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Träfflista för sökning "bertil persson ;lar1:(lu);pers:(Nittby Henrietta)"

Sökning: bertil persson > Lunds universitet > Nittby Henrietta

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1.
  • Persson, Bertil R, et al. (författare)
  • Non-thermal" Effects on the Blood-Brain Barrier in Fischer rats by exposure to microwaves
  • 2012
  • Ingår i: Acta Scientiarum Lundensia. - 1651-5013. ; 2012-006:006, s. 1-39
  • Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
    • Effect of 915 MHz electromagnetic fields (EMF) on the blood brain-barrier (BBB) permeability has been studied in Fischer 344 rats of both sexes. Male and female Fischer 344 rats were exposed in a Transverse Electromagnetic Transmission line chamber to microwaves of 915 MHz as continuous wave (CW) and pulse-modulated with different pulse power and at various time intervals. The CW-pulse power varied from 0.001W to 10 W and the exposure time from 2 min. to 960 min. In each experiment we randomly placed 4 rats in excited and 4 control rats in non-excited TEM-cells respectively. The rats were not anaesthetised during the exposure. The rats were exposed to 915 MHz microwaves, either continuous wave (CW) or pulse modulated at 4,8,16 or 217 Hz with 0.57 ms pulse width, or pulse modulated at 50 Hz with 6.6 ms pulse width as well as from a real GSM-900 telephone. All animals were sacrificed by perfusion-fixation of the brains under chloralhydrate anaesthesia after the exposure. The brains were then perfused, first with saline for 3-4 minutes, and then with 4% formaldehyde for 5-6 minutes. Whole coronal sections of the brains were dehydrated and embedded in paraffin and sectioned at 5 μm. The degree of albumin leakage was demonstrated immune-histo-chemically and classified in order of increased number of albumin extravasations by a rank number: 0 - 0.5 - 1.0 - 1.5 - 2 - 3. Pathological albumin leakage was judged as albumin extravasations equal to or larger than 1. The frequency of pathological rats in all control groups was about 17%. Among rats exposed to pulse modulated microwaves the ratio of pathological rats was 170/481(0.35±0.03) and among rats exposed to continuous wave exposure (CW) it was 74/149 (0.50±0.07). These results are both highly significantly different to their corresponding controls (p<0.0001). The rats were exposed to SAR various values: 0.2; 2; (20-40); (100-500); (1000-3000) mW/kg. In the 217 Hz modulated group (GSM simulated) we found the most increased ratio of albumin extravasations OR= 4 at 0.2 mW/kg. But no significant increased ratio at SAR 2000 mW/kg. The response curve of OR versus log(SAR) had the shape of a bathtub, with a minimum at a100 mW/kg. A similar curve was recorded for OR versus Specific Absorbed Energy (SAE Joule / kg) with a minimum at 100 J/kg. Similar response curves were recorded for the various modulation frequencies 4; 8; 16; 50 Hz. We found no pronounced difference between the various modulation frequencies other than the effect of CW exposure seems to be more effective than pulse modulated exposure in opening the BBB at high SAR values 100-2000 mW/kg. Conclusion: The opening of the BBB is most effective at SAR values in the range of 0.1-0.5 mW.kg-1 and less effective in the range of 50-500 mW.kg-1. In this low SAR range thermal effects are unlikely. Thus there seems to be a non-thermal mechanism involved triggering the opening of the BBB.
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2.
  • Persson, Bertil R, et al. (författare)
  • “Abscopal” Effect of Radiation Therapy Combined with Immune-Therapy Using IFN-γ Gene Transfected Syngeneic Tumor Cells, in Rats with Bilateral Implanted N29 Tumors
  • 2011
  • Ingår i: ISRN Immunology. - : Hindawi Limited. - 2090-5645 .- 2090-5653. ; 2011
  • Tidskriftsartikel (refereegranskat)abstract
    • The tumor growth rate response was studied on N29 rat glioma tumor cells subcutaneously implanted on both hind legs of Fischer-344 rats. At around 30 days after inoculation, RT was given with 60Co gamma radiation with 4 daily fractions of 5 Gy only to the right-lateral tumors. At days 26, 42, and 54 after inoculation, immunization was performed with irradiated syngeneic IFNγ-gene transfected cells. Tumor growth rate (TGR % per day) of the right-lateral irradiated tumor was significantly decreased (P<0.01) after RT alone and with the combination of RT and immunization. But immunization alone gave no significant decrease of the TGR but significantly increased time of survival. The TGR of the unirradiated left-lateral tumors was significantly decreased (P<0.02) only in the group of rats treated with RT alone. It is apparent that tumor cells killed by the radiation mediate suppression of tumor cells outside the target area. This effect is called the abscopal effect.
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3.
  • Persson, Bertil R, et al. (författare)
  • Mörka Neuron och Mobiltelefoner : Dedicerad till en 90-årig man, Arne Brun i Lund
  • 2021
  • Ingår i: Acta Scientiarum Lundensia. - 1651-5013. ; 2021:001, s. 1-23
  • Tidskriftsartikel (refereegranskat)abstract
    • Med denna svenska översikt av våra egna och andra forskares observationer av mörka neuron vid mikrovågs exponering från mobiltelefoner, som lite senkommet tillägnas Arne Brun på hans 90 års-dag, vill vi att hans insatser blir uppmärksammade och inte faller i glömska.Kring 2000 millennium skiftet pågick ett intensivt arbete i Lund med att sammanfatta och bekräfta effekterna av exponering med GSM-900 MHz mikrovågor på blod-hjärna barriären och hjärnans neuroner. Leif G. Salford, Arne Brun och medarbetare presenterade år 2003 i tidskriften Environmental Health Perspectives resultaten från en undersökning av skador på nervcellerna i råtthjärna efter exponering för mikrovågor från GSM Mobiltelefoner. Kontroller och testdjur visade alla tecken på närvao av albumin i hypotalamus, vilket år normalt och indikerar att albumin infärgningen av BBB läckaget också fungerar. Cresylviolettfärgningen avslöjade förekomst av spridda och grupperade mörka nervceller, som ofta var skrumpna och mörkt homogent färgade utan urskiljbara interna cellstrukturer. Några av dessa mörka nervceller var också albuminpositiva eller visade cytoplasmatiska mikrovakuoler som indikerar en aktiv patologisk process. År 2008 presenterades resultaten av ytterligare undersökningar av blod-hjärn barriärens permeabilitet och nervcellsskador i råtthjärnan efter en återhämtningstid på antingen 14 och 28 dagar efter 2 timmas exponering för mikrovågor från GSM-mobiltelefoner i 900 MHz-bandet. Efter 14 dagars återhämtningstid observerades albumin-läckage i BBB och albumin upptag i neuroner. Mörka neuron observerades endast hos råttor som exponerats med det lägsta SAR-värdet, 0,12 mW/kg. Efter 28 dagars återhämtnings period observerades läckage av albumin endast hos råttor som exponerats med det högsta SAR-värdet, 100 mW/kg. Däremot observerades efter 28 dagar förekomst av mörka neuron i råtthjärnor hos alla grupperna vilket korrelerade väl med neuronernas albumin upptag.I studien observeras neuro-patologiska förändringar redan vid SAR-värden så låga som 0,12 mW/kg vilket överensstämmer med våra tidigare resultat. Speciellt iögonfallande är att det högsta albumin upptaget i neuroner observeras vid den lägsta SAR nivån på 0,12 mW/kg. Frekvensen hos förekomsten av mörka nervceller ökade, jämfört med kontrollerna både efter 14 och 28 dagars återhämtning, men var endast signifikant vid 28 dagar efter exponering. Inga signifikanta tecken på förekomsten av mörka neuron observerades emellertid efter 7 dagars återhämtning.I en Fransk studie redovisad av Poulletier de Gannes och medarbetare 2009 exponerades enbart huvudet hos 16 st. Fischer 344-råttor (14 veckor gamla) för GSM-900 under 2 timmar vid SAR värden 0,14 och 2,0 W/kg. Fjorton alternatvt 50 dagar efter GSM-900 exponeringen kunde varken BBB-läckage eller förekomst av mörka nervceller upptäckas i rått hjärnorna. Deras resultat indikerar att det föreligger en väsentlig skillnad i resultaten vid helkropp exponering jämfört med exponering av endast huvudet.År 2015 presenterades en studie, stödd av Nationella Vetenskaps Akademin i Kina (NSFC), avseende albumin-läckage i blod-hjärnbarriären efter exponering med kontinuerliga mikrovågor på 900 MHz med SARvärden mellan 0,016 (hela kroppen) och 2 W/kg (lokalt i huvudet). Hos råttor som exponerats under 28 dagar observerades cellulärt ödem och neuronal cellorganell degeneration hos råttorna. Dessutom observerades med immun-färgning BBB-läckage av albumin i hippocampus och cortex. Efter exponering för 900 MHz mikrovågor under 14 respektive 28 dagar hade serum albumin diffunderat in i neuropilen mellan cellkropparna, som omger neuronerna. Upptag av Albumin i hippocampus neuron hos råttor exponerade under 28 dagar, visar förekomst av mörka neuron. Deras resultat är i linje med Lunda-resultaten som publicerades 2003 och 2008.
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4.
  • Persson, Bertil R, et al. (författare)
  • Radiation immunomodulatory gene tumor therapy of rats with intracerebral glioma tumors.
  • 2010
  • Ingår i: Radiation Research. - 0033-7587. ; 173:4, s. 433-440
  • Tidskriftsartikel (refereegranskat)abstract
    • Single-fraction radiation therapy with 5 or 15 Gy (60)Co gamma radiation was combined with intraperitoneal injections of syngeneic interferon gamma (IFN-gamma)-transfected cells in rats with intracerebral N29 or N32 glioma tumors at days 7, 21 and 35 after inoculation. For intracerebral N29 tumors, single-fraction radiation therapy with 5 or 15 Gy had no significant effect on the survival time. Immunization with IFN-gamma-transfected N29 cells significantly increased the survival time by 61%. Single-fraction radiation therapy with 5 Gy combined with immunization increased the survival time significantly by 87% and complete remissions by 75% while with 15 Gy the survival time increased 45% with 38% complete remissions. For intracerebral N32 tumors, single-fraction radiation therapy with 15 Gy increased the survival time significantly by 20%. Immunization by itself had no significant effect with IFN-gamma-transfected N32 cells, but combined with 15 Gy single-fraction radiation therapy it increased survival time significantly by 40%, although there were no complete remissions. Based on these findings, we suggest a new therapeutic regimen for malignant glioma using single-fraction radiation therapy with a target absorbed dose of the order of 5-10 Gy combined with clinically verified immunotherapy.
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5.
  • Persson, Bertil R, et al. (författare)
  • S-100 protein levels in the blood of Fischer rats exposed to 915 MHz CW-microwaves and magnetic fields.
  • 2020
  • Ingår i: Acta Scientiarum Lundensia. - 1651-5013. ; 2020:005, s. 1-9
  • Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
    • EnglishPersson, B. R. R., Nittby Redenbrant, H., Malmgren, L., Brun, A., and Salford, L. G. (2020). S-100 protein levels in the blood of Fischer rats exposed to 915 MHz CW-microwaves and magnetic fields. Acta Scientiarum Lundensia, Vol. 2020-005, pp. 1-9, ISSN 1651-5013Abstrakt.Syftet var att studera nivån av S-100 i blodprover som tagits från Fischer-344-råttor efter exponering för 915 MHz CW-mikrovågor och ELF-magnetfält i TEM-celler. Magnetfältsexponering ägde rum med TEM-cellen i ett Helmholtz-spolarrangemang med antingen 50 Hz sinusformat magnetfält på 5 µT eller inkoherent magnetfältbrus IMF med en maximal amplitud på 50 µT.Det verkar inte finnas någon signifikant förändring i S-100-koncentrationen i blod hos råttor som exponerats under 6 timmar för höga nivåer (4W) av kontinuerlig våg (CW) 915MHz mikrovågor, 50Hz sinusformade magnetfält (5µT) och osammanhängande magnetfält (IMF) vid 50µT. Däremot indikerar resultaten av den kombinerade exponeringen CW + IMF en minskad koncentration av S100 i blod.Minskningen överensstämmer med resultaten av en undersökning under 2010 att de extremt lågfrekventa (ELF) magnetfälten från fläktmotorn (50Hz AC, 0,3-1,5 T) minskade det förväntade BBB-läckaget av albumin på grund av mikrovågsexponering .Resultaten från andra studier indikerar också att bioeffekter orsakade av exponering för mikrovågor reduceras genom överläggning med extremt lågfrekventa magnetfält ELF. Det är därför av yttersta vikt när man undersöker bioeffekter från mikrovågor för att också kontrollera nivåer och frekvenser av lågfrekventa magnetfält i omgivningen, vilket kan vara en av anledningarna till den breda spridningen i de rapporterade resultaten.
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6.
  • Ceberg, Crister, et al. (författare)
  • Photon activation therapy of RG2 glioma carrying Fischer rats using stable thallium and monochromatic synchrotron radiation.
  • 2012
  • Ingår i: Physics in Medicine and Biology. - : IOP Publishing. - 1361-6560 .- 0031-9155. ; 57:24, s. 8377-8391
  • Tidskriftsartikel (refereegranskat)abstract
    • 75 RG2 glioma-carrying Fischer rats were treated by photon activation therapy (PAT) with monochromatic synchrotron radiation and stable thallium. Three groups were treated with thallium in combination with radiation at different energy; immediately below and above the thallium K-edge, and at 50 keV. Three control groups were given irradiation only, thallium only, or no treatment at all. For animals receiving thallium in combination with radiation to 15 Gy at 50 keV, the median survival time was 30 days, which was 67% longer than for the untreated controls (p = 0.0020) and 36% longer than for the group treated with radiation alone (not significant). Treatment with thallium and radiation at the higher energy levels were not effective at the given absorbed dose and thallium concentration. In the groups treated at 50 keV and above the K-edge, several animals exhibited extensive and sometimes contra-lateral edema, neuronal death and frank tissue necrosis. No such marked changes were seen in the other groups. The results were discussed with reference to Monte Carlo calculated electron energy spectra and dose enhancement factors.
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7.
  • Grafström, Gustav, et al. (författare)
  • Histopathological examinations of rat brains after long-term exposure to GSM-900 mobile phone radiation.
  • 2008
  • Ingår i: Brain Research Bulletin. - : Elsevier BV. - 0361-9230. ; 77, s. 257-263
  • Tidskriftsartikel (refereegranskat)abstract
    • In order to mimic the real life situation, with often life-long exposure to the electromagnetic fields emitted by mobile phones, we have investigated in a rat model the effects of repeated exposures under a long period to Global System for Mobile Communication-900MHz (GSM-900) radiation. Out of a total of 56 rats, 32 were exposed once weekly in a 2-h period, for totally 55 weeks, at different average whole-body specific absorption rates (SAR) (of in average 0.6 and 60mW/kg at the initiation of the experimental period). The animals were exposed in a transverse electromagnetic transmission line chamber (TEM-cell) to radiation emitted by a GSM-900 test phone. Sixteen animals were sham exposed and eight animals were cage controls, which never left the animal house. After behavioural tests, 5-7 weeks after the last exposure, the brains were evaluated for histopathological alterations such as albumin extravasation, dark neurons, lipofuscin aggregation and signs of cytoskeletal and neuritic neuronal changes of the type seen in human ageing. In this study, no significant alteration of any these histopathological parameters was found, when comparing the GSM exposed animals to the sham exposed controls.
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8.
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9.
  • Nittby, Henrietta, et al. (författare)
  • Analgetic effects of non-thermal GSM-1900 radiofrequency electromagnetic fields in the land snail Helix pomatia
  • 2012
  • Ingår i: International Journal of Radiation Biology. - : Informa UK Limited. - 0955-3002 .- 1362-3095. ; 88:3, s. 245-252
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose : To investigate whether mobile phone radiation might affect snail nociception, employing radiofrequency (RF) electromagnetic fields (EMF) which, to our knowledge, have hitherto not been studied in a snail model. Exposure to extremely low frequency (ELF) magnetic fields has however been shown to significantly affect nociceptive responses. Materials and methods : In the present study, we exposed 29 land snails of the strain Helix pomatia to global system for mobile communications (GSM) EMF at 1900 MHz at the non-thermal level 48 mW/kg for 1 hour each and 29 snails were sham controls. The experiments took place during the onset of summer, with all snails being well out of hibernation. Before and after GSM or sham exposure, the snails were subjected to thermal pain by being placed on a hot plate. The reaction time for retraction from the hot plate was measured by two blinded observers. Results : Comparing the reaction pattern of each snail before and after exposure, the GSM-exposed snails were less sensitive to thermal pain as compared to the sham controls, indicating that RF exposure induces a significant analgesia (Mann-Whitney p < 0.001). Conclusion : This study might support earlier findings, describing beneficial effects of EMF exposure upon nociception.
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10.
  • Nittby, Henrietta, et al. (författare)
  • Cognitive impairment in rats after long-term exposure to GSM-900 mobile phone radiation
  • 2008
  • Ingår i: Bioelectromagnetics. - : Wiley. - 0197-8462 .- 1521-186X. ; 29:3, s. 219-232
  • Tidskriftsartikel (refereegranskat)abstract
    • Considering the frequent use of mobile phones, we have directed attention to possible implications on cognitive functions. In this study we investigated in a rat model the long-term effects of protracted exposure to Global System for Mobile Communication-900 MHz (GSM-900) radiation. Out of a total of 56 rats, 32 were exposed for 2 h each week for 55 weeks to radio-frequency electromagnetic radiation at different SAR levels (0.6 and 60 mW/kg at the initiation of the experimental period) emitted by a (GSM-900) test phone. Sixteen animals were sham exposed and eight animals were cage controls, which never left the animal house. After this protracted exposure, GSM-900 exposed rats were compared to sham exposed controls. Effects on exploratory behaviour were evaluated in the open-field test, in which no difference was seen. Effects on cognitive functions were evaluated in the episodic-like memory test. In our study, GSM exposed rats had impaired memory for objects and their temporal order of presentation, compared to sham exposed controls (P = 0.02). Detecting the place in which an object was presented was not affected by GSM exposure. Our results suggest significantly reduced memory functions in rats after GSM microwave exposure (P = 0.02).
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