Biomedical subjects

E Sagratella

Publications and source records attributed to E Sagratella.

6 recordsLinked to original sources

PubMed2003

Two polyclonal antisera detect different AGE epitopes in human plasma samples.

Advanced glycation end products (AGEs), involved in the pathogenesis of diabetic complications, comprise a series of related chemical structures which might possess dissimilar immunogenic characteristics. In this study the levels of AGE in plasma samples from normal subjects (N=41) and diabetic patients (N=44) were measured by ELISA using two polyclonal antisera (named CF5 and CF199, respectively, and immunologically characterized) raised using two different immunogens and immunization techniques. Age levels were significantly higher in diabetic than in normal plasma samples (P<0.0001) with both antisera. However, CF199 detected higher AGE levels than CF5 both in normal (P<0.0001) and diabetic (P<0.005) samples. Pre-incubation with AGE-bovine serum albumin (BSA) caused the loss of most the reactivity of both antisera. Pre-incubation with carboxy-methyl-lysine-BSA (an oxidation-derived AGE) induced the loss of nearly all CF5 reactivity while CF199 retained a significant amount of activity against AGE antigens. Moreover, CF5 lost over 90% of its reactivity against BSA incubated with high glucose under non-oxidative conditions, suggesting its recognition of mainly oxidation-derived AGE epitopes. The different AGE levels measured by the two antisera suggests, therefore, that one single antiserum is unable to recognize all the various AGE epitopes which might be present, at any time, in tissues and body fluids in health and disease.

Diabetes Mellitus↗

PubMed2001

Advanced glycation end product levels in eye lenses, aorta, and tail tendon in transplanted diabetic inbred Lewis rats.

BACKGROUND: Pancreatic islet transplantation in diabetes, by restoring euglycemia, should in time correct the abnormal accumulation of advanced glycation end products (AGEs) over target tissues, thus delaying the development of late diabetic complications. METHODS: Homologous islet transplantation was performed in inbred Lewis rats 15 days (TA), 4 months (TB), and 8 months (TC) after streptozotocin diabetes. Group TA was studied for 12 months and groups TB and TC were studied for 4 months after transplantation. Normal (N) and diabetic (D) rats formed the control groups. Metabolic control in the transplant (T) groups was evaluated by oral glucose tolerance test. Blood glucose, glycated hemoglobin, and body weight were determined in all groups. AGE levels were determined by spectrofluorometry in eye lens proteins and by ELISA in aortic and tail tendon collagen. RESULTS: T groups showed normal oral glucose tolerance tests and metabolic parameters. The latter were altered in all D groups (P<0.005 to P<0.0001 versus N and T groups). AGEs were increased in the D groups (P<0.05 to P<0.001) versus the N groups. AGEs in the TA and TB groups were not different from those of the N groups but were significantly reduced (P<0.05 to P<0.001) when compared with those of the D groups. In the TC group, eye lens AGEs were significantly elevated (P<0.001) or significantly reduced (P<0.01) when compared with those of the N or D groups, respectively. Aortic collagen AGEs were elevated (P<0.01) by comparison with those of the N groups and not statistically different from those of the D groups. Tail tendon collagen AGE levels lay between those of the N and D groups, without reaching a statistical significance. CONCLUSIONS: These results indicate that primary and early secondary (groups TA and TB) but not late secondary (group TC) islet transplantations are capable of blocking or reducing an abnormal accumulation of AGEs, thus confirming the importance of preventive transplantation therapies.

Animals↗

PubMed2000

Altered IgG(4) renal clearance in patients with inflammatory bowel diseases. Evidence for a subclinical impairment of protein charge renal selectivity.

BACKGROUND: A loss of intestinal glycosaminoglycans (GAGs) has been shown in inflammatory bowel diseases (IBD). Since GAGs are involved in the regulation of renal protein filtration and GAGs disruption is associated with anionic proteinuria, we examined whether changes in the selectivity of renal protein filtration occur in IBD. METHODS: From 46 patients with IBD (17 with Crohn's disease (CD), and 29 with ulcerative colitis (UC)) and 21 healthy subjects, urine and serum samples were obtained. Albumin, total IgG and IgG(4) clearances were measured using sensitive methods. Serum p-ANCA and TNF-alpha were tested. RESULTS: Median IgG(4) clearance was 0.041 ml/ min/10(-3) in patients with UC and 0.10 ml/ min/10(-3) in CD patients, both significantly higher than in controls (0.03 ml/min/10(-3)) (P<0.03). IgG(4) clearance was above the upper normal limit in 9/17 CD (53%) and in 10/29 UC (34.5%). Eighteen of 19 patients showing abnormal IgG(4) clearance were taking mesalazine. In patients on maintenance oral mesalazine, IgG(4) clearance was higher than that in patients off treatment (0.12 vs 0.03 ml/min/10(-3), P=0.04). No clinical/laboratory sign of renal dysfunction was documented in patients with altered IgG(4) clearance and maintained on mesalazine treatment. CONCLUSION: Renal protein charge permselectivity is impaired in 40% of patients with IBD with no overt proteinuria. Our data suggest that altered IgG(4) clearance may represent a subclinical marker of renal involvement in IBD.

Administration, Oral↗

PubMed1998

Reduction of advanced glycation end-product (AGE) levels in nervous tissue proteins of diabetic Lewis rats following islet transplants is related to different durations of poor metabolic control.

Advanced glycation end-products (AGEs) are irreversible compounds which, by abnormally accumulating over proteins as a consequence of diabetic hyperglycaemia, can damage tissues and thus contribute to the pathogenesis of diabetic complications. This study was performed to evaluate whether restoration of euglycaemia by islet transplantation modifies AGE accumulation in central and peripheral nervous tissue proteins and, as a comparison, in proteins from a non-nervous tissue. Two groups of streptozotocin diabetic inbred Lewis rats with 4 (T1) or 8 (T2) months disease duration were grafted into the liver via the portal vein with 1200-1500 islets freshly isolated from normal Lewis rats. Transplanted rats, age-matched control and diabetic rats studied in parallel, were followed for a further 4-month period. At study conclusion, glycaemia, glycated haemoglobin and body weight were measured in all animals, and an oral glucose tolerance test (OGTT) performed in transplanted rats. AGE levels in cerebral cortex, spinal cord, sciatic nerve proteins and tail tendon collagen were measured by enzyme-linked immunosorbent assay (ELISA). Transplanted animal OGTTs were within normal limits, as were glycaemia and glycated haemoglobin. Diabetic animal AGEs were significantly higher than those of control animals. Protein AGE values were reduced in many transplanted animals compared to diabetic animals, reaching statistical significance in spinal cord (P < 0.05), sciatic nerve (P < 0.02) and tail tendon collagen (P < 0.05) of T1 animals. Thus, return to euglycaemia following islet transplantation after 4 months of diabetes with poor metabolic control reduces AGE accumulation rate in the protein fractions of the mixed and purely peripheral nervous tissues (spinal cord and sciatic nerve, respectively). However, after a double duration of bad metabolic control, a statistically significant AGE reduction has not been achieved in any of the tissues, suggesting the importance of an early therapeutic intervention to prevent the possibly pathological accumulation of AGEs in nervous and other proteins.

Animals↗

PubMed1997

Levels of advanced glycosylation end-products (AGE) in sera of pregnant diabetic women: comparison between type 1, type 2 and gestational diabetes mellitus.

The chronic hyperglycemia can lead to an increase of the advanced glycosylation end-products (AGE) levels on proteins and macromolecules. Abnormal levels of AGE in several tissues has been associated with the pathogenesis of late diabetic complications. In diabetic pregnant women, high AGE levels might influence the delicate maternal-fetal balance and therefore alter the pregnancy outcome. In this preliminary study, we have measured the AGE in sera of 44 diabetic women in two trimester. Sixteen sera from non diabetic pregnant women have been used as controls. The AGE have been analyzed by means of an ELISA method with an antiserum anti-RNAse-AGE, produced in the Laboratory of Clinical Biochemistry of the Istituto Superiore di Sanità. Diabetic patients type 1 and type 2, in good metabolic control, showed normal AGE levels at both trimester. Patients with gestational diabetes showed significantly high serum AGE levels (p < 0.05). A more extended study will give better insight on the association between AGE levels and a physiopathology of diabetic pregnancy.

Adult↗

PubMed1996

Antineutrophil cytoplasmic antibodies are present in long standing type 1 diabetics but do not correlate with selective proteinuria.

Antineutrophil cytoplasmic antibodies (ANCA) are present in systemic vasculitis with or without renal involvement and in inflammatory bowel diseases, conditions which share damage in proteoglycan content of basal membrane. In diabetes, there is a reduction in proteoglycans in the kidney basal membrane, responsible for the decrease in fixed anionic charges and, consequently, for the prevalent anionic proteinuria (albumin, IgG4) even in the early preclinical stage of nephropathy. The aims of this study were to search for the presence of ANCA in long-standing type 1 diabetic patients and to evaluate possible correlations with size- and/or charge-selective proteinuria. Twenty-two type 1 diabetic patients (duration of diabetes 24 years, range 9-30) selected and grouped according to albumin excretion rate values, were studied together with 21 age and sex comparable normal subjects. ANCA, albumin excretion rate, and the clearances of albumin, of prevalently cationic total IgG (IgG) and of anionic IgG4 were evaluated. ANCA were measured using ELISA and indirect immunofluorescence methods; albumin, IgG and IgG4 were tested with RIA or ELISA methods developed in our laboratory. ANCA were found in five patients, three of whom showed proteinuria. 33.3% and 18.2% of patients with normal IgG and albumin clearances respectively had elevated IgG4 clearance. This study shows for the first time the presence of ANCA in long-standing type 1 diabetic patients and confirms a prevalent anionic protein excretion in these patients, but does not show a correlation between the presence of ANCA and proteinuria, even if the presence of ANCA in diseases sharing alterations in proteoglycan content of vascular basal membrane is noteworthy.

Adult↗