c-peptide and Ischemia

BACKGROUND The main purpose of diagnostic imaging after pancreas transplantation is to exclude potential complications. As long as standard anatomical imaging such as sonography, contrast-enhanced computed tomography, and magnetic resonance imaging (MRI) are sufficient to display macroscopic vasculature, early changes within the graft caused by insufficient microperfusion will not be displayed for evaluation. MATERIAL AND METHODS Patients with pancreas allograft function in good condition were included in the study. No specific preparation was demanded before the MRI examination. The results of MRI were correlated with Igls criteria. It was a preliminary study to examine diffusion tensor imaging (DTI) value and safety in pancreas transplantation. RESULTS Our results indicated that higher fractional anisotropy (FA) values of the graft's head were associated with delayed graft function and insulin intake. We also compared grafts' images in early and late periods and found differences in T1 signal intensity values. DTI is a reliable noninvasive tool, requiring no contrast agent, to assess graft microstructure in correlation with its function, with FA values showing the most consistent results. By Igls criteria, no graft failure, 76% had optimal function, 10% had good function, and 14% had marginal function. CONCLUSIONS Our results suggest that DTI can be safely used in patients after pancreas transplantation and is advantageous in detecting early as well as late postoperative complications such as intra-abdominal fluid collection, malperfusion, and ischemia of the graft. Our findings correspond with clinical condition and Igls criteria. DTI is free of ionizing agents and is safe for kidney grafts.

Topics: Adult; Allografts; Anisotropy; C-Peptide; Contrast Media; Delayed Graft Function; Diffusion Tensor Imaging; Female; Glycated Hemoglobin; Humans; Hypoglycemia; Insulin; Insulin-Secreting Cells; Ischemia; Male; Pancreas Transplantation; Postoperative Complications; Prospective Studies; Transplantation, Homologous; Treatment Outcome

The therapeutic potential of adipose-derived stem cell conditioned medium (ASC-CM) was studied in the rabbit model of critical limb ischemia (CLI).. Rabbits received treatment with ASC-CM or placebo. Gastrocnemius muscle tissue was collected 35 days after ischemia induction. Ischemic changes were evaluated in hematoxylin-eosin stained tissues for early (necrotic lesions/granulation tissue) and late (fibrous scars) phases of tissue repair. The expression of proangiogenic miR-126 was also evaluated using in situ hybridization. The levels of cytokines, insulin, and C-peptide were measured in blood.. Early repair phases were observed more often in placebo-treated samples (45.5%) than in ASC-CM-treated ones (22.2%). However, the difference was not statistically significant. We demonstrated a statistically significant positive correlation between the early healing phases in tissue samples and C-peptide levels in peripheral blood. The expression of proangiogenic miR-126 was also shown in a number of structures in all phases of ischemic tissue healing.. Based on our results, we believe that treatment with ASC-CM has the potential to accelerate the healing process in ischemic tissues in the rabbit model of CLI. The whole healing process was accompanied by miR-126 tissue expression. C-peptide could be used to monitor the course of the tissue healing process.

Topics: Adult; Animals; C-Peptide; Cicatrix; Culture Media, Conditioned; Cytokines; Diabetes Mellitus, Experimental; Diabetic Foot; Disease Models, Animal; Fibrosis; Granulation Tissue; Hindlimb; Humans; In Situ Hybridization; Insulin; Ischemia; Male; Mesenchymal Stem Cells; MicroRNAs; Muscle, Skeletal; Necrosis; Neovascularization, Physiologic; Rabbits; Wound Healing

To further improve the outcome of clinical islet transplantation analysis of the impact of donor- and process-related factors could be of great importance.. Thirty-eight consecutive clinical islet transplantations were performed with consecutive islet isolations. Univariate analysis for donor- and isolation-related variables were correlated with recipient C-peptide levels at 2 and 4 weeks after transplantation. "Warm ischemia time" was defined as the time from start of University of Wisconsin solution perfusion in the donor until the pancreas was removed to the back table.. Short "warm ischemia time" (WIT), low expression of tissue factor (TF) in pancreatic tissue, and high creatinine levels in the donor were variables related to high C-peptide values after islet transplantation. Furthermore, hospitalization length longer than 4 days was associated with low C-peptide levels. The number of islet equivalents (IEQ) did not correlate with the clinical outcome, possibly due to the fact that IEQ number was included in the release criteria for clinical islet transplantation. Successful clinical islet transplantation is strongly correlated with donor and pancreas procurement factors rather than isolation process-related variables. "WIT" may induce TF expression in the pancreatic tissues. TF has been identified as the main trigger of the instant blood-mediated-inflammatory reaction in clinical islet transplantation. Therefore, assay of TF expression in pancreatic tissues could be applied as useful screening tool to identify "good" pancreata for clinical transplantation.

Topics: Analysis of Variance; C-Peptide; Cell Separation; Humans; Ischemia; Islets of Langerhans; Islets of Langerhans Transplantation

Pancreatic graft procurement, preservation, and transplantation surgery may result in damage to and loss of the integrity of endocrine cells and consequently in leakage of cell products into the insular vascular capillaries. Thus, the amount of alpha-, beta-, and pancreatic polypeptide (PP) cell products released into the vascular space of the recipient immediately after graft reperfusion may reflect islet cell injury. To test this hypothesis, we assessed glucagon, PP, C-peptide, and insulin levels in a prospective study of 22 consecutive renal-pancreatic transplantations. Transplantation-related parameters were used to account for differences in hormone release. Five grafts were preserved using Euro-Collins preservation fluid and 17 grafts were preserved using University of Wisconsin solution (UW). The first sign of a reinstalled physiological axis was the decrease of the blood glucose concentration after a median duration of 40 min (range 5-90 min) and the association of the recipient's ambient blood glucose levels with insulin release between 25 and 180 min after reperfusion. The delay period before a fall in blood glucose was observed correlated with cold ischemia time (rs = 0.73, P < 0.001, n = 21). An immediate and marked increase in plasma levels of glucagon (from 180 +/- 18 to 585 +/- 99 ng/L, mean +/- SEM), PP (from 57 +/- 8 to 122 +/- 13 pmol/L), C-peptide (from < 0.06 +/- 0.02 to 5.43 +/- 0.63 nmol/L), and insulin (from 0.15 +/- 0.21 to 2.05 +/- 0.26 nmol/L) was observed. C-peptide release correlated with glucagon (r = 0.76, P < 0.001) and PP (r = 0.60, P < 0.01). The hormone release was compared with computed tomography scans that were performed in the immediate postoperative period in 15 UW-preserved allografts. The diameter of the pancreatic head was increased and ranged from 4.5 to 7.7 cm (mean 6.2 cm). Peroperative C-peptide release significantly correlated with morphological graft changes reflected by the pancreatic head diameter (r = 0.58, P = 0.02). In a stepwise multiple regression analysis, cold ischemia time was a significant factor for the release of PP (r2 = 0.18, P = 0.049) and C-peptide (r2 = 0.35, P = 0.004). We suggest that peroperative hormone release reflects endocrine tissue damage. Furthermore, cold ischemia time may jeopardize the pancreatic allograft after relatively short preservation times, even when UW is used.

Topics: Adult; Blood Glucose; C-Peptide; Cold Temperature; Female; Humans; Ischemia; Male; Middle Aged; Organ Preservation; Pancreas; Pancreas Transplantation; Pancreatic Hormones; Pancreatic Polypeptide; Regression Analysis; Time Factors; Tissue and Organ Procurement

Topics: Animals; Blood Glucose; C-Peptide; Female; Glucagon; Insulin; Insulin Secretion; Ischemia; Islets of Langerhans; Kinetics; Pancreas Transplantation; Pancreatic Polypeptide; Portal Vein; Swine; Time Factors; Transplantation, Autologous