Objective To investigate the effects of low dose radiation on dendritic growth of newborn neurons in the hippocampus of young rat.Methods One month-old male rats were randomized into radiation group aind sham control group.Radiation group received whole brain irradiation at a single dose of 2 Gy.Retrovirus expressing green fluorescent protein (GFP) was used to label newborn neurons in the hippocampus through stereotaxic intracranial infusion.Immunofluorescence assays were performed to detect dendritic architecture alterations induced by irradiation at different time points.Results Compared with control group,the lengths of total dendrite and the longest dendrite significantly decreased at 2 and 4 weeks after irradiation (t =3.10,2.07,2.94,4.02,P ＜ 0.05).The branching points of new born neurons were also decreased significantly at 2 weeks post irradiation (t =2.23,P ＜ 0.05).The number of new born neurons reduced at 4 weeks post irradiation (t =8.43,P ＜ 0.05).Conclusions Low dose radiation could inhibit newborn neuron growth in the hippocampus of young rat,which may be one of the most important mechanisms involved in radiation-induced cognitive impairment.

Objective To investigate the inhibitory effect of the lentiviral vector (LV)-mediated RNA interference (RNAi) targeting HIF-1α on the expression of HIF-1α and Glut-1 in human pancreatic cancer Patu8988 cells.Methods The RNAi targeting HIF-1α was combined to LV,and transfected into Patu8988 cells.The Patu8988 cells transfected with the empty vector and exposed to 0.5％ O2 for 4 h served as hypoxia negative control,the Patu8988 cells not transfected with vector and exposed to 0.5％ O2 for 4 h as hypoxia blank control,and the Patu8988 cells transfected with LV-RNAi-HIF-1α and exposed to 0.5％O2 for 4 h as experimental group.The expression of HIF-1α was measured by RT-PCR and Western blot respectively.The expression of Glut-1 was measured by RT-PCR.Each group was compared according to oneway analysis of variance and two-sample t test.Results After transfection with LV-RNAi-HIF-1α,HIF-1α mRNA expression decreased by 65.1％ (0.209/0.321) and 80.6％ (0.791/0.982) (t=10.52,15.24,both P＜0.05) under normoxia and hypoxia conditions,meanwhile with the empty vector,HIF-1α mRNA expression decreased by 0.6％ (0.002/0.321) and 7.2％ (0.071/0.982) (t =5.26,7.38,both P＜0.05).Under hypoxia conditions,the protein of HIF-1α in experimental group cells (0.159±0.010) was down-regulated obviously compared to the negative control group (0.745± 0.012) and the blank control group (0.711 ± 0.023)(F=35.52,t =6.72,10.56,all P＜0.05).The expression of Glut-1 mRNA in experimental group cells (0.040±0.003) decreased obviously compared to the negative control group (0.054±0.003) and blank control group (0.062±0.004) (F=35.28,t=5.94,8.55,all P＜0.01).Conclusion Gene silencing of HIF-1α using LV-mediated RNAi can inhibit the expression of HIF-1α and decrease the expression of Glut-1mRNA in Patu8988 cells.

Objective: To analyze the epidemiological and etiological characteristics of aggregation epidemics of infectious diarrhea induced by norovirus, and to provide the scientific basis for the prevention and control. Methods: A descriptive epidemiological analysis of aggregation epidemics events occurred during 2016-2018 in Longhua District of Shenzhen was carried out, with subtypes identified by real-time fluorescence quantitative PCR, Region B and Region C fragment sequence determination. Results: There were 34 aggregation epidemic events,including 448 cases, the mean attack rate was 18.26%(448/2 454). The median duration of aggregation epidemic was 3 days. The peak season appeared in autumn and winter, and the peak of epidemic emerged from December 2016 to April 2017. About 91.18% (31/34) of the epidemics occurred in schools and child care centers, and among children aged 3-6 years (78.79%, 353/448). The clinical symptoms were mainly nausea and vomiting (95.77%, 408/426) in children and adolescents but diarrhea in adult group (95.45%, 21/22). The differences between vomiting and diarrhea were both statistically significant in the two age groups (χ2=98.89，99.61，P<0.01). 29 cases were transmitted through interpersonal network, of which 21 cases were found to have unregulated treatment of vomit on campus. The detection rate of biological samples was 49.15% (203/413), all of which were G Ⅱ norovirus. The genotype was mainly GⅡ.P16-G Ⅱ.2(n=49)from November 2016 to April 2017. Conclusion Norovirus can cause large-scale outbreaks in child care centers and schools easily. Early standardized patient isolation and proper management of vomit and diarrhea are the key steps in prevention and control measures.

Objective: To analyze the clinical features of perianal condyloma acuminatum in HIV infected men who have sex with men (MSM) and assess the effects of combined treatment of microwave and photodynamic therapy. Methods: Clinical and laboratory data of 260 male patients with perianal condyloma acuminatum were collected and microwave combined with photodynamic therapy was applied on them. Results: The majority of the patients with perianal condyloma acuminatum were young people (243/260). Warts were mainly located in the anus or from the outside to inside of the anus (245/260). Among them, the proportion of warts position of extraanal in HIV-infected group (8/220) was lower than that of non-HIV-infected group (7/40). HPV types 11 (70/118), 6 (44/118) and 16 (40/118) were the most common types of HPV infection. People with HIV infection were more likely to develop high-risk, mixed types HPV infection and multiple HPV infection than those without HIV infection. More than half of the patients (146/260) needed only 1-3 sessions of photodynamic treatments. There was no significant difference in the times of photodynamic treatments and the numbers of photosensitizers required between the HIV-infected and non-HIV-infected groups. The recurrence rate of HIV-infected group (13.6%, 30/220) was also similar to that of non-HIV-infected group (15.0%, 6/40), but far lower than those who underwent microwave therapy alone (45%, 18/40). Conclusions The combination therapy significantly reduced the recurrence rate of perianal condyloma acuminatum in HIV infected MSM.

Objective To explore the effects of various radiation doses on the NFAT3/c4 signaling pathway and the improvement effect of exogenous brain-derived neurotrophic factor(BDNF)on this pathway. Methods Four groups of one-month-old Sprague-Dawley rats received radiation doses of 0,2,10,and 20 Gy, respectively, in a single radiation. At three days after radiation, exogenous BDNF was injected stereotaxically into the bilateral hippocampus. Western blotting and RT-PCR were used to assess the levels of NFAT3/c4-related proteins in the hippocampus. Results The results of Western blotting and RT-PCR showed that the level of NFAT3/c4 was reduced in a dose-and time-dependent manner after ionizing radiation. Compared with the radiation alone group,the ionizing radiation plus BDNF group had significantly increased levels of NFAT3/c4 and CaN with increases in radiation dose and time. Conclusions Whole brain radiotherapy inhibits the CaN/NFAT3/c4 signaling pathway. Exogenous BDNF can promote the NFAT-dependent transcription and then improve the cognitive function.