Salivary secretory immunoglobulin A reactivity: a comparison to cortisol and α-amylase patterns in the same breast cancer survivors.

INTRODUCTION: One way to examine the extent to which the stress associated with a breast cancer experience (BC) impacts stress-related physiological mechanisms is to study the secretion patterns of associated biomarkers. Unlike cortisol and α-amylase (sAA), biomarkers of immune functioning such as secretory immunoglobulin A (SIgA) have rarely been examined in BC survivors. AIM OF THE STUDY: This study had two principal aims: the first was to evaluate the basal secretion profiles of SIgA as well as its response to an acute stressor as a marker of immune health in BC survivors and women with no history of BC, and the second was to determine how SIgA stress-related patterns compare to published cortisol and sAA patterns in the same women. RESULTS: Overall, the findings indicate that BC survivors exhibit a blunted cortisol reaction to an acute stressor, a generally elevated diurnal sAA concentration pattern, and normal SIgA profiles, compared to women with no history of cancer. This study serves as a foundation for future research to elucidate the relationships between BC experience variables, stress biomarkers, and health outcomes in BC survivors.

The role of stressful life events on the cortisol reactivity patterns of breast cancer survivors.

OBJECTIVE: Atypical patterns of cortisol secretion following an acute stressor have been commonly reported in breast cancer survivors. Stressful life events have been associated with blunted acute cortisol levels in other populations. The purpose of this study was to explore the role of stressful life events on cortisol secretion patterns of breast cancer survivors following an acute stressor. DESIGN: The Trier Social Stress (TSST) was used to elicit a moderate stress response in breast cancer survivors (n = 19) and a control group (n = 17). Saliva samples were collected before, during and after the TSST to provide cortisol concentrations. During recovery, we recorded the frequency and subjective impact of stressful life events in the past year using the Life Experience Survey. RESULTS: Simple regressions analyses were performed; results suggest no group differences between the total number of stressful life events and their subjective impact. However, the total number of stressful life events as well as their subjective impact correlated negatively with the peak cortisol concentration in breast cancer survivors. CONCLUSIONS: The cumulative effect of stressful life events, positive and negative, may impact the endocrine stress system of breast cancer survivors more so than that of women with no history of cancer.

Salivary Alpha-Amylase Reactivity in Breast Cancer Survivors.

The two main components of the stress system are the hypothalamic-pituitary-adrenal (HPA) and sympathetic-adrenal-medullary (SAM) axes. While cortisol has been commonly used as a biomarker of HPA functioning, much less attention has been paid to the role of the SAM in this context. Studies have shown that long-term breast cancer survivors display abnormal reactive cortisol patterns, suggesting a dysregulation of their HPA axis. To fully understand the integrity of the stress response in this population, this paper explored the diurnal and acute alpha-amylase profiles of 22 breast cancer survivors and 26 women with no history of cancer. Results revealed that breast cancer survivors displayed identical but elevated patterns of alpha-amylase concentrations in both diurnal and acute profiles relative to that of healthy women, F (1, 39) = 17.95, p < 0.001 and F (1, 37) = 7.29, p = 0.010, respectively. The average area under the curve for the diurnal and reactive profiles was 631.54 ± 66.94 SEM and 1238.78 ± 111.84 SEM, respectively. This is in sharp contrast to their cortisol results, which showed normal diurnal and blunted acute patterns. The complexity of the stress system necessitates further investigation to understand the synergistic relationship of the HPA and SAM axes.

Primary production in headwater streams of the Seine basin: the Grand Morin river case study.

Periphytic biomass has an important influence on the water quality of many shallow streams. The purpose of this paper is to synthesize the knowledge obtained on periphyton during the PIREN Seine research program. Periphyton was sampled using chl a measurements by acetone extraction and oxygen measurements with microelectrodes. The experiments reveal the presence of an important fixed biomass ranging between 123 and 850 mgchl a m(-2) and the mean gross production (photosynthesis) is shown to range between 180 and 315 mgC m(-2) h(-1). An independent approach was performed using the ProSe model, which simulates transport and biogeochemical processes in 22 km of the Grand Morin stream. A strong agreement between in situ measurements and the model results was obtained. The gross production obtained using ProSe is 220 mgC m(-2) h(-1) for the periphyton, which matches the experimental data. Although the net photosynthetic activity of the phytoplankton (0.84 gC gC(-1) d(-1)) is higher than the periphytic one (0.33 gC gC(-1) d(-1)), the absolute periphytic activity is greater since the mean biomass (3.4 gC m(-)(2)) is 10 times higher than the phytoplanktonic one (0.3 gC m(-2)), due to the short residence time of the water body (1.5d).