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J.$A.$CABEZAS$FERNANDEZ$DEL$CAMPO$$y"col.$

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We! have! studied! the! potential! use! of! certain! lectins! as! indicators! for! the!

possible! follow6up! of! the! health! status! of! human! operated! for! colorectal! cancer!
(who! remained! apparently! healthy! at! least! 769! months! after! surgery).! We! have!
employed! simple! assays! with! some! selected! (commercially! available)! lectins.! To!
our! knowledge,! this! aspect! of! the! issue! has! received! little! attention.! These! lectins!
could! detect! changes! in! Neu5Ac6,! GlcNAc6,! a6L6Fuc,! a6Gal6,! a6Man6! y! GalNAc6!
containing!glycoconjugates!from!the!sera!of!colorectal!cancer!operated!subjects!in!
comparison!to!control!sera.!

2.)MATERIAL)AND)METHODS)
2.1$Patients$

Serum! specimens! were! collected! from! 86! adults! (age! 51688! years)! after!
informed! consent! had! been! obtained.! The! control! group! comprised! 13! individual!
judged!to!be!healthy!on!the!basis!of!their!medical!history.!The!experimental!groups!
comprised! 72! subjects! with! a! diagnosis! of! colorectal! cancer! as! demonstrated! by!
histological! tests.! Patients/formerly! patients! were! distributed! in! three! groups:!
Group! I,! of! 28! subjects! explored! 1! day! before! surgical! exeresis;! group! II,! with! 18!
subjects! analysed! 467! days! after! surgery;! and! group! III,! with! 27! subjects!
investigated!769!months!after!surgical!exeresis.!

2.2$Blood$sampling$$

Blood!was!taken!by!venipuncture!from!fasting!subjects!between!09:00!and!
10:00! under! standard! conditions.! Samples! were! collected! in! sterile! tubes!
(Terumo®)! with! coagulation! activators! and! a! silicone! coated! gel! barrier! to! aid!
separation!of!the!serum.!After!being!allowed!to!settle!for!a!suitable!time!(<!1!h)!at!
room!temperature,!tubes!were!centrifuged!at!3000!x!g!for!10!min.!The!serum!thus!
collected!was!distributed!in!aliquots!of!500!µl!each!and!stored!at!680!°C!until!use.!

2.3$Chemicals$

All!reagents!were!of!analytical!grade!or!the!highest!purity!available.!

2.4$Protein$Ddetermination$

! Proteins!were!determined!by!the!method!of!Lowry!et!al.!(14,!15).!

2.5$Lecitinas$

! Biotinylated! lectins! were! from! Vector! Laboratories! (USA),! except! Helix!
pomatia! (HPA)! and! Vicia! villosa! (VVA)! lectins! (Sigma,! USA).! ExtraAvidin®! 6
Peroxidase!and!2,2’6azino6bis!(36ethylbenzthiazoline666sulfonic!acid)!(ABTS)!were!
also!from!Sigma!(USA).!

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