julilili42/papers huggingface dataset:
The Unique Cellular Interaction between the Leaf Pathogen Cymadothea trifolii and Trifolium repens
2004-11-01

AbstractCellular interactions between the ascomycete Cymadothea trifolii and Trifolium repens (white clover) were analyzed using high-pressure freezing and freeze substitution. Cymadothea trifolii, a biotrophic leaf pathogen, forms a unique structure within its own hyphae, presumably for nutrient uptake from its host. This structure, called an interaction apparatus, consists of long, thin, often net-like cisternae surrounded by a membrane continuous with the fungal plasma membrane. The plant plasmalemma opposite the interaction apparatus invaginates to produce a host bubble. The interaction apparatus and host bubble are apoplastic and are linked by a tube with an electron dense sheath that may channel nutrients from the host to the pathogen. Within the tube, the cell walls of host and parasite appear altered. The interaction apparatus and host bubble may be analogous to haustoria in other obligately biotrophic fungi while the electron dense sheath of the tube may be equivalent to the haustorial neckband.Keywordscell wallcloverfreeze substitutionhigh-pressure freezinghost-parasite interactioninteraction apparatus We would like to express our gratitude to R. Kirschner for specimens of C. trifolii, H. Schwarz for his help with cryofixation and freeze substitution and Y. Stierhof and U. Nehls for many inspiring discussions. The valuable technical assistance of E. Wagner-Eha, F. Albrecht and H. Steigerle is appreciated greatly. We also thank the reviewers for their helpful suggestions. This work was financed by a DFG-fellowship to U. Simon (Graduate College “Infection Biology” 685).
High resolution electron beam lithography using a chemically amplified calix[4]arene based resist
2004-11-01

The calix[4]arene based resist tetrakis(oxiran-2-ylmethoxy)-tetra-tert-butylcalix[4]arene is presented. The well known chemical amplification techniques can be applied to the nonpolymeric class of calixarenes resulting in area doses below 100μC∕cm2 at 30keV beam energy. This is achieved by application of the concept of cationic polymerization to a calix[4]arene derivative bearing four epoxide residues together with a photoacid generating triarylsulfonium salt. The high resolution capabilities of this calixarene based resist remain mainly intact under optimized bake parameters.
Endothelin-1 Regulates Protein Kinase C Isoforms Differently in Smooth Muscle Cells and in Cardiomyocytes
2004-11-01

Endothelin-1 (ET-1) is known to increase the mitotic response of different growth factors but also to different vasoactive hormones already at threshold concentrations. The aim of this study was to investigate the influence of chronic elevated ET-1 concentrations on protein kinase C (PKC) isoforms in vitro and in vivo. Smooth muscle cells were incubated with ET-1 at a concentration of 10 mol/L. The incubation lasted for 1-96 hours. For in vivo studies, rats were chronically infused with ET-1 for 4 weeks using minipumps. Specific antibodies were used to determine the amount of PKC isoform in western blots. Incubation of smooth muscle cells with ET-1 revealed an increase in PKC-alpha (48 hours, 314 +/- 31.7%). In vivo PKC-alpha was augmented to 166 +/- 17.5%. In vitro PKC-epsilon showed an elevated concentration after 18 hours of 213 +/- 15.9% (maximum, 339 +/- 4.5% at 72 hours). In vivo PKC-epsilon was elevated to 162 +/- 4.2%. In the immunofluorescence microscopy after 48 hours of ET-1 incubation PKC-alpha was localized in the cytoplasm. Addition of angiotensin II resulted in a translocation of it into the nucleus. These data show that chronic elevated ET-1 concentrations modulate PKC isoforms. This might explain the increased response to different vasoactive hormones after ET-1 incubation.
SHORT REPORT: EVALUATION OF A SIMPLE AND INEXPENSIVE PHOTOMETRIC DEVICE FOR THE MEASUREMENT OF HEMOGLOBIN
2004-11-01

We have evaluated the accuracy of a simple and inexpensive photometric device (DHT) for the estimation of the blood concentration of hemoglobin by comparison with an automated, high-resolution, flow cytometry-based hematology analyzer (CellDyn 3000) and a centrifugal quantitative buffy coat hematology system (QBC I). We have analyzed the hemoglobin values of 163 individual blood samples. Bland-Altman analysis showed that the methods agreed only poorly: mean differences were 1.0 g/dL with limits of agreement (LOA) of −1.2 g/dL to 3.2 g/dL for the comparison of DHT and CellDyn measurements, 0.5 g/dL with LOA of -2.0 g/dL to 3.0 g/dL for the comparison of DHT with QBC measurements, and 0.5 g/dL with LOA of −1.1 g/dL to 2.1 g/dL for the comparison of QBC with CellDyn measurements. We conclude that the poor agreement of the DHT with the CellDyn does not permit the use of the DHT for critical hemoglobin measurements, particularly in transfusion services.
Optimum mode of operation for a low energy focused ion beam system
2004-11-01

The system design and mode of operation for a dedicated low energy focused ion beam system based on immersion optics is presented. The ion beam is accelerated using a gun lens and the intermediate lens space is set on high potential. Beam retarding to the landing energy is accomplished within the objective lens. With this design the target is field free and can be kept on ground potential. As all voltage levels are comparatively low, both gun as well as objective lens can be operated in accel mode, thus improving system performance. The influence of Coulomb interactions is also taken into account. Calculations predict a spot size of approximately 80nm and a corresponding probe current density of 1A∕cm2 at a working distance of 15mm and a final beam energy of 3keV, respectively.
Influence of Endothelin Receptor Antagonism on Smooth Muscle Cell Proliferation After Chronic Renal Failure
2004-11-01

Uremic patients suffer from an accelerated development of atherosclerosis. In uremia the angiotensin-aldosterone-endothelin system is activated. It is not known, however, whether endothelin receptor antagonism inhibits atherosclerosis in uremia. An experimental model of mild renal insufficiency is subtotal nephrectomy in rats. The aim of this study was to assess the proliferative response of vascular smooth muscle cells from rats that have undergone subtotal nephrectomy and are treated with an endothelin-A or combined endothelin-A/endothelin-B receptor antagonist to the proatherogenic growth factors platelet-derived growth factor-BB and basic fibroblast growth factor. For 12 weeks 5/6-nephrectomized rats were treated with the endothelin-A receptor antagonist LU 302146 or the combined endothelin-A/endothelin-B receptor antagonist LU 302872 (10 mg/kg bodyweight)or received no medication (subtotal nephrectomy). Aortal smooth muscle cells were isolated and cultivated. After incubation with platelet-derived growth factor-BB (10(-13)-10(-9) mol/L for 5 days) or basic fibroblast growth factor (10(-14)-10(-10) mol/L for 7 days) proliferation was measured using bromodeoxyuridine enzyme-linked immunosorbent assay. Both growth factors increased proliferation in vascular smooth muscle cells from untreated subtotally nephrectomized rats (platelet-derived growth factor-BB10(-9) mol/L: 487%, basic fibroblast growth factor 10(-10) mol/L:175%). Treatment with the endothelin-A receptor antagonist resulted in a reduced proliferation (platelet-derived growth factor-BB: 137%, basic fibroblast growth factor: 109%). After treatment with the combined endothelin-A/endothelin-B receptor antagonist findings were similar (platelet-derived growth factor-BB: 123%,basic fibroblast growth factor: 110%). These data demonstrate that chronic endothelin-A and combined endothelin-A/endothelin-B receptor antagonism inhibits vascular smooth muscle cell proliferation in rats treated with subtotal nephrectomy. This indicates a regulatory influence of these drugs on gene transcription and supports the importance of early treatment to inhibit coronary artery disease in uremic patients.
Endothelin-1 Increases Serum-glucocorticoid-regulated Kinase-1 Expression in Smooth Muscle Cells
2004-11-01

The mechanism of salt-sensitive hypertension is not fully understood. Several studies point to a possible role of endothelin (ET)-1 in this form of hypertension. Serum-regulated and glucocorticoid-regulated kinase-1 (SGK1) mediates trafficking of the renal epithelial sodium channel. The aim of the study was to find out whether ET-1 regulates SGK1. Rat smooth muscle cells were incubated with ET-1 (10(-7) M, 0-120 minutes). After 30 minutes a significant increase in SGK1 mRNA was found (122 +/- 4.2%), and a maximum was reached after 120 minutes (217 +/- 7.6%). Incubation of smooth muscle cells with ET-1 (10(-7) mol/L) in the presence of an ETA receptor antagonist inhibited SGK1 gene transcription (93 +/- 3.7%). Western blot analysis showed a time-dependent increase in SGK1 protein in smooth muscle cells. These data indicate that ET-1 increases SKG1 mRNA and protein concentration. Inhibition of ET-1 by ET antagonism prevented a SGK1 increase. Therefore, ET antagonism might influence blood pressure by regulating the sodium balance through reducing SGK1 gene expression.
Political implications of cultural evolution
2004-11-01

In the course of cultural evolution, certain institutions have emerged and become dominant in the Western world that have led to an unprecedented rise in prosperity and population. This paper first explains the characteristics and significance of cultural evolution. Subsequently, it explains the fundamental role of politics and the scope for political action in cultural evolution, clearing up some fairly widespread misconceptions about this question. Finally, it derives three specific guidelines from the characteristics of cultural evolution that should be followed in politics. First, the principle of individual freedom should be realized as far as possible. Second, the rule of law should be secured. Third, the scope of action of the state should be closely limited and the state should be decentrally organized. The more consistently these guidelines are followed, the better the prospects of the respective society to survive and prosper in the competitive process of cultural evolution.
Why Quarks are Different from Leptons – An Explanation by a Fermionic Substructure of Leptons and Quarks
2004-11-01

To explain the difference between leptons and quarks, it is assumed that electroweak gauge bosons, leptons and quarks are composites of elementary fermionic constituents denoted by partons (not to be identified with quarks) or subfermions, respectively. The dynamical law of these constituents is assumed to be given by a relativistically invariant nonlinear spinor field theory with local interaction, canonical quantization, selfregularization and probability interpretation. According to the general requirements of field operator algebraic theory, this model is formulated in algebraic Schroedinger representation referred to generating functionals in functional state spaces. The derivation of the corresponding effective dynamics for the composite particles is studied by the construction of a map between the spinor field state functionals and the state functionals of the effective theory for gauge bosons, leptons and quarks. A closer examination of this map shows that it is then and then only selfconsistent if certain boundary conditions are satisfied. The latter enforce in the case of electroweak symmetry breaking the difference between lepton and quark states. This difference can be analytically expressed as conditions to be imposed on the wave functions of these composite particles and leads ultimately to the introduction and interpretation of color for quarks, i.e., the characteristic of their strong interaction
Nematococcomyces rhododendri, a New Species in a New Genus of the Rhytismatales from China
2004-11-01

A fungus belonging to the Rhytismatales found on twigs of Rhododendron lutescens in Yunnan, southwestern China, is described as a new species in a new genus. It is characterized by Coccomyces-like ascomata but differs in having elliptical ascospores with filiform, hyaline appendages. The ascospores of this new taxon are somewhat similar to those of species of Parvacoccum, but the latter has symmetrical, fusiform ascospores with funnel-shaped appendages. The new genus also is distinct from Hypoderma, Hypodermella, Myriophacidium, Ploioderma, Neococcomyces and Therrya.
Total Synthesis of Apicularen A through Transannular Pyran Formation
2004-11-02

A macrocyclization–transannulation strategy is the crux of an efficient total synthesis of the benzolactone enamide apicularen A (see scheme; Bn=benzyl). Key steps include a four-component coupling, a Stille cross-coupling to introduce the aromatic moiety, and the formation of the enamide from a hemiaminal. The size-selective macrolactonization of the ethoxyvinyl ester shown was followed by transannular etherification in excellent yield.
Total Synthesis of Apicularen A through Transannular Pyran Formation
2004-11-02

Eine Makrocyclisierungs-Transannulierungs-Strategie bildet das Herzstück einer effizienten Totalsynthese des Benzolacton-Enamids Apicularen A (siehe Schema, Bn=Benzyl). Schlüsselschritte sind eine Vierkomponentenkupplung, eine Stille-Kreuzkupplung zur Einführung der aromatischen Einheit und die Bildung des Enamids aus einem Halbaminal. Im Anschluss an die selektive Makrolactonisierung des Ethoxyvinylesters gelang die transannulare Veretherung mit ausgezeichneter Ausbeute.
Statins Enhance Migratory Capacity by Upregulation of the Telomere Repeat-Binding Factor TRF2 in Endothelial Progenitor Cells
2004-11-03

Background— Cultivation of endothelial progenitor cells (EPCs) leads to premature replicative senescence, limiting ex vivo expansion for potential clinical cell therapy. Recent studies have linked senescence to the dysfunction of telomeres, the “ends” of chromosomes, via the so-called mitotic clock or culture-induced stress. The purpose of this study was to elucidate a possible role of telomere biology in the functional augmentation of EPCs by statins. Methods and Results— Human EPCs were isolated from peripheral blood. Using flow cytometry after fluorescence in situ hybridization with a telomere-specific (C 3 TA 2 ) 3 peptide nucleic acid probe (Flow-FISH), we found mean telomere length in untreated EPCs from healthy subjects to range between 8.5±0.2 and 11.1±0.5 kb with no change over 6 days of culture, excluding telomere erosion as one cause for premature senescence. Although mean telomere length did not differ between statin-treated and untreated EPCs, atorvastatin (0.1 μmol/L) and mevastatin (1.0 μmol/L) both led to a more than 3-fold increase in the expression of the telomere capping protein TRF2 (telomere repeat-binding factor), as shown by immunoblotting, whereas quantitative reverse transcription–polymerase chain reaction demonstrated no increase in TRF2 mRNA. Telomere dysfunction of EPCs was also paralleled by a 4-fold increase in the DNA damage checkpoint-kinase 2 (Chk2). Conversely, statin cotreatment or overexpression of TRF2 completely suppressed Chk2 induction. Finally, overexpression of a dominant negative mutant of the TRF2 protein abrogated statin-induced enhancement of migratory activity down to baseline values. Conclusions— Ex vivo culturing of EPCs leads to “uncapping” of telomeres, indicated by the loss of TRF2. Statin cotreatment of EPCs prevents impairment of their functional capacity by a TRF2-dependent, posttranscriptional mechanism. This is the first time a beneficial effect of statins on telomere biology has been described.
Rubidium spectroscopy at 778–780 nm with a distributedfeedback laser diode
2004-11-03

We have performed high resolution spectroscopy of rubidium with a single mode continuous wave distributed feedback (DFB) laser diode. The saturation spectrum of the D 2 -line of 85 Rb and 87 Rb was recorded with a resolution close to the natural line width. The emission frequency was actively stabilized to Doppler-free transitions with a relative accuracy of better than 7 parts in 10 9 using commercially available servo devices only. An output power of 80 mW was sufficient to allow for two-photon spectroscopy of the 5S-5D-transition of 87 Rb. Further, we report on the spectral properties of the DFB diode, its tuning range and its frequency modulation properties. The line width of the diode laser, determined with high resolution Doppler free two photon spectroscopy, was 4 MHz without applying any active stabilization techniques. For time scales below 5 μs the line width drops below 2 MHz.
Multislice CT in cardiac and coronary angiography
2004-11-05

In the last 2 years, mechanical multidetector-row CT (MDCT) systems with simultaneous acquisition of four slices and a half second scanner rotation time have become widely available. Data acquisition with these scanners allows for considerably faster coverage of the heart volume compared with single slice scanning. This increased scan speed can be used for retrospective gating together with 1 mm collimated slice widths and allows coverage of the entire cardiac volume in one breath-hold. First results from studies in correlation with intracoronary ultrasound suggest that MDCT technology not only offers the possibility to visualize intracoronary stenoses non-invasively, but also to differentiate plaque morphology. This is especially the case with the next generation of 16-row MDCT systems. An increased number of simultaneously acquired slices and submillimetre collimation for cardiac applications allows true isotropic scanning with high temporal resolution. Contrast-enhanced MDCT is a promising non-invasive technique for the detection, visualization and characterization of stenotic artery disease. It could act as a gatekeeper prior to cardiac catherization and finally replace conventional diagnostic modalities.
Complete structure determination ofN-acetyl-D-galactosamine-binding mistletoe lectin-3 fromViscum album L. album
2004-11-05

The primary structure of the B chain of the N-acetyl-D-galactosamine-recognizing mistletoe lectin-3 (ML-3B) has been deduced from proteolytic digest peptides of the purified glycoprotein, their HPLC-separation and Edman degradation and confirmation of the peptide sequences by MALDI-MS. ML-3B consists of 262 amino acid residues including 10 cysteine moieties. The structure and linkage of the carbohydrate side chains, connected to two N-glycosylation sites at positions Asn(95) and Asn(135) of the lectin, were determined by a combination of glycosidase treatment and MALDI-MS of corresponding glycopeptide fragments. The sequence alignment reveals a high homology with other B chains of type-II RIPs, although there are remarkable differences in the D-galactose-specific mistletoe lectin-1B chain. The recently published primary structure of the mistletoe lectin-3A chain1 and the now available primary sequence of the 3B chain allowed the construction of a preliminary homology model of ML-3. The model demonstrates, unequivocally, that ML-3 is a member of the type-II RIP family with rigid conservation of the enzymatic active site of the A chain and an identical overall protein fold. Specific amino acid residue exchanges and the different glycosylation pattern in comparison with ML-1 are discussed and related to the properties of the two glycoproteins. The knowledge of the complete primary structure of mistletoe lectin-3 is a major contribution towards more insight into the mechanism of the biological activity of commercial mistletoe preparations.
Bartonella Adhesin A Mediates a Proangiogenic Host Cell Response
2004-11-08

Bartonella henselae causes vasculoproliferative disorders in humans. We identified a nonfimbrial adhesin of B. henselae designated as Bartonella adhesin A (BadA). BadA is a 340-kD outer membrane protein encoded by the 9.3-kb badA gene. It has a modular structure and contains domains homologous to the Yersinia enterocolitica nonfimbrial adhesin (Yersinia adhesin A). Expression of BadA was restored in a BadA-deficient transposon mutant by complementation in trans. BadA mediates the binding of B. henselae to extracellular matrix proteins and to endothelial cells, possibly via β1 integrins, but prevents phagocytosis. Expression of BadA is crucial for activation of hypoxia-inducible factor 1 in host cells by B. henselae and secretion of proangiogenic cytokines (e.g., vascular endothelial growth factor). BadA is immunodominant in B. henselae–infected patients and rodents, indicating that it is expressed during Bartonella infections. Our results suggest that BadA, the largest characterized bacterial protein thus far, is a major pathogenicity factor of B. henselae with a potential role in the induction of vasculoproliferative disorders.
Nonlinear microwave response of MgB2
2004-11-08

We calculate the intrinsic nonlinear microwave response of the two gap superconductor MgB2 in the clean and dirty limits. Due to the small value of the π-band gap, the nonlinear response at low temperatures is larger than for a single gap Bardeen–Cooper–Schrieffer s-wave superconductor with a transition temperature of 40K. Comparing this result with the intrinsic nonlinear d-wave response of YBa2Cu3O7, we find a comparable response at temperatures around 20K. Due to its two gap nature, impurity scattering in MgB2 can be used to reduce the nonlinear response if the scattering rate in the π-band is made larger than the one in the σ-band.
Cytotoxic and Apoptotic Effects of Novel Heterodinucleoside Phosphates Consisting of 5‐Fluorodeoxyuridine and Ara‐C in Human Cancer Cell Lines
2004-11-08

In search for possible alternatives in the treatment of human malignancies we investigated several new heterodinucleoside phosphates consisting of 5-Fluorodeoxyuridine (5-FdUrd) and Arabinofuranosylcytosine (Ara-C). We show that all dimers tested inhibited the number of colonies of CCL228, CCL227, 5-FU resistant CCL227 and HT-29 human colon tumor cells with IC50 values ranging from 0.65 to 1 nM. Dimer # 2 inhibited the number of sensitive and Ara-C resistant H9 human lymphoma cells with IC50 values ranging from 200 to 230 nM. Since no significant difference in the cytotoxicity of the dimers could be observed between sensitive and resistant cells, these compounds might be used in the treatment of 5-FU and Ara-C resistant tumors.
Tetrasubstituted Imidazole Inhibitors of Cytokine Release:  Probing Substituents in the N-1 Position
2004-11-10

We prepared novel 1,2,4,5-tetrasubstituted imidazole derivatives with high anti-inflammatory activity by using our previously described regiospecific synthesis. Systematic optimization of the imidazole N-1 substituent resulted in compound 9b that potently inhibited the mitogen-activated protein kinase p38 (p38 IC(50) = 0.218 microM) as well as the release of the proinflammatory cytokines interleukin-1 beta (IL-1 beta) and tumor necrosis factor alpha (TNF alpha) from human whole blood after stimulation with LPS. Furthermore, compound 9b exhibited reduced cytochrome P450 interaction in comparison with SB203580. This result is particularly important, since cytochrome P450 interaction is observed for some p38 inhibitors and in turn can potentially cause drug-drug interaction or lead to other hepatic changes such as P450 enzyme induction.
Severe cartilage damage by broken poly–L–lactic acid (PLLA) interference screw after ACL reconstruction
2004-11-10

Abstract Poly– L –lactic acid (PLLA) bioabsorbable interference screws are widely used for fixation of tendon to bone and bone to bone in anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) reconstructions. Complications are rare. To our knowledge this is the first report of severe chondral damage caused by late breakage of the screw. Breakage of bioscrews has only been published in cases with tendon to bone fixation.