julilili42/papers huggingface dataset:
Different actions of protein kinase C isoforms α and ε on gastric acid secretion
2002-07-01

The phorbol ester TPA, an activator of protein kinase C (PKC), inhibits cholinergic stimulation of gastric acid secretion but increases basal H + secretion. Since these contradictory findings suggest the action of different PKC isozymes we analysed the role of calcium‐dependent PKC‐α, and calcium‐independent PKC‐ε in gastric acid secretion. Inhibition of PKC‐α by the indolocarbazole Gö 6976 revealed that about 28% of carbachol‐induced acid secretion was inhibited by PKC‐α. In the presence of Gö 6976 approximately 64% of the carbachol‐induced signal transduction is mediated by Ca 2+ /calmodulin‐dependent protein kinase II (CaMKII), and 14% is conveyed by PKC‐ε as deduced from the inhibition with the bisindolylmaleimide Ro 31‐8220. Inhibition of carbachol‐induced acid secretion by TPA was accompanied by a decrease in CaMKII activity. The stimulation of basal acid secretion by TPA was biphasic with a peak at a very low concentration (10 p M ), resulting in an activation of the calcium‐sensor CaMKII. The activation was determined with a phosphospecific polyclonal antibody against active CaMKII. The TPA‐induced increase of H + secretion was sensitive to the cell‐permeable Ca 2+ ‐chelator BAPTA/AM, Ro 31‐8220, and the CaMKII‐inhibitor KN‐62, but not to Gö 6976. Since TPA induced the translocation of PKC‐ε but not of PKC‐α in resting parietal cells, PKC‐ε seems to be at least responsible for an initial elevation of free intracellular calcium to initiate TPA‐induced acid secretion. Our data indicate the different roles of two PKC isoforms: PKC‐ε activation appears to facilitate cholinergic stimulation of H + ‐secretion likely by increasing intracellular calcium. In contrast, PKC‐α activation attenuates acid secretion accompanied by a down‐regulation of CaMKII activity. British Journal of Pharmacology (2002) 136 , 938–946. doi: 10.1038/sj.bjp.0704790
Hemocompatibility of Medical Connectors with Biopassive or Bioactive Surface Coatings
2002-07-01

Although medical connectors compose very small parts of the extracorporeal circulation (ECC) systemthey represent a critical localization where early thromboembolic processes can manifest. In the present study we modified an in vitro closed-loop model with fresh human whole blood for the preclinical evaluation of the hemocompatibility of three types of medical connectors: non-coated (control); with silicone-, and heparin-coating. Each single loop consists of five polycarbonate connectors joined together by five pieces of silicone tubes. Thrombin-antithrombin-III, β-thromboglobulin (β-TG), PMN-Elastase, terminal complement complex, CD 11b expression, and surface-absorbed fibrinogen were measured. After 1 and 2 h recirculation, platelet loss, release of β-TG, and adsorption of fibrinogen were significantly higher ( p&lt;0.05) within the non-coated connectors compared to the silicone- and heparin-coated groups. Following this experiment, the connectors were filled again with fresh heparinized whole blood from the same donor to evaluate the influence of prior blood contact. Here, the activation of platelets and coagulation was dependent on the duration of the blood preincubation period. Probably, the coated surfaces possess a reduced, or selective adsorption of plasma proteins, which in turn leads to a faster creation of a blood-friendly secondary superficial membrane, and prevents a further denaturation and hence activation of the adsorbed proteins.
Borate, an Effective Mummification Agent in Pharaonic Egypt
2002-07-01

Mummification salts and mummified bones were assayed for borate. In two samples of mummification salt one from Deir el-Bahari (26 th Dynasty, 700-600 BC) and salt from the embalming material of Tutankhamen (18 th Dynasty, 1370-1335 BC) 3.9 and 2.1 μMol borate/ gram were found, respectively. Six mummified bone fragments from the Old Kingdom contained up to 1.2 μMol/gram. It is suggested that borate containing salt was used during mummification. The reactivity of borate on bone alkaline phosphatase, which is known to survive mummification for more than 4000 years, was examined. Borate forms high relative molecular mass adducts of this enzyme being temperature resistant and functionally distinct.
T‐wave response: a sensitive test for latent alcoholic polyneuropathy
2002-07-01

Abstract To date, the H‐reflex is the most sensitive test to measure nerve conduction velocity in alcoholic polyneuropathy. Analogous to the H‐reflex, we investigated the T‐wave response from the soleus muscle using a hand‐held reflex hammer. Twenty‐four inpatients suffering from chronic alcoholism and 24 healthy volunteers were recruited. All probands had a careful neurological examination and were graded (PNP‐classifications). The T‐ and H‐reflexes were measured. In the clinical examination, only a few patients exhibited symptoms of alcoholic PNP. However, when the autonomic nervous system was also tested, 50% exhibited signs of alcoholic PNP. Both the T‐ and H‐reflex responses were pathologically retarded, indicating latent alcoholic PNP in 60% of the patients. Thus the main finding in our study is the difference between clinical and electrophysiological examinations: only a few of the patients had neurological symptoms for alcoholic PNP but 14 patients (60%) exhibited a so‐called latent, subclinical alcoholic PNP by showing delayed reflex latencies. Measuring the T‐wave proved to be a simple and painless screening method for diagnosis and monitoring of alcoholic PNP. Among the clinical tests the best indicator for alcoholic PNP was the test for autonomous alcoholic PNP.
Three Pyrone Glucosidic Derivatives from Conyza albida
2002-07-01

Three new pyrone glucosidic derivatives, together with the known pyromeconic acid glucoside, three acytelenes and two eudesmanes, were obtained from the aerial parts of Conyza albida. The structures were elucidated by high field NMR spectroscopy.
Iron abundance in hot hydrogen-deficient central stars and white dwarfs from FUSE, HST, and IUE spectroscopy
2002-07-01

We present a first systematic investigation of the iron abundance in very hot (Teff>50,000K) hydrogen-deficient post-AGB stars. Our sample comprises 16 PG1159 stars and four DO white dwarfs. We use recent FUSE observations as well as HST and IUE archival data to perform spectral analyses with line blanketed NLTE model atmospheres. Iron is not detected in any PG1159 star. In most cases this is compatible with a solar iron abundance due to limited quality of HST and IUE data, although the tendency to an iron underabundance may be recognized. However, the absence of iron lines in excellent FUSE spectra suggests an underabundance by at least 1 dex in two objects (K1-16 NGC 7094). A similar result has been reported recently in the [WC]-PG1159 transition object Abell 78 (Werner et al. 2002). We discuss dust fractionation and s-process neutron-captures as possible origins. We also announce the first identification of sulfur in PG1159 stars.
Iron abundance in hot hydrogen-deficient central stars and white dwarfs\\nfrom FUSE, HST, and IUE spectroscopy
2002-07-01

\\n We present a first systematic investigation of the iron abundance in very hot\\n(Teff K) hydrogen-deficient post-AGB stars. Our sample comprises\\n16 PG 1159 stars and four DO white dwarfs. We use recent FUSE observations as\\nwell as HST and IUE archival data to perform spectral analyses with line\\nblanketed NLTE model atmospheres. Iron is not detected in any PG 1159 star. In\\nmost cases this is compatible with a solar iron abundance due to limited\\nquality of HST and IUE data, although the tendency to an iron underabundance\\nmay be recognized. However, the absence of iron lines in excellent FUSE spectra\\nsuggests an underabundance by at least 1 dex in two objects (, NGC 7094). A\\nsimilar result has been reported recently in the [WC]-PG 1159 transition\\nobject Abell 78 (Werner et al. [CITE]). We discuss dust fractionation and\\ns-process neutron-captures as possible origins. We also announce the first\\nidentification of sulfur in PG 1159 stars.\\n\\n
CD95/CD95 ligand-independent potentiation of treosulfan cytotoxicity by BSO in malignant glioma cells in vitro and in vivo
2002-07-01

The glutathione synthase inhibitor, buthionine sulfoximine (BSO), specifically enhances the cytotoxic effects of treosulfan in human glioma cells. BSO depletes glutathione and greatly enhances treosulfan cytotoxicity in all the 12 human malignant glioma cell lines examined. None of these cell lines showed enhanced susceptibility to CD95L- or tumor necrosis factor (TNF)-alpha-induced apoptosis when glutathione is depleted. The combination of serial systemic BSO applications (300 mg/kg) and a single systemic dose of treosulfan (2.5 g/kg) reduced the growth of intracranially growing rat C6 gliomas in vivo by 73% whereas treosulfan alone reduced tumor growth by 16% and BSO alone had no effect. BSO lowered glutathione levels to 25-30% in peripheral blood mononuclear cells (PBMC) and to 50% in the glioma tissue. The glutathione levels in the non-tumor-bearing contralateral hemisphere were unaffected by systemic BSO treatment. The main side effects of treosulfan, gastrointestinal and bone marrow toxicity, were not significantly enhanced by BSO.
How social is European social policy?
2002-07-01

During the course of European integration social policy has become an increasingly important policy area of the European Union. The paper analyses whether the EU’s social‐policy measures improve the living conditions of the socially weaker groups. All three areas of European social policy are analysed: the co‐ordination of the member states’ social security systems, the harmonisation of the working conditions and the promotion of equal opportunities, social integration and vocational training. This paper shows that the EU’s social‐policy measures have numerous disadvantages. In particular, they often are detrimental to the very people who the EU intends to protect and promote.
Glial fibrillary acidic protein‐positive cells of the kidney are capable of raising a protective biochemical barrier similar to astrocytes: Expression of metallothionein in podocytes
2002-07-02

Abstract Blood–tissue exchange and homeostasis within the organs depend on various interactions between endothelial and perivascular cells (Buniatian, 2001 ). Podocytes possess anatomical and cellular features intermediate between those of astrocytes and hepatic stellate cells (HSCs). Podocytes, like HSCs, are associated with fenestrated capillaries and, similar to astrocytes, interact with the capillaries via the basement membrane and participate in permeability‐limiting ultrafiltration. The fact that podocytes come in direct contact with xenobiotics prompted us to investigate whether they express metallothionein (MT), an anticytotoxic system characteristic of astrocytes. In comparative studies, cryosections of 1‐ and 3‐month‐old rat kidney and adult rat brain, as well as podocytes and astrocytes from early and prolonged primary cultures of glomerular explants and newborn rat brain, respectively, were investigated. The cells were double‐labeled with antiserum against glial fibrillary acidic protein (GFAP) and monoclonal antibody (MAb) against the lysine‐containing epitope of Cd/Zn‐MT‐I (MAb MT) or MAb against alpha‐actin. In kidney sections, MT immunoreactivity was detected in GFAP‐positive glomerular cells and in interstitial fibroblasts. The pattern of staining for MT and GFAP in glomerular cells was similar to that of astrocytes in vivo. In glomerular cell cultures, MT was expressed in cobblestone‐like podocytes which contained Wilms' tumor protein and lacked desmin. MT was upregulated at later culture periods, during which podocytes acquired features typical of undifferentiated astrocytes. This study hints at the existence of common regulatory mechanisms of blood–tissue interactions by neural and non‐neural perivascular cells. These mechanisms appear to be used in an organ‐specific manner. Anat Rec 267:296–306, 2002. © 2002 Wiley‐Liss, Inc.
ChemInform Abstract: Synthesis of the Core Structure of Apicularen A by Transannular Cyclization.
2002-07-02

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Visualization of maltose uptake in living yeast cells by fluorescent nanosensors
2002-07-03

Compartmentation of metabolic reactions and thus transport within and between cells can be understood only if we know subcellular distribution based on nondestructive dynamic monitoring. Currently, methods are not available for in vivo metabolite imaging at cellular or subcellular levels. Limited information derives from methods requiring fixation or fractionation of tissue (1, 2). We thus developed a flexible strategy for designing protein-based nanosensors for a wide spectrum of solutes, allowing analysis of changes in solute concentration in living cells. We made use of bacterial periplasmic binding proteins (PBPs), where we show that, on binding of the substrate, PBPs transform their hinge–bend movement into increased fluorescence resonance energy transfer (FRET) between two coupled green fluorescent proteins. By using the maltose-binding protein as a prototype, nanosensors were constructed allowing in vitro determination of FRET changes in a concentration-dependent fashion. For physiological applications, mutants with different binding affinities were generated, allowing dynamic in vivo imaging of the increase in cytosolic maltose concentration in single yeast cells. Control sensors allow the exclusion of the effect from other cellular or environmental parameters on ratio imaging. Thus the myriad of PBPs recognizing a wide spectrum of different substrates is suitable for FRET-based in vivo detection, providing numerous scientific, medical, and environmental applications.
Total Synthesis of the Nematicidal Cyclododecapeptide Omphalotin A by Using Racemization-Free Triphosgene-Mediated Couplings in the Solid Phase
2002-07-03

Racemization-free coupling of Fmoc-N-methyl amino acids on a solid support is quantitative with a new triphosgene-activation method. With this method, the total synthesis of the nematicidal cyclododecapeptide omphalotin A (see picture) was accomplished, which because of its high content of N-methyl amino acids had not yet been accessible.
Ones, Thiones, andN-Oxides: An Exercise in Imidazole Chemistry
2002-07-03

Regioselective synthetic approaches to tetrasubstituted imidazoles (see picture) are reported. These highly substituted heterocycles are potent inhibitors of cytokine release and therefore interesting candidates for anti-inflammatory drugs. Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2002/2002/z18173_s.pdf or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.
Relative effectiveness of differently framed health messages: the influence of ambivalence
2002-07-03

Abstract The present studies test the hypothesis that the degree of experienced ambivalence toward health behaviors moderates the impact of differently framed messages. In line with prospect theory, it is argued that positive frames can either involve attaining desirable outcomes or avoiding undesirable outcomes, and negative frames can either emphasize the presence of undesirable outcomes or the absence of desirable outcomes. The results of three studies are supportive of the hypothesis that highly ambivalent individuals are more persuaded by negatively framed messages whereas individuals low in ambivalence are more persuaded by positively framed messages. The greater persuasiveness of negatively framed messages at higher levels of ambivalence can be explained by a negativity bias involved in ambivalence. Several preventive behaviors such as eating a low‐fat diet or using condoms were addressed. Theoretical and practical implications of these findings are discussed in light of current theories on health behavior. Copyright © 2002 John Wiley &amp; Sons, Ltd.
Tools for the analysis of dose optimization: I. Effect$ndash$volume histogram
2002-07-03

With the advent of dose optimization algorithms, predominantly for intensity-modulated radiotherapy (IMRT), computer software has progressed beyond the point of being merely a tool at the hands of an expert and has become an active, independent mediator of the dosimetric conflicts between treatment goals and risks. To understand and control the internal decision finding as well as to provide means to influence it, a tool for the analysis of the dose distribution is presented which reveals the decision-making process performed by the algorithm. The internal trade-offs between partial volumes receiving high or low doses are driven by functions which attribute a weight to each volume element. The statistics of the distribution of these weights is cast into an effect-volume histogram (EVH) in analogy to dose-volume histograms. The analysis of the EVH reveals which traits of the optimum dose distribution result from the defined objectives, and which are a random consequence of under- or misspecification of treatment goals. The EVH can further assist in the process of finding suitable objectives and balancing conflicting objectives. If biologically inspired objectives are used, the EVH shows the distribution of local dose effect relative to the prescribed level.
Molecular breakpoint analysis and relevance of variable mosaicism in a woman with short stature, primary amenorrhea, unilateral gonadoblastoma, and a 46,X,del(Y)(q11)/45,X karyotype
2002-07-08

Abstract We report on a 30‐year‐old woman with short stature, completely female external genitalia, primary amenorrhea, bilateral streak gonads, unilateral gonadoblastoma, and a 46,X,del(Y)(q11)/45,X karyotype. Variable levels of mosaicism were found in blood and cultivated fibroblasts from both the skin and ovaries, with the percentage of the 45,X lineage never exceeding 33%. Fluorescence in situ hybridization (FISH) was performed with alpha satellite centromere region probes of the X and Y chromosomes (DXZ1 and DXZ3) as well as with the unique‐sequence, locus‐specific, sex‐determining region of the Y chromosome gene ( SRY ) and the DXZ1 probes. Each signal was noted for DXZ1 on the X chromosome and for the Y probes on the marker chromosome. Molecular investigations with a panel of PCR markers spread over the whole Y chromosome indicated a deletion breakpoint between sY 78 (interval 4) and sY 151 (interval 5F). No mutation of the high mobility group‐box (HMG‐box) of the SRY gene could be found following sequence analysis. The phenotype/genotype correlation demonstrates the broad phenotypic range of low‐level 45,X mosaicism with the resultant short stature and external female phenotype, despite the presence of SRY in a high proportion of cells in various tissues. © 2002 Wiley‐Liss, Inc.
A comparison of memetic recombination operators for the traveling salesman problem
2002-07-09

Several memetic algorithms (MAs) – evolutionary algorithms incorporating local search – have been proposed for the traveling salesman problem (TSP). Much effort has been spent to develop recombination operators for MAs which aim to exploit problem characteristics to achieve a highly effective search. In this paper, several recombination operators for the TSP are compared. For the purpose of identifying the important properties of a recombination operator, a new generic recombination operator (GX) is proposed which is comprised of four phases. These phases can be controlled by parameters reflecting the most important properties of recombination operators. It is shown that GX recombination is superior to MPX and DPX when all common edges are preserved in the offspring. 1
MOCS: multi-objective clustering selection evolutionary algorithm
2002-07-09

Considerable progress has been achieved in the medical therapy for metastasised colorectal cancer. The targeted application of already available as well as recently developed substances requires further evaluation by appropriate studies.
ChemInform Abstract: Vancomycin Resistance: Small Molecule Approaches Targeting the Bacterial Cell Wall Biosynthesis.
2002-07-09

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
<title>Characterization of electroactive behavior and of progress in developments and applications of ionic polymer gels</title>
2002-07-10

Polyelectrolyte gels are distinguished by enormous swelling capabilities under the influence of external physical or chemical stimuli. No other kind of material attains similar volume expansiveness. These properties make them most attractive candidates for a new generation of pseudomuscular actuators. In contrast to chemical stimulations which are able to trigger large in-toto deformations, weak electric fields can only induce considerable bending strains in ionic polymer gels when confined to direct electrical effects. This, of course, restricts their potential for technical applications. To characterize their chemo-mechanical and electrical behavior and the underlying physico-chemical processes, experimental and theoretical findings are presented. Measurements of basic mechanical and electrical parameters on polyelectrolyte gels allow quantification of their electroactive responses, especially with respect to the direct effects of external electric fields on the Donnan potential inside the gels. Model calculations on the basis of a coupled chemo-electro-mechanical multi- field formulation are in good agreement with the experimental results. Although the emphasis of this study is given to various anionic and cationic gels of the polyacrylamide family, a new class of hydrogels based on the biopolymer chitosan is included. These natural polymers have excellent properties such as biocompatibility, biodegradability, non-toxicity etc. making them predestinate to biomedical applications.
<title>Numerical simulation of a coupled chemo-electric-formulation for ionic polymer gels in electric fields</title>
2002-07-10

Ionic polymer gels, consisting of a polymer network with ionizable groups and a liquid phase with mobile ions, exhibit very good actuatoric capabilities due to their large swelling ratios. In this paper we investigate gels immersed in salt solution at different positions - in direct contact with the anode, the cathode or in the middle of the electric field. The concentrations of anions and cations in these gels as well as the electric potential inside and outside the gel are calculated for a given number of anionic groups fixed to the polymer. The applied chemo-electric formulation consists of a convection-diffusion equation for the chemical field and a Laplace equation for the electric field. The numerical simulation of the coupled formulation has been performed by using unconditionally stable space-time finite elements. Based on the results of the numerical simulation we compare the concentrations inside and outside the gel for the different test cases in order to optimize the position of the gel film. The highest swelling ratio of the gel has been taken as criterium for the optimization. The optimal condition is characterized by a maximum value of the concentration differences and of the Donnan potential.