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Biomedical subjects

Matthew J Carpenter

Publications and source records attributed to Matthew J Carpenter.

6 recordsLinked to original sources

The feasibility of smoking reduction: an update.

AIM: To update conclusions of a previous review of smoking reduction on the extent to which (1) smokers spontaneously reduce their smoking, (2) smokers who try to quit and fail return to smoking less, (3) smokers can substantially reduce and maintain reductions via pharmacological and behavioral treatments and (4) smokers compensate when they reduce. METHOD: Qualitative systematic review. DATA SOURCES: Systematic computer searches and other methods. STUDY SELECTION: Published and unpublished studies of smokers not trying to stop smoking. We located 13-26 studies for each of the four aims. DATA EXTRACTION: The first author entered data with confirmation by second author. DATA SYNTHESIS: Due to the heterogeneity of methods and necessity of extensive recalculation, a meta-analysis was not feasible. RESULTS: Few daily smokers spontaneously reduce. Among those who try to stop smoking and relapse, some return to reduced smoking but whether they maintain this reduction is unclear. Nicotine replacement (and perhaps behavior therapies) can induce smokers not interested in quitting to make significant reductions in their smoking and maintain these over time. Some compensatory smoking occurs with reduction but significant declines in smoke exposure still occur. CONCLUSIONS: These results indicate that reduction is feasible when aided by treatment. Whether reduction should be promoted will depend on the effect of reduction on health outcomes and future cessation.

Adolescent↗

Both smoking reduction with nicotine replacement therapy and motivational advice increase future cessation among smokers unmotivated to quit.

Smokers not currently interested in quitting (N = 616) were randomized to receive telephone-based (a) reduction counseling plus nicotine replacement therapy (NRT) plus brief advice to quit, (b) motivational advice plus brief advice, or (c) no treatment. More smokers in the reduction (43%) and motivational (51%) conditions made a 24-hr quit attempt over 6 months than smokers in the no-treatment condition (16%; p < or = .01), but the 2 active conditions did not differ (p > or = .05). Similarly, 18%, 23%, and 4% of each condition were abstinent (7-day point prevalence) at 6 months (p < or = .01). Results indicate smoking reduction using NRT does not undermine cessation but rather increases the likelihood of quitting to a degree similar to motivational advice.

Administration, Oral↗

Effect of smoking reduction on later cessation: a pilot experimental study.

It is unclear whether reducing the number of cigarettes in smokers not trying to quit increases or decreases the likelihood of future quitting. In a pilot study, smokers not currently interested in quitting (n=67) were randomized to two groups. Experimental participants received behavioral treatment and nicotine replacement therapy (choice of gum, patch, or inhaler) to reduce smoking by 50% over 4 weeks, followed by brief advice to quit. Usual-care participants received only brief advice to quit and nicotine replacement if they decided to quit. During the 4-week treatment period, nonabstaining reduction participants decreased from 23 to 14 cigarettes per day (p<.01) and maintained their reduction over the 6-month follow-up period. At the 6-month follow-up, 35% of usual-care and 41% of reduction participants (nonsignificant [ns]) moved forward in their stage of change. Over the 6 months, 34% of usual-care participants had at least one 24-h quit attempt, compared with 25% of reduction participants (ns). A total of 9% of usual-care participants remained quit at 6 months vs. 13% in the reduction group (ns). These preliminary results suggest that adding a reduction option neither increases nor undermines interest in cessation. Higher than expected rates of attempted cessation and quitting in the usual-care group suggest that we recruited smokers whose motivation to quit was above average. Thus, a replication test in a less-motivated group of smokers is needed.

Administration, Cutaneous↗

Notch ligation by Delta1 inhibits peripheral immune responses to transplantation antigens by a CD8+ cell-dependent mechanism.

Notch signaling plays a fundamental role in determining the outcome of differentiation processes in many tissues. Notch signaling has been implicated in T versus B cell lineage commitment, thymic differentiation, and bone marrow hematopoietic precursor renewal and differentiation. Notch receptors and their ligands are also expressed on the surface of mature lymphocytes and APCs, but the effects of Notch signaling in the peripheral immune system remain poorly defined. The aim of the studies reported here was to investigate the effects of signaling through the Notch receptor using a ligand of the Delta-like family. We show that Notch ligation in the mature immune system markedly decreases responses to transplantation antigens. Constitutive expression of Delta-like 1 on alloantigen-bearing cells renders them nonimmunogenic and able to induce specific unresponsiveness to a challenge with the same alloantigen, even in the form of a cardiac allograft. These effects could be reversed by depletion of CD8+ cells at the time of transplantation. Ligation of Notch on splenic CD8+ cells results in a dramatic decrease in IFN-gamma with a concomitant enhancement of IL-10 production, suggesting that Notch signaling can alter the differentiation potential of CD8+ cells. These data implicate Notch signaling in regulation of peripheral immunity and suggest a novel approach for manipulating deleterious immune responses.

Animals↗

Genetic testing for alpha1-antitrypsin deficiency.

PURPOSE: The Alpha Coded Testing Study investigated the risks, benefits, and psychological impact of home genetic testing for alpha1-antitrypsin deficiency. METHODS: In the study, 996 adult individuals requested and returned a home-administered, confidential, fingerstick blood test. RESULTS: Individuals highly rated the benefits of establishing a diagnosis (82%), helping family members (86%), and anticipating peace of mind (79%). 78% of 239 current smokers reported a high likelihood of smoking cessation if diagnosed with AATD. After testing, more than 60% indicated that they would share the results with family and physicians but < 30% would share results with insurance companies. CONCLUSIONS: Confidential home testing for genetic disorders requires a comprehensive program of participant support.

Adolescent↗