[Case report: aortic valve endocarditis in a horse]. / Fallbericht: Aortenklappenendokarditis beim Pferd.

A case of endocarditis of the aortic valve in a 11 year old thoroughbred is presented. Diagnostic approach, the value of echocardiography, and the various symptoms, complications and prognosis are discussed. The horse with ruptured aortic valves due to endocarditis with severe aortic and mitral regurgitation causing congestive heart failure, was euthanised due to bad prognosis.

Human neutrophil chemotaxis in response to diepoxides of linolenic acid.

Diepoxides of linolenic acid were found to be chemoattractants. The concentration that produces 50% of maximal chemotaxis was 4.5 10(-7) mol/l for human neutrophils when investigated in a chemotaxis test based on the method of spectrophotometric determination of myeloperoxidase activity with buffers containing bovine serum albumin. Leukotriene B4 was used as positive control. The concentration of leukotriene B4 that produces 50% of maximal chemotaxis was 1.8 nmol/l. No chemotactic activity was observed when monoepoxides of linoleic or linolenic acid, diepoxides of linoleic acid or triepoxides of linolenic acid were used. Mono-, di- and triepoxides of polyunsaturated fatty acids were synthesized with meta-chloroperbenzoic acid, separated by TLC and HPLC and identified by GC/MS.

[Significance of heart rate deceleration in pattern recognition tasks]. / Zur Bedeutung von dezelerativen Veränderungen der Herzschlagfrequenz in Musterwiedererkennungsaufgaben.

As strength of foreperiod heart rate (HR) deceleration in reaction time paradigms with a fixed foreperiod has been discussed in terms of activities related to differences in regulations of attentional processes, the present study was concerned with the question of whether this variable also accounts for the variance in the latency of response in two attention-demanding pattern recognition tasks, one of which involved mental rotation. Subjects were required to determine as quickly and as correctly as possible whether a two-dimensional asymmetrical shape was intrinsically identical to a previously presented visual pattern or not, regardless of its rotational position within the picture plane. The first stimulus was always in normal upright position, whereas the probe stimulus could either be rotated or presented in an upright position. The findings of the study are indicative of a reliable relation between anticipatory HR deceleration and reaction time. It was not restricted to detection and response requirements but also held true in the case of additional mental rotation requirements. Strength of anticipatory HR deceleration is therefore interpreted as an indicator of regulations of attentional processes mustered in order to facilitate or to support stimulus detection and response elicitation as well as to prime or to set up the mental structures required in mental rotation. Additional support for this assumption could be found in the analyses of HR changes at the beginning of the response interval.

[Marker identification and mental rotation in automatic conditions]. / Merkmalsidentifikation und "Mentale Rotation" unter Automatisierungsbedingungen.

A basic finding of mental rotation research is that the time required to discriminate an asymmetrical visual stimulus from its reflected or backward version typically varies systematically with the angular departure of the probe stimulus from its normal upright (or expected) position within the picture plane. This regular dependence of reaction time (RT) on the rotational position (orientation) of the probe stimulus was interpreted by assuming an internal process working as a kind of mental analog of an external physical rotation and being carried out to bring the internal representations of the stimuli into congruence with each other before a decision is made. The present study was designed to investigate whether the dependence of RT on orientation also holds true in the case of a probe that can be identified on the basis of a single distinctive feature. In addition, it was examined whether the efficiency of the underlying processes could be improved by training. Results showed that the dependence of RT on orientation (RT function) does not occur if the presented visual probes differ with regard to a simple feature as, for example, an easily detectable angular difference. A change of the RT function, which would have indicated a change in the speed of the underlying processes, did not occur despite an "automatization" training.

Individual differences in resting heart rate and spontaneous electrodermal activity as predictors of attentional processes: effects on anticipatory heart rate deceleration and task performance.

The present study was concerned with the question of whether tonic resting heart rate (HR) and resting spontaneous electrodermal activity account for the association between anticipatory HR deceleration and task performance in a choice reaction time (RT) task with a fixed foreperiod. The task employed (a varied mapping paradigm) differed from simple RT tasks especially with regard to processing and attention demands. Subjects were required to determine as quickly and accurately as possible whether a 'complex' probe, presented for 80 ms, was identical or not to one of two distinct memory items, presented at the onset of each trial. Reaction times as well as accuracy of responses were determined. Additionally, reaction time and error data were synthesized to obtain a joint measure of response behaviour. The results of the present study were indicative of a reliable anticipatory HR deceleration extended over the last seconds preceding the probe stimulus. In agreement with previous findings, the HR deceleration grew stronger over blocks of trials and was sensitive to detection requirements, i.e. probe complexity. Furthermore, HR deceleration was related to task performance. Subjects with stronger decelerations (below the median on mean deceleration) exhibited a more impulsive (fast-inaccurate) and subjects above the median a more reflective (slow-accurate) response style. The effect was mainly due to a significant difference in RT. Further results indicated that the relationship between anticipatory deceleration and RT performance was especially due to the response behaviour of one group of subjects. Subjects above the median of resting HR and resting spontaneous electrodermal activity behaved in a prominent reflective manner and also displayed the lowest foreperiod deceleration. Results were discussed in terms of differences in the regulation or control of attentional processes.

[Anticipatory and event related changes in heart rate as indicators of attention processes]. / Antizipatorische und ereignisbezogene Veränderungen der schlagfrequenz des Herzens als indikatoren der Aufmerksamkeitsregulation.

The present study was concerned with the question of whether phasic event-related heart rate (HR) changes under easy intake conditions account for the association between anticipatory HR deceleration and task performance in a choice reaction time (RT) task with a fixed foreperiod. The task employed differed from simple RT tasks especially with regard to processing and attention demands. Subjects were required to determine as quickly and accurately as possible whether a probe, presented for 80 ms, was identical or not to one of two distinct memory items, presented at the onset of each trial. Reaction times as well as accuracy of responses were determined. The results of the present study were indicative of a reliable anticipatory HR deceleration which was related to latency of responses to the probe stimulus. Subjects with stronger decelerations reacted faster than subjects with diminished or missing decelerations. Furthermore a relation was found between this association and the heart rate changes to repeated presentations of a non-signal auditory stimulus under habituation conditions. Results were discussed in terms of differences in the regulation or control of attentional processes.

Synergistic interaction between prostaglandins and PAF-acether in experimental animals and man.

Platelet activating factor (PAF-acether) is released from a variety of inflammatory cell types and has properties appropriate to a mediator of allergy and inflammation. Here, we have examined the interaction between PAF-acether and the prostaglandins, PGE2 and ZK 36374 (a stable analogue of prostacyclin, PGI2) in the skin of guinea-pigs and human volunteers. PGE2 and ZK 36374 significantly potentiated increased plasma protein extravasation induced by PAF-acether in guinea-pigs, assessed by extravasation of I-125-HSA. In addition, PGE2 significantly potentiated the ability of PAF-acether to elicit acute wheal (volume) and flare responses in human skin. The inflammatory properties of PAF-acether should not be considered in isolation since this phospholipid interacts synergistically with prostaglandins which are recognised as modulators of inflammation.

[Demonstration of Leptospirae antibodies in the sera of immunized rabbits by the indirect immunofluorescence test (author's transl)]. / Nachweis von Leptospiren-Antikörpern in Seren immunisierter Kaninchen mit Hilfe des indirekten Immunfluoreszenztestes.

Antibodies of Leptospirae were demonstrated in the sera of immunized rabbits by the indirect immunofluorescence test, only after a suitable dilution of the "anti-rabbit-gamma-globulin fluorescin conjugated" was carried out in a cross reference titration ("chessboard method"). A distinct crossreaction was observed when anti-icterohaemorrhagiae - and anti-bratislava-immunsera reacted with several serotypes out of the "interrogans complex". But only a weak crossreaction was found when both sera reacted with the serotyp patoc from the "biflexa complex". The evaluation of the indirect immunofluorescence test was complicated by a streaky background of fluorescence. The agargeldiffusion tests (Ouchterolony) exhibited four, three and two precipitation bands according to the conbination of antigens and immunsera.