bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of monensin liposomes on the cytotoxicity, apoptosis and expression of multidrug resistance genes in doxorubicin-resistant human breast tumour (MCF-7/dox) cell-line
Authors: Shaik Madhu Sudhan , Chatterjee Abhijit , Singh Mandip 
Published: July 2004

Abstract
We have evaluated the effects of monensin liposomes on drug resistance reversal, induction of apoptosis and expression of multidrug resistance (MDR) genes in a doxorubicin-resistant human breast tumour (MCF-7/dox) cell line. Monensin liposomes were prepared by the pH-gradient method. MCF-7/dox cells were treated with various anticancer drugs (doxorubicin, paclitaxel and etoposide) alone and in combination with monensin liposomes. The cytotoxicity was assessed using the crystal violet dye uptake method. The induction of apoptosis in MCF-7/dox cells was assessed by established techniques such as TUNEL (terminal deoxynucleotidyl transferase-mediated nick end labelling) staining and caspase-3 assay. The effect of monensin liposomes on doxorubicin accumulation in MCF-7/dox cells was monitored by fluorescent microscopy. Finally, the expression of MDR genes (MDR1 and MRP1) in MCF-7/dox cells following the exposure to doxorubicin alone and in combination with monensin liposomes was evaluated by semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR). Our results indicated that monensin liposomes overcame drug resistance in MCF-7/dox cells to doxorubicin, etoposide and paclitaxel by 16.5-, 5.6- and 2.8-times, respectively. The combination of doxorubicin (2.5 μg mL−1) with monensin liposomes (20 times 10−8M) induced apoptosis in approximately 40% cells, whereas doxorubicin (2.5 μg mL−1) or monensin liposomes (20 times 10−8M) alone produced minimal apoptosis (&lt;10%) in MCF-7/dox cells. Fluorescent microscopy revealed that monensin liposomes increased the accumulation of doxorubicin in MCF-7/dox cells. RT-PCR studies demonstrated that the expression of MDR1 and MRP1 was increased by 33 and 57%, respectively, in MCF-7/dox cells following treatment with doxorubicin (2.5 μg mL−1) for 72 h as compared with control MCF-7/dox cells. Furthermore, the levels of MDR1 and MRP1 in MCF-7/dox cells exposed to both doxorubicin and monensin liposomes showed a modest decrease as compared with MCF-7/dox cells treated with doxorubicin alone. In conclusion, the delivery of monensin via liposomes provided an opportunity to overcome drug resistance.
Evaluation of the anti-inflammatory and cytotoxic effects of anthraquinones and anthracenes derivatives in human leucocytes
Authors: Chen Rong-Fu , Shen Yuh-Chiang , Huang Hsu-Shan , Liao Jyh-Fei , Ho Li-Kang , Chou Yueh-Ching , Wang Wen-Yen , Chen Chieh-Fu 
Published: July 2004

Abstract
A variety of anthracene- and anthraquinone-related derivatives, modified from three types of lead structures, including 9-acyloxy 1,5-dichloroanthracene (type I), 1,5-bisacyloxy-anthraquinones with O-linked substituents (type II) and 1,5-bisacyloxy-anthraquinones with S-linked substituents (type III), were synthesized and evaluated by an in-vitro bioassay for their anti-inflammatory and cytotoxic effects in human leucocytes. Among these derivatives, type I compounds displayed potent anti-inflammatory activity against phorbol-12-myristate-13-acetate (PMA)-induced superoxide anion production, a bio-marker of inflammatory mediator production by neutrophils, with 50% inhibition (IC50) concentrations (μM) for compounds 1f, 1g, 1h and 1m being 13.8±3.0, 6.3±4.1, 33.2±1.3 and 33.9±5.7, respectively. Type II and type III derivatives (i.e., 1,5-bisacyloxy anthraquinone-related compounds) and the reference compound, emodin, exhibited relatively minor (20–40%) inhibitory effect against superoxide production by neutrophils. Furthermore, none of these compounds showed a significant cytotoxic effect in human neutrophils. In conclusion, these results suggest that compounds modified from 9-acyloxy 1,5-dichloroanthracence (type I) are more powerful than the other two types as anti-inflammatory drugs. This is the first demonstration that derivatives modified from anthracenes or anthraquinones possess anti-inflammatory activity with no significant cytotoxicity in human neutrophils.
Effect of acyl chains of phosphatidylcholines on the pharmacokinetics of menatetrenone incorporated in O/W lipid emulsions prepared with phosphatidylcholines and soybean oil in rats
Authors: Ueda Kumiko , Fujimoto Masanori , Noto Hiromi , Sakaeda Toshiyuki , Iwakawa Seigo 
Published: July 2004

Abstract
Oil-in-water (O/W) lipid emulsions were prepared with phosphatidylcholines (PCs) of various acyl chains and soybean oil (SO) using a microfluidizer system, and the pharmacokinetics of menatetrenone incorporated in these oil particles were examined at the clinical injection volume (0.1 mL kg−1) in rats. The plasma half-life of menatetrenone incorporated in the oil particles prepared with SO and dipalmitoylphosphatidylcholine (DPPC) (SO/DPPC) was longer than that prepared with SO and egg-yolk phosphatides (EYP) (SO/EYP) by 3 fold, while those of menatetrenone as oil particles prepared with SO and either dilauroyl phosphatidylcholine (DLPC), dimyristoyl phosphatidylcholine (DMPC), distearoyl phosphatidylcholine (DSPC), dioleoyl phosphatidylcholine (DOPC) or dilinoleoyl phosphatidylcholine (DLoPC) (SO/DLPC, SO/DMPC, SO/DSPC, SO/DOPC and SO/DLoPC, respectively) were similar to that of menatetrenone as SO/EYP. The menatetrenone uptake by the liver was not significantly different from that as SO/EYP in all SO/PCs examined, but the menatetrenone uptake by the spleen as SO/DPPC and SO/DSPC was higher than that as SO/EYP. The menatetrenone uptake by the lungs as SO/DPPC was also higher than that as SO/EYP. These findings suggest that SO/DPPC is a good candidate drug carrier for the prolonged plasma circulation of lipophilic drugs.
In-vitro and in-vivo anti-allergic actions of Arecae semen
Authors: Lee Jun Ho , Chang Sung Ho , Park Yun Sim , Her Erk , Lee Hoi Young , Park Jong Woo , Han Jeung Whan , Kim Young Mi , Choi Wahn Soo 
Published: July 2004

Abstract
The effects of various extracts from oriental medicinal herbs on mast cell-mediated allergic reactions have been investigated. Among the extracts, Arecae semen was the most potent inhibitor of antigen-induced degranulation in RBL-2H3 mast cells. A. semen inhibited DNP-BSA- and compound 48/80-induced degranulation in RBL-2H3 mast cells with IC50 values of approximately 53 and 52 μg mL−1, respectively, and inhibited compound 48/80-induced systemic anaphylaxis by 46% at 300 mg kg−1 in mice. A. semen also inhibited the expression of TNF-α and the activation of mitogen activated protein kinase, ERK1/2, which is critical for the production of inflammatory cytokines in mast cells, as indicated by the suppression of the activating phosphorylation of ERK1/2. These results suggest that A. semen may be useful for the treatment of various immediate and delayed allergic diseases.
Biofilm formation and changes in bacterial cell surface hydrophobicity during growth in a CAPD model system
Authors: Hanlon G W , Denyer S P , Hodges N A , Brant J A , Lansley A B , Al-Rustamani W A 
Published: July 2004

Abstract
Peritonitis is a frequent complication of continuous ambulatory peritoneal dialysis (CAPD), with patients suffering recurrent attacks. The microorganisms most frequently implicated in the infection are the skin microflora, in particular, the coagulase-negative staphylococci such as Staphylococcus epidermidis. These microorganisms gain access to the peritoneal cavity via the in-dwelling silicone rubber catheter in the abdominal wall and often persist as biofilms on the surface of the catheter. The surface characteristics of S. epidermidis were monitored during growth in a CAPD in-vitro model together with their ability to adhere to silicone rubber substrata. Fresh dialysis fluid exerted an injurious effect on the cells leading to a decrease in cell numbers but during the simulated dialysis period the cells adapted to the applied stresses. Over a 96-h period in the model both a clinical isolate and a skin isolate of S. epidermidis adopted a more hydrophobic phenotype. The data presented here show that the bacteria grown in this in-vivo reflective CAPD model continually adapt to their environment and become more tolerant to the stresses imposed. The adapted cells were seen to colonise silicone rubber substrata.
Effects on Walker 256 tumour of carmustine associated with a cholesterol-rich microemulsion (LDE)
Authors: Teixeira Raquel S , Curi Rui , Maranhão Raul C 
Published: July 2004

Abstract
A cholesterol-rich microemulsion that binds to low-density lipoprotein (LDL) receptors (LDE), after injection into the bloodstream, concentrates in neoplastic tissues that over-express those receptors. LDE can thus serve as a vehicle for drug targeting. It was shown that carmustine side effects are pronouncedly reduced when the drug is associated with LDE in cancer patients. In this study, the therapeutic action of LDE associated with carmustine was compared with that of the non-associated drug in rats implanted with Walker 256 tumour. The toxicity and anti-tumour activity in rats treated with either free carmustine or carmustine associated with LDE and in control rats treated with saline solution were determined after a single intraperitoneal injection. The LD90 (90% lethal dose) of LDE-carmustine was 77 mg kg−1 and of free carmustine was 44 mg kg−1, indicating that LDE decreases toxicity. LDE-carmustine was able to decrease tumour mass at a lower dose level than free carmustine. Tumour regression time was shorter in LDE-carmustine- than in free carmustine-treated animals. Therefore, this study shows that the association of carmustine with LDE increases the therapeutic index of carmustine.
Eudragit RL100 nanoparticle system for the ophthalmic delivery of cloricromene
Authors: Bucolo Claudio , Maltese Adriana , Maugeri Francesco , Busà Barbara , Puglisi Giovanni , Pignatello Rosario 
Published: July 2004

Abstract
A Eudragit RL100 polymer nanoparticle system loaded with cloricromene was prepared and characterized on the basis of physicochemical properties, stability and drug release features. To investigate the ocular bioavailability of cloricromene after inclusion in the polymer matrix, the new nanoparticle system was topically administered in the rabbit eye and compared with an aqueous solution of the same drug. The nanoparticle system showed interesting size distribution and surface charge values, suitable for ophthalmic application. The results indicated that the dispersion of cloricromene within Eudragit RL100 polymer nanoparticles increased its ocular bioavailability and enhanced the biopharmaceutical profile. The new cloricromene-loaded nanoparticle system described here may be useful in clinical practice.
A parametric library for the simulation of a Union Internationale des Chemins de Fer (UIC) pneumatic braking system
Authors: Pugi L , Malvezzi M , Allotta B , Banchi L , Presciani P 
Published: July 2004

European trains are equipped with a pneumatic braking system that has to respect severe specifications concerning both performances and safety. The pneumatic braking system is composed of hundreds of different pneumatic components that reproduce the prescribed response by a complex logic of pneumatic and mechanical elements. In this paper a tool for a complete simulation of the pneumatic braking system is described, it was developed using the Matlab-Simulink numerical environment. The tool is composed of three different libraries of pneumatic components. The first includes the elementary components such as pipes, orifices, valves and the reservoir. By assembling elementary components, an advanced user can build a customized version of general pneumatic components or plants. Complex components of general use for railway pneumatic brake such as brake cylinders, distributors, pressure transformers and brake valves are available in a second library that can be used to assemble a customized braking plant for a vehicle. The last library is composed of macro-pneumatic subsystems that reproduce the braking system of a typical railway vehicle. Many common plant layouts are reproduced in this library (freight car, passenger coaches, locomotives, etc.). The pneumatic brake system of a train can be simulated by assembling in a single Matlab-Simulink model the elements of the library. In this paper the main features of this numerical tool and the test procedures developed to validate the software are described. Experimental data have been kindly supplied by Trenitalia SPA and they are referred to several test campaigns managed by Italian railway in order to verify and release existing components of the pneumatic brake.
Sodium and Sodium Alloys
Authors: Lemke Charles H. , Markant Vernon H. 
Published: July 2004

AbstractOf all the alkali metals, sodium has had perhaps the greatest commercial success, owing to its relative ease of manufacture and its important role worldwide in the manufacture of organolead compounds for use as gasoline octane enhancers. The decline of organoleads in North America has greatly affected U.S. production. Other sodium uses exist, but none requiring the massive quantities needed for lead antiknock compounds. Most sodium is made electrolytically. Various electrochemical cells are described. Sodium continues to have an important role in the manufacture of many organic chemicals as a reducing agent.
Has the transition to agriculture reshaped the demographic structure of prehistoric populations? New evidence from the Levant
Authors: Eshed Vered , Gopher Avi , Gage Timothy B. , Hershkovitz Israel 
Published: July 2004

AbstractThis paper presents the demographic changes that followed the transition from a hunting‐gathering way of life (Natufian) to an agricultural, food‐producing economy (Neolithic) in the southern Levant. The study is based on 217 Natufian (10,500–8,300 BC) skeletons and 262 Neolithic (8,300–5,500 BC) skeletons. Age and sex identification were carried out, and life tables were constructed. A five‐parameter competing hazard model developed by Siler ([1979] Ecology 60:750–757) was used to smooth life‐table data. No indication of increased mortality with the advent of agriculture was noted. On the contrary, both life expectancy at birth (24.6 vs. 25.5 years) and adults' mean age at death (31.2 vs. 32.1 years) increased slightly from the Natufian to the Neolithic period (assuming stationary populations). Yet the transition to agriculture affected males and females differently: mean age at death in the Natufian was higher for adult females compared to adult males, while in the Neolithic, it was the reverse. One interpretation given to the distribution of female ages at death is that with the onset of the Neolithic period, maternal mortality increased as a result of a concomitant increase in fertility. If the adoption of agriculture in the Levant increased the rate of population growth at the beginning of the Neolithic, expectation of life may have increased dramatically. Am J Phys Anthropol, 2003. © 2003 Wiley‐Liss, Inc.
Circadian rhythms in diet and habitat use in red ruffed lemurs (Varecia rubra) and white‐fronted brown lemurs (Eulemur fulvus albifrons)
Authors: Vasey Natalie 
Published: July 2004

AbstractDaily variation in niche use among vertebrates is attributed to a variety of factors, including thermoregulatory, reproductive, and nutritional requirements. Lemuriform primates exhibit many behavioral and physiological adaptations related to thermoregulation and sharp, seasonal reproduction, yet they have rarely been subjects of a quantitative analysis of circadian (or daily) rhythms in niche use. In this study, I document daily rhythms in diet and microhabitat use over an annual cycle in two sympatric, frugivorous lemurs, Varecia rubra and Eulemur fulvus albifrons. Data on diet, forest site, and forest height were recorded at 5‐min time points on focal animals and divided into three time blocks for analysis (06:00–10:00 hr, 10:00–14:00 hr, and 14:00–18:00 hr). I employed multivariate tests of independence to examine daily rhythms in diet and microhabitat use according to sex, season, and reproductive stage. Throughout the day, V. rubra is frugivorous and dwells in the upper canopy, with notable departures (especially for females) during the hot seasons, gestation, and lactation. E. f. albifrons has heterogeneous daily rhythms of food choice and microhabitat use, particularly across seasons, and both sexes are equally variable. These daily rhythms in diet and microhabitat use appear related to thermoregulatory and nutritional requirements, seasonal food availability and circadian rhythms of plant (and possibly insect) palatability, predator avoidance tactics, and in the case of Varecia, to reproduction. Daily rhythms of food choice in V. rubra support two previously suggested hypotheses explaining why primates consume more nonfruit items late in the day, whereas those of E. f. albifrons are too variable to lend support to these hypotheses. Am J Phys Anthropol, 2003. © 2003 Wiley‐Liss, Inc.
Genetic signatures of pre‐expansion bottleneck in the Choctaw population of Oklahoma
Authors: Wang Ning , Zhou Xiaodong , Tan Filemon K. , Foster Morris W. , Arnett Frank C. , Chakraborty Ranajit 
Published: July 2004

AbstractPrevious research showed that the Choctaw Indians of Oklahoma exhibit considerable linkage disequilibria (LD) in a number of regions of the genome that has allowed genetic fine mapping for potential susceptibility genes for the autoimmune connective tissue disease scleroderma, or systemic sclerosis (SSc). In principle, such enhanced background LD in the Choctaws could be caused by population bottleneck event(s) followed by recent population expansion. This investigation utilizes genome‐scan data on 175 dinucleotide loci from 76 Choctaw individuals to seek genetic evidence of the demographic history of the Choctaw Nation. Of the 175 loci examined, 105 are in Hardy‐Weinberg equilibrium. The average unbiased homozygosity over the 105 loci for the Choctaws (29.3%) is significantly higher than that in the European descent group (20.9%); and when adjusted for sample‐size differences, the Choctaw also exhibit a significantly smaller number of segregating alleles (6.65 vs. 8.14) at these loci. Both of these observations are consistent with the trend expected in an isolated population. Comparison of the allele size variance and gene diversity yields an imbalance index (lnβ) of 0.811 in the Choctaw. Of the 105 loci examined, 93 exhibit excess expected homozygosity in comparison to the expectations of a stepwise mutation model in a population of constant size. Taken together, these observations are consistent with a signature of the recent population size expansion of the Choctaws, preceded by bottleneck event(s). Am J Phys Anthropol, 2003. © 2003 Wiley‐Liss, Inc.
Modellreaktionen für die Rhodium‐katalysierte Oxygenierung von Alkenen
Authors: de Bruin Bas , Budzelaar Peter H. M. , Gal Anton W. 
Published: July 2004

AbstractDie Oxygenierung der C‐H‐ und CC‐Bindungen von Kohlenwasserstoffen, meist mit H2O2 und O2, ist ein wichtiger industrieller Prozess zur Überführung von Mineralöl in hochwertige Chemikalien. Trotz ihrer enormen wirtschaftlichen Bedeutung (und einer entsprechend intensiven Erforschung der Alkenoxygenierung) sind diese Reaktionen aber bislang nur lückenhaft verstanden. Bereits in den frühen 70er Jahren ist eine Anwendung von Rhodium‐ und Iridiumkomplexen in Alkenoxygenierungen eingehend untersucht worden, und einfache anorganische Salze dieser Metalle erwiesen sich verglichen mit dem traditionellen Wacker‐System als weitgehend untauglich. Mit geeigneten Liganden kann andererseits die Oxidation von Alkenen an Rhodium‐ oder Iridiumkomplexen Schritt für Schritt verfolgt werden. Diese Katalysatoren sind daher zur Untersuchung mechanistischer Details der Substratkoordination und der Bildung von C‐O‐Bindungen am Metallzentrum besonders geeignet. Mit den erhaltenen Resultaten lassen sich katalytische Reaktionen mit diesen und eventuell auch mit anderen Metallen besser verstehen. Die Kenntnis der Unterschiede zwischen der Rhodium‐katalysierten Oxidation und der herkömmlichen Wacker‐Oxidation am Palladium könnte zu nützlichen Anwendungen in der Katalyse führen.
Mechanical and aging properties of cross‐linked ethylene propylene diene rubber / styrene butadiene rubber blends
Authors: Nair T. Muraleedharan , Kumaran M. G. , Unnikrishnan G. 
Published: July 2004

AbstractThe mechanical properties and aging characteristics of blends of ethylene propylene diene monomer (EPDM) rubber and styrene butadiene rubber (SBR) were investigated with special reference to the effect of blend ratio and cross‐linking systems. Among the blends, the one with 80/20 EPDM/SBR has been found to exhibit the highest tensile, tear, and abrasion properties at ambient temperature. The observed changes in the mechanical properties of the blends have been correlated with the phase morphology, as attested by scanning electron micrographs (SEMs). The effects of three different cure systems, namely, sulfur (S), dicumyl peroxide (DCP), and a mixed system consisting of sulfur and peroxide (mixed) on the blend properties also were studied. The stress‐strain behavior, tensile strength, elongation at break, and tear strength of the blends were found to be better for the mixed system. The influence of fillers such as high‐abrasion furnace (HAF) black, general‐purpose furnace (GPF) black, silica, and clay on the mechanical properties of 90/10 EPDM/SBR blend was examined. The ozone and water aging studies also were conducted on the sulfur cured blends, to supplement the results from the mechanical properties investigation. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2606–2621, 2004
New side‐chain liquid‐crystalline ionomers. I. Synthesis and characterization of a homopolymer derived from ionic mesogenic groups
Authors: Zang Bao‐Ling , Hu Jian‐She , Meng Fan‐Bao , Zhang Bao‐Yan 
Published: July 2004

AbstractLiquid‐crystalline monomer cholesteryl 4‐allyloxybenzoate (M1), new ionic mesogenic monomer cholesteryl 4‐allyloxy‐3‐(potassium sulfonate)benzoate (M2), and corresponding polymer P1 and ionomer P2 were synthesized. The chemical structures of the monomers and homopolymer were confirmed with Fourier transform infrared and 1H‐NMR spectroscopy. The mesogenic properties were studied with differential scanning calorimetry, thermogravimetric analysis, polarizing optical microscopy, and X‐ray diffraction measurements. The effect of the ionic units on the phase behavior was examined. M1 showed a cholesteric phase, and M2 revealed a smectic A phase. P1 and P2 displayed smectic A phases. The experimental results demonstrated that the addition of ionic units to the mesogenic molecule not only affected the phase‐transition temperature but also changed the mesogenic phase type. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2511–2516, 2004
Photocontrol of the refractive index of poly(methyl methacrylate) with a nitrone additive
Authors: Tanaka Kenta , Shima Koichi , Kondoh Harunobu , Igarashi Tetsutaro , Sakurai Tadamitsu 
Published: July 2004

AbstractHydroxy‐substituted aromatic nitrone derivatives were used for the photochemical control of the refractive index of poly(methyl methacrylate) (PMMA) films. Upon irradiation with 366‐nm light in solution, these derivatives underwent rearrangement reactions, which eventually produced N,N‐diarylformamide derivatives in quantitative yields. Similar photoreactions of the aromatic nitrones in the PMMA films lowered the refractive index of the films by as much as 0.014. The magnitude of the observed refractive‐index change was enough for hydroxy‐substituted nitrones to be used as additives for the fabrication of graded‐index‐type polymer optical fibers. In addition, the refractive index of the PMMA films remained almost constant at any conversion of the starting nitrone derivatives for at least 70 days at room temperature. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2517–2520, 2004