RATIONALE

Repeated, short-term exposures to ozone (O3) lead to attenuation of the acute lung function and airway inflammatory responses seen after a single exposure in healthy subjects, but it is unclear whether these acute responses also attenuate in subjects with asthma.

OBJECTIVE

To address this question by exposing 14 subjects with asthma to 0.2 ppm O3 for either 4 hours on a single day or 4 hours on 4 consecutive days (multiday [MD]). At least 3 weeks later, subjects underwent the alternate exposure.

METHODS

Spirometry was performed immediately pre- and postexposure and bronchoalveolar lavage (BAL) was obtained 18 hours after each exposure.

MAIN RESULTS

The decrease in FEV1 was greatest across Day 2 of the MD (MD2) exposure and then gradually declined on successive days of the MD exposure (mean +/- SD decrease in FEV1 of 25.4 +/- 18.0% across MD2 compared with 4.2 +/- 6.5% across MD4). Respiratory symptoms followed a similar pattern to that of FEV1. Although the concentration of neutrophils in BAL after the MD4 exposure was not significantly different from that after the single-day exposure (1.7 +/- 1.3 x 10(4) cells/ml vs. 1.2 +/- 0.8 x 10(4) cells/ml, p = 0.20), the concentration of alveolar macrophages did significantly increase in BAL after the MD exposure (19.9 +/- 9.7 x 10(4) cells/ml after MD4 vs. 12.1 +/- 6.4 x 10(4) cells/ml after the single day).

CONCLUSIONS

Alveolar macrophages are recruited to the airways of subjects with asthma with repeated short-term exposures to O3, suggesting a possible role for these cells in the chronic response to oxidant-induced injury.

BACKGROUND

Little is known about the participation of minorities in health behavior research. This manuscript assesses factors associated with participation among women in four racial/ethnic groups.

METHODS

A total of 2800 Asian/Pacific Islander (API), Black, Latina, and non-Latina White women recruited through the San Francisco Mammography Registry was invited in 2002 and 2003 to participate in a telephone survey about breast cancer prevention.

RESULTS

Minorities participated at lower rates (49% for APIs, 60% for Latinas, and 64% for Blacks) than Whites (77%). Increased participation was associated with younger age for Latinas (OR = 1.90, 95% CI 1.05-3.44) and Whites (OR = 1.77, CI 1.08-2.91), and with a family history of breast cancer for APIs (OR = 2.09, CI 1.24-3.52). Decreased participation was associated with having less than a high school education for APIs (OR = 0.47, CI 0.26-0.86), Blacks (OR = 0.29, CI 0.11-0.78), and Latinas (OR = 0.51, CI 0.28-0.94).

CONCLUSIONS

Results suggest minorities' participation in health behavior research does not match Whites' and should be enhanced.

Using high-throughput screening, Jo et al. in this issue of Chemistry & Biology [1] have identified SEW2871 as a structurally unique sphingosine 1-phosphate(1) (S1P(1)) receptor agonist. SEW2871 binds to and activates the S1P(1) receptor and initiates a survival signaling pathway similar to that of S1P.

BACKGROUND & AIMS

Proton pump inhibitors (PPIs) are often taken for short-term treatment of heartburn. We performed a systematic review of the efficacy of PPIs for heartburn relief within the first 1-2 days of therapy.

METHODS

Bibliographic databases were searched for clinical trials of PPIs in patients with heartburn that provided information about the proportion with heartburn relief at day 1-2. The sample size-weighted pooled proportions of patients with complete or sustained (7 consecutive days) relief were calculated. Meta-analyses of randomized comparisons of PPIs were also performed.

RESULTS

Eighteen trials met inclusion criteria. At day 1 of PPI therapy, complete 24-hour, daytime, nighttime, and sustained heartburn relief occurred in 0.31 (95% confidence interval [CI], 0.30-0.32), 0.49 (95% CI, 0.48-0.50), 0.55 (95% CI, 0.53-0.56), and 0.21 (95% CI, 0.20-0.22) of patients. Up to 37% of the heartburn relief achievable with 28 days of PPIs occurred on day 1. Placebo was significantly less effective than PPIs for 24-hour relief on day 1 (relative risk [RR], 0.41; 95% CI, 0.29-0.58), and single-dose PPI therapy was less effective than double-dose therapy (RR, 0.82; 95% CI, 0.74-0.92).

CONCLUSIONS

Complete heartburn relief for the entire day occurs in approximately 30% of patients after their first PPI dose and 9% of patients after their first placebo (RR for relief on day 1 for placebo versus PPI was 0.41 [95% CI, 0.28-0.58]). Although PPIs might provide benefit from the first day of therapy, most patients will not have symptom relief with 1 or 2 days of PPI therapy.

The gspB-secY2A2 locus of Streptococcus gordonii strain M99 encodes the platelet-binding glycoprotein GspB, along with proteins that mediate its glycosylation and export. We have identified two additional components of the accessory Sec system (Asp4 and Asp5) encoded just downstream of gtfB in the gspB-secY2A2 locus. These proteins are required for GspB export and for normal levels of platelet binding by M99. Asp4 and Asp5 may be functional homologues of SecE and SecG, respectively.