bluuebunny/crossref_metadata_2025_split huggingface dataset:
At-sea distribution of female southern elephant seals relative to variation in ocean surface properties
Authors: Bradshaw Corey J.A. , Higgins Jane , Michael Kelvin J. , Wotherspoon Simon J. , Hindell Mark A. 
Published: September 2004

AbstractWe examined the relationships between physical oceanography (sea surface temperature – SST, sea surface height anomaly – SSH, ocean colour – OC, bathymetry – BA, sea-ice concentration – SI, and their associated gradients) and the foraging distribution (time at sea) of female southern elephant seals using generalized linear and generalized additive models (GLM and GAM). Using data from 28 separate foraging trips (22 unique individuals) over two years, we found that during the post-lactation trips (summer), the best GLM demonstrated a negative relationship between time at sea and SST and BA, but a positive relationship with SST gradient and SSH. During the post-moult (winter) trips, there was a negative relationship with OC gradient, SSH, and BA. The best post-lactation GAM identified a positive relationship with OC gradient, negative relationships with OC and SST gradient, and a non-linear relationship with SST. For the post-moult trip there was a negative relationship with OC, SST, BA and BA gradient, and a positive relationship with SST gradient. The relationship between the predicted time and observed time at sea was significant only for the post-lactation GAM, although predictability was low. That SST and its gradient predicted a small, but significant proportion of the variation in time at sea is indicative of the frontal zones within this area that are generally more biologically productive than surrounding regions. It appears that coarse-scale oceanographic configuration influences foraging behaviour in southern elephant seals only subtly. Nonetheless, some of the mechanisms influencing predator foraging are congruent with expectations of distribution of marine food resources at coarse spatial scales.
Neurodegeneration and plasticity
Authors: Arendt Thomas 
Published: September 2004

AbstractNeurofibrillary degeneration, associated with the formation of paired helical filaments (PHF), is one of the critical neuropathological hallmarks of Alzheimer's disease (AD). Although the microtubule‐associated protein tau in a hyperphosphorylated form has been established as primary PHF constituent, the process of tau phosphorylation and its potential link to degeneration is not very well understood, mostly because of the lack of a physiological in vivo model of PHF‐like tau phosphorylation. PHF formation in AD follows a hierarchial pattern of development throughout different cortical areas, which closely matches the pattern of neuronal plasticity in the adult brain. Those brain areas are most early and most severely affected which are involved in the regulation of memory, learning, perception, self‐awareness, consciousness, and higher brain functions that require a life‐long re‐fitting of connectivity, a process based on a particularly high degree of plasticity. Failures of synaptic plasticity are, thus, assumed to represent early events in the course of AD that eventually lead to alteration of tau phosphorylation. Recently, we have used the hibernation cycle, a physiological model of adaptation associated with an extraordinary high degree of structural neuronal plasticity, to analyze the potential link between synaptic plasticity, synaptic detachment and the regulation of tau phosphorylation. During torpor, a natural state of hypothermia, synaptic contacts between mossy fibers and hippocampal pyramidal neurons undergo dramatic regressive changes that are fully reversible very rapidly during euthermy. This rapid, reversible, and repeated regression of synaptic and dendritic components on CA3 neurons is associated with a reversible PHF‐like phosphorylation of tau at a similar time course. The repeated formation and degradation of PHF‐tau might, thus, represent a physiological mechanism not necessarily associated with pathological effects. These findings implicate an essential link between neuronal plasticity and PHF‐like phosphorylation of tau, potentially involved in neurofibrillary degeneration.
Purinergic modulation of extracellular glutamate levels in the nucleus accumbens in vivo
Authors: Krügel Ute , Schraft Thomas , Regenthal Ralph , Illes Peter , Kittner Holger 
Published: September 2004

AbstractIn the present study, the P2 receptor‐mediated modulation of the extracellular glutamate concentration was investigated by microdialysis in the nucleus accumbens (NAc) of freely moving rats. Because of the known interference of dopaminergic and glutamatergic mechanisms in this area the experiments were performed with animals intra‐accumbally treated with 6‐hydroxydopamine (6‐OHDA) to deplete dopamine pools. Perfusion of the NAc with the prototypic P2 receptor agonist 2‐methylthioadenosine 5′‐triphosphate (2‐MeSATP, 0.1, 1 and 10 mM) concentration‐dependently increased the extracellular level of glutamate in this area. Pretreatment with the P2 receptor antagonist pyridoxalphosphate‐6‐azophenyl‐2′,4′‐disulphonic acid (PPADS, 0.1 mM) decreased the basal extracellular glutamate concentration and inhibited the 2‐MeSATP‐induced outflow of glutamate. In rats treated with 6‐OHDA, 2‐MeSATP increased the total extracellular glutamate to an extent about fivefold larger than in sham‐lesioned rats. The perfusion of the dopamine‐depleted NAc with the D2/D3 dopamine receptor agonist quinpirole (0.1 mM) diminished the basal concentration of glutamate and reduced the effect of 2‐MeSATP on the extracellular glutamate.These results provide evidence that the stimulation of P2 receptors is involved in the increase of accumbal extracellular glutamate in vivo. This behaviourally relevant mechanism depends on a dopamine D2 receptor‐mediated tone in the nucleus accumbens. Furthermore, the inhibition of P2 receptors may prevent, at least partly, glutamate‐mediated neurodegeneration.
Expression of cell cycle‐related proteins in developing and adult mouse hippocampus
Authors: Schmetsdorf Stefanie , Gärtner Ulrich , Arendt Thomas 
Published: September 2004

AbstractDevelopmental structuring of brain is the result of a strictly coordinated process that involves controlled cell division, neuronal migration and terminal differentiation. Neurogenesis occurs generally during embryonic and early postnatal stages and will be finished in the mature brain. Once differentiated, neurons are incapable of further division but retain the capability of structural and functional plasticity. However, there are distinct regions in the adult brain of mammals that generate neurons continuously throughout life. Among them, the hippocampus, which is known as a region with a high degree of neuroplasticity, is of particular interest in the context of adult neurogenesis.In general, progression through cell cycle phases is regulated by the sequential expression and activation of regulatory proteins like cyclin dependent kinases (cdk), cyclins, or cdk inhibitors (cdki). In postmitotic and terminally differentiated neurons, cell cycle activity is arrested by enrichment of cdkis. The timing of cell cycle exit and neuronal differentiation is likely to be regulated in part by cell cycle regulatory proteins. However, the expression of cell cycle markers in the postnatal or adult brain is still a matter of controversial debate. In the present study, we examined the expression of cdks, cyclins and cdkis within the mouse hippocampus at different developmental stages (embryonic days 17, 19; postnatal day 11 and adult) using immunohistochemical methods. During the prenatal development, cell cycle proteins were localized predominantly in nuclei of all presumptive neuronal populations but expression was not restricted to proliferative cells. With developmental progression, the subcellular localization of most markers was increasingly shifted from nuclear to the cytoplasmic compartment. However, even in the adult, cell cycle‐related proteins were found in terminally differentiated pyramidal and granule neurons. Here, they were mainly localized in the perikaryal cytoplasm but only sporadically in neuronal nuclei. Occasionally, immunoreactivity was also found in dendrites and mossy fibers. The present results suggest that cell cycle arrest and terminal differentiation is not necessarily incompatible with the expression of cell cycle‐related markers. Thus, they may have supplementary functions in differentiated neurons that might be associated with neuronal plasticity.
Tension in a double loop tendon anterior cruciate graft during a simulated open chain knee extension exercise
Authors: Karchin Ari , Hull M. L. , Howell S. M. 
Published: September 2004

AbstractConcerns exist regarding the tension developed in a reconstructed anterior cruciate ligament (ACL) during open chain knee extension exercises used to rehabilitate the knee. Therefore, the primary objective was to measure tension in an ACL graft during a simulated open chain knee extension exercise as a function of ankle weight. A secondary objective was to determine whether the graft tension was reduced with relatively high stiffness fixation. The open chain exercise was simulated in seven cadaveric specimens in which the ACL had been reconstructed with double loop tendon grafts. Graft tension was measured at 15° of flexion as the effective ankle weight was increased from 22.5 to 67.5 and then to 112.5 N for three different fixation stiffnesses (25, 125, and 225 N/mm). The initial tension was set to restore the 225 N anterior limit of motion to that of the intact knee at 30° of flexion. Increasing the ankle weight caused the graft tension to increase significantly (p < 0.0001), but the increase with the highest ankle weight was only 62 N on average. Increasing the fixation stiffness caused the graft tension to decrease significantly (p < 0.0001) because the initial tension decreased by 107 N as the fixation stiffness increased. Because the graft tension with the highest ankle weight was limited to 112 N on average, high stiffness fixation methods, which are also resistant to lengthening in the region of the fixation, may reduce the risk of graft construct lengthening during open chain knee extension exercises. © 2004 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved.
Nasal Colonization with Staphylococcus Aureus is not Associated with the Severity of Symptoms or the Extent of the Disease in Chronic Rhinosinusitis
Authors: Damm Michael , Quante Gero , Jurk Thorsten , Sauer Jan Alex 
Published: September 2004

OBJECTIVESThere is an increasing knowledge that the severity of perennial allergic rhinitis is associated with nasal carriage of Staphylococcus aureus (S. aureus). The aim of this study was to evaluate the rate of bacterial colonization with S. aureus in the nose of subjects with and without chronic rhinosinusitis (CRS) and to correlate these findings with the severity of symptoms and the extent of the disease.STUDY DESIGN AND SETTINGOpen, prospective controlled trial.METHODS190 subjects with CRS and 42 subjects with septal deviation without sinusitis (control subjects) were included in this study. Swabs were taken endoscopically from the middle meatus and bacteria were cultured and identified. Airway symptoms were assessed by subjects in standardized questionnaires and frequencies of respiratory tract infections were noted. The rhinosinusitis extent was graded by CT scan assessment. Analysis of variance, chi‐square test, and Pearson's correlation test were applied for statistical analyses.RESULTSThe S. aureus carriage rate was 25.5% in CRS and 31.4% in control subjects. Further facultative pathogens were cultured in 20.6% of subjects with CRS and in 8.5% of controls. 73.8% of S. aureus were ampicillin‐resistant, multiresistant strains were cultured in 5.8%. Most airway symptoms and the frequencies of respiratory tract infections were significantly higher in the CRS group compared with control subjects. In post hoc comparison between the subgroups with and without S. aureus colonization, no significant differences were found between the extent of rhinosinusitis and the severity of airway symptoms.CONCLUSIONSFacultative pathogens were detected in more than 40% of CRS patients without acute respiratory tract infections. In contrast to the findings in atopic dermatitis and perennial allergic rhinitis, the colonization rate with S. aureus is not increased and S. aureus carriage is not a risk factor for the severity or the extent of rhinosinusitis.
Ilf3 and NF90 associate with the axonal targeting element of Tau mRNA
Authors: Larcher Jean-Christophe , Gasmi Laila , Viranaïcken Wildriss , Eddé Bernard , Bernard Rozenn , Ginzburg Irith , Denoulet Philippe 
Published: September 2004

ABSTRACTIn neurons, the selective translocation of Tau mRNA toward axons is due to the presence of a nucleotide sequence located in its 3′ untranslated region and serving as axonal targeting element. Using this RNA sequence as a probe by a Northwestern approach, we have detected several proteins that interact with the targeting RNA element and could potentially be involved in Tau mRNA translocation, translation halting, and/or stabilization. Among them, two proteins were identified as the interleukin enhancer binding factor 3 (Ilf3) and NF90, two isoforms derived from a single gene product through alternative splicing. Each protein comprises two double‐stranded RNA binding motifs that can interact with the predicted stem‐loop secondary structure of the axonal targeting element. Specific antibodies raised against common or specific peptide sequences showed that both Ilf3 and NF90 are polymorphic proteins that are detected in neuronal nuclei and cell bodies, as well as in the proximal neuritic segments. This observation favors the idea that Ilf3 and NF90 are part of a protein complex that escorts Tau mRNA toward the axon.
A non‐classical type of alveolar macrophage response to Trichinella spiralis infection
Authors: Dzik J. M. , Gołos B. , Jagielska E. , Zieliṅski Z. , Wałajtys‐Rode E. 
Published: September 2004

SUMMARY Studies of arginase expression and activity in guinea pig alveolar macrophages during Trichinella spiralis infection, prompted by earlier observation of innate lung response to the parasite, showed the macrophages to express both activity and protein of arginase type I. In cultured macrophages part of the enzyme was found to be always released to the extracellular medium. Whereas BCG in vivo treatment, alone or preceded by T. spiralis infection, stimulated arginase activity, T. spiralis infection alone affected the enzyme distribution between intracellular and extracellular fractions, and properties (Km and Vmax), rather than total (intracellular + extracellular) activity, with TGF‐β apparently responsible for a part of the effect. Anti‐TGF‐β antibody treatment of the animals influenced both arginase activation by Mn2+ and dependence of the enzyme‐catalysed reaction on pH. Whereas T. spiralis infection activated guinea pig alveolar macrophages by the type II macrophage activation, as indicated by constant arginase expression, associated with previously demonstrated lack of stimulation of nitric oxide production, BCG treatment invoked an alternative type of activation mechanism, reflected by stimulation of macrophage arginase, but not iNOS, activity.
Home oxygen therapy after preterm birth in Western Australia
Authors: Saletti A , Stick S , Doherty D , Simmer K 
Published: September 2004

Objectives:  To review our management of infants discharged home receiving supplemental oxygen. Stable preterm infants receive low flow O2 by nasal cannulae aiming for SaO2 of ≥ 95%. Oxygen‐dependent infants must pass an air test (ability to maintain SaO2 > 80% during 4 h disconnection from oxygen) before discharge home with supplemental oxygen. A sleep study is performed before nocturnal O2 is ceased.Methods:  Infants less than 33 weeks gestational age (GA) who were admitted January 1999−June 2001 and discharged home with supplemental oxygen were identified through the databases and medical records of the King Edward Memorial/Princess Margaret Hospitals. The data collected were compared with an audit performed a decade earlier.Results:  Ninety‐three infants were discharged home with supplemental oxygen between 1999 and 2001 (10% neonatal intensive care unit admissions less than 33 weeks GA; median GA 26 weeks (interquartile range 25−28). All infants had an air test before discharge: 63% failed the first air test and 30% at least two air tests. The median delay between the first air test and discharge was 2 weeks. The median postmenstrual age at discharge was 40 weeks gestation (interquartile range 38−41). Ninety infants had a sleep study before nocturnal oxygen was ceased and nine failed the first sleep study. Hospital readmission rate was 60%. More preterm infants (less than 33 weeks) were discharged with supplemental oxygen in 1999−2001 (10%, n = 96 in 1999−2001) than in 1987−1992 (2.5%, n = 53) and this was associated with an earlier discharge (40 vs 44 weeks postmenstrual age), lower oxygen requirements at discharge (60 vs 125 mL/min), earlier discontinuation of daytime and nocturnal oxygen (1 vs 4 months postmenstrual age and 2.5 vs 6 months postmenstrual age) and no increase in readmission rate (64% vs 60%). The incidence of bronchopulmonary dysplasia for these infants has remained stable at 20%.Conclusion:  Our home oxygen programme, based on an air test predischarge and a sleep study prediscontinuation of nocturnal oxygen, facilitates early discharge home. Our data suggest that over the last decade, bronchopulmonary dysplasia is associated with less impairment in lung function. Further evidence from randomized clinical trials is required to determine optimal target range for oxygen saturation in preterm infants.
How Should the Allocation of Resources Adjust to the Baby Bust?
Authors: De La Croix David , Mahieu Géraldine , Rillaers Alexandra 
Published: September 2004

AbstractWe analyze the impact of a drop in fertility on the optimal allocation of resources in an overlapping generations economy where old workers care about leisure. We also characterize optimal dynamics and study the decentralization of the optimum by means of inter‐generational transfers and/or public debt. We conclude that the policy recommendations of postponing retirement is fragile and depend on preferences and technologies. Also, even when the optimal adjustment of public debt goes into the expected direction in the long run—i.e., public debt should decrease—this may not be the case during the transition.
Skin lifting in aesthetic cervicofacial rhytidectomy: personal experience in more than 1500 patients
Authors: Hodgkinson D , Tiong J 
Published: September 2004

SummaryBackground  Skin lifting alone in face‐lifting surgery is limited to minor lifts in younger patients. The extent of skin undermining depends on the operative plan.Aims  An optimal aim is to minimize the amount of undermining to achieve a pleasing, natural rejuvenated result.Results  By respecting the extensive network of the dermal vascular plexus and by good surgical technique, ischaemia of the elevated skin may be minimized.Conclusion  Moderate to maximal lifting, however, has proven to be anatomically sound in over 1500 cases operated on over the last 20 years using classical face‐lift techniques to correct the pathoanatomy of the ageing face.
Sensitive skin: a complex and multifactorial syndrome
Authors: Pons‐Guiraud A 
Published: September 2004

SummaryMany people complain of discomfort after application of commonly used skin care products, particularly to the face. This hyperreactivity of the skin is a non‐immunologically mediated skin inflammation. It seems to be the result of an intolerance of the skin to various stimuli that are normally well tolerated. It is difficult to assess the prevalence of ‘sensitive skin’ and sensitive skin‐related cosmetic intolerance because of the many possible exogenous and endogenous factors that trigger or aggravate this multifactorial syndrome. A thorough history is essential. Sometimes patch testing is needed both to standard allergens and also to all the patients’ cosmetics and skin care products. All cosmetics should be stopped and then reintroduced one by one, at intervals of one to two weeks. The number, type and frequency of the application of skin care products used in the final programme should remain limited. Some patients benefit from psychological or even psychiatric help. Management is usually difficult and all therapeutic measures should be undertaken with patience and tenacity.
Human Cytomegalovirus Inhibits Cytokine-Induced Macrophage Differentiation
Authors: Gredmark Sara , Tilburgs Tamara , Söderberg-Nauclér Cecilia 
Published: September 2004

ABSTRACTHuman cytomegalovirus (HCMV) infection in immunocompromised patients is associated with impaired immunological function. Blood monocytes, which differentiate into macrophage effector cells, are of central importance for immune reactivity. Here, we demonstrate that HCMV transiently blocks cytokine-induced differentiation of monocytes into functionally active phagocytic macrophages. In HCMV-treated cultures, the cells had classical macrophage markers but lacked the classical morphological appearance of macrophages and had impairments in migration and phagocytosis. Even at very low multiplicities of infection, macrophage differentiation was almost completely inhibited. The inhibition appeared to be mediated by a soluble factor released upon viral treatment of monocytes. Human immunodeficiency virus or measles virus had no such effects. These findings suggest that HCMV impairs immune function by blocking certain aspects of cytokine-induced differentiation of monocytes and demonstrate an efficient pathway for this virus to evade immune recognition that may have clinical implications for the generalized immunosuppression often observed in HCMV-infected patients.
RNAs Are Packaged into Human Cytomegalovirus Virions in Proportion to Their Intracellular Concentration
Authors: Terhune Scott S. , Schröer Jörg , Shenk Thomas 
Published: September 2004

ABSTRACT

The assembly of human cytomegalovirus (HCMV) virions is a complex process and involves the incorporation of viral transcripts. These RNAs are delivered to the newly infected cells and have the potential to be translated in the absence of HCMV gene expression. We have quantified the relative amount of RNAs in HCMV virions and infected cells with real-time reverse transcription-PCR and observed that viral and cellular RNAs are packaged in proportion to the amount of RNA within the cell at the time of assembly. To determine whether
cis
elements influenced RNA packaging, we constructed a recombinant HCMV mutant virus that expressed the yellow fluorescence protein (YFP) gene fused to the virion RNA UL21.5. We also constructed a mutant virus in which the UL21.5 transcription unit was replaced with the YFP gene. YFP RNA was incorporated into both viruses, indicating that RNA is incorporated in the absence of a virus-specific signal motif. Furthermore, with in situ hybridization, packaged transcripts were observed throughout the cytoplasm of the infected cells, including the site of virus assembly. Several proteins that nonspecifically interact with RNA, including the tegument protein pp28, were found within HCMV virions. These studies demonstrate that both viral and cellular RNAs are nonspecifically incorporated into HCMV, potentially through interactions with several virion proteins.