Review for 10.1186/1471-230X-2-3 (2002)

Reviewer's□report 
□Analysis□of□gallstones□from□children□and□adults□using□spectroscopic□methods Title: 
Authors: 
oleg□kleiner□( finaly@bgumail.bgu.ac.il )
jagannathan□ramesh□( jram@bgumail.bgu.ac.il )
mahmoud□huleihel□( mahmoudh@bgumail.bgu.ac.il )
beny□cohen□( bcohen@bgumail.bgu.ac.il )
keren□kantarovich□( kerenk@bgumail.bgu.ac.il )
chen□levi□( chenl@bgumail.bgu.ac.il )
boris□polyak□( polyak@bgumail.bgu.ac.il )
robert□s□marks□( rsmarks@bgumail.bgu.ac.il )
jacov□mordehai□( mordehai@bgumail.bgu.ac.il )
zahavi□cohen□( zahavic@bgumail.bgu.ac.il )
shaul□mordechai□( shaulm@bgumail.bgu.ac.il )
□1□ □16□Dec□2001 Version: Date: 
□Dr□Edeline□Wentrup-Byrne 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 
I□found□this□an□interesting□but□difficult□paper□to□read.□The□title□is□a□little□deceptive□because□only□a□fraction□ 
of□the□stones□were□from□children□and□yet□this□seems□to□be□the□emphasis□of□the□originality□of□the□study.□ 
Perhaps□a□title□such□as□"A□comparative□study□of□---"□might□be□more□appropriate.□ 
Some□general□comments□first.□ 
One□difficulty□was□the□somewhat□repetitive□nature□of□the□writing.□Every□so□often□statements□re□the□origen□ 
of□gallstone□disease□are□presented□without□any□clear□reason□as□to□why.□ 
Most□of□these□general□statements□could□be□made□once□in□the□background.□The□statement□on□page□3□re□ 
myocardial□infarction□is□rather□specific□and□irrelevant.□There□are□plenty□of□examples□of□IR□studies□of□both gallstones□and□kidney□stones□which□I□feel□would□be□of□more□interest□to□the□would-be□readers.□ 
The□difficulty□was□mainly□due□to□the□overall□lack□of□organisation□in□presentation□of□the□data.□While□I□ 
realise□that□the□accepted□presentation□of□a□paper□such□as□this□when□submitted□to□a□"science"□journal□as□ 
opposed□to□a□more□medically□oriented□journal□may□be□different□I□feel□that□the□paper□would□benefit□greatly□ 
from□the□inclusion□of□a□few□tables□summarising□the□types□and□percentages□of□stones□found□both□in□adults 
and□children□as□well□as□the□principal□absorption□bands□found□in□this□study□and□compared□with□the□ 
literature□values.□ 
The□authors□refer□often□to□a□well-known□set□of□published□papers□which□describe□various□vibrational□ 
spectroscoplic□studies□of□gallstones□but□miss□a□couple□of□very□important□ones□which□might□have□greatly□ 
helped□in□the□analysis□of□thier□data□and□the□writing□up.□ 
[1]□Examples□are:□"Comparison□of□Vibrational□Spectroscopic□techniques□for□the□Characterization□of□ 
Human□Gallstones"□by□Wentrup-Byrne□et□al.□Applied□Spectroscopy□49,□7,□1028□1995.□ 
[2]"FT-Raman,□FT_IR□and□PIXIE□analysis□applied□to□Gallstone□Specimens"□ 
C.Paluszkiewicz□et□al.□Journal□of□Cellular□and□Molecular□Biology,□44□(1)□65□1998□ 
The□special□Edition□of□Biospectroscopy□dedicated□to□gallstone□and□kidney□stone□research□in□1997.□ 
Volume□3,□(5).□ 
to□name□but□a□few.□The□authors□refer□to□one□paper□in□this□issue□but□not□a□following□paper□which□has□ 
relevant□FTIR□information.□ 
The□authors□claim□that□there□are□three□main□categories□of□gallstones□but□most□of□the□spectroscopic□ 
studies□published□have□shown□clearly□that□as□well□as□4□main□types□ 
[1]□cholesterol□ 
[2]□mixed□ 
[3]□black□ [4]□brown□ 
there□are□several□sub-categories□of□pigment□stones.□One□such□category□is□whether□or□not□Calcium□ 
carbonate□is□present□or□not.□ 
The□authors□refer□to□apitite□and□apatite□several□times□in□the□text.□They□do□not□specify□what□they□mean□by□ 
this□so□I□assume□they□mean□calcium□hydroxy□phosphate□which□has□NO□C-C□bonds□and□hence□cannot□ 
have□a□C-C□stretching□mode□in□the□IR□as□stated□on□p□17□.□The□characteristic□IR□band□for□the□P-O□stretch□ in□apatite□according□to□the□literature□(on□p□382□Biospectroscopy□3□(5)□1997)□ is□1030□cm-1.□ 
The□authors□refer□to□a□"new"□green□stone□which□although□rare□has□been□studied□using□vibrational□ 
spectroscopy□(see□page□1032□recommended□reference□1□above).□Both□the□calcite□and□aragonite□forms□ of□calcium□carbonate□have□been□detected□in□such□stones.□But□not□to□my□knowledge□apatite.□The□ 
spectrum□in□Figure□5□shows□no□apatite□phosphate□stretch.□ 
The□spectra□in□Figures□1□nad□5□would□benefit□from□stacking□rather□than□overlapping.□Also□mark□some□of□ 
the□significant□bands□for□ease□of□identification.□ 
A□few□complete□spectra□should□be□included:□a□typical□balck□I,□typical□black□II□and□brown□together□with□a□ 
reference□cholesterol,□bilirubin□and□calcium□carbonate□??□ 
Finally,□regarding□the□FTIR□sampling□techniques□used.□Usually□FTIR□ATR□is□used□on□biological□samples□ 
where□there□is□a□desire□NOT□to□have□to□grind□up□the□sample□for□the□more□conventional□KBR□pellet□ 
method.□On□p□4□in□Materials□and□Methods□it□is□stated□that□KBr□discs□were□made.□ 
And□that□for□FTIR□ATR□only□"stone□powder"□was□used.□Yet□on□page□7□under□the□comparison□section□ 
"regular□FTIR□spectra□of□the□entire□and□part□of□the□surface□of□a□brown□stone"□is□mentioned.□They□talk□ 
about□the□outer□and□inner□surfaces□but□this□is□contradicted□by□the□statement□in□the□methods.□The□ significant□"changes"□(differences)□in□the□spectra□elude□me□I□must□confess.□ 
I□feel□that□a□clearer□distinction□should□be□made□-□both□in□the□text□and□in□the□spectra□-□between□the□two□ 
types□of□black□stones□and□brown□stones.□it□all□gets□a□little□confusing.□ 
On□page□10□the□authors□discuss□Copper□vs□Calcium□bilirubinate□salts□in□balck□vs□brown□stones.□They□ 
should□refer□to□reference□2□mentioned□above□for□a□detailed□FTIR□study□of□such□salts.□ 
From□a□medical□point□of□view□I□found□myself□wondering□if□any□of□the□patients□are□know□to□be□suffering□ 
from□thalassemia?□ 
It□is□now□generally□accepted□that□FTIR□alone□will□not□provide□ALL□the□molecular□information□which□might□ 
be□needed□for□an□analysis□of□gallstones.□A□combination□of□vibrational□spectroscopic□techniques□will□give□ a□more□complete□picture.□ 
I□feel□that□this□work□would□benefit□greatly□from□a□critical□rewriting□and□should□be□considered□for□ 
publication□after□a□rewrite. 
Competing□interests: 
None□declared.