Medizinische/biologische Studie (experimentelle Studie)

Continuous wave and simulated GSM exposure at 1.8 W/kg and 1.8 GHz do not induce hsp16-1 heat-shock gene expression in Caenorhabditis elegans med./bio.

[Kontinuierliche Welle und simulierte GSM-Exposition bei 1.8 W/kg und 1.8 GHz induziert nicht die hsp16-1 Hitzeschock-Genexpression in Caenorhabditis elegans]

Von: Dawe AS, Nylund R, Leszczynski D, Kuster N, Reader T, de Pomerai DI

Veröffentlicht in: Bioelectromagnetics 2008; 29 (2): 92-99

Ziel der Studie (lt. Autor)

Um zu untersuchen, ob höhere Befeldungs-Dosen und/oder Pulsmodulation unter Ausschluss von Erwärmungs-Artefakten eine messbare Hitzeschock-Protein-Reportergen-Induktion in Caenorhabditis elegans (Nematoden) verursachen können, wurden transgene Würmer bei elektromagnetischen Feldern von 1.8 GHz und bei SAR-Werten von 1.8 W/kg für 2.5 Stunden bei 25°C exponiert.

Hintergrund/weitere Details

Die Hochfrequenz-Felder, die in früheren Caenorhabditis elegans-Studien verwendet wurden, waren viel schwächer (siehe Publikation 4466, Publikation 4467, Publikation 6611 und Publikation 12968).

Endpunkt

molekulare Biosynthese: Expression von Hitzeschock-Protein

Exposition/Befeldung (teilweise nur auf Englisch)

Exposition	Parameter
Exposition 1: 1,8 GHz Modulationsart: CW Expositionsdauer: kontinuierlich für 2,5 h	SAR: 1,8 W/kg Mittelwert magnetische Feldstärke: 1,6 A/m
Exposition 2: 1,8 GHz Modulationsart: gepulst Expositionsdauer: kontinuierlich für 2,5 h	SAR: 1,8 W/kg Mittelwert magnetische Feldstärke: 1,6 A/m

Allgemeine Informationen

In total, seven CW runs and five Talk-pulsed runs were completed, each involving six exposed replicates compared against six sham replicates.

Exposition 1

Hauptcharakteristika

Frequenz	1,8 GHz
Typ	elektromagnetisches Feld
Charakteristik	gerichtetes Feld
Expositionsdauer	kontinuierlich für 2,5 h

Modulation

Modulationsart	CW

Expositionsaufbau

Expositionsquelle	Wellenleiter resonant R18
Kammer	The fully automated exposure system consisted of two identical chambers for RF or sham exposure, mounted in the same incubator, and enabled well-controlled exposures of cells in monolayers or in suspension [Schuderer et al., 2004].
Aufbau	The Petri dishes were exposed in H-polarization. The induced E-fields had a pronounced polarization parallel to the bottom and in the direction of the waveguide axis. The induced H-fields were orthogonal to the induced E-fields, both of which were dominantly parallel to the bottom of the dish.
Schein-Exposition	Eine Schein-Exposition wurde durchgeführt.

Parameter

Messgröße	Wert	Typ	Methode	Masse	Bemerkungen
SAR	1,8 W/kg	Mittelwert	-	-	-
magnetische Feldstärke	1,6 A/m	-	-	-	-

Zusätzliche Parameterdetails

The ambient ELF exposure measured in several positions within the incubator was below 5 µT rms in the entire volume of the waveguide.

Mess- und Berechnungsdetails

The system monitored incident electric field strengths, ventilator currents, outlet air temperatures and state of all equipment every 10 s. Previous dosimetry [Schuderer et al., 2004] had to be extended due to the larger dimensions of C. elegans compared to cells. The gradient in z-direction was about 4 W/kg/mm, which means that the bottoms of the worms were exposed to an SAR of about 2 W/kg and the tops to 1.6 W/kg. The non-uniformity within the bottom of the dish was 23%, and the relative variability between Petri dishes and experiments was estimated to be less than 5%.

Exposition 2

Hauptcharakteristika

Frequenz	1,8 GHz
Typ	elektromagnetisches Feld
Charakteristik	gerichtetes Feld
Expositionsdauer	kontinuierlich für 2,5 h

Modulation

Modulationsart	gepulst
Zusatzinfo	GSM Talk signal characterized by a random change between the DTX and non-DTX or GSM Basic modes. The distribution in time was exponential with a mean duration of 10.8 s for non-DTX and 5.6 s for DTX. The dominant modulation components of this signal are 2, 8, 217, 1733 Hz, and higher harmonics [Tillmann et al., 2007].

Expositionsaufbau

Expositionsquelle	gleicher Aufbau wie Exposition 1
Schein-Exposition	Eine Schein-Exposition wurde durchgeführt.

Parameter

Messgröße	Wert	Typ	Methode	Masse	Bemerkungen
SAR	1,8 W/kg	Mittelwert	-	-	-
magnetische Feldstärke	1,6 A/m	-	-	-	-

Referenzartikel

Tillmann T et al. (2007): Carcinogenicity study of GSM and DCS wireless communication signals in B6C3F1 mice
Schuderer J et al. (2004): High Peak SAR Exposure Unit With Tight Exposure and Environmental Control for In Vitro Experiments at 1800 MHz

Exponiertes System:

Wirbellose
Caenorhabditis elegans (Fadenwurm; PC72 (transgen, mit Reportergen-Konstrukt, das für beta-Galaktosidase kodiert unter Kontrolle des hsp16 Hitzeschock-Promotors))
Ganzkörperexposition

Methoden Endpunkt/Messparameter/Methodik

molekulare Biosynthese: Expression von Hitzeschock-Protein bzw. Reportergen-Expression (beta-Galaktosidase-Aktivität)

Untersuchtes System:

isolierte biol./chemische Substanz (in vitro)
tote Würmer

Untersuchungszeitpunkt:

nach der Befeldung

Hauptergebnis der Studie (lt. Autor)

Sowohl für die Hochfrequenz-Exposition mit kontinuierlicher Welle als auch mit gepulster Welle gab es keinen Hinweis, dass die Hochfrequenz-Exposition eine Reportergen-Expression induzieren könnte, die oberhalb der Schein-Expositions-Werte liegt. Folglich wird dieses bestimmte Nematoden-Hitzeschock-Protein bei einer viel höheren Hochfrequenz-Feldstärke (als bei den früheren Studien und nahe der maximal erlaubten Exposition eines Mobiltelefons) nicht hochreguliert.

Studienmerkmale:

medizinische/biologische Studie
experimentelle Studie
Voll-/Hauptstudie
Blindstudie

Studie gefördert durch

IT'IS Foundation (Foundation for Research on Information Technologies in Society), Zurich, Switzerland
Mobile Telecommunications and Health Research (MTHR), UK
STUK (Radiation and Nuclear Safety Authority), Helsinki, Finland

Themenverwandte Artikel

Fasseas MK et al. (2015): Response of Caenorhabditis elegans to wireless devices radiation exposure
Ding GR et al. (2009): Comparison of Hsps expression after radio-frequency field exposure in three human glioma cell lines
Dawe AS et al. (2009): Low-intensity microwave irradiation does not substantially alter gene expression in late larval and adult Caenorhabditis elegans
Yu Y et al. (2008): Effects of exposure to 1.8 GHz radiofrequency field on the expression of Hsps and phosphorylation of MAPKs in human lens epithelial cells
Lantow M et al. (2006): ROS release and Hsp70 expression after exposure to 1,800 MHz radiofrequency electromagnetic fields in primary human monocytes and lymphocytes
Copty AB et al. (2006): Evidence for a specific microwave radiation effect on the green fluorescent protein
Chauhan V et al. (2006): Analysis of proto-oncogene and heat-shock protein gene expression in human derived cell-lines exposed in vitro to an intermittent 1.9 GHz pulse-modulated radiofrequency field
Wang J et al. (2006): Effects of a 2450 MHz high-frequency electromagnetic field with a wide range of SARs on the induction of heat-shock proteins in A172 cells
Chauhan V et al. (2006): Gene Expression Analysis of a Human Lymphoblastoma Cell Line Exposed In Vitro to an Intermittent 1.9 GHz Pulse-Modulated Radiofrequency Field
Dawe AS et al. (2006): A small temperature rise may contribute towards the apparent induction by microwaves of heat-shock gene expression in the nematode Caenorhabditis Elegans
Belyaev IY (2005): Non-thermal Biological Effects of Microwaves
Laszlo A et al. (2005): The heat-shock factor is not activated in mammalian cells exposed to cellular phone frequency microwaves
Lim HB et al. (2005): Effect of 900 MHz electromagnetic fields on nonthermal induction of heat-shock proteins in human leukocytes
Shallom JM et al. (2002): Microwave exposure induces Hsp70 and confers protection against hypoxia in chick embryos
Leszczynski D et al. (2002): Non-thermal activation of the hsp27/p38MAPK stress pathway by mobile phone radiation in human endothelial cells: Molecular mechanism for cancer- and blood-brain barrier-related effects
Tian F et al. (2002): 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
Kwee S et al. (2001): Changes in cellular proteins due to environmental non-ionizing radiation. I. Heat-shock proteins
de Pomerai DI et al. (2000): Microwave radiation induces a heat-shock response and enhances growth in the nematode Caenorhabditis elegans
Daniells C et al. (1998): Transgenic nematodes as biomonitors of microwave-induced stress
Cleary SF et al. (1997): Stress proteins are not induced in mammalian cells exposed to radiofrequency or microwave radiation