bluuebunny/crossref_metadata_2025_split huggingface dataset:
Threat‐Sensitive Responses to Predator Attacks in a Damselfly
Authors: Gyssels Freya G. M. , Stoks Robby 
Published: March 2005

AbstractThe threat sensitivity hypothesis predicts that prey species assess and adjust their behavior flexibly in accordance with the magnitude of the threat imposed by a predator. We tested this hypothesis with regard to escape behavior and thanatosis (feigning of death to escape predation) in larvae of the damselfly Ischnura elegans. We manipulated the perceived predation threat of the larvae by changing three factors: lamellae autotomy (an escape strategy where animals sacrifice a body part when grasped by a predator; lamellae present or absent), kairomone type (odors released by predators; control, dragonfly kairomones or fish kairomones), and population of origin (fishpond or fishless pond). We demonstrated that thanatosis increased survival both when confronted with dragonfly and fish predators. We could show, for the first time, costs of past autotomy to be predator‐dependent: larvae without lamellae suffered higher predation mortality but only in the presence of a dragonfly predator and not in the presence of a fish predator. This is in accordance with the observed reduced escape speed of larvae after autotomy, which may affect escape probability toward dragonfly predators but not to the very fast fish predators. Unexpectedly, kairomone type did not affect the escape response of the larvae. In accordance with the threat sensitivity hypothesis, after an unsuccessful attack, larvae without lamellae had a higher frequency to enter thanatosis than larvae with lamellae and larvae from the fishpond showed longer thanatosis durations than larvae from the fishless pond. Consistent with the hypothesis, the reaction of the larvae to a simulated attack depended jointly on lamellae status and population. In fishless ponds, larvae with lamellae swam away more frequently than larvae without lamellae; in fishponds both groups almost never swam away and relied mostly upon immobility. Given the obvious benefits of adaptively varying escape responses we hypothesize this threat sensitivity to be widespread. Moreover, we argue that former inconsistencies between studies with regard to escape behavior may have been partly because of such adaptive variation.
Erschwerter Verlauf von Ösophagusperforationen durch Pilzinfektion
Authors: Jungbluth T. , Bouchard R. , Kujath P. , Bruch H.‐P. 
Published: March 2005

ZusammenfassungDie Ösophagusperforation hat eine hohe Letalitätsrate, welche zwischen 7 und 49% schwankt. Im untersuchten Kollektiv aus den Jahren 1986 bis 2003 war die hohe Letalitätsrate von 28% vorwiegend durch septische Komplikationen wie Mediastinitiden und Pneumonien verursacht. In den mikrobiologischen Untersuchungen unterschiedlicher Lokalisationen und Sekrete wurden bei 28% der Patienten (n = 16) Pilze nachgewiesen. Im Vergleich zum Gesamtkollektiv führte der Pilzbefall zu einer erhöhten Letalität um 50%. Die invasive ösophageale Candidose kann ihrerseits Ursache einer Ösophagusperforation sein. Begleitende Pilzinfektionen entstehen bei Ösophagusperforationen durch das Einbrechen der Perforation in sterile Kompartimente oder durch hämatogene und lymphogene Ausbreitung bis hin zur Sepsis. Bei unkompliziertem Krankheitsverlauf ist eine antimykotische Therapie nicht erforderlich. Vom Anfang der Behandlung an sollte ein mikrobiologisches Monitoring erfolgen, insbesondere des intraoperativen Befundes. Je nach Risikofaktoren und klinischem Verlauf der Patienten muss mit einer antimykotischen Therapie reagiert werden. Besondere Bedeutung kommt einer chirurgischen Sanierung und einer suffizienten Drainage der beteiligten Kompartimente wie Pleura und Mediastinum zu.
Die chirurgische Therapie des pulmonalen Aspergilloms
Authors: Schulte T. , Welcker K. , Schatz J. , Branscheid D. 
Published: March 2005

ZusammenfassungDie invasive pulmonale Aspergillose ist eine potentiell lebensbedrohliche Erkrankung, die durch die Besiedlung der Lunge oder Pleurahöhle überwiegend mit dem Fadenpilz Aspergillus fumigatus hervorgerufen wird. Insbesondere findet sich diese opportunistische Mykose bei immunsupprimierten Patienten, bei Tuberkulose‐, AIDS‐ oder Tumor‐Patienten. In vielen Fällen kommt es zu Hämoptoe oder sogar zu lebensgefährlichen Massenblutungen. Der Stellenwert der Chirurgie bezüglich des Aspergilloms wird herausgestellt, insbesondere übe Zeitpunkt und Indikation von operativen Maßnahmen sollte interdisziplinär entschieden werden. In jedem Falle sollte eine Resektion den anatomischen Grenzen folgen um ein Rezidiv sicher zu verhindern. Das Ligamentum pulmonale muss immer gelöst werden, um das Aufsteigen der Restlunge in den Apex zu ermöglichen und somit keine intrathorakalen Hohlräume zu hinterlassen. Sollten trotzdem Hohlräume zurückbleiben, stehen Verfahren wie die Thorakoplastik oder die Muskelplombe mit z. B. Latissimus dorsi oder Pectoralismuskel zur Verfügung. Werden die genannten Maßnahmen konsequent durchgeführt, lassen sich auch bei schwerkranken Patienten befiedigende Ergebnisse hinsichtlich Mortalität, Morbidität und Rezidivhäufigkeit erzielen.
Indikationsstellung zur antimykotischen Therapie bei der tracheobronchialen Candidose unter Beatmung
Authors: Großherr M. , Sedemund‐Adib Beate , Klotz K.‐F. 
Published: March 2005

ZusammenfassungDie Candidose der Atemwege bei beatmeten Patienten stellt eine schwerwiegende Komplikation des intensivmedizinischen Verlaufes dar. Die vorliegende Arbeit stellt ein Konzept vor, das durch die Erfassung der Häufigkeiten von Untersuchungsmaterial, Keimart und Resistenz Rückschlüsse auf die Wirksamkeit der geleisteten Arbeit geben kann. Ein Vergleich von Intensivstationen im Sinne des Benchmarkings wird durch diese qualitätssichernde Maßnahme ermöglicht. Die Aufarbeitung von entsprechenden Krankheitsverläufen eröffnet die Möglichkeit, die eigene Arbeit im Einzelfall zu reflektieren und an den aktuellen Therapieempfehlungen auszurichten. Ziel ist es, gezielt durch beide Vorgehensweisen die antimykotische Therapie auf einer Intensivstation zu verbessern und Resistenzlagen zu vermeiden. Pilznachweise im respiratorischen System sind häufig, dies alleine rechtfertigt keine Therapie. Die aktuelle Literatur empfiehlt strikte Zurückhaltung, relativiert diese aber bei häufig unklarer Infektionslage, kritischem Allgemeinzustand des Patienten bei Multiorganversagen und zusätzlicher Infektion und bei Langzeitbeatmung. Daher wird die Festlegung einer Therapiestrategie für individuelle Situationen und eine engmaschige Diagnostik empfohlen. Eine frühzeitige Therapie der tracheobronchialen Candidose ist indiziert bei positiver Blutkultur oder bei Candida‐Nachweis aus zwei Untersuchungsmaterialien.
Fehlendes granulozytäres Infiltrat bei der Pityriasis versicolor – ein Hinweis für eine spezifische antiinflammatorische Aktivität des Erregers?
Authors: Wroblewski N. , Bär Silja , Mayser P. 
Published: March 2005

ZusammenfassungDer Hefepilz Malassezia furfur gehört zur Standortflora des Menschen. Gleichzeitig ist er Erreger verschiedener Erkrankungen wie der Pityriasis versicolor. Bei dieser Erkrankung finden sich trotz deutlicher klinischer Symptome (z.B. Hypopigmentierung) kaum Entzündungszeichen. Aufschluss hierüber könnte das aus der Pathophysiologie resultierende morphologische Bild geben. Angaben in der Literatur sind zum Teil kontrovers, daher wurde in dieser Arbeit das Entzündungsinfiltrat der Pityriasis versicolor mit dem der Tinea corporis verglichen. Als Untersuchungsmaterial dienten jeweils 40 humane Hautpräparate von Pityriasis versicolor bzw. Tinea corporis, die im Rahmen der klinischen Diagnostik entnommen wurden. Jedes Präparat wurde HE und PAS gefärbt. In der HE‐Färbung wurden alle neutrophilen Granulozyten, in der PAS‐Färbung die Hyphen und Sporen gezählt. Die Anzahl der ausgezählten Zellen wurde auf die Größe der jeweiligen Fläche bezogen und die Werte zwischen Pityriasis versicolor und Tinea corporis verglichen. Bei der Tinea corporis fanden sich signifikant mehr neutrophile Granulocyten (P > 0,01). Diese waren bei der Pityriasis versicolor praktisch nicht nachzuweisen. Dies ist insofern erstaunlich, da die Pilzlast im Stratum corneum bei Pityriasis versicolor signifikant erhöht ist (P > 0,01). Trotz hoher Erregerlast bleibt offensichtlich die Immunantwort mit neutrophilen Granulozyten aus. Ein Erklärungsmodell könnte eine verminderte Immunogenität durch den hohen Gehalt an Lipiden in der Zellmembran sein. Ferner könnten auch die im Rahmen des Tryptophan‐Stoffwechsels gebildeten Pityriarubine beteiligt sein, die in vitro die ROS‐Produktion neutrophiler Granulozyten stimulusabhängig unterdrücken können.
WITHDRAWAL OF INTRAVENOUS GLYCERYL TRINITRATE: ABSENCE OF REBOUND PHENOMENA WITH TRANSITION TO ORAL ISOSORBIDE DINITRATE
Authors: Kelly Elizabeth A , Ahmed Rebekah M , Horowitz John D 
Published: March 2005

SUMMARY1. Glyceryl trinitrate (GTN) is frequently infused intravenously as a component of the management of acute coronary syndromes (ACS). Abrupt cessation of GTN infusion after periods of more than 24 h administration often induces rebound vasoconstriction reflecting ‘pseudotolerance’; this is also the basis of the ‘zero hour phenomenon’ during chronic nitrate therapy. The efficacy of oral nitrate regimens to prevent vasoconstriction following cessation of intravenous GTN has not been previously examined. Therefore, we investigated the effects of transition from intravenous GTN to oral isosorbide dinitrate (ISDN) on a parameter of apparent arterial stiffness in patients with ACS.2. The effects of GTN infusion at 5 µg/min on augmentation index (AIx) were quantified in patients (n = 10) with stable angina pectoris in order to establish the magnitude of effect on apparent arterial stiffness.3. This infusion rate of GTN reduced AIx from 23 ± 10% (SD) to 3 ± 14% (SD) (P < 0.01). The effect of transition from GTN infusion of greater than 24 h duration to ISDN (10 mg tds) were examined in patients (n = 16) with ACS (unstable angina/non‐Q‐wave myocardial infarction). No patient developed recurrent angina during the 24 h following cessation of GTN infusion. The level of AIx was 8 ± 4% (SD) prior to GTN cessation and fell to 5 ± 6% (SD) on ISDN (P = 0.05).4. Thus, in patients treated for ACS, transition from intravenous GTN to low dose oral ISDN is associated with an incremental vasodilatation and no evidence of ‘rebound’ ischaemia.
Modelling curved S–N curves
Authors: LORÉN S. , LUNDSTRÖM M. 
Published: March 2005

ABSTRACTThe fatigue limit distribution is estimated using fatigue data and under the assumption that the fatigue limit is random. The stress levels for the broken and unbroken specimens are used. For the broken specimen the number of cycles to failure is also used. By combining the finite life and fatigue limit distribution it is possible to get the probability of not surviving a certain life. This probability is used to estimate a curved S–N curve by using the method of likelihood. The whole S–N curve is estimated at the same time. These curves show the predictive life given a certain stress level. The life and the quantile of the fatigue limit distribution are also predicted by using profile predictive likelihood. In this way the scatter around the S–N curve as well as the uncertainty of the S–N curve are taken into account.
Differential resistance to freezing and spatial distribution in a chemically polymorphic plant Thymus vulgaris
Authors: Amiot Justin , Salmon Yann , Collin Christian , Thompson John D. 
Published: March 2005

AbstractSecondary compounds play multiple ecological roles. In this study, we present novel experimental evidence of differential tolerance to freezing temperatures among chemotypes of a chemically polymorphic plant, Thymus vulgaris. Non‐phenolic chemotypes showed a significantly better survival and re‐growth after early‐winter freezing (−10° in early December) than phenolic chemotypes. Comparison of temperature data (1971–2002) at a phenolic and non‐phenolic site showed that whereas early‐winter freezing occurred in 6 years in the non‐phenolic site they never occurred at the phenolic site. Observations of trichome morphology (where the essential oil is stocked) with and without intense freezing indicate that non‐phenolic chemotypes may escape any negative effects of freezing by releasing their essential oil into the atmosphere during severe freezing. The correlation between tolerance of freezing and local temperature regimes strongly suggests that differential freezing resistance is a key ingredient of the distribution of thyme chemotypes in space.
Overyielding in experimental grassland communities – irrespective of species pool or spatial scale
Authors: Roscher Christiane , Temperton Vicky M. , Scherer‐Lorenzen Michael , Schmitz Martin , Schumacher Jens , Schmid Bernhard , Buchmann Nina , Weisser Wolfgang W. , Schulze Ernst‐Detlef 
Published: March 2005

AbstractIn a large integrated biodiversity project (‘The Jena Experiment’ in Germany) we established two experiments, one with a pool of 60 plant species that ranged broadly from dominant to subordinate competitors on large 20 × 20 m and small 3.5 × 3.5 m plots (= main experiment), and one with a pool of nine potentially dominant species on small 3.5 × 3.5 m plots (= dominance experiment). We found identical positive species richness–aboveground productivity relationships in the main experiment at both scales. This result suggests that scaling up, at least over the short term, is appropriate in interpreting the implications of such experiments for larger‐scale patterns. The species richness–productivity relationship was more pronounced in the experiment with dominant species (46.7 and 82.6% yield increase compared to mean monoculture, respectively). Additionally, transgressive overyielding occurred more frequently in the dominance experiment (67.7% of cases) than in the main experiment (23.4% of cases). Additive partitioning and relative yield total analyses showed that both complementarity and selection effects contributed to the positive net biodiversity effect.
When do localized natural enemies increase species richness?
Authors: Adler Frederick R. , Muller‐Landau Helene C. 
Published: March 2005

AbstractThe Janzen–Connell hypothesis states that local species‐specific density dependence, mediated through specialist enemies of offspring such as fungal pathogens and insect seed predators, can facilitate coexistence of species by preventing recruitment near conspecific adults. We use spatially explicit simulation models and analytical approximations to evaluate how spatial scales of offspring and enemy dispersal affect species richness. In comparison with model communities in which both offspring and enemies disperse long distances, species richness is substantially decreased when offspring disperse long distances and enemies disperse short distances. In contrast, when both offspring and enemies disperse short distances species richness more than doubles and adults of each species are highly spatially clumped. For the range of conditions typical of tropical forests, locally dispersing specialist enemies may decrease species richness relative to enemies that disperse long distances. In communities where dispersal distances of both offspring and enemies are short, local effects may enhance species richness.
An anatomical and biometrical study of the femoral trochlear groove in the human fetus
Authors: Glard Yann , Jouve Jean‐Luc , Panuel Michel , Adalian Pascal , Tardieu Christine , Bollini Gérard 
Published: March 2005

AbstractWe performed a biometric analysis of the femoral trochlear groove in the fetus and compared our findings with those observed in adults. We studied 44 formalin‐preserved fetuses (13–38 weeks) and used digitized images to obtain measurements (α angle of the groove, trochlear slopes θL and θM). A comparison of means between our series and adults was achieved. For each angle of the distal epiphysis (α, θL, θM) there was no significant difference between our fetal series and adults. This is the first biometric study of fetal trochlea. The morphology of the lower femur appears to be the same in the fetus and the adult.
The role of cartilage canals in endochondral and perichondral bone formation: are there similarities between these two processes?
Authors: Blumer Michael J. F. , Longato Stefano , Richter Elisabeth , Pérez Maria Teresa , Konakci Kadriye Zeynep , Fritsch Helga 
Published: March 2005

AbstractWe investigated the development of cartilage canals to clarify their function in the process of bone formation. Cartilage canals are tubes containing vessels that are found in the hyaline cartilage prior to the formation of a secondary ossification centre (SOC). Their exact role is still controversial and it is unclear whether they contribute to endochondral bone formation when an SOC appears. We examined the cartilage canals of the chicken femur in different developmental stages (E20, D2, 5, 7, 8, 10 and 13). To obtain a detailed picture of the cellular and molecular events within and around the canals the femur was investigated by means of three‐dimensional reconstruction, light microscopy, electron microscopy, histochemistry and immunohistochemistry [vascular endothelial growth factor (VEGF), type I and II collagen]. An SOC was visible for the first time on the last embryonic day (E20). Cartilage canals were an extension of the vascularized perichondrium and its mesenchymal stem cell layers into the hyaline cartilage. The canals formed a complex network within the epiphysis and some of them penetrated into the SOC were they ended blind. The growth of the canals into the SOC was promoted by VEGF. As the development progressed the SOC increased in size and adjacent canals were incorporated into it. The canals contained chondroclasts, which opened the lacunae of hypertrophic chondrocytes, and this was followed by invasion of mesenchymal cells into the empty lacunae and formation of an osteoid layer. In older stages this layer mineralized and increased in thickness by addition of further cells. Outside the SOC cartilage canals are surrounded by osteoid, which is formed by the process of perichondral bone formation. We conclude that cartilage canals contribute to both perichondral and endochondral bone formation and that osteoblasts have the same origin in both processes.
Thromboxane A2 Receptor‐Mediated Cell Proliferation, Survival and Gene Expression in Oligodendrocytes
Authors: Lin Xin , Ramamurthy Santosh K. , Le Breton Guy C. 
Published: March 2005

AbstractThromboxane A2 receptors (TP) were previously localized to discrete regions in the rat brain on myelinated fiber tracts and oligodendrocytes (OLGs). The present studies extended these findings and investigated the effects of TP signaling on cell proliferation, survival, and gene expression in OLG progenitor cells (OPCs) and OLGs. It was found that the TP agonist, U46619 stimulated the proliferation of OPCs and promoted the survival of mature OLGs. Examination of the early gene expression events involved in OPC proliferation, revealed that c‐fos expression was substantially increased by U46619 stimulation. Treatment of OPCs or OLGs with U46619 caused activation of the mitogen‐activated protein kinases (MAPK) ERK 1/2. In OPCs this activation was blocked by inhibition of src. However, in OLGs this phosphorylation was not only blocked by inhibition of src but also by inhibition of protein kinase C (PKC). Furthermore, U46619 was found to increase CREB phosphorylation in both OPCs and OLGs. Similar to ERK 1/2 activation, there was a divergence in the mechanism of the TP‐mediated CREB response for each cell type. Specifically, U46619 activation was attenuated by src and protein kinase A (PKA) inhibition in OPCs, whereas in OLGs this effect was blocked by inhibition of src, PKA as well as by inhibition of PKC. Collectively, these results provide the first demonstration that TP‐activated nuclear signaling events are involved in the proliferation of OPCs, the survival of mature OLGs, and the stimulation of gene expression.
Sequestration of serum response factor in the hippocampus impairs long‐term spatial memory
Authors: Dash Pramod K. , Orsi Sara A. , Moore Anthony N. 
Published: March 2005

AbstractThe formation of long‐term memory has been shown to require protein kinase‐mediated gene expression. One such kinase, mitogen‐activated protein kinase/extracellular signal‐regulated kinase (MAPK/ERK), can lead to the phosphorylation of serum response factor (SRF) and Elk‐1, enhancing the expression of target genes. However, a direct involvement of these transcription factors in memory storage has not been demonstrated. We have employed an oligonucleotide decoy technique to interrogate SRF and Elk‐1. Previously, it has been shown that intra‐amygdalal infusion of small double‐stranded decoy oligonucleotides for nuclear factor‐kappaB (NFkappaB) can impair long‐term memory for fear‐potentiated startle. Using this approach, we found that intra‐hippocampal infusion of NFkappaB decoy oligonucleotides also impairs long‐term spatial memory, consistent with a role for this factor in long‐term memory storage. Decoy oligonucleotides containing the binding site for SRF, as confirmed by shift‐western, did not influence memory acquisition but impaired long‐term spatial memory. Analysis of search behavior during the transfer test revealed deficits consistent with a loss of precise platform location information. In contrast, oligonucleotides with a binding site for either Elk‐1 or another target of ERK activity, SMAD3/SMAD4, did not interfere with memory formation or storage. These findings suggest that SRF‐mediated gene expression is required for long‐term spatial memory.
Alcohol‐responsive genes in the frontal cortex and nucleus accumbens of human alcoholics
Authors: Flatscher‐Bader Traute , van der Brug Marcel , Hwang John W , Gochee Peter A , Matsumoto Izuru , Niwa Shin‐ichi , Wilce Peter A 
Published: March 2005

AbstractThe molecular processes underlying alcohol dependence are not fully understood. Many characteristic behaviours result from neuroadaptations in the mesocorticolimbic system. In addition, alcoholism is associated with a distinct neuropathology. To elucidate the molecular basis of these features, we compared the RNA expression profile of the nucleus accumbens and prefrontal cortex of human brain from matched individual alcoholic and control cases using cDNA microarrays. Approximately 6% of genes with a marked alcohol response were common to the two brain regions. Alcohol‐responsive genes were grouped into 11 functional categories. Predominant alcohol‐responsive genes in the prefrontal cortex were those encoding DNA‐binding proteins including transcription factors and repair proteins. There was also a down‐regulation of genes encoding mitochondrial proteins, which could result in disrupted mitochondrial function and energy production leading to oxidative stress. Other alcohol‐responsive genes in the prefrontal cortex were associated with neuroprotection/apoptosis. In contrast, in the nucleus accumbens, alcohol‐responsive genes were associated with vesicle formation and regulation of cell architecture, which suggests a neuroadaptation to chronic alcohol exposure at the level of synaptic structure and function. Our data are in keeping with the previously reported alcoholism‐related pathology characteristic of the prefrontal cortex, but suggest a persistent decrease in neurotransmission and changes in plasticity in the nucleus accumbens of the alcoholic.