Renate Deinzer

Prolonged reduction of salivary immunoglobulin A (sIgA) after a major academic exam

OBJECTIVEnIn a previous study we observed a continuous reduction of salivary IgA concentration ([sIgA]) during a period of academic stress. This reduction of sIgA concentration exceeded the stress period by at least 1 week. The present study aimed to replicate and extend our previous finding. In particular, we wanted to examine the time of recovery of [sIgA] alterations associated with academic stress.nnnMETHODnTwenty-seven participants in a major medical exam and 27 controls not participating in any exam during the study provided daily saliva samples (immediately after awakening), from the 6th day prior to their last exam until the 14th day afterwards, for analysis of salivary IgA. Data were averaged for the last weeks of exams and the first and second week after exams, respectively.nnnRESULTSnA prolonged reduction of sIgA in exam students as compared to controls was observed. Fourteen days post-stress sIgA concentrations of exam students were still significantly lower than control levels (P=0.004). No recovery was observable. At the same time exam students and controls did not differ in terms of self-reported stress and recovery.nnnCONCLUSIONSnPsychological and immunological stress effects may be dissociated, the latter considerably exceeding the stress period. A closer look at the temporal dynamics of stress-induced immune alterations might increase our understanding of psychoimmuno relationships.

Situational effects in trait assessment: The FPI, NEOFFI, and EPI questionnaires

While most researchers do agree now that situations may have an effect in the assessment of traits, the consequences have been neglected, so far: if situations affect the assessment of traits we have to take this fact into account in studies on reliability and validity of measurement instruments and their application. In the theoretical part of this article we provide a more formal exposition of this point, introducing the basic concepts of latent state–trait (LST) theory. LST theory and the associated models allow for the estimation of the situational impact on trait measures in non‐experimental, correlational studies. In the empirical part, LST theory is applied to three well known trait questionnaires: the Freiburg Personality Inventory, the NEO Five‐Factor Inventory and the Eysenck Personality Inventory. It is shown that significant proportions of the variances of the scales of these questionnaires are due to situational effects. The following consequences of this finding are discussed, (i) Instead of the reliability coefficient, the proportion of variance due to the latent trait, the consistency coefficient, should be used for the estimation of confidence intervals for trait scores, (ii) To reduce the situational effects on trait estimates it may be useful to base such an estimate on several occasions, i.e., to aggregate data across occasions. (iii) Reliability and validity studies should not only be based on a sample of persons representative of those to whom the test will be applied; they should also be conducted in situational contexts representative of the intended applications.

Acute stress effects on local Il-1β responses to pathogens in a human in vivo model

The combined effects of stress and antigen on interleukin-1beta (Il-1beta) have rarely been studied locally at the site of microbial challenges in vivo, so far. We here propose a model for the analysis of such effects in humans and examine its utility for acute stress trials. Twelve students (6 male, 6 female) refrained from oral hygiene in two antagonistic quadrants for 28 days to allow for increasing bacterial stimulation of the respective gingival sites due to accumulation of microbial plaque. Good oral hygiene was maintained in the remaining quadrants. At day 27 and 28 students were subjected to either stress (public speech) or a control condition, in a cross-over design. Samples of gingival crevicular fluid (GCF) which emerges between the tooth surface and the gingival epithelium as transudate of healthy and exudate of inflamed gingival tissue, were taken immediately after stress and 60 min later for Il-1beta analysis. Salivary cortisol was assessed to prove the validity of the stress protocol. Stress induced a profound increase of salivary cortisol (p=.001). Repeated measures (stress x time x hygiene) ANOVA with gender as between factor revealed significant stress (p=.014) and hygiene (p=.038) effects on GCF-Il-1beta concentrations and tentatively significant hygiene x time (p = .097) and stress x time x hygiene x gender (p=.107) interactions. Stress induced an increase of Il-1beta as did plaque accumulation. The merits of the proposed model are discussed. It is concluded that it is well suited for the assessment of the effects of stress on inflammatory responses in vivo in humans.

Stress, oral health behaviour and clinical outcome

OBJECTIVEnSeveral studies indicate that stress adversely affects various health behaviours. Oral hygiene behaviour, however, has been rarely studied in this context. The present study thus aims to assess the effects of stress on oral hygiene behaviour and clinical outcome.nnnDESIGNnIn a prospective matched controlled design 12 pairs of medical students, each consisting of 1 student participating in a major academic exam and 1 student not participating in any exams (control) were studied.nnnMETHODSnA professional tooth cleaning was performed 4 weeks prior to exams to obtain plaque levels of 0 at all sites. Immediately prior to professional tooth cleaning and 4 weeks after exams plaque levels (as indicator of oral hygiene behaviour) and bleeding on probing (an indicator of gingivitis) were assessed.nnnRESULTSnNo group differences were observed at the beginning of the exam period; after exams significant higher rates of plaque (p=.0005, d=1.74) and gingivitis (p=.016, d=1.01) were observed in exam students as compared with controls.nnnCONCLUSIONSnThe study illustrates the clinical significance of stress effects on health behaviour. Stress should be included as a factor in models of patient compliance and health behaviour.

Effects of acute stress on local IL-1β and IL-8 in a human in vivo model of chronic inflammation

(1–3 h), whereas a 10.0 mg/kg dose of heroin produced hypothermia during the same period of time. These effects are similar to effects of morphine at comparatively similar doses. Furthermore, the results showed that both doses of heroin inhibited LPS-induced hyperthermia, which occurs 4–8 h after administration. The results indicate an inhibitory effect of heroin on the LPS-induced fever that is not dependent on the nature of initial heroin-induced alterations in body temperature, as evidenced by the fact that both early hypothermia and hyperthermia reduced LPSinduced fever. Previous research has supported the hypothesis that LPS-induced fever is prostaglandin E2 (PGE2)-mediated. Further experimentation will investigate if heroin has similar effects on other PGE2-mediated fevers, such as fever induced by glycoprotein 120 (gp120), which has been implicated in the development of HIV-associated dementia. The investigation of opioid-induced alterations of fever could lead to a greater understanding of the mechanisms that promote infection in opioid users.