Examination of platelet function in whole blood under dynamic flow conditions with the cone and plate(let) analyzer: effect of erythrocytosis and thrombocytosis.

We studied cone and plate(let) analysis (CPA) for evaluating global platelet function in whole blood under arterial flow conditions (approximately 1,800 seconds(-1)). CPA allows direct visualization and quantitation of platelet adhesion (surface coverage [SC]) and determination of average aggregate size (AS) following brief shearing of a small blood sample (3.2% sodium citrate) in plastic wells. By using blood from healthy volunteers manipulated to alter platelet or RBC counts and blood from patients with myeloproliferative disorders (MPDs), quantitative and qualitative changes in SC and AS were observed. Thrombocytosis resulted in increased SC, whereas erythrocytosis increased AS. The RBC volume (mean corpuscular volume) had no effect. It is interesting that differences in CPA AS were discerned among subgroups of patients with MPD undergoing different treatment regimens. These studies suggest that CPA platelet deposition patterns may provide novel insight into global platelet function during hemodynamic flow.

Secondhand Smoke Exposure Among Community-Dwelling Adult Cancer Survivors in the United States: 1999-2012.

Background: Little is known about the prevalence of secondhand smoke exposure (SHSe) among cancer survivors. We sought to determine the prevalence, trends, and correlates of SHSe among nonsmoking adult cancer survivors in the United States.Methods: Interview and serum cotinine data for nonsmoking adults, age 20 years and older, with a history of cancer (N = 686) were obtained from consecutive two-year cross-sectional cycles of the National Health and Nutrition Examination Survey from 1999 to 2012. SHSe was defined as serum cotinine 0.05-10 ng/mL among nonsmokers. We calculated and trended the prevalence of SHSe among nonsmoking cancer survivors. Multivariable logistic regression was used to examine the associations of SHSe with sociodemographic, smoking, and clinical characteristics. Survey weights were applied in estimating prevalence rates, adjusted ORs, and confidence intervals (CI).Results: The weighted aggregate SHSe and self-reported indoor SHSe prevalence rates over the study period were 28.26% (95% CI: 24.97%-31.55%) and 4.53% (95% CI: 3.48%-5.57%), respectively. SHS exposure declined from 39.61% (95% CI: 27.88%-51.34%) in 1999/2000 to 15.68% (95% CI: 9.38%-21.98%) in 2011/2012 (Ptrend < 0.001). Age ≥ 60 years was protective against SHSe, while being black, having less than high school education, poverty, and a smoking-related cancer history were associated with higher odds of SHSe.Conclusions: Fortunately, SHSe among nonsmoking cancer survivors in the United States is on the decline, although certain subgroups remain disproportionately burdened.Impact: These findings highlight clinical and public health imperatives to target socioeconomically disadvantaged nonsmoking cancer survivors to reduce their SHSe. Cancer Epidemiol Biomarkers Prev; 26(8); 1296-305. ©2017 AACR.