Roy George Jacob

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Understanding tolerance to effects of nicotine in humans may elucidate processes involved in the onset and maintenance of tobacco dependence. Subjective, behavioral and cardiovascular responses to nicotine were examined as a function of past history of nicotine exposure (i.e., smokers vs. nonsmokers, chronic tolerance) and of immediately preceding nicotine(More)
Tolerance to subjective effects of nicotine may induce novice smokers to increase the magnitude and frequency of their nicotine self-dosing. In this study, smokers (n = 8) and nonsmokers (n = 7) participated in three sessions involving presentation of 0, 7.5, or 15 micrograms/kg nicotine 30 min for 2 h via measured-dose nasal spray, with different doses(More)
Performance on finger-tapping and handsteadiness, tasks opposite in response requirements, was compared between male smokers and nonsmokers (n = 10 each) on two occasions, once following intake of nicotine (15 micrograms/kg) by measured-dose nasal spray and once following placebo. Compared with nonsmokers, smokers had significantly greater increase in(More)
The acute effects of nicotine on resting metabolic rate (RMR) were examined to identify a mechanism that may help explain the inverse association between smoking and body weight. Multiple administrations of two nicotine doses (moderate [15 micrograms/kg body wt] and low [7.5 micrograms/kg body wt]) and a placebo (0 micrograms) were presented to 18 male(More)
The metabolic effects of nicotine have been implicated in the relation between smoking and lower body weight. This study examined whether the nicotine-induced increase in the metabolic rate observed at rest is also present during physical activity. We compared the energy expenditure of 10 male smokers receiving nicotine (15 micrograms per kilogram of body(More)
The thermogenic effect of nicotine intake after calorie consumption was investigated to determine if nicotine influences metabolic response to a calorie challenge. Smokers and nonsmokers (10 males in each group), matched for body weight, age, and physical fitness, each participated in four sessions that involved consuming a liquid calorie load (4.77 kcal/kg(More)
Despite the advances in pharmacotherapy for heart failure due to reduced left ventricular function, mortality still remains high and many patients are hospitalized over time due to worsening heart failure symptoms. There is some experimental evidence that vasoconstriction and nitric oxide (NO) deficiency in the vasculature play a role in aggravating the(More)
The acute thermogenic effect of nicotine was examined in cigarette smokers under conditions of rest and two levels of low-intensity physical activity comparable to that normally engaged in by sedentary adults. Male and female smokers (n = 10 each) each received 0 (placebo), 7.5, 15, or 30 micrograms/kg nicotine via measured-dose nasal spray once every 30(More)
Nicotine's effects on reducing perception and/or hedonics of sweet and fat taste may lead to less intake of sweet tasting, high-fat foods by smokers, helping to explain their generally lower body weights. Smokers and nonsmokers (n = 10 males each) rated perception (intensity and sensitivity) and hedonics (liking) of sweet/fat taste in milk samples varying(More)