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1.
The health concerns have been raised following the enormous increase in the use of wireless mobile telephones throughout the world. This investigation had been taken, with the motive to find out whether mobile phone radiations cause any in vivo effects on the frequency of micronucleated exfoliated cells in the exposed subjects. A total of 109 subjects including 85 regular mobile phone users (exposed) and 24 non-users (controls) had participated in this study. Exfoliated cells were obtained by swabbing the buccal-mucosa from exposed as well as sex–age-matched controls. One thousand exfoliated cells were screened from each individual for nuclear anomalies including micronuclei (MN), karyolysis (KL), karyorrhexis (KH), broken egg (BE) and binucleated (BN) cells. The average daily duration of exposure to mobile phone radiations is 61.26 min with an overall average duration of exposure in term of years is 2.35 years in exposed subjects along with the 9.84 ± 0.745 micronucleated cells (MNCs) and 10.72 ± 0.889 total micronuclei (TMN) as compared to zero duration of exposure along with average 3.75 ± 0.774 MNC and 4.00 ± 0.808 TMN in controls. The means are significantly different in case of MNC and TMN at 0.01% level of significance. The mean of KL in controls is 13.17 ± 2.750 and in exposed subjects is 13.06 ± 1.793. The value of means of KH in exposed subjects (1.84 ± 0.432) is slightly higher than in controls (1.42 ± 0.737). Mean frequency of broken egg is found to be more in exposed subjects (0.65 ± 0.276) as compared to controls (0.50 ± 0.217). Frequency of presence of more than one nucleus in a cell (binucleated) is also higher in exposed (2.72 ± 0.374) in comparison to controls (0.67 ± 0.231). Although there is a slight increase in mean frequency of KH, BE and BN in exposed subjects but the difference is not found statistically significant. Correlation between 0–1, 1–2, 2–3 and 3–4 years of exposure and the frequency of MNC and TMN has been calculated and found to be positively correlated.  相似文献   
2.
The mutagenicities of 17 closely related oxiranes were determined in 4 tester strains (Salmonella typhimurium TA98, TA100, TA1535, TA1537). The test compounds comprised all possible oxides of benzene and its partially hydrogenated congeners. In TA100 and TA1535, 12 of the tested oxiranes were weak to moderate mutagens. 4 of these were also active in TA98. No mutagenicity was observed with the remaining 5 compounds in any of the 4 strains.The presence of a double bond in formal conjugation with the epoxide ring increased the mutagenicity relative to that of the saturated oxirane. Interestingly, additional epoxide rings within the same molecule did not markedly increase the mutagenic activity, and for the oxiranes that are not activated by a double bond, the relationship between mutagenic activity and the number of epoxide rings in the molecule was even inverse.The influence of bromo and hydroxyl substitution on oxirane mutagenicity is discussed. Most notably, a compound having a 4-hydroxyl group in syn position to a 1,2-epoxide ring fused to the cyclohexane ring, a structure which has been suggested to increase the electrophilic reactivity of dihydrodiol epoxides through hydrogen bonding, was almost inactive.  相似文献   
3.
It is known that the endocrine system of experimental animals is susceptible to perturbation by radiofrequency (RF) radiation. Because of the recent interest in health and safety issues of cellular telephones, an experiment was designed to evaluate the effect of a 900 MHz RF radiation emitted by a Global System for Mobile radiotelephone (217 Hz impulses, one-eighth duty cycle, 2 W peak power) on human endocrine functions. Twenty healthy male volunteers aged from 19 to 40 were inducted in the present experiment. Each subject was exposed to RF radiation through the use of a cellular phone 2 h/day, 5 days/wk, for 1 month. Subjects were their own control. End points were serum adrenocorticotropin, thyrotropin, growth hormone, prolactin, luteinizing hormone, and follicle stimulating hormone concentrations. These end points were determined in nine weekly blood samples obtained starting 3 weeks before the commencement of the exposure and ending 2 weeks after exposures. All but one blood sample was drawn 48 h after each weekly session. The seventh drawing was performed the morning after the last weekly exposure. Within each individual, the preexposure hormone concentration was used as a control. Results indicated that all hormone concentrations remained within normal physiologic ranges. A difference was not noted among the nine weekly samples in five of six hormones studied. There was a significant change only in thyrotropin concentration, showing a 21% decrease on the seventh sampling. Because this change recovered fully during the postexposure period, it is concluded that 1 month of intermittent exposures to RF radiation from a cellular telephone does not induce a long-lasting or cumulative effect on the hormone secretion rate of the anterior pituitary gland in humans. Bioelectromagnetics 19:271–278, 1998. © 1998 Wiley-Liss, Inc.  相似文献   
4.
Objective: The objective was to develop effective weight‐loss methods for women who have had breast cancer, because obesity may result in an adverse prognosis. Research Methods and Procedures: This randomized pilot study tested an individualized approach toward weight loss in obese women who have had a diagnosis of breast cancer. An individualized approach was applied either alone or combined with the commercial Weight Watchers program. Forty‐eight women (body mass index of 30 to 44 kg/m2) were enrolled. Results: Weight change after 12 months of intervention was as follows (mean ± SD): 0.85 ± 6.0 kg in the control group, ?2.6 ± 5.9 kg in the Weight Watchers group, ?8.0 ± 5.5 kg in the individualized group, and ?9.4 ± 8.6 kg in the comprehensive group that used both individualized counseling and Weight Watchers. Weight loss relative to control was statistically significant in the comprehensive group 3, 6, and 12 months after randomization, whereas weight loss in the individualized group was significant only at 12 months. Weight loss of 10% or more of initial body weight was observed in 6 of 10 women in the comprehensive group at 12 months. In the comprehensive and Weight Watchers–only groups, weight loss was significantly related to frequency of attendance at Weight Watchers meetings, and attendance was more frequent in the comprehensive group. Discussion: These data indicate that the most weight loss was achieved when the counseling approach combined both Weight Watchers and individualized contacts. This was effective even though most of the individualized contacts were by telephone.  相似文献   
5.
We previously reported that electromagnetic fields (EMFs) [GSM 1800 standard (Global System for Mobile Communications, 1800 MHz)] increased sucrose permeation across the blood-brain barrier (BBB) in vitro. The cell culture model used in our previous study was comprised of rat astrocytes in coculture with porcine brain microvascular endothelial cells (PBECs). In this study, after optimization of cell culture conditions, distinctly improved barrier tightness was observed, accompanied by a loss of susceptibility to EMF-related effects on BBB permeability. Cell cultures were exposed for 1-5 days at an average specific absorption rate (SAR) of 0.3 W/kg in the identical exposure system as described before. To quantify barrier tightness, sucrose permeation across exposed PBEC was measured and compared to values of sham exposed cells and to a control group. Additionally, observations in the BBB coculture system were complemented by similar experiments using two other in vitro models, composed of PBEC monocultures with or without serum. These three models display distinctly higher barrier tightness than the previously used system. In all three BBB models, sucrose permeation across the cell layers remained unaffected by exposure to a GSM 1800 field for up to 5 days. We thus could not confirm enhanced permeability of the BBB in vitro after EMF exposure as reported before since the in vitro barrier tightness in these experiments is now more like that of the in vivo situation.  相似文献   
6.
ABSTRACT

This study investigates the effect of passenger and phone conversations on sleep-restricted driving. Six volunteers (50% male, mean age 24.8 ± 4.3 years) had their sleep restricted to 4 h in bed followed by a 20-min simulated drive on three separate occasions. Each drive included either a passenger conversation, a mobile phone conversation or a quiet passenger. The effect size of a phone conversation on lane deviation was large while passenger conversation was small. The main effect of conversation on lane deviation was non-significant (F(2,10) = 2.57, p = 0.126). Combining sleep-restricted driving with conversations warrants further investigation.  相似文献   
7.
8.
A recent study reported the results of an exploratory study of alterations of the quantitative sleep profile due to the effects of a digital mobile radio telephone. Rapid eye movement (REM) was suppressed, and the spectral power density in the 8–13 Hz frequency range during REM sleep was altered. The aim of the present study was to illuminate the influence of digital mobile radio telephone on the awake electroencephalogram (EEG) of healthy subjects. For this purpose, we investigated 34 male subjects in a single-blind cross-over design experiment by measuring spontaneous EEGs under closed-eyes condition from scalp positions C3 and C4 and comparing the effects of an active (0.05 mW/cm2) and an inactive digital mobile radio telephone (GSM) system. During exposure of nearly 3.5 min to the 900 MHz electromagnetic field pulsed at a frequency of 217 Hz and with a pulse width of 580 μs, we could not detect any difference in the awake EEGs in terms of spectral power density measures. Bioelectromagnetics 18:172–176, 1997. © 1997 Wiley-Liss, Inc.  相似文献   
9.
To carry out in vivo studies of the possible health effects of radiation from cellular telephone handsets, it is necessary to expose large numbers of small mammals at realistic power densities, modulations, and frequencies. Because even microwatt leakage could compromise the local cellular system, extreme care in shielding is required. Experimental logistics dictate, however, that the irradiated animals be easily accessed and that it be possible to irradiate them in small groups, while other groups are being loaded into or unloaded from the irradiators. This problem has been resolved by exposing the animals in aluminum-sheathed rectangular parallelepipeds, lined with microwave absorber and having doors that can be opened readily. Inside each of these microwave anechoic “chamberettes” is a vertical, four-element collinear array of dipole antennas; and around each antenna, 10 animal restrainers can be arranged like spokes on a wheel. The system has worked efficiently in studies of up to 480 rats. There is negligible coupling between antennas, and back reflection at an antenna's feed line is down 7–9 dB. Received CDMA power at the local base station is below the receiver's noise floor. Interior illumination reinforces the rats' diurnal rhythms, and the rats sleep during irradiation. Experimental logistics are excellent. In this paper, the irradiator design is presented. Bioelectromagnetics 19:459–468, 1998. © 1998 Wiley-Liss, Inc.  相似文献   
10.
Low level radio-frequency (RF) signals may produce disorientation, headache and nausea. This double blind study tested nine case-subjects, who complained of various symptoms after prolonged mobile telephone use and 21 control subjects. Each subject underwent a series of trials, in which a dummy mobile telephone exposure system was held to each ear for 30 min in (a) pulsed, (b) continuous RF emission or, (c) no emission test modes. In the active pulsed and continuous modes the same mean power as the output of a typical handset was delivered at a carrier frequency of 882 MHz and at a maximum specific absorption rate (SAR) value of 1.3 W kg(-1) (+/- 30%). In Experiment I (auditory), transient evoked otoacoustic emissions (TEOAE), which assess the outer hair cells in the inner ear, were conducted. In Experiment II (vestibular) the vestibulo-ocular reflex was recorded by video-oculography (VOG), at baseline and immediately post exposure. There were no significant TEOAE changes from baseline to post-exposure recording for any of the exposures and no significant differences in the TEOAEs' change from baseline to post exposure between cases and controls. The VOG did not identify any effect of the exposure on the vestibular end organ in either cases or controls. In conclusion, 30 min exposure to mobile phone RF did not show any immediate effects on vestibulocochlear function as measured by TEOAE and the VOR.  相似文献   
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