Reviewer's report 
 Cytotoxic isolates of Helicobacter pylori from Peptic Ulcer Diseases decrease K+ -dependent Title: 
ATPase Activity in HeLa cells. 
Authors: 
Shanjana Awasthi ( awasthi@uthscsa.edu )
Archana Ayyagari ( archana@sgpgi.ac.in )
 1  9 Jul 2003 Version: Date: 
 Naibedya Chattopadhyay Reviewer: 
 A paper of considerable general medical or scientific interest Level of interest: 
 Accept after discretionary revisions Advice on publication: 
The manuscript by Awasthi and Ayyagari shows that cytotoxic H. pylori is isolated more frequently 
from peptic ulcer compared with gastritis patients. Cytotoxin assessment was made by measuring 
inhibition of a K+-dependent ATPase activity of HeLa cells upon incubation with H. pylori BCF. The study is clinically relevant and also has epidemiological significance. The paper is very well written and data are convincing. However, I would recommend the following minor changes before the 
manuscript is finally accepted. 
1. Please mark H. pylori in Fig 1 (b) and (c). Fig 1(e) is not necessary and should be deleted. 
2. Although the rounding of HeLa cells is visible in Fig 2 (b). It would be very effective if these 
changes are marked inside Fig 2 (b). 
3. Authors mention in Results section that a heat-labile factor was responsible for cytotoxicity. Was any attempt made to identify the proteins in BCFs or H. pylori strains? 
4. Delete lines 9 (In a very recent -----) and 12 (The 
sialyl-chimeric------) on page 13, Discussion section. These lines do not have relevance in context 
with the subject of the manuscript. 
Competing interests: 
None declared. 
Reviewer's report 
 Cytotoxic isolates of Helicobacter pylori from Peptic Ulcer Diseases decrease K+ -dependent Title: 
ATPase Activity in HeLa cells. 
Authors: 
Shanjana Awasthi ( awasthi@uthscsa.edu )
Archana Ayyagari ( archana@sgpgi.ac.in )
 1  9 Jul 2003 Version: Date: 
 Naibedya Chattopadhyay Reviewer: 
 A paper of considerable general medical or scientific interest Level of interest: 
 Accept after discretionary revisions Advice on publication: 
The manuscript by Awasthi and Ayyagari shows that cytotoxic H. pylori is isolated more frequently 
from peptic ulcer compared with gastritis patients. Cytotoxin assessment was made by measuring 
inhibition of a K+-dependent ATPase activity of HeLa cells upon incubation with H. pylori BCF. The study is clinically relevant and also has epidemiological significance. The paper is very well written and data are convincing. However, I would recommend the following minor changes before the 
manuscript is finally accepted. 
1. Please mark H. pylori in Fig 1 (b) and (c). Fig 1(e) is not necessary and should be deleted. 
2. Although the rounding of HeLa cells is visible in Fig 2 (b). It would be very effective if these 
changes are marked inside Fig 2 (b). 
3. Authors mention in Results section that a heat-labile factor was responsible for cytotoxicity. Was any attempt made to identify the proteins in BCFs or H. pylori strains? 
4. Delete lines 9 (In a very recent -----) and 12 (The 
sialyl-chimeric------) on page 13, Discussion section. These lines do not have relevance in context 
with the subject of the manuscript. 
Competing interests: 
None declared. 
Please review this paper.
user
Reviewer's report 
 Cytotoxic isolates of Helicobacter pylori from Peptic Ulcer Diseases decrease K+ -dependent Title: 
ATPase Activity in HeLa cells. 
Authors: 
Shanjana Awasthi ( awasthi@uthscsa.edu )
Archana Ayyagari ( archana@sgpgi.ac.in )
 1  9 Jul 2003 Version: Date: 
 Naibedya Chattopadhyay Reviewer: 
 A paper of considerable general medical or scientific interest Level of interest: 
 Accept after discretionary revisions Advice on publication: 
The manuscript by Awasthi and Ayyagari shows that cytotoxic H. pylori is isolated more frequently 
from peptic ulcer compared with gastritis patients. Cytotoxin assessment was made by measuring 
inhibition of a K+-dependent ATPase activity of HeLa cells upon incubation with H. pylori BCF. The study is clinically relevant and also has epidemiological significance. The paper is very well written and data are convincing. However, I would recommend the following minor changes before the 
manuscript is finally accepted. 
1. Please mark H. pylori in Fig 1 (b) and (c). Fig 1(e) is not necessary and should be deleted. 
2. Although the rounding of HeLa cells is visible in Fig 2 (b). It would be very effective if these 
changes are marked inside Fig 2 (b). 
3. Authors mention in Results section that a heat-labile factor was responsible for cytotoxicity. Was any attempt made to identify the proteins in BCFs or H. pylori strains? 
4. Delete lines 9 (In a very recent -----) and 12 (The 
sialyl-chimeric------) on page 13, Discussion section. These lines do not have relevance in context 
with the subject of the manuscript. 
Competing interests: 
None declared. 
assistant