Biliopancreatic diversion for severe obesity: long-term weight maintenance and occurrence of nutritional complications are two facets of the same coin.

BACKGROUND: Despite the widespread clinical use of hypoabsorptive metabolic bariatric surgery, very long-term outcomes are still lacking. The aim of the study was to assess the long-term safety and efficacy of biliopancreatic diversion at 30 years in patients with class 3 obesity (BMI over 40 kg/m2). METHODS: This retrospective single-centre study used data from a prospectively collected database on a sample of consecutive patients submitted to biliopancreatic diversion with a minimum follow-up of 30 years. Outcomes assessed included overall survival, long-term weight loss and weight maintenance, remission of obesity-related co-morbidities, and short- and long-term surgical and/or nutritional or metabolic complications. RESULTS: Among 199 consecutive patients (136 female, 63 male) who had surgery between November 1992 and April 1994, the mean age at operation was 38 (range 14-69) years and mean preoperative BMI was 48.7 (32.0-74.3) kg/m2. At baseline, 91 of 199 patients (45.7%) had type 2 diabetes. At 20 and 30 years, 122 (61%) and 38 (19%) of the 199 patients respectively were available for follow-up. At 30 years, the overall mortality rate was 12% (23 of 199). Surgical complications were concentrated in the short-term follow-up, whereas nutritional or metabolic complications increased progressively over time. A nutritional complication was diagnosed in 73 of 122 patients (60%) at 20 years and 28 of 38 (74%) at 30 years. Weight loss and glycaemic control were maintained throughout the follow-up; mean % total weight loss was 32.8 (range 14.1-50.0) at 1 year and 37.7 (range 16.7-64.8) at 30 years. One patient presented with recurrence of type 2 diabetes at 20 and 30 years; there were no patients with new-onset type 2 diabetes. CONCLUSION: Biliopancreatic diversion leads to good and sustained weight maintenance up to 30 years with low perioperative risk, but at the cost of a high long-term prevalence of nutritional complications.

Pyrrhic victory? Long-term results of biliopancreatic diversion on patients with type 2 diabetes and severe obesity.

BACKGROUND: The long-term results after biliopancreatic diversion (BPD) in patients with type 2 diabetes (T2D) and severe obesity is still being debated. OBJECTIVE: Retrospective evaluation of the long-term metabolic and clinical conditions of patients with T2D following BPD. SETTING: University hospital. METHODS: A total of 173 patients with T2D and severe obesity were investigated prior to and at 3-5 and 10-20 years after BPD. Anthropometric, biochemical, and clinical findings preoperatively and throughout follow-up were considered. The long-term data were compared with those of a cohort of 173 T2D patients with obesity treated with conventional therapy. RESULTS: T2D resolved within the first postoperative phases in most patients, and in the long and very long term, the fasting blood glucose level remained above the normal range in only 8% of patients. Likewise, a stable improvement of blood lipid pattern was observed (follow-up rate 63%). In contrast, in nonsurgical patients in the long term, the glucose and lipid metabolic parameters remained in the pathologic range in all cases. In the BPD group, a very high number of severe BPD-related complications was recorded, and 27% of the BPD patients died, whereas in the control group, 87% of patients were still alive at the end of the follow-up period (P < .02). CONCLUSION: Despite the high T2D stable resolution rate and the normalization of most metabolic data at 10-20 years following surgery, these results indicate that BPD should be indicated with caution in the surgical treatment of T2D in patients with severe obesity.

Plasma Modeling and Prebiotic Chemistry: A Review of the State-of-the-Art and Perspectives.

We review the recent progress in the modeling of plasmas or ionized gases, with compositions compatible with that of primordial atmospheres. The plasma kinetics involves elementary processes by which free electrons ultimately activate weakly reactive molecules, such as carbon dioxide or methane, thereby potentially starting prebiotic reaction chains. These processes include electron-molecule reactions and energy exchanges between molecules. They are basic processes, for example, in the famous Miller-Urey experiment, and become relevant in any prebiotic scenario where the primordial atmosphere is significantly ionized by electrical activity, photoionization or meteor phenomena. The kinetics of plasma displays remarkable complexity due to the non-equilibrium features of the energy distributions involved. In particular, we argue that two concepts developed by the plasma modeling community, the electron velocity distribution function and the vibrational distribution function, may unlock much new information and provide insight into prebiotic processes initiated by electron-molecule collisions.

Stochastic models of systems for Nanotechnology: from micro to macro scale.

Computer modeling technique based on the theory of stochastic processes have been used in order to provide a realistic simulation of the behavior of nanoscopic systems, related in particular to plasma reactors in microelectronic device production. Basing on decades of experience, we show here, with new results, that the universality of such methods allows the development of codes with the highest reusability and versatility, crossing the barrier of scale. At the smallest scale, the quantum calculations of the potential energy surface of hydrogen species under nano-confinement conditions display the effects due to the dimension and the symmetry of the confining potential well. At a slightly larger scale, nanoparticles dispersed as aerosol in plasma feature strong fluctuations in temperature and charge which may affect the processing of silicon wafers. At the macroscopic scale, using a stochastic solution of transport equations, it is possible to describe laboratory or industrial systems for the production or treatment of nanomaterials, also exploiting the analogy between neutral particle transport and radiative transfer and information obtained by molecular simulations. These findings are relevant in the control of solid-particle contamination in the manufacture of electronic components and in other fields.