Double-blind,placebo-controlled investigation of the effect of combined phototherapy/low intensity laser therapy upon experimental ischaemic pain in humans

Background and Objective: This study assessed the putative analgesic effect of combined monochromatic light/laser irradiation at low intensity (660–950 nm; 31.9 J/cm²; pulsed at 16 or 73 Hz). Study Design/Materials and Methods: The investigation was completed under double-blind conditions using a standardised form of the submaximal effort tourniquet technique. Healthy male volunteers naive to the experimental conditions (n = 45) attended on two occasions for the purposes of pain induction, the first during which baseline data were obtained and on a second occasion during which they were randomly allocated to one of two treatments or a placebo condition. For the treatment conditions, irradiation was applied to the ipsilateral Erb's point at the parameters stated; for the placebo condition, sham “irradiation” was delivered using a dummy unit. Pain was measured using computerised visual analogue scales and McGill Pain Questionnaires (MPQ) to assess “current pain intensity” and “worst pain experienced,” respectively. Results: Analysis of variance and appropriate post hoc tests demonstrated only a weak (but significant) hypoalgesic effect compared to placebo (P<0.05) in the treatment group irradiated at 16Hz for the sensory component of the MPQ; other comparisons were found to be nonsignificant. Conclusions: These results do not provide convincing evidence for the hypoalgesic potential of combined monochromatic light/laser irradiation, at least at the parameters used here, and thus indicate the necessity of additional work to investigate this modality further in order to assess the potential benefit, if any, of such treatment in the clinical setting. © 1995 Wiley-Liss, Inc.     

推拿对一次性离心运动后延迟性肌肉酸痛影响及机制的随机对照试验

目的：观察比较运动前、后推拿及自然恢复对一次性离心运动所致延迟性肌肉酸痛（DOMS）的影响,并从氧自由基代谢方面对推拿的作用机制进行探讨。方法：本研究地点为南京中医药大学,时间2008年4—7月。将30名健康男性学生按照条件对等原则随机分成运动前推拿组（A）、运动后推拿组（B）和对照组（自然恢复组,即C组）,每组各10名。A组学生于训练前在左上肢进行30inin推拿,推拿结束5min后开始训练;B组学生于训练后30min在左上肢进行30min推拿,并在此后的3d内按规定时间继续接受推拿治疗,每次30min,每日1次。C组学生仅参加训练,不做任何的准备活动或整理活动,也不接受任何治疗。分别于训练前、训练后即刻及训练后24、48、72h测定肌肉酸痛程度和持续时间、肌肉最大等长收缩力量、臂围、肘关节的屈伸度。血清肌酸激酶（CK）、血清超氧化物歧化酶（SOD）、血清丙二醛（MDA）测定安排在训练前1h、训练后即刻及训练后24、48h。同时观察酸痛消失的具体时间。结果：与C组相比,A组和B组酸痛峰值均降低（P〈0．01,P〈0．05）;运动后72h肘关节屈曲程度的恢复优于C组（P〈0．05,P〈0．01）;运动后48h的血清CK升高幅度低于C组（P〈0．01）。A组肌肉酸痛持续时间缩短（P〈0．01）,运动后72h肌肉最大等长收缩力量的恢复优于C组（P〈0．01）;B组在运动后72h的肘关节伸直程度的恢复优于C组（P〈0．01）。A、B纽的臂围变化与对照组无明显差异。A、B组在运动后48h时的血清SOD、MDA和SOD／MDA变化程度与C组差异均有统计学意义（P〈0．01或0．05）。结论：运动前、后推拿能通过改善DOMS过程中氧自由基的代谢水平而分别对DOMS具有一定的预防和治疗作用。     

The effect of low intensity shockwave treatment (Li-SWT) on human myoblasts and mouse skeletal muscle

Background

Transplanting myogenic cells and scaffolds for tissue engineering in skeletal muscle have shown inconsistent results. One of the limiting factors is neovascularization at the recipient site. Low intensity shockwave therapy (Li-SWT) has been linked to increased tissue regeneration and vascularization, both integral to survival and integration of transplanted cells. This study was conducted to demonstrate the response of myoblasts and skeletal muscle to Li-SWT.

Method

Primary isolated human myoblasts and explants were treated with low intensity shockwaves and subsequently cell viability, proliferation and differentiation were tested. Cardiotoxin induced injury was created in tibialis anterior muscles of 28 mice, and two days later, the lesions were treated with 500 impulses of Li-SWT on one of the legs. The treatment was repeated every third day of the period and ended on day 14 after cardiotoxin injection.. The animals were followed up and documented up to 21 days after cardiotoxin injury.

Results

Li-SWT had no significant effect on cell death, proliferation, differentiation and migration, the explants however showed decreased adhesion. In the animal experiments, qPCR studies revealed a significantly increased expression of apoptotic, angiogenic and myogenic genes; expression of Bax, Bcl2, Casp3, eNOS, Pax7, Myf5 and Met was increased in the early phase of regeneration in the Li-SWT treated hind limbs. Furthermore, a late accumulative angiogenic effect was demonstrated in the Li-SWT treated limbs by a significantly increased expression of Angpt1, eNOS, iNOS, Vegfa, and Pecam1.

Conclusion

Treatment was associated with an early upregulation in expression of selected apoptotic, pro-inflammatory, angiogenic and satellite cell activating genes after muscle injury. It also showed a late incremental effect on expression of pro-angiogenic genes. However, we found no changes in the number of PAX7 positive cells or blood vessel density in Li-SWT treated and control muscle. Furthermore, Li-SWT in the selected doses did not decrease survival, proliferation or differentiation of myoblasts in vitro.

     

Influence of transcutaneous electrical nerve stimulation on pain, range of motion, and serum cortisol concentration in females experiencing delayed onset muscle soreness

beta-Endorphin (BEP) has been implicated in the analgesic response to transcutaneous electrical nerve stimulation (TENS). The anterior pituitary gland is a source of beta-endorphin which shares the prohormone proopiomelanocortin (POMC) with adrenocorticotropin (ACTH). Current theory proposes that the stimulation-induced breakdown of POMC results in ACTH release with a subsequent elevation in blood cortisol levels. The purpose of this study was to determine the potential application and mechanism of TENS as an anti-inflammatory agent. Eight female subjects received low frequency, 300 musec pulse width TENS at four sites associated with relief of upper arm pain once when pain free and again while experiencing delayed onset muscle soreness (DOMS) of the elbow flexor muscle group. Blood samples were withdrawn 15 and 1 minute before and 1, 20, and 40 minutes after treatment. Serum was analyzed for cortisol by radioimmunoassay. TENS treatment failed to elevate serum cortisol concentration, but there was a significant reduction in perception of pain (p < 0.05) and an improvement in range of elbow extension (p < 0.05) when subjects were treated for DOMS. These results suggest that the anterior pituitary is not a source of BEP in TENS-induced analgesia. J Orthop Sports Phys Ther 1989;11(3):100-103.     

Effect of exercise intensity on skeletal muscle AMPK signaling in humans

The effect of exercise intensity on skeletal muscle AMP-activated protein kinase (AMPK) signaling and substrate metabolism was examined in eight men cycling for 20 min at each of three sequential intensities: low (40 +/- 2% VO(2) peak), medium (59 +/- 1% VO(2) peak), and high (79 +/- 1% VO(2) peak). Muscle free AMP/ATP ratio only increased at the two higher exercise intensities (P < 0.05). AMPK alpha 1 (1.5-fold) and AMPK alpha 2 (5-fold) activities increased from low to medium intensity, with AMPK alpha 2 activity increasing further from medium to high intensity. The upstream AMPK kinase activity was substantial at rest and only increased 50% with exercise, indicating that, initially, signaling through AMPK did not require AMPK kinase posttranslational modification. Acetyl-CoA carboxylase (ACC)-beta phosphorylation was sensitive to exercise, increasing threefold from rest to low intensity, whereas neuronal NO synthase (nNOS) micro phosphorylation was only observed at the higher exercise intensities. Glucose disappearance (tracer) did not increase from rest to low intensity, but increased sequentially from low to medium to high intensity. Calculated fat oxidation increased from rest to low intensity in parallel with ACC beta phosphorylation, then declined during high intensity. These results indicate that ACC beta phosphorylation is especially sensitive to exercise and tightly coupled to AMPK signaling and that AMPK activation does not depend on AMPK kinase activation during exercise.     

低强度脉冲超声波对大鼠失神经骨骼肌萎缩的影响

[目的]探讨低强度脉冲超声波(LIPUS)对失神经骨骼肌萎缩的影响。[方法]50只健康雄性SD大鼠随机分为五组:假手术组、模型组、60 m W/cm2、110 m W/cm2、170 m W/cm2LIPUS治疗组(即A、B、C、D、E组),n=10。右股后外侧纵向切口暴露并切断坐骨神经造成失神经动物模型,A组不切断神经。术后1 d,C、D、E组术侧腓肠肌分别给予相应强度LIPUS治疗(A、B组不行任何治疗)。术后4周和8周,测定术侧腓肠肌湿重比和肌纤维直径、截面积,Western Blot检测Caspase-3、Caspase-8、Caspase-9表达,TUNEL法检测细胞凋亡,透射电镜观察腓肠肌超微结构。[结果]术侧腓肠肌湿重比和肌纤维直径、截面积,B组明显低于C、D、E组,差异有统计学意义(P0.05)。Caspase-3、Caspase-8、Caspase-9蛋白表达及细胞凋亡指数,C、D、E组明显低于B组(P0.05)。透射电镜显示,C、D、E组肌丝溶解、Z线断裂和线粒体肿胀、空泡化均轻于B组。[结论]LIPUS可延缓失神经骨骼肌萎缩进程,其机制可能与调控凋亡相关蛋白表达、减少细胞凋亡有关。     

The delayed effect of growth hormone on renal function in humans

Growth hormone is reported to increase renal plasma flow (RPF) and glomerular filtration rate (GFR) in some but not all studies. The discrepant results could be due to a delay in the effects of growth hormone on renal function. We therefore examined whether a growth hormone injection does increase RPF and GFR, whether this increase is delayed, and whether elevation in RPF and GFR is associated with increased plasma levels of insulin-like growth factor I (IGF-I). Seven normal adults received a single intramuscular injection of growth hormone, 0.15 mg/kg, and serial PAH and inulin clearances were then monitored for three consecutive days. Plasma growth hormone levels peaked an average of 2.25 hours after injection, at 128 +/- 12 SEM ng/ml, and then began to decrease; on the second day values were only slightly elevated and on the third day they were not different from baseline. Plasma IGF-I, analyzed by direct radioimmunoassay, did not change on the first day during 5.5 hours of measurements after injection. By the second day, plasma IGF-I was elevated to over twice baseline levels (P less than 0.05) and remained elevated on the third day (P less than 0.05). RPF and GFR did not change from baseline (546 +/- 19 and 100 +/- 3 ml/min/1.73 m2, respectively) during the 5.5 hours after injection on the first day.(ABSTRACT TRUNCATED AT 250 WORDS)     

弱激光疗法在创面愈合中的作用研究进展

Low level laser therapy (LLLT) is a therapeutic method which regulates the biological behavior of cells with light.The effects of LLLT consist of promotion of tissue repair,inhibition of inflammation,and relief of pain by promoting or inhibiting the cell proliferation,increasing or decreasing the release of some bioactive substances.Therefore,LLLT is also known as photomodulation.At present,there are many relevant experimental studies of LLLT abroad,and they are also used clinically.This article reviews the effect of LLLT on wound healing.     

Low intensity monochromatic infrared therapy: a preliminary study of the effects of a novel treatment unit upon experimental muscle soreness.

BACKGROUND AND OBJECTIVE: The current study (for which ethical approval was obtained) sought to assess the effect of low intensity monochromatic infrared therapy (LIMIRT) on experimentally induced delayed onset muscle soreness (DOMS). STUDY DESIGN/MATERIALS AND METHODS: Healthy volunteers were recruited (n = 24, 12M:12F) and randomly allocated under strict double blind conditions to one of three experimental groups (n = 8, 4M:4F): Control, Placebo, or Treatment (840 nm; 3.0 J cm(-2), pulse frequency 1 kHz). DOMS was induced in a standardised manner in the biceps brachii of the nondominant arm. Subjects attended on 5 consecutive days during which the degree of pain and functional impairment was assessed. RESULTS: Analysis of results by using nonparametric Freidman and Kruskal-Wallis H tests (with relevant post hoc tests) revealed significant differences (P < 0.05) between Control and LIMIRT treatment groups for pain and tenderness scores. Despite trends in favour of the Treatment group, analysis failed to show any significant differences between the LIMIRT treatment and Placebo groups for all variables except mechanical pain threshold points 3-6 on day 2. CONCLUSION: The results of the current study suggest that LIMIRT is ineffective in the management of DOMS at the parameters investigated.     

Protective effect of low-level laser therapy (LLLT) on acute zymosan-induced arthritis

The aim of this study was to evaluate the effect of low-level laser therapy on acute zymosan-induced arthritis, with respect to the laser action on inflammatory cells influx, release of pro-inflammatory mediators, metalloproteinases activity into the joint cavity and the cartilage repair process. Arthritis was induced in male Wistar rats (250–280 g) by intra-articular injection of zymosan (1 mg dissolved in 50 μl of a sterile saline solution) into one rear knee joint. Animals were irradiated immediately, 1 and 2 h after zymosan administration with a semiconductor laser InGaAIP (660 nm, 10 mW, 2.5 J/cm², 10 s). In the positive control group, animals were injected with the anti-inflammatory drug dexamethasone 1 h prior to the zymosan administration. Treatment with laser significantly inhibited leukocytes influx, the release of IL-1 and IL-6 and also the activity of metalloproteinase-2 and 9, into the joint cavity. In conclusion, laser therapy was effective in reducing inflammation to sites of injury and inhibit activation of proteases (gelatinase) suggesting less degradation of collagen tissue in experimental model of acute arthritis.