Reviewer's report
Title:Tryptophan degradation in Irritable Bowel Syndrome: Evidence of
indoleamine 2,3-dioxygenase activation in a male cohort.
Version: 1Date:17 July 2008
Reviewer: Dietmar Fuchs
Reviewer's report:
This paper describes enhanced degradation of tryptophan in the peripheral blood
of patients with inflammatory bowel disease. Authors conclude that
inflammation-induced indoleamine 2,3-dioxygenase may represent the
biochemical background of this observation. The study is well performed and
sound. However, it suffers from the small number of patients (n = 10; kynurenic
acid was measured in only 6 of them!), and so the rather lengthy discussion of
the data is not really justified. The manuscript can go as a brief and preliminary
report instead of a full paper.
Interestingly the significance to distinguish patients and controls is much greater
than that for tryptophan or ratio. Authors should comment on that finding. Authors
should briefly comment on the rather huge overlap of tryptophan and kynurenine
between groups. Neopterin has been described as a potential marker of disease
activity in IBD patient, however not cited.
Authors measured tryptophan metabolic abnormalities + neopterin. To
substantiate the association between neopterin and tryptophan degradation the
correlation should be calculated and shown as a graph.
Discussion, line 8: ... decreased availability of tryptophan… has not been found
in patients. So to discuss potential consequences of subnormal tryptophan
seems rather obsolete.
Tables 1 and 2 are not really necessary, content can be easily included in the
text. All marker concentrations were independent of age, so the details for all
individual compounds are not necessary. Group comparisons are given anyhow
(text and figures).
Concentrations of tryptophan and catabolites should be given in µmol/L instead
of ng/mL.
Minor:
should read L-kynurenine instead of l-kynurenine throughout
References (instead of referances)
Level of interest: An article of importance 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:Tryptophan degradation in Irritable Bowel Syndrome: Evidence of
indoleamine 2,3-dioxygenase activation in a male cohort.
Version: 1Date:17 July 2008
Reviewer: Dietmar Fuchs
Reviewer's report:
This paper describes enhanced degradation of tryptophan in the peripheral blood
of patients with inflammatory bowel disease. Authors conclude that
inflammation-induced indoleamine 2,3-dioxygenase may represent the
biochemical background of this observation. The study is well performed and
sound. However, it suffers from the small number of patients (n = 10; kynurenic
acid was measured in only 6 of them!), and so the rather lengthy discussion of
the data is not really justified. The manuscript can go as a brief and preliminary
report instead of a full paper.
Interestingly the significance to distinguish patients and controls is much greater
than that for tryptophan or ratio. Authors should comment on that finding. Authors
should briefly comment on the rather huge overlap of tryptophan and kynurenine
between groups. Neopterin has been described as a potential marker of disease
activity in IBD patient, however not cited.
Authors measured tryptophan metabolic abnormalities + neopterin. To
substantiate the association between neopterin and tryptophan degradation the
correlation should be calculated and shown as a graph.
Discussion, line 8: ... decreased availability of tryptophan… has not been found
in patients. So to discuss potential consequences of subnormal tryptophan
seems rather obsolete.
Tables 1 and 2 are not really necessary, content can be easily included in the
text. All marker concentrations were independent of age, so the details for all
individual compounds are not necessary. Group comparisons are given anyhow
(text and figures).
Concentrations of tryptophan and catabolites should be given in µmol/L instead
of ng/mL.
Minor:
should read L-kynurenine instead of l-kynurenine throughout
References (instead of referances)
Level of interest: An article of importance 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:Tryptophan degradation in Irritable Bowel Syndrome: Evidence of
indoleamine 2,3-dioxygenase activation in a male cohort.
Version: 1Date:17 July 2008
Reviewer: Dietmar Fuchs
Reviewer's report:
This paper describes enhanced degradation of tryptophan in the peripheral blood
of patients with inflammatory bowel disease. Authors conclude that
inflammation-induced indoleamine 2,3-dioxygenase may represent the
biochemical background of this observation. The study is well performed and
sound. However, it suffers from the small number of patients (n = 10; kynurenic
acid was measured in only 6 of them!), and so the rather lengthy discussion of
the data is not really justified. The manuscript can go as a brief and preliminary
report instead of a full paper.
Interestingly the significance to distinguish patients and controls is much greater
than that for tryptophan or ratio. Authors should comment on that finding. Authors
should briefly comment on the rather huge overlap of tryptophan and kynurenine
between groups. Neopterin has been described as a potential marker of disease
activity in IBD patient, however not cited.
Authors measured tryptophan metabolic abnormalities + neopterin. To
substantiate the association between neopterin and tryptophan degradation the
correlation should be calculated and shown as a graph.
Discussion, line 8: ... decreased availability of tryptophan… has not been found
in patients. So to discuss potential consequences of subnormal tryptophan
seems rather obsolete.
Tables 1 and 2 are not really necessary, content can be easily included in the
text. All marker concentrations were independent of age, so the details for all
individual compounds are not necessary. Group comparisons are given anyhow
(text and figures).
Concentrations of tryptophan and catabolites should be given in µmol/L instead
of ng/mL.
Minor:
should read L-kynurenine instead of l-kynurenine throughout
References (instead of referances)
Level of interest: An article of importance 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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