Objective To study the effect of integrin β1 antisense oligodeoxynucleotide(ASODN)on the expression of F-actin in ECV-304 ceils exposed to infrasound,and to explore the pathway of infrasound signal transfer into the cells.Methods integrin β1 oligodeoxynucleotides were embedded in cationic liposome lipofectamine 2000 reagent and transfected into ECV-304 cells.Laser scanning confoeal microscopv was used to observe F-actin's expression when the cells were exposed to 16 Hz infrasound at 130 dB for 2 h.The cells' average fluorescence was examined using spectrofluorimetric quantification after immunofluorescent staining. Results Among the three false exposure groups,most fluorescein-labelled substances in the cells were in a diffuse state.There were few actin filaments,and they were tenuous and short, without direction.The cells' fluorescence intensities were almost the same.In a group exposed to infrasound,F-actin was thick and long with a longitudinal arrangement.Fluorescence intensities were strong.However,less F-actin expression was observed in the ceils of the ASODN group exposed to infrasound compared with the others similarly exposed.Correspondingly.F-actin expression in the ASODN group exposed to infrasound was almost the same as in the other exposed group.Conclusion F-actin expression can be increased in ECV-304 cells by infrasound exposure,but integrin β1 ASODN may partially inhibit its expression.The extraeellular matrix-integrin-cytoskeleton may be one of the transduetion pathways for infrasound signals into the cells.

Objective To observe the expression of polysialic acid-neural cell adhesion molecule (PSA-NCAM) in the rat hippocampus after infrasound exposure. Methods Ninety-six Sprague-Dawley rats were random-ized into a 16 Hz 130 dB infrasound exposure group (n =72) and a control group (n =24). Rats of the infrasound exposure group were exposed to 16 Hz 130 dB infrasound in a barochamber 2 h/d for 1, 7, 14 and 21 d. The rats' brains were removed and immunohistochemieal methods were used to detect the expression of PSA-NCAM in the hip-pocampus on the 1st, 7th, 14th, and 21st day during treatment and on the lat, 7th, and 14th day after the treatment ended. Results The expression of PSA-NCAM in the rats' hippocampuses increased after exposure for 1 d, reached its peak at the 14th day, then had decreased by the 21st day but remained at a higher level than in the controls (P≤ 0.05). Conclusion The expression of PSA-NCAM in the rat hippocampus is increased by exposure to 16 Hz 130 dB infrasound, but the levels recover somewhat after infrasound exposure ends. lnfrasound could induce neural injury and promote the migration of neural stem cells. PSA-NCAM might participate in the repair of neural injuries re-suiting from infrasound exposure.

Objective To study the effect of 16 Hz infrasound on the proliferation of the neural stem cells in rats' hippocampus.Methods72 SD rats were randomized into 16 Hz-130 dB infrasound exposure group(n=24),16 Hz-90 dB infrasound exposure group(n=24)and control group(n=24).Rats of the infrasound exposure groups were exposed to 16Hz 90dB/130dB infrasound barochamber system,2 h/d for 1 d,7 d,14 d,or 21 d.Their brains were removed and anti-nestin immunohistochemistry was used to observe the neural stem cells in rats' hippocampus.ResultsThe expression of nestin in rats' hippocampus increased after exposure for once and increased with the exposure time.It reached its peak on the 14th day,decreased on the 21st day but remained higher level.The reaction of 90 dB group was weaker than that of 130 dB group.ConclusionThe brain injuries result from 16 Hz infrasound exposure can enhance the proliferation of neural stem cells in rats' hippocampus which might participate in the repair of neural injuries.

ObjectiveTo study the effects of Jiawei Buyang Huanwu Decoction on learning and memory abilities of mice exposed to 130 dB infrasound (16 Hz). Methods80 BALB/c mice were divided into blank-control group, infrasound-control group, infrasound and drug-treated group (it was divided into 3 sub-groups according to dose). Learning and memory abilities were measured 14 d later. ResultsCompared with blank-control group, learning and memory abilities decreased (P<0.05) in infrasound-control group. Compared with infrasound-control group, learning and memory abilities increased(P<0.01) in infrasound and drug-treated group. Conclusion16 Hz,130 dB infrasound could damage learning and memory abilities. Jiawei Buyang Huanwu Decoction could protect mice from learning and memory harm exposed to the infrasound.

Objective To study the effects of Jia Wei Bu Yang Huan Wu decoction on learning and memory abilities, superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX) activities and the contents of malondialdehyde (MDA) in mice exposed to 16 Hz,130 dB infrasound. Methods Fifty BALB/c mice were divided into a control group (group C), an infrasound-control group (IC group), an infrasound and drug-treated group (ID group). Learning and memory abilities,SOD and GSH-PX activities and MDA contents were measured 14 d after corresponding treatment. Results Compared with those in group C, learning and memory abilities was significantly decreased(P0.05)in IC group. Compared with those in IC group, learning and memory abilities was increased(P

0.05),but there are increases of that in 90dB/7d ( P 0.05). Conclusion The results showed that 8Hz, 90dB/130dB infrasound definitely induced increases of apoptosis ratio in the hippocampus cells after certain time of exposure, suggesting that there are damages occurred by infrasound field with 90dB or 130dB and some adaptation of the hippocampal cells ensued after a certain period of time.

Objective To study the effect of 8Hz infrasound on the expression of 5-HTR of hippocampus and temporal cortex in rats. Methods SD rats were exposed to 8Hz, 90dB,100dB or 130dB infrasound, respectively for 2 hours daily. Then the rats' brains were taken and given stained immunohistochemically for (5-hydroxy tryptamine receptor,5-HTR). The content of 5-HTR in hippocampus and temporal cortex were detected under an optical microscope. Results The animals in the infrasound groups had less expression of 5-HTR in hippocampus and temporal cortex, and the least were at the 35th day for 90dB group and 100dB group and the 28th day for 130dB group (P

Objective To observe the effects of infrasound on rat myocardial cells and to study its underlying mechanism. Methods One hundred Sprague-Dawley rats were divided into a normal control group and a infrasound exposure group, composed of various subgroups subject to exposure to infrasound for 2 hours daily for 1 d,7 d,14 d,21 d,and 28 d, respectively. The ultra-microstructure and apoptosis of the rat myocardial cells were observed, and SOD and MDA were measured. Results After exposure to infrasound, significant ultra-microstructural impairment and increased apoptosis of the myocardial cells were observed in the infrasound exposure group as compared to those of the normal control group,(P

Objective To explore the effects of infrasound frequency and intensity on gastric emptying in rats. Methods One hundred and forty rats were randomly divided into a control group, and groups receiving 8 Hz-90 dB, 8 Hz-130 dB and 16 Hz-130 dB infrasound. Another 70 rats were randomly divided into a control group and an exposure group continuously stimulated with infrasound at 8 Hz and 130 dB. The control group again was not exposed. The gastric emptying rate of the rats in all the groups was tested at different time points. Results ①Compared with the control group, gastric emptying rate decreased significantly after exposure to infrasound for 7 or 14 days. After exposure for 1 day, no significant difference was found. After exposure for 7 , 14, 21 or 28 days, gastric emptying decreased significantly more in the 8 Hz-130 dB group than in the 8 Hz-90 dB group or the control group. ②Compared with the controls, gastric emptying decreased in the 16 Hz-130 dB group after exposure for 1 , 7 and 14 days, but there was no significant difference between these two groups after 21 or 28 days. Gastric emptying decreased significantly more at 8 Hz-130 dB than at 16 Hz-130 dB after exposure for 14 or 28 days.③Gastric emptying tended to recover after exposure of 14 days to 8 Hz-130 dB infrasound, but compared with the controls, gastric emptying was still reduced after exposure had been stopped for 1 , 7 , 14, 21 and 28 days. Conclusion Infrasound at 8 Hz-90 dB, 8 Hz-130 dB or 16 Hz-130 dB can restrain stomach emptying. The extent of the reduction is closely related to the frequency, intensity and exposure time. Gastric emptying tends to recover after infra-sound exposure is stopped.

Objective To further investigate the threshold value and the dose-effect relationship of infrasound on the rat pallium, and to observe the effects on the pallium's ultrastructure. Methods Rats were exposed to 16 Hz, 90 dB infrasound for 2 hours daily. With a transmission electron microscope, changes in the ultrastructure of the cortex of the rats' parietal lobes were observed 2 hours, 3 days and 7 days after the treatment. Results There were no changes in the ultrastructure of the pallium in rats which had been exposed for 7 days or 14 days. Denaturation appeared when the rats had been exposed for 21 days, 28 days or 35 days. Denaturation become more serious as the exposure time increased beyond 21 days. Denaturation and damage gradually returned to normal with time after exposure. Conclusion 16 Hz, 90 dB infrasound exposure over an extended time may cause denaturation and other changes in the ultrastructure of the pallium in rats. Such changes can return to normal with time.