| BACKGROUNDStroke has the characteristics of high morbidity and high disability. About200million people get stroke every year in China, ischemic cerebrovascular disease accounts for about70-80%of the most common disease. Timely thrombolysis for ischemic brain tissue is to achieve re-perfusion for treatment of ischemic stroke, but cerebral ischemia re-perfusion will cause a series of reaction, such as the micro-environment of disorder and destruction of the blood-brain barrier, radicals metabolic disorders, calcium overload, the damaging effects of inflammation, changes in mitochondrial stability, acceleration of apoptosis, neurons, glial cells, synapses, dendrites, axons structure changes. Therefore, to inhibit the neuronal apoptosis after re-perfusion of ischemic tissue, promoting interaction between glial cells, synapses and neurons has important significance on the survival of neurons. In recent years, in addition to early thrombolytic medication on cerebral ischemic stroke treatment, with the advances of modern medicine, and early rehabilitation intervention also increasingly attracted the majority of medical personnel attention, achieved remarkable results too. In order to achieve the purpose of the neurological rehabilitation, looking for effective interventions actively to promote the recovery the function of neurological, has become a new hotspot of Rehabilitation Medicine. It has considerable social significance and considerable economic values. At present, the main means of rehabilitation, including mandatory passive training, intent functional training, functional electrical stimulation, trans-cranial magnetic stimulation, pulsed magnetic therapy and traditional Chinese medicine comprehensive rehabilitation means. But as a means of rehabilitation the low sound pressure level of infrasound is used seldom.Infrasound is the frequency of mechanical vibration wave between0.000120Hz, while infrasound of the biological effects is related with the intensity of sound. Related studies had shown that the disadvantage of the high intensity of the infrasound on the body is clear, especially for the brain injury. But the biological effects of small dosage of infrasound are not very clear. In accordance with the "bioresonance" theory, the infrasound range of security domains should have a very unique role of the various organs of the human body, may have a beneficial effect. Therefore, there is a huge development potential in the diagnosis and treatment of the disease. The small dose of infrasound below90dB acted on organisms may produce a slight resonance. This is because the low frequency infrasound can not be easily absorbed, but it can penetrate tissue by mechanics, produce acoustics, electrical, optical, and other physical effects of soft and gentle. It does not only produce injury organisms, but also benefit for organisms massage biological organization, enable occlusion of blood vessels of pathological tissue re-open, improve blood flow, improve pathological blood circulation, oxygen, phagocytic cells and other substances to create favorable conditions for delivery to the diseased tissue. Performance of biological effects of infrasound can change the body’s tissues and organs, cell structure and function. Some reports suggested that a small dose of infrasound could promote the proliferation of bone marrow mesenchymal stem cells, some foreign scholars reported that low frequence of infrasound might be associated with body’s antioxidant system enzymes increased vitality, increased compensatory response. CHI company had developed the8TM infrasound therapy instrument could produce less than90dB infrasound, improve circulation, enhance immunity, anti-inflammatory, analgesic and sedative hypnotic effect. Researches about cerebral protective effects of infrasound has more and more in recent years, we have made use of the8TM infrasound therapy instrument to intervene the rats after cerebral ischemia re-perfusion, the results confirmed that the low sound pressure level infrasound in the role of120minutes per day, could significantly improve the neurological symptoms, reduce infarct size, and thus play a cerebral protective effects by stimulating IGF-1secretion after seven days. Some researchers once used infrasound with8Hz90dB and130dB on rats,2h/daily,after1,7,14,21,28days respectively positively increased the number of glial cells in the hippocampal, got a conclusion that8Hz90dB and130dB infrasound could activate a large number of astrocytes cells, had a protective effect on neurons. Some others once used16Hz to130dB infrasound on rats with cerebral ischemia re-perfusion injury resulted that infrasound can reduce the volume of the rat cerebral infarction significantly and improved neurological function score. Other researchers also used low sound pressure level of infrasound on rat to observe the expression of hippocampal poly sialic acid neural cell adhesion molecule,16Hz,90dB infrasound could get the expression of PSA-NCAM increased at hippocampal, suggesting that intensity infrasound could not only cause central nervous system damage, but also the body could start the repair mechanism, enhance the ability of neural stem cell migration, and thus participate in repairing the brain injury with infrasound.Astrocyte cells have an important role in the central nervous system, accounting for about40%of the total number of normal adult brain cells. In the process of cerebral ischemia, the increase of astrocytes is one of the major changes in the central nervous system, with the growing number of astrocytes, a growing number of studies have found that astrocytes in the central nervous injury interstitial cells by maintaining ion balance, clearing the excitatory amino acid against oxidative stress, adjustment of energy metabolism and the secretion of various neurotrophic factors, such as vascular endothelial growth factor(VEGF), brain-derived neurotrophic factor(BNF), nerve growth factor(NGF), basic fibroblast cell growth factor(bFGF), protect damaged neurons, increased synaptic connections, promoted nerve repair and recovery of neurological function.Survivin is an apoptosis inhibitory protein discovered in recent years, which is the smallest member of the IAP family, the molecular weight of only16,500, primarily by inhibiting the activity of apoptotic proteins caspase-3and caspase-7and blocking the apoptotic process. Studies on expression of survivin have been reported mainly in tumors, but studies on expression of survivin with cerebral ischemia have rarely reported at home and abroad in recent years. Survivin mainly expressed in the choroid plexus, ependymal film cells, neurons, astrocytes and oligodendrocytes, glial cells in the adult nervous system survivin. In studies of rat MCAO model found that expression of survivin increased in brain tissue ischemia, ischemia surrounding region corresponding to the meninges, capillary endothelial cells, and a certain degree of regeneration of blood vessels were related with the level of survivin expression. The results showed that as a apoptosis inhibitory protein, survivin primarily inhibited the activity of apoptotic proteins caspase-3and caspase-7and blocking the apoptotic process, was one of anti-apoptotic protection mechanisms.ObjectiveTo investigate the expression of glial fibrillary acidic protein(GFAP) and survivin surrounding cerebral ischemia, the changes of behavior after ischemia re-perfusion with low sound pressure level of infrasound. In order to find evidence of the protective effects of infrasound after cerebral ischemia re-perfusion by affecting astrocytes, inhibiting neuronal apoptosis.MethodsThe model of cerebral ischemia re-perfusion in rats was induced with intraluminal middle cerebral artery occlusion (MCAO) with nylon monofilament suture. Thirty-six male adult Sprague-Dawley rats were divided into3groups:sham group (n=12),infrasound group (n=12) and model group (n=12),then all the groups were randomly divided into3,7day groups(6/group). Rats in the infrasound group were treated with infrasound for2h per day12hours after operation, the model groups were treated in the same way without opening the power,the sham groups did n’t receive any therapy. The scores (mNSS) of neurological function were scored after3days and7days treatment (before death), brain tissue slices were immunohistochemistry stained to observe the expression of GFAP and survivin around the ischemic sites after3,7days treatment.STATISTICAL METHODSThe data was compared by using SPSS13.0version statistical software. Each set of data (x±s) that fit the normal distribution of the data, the comparison between different groups by using independent samples t-test, and the significance level a=0.05.RESULTS1. The sham-operated groups were basically normal, at each time point the scores mNSS were0. The infrasound groups, model groups all had neurological deficit. Infrasound3day group compared to the model3day group the difference of the scores was not statistically significant (P>0.05); compared model7day group to model3day group, the difference of the scores was statistically significant; The scores of infrasound7day group model7day group was statistically significant (P <0.05); Scores of the infrasound7day group and scores of infrasound3days group had very significant differences (P<0.01).2. IOD of glial fibrillary acidic protein:3,7-day sham operated group a small amount of positive expression, lighter in color, the projection slender, smaller IOD. The positive expression of GFAP increased significantly, the color stained increased in each infrasound group and in the model groups,specially in the infrasound groups. Compared with the model3day group, the expression of GFAP of the model7day had statistically difference (P<0.01); the differences between infrasound groups and corresponding model groups was significant (P<0.01); the difference of infrasound7day group and the infrasound3day group was significant (P<0.01).3.The expression of survivin around ischemia after cerebral ischemia re-perfusion was strongly after3days, the expression of survivin was significantly reduced7days later, the cells of the3day model group were significantly more than that of the7day model group(P<0.01), the number of cells of the3day infrasound group was significantly more than that of the7day infrasound group (P<0.01); Compared with the3day model group, the number of survivin cells of the3day infrasound group was increased more significantly(P<0.01), Compared with the7day model group, the number of survivin cells of the7day infrasound group was also increased significantly (P<0.05)Conclusions1. Infrasound7days of treatment can significantly reduce the mNSS assessed total score, and promote the recovery of neurological function. 2. Infrasound with low sound pressure level can enhance GFAP expression after cerebral ischemia re-perfusion,especially the infrasound7days group enhanced more significantly.3. Infrasound with low sound pressure level can increase the expression of survivin, which might be one of its neuroprotective mechanisms in brain after ischemia re-perfusion4. Infrasound with low sound pressure level have neuroprotective effects on cerebral ischemia and re-perfusion in rats. |
PDF Full Text Request