| Herpes Simplex encephalitis( HSE) accounts for 10%～20% of acute viral encephalitis which is a sporadic, non-epidemic and the most common viral encephalitis in adults. If untreated, the mortality will be approximately 60%～80%. About 20% is directly caused by the primary infection, while most of the disease occur when the latent virus is reactivated. Although the latency rate in population is as high as 70%, the mechanism of reactivation is still unclear. The vulnerability of the human body, the strain and virulence of the virus and the immune response to the various stimuli, might be invloved. The nonspecific response of the body to abnormal stimulation is called stress. Either insufficient or over responce leads to diseases. In present, more attentions are focused on the relationship between stress and stress-related disorders, including the important event stress, disastrous stress and mental stress, etc. Some experiments have already confirmed the causality. The investigation of the reactivated infection of this virus abroad is limited on the heat stress, in vitro. We haven't seen any similar report in China yet. It is not clear, whether some other stresses can also trigger HSE. This study aimed to explore the causality between different stresses and reactivation of HSV. It also intended to investigate the pathogenesis of reactivated infection of this virus in brain for preventing and controlling HSE in time. It was divided into four parts: (?) establishment of HSV-1 latent infection model; (??) detection of HSV-1 latent infection in brain;(???) exploration for the reactivated infection of this virus induced by various stresses;(????) observation of the activated infection in brain after heat stress. Main methods and techniques 1. Sixty-nine Balb/c mice were divided into 4 groups randomly: intranasal group(IN), ocular abrasion group(OC), intraperitoneal injection group(IP) and normal control group(N) and then were inoculated with HSV-1 F strain, respectively. Four weeks later the trigeminal ganglias (TG) were removed to detect the expression of HSV-1 antigen and the HSV DNA segment by PCR to identify the existence of latent infection. In order to find out the ideal method to establish the model, the latency incidence and mortality rate among the three groups were compared. 2. Ten samples of RNA and DNA from above were collected. PCR and RT-PCR assay were used to detect the DNA segment of HSV and LAT mRNA expression, respectively in TG, temporal lobe of brain, cerebelleum and brain stem. The positive production of LAT mRNA was assayed by semi-quantitave method for exploring the difference of reactivated incidence between brain and TG. 3. Seventy-seven HSV-1 latent infection mice were exposed to hyperthermia, coldness, fatigue and immunosuppressant, respectively. Thirty-two(HS) were given 42 ℃ heat treatment for 15min , and then were divided into 12h, 24h, 36h and 48h groups after stress. Fifteen(CS) were exposed in 4 ℃ for 12hours, 15(FS) were made intermitted swimming for 12hours and other 15(CP) were injected cyclophosphamide once a day for five days. Then immunohistochemistry and RT-PCR assay were used to detect the expression of HSV-1 antigens, ICP4 mRNA in TG in mice respectively, so as to determine the existence of reactivation of this virus in mice after stress. 4. Forty-five mice were divided into 4 groups randomly: heat stress group(HS, n=25), according to the time after heat stress it was further divided into 5 groups(12h,36h,72h,5d and 7d, n=5), then were given 42℃ treatment for 15min; stress control group(HS-C, n=5); HSE group, n=5; normal group(N, n=5). The weight measure, neurological assessment and behavioral tests were done to evaluate the clinical character of the mice in different groups. After evaluation, the mice in heat stress and HSE group were killed, then expression of HSV antigen in brain was detected by immunofluorescence and immunochemistry method. Main Results 1. Methods of intranasal inoculation, ocular abrasion and intraperitoneal injection succeeded to establi...
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