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51.
Perkins Kenneth A.; Ciccocioppo Melinda; Conklin Cynthia A.; Milanak Melissa E.; Grottenthaler Amy; Sayette Michael A. 《Canadian Metallurgical Quarterly》2008,117(1):79
Acute responses to smoking are influenced by nicotine and by nonpharmacological factors such as nicotine dose expectancy and sensory effects of smoke inhalation. Because negative mood increases smoking reinforcement, the authors examined whether these effects may be altered by mood context. Smokers (n=200) participated in 2 sessions, negative or positive mood induction, and were randomized to 1 of 5 groups. Four groups comprised the 2×2 balanced placebo design, varying actual (0.6 mg vs. 0.05 mg yield) and expected nicotine dose (expected nicotine vs. denicotinized [denic]) of cigarettes. A fifth group was a no-smoking control. Smoking, versus not smoking, attenuated negative affect, as well as withdrawal and craving. Negative mood increased smoking reinforcement. However, neither actual nor expected nicotine dose had much influence on these responses; even those smokers receiving and expecting a denic cigarette reported attenuated negative affect. A follow-up comparison suggested that the sensory effects of smoke inhalation, but not the simple motor effects of smoking behavior, were responsible. Thus, sensory effects of smoke inhalation had a greater influence on relieving negative affect than actual or expected nicotine intake. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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Acrylamide/itaconic acid hydrogels (AAm/IA) containing different amounts of itaconic acid prepared by irradiating with γ radiation were used in experiments on swelling, diffusion, and interactions of the pharmaceuticals nicotine, nicotinic acid, nicotinamide, and nikethamide. AAm/IA hydrogel containing 60 mg itaconic acid and irradiated at 4.65 kGy has been used for swelling and diffusion studies in water and aqueous solutions of the pharmaceuticals. For this hydrogel, swelling studies indicated that swelling increased with the following order: water > nicotine > nikethamide > nicotinamide > nicotinic acid. Diffusions of water and the pharmaceuticals within hydrogels were found to be non-Fickian in character. The uptake of the pharmaceuticals to AAm/IA hydrogels was studied by batch adsorption technique at 25°C. In the experiments of the adsorption, C-type adsorption in Giles's classification system was found. Some binding and thermodynamic parameters for AAm/IA hydrogel-pharmaceutical systems were calculated by using the Klotz method. The values of adsorption heat, free energy, and entropy of this system were found as negative values. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 733–739, 1997 相似文献
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超声提取-高效液相色谱法测定烟草中烟碱含量 总被引:4,自引:0,他引:4
确定了制备烟碱分析样品的超声波提取条件:0.4% NaOH溶液为溶剂,液固比40:1(mL·g-1),提取时间4 h.确定了高效液相色谱法检测烟碱含量的条件为Kromasil C18色谱柱(250 mm×4.6 mm,5 μm),检测波长259 nm,检测温度35 ℃,流动相CH3OH/0.02 mol·L-1磷酸盐缓冲溶液(V/V)为60/40,流速1.0 mL·min-1,进样量10 μL.平均加样回收率98.8%,相对标准偏差1.2%.结果表明超声提取-高效液相色谱法是一种准确度高,速度快的测定烟草中烟碱含量的检测方法. 相似文献
56.
新烟碱类杀虫剂选择作用的分子机理 总被引:5,自引:0,他引:5
新烟碱类杀虫剂的选择作用可以从昆虫和脊椎动物烟碱型乙酰胆碱受体(nAChR)的特点、新烟碱类杀虫剂同nAChR天然激动剂乙酰胆碱(acetylcholine,ACh)的分子特点以及激动剂和受体之间互作的分子机制等方面加以说明。激动剂的分子特点研究表明,新烟碱类杀虫剂和ACh药效基团在静电性上分别显示负电性和正电性。用昆虫α亚基和脊椎动物β亚基组成的杂合受体同激动剂相互作用的研究,主要集中在受体亚基上不同氨基酸残基与不同激动剂结合电生理效应的特点上。研究结果发现,ACh结合部位D环上的碱性氨基酸对新烟碱类杀虫剂选择性的作用尤其明显,同时C环上YXCC模序也引起了大家的注意,而吡虫啉结合部位的芳香氨基酸残基有可能在稳定激动剂四氢咪唑环部分上起作用。乙酰胆碱结合蛋白的晶体结构帮助人们进一步认识了D环上碱性氨基酸残基在新烟碱类选择机制上的作用。 相似文献
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We examined the effects of inhibitors of the octadecanoid pathway (n-propyl gallate, acetosalicylic acid, salicylhydroxamic acid, methyl salicylate, and antipyrine) on wound- and jasmonate-induced nicotine accumulation and compared the nicotine-inducing ability of exogeneous additions of linolenic acid (18:3) and its methyl ester, linoleic acid (18:2), abscisic acid, traumatic acid, and methyl dihydrojasmonate to the nicotine-inducing ability of exogenous additions of methyl jasmonate (MJ). The first four of these inhibitors significantly reduced wound-induced nicotine accumulation when applied in a lanolin paste to wounded tissues immediately after wounding at concentrations of 89–90µg/plant. When methyl salicylate and propyl gallate were mixed individually with MJ, neither inhibited MJ-induced nicotine synthesis, which suggests that the inhibitors block jasmonate synthesis or release from stored pools and not its effects. Linolenic acid or its methyl ester applied to undamaged plants or damaged plants (to either damaged or undamaged leaves) or to the roots of hydroponically growing plants did not induce nicotine accumulation or increase nicotine accumulation above levels found in damaged plants. Similarly, traumatic acid, linoleic acid, and abscisic acid did not induce nicotine accumulations. Methyl dihydrojasmonate, which is biosynthetically derived from linoleic acid, had 12–56% of the nicotine-inducing acitivity of MJ when added to the roots of hydroponically grown plants. The signal transduction pathway mediating wound-induced nicotine production therefore shares many features of the pathway eliciting wound-induced proteinase inhibitor production but differs in not being regulated at the lipase step in jasmonic acid production and not being responsive to abscisic acid. 相似文献
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Nicotine addiction continues to be the main cause of preventable death in developed countries. Women and teen girls appear to be more vulnerable on certain aspects of nicotine addiction compared with men and boys. While the mechanism of gender differences in nicotine addiction is not yet clear, evidence suggests that while estrogen may underlie enhanced vulnerability in females, progesterone may protect females. Thus, progesterone may have therapeutic use for tobacco addiction, especially in female smokers. A greater understanding of the role of progesterone in nicotine addiction is important not only from a treatment standpoint, but also from a prevention standpoint: hormone transition phases, such as those that occur at adolescence, and during pregnancy and following birth, as well as following hormonal manipulation (e.g., using methods of hormonal birth control), may all contribute to changes in vulnerability to nicotine addiction. In this review, we summarize recent evidence from clinical and preclinical studies examining the role of progesterone in nicotine addiction focusing on its role during initiation of use and during later phases of the addiction process as a potential relapse prevention treatment. We conclude with future directions including further examination of progesterone as a potential intervention and treatment of nicotine addiction. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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Objective: Nicotine patch improves treatment outcomes, but lapses are still common. To understand the process of relapse on patch, we investigated differences in the antecedents (withdrawal, setting, triggers) of lapse episodes experienced on high-dose (35 mg) nicotine patches versus placebo. Design: Participants were smokers who lapsed during a randomized, double-blind trial of active patches (n = 100) versus placebo (n = 85). Participants used electronic diaries to monitor their smoking, affect, and activities in real time for 5 weeks during their cessation attempt. Results: We analyzed 490 lapse episodes (active: 266; placebo: 224). Lapses on nicotine patch were characterized by significantly lower positive affect and higher negative affect than placebo lapses. Participants treated with high-dose patch were also significantly more likely to lapse in situations involving little or no craving. Situational antecedents of lapses on patch resembled those on placebo. Conclusion: The results suggest that treatment with patch may set a higher threshold for affective stimuli to provoke lapses, but does not change the proximal cues that trigger lapses. This suggests that behavioral relapse-prevention strategies developed for unmedicated smokers should also apply to those treated with nicotine patch. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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