human stress

Objective: This study tests the feasibility and validity of analyzing cortisol levels within human teeth and the possibility of any potential gender differences. Methods: As a precursor, to confirm the general presence and existence of cortisol within teeth, six healthy supernumerary teeth were initially extracted and examined following the ELISA method. After confirming that cortisol was in fact present within human teeth, we began the main experiment. In order to examine any potential gender differences, twenty-one extracted wisdom teeth were collected from subjects (11 male and 10 female) within the age range of 27-29 yrs. Results: The results showed irrefutable proof of the existence of cortisol within the dentin of the teeth. Observations revealed that gender had no significant impact upon a subject's dental cortisol levels (p>0.05), suggesting that cortisol in teeth can be used as an unbiased and reliable means of studying stress. Conclusions: This is the first report on extraction and analysis of cortisol levels in hard tissues, such as teeth, leading to the discovery of a novel biomarker that can be used when studying chronic stress. Practical application of this study can be used postmortem to assess cortisol levels in patients suffering from prolonged disorders, including patients having undergone chemotherapy treatments, when hair cortisol analysis proved to be problematic.

In this paper, a statistical analysis is applied to the systolic (SBP) and diastolic blood pressure (DBP) and heart rate (HR) data of 23 normotensive (NT) and 24 hypertensive (HT) adolescents who underwent a 10-minute mental stress regimen. Readings were measured at one-minute intervals. The harmonic time series analysis is based on the data of an eight-minute interval of the stress phase. The NT group established a statistically significant (p less than .05) rhythmic variation described by a sinusoidal wave about a near pre-stress mean. The HT group exhibits for the three parameters a near constant response about a significantly elevated level. The consistent existence of a rhythmic pattern for the NT subjects under mental stress, in contrast to the constant response for the HT subjects, suggests that mental stress causes a change in the "natural" rhythmic pattern of cardiac response for the HT subject alone.

A study was designed to investigate the effects of behavioral and cognitive control on post-stress performance. Half of the subjects exposed to loud unpredictable noise bursts were given "behavioral" control (a button which would terminate the noise), while the other half had no behavioral control. In addition, subjects were provided with one of three levels of feedback (success, failure, or no feedback) regarding their performance during the noise. It was expected that information about performance would provide subjects with an increased sense of "cognitive" control which would affect their appraisal of stressful events and their later performance. The results indicated that subjected that subjects given feedback performed better on subsequent tasks than those given no feedback. Perceived behavioral control had little effect on performance. The causal attributions made by subjects were used to interpret these effects. These findings were viewed as supportive of Averill's notion than various types of control are related to stress in a complex fashion. The data may also support Abramson, Seligman, and Teasdale's reformulation of learned helplessness theory.