动物造模,微波辐射 z-bo 2020-09-08 396

　　Introduction: Microwave (MWS) is a subgroup of electromagnetic waves between 300 MHz and 300 GHz. Many modern devices, such as cellular phone transmitters and receivers, radars, broadcast television transmitters, and video display terminals transmit MWS. In recent years, the application of these devices has increased dramatically, causing the public to have harmful effects on human health. In fact, it has been confirmed that MWS affects the biological functions of organisms at the cellular and molecular levels. MWS can generate heat in the organism, which in turn has health effects. They may also affect cell growth, cell cycle progression, and DNA synthesis through unknown non-thermal mechanisms. Due to its natural sensitivity to radiation, after experimental MW exposure, possible complications of the eye were evaluated. In fact, cataract is the most common complication of MW wave exposure. Previous studies have shown the effect of the thermal effect of MWS on the occurrence of cataracts. However, recent studies have emphasized the possible role of the non-thermal effects of MWS in cataract formation. Despite extensive research on MWS and cataracts, the possible effects of MWS on the retina have not been evaluated in detail. So far, with the widespread use of mobile phones, there are strong reasons to determine the harmful effects of MWS emitted from these devices on health. Due to the way they are used, mobile phones are usually kept near the eyes for several hours a day. Considering its fine structure, the eyes may be the main part of injury caused by these devices.

　　Method: Animal: Considering the fine structure of the eye, it may be the main part of the injury. Our purpose is to evaluate the possible side effects of mobile phone simulated MWS on rabbit retina. Place the rabbit in a controlled environment with suitable temperature (23℃～25℃), ventilation and 12-hour on/off light cycle. Eat and drink freely.

　　Microwave radiation: The Global System for Mobile Communications (GSM) mobile phone simulator is designed for MW radiation. The frequency of the device is set at 915 MHz, and the transmitter power (circular spatial distribution) of the generator is fixed at 2 W during the exposure period. Prior to the study, all equipment was checked and controlled in the laboratory to ensure that they produced a constant wavelength for the duration of the study. After measuring the baseline ERG, the rabbits were randomly divided into five groups (8 in each group). Treatment group: Group 1: No radiation (sham operation); Group 2: Radiation from 10 cm for 1 day; Group 3, Radiation from 30 cm 1 day; Group 4, 3 days from 10cm radiation; Group 5, 3 days from 30cm radiation. In order to ensure that the rabbits receive MW irradiation as planned, each rabbit is confined in a restrictor during the irradiation period and the device is placed in front of the animal's head (the above distance is measured after the animal's eyes are put in). The radiation dose is trying to be set similar to a regular GSM mobile phone. When the device is used on the ear for a voice call (10 cm) or as a video call (30 cm), set the distance according to the usual distance between the device and the human eye. Choose the exposure time (1 VS3 days) to simulate an exaggerated exposure, which may produce positive results.

　　Inspection: After anesthesia and pupil dilation, scotopic and photopic electroretinogram (ERG) responses were obtained at baseline and 7 days after exposure. The rabbits are dark adapted for at least 1 hour and anesthetized 10 minutes before the ERG recording. All rabbits underwent ERG recordings under general anesthesia induced by intramuscular injection of ketamine (35 mg/kg) and thiazide hydrochloride (5 mg/kg). Topical use of 0.1% tropicamide and 2.5% epinephrine hydrochloride to dilate pupils. Record and analyze the following ERG parameters: dark wave B wave amplitude, combined A wave amplitude, combined B wave amplitude, photopic B wave amplitude, 30 Hz flicker N1P1 amplitude, and 30 Hz flicker P1 implicit time. The animals were euthanized with an overdose of pentobarbital (200 mg) intracardiac immediately after performing ERG 1 week later. Then the eyeballs were removed and fixed in 10% formalin for 24 hours. After the gross examination, the optic nerve head and macula were sectioned and evaluated with hematoxylin and eosin staining light microscope.

　　Result: Summarize the ERG response of all groups at baseline and after treatment. The baseline average ERG parameters of each index are statistically different. The corresponding p value is given from the statistical analysis. The photopic and dark ERG responses obtained 7 days after irradiation did not show statistically significant differences between the groups. Due to the high variation of ERG records in the normal population, (except for the average difference in the graph and table), we also compare each record with the baseline to explore whether there is a change of more than 50%. Pathological examination was normal, with no signs of degeneration or infiltration. The tissue section of the ciliary body showed hyperemia of the ciliary body after MW irradiation. Group 1, 0%; Group 2, 50%; Group 3, 501%, Group 4, 87.5%; Group 5, 87.5%. The ciliary body contains ciliary muscle, blood vessels, and fibrous connective tissue. In normal eyes, there are scattered red blood cells in a small number of blood vessels in the ciliary body. Congestion means excess blood.

　　Discussion: A much higher MW intensity than GSM mobile phones was used, which is simulated in the current work. A study on the human eye to assess the harmful functional effects of MW. To study the potential impact of radio frequency (RF) exposure on the human eye. A GSM signal of 902.4 MHz (pulse of 217 Hz) was applied to the subject. Use the visual discrimination threshold as a functional parameter to evaluate the influence of the GSM signal. Comparing the data obtained from the RF-exposed eyes with the data obtained from the false-exposed eyes, no statistically significant difference was found in the visual discrimination threshold. Although they only evaluated the functional effects of GSM signals, their application frequencies are similar to our research (902.4 MHz and 915 MHz), and their results support our findings. Histopathological examination revealed that the retina was normal after MW exposure, with no signs of degeneration or infiltration. . It has been confirmed that MW-induced hyperthermia (2.45 GHz) can cause damage to the retina and retinal pigment epithelium and scar formation without significant damage to the sclera and choroid. In another study, the in vitro effect of 2450 MHz MW on retinal ganglion cells was evaluated and demonstrated dose-dependent damage to these cells. In the above two histopathological studies, MW with a frequency of 2450 MHz was used. Compared with the above research, we used the MW frequency and intensity similar to GSM mobile phones, and we did not find a significant adverse effect on the histopathological examination of the retina. Another important finding of this study is the dose-dependent rate of ciliary body filling with MW radiation. The ciliary body is involved in several important functions of the eye, such as regulation and secretion of aqueous humor. Ciliary body inflammation or spasm is an important source of eye pain and headaches such as traumatic iritis, uveitis, and untreated presbyopia. The clinical relevance of the findings is currently unclear, and future studies may evaluate ciliary body hyperemia as a possible explanation for some cell phone-related headaches.

　　Conclusion: Our research results show that the distance, duration, and dose of MW radiation simulated by mobile phones have no obvious adverse effects on retinal tissue slices in this study. However, hyperemia of the ciliary body was observed in animals that received more doses of MW radiation. Regarding the findings of ERG, although there was no significant difference in the average electroretinogram value after treatment, compared with the control group, the MW-irradiated eyes had a greater statistical trend. Therefore, future studies with larger sample sizes are needed to further evaluate the effects of MW radiation on the eyes. Further research will also help clarify the effects of long-term exposure.