Reviewer's report
Title:Peroxisome Proliferators-Activated Alpha Agonist Treatment Improves
Hepatic Damage in Rats with Obstructive Jaundice: An Experimental Study
Version: 3Date:16 July 2007
Reviewer: Girdhar Agarwal
Reviewer's report:
General
Referee’s Report on the paper “Prexisome Proliferators – Activated Alpha
Agnonist Treatment: Ameeliorates Hepatic Damage in Rats with Obstructive
Jaundice: An Experimental Study” by Mehmet Cindoruk and others
It seems that the paper has been already reviewed earlier. So I am concentrating
on Statistical Analysis and methodology part.
1. 1. “Statistics” section is ambiguous. They talk about post hoc test about
equality of variances. Actually this has to be performed before one can use
ANOVA. It is not clear in what context “Bonferroni’s test” and “Duncan’s test” are
being used.
These two tests are “multiple comparisons” tests. They don’t have to do anything
with “equality or unequality of variances” as quoted in this section.
2. Sample size is small in each group, ANOVA is to be used very carefully.
Actually the assumptions of ANOVA (normality and homogeneity of variances
among four groups) may not be valid here. In that case, non-parametric test
(Kruskal-Wallis test) would be more appropriate.
3. It is not clear whether ANOVA is performed on all four groups or three groups
(BDL groups).
4. Once hypothesis is rejected in ANOVA test, multiple comparison (pair wise
comparison ) have to be performed. This is not done here.
5. The most important pair wise comparison is among the two groups: (i) Sham
and (ii) BDL + ferofibrate. This is not clear whether this is done here. See remark
4 also.
6. In my view, ultimate aim of the study should be whether the subjects
recovered fully after treatment. This can be answered by pair wise comparison
mentioned above in remark 5. A scant comparison between the two groups show
that the two groups are significantly different, a fact contradicting the recovery of
rats.
7. The value p < 0.001 is O.K. But wherever, they have mentioned p < 0.05, the
exact p-value should be given to express the strength of “significance difference”.
The above remarks should be considered before any decision is taken on the
paper.
-------------------------------------------------------------------------------
Major Compulsory Revisions (that the author must respond to before a decision
on publication can be reached)
-------------------------------------------------------------------------------
Minor Essential Revisions (such as missing labels on figures, or the wrong use of
a term, which the author can be trusted to correct)
-------------------------------------------------------------------------------
Discretionary Revisions (which the author can choose to ignore)
What next?: Unable to decide on acceptance or rejection until the authors have
responded to the major compulsory revisions
Level of interest: An article of importance in its field
Quality of written English: Acceptable
Statistical review: Yes, and I have assessed the statistics in my report.
Declaration of competing interests:
I declare that I have no competing interests.
Reviewer's report
Title:Peroxisome Proliferators-Activated Alpha Agonist Treatment Improves
Hepatic Damage in Rats with Obstructive Jaundice: An Experimental Study
Version: 3Date:16 July 2007
Reviewer: Girdhar Agarwal
Reviewer's report:
General
Referee’s Report on the paper “Prexisome Proliferators – Activated Alpha
Agnonist Treatment: Ameeliorates Hepatic Damage in Rats with Obstructive
Jaundice: An Experimental Study” by Mehmet Cindoruk and others
It seems that the paper has been already reviewed earlier. So I am concentrating
on Statistical Analysis and methodology part.
1. 1. “Statistics” section is ambiguous. They talk about post hoc test about
equality of variances. Actually this has to be performed before one can use
ANOVA. It is not clear in what context “Bonferroni’s test” and “Duncan’s test” are
being used.
These two tests are “multiple comparisons” tests. They don’t have to do anything
with “equality or unequality of variances” as quoted in this section.
2. Sample size is small in each group, ANOVA is to be used very carefully.
Actually the assumptions of ANOVA (normality and homogeneity of variances
among four groups) may not be valid here. In that case, non-parametric test
(Kruskal-Wallis test) would be more appropriate.
3. It is not clear whether ANOVA is performed on all four groups or three groups
(BDL groups).
4. Once hypothesis is rejected in ANOVA test, multiple comparison (pair wise
comparison ) have to be performed. This is not done here.
5. The most important pair wise comparison is among the two groups: (i) Sham
and (ii) BDL + ferofibrate. This is not clear whether this is done here. See remark
4 also.
6. In my view, ultimate aim of the study should be whether the subjects
recovered fully after treatment. This can be answered by pair wise comparison
mentioned above in remark 5. A scant comparison between the two groups show
that the two groups are significantly different, a fact contradicting the recovery of
rats.
7. The value p < 0.001 is O.K. But wherever, they have mentioned p < 0.05, the
exact p-value should be given to express the strength of “significance difference”.
The above remarks should be considered before any decision is taken on the
paper.
-------------------------------------------------------------------------------
Major Compulsory Revisions (that the author must respond to before a decision
on publication can be reached)
-------------------------------------------------------------------------------
Minor Essential Revisions (such as missing labels on figures, or the wrong use of
a term, which the author can be trusted to correct)
-------------------------------------------------------------------------------
Discretionary Revisions (which the author can choose to ignore)
What next?: Unable to decide on acceptance or rejection until the authors have
responded to the major compulsory revisions
Level of interest: An article of importance in its field
Quality of written English: Acceptable
Statistical review: Yes, and I have assessed the statistics in my report.
Declaration of competing interests:
I declare that I have no competing interests.
Please review this paper.
user
Reviewer's report
Title:Peroxisome Proliferators-Activated Alpha Agonist Treatment Improves
Hepatic Damage in Rats with Obstructive Jaundice: An Experimental Study
Version: 3Date:16 July 2007
Reviewer: Girdhar Agarwal
Reviewer's report:
General
Referee’s Report on the paper “Prexisome Proliferators – Activated Alpha
Agnonist Treatment: Ameeliorates Hepatic Damage in Rats with Obstructive
Jaundice: An Experimental Study” by Mehmet Cindoruk and others
It seems that the paper has been already reviewed earlier. So I am concentrating
on Statistical Analysis and methodology part.
1. 1. “Statistics” section is ambiguous. They talk about post hoc test about
equality of variances. Actually this has to be performed before one can use
ANOVA. It is not clear in what context “Bonferroni’s test” and “Duncan’s test” are
being used.
These two tests are “multiple comparisons” tests. They don’t have to do anything
with “equality or unequality of variances” as quoted in this section.
2. Sample size is small in each group, ANOVA is to be used very carefully.
Actually the assumptions of ANOVA (normality and homogeneity of variances
among four groups) may not be valid here. In that case, non-parametric test
(Kruskal-Wallis test) would be more appropriate.
3. It is not clear whether ANOVA is performed on all four groups or three groups
(BDL groups).
4. Once hypothesis is rejected in ANOVA test, multiple comparison (pair wise
comparison ) have to be performed. This is not done here.
5. The most important pair wise comparison is among the two groups: (i) Sham
and (ii) BDL + ferofibrate. This is not clear whether this is done here. See remark
4 also.
6. In my view, ultimate aim of the study should be whether the subjects
recovered fully after treatment. This can be answered by pair wise comparison
mentioned above in remark 5. A scant comparison between the two groups show
that the two groups are significantly different, a fact contradicting the recovery of
rats.
7. The value p < 0.001 is O.K. But wherever, they have mentioned p < 0.05, the
exact p-value should be given to express the strength of “significance difference”.
The above remarks should be considered before any decision is taken on the
paper.
-------------------------------------------------------------------------------
Major Compulsory Revisions (that the author must respond to before a decision
on publication can be reached)
-------------------------------------------------------------------------------
Minor Essential Revisions (such as missing labels on figures, or the wrong use of
a term, which the author can be trusted to correct)
-------------------------------------------------------------------------------
Discretionary Revisions (which the author can choose to ignore)
What next?: Unable to decide on acceptance or rejection until the authors have
responded to the major compulsory revisions
Level of interest: An article of importance in its field
Quality of written English: Acceptable
Statistical review: Yes, and I have assessed the statistics in my report.
Declaration of competing interests:
I declare that I have no competing interests.
assistant