bluuebunny/crossref_metadata_2025_split huggingface dataset:
Welche Faktoren sind mit subjektiver Belastung und Depressivität bei Pflegepersonen kognitiv beeinträch tigter älterer Menschen assoziiert?
Authors: Schäufele Martina , Köhler Leonore , Lode Sandra , Weyerer Siegfried 
Published: March 2008

Ziele: Ziel der vorliegenden Studie war es, erstmals für Deutschland repräsentative Daten zur Situation von privaten Pflegepersonen kognitiv beeinträchtigter älterer Menschen bereit zu stellen. Dabei sollten (modifizierbare) Faktoren ermittelt werden, die mit der subjektiven Belastung und Depressivität der Pflegenden assoziiert sind. Methode: Ausgehend von einer Zufallsstichprobe der deutschen Bevölkerung (N = 52,916) wurden alle über 60-jährigen Personen mit mindestens einer (I)ADL-Beeinträchtigung und kognitiven Auffälligkeiten kontaktiert. Die teilnehmenden Personen und ihre Hauptpflegepersonen (HPP) wurden mittels eines standardisierten Instrumentariums, das u. a. die Häusliche Pflegeskala (subjektive Belastung) und die Allgemeine Depressionsskala (Depressivität) enthielt, befragt. Ergebnisse: Die HPP der gepflegten Personen waren zumeist nahe Familienangehörige (N = 262; mittleres Alter = 61 Jahre; 73 % Frauen). Multivariate Regressionsanalysen erbrachten folgende Faktoren, die signifikant mit erhöhten Belastungs- und erhöhten Depressivitätswerten bei den HPP assoziiert waren: schwerere nicht kognitive Symptomatik (z. B. Apathie, Depression, Agitiertheit/Aggression) bei der gepflegten Person und weibliches Geschlecht der HPP. Verminderte Belastungs- und Depressionswerte resultierten, wenn die HPP die Wahrnehmung hatte, von ihrem privaten Umfeld gut unterstützt zu werden. Schlussfolgerungen: Maßnahmen zur Prävention und Linderung nicht kognitiver Symptome bei den gepflegten Personen sowie kognitive und andere psychosoziale Interventionen bei den Pflegenden könnten die HPP entlasten und die häusliche Pflege kognitiv beeinträchtigter älterer Menschen insgesamt fördern.
«In guten wie in schlechten Zeiten ...»
Authors: Kofahl Christopher , Arlt Sönke , Mnich Eva 
Published: March 2008

Die Pflege von älteren betreuungsbedürftigen Menschen wird mehrheitlich von Angehörigen wie Lebenspartner und Kinder oder von anderen nahestehenden Personen übernommen. Nur wenige Studien vergleichen die aus der Pflege resultierende Belastung von Lebenspartnern mit der von anderen, meist jüngeren pflegenden Angehörigen. Die vorliegende Untersuchung basiert auf der deutschen Stichprobe des EU-geförderten Projektes EUROFAMCARE. In diese wurden 1003 betreuende Angehörige eingeschlossen, von denen 908 den Bedingungen der ambulanten Versorgung unterlagen. Diese wurden zu ihrer Beziehung zur betreuungsbedürftigen Person, zu ihren Motiven, der empfundenen Belastung (COPE-Index) und Lebensqualität (SF-36, WHO-5) untersucht. Hierbei wurde insbesondere auf die Situation pflegender Lebenspartner im Vergleich zu Pflegepersonen anderer Verwandtschaftsgrade fokussiert. Insgesamt wird die Mehrzahl der zu pflegenden Personen von weiblichen Angehörigen (76 %) versorgt, 19 % der Pflegepersonen waren Ehepartner oder Lebensgefährten. Hauptbetreuungsmotive waren eine enge Bindung oder das Gefühl der moralischen Verpflichtung. Lebenspartner zeigten eine höhere Belastung durch die Pflege und eine schlechtere Lebensqualität als andere Betreuungsgruppen. Faktoren, die mit einer erhöhten Pflegebelastung einhergehen, waren unter anderem Verhaltensauffälligkeiten der zu pflegenden Person, fehlende soziale Unterstützung und eigene gesundheitliche Probleme. Die Ergebnisse der Untersuchung legen nahe, dass insbesondere pflegende Lebenspartner sowie emotional stark beteiligte Familienmitglieder des engeren Familienkreises unter der Pflegebelastung zu leiden haben. Aufgrund ihrer starken Betroffenheit sollte ihre Rolle in der Beurteilung des Pflegebedarfs z. B. im Rahmen der SGB XI-Pflegebedürftigkeitsbegutachtung oder in der ärztlichen wie pflegerischen Sozialanamnese der betreuungsbedürftigen Personen eine stärkere Berücksichtigung erfahren und entsprechende psychosoziale Beratungsangebote vermittelt werden.
Lactoferrin receptor mediates apo- but not holo-lactoferrin internalization via clathrin-mediated endocytosis in trophoblasts
Authors: Lopez Veronica , Kelleher Shannon L. , Lönnerdal Bo 
Published: March 2008

LfR [Lf (lactoferrin) receptor] is expressed in most mammalian tissues, including placental trophoblasts, and is presumed to mediate the internalization of Lf. However, the physiological significance of trophoblast LfR is not understood. Using the CT (cytotrophoblast) cell model BeWo, we demonstrated that transfection with LfR siRNA (small interfering RNA) significantly decreased apo- but not holo-Lf uptake compared with mock-transfected controls and that apo- but not holo-Lf significantly increased MMP (matrix metalloproteinase)-2 activity. As Lf functionality is related to the presence (holo-Lf) or absence (apo-Lf) of iron within the Lf molecule, our results suggest that apo-Lf may play a role in cellular invasion. Moreover, we detected LfR (∼105 kDa) in association with the plasma membrane, and ligand blotting confirmed that Lf binds to a LfR of ∼105 kDa. Apo-Lf treatment significantly increased LfR abundance at the plasma membrane and internalization probably occurs via clathrin-mediated endocytosis through early and recycling endosomes, as LfR was co-localized with EEA1 (early endosome antigen 1) and TfR (transferrin receptor) using confocal microscopy, and hypertonic medium (0.4 M sucrose) significantly inhibited apo-Lf internalization. In summary, our data demonstrate that apo- but not holo-Lf is internalized by LfR and suggest that, following internalization via LfR, apo-Lf plays a role in CT invasiveness by inducing MMP-2 activity. Moreover, LfR facilitates apo-Lf uptake specifically through clathrin-mediated endocytosis into early endosomes and potentially into a recycling pathway. Taken together, our data provide a new dimension in understanding ligand-dependant function that may be directly related to the ability of LfR to selectively internalize apo- but not holo-Lf.
Quantification of PtdIns(3,4,5)P3 dynamics in EGF-stimulated carcinoma cells: a comparison of PH-domain-mediated methods with immunological methods
Authors: Yip Shu-Chin , Eddy Robert J. , Branch Angie M. , Pang Huan , Wu Haiyan , Yan Ying , Drees Beth E. , Neilsen Paul O. , Condeelis John , Backer Jonathan M. 
Published: March 2008

Class IA PI3Ks (phosphoinositide 3-kinases) generate the secondary messenger PtdIns(3,4,5)P3, which plays an important role in many cellular responses. The accumulation of PtdIns(3,4,5)P3 in cell membranes is routinely measured using GFP (green fluorescent protein)-labelled PH (pleckstrin homology) domains. However, the kinetics of membrane PtdIns(3,4,5)P3 synthesis and turnover as detected by PH domains have not been validated using an independent method. In the present study, we measured EGF (epidermal growth factor)-stimulated membrane PtdIns(3,4,5)P3 production using a specific monoclonal anti-PtdIns(3,4,5)P3 antibody, and compared the results with those obtained using PH-domain-dependent methods. Anti-PtdIns(3,4,5)P3 staining rapidly accumulated at the leading edge of EGF-stimulated carcinoma cells. PtdIns(3,4,5)P3 levels were maximal at 1 min, and returned to basal levels by 5 min. In contrast, membrane PtdIns(3,4,5)P3 production, measured by the membrane translocation of an epitope-tagged BTKPH (PH domain of Bruton's tyrosine kinase), remained approx. 2-fold above basal level throughout 4–5 min of EGF stimulation. To determine the reason for this disparity, we measured the rate of PtdIns(3,4,5)P3 hydrolysis by measuring the decay of the PtdIns(3,4,5)P3 signal after LY294002 treatment of EGF-stimulated cells. LY294002 abolished anti-PtdIns(3,4,5)P3 membrane staining within 10 s of treatment, suggesting that PtdIns(3,4,5)P3 turnover occurs within seconds of synthesis. In contrast, BTKPH membrane recruitment, once initiated by EGF, was relatively insensitive to LY294002. These data suggest that sequestration of PtdIns(3,4,5)P3 by PH domains may affect the apparent kinetics of PtdIns(3,4,5)P3 accumulation and turnover; consistent with this hypothesis, we found that GRP-1 (general receptor for phosphoinositides 1) PH domains [which, like BTK, are specific for PtdIns(3,4,5)P3] inhibit PTEN (phosphatase and tensin homologue deleted on chromosome 10) dephosphorylation of PtdIns(3,4,5)P3in vitro. These data suggest that anti-PtdIns(3,4,5)P3 antibodies are a useful tool to detect localized PtdIns(3,4,5)P3, and illustrate the importance of using multiple approaches for the estimation of membrane phosphoinositides.
Structural basis for mannose recognition by a lectin from opportunistic bacteria Burkholderia cenocepacia
Authors: Lameignere Emilie , Malinovská Lenka , Sláviková Margita , Duchaud Eric , Mitchell Edward P. , Varrot Annabelle , Šedo Ondrej , Imberty Anne , Wimmerová Michaela 
Published: March 2008

Chronic colonization of the lungs by opportunist bacteria such as Pseudomonas aeruginosa and members of the Bcc (Burkholderia cepacia complex) is the major cause of morbidity and mortality among CF (cystic fibrosis) patients. PA-IIL (lecB gene), a soluble lectin from Ps. aeruginosa, has been the subject of much interest because of its very strong affinity for fucose. Orthologues have been identified in the opportunist bacteria Ralstonia solanacearum, Chromobacterium violaceum and Burkholderia of Bcc. The genome of the J2315 strain of B. cenocepacia, responsible for epidemia in CF centres, contains three genes that code for proteins with PA-IIL domains. The shortest gene was cloned in Escherichia coli and pure recombinant protein, BclA (B. cenocepacia lectin A), was obtained. The presence of native BclA in B. cenocepacia extracts was checked using a proteomic approach. The specificity of recombinant BclA was characterized using surface plasmon resonance showing a preference for mannosides and supported with glycan array experiments demonstrating a strict specificity for oligomannose-type N-glycan structures. The interaction thermodynamics of BclA with methyl α-D-mannoside demonstrates a dissociation constant (Kd) of 2.75×10−6 M. The X-ray crystal structure of the complex with methyl α-D-mannoside was determined at 1.7 Å (1 Å=0.1 nm) resolution. The lectin forms homodimers with one binding site per monomer, acting co-operatively with the second dimer site. Each monomer contains two Ca2+ ions and one sugar ligand. Despite strong sequence similarity, the differences between BclA and PA-IIL in their specificity, binding site and oligomerization mode indicate that the proteins should have different roles in the bacteria.
Crystal structure and kinetic study of dihydrodipicolinate synthase from Mycobacterium tuberculosis
Authors: Kefala Georgia , Evans Genevieve L. , Griffin Michael D. W. , Devenish Sean R. A. , Pearce F. Grant , Perugini Matthew A. , Gerrard Juliet A. , Weiss Manfred S. , Dobson Renwick C. J. 
Published: March 2008

The three-dimensional structure of the enzyme dihydrodipicolinate synthase (KEGG entry Rv2753c, EC 4.2.1.52) from Mycobacterium tuberculosis (Mtb-DHDPS) was determined and refined at 2.28 Å (1 Å=0.1 nm) resolution. The asymmetric unit of the crystal contains two tetramers, each of which we propose to be the functional enzyme unit. This is supported by analytical ultracentrifugation studies, which show the enzyme to be tetrameric in solution. The structure of each subunit consists of an N-terminal (β/α)8-barrel followed by a C-terminal α-helical domain. The active site comprises residues from two adjacent subunits, across an interface, and is located at the C-terminal side of the (β/α)8-barrel domain. A comparison with the other known DHDPS structures shows that the overall architecture of the active site is largely conserved, albeit the proton relay motif comprising Tyr143, Thr54 and Tyr117 appears to be disrupted. The kinetic parameters of the enzyme are reported: KMASA=0.43±0.02 mM, KMpyruvate=0.17±0.01 mM and Vmax=4.42±0.08 μmol·s−1·mg−1. Interestingly, the Vmax of Mtb-DHDPS is 6-fold higher than the corresponding value for Escherichia coli DHDPS, and the enzyme is insensitive to feedback inhibition by (S)-lysine. This can be explained by the three-dimensional structure, which shows that the (S)-lysine-binding site is not conserved in Mtb-DHDPS, when compared with DHDPS enzymes that are known to be inhibited by (S)-lysine. A selection of metabolites from the aspartate family of amino acids do not inhibit this enzyme. A comprehensive understanding of the structure and function of this important enzyme from the (S)-lysine biosynthesis pathway may provide the key for the design of new antibiotics to combat tuberculosis.
Lipid phosphate phosphatases form homo- and hetero-oligomers: catalytic competency, subcellular distribution and function
Authors: Long Jaclyn S. , Pyne Nigel J. , Pyne Susan 
Published: March 2008

Lipid phosphate phosphatases (LPP1–LPP3) have been topographically modelled as monomers (molecular mass of 31–36 kDa) composed of six transmembrane domains and with the catalytic site facing the extracellular side of the plasma membrane or the luminal side of intracellular membranes. The catalytic motif has three conserved domains, termed C1, C2 and C3. The C1 domain may be involved in substrate recognition, whereas C2 and C3 domains appear to participate in the catalytic dephosphorylation of the substrate. We have obtained three lines of evidence to demonstrate that LPPs exist as functional oligomers. First, we have used recombinant expression and immunoprecipitation analysis to demonstrate that LPP1, LPP2 and LPP3 form both homo- and hetero-oligomers. Secondly, large LPP oligomeric complexes that are catalytically active were isolated using gel-exclusion chromatography. Thirdly, we demonstrate that catalytically deficient guinea-pig FLAG-tagged H223L LPP1 mutant can form an oligomer with wild-type LPP1 and that wild-type LPP1 activity is preserved in the oligomer. These findings suggest that, in an oligomeric arrangement, the catalytic site of the wild-type LPP can function independently of the catalytic site of the mutant LPP. Finally, we demonstrate that endogenous LPP2 and LPP3 form homo- and hetero-oligomers, which differ in their subcellular localization and which may confer differing spatial regulation of phosphatidic acid and sphingosine 1-phosphate signalling.
The human SIRT3 protein deacetylase is exclusively mitochondrial
Authors: Cooper Helen M. , Spelbrink Johannes N. 
Published: March 2008

It has recently been suggested that perhaps as many as 20% of all mitochondrial proteins are regulated through lysine acetylation while SIRT3 has been implicated as an important mitochondrial protein deacetylase. It is therefore of crucial importance that the mitochondrial localization of potential protein deacetylases is unambiguously established. Although mouse SIRT3 was recently shown to be mitochondrial, HsSIRT3 (human SIRT3) was reported to be both nuclear and mitochondrial and to relocate from the nucleus to the mitochondrion upon cellular stress. In the present study we show, using various HsSIRT3 expression constructs and a combination of immunofluorescence and careful subcellular fractionation, that in contrast with earlier reports HsSIRT3 is exclusively mitochondrial. We discuss possible experimental explanations for these discrepancies. In addition we suggest, on the basis of the analysis of public genome databases, that the full-length mouse SIRT3 protein is a 37 kDa mitochondrial precursor protein contrary to the previously suggested 29 kDa protein.
The pluripotency rheostat Nanog functions as a dimer
Authors: Mullin Nicholas P. , Yates Adam , Rowe Arthur J. , Nijmeijer Bianca , Colby Douglas , Barlow Paul N. , Walkinshaw Malcolm D. , Chambers Ian 
Published: March 2008

The defining activity of the homeodomain protein Nanog is the ability to confer cytokine-independent self-renewal upon ES (embryonic stem) cells in which it is overexpressed. However, the biochemical basis by which Nanog achieves this function remains unknown. In the present study, we show that Nanog dimerizes through a functionally critical domain. Co-immunoprecipitation of Nanog molecules tagged with distinct epitopes demonstrates that Nanog self-associates through a region in which every fifth residue is tryptophan. In vitro binding experiments establish that this region participates directly in self-association. Moreover, analytical ultracentrifugation indicates that, in solution, Nanog is in equilibrium between monomeric and dimeric forms with a Kd of 3 μM. The functional importance of Nanog dimerization is established by ES cell colony-forming assays in which deletion of the tryptophan-repeat region eliminates the capacity of Nanog to direct LIF (leukaemia inhibitory factor)-independent self-renewal.
Longitudinal and Radial Gradients of PO2 in the Hamster Cheek Pouch Microcirculation
Authors: Carvalho Helena , Pittman Roland N. 
Published: April 2008

ABSTRACTObjectives: The aim of this study was to determine longitudinal and radial gradients in oxygen tension (PO2) in microvessels of the hamster cheek pouch.Methods: We measured PO2 using the phosphorescence‐quenching method in two orders of arterioles (45.8 ± 5.5 and 19.9 ± 1.8 μ m diameter), capillaries, and two orders of venules (50.5 ± 3.4 and 21.4 ± 2.0 μ m diameter) in order to determine the longitudinal PO2 gradient. At the arteriolar and venular sites, we also measured PO2 at four different sites for an analysis of radial PO2 gradients: centerline, inside wall (larger arteriole and venule only), outside wall, and interstitium. We used 10 hamsters weighing 115 ± 27 g anesthetized with pentobarbital intraperitoneally and maintained with alpha‐chloralose intravenously. The cheek pouch was everted and a single‐layered preparation was studied by intravital microscopy. Albumin‐bound Pd‐porphyrin was infused into the circulation and excited by flash illumination at 10 Hz, with a rectangular diaphragm limiting the excitation field to 5 × 25 μ m.Results: In the longitudinal direction, intravascular PO2 decreased significantly (P < 0.01) from large arterioles (39.5 ± 2.3 mmHg) to small arterioles (32.2 ± 0.3 mmHg), then to capillaries (30.2 ± 1.8 mmHg), and on to small venules (27.3 ± 2.1 mmHg) and large venules (25.5 ± 2.2 mmHg). In the radial direction, PO2 decreased significantly (P < 0.01) in and around larger arterioles, and to a lesser extent, around the smaller ones (P < 0.05). There was no significant PO2 gradient, longitudinal or radial, associated with venules. The PO2 difference from the centerline to the outside wall in large arterioles was 8.3 ± 1.4 mmHg, and most of the decline in PO2 in the radial direction was contributed by the intravascular difference (4.7 ± 2.1 mmHg) and only about 1.0 ± 2.7 mmHg by the transmural difference.Conclusions: Our data show that there are large intra‐arteriolar radial PO2 gradients, but no large transmural PO2 differences, suggesting that the oxygen consumption of the microvessel wall is not exceptionally high.
Xanthine Oxidase Interaction with Vascular Endothelial Growth Factor in Human Endothelial Cell Angiogenesis
Authors: Kou Baijun , Ni Jinsong , Vatish Manu , Singer Donald R. J. 
Published: April 2008

ABSTRACTObjectives: Reduced capillary density occurs early in cardiovascular diseases. Oxidant stress is implicated in endothelial apoptosis. We investigated the effects of xanthine oxidase (XO) on endothelial survival signaling: protein kinase B/Akt, its cross‐talk with p38 MAPK and apoptosis pathways, and its effect on vascular tube formation in vascular endothelial growth factor (VEGF)‐simulated human umbilical vein cells.Methods: We studied primary cultured human endothelial cells from the umbilical cord. Reactive oxygen species (ROS) production was detected by dihydroethidium staining, cell‐signaling pathways by western blots, cell survival by western blots, and nuclear chromatin and angiogenesis response by MTT proliferation assay and three‐dimensional Matrigel cultures.Results: Exogenous XO increased cellular ROS production and caused superoxide‐dependent inhibition of Akt phosphorylation and enhancement of p38 MAPK phosphorylation in a time‐and dose‐dependent manner. In contrast, application of the XO inhibitor oxypurinol or allopurinol inhibited VEGF‐stimulated Akt phosphorylation, indicating that endogenous XO promotes VEGF‐induced endothelial cell (EC) survival signaling. Exogenous XO induced activation of caspase‐3 and reduced expression of the anti‐apoptosis protein Bcl‐2. Exogenous XO also reduced EC viability, proliferation, and vascular tube formation by p38 MAPK‐dependent, phosphoinositide 3‐kinase (PI3‐K) reversible mechanisms; whereas VEGF promoted EC survival by PI3‐K‐dependent, p38 MAPK‐independent effects.Conclusions: Exogenous XO activity is an important contributor to endothelial mechanisms for microvascular rarefaction, by modulation of cell survival signaling pathways; however, endogenous XO is necessary for maintaining EC survival.
Structure and ligand binding of the soluble domain of a Thermotoga maritima membrane protein of unknown function TM1634
Authors: McCleverty Clare J. , Columbus Linda , Kreusch Andreas , Lesley Scott A. 
Published: March 2008

AbstractAs a part of the Joint Center for Structural Genomics (JCSG) biological targets, the structures of soluble domains of membrane proteins from Thermotoga maritima were pursued. Here, we report the crystal structure of the soluble domain of TM1634, a putative membrane protein of 128 residues (15.1 kDa) and unknown function. The soluble domain of TM1634 is an α‐helical dimer that contains a single tetratrico peptide repeat (TPR) motif in each monomer where each motif is similar to that found in Tom20. The overall fold, however, is unique and a DALI search does not identify similar folds beyond the 38‐residue TPR motif. Two different putative ligand binding sites, in which PEG200 and Co2+ were located, were identified using crystallography and NMR, respectively.
Overexpression of osteopontin in clear cell carcinoma of the ovary: close association with HNF‐1β expression
Authors: Kato N , Motoyama T 
Published: April 2008

Aims: Transcription factor hepatocyte nuclear factor (HNF)‐1β is selectively expressed in clear cell carcinoma (CCC) of the ovary. One of the potential HNF‐1β target genes is osteopontin (OPN). Although elevation of OPN mRNA has been reported in CCC, it remains unclear whether CCC cells overexpress OPN protein. The aim was to investigate the expression of OPN protein and its correlation with HNF‐1β status in CCC.Methods and results: Three CCC and two serous adenocarcinoma (SA) cell lines were evaluated for expression of OPN by reverse transcriptase‐polymerase chain reaction and immunocytochemistry. OPN expression, at both the mRNA and protein levels, was higher in the three CCCs than in the two SAs. HNF‐1β expression was detected in the CCCs but not in the SAs. Subsequently, 60 surgical specimens (30 CCCs and 30 SAs) were examined immunohistochemically for expression of OPN and HNF‐1β. All 30 CCCs showed immunopositivity for both OPN and HNF‐1β. The 12 (40%) CCCs with a high OPN score all had a high HNF‐1β score. In contrast, SAs rarely showed immunoreactivity for OPN or HNF‐1β.Conclusions: OPN expression is elevated in ovarian CCC and is closely associated with HNF‐1β overexpression. HNF‐1β is likely to participate in OPN up‐regulation in CCC.