Histochemical analysis of phenylphenalenone-related compounds in <Emphasis Type="Italic">Xiphidium caeruleum</Emphasis> (Haemodoraceae)

Phenylphenalenones represent a typical group of secondary metabolites of the Haemodoraceae. Some of these phenolic compounds show organ-specific distribution within the plant. However, detailed information on cellular localisation is still lacking. To this end, confocal laser-scanning microscopy, microspectral photometry and high-performance liquid chromatography were used to study the tissue localisation of phenylphenalenone-type compounds in Xiphidium caeruleum Aubl. From the autofluorescence potential of these compounds, specific distribution of allophanylglucosides and non-glucosidic compounds of the phenylphenalenone-type in distinct cells of the roots (apical meristem, cortex, cap, epidermis) and the shoot system was revealed. Fluorescence enhancement using "Naturstoff reagent A" (NA) indicated the occurrence of NA-positive natural products in the vacuoles of leaf epidermal cells. The present results provide new insights into the possible functions of phenylphenalenone-related compounds in the context of their localisation. Additionally, the advantages and limitations of the techniques are discussed.     

Stress induced IL-10 does not seem to be essential for early monocyte deactivation following cardiac surgery

An increase in circulating levels of IL-10 is believed to contribute to immunosuppression caused by major surgery. Cortisol and catecholamines have been shown to be important costimulatory factors for IL-10 secretion in humans. As thoracic epidural block (TEB) should blunt the perioperative increases in cortisol and catecholamines we investigated whether IL-10 secretion is influenced by TEB. Twenty-six patients undergoing coronary artery bypass graft surgery using cardiopulmonary bypass were randomized to receive either general anesthesia (GA) or GA plus TEB. Sensory and pain levels were measured to demonstrate clinical effectiveness. Plasma concentrations of epinephrine, norepinephrine, cortisol, IL-6 and IL-10 as well as monocyte surface expression of HLA-DR and their ex vivo capacity to release TNF-alpha after LPS stimulation were measured perioperatively. TEB was clinically effective and patients receiving TEB showed decreased circulating levels of IL-10. However, this decrease was independent of decreased levels of cortisol or epinephrine. No influence of TEB on IL-6 levels, monocyte capacity to ex vivo release TNF-alpha upon LPS stimulation or their expression of HLA-DR was found. In conclusion, high TEB reduces antiinflammatory immune suppressing mediators including IL-10 and stress mediators. At least in cardiac surgery patients the monocyte functional depression is not related to systemic release of IL-10 and the influence of cortisol or epinephrine is less important for early monocyte deactivation than what in vitro and animal models have suggested.     

Roosting and Foraging Behavior of Two Neotropical Gleaning Bats,Tonatia silvicola and Trachops cirrhosus (Phyllostomidae)1

We studied roosting and foraging behavior of two Neotropical gleaning bats, ?Orbigny's round-eared bat, Tonatia silvicola, and the fringe-lipped bat, Trachops cirrhosus (Phyllostomidae). Techniques included radio-tracking in a tropical lowland forest in Panama and analysis of data from long-term studies in Panama and Venezuela. Day roosts of T. silvicola were in arboreal termite nests. T. cirrhosus roosted in a hollow tree. T. silvicola emerged late (ca 60 min after sunset), and foraged close to the roosts (maximum distance 200–500 m). T. cirrhosus emerged early (ca 30 min after local sunset), and foraged farther from its roost (>1.5 km). Both bats used small foraging areas (3–12 ha) in tall, open forest. They foraged in continuous flight (maximum 27–36 min) or in short sally flights (<1 minute) from perches (“hang-and-wait” strategy). The small foraging areas of these bats and their sedentary foraging mode most likely make them vulnerable to habitat fragmentation.     

Echolocation and obstacle avoidance in the hipposiderid batAsellia tridens

Summary The echolocation sounds of the hipposiderid batAsellia tridens consist of a constant frequency (cf) component followed by a frequency modulated (fm) terminal downward sweep of 19–21 kHz. The cf-part constitutes about 7/10 of the entire signal. In individual roosting animals the frequencies of the cf-part of consecutive sounds (resting frequency) is kept very constant but varies from bat to bat. In 18Asellia tridens resting frequencies between 111–124 kHz have been measured.The sound duration in roosting and free flying bats is between 7–10 ms. In the approach and terminal phase of bats landing on a perch or flying through obstacles, the sound duration is reduced and the repetition rate increased the nearer the bat approaches the target. At the end of the terminal phase sound durations of a minimum of 3 ms have been measured. Flying bats lower their emission frequency in order to compensate for Doppler shifts caused by the flight movement. The echofrequency is therefore kept constant about 150–200 Hz above the resting frequency.In flights through obstacles consisting of vertically stretched wires with different diameters, the bats were able to avoid wires down to a diameter of 0.065 mm whereas at 0.05 mm the percentage of flights without collisions is far below the chance level. The results demonstrate that the echolocation behavior of the hipposiderid batAsellia tridens does not differ fundamentally from that of rhinolophid bats. As a result, a new suggestion for categorization of bats producing cf-fm orientation sounds is put forward.Abbreviations cf constant frequency component - fm frequency modulated component - P probability of collision-free flights through an obstacle of ertically tretched wires - I interval between wires - D minimal diameter of a bat with folded wings; , angle at which a bat approaches an obstacle - f _A frequency of the cf-component of the emitted sound - f _E frequency of the cf-component of the echo - f _M frequency of the cf-component of the sounds recorded with the microphone - c speed of sound Supported by the Deutsche Forschungsgemeinschaft grant no. Schn 138/6-9We thank W. Hollerbach for technical assistance.     

Monoterpene synthase activities in leaves of Picea abies (L.) Karst. and Quercus ilex L

In addition to direct ecological functions in the interaction of plants with the environment, the emission of monoterpenes, especially from the foliage of evergreen trees, is of great importance for the production of ozone and photochemical oxidants in the troposphere. In the present work, we established a reproducible non-radioactive standard enzyme assay and characterized monoterpene synthase activities in needles of Norway spruce (Picea abies (L.) Karst.) and in leaves of holm oak (Quercus ilex L.). In Norway spruce, the dominant monoterpenes formed were alpha-pinene, camphene, and to a lesser extent beta-pinene and limonene. In holm oak, alpha-pinene, sabinene, and beta-pinene were the main products, while limonene was a minor component. Under optimum conditions, in both Norway spruce and holm oak, monoterpene formation remained constant up to 180 min and 90 min, respectively, and varied with the buffer and Mg2+ and Mn2+ concentrations used. Optimum temperature for monoterpene synthase activity was 40 degrees C in both species; optimal pH ranged between 6.5 and 7.5 in both species. Apparent Michaelis-constants for the substrate GDP were ca. 17.9 +/- 5.1 microM for Norway spruce and ca. 69.4 +/- 22.1 microM for holm oak. Molecular weight determination by FPLC indicated that the monoterpene synthases in Norway spruce and holm oak have native molecular weights of ca. 59 and 50 kDa, respectively.