenous regulator of caspase activation in axotomized RGCs, thereby, contributing to the late onset of RGC death following axotomy.
Experimental Eye Research | 2002
Andrew W. Siu; Mason C.P. Leung; Chi Ho To; Flora K.W. Siu; Jianzhong Ji; Kf So
Nitric oxide (NO) is a well-known vaso-dilator but its regulation in the retina is unclear. This study was conducted to quantify total NO production and retinal ganglion cell (RGC) loss in an experimental glaucoma model. Three quarters of the peri-limbal/episcleral drainage vessels and anterior angle (right eyes) of Sprague-Dawley rats were thermally blocked using laser irradiation, while the left eyes served as controls. We measured the intraocular pressure (IOP) of both eyes using a digital tonometer (Tonopen) 21, 28 and 35 days after the laser treatment. After 35 days, we determined the total NO level in retinas and remaining ocular tissues for the laser-treated and control eyes using a spectro-photometric assay. The viable RGC numbers were also determined by counting the cell bodies stained retrogradely by fluoro-gold. The laser treatment significantly increased the IOP 2.0-2.6x throughout the whole periodof measurements (P<0.0001). The mean total RGC number decreased significantly from 98725+/-5383 (+/-S.E. (M.)) to 69276+/-5592, or 29.8% reduction, in the laser-treated eyes after 35 days (P=0.008). The mean total NO level in the laser-treated retina was significantly increased by 2.4x compared with controls (P=0.016), but no significant difference was found in the eyecups (P>0.05). Laser treatment resulted in significant IOP elevation and RGC loss, suggesting that thermal coagulation of the perilimbal region may provide an alternate protocol for glaucoma study. NO level was increased by two-fold in the retina but not in other ocular tissues. Since NO is capable of producing powerful peroxynitrite anions and hydroxyl radicals, elevated level of NO has a potential role in glaucoma.
Physics in Medicine and Biology | 2006
Zengyong Li; Eric W. C. Tam; Maggie P. C. Kwan; Arthur F. T. Mak; Samuel Chun-Lap Lo; Mason C.P. Leung
The objective of this study is to assess the effect of prolonged surface compression on the skin blood flowmotion in rats using spectral analysis based on wavelets transform of the periodic oscillations of the cutaneous laser Doppler flowmetry (LDF) signal. An external pressure of 13.3 kPa (100 mmHg) was applied to the trochanter area and the distal lateral tibia of Sprague-Dawley rats via two specifically designed pneumatic indentors. The loading duration was 6 hours/day for 4 consecutive days. Five frequency intervals were identified (0.01-0.04 Hz, 0.04-0.15 Hz, 0.15-0.4 Hz, 0.4-2 Hz and 2-5 Hz) corresponding to endothelial related metabolic, neurogenic, myogenic, respiratory and cardiac origins. The absolute amplitude of oscillations of each particular frequency interval and the normalized amplitude were calculated for quantitative assessments. The results showed that (1) tissue compression following the above schedule induced significant decrease in the normalized amplitude in the frequency interval of 0.01-0.04 Hz both in the trochanter area (p < 0.001) and tibialis area (p = 0.023), (2) prolonged compression induced significant increase in the absolute amplitude (p = 0.004 for the trochanter area and p = 0.017 for the tibialis area) but significant decrease in the normalized amplitude (p = 0.023 for the trochanter area and p = 0.026 for the tibialis area) in the frequency interval of 0.15-0.4 Hz, and (3) at the tibialis area, the flowmotion amplitude (frequency interval 0.15-0.4 Hz) measured prior to the daily tissue compression schedule was found to be significantly higher on day 4 than the measurements obtained on day 1. However, this finding was not observed at the trochanter area. Our results suggested that prolonged compression might induce endothelial damage and affect the endothelial related metabolic activities.
Neuroscience Letters | 2004
Flora K.W. Siu; Samuel Chun-Lap Lo; Mason C.P. Leung
Reactive oxygen species can be scavenged by superoxide dismutase (SOD) and glutathione peroxidase (GPx). During ischemia-reperfusion, the normal functioning of these antioxidant enzymes may be insufficient for the prevention of oxidant-induced peroxidation of membrane lipids and hence cerebral infarction. We therefore investigated whether electroacupuncture (EA) treatment at Fengchi points in post-ischemic rats could increase the antioxidant enzyme activities and thereby reduce the extent of lipid peroxidation. The results indicated that while EA did not alter the antioxidant enzyme activities in non-ischemic normal rat brains, ischemia-reperfusion caused significant increases in SOD and GPx activities. EA treatment further increased the antioxidant enzyme activities in ischemic-reperfused brain tissues, with a concomitant decrease in the extent of lipid peroxidation. Our finding suggests that EA treatment at Fengchi reduced the extent of lipid peroxidation in ischemic-reperfused rat brains, possibly by increasing the activities of SOD and GPx.
Cellular and Molecular Neurobiology | 2008
Zelda H. Cheung; Mason C.P. Leung; Henry K. Yip; Wutian Wu; Flora K.W. Siu; Kf So
It was previously demonstrated that Menta-FX, a mixture of Panax quinquefolius L. (PQE), Ginkgo biloba (GBE), and Hypericum perforatum extracts (HPE), enhances retinal ganglion cell survival after axotomy. However, the mechanisms of neuroprotection remain unknown. The aim of this study is to elucidate the neuroprotective mechanisms of Menta-FX. Since PQE, GBE and HPE have all been observed to display anti-oxidative property, the involvement of anti-oxidation in Menta-FX’s neuroprotective effect was investigated. Menta-FX lowered nitric oxide (NO) content in axotomized retinas without affecting nitric oxide synthase activity, suggesting that Menta-FX possibly exhibited a NO scavenging property. In addition, the effect of Menta-FX on the frequency of axotomy-induced nuclear fragmentation and caspase-3 activation was investigated. Menta-FX treatment significantly reduced nuclear fragmentation in axotomized retinas. Surprisingly, Menta-FX had no effect on caspase-3 activation, but selectively lowered caspase-3-independent nuclear fragmentation in axotomized retinal ganglion cells. In addition, inhibition of PI3K activity by intravitreal injection of wortmannin, a phosphoinositide-3 kinase (PI3K) inhibitor, completely abolished the neuroprotective effect of Menta-FX, indicating that Menta-FX’s neuroprotective effect was PI3K-dependent. Data here suggest that Menta-FX displayed a PI3K-dependent, selective inhibition on a caspase-3-independent apoptotic pathway in axotomized RGCs, thus, highlighting the potential use of herbal remedies as neuroprotective agents for other neurodegenerative diseases.
PLOS ONE | 2014
Zhijie He; X. Wang; Yi Wu; Jie Jia; Yongshan Hu; Xiaojiao Yang; Jianqi Li; Mingxia Fan; Li Zhang; Jinchun Guo; Mason C.P. Leung
Objective Treadmill pre-training can ameliorate blood brain barrier (BBB) dysfunction in ischemia-reperfusion injury, however, its role in ischemic brain edema remains unclear. This study assessed the neuroprotective effects induced by treadmill pre-training, particularly on brain edema in transient middle cerebral artery occluded model. Methods Transient middle cerebral artery occlusion to induce stroke was performed on rats after 2 weeks of treadmill pre-training. Magnetic resonance imaging (MRI) was used to evaluate the dynamic impairment of cerebral edema after ischemia-reperfusion injury. In addition, measurements of wet and dry brain weight, Evans Blue assay and Garcia scores were performed to investigate the cerebral water content, BBB permeability and neurologic deficit, respectively. Moreover, during ischemia-reperfusion injury, the expression of Aquaporin 4 (AQP4) was detected using immunofluorescence and Western bloting analyses. Results Treadmill pre-training improved the relative apparent diffusion coefficient (rADC) loss in the ipsilateral cortex and striatum at 1 hour and 2.5 hours after cerebral ischemia. In the treadmill pre-training group, T2W1 values of the ipsilateral cortex and striatum increased less at 7.5 hours, 1 day, and 2 days after stroke while the brain water content decreased at 2 days after ischemia. Regarding the BBB permeability, the semi-quantitative amount of contrast agent leakage of treadmill pre-training group significantly decreased. Less Evans Blue exudation was also observed in treadmill pre-training group at 2 days after stroke. In addition, treadmill pre-training mitigated the Garcia score deficits at 2 days after stroke. Immunofluorescence staining and Western blotting results showed a significant decrease in the expression of AQP4 after treadmill ischemia following pre-training. Conclusions Treadmill pre-training may reduce cerebral edema and BBB dysfunction during cerebral ischemia/reperfusion injury via the down-regulation of AQP4.