Th. Köhler

Relapse-Precipitating Life Events and Feelings in Patients with Inflammatory Bowel Disease

This study examined whether life event stress under general or more specific conditions (fear of separation, feeling of being under pressure, feeling of being caught between two quarreling parties, separation experiences) contribute to the aggravation of inflammatory bowel disease (IBD). Firstly, 51 patients with ulcerative colitis, 57 patients with Crohns disease, and 60 controls were compared in terms of these variables. In addition, the IBD patients filled out questionnaires asking for life events, the specific psychological conditions mentioned above, and their symptoms every 3 months for 1 year after the first measurement. Patients with Crohns disease and patients with ulcerative colitis reported a lower amount of life event stress than members of the control group, but listed more feelings of being under pressure. Within group comparisons between patients in relapse and patients in remission, as well as comparisons between patients with recently increased disease activity and patients without increased disease activity did not yield clear results. We conclude that the variables in question have little influence on the beginning of a relapse.

The relationship between neuroticism and blood pressure reexamined. An investigation of a nonclinical sample of military conscripts

Given the contradictory results reported in the literature on the relationship between neuroticism and blood pressure, it was decided to reexamine this topic. This was done with a large sample very homogeneous for age, sex, food intake and life style and basically unselected in terms of medical history. In the frame of a blood donation program blood pressure was measured in 810 conscripts. In addition, subjects completed either form A or form B of the Eysenck Personality Inventory (EPI). Data from a total of 624 subjects were suitable for evaluation. No significant correlations were obtained between systolic or diastolic blood pressure and scores of neuroticism or extraversion (r = -0.10 to 0.06) nor did groups with different blood pressure values differ substantially in terms of these variables. This supports work showing that there is no essential connection between blood pressure and emotional lability as measured by the EPI.

Psychophysiological Reactivity of Borderline Hypertensives and Their Recovery after Mental Stress

UNLABELLED The question of psychophysiological reactivity of borderline hypertensives is still controversial. METHODS Young males with borderline blood pressure levels and normotensive controls were recruited during a routine examination. Samples of study I comprised 19 subjects, samples of study II 18 subjects. Two stressors were presented (distressing movie, mental arithmetic), each followed by a recovery phase. Systolic and diastolic blood pressure, heart rate, and electrodermal parameters were assessed repeatedly. RESULTS Borderline hypertensives showed greater reactions to stressors in systolic blood pressure only. Changes in percentage of baseline levels were essentially the same. Recovery after stress did not differ between groups. CONCLUSION Only moderate support is given to the hypothesis that borderline hypertensives show increased and slowly recovering psychophysiological responses.

Psychophysiological Responses of Borderline Hypertensives in Two Experimental Situations

Given the contradictory reports concerning psychophysiological reactivity of hypertensives this issue was reexamined. In contrast to the large majority of studies, the hypertensive sample should not be made up of patients in medical care and the control group should be comparable in all relevant aspects other than blood pressure. Twelve male subjects with blood pressure values in the borderline range and 12 normotensive controls were recruited from a blood donation program. Experiments consisted of two parts with baseline, stress and follow-up. Stressors were a short distressing movie and mental arithmetic. Systolic and diastolic blood pressure (SBP and DBP), heart rate (HR), skin conductance level (SCL) and number of spontaneous electrodermal fluctuations (SF) were assessed in 2-min intervals, plasma adrenaline and noradrenaline once during baselines, stress 2 and follow-up 2. Hypertensives exhibited significantly higher SPB levels, and partially elevated values for DBP, HR and SCL. Response reactions to stressors, however, did not differ between groups. There was no evidence that psychophysiological adaptation during stress and recovery thereafter was impaired in hypertensives. Our results do not support the reactivity hypothesis of hypertension. Possible reasons for our failure to replicate findings from other studies are discussed.

The Hamburg Objective-Prism Surveys for Bright Quasars

We report about the progress of two ongoing wide-angle survey projects: the Hamburg Quasar Survey (HQS) in the northern hemisphere, and the Hamburg/ESO survey (HES), its southern counterpart. Prime scientific goals of these projects are: to compile large samples of high-redshift (1.5 ≲ z ≲ 3.2), bright (B≲18) QSOs suitable for high-resolution spectroscopy; to provide targets with unabsorbed lines-of-sight for ultraviolet spectroscopy with HST; to discover new gravitationally lensed systems; to directly determine the local luminosity function of QSOs; to study evolution of the most luminous part of the QSO population; to construct a spectroscopic database for the identification of ROSAT X-ray sources.An ESO Key programme dedicated to an Homogeneous Bright QSO Survey (HBQS) has been completed. 327 QSOs (Mb<-23, 0.3<z<2.2) have been selected over 555 deg^2 with 15<B<18.75. For B<16.4 the QSO surface density turns out to be a factor 2.2 higher than what measured by the PG survey, corresponding to a surface density of 0.013+/-.006 deg^{-2}. If the Edinburgh QSO Survey is included, an overdensity of a factor 2.7 is observed, corresponding to a density of 0.016+/-0.005 deg^{-2}. In order to derive the QSO optical luminosity function (LF) we used Monte Carlo simulations that take into account of the selection criteria, photometric errors and QSO spectral slope distribution. The LF can be represented with a Pure Luminosity Evolution (L(z)\propto(1+z)^k) of a two power law both for q_0=0.5 and q_0=0.1. For q_0=0.5 k=3.26, slower than the previous Boyles (1992) estimations of k=3.45. A flatter slope beta=-3.72 of the bright part of the LF is also required. The observed overdensity of bright QSOs is concentrated at z<0.6. It results that in the range 0.3<z<0.6 the luminosity function is flatter than observed at higher redshifts. In this redshift range, for Mb<-25, 32 QSOs are observed instead of 19 expected from our best-fit PLE model. This feature requires a luminosity dependent luminosity evolution in order to satisfactorily represent the data in the whole 0.3<z<2.2 interval.

The gravitational lens candidate HE 1104-1805 and the size of absorption systems

We obtained 1.2 A resolution spectra over the range 3175–7575 A for the two components of the gravitational lens candidate HE 1104–1805 (z = 2.31, m B = 16.7 and 18.6, separation = 3.0 arcsec; cf. Wisotzki et al. 1993), with the aim of setting limits on the sizes of the clouds producing the Ly-α, C IV, and Mg II absorption systems. We refer to Smette et al. (1995) for a detailed account of this study.