| 1. |
- Persson, Bertil R.R., et al.
(författare)
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Effects of microwaves from GSM mobile phones on the blood-brain barrier and neurons in rat brain
- 2005
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Ingår i: PIERS 2005 - Progress in Electromagnetics Research Symposium, Proceedings. - 1933077077 - 9781933077079 ; , s. 638-641
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Konferensbidrag (refereegranskat)abstract
- Our group has since 1988 studied the effects of different intensities and modulations of 915MHz RF in a rat model where the exposure takes place in a TEM-cell during various time periods and post exposure recovery times. The power fed into TEM-cells was 0.125, 1.25, 12.5 or 125mW corresponding to whole body SAR (determined experimentally): 0.2, 2, 20 or 200mW/kg. The rats were awake and not restrained during exposure and after the recovery period the animals were anaesthetized and sacrificed by perfusion-fixation with 4% formaldehyde. Paraffin embedded 5 μm. thick brain slices were stained for albumin by applying albumin antibodies (Dakopatts), by which albumin is revealed as brownish discolorations. Dark neurons were revealed by staining for RNA/DNA with cresyl violet. In series of more than 1800 Fisher rats, we have proven that sub thermal power levels from both pulse-modulated and continuous RF fields - including those from real GSM mobile phones - have the potency to significantly open the BBB for the animals' own albumin (but not fibrinogen) to pass out into the brain and to accumulate in the neurons and glial cells surrounding the capillaries. Albumin extravasations are most prominent at the lower SAR values. This dose-response behaviour suggests some kind of energy or electromagnetic field strength windowing effect. A linear dose-response relationship for dark neurons was found at 50 days after exposure, with most prominent occurrence at SAR 200mW/kg.
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| 2. |
- Persson, Bertil R, et al.
(författare)
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Brain tumour growth in rats exposed to electromagnetic fields used in wireless cellular communication
- 2014
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Ingår i: Acta Scientiarum Lundensia. - 1651-5013. ; 2014:001, s. 1-23
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Tidskriftsartikel (refereegranskat)abstract
- In 1996 there was no convincing laboratory evidence that EMFs used in wireless communication could cause tumour promotion at non-thermal exposure levels. Therefore we then performed a study of the effects from exposure to such electromagnetic fields in the rat brain glioma model we were using in our research for brain tumour therapy. By stereotaxic technique rat glioma cells (RG2 or N32) were injected into the head of the right caudate nucleus in 154 pairs of Fischer 344 rats in both exposed and matched controls. Starting on day 5 after inoculation, the animals were exposed for 7 hours a day, 5 days a week during 2 - 3 weeks. Rats of both sexes were exposed to electromagnetic fields in the microwaves frequency range 915 MHz both as continuous waves (1 W), and as pulse-modulated at 4, 8, 16 and 217 Hz in 0.57 ms long pulses and 50 Hz in 6.67 ms pulses, all with a maximum power amplitude of 2 W per pulse. The animals were kept un-anaesthetized in well-ventilated TEM cells during 7 hours a day for 5 days a week for 2-3 weeks. Their matched controls were kept in identical TEM cells without EMF exposure. At the end of the exposure period the rat brains were examined histopathologically. The tumour size was measured with a calliper and the volume estimated as an ellipsoid. Our study of the 154 matched pairs of rats did not show any significant difference in tumour volume between animals exposed to 915 MHz microwaves, and those not exposed. Thus our results did not support that daily exposure to EMF promotes tumour growth when given from the fifth day after the start of tumour growth in the rat brain until the sacrifice of the animal 16 days later. In the present review our results published 1997 have been re-evaluated in terms of SAR dependence of tumour volume observed ratio (exposed / control). We thus surprisingly found that the shape of tumour volume-OR versus SAR response was of bath-tube pattern, similar to that found in our parallel studies of albumin leakage through the blood-brain barrier. Since the SAR varies between most other animal studies reviewed and human epidemiological studies this SAR dependence might explain the controversy in rendering the results.
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| 3. |
- Persson, Bertil R, et al.
(författare)
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Interaction mechanisms of low-level electromagnelic fields in living systems / edited by Bengt Nordön and Claes Romel.
- 1992
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Ingår i: Interaction mechanisms of low-level electromagnelic fields in living systems. - 0198577591 ; , s. 199-209
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Bokkapitel (refereegranskat)abstract
- The 'ion cyclotron resonance hypothesis' was explored by Liboff et al. (1987) in an experiment involving incorporation of calcium-45 (n5Ca2*) in mixed human lymphocytes. The geomagnetic horizontal field component was'adjusted to 2l pT. The experiment was first performed at an amplitude of the applied oscillating field of 150 pT and a sharp minimum was obtained at the frequency of l43Hz, which corresponds to the ion cyclotron frequencyat 2l p,T . The experiment was then repeated at an amplitude of 2l prTand now a sharp, narrow maximum occurred at l4.3Hz.Although there appears to be experimental evidence for resonancephenomena, the cyclotron resonance hypothesis is shown to violate the laws of classical mechanics (Halle 1988). Lednev (1990) and Hart (1990) treat quantum mechanically the interaction of a low-frequency field with an ion bound loosely to a membrane surface in the presence of a static magnetic field, and claim evidence for resonancephenomena.In the present paper we have tried to demonstrate the presence of resonance phenomena for influx and efflux of radioactive calcium-45 ions in human normal and transformed lymphocytes and in rat thymocytes.
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| 4. |
- Persson, Bertil R, et al.
(författare)
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Non-thermal" Effects on the Blood-Brain Barrier in Fischer rats by exposure to microwaves
- 2012
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Ingår i: Acta Scientiarum Lundensia. - 1651-5013. ; 2012-006:006, s. 1-39
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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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| 5. |
- Persson, Bertil R, et al.
(författare)
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Studies of 1H-NMR Relaxation Dispersion in Human Brain- tissue Samples: Implications for Magnetic Resonance Relaxation Dispersion Imaging (MARDI)
- 2012
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Ingår i: Acta Scientiarum Lundensia. - 1651-5013. ; 2012:001, s. 1-22
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Tidskriftsartikel (refereegranskat)abstract
- Studies of 1H-NMR Relaxation Dispersion in Human Brain- tissue Samples: Implications for Magnetic Resonance Relaxation Dispersion Imaging (MARDI) Bertil R.R. Persson1, Lars Malmgren1,2 and Leif G. Salford3 1Medical Radiation Physics 2MAX Laboratory 3Dept. of Neurosurgery, Lund University, Lund Sweden [Bertil R.R. Persson, Lund University, Dept. of medical radiation physics, Barngatan 2, S-22185 Lund Sweden] bertil_r.persson@med.lu.se Abstract. In order to analyze the relaxation characteristics in fresh human brain tissue and blood samples we studied the proton relaxation rate dispersion in the frequency interval from 0.01 to 10 MHz. With the Field cycling method we apply, the sample is first magnetized in a relatively high magnetic fields (0.5 Tesla), which then by electronic means rapidly (10-3 s) is reduced to lower values (0.0001 - 0.5 Tesla) where the excited proton spin may relax during a time interval of about 3*T1max. Then the magnetic field is again quickly raised up to higher level for the detection of NMR-signal. In order to analyse the relaxation characteristics we applied a model with three compartments of water exchange. For each compartment we estimate a characteristic frequency by fitting the dispersion curves to a sum of Lorentz distributions. The characteristic frequencies thus obyained for various human yissuesater given in the following table. TissueFrequency n1 (low) / kHzFrequency n2 (middle) / kHzFrequency n3 (High) / kHz Whole blood285 7600 Blood plasma37 ± 4220 ± 101480 ± 40 Cerebral Spinal Fluid16 ± 42200 ± 140 Brain Gray Matter18,3 ± 0.3159 ± 21660 ± 20 Brain White Matter16 ± 1170 ± 102700 ± 100 Meningioma23 ±1190 ±102350 ±80 Studying the effect on the relaxation rate dispersion by heat treatment of blood plasma we found a breakpoint in the relaxation rate at 80 ºC The relaxation rate at low frequency 0.02 MHz gives an activation energy of 103 kJ/ mol above the breakpoint at 80 ºC and a very low value of 3.1±0.5 kJ/mol below 80 ºC. There seems to be no effect of Mn2+ after heating to 80 oC. This support the idea that paramagnetic ions has no effect on the firmly bound water in proteins. At room temperature, however, we found that paramagnetic ions (Mn2+) have a great influence on the relaxation rate dispersion in the low frequency region (10 - 20 kHz). Magnetic resonance relaxation dispersion imaging (MARDI) might be useful for imaging of reactive oxygen radicals and oxygen distribution by using paramagnetic or organic free-radical contrast agents. Keywords: field cycling, NMR, relaxation, dispersion, human brain, tissue, paramagnetic,
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| 6. |
- Persson, Bertil R, et al.
(författare)
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Mörka Neuron och Mobiltelefoner : Dedicerad till en 90-årig man, Arne Brun i Lund
- 2021
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Ingår i: Acta Scientiarum Lundensia. - 1651-5013. ; 2021:001, s. 1-23
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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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| 7. |
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| 8. |
- Persson, Bertil R, et al.
(författare)
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S-100 protein levels in the blood of Fischer rats exposed to 915 MHz CW-microwaves and magnetic fields.
- 2020
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Ingår i: Acta Scientiarum Lundensia. - 1651-5013. ; 2020:005, s. 1-9
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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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| 9. |
- Belyaev, Igor Y, et al.
(författare)
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Microwaves From UMTS/GSM Mobile Phones Induce Long-Lasting Inhibition of 53BP1/gamma-H2AX DNA Repair Foci in Human Lymphocytes
- 2009
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Ingår i: Bioelectromagnetics. - : Wiley. - 0197-8462 .- 1521-186X. ; 30:2, s. 129-141
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Tidskriftsartikel (refereegranskat)abstract
- We have recently described frequency-dependent effects of mobile phone microwaves (MWs) of global system for mobile communication (GSM) on human lymphocytes from persons reporting hypersensitivity to electromagnetic fields and healthy persons. Contrary to GSM, universal global telecommunications system (UMTS) mobile phones emit wide-band MW signals. Hypothetically, UMTS MWs may result in higher biological effects compared to GSM signal because of eventual "effective" frequencies within the wideband. Here, we report for the first time that UMTS MWs affect chromatin and inhibit formation of DNA double-strand breaks co-localizing 53BP1/gamma-H2AX DNA repair foci in human lymphocytes from hypersensitive and healthy persons and confirm that effects of GSM MWs depend oil carrier frequency. Remarkably, the effects of MWs on 53BP1/gamma-H2AX foci persisted up to 72 h following exposure of cells, even longer than the stress response following heat shock. The data are in line with the hypothesis that the type of signal, UMTS MWs, may have higher biological efficiency and possibly larger health risk effects compared to GSM radiation emissions. No significant differences in effects between groups of healthy and hypersensitive subjects were observed, except for the effects of UNITS MWs and GSM-915 MHz MWs on the formation of the DNA repair foci, which were different for hypersensitive (P < 0.02[53BP1)//0.01[gamma-H2AX]) but not for control subjects (P > 0.05). The non-parametric statistics used here did not indicate specificity of the differences revealed between the effects of GSM and UMTS MWs oil cells from hypersensitive subjects and more data are needed to study the nature of these differences, Bioelectromagnetics 30: 129-141, 2009. (C) 2008 Wiley-Liss, Inc.
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| 10. |
- Eberhardt, Jacob, et al.
(författare)
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Blood-brain barrier permeability and nerve cell damage in rat brain 14 and 28 days after exposure to microwaves from GSM mobile phones.
- 2008
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Ingår i: Electromagnetic Biology and Medicine. - : Informa UK Limited. - 1536-8386 .- 1536-8378. ; 27:3, s. 215-229
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Tidskriftsartikel (refereegranskat)abstract
- We investigated the effects of global system for mobile communication (GSM) microwave exposure on the permeability of the blood-brain barrier and signs of neuronal damage in rats using a real GSM programmable mobile phone in the 900 MHz band. Ninety-six non-anaesthetized rats were either exposed to microwaves or sham exposed in TEM-cells for 2 h at specific absorption rates of average whole-body Specific Absorption Rates (SAR) of 0.12, 1.2, 12, or 120 mW/kg. The rats were sacrificed after a recovery time of either 14 or 28 d, following exposure and the extravazation of albumin, its uptake into neurons, and occurrence of damaged neurons was assessed. Albumin extravazation and also its uptake into neurons was seen to be enhanced after 14 d (Kruskal Wallis test: p = 0.02 and 0.002, respectively), but not after a 28 d recovery period. The occurrence of dark neurons in the rat brains, on the other hand, was enhanced later, after 28 d (p = 0.02). Furthermore, in the 28-d brain samples, neuronal albumin uptake was significantly correlated to occurrence of damaged neurons (Spearman r = 0.41; p < 0.01).
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