RESUMO
BACKGROUND: There are no effective indicators of graft dysfunction in islet transplantation. This study evaluated the role of the Continuous Glucose Monitoring System (CGMS) as an early indicator of graft dysfunction in islet transplant recipients. METHODS: In 5 islet allograft recipients, we retrospectively determined the date of graft dysfunction: 3 fasting blood glucose levels >7.8 mmol/L (140 mg/dL) and/or 3 postprandial blood glucose levels >10 mmol/L (180 mg/dL) in 1 week. We then determined 2 time points in respect to graft dysfunction, 5 to 9 months before (time point A) and 2 to 3 months before (time point B). For these 2 time points, we assessed the following: HbA1c, C-peptide (CP), C-peptide glucose ratio (CPGR), 90-minute glucose from mixed meal tolerance test, and percentage of capillary blood glucose levels >7.8 mmol/L (%CBG >7.8) in a 15-day interval (1 week before and after CGMS placement). From the CGMS recordings, we calculated the glucose variability and the percentage of time spent in hyperglycemia >7.8 mmol/L (%HGT >7.8) and >10 mmol/L (%HGT >10). RESULTS: No difference was found between time points A and B for the following parameters: HbA1c, CP, CPGR, 90-minute glucose, %CBG >7.8, and %HGT >10. We observed a statistically significant increase from time point A to time point B in glucose variability (1.1 +/- 0.5 mmol/L to 1.6 +/- 0.6 mmol/L; P = .004), and in the %HGT >7.8 (11 +/- 12% to 22 +/- 18%; P = .036). CONCLUSION: Glucose variability and %HGT >7.8 determined using CGMS are useful as early indicators of graft dysfunction in islet transplant recipients. Further studies with larger sample sizes will help validate these observations.
Assuntos
Glicemia/metabolismo , Transplante das Ilhotas Pancreáticas/fisiologia , Monitorização Ambulatorial/métodos , Monitorização Fisiológica/métodos , Adulto , Peptídeo C/sangue , Feminino , Humanos , Imunossupressores/uso terapêutico , Transplante das Ilhotas Pancreáticas/patologia , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/sangue , Estudos Retrospectivos , Transplante HomólogoRESUMO
Infrared spectroscopy was used to examine the kinetics of deuterium exchange in collagen films prepared from its 0.5% dispersions obtained from cattle tendons and healed at 25--100 degrees C for 30 min. The temperature relationships to the denaturation degree and time of deuterium exchange suggested that an almost complete heat denaturation of dispersions can be achieved at 31.5 degrees C. The temperature of semi-denaturation of dispersions was 28.5--29.0 degrees. The occurrence of intact supermolecular aggregates of collagen molecules in its dispersions had no effect on the system resistance to heat denaturation.