Impact of glycemic variability on myocardial infarct size in patients with ST-segment elevation myocardial infarction: quantitative assessment of left ventricular wall motion severity.

Glycemic variability (GV) is relevant to impaired myocardial salvage in acute ST-elevation myocardial infarction (STEMI). Severity of hypokinesis at the infarct site as assessed from contrast left ventriculography can reportedly predict infarct size in STEMI. We prospectively studied 58 consecutive patients (mean age, 63 ± 11 years) with anterior or inferior STEMI who underwent successful reperfusion therapy. Mean amplitude of glucose excursion (MAGE) was obtained from continuous glucose monitoring system. Patients were divided into the upper tertile of MAGE as Group H, and the other two-thirds as Group L. Serial regional wall motion severity at the infarct site was computed postprocedure and at follow-up using a quantitative left ventricular analysis system. Impaired myocardial salvage was defined as severity recovery ratio < 20%. Significantly shorter onset-to-balloon time (196.9 vs. 279.0 min, p = 0.033) and relatively lower postprocedural wall motion severity (2.4 vs. 2.9, p = 0.096) were observed in Group H, but absolute severity recovery was significantly smaller in Group H (0.5 vs. 1.3, p = 0.017). Multivariate analysis showed higher MAGE as predictive of impaired myocardial salvage (OR, 406.10; 95% CI, 4.41-37,366.60; p = 0.009). Recovery of reginal wall motion severity at the infarct site was compromised in STEMI patients with higher MAGE. Our results suggest that final infarct size is potentially larger than expected in STEMI patients with higher GV.

Risk assessment of skin lightening cosmetics containing hydroquinone.

Following reports on potential risks of hydroquinone (HQ), HQ for skin lightening has been banned or restricted in Europe and the US. In contrast, HQ is not listed as a prohibited or limited ingredient for cosmetic use in Japan, and many HQ cosmetics are sold without restriction. To assess the risk of systemic effects of HQ, we examined the rat skin permeation rates of four HQ (0.3%, 1.0%, 2.6%, and 3.3%) cosmetics. The permeation coefficients ranged from 1.2 × 10-9 to 3.1 × 10-7 cm/s, with the highest value superior than the HQ aqueous solution (1.6 × 10-7 cm/s). After dermal application of the HQ cosmetics to rats, HQ in plasma was detected only in the treatment by highest coefficient cosmetic. Absorbed HQ levels treated with this highest coefficient cosmetic in humans were estimated by numerical methods, and we calculated the margin of exposure (MOE) for the estimated dose (0.017 mg/kg-bw/day in proper use) to a benchmark dose for rat renal tubule adenomas. The MOE of 559 is judged to be in a range safe for the consumer. However, further consideration may be required for regulation of cosmetic ingredients.

[Assessment of three methods for the identification of enzymatically hydrolyzed guar gum].

Enzymatically hydrolyzed guar gum (EHGG), which is used as a thickener or a soluble dietary fiber, is produced by partial hydrolysis of the guar gum (GG) backbone using mannan endo-ß-1,4-mannosidase. In this study, we compared and evaluated 3 methods to distinguish EHGG from other polysaccharides used as food additives or monosaccharides. The first method is based on cross-linking reaction of saccharide hydroxyl groups mediated by borate ions. EHGG showed gelation and was distinguished from some soluble polysaccharides, which did not form gels, and also from polysaccharides with low solubility in water. The second method is based on co-gelation with xanthan gum. It was applicable to GG, but not to EHGG. The third method is based on the alcohol precipitation of hydrophilic polymers. EHGG, some soluble polysaccharides and monosaccharides were dissolved in water at the concentration of 10%, while GG and some polysaccharides were not. The 10% solutions thus obtained were mixed with 2-propanol at the ratio of 1 : 1 (v/v). A white precipitate was formed in the EHGG solutions and the tested soluble polysaccharide solutions, while it was not produced in the monosaccharide solutions. This result demonstrated that soluble polysaccharides including EHGG can be distinguished from polysaccharides with low solubility or monosaccharides by the third method.