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fucose-specific lectins secreted by the liver
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C A R B O H Y D R A T E - B I N D I N G P R O T E I N S OF H U M A N S E R U M I N C L U D E TWO M A N N O S E / F U C O S E - S P E C I F I C L E C T I N S S E C R E T E D BY THE L I V E R M.E. Taylor, J.A. Summerfield, D e p a r t m e n t of Medicine, Royal H o s p i t a l School of Medicine, L o n d o n NW3 2QG.
Free
H u m a n s e r u m c o n t a i n s m a n n o s e - b i n d i n g p r o t e i n s (MBP) w h i c h i n h i b i t the u p t a k e by rat s i n u s o i d a l cells of m a n n o s e - t e r m i n a t e d g l y c o p r o t e i n s . We have i s o l a t e d two of t h e s e lectins from h u m a n s e r u m by a f f i n i t y c h r o m a t o g r a p h y . One l e c t i n (MBP I) has a n a t i v e M_ of 7 0 0 , 0 0 0 w i t h s u b u n i t s of M 32,000 and the o t h e r (MBP 2) has a M o f t 2 0 0 , 0 0 0 w i t h s u b u n i t s of M 28[000. Both lectins are M a n / F u c o s e s p e c i f i c but MBP 1 also has s p e c i f i c i ~ i e s for Na c e t y l g l u c o s a m i n e , g l u c o s e and N - a c e t y l m a n n o s a m i n e . MBP 2 r e c o g n i z e s the core s u g a r s of o l i g o s a c c h a r i d e s as well as the t e r m i n a l s u g a r s and in this r e s p e c t it d i f f e r s from the s i n u s o i d a l cell m a n n o s e receptor. B o t h lectins are c a l c i u m d e p e n d e n t and the c o n c e n t r a t i o n of Ca r e q u i r e d for half maximal b i n d i n g (0.095mM) is well b e l o w the Ca c o n c e n t r a t i o n of serum. MBP 1 binds m a x i m a l l y b e t w e e n pH 7-9 w h e r e a s MBP 2 has a pH o p t i m u m of 6-7, s u g g e s t i n g that d i f f e r e n t amino acids are i n v o l v e d in the b i n d i n g site of e a c h lectin. S c a t c h a r d p l o t s of e q u i l i b r i u m - b i n d i n g to m a n n a n (a m a n n o s e - c o n t a i n i n g p r o t e o g l y c a n ) w e r e l i n e a r i n d i c a t i n g that each l e c t i n has a s i n g l e type of b i n d i n g ~ite~ The a p p a r e n t a s s o c i a t i o n c g n s t a n t s for b i n d i n g to m a n n a n are 2.1 x i0- M-- for MBP 1 and 1.3 x i0 ~ M-~ for MBP 2. A n t i b o d i e s against an MBP i s o l a t e d from h u m a n liver r e a c t w i t h MBP i. MBP 2 can also be i s o l a t e d from liver s u g g e s t i n g that b o t h s e r u m MBPs m a y be s e c r e t e d from the liver. The p h y s i o l o g i c a l ligands and f u n c t i o n s of s e r u m M B P s and t h e i r r e l a t i o n s h i p w i t h the s i n u s o i d a l cell m a n n o s e r e c e p t o r are unknown. They c o u l d act as part of the i m m u n e system, b i n d i n g y e a s t s and bacteria, as g r o w t h factors or as i n a c t i v a t o r s of l y s o s o m a l enzymes.
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SPECTRAL ANALYSIS OF THE ELECTROENCEPHALOGRAM (EEG) PREDICTS PORTAL SYSTEMIC ENCEPHALOPATHY (PSE) IN CIRRHOTIC PATIENTS SUBMITTED TO A DISTAL SPLENO-RENAL SHUNT (SRS). J. Ter~s, G. Silva, J. Masana, J. Rod,s. Liver Unit and Neurology Service. Hospital Clinic i Provincial Medical School. Barcelona. Spain.
Recently published c l i n i c a l t r i a l s comparing SRS with endoscopic sclerotherapy (ES) in the elective treatment of esophageal varices have shown that SRS is more effective than ES in preventing further bleeding. However, ES is preferred to SRS because its major protection against PSE. This study was aimed to identify preoperative factors with predictive value of postoperative PSE in order to improve selection c r i t e r i a for elective SRS.With this purpose, 30 preoperative c l i n i c a l and biological variables and 25 from the spectral analysis of the preoperative EEG of 43 Child class A and B cirrhotic patients submitted to an SRS were analyzed in relation to the presence of PSE during a mean follow-up of 33.6+22 months.PSE was detected in 15 patients (34.8%). In the univariate analysis (Kaplan-Meier-curves compared by Mantel-Cox test), prothrombina c t i v i t y <80%, BUN>20mg/dl, mean dominant frequency0.29 had 38% and 57 months respectively (X2=7.67, pC006). I t is concluded that spectral analysis of EEG can help in the election between SRS and EV in the elective treatment of bleeding varices.
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C A R B O H Y D R A T E - B I N D I N G P R O T E I N S OF H U M A N S E R U M I N C L U D E TWO M A N N O S E / F U C O S E - S P E C I F I C L E C T I N S S E C R E T E D BY THE L I V E R M.E. Taylor, J.A. Summerfield, D e p a r t m e n t of Medicine, Royal H o s p i t a l School of Medicine, L o n d o n NW3 2QG.
Free
H u m a n s e r u m c o n t a i n s m a n n o s e - b i n d i n g p r o t e i n s (MBP) w h i c h i n h i b i t the u p t a k e by rat s i n u s o i d a l cells of m a n n o s e - t e r m i n a t e d g l y c o p r o t e i n s . We have i s o l a t e d two of t h e s e lectins from h u m a n s e r u m by a f f i n i t y c h r o m a t o g r a p h y . One l e c t i n (MBP I) has a n a t i v e M_ of 7 0 0 , 0 0 0 w i t h s u b u n i t s of M 32,000 and the o t h e r (MBP 2) has a M o f t 2 0 0 , 0 0 0 w i t h s u b u n i t s of M 28[000. Both lectins are M a n / F u c o s e s p e c i f i c but MBP 1 also has s p e c i f i c i ~ i e s for Na c e t y l g l u c o s a m i n e , g l u c o s e and N - a c e t y l m a n n o s a m i n e . MBP 2 r e c o g n i z e s the core s u g a r s of o l i g o s a c c h a r i d e s as well as the t e r m i n a l s u g a r s and in this r e s p e c t it d i f f e r s from the s i n u s o i d a l cell m a n n o s e receptor. B o t h lectins are c a l c i u m d e p e n d e n t and the c o n c e n t r a t i o n of Ca r e q u i r e d for half maximal b i n d i n g (0.095mM) is well b e l o w the Ca c o n c e n t r a t i o n of serum. MBP 1 binds m a x i m a l l y b e t w e e n pH 7-9 w h e r e a s MBP 2 has a pH o p t i m u m of 6-7, s u g g e s t i n g that d i f f e r e n t amino acids are i n v o l v e d in the b i n d i n g site of e a c h lectin. S c a t c h a r d p l o t s of e q u i l i b r i u m - b i n d i n g to m a n n a n (a m a n n o s e - c o n t a i n i n g p r o t e o g l y c a n ) w e r e l i n e a r i n d i c a t i n g that each l e c t i n has a s i n g l e type of b i n d i n g ~ite~ The a p p a r e n t a s s o c i a t i o n c g n s t a n t s for b i n d i n g to m a n n a n are 2.1 x i0- M-- for MBP 1 and 1.3 x i0 ~ M-~ for MBP 2. A n t i b o d i e s against an MBP i s o l a t e d from h u m a n liver r e a c t w i t h MBP i. MBP 2 can also be i s o l a t e d from liver s u g g e s t i n g that b o t h s e r u m MBPs m a y be s e c r e t e d from the liver. The p h y s i o l o g i c a l ligands and f u n c t i o n s of s e r u m M B P s and t h e i r r e l a t i o n s h i p w i t h the s i n u s o i d a l cell m a n n o s e r e c e p t o r are unknown. They c o u l d act as part of the i m m u n e system, b i n d i n g y e a s t s and bacteria, as g r o w t h factors or as i n a c t i v a t o r s of l y s o s o m a l enzymes.
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SPECTRAL ANALYSIS OF THE ELECTROENCEPHALOGRAM (EEG) PREDICTS PORTAL SYSTEMIC ENCEPHALOPATHY (PSE) IN CIRRHOTIC PATIENTS SUBMITTED TO A DISTAL SPLENO-RENAL SHUNT (SRS). J. Ter~s, G. Silva, J. Masana, J. Rod,s. Liver Unit and Neurology Service. Hospital Clinic i Provincial Medical School. Barcelona. Spain.
Recently published c l i n i c a l t r i a l s comparing SRS with endoscopic sclerotherapy (ES) in the elective treatment of esophageal varices have shown that SRS is more effective than ES in preventing further bleeding. However, ES is preferred to SRS because its major protection against PSE. This study was aimed to identify preoperative factors with predictive value of postoperative PSE in order to improve selection c r i t e r i a for elective SRS.With this purpose, 30 preoperative c l i n i c a l and biological variables and 25 from the spectral analysis of the preoperative EEG of 43 Child class A and B cirrhotic patients submitted to an SRS were analyzed in relation to the presence of PSE during a mean follow-up of 33.6+22 months.PSE was detected in 15 patients (34.8%). In the univariate analysis (Kaplan-Meier-curves compared by Mantel-Cox test), prothrombina c t i v i t y <80%, BUN>20mg/dl, mean dominant frequency
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