Carotenoid oxidation products are stress signals that mediate gene responses to singlet oxygen in plants

(1)O(2) (singlet oxygen) is a reactive O(2) species produced from triplet excited chlorophylls in the chloroplasts, especially when plants are exposed to excess light energy. Similarly to other active O(2) species, (1)O(2) has a dual effect: It is toxic, causing oxidation of biomolecules, and it can act as a signal molecule that leads to cell death or to acclimation. Carotenoids are considered to be the main (1)O(2) quenchers in chloroplasts, and we show here that light stress induces the oxidation of the carotenoid β-carotene in Arabidopsis plants, leading to the accumulation of different volatile derivatives. One such compound, β-cyclocitral, was found to induce changes in the expression of a large set of genes that have been identified as (1)O(2) responsive genes. In contrast, β-cyclocitral had little effect on the expression of H(2)O(2) gene markers. β-Cyclocitral-induced reprogramming of gene expression was associated with an increased tolerance to photooxidative stress. The results indicate that β-cyclocitral is a stress signal produced in high light that is able to induce defense mechanisms and represents a likely messenger involved in the (1)O(2) signaling pathway in plants.     

Outcome and clinical changes in patients 3, 6, 12 months after a severe or major hand injury - can sense of coherence be an indicator for rehabilitation focus?

Background  

Our objective was to explore outcome and clinical changes in hand function, satisfaction in daily occupations, sleep disturbances, health and quality of life in consecutive patients after a severe or major hand injury. Our objective was also to investigate possible differences between groups according to severity of injury, presence of peripheral nerve injury and the patients' sense of coherence.     

Symptoms, laryngeal findings, and 24-hour pH monitoring in patients with suspected gastroesophago-pharyngeal reflux.

OBJECTIVES: To investigate the laryngeal signs and symptoms associated with gastroesophago-pharyngeal reflux (GEPR). STUDY DESIGN: A prospective controlled study. METHODS: Nineteen healthy control subjects and 43 patients, 26 with posterior laryngitis (PL) and 17 with a normal larynx and suspected GEPR, were examined using videolaryngoscopy and 24-hour ambulatory dual-probe pH monitoring. RESULTS: Pharyngeal acid reflux occurred in 18 (69%) patients with PL, in 9 (53%) patients with a normal larynx, and in 5 (26%) healthy control subjects. Multiple-comparison procedure showed that pharyngeal reflux was significantly more prevalent in patients with PL than in the healthy control subjects (P < .05). The laryngoscopic findings in patients with pharyngeal reflux varied from normal mucosa to thickening or edema of the posterior wall of the glottis, which was the most frequent finding in the PL group. Erythema was uncommon; it was found only in patients with verified pharyngeal reflux. There was no difference in symptom profile between the patients with PL and patients with a normal larynx or patients with or without pharyngeal reflux. CONCLUSIONS: Pharyngeal reflux is significantly more prevalent in patients with posterior laryngitis than in healthy control subjects. Moreover, a certain degree of pharyngeal reflux appears to be a normal phenomenon. The most common laryngeal finding in patients with posterior laryngitis is thickening or edema of the posterior wall of the glottis. GEPR does not yield specific laryngeal symptoms. Thus, it is unreliable to base the reflux diagnosis on symptoms alone.     

Attention and emotion influence the relationship between extraversion and neural response

Extraversion has been shown to positively correlate with activationwithin the ventral striatum, amygdala and other dopaminergicallyinnervated, reward-sensitive regions. These regions are implicatedin emotional responding, in a manner sensitive to attentionalfocus. However, no study has investigated the interaction amongextraversion, emotion and attention. We used fMRI and dynamic,evocative film clips to elicit amusement and sadness in a sampleof 28 women. Participants were instructed either to respondnaturally (n = 14) or to attend to and continuously rate theiremotions (n = 14) while watching the films. Contrary to expectations,striatal response was negatively associated with extraversionduring amusement, regardless of attention. A negative associationwas also observed during sad films, but only when attendingto emotion. These findings suggest that attentional focus doesnot influence the relationship between extraversion and neuralresponse to positive (amusing) stimuli but does impact the responseto negative (sad) stimuli.     

A noninstrumented quantitative test system and its application for determining cholesterol concentration in whole blood

A novel noninstrumented technology has been developed for quantifying analytes of clinical interest in biological fluids. Application of this technology is exemplified by the development of a quantitative cholesterol test with performance equivalent to state-of-the-art instrumented methods. The assay chemistry combines two separate processes located in different areas of a test strip: enzymatic action on serum cholesterol to produce hydrogen peroxide (5 x 10 mm enzyme reagent pad) and quantification of the hydrogen peroxide (5 x 70 mm measurement region). Color bands are formed in the measurement area through the use of a redox-coupled indicator system. The height of the color band on the strip is directly proportional to the sample cholesterol concentration. A one-step cassette contains all components necessary to run the test and includes blood filtration and automatic sample measurement, so that unmeasured finger-stick whole-blood specimens can be analyzed by the non-technically trained user. The test is complete in less than 15 min, is read visually like a thermometer, and gives results that are in excellent correlation with established instrumented methods.     

Beitrag zum Studium des Mikrobischen Ekzems

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