Publications

BACKGROUND

Snus (a form of smokeless tobacco) is less dangerous than cigarettes. Some health professionals argue that snus should be promoted as a component of a harm reduction strategy, while others oppose this approach. Major US tobacco companies (RJ Reynolds and Philip Morris) are marketing snus products as cigarette brand line extensions. The population effects of smokeless tobacco promotion will depend on the combined effects of changes in individual risk with population changes in tobacco use patterns.

OBJECTIVE

To quantitatively evaluate the health impact of smokeless tobacco promotion as part of a harm reduction strategy in the US.

METHODS

A Monte Carlo simulation of a decision tree model of tobacco initiation and use was used to estimate the health effects associated with five different patterns of increased smokeless tobacco use.

RESULTS

With cigarette smoking having a health effect of 100, the base case scenario (based on current US prevalence rates) yields a total health effect of 24.2 (5% to 95% interval 21.7 to 26.5) and the aggressive smokeless promotion (less cigarette use and increased smokeless, health-concerned smokers switching to snus, smokers in smokefree environments switching to snus) was associated with a health effect of 30.4 (5% to 95% interval 25.9 to 35.2). The anticipated health effects for additional scenarios with lower rates of smokeless uptake also overlapped with the base case.

CONCLUSIONS

Promoting smokeless tobacco as a safer alternative to cigarettes is unlikely to result in substantial health benefits at a population level.

Wear particle-induced periprosthetic osteolysis has been a clinical problem driving the development of wear resistant ultrahigh molecular weight polyethylene (UHMWPE) for total joint replacement. Radiation crosslinking has been used to decrease wear through decreased plastic deformation; but crosslinking also reduces mechanical properties including fatigue resistance, a major factor limiting the longevity of joint implants. Reducing UHMWPE wear with minimal detriment to mechanical properties is an unaddressed need for articular bearing surface development. Here we report a novel approach to achieve this by limiting crosslinking to the articular surface. The antioxidant vitamin E reduces crosslinking efficiency in UHMWPE during irradiation with increasing concentration, thus we propose to spatially control the crosslink density distribution by controlling the vitamin E concentration profile. Surface crosslinking UHMWPE prepared using this approach had high wear resistance and decreased crosslinking in the bulk resulting in high fatigue crack propagation resistance. The interface region did not represent a weakness in the material due to the gradual change in the crosslink density. Such an implant has the potential of decreasing risk of fatigue fracture of total joint implants as well as expanding the use of UHMWPE to younger and more active patients.

OBJECTIVE

To assess racial differences in attitudes and knowledge about sterilization.

DESIGN

Cross-sectional survey.

SETTING

Questionnaires were mailed to participants' home addresses.

PATIENT(S)

One hundred ninety-three women, aged 18-45, who had undergone tubal sterilization.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Attitudes and knowledge about tubal sterilization and awareness of contraceptive alternatives.

RESULT(S)

We received 193 completed surveys (64% response rate). African American (AA) woman were more likely to have a family member who had undergone tubal sterilization, to report that their mothers influenced their sterilization decisions, and to report that prior unintended pregnancy and desire to avoid insertion of a foreign object were very important factors in their decision to choose sterilization over other methods. Compared with white women, AA women more often thought that sterilization reversal could easily restore fertility (62% vs. 36%); that a woman's sterilization would reverse itself after 5 years (60% vs. 23%); and that a man cannot ejaculate after vasectomy (38% vs. 13%). Fewer AA women had ever heard of intrauterine contraception (90% vs. 98%). Racial differences in knowledge remained statistically significant after adjusting for socioeconomic confounders.

CONCLUSION(S)

Misinformation about sterilization and limited awareness of contraceptive alternatives among AA women may contribute to racial disparities in tubal sterilization rates.

BACKGROUND

Airflow in the lungs of patients with allergic asthma is impaired by excessive mucus production and airway smooth muscle contractions. Elevated levels of the cytokines IL-4 and IL-13 are associated with this pathology. In vitro studies have suggested that IL-4 receptor alpha (IL-4Ralpha) signaling on smooth muscle cells is critical for airway inflammation and airway hyperresponsiveness.

OBJECTIVE

To define the contribution of IL-4 and IL-13 to the onset of asthmatic pathology, the role of their key receptor IL-4Ralpha in smooth muscle cells was examined in vivo.

METHODS

By using transgenic smooth muscle myosin heavy chain(cre)IL-4Ralpha(-/lox) mice deficient in IL-4Ralpha in smooth muscle cells, in vivo effects of impaired IL-4Ralpha signaling in smooth muscle cells on the outcome of asthmatic disease were investigated for the first time. Allergic asthma was introduced in mice by repeated sensitization with ovalbumin/aluminum hydroxide on days 0, 7, and 14, followed by intranasal allergen challenge on days 21 to 23. Mice were investigated for the presence of airway hyperresponsiveness, airway inflammation, allergen-specific antibody production, T(h)2-type cytokine responses, and lung pathology.

RESULTS

Airway hyperresponsiveness, airway inflammation, mucus production, T(h)2 cytokine production, and specific antibody responses were unaffected in smooth muscle myosin heavy chain(cre)IL-4Ralpha(-/lox) mice compared with control animals.

CONCLUSION

The impairment of IL-4Ralpha on smooth muscle cells had no effect on major etiologic markers of allergic asthma. These findings suggest that IL-4Ralpha responsiveness in airway smooth muscle cells during the early phase of allergic asthma is not, as suggested, necessary for the outcome of the disease.