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Biomedical subjects

F Gavazzi

Publications and source records attributed to F Gavazzi.

8 recordsLinked to original sources

Fresh human islet transplantation to replace pancreatic endocrine function in type 1 diabetic patients. Report of six cases.

The aim of this study was to evaluate the feasibility of islet allografts in patients with type 1 diabetes mellitus. Six patients received human islets from either one or two donors via the portal vein, after (n = 4) or simultaneously with (n = 2) a kidney graft. The patients with functioning kidney grafts (nos. 1-4) were already on triple immunosuppressive therapy (cyclosporine A, azathioprine, prednisone). Prednisone was increased to 60 mg/day for 15 days after the islet transplant in patient 1. Patients 2-4 and the patients who underwent a simultaneous kidney-islets graft (nos. 5, 6) also received antilymphocyte globulin. Intravenous insulin was given for the first 15 days to maintain blood glucose concentrations within the normal range. Patient 1 rejected the islets within 15 days of islet transplantation. In patient 2, a 25% reduction in insulin requirement was observed and 12 months after transplantation post-prandial serum C-peptide was 1.5 ng/ml. In patient 3, the insulin requirement decreased from 40 to 8 units/day with a post-prandial serum C-peptide of 4.1 ng/ml 12 months after islet transplantation. In patient 4 the post-prandial secretion of C-peptide increased to 6.4 ng/ml. Six months after the islet infusion, insulin therapy was discontinued and HbA1c, 24-h metabolic profile and oral glucose tolerance test remained within the normal range. He had remained off insulin for 5 months until recently, when foot gangrene paralleled a worsening of post-prandial glycaemic control. Twelve months after transplantation he is receiving 8 units insulin/day.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

Swine islet isolation and transplantation.

An isolation procedure for large scale isolation of swine islets is described. The results from 15 consecutive isolations are reported. The glands were excised from heart beating animals with no warm ischemia time. The pancreases were digested by a modification of the automated method for human islet isolation. It was possible to separate an average of 690,000 +/- 279,429 islets per pancreas corresponding to 10,360 +/- 4034 islets for gram of pancreas with a volume of 714 +/- 480 mm3. After purification the recovery was 255,000 +/- 32,407 islets corresponding to 4,000 +/- 567 islets per gram of pancreas. Purity of the final preparation was 80-95% islets. Insulin content resulted in an average of 146.8 +/- 78 U before purification and 71 +/- 53 after purification. After transplantation of an aliquot of the final preparation in diabetic nude mice normoglycemia occurred in six mice. 30 days after transplantation nephrectomy of the kidneys bearing the grafts produced a rapid return to the diabetic state in all cases.

Animals

Selection of donors significantly improves pig islet isolation yield.

The purpose of the present study was to test the influence of donor age on islet isolation yield in swines. Large White pigs of 10 months (group 1, n = 10) and 2-3 years (group 2, n = 5) were used. A modification of the automated method for human islet isolation was used for pig islet separation. After ductal injection of a collagenase solution (Seromed, type C-1000) the islets were separated through a continuous digestion process. In group 1 it was possible to obtain an average of 636,100 islets (volume = 476.1 mm3, insulin content = 101.4 Units). In group 2 the average total islet number was 799,800 representing a volume of 1190.6 mm3 (Insulin content 210 Units). Total islet number was not significantly different in the two groups, however when islet volume and total insulin content were considered, older animals allowed a significantly higher yield (P less than 0.01 for volume and P less than 0.05 for insulin content). These findings indicate that it is possible to separate large number of pig islets from both young (10 months) and older (2-3 years) animals and that selection of donor pigs will improve islet isolation yield. These results may be of assistance in the definition of requirements for more effective islet isolation in swines.

Animals

Isolation of the elusive pig islet.

This study describes a procedure for large scale isolation of swine islets. The reported results are from 15 consecutive isolations. The glands were removed from live animals with no warm ischemia, and the pancreata were digested by a modification of the automated method for human islet isolation. It was possible to separate an average of 690,000 +/- 279,429 islets per pancreas corresponding to 10,360 +/- 4034 islets per gram of pancreas with a volume of 714 +/- 480 mm3. After purification the recovery was 255,000 +/- 32,407 islets corresponding to 4,000 +/- 567 islets per gram of pancreas. Purity of the final preparation was 80% to 95% islets. Insulin content resulted in an average of 146.8 +/- 78 U before purification and 71 +/- 53 U after purification. After a 10 mm3 aliquot of the final preparation was transplanted under the renal subcapsular space of seven nude mice with diabetes, normoglycemia occurred in six of the mice. Thirty days after transplantation, nephrectomy of the kidneys bearing the grafts produced a rapid return to the diabetic state in all cases. This method makes it possible to provide large numbers of intact swine islets for preliminary studies of prevention of the rejection of pig islet xenograft by immunoalteration and immunoisolation procedures.

Animals

[Current knowledge on memory in the elderly].

In geriatric practice, much thought must be given to initial changes in intelligence and memory due to old age and often suddenly aggravated by dysmetabolic and circulatory disease. Awareness of the memory faculty in the elderly is vital in clinical practice for the purposes of pharmacological and psychological designed to reduce the intellectual decline of the patients. This deficiency in mental personality is an important limitation to rehabilitation which remains the aim of medical attention.

Age Factors