Increased pain sensitivity in low blood pressure.

Abstract. There is broad evidence for a functional interaction between the cardiovascular and pain regulatory systems. One result of this interaction is the reduced sensitivity to acute pain in individuals with elevated blood pressure, which has been established in numerous studies. In contrast to this, possible alterations in pain perception related to the lower range of blood pressure have not yet been investi-gated. In the present study pain sensitivity was assessed in 30 hypotensive women (mean blood pressure 95/56 mmHg) and 30 normo-tensive control persons (mean blood pressure 119/77 mmHg) based on a cold pressor test. Possible effects on pain perception of hypo-tension-related impairment of subjective state were controlled for by including a mood-scale. The hypotensive as compared to the normotensive group displayed lower pain threshold and pain tolerance levels, as well as increased sensory and affective experiences of pain. Moreover, a slight negative correlation was found, both in hypotensive and control persons, between pain sensitivity and the degree of blood pressure increase during the execution of the cold pressor test. In accordance with the previous findings on hypertension-related hypoalgesia, the present results suggest an inverse relationship between blood pressure and pain sensitivity across the total blood pressure spectrum. Different degrees of pain attenuation through afferent input from the arterial baroreceptor system are discussed as a physio-logical mechanism mediating this relationship

Early contingentnegative variation of the EEG and attentional flexibility are reduced in hypotension

This study explored the question as to whether hypotension is related to decreased attentional performance and reduced cortical activation. A total of 50 females aged 19 44 years participated in the study. Attentional performance was assessed using three subtests of the Attentional and Cognitive Efficiency (ACE) battery. Contingent negative variation (CNV) as a measure of cortical activation was registered during a constant fore-period reaction time paradigm: two conditions were defined using tones as S1 (80 or 60 dB) and S2 (70 dB). The following results were obtained. Hypotensive patients performed significantly more poorly on one subtest of the ACE, which indicates a reduced speed for switching from a routine to a controlled response (quantifying attentional flexibility). They also had longer reaction times and revealed a significantly smaller amplitude of the early CNV component. In addition, a significant correlation was observed between systolic blood pressure and the amplitude of the early CNV component. The data support previous findings that hypotension can be related to lowered cortical activation and indicate that specific aspects of attentional performance might be negatively affected by hypotension

Diversity, evolution and function of Ralstonia solanaceaurm TALE-likes

The bacterial Ralstonia solanacearum species complex (Rssc) posses a large effector repertoire and is set apart from many other bacterial plant pathogens by its broad host range of over 200 plant species and the lethality of the disease. Diseases caused by the Rssc impact the yield and possibility to cultivate certain plant species in tropical areas, where these bacteria are endemic. Most host plants are solanaceous, such as tomato, pepper or potato, but certain lineages within the Rssc specialized on economically important crops of the Musa family, such as banana or plantain. Among the large effector repertoire are homologs of the Transcription Activator Like Effectors (TALEs), termed RipTALs. RipTALs are able to recognize specific DNA sequences and activate transcription of neighbouring genes. This work provides a comprehensive overview of the abundance of RipTAL genes within the Rssc, as well as their coding sequences. It is demonstrated that all identified RipTALs act as sequence specific transcription factors in plants. In contrast to TALEs, the diversity of RipTAL target sequences is limited. Yet, RipTALs form distinct functional groups of overlapping sequence specificity, which can be correlated to strain host ranges. Based on the comparison of RipTALs and TALEs a model explaining the behavior of these genes in natural bacterial populations is presented. The utilization of RipTALs in the context of disease resistance in plants constitutes a second central theme of this work. Two distinct approaches were followed. Firstly, the natural diversity of the model plant Arabidopsis thaliana was assessed regarding naturally occurring RipTAL mediated defense reactions. This unveiled four candidate ecotypes that exhibit a RipTAL dependent disease phenotype. Secondly, a translational, synthetic approach to establish RipTAL-dependent disease resistance in the model plant A. thaliana, as well as in the crop model Solanum lycopersicum was employed. Experimental results showed a RipTAL-dependent resistance response, in plant tissues transformed with the synthetic construct.Der bakterielle Ralstonia solanacearum Spezienkomplex verfügt über eine große Anzahl an Effektoren und zeichnet sich unter den bakteriellen Krankheitserregern durch ein sehr breites Wirtsspektrum von über 200 Pflanzenarten, sowie den für die Pflanze tödlichen Ausgang der Krankheit aus. Dies führt vorallem in tropischen Regionen zu starken Einschränkungen in der Kultivierbarkeit bestimmter Pflanzen bzw. zu Ernteausfällen. Viele der Wirte sind Nachtschattengewächse (z.B. Kartoffel, Tomate, Paprika), jedoch sind auch Erreger von Krankheiten einkeimblättriger Pflanzen, die ökonomisch relevante Vertreter der Bananengewächse infizieren und töten, teil des Spezienkomplexes. Unter den Effektoren finden sich Homologe der “Transcription activator like effectors” (TALEs), die RipTALs, die in der Lage sind spezifische DNS Sequenzen zu erkennen und die Transkription benachbarter Gene zu aktivieren. Die vorliegende Arbeit bietet den ersten umfassenden Überblick über die Verteilung von RipTAL Genen im Spezienkomplex, sowie deren kodierende Sequenzen. Darüber hinaus konnte experimentell gezeigt werden, dass alle RipTALs sequenzspezifische Transkriptionsfaktoren sind. Im Gegensatz zu TALEs sind RipTALs wenig divers in ihren Zielsequenzen, jedoch bilden sie, in Abhängigkeit der präferierten Wirtspflanzen, nicht überlappende Spezifitätsgruppen. Auf Basis eines Vergleichs von RipTAL und TALE Genen wird ein erklärendes Konzept zum Verhalten dieser Gene in natürlichen Bakterienpopulationen vorgestellt. Zusätzlich war die Nutzbarkeit von RipTALs im Kontext von pflanzlicher Resistenz eine zentrale Fragestellung. Hierzu wurde die natürliche Diversität der Modellpflanze Arabidopsis thaliana hinsichtlich RipTAL abhängiger Resistenz untersucht. Es konnten vier Ökotypen identifiziert werden, die einen RipTAL-abhängigen Krankheitsphänotyp zeigen. Darüber hinaus wurde ein synthetisch-translationaler Ansatz zur Etablierung RipTAL-induzierter Resistenz gegen R. solanacearum im Nutzpflanzenmodell Solanum lycopersicum, sowie in A. thaliana, verfolgt. Experimentell konnte eine RipTAL abhängige Resistenzreaktion in, mit dem synthetischem Konstrukt transformiertem, pflanzlichem Gewebe gezeigt werden

Neuroimaging and psychophysiological investigation of the link between anxiety, enhanced affective reactivity and interoception in people with joint hypermobility

Objective: Anxiety is associated with increased physiological reactivity and also increased “interoceptive” sensitivity to such changes in internal bodily arousal. Joint hypermobility, an expression of a common variation in the connective tissue protein collagen, is increasingly recognized as a risk factor to anxiety and related disorders. This study explored the link between anxiety, interoceptive sensitivity and hypermobility in a sub-clinical population using neuroimaging and psychophysiological evaluation. Methods: Thirty-six healthy volunteers undertook interoceptive sensitivity tests, a clinical examination for hypermobility and completed validated questionnaire measures of state anxiety and body awareness tendency. Nineteen participants also performed an emotional processing paradigm during functional neuroimaging. Results: We confirmed a significant relationship between state anxiety score and joint hypermobility. Interoceptive sensitivity mediated the relationship between state anxiety and hypermobility. Hypermobile, compared to non-hypermobile, participants displayed heightened neural reactivity to sad and angry scenes within brain regions implicated in anxious feeling states, notably insular cortex. Conclusions: Our findings highlight the dependence of anxiety state on bodily context, and increase our understanding of the mechanisms through which vulnerability to anxiety disorders arises in people bearing a common variant of collagen

Transcriptional response of a target plant to benzoxazinoid and diterpene allelochemicals highlights commonalities in detoxification

Background Plants growing in proximity to other plants are exposed to a variety of metabolites that these neighbors release into the environment. Some species produce allelochemicals to inhibit growth of neighboring plants, which in turn have evolved ways to detoxify these compounds. Results In order to understand how the allelochemical-receiving target plants respond to chemically diverse compounds, we performed whole-genome transcriptome analysis of Arabidopsis thaliana exposed to either the benzoxazinoid derivative 2-amino- 3H-phenoxazin-3-one (APO) or momilactone B. These two allelochemicals belong to two very different compound classes, benzoxazinoids and diterpenes, respectively, produced by different Poaceae crop species. Conclusions Despite their distinct chemical nature, we observed similar molecular responses of A. thaliana to these allelochemicals. In particular, many of the same or closely related genes belonging to the three-phase detoxification pathway were upregulated in both treatments. Further, we observed an overlap between genes upregulated by allelochemicals and those involved in herbicide detoxification. Our findings highlight the overlap in the transcriptional response of a target plant to natural and synthetic phytotoxic compounds and illustrate how herbicide resistance could arise via pathways involved in plant-plant interaction

Zum Zusammenhang zwischen Streßbewältigung und Blutdruckreaktion

Die vorliegende Untersuchung geht der Frage nach, welcher Zusammenhang zwischen der Blutdruckreaktion bei mentalem Streß und individuellen Copingstrategien besteht. An 27 normotensiven Personen wurden die arteriellen Blutdruckwerte noninvasiv und kontinuierlich vor, während und nach einer psychischen Streßsituation gemessen. Zur Erfassung der habituellen Copingstrategien wurde der Streßverarbeitungsfragebogen (SVF) herangezogen. Ein hinsichtlich der SVF-Werte vorgenommener Extremgruppenvergleich lieferte folgende Befunde: a) Probanden, die Streß vermehrt über direkte und konstruktive Kontrolle der Situation verarbeiten, wiesen im Gegensatz zu Personen, welche diese Copingstrategien nicht einsetzen, einen geringeren Blutdruck in der Streßphase und einen schnelleren Rückgang der Werte in der Erholungsphase auf. b) Personen mit einem Copingverhalten, das sich durch den vermehrten Einsatz von Abwehrmechanismen wie Verleugnung und Verdrängung kennzeichnet, zeigten einen geringeren Streßblutdruck, reagierten aber mit einem signifikant verzögerten Abfall der Werte während der Erholung.This study explored the relationship between individual strategies of coping and blood pressure responses during and after mental stress. Blood pressure behavior was measured noninvasively and continuously before, during and after a mental stress situation with the Streßverarbeitungsfragebogen (SVF; coping with stress inventory). Results were: (a) Individuals who used coping strategies characterized by controlling the situation directly and constructively, in contrast to probands not using these strategies, exhibited lower blood pressure during the stress situation and a faster return to the baseline levels after cessation of stress. (b) Subjects using a coping behavior characterized by the use of defense mechanisms such as suppression and denial, also showed lower blood pressure during stress but a significantly delayed return to baseline levels of blood pressure after stress was concluded

Multisensory integration across exteroceptive and interoceptive domains modulates self-experience in the rubber-hand illusion

Identifying with a body is central to being a conscious self. The now classic “rubber hand illusion” demonstrates that the experience of body ownership can be modulated by manipulating the timing of exteroceptive(visual and tactile)body-related feedback. Moreover,the strength of this modulation is related to individual differences in sensitivity to internal bodily signals(interoception). However the interaction of exteroceptive and interoceptive signals in determining the experience of body-ownership within an individual remains poorly understood.Here, we demonstrate that this depends on the online integration of exteroceptive and interoceptive signals by implementing an innovative “cardiac rubber hand illusion” that combined computer-generated augmented-reality with feedback of interoceptive (cardiac) information. We show that both subjective and objective measures of virtual-hand ownership are enhanced by cardio-visual feedback in-time with the actual heartbeat,as compared to asynchronous feedback. We further show that these measures correlate with individual differences in interoceptive sensitivity,and are also modulated by the integration of proprioceptive signals instantiated using real-time visual remapping of finger movements to the virtual hand.Our results demonstrate that interoceptive signals directly influence the experience of body ownership via multisensory integration,and they lend support to models of conscious selfhood based on interoceptive predictive coding