Vittorio Pasquali

A large variety of positive outcomes including social adjustment, psychological well-being and health, have been recently closely associated with positivity (POS). On the assumption that differences in the POS degree might be associated with different individual neuroendocrine assets that enables people to cope effectively with stress, the present study examined the association between POS, salivary cortisol and α-Amylase (α-Amy) production in a group of healthy male volunteers university students, respectively scoring high (POS-H, N = 10) and low (POS-L, N = 10) in POS. Participants were selected from a larger sample of 300 students of the Medical School at Sapienza University of Rome on the basis of their positivity level: POS was analysed and the upper and lower 25% were invited to participate in this new study. The findings report a distinct salivary cortisol and α-Amy production in the study population: in comparison to the POS-H group, the POS-L subjects presented a lower salivary cortisol awake response (CAR) and a flattened α-Amy production at 30 and 60 min after awakening. In addition, salivary cortisol and α-Amy areas under the curve (AUCs), which were calculated as indicators of the two subclinical biomarkers production during the first hour after awakening, resulted significantly lower in the POS-L group in comparison to the POS-H group. Further studies on larger and different populations are needed to definitively confirm that the different cortisol and α-Amy secretion patterns between POS-H and POS-L individuals is associated with a potentially better capacity to preserving an adequate quality of life in individuals being equipped with a system apparently able to better respond to external and/or internal stimuli. Lastly, a better understanding of the biological correlates of POS is crucial to design psychological interventions able to take advantage of individuals’ assets and thus to integrate and strengthen the efficacy of traditional medications.

It has been hypothesized that the occurrence of central serous chorioretinopathy (CSC) might be associated with stress. Therefore, our purpose was to investigate the diurnal trajectories of salivary cortisol and α-amylase (α-Amy) – markers of hypothalamic-pituitary-adrenal (HPA) axis and sympathetic-adrenal-medullary (SAM) system activity, respectively – and psychological profiles in idiopathic acute CSC. This cross-sectional observational case-control study, which included self-reported psychometric questionnaires, was formally approved by the Ethics Committee. Written informed consent was obtained from all participants. Home diurnal saliva collection was scheduled at several timepoints: at awakening, 30 and 60 min later, and at approximately 13:00 h and 20:00 h. Twenty consecutive male subjects with first-episode CSC attending the outpatient clinic of the Retina Medical Service at the Bietti Foundation were enrolled in the study. Twenty age-matched subjects were recruited as controls. After their initial enrollment, 3 subjects per group were excluded. The production of cortisol and α-Amy and the scores on the negative subscale of the Positive/Negative Affect Schedule, the Daily Hassles and Stress Scale and the Beck Depression Inventory were higher in the CSC group than in the control group. To estimate the diurnal trends in the production of salivary cortisol and α-Amy, an equation was derived for each group of the study population. The equations describing the interpolated regression lines gave salivary cortisol and salivary α-Amy slopes that were determined to be significantly different by Student’s t-test (cortisol: t = 3.533, p < .001; α-Amy: t = 2.382, p = .018). Furthermore, the area under the curve with respect to the ground (AUC_G) was calculated to summarize repeated salivary biomarker measurements from 07:00 h to 08:00 h for assessment of the cortisol awakening response (CAR) and the α-Amy awakening response (AR). The diurnal cortisol AUC_G and diurnal α-Amy AUC_G were calculated from 07:00 h to 20:00 h. The CAR AUC_G values of the CSC patients were significantly higher than those of the controls. No differences between the two groups were detected for the α-Amy AR AUC_G. The present study adds novel information to the growing body of data suggesting that abnormal diurnal activity of the HPA axis and the SAM system is associated with CSC in susceptible individuals, providing ophthalmologists with a new chronobiological approach for these patients.

Dormancy, which arrests development, is a well-known survival strategy among animals living in the Arctic to overcome harsh periods. It is not clear if the dormant state in notostracans is controlled endogenously (diapause) or exogenously (quiescence). For Lepidurus arcticus, it is unknown how it responds to the photoperiod entrainment, if it has a biological clock and if it has a rhythmic expression of the clock genes. We studied the hatching success of resting eggs at four constant temperatures (5, 10, 15 and 25 °C) and under different illumination regimes [continuous light (LL) and continuous dark (DD)]. It was assumed that light and temperature are both important triggers, with temperature having the most pronounced effect. In our experiment, hatching occurred only at 5 and 10 °C, while we did not observe hatching at 15 and 25 °C. The highest percentage of eggs hatched was at 10 °C in LL (60%); the lowest was at 5 °C in DD (18%). The percentages hatched at 5 °C in LL (24%) and at 10 °C in DD (26%) were similar. Our results indicate that both temperature and light had a significant and interacting effect on hatching in L. arcticus, with temperature being the dominant factor controlling the process. This suggests that changes in temperature affecting the Arctic may significantly impact phenology of this key species in the region. Given that no hatching was observed at 15 °C or above, the persistence of this species may be at risk in areas were arctic lakes are expected to warm to such levels during the summer months.

The vestibular acute stress induces reversible alert-like reactions that involve the sympathetic adrenal-medullar system and hypothalamic-pituitary-adrenal axis responses. The present study aimed to evaluate salivary α-amylase and salivary cortisol production in relation with cardiovascular reactivity induced by acute stress in healthy subjects. Forty-eight young healthy male volunteers were examined under basal conditions and at various times after reaching the maximal nystagmic reaction following air caloric vestibular test. Heart rate, systolic blood pressure, diastolic blood pressure and mean arterial pressure were recorded at the same time as measurement of the salivary α-amylase and salivary cortisol. At the end of the caloric vestibular test session, perceived stress scale questionnaires were administered to measure the self-perceived stress impact induced by the task, and individual scores were compared with those measured on the enrollment day. Following caloric vestibular test-evoked vertigo, salivary α-amylase and cortisol showed distinct trends in their production after acute stress: Student’s t-test was used to compare the α-amylase vs cortisol slopes of the respective interpolated regression lines, and the difference was significant (t = -3.283; p<0.001); an increase in salivary cortisol production corresponded with a decrease in the salivary α-amylase concentration. In addition, salivary biomarker modifications were associated with consistent changes in the heart rate, systolic blood pressure and mean arterial pressure. Using the air caloric vestibular test task as a stressor, the present study demonstrated a connection between the acute hormonal stress response to vestibular stimulation and cardiovascular output. However, further research is needed before we can define the potential importance of the consistent cardiovascular activity changes evoked by vestibular stimulation and the possible functional consequences for cardiovascular regulation and orthostatic tolerance in humans.

Xylella fastidiosa is a Gram‐negative, xylem‐limited, bacterium which is responsible, in Italy, for the olive quick decline syndrome (OQDS). The disease is caused by the subspecies pauca and emerged a few years ago in the Apulia province of Lecce, in the Salento peninsula, on Olea europaea plants. X. fastidiosa can infect different plant species and is well known in California as the causal agent of Pierce's disease on grape. Infections of susceptible hosts with X. fastidiosa are known to result in xylem vessel occlusions, water movement impairment, and accordingly to induce the typical desiccation symptoms. In this study, we investigated xylem vessel occlusions in healthy and naturally infected O. europaea plants grown in open field by analysing three olive cultivars widespread in the region that show different degree of susceptibility to the disease: the susceptible cultivars “Ogliarola salentina” and “Cellina di Nardò,” and the tolerant cultivar “Leccino.” Our results show that occlusions were caused by tyloses and gums/pectin gels, and not by bacterial cell aggregates. Our data also indicate that occlusions are not responsible for the symptomatology of the OQDS and, as observed in Leccino plants, they are not a marker of tolerance/resistance to the disease.

Currently, the potential for cardiovascular (CV) stress-induced risk is primarily based on the theoretical (obvious) side effects of stress on the CV system. Salivary cortisol and α-amylase, produced respectively by the hypothalamus-pituitary-adrenal (HPA) axis and the sympathetic-adrenomedullary (SAM) system during stress response, are still not included in the routine evaluation of CV risk and require additional and definitive validation. Therefore, this article overviews studies published between 2010 and 2015, in which salivary cortisol and α-amylase were measured as stress biomarkers to examine their associations with CV/CMR (cardiometabolic risk) clinical and subclinical indicators. A comprehensive search of PubMed, Web of Science and Scopus electronic databases was performed, and 54 key articles related to the use of salivary cortisol and α-amylase as subclinical indicators of stress and CV/CMR factors, including studies that emphasized methodological biases that could influence the accuracy of study outcomes, were ultimately identified. Overall, the biological impact of stress measured by salivary cortisol and α-amylase was associated with CV/CMR factors. Results supported the use of salivary cortisol and α-amylase as potential diagnostic tools for detecting stress-induced cardiac diseases and especially to describe the mechanisms by which stress potentially contributes to the pathogenesis and outcomes of CV diseases.