Circulating leptin levels are associated with increased craving to smoke in abstinent smokers.

The adipocyte hormone leptin regulates satiety and energy expenditure. Recent evidence suggests that leptin is associated with increased craving for alcohol and with shorter length of abstinence during alcohol treatment. This study examined leptin's associations with craving for cigarettes and smoking relapse among smokers interested in cessation.

Blunted opiate modulation of hypothalamic-pituitary-adrenocortical activity in men and women who smoke.

Objective: To examine the extent to which nicotine dependence alters endogenous opioid regulation of the hypothalamic-pituitary-adrenocortical (HPA) axis functions. Endogenous opiates play an important role in regulating mood, pain, and drug reward. They also regulate the HPA functions.

Nociceptive flexion reflex and pain rating responses during endogenous opiate blockade with naltrexone in healthy young adults.

The effect of opioid blockade on nociceptive flexion reflex (NFR) activity and subjective pain ratings was examined in 151 healthy young men and women. Using a within-subjects design, NFR threshold was assessed on 2 days after administration of either placebo or a 50mg dose of naltrexone. Electrocutaneous pain threshold and tolerance levels were measured after NFR threshold assessment on each day.

Assessment of opiate modulation of pain and nociceptive responding in young adults with a parental history of hypertension.

This double blind, placebo-controlled study examined the effects of an opiate antagonist, naltrexone, on nociceptive flexion reflex (NFR) thresholds and subjective pain in individuals with and without a parental history of hypertension. Using a repeated measures design, NFR threshold was repeatedly assessed on two testing days after administration of either placebo or naltrexone. Immediately after NFR threshold was determined, participants rated the level of pain experienced during the preceding NFR assessment, and at the end of each session participants' electrocutaneous pain threshold was assessed.

Nociception and baroreceptor stimulation in hypertension-prone men and women.

We examined the effects of baroreceptor stimulation on nociceptive responding in men and women with a positive or negative parental history of hypertension. The effects of three baroreceptor conditions (stimulation, inhibition, and control) on subjective pain and nociceptive responding were evaluated during electrocutaneous sural nerve stimulation. Pain ratings were lower in men with positive parental history relative to men with negative parental history, but this difference was not found in women.

Sex differences in pain and hypothalamic-pituitary-adrenocortical responses to opioid blockade.

Objective: Sex differences in pain sensitivity and stress reactivity have been well documented. Little is known about the role of the endogenous opioid system in these differences. This study was conducted to compare adrenocortical, pain sensitivity, and blood pressure responses to opioid blockade using naltrexone in men and women.

Prospective examination of effects of smoking abstinence on cortisol and withdrawal symptoms as predictors of early smoking relapse.

This study addressed the hypothesis that exaggerated mood and cortisol changes during the first 24h of smoking abstinence are associated with early relapse. Salivary cortisol levels and mood reports were measured during 24-h ad libitum smoking and the first 24-h abstinence period of a quit attempt. Seventy-two habitual smokers (34 women and 38 men) who were interested in smoking cessation participated.

A 9,000-year record of Chagas' disease.

Tissue specimens from 283 principally spontaneously (naturally) desiccated human mummies from coastal and low valley sites in northern Chile and southern Peru were tested with a DNA probe directed at a kinetoplast DNA segment of Trypanosoma cruzi. The time interval spanned by the eleven major cultural groups represented in the sample ranged from approximately 9,000 years B.P.

Enhanced adrenocortical responses to stress in hypertension-prone men and women.

Hypertension risk may be associated with increased adrenocortical activity, but the extent to which this enhanced activation differs between men and women at rest and in response to psychological stress is not known. This study examined gender differences in adrenocortical responses to an extended public-speaking stressor in persons at high (resting systolic blood pressure > median; n = 21) or low risk (negative parental history and < or = median systolic blood pressure; n = 26). Salivary cortisol levels were assessed at rest and in response to public speaking in a repeated measure design on two test sessions held on separate days.

Attenuated adrenocortical and blood pressure responses to psychological stress in ad libitum and abstinent smokers.

Chronic smoking may alter physiological systems involved in the stress response. This study was designed to examine the effects of ad libitum smoking and abstinence on adrenocortical and cardiovascular responses to acute psychological stress in dependent cigarette smokers. We evaluated differences among abstinent smokers, smokers who continued to smoke at their normal rate, and nonsmokers in salivary cortisol concentrations, systolic and diastolic blood pressure (BP), heart rate (HR), and mood reports.

Psychophysiological effects of nicotine abstinence and behavioral challenges in habitual smokers.

We tested the hypothesis that psychophysiological responses to behavioral challenges are enhanced by short-term abstinence from smoking. Blood pressure (BP), salivary cortisol levels, and withdrawal symptoms were measured after a period of smoking abstinence (18 h) or ad libitum smoking, during rest, and in response to acute behavioral challenges. Thirty habitual smokers (15 women and 15 men) participated in two laboratory sessions conducted on two separate days (after abstinence or ad libitum smoking).

Adrenocortical and hemodynamic predictors of pain perception in men and women.

Research has demonstrated that women report more pain than men, and clinical observations suggest that attenuated adrenocortical activity is associated with high pain sensitivity. The extent to which cortisol concentrations and hemodynamics contribute to gender differences in pain sensitivity has not been investigated. Thirty-four women and 31 men performed the hand cold pressor test (CPT).

Blood pressure but not parental history for hypertension predicts pain perception in women.

Previous work has suggested an attenuated sensitivity to painful stimulation in hypertensive men. We recently reported that, compared with persons with negative parental history, men, but not women, with a positive history for hypertension showed attenuated pain perception. This study specifically addressed factors that predict pain perception in women, including blood pressure, parental history and mood states.