The effects of platelet-derived growth factor-BB on healing of the rabbit medial collateral ligament. An in vivo study

Cigarette smoking poses significant risk to mother and infant during pregnancy and the postpartum period. Recruitment of pregnant smokers to intervention studies has often been reactive and has excluded certain subgroups of women, such as those who have recently quit smoking. In this study, we examined smoking patterns among a proactively recruited sample of women presenting to six urban community maternity clinics. The current report describes the patterns of smoking in this population of ethnoculturally diverse low-income urban pregnant women and examines differences across subgroups. The majority of the total sample in the current study reported that they had never smoked. Of the total, 30% reported having "ever" smoked and 16% were current smokers. Of the group of "ever" smokers, 18% quit greater than 12 months before pregnancy, 5% quit 0-12 months before pregnancy and 23% quit during this pregnancy. On the average, women who quit during pregnancy did so about 5 weeks after diagnosis. Of those women who continued to smoke during pregnancy, the average number of cigarettes smoked per day was 10 +/- 8. Differences were found in smoking patterns across the ethnocultural subgroups. Recruitment represents the first and one of the most important phases in intervening with pregnant women. Inclusion of both current smokers and recent self-quitters takes the fullest advantage of the window of opportunity to help women quit smoking and remain cigarette free for good.     

Delay discounting predicts postpartum relapse to cigarette smoking among pregnant women.

Delay discounting (DD), a measure of impulsivity, describes the rate at which rewards lose value as the delay to their receipt increases. Greater discounting has been associated with cigarette smoking and various other types of drug abuse in recent research. The present study examined whether DD predicts treatment outcome among cigarette smokers. More specifically, the authors examined whether baseline discounting for hypothetical monetary rewards predicted smoking status at 24 weeks postpartum among women who discontinued smoking during pregnancy. Participants were 48 pregnant women (10.5 = 4.1 weeks gestational age at study entry) who participated in a clinical trial examining the use of incentives to prevent postpartum relapse. Several sociodemographic characteristics (being younger, being less educated, and reporting a history of depression) assessed at study entry were associated with increased baseline DD, but in multivariate analyses only DD predicted smoking status at 24 weeks postpartum. Greater baseline DD was a significant predictor of smoking status at 24 weeks postpartum. DD was reassessed periodically throughout the study and did not significantly change over time among those who eventually resumed smoking or those who sustained abstinence. The results extend the association of DD with risk for substance abuse to pregnant and recently postpartum cigarette smokers and demonstrate a significant relationship between DD and treatment outcome. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Leaving work to smoke

Work-place smoking bans have not only reduced work-day cigarette consumption but also been associated with going outside to smoke during working hours. We examined the extent of "exiled smoking", estimated how much work-day cigarette consumption can be attributed to it, and examined proximal predictors of both these two variables. Some 794 smokers from 42 medium-sized work-places were surveyed as the baseline for an intervention study. A self-completed questionnaire assessed smoking behaviour on work and non-working days, leaving work to smoke, and beliefs and opinions about smoking and smoking bans. Multiple regressions were used to examine predictors of leaving work to smoke, and of the amount smoked when doing so. Smokers reported consuming an average of 5.4 cigarettes during work breaks, 3.5 of which were associated with deliberately seeking opportunities to smoke; 39% reported leaving work to smoke one or more times per day during non-break periods. Indices of addiction were significant predictors of both leaving work to smoke and of cigarette consumption while doing so. Leaving work to smoke is in part an activity of addicted smokers, presumably to maintain blood nicotine levels. There is the potential to further reduce rates of cigarette consumption associated with work-place smoking bans if this "exiled smoking" can be reduced. This may be easier to achieve in light smokers.     

Smoking behavior and smoking history of tobacco chippers.

Nicotine produces dependence in almost all cigarette smokers. 65 chippers (anomalous smokers who smoke regularly but at very low levels [1–5 cigarettes/day]) were compared with 72 matched regular smokers (20–40 cigarettes/day). Despite having smoked an average of 46,000 cigarettes in 19 yrs of smoking, chippers demonstrated little sign of nicotine dependence. They reported frequent casual abstinence from smoking without withdrawal symptoms, smoked their 1st cigarette of the day hours after waking, and scored low on a modified Fagerstrom Tolerance Questionnaire, a measure of tobacco dependence. Although most chippers had never smoked heavily, a small subgroup of chippers reported previous extended periods of heavy smoking, which suggests that some people may be able to overcome dependence while continuing to smoke. These "converted chippers" could not be distinguished from "native chippers" on the basis of their current smoking behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Partner smoking status and pregnant smoker's perceptions of support for and likelihood of smoking cessation.

Perceptions of support for cessation of smoking during pregnancy, likelihood of quitting, and partner smoking status were explored in a sample of 688 pregnant smokers (372 baseline smokers and 316 baseline quitters). Women with nonsmoking partners were significantly more likely to be baseline quitters than women with partners who smoked. Baseline quitters reported significantly more positive support from their partners than did continuing smokers (p?=?.02). Neither partner smoking status nor partner support at baseline was associated with cessation or relapse later in pregnancy. Women reported greater support, both positive and negative, from nonsmoking partners than from partners who smoked (p?=?.001). Among partner smokers, those who were trying to quit were perceived to be particularly supportive. Cessation interventions for expectant fathers may increase pregnant women's success at quitting. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Experimental analysis of the role of expectancy in nicotine withdrawal.

Manipulated the withdrawal symptoms experienced by 62 cigarette smokers during a 48-hr smoking abstinence period. Ss were randomly assigned to 1 of 4 expectancy manipulation groups (psychological complaints, somatic complaints, no complaints, and no-expectancy control), and withdrawal symptoms were measured during 48 hrs of ad libitum smoking and 48 hrs of abstinence. The expectancy manipulation consisted of placebo nicotine gum and specific instructions as to the type of withdrawal symptoms to expect during smoking abstinence. Ss instructed to expect no complaints during abstinence reported fewer somatic complaints and less mood disturbance than the no-expectancy controls. Ss instructed to expect somatic, but not psychological, complaints reported more numerous and severe somatic withdrawal symptoms than did Ss instructed not to expect such symptoms. Results suggest expectancy may play a role in nicotine withdrawal experiences. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Non-transferrin iron uptake by trophoblast cells in culture. Significance of a NADH-dependent ferrireductase

BACKGROUND: Glucocorticoids have been linked to self-administration of a wide range of drugs in animals and are increased endogenously by chronic nicotine intake. Corticosteroids have also been shown to regulate nicotine receptor sensitivity and to be involved in behavioral sensitization to nicotine. METHODS: Cortisol levels and cortisol suppression in response to dexamethasone were measured in a sample of smokers participating in a smoking cessation treatment trial. RESULTS: Cortisol levels dropped significantly during the early quitting process (2 weeks post-quit) and returned to a level below baseline 1 month post-quit. The magnitude of the initial drop in cortisol was strongly related to post-quit distress and marginally predictive of abstinence. Neither baseline nor post-quit changes in percent cortisol suppression after dexamethasone were related to abstinence success or withdrawal distress. CONCLUSIONS: Withdrawal from cigarette smoking is marked by a reduction in cortisol levels that appears to be related to the degree of distress experienced during the early quitting period. Further work is needed to determine whether withdrawal-related cortisol changes or distress are predictive of abstinence success.     

Stress, depressive symptoms, and smoking cessation among pregnant women.

Perceived stress and depressive symptoms were examined as correlates and predictors of smoking cessation during pregnancy in a sample of 819 pregnant smokers (454 baseline smokers and 365 baseline quitters). Women who quit early in pregnancy had lower levels of stress and depressive symptoms than baseline smokers. Adjusting for level of addiction and other demographic factors related to stress and depressive symptoms eliminated the significant association between depressive symptoms and smoking cessation. Lower levels of stress and depressive symptoms were not predictive of cessation in later pregnancy. Prenatal healthcare providers should continue to assess level of addiction and provide targeted intensive cessation interventions. Interventions that reduce stress and depression may also be of benefit to women who are continuing smokers in early pregnancy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The acute effects of nicotine on positive and negative affect in adolescent smokers.

Although adolescent cigarette smoking remains a critical public health concern, little is known about the reinforcing mechanisms governing smoking in this vulnerable population. To assess predictions derived from both positive and negative reinforcement models of drug use, the authors measured the acute effects of nicotine, as administered via tobacco cigarettes, on both positive and negative affect in a group of 15- to 18-year-old smokers. A matched group of nonsmokers served as a comparison group. Findings revealed that whereas adolescents who smoked a cigarette experienced reductions in both positive and negative affect, the observed reductions in negative affect were moderated by nicotine content of the cigarette (high yield vs. denicotinized), level of nicotine dependence, level of baseline craving, and smoking expectancies pertinent to negative affect regulation. Nonsmokers experienced no change in affect over the 10-min assessment period, and no interaction effects were observed for positive affect. Overall, the findings conform to a negative reinforcement model of nicotine effects and strongly suggest that, even among young light smokers, nicotine dependence and resultant withdrawal symptomatology may serve as motivating factors governing smoking behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Motivation for smoking cessation among pregnant women.

The authors evaluated an expanded measure of intrinsic and extrinsic motivation for smoking cessation in a population-based sample of 897 pregnant smokers (500 current smokers and 397 recent quitters). The measure assessed motivation related to pregnancy and parenthood in addition to general intrinsic and extrinsic dimensions. Current smokers at baseline who quit smoking by 28 weeks of pregnancy (n?=?102) had significantly higher baseline levels of pregnancy-related motivation than continuing smokers. Extrinsic and pregnancy motivation dropped between baseline and 28 weeks of pregnancy among continuing smokers. Higher levels of intrinsic relative to extrinsic motivation at baseline were associated with sustained abstinence during the first 2 months postpartum. Results suggest that both general and pregnancy-specific motivation are important for smoking cessation and relapse prevention during pregnancy. Interventions to enhance the salience of health benefits over and above those related to pregnancy and other intrinsic benefits of a greater sense of self-control could protect against postpartum relapse. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cigarette smoking, nicotine addiction, and relaxation.

Shock endurance was used to measure the amount of anxiety experienced in a stressful situation by nonsmokers, smokers allowed to smoke cigarettes containing low levels or moderately high levels of nicotine, and smokers not allowed to smoke. Ss were 51 university students. Smokers deprived of cigarettes and those who smoked cigarettes containing low levels of nicotine behaved more anxiously than nonsmokers and Ss allowed to smoke high-nicotine cigarettes, but the high-nicotine smokers behaved no less anxiously than nonsmokers. Results support the hypothesis that the calming effect of smoking is due to the action of nicotine in ending withdrawal symptoms in addicted smokers rather than to a sedative property of cigarette smoking. (12 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Gender differences in acute tobacco withdrawal: Effects on subjective, cognitive, and physiological measures.

Gender differences in tobacco withdrawal are of considerable clinical importance, but research findings on this topic have been mixed. Methodological variation in samples sizes, experimental design, and measures across studies may explain the inconsistent results. The current study examined whether male (n = 101) and female (n = 102) smokers (≥15 cigarettes/day) differed in abstinence-induced changes on a battery of self-report measures (withdrawal, affect, craving), cognitive performance tasks (attention, psychomotor performance), and physiological responses (heart rate, blood pressure, brain electroencephalogram). Participants attended 2 counterbalanced laboratory sessions, 1 following 12 hr of abstinence and the other following ad libitum smoking. Results showed that women reported greater abstinence-induced increases in negative affect, withdrawal-related distress, and urge to smoke to relieve withdrawal distress. In contrast, both genders reported similar abstinence-induced changes in positive affect and urge to smoke for pleasure. Men and women exhibited generally similar abstinence-induced changes in physiological and cognitive performance measures. In addition, gender did not moderate the association between withdrawal symptoms and baseline measures of smoking behavior and dependence. Abstinence-induced changes in withdrawal distress mediated the effect of gender on latency until the 1st cigarette of the day at trend levels ( p     

Nicotine withdrawal in chippers and regular smokers: Subjective and cognitive effects.

From previous studies, chippers (very light, long-time cigarette smokers) seem not to be nicotine dependent, despite decades of smoking. The effect of tobacco deprivation on chippers' withdrawal reactions was examined. Matched groups of 26 chippers and 25 regular smokers were studied while abstaining or smoking for 2-day blocks, with assessments administered 5 times daily by palm-top computers. As hypothesized, chippers showed no changes as a result of nicotine deprivation. In contrast, regular smokers demonstrated distinct changes in craving, mood, arousal, and sleep disturbance. The computers also tested participants' cognitive performance. Unlike chippers, regular smokers' performance on complex tasks was slower under deprivation; the effect could not be explained by changes in motor performance or simple reaction time. Results suggest performance may have been improved by nicotine rather than worsened by withdrawal. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of nicotine on negative affect among more impulsive smokers.

In the present study, the authors tested the hypothesis that nicotine would provide greater relief from negative affect for more impulsive smokers than for less impulsive smokers. Euthymic adult smokers (N=70) participated in 2 laboratory sessions, during which they underwent a negative mood induction (music + autobiographical memory), then smoked either a nicotinized or de-nicotinized cigarette. Mixed-effects regression yielded a significant Impulsivity × Condition (nicotinized vs. de-nicotinized) × Time interaction. Simple effects analyses showed that heightened impulsivity predicted greater negative affect relief after smoking a nicotinized cigarette but not after smoking a de-nicotinized cigarette. These data suggest that nicotine may be a disproportionately powerful negative reinforcer for highly impulsive smokers, promoting higher levels of nicotine dependence and inhibiting smoking cessation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A comparison of two different systems for CD34+ selection of autologous or allogeneic PBSC collections

Narghile smoking, a common habit among women in many non-Western societies, is assumed by the public to be minimally harmful. This study aims at identifying the effect of smoking narghiles during pregnancy on the weight of the newborn and other pregnancy outcomes. Three groups of pregnant women were interviewed in several hospitals in Lebanon between 1993 and 1995: 106 who smoked narghiles during their pregnancy, 277 who smoked cigarettes, and 512 who did not smoke. The adjusted mean birth weight of babies born to women who smoked one or more narghiles a day during pregnancy and to women who started smoking in the first trimester was more than 100 g less than that of babies born to nonsmokers (p < 0.1). The adjusted odds ratio of having babies with low birth weight (<2,500 g) among the narghile smokers was 1.89 (95% confidence interval (CI) 0.67-5.38). The risk increased to 2.62 (95% CI 0.90-7.66) among those who started smoking narghiles in the first trimester. A stronger association and a dose-response relation were found among cigarette smokers. The association between narghile smoking and other pregnancy outcomes, especially Apgar score and respiratory distress, was also noticeable. Further research and a policy action to fight the misperception that narghile smoking is safe are both recommended.     

Intrauterine alcohol and nicotine exposure: Attention and reaction time in 4-year-old children.

452 4-yr-old children whose mothers had been interviewed during pregnancy regarding alcohol, smoking, and drug use were examined with a computer-controlled vigilance task to assess attention and RT. Multiple regression analyses were used to permit testing of alcohol and nicotine effects after adjusting for the S's birth order, maternal education, nutrition, and caffeine (and alcohol or nicotine, whichever was relevant). Maternal alcohol use during early pregnancy was significantly related to poor attention (more errors of omission and more errors of commission) and longer RT. Maternal cigarette use was significantly related to poor attention and poor orientation to the display board. Results support the hypothesis that both alcohol use (even in the absence of self-reported problems with alcohol abuse) and cigarette use by pregnant women are related to poorer attention in preschool age offspring, even when adjusting for a variety of potentially confounding variables. (33 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Motivational Enhancement Therapy for Nicotine Dependence in Methadone-Maintained Pregnant Women.

Pregnant women who are dependent on nicotine and illicit substances are at especially high risk for health complications and psychosocial problems. Motivational enhancement therapy (MET) for reducing smoking during pregnancy was compared with standard-care practitioner advice in a 2-group randomized design. Participants were 63 pregnant opioid-dependent smokers seeking substance abuse treatment, methadone maintenance, and prenatal care. At a 10-week follow-up, self-report and biological measures (i.e., CO, cotinine) indicated no differences in smoking between the MET and standard-care groups. However, MET participants were more likely to have moved forward on the stage of change continuum than those in standard care. Intensive treatment for nicotine dependence, environmental interventions, and innovative harm reduction strategies are recommended to address the barriers to quitting observed in this population of pregnant women. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Facial EMG as an index of affective response to nicotine.

Negative affect reduction has been postulated to be a key feature of cigarette smoking. In the present study, facial electromyography (EMG), heart rate (HR), and skin conductance response (SCR) were used to evaluate the affective significance of acute nicotine administration and overnight withdrawal. Smokers (N = 115) attended four 90-min laboratory assessment sessions scheduled approximately 3 days apart. The sessions provided a complete crossing of 2 prelaboratory deprivation conditions (12-hr deprived vs. nondeprived) with 2 drug conditions (nicotine vs. placebo nasal spray). During each session, smokers viewed affective slides while facial EMG, HR, and SCR were recorded. Results indicated that for women, nicotine nasal spray resulted in lower corrugator EMG activity during both smoking-deprived and nondeprived sessions, compared with placebo. However, nondeprived women also showed an increase in zygomaticus EMG when given nicotine compared with placebo spray, whereas smoking-deprived women demonstrated a decrease in the zygomaticus response to nicotine compared with placebo. With men, nicotine also appeared to lower corrugator during deprivation, but not nondeprivation, compared with placebo spray, though the contrast only approached significance. With zygomaticus EMG, nicotine spray decreased men's zygomaticus responding during nondeprivation but not during deprivation, compared with placebo spray. The HR results reflected the stimulatory properties of the drug rather than nicotine's affective properties, whereas SCR was unresponsive to our experimental manipulations. The corrugator EMG results support negative reinforcement models of smoking that postulate that acute nicotine use reduces withdrawal-driven negative affect. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The smoking addiction of pregnant women and the consequences on their offspring's intellectual development

Many scientists have studied the effects of smoking by pregnant women on intrauterine development. Because nicotine and other toxic substances in cigarette smoke are not stopped by the placental barrier, there is a risk that the development of the child could be hindered. It has been shown, for instance, that babies whose mothers smoked during pregnancy have lower size and weight at birth. Few authors have studied the consequences a mother's pre-natal smoking may have on the intellectual development of her child. We compared two samples of children, aged 4 to 5, and aged 6 to 7 (40 children in total), whose mothers had smoked during pregnancy, with two samples of 40 children of the same ages whose mothers had not smoked. We tested them on the Wechsler scale. The social and cultural levels were equivalent. We found a difference of more than 15 IQ points in favor of the children of nonsmoking mothers. These results permit us to suppose that smoking during pregnancy hinders the intellectual development of the child.     

High-dose transdermal nicotine and naltrexone: Effects on nicotine withdrawal, urges, smoking, and effects of smoking.

Although treatment with transdermal nicotine replacement (TNR) has improved smoking abstinence rates, higher doses of TNR could improve effects on urge to smoke, nicotine withdrawal, and reinforcement from smoking, and naltrexone might further reduce reinforcement and urges. A laboratory investigation with 134 smokers using a 3 × 2 parallel-group design evaluated the effects of TNR (42-mg, 21-mg, or 0-mg patch) as crossed with a single dose of naltrexone (50 mg) versus placebo on urge to smoke, withdrawal, and responses to an opportunity to smoke (intake, subjective effects) after 10 hr of deprivation. Urge and withdrawal were assessed both prior to and after cigarette cue exposure. Only 42 mg TNR, not 21 mg, prevented urge to smoke, heart rate change, and cue-elicited increase in withdrawal. Both 21 and 42 mg TNR blocked cue-elicited drop in heart rate and arterial pressure. Naltrexone reduced cue-elicited withdrawal symptoms but not urges to smoke or deprivation-induced withdrawal prior to cue exposure. Neither medication significantly affected carbon monoxide intake or subjective effects of smoking except that 42 mg TNR resulted in lower subjective physiological activation. No interaction effects were found, and no results differed by gender. Results suggest that starting smokers with 42 mg TNR may increase comfort during initial abstinence, but limited support is seen for naltrexone during smoking abstinence. (PsycINFO Database Record (c) 2010 APA, all rights reserved)