1,218 smokers able to quit smoking for 48 hr were randomly assigned to one of 12 cells in a 4 x 3 fully crossed factorial experiment. A pharmacologic factor contained four levels: nicotine polacrilex (gum) delivered ad lib or on a fixed regimen, placebo gum, and no gum. A self-guided behavioral treatment factor contained three levels: self-selected relapse prevention modules, randomly administered modules, and no modules. Those receiving nicotine gum were more likely to be abstinent at the 2- and 6-month follow-ups. The fixed regimen accounted for most of the effect for gum. There was no effect for the relapse prevention module factor. Men and women showed a differential treatment response. Men who received nicotine gum were more likely to be abstinent at each follow-up (2, 6, and 12 months). No treatment was significantly better among women. We conclude that research on different gum chewing regimens is warranted and that further examination of possible gender differences in response to replacement therapy is needed.

Results of a prospective examination (N = 618) of factors associated with smoking relapse are reported. At 1-year follow-up, a modified version of the Fagerstrom Tolerance Questionnaire (Dependence Index; DI) and a measure of craving entered the logistic model (odds ratio of 2.7 [p less than .001]). At Year 2, only the DI entered the model (odds ratio of 2.2 [p less than .001]). The ability of signal detection analysis (SDA) to produce clinically useful decision rules was also examined. At Year 1, SDA produced 1 subgroup with a 25% nonrelapse rate and another with a 9% nonrelapse rate (odds ratio of 3.4 [p less than .001]). At Year 2, SDA produced 1 subgroup with a nonrelapse rate of 19% and another with a nonrelapse rate of 7% (odds ratio of 3.0 [p less than .001]). The use of signal detection methods may help clinicians to identify those at greater or lesser risk of relapse.

Ferredoxin-NADP(+) reductase has been purified to homogeneity from pea leaves and has been resolved into two forms by ion exchange chromatography and SDS gel electrophoresis. Antibodies to the proteins have been used to isolate pea leaf cDNA clones from a library in λgt11. A full-length clone of 1 400 bp encodes a polypeptide of 360 amino acid residues, of which 52 residues constitute an N-terminal transit peptide and 308 residues make up the mature protein. Transcription and translation of the cDNA in vitro produces a protein of 40 kDa, which is imported by isolated pea chloroplasts and processed to the mature 34 kDa protein. Southern hybridisation to pea genomic DNA indicates that there are probably two genes in the haploid genome.

There have been few prospective studies of craving following smoking cessation. This paper presents findings from a prospective examination of factors associated with craving over an 8-week treatment period. Two findings merit attention: (1) dependence, as measured by the Dependence Index (DI), was associated with craving at 48 h, 4 and 8 weeks post-cessation. The magnitude of the association between the DI and short-term craving was, at the least, comparable to that previously reported among several biochemical measures of smoke intake; (2) a measure of craving obtained 48 h after smoking cessation was associated with treatment outcome. Forty-three per cent of participants with low initial craving scores were abstinent at a 2-month follow-up compared to only 26% of those with high craving scores. The DI was also associated with participants' status at follow-up. This result is interesting because evidence that craving or other abstinence effects are prospectively associated with outcome has been lacking.