Smoking Cessation and Pregnancy: Timing of Cessation Reduces or Eliminates the Effect on Low Birth Weight.

BACKGROUND: Women who smoke cigarettes while pregnant are at elevated risk of having low birth weight infants (LBW, < 2500 g) which increases risks of infant mortality and morbidity, including chronic conditions later in life. OBJECTIVE: Smoking cessation during pregnancy can reduce the risk of poor birth outcomes. However, the effect that timing of smoking cessation has on the reduction of poor birth outcomes in term pregnancies is unknown. STUDY DESIGN: This retrospective cohort study used birth certificate data from Missouri singleton, full-term, live births from 2010 to 2012 (N = 179,653) to examine the rates and timing of smoking cessation during pregnancy on birthweight. Smoking exposure was categorized as non-smoker, preconception cessation, first trimester cessation, second trimester cessation, and smoker. The outcome was low birth weight (LBW). Covariates included maternal race/ethnicity, age, education level, type of payment for the delivery, marital status, paternal acknowledgement, prenatal sexually transmitted infection (STI), comorbidities, and body mass index. Bivariate and multivariable analyses were used to assess relationships between smoking and LBW status. RESULTS: Preconception cessation did not have a statistically higher risk for LBW than mothers who never smoked (aOR 1.12; 95% CI 0.98, 1.28). First trimester cessation (aOR 1.26; 95% CI 1.05, 1.52), second trimester cessation (aOR 2.00; 95% CI 1.60, 2.67), and smoker (aOR 2.46; 95% CI 2.28, 2.67) had increasing odds for LBW relative to mothers who did not smoke. All covariates had significant relationships with the smoking exposure. CONCLUSION: Preconception cessation yielded LBW rates comparable to non-smokers. The risk for LBW increased as smoking continued throughout pregnancy among full term births, an important new finding in contrast with other studies.

Phage-derived anti-idiotype and anti-YTE antibodies in development of MK-1654 pharmacokinetic and immune response assays.

Background: MK-1654 is a fully human monoclonal antibody with YTE mutations currently in phase III clinical trials for prophylactic use in protecting infants from human respiratory syncytial virus infection. Materials & methods: We generated anti-idiotype (anti-ID) and anti-YTE antibodies against MK-1654 by panning with MorphoSys HuCal phage libraries, and used the antibodies in the development of MK-1654 pharmacokinetic (PK) and immune response (IR) assays. Results: Detection of MK-1654 in nonhuman primate and human nasal wash samples showed combined use of anti-ID and anti-YTE antibodies can deliver desired sensitivity and accuracy in PK studies. IR studies showed anti-ID can serve as suitable positive control in neutralizing antibody assays. Conclusion: Phage-derived anti-IDs and anti-YTEs are suitable for PK and IR assays.

Prediction of frozen virus stability based on degradation mechanisms, real-time data and modeling.

Aim: Critical virus reagents in regulated bioanalytical assays require stability monitoring. Although stability at ultra-low frozen temperatures is generally assumed, published data are limited and real-time studies are time consuming. Materials & methods: The authors reviewed literature data, typical mechanisms of molecular degradation, glass transition temperatures of commonly used buffers and available real-time storage data to model frozen virus reagent stability. Results: Storage at ultra-low temperatures below the glass transition temperature was critical for virus stability. Modeling of real-time data suggested that virus potency remained within 0.5 log10 of its starting potency at a probability of >99, 90 and 73% after 10, 20 and 30 years, respectively. Conclusion: The study supports the practice of virus storage at -70°C or below for 20-30 years.