Effects of a single dose of amisulpride on functional brain changes during reward- and motivation-related processing using task-based fMRI in healthy subjects and patients with major depressive disorder - study protocol for a randomized clinical trial

BACKGROUND

Anhedonia and other deficits in reward- and motivation-related processing in psychiatric patients, including patients with major depressive disorder (MDD), represent a high unmet medical need. Neurobiologically, these deficits in MDD patients are mainly associated with low dopamine function in a frontostriatal network. In this study, alterations in brain activation changes during reward processing and at rest in MDD patients compared with healthy subjects are explored and the effects of a single low dose of the dopamine D2 receptor antagonist amisulpride are investigated.

METHODS

This is a randomized, controlled, double-blind, single-dose, single-center parallel-group clinical trial to assess the effects of a single dose of amisulpride (100 mg) on blood-oxygenation-level-dependent (BOLD) responses during reward- and motivation-related processing in healthy subjects (n = 60) and MDD patients (n = 60). Using functional magnetic resonance imaging (fMRI), BOLD responses are assessed during the monetary incentive delay (MID) task (primary outcome). Exploratory outcomes include BOLD responses and behavioral measures during the MID task, instrumental learning task, effort-based decision-making task, social incentive delay task, and probabilistic reward task as well as changes in resting state functional connectivity and cerebral blood flow.

DISCUSSION

This study broadly covers all aspects of reward- and motivation-related processing as categorized by the National Institute of Mental Health Research Domain Criteria and is thereby an important step towards precision psychiatry. Results regarding the immediate effects of a dopaminergic drug on deficits in reward- and motivation-related processing not only have the potential to significantly broaden our understanding of underlying neurobiological processes but might eventually also pave the way for new treatment options.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05347199. April 12, 2022.

Brain Activation During Conceptual Processing of Action and Sound Verbs

Grounded cognition approaches to conceptual representations postulate a close link between conceptual knowledge and the sensorimotor brain systems. The present fMRI study tested, whether a feature-specific representation of concepts, as previously demonstrated for nouns, can also be found for action- and sound-related verbs. Participants were presented with action- and soundrelated verbs along with pseudoverbs while performing a lexical decision task. Sound-related verbs activated auditory areas in the temporal cortex, whereas action-related verbs activated brain regions in the superior frontal gyrus and the cerebellum, albeit only at a more liberal threshold. This differential brain activation during conceptual verb processing partially overlapped with or was adjacent to brain regions activated during the functional localizers probing sound perception or action execution. Activity in brain areas involved in the processing of action information was parametrically modulated by ratings of action relevance. Comparisons of action- and sound-related verbs with pseudoverbs revealed activation for both verb categories in auditory and motor areas. In contrast to proposals of strong grounded cognition approaches, our study did not demonstrate a considerable overlap of activations for action- and sound-related verbs and for the corresponding functional localizer tasks. However, in line with weaker variants of grounded cognition theories, the differential activation pattern for action- and sound-related verbs was near corresponding sensorimotor brain regions depending on conceptual feature relevance. Possibly, action-sound coupling resulted in a mutual activation of the motor and the auditory system for both action- and sound-related verbs, thereby reducing the effect sizes for the differential contrasts.

Film Thickness of Pb Islands on the Si(111) Surface

We analyze topographic scanning force microscopy images together with Kelvin probe images obtained on Pb islands and on the wetting layer on Si(111) for variable annealing times. Within the wetting layer we observe negatively charged Si-rich areas. We show evidence that these Si-rich areas result from islands that have disappeared by coarsening. We argue that the islands are located on Si-rich areas inside the wetting layer such that the Pb/Si interface of the islands is in line with the top of the wetting layer rather than with its interface to the substrate. We propose that the Pb island heights are one atomic layer smaller than previously believed. For the quantum size effect bilayer oscillations of the work function observed in this system, we conclude that for film thicknesses below 9 atomic layers large values of the work function correspond to even numbers of monolayers instead of odd ones. The atomically precise island height is important to understand ultrafast "explosive" island growth in this system.

Processing of Action and Sound Verbs in Context: An FMRI Study

Recent theories propose a flexible recruitment of sensory and motor brain regions during conceptual processing depending on context and task. The present functional magnetic resonance imaging study investigated the influence of context and task on conceptual processing of action and sound verbs. Participants first performed an explicit semantic context decision task, in which action and sound verbs were presented together with a context noun. The same verbs were repeatedly presented in a subsequent implicit lexical decision task together with new action and sound verbs. Thereafter, motor and acoustic localizer tasks were administered to identify brain regions involved in perception and action. During the explicit task, we found differential activations to action and sound verbs near corresponding sensorimotor brain regions. During the implicit lexical decision task, differences between action and sound verbs were absent. However, feature-specific repetition effects were observed near corresponding sensorimotor brain regions. The present results suggest flexible conceptual representations depending on context and task. Feature-specific effects were observed only near, but not within corresponding sensorimotor brain regions, as defined by the localizer tasks. Our results therefore only provide limited evidence in favor of grounded cognition theories assuming a close link between the conceptual and the sensorimotor systems.

Feature-Specific Event-Related Potential Effects to Action- and Sound-Related Verbs during Visual Word Recognition

Grounded cognition theories suggest that conceptual representations essentially depend on modality-specific sensory and motor systems. Feature-specific brain activation across different feature types such as action or audition has been intensively investigated in nouns, while feature-specific conceptual category differences in verbs mainly focused on body part specific effects. The present work aimed at assessing whether feature-specific event-related potential (ERP) differences between action and sound concepts, as previously observed in nouns, can also be found within the word class of verbs. In Experiment 1, participants were visually presented with carefully matched sound and action verbs within a lexical decision task, which provides implicit access to word meaning and minimizes strategic access to semantic word features. Experiment 2 tested whether pre-activating the verb concept in a context phase, in which the verb is presented with a related context noun, modulates subsequent feature-specific action vs. sound verb processing within the lexical decision task. In Experiment 1, ERP analyses revealed a differential ERP polarity pattern for action and sound verbs at parietal and central electrodes similar to previous results in nouns. Pre-activation of the meaning of verbs in the preceding context phase in Experiment 2 resulted in a polarity-reversal of feature-specific ERP effects in the lexical decision task compared with Experiment 1. This parallels analogous earlier findings for primed action and sound related nouns. In line with grounded cognitions theories, our ERP study provides evidence for a differential processing of action and sound verbs similar to earlier observation for concrete nouns. Although the localizational value of ERPs must be viewed with caution, our results indicate that the meaning of verbs is linked to different neural circuits depending on conceptual feature relevance.

Emotions in robot psychology

In his famous thought experiments on synthetic vehicles, Valentino Braitenberg stipulated that simple stimulus-response reactions in an organism could evoke the appearance of complex behavior, which, to the unsuspecting human observer, may even appear to be driven by emotions such as fear, aggression, and even love (Braitenberg, Vehikel. Experimente mit künstlichen Wesen, Lit Verlag, 2004). In fact, humans appear to have a strong propensity to anthropomorphize, driven by our inherent desire for predictability that will quickly lead us to discern patterns, cause-and-effect relationships, and yes, emotions, in animated entities, be they natural or artificial. But might there be reasons, that we should intentionally "implement" emotions into artificial entities, such as robots? How would we proceed in creating robot emotions? And what, if any, are the ethical implications of creating "emotional" robots? The following article aims to shed some light on these questions with a multi-disciplinary review of recent empirical investigations into the various facets of emotions in robot psychology.

Simultaneous quantification of verbenalin and verbascoside in Verbena officinalis by ATR-IR and NIR spectroscopy

Attenuated-total-reflectance infrared spectroscopy (ATR-IR) and near-infrared diffuse reflectance spectroscopy (NIR) in hyphenation with multivariate analysis was utilized to quantify verbenalin and verbascoside in Verbena officinalis. A new high performance liquid chromatography (HPLC) method as a reference was established and validated. For both vibrational spectroscopic methods test-set and cross validation were performed. Different data-pre-treatments like SNV, 1st and 2nd derivative were applied to remove systematic errors and were evaluated. Quality parameters obtained for the test-set validation revealed that ATR-IR (verbenalin: R(2)=0.94, RPD=4.23; verbascoside: R(2)=0.93, RPD=3.63) has advantages over NIR (verbenalin: R(2)=0.91, RPD=3.75; verbascoside: R(2)=0.80, RPD=2.35) in the given application.

Interferometry with Bose-Einstein condensates in microgravity

Atom interferometers covering macroscopic domains of space-time are a spectacular manifestation of the wave nature of matter. Because of their unique coherence properties, Bose-Einstein condensates are ideal sources for an atom interferometer in extended free fall. In this Letter we report on the realization of an asymmetric Mach-Zehnder interferometer operated with a Bose-Einstein condensate in microgravity. The resulting interference pattern is similar to the one in the far field of a double slit and shows a linear scaling with the time the wave packets expand. We employ delta-kick cooling in order to enhance the signal and extend our atom interferometer. Our experiments demonstrate the high potential of interferometers operated with quantum gases for probing the fundamental concepts of quantum mechanics and general relativity.

Use of Chromatographic (SPE-HPLC) and Spectrophotometric Methods for Differentiation of Salix Species Through Correlation Analysis and FreeViz Projection

The major concern of the present article is research into the combination of analytical assessment and multi-correlative data interpretation. For this purpose, a high performance liquid chromatography (HPLC) procedure was developed for the simultaneous quantification of salicin, salicylalcohol derivatives, phenolic acids, flavonoids, and monomeric catechins after solid phase extraction (SPE). On the basis of an established and validated HPLC method, 49 different Salix samples were extracted, purified, and analysed. Furthermore, the quantity of total polyphenols (Folin-Ciocalteau colorimetric reaction) and the antioxidant activity (DPPH radical scavenging activity test) were determined and correlated. This yielded correlation coefficients at P-values less than 0.05 of 0.775, 0.967, 0.932, and 0.989 for Salix fragilis, Salix rubens, Salix purpurea (2006), and Salix purpurea (2007), respectively. Correlation with mean values of each species between total polyphenols content and % DPPH inhibition values occurred at a correlation coefficient (r) of 0.851. Linear correlations of quantified HPLC data with DPPH data and with total polyphenols content could also be found for salicin, gentisic acid, naringin, and salicylic acid. Finally, by combining HPLC data with total polyphenols content and antioxidant capacity through 3-D scatter plots and FreeViz data projection, it was shown that primarily the amount of epicatechin and saligenin beside DPPH values and total polyphenols content enable the classification into plant species and further by year of harvest.

Nuclear vs. plastid data: complex Pleistocene history of a circumpolar key species

To fully understand the contemporary genetic structure of plants, both nuclear and plastid markers are needed. Three chloroplast DNA (cpDNA) lineages, which probably diverged before the major Pleistocene glaciations, have been identified in the circumpolar/circumboreal Vaccinium uliginosum. Here we investigate its nuclear DNA variation using nuclear ribosomal internal transcribed spacer (ITS) sequences, DNA ploidy level measurements and amplified fragment length polymorphisms (AFLPs). We also extend the cpDNA dataset. Two ITS lineages, corresponding to diploids and tetraploids, respectively, were identified. However, both main sequence types apparently occurred in most individual plants but showed ploidy-biased homogenization and possibly reflect paralogy predating the origin of V. uliginosum. The ploidy levels were largely consistent with the cpDNA lineages, suggesting that the initial cpDNA divergence followed early polyploidizations. Five main AFLP groups were identified, consistent with recent glacial refugia in Beringia, western Siberia, the southern European mountains and areas south/east of the Scandinavian and Laurentide ice sheets. Except from the southern European mountains, there has been extensive expansion from all refugia, resulting in several contact zones. Surprisingly, the presumably older ploidy and cpDNA patterns were partly inconsistent with the main AFLP groups and more consistent with AFLP subgroups. A likely major driver causing the inconsistencies is recent nuclear gene flow via unreduced pollen from diploids to tetraploids. This may prevent cytoplasmic introgression and result in overlayed patterns formed by processes dominating at different time scales. The data also suggest more recent polyploidizations, as well as several chloroplast capture events, further complicating this scenario. This study highlights the importance of combining different marker systems to unravel intraspecific histories.

Comparative analysis of naphthodianthrone and phloroglucine derivatives in St. John's Wort extracts by near infrared spectroscopy, high-performance liquid chromatography and capillary electrophoresis

A near infrared spectroscopic (NIRS) method is established for quantitative determination of naphthodianthrones and phloroglucine derivatives in St. John's Wort extracts. The validated NIRS method is compared with optimised liquid chromatography (LC) and capillary electrophoresis (CE), applying UV as a detection tool. Optimisation of stationary and mobile phase conditions in reversed-phase liquid chromatography (RP-LC) allow separating the derivatives of interest with high peak symmetry and robustness. Elution takes 15 and 25 min on non-porous or porous silica C18 with different porosities, respectively. Capillary electrophoresis (CE) is used for cross-validation of RP-LC. CE enables baseline separation of hypericine and pseudohypericine in less than 2min, but is ten times less sensitive. The validated RP-LC is chosen as a reference method for calibration of the NIRS-system. Analysis of 80 St. John's Wort extracts (320 NIR spectra) and the subsequent chemometric calculations of the best regression model show that NIRS is suitable for analysis of hypericine, pseudohypericine and hyperforine. RP-LC or CE must be employed for the other remaining lower concentrated naphthodianthrone and phloroglucine derivatives. Hypericine and hyperforine are analysed via NIRS with a standard error of estimation (SEE) of 0.52 and 0.50 microg mL(-1) and standard error of prediction (SEP) of 0.64 and 0.71 microg mL(-1) within few seconds. The current study demonstrates the suitability of NIRS as an alternative to LC and CE for St. John's Wort producing phytopharmaceutical industry. The short analysis time of few seconds' assures high sample throughput in routine analysis.

Successful resuscitation of a patient with ropivacaine-induced asystole after axillary plexus block using lipid infusion*

Ropivacaine 1% 40 ml was mistakenly injected as part of an axillary plexus block in an 84-year-old woman. After 15 min the patient complained of dizziness and drowsiness and developed a generalised tonic-clonic seizure followed by an asystolic cardiac arrest. After 10 min of unsuccessful cardiopulmonary resuscitation, a bolus of 100 ml of Intralipid 20% (2 ml.kg(-1)) was administered followed by a continuous infusion of 10 ml.min(-1). After a total dose of 200 ml of Intralipid 20% had been given spontaneous electrical activity and cardiac output was restored. The patient recovered completely. We believe the cardiovascular collapse was secondary to ropivacaine absorption following the accidental overdose. This case shows that lipid infusion may have a beneficial role in cases of local anaesthetic toxicity when conventional resuscitation has been unsuccessful.

Rare arctic-alpine plants of the European Alps have different immigration histories: the snow bed species Minuartia biflora and Ranunculus pygmaeus

Minuartia biflora and Ranunculus pygmaeus are circumarctic plants with a few isolated occurrences in the European Alps. We analysed amplified fragment length polymorphism (AFLP) and chloroplast DNA sequence data to unravel the history of their immigration into the Alps and to provide data on their circumpolar phylogeography. In spite of the similar ecological requirements of the two species, they exhibit strikingly different immigration histories into the Alps. In M. biflora, the Alpine populations are most probably derived from source populations located between the Alpine and Scandinavian ice sheets, in accordance with the traditional biogeographic hypothesis. In contrast, the Alpine populations of R. pygmaeus cluster with those from the Tatra Mountains and the Taymyr region in northern Siberia, indicating that the distant Taymyr area served as source for the Alpine populations. Both species showed different levels of genetic diversity in formerly glaciated areas. In contrast to the considerable AFLP diversity observed in M. biflora, R. pygmaeus was virtually nonvariable over vast areas, with a single phenotype dominating all over the Alps and another, distantly related one dominating the North Atlantic area from Greenland over Svalbard to Scandinavia. The same pattern was observed in chloroplast DNA sequence data. Thus, postglacial colonization of R. pygmaeus was accompanied by extreme founder events.

Simultaneous determination of gentisic, salicyluric and salicylic acid in human plasma using solid-phase extraction, liquid chromatography and electrospray ionization mass spectrometry

A method is developed for the simultaneous extraction of gentisic (GA), salicyluric (SUA) and salicylic acid (SA) in human plasma from Willow Bark extract, by solid phase extraction (SPE) using Waters Oasis HLB (divinylbenzene-n-vinylpyrrolidone copolymer) cartridges. Also, a method is optimized comprising of reversed-phase (RP) high-performance liquid chromatography (HPLC) in connection with electrospray ionization mass spectrometry (ESI-MS), fluorescence detection (FLD) and photo diode array detection (DAD) to identify and quantify GA, SUA and SA in the SPE effluents. An improved sensitivity regarding the lower detection limit (LOD) of < 7 ng/ml, the limit of quantitation (LOQ) of 20 ng/ml and short analysis times of < 15 min is required. The validated SPE method shows linearity in the range of 9.0-58.2 ng/ml for GA, 9.4-191.5 ng/ml for SUA and 12.8-1101.6 ng/ml for SA. The correlation coefficient values are > 0.9994 and 0.99 for fluorescence detection (FLD) and electrospray ionization mass spectrometry (ESI-MS), respectively. The recoveries are from 91.3-102.1% for gentisic acid (GA), 86.8-100.5% for salicyluric acid (SUA) and 75.8-81.4% for salicylic acid (SA) depending on the starting concentrations. RP-LC-ESI-MS/MS studies using collision induced dissociation (CID) confirm that the investigated analytes are not artifacts and facilitate further specific identification in addition to the determination of the parent ion mass even in the presence of co-eluting peaks. The established method is also used to analyze gentisic (GA), salicyluric (SUA) and salicylic acid (SA), not only after intake of Willow Bark capsules (Assalix, BNO 1455) but also as naturally occurring constituents in human plasma after the intake of salicylic acid containing foods.

Entanglement versus correlations in spin systems

We consider pure quantum states of N>>1 spins or qubits and study the average entanglement that can be localized between two separated spins by performing local measurements on the other individual spins. We show that all classical correlation functions provide lower bounds to this localizable entanglement, which follows from the observation that classical correlations can always be increased by doing appropriate local measurements on the other qubits. We analyze the localizable entanglement in familiar spin systems and illustrate the results on the hand of the Ising spin model, in which we observe characteristic features for a quantum phase transition such as a diverging entanglement length.

Results of surgical therapy of adenocarcinomas of the esophagogastric junction according to a standardized surgical resection technique

AIM

The aim of this retrospective analysis was to exclusively present the surgical results of patients with type-I-III adenocarcinomas of the esophagogastric junction thereby providing a basis for comparison with other approaches.

METHODS

56 patients with Barrett's carcinomas and 74 patients with cardial and subcardial tumors were operated on and evaluated. The surgical procedure for type-II/III carcinomas was identical: total gastrectomy, omentectomy and splenectomy with lymph node dissection after a combined left thoraco-abdominal incision. Both tumor entities were summarized into 1 group and compared with the results of surgery for Barrett's carcinomas: subtotal esophagectomy and proximal stomach resection with lymph node dissection after right thoracotomy and an additional abdominal incision.

RESULTS

In 93% of all patients an R0 resection was possible. In patients with Barrett's carcinomas pulmonal complications (41%) were the predominant postoperative problems. The 30-day lethality (5.3%) was higher in the group of patients with type-I carcinomas compared to those with type-II/III carcinomas (1.4%). Tumor infiltration and nodal involvement determined the prognosis after R0 resection. The presence of Barrett's mucosa in type-I adenocarcinomas and the histological assessment according to Lauren's classification into type-II/III carcinomas also influenced the long-term prognosis.

CONCLUSION

After R0 resection it is not the tumor location but tumor infiltration, lymph node status and a differentiated histological assessment that determine the prognosis of patients with adenocarcinomas of the esophagogastric junction.

Mucilages and polysaccharides in Ziziphus species (Rhamnaceae): localization, composition and physiological roles during drought-stress

The drought-tolerant tree species Ziziphus mauritiana Lamk. and Z. rotundifolia Lamk. were shown to have similar high mucilage concentrations (7-10% dry weight) in their leaves, with large numbers of mucilage-containing cells in the upper epidermis and extracellular mucilage-containing cavities in the leaf veins and stem cortex. The main sugar constituents of the water-soluble mucilage extract were rhamnose, glucose and galactose. During drought-stress in two independent studies, foliar mucilage content was unaffected in both species, but glucose and starch contents declined significantly in crude mucilage extracts from droughted leaves. Enzymatic hydrolysis of the mucilage extract using alpha-amylase and amyloglucosidase released glucose, indicating that a mucilage-associated water-soluble glucan, with alpha-1,4- and alpha-1,6-linkages, may exist which was extracted together with the mucilage. From the current data, it is not possible to localize the glucan to determine whether or not it is associated with mucilage-containing cells. Data from pressure-volume analyses of drought-stressed and control leaves showed that, in line with their similar mucilage contents, the relative leaf capacitance isotherm (change in relative water content per unit change in water potential) was similar in both species. During drought-stress, reduced relative capacitance resulted from osmotic adjustment and decreased wall elasticity. Data suggest that in Ziziphus leaves, intracellular mucilages play no part in buffering leaf water status during progressive drought. In Ziziphus species, growing in environments with erratic rainfall, the primary role of foliar mucilage and glucans, rather than as hydraulic capacitors, may be as sources for the remobilization of solutes for osmotic adjustment, thus enabling more effective water uptake and assimilate redistribution into roots and stems prior to defoliation as the drought-stress intensified.

Determination of flavonoids and stilbenes in red wine and related biological products by HPLC and HPLC-ESI-MS-MS

To investigate probable health benefits of flavonoids and stilbenes in red wine a new reversed-phase (RP) high-performance liquid-chromatographic (HPLC) method with enhanced separation efficiency and improved selectivity, sensitivity, and speed has been established for determination of the flavonoids quercetin, myricetin and kaempferol and the stilbenes cis- and trans-resveratrol, in a single run . UV-absorbance, fluorescence (FLD), and mass-spectrometric (MS) detection were also evaluated. UV-absorbance detection at 320 nm for stilbenes and 377 nm for flavonoids enables their determination up to the nanogram range with a linearity of R2>0.9999 (linear range 50 ng mL(-1)-50 microg mL(-1)). Calculated values of average recoveries were between 95 and 105% for all analytes. For resveratrol, fluorescence detection was highly selective and twice as sensitive as UV detection, and linearity was satisfactory (R2>0.9996; linear range see UV detection). For the detection of the hydrophilic glycosidic compounds piceid and rutin, which are coeluted with other hydrophilic ingredients, the validated RP HPLC system was coupled to a quadrupole ion-trap mass-spectrometer (MS) via an electrospray interface (ESI) with 25% ammonia solution as sheath liquid. MS detection was, highly linear (R2>0.9878; linear range 50 ng mL(-1)-50 microg mL(-1)) for all investigated analytes and the limits of detection were in the low nanogram range. Compared with UV detection MS detection resulted in a 200% increase in signal intensity for myricetin and 400% increases for quercetin and kaempferol, but equal signal intensity for resveratrol. Calculated values of average recoveries were 102% for myricetin and 79% for piceid. Collision induced dissociation (CID) was also used to obtain characteristic fragmentation fingerprints to facilitate qualitative and quantitative analysis even in complex matrices. Finally, this hyphenated HPLC-ESI-MS method was highly suitable and an essential improvement compared with UV- and fluorescence detection.

Inferring the history of the polyploid Silene aegaea (Caryophyllaceae) using plastid and homoeologous nuclear DNA sequences

The origin of the rare allotetraploid Silene aegaea was inferred from plastid rps16 intron sequences, homoeologous copies of nuclear ribosomal internal transcribed spacer (ITS) sequences, and an intron from the nuclear gene coding for the second largest subunit of RNA polymerase II (RPB2). The nuclear DNA regions support the S. sedoides and S. pentelica lineages as most closely related to the two S. aegaea paralogues. A few recombinant ITS sequences were found, but as PCR recombination could be demonstrated, no true recombination could be demonstrated. No recombination was found in the RPB2 sequences. Plastid rps16 intron sequences strongly support S. pentelica as the maternal lineage. The strength of the approach of using homoeologous sequences of several loci is demonstrated, and its usefulness for the study of phylogenies of groups including polyploids is emphasized.

Physiological and morphological adaptations of the fruit tree Ziziphus rotundifolia in response to progressive drought stress

The physiological basis of drought resistance in Ziziphus rotundifolia Lamk., which is an important, multipurpose fruit tree of the northwest Indian arid zone, was investigated in a greenhouse experiment. Three irrigation regimes were imposed over a 34-day period: an irrigation treatment, a gradual drought stress treatment (50% of water supplied in the irrigation treatment) and a rapid drought stress treatment (no irrigation). Changes in gas exchange, water relations, carbon isotope composition and solute concentrations of leaves, stems and roots were determined. The differential rate of stress development in the two drought treatments did not result in markedly different physiological responses, but merely affected the time at which they were expressed. The initial response to decreasing soil water content was reduced stomatal conductance, effectively maintaining predawn leaf water potential (Psi(leaf)), controlling water loss and increasing intrinsic water-use efficiency, while optimizing carbon gain during drought. Carbon isotope composition (delta13C) of leaf tissue sap provided a more sensitive indicator of changes in short-term water-use efficiency than delta13C of bulk leaf tissue. As drought developed, osmotic potential at full turgor decreased and total solute concentrations increased in leaves, indicating osmotic adjustment. Decreases in leaf starch concentrations and concomitant increases in hexose sugars and sucrose suggested a shift in carbon partitioning in favor of soluble carbohydrates. In severely drought-stressed leaves, high leaf nitrate reductase activities were paralleled by increases in proline concentration, suggesting an osmoprotective role for proline. As water deficit increased, carbon was remobilized from leaves and preferentially redistributed to stems and roots, and leaves were shed, resulting in reduced whole-plant transpiration and enforced dormancy. Thus, Z. rotundifolia showed a range of responses to different drought intensities indicating a high degree of plasticity in response to water deficits.

Oral mucosal blood flow in patients with burning mouth syndrome

The pathophysiology of burning mouth syndrome (BMS) is largely unknown. Thus, the aim was to study oral mucosal blood flow in BMS-patients using laser Doppler flowmetry (LDF). Thirteen BMS patients (11 female, two male; mean age+/-SD 64.3+/-7.9 years, mean disease duration 18.9+/-6.2 months) and 13 healthy non-smoking controls matched for age and gender (11 female, two male; mean age 64.7+/-8.1 years) were investigated. Using the LDF technique mucosal blood flow (mBF) was measured at the hard palate, the tip of the tongue, on the midline of the oral vestibule, and on the lip. Measurements were made at rest and over 2 min following dry ice application of 10 s duration using a pencil shaped apparatus. In addition, blood pressure (BP), heart rate (HR), peripheral cutaneous blood flow, and transcutaneous pCO(2) were continuously recorded. Mucosal blood flow (mBF) increased at all measurement sites in response to dry ice application (P<0.001) with peak flow at 0.5--1.5 min after stimulation onset. During the following 1.5--2 min, blood flow decreased at all sites with a tendency to return to baseline towards the end of the observation period. Except for BP and peripheral blood flow, all of the cardiovascular changes exhibited significant changes during the observation period; no differences between groups were detected. When compared to healthy controls BMS patients generally exhibited larger changes in mBF. These changes were significant for recordings made on the hard palate (F[1,24]=13.9, P<0.001). Dry ice stimulation appears to be an effective, non-invasive and reasonably tolerable means to investigate mucosal blood flow at different mucosal sites. In general, vasoreactivity in BMS patients was higher than in healthy controls. BMS patients exhibited a higher response on the hard palate compared to controls. These changes in oral blood flow appear to be specifically related to BMS symptoms indicating a disturbed vasoreactivity.

Cyclitols as cryoprotectants for spinach and chickpea thylakoids

Thylakoid membranes isolated from either spinach or chickpea leaves were used as a model system for evaluating the capacity of cyclitols to act as cryoprotectants. The effect of freezing for 3 h at -18 degrees C on cyclic photophosphorylation and electron transport was measured. The cyclitols, ononitol, O-methyl-muco-inositol, pinitol, quebrachitol and quercitol at 50-150 mol m(-3) decreased membrane damage by freezing and thawing to a similar degree as the well known cryoprotectants sucrose and trehalose. On addition of the cryotoxic solute NaCl (100 mol m(-3)) to the test system these methylated cyclohexanhexols again provided a protection comparable to that of the two disaccharides. Quercitol (cyclohexanpentol) was not effective when added in lower concentrations (50-100 mol m(-3)) and in case of this cyclitol a ratio of membrane toxic to membrane compatible solute of 0.66 was apparently needed to prevent a loss of cyclic photophosphorylation. Little difference was observed in the results from spinach or chickpea thylakoids although these plants naturally accumulate different cyto-solutes (spinach: glycinebetaine; chickpea: pinitol).

Development and evaluation of a new method for the determination of the carotenoid content in selected vegetables by HPLC and HPLC-MS-MS

Epidemologic studies have shown inverse correlation between the consumption of carotenoid-rich vegetables and the incidence of cancer. Therefore, analytical techniques for the quantitative determination of carotenoids in complex sample matrices are important. The most used method is reversed-phase (RP)-high-performance liquid chromatography (HPLC). In this study, seventeen mobile-phase systems described in the literature and six RP-HPLC columns with differences in particle size and porosity are evaluated. Derived from these results, a new mobile-phase (acetonitrile, methanol, chloroform, and n-heptane) including solvent modifiers is presented, which allows an improved and more efficient separation of carotenoids. From all columns tested, the best chromatographic parameters are found using a silica C18 column (250 x 2 mm, 5 microm, 100 A). As was found, absorbance detection at 450 nm allows the determination of the carotenoids down to the picogram range with good linearity (R2 > 0.98). For the identification and quantitation of carotenoids in complex sample matrices (containing additionally other ultraviolet-absorbing compounds), the optimized RP chromatographic system is coupled to a mass spectrometer (MS) using an atmospheric pressure ionization interface. The calibration plots show high linearity (R2 > 0.99), and the detection limit is found in the lower nanogram range. Furthermore, collision-induced dissociation in the ion source allows for the identification of carotenoids by their characteristic fragmentation pathways. In this study, a total of nine species of vegetables commonly consumed in Central Europe are analyzed for their contents of carotenoids (namely lutein, zeaxanthin, beta-cryptoxanthin, and beta-carotene) by RP-HPLC and RP-HPLC-MS-MS. It is found that good sources for lutein are spinach, kale, and broccoli, and sources for beta-carotene are broccoli, spinach, kale, carrots, and tomatoes. This new method is an improvement for the identification and quantitation of carotenoids in complex biological tissues.

Oral mucosal blood flow following dry ice stimulation in humans

The aim of the current pilot study was to establish a procedure that would allow the investigation of microcirculatory changes in the oral cavity. The authors studied the effects of painful stimulation using dry ice (CO2). To investigate potential regional differences in the change of blood flow, recordings were made for the tongue and at the mucosa of the hard palate, lip, and oral vestibule. The authors investigated 26 patients divided into groups of younger subjects (10 men, 3 women; age range 21-31 y) and older patients (2 men, 11 women; age range 54-74 y). Mucosal blood flow (mBF) was obtained at the hard palate, at the tip of the tongue, on the midline of the oral vestibule, and at the lip. Measurements were made during rest and for 2 minutes after application of dry ice for a 10-second duration, using a pencil-shaped apparatus. Blood pressure, heart rate, cutaneous blood flow, transcutaneous partial pressure of carbon dioxiode (PCO2) and partial pressure of oxygen (PO2) were recorded. Mucosal blood flow increased at all sites in response to application of dry ice (p <0.001), with peak flow at 0.5 minute to 1.5 minutes after onset of stimulation. During the 1.5 minutes to 2 minutes, blood flow decreased at all measurement sites with a tendency to return to baseline. Heart rate, blood pressure, pCO2, PO2, and cutaneous blood flow did not show significant changes. Overall, responses in older patients showed more variance when compared with younger patients. Stimulation by dry ice appears to be an effective, noninvasive, and tolerable means to investigate mucosal blood flow at different mucosal sites. Preliminary data indicate different levels of responsiveness to painful cold stimulation at different sites on the oral and perioral mucosa; particularly, mucosal blood flow response at the tongue was least pronounced. Therefore, assessment of stimulated mucosal blood flow appears to be a promising tool to investigate the pathophysiology of a number of neurologic symptoms, eg, the burning mouth syndrome.

Klinische Ergebnisse der Behandlung der koronaren Herzkrankheit mit Wachstumsfaktoren

Die aktuellen Behandlungsmethoden der koronaren Herzkrankheit zielen auf Minimierung des Infarktrisikos und Reduktion der Symptome durch Senkung des myokardialen Sauerstoffbedarfs, durch Verbesserung der myokardialen Perfusion sowohl medikamentös als auch mechanisch durch PTCA oder Bypasschirurgie und durch Prävention einer weiteren Progression der Erkrankung. Trotz des hohen technischen Standards der interventionellen oder operativen Verfahren der myokardialen Revaskularisation sind diese bei Patienten mit diffuser Arteriosklerose und peripherem Gefäßbefall nicht anwendbar. Die Induktion der Angiogenese durch humane angiogenetische Wachstumsfaktoren entwickelt sich speziell bei dieser Patientengruppe zu einer neuen Therapiemodalität und stellt neben medikamentöser Therapie, PTCA und Bypasschirurgie ein viertes, neuartiges Behandlungsprinzip der koronaren Herzkrankheit dar. »Polypeptide Fibroblast Growth Factor« (FGF) und »Vascular Endothelial Growth Factor« (VEGF) scheinen einen besonders starken Effekt im Hinblick auf die Induktion der Angiogenese im hypoxischen Gewebe auszuüben.

Stachyose synthesis in seeds of adzuki bean (Vigna angularis): molecular cloning and functional expression of stachyose synthase

Stachyose is the major soluble carbohydrate in seeds of a number of important crop species. It is synthesized from raffinose and galactinol by the action of stachyose synthase (EC 2.4.1.67). We report here on the identification of a cDNA encoding stachyose synthase from seeds of adzuki bean (Vigna angularis Ohwi et Ohashi). Based on internal amino acid sequences of the enzyme purified from adzuki bean, oligonucleotides were designed and used to amplify corresponding sequences from adzuki bean cDNA by RT-PCR, followed by rapid amplification of cDNA ends (RACE-PCR). The complete cDNA sequence comprised 3046 nucleotides and included an open reading frame which encoded a polypeptide of 857 amino acid residues. The entire coding region was amplified by PCR, engineered into the baculovirus expression vector pVL1393 and introduced into Spodoptera frugiperda (Sf21) insect cells for heterologous expression. The recombinant protein was immunologically reactive with polyclonal antibodies raised against stachyose synthase purified from adzuki bean and was shown to be a functional stachyose synthase with the same catalytic properties as its native counterpart. High levels of stachyose synthase mRNA were transiently accumulated midway through seed development, and the enzyme was also present in mature seeds and during germination.

A high-density integrated genetic linkage and radiation hybrid map of the laboratory rat

The laboratory rat (Rattus norvegicus) is a key animal model for biomedical research. However, the genetic infrastructure required for connecting phenotype and genotype in the rat is currently incomplete. Here, we report the construction and integration of two genomic maps: a dense genetic linkage map of the rat and the first radiation hybrid (RH) map of the rat. The genetic map was constructed in two F2 intercrosses (SHRSP x BN and FHH x ACI), containing a total of 4736 simple sequence length polymorphism (SSLP) markers. Allele sizes for 4328 of the genetic markers were characterized in 48 of the most commonly used inbred strains. The RH map is a lod >/= 3 framework map, including 983 SSLPs, thereby allowing integration with markers on various genetic maps and with markers mapped on the RH panel. Together, the maps provide an integrated reference to >3000 genes and ESTs and >8500 genetic markers (5211 of our SSLPs and >3500 SSLPs developed by other groups). [Bihoreau et al. (1997); James and Tanigami, RHdb (http:www.ebi.ac.uk/RHdb/index.html); Wilder (http://www.nih.gov/niams/scientific/ratgbase); Serikawa et al. (1992); RATMAP server (http://ratmap.gen.gu.se)] RH maps (v. 2.0) have been posted on our web sites at http://goliath.ifrc.mcw.edu/LGR/index.html or http://curatools.curagen.com/ratmap. Both web sites provide an RH mapping server where investigators can localize their own RH vectors relative to this map. The raw data have been deposited in the RHdb database. Taken together, these maps provide the basic tools for rat genomics. The RH map provides the means to rapidly localize genetic markers, genes, and ESTs within the rat genome. These maps provide the basic tools for rat genomics. They will facilitate studies of multifactorial disease and functional genomics, allow construction of physical maps, and provide a scaffold for both directed and large-scale sequencing efforts and comparative genomics in this important experimental organism.

Overexpression of chicken interferon regulatory factor-1 (Ch-IRF-1) induces constitutive expression of MHC class I antigens but does not confer virus resistance to a permanent chicken fibroblast cell line

The chicken fibroblast cell line C32 has been transfected with the chicken homolog (Ch-IRF-1) of the mammalian transcription factor IRF-1. Stable transfectants were generated, constitutively overexpressing Ch-IRF-1 mRNA and protein. Cells overexpressing Ch-IRF-1 showed enhanced constitutive expression of MHC class I (B-F, beta-microglobulin) antigens. With increasing number of passages cells with normal B-F IV surface antigen expression accumulated. In the revertants, the amount of Ch-IRF-1 mRNA was reduced. Overexpression of Ch-IRF-1 had no effect on the constitutive expression and the induction by chicken interferon type-I and type-II (Ch-IFN) of guanylate-binding protein (GBP). Susceptibility to vesicular stomatitis virus, sindbis virus, Newcastle disease virus and vaccinia virus was not altered by overexpression of Ch-IRF-1. An antiviral state could be induced against all viruses tested by similar amounts of Ch-IFN type I in clone 20-18 expressing Ch-IRF-1 and cells transfected with empty vector.

High-Resolution High-Count-Rate X-ray Spectroscopy with State-of-the-Art Silicon Detectors

For the European X-ray multi-mirror (XMM) satellite mission and the German X-ray satellite ABRIXAS, fully depleted pn-CCDs have been fabricated, enabling high-speed low-noise position-resolving X-ray spectroscopy. The detector was designed and fabricated with a homogeneously sensitive area of 36 cm(2). At 150 K it has a noise of 4 e(-) r.m.s., with a readout time of the total focal plane array of 4 ms. The maximum count rate for single-photon counting was 10(5) counts s(-1) under flat-field conditions. In the integration mode more than 10(9) counts s(-1) can be detected at 6 keV. Its position resolution is of the order of 100 micro m. The quantum efficiency is higher than 90% from carbon K X-rays (277 eV) up to 10 keV. New cylindrical silicon drift detectors have been designed, fabricated and tested. They comprise an integrated on-chip amplifier system with continuous reset, on-chip voltage divider, electron accumulation layer stabilizer, large area, homogeneous radiation entrance window and a drain for surface-generated leakage current. At count rates as high as 2 x 10(6) counts cm(-2) s(-1), they still show excellent spectroscopic behaviour at room-temperature operation in single-photon detection mode. The energy resolution at room temperature is 220 eV at 6 keV X-ray energy and 140 eV at 253 K, being achieved with Peltier coolers. These systems were operated at synchrotron light sources (ESRF, HASYLAB and NLS) as X-ray fluorescence spectrometers in scanning electron microscopes and as ultra low noise photodiodes. The operation of a multi-channel silicon drift detector system is already foreseen at synchrotron light sources for X-ray holography experiments. All systems are fabricated in planar technology having the detector and amplifiers monolithically integrated on high-resistivity silicon.

A new type of congenital dysfibrinogen, fibrinogen Bremen, with an A alpha Gly-17 to Val substitution associated with hemorrhagic diathesis and delayed wound healing

We have identified a new type of A alpha Gly-17 to Val substitution in a congenital dysfibrinogen, fibrinogen Bremen, derived from a 15-year-old boy having manifested easy bruising and delayed wound healing. The functional abnormality was characterized by altered fibrin monomer polymerization, which became evident by increasing the salt concentration and pH. A synthetic tetrapeptide with a sequence of the amino-terminal segment of normal fibrin alpha-chain, Gly-Pro-Arg-Val, substantially inhibited polymerization of both normal and the patient-derived fibrin monomers. A synthetic tetrapeptide with the Bremen type sequence of Val-Pro-Arg-Val inhibited polymerization of the patient's fibrin monomers partially at a peptide: fibrin monomer molar ratio of 4,000:1, and that of normal one at a much higher ratio of 10,000:1. Likewise, a synthetic peptide Ala-Pro-Arg-Val with a replacement of the Gly residue by another aliphatic amino acid Ala inhibited similarly the patient's fibrin monomer polymerization. Thus, the hypothetical two-pronged socket-like structure consisting of the alpha-amino group of the amino-terminal Gly and the guanidino group of an Arg at position 3 of the normal fibrin alpha-chain seems to be restored considerably in the mutant fibrin alpha-chain at low ionic strengths and pH's, despite the replacement of the amino-terminal Gly by another aliphatic amino acid Val.

Capillary electrophoretic analysis of flavonoids

Combining the effects of electrophoresis and electroendosmosis, flavonoids were separated in less than ten minutes in a fused silica capillary tube with a borate buffer adjusted to pH 10. An increase in the concentration of borate from 0.1 to 0.2 M resulted in longer migration times due to a decrease in electroosmotic flow, but also in improved selectivity and higher resolution of flavonoids. The calibration curve of rutin showed a detection limit of 0.02 mg/mL and linearity over its pharmaceutical concentration range. Using an internal standard of known concentration, the content of rutin in a methanolic extract of Sambuci flos could be determined with a coefficient of variation as small as 3.8% by the molar ratio-peak area ratio method.

Ecophysiological comportment of the tropical CAM-tree Clusia in the field: I. Growth of Clusia rosea Jacq. on St John, US Virgin Islands, Lesser Antilles

Clusia rosea Jacq. is abundant in the moist parts of the Caribbean island of St John (US Virgin Islands, Lesser Antilles) but relatively rare along the dry south coast. Three types of seedlings were encountered, terrestrial seedlings, seedlings growing as humus-epiphytes on other trees, and seedlings growing inside the tanks of the bromeliad Aechmea lingulata (L.) Baker. Free-living trees grow from terrestrial seedlings or from epiphytic seedlings strangling and shading their host trees. Leaf-Na⁺ levels were always low (1-4 mequiv I^-1 tissue water); trees close to the shore were not affected by salinity. In leaves of mature C. rosea trees, levels of Ca²⁺ , Mg²⁺ and K⁺ were about 60-90, 40-50, 45-55 mequiv I^-1 tissue water, respectively. Epiphytic seedlings tended to contain lower levels of these inorganic cations than seedlings growing terrestrially or in the tanks of Ae. lingulata. Epiphytic seedlings contained significantly less nitrogen than terrestrial seedlings. In the leaves of mature trees N-levels were independent of altitude and location on the island, but shaded leaves had significantly higher N-levels than exposed leaves. Light compensation point of photosynthesis in epiphytic seedlings performing C₃ -photosynthesis was 17-5 (μmol photons m^-2 s^-1 ), photosynthesis was saturated at about 300μmol photons m^-2 s^-1 showing a maximum rate of CO₂ -uptake of 2-3 μmol m^-2 s^-1 .

Na,K-ATPase and the development of Na+ transport in rat distal colon

Na,K-ATPase function was studied in order to evaluate the mechanism of increased colonic Na+ transport during early postnatal development. The maximum Na(+)-pumping activity that was represented by the equivalent short-circuit current after addition of nystatin (ISCN) did not change during postnatal life or after adrenalectomy performed in 16-day-old rats. ISCN was entirely inhibited by ouabain; the inhibitory constant was 0.1 mM in 10-day-old (young) and 0.4 mM in 90-day-old (adult) rats. The affinity of the Na,K pump for Na+ was higher in young (11 mM) than in adult animals (19 mM). The Na,K-ATPase activity (measured after unmasking of latent activity by treatment with sodium dodecylsulfate) increased during development and was also not influenced by adrenalectomy of 16-day-old rats. The inhibitory constant for ouabain (KI) was not changed during development (0.1-0.3 mM). Specific [3H]ouabain binding to isolated colonocytes increased during development (19 and 82 pmol/mg protein), the dissociation constant (KD) was 8 and 21 microM in young and adult rats, respectively. The Na+ turnover rate per single Na,K pump, which was calculated from ISCN and estimated density of binding sites per cm2 of tissue was 500 in adult and 6400 Na+/min.site in young rats. These data indicate that they very high Na+ transport during early postnatal life reflects an elevated turnover rate and increased affinity for Na+ of a single isoform of the Na,K pump. The development of Na+ extrusion across the basolateral membrane is not directly regulated by corticosteroids.