James W. Fenwick

Smoking cessation among self-quitters.

We examined cessation among 630 smokers who quit abruptly on their own. Continuous, complete abstinence rates were 33% at 2 days, 24% at 7 days, 22% at 14 days, 19% at 1 month, 11% at 3 months, 8% at 6 months postcessation, and 3% at 6 months with biochemical verification. Slipping (smoking an average of less than 1 cigarette/day) was common (9% to 15% of subjects) and was a strong predictor of relapse; however, 23% of long-term abstainers slipped at some point. These results challenge beliefs that most smokers can initially stop smoking and that most relapse occurs later on postcessation.

Effect of Cost on the Self-Administration and Efficacy of Nicotine Gum: A Preliminary Study'

METHODS. One hundred six smokers seen in a family practice received brief physician advice and a prescription for nicotine gum. Smokers were randomly assigned to pay

Development of the Child's Arch

20,

Pneumatosis intestinalis in patients with Crohn's disease

6, or

Smoking history, instructions and the effects of nicotine: two pilot studies.

0/box of nicotine gum and followed for 6 months. RESULTS. Decreased cost increased the incidence of obtaining gum, the amount of gum used, and the incidence of long-term use (P less than 0.05). Decreased cost also increased cessation attempts and 1-week cessation (P less than 0.05) and appeared to increase abstinence at 6-month follow-up (19% vs 6% vs 8%, P less than 0.10). Cost-benefit estimates suggest that an insurance plan, HMO, etc., would recoup any costs in subsidizing nicotine gum and perhaps incur a net financial gain.

Triazolam as a discriminative stimulus in humans

The purposes of the project were to monitor the development of the lower extremities and the longitudinal arch of the foot and to determine whether or not arch support footwear (three types) affected development of a neutral arch in toddlers 11 to 14 months of age until age 5 years. A total of 125 beginner walkers were recruited through the pediatrics department during a period of 1 ½ years and divided by lot into four different footwear groups (one nonarch supportive). The group was studied for 4 years by physical examinations, x-ray films, and pedotopography (a Moire fringe technique of photography). At initial examination all of the apparently normal toddlers had pes planus by all clinical, roentgenographic, and photographic measurements. There were no cavus feet at that time or at 5 years of age. Arches developed regardless of the footwear worn but development was faster during the first 2 years (until age 3 years) with arch support footwear. The rapidity of arch development until 5 years of age continued in those children who wore longitudinal arch cookies. Ossification of the sustentaculum tali begins at approximately 5 years of age but is not complete for at least another 1 to 2 years. Hyperpronation was present in 77.9% and genu valgum in 92.3% of the 5-year-old children. These conditions are apparently the norm at this age in both boys and girls.

Forced-choice versus free-choice procedures: caffeine self-administration in humans.

The prevalence, predictors, and significance of pneumatosis were determined in 50 patients with Crohns disease who had abdominal CT scans to rule out abscess. The presence or absence of six CT descriptors and 17 clinical descriptors was documented. CT scans of a control group of 50 subjects without inflammatory bowel disease were also examined. Data was analyzed by two-sample t tests and Fishers exact test. Pneumatosis was found in six of 50 patients with Crohns disease and in none of the controls. Corticosteroid treatment was the single clinical variable relating significantly (P=0.025) to pneumatosis, although trends toward absence of resection, short duration of illness, and more severe anemia were also evident in this group. This study suggests that the presence of pneumatosis alone does not dictate a specific course of treatment, but when pneumatosis is present, careful monitoring is required and therapy is based on the overall clinical picture.

Effect of dose on the ability of caffeine to serve as a reinforcer in humans.

In Study 1, ten never-smokers, ten ex-smokers and nine current smokers received nicotine (2 mg) and placebo gum hourly for 4 hours on 2 consecutive days in a randomized, double-blind, cross-over protocol. Dysphoria from nicotine was greatest in never-smokers, intermediate in ex-smokers, and least in current smokers (p less than 0.05). On the third day, subjects were given concurrent access to the same gums and told to chew ad lib. Across all subjects, nicotine was an aversive stimulus (i.e., self-administered less than placebo). Nicotine was avoided most in never-smokers, intermediate in ex-smokers and least in current smokers (p less than 0.05). Study 2 used a similar protocol and compared the nine current smokers in Study 1 who were not told they would receive nicotine with eight informed smokers, i.e., smokers told they would receive nicotine. Although nicotine appeared to be a reinforcer more often in the informed smokers than in the uniformed smokers (63% vs. 22%), this result was not statistically significant. Our results suggest 1) past drug history can influence the stimulus effects of nicotine and 2) the effects of instructions on the response to nicotine may be less in experimental settings than in therapeutic settings.

Effects of caffeine on tobacco withdrawal

Seven healthy normal male and female volunteers (19-42 years) were trained to discriminate between the benzodiazepine triazolam (0.32 mg/70 kg; e.g. drug A) and placebo (e.g. drug B). During the first four daily sessions, drug A and drug B were administered orally in capsules 60 min prior to the session on alternate days and subjects were informed of the drug label at the time of drug administration. Subsequently, drug A and drug B were administered in a randomized-block fashion and subjects identified the drug code they thought they received. Subjects were informed of the drug code post-session. Once the criterion for discrimination was met (i.e. correct drug code identification on four consecutive sessions), the dose-effect curve for triazolam (0.1-0.75 mg/70 kg) was determined. The discrimination was acquired in all subjects; triazolam (0.32 mg/70 kg) and placebo produced approximately 85-95% correct responding. During the dose-effect curve determination, triazolam produced dose-related increases in triazolam-appropriate responding and self-reported sedation and drug strength. These results indicate that a triazolam-placebo discrimination can be acquired and that the triazolam discriminative stimulus effect is related to dose and to self-reported sedation.

A Behavioral Approach to Achieving Initial Cocaine Abstinence

Methodological comparisons of procedures for drug self-administration are rare. In studies examining the reinforcing effect of caffeine in humans, caffeine self-administration usually has been inferred from performance under forced-choice procedures. In the present experiment, caffeine self-administration via coffee was compared under forced-choice and free-choice conditions; i.e., when subjects were and were not required to use a minimum number of coffees. Ten moderate coffee drinkers (2–7 cups/day) were assigned to forced- and free-choice conditions using a randomized cross-over design. Under each choice condition, subjects completed six independent, double-blind trials, consisting of a 2-day exposure period followed by a 2-day test period. During exposure, subjects consumed either decaffeinated or caffeinated (100 mg/serving) coffee on day 1 and the other coffee on day 2. During the test period, subjects had concurrent access to the same decaffeinated and caffeinated coffees. Under the forced-choice condition, subjects were required to drink at least four cups of coffee per day during the test period. Under the free-choice condition, subjects did not have a minimum-cup requirement. In general, the relative rate at which subjects self-administered caffeinated versus decaffeinated coffee was similar across choice conditions, even though subjects self-administered significantly fewer cups of both coffee types under the free-choice than the forced-choice condition. These results suggest that, at least for caffeine, forced-choice and free-choice procedures produce comparable results. Whether this finding generalizes to a context in which caffeine or another drug is more robustly self-administered, remains to be determined.