bluuebunny/crossref_metadata_2025 huggingface dataset:
Preparation and development of the surface charge density of vanadium phosphate membranes in electrolyte solutions
Authors: Jabeen Fakhra , Rafiuddin
Published: September 2008

Polystyrene‐based vanadium phosphate membranes prepared by a sol–gel route process from aqueous solutions were studied. The uni‐univalent electrolytes (KCl, NaCl, and LiCl) were diffused from the feed solution as a carrier through the prepared membranes with saturated calomel electrodes. The Teorell, Meyer, and Sievers equation was used to estimate the membrane potential, surface charge density, distribution coefficient, transport numbers, and other electrochemical parameters to characterize the prepared membranes. The membrane potentials offered by the uni‐univalent electrolytes through prepared membranes were cation selective and found to be in the order LiCl > NaCl > KCl. The membranes prepared at lower pressures had wider pores and an essentially low surface charge density, whereas membranes prepared at higher pressures carried a high surface charge density and narrow surface openings. The order of charge effectiveness of the electrolytes in the membranes depended on the hydration of the solute–solute interaction and ionic radii of the counterions. The experimental results for membrane potential were consistent with the theoretical prediction. The morphology of the membrane surface was studied by scanning electron microscopy. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Manipulating the conductivity of carbon‐black‐filled immiscible polymer composites by insulating nanoparticles
Authors: Li Bo , Xu Xiang‐Bin , Li Zhong‐Ming , Song Yin‐Chun
Published: September 2008

The conductivity of an immiscible polymer blend system, microfibrillar conductive poly(ethylene terephthalate) (PET)/polyethylene (PE) composite (MCPC) containing carbon black (CB), was changed by the addition of insulating CaCO3 nanoparticles. In MCPC, the PET forms microfibrils during processing and PE forms the matrix. The CB particles are selectively localized in the PET microfibrils. When the insulating CaCO3 nanoparticles are added, they substitute for some of the conductive CB particles and obstruct the electron paths. As a result, the resistivity of the MCPC can be tailored depending on the insulating filler content. The resistivity‐insulating filler content curve displays a sluggish postpercolation region (the region immediately following the percolation region and in front of the equilibrium flat of the resistivity‐filler content curve), suggesting that the MCPC in the postpercolation region possesses an enhanced manufacturing reproducibility and a widened processing window. These features are of crucial importance in making sensor materials. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008.
A semi‐empirical cell voltage model for polymer electrolyte/methanol systems: Applicability of the group contribution method
Authors: Seong Ji Yun , Bae Young Chan
Published: September 2008

A new group contribution model is established to describe the cell voltage of a direct methanol fuel cell as a function of the current density. The model equation is validated with experimental data over a wide range of methanol concentrations and temperatures. The proposed model focuses on very unfavorable conditions for cell operation, that is, low methanol solution concentrations and relatively low cell temperatures. The proposed group contribution method includes a methanol crossover effect that plays a major role in determining the cell voltage of a direct methanol fuel cell. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Differential scanning calorimetry analysis of the thermal treatment of ternary mixtures of ethylene vinyl acetate, polyethylene, and azodicarbonamide
Authors: Reyes‐Labarta J. A. , Marcilla A.
Published: September 2008

The different transitions and reactions involved in the thermal processing of ternary ethylene vinyl acetate (EVA)–polyethylene (PE)–azodicarbonamide (ADC) mixtures with different concentrations of PE and ADC, which was used as a foaming agent, were studied by means of differential scanning calorimetry. The effect of the concentration of PE in the ternary samples was practically linear, which showed an increase in the fusion heat of the PE and the PE domains of the EVA. On the contrary, the mechanism of the thermal decomposition of ADC that the ternary mixtures contained was strongly dependent on its concentration in the sample, which showed clear deviations from linearity. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
γ→β Phase transformation induced in poly(vinylidene fluoride) by stretching
Authors: Imamura R. , Silva A. B. , Gregorio R.
Published: September 2008

The purpose of this work was to show in a conclusive way the γ→β phase transformation induced by uniaxial stretching in poly(vinylidene fluoride). Poly(vinylidene fluoride) films were melted and crystallized at 163°C for 36 h. Under these conditions, a mixture of α and γ phases was formed, with a predominance of the latter. These films were uniaxially stretched at 130°C at a draw ratio of 4. Fourier transform infrared and differential scanning calorimetry analyses showed a γ→β phase transition in the solid state, whereas orientation of the α phase without any transition was observed. Optical microscopy analysis permitted the observation of the transformation of spherulitic structures into oriented lamellae during stretching. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis and properties of polyaniline nanolayers in the presence of retinol in aqueous ethanol
Authors: Wang Donghong , Qi Shuhua , Wu Youming , An Qunli , Li Chunhua
Published: September 2008

Polyaniline (PANI) nanolayers were shown to form spontaneously during the chemical oxidation in the presence of retinol using pure water and aqueous ethanol as reaction media. The effects of the retinol, the volume fraction of ethanol, and the acidity of the polymerization medium on the D.C. conductivity of PANI were investigated through two‐probe method at room temperature. The introduction of 0.2 g retinol improved the D.C. conductivity value of PANI to 3.0 S/cm in pure water and 4.46 S/cm in 50% aqueous ethanol when the H+ concentration was 0.5M. The D.C. conductivity values were 5.1 and 5.49 S/cm when the concentration of H+ was 1.0M in pure water and 2.5M in 50% aqueous ethanol, respectively. The products were also characterized by Fourier transform infrared spectroscopy, ultraviolet–visible spectroscopy, scanning electron microscope, cyclic voltammetry, and X‐ray diffraction techniques. Moreover, the resulting PANI nanolayers exhibited an unusual electromagnetic loss at the microwave frequency (f = 8.2–12.4 GHz) and it arose from order arrangement of polaron as charge carrier caused by nanolayers morphologies and the materials can be used for the potential application as microwave absorbing materials. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Thermal bonding of polypropylene films and fibers
Authors: Hegde Raghavendra R. , Bhat Gajanan S. , Campbell R. A.
Published: September 2008

The thermal bonding behavior of different grades of polypropylene was studied in this research. Initial bonding studies were done with polypropylene films of different grades of polymer with varying morphology, and the studies were extended to polypropylene fibers. Polypropylene fibers manufactured with different cross‐sections, deniers, polymer melt‐flow rates, and different processing conditions were bonded under various conditions. The effect of film structure, properties, and bonding conditions on the bonding efficiency was studied by comparing the tensile strength of bonded films. Thermal bonding was carried for a range of temperatures covering poor, optimum, and over bonding. Changes taking place to the polymer in bond point and the original surface were analyzed using the SEM. Higher bond strength was observed in the vicinity of melting temperature and the strength reduced with a further increase in bonding temperature. The frequent failure point was observed at the bond edge crossover points where film undergoes maximum thickness transition. Lower pressure and shorter time were found to be appropriate for bonding. Films with lower orientation formed better bonds. The optimum bond strength and the optimum bonding temperature observed were different for different polymers. Fiber bond strength results were similar to the results observed in the case of films with respect to the bonding temperatures studied. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Antibacterial poly(vinyl alcohol) film containing silver nanoparticles: Preparation and characterization
Authors: Galya Tsermaa , Sedlařík Vladimír , Kuřitka Ivo , Novotný Radko , Sedlaříková Jana , Sáha Petr
Published: September 2008

The importance of antibacterial materials for biomedical applications is growing nowadays. The presented article deals with the characterization of structural, mechanical and thermal properties and of antibacterial polymeric films based on polyvinyl alcohol (PVA) and silver nitrate, which can find their applicability in wound dressing components and protective coating. The methods of transmission electron microscopy, UV–vis and XRD spectroscopy, optical microscopy, differential scanning calorimetry, stress–strain analysis, and agar diffusion test were used to characterize the polymer films prepared. The results showed strong antibacterial activity against Escherichia coli and Staphylococcus aureus already at the lowest addition level of silver nitrate. An improvement of mechanical properties (Young's modulus) was also noticed due to a modification of PVA with silver nitrate up to 1 wt. % of silver content. Furthermore, the results show a strong effect of the thermal history of the sample preparation on the degree of silver‐ion reduction and formation of nanoparticles. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Structural and photooxidation studies of poly(styrene oxide) prepared with Maghnite‐H+ as cationic catalyst
Authors: Hachemaoui Aïcha , Yahiaoui Ahmed , Belbachir Mohammed
Published: September 2008

The nature of irregularities and end‐groups in poly(styrene oxide) samples prepared using Maghnite‐H+ as a cationic catalyst were studied by 1H‐ and 13C‐NMR at 200 MHz. Head‐to‐head (H‐H) and tail‐to‐tail (T‐T) irregularities are detected in all the samples studied. Secondary hydroxyl terminal groups are identified in polymers prepared with Maghnite‐H+. Poly(styrene oxide) was found to undergo chain scission by aging at 25°C. It was confirmed that oxidation of this type of polymers results from the important sensitivity of the polyether soft segment to oxidative degradation. For this reason, the scissions due to the oxidation of the material lead to notable quantities of low molecular weight photoproducts. Among the various structures produced by the oxidative degradation process, benzoate and secondary hydroxyl groups are identified by MALDI‐TOF‐MS. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Application of laccases with cellulases on denim for clean effluent and repeatable biowashing
Authors: Montazer M. , Maryan A. Sadeghian
Published: September 2008

In this study, we try to use laccases with cellulases to investigate their effects on the garments and possible reusing of biowashing effluent to save water, enzyme, and energy. To achieve these goals, denim garments treated with different percentages of laccases and cellulases and the remaining baths (effluent) used three times with three different methods. Color indices of fabric samples were measured by colorimeter on the front and back of garment and on the white pocket. The effluents in the remaining baths were also monitored by spectrophotometer after each processing. The XRD spectrums were used to calculate the crystalline degrees of the chosen samples. The fiber surfaces of some treated samples were observed by SEM. The results revealed that using optimum concentration of laccases and cellulases produces the same biowashing effect on the garment after three‐repeated biowashing. By using this method, laccases helps to discolor the effluent and enzyme residuals of both cellulases and laccases are useful for repeated processing. Overall, this method is recommending a biowashing process with considerable reduce in consumption of laccases, cellulases, water, time, and energy. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Rheology of 1‐butyl‐3‐methylimidazolium chloride cellulose solutions. III. Elongational rheology
Authors: Sammons Rhea J. , Collier John R. , Rials Timothy G. , Petrovan Simioan
Published: September 2008

The elongational rheology of solutions of cellulose in the ionic liquid solvent 1‐butyl‐3‐methylimidazolium chloride ([Bmim]Cl) was measured at 80, 90, and 100°C; 8, 10, and 12 wt% cellulose; Hencky strains 5, 6, 7; and strain rates from 1 to 100 s−1. Master curves were generated by shifting the elongational viscosity curves with respect to temperature and Hencky strain. Also, general master curves were generated by simultaneously shifting with respect to both temperatures and Hencky strain. From the Arrhenius plots of the temperature shift factors, the activation energy for elongational flow was determined. The elongational rheology of these solutions was elongational strain rate thinning similar to that of their shear behavior and polymer melts and they were also strain hardening. Both effects and the viscosity increased with cellulose concentration. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Effect of length of hydroxyalkyl groups in the clay modifier on the properties of thermoplastic polyurethane/clay nanocomposites
Authors: Kim Wantae , Chung Dae‐won , Kim Jeong Ho
Published: September 2008

Polyether‐ and polyester‐based thermoplastic polyurethane (TPU) nanocomposites containing the montmorillonite modified with quaternary ammonium salts having a relatively long hydroxyalkyl branch (MMT‐OH) were prepared via solution mixing. Quaternary ammonium salts with dimethyl, octyl, hydroxyundecyl branches were synthesized by the addition reaction of dimethyloctylamine and 11‐bromo‐1‐undecanol and were used for the preparation of MMT‐OH. In this MMT‐OH clay, hydroxyl groups are located at the outer end of the relatively long undecyl branch, which may make the hydroxyl groups more exposed to the matrix polymers compared to the clays with the modifiers having shorter hydroxyalkyl chain such as C30B. Actually, more hydroxyl groups in MMT‐OH's are thought to be exposed outside the modified clay, since MMT‐OH's were observed to be somewhat dispersed in water, while clays with shorter alkyl chains were not. From XRD and TEM results, the silicate layers of MMT‐OH were shown to be very well dispersed in ether‐TPU and ester‐TPU nanocomposites prepared from dimethyl acetamide solution. In the case of ester‐TPU nanocomposites, much better clay dispersion was observed for nanocomposites containing MMT‐OH than the ones with C30B in the TEM images. The tensile properties measurement showed the similar trend. Although MMT‐OH has only one hydroxyl group while C30B has two, above results of better tensile properties and water dispersibility of MMT‐OH than C30B having two hydroxyls indicate that the position of hydroxyls may be a important factor in determining the properties of TPU/clay nanocomposites. Fourier transform infrared spectroscopy analyses showed that the long hydroxyalkyl chain modifiers may provide more hydrogen bonding sites than short hydroxyalkyl chain modifiers. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
The Relationship Between the Infraorbital Foramen, Infraorbital Nerve, and Maxillary Mechanoreception: Implications for Interpreting the Paleoecology of Fossil Mammals Based on Infraorbital Foramen Size
Authors: Muchlinski Magdalena N.
Published: September 2008

Osteological cranial features, such as foramina, assist in phylogenetic and ecological interpretations of fossil mammals. However, the validity of using foramina in these interpretations when their contents are not well documented is questionable. For decades, the infraorbital foramen (IOF) has been used to interpret aspects of the fossil record, yet there are conflicting accounts about what passes through the foramen and little known about how neural and vascular structures contribute to its contents. This study tracks and documents the neural and/or vascular anatomy of the IOF and examines the correlation of infraorbital nerve (ION) and IOF cross‐sectional area. To address this question, 161 mammalian cadavers, including 80 primates, were injected with latex dye to track the vascular anatomy associated with the IOF. All ION fibers were then removed from the infraorbital canal, and ION cross‐sectional area was calculated from histological slides. Latex injections and histological slides revealed that only the ION and a small infraorbital artery pass through the IOF. Variation in ION size explains 85% of variation in IOF area, and the artery represents a negligible portion of the foramen. The strong positive correlation between the ION and IOF size suggests that, in the absence of nerve tissue, the IOF can serve as a proxy for ION area. IOF area maybe used to evaluate differences in maxillary mechanoreception in both extinct and extant taxa. Anat Rec, 291:1221–1226, 2008. © 2008 Wiley‐Liss, Inc.
Serous Cells in the Parotid Glands of Two Species of Tamarins: Polarized Secretory Granules
Authors: Tandler Bernard
Published: September 2008

The parotid glands of two species of tamarins were examined by electron microscopy. Endpiece cells are typical in appearance, with an extensive rough endoplasmic reticulum, prominent Golgi apparatuses, and numerous serous granules. In the saddleback tamarin, the secretory granules contain a dense spherule pressed against the inner aspect of the limiting membrane, leading to a surface bulge. During the course of merocrine secretion (a form of exocytosis), such morphologically polarized granules approach the luminal plasma membranes with the bulge in the vanguard. It is these protuberances that fuse with the plasmalemma. In contrast, although serous granules in the cotton top tamarin contain a spherule, they lack surface bulges and their docking on luminal membranes seems to be a random event with respect to their surface morphology. Moreover, certain other types of cells in a taxonomically wide spectrum of species have granules with a less obvious structural polarity, as well as cells whose granules lack morphological polarity but have a functional polarity that comes into play during exocytosis of such secretory granules. Anat Rec, 291:1254–1261, 2008. © 2008 Wiley‐Liss, Inc.
Architectonic Subdivisions of Neocortex in the Gray Squirrel (Sciurus carolinensis)
Authors: Wong Peiyan , Kaas Jon H.
Published: September 2008

Squirrels are highly visual mammals with an expanded cortical visual system and a number of well‐differentiated architectonic fields. To describe and delimit cortical fields, subdivisions of cortex were reconstructed from serial brain sections cut in the coronal, sagittal, or horizontal planes. Architectonic characteristics of cortical areas were visualized after brain sections were processed with immunohistochemical and histochemical procedures for revealing parvalbumin, calbindin, neurofilament protein, vesicle glutamate transporter 2, limbic‐associated membrane protein, synaptic zinc, cytochrome oxidase, myelin or Nissl substance. In general, these different procedures revealed similar boundaries between areas, suggesting that functionally relevant borders were being detected. The results allowed a more precise demarcation of previously identified areas as well as the identification of areas that had not been previously described. Primary sensory cortical areas were characterized by sparse zinc staining of layer 4, as thalamocortical terminations lack zinc, as well as by layer 4 terminations rich in parvalbumin and vesicle glutamate transporter 2. Primary areas also expressed higher levels of cytochrome oxidase and myelin. Primary motor cortex was associated with large SMI‐32 labeled pyramidal cells in layers 3 and 5. Our proposed organization of cortex in gray squirrels includes both similarities and differences to the proposed of cortex in other rodents such as mice and rats. The presence of a number of well‐differentiated cortical areas in squirrels may serve as a guide to the identification of homologous fields in other rodents, as well as a useful guide in further studies of cortical organization and function. Anat Rec, 291:1301–1333, 2008. © 2008 Wiley‐Liss, Inc.
Role of p53 family in birth defects: Lessons from zebrafish
Authors: Danilova Nadia , Sakamoto Kathleen M. , Lin Shuo
Published: September 2008

p53 protein family is an important teratologic suppressor, but in certain conditions it can cause congenital abnormalities. p53 family performs this dual role in development by integrating information from cell's interior with that from the environment to determine the choice between life and death. Understanding of p53 family developmental functions may lead to new therapeutic approaches for treatment and prevention of birth defects. Zebrafish is becoming the vertebrate system of choice for studying p53 family role in development. Birth Defects Research (Part C) 84:215–227, 2008. © 2008 Wiley‐Liss, Inc.
Effects of short‐term W‐CDMA mobile phone base station exposure on women with or without mobile phone related symptoms
Authors: Furubayashi Toshiaki , Ushiyama Akira , Terao Yasuo , Mizuno Yoko , Shirasawa Kei , Pongpaibool Pornanong , Simba Ally Y. , Wake Kanako , Nishikawa Masami , Miyawaki Kaori , Yasuda Asako , Uchiyama Mitsunori , Yamashita Hitomi Kobayashi , Masuda Hiroshi , Hirota Shogo , Takahashi Miyuki , Okano Tomoko , Inomata‐Terada Satomi , Sokejima Shigeru , Maruyama Eiji , Watanabe Soichi , Taki Masao , Ohkubo Chiyoji , Ugawa Yoshikazu
Published: September 2008

To investigate possible health effects of mobile phone use, we conducted a double‐blind, cross‐over provocation study to confirm whether subjects with mobile phone related symptoms (MPRS) are more susceptible than control subjects to the effect of electromagnetic fields (EMF) emitted from base stations. We sent questionnaires to 5,000 women and obtained 2,472 valid responses from possible candidates; from these, we recruited 11 subjects with MPRS and 43 controls. There were four EMF exposure conditions, each of which lasted 30 min: continuous, intermittent, and sham exposure with and without noise. Subjects were exposed to EMF of 2.14 GHz, 10 V/m (W‐CDMA), in a shielded room to simulate whole‐body exposure to EMF from base stations, although the exposure strength we used was higher than that commonly received from base stations. We measured several psychological and cognitive parameters pre‐ and post‐exposure, and monitored autonomic functions. Subjects were asked to report on their perception of EMF and level of discomfort during the experiment. The MPRS group did not differ from the controls in their ability to detect exposure to EMF; nevertheless they consistently experienced more discomfort, regardless of whether or not they were actually exposed to EMF, and despite the lack of significant changes in their autonomic functions. Thus, the two groups did not differ in their responses to real or sham EMF exposure according to any psychological, cognitive or autonomic assessment. In conclusion, we found no evidence of any causal link between hypersensitivity symptoms and exposure to EMF from base stations. Bioelectromagnetics 30:100–113, 2009. © 2008 Wiley‐Liss, Inc.
Rapid chemiluminometric determination of gabapentin in pharmaceutical formulations exploiting pulsed‐flow analysis
Authors: Manera Matías , Miró Manuel , Ribeiro Marta F. T. , Estela José Manuel , Cerdà Víctor , Santos João L. M. , Lima José L. F. C.
Published: September 2008

In this study, a straightforward and automated pulsed flow‐based procedure was developed for the chemiluminometric determination of gabapentin [1‐(aminomethyl)cyclo‐hexaneacetic acid], a new generation antiepileptic drug, in different formulated dosage forms. The software‐controlled time‐based injection method capitalizes on the decrease of the background chemiluminescence (CL) readout of the luminol–hypochlorite reaction in the presence of gabapentin. In short, gabapentin works as a hypochlorite scavenger. The analytical procedure was implemented in a multi‐pumping flow network furnished with a suite of microdispensing solenoid‐actuated pumps. The diaphragm‐type micropumps might be configured to operate as fluid propellers, commutation units and metering injectors. A dynamic linear working range for gabapentin concentrations in the range 60–350 µmol/L was obtained, with an estimated detection limit of 40 µmol/L. The flow analyser handles about 41 injections/h and yields precise results (RSD < 2%). The miniaturized flow analyser thus has potential to be exploited for in‐line monitoring of drug manufacturing within the quality assurance framework of modern pharmaceutical companies. Copyright © 2008 John Wiley & Sons, Ltd.
Luminescent and hydrophilic LaF3–polymer nanocomposite for DNA detection
Authors: Wang Lun , Li Peng , Wang Leyu
Published: September 2008

Luminescent LaF3–Ce3+/Tb3+ nanocrystals have been successfully prepared via a simple wet chemical technique. For the next bioapplication, these nanoparticles dispersed in cyclohexane have also been functionalized with poly(St‐co‐MAA), based on a designed oil‐in‐water microemulsion system. These polymer‐coated nanospheres are water‐soluble and bioconjugable. Unlike semiconductor quantum dots, the as‐prepared lanthanum fluoride nanocrystals possess non‐size‐dependent emissions and completely stable photocycles. With functionalized LaF3 nanospheres as fluorescence probes, a fluorescence method was developed for the rapid quantitative analysis of DNA, due to the quenching effect of fluorescence by the DNA. Under optimum conditions, the fluorescence intensity was proportional to the concentration of the introduced DNA over the range 2.5–35 µg/mL for calf thymus DNA (ctDNA) and 2.5–30 µg/mL for fish sperm DNA (fsDNA), respectively. Copyright © 2008 John Wiley & Sons, Ltd.
Development of a chemiluminescent imaging assay for the detection of anti‐erythropoietin antibody in human sera
Authors: Wang Wenjun , Lu Yanyan , Zhang Sichun , Wang Shidong , Cao Po , Tian Yaping , Zhang Xinrong
Published: September 2008

Measuring low amounts of anti‐erythropoietin antibodies (anti‐EPO Abs) is important to evaluate the therapeutic safety of recombinant human erythropoietin (rhEPO). In this work, a simple, sensitive and high‐throughput chemiluminescent (CL) imaging assay was developed for the detection of anti‐EPO Abs in human sera. The influence of several physicochemical parameters, such as coating conditions, incubation time, detergent concentration and exposure time, were investigated. A calibration curve was established and the range of quantitative detection was 0.12–13.91 ng/mL. The limit of detection (LOD, 3σ) for the CL‐imaging assay was 0.033 ng/mL. Compared to conventional colorimetric enzyme‐linked immunosorbent assay (ELISA), the LOD of the CL‐imaging assay is 50‐fold lower. The recoveries of anti‐EPO Abs in the fortified serum were in the range 87.1–116.9% using the present method, which highlighted the validity of the CL‐imaging assay system to accurately determine the anti‐EPO Abs in serum samples. CL‐imaging assay was used to evaluate the presence of anti‐EPO Abs in serum samples obtained from chronic renal failure (CRF) patients treated with rhEPO. Contrary to what was expected, the sera from CRF patients did not contain anti‐EPO Abs. Copyright © 2008 John Wiley & Sons, Ltd.
Chiral HPLC separation and absolute configuration of novel S‐DABO derivatives
Authors: Cirilli Roberto , Ferretti Rosella , La Torre Francesco , Borioni Anna , Fares Vincenzo , Camalli Mercedes , Faggi Cristina , Rotili Dante , Mai Antonello
Published: September 2008

Chiral 2‐(sec‐butylthio)‐6‐[1‐(2,6‐dichlorophenyl)propyl]‐5‐methylpyrimidin‐4(3H)‐one (compound 1) was synthesized to serve as a model compound for structural elucidation of novel S‐DABO (dihydroalkoxybenzyloxopyrimidine) derivatives endowed with potential HIV‐1 reverse transcriptase inhibitory activity. Stereochemical characterization of four stereoisomers of 1 was achieved by an experimental approach based on the following steps: (a) direct HPLC enantio‐ and diastereoseparation at semipreparative scale; (b) determination of elution order of stereomeric mixture by using chiroptical detection (polarimeter or circular dichroism (CD)); (c) X‐ray crystallography of two diastereoisomers isolated at semipreparative scale. The CD analysis of 1 and its two analogues (compounds 2 and 3), both having a single stereogenic center located in two different alkyl side chains of the dihydropyrimidinone structure, was carried out. The results of this study indicated a correlation between the absolute configuration at C‐1 of alkyl side chain of the dihydropyrimidinone structure and the sign of the CD band at around 245 nm. Chirality, 2008. © 2009 Wiley‐Liss, Inc.
Clofarabine
Authors: Musto Pellegrino , Ferrara Felicetto
Published: September 2008

Although relapse still represents the most relevant obstacle to achieving a cure in acute myeloid leukemia, it offers an opportunity to investigate new therapeutic strategies, mainly in patients who are expected to gain negligible advantage from conventional salvage chemotherapy. In this setting, clofarabine represents 1 of the most promising drugs.
Prostate‐specific antigen levels in relation to consumption of nonsteroidal anti‐inflammatory drugs and acetaminophen
Authors: Singer Eric A. , Palapattu Ganesh S. , van Wijngaarden Edwin
Published: September 2008

BACKGROUND.

Inflammation has been implicated in prostate carcinogenesis; therefore, the use of nonsteroidal anti‐inflammatory drugs (NSAIDs) has the potential of decreasing the risk of prostate cancer. However, to the authors' knowledge the precise correlation between oral NSAID use, serum prostate‐specific antigen (PSA), and prostate cancer risk is unknown. To further characterize this association, the authors evaluated serum PSA levels with regard to NSAID and acetaminophen consumption in a large cross‐sectional study of men in the US.

METHODS.

PSA levels were determined in 1319 men aged >40 years in the 2001‐2002 National Health and Nutrition Examination Survey (NHANES). Linear regressions were performed on log‐transformed PSA levels, accounting for the complex survey design, to evaluate the relations between PSA and the use of NSAIDs and acetaminophen after adjusting for the effects of age, race, educational level, smoking status, body mass index, coexisting inflammatory conditions, and heart disease.

RESULTS.

NSAID and acetaminophen consumption displayed a negative association with PSA levels, namely, individuals who reported using NSAIDs (19.8%) or acetaminophen (1.3%) regularly had lower PSA levels than individuals who did not take these drugs, although the impact of acetaminophen was not statistically significant. PSA levels among NSAID users were 0.9 times the levels among nondrug takers (P = .038), whereas PSA levels among acetaminophen users were 0.76 times the levels in nondrug takers (P = .14). Individuals who stated they took both NSAIDs and acetaminophen (0.99%) on a regular basis had higher PSA levels (1.8 times greater), although not statistically significantly so (P = .24), than individuals who stated they did not take either of these drugs regularly.

CONCLUSIONS.

The findings of the current study suggest that regular NSAID consumption may reduce serum PSA levels. Whether this is indicative of a protective effect on prostate cancer risk or masks possible prostate injury resulting in reduced detection of prostate cancer is unclear. Given the widespread consumption of NSAIDs and the regular use of PSA for the assessment of prostate cancer risk, the potential implications of the current study's findings may be substantial and warrant further investigation. Cancer 2008. © 2008 American Cancer Society.
Treatment of malignant pheochromocytoma/paraganglioma with cyclophosphamide, vincristine, and dacarbazine
Authors: Huang Hui , Abraham Jame , Hung Elizabeth , Averbuch Steven , Merino Maria , Steinberg Seth M. , Pacak Karel , Fojo Tito
Published: September 2008

BACKGROUND

A long‐term follow‐up was conducted of 18 patients with a diagnosis of pheochromocytoma/paraganglioma treated with a combination of cyclophosphamide, vincristine, and dacarbazine (CVD).

METHODS

The study design was a nonrandomized, single‐arm trial conducted at a government medical referral center. Eighteen patients with metastatic malignant pheochromocytoma/paraganglioma were studied. After controlling symptoms of catecholamine excess, patients were treated with cyclophosphamide at 750 mg/m2, vincristine at 1.4 mg/m2, and dacarbazine at 600 mg/m2 on Day 1 and dacarbazine at 600 mg/m2 on Day 2, every 21 to 28 days.

RESULTS

Combination chemotherapy with CVD produced a complete response rate of 11% and a partial response rate of 44%. Median survival from a landmark was 3.8 years for patients whose tumors responded to therapy and 1.8 years for patients whose tumors did not respond (P = .65). All patients with tumors scored as responding reported improvement in their symptoms related to excessive catecholamine release and had objective improvements in blood pressure. CVD was well tolerated with only grade I/II toxicities.

CONCLUSIONS

Combination chemotherapy with CVD produced objective tumor responses in patients with advanced malignant pheochromocytoma/paraganglioma. In this 22‐year follow‐up there was no difference in overall survival between patients whose tumors objectively shrank and those with stable or progressive disease. However, patients reported improvement in symptoms, had objective improvements in blood pressure, and had tumor shrinkage that made surgical resection possible. The authors conclude that CVD therapy is not indicated in every patient with metastatic pheochromocytoma/paraganglioma, but should be considered in the management of patients with symptoms and where tumor shrinkage might be beneficial. Cancer 2008. © 2008 American Cancer Society.
Patient navigation: State of the art or is it science?
Authors: Wells Kristen J. , Battaglia Tracy A. , Dudley Donald J. , Garcia Roland , Greene Amanda , Calhoun Elizabeth , Mandelblatt Jeanne S. , Paskett Electra D. , Raich Peter C. ,   the Patient Navigation Research Program
Published: September 2008

First implemented in 1990, patient navigation interventions are emerging today as an approach to reduce cancer disparities. However, there is lack of consensus about how patient navigation is defined, what patient navigators do, and what their qualifications should be. Little is known about the efficacy and cost‐effectiveness of patient navigation. For this review, the authors conducted a qualitative synthesis of published literature on cancer patient navigation. By using the keywords ‘navigator’ or ‘navigation’ and ‘cancer,’ 45 articles were identified in the PubMed database and from reference searches that were published or in press through October 2007. Sixteen studies provided data on the efficacy of navigation in improving timeliness and receipt of cancer screening, diagnostic follow‐up care, and treatment. Patient navigation services were defined and differentiated from other outreach services. Overall, there was evidence of some degree of efficacy for patient navigation in increasing participation in cancer screening and adherence to diagnostic follow‐up care after the detection of an abnormality. The reported increases in screening ranged from 10.8% to 17.1%, and increases in adherence to diagnostic follow‐up care ranged from 21% to 29.2% compared with control patients. There was less evidence regarding the efficacy of patient navigation in reducing either late‐stage cancer diagnosis or delays in the initiation of cancer treatment or improving outcomes during cancer survivorship. There were methodological limitations in most studies, such as a lack of control groups, small sample sizes, and contamination with other interventions. Although cancer‐related patient navigation interventions are being adopted increasingly across the United States and Canada, further research will be necessary to evaluate their efficacy and cost‐effectiveness in improving cancer care. Cancer 2008. © 2008 American Cancer Society.
Salvage stereotactic radiosurgery effectively treats recurrences from whole‐brain radiation therapy
Authors: Chao Samuel T. , Barnett Gene H. , Vogelbaum Michael A. , Angelov Lilyana , Weil Robert J. , Neyman Gennady , Reuther Alwyn M. , Suh John H.
Published: September 2008

BACKGROUND.

The purpose of the current study was to examine overall survival (OS) and time to local failure (LF) in patients who received salvage stereotactic radiosurgery (SRS) for recurrent brain metastases (BM) after initial management that included whole‐brain radiation therapy (WBRT).

METHODS.

The records of 1789 BM patients from August 1989 to November 2004 were reviewed. Of these, 111 underwent WBRT as part of their initial management and SRS as salvage. Patients were stratified by Radiation Therapy Oncology Group (RTOG) recursive partitioning analysis class, primary disease, dimension of the largest metastases and number of BM at initial diagnosis, and time to first brain recurrence after WBRT. Overall survival, survival after SRS, and time to local and distant failure were analyzed.

RESULTS.

The median OS from the initial diagnosis of BM was 17.7 months. Median survival after salvage SRS for the entire cohort was 9.9 months. Median survival after salvage SRS was 12.3 months in patients who had their first recurrence >6 months after WBRT versus 6.8 months for those who developed disease recurrence ≤6 months after (P = .0061). Primary tumor site did not appear to affect survival after SRS. Twenty‐eight patients (25%) developed local recurrence after their first SRS with a median time of 5.2 months. A dose <22 grays and lesion size >2 cm were found to be predictive of local failure.

CONCLUSIONS.

In this study, patients who recurred after WBRT and were treated with salvage SRS were found to have good local control and survival after SRS. WBRT provided good initial control, as 45% of these patients failed >6 months after WBRT. Those with a longer time to failure after WBRT had significantly longer survival after SRS. Cancer 2008. © 2008 American Cancer Society.
Receipt of guideline‐recommended follow‐up in older colorectal cancer survivors
Authors: Cooper Gregory S. , Kou Tzuyung Doug , Reynolds Harry L.
Published: September 2008

BACKGROUND

After curative resection for colorectal cancer, routine follow‐up with office visits, carcinoembryonic antigen (CEA), and colonoscopy is recommended. The actual adherence to these guidelines as well as the potential overuse of testing in routine practice has not been well studied.

METHODS

The authors identified 9426 eligible patients aged ≥66 years in a linked tumor registry‐claims database who were diagnosed with adenocarcinoma of the colon or rectum from 2000 to 2001. Patients were observed to 3 years after diagnosis. Receipt of ≥2 office visits per year, ≥2 CEA tests per year (years 1 and 2), and ≥1 colonoscopy within 3 years constituted guideline fulfillment.

RESULTS

Guidelines for office visits, colonoscopy, and CEA testing were met in 92.3%, 73.6%, and 46.7% of patients, respectively. In addition, receipt of 2 nonrecommended procedures, abdominal/pelvic computed tomography scans and positron emission tomography scans, was documented in 47.7% and 6.8%, respectively. Overall, 60.2% received testing below recommended levels, 17.1% at recommended frequency, and 22.7% above guideline recommendations. In a multivariate analysis, factors associated with meeting guidelines included younger age group, white race, regional stage cancers, and poorly differentiated tumors. Considerable geographic variation in meeting guidelines was also observed.

CONCLUSIONS

Many older colorectal cancer survivors in this population‐based cohort underwent testing below a minimum frequency specified by clinical practice guidelines, especially with regard to CEA. Further studies should ascertain the reasons for poor compliance and the effect on patient outcome. Cancer 2008. © 2008 American Cancer Society.
Patient‐physician disagreement regarding performance status is associated with worse survivorship in patients with advanced cancer
Authors: Schnadig Ian D. , Fromme Erik K. , Loprinzi Charles L. , Sloan Jeff A. , Mori Motomi , Li Hong , Beer Tomasz M.
Published: September 2008

BACKGROUND.

Physician‐reported performance status (PS) is an important prognostic factor and frequently influences treatment decisions. To the authors' knowledge, the extent, prognostic importance, and predictors of disagreements in PS assessment between physicians and patients have not been adequately examined.

METHODS.

Using North Central Cancer Treatment Group (NCCTG) clinical trial data from 1987 through 1990, the authors compared PS (Eastern Cooperative Oncology Group [ECOG] and Karnofsky [KPS]) and nutrition scores reported by physicians and patients individually. Differences were analyzed using a Student t test for paired data and degree of disagreement by kappa statistic. The effect of disagreement on overall survival was determined by the Kaplan‐Meier method and Cox regression analysis. Predictors of disagreement were identified by logistic regression.

RESULTS.

In all, 1636 patients with advanced lung and colorectal cancer had a median survival of 9.8 months (95% confidence interval [95% CI], 9.4‐10.4 months). Percent disagreement between patients and physicians regarding KPS, ECOG PS, and nutrition score were 67.1%, 56.6%, and 58.0%, respectively. Physicians were more likely to rate patients better than individual patients were to rate themselves: ECOG (mean 0.91 vs 1.30; P < .0001), KPS (mean 83.3 vs 81.7; P < .0001), and nutrition score (mean 1.6 vs 2.1; P < .0001). Disagreement between patients and their physicians was associated with increased risk of death: KPS (hazards ratio [HR] of 1.16; 95% CI, 1.04‐1.30 [P = .008]) and nutrition scores (HR of 1.44; 95% CI, 1.29‐1.61 [P < .0001]) after adjustment for covariates. Patient sociodemographic factors that predict disagreement were identified.

CONCLUSIONS.

Physicians and patients frequently disagree regarding PS and nutritional status. Disagreement is associated with an increased risk of death in patients with advanced malignancies. These findings illustrate the limitations of physician‐only assessed PS. Cancer 2008. © 2008 American Cancer Society.
A phase 2 trial of whole‐brain radiotherapy combined with intravenous chemotherapy in patients with brain metastases from breast cancer
Authors: Cassier Philippe A. , Ray‐Coquard Isabelle , Sunyach Marie‐Pierre , Lancry Laurence , Guastalla Jean‐Paul , Ferlay Céline , Gomez Frédéric , Curé Hervé , Lortholary Alain , Claude Line , Blay Jean‐Yves , Bachelot Thomas
Published: September 2008

BACKGROUND

A study was conducted to determine the efficacy, tolerability, and safety of concurrent cisplatin and vinorelbine chemotherapy and radiotherapy in patients with previously untreated brain metastases from breast cancer.

METHODS

Twenty‐five patients with untreated brain metastases from breast cancer were treated with cisplatin (at a dose of 20 mg/m2/day, Days 1‐5) and vinorelbine (6‐mg/m2 bolus on Day 1 and 6 mg/m2/day continuous infusion on Days 1‐5) chemotherapy combined with concurrent 30‐gray fractionated external‐beam radiotherapy. Chemotherapy was given at 3‐week intervals for a total of 4 cycles. Primary endpoint was the rate of radiologic response of brain metastases.

RESULTS

Complete response in the brain was observed in 3 patients, and partial response was noted in 16 patients, yielding a 76% response rate in the brain. The overall systemic response rate was 44%. Progression‐free and overall survival were 3.7 months and 6.5 months, respectively. Overall toxicity was acceptable; nonhematologic grade 3‐4 events were noted in 5 (20%) patients, and there were no toxic deaths.

CONCLUSIONS

Concurrent chemoradiation with cisplatin and vinorelbine for brain metastases from breast cancer appears to be active and well tolerated. Cancer 2008. © 2008 American Cancer Society.
Management of brain metastases from ovarian and endometrial carcinoma with stereotactic radiosurgery
Authors: Monaco Edward , Kondziolka Douglas , Mongia Sanjay , Niranjan Ajay , Flickinger John C. , Lunsford L. Dade
Published: September 2008

BACKGROUND

Metastases to the brain from ovarian and endometrial carcinoma are uncommon and to the authors' knowledge consensus regarding optimal management is lacking. Stereotactic radiosurgery (SRS) has proven useful for the treatment of many benign and malignant brain tumors. In the current study, the authors evaluated outcomes after SRS in patients with ovarian and endometrial carcinoma.

METHODS

Twenty‐seven patients with brain metastases underwent gamma–knife SRS. Six patients had endometrial carcinoma, whereas 21 patients had ovarian carcinoma. Eighteen patients also received whole–brain radiotherapy. A total of 68 tumors were treated with gamma–knife SRS.

RESULTS

At the time of last follow–up, 1 patient was still alive and 26 had died. The median survival was 7 months after the initial diagnosis of brain metastasis and 5 months after SRS. The 1‐year survival rate after radiosurgery was 15% and that from the diagnosis of brain metastases was 22%. On final imaging, all tumors were controlled without further growth. Two patients (7.4%) developed new or progressive neurologic deficits after SRS.

CONCLUSIONS

SRS is an acceptable choice for the treatment of brain metastases resulting from ovarian and endometrial carcinoma, and provides local tumor control with limited morbidity. Careful patient selection is warranted in the setting of patients with uncontrolled systemic disease in whom a limited survival benefit is expected. Cancer 2008. © 2008 American Cancer Society.
Performance status and sensitivity to first‐line chemotherapy are significant prognostic factors in patients with recurrent small cell lung cancer receiving second‐line chemotherapy
Authors: Kim Young Hak , Goto Koichi , Yoh Kiyotaka , Niho Seiji , Ohmatsu Hironobu , Kubota Kaoru , Saijo Nagahiro , Nishiwaki Yutaka
Published: September 2008

BACKGROUND

To the authors' knowledge, the prognostic factors in recurrent small cell lung cancer (SCLC) patients treated with second‐line chemotherapy have not yet been clearly identified to date.

METHODS

Between July 1992 and December 2003, 232 of 515 patients who were diagnosed to have SCLC at the National Cancer Center Hospital East were administered second‐line chemotherapy for recurrent disease. The authors retrospectively analyzed the relation between clinical factors evaluated at the time of recurrence and the response to second‐line chemotherapy or survival in these patients.

RESULTS

The results of univariate analyses revealed that response was significantly associated with the performance status (PS) alone, whereas survival was significantly associated with the PS, disease extent, and sensitivity to first‐line chemotherapy. Multivariate analysis identified PS (P < .0001) and sensitivity to first‐line chemotherapy (P = .0024) as the independent prognostic factors for survival. When the patients were grouped according to these 2 significant prognostic factors, the survival of patients with a PS of 0 to 1 was significantly better than that of the patients with a PS of 2 to 4 both among cases that were sensitive and those that were refractory to first‐line chemotherapy. Although the survival of sensitive recurrent cases was significantly better than that of the refractory recurrent cases among the patients with a PS of 0 to 1 patients, no survival difference was observed between the sensitive and refractory recurrent cases in the patients with a PS of 2 to 4.

CONCLUSIONS

Both PS and sensitivity to initial chemotherapy were found to be significant prognostic factors for survival in recurrent SCLC patients treated with second‐line chemotherapy. These 2 factors should therefore be used as stratification factors in future clinical trials. Cancer 2008. © 2008 American Cancer Society.