Reviewer's report
 cagA and vacA in strains of Helicobacter pylori from ulcer and NUD patients Title:
Authors:
Gustavo Z Faundez (gfaundez@uec.inta.uchile.cl )
Miriam H Troncoso (mtronco@uec.inta.uchile.cl )
Guillermo G Figueroa (gfiguero@uec.inta.uchile.cl )
 1  11 May 2002 Version: Date:
 Dr Yoshio Yamaoka Reviewer:
 A paper whose findings are important to those with closely related research interests Level of interest:
 Unable to decide on acceptance or rejection until the authors have responded Advice on publication:
to the compulsory revisions
The authors examined the cagA and vacA status in Chilean population and found that cagA+/vacA 
s1m1 genotypes are closely related to duodenal ulcer. There are many similar reports including from South American population. 
cagA+/vacA s1m1 genotypes were really aEoestatisticallyaE higher in duodenal ulcer patients 
compared with in NUD patients, however the differences were trivial (p = 0.035). 
The authors should increase the patientsaETM number; otherwise it is very difficult to evaluate this 
small difference. 
They evaluated the cagA status only by PCR method using one sets of primers. The authors should use
1) multiple sets of primers, 2) PCR for cag empty site or 3) the combination of PCR and Southern blot 
hybridization. 
In title, the authors should not use abbreviations (NUD). 
Competing interests:
None declared.
Reviewer's report
 cagA and vacA in strains of Helicobacter pylori from ulcer and NUD patients Title:
Authors:
Gustavo Z Faundez (gfaundez@uec.inta.uchile.cl )
Miriam H Troncoso (mtronco@uec.inta.uchile.cl )
Guillermo G Figueroa (gfiguero@uec.inta.uchile.cl )
 1  11 May 2002 Version: Date:
 Dr Yoshio Yamaoka Reviewer:
 A paper whose findings are important to those with closely related research interests Level of interest:
 Unable to decide on acceptance or rejection until the authors have responded Advice on publication:
to the compulsory revisions
The authors examined the cagA and vacA status in Chilean population and found that cagA+/vacA 
s1m1 genotypes are closely related to duodenal ulcer. There are many similar reports including from South American population. 
cagA+/vacA s1m1 genotypes were really aEoestatisticallyaE higher in duodenal ulcer patients 
compared with in NUD patients, however the differences were trivial (p = 0.035). 
The authors should increase the patientsaETM number; otherwise it is very difficult to evaluate this 
small difference. 
They evaluated the cagA status only by PCR method using one sets of primers. The authors should use
1) multiple sets of primers, 2) PCR for cag empty site or 3) the combination of PCR and Southern blot 
hybridization. 
In title, the authors should not use abbreviations (NUD). 
Competing interests:
None declared.
Please review this paper.
user
Reviewer's report
 cagA and vacA in strains of Helicobacter pylori from ulcer and NUD patients Title:
Authors:
Gustavo Z Faundez (gfaundez@uec.inta.uchile.cl )
Miriam H Troncoso (mtronco@uec.inta.uchile.cl )
Guillermo G Figueroa (gfiguero@uec.inta.uchile.cl )
 1  11 May 2002 Version: Date:
 Dr Yoshio Yamaoka Reviewer:
 A paper whose findings are important to those with closely related research interests Level of interest:
 Unable to decide on acceptance or rejection until the authors have responded Advice on publication:
to the compulsory revisions
The authors examined the cagA and vacA status in Chilean population and found that cagA+/vacA 
s1m1 genotypes are closely related to duodenal ulcer. There are many similar reports including from South American population. 
cagA+/vacA s1m1 genotypes were really aEoestatisticallyaE higher in duodenal ulcer patients 
compared with in NUD patients, however the differences were trivial (p = 0.035). 
The authors should increase the patientsaETM number; otherwise it is very difficult to evaluate this 
small difference. 
They evaluated the cagA status only by PCR method using one sets of primers. The authors should use
1) multiple sets of primers, 2) PCR for cag empty site or 3) the combination of PCR and Southern blot 
hybridization. 
In title, the authors should not use abbreviations (NUD). 
Competing interests:
None declared.
assistant