Early Regression of Carotid Intima-Media Thickness after Bariatric Surgery and Its Relation to Serum Leptin Reduction.

PURPOSE: Bariatric surgery (BS) promotes carotid intima-media thickness (C-IMT) regression as early as 6 months post-surgery. To verify whether C-IMT regression occurs even earlier, we aimed at the effect of Roux-en-Y gastric bypass (RYGBP) and biliopancreatic diversion (BPD) on C-IMT 1-2 months and 12 months post-surgery. SUBJECTS/METHODS: Prospective trial. BS was performed on 109 patients either with (RYGBP = 42; BDP = 40) or without type 2 diabetes (RYGBP = 27). Healthy volunteers served as control group. FOLLOW-UP: baseline, 1-2 months, 12 months post-surgery. ENDPOINTS: changes (∆) in C-IMT, weight, body mass index, fat mass, waist and neck circumferences, blood pressure, HbA1c, glucose, insulin, insulin sensitivity [HOMA-IR; OGIS, from meal tolerance test], lipids, C-reactive protein, leptin, adiponectin, MCP-1. RESULTS: All surgery subgroups had similar levels of ∆-C-IMT. C-IMT in the pooled surgery group reduced from [mean (95% confidence interval)] 0.81 (0.77-0.84) mm to 0.66 (0.63-0.69) mm, p < 0.001 [-17.1 (-20.4 to -13.8)%] at 1-2 months, and to 0.63 (0.59-0.66) mm, p < 0.001 [-21.8 (-25.3 to -18.4)%] at 12 months post-surgery. ∆-C-IMT 1-2 months and 12 months post-surgery correlated to baseline C-IMT, and with ∆-leptin at 1-2 months, but not at 12 months post-surgery. In linear regression analysis, ∆-leptin and baseline C-IMT were predictors of ∆-C-IMT 1-2 months post-surgery. CONCLUSIONS: A remarkable C-IMT regression occurred as early as 1-2 months after BS in obese patients either with or without type 2 diabetes, which was associated to the early reduction in leptin, (at least partially) independent of weight loss. Whether this is a causative or correlative association needs further investigation.

Role of excitons in electron- and photon-stimulated desorption of neutrals from alkali halides.

Low-energy (5-15 eV) electron- and photon-stimulated desorption of KI(100) yields I2P3/2 and 2P1/2 with hyperthermal (0.3 eV) and thermal velocity components. The desorption threshold for both components is 5.3 eV and is correlated with the gamma3/2-exciton long-wavelength edge. Exciton decay at the surface directly produces I2P3/2 and 2P1/2 with hyperthermal velocity and is in competition with self-trapping. Spin memory of the gamma-exciton hole-component is also evident in the hyperthermal channel. An exciton mediated desorption mechanism is presented which is general in alkali halides.

Molecular structure of DNA by scanning tunneling microscopy.

Uncoated DNA molecules marked with an activated tris(l-aziridinyl) phosphine oxide (TAPO) solution were deposited on gold substrates and imaged in air with the use of a high-resolution scanning tunneling microscope (STM). Constant-current and gap-modulated STM images show clear evidence of the helicity of the DNA structure: pitch periodicity ranges from 25 to 35 angstroms, whereas the average diameter is 20 angstroms. Molecular structure within a single helix turn was also observed.