We sought to determine whether or not optimizing pancreas preservation, islet processing, and induction immunosuppression would facilitate sustained diabetes reversal after single-donor islet transplants. Islets were isolated from two-layer preserved pancreata, purified, cultured for 2 days; and transplanted into six C-peptide-negative, nonuremic, type 1 diabetic patients with hypoglycemia unawareness. Induction immunosuppression, which began 2 days pretransplant, included the Fc receptor nonbinding humanized anti-CD3 monoclonal antibody hOKT3c 1 (AlaAla) and sirolimus. Immunosuppression was maintained with sirolimus and reduced-dose tacrolimus. Of our six recipients, four achieved and maintained insulin independence with normal HbA1c levels and freedom from hypoglycemia; one had partial islet graft function; and one lost islet graft function 2 weeks post-transplant. The four insulin-independent patients showed prolonged CD4 + T-cell lymphocytopenia; inverted CD4:CD8 ratios; and increases in the percentage of CD4 + CD25 + T cells. These cells suppressed the in-vitro proliferative response to donor cells and, to a lesser extent, to third-party cells. Severe adverse events were limited to a transient rash in one recipient and to temporary neutropenia in three. Our preliminary results thus suggest that a combination of maximized viable islet yield, pretransplant islet culture, and preemptive immunosuppression can result in successful single-donor islet transplants.

This study intended to evaluate the impact of donor age on the function of isolated islets. Analysis of human islets from cadaveric donors (age 16 -70 years) was performed using glucose-stimulated insulin release (GSIR) (n ‫؍‬ 93), islet ATP content (n ‫؍‬ 27), diabetic nude mouse bioassay (n ‫؍‬ 72), and the insulin secretory function after singledonor clinical islet allotransplantation (n ‫؍‬ 7). The GSIR index was significantly higher in younger donors (age <40 years) than in older donors and negatively correlated with the donor age (r ‫؍‬ ؊0.535). Islet ATP was higher in younger donors (115.7 ؎ 17.7 vs. 75.7 ؎ 6.6 pmol/g DNA).The diabetes reversal rate of mice with 2,000 IE was significantly higher in younger donors (96 vs. 68%). Cpeptide increment to glucose during intravenous glucose tolerance test at days 90 -120 after clinical transplantation showed negative correlation with donor age (r ‫؍‬ ؊0.872) and positive correlation with the islet mass (r ‫؍‬ 0.832). On the other hand, acute insulin response to arginine only showed correlation with the islet mass and not with donor age. These results show that insulin secretory response to glucose deteriorates with increasing age and that it may be related to changes in ATP generation in ␤-cells. Diabetes

Summary The Edmonton protocol for islet transplantation utilizes fresh islet grafts but other protocols increasingly transplant short‐term cultured grafts mainly for practical reasons. To improve our understanding of the impact of culture pretreatment of human islets, we assessed post‐transplant function by nude mouse bioassay, islet ATP, activity of stress‐activated MAP kinases, and expression of stress‐related genes by focused cDNA array in freshly isolated and cultured islets. Mean blood glucose levels over 4 weeks after transplantation (2000 IE) of (i) freshly isolated, (ii) cultured and preculture counted (recovery rate; 78 ± 6%), and (iii) cultured and postculture counted islets in diabetic mice were 330 ± 40, 277 ± 65, and 256 ± 52 mg/dl (i versus ii, P = 0.004; i versus iii, P = 0.002). During culture, islet ATP/DNA and ATP/ADP increased; JNK and p38 MAPK activities decreased. Among 96 genes studied, mRNA expression of heat shock protein 70 genes decreased >twofold during culture in all four pairs; expression of cyclooxygenase‐2, superoxide dismutase‐2, interleukin‐6 and cytochromes P450 1A1 genes increased. Our results show that culturing human islets before transplantation is not disadvantageous in regard of functional recovery from changes induced by nonphysiologic stimuli during islet isolation. The increase in expression of several stress‐related genes during culture also shows that improving culture conditions may further enhance post‐transplant islet function.

Analysis of volatile profiles from differently processed flaxseed oils (FSO) was performed by SPME-GC-MS, electronic nose (E-nose) and descriptive sensory analysis. A total of 61 volatiles were tentatively identified and then quantified. Among these components, 51 volatiles were obtained from the hot-pressed FSO, 47 from cold-pressed FSO, and 40 by solvent extraction. Principal component analysis (PCA) demonstrated that three FSO samples tested resulted in significant differences of three treatments (p<0.05) and the marker compounds that contributed to discrimination of different processed FSO were hexanal, (E, E)-2, 4-pentadienal, (E, E)-2, 4-heptadienal, 6-hydroxy-2-hexanone, 1-hexanol, methylpyrazine, nonanal, 2,3-pentanedione, 1-butanol, acetic acid, hexanoic acid, and ethyl acetate. In addition, there was good consistency among GS-MS, sensory evaluation and E-nose analysis results. These results indicated that the process method has a significant effect on the aroma quality of FSO and may be helpful in evaluating aroma quality and the detection of frauds. Practical applications:The results showed that the major volatile components could be used as chemical markers to distinguish differently processed FSOs by the chemometric method. There was good consistency among GS-MS, sensory evaluation and E-nose analysis results, suggesting that E-nose technique combined with a PCA of the data provided by the sensor arrays has the good potential to evaluate FSO quality and the detection of frauds.