bluuebunny/crossref_metadata_2025_split huggingface dataset:
Increased Fecal Bile Acid Excretion in Transgenic Mice With Elevated Expression of Human Phospholipid Transfer Protein
Authors: Post Sabine M. , de Crom Rini , van Haperen Rien , van Tol Arie , Princen Hans M.G. 
Published: May 2003

Objective—HDL plays a key role in protection against development of atherosclerosis by promoting reverse cholesterol transport from peripheral tissues to the liver for secretion into bile. Phospholipid transfer protein (PLTP) promotes the transfer of phospholipids between lipoproteins and modulates HDL size and composition, thereby having a crucial role in HDL metabolism. We investigated the effect of increased PLTP activity on removal of cholesterol from the body.Methods and Results—On a chow diet, transgenic mice overexpressing human PLTP have a 15-fold increased plasma PLTP activity compared with wild-type mice (572.4±59.2 versus 38.6±3.6 μmol/mL per h). Plasma cholesterol, mainly present in HDL, is strongly decreased (−92%), caused by a rapid clearance from the circulation by the liver and leading to a 1.8-fold increase in hepatic cholesteryl esters. This results in a 2-fold increase in biliary bile acid secretion without changing the bile saturation index. Consequently, the transgenic mice show a 1.4-fold increase in the amount of excreted fecal bile acids compared with wild-type mice, whereas fecal neutral sterol excretion is unchanged.Conclusions—Our data show that elevation of PLTP activity results in rapid disposal of cholesterol from the body via increased conversion into bile acids and subsequent excretion.
Statins Inhibit Secretion of Metalloproteinases-1, -2, -3, and -9 From Vascular Smooth Muscle Cells and Macrophages
Authors: Luan Zhaoxia , Chase Alex J. , Newby Andrew C. 
Published: May 2003

Objective—Production of several metalloproteinases (MMPs) from smooth muscle cells (SMCs) and macrophages causes matrix destruction and atherosclerotic plaque instability. Statins, which inhibit HMG-CoA reductase and hence cholesterol and isoprenoid synthesis, stabilize plaques. We investigated whether statins inhibit MMP secretion from SMCs and macrophages.Methods and Results—We used human saphenous vein and rabbit aortic SMC and foamy macrophages from cholesterol-fed rabbits. Cerivastatin (50 nmol/L) inhibited inducible MMP-1, -3, and -9 secretion from human SMC by 52±19%, 71±18%, and 73±17%, respectively (P<0.01, n=3). Similar dose-related effects of cerivastatin (50 to 500 nmol/L), simvastatin (1 to 20 μmol/L), and lovastatin (5 to 20 μmol/L) were consistent with their relative potencies against HMG-CoA reductase. Statins also inhibited inducible MMP-1, -3, and -9 and constitutive MMP-2 secretion but not TIMP-1 or -2 secretion from rabbit SMC. Statins also dose-dependently inhibited MMP-1, -3, and -9 secretion from rabbit foam cells; cerivastatin (50 nmol/L) inhibited by 68±18%, 74±14%, and 74±14%, respectively (P<0.01, n=4). Statins similarly decreased collagenolytic, caseinolytic, and gelatinolytic activity. Mevalonate and geranylgeranylpyrophosphate but not squalene reversed the effects, showing dependence on isoprenoid, not cholesterol depletion. Statins did not affect MMP mRNA levels.Conclusions—Statins inhibit secretion of a several MMPs from both SMCs and macrophages, which could therefore contribute to their plaque-stabilizing effects.
Lysophosphatidylcholine Regulates Synthesis of Biglycan and the Proteoglycan Form of Macrophage Colony Stimulating Factor
Authors: Chang Mary Y. , Tsoi Christina , Wight Thomas N. , Chait Alan 
Published: May 2003

Objective—We have shown that copper-oxidized LDL (Ox-LDL) regulates proteoglycan synthesis by arterial smooth muscle cells. Ox-LDL specifically upregulates biglycan expression while causing elongation of glycosaminoglycan chains on all of the major secreted proteoglycans (biglycan, decorin, and versican), resulting in enhanced lipoprotein-binding interactions. It is not known which component of Ox-LDL is responsible for these effects. This study investigated the ability of several bioactive components of Ox-LDL to regulate proteoglycan synthesis.Methods and Results—Those tested included 2 oxysterols (7-ketocholesterol and 7β-hydroxycholesterol) and 2 lysolipids (lysophosphatidylcholine and lysophosphatidic acid) formed during LDL oxidation. 7-ketocholesterol, lysophosphatidylcholine, and lysophosphatidic acid all increased proteoglycan MWapp, which is correlated with chain elongation and enhanced lipoprotein-binding properties in vitro. Lysophosphatidylcholine mimics the ability of Ox-LDL to stimulate biglycan expression and also causes a marked induction of the core protein for the proteoglycan form of macrophage colony stimulating factor.Conclusions—Multiple oxidized lipid molecules can modulate proteoglycan synthesis and may have important consequences to atherogenesis via processes that involve enhanced lipoprotein retention as well as the promotion of macrophage survival and differentiation.
Big science, little news: science coverage in the Italian daily press, 1946-1997
Authors: Bucchi Massimiano , Mazzolini Renato G. 
Published: May 2003

This article reports on a content analysis of science coverage by the leading Italian newspaper, Il Corriere della Sera, over a period of fifty years. Results show an expansion of such coverage over time, although it was increasingly “institutionalized” in new sections devoted to science and medicine. The typical science story can be described as dealing with biomedical issues, referring to a geographical context outside Italy, relying on uncontested scientific expertise and presenting the consequences of science activity in a positive fashion. However, deeper analysis suggests the presence of a marked dualism between two distinct journalistic genres: (1) “science-popularization,” which is characteristic of special sections, overwhelmingly dominated by biomedical topics, depicting science as straightforward, consensual, and bringing improvement to people's lives; and (2) “science as news,” dealing more frequently with other fields such as the physical sciences, paying closer attention to controversy and to the harmful consequences of scientific enterprise. A comparison with similar studies in other countries is also presented.
Gastric versus post-pyloric feeding: a systematic review
Authors: Marik Paul E , Zaloga Gary P 
Published: May 2003

Abstract
Background
Our objective was to evaluate the impact of gastric versus post-pyloric feeding on the incidence of pneumonia, caloric intake, intensive care unit (ICU) length of stay (LOS), and mortality in critically ill and injured ICU patients.

Method
Data sources were Medline, Embase, Healthstar, citation review of relevant primary and review articles, personal files, and contact with expert informants. From 122 articles screened, nine were identified as prospective randomized controlled trials (including a total of 522 patients) that compared gastric with post-pyloric feeding, and were included for data extraction. Descriptive and outcomes data were extracted from the papers by the two reviewers independently. Main outcome measures were the incidence of nosocomial pneumonia, average caloric goal achieved, average daily caloric intake, time to the initiation of tube feeds, time to goal, ICU LOS, and mortality. The meta-analysis was performed using the random effects model.

Results
Only medical, neurosurgical and trauma patents were enrolled in the studies analyzed. There were no significant differences in the incidence of pneumonia, percentage of caloric goal achieved, mean total caloric intake, ICU LOS, or mortality between gastric and post-pyloric feeding groups. The time to initiation of enteral nutrition was significantly less in those patients randomized to gastric feeding. However, time to reach caloric goal did not differ between groups.

Conclusion
In this meta-analysis we were unable to demonstrate a clinical benefit from post-pyloric versus gastric tube feeding in a mixed group of critically ill patients, including medical, neurosurgical, and trauma ICU patients. The incidences of pneumonia, ICU LOS, and mortality were similar between groups. Because of the delay in achieving post-pyloric intubation, gastric feeding was initiated significantly sooner than was post-pyloric feeding. The present study, while providing the best current evidence regarding routes of enteral nutrition, is limited by the small total sample size.
The role of leukocyte depletion in ex vivo evaluation of pulmonary grafts from (non-)heart-beating donors
Authors: Rega Filip R , Vandezande Eddy J , Jannis Nicole C , Verleden Geert M , Lerut Toni E , Van Raemdonck Dirk EM 
Published: May 2003

If lungs could be retrieved for transplantation after circulatory arrest, the shortage of donors might be significantly alleviated. An important issue in using lungs from these so-called non-heart-beating donors is the development of a technique to assess their quality prior to transplantation without jeopardizing the life of the recipient. In our laboratory we tested the reliability of an ex vivo model for such an evaluation. We used pig lungs from optimal control animals, in casu heart-beating donors. This model enabled us to preserve and evaluate lungs with perfect function up to 24 hours after death. The intermediate assessment is performed in an isolated circuit where the lungs are being ventilated and reper-fused via the pulmonary artery (PA) with autologous and haemodiluted blood. Haemodynamic, aerodynamic and oxygenation parameters are measured at 37.5°C and a maximum PA pressure of 20 mmHg. These data were correlated with premortem values. During this ex vivo evaluation, leukocyte depletion plays an important role since neutrophils have been recognized as critical components in the inflammatory cascade, which is responsible for graft dysfunction soon and long after transplantation.
Neurological and neuropsychological examination and outcome after use of an intra-aortic filter device during cardiac surgery
Authors: Eifert S , Reichenspurner H , Pfefferkorn T , Baur B , von Schlippenbach C , Mayer T E , Hamann G , Reichart B 
Published: May 2003

Cerebral embolization of particles after cardiac surgery is frequently associated with neurological deficits. Aortic crossclamp manipulation seems to be the most significant cause of emboli release during cardiac surgery. The goal of this study was to demonstrate whether the use of an intra-aortic filter device has an effect on the magnet resonance imaging (MRI) and functional neurological outcome. Twenty-four patients undergoing cardiosurgical procedures using cardiopulmonary bypass (CPB) were selected: coronary artery bypass graft (CABG) surgery (n=17), aortic valve replacement (AVR) surgery (n= 4) or combined procedures (n=3). Patients were evaluated by diffusion weighted MRI of the brain, neurological examination and neuropsychological assessment regarding alertness as well as divided and selective attention before and five to seven days after surgery. The patients were divided into two groups. In group I, 12 patients received a filter through a modified 24 F arterial cannula immediately before the aortic crossclamp was released. Filters remained in the aorta until CPB was discontinued. Intraoperatively, bilateral middle cerebral artery transcranial Doppler (TCD) was monitored at baseline, at the beginning of CPB, at a timepoint when the aorta was crossclamped, when the filter was inserted and while the crossclamp was switched to partial clamping until the CPB was discontinued. TCD was used for detection of microembolic signals (MES). The captured material in the filter was examined histologically. Twelve patients served as controls without aortic filtration (group II). The MRI of the brain did not show any diffusion alterations in either group before or after surgery. No patient developed a focal neurological deficit or stroke. Intraoperative quantitative MES detection revealed a four to tenfold increase in patients of group I compared with group II (5 - 6 versus 0.5 - 1 MES/min) during the filter dwell time. There was no consistent pattern regarding the neurobehavioural sequelae. Filters showed arteriosclerotic debris in 75% of the patients. The use of the intra-aortic filter device did not show a positive effect on neurological, neuroradiographical and neuropsychological outcomes. The increase of the MES rate in group I patients may be due to microbubbles generated as microcavitations by the filter or the aortic filter cannula. The intra-aortic filter was able to capture atheromatous material in 75% of the patients.
Prebypass filtration of cardiopulmonary bypass circuits: an outdated technique?
Authors: Merkle Frank , Böttcher Wolfgang , Hetzer Roland 
Published: May 2003

Filtration of cardiopulmonary bypass (CPB) priming fluid before connection of the circuit to the patient was first accomplished by arterial line filtration. When dedicated prebypass filters (PBFs) with smaller pore sizes became available, a large number of particles could be found on the filter surface. In recent years, modern manufacturing methods for CPB circuit components were believed to be associated with a reduced number of particles found in components of extracorporeal circuits, making separate filtration of CPB priming solution unnecessary. Microemboli generated during the preparation and priming procedure of the CPB circuit may consist of either solid particles or gaseous emboli and may contribute to patient morbidity. Endotoxins found in infusion solutions and CPB priming solutions may trigger inflammatory responses when administered into the circulatory system. Filtration of crystalloid CPB priming solutions with a PBF consisting of a filter membrane with a pore size of0.2 mm was found to effectively reduce the number of microemboli. Infusion filters with a filter pore size of 0.2 mm were found to reduce the endotoxin contamination in infusion solutions. Prebypass filtration with filters containing pores of 0.2 mm should be a necessity for contemporary perfusion practice.
What is the best way to help caregivers in cancer and palliative care? A systematic literature review of interventions and their effectiveness
Authors: Harding R , Higginson I J 
Published: May 2003

Informal carers in cancer and palliative care are known to have high needs and psychological morbidity, yet a literature review identified few targeted interventions. This systematic review of interventions for carers of patients using home cancer and palliative care services searched Medline, CancerLit, PsycInfo and Cinahl databases. The terms used were carer(s), caregiver(s), palliative and cancer. Papers that reported interventions for adults actively providing informal care for noninstitutionalized cancer and palliative care patients were reviewed. Twenty-two interventions were identified, comprising home nursing care (four), respite services (three), social networks and activity enhancement (two), problem solving and education (three) and group work (10). Of these, nine were delivered solely to carers (i.e., were targeted services). Only six of the carers' interventions had been evaluated, two of these had used a randomized control trial (RCT; grades IB), three employed a single group methodology (two prospective grades IIIC and one retrospective grade IIIC) and one was evaluated using facilitator feedback. There was a lack of outcome evaluation designs, small sample sizes and a reliance on intervention descriptions and formative evaluations. Methodological challenges may mean alternatives to ‘pure’ RCTs should be considered. The current evidence contributes more to understanding feasibility and acceptability than to effectiveness. Practitioners and evaluators must prioritize the further development of intervention studies.
Katalytische Ammoniaksynthese – eine “unendliche Geschichte”?
Authors: Schlögl Robert 
Published: May 2003

AbstractStickstoffatome sind funktional notwendig in biologischen Molekülen und finden sich daher auch in Düngemitteln und Pharmaka. Nichtbiologische Nutzanwendungen von Bindungen zu Stickstoffatomen sind Farbstoffe, Sprengmittel und Hartstoffe. Alle Synthesen dieser Materialien verwenden das Schlüsselmolekül Ammoniak als aktivierten Stickstoffbaustein. Dies gilt für natürliche Prozesse ebenso wie für die chemische Technik. Das Wissen um die vielfältigen Verfahren zur Herstellung von Ammoniak ist daher von zentraler Bedeutung für die Chemie. Die Haber‐Bosch‐Synthese ist das erste und noch heute eingesetzte Verfahren der industriellen heterogenen Katalysetechnik. Die Aufklärung des Wirkmechanismus und die Umsetzung zur technischen Perfektion wurden zum Prüfstein für die wissenschaftliche Grundlagenentwicklung der Katalyseforschung.
Dark reactions of free radicals trapped in densely crosslinked polymer networks after photopolymerization
Authors: Pavlinec Juraj , Moszner Norbert 
Published: May 2003

AbstractDifunctional methacrylate monomers containing stiff or flexible spacers were combined with a vinylcyclopropane derivate in a copolymerization to form densely crosslinked networks. The high rate of visible light photoinitiation at 20–22°C was used for starting the polymerization. By switching off the light after 40 s, the long‐lived free radicals, trapped in the polymer network, retain radical processes, however, at substantially retarded rates. The postcuring development of the network structure in the investigated samples lasting at least 12 weeks was proved by the increasing density of the crosslinks, by the increasing amount of the gel fraction, and by the decreasing of the residual unsaturation. The relaxation spectra from dynamic mechanical thermal analyses (DMTA) show curves with two evident maxima. The first one belonged the glass transition (Tg) of original network and increases in the postcuring period. The second one belonged to the final structure to which the crosslinked polymer approaches slowly during aging. The final state develops fast during a DMTA thermal scan to 200°C. All procedures proceeded in the dark, but in the presence of air oxygen. The chemiluminescence (CL) response of the postcured samples proved the accumulation of hydroperoxides. The oxidation chain reaction took place in the postcuring time and competed with the building up of additional crosslinks. The majority of postcuring changes were observed during the first 3 weeks of aging. Nine weeks later, the long‐lived radicals were still present in the network and maintained the sensibility of the crosslinked polymer to free‐radical reactions. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 579–588, 2003
Butadiene polymerization in the presence of VOCl3–dialkylmagnesium catalytic system
Authors: Monakov Yu. B. , Mullagaliev I. R. , Kharitonova E. Yu. 
Published: May 2003

AbstractThe butadiene polymerization in toluene at 25°C on VOCl3(n‐C4H9)Mg(iso‐C8H17) catalytic system was investigated. The kinetic parameters of polymerization and molecular characteristics of polybutadiene were determined. It was shown that substitution of traditional organoaluminum cocatalysts in trans‐regulating vanadium systems does not have an effect on its stereospecificity, but significantly influences on the active centers reaction ability. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 596–600, 2003
Structure of active centers, their stereospecificity distribution, and multiplicity in diene polymerization initiated by NdCl3‐based catalytic systems
Authors: Urazbaev V. N. , Efimov V. P. , Sabirov Z. M. , Monakov Yu. B. 
Published: May 2003

AbstractOn the basis of quantum‐chemical calculations, it was shown that among six types of active centers (ACs) that can form during the polymerization of butadiene with lanthanide‐based catalytic systems, five types (containing electron‐accepting chlorine atoms in the coordination sphere of a lanthanide) exhibit a π‐allyl binding of the terminal unit of a growing polymer chain to a lanthanide atom and function as cis‐regulating. The sixth type of ACs is characterized by a σ‐alkyl structure and shows a trans‐stereospecificity. This results was used to interpret the data on the microstructure of polybutadiene prepared using NdCl3 · 3TBP‐Al(iso‐C4H9)3, NdCl3 · 3TBP–Mg(n‐C4H9)(iso‐C8H17) catalytic systems and their combinations (TBP is tributyl phosphate). © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 601–603, 2003
Fiber spinning from poly(propylene)–organoclay nanocomposite
Authors: Pavliková Silvia , Thomann Ralf , Reichert Peter , Mülhaupt Rolf , Marcinčin Anton , Borsig Eberhard 
Published: May 2003

AbstractSOMASIF ME C16, a filler that enables generation of anisotropic nanoparticles by in situ exfoliation of organic layered silicates, was melt compounded with poly(propylene) (PP) in the presence of maleic anhydride‐grafted PP. Fibers were prepared from this composite by a spinning procedure. The prepared anisotropic fibers were partially oriented by using different drawing ratios. The morphological study showed that the drawing ratio of the fibers particularly influences the level of exfoliation of the SOMASIF ME C16 where the nanoparticles are formed. The layered sheets of the SOMASIF particles are oriented in the direction of the fiber axis. The tensile strength of the filled fibers increases with the increase of drawing ratio much more than that of unfilled PP fibers. This result is accounted for by the formation of exfoliated structures from the nanoparticles of SOMASIF ME C16 by fiber drawing. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 604–611, 2003
Isothermal and nonisothermal transition kinetics of trans‐1,4‐polybutadiene
Authors: Cai Jiali , Bo Shuqin , Li Gao , Zhou Enle , Cheng Rongshi 
Published: May 2003

AbstractAnalysis of the isothermal and nonisothermal transitions of hexagonal crystal formation from the melt (transition 1) and of monoclinic crystal formation from hexagonal crystals (transition 2) for trans‐1,4‐polybutadiene (TPBD) was carefully carried out by differential scanning calorimetry (DSC) and transmission electron microscopy (TEM). Isothermal transitions 1 and 2 are described by Avrami exponents (n) of ≈1, whereas nonisothermal transitions 1 and 2 are described by n ≈ 4. These different n values indicate that different crystallization mechanisms took place for different crystallization driving forces under isothermal and nonisothermal crystallization. The Ozawa equation was also used to analyze the nonisothermal crystallization data. For transition 1 at lower temperature, the Ozawa equation fits the data well; however, at higher temperature, there is an inflection that shifts to lower crystallinity with increasing temperature. Inflections are also observed with the Ozawa analysis for transition 2. Furthermore, the crystallinities at the turning points are almost in the same range as those determined by Avrami analysis for nonisothermal transitions 1 and 2, which suggests that the Ozawa analysis inflections are due to secondary crystallization. However, TEM revealed no morphology discrepancy between the TPBD hexagonal crystals formed from melt by isothermal and nonisothermal crystallization. The agreement in activation energy (ΔE) values determined by the Arrhenius and Kissinger methods indicates that the Avrami equation can describe the initial stage of transitions 1 and 2 in the nonisothermal transition process quite well. The ΔE values determined by the Arrhenius and Kissinger methods for transition 1 are 167.4 and 179.2 KJ/mol, respectively, and those for transition 2 are 186.1 and 196.3 KJ/mol; respectively. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 612–619, 2003