Review for 10.1186/1471-230X-14-89 (2014)

Reviewer's report
Title:Fast food diet with CCl4 micro-dose induced hepatic-fibrosis -A Novel
animal model
Version:1Date:28 November 2013
Reviewer: Dina Tiniakos
Reviewer's report:
Major compulsory revisions
1. Background, 2nd paragraph: The ALIOS diet (Tetri LH et al, 2008) should be
included among the diet modulations producing experimental NASH and
compared to the FFD mouse model.
2. Methods, Pathology, grading and scoring: The references used do not
adequately correspond to the histological methods for grading and staging
applied. In the Tables section, Kleiner et al 2005 reference (numbered 31 in this
manuscript) is mentioned and this, as well well other more appropriate
references, should be included here. When referring to fibrosis the terms
"staging" and "stage" is more appropriate than "scoring" and "grade". The
method used for assessing fibrosis ( Table 1) needs to be referenced. In Table 1,
the meaning of the contents in the percentage column is not clear. Does this
percentage refer to the extent of fibrosis compared to the whole tissue area? The
method of assessing severity of fibrosis needs to be modified according to
previously used and widely staging criteria i.e. Kleiner et al, 2005, Brunt et al,
1999. In Table 2, scoring for ballooning is modified and does not correspond to
Kleiner et al, 2005. The histological criteria used need to be defined in more
detail.
3. Results, paragraph 5: The topography of the steatohepatitic lesions is not
described nor the presence of Mallory-Denk bodies. The periseptal
predominance of lesions in FFD/CCl4 treated animals (Figure 1, 4th row) should
be mentioned and adequately explained in the discussion section. The type of
inflammatory cells present in the necroinflammatory foci should be described.
4. Results: The metabolic background of this new animal model has to be
described and assessed in detail. Its lack of similarity to that of human NAFLD
has to be further analysed and a section on the limitations of the model should be
added in the discussion.
5. Results, last page: The authors state that inflammation is indicative of
steatohepatitis in their model. Steatohepatitis is diagnosed as a combination of
steatosis, hepatocellular ballooning and inflammation and therefore this sentence
needs correction.
6. Discussion: Discussion is repetitive regarding the histology of the model and
should be amended accordingly.
7. Discussion, 4th paragraph: Needs rephrasing and attention to the use of
English. Progression to fibrosis is not the result of increased fatty acid import or
synthesis by hepatocytes as wrongly stated. In addition, the two-hit model of
NASH pathogenesis is not supported by current evidence. The authors should
revise this part of the discussion and better support their arguments on the
pathophysiological mechanisms underlying the development of the new animal
model.
8. Figures: Additional arrows needed to point to histological features discussed in
the legends. In Figure 2 the arrows do not point to inflammatory foci as stated in
the legend. Actually, inflammation is very mild In these photos and not
representative of the moderate inflammatory activity that is described in the
results. Magnification in Figure 2 is stated as x400 but it looks lower.
Minor essential revisions
1. Abstract, Results: The acronym TG should be explained here and where it first
appears in the text (background, last paragraph)
2. Abstract, Conclusions: The term "pathologies" should be replaced by
"histological features" or " histological lesions". The plural of the word "pathology"
although occasionally appears in some scientific texts is not correct and should
be avoided. It should be replaced wherever it appears in this manuscript
3. Methods, Development of animal model, last paragraph: The use of the terms
"sacrificing - sacrificed" is recommended instead of "killing-killed"
4. Methods: The initials of the pathologist who performed the histological analysis
should be included here and he/she should be listed among the co-authors
5. Table 2: Change number of reference from 33 to 31
6. Tables 1 & 2: when referring to microscopic fields please define power (x20,
x40 etc)
Level of interest: An article whose findings are important to those with closely
related research interests
Quality of written English: Needs some language corrections before being
published
Statistical review: Yes, but I do not feel adequately qualified to assess the
statistics.
Declaration of competing interests:
I declare I have no competing interests