Effects of high-frequency electromagnetic field on morphology of hippocampal cells in female rats / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To analyze the effects of high-frequency electromagnetic field (HF-EMF, 30 MHz, 0-1600 V/m) on the apoptosis and ultramicrostructure of the hippocamp and demonstrate the cytotoxicity of hippocamp.</p><p><b>METHODS</b>120 Wistar female adult rats were randomly divided into ten groups based on body weight with different levels of 30 MHz electromagnetic field (0, 25, 100, 400, 1600 V/m) for eight hours daily. Five group rats were irradiated for three days. The other five group rats were irradiated for fifty-six days. Weekly the rats were continuously exposed five days. The apoptotic rate of the hippocamp was detected with TUNEL System. Meanwhile, the ultramicrostructure was observed with the transmission electron microscope.</p><p><b>RESULTS</b>(1) There was no significant difference on the apoptotic rate and pathological change of the hippocamp cell between the exposure and the control groups through short term experiment (P > 0.05). (2) The apoptotic rate of the granulocyte on the DG campus of the hippocamp in the 400 V/m group and the 1600 V/m group (0.165% +/- 0.049%, 0.189% +/- 0.049% respectively) were increased significantly (P < 0.01) through inferior chronic experiment compared with the control group (0.052% +/- 0.016%). Along with the increase of radiation dose, the ultramicrostructure of the neuron cell appeared more abnormal cells. Especially there were marked change on the neuron in the 1600 V/m group.</p><p><b>CONCLUSIONS</b>There is no association between cell apoptotic rate of the hippocamp and short period exposure to HF-EMF (30 MHz, 25-1600 V/m). However inferior chronic exposures to HF-EMF might induce the cytotoxicity, especially in the high dose exposure (1600 V/m) under our experiment.</p>

Female genital toxicities of high-frequency electromagnetic field on rats / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study on the effects of sub-chronic exposures to high-frequency electromagnetic field (HF-EMF) on the estrous cycle, ovarian pathological changes and related hormones and preliminarily investigate the female genital toxicities of HF-EMF in rats.</p><p><b>METHODS</b>60 Wistar female adult rats were randomly divided into five groups based on body weight and radiated with different levels of 30 MHz electromagnetic field (0, 25, 100, 400 and 1600 V/m) for eight hours daily. Weekly the rats were continuously exposed five days. From the 48th day the four stage of estrus cycle were observed with smear method of the vaginal cell. Fifty-six days later the serum levels of sexual hormones were detected with the radioimmunoassay on estrus stage. The constituent ratio of the distinct follicle number on ovaries were observed with the HE staining and the ultrastructure was observed with the transmission electron microscope. Meanwhile, the ovarian humid weight and organ coefficient were observed.</p><p><b>RESULTS</b>There was no significant difference in ovarian humid weight and organ coefficient between the exposure and the control groups. The time of proestrus in the 100 V/m group, the 400 V/m group and the 1600 V/m group was decreased significantly [(15.00 +/- 5.06), (11.40 +/- 2.05) and (10.56 +/- 0.96) h in the exposure group compared with (18.70 +/- 2.96) h in the control group, P < 0.01], and the time of Anestrum in the 400 V/m group and the 1600 V/m group were increased significantly [(101.20 +/- 17.81) and (115.33 +/- 19.28) h in the exposure group compared with (69.80 +/- 11.42) h in the control group, P < 0.01)]. Serum LH in the 400 V/m and 1600 V/m group was increased significantly [(11.02 +/- 1.11) and (14.70 +/- 1.94) mU/ml in the exposure groups compared with (8.70 +/- 0.53) mU/ml in the control group, P < 0.01], and serum E2 was decreased significantly [(57.16 +/- 31.56) and (50.57 +/- 25.16) pg/ml in the exposure groups compared with (95.04 +/- 32.62) pg/ml in the control group, P < 0.01]. The composition ratio of the corpus luteum/albicans number in the 400 V/m group and the 1600 V/m group was increased significantly (19.75% and 19.04% in the exposure groups compared with 14.01% in the control group, P < 0.05). The composition ratio of the atretic follicle number was increased significantly in the 100 V/m, the 400 V/m and the 1600 V/m group (8.45%, 9.95% and 11.70% in the exposure groups compared with 7.72% in the control group, P < 0.01). The composition ratio of the mature follicle and the pri/sec follicle was decreased significantly in the 400 V/m and the 1600 V/m group (1.50% and 1.55% in the exposure groups compared with 3.36% in the control group. 22.24% and 21.09% in the exposure groups compared with 26.60% in the control group, P < 0.01). Along with the increase of radiation dose, the ultrastructure of cell on the ovaries appeared more abnormal.</p><p><b>CONCLUSIONS</b>The toxicities of female gonads are closely associated with exposures to HF-EMF. The nonage damage of female gonadal toxicities might emerge on the ovaries.</p>

Study on the epidemiology and etiologic agent of Dengue fever outbreaks in Fuzhou in 2004 / 中华流行病学杂志

<p><b>OBJECTIVE</b>To study the epidemiology and etiologic characteristics of a Dengue fever outbreak in Fuzhou from the beginning of September to the end of October in 2004 in order to understand the source of infection.</p><p><b>METHODS</b>Data on descriptive epidemiology was collected to study the characteristics and related factors to the epidemic. Dengue virus was isolated through the use of C6/36 cell line while viral serotypes were identified by indirect immunofluorecent assay with type-specific monoclonal antibody. The sources of infection were traced by nucleotide sequencing.</p><p><b>RESULTS</b>During the epidemic, 93 cases occured consistently with the region entomoplily growth and decay. The viruses of 6 strains isolated from 10 patients' blood specimens were identified as dengue virus type 1. Phylogenetic evidence suggested that the viral isolate had high genetic relation with the isolates from Kampuchea (DENV-1/KHM/2001; GenBank Accession No. L0904278).</p><p><b>CONCLUSION</b>The epidemic was caused by introduction of patients migrating into Fuzhou.</p>