Several properties of pancreatic β-cells in type 2 diabetes (T2D) were studied by using islets isolated from T2D subjects. Moreover, because metformin has protective effects on nondiabetic β-cells exposed to high glucose or free fatty acid levels, we investigated its direct action on T2D islet cells. Diabetic islets were characterized by reduced insulin content, decreased amount of mature insulin granules, impaired glucose-induced insulin secretion, reduced insulin mRNA expression, and increased apoptosis with enhanced caspase-3 and -8 activity. These alterations were associated with increased oxidative stress, as shown by higher nitrotyrosine concentrations, increased expression of protein kinase C-β2 and nicotinamide adenine dinucleotide phosphate reduced-oxidase, and changes in mRNA expression of manganese- superoxide dismutase, Cu/Zn-superoxide dismutase, catalase, and glutathione peroxidase. Twenty-four-hour incubation of T2D islets with metformin was associated with increased insulin content, increased number and density of mature insulin granules, improved glucose-induced insulin release, and increased insulin mRNA expression. Moreover, apoptosis was reduced, with concomitant decrease of caspase-3 and -8 activity. These changes were accompanied by reduction or normalization of several markers of oxidative stress. Thus, T2D islets have several functional and survival defects, which can be ameliorated by metformin; the beneficial effects of the drug are mediated, at least in part, by a reduction of oxidative stress.
A kidney from a 56-year-old mother was transplanted to her 37-year-old daughter laparoscopically using the daVinci HDSi surgical system. The kidney was introduced into the abdomen through a 7-cm suprapubic incision used also for the uretero-vescical anastomosis. Vascular anastomoses were carried out through a total of three additional ports. Surgery lasted 154 min, including 51 min of warm ischemia of the graft. Urine production started immediately after graft reperfusion. Renal function remains optimal at the longest follow-up of 3 months. The technique employed in this case is discussed in comparison with the only other two contemporary experiences, both from the USA. Furthermore, possible advantages and disadvantages of robotics in kidney transplantation are discussed extensively. We conclude that the daVinci surgical system allows the performance of kidney transplantation under optimal operative conditions. Further experience is needed, but it is likely that solid organ transplantation will not remain immune to robotics.
Background/Purpose: Few data are available on the learning curve (LC) in robot-assisted pancreaticoduodenectomy (RAPD) and no study specifically addresses the LC of a single surgeon. Methods: The LC of a single surgeon in RAPD was determined using the cumulative sum method, based on operative time (OT). Data were extracted from a prospectively maintained database and analyzed retrospectively considering all events occurring within 90 days of index operation. Results: Seventy RAPD were analyzed. One operation was converted to open surgery (1.4%). One patient died within 30 days (1.4%) and one within 90 days (2.8%). Postoperative complications occurred in 53 patients (75.7%) and exceeded Clavien-Dindo grade IIIb in 7 patients (10%). OT dropped after 33 operations from a mean of 564 ± 101.7 min to a mean of 484.1 ± 77.9 min (p = 0.0005) and was associated to reduced incidence of delayed gastric emptying (72.7 vs. 48.7%; p = 0.039). The rate of hospital readmission improved after 40 operations from 20.0 (8 of 40) to 3.3% (1 of 30) (p = 0.04). Conclusions: RAPD was safely feasible in selected patients. OT dropped after the first 33 operations and was associated with reduced rate of delayed gastric emptying. Readmission rate improved after 40 operations.
23 February 2007 in Diabetes/Metabolism Research and Reviews