Reviewer's report
Title:The EPIYA-ABCC motif pattern in CagA of Helicobacter pylori is associated
with peptic ulcer and gastric cancer in Mexican population
Version:3Date:14 October 2014
Reviewer: Robert Raffaniello
Reviewer's report:
This study examines the relationship between H pylori and GI disorders in
Mexican patients with gastric pathologies. The prevalence of the CagA gene and
the EPIYA motif patterns of this virulence factor are also examined. The sample
size is adequate and the paper is well written. The results are presented well and
discussed intelligently. The findings are interesting and important. However, I
have a couple of issues regarding the study:
Major issues:
I am not sure why the authors chose to determine CagA types (ABC, ABCC, etc)
by PCR as opposed to sequencing the C-terminal of all 214 CagA+ samples.
This may actually be less expensive than all the PCR rxs involved. Instead, only
20 random samples were sequenced. With the complete sequence data, there
would be little ambiguity regarding the EPIYA arrangements, CRIPA sequences
and EPIYA-B polymorphisms. A more detailed and meaningful analysis would be
obtained.
My other question involves the histology samples. As mentioned in methods,
samples were taken for histology, but the results are not presented. If the
samples were examined for precancerous changes (atrophy, metaplasia),
inflammatory intensity, anaplasia, etc., this data could be related to Hp infection
and the presence of CagA. Do the authors intend to present this as a separate
study?
Minor issues (suggestions):
Line 280 It may be better to say “on the other hand.” (not by other hand)
Lines 306-308 should be reworded to be more clear.
Line 320-‘de cases’??
Line 350-change ‘likely’ to ‘possible’.
Figure 1 X-axis of top two graphs should be % H pylori positive % CagA positive.
Figure 2 It is Not clear what primers were used in these experiments. It is not
stated in legend.
Level of interest: An article of outstanding merit and interest in its field
Quality of written English: Acceptable
Statistical review: No, the manuscript does not need to be seen by a statistician.
Declaration of competing interests:
'I declare that I have no competing interests'
Reviewer's report
Title:The EPIYA-ABCC motif pattern in CagA of Helicobacter pylori is associated
with peptic ulcer and gastric cancer in Mexican population
Version:3Date:14 October 2014
Reviewer: Robert Raffaniello
Reviewer's report:
This study examines the relationship between H pylori and GI disorders in
Mexican patients with gastric pathologies. The prevalence of the CagA gene and
the EPIYA motif patterns of this virulence factor are also examined. The sample
size is adequate and the paper is well written. The results are presented well and
discussed intelligently. The findings are interesting and important. However, I
have a couple of issues regarding the study:
Major issues:
I am not sure why the authors chose to determine CagA types (ABC, ABCC, etc)
by PCR as opposed to sequencing the C-terminal of all 214 CagA+ samples.
This may actually be less expensive than all the PCR rxs involved. Instead, only
20 random samples were sequenced. With the complete sequence data, there
would be little ambiguity regarding the EPIYA arrangements, CRIPA sequences
and EPIYA-B polymorphisms. A more detailed and meaningful analysis would be
obtained.
My other question involves the histology samples. As mentioned in methods,
samples were taken for histology, but the results are not presented. If the
samples were examined for precancerous changes (atrophy, metaplasia),
inflammatory intensity, anaplasia, etc., this data could be related to Hp infection
and the presence of CagA. Do the authors intend to present this as a separate
study?
Minor issues (suggestions):
Line 280 It may be better to say “on the other hand.” (not by other hand)
Lines 306-308 should be reworded to be more clear.
Line 320-‘de cases’??
Line 350-change ‘likely’ to ‘possible’.
Figure 1 X-axis of top two graphs should be % H pylori positive % CagA positive.
Figure 2 It is Not clear what primers were used in these experiments. It is not
stated in legend.
Level of interest: An article of outstanding merit and interest in its field
Quality of written English: Acceptable
Statistical review: No, the manuscript does not need to be seen by a statistician.
Declaration of competing interests:
'I declare that I have no competing interests'
Please review this paper.
user
Reviewer's report
Title:The EPIYA-ABCC motif pattern in CagA of Helicobacter pylori is associated
with peptic ulcer and gastric cancer in Mexican population
Version:3Date:14 October 2014
Reviewer: Robert Raffaniello
Reviewer's report:
This study examines the relationship between H pylori and GI disorders in
Mexican patients with gastric pathologies. The prevalence of the CagA gene and
the EPIYA motif patterns of this virulence factor are also examined. The sample
size is adequate and the paper is well written. The results are presented well and
discussed intelligently. The findings are interesting and important. However, I
have a couple of issues regarding the study:
Major issues:
I am not sure why the authors chose to determine CagA types (ABC, ABCC, etc)
by PCR as opposed to sequencing the C-terminal of all 214 CagA+ samples.
This may actually be less expensive than all the PCR rxs involved. Instead, only
20 random samples were sequenced. With the complete sequence data, there
would be little ambiguity regarding the EPIYA arrangements, CRIPA sequences
and EPIYA-B polymorphisms. A more detailed and meaningful analysis would be
obtained.
My other question involves the histology samples. As mentioned in methods,
samples were taken for histology, but the results are not presented. If the
samples were examined for precancerous changes (atrophy, metaplasia),
inflammatory intensity, anaplasia, etc., this data could be related to Hp infection
and the presence of CagA. Do the authors intend to present this as a separate
study?
Minor issues (suggestions):
Line 280 It may be better to say “on the other hand.” (not by other hand)
Lines 306-308 should be reworded to be more clear.
Line 320-‘de cases’??
Line 350-change ‘likely’ to ‘possible’.
Figure 1 X-axis of top two graphs should be % H pylori positive % CagA positive.
Figure 2 It is Not clear what primers were used in these experiments. It is not
stated in legend.
Level of interest: An article of outstanding merit and interest in its field
Quality of written English: Acceptable
Statistical review: No, the manuscript does not need to be seen by a statistician.
Declaration of competing interests:
'I declare that I have no competing interests'
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