Estimation of RF energy absorbed in the brain from mobile phones in the Interphone Study.

OBJECTIVES: The objective of this study was to develop an estimate of a radio frequency (RF) dose as the amount of mobile phone RF energy absorbed at the location of a brain tumour, for use in the Interphone Epidemiological Study. METHODS: We systematically evaluated and quantified all the main parameters thought to influence the amount of specific RF energy absorbed in the brain from mobile telephone use. For this, we identified the likely important determinants of RF specific energy absorption rate during protocol and questionnaire design, we collected information from study subjects, network operators and laboratories involved in specific energy absorption rate measurements and we studied potential modifiers of phone output through the use of software-modified phones. Data collected were analysed to assess the relative importance of the different factors, leading to the development of an algorithm to evaluate the total cumulative specific RF energy (in joules per kilogram), or dose, absorbed at a particular location in the brain. This algorithm was applied to Interphone Study subjects in five countries. RESULTS: The main determinants of total cumulative specific RF energy from mobile phones were communication system and frequency band, location in the brain and amount and duration of mobile phone use. Though there was substantial agreement between categorisation of subjects by cumulative specific RF energy and cumulative call time, misclassification was non-negligible, particularly at higher frequency bands. Factors such as adaptive power control (except in Code Division Multiple Access networks), discontinuous transmission and conditions of phone use were found to have a relatively minor influence on total cumulative specific RF energy. CONCLUSIONS: While amount and duration of use are important determinants of RF dose in the brain, their impact can be substantially modified by communication system, frequency band and location in the brain. It is important to take these into account in analyses of risk of brain tumours from RF exposure from mobile phones.

Expression and rearrangement of the alpha, beta, and gamma chain genes of the T cell receptor in cloned murine large granular lymphocyte lines. No correlation with the cytotoxic spectrum.

Using cloned murine large granular lymphocyte (LGL) lines, the expression and the rearrangement of the alpha, beta, and gamma chain genes of the T cell receptor (TCR) were analyzed. Morphological, phenotypical, as well as functional studies indicated that the LGL lines were identical to normal, endogenous NK cells. Northern blot hybridization analysis indicated that the full-length transcripts of all the alpha, beta, and gamma chain genes were expressed in most of the LGL lines, including two lines derived from athymic nude mice. In one line, SPB, however, no transcript of the gamma chain gene was detected, whereas the alpha and beta chain genes were clearly expressed. In every LGL line studied, all of the alpha, beta, and gamma chain genes were rearranged. Conforming to the results of Northern blot hybridization study, the gamma chain gene of the SPB line was aberrantly rearranged, whereas those of all the other lines were productively rearranged. The results clearly revealed that NK cells represented a population of lymphocytes genetically committed to the T cell lineage. It was also suggested that the expression and rearrangement of the TCR genes of NK cells might occur in a thymus-independent fashion. An SPB line without expression of the gamma chain gene could exhibit NK activity indistinguishable from other NK lines. Furthermore, the rearrangement patterns of the beta chain gene did not correlate with the specificity of the cytotoxic activity. These results strongly suggested that the cytotoxic activity in NK cells was not directly mediated by TCR on them. We particularly noted that the beta chain gene of most independently established LGL lines showed identical patterns of rearrangement, indicating that they used the same V beta and J beta gene segments. The significance of the restricted pattern of rearrangement of the beta chain gene in LGL lines, as well as the possible functional roles of TCR on NK cells, was discussed.

A girl with acute encephalitis followed by acute cerebellitis/cerebellopathy.

OBJECTIVE: The purpose of this study is to bring attention to a case of acute encephalitis not concurrent with acute cerebellitis. CASE PRESENTATION: Five days after onset of common cold symptoms, a 17-months-old girl suffered convulsions, vomiting and respiratory arrest. On exam, she had pharyngeal inflammation, brisk deep tendon reflexes, respiratory acidosis, leukocytosis, negative rapid antigen tests, and segmental pneumonia. Brain CT and MRI/MRA were negative, and EEG was consistent with acute encephalitis. Following hypothermic therapy, methylprednisolone pulse therapy and cefotaxime, she recovered. Four days after discharge, she sustained limb and truncal ataxia associated with normal EEG, followed by bilateral intention tremor. Blood and CSF chemistry and cell counts were normal. Brain MRI revealed high intensity signals in the dentate nuclei and enhancement in the cerebellar white matter, suggestive of acute cerebellitis/cerebellopathy. SPECT imaging showed reduced blood flow in the cerebellum, right thalamus and brain stem. Following short-term administration of g-globulin and prednisolone, she regained her ability to sit and, eventually, to walk. Four months after initial presentation, her brain MRI was normal. No relapse has occurred in 5 years. CONCLUSIONS: The uncommon sequential development of acute encephalitis followed by acute cerebellitis suggests an immune-mediated cerebellar ataxia.

Distribution of RF energy emitted by mobile phones in anatomical structures of the brain.

The rapid worldwide increase in mobile phone use in the last decade has generated considerable interest in possible carcinogenic effects of radio frequency (RF). Because exposure to RF from phones is localized, if a risk exists it is likely to be greatest for tumours in regions with greatest energy absorption. The objective of the current paper was to characterize the spatial distribution of RF energy in the brain, using results of measurements made in two laboratories on 110 phones used in Europe or Japan. Most (97-99% depending on frequency) appears to be absorbed in the brain hemisphere on the side where the phone is used, mainly (50-60%) in the temporal lobe. The average relative SAR is highest in the temporal lobe (6-15%, depending on frequency, of the spatial peak SAR in the most exposed region of the brain) and the cerebellum (2-10%) and decreases very rapidly with increasing depth, particularly at higher frequencies. The SAR distribution appears to be fairly similar across phone models, between older and newer phones and between phones with different antenna types and positions. Analyses of risk by location of tumour are therefore important for the interpretation of results of studies of brain tumours in relation to mobile phone use.

Adult-born dentate granule cell excitability depends on the interaction of neuron age, ontogenetic age and experience.

Early during their maturation, adult-born dentate granule cells (aDGCs) are particularly excitable, but eventually develop the electrophysiologically quiet properties of mature cells. However, the stability versus plasticity of this quiet state across time and experience remains unresolved. By birthdating two populations of aDGCs across different animal ages, we found for 10-month-old rats the expected reduction in excitability across cells aged 4-12 weeks, as determined by Egr1 immunoreactivity. Unexpectedly, cells 35 weeks old (after genesis at an animal age of 2 months) were as excitable as 4-week-old cells, in the dorsal hippocampus. This high level of excitability at maturity was specific for cells born in animals 2 months of age, as cells born later in life did not show this effect. Importantly, excitability states were not fixed once maturity was gained, but were enhanced by enriched environment exposure or LTP induction, indicating that any maturational decrease in excitability can be compensated by experience. These data reveal the importance of the animal's age for aDGC excitability, and emphasize their prolonged capability for plasticity during adulthood.

Mobile phone use and acoustic neuroma risk in Japan.

OBJECTIVES: The rapid increase of mobile phone use has increased public concern about its possible health effects in Japan, where the mobile phone system is unique in the characteristics of its signal transmission. To examine the relation between mobile phone use and acoustic neuroma, a case-control study was initiated. METHODS: The study followed the common, core protocol of the international collaborative study, INTERPHONE. A prospective case recruitment was done in Japan for 2000-04. One hundred and one acoustic neuroma cases, who were 30-69 years of age and resided in the Tokyo area, and 339 age, sex, and residency matched controls were interviewed using a common computer assisted personal interview system. Education and marital status adjusted odds ratio was calculated with a conditional logistic regression analysis. RESULTS: Fifty one cases (52.6%) and 192 controls (58.2%) were regular mobile phone users on the reference date, which was set as one year before the diagnosis, and no significant increase of acoustic neuroma risk was observed, with the odds ratio (OR) being 0.73 (95% CI 0.43 to 1.23). No exposure related increase in the risk of acoustic neuroma was observed when the cumulative length of use (<4 years, 4-8 years, >8 years) or cumulative call time (<300 hours, 300-900 hours, >900 hours) was used as an exposure index. The OR was 1.09 (95% CI 0.58 to 2.06) when the reference date was set as five years before the diagnosis. Further, laterality of mobile phone use was not associated with tumours. CONCLUSIONS: These results suggest that there is no significant increase in the risk of acoustic neuroma in association with mobile phone use in Japan.

Conductivities of epidermis, dermis, and subcutaneous tissue at intermediate frequencies.

Novel data for the conductivities of the tissues composing the skin, which are the epidermis, dermis and subcutaneous tissue, were obtained at intermediate frequencies by in vitro measurement. The conductivity of the epidermis was determined from those of the dermis and bulk skin. The conductivities of the dermis and subcutaneous tissue were almost constant from 10 kHz to 1 MHz. On the other hand, a frequency dependence was observed for the epidermis; the conductivity decreases with decreasing frequency. It was found that the conductivity of bulk skin is not determined by that of the dermis but by that of the epidermis. The presented data are expected to contribute to the assessment of safety and to the research and development of medical applications.

Acute encephalopathy associated with hemolytic uremic syndrome caused by Escherichia coli O157: H7 and rotavirus infection.

We reported a case of a 22-months child with hemolytic uremic syndrome associated with encephalopathy. As the cause of this case, the involvements of verotoxin 1 and 2 caused by O157: the H7 strain of the enterohemorrhagic Escherichia coli and rotavirus were presumed. We administered brain hypothermic therapy and steroid pulse therapy in the intensive care unit, but we were not able to save his life and the child died on the 6th day from the onset.

Dielectric property measurement of ocular tissues up to 110 GHz using 1 mm coaxial sensor.

Measurement of the dielectric properties of ocular tissues up to 110 GHz was performed by the coaxial probe method. A coaxial sensor was fabricated to allow the measurement of small amounts of biological tissues. Four-standard calibration was applied in the dielectric property measurement to obtain more accurate data than that obtained with conventional three-standard calibration, especially at high frequencies. Novel data of the dielectric properties of several ocular tissues are presented and compared with data from the de facto database.

Treatment with mild brain hypothermia for cardiopulmonary resuscitation after myoclonic seizures in infant with robertsonian type of trisomy 13.

Congenital chromosomal abnormality with trisomy 13 is known to be associated with poor life prognosis and lethal. Therefore, physician advice the patients be kept in intensive treatment with resuscitation and state of the art intensive care when sudden change in the general condition with this trisomy is observed. We report herein, the treatment with mild brain hypothermia therapy for cardiopulmonary resuscitation after myoclonic seizures in infant with Robertsonian type of trisomy 13 in intensive care unit. Our study indicated that brain hypothermia therapy and steroid pulse therapy on an infant who was believed to have post-resuscitation hypoxic encephalopathy was highly effective as the patient's general condition recovered to the original state after four months.

Morphometric analysis of infiltrating cells that adhere to the sinusoidal wall and migrate into the space of disse in the orthotopically transplanted rat liver.

To reveal the kinetics of infiltrating cells in the hepatic parenchyma after the liver transplantation, we identified the cell type (macrophages, monocytes, agranular lymphocytes, large granular lymphocytes, and neutrophils) and localization on toluidine blue-stained sections of perfusion-fixed liver grafts in rejecting and tolerant combinations and performed quantitative analysis of the density of each cell species infiltrating inside and outside the sinusoid at days 4 and 7. The number of total infiltrating cells per unit square became 9 times as high as that of an untreated liver at day 4 and 30 times as high at day 7. Macrophages accounted for a large part of the infiltrating cells both in and around the sinusoid: 72% of intrasinusoidal infiltrating cells and 88% of extrasinusoidal ones at day 4; 73% of intrasinusoidal ones and 93% of extrasinusoidal ones at day 7. The ratio of extrasinusoidal cell to intrasinusoidal cell of macrophages was 9:91 at day 4 and 34:66 at day 7, much higher than ratios of other infiltrating cells. This fact means that macrophages show a marked tendency to migrate out of the sinusoid in the liver graft. The proportion of macrophages to total infiltrating cells dropped at day 4 and went up again at day 7, while that of monocytes showed a reverse pattern. Histologically, immature macrophages, possibly derived from recipient monocytes, coexisted with vacuolated donor macrophages in the sinusoid at day 4, but the latter cells were diminished at day 7. These data indicate that transformation of recipient monocytes into macrophages in the sinusoid and subsequent extrasinusoidal migration of newly formed macrophages occur soon after the cell influx into the liver graft begins at day 4. The present study has revealed that macrophages, especially those migrating into the space of Disse, will be closely related to the pathogenesis of the liver transplantation.

24-hour rat liver preservation using UW solution and some simplified variants.

The results of a series of 32 rat liver transplants are described to analyze the efficacy of components of UW solution. Rat livers were stored at 4 degrees C in standard UW solution or one of three simplified variants for 24 hr prior to orthotopic liver transplantation. In standard UW solution (solution A) the one-week survival rate was 3 of 8. Using solution B, which differs from solution A in the omission of hydroxyethyl starch and adenosine, the one-week survival rate was 2 of 8. Solution C, a further-simplified version of solution B with omission of allopurinol, Bactrim, and insulin, gave a one-week survival rate of 3 of 8. Solution D is identical to solution B except that the sodium and potassium concentrations are reversed. Using this solution, 5 of 8 rats survived more than one week. We conclude that the effectiveness of UW solution is maintained in a substantially simplified form, and that solution D, with the Na/K ratio reversed to give a high Na variant, may improve survival.

Expression of neuron-specific enolase in the developing rat retina as revealed by immunocytochemistry.

Expression of neuron-specific enolase (NSE) in retinal neurons was immunocytochemically investigated during the development of the rat retina. At embryonic day 14 (E14), the first immunoreaction of NSE was identified in the pigment epithelium. NSE-positive ganglion cells occurred at the inner surface of the retina by E15. Horizontal cells and photoreceptor cells became stainable for NSE in the outer portion of the neuroblastic layer as early as E17. At E20, when the majority of ganglion cells were intensely positive for NSE, immunoreactive amacrine cells first appeared at the outer surface of the developing inner plexiform layer. It was not until postnatal day 7 (P7) that NSE-positive bipolar cells occurred in the middle of the inner nuclear layer. At this stage, most of the photoreceptor cells located in the outer nuclear layer were immunolabeled, whereas the ectopic photoreceptor cells in the inner nuclear layer were devoid of immunoreaction. Most identifiable retinal neurons became strongly immunostained for NSE by P14. Our results indicate that the NSE expression of retinal neurons occurs just after their migration to the final location and prior to establishing the synaptic structures. In this paper, the characteristic sequence in which different types of retinal neurons exhibit NSE immunoreaction is discussed in the light of certain autoradiographic data on the sequence of retinal cell genesis.

Exaggerated responses to chronic nociceptive stimuli and enhancement of N-methyl-D-aspartate receptor-mediated synaptic transmission in mutant mice lacking D-amino-acid oxidase.

Formalin-induced nociceptive behaviors and N-methyl-D-aspartate (NMDA) subtype glutamate receptor-mediated excitatory synaptic transmission were analyzed in mutant mice lacking D-amino-acid oxidase, which catalyzes the oxidative deamination of D-amino acids. The second phase of the formalin-induced licking response, a part of which is known to be mediated by NMDA receptors in the spinal cord, was significantly augmented in mutant mice. NMDA receptor-mediated excitatory postsynaptic currents recorded from spinal cord dorsal horn neurons by tight-seal whole-cell methods were significantly potentiated in mutant mice. The present observations provide another line of evidence that D-serine functions as an endogenous coagonist at the glycine site of NMDA receptors, and raise the possibility that D-amino-acid oxidase exerts a neuromodulatory function by controlling the concentration of D-serine in the central nervous system.

Increase in hypoxanthine-guanine phosphoribosyl transferase gene mutations by exposure to electric field.

Previously, we reported that exposure to extremely low frequency magnetic field (400 mT) increased in hypoxanthine-guanine phosphoribosyl transferase (HPRT) gene mutations. However, it is unclear these mutations were induced by magnetic field (MF), electric field (EF), or both. To explore this question, a new exposure apparatus for EF was manufactured. We observed an increase in HPRT gene mutations in Chinese hamster ovary (CHO) cells after exposure to EF (10 V/m, 60 Hz) for 10 h. The mutant frequency by EF-exposure was an approximate 2-fold of that by sham-exposure. Our data suggest that the mutations induced by exposure of cells to the variable magnetic field at 400 mT may be, in part, due to the induced EF.

Exposure to 2.45 GHz electromagnetic fields induces hsp70 at a high SAR of more than 20 W/kg but not at 5W/kg in human glioma MO54 cells.

PURPOSE: To determine potential hazards from exposure to a high-frequency electromagnetic field (HFEMF) at 2.45 GHz by studies of the expression of heat-shock protein 70 (hsp70) in MO54 cells. METHOD: MO54 cells were exposed to a HFEMF at average specific absorption rates (SAR) of 5, 20, 50 and 100 W/kg, using input powers of 0.8, 3.2, 7.8 and 13 W, at a temperature of up to 39 degrees C. An annular culture dish provided three levels of exposure for a given input power, designated inner, middle and outer rings. Two control groups were used: the first was subjected to sham exposure and the second was a temperature control, used to determine the effect of high temperature using incubation in a conventional incubator at 39 degrees C. Cell survival was determined in intervals up to 24 h. Protein was extracted from MO54 cells in both groups after 2, 4, 8 and 16 h exposure times. Changes in the hsp70 protein levels were analysed by Western blots. RESULTS: Little or no cell death was observed in the sham-exposed cells, nor for incubation at 39 degrees C for up to 16 h. Cell survival decreased to about 30% after exposure to HFEMF for 24 h at an average SAR of 100 W/kg. A slight increase in hsp70 was observed in cells in both the inner and outer rings of the plate after exposure at SAR levels of 25 and 78 W/kg, respectively, for 2 h. With increasing exposure time, hsp70 expression increased except for an SAR of 5 W/kg. In the raised temperature control at 39 degrees C, hsp70 expression also increased as the incubation time increased. However, the expression level of hsp70 for the HFEMF exposure was greater than that for the raised temperature control. CONCLUSION: HFEMF can produce an increased level of hsp70 expression in MO54 cells at SAR levels above 20 W/kg, even when the effect of raised temperature is taken into account.

A review of the trend in facilities for health services in the community.

After the Second World War, the field of medicine has changed remarkably in Japan. A comprehensive health and medical care system has been organized to meet the increasing needs and demands for health and medical care services. Health centers have played an important role in promoting health care activities in the community. The authors describe the development of health centers and other health care facilities in Japan. The authors propose that it is necessary to build a new health facility specifically designed for public health nurse activities, termed a "public health nurse station". The authors also describe the status of the health care facilities in service and the activities of the stations and evaluated them. It is concluded that the stations have brought many changes in the field of health and medical care; moreover that the station should not become a substitute for a health center but should be a facility for public health nurse activities in a community. Health centers should also play important roles for comprehensive medical services in the future.

Dosimetry considerations in the head and retina for extremely low frequency electric fields.

Magnetophosphenes are investigated from the viewpoint of electromagnetic dosimetry. Induced current density and internal electric fields at the threshold of perception are estimated by analytical and numerical calculations, assuming different models. Dosimetry for electrophosphenes is also discussed and compared with that for magnetophosphenes. The distribution of current density and internal electric fields is consistent with the experimental observation that flashing sensations reach their greatest intensity at the periphery of the visual field, for both electro and magnetophosphenes. The estimated thresholds in internal electric fields are consistent for magnetophosphenes and for electrophosphenes, respectively. The magnitudes of the thresholds, however, differ by about 10-fold. The thresholds in induced current density are critically dependent on the conductivity of the eye assumed for the calculations. The effect of thin membrane structure is also discussed with regard to the difference between electric field and magnetic field exposures.

Studies on the effects of microgravity on the ultrastructure and function of cultured mammalian cells.

Four cultures of monkey kidney cell line, JTC-12, were flown on the Spacelab-J (SL-J) mission during 8 days. The results of the present study showed that the space flight gave no essential effect on morphology, cell cycle, glucose consumption and urokinase production of the mammalian culture cell. However, the cell proliferation slightly decreased under microgravity. Moreover, the lack of gravity induced the trypsin-treated dissociated cells to keep floating in the culture medium. Therefore, the attachment of the cells onto the substratum was delayed, and that caused difficulties in subculturing the cells. The present research also offered some important information on techniques for establishment of cell cultures in space laboratories.