Effects of Static Magnetic Field (SMF) Exposure on Coronary Heart Disease (CHD) Risk Indicators
Round 1
Reviewer 1 Report
The manuscript entitled "Effects of Static Magnetic Field (SMF) Exposure on Coronary Heart Disease (CHD) Risk Indicators" offered a piece of explicit information on the exposure SMF that affects the membrane to modulate the amount of intracellular Ca2+ through the calmodulin pathway using several new strategies. This is a detailed, concise, and authentic manuscript. The introduction is relevant and statics based; however, some more explanation needs to incorporate in a few places. Sufficient information about the previous study findings is presented for readers to follow the present study rationale. Though the manuscript is written well, extensive modifications in a few sentences and adding details and references could improve it. Given these shortcomings, the manuscript requires significant revisions, and I believe the manuscript is suitable for publication after the authors have addressed the following comments and questions.
1. Abstract
Comment: In the abstract, please mention your take-home message from this article, and it should be better described and highlighted with the effects of Static Magnetic Field (SMF) exposure on CHD. A recommendation statement at the end of the abstract is also needed.
2. Authors- The exposure SMF influences... Ca2+ through the calmodulin pathway.
Comment: Please use the full abbreviation of SMF here, as it is the first time you have introduced this.
3. Introduction-Obesity is a world health ... high intake of calories compared to output.
Comment: Is this the only cause of obesity? If not, please mention some other causes with references.
3-Authors: Obesity can increase .. CVD directly and indirectly.
Comments: Authors must explain this adequately with more description.
4 Comments: Please provide full forms of LDL and HDL in the introduction section, and then they can use the short forms.
5 Comments: Please rewrite in vivo and in vitro accordingly.
6-Authors: Based on its intensity..moderate, strong, and very strong.
Comment: What do you mean by weak to strong? Can you provide the range for this? This would make it a proper statement to follow the readers.
7-Authors: This classification is widely used...biological and therapeutic effects is extensively worked out.
Comment: Can you explain what are those biological and therapeutical effects? These details are necessary for the statement to look appropriate.
8 Comment: This is a general comment regarding the introduction. Though the authors have described this section, it needs some improvement and the incorporation of more details about the use of SMF in CVD/CHD from previous studies. Also, the relationship between LDL, HDL, and their levels concerning CVD/CHD diseases.
9. Authors: Methods: High-Fat Diet Induction;
Comment: Please give the appropriate reference for the Lee index formula.
10. Authors: Lines 92-100, LDLR gene expression section
Comment: This paragraph seems monotonous and very hard to read. Please rewrite this entire section in either active or passive voice (whatever you prefer).
2. Please provide the proper reference for the livak formula you used here.
11. Authors: Result section: Figure 1.
Comment: Can the authors provide the error bars here (just a suggestion)?
12. Authors: SMF Exposure section
Comment: Please rewrite this section as the authors have used can be seen very frequently here, which seems inappropriate and scientifically odd. It would be better explained grammatically to observe the readers.
13. Authors: Discussion section
Comment: Please start your discussion with an essential background rather than beginning the para with your results directly. This would strengthen the essence of the study.
14. Authors: used liver tissue to look at the expression of the SREBP-2 protein.
Comment: Use the capital letter here for used.
15. Authors: SREBP-2 has a long transcriptional activation domain.. from Obes2 to Obes7, then tends to decrease from Obesand Obes21.
Comment: What do the authors mean here? Please explain your results in line with the previous studies or other relevant information. Correlate your results (all results) with other studies and discuss them properly.
16. Authors: Based on the results obtained.. Ca2+ ions in the tissue.
Comment: Are there any other studies available on the same if yes, please correlate/link your results with them.
17. Comment: Though the authors have explained all the essential points in the discussion section, the conclusion must be better discussed. Please incorporate more details regarding the effect of SMF exposure on CVD/CHD, LDL and cholesterol levels, and other future development.
Author Response
Dear Reviewer,
Thank you for the constructive response and review to improve this article. In the following, we will send a revised article that we have tried to improve based on the suggestions that have been given.
Warm Regrads, Sari
Author Response File: 
Author Response.docx
Reviewer 2 Report
A lot of work was invested in this project, but the study is small and has a high risk of bias. Nevertheless, I think that most of my concerns can be addressed by major revision.
1. Study design. The use of controls needs to be explained better, perhaps with a figure indicating the overall flow of the experiment. Specifically, there was 1 control group, 5 exposed groups. In the tables of results, all exposed groups are compared to "controls" - what was the time difference between the "exposed" and "control" measurements? In Fig 2 etc, were the "pre LDL" and "post LDL" measurements done on the same animals at different times - what is being compared? The timing of measurements on "controls" and exposed groups needs to be clarified. I expect that all quantities being measured will vary with time and maybe the various effects are simply due to differences in time.
Please add a section "study limitations" and explicitly discuss these limitations: unblinded study, no positive controls, no cage controls, small "n".
2. Statistics. How many measurements were excluded from the analysis, for what reason?
Please replace all bar charts with scatterplots showing the actual data.
Are the "error bars" SEM or SD? Please state the SDs.
Do not use term the ambiguous term "significant" without qualifying it - "statistically significant"
All of the reported effects appear to be biologically small, within the range of normal variability in the animals. Is that correct? Please discuss.
The "n" is too small for reliable use of the t-test, which becomes a highly nonrobust measure for small groups. I wonder whether any of the reported "statistically significant" effects are real or just noise.
Need correction for multiple comparisons (e.g. Bonferroni)
minor
translate legend to Fig 5 to English
What fields were used? paper mentions two different fields - SMF (static field) and PEMF (pulsed field). If the field was modulated please provide waveform with modulation characteristics.
Author Response
Thank you for the very constructive response and review. Here we send the results of the requested revision, and we try to fix it. For some of the following questions, we send our feedback. Thank you
- Observing and taking samples is 21 days following the most extended exposure group, obesity21.
- Pre and post-LDL samples were taken from the same animal. The pre-exposed sample was taken when the mice had not been exposed, while post-exposure was done for each group. For the control group and the Obes21 group, pre-sampling was carried out before the age of 21 days. After 21 days, a blood sample was taken for the post.
- The reported biological effects are indeed fewer. However, this study can also provide further research that the effects of SMF exposure apart from intensity can also be affected by the length of time. There was an increase in expression between the SMF-exposed group and those not in the Obes7 group, but there was a decrease afterward; these results can provide information that exposure for a long time will have an unfavorable effect.
- The value of n is not too small because here, we use the Federer formula to refer to the number of samples. In this formula, the minimum sample we use is four mice for one group, and in this study, five mice are used for one group. The ethical committee also approves this number of samples in our place. 5. For a significant difference in value, we look at the statistical results that are PValue <0.05.
Warm Regrads
-Sari-
Author Response File: Author Response.docx
