Serum HMGB1 levels are independently associated with glucose clamp-derived measures of insulin resistance in women with PCOS.

PURPOSE: PCOS is associated with low grade inflammation which could play a role in insulin resistance and ovarian dysfunction. Preliminary findings suggested that serum levels of HMGB1, a cytokine involved in inflammation, might be altered in women with PCOS. Primary aim of this study was to assess whether HMGB1 serum concentrations are associated with PCOS and with the state of insulin resistance of these women. METHODS: Sixty women with PCOS, selected to have a similar proportion of subjects with altered or normal insulin sensitivity, and 29 healthy controls were studied. Serum HMGB1 levels were compared in subgroups of PCOS women and controls. In PCOS women, insulin sensitivity was assessed by the glucose clamp technique and HMGB1 was measured at baseline and after acute hyperinsulinemia. RESULTS: HMGB1 levels were similar in women with PCOS and controls and no elements used for diagnosing PCOS were associated with serum HMGB1. However, HMGB1 concentrations were higher in insulin-resistant vs insulin-sensitive PCOS women (p = 0.017), and inversely associated with insulin-induced total and non-oxidative glucose metabolism. In both subgroups of PCOS women, serum HMBG1 levels significantly increased after acute hyperinsulinemia. CONCLUSIONS: These data suggest that HMGB1 levels are not associated with PCOS per se, but with insulin resistance. Further research should establish the underlying nature of this relationship, and whether this protein might play a role in the metabolic complications of PCOS.

Melatonin affects conjugation of 4-hydroxynonenal with glutathione in liver of pacu, a hypoxia-tolerant fish.

In cytosol from liver of pacu, Piaractus mesopotamicus, a hypoxia-tolerant fish that dwells in Pantanal, we found an enzyme activity capable of modulating the alkenal 4-hydroxy-2-nonenal (HNE) by conjugating it with glutathione (GST-HNE activity). HNE is a downstream metabolite from the oxidation of polyunsaturated fatty acids by reactive oxygen species arisen from mitochondria of animal cells. HNE production may increase more intensively under oxidative stress. Harmful effects to cell survival may occur when HNE increases over 10(-4) M. Pacus submitted to hypoxia in July (cold season in Pantanal) showed 40% less of this GST-HNE conjugating activity in their liver cytosol. Injecting pacus subjected to hypoxia during the cold season with a summer physiological dose of melatonin caused their liver cytosolic GST-HNE activity to increase up to the levels found in the warm season. From October to March (warm season in Pantanal), pacus are prone to oxidative stress particularly during potamodromous active oxygen-demanding swimming, when they migrate up rivers to spawn. Thus, our findings point out that the higher levels of melatonin in circulation during the summer are important to avoid the increase of 4-HNE inside liver cells of this fish species.

Oral commissure reconstruction with orbicularis oris elastic musculomucosal flaps.

Surgical reconstruction of the oral commissure aims to restore both symmetry of the lips at rest and, more importantly, full oral competence. Moulding the lip commissure with functional and cosmetic fidelity remains till today a difficult task. A possible surgical solution, the 'elastic flap' principle described by Goldstein, may be found in the wide full-thickness mobilization of the upper and lower vermilion as two composite myocutaneous flaps - tissue sandwiches consisting of labial skin, orbicularis oris muscle and oral mucosa - on the axial pattern of the superior and inferior labial arteries. Based on the contralateral commissure, both flaps are easily 'stretched', accordion-like, to reach the predetermined point of the new commissure, using to full advantage the inherent elastic potential of both vermilions. The fibres of the orbicularis oris muscle at each end of both flaps are embricated to reconstitute a neo-modiolus, which is anchored to the residual buccinator muscle in primary reconstructions, or to the available peri-oral fibrous tissue in secondary procedures. The authors present a select group of 22 patients, who, between 1993 and 2008, underwent this reconstruction procedure for primary or secondary defects involving the oral commissure. The results were generally satisfactory, both functionally and cosmetically. The advantages of this procedure include full restoration of the dynamic function of the orbicularis ring in a single-stage operation and avoidance of either lipswitching procedures or of mobilization of mucosa and cheek skin. The final scars remain well camouflaged within the oral mucosa and the mucocutaneous junction of each lip.

Microsurgical scalp and skull reconstruction using a combined flap composed of serratus anterior myo-osseous flap and latissimus dorsi myocutaneous flap.

A combined microvascular flap composed of serratus anterior myo-osseous and a latissimus dorsi myocutaneous flap has been performed for resurfacing massive scalp and skull defects, accompanied by chronic infection and heavy radiation damage. The authors present a case report where the combined procedure allowed a single-stage reconstruction of this complex defect.