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[Effects of electromagnetic noise on the enhancement of stress-activated protein kinase(SAPK) phosphorylation induced by 50 Hz magnetic fields].

Zhonghua lao dong wei sheng zhi ye bing za zhi = Zhonghua laodong weisheng zhiyebing zazhi = Chinese journal of industrial hygiene and occupational diseases · 2002 · Mixed · Low evidence

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MixedLow evidencePaper 3807

Exposure to 0.4 mT 50 Hz magnetic field for 3 min and 15 min increased SAPK phosphorylation versus control (reported phosphorylated SAPK 49.3% and 57.0%; P<0.05; n=4). Electromagnetic noise alone at 0.4 mT did not increase SAPK phosphorylation (37.7% and 31.8…

Study snapshot

PublicationZhonghua lao dong wei sheng zhi ye bing za zhi = Zhonghua laodong weisheng zhiyebing zazhi = Chinese journal of industrial hygiene and occupational diseases · 2002
Study typein_vitro
Reported directionMixed
Evidence ratingLow

Abstract

OBJECTIVE: To investigate the possible interference effect of electromagnetic noise exposure on phosphorylation of stress-activated protein kinase(SAPK) induced by 50 Hz magnetic field(MF). METHODS: Chinese hamster lung(CHL) cells were exposed to sham exposure(C), 0.4 mT 50 Hz sinusoidal MF, 0.4 mT electromagnetic noise and the combined noise MF with 50 Hz MF for 3 min and 15 min respectively. After exposure, the cells were lysed, and the proteins were extracted. The SAPK and phosphorylated SAPK (activated form of SAPK) were measured indirectly by Western blot with corresponding antibodies. The percentage of phosphorylated SAPK was calculated and analyzed. RESULTS: Exposure of cells to 50 Hz MF for 3 min and 15 min enhanced the SAPK phosphorylation. The percentage of phosphorylated SAPK were 49.3% and 57.0% respectively, and were significantly different from those of control(P < 0.05, n = 4). However, single noise MF exposure with the same intensity did not enhance the SAPK phosphorylation, the percentage of phosphorylated SAPK were 37.7% and 31.8% (P > 0.05). When cells were exposed to the combined noise MF with 50 Hz MF for 3 min, the SAPK phosphorylation was significantly inhibited (24.4%, P < 0.05); for 15 min, the SAPK phosphorylation was also decreased (39.0%), but there was no significant difference from control and 50 Hz MF exposure(P > 0.05). CONCLUSION: Noise MF with certain intensity could inhibit the biological effect induced by 50 Hz MF.

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AI evidence extraction

Structured fields below were generated from the paper’s abstract and metadata to make the evidence easier to inspect. Automated extraction may be incomplete or incorrect; verify important details against the original paper.

Study typein_vitro
Effect directionmixed
PopulationChinese hamster lung (CHL) cells
Sample sizeNot supplied
ExposureELF · 0.05 MHz · 3 min and 15 min
Evidence strengthLowConfidence: 74% · Peer reviewed: yes

Main findings

Exposure to 0.4 mT 50 Hz magnetic field for 3 min and 15 min increased SAPK phosphorylation versus control (reported phosphorylated SAPK 49.3% and 57.0%; P<0.05; n=4). Electromagnetic noise alone at 0.4 mT did not increase SAPK phosphorylation (37.7% and 31.8%; P>0.05). Combined exposure (noise + 50 Hz) reduced SAPK phosphorylation at 3 min (24.4%; P<0.05) and decreased it at 15 min (39.0%) without a significant difference versus control or 50 Hz alone (P>0.05).

Outcomes measured

  • SAPK phosphorylation
  • phosphorylated SAPK (activated form) measured by Western blot
  • percentage of phosphorylated SAPK

Limitations

  • In vitro cell study; findings may not generalize to humans.
  • Exposure conditions limited to 0.4 mT and short durations (3 and 15 min).
  • Sample size not fully reported for all comparisons (only n=4 mentioned).
  • Outcome is a biochemical marker (SAPK phosphorylation) rather than a health endpoint.
View raw extracted JSON
{
  "study_type": "in_vitro",
  "exposure": {
    "band": "ELF",
    "source": null,
    "frequency_mhz": 0.05,
    "sar_wkg": null,
    "duration": "3 min and 15 min"
  },
  "population": "Chinese hamster lung (CHL) cells",
  "sample_size": null,
  "outcomes": [
    "SAPK phosphorylation",
    "phosphorylated SAPK (activated form) measured by Western blot",
    "percentage of phosphorylated SAPK"
  ],
  "main_findings": "Exposure to 0.4 mT 50 Hz magnetic field for 3 min and 15 min increased SAPK phosphorylation versus control (reported phosphorylated SAPK 49.3% and 57.0%; P<0.05; n=4). Electromagnetic noise alone at 0.4 mT did not increase SAPK phosphorylation (37.7% and 31.8%; P>0.05). Combined exposure (noise + 50 Hz) reduced SAPK phosphorylation at 3 min (24.4%; P<0.05) and decreased it at 15 min (39.0%) without a significant difference versus control or 50 Hz alone (P>0.05).",
  "effect_direction": "mixed",
  "limitations": [
    "In vitro cell study; findings may not generalize to humans.",
    "Exposure conditions limited to 0.4 mT and short durations (3 and 15 min).",
    "Sample size not fully reported for all comparisons (only n=4 mentioned).",
    "Outcome is a biochemical marker (SAPK phosphorylation) rather than a health endpoint."
  ],
  "evidence_strength": "low",
  "confidence": 0.74,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "50 Hz",
    "extremely low frequency",
    "magnetic field",
    "electromagnetic noise",
    "SAPK",
    "stress-activated protein kinase",
    "phosphorylation",
    "Western blot",
    "CHL cells"
  ],
  "suggested_hubs": [
    {
      "slug": "occupational-exposure",
      "weight": 0.35,
      "reason": "Published in an industrial hygiene/occupational diseases journal and involves ELF magnetic field exposure, though the experiment is in vitro."
    }
  ]
}
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AI-extracted fields are generated from the abstract and metadata and may be incomplete or incorrect. This material is for informational purposes and is not medical advice.

Identifiers and source

DOI: Not supplied
PubMed: 14694644

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