Diabetes has recently become a leading cause of death worldwide. To date, although there is no means to cure or prevent diabetes, appropriate medication and blood sugar monitoring can enhance treatment efficiency, alleviate the symptoms, and diminish the complications of the condition. This review article deals with current growth areas in the market for blood glucose sensors and possible future alternatives, which are generally considered to be the point sample test and the continuous glucose monitor (CGM). Most glucose sensors are enzyme-based, whereas others are enzyme-free. The former class is sensitive and some products are extensively employed for daily self-sensing and in hospital environments as reliable diagnostic tools. The latter class, particularly the boronic acid fluorescent sensor, is facile and extremely promising. Practicality demands that all types of sensors offer accuracy, specificity, and real-time detection.

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The alcohol dehydrogenase (ADH) family is involved in the metabolism of both ethanol and retinoids. To quantitatively assess the potential contributions to first-pass metabolism of ethanol and the ethanol interference with retinoid homeostasis, saturation kinetics for ethanol oxidation as well as inhibition kinetics by ethanol for all-trans-retinol oxidation of human class I AA, β 1 β 1 , β 2 β 2 , γ 1 γ 1 , class II ππ, class III χχ, and class IV µµ were evaluated and compared. Class I and class II ADHs exhibited substrate inhibition with inhibition constants ranging over 250Ϫ720 mM (except γ 1 γ 1 ) ethanol. Class IV ADH displayed no appreciable inhibition up to 1 M ethanol. Activity of the class III enzyme (190 nM subunit) was undetectable at 250 mM ethanol. The kinetic simulations indicate that the hepatic ππ and the gastric µµ can most effectively contribute to first-pass metabolism of alcohol. The Michaelis constant (K m ), turnover number (k cat ), and catalytic efficiency (k cat /K m ) for retinol oxidation relative to that for ethanol oxidation in class I, class II, and class IV ADHs ranged over 0.00022Ϫ1.3, 0.071Ϫ0.48, and 0.24Ϫ650, respectively. Ethanol was a competitive inhibitor against retinol for class I, II, and IV ADHs with apparent inhibition constants ranging over 0.037Ϫ11 mM, indicating that retinoic acid synthesis through the ADH pathways can be tremendously blocked during social/heavy drinking. These findings support the notion that first-pass metabolism of alcohol may occur mainly in the liver through class II ππ and that cellular retinoid signaling may be perturbed by ethanol via ADH pathways.Keywords : alcohol dehydrogenase ; retinol oxidation; first-pass metabolism; fetal alcohol syndrome ; alcohol-related disease.Alcohol dehydrogenase (ADH) constitutes a complex en-pass metabolism continues. It is difficult to measure directly the liver and gastric contribution to the metabolism of newly abzyme family [1]. Recently at least five classes of ADH have been categorized in humans on the basis of their structural and sorbed alcohol from the gastrointestinal tract. Dosage and the absorption rate, which can be influenced by gastric emptying, kinetic characteristics [2]. Class I homodimeric and heterodimeric A, β, and γ-ADHs are the low-K m forms for ethanol oxida-are among the major confounding factors [6Ϫ8, 11]. To assess the effective potential of ADHs to metabolize first-passed ethation ; class II ππ and class IV µµ (or denoted σσ), the high-K m forms. Class III χχ, a glutathione-dependent formaldehyde nol it is important to measure the magnitude of enzyme activity increase in the liver and stomach corresponding to the alcohol dehydrogenase, appears not to be saturable with ethanol. Kinetic features of class V ADH remain to be defined. Genetic polymor-concentration difference between organ and systemic blood during the period of first-pass metabolism. phism occurs in the class I isozymes among racial populations, which can affect the development of alcoholism [3,4]. Intraclass It is well ac...

Two new diterpenoids, designated neocryptotanshinone and isotanshinone IIB, have been isolated from "Tan-Shen," the root of Salvia miltiorrhiza, together with a known compound, danshexinkun A. Their structures are established by spectral and physical data. Isotanshinone IIB exhibits significant inhibitory activity in vitro on ADP- and collagen-induced aggregation.