bluuebunny/crossref_metadata_2025 huggingface dataset:
Water‐uptake kinetics in poly(methyl methacrylate) films with a fluorescent rotor probe
Authors: Goodelle J. P. , Pearson R. A. , Santore M. M.
Published: October 2002

A fluorescence method was adapted to measure moisture‐uptake kinetics in films of poly(methyl methacrylate), and data were interpreted in the context of a Fickian diffusion model. The films, 2–60 μm thick, were supported on acid‐etched microscope slides. They were compared with several freestanding slabs about 1 mm thick. The moisture diffusion in the slabs was Fickian with a diffusivity of 3.2 × 10−9 cm2/s. The apparent Fickian diffusivity in the films decreased substantially with decreasing film thickness; however, a careful examination revealed that the initial moisture uptake was governed by a thickness‐independent diffusivity for a wide range of film thicknesses. This suggested that the appearance of non‐Fickian behavior originated within about a micrometer of the buried interface, possibly as a result of water accumulation beneath the film or slight thickness variations. Moisture uptake in the thickest films was more rapid than in the slabs, most likely because of residual thermal stresses. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2463–2471, 2002
The effect of structural features on mechanical properties of loose optical fiber poly(butylene terephthalate) tubes
Authors: Ambroziak Mariusz , Gruin Irma , Wronikowski Marian , Zdunek Krzysztof
Published: October 2002

Results of a study on the modifying mechanical properties of loose optical‐fiber poly(butylene terephthalate) (PBT) tubes, produced during the standard industrial extrusion process, show that heat treatment make the structure of their material to change. The study comprised measurements of mechanical strengths properties of the tubes (tensile strength, compression strength, kinking) and determination of tube material structure [by differential thermal analysis (DTA), wide angle X‐ray scattering analysis (WAXD), and scanning electron microscopy (SEM)]. Results of the study allowed observation that the annealing at 70°C for 34 h of the tubes caused the crystalline α phase to increase in the tube material from ∼28.5% to ∼31.5% and the structure of the existing crystallites to become more perfect. This made the values of certain mechanical properties of the tubes to increase even by as much as 30%. The tubes following such thermal treatment could be used in cables exposed to heavy‐duty operation in arduous environments, where a larger margin from the standpoint of mechanical properties is required. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2130–2134, 2002
Degradation of low density polyethylene during extrusion. I. Volatile compounds in smoke from extruded films
Authors: Andersson Thorbjörn , Wesslén Bengt , Sandström John
Published: October 2002

Many problems with odor and taste in food packaging can be traced to degradation of the packaging materials during processing. From this starting point, the degradation of polyethylene in a commercial extrusion coating process was studied by analyzing degradation products present in smoke sampled at the extruder die orifice. Two low‐density polyethylenes, A and B, with similar melt flow indexes and densities and obtained from different producers, were investigated. A third polymer, C, consisting of recycled material B, was also investigated. More than 40 aliphatic aldehydes and ketones, together with 14 different carboxylic acids, were identified in the smoke. The highest concentration was found for acetaldehyde, regardless of polymer and processing conditions. Increasing the extrusion temperatures in the range 280–325 °C increased the amounts of the oxidized products in the smoke. The extruded film thickness, 12 and 25 μm, influenced the concentrations of degradation products, with the thicker film giving higher amounts of product. The recycled polymer C generally gave lower concentrations of degradation products compared with the virgin polymer B. Differences in the product spectrum between the two virgin polymers may be related to differences in the manufacturing process. Many of the identified compounds have very characteristic taste and smell and are consequently of interest from an odor and taste point of view in food packaging applications. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1580–1586, 2002
Mechanical properties of conducting H‐type polysiloxane–polypyrrole graft copolymers and polytetrahydrofuran–polypyrrole block copolymers
Authors: Biran C. , Toppare L. , Tinçer T. , Yağci Y. , Harabagiu V.
Published: October 2002

The mechanical properties of block copolymers of polypyrrole and pyrrolyl‐ended azobis‐polytetrahydrofuran (TPPy) and graft copolymers of pyrrolyl‐ended H‐type polydimethylsiloxane (SPPy) were investigated and compared with those of polypyrrole (PPy). Conducting films were prepared electrochemically at a constant potential and doped with p‐toluene sulfonate. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1663–1666, 2002
Synthesis and characterization of degradable copoly(ester–amide)s: Poly(trans‐4‐hydroxy‐L‐proline‐co‐ε‐caprolactam)
Authors: Lee Ren‐Shen , Yang Jen‐Ming
Published: October 2002

Novel copolyesteramides were synthesized by reacting trans‐4‐hydroxy‐N‐benzyloxycarbonyl‐L‐proline (N‐CBz‐Hpr) with ε‐caprolactam (CLM) in the presence of stannous octoate [Sn(II) Oct.] as a catalyst. Various techniques, including 1H‐NMR, IR, DSC, and viscosity, were used to elucidate structural characteristics and thermal properties of the resulting copolymers. Data showed that the optimal reaction condition for the synthesis of the copolymers was obtained by using 3 wt % Sn(II) Oct. at 170°C for 24 h. The DSC analysis demonstrated amorphous structure for most of the copolymers. The glass‐transition temperature of the copolymers shifts to a higher temperature with increasing Hpr/CLM molar ratio. In vitro degradation of these poly(N‐CBz‐Hpr‐co‐CLM)s was evaluated by weight loss measurements. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1615–1621, 2002
Synthesis, degradation, and drug delivery of cycloaliphatic poly(ester anhydride)s
Authors: Zhang Tao , Xu Min , Chen Hong , Yu Xuehai
Published: October 2002

The high melting point of poly(1,4‐cyclohexanedicarboxylic anhydride) [poly(CHDA)] is a disadvantage, in that it is intractable in the melting process of a drug delivery system. This report relates to diols introduced into the polyanhydride main chain to decrease its melting point. Various poly(ester anhydride)s containing ethylene glycol, 1,3‐propanediol, 1,4‐butanediol, or 1,6‐hexandiol [poly(CHDA–XDO)] were synthesized by the esterification reaction and melt polycondensation. FTIR, DSC, WAXD, and intrinsic viscosity of polymers were recorded and hydrolytic degradation, as well as in vitro drug delivery, was conducted. The results show that the samples are stable in an anhydrous environment at room temperature and degrade in water following a surface erosion mechanism. The degradation period of poly(CHDA–XDO) ranged from 130 to 320 h as a result of the different diols and amounts of XDO introduced. The in vitro drug delivery gave 130–350 h of stable delivery along with the typical surface erosion mechanism. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2509–2514, 2002
Synthesis and characterization of the copolymer of dodecyl methacrylate/styrene containing an amidine functional group
Authors: Erhan Sevim Z. , Sheng Quan , Adhvaryu Atanu
Published: October 2002

A copolymer of dodecyl methacrylate/styrene (DMA/St) containing the amidine functionality was synthesized and characterized. The one‐step solution copolymerization process was carried out using a mixed solvent, high temperature, and a functional azo initiator, 2,2′‐azobis[N,N′‐dimethylene isobutyramidine]. Copolymers with different compositions (DMA/St 10/1 to 1/2), molecular weight (Mn 2000–9000), and functionality (1.0–2.0) were prepared and characterized by NMR, FTIR, DSC, and elemental analysis. The molecular weight of the copolymers could be controlled by the amount of the initiators. Copolymer composition depends on the feed molar ratio of comonomers. The amidine functionality of the copolymers was determined by elemental analysis. It was found that 72% of the polymer chain has one functionality. The Tg of the copolymer depends on the feed molar ratio. This copolymer could be used as a potential dispersant for lubricant oil. Published 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1684–1691, 2002
On the development of natural fiber composites of high‐temperature thermoplastic polymers
Authors: Jana Sadhan C. , Prieto Alberto
Published: October 2002

A new method is presented for the development of natural fiber composites of high‐performance thermoplastic polymers considering poly(phenylene ether) (PPE) and wood flour as an example system. The large gap between the high processing temperature of PPE, typically between 280 and 320°C, and the low decomposition temperature of wood flour, about 200°C, was reduced by using a reactive solvent, a low molecular weight epoxy. The epoxy formed miscible blends with PPE, which offered much lower viscosity compared to PPE and processing temperatures well below the decomposition temperature of wood flour. In addition, the epoxy component accumulated around the polar wood flour particles upon polymerization during the fabrication step. The composite materials consisted of a thermoplastic continuous phase and two dispersed phases, one of polymerized epoxy and the other of wood flour particles coated with polymerized epoxy. These composites offered a significant reduction in density and better mechanical and physical properties when compared to commercially available grades of engineering polymer blends filled with short glass fibers. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2159–2167, 2002
Synthesis and characterization of side‐chain liquid‐crystalline polyacrylates containing azobenzene moieties
Authors: Silong S. , Lutfor M. R. , Ab Rahman M. Z. , Wan Yunus W. M. Z. , Haron M. J. , Ahmad M. B. , Wan Yusoff W. M. D.
Published: October 2002

Syntheses of novel liquid‐crystalline polymers containing azobenzene moieties were performed by a convenient route with an acrylate backbone. The azobenzenes were key intermediates of the monomers, and side‐chain liquid‐crystalline polymers were prepared, that is, poly[α‐{4‐[(4‐acetylphenyl)azo]phenoxy}alkyloxy]acrylates, for which the spacer length was 3 or 11 methylene units. In addition, poly[3‐{4‐[(3,5‐dimethylphenyl)azo]phenoxy}propyloxy]acrylate was prepared with a spacer length of 3 methylene units. The structures of the precursors, monomers, and polymers were characterized with Fourier transform infrared, 1H‐NMR, and 13C‐NMR techniques. The polymers were obtained by conventional free‐radical polymerization with 2,2′‐azobisisobutyronitrile as an initiator. The phase‐transition temperatures of the polymers were studied with differential scanning calorimetry, and the phase structures were evaluated with a polarizing optical microscopy technique. The results showed that two of the monomers and their corresponding polymers exhibited nematic liquid‐crystalline behavior, and one of the monomers and its corresponding polymer showed smectic liquid‐crystalline behavior. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2653–2661, 2002
Modification of epoxy resin with optically active carboxylic acid
Authors: Samui A. B. , Ratna D. , Chavan J. G. , Deb P. C.
Published: October 2002

L‐leucine was converted to S‐2‐chloro, 4‐methyl pentanoic acid (CMPA) with retention of optical activity. CMPA was reacted with the epoxy resin to form chiral monoester and chiral diester compounds. The modified epoxy resin (MER) was characterized by FTIR spectrophotometer and polarimeter and was analyzed for epoxy content. The MER shows optical activity and the optical rotation increases with increasing concentration of CMPA. DSC studies indicate similar reactivity of the enantiomers of CMPA as well as the recemic mixture. The MER containing different concentrations of chiral modifier was cured with a stoichiometric amount of amine hardener. The cured film (obtained up to 21 mol % of CMPA) exhibits chiral property as well. Dynamic mechanical thermal analysis (DMTA) studies indicate high damping behavior. A shift in tan δ peak toward lower temperature was observed with increasing concentration of chiral modifier. The tan δmax increases up to 14 mol % of CMPA in MER and decreases thereafter. However, storage modulus gradually decreases with an increase in CMPA. Cured film based on two enantiomer‐modified epoxy samples shows different damping behavior. CMPA was also blended with poly(methyl methacrylate) and the blend films were studied similarly. The system behaves in a similar fashion as observed with cured MER films. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2523–2529, 2002
On the compatibility of polysaccharide/maleic copolymer blends. II. Thermal behavior of pullulan‐containing blends
Authors: Bumbu Gina‐Gabriela , Vasile Cornelia , Chiţanu Gabrielle Charlotte , Carpov Adrian
Published: October 2002

The compatibility of pullulan with maleic acid/vinyl acetate copolymers in the solid state in the form of thin films was studied with thermogravimetry, differential scanning calorimetry, infrared spectroscopy, and optical microscopy. With respect to morphology, blends with a content of pullulan greater than 85 wt % exhibited an even distribution of finely dispersed particles. The thermal properties were dependent on the mixing ratio, and the interactions between components were quite pronounced in the pullulan‐rich blends. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1782–1791, 2002
Synthesis and properties of polyether with short alternating conjugated and nonconjugated blocks containing oxadiazole units
Authors: Meng Fanbao , Zhang Baoyan , Zhi Junge , Guan Yan , Jia Yinggang
Published: October 2002

A polyether, poly[(2,5‐dimethylene‐1,3,4‐oxadiazole)dioxy‐1,4‐phenylene‐1,2‐ethenylene‐1,4‐phenylene‐1,2‐ethenylene‐1,4‐phenylene], based on short alternating conjugated oxadiazole units, has been synthesized, which is a kind of PPV derivative that emits blue light. The resulting polymer is fairly soluble in chloroform. The synthesized polymer shows a UV–visible absorbency maximum wavelength around 310 nm in solution. The photoluminescence maximum wavelength for the resulting polymer appears around 470 nm. The polymer also exhibits good thermal stability up to 300°C under N2 atmosphere. It is also observed that the onset temperature of thermal decomposition is as high as 355°C. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2682–2686, 2002
Mechanical properties of films prepared from model high‐glass‐transition‐temperature/low‐glass‐transition‐temperature latex blends
Authors: Tang Jiansheng , Daniels Eric S. , Dimonie Victoria L. , Vratsanos Menas S. , Klein Andrew , El‐Aasser Mohamed S.
Published: October 2002

The mechanical properties of films prepared from model high‐glass‐transition‐temperature (Tg)/low‐Tg latex blends were investigated with tensile testing and dynamic mechanical analysis. Polystyrene (PS; carboxylated and noncarboxylated) and poly(n‐butyl methacrylate‐co‐n‐butyl acrylate) [P(BMA/BA); noncarboxylated] were used as the model high‐Tg and low‐Tg latexes, respectively. Carboxyl groups were incorporated into the PS latex particles to alter their surface properties. It was found that the presence of carboxyl groups on the high‐Tg latex particles enhanced the Young's moduli and the yield strength of the PS/P(BMA/BA) latex blend films but did not influence ultimate properties, such as the stress at break and maximum elongation. These phenomena could be explained by the maximum packing density of the PS latex particles, the particle–particle interfacial adhesion, and the formation of a “glassy” interphase. The dynamic mechanical properties of the latex blend films were also investigated in terms of the carboxyl group coverage on the PS latex particles; these results confirmed that the carboxyl groups significantly influenced the modulus through the mechanism of a glassy interphase formation. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2788–2801, 2002
Effect of the thermal treatment of ionomer films on permeability and permselectivity
Authors: Al‐Ati Tareq , Hotchkiss Joseph H.
Published: October 2002

Ionomers have been studied in detail and have gained widespread commercial use. Interested in altering the ratio of CO2/O2 permeability (i.e., permselectivity) of films for use in packaging respiring produce, we pressed sodium‐neutralized poly(ethylene methacrylic acid) ionomers into films at 120–160°C and investigated their thermal, morphological, and permeability properties. The heat treatment of the ionomers at 160°C increased the gas permeability for O2 more than for CO2 and reduced the CO2/O2 permselectivity ratio from 4.1 to 1.6. The reasons for these changes in the permeability characteristics of the ionomers are not understood but could be related to a reduction in the polyethylene (PE) crystallinity and the destruction of the aggregates into smaller, dispersed clusters. These results were supported by differential scanning calorimetry data and scanning electron micrographs. This suggests that the heat treatment of ethylene–methacyrlic ionomers may improve their potential for applications as selective barriers for modified‐atmosphere packaging of respiring produce. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2811–2815, 2002
Synthesis and properties of poly(amide imide)s based on 2,2′‐ or 4,4′‐bis(4‐aminophenoxy)biphenyl and various bis(trimellitimide)s
Authors: Yang Chin‐Ping , Liou Guey‐Sheng , Jeng Shu‐Huei , Chen Ruei‐Shin
Published: October 2002

Three series of isomeric poly(amide imide)s (series III, IV, and V) were synthesized by the direct polycondensation of 2,2′‐bis(4‐aminophenoxy)biphenyl (2,2′‐BAPB), 4,4′‐bis(4‐aminophenoxy)biphenyl (4,4′‐BAPB), or their equimolar mixture (2,2′‐BAPB/4,4′‐BAPB = 1/1) with 12 diimide diacids and with triphenyl phosphite and pyridine as condensing agents. A comparison of the physical properties of these three series was also made. The inherent viscosities of series III, IV, and V were 0.25–0.84, 0.25–1.52, and 0.43–1.30 dL g−1, respectively. Most of the series III polymers showed better solubility because of the non‐para structure, with the solubility order found to be III > V > IV. According to X‐ray diffraction patterns, the amorphous poly(amide imide)s had excellent solubility, whereas the crystalline polymers were less soluble. All the soluble polymers afforded transparent, flexible, and tough films, which had tensile strengths of 57–104 MPa, elongations at break of 3–20%, and initial moduli of 2.05–2.86 GPa. The glass‐transition temperatures (measured by differential scanning calorimetry) were highest for series IV, which contained the rigid 4,4′‐biphenyl units (254–299°C); copolymer series V ranked second (237–277°C), and series III, with crank 2,2′‐biphenyl structures, had the lowest values (227–268°C). The 10% weight‐loss temperatures (measured by thermogravimetric analysis) were close to one another, ranging from 527 to 574°C in nitrogen and from 472 to 543°C in air. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2763–2774, 2002
Radiation‐induced graft polymerization of methyl methacrylate onto ultrahigh molecular weight polyethylene in the presence of a metallic salt and acid
Authors: Kwon Oh Hyun , Nho Young Chang
Published: October 2002

An attempt was made to graft methyl methacrylate (MMA) onto ultrahigh molecular weight polyethylene preirradiated in air in the presence of a metallic salt and acid. The grafting yield increased with increasing monomer concentration. The maximum grafting yield was around a 60 vol % monomer concentration. The results showed that the inclusion of FeSO4 · 7H2O and sulfuric acid in MMA grafting solutions was extremely beneficial and led to a most unusual synergistic effect in the radiation grafting, much more than with only a metallic salt. However, CuSO4 · 5H2O led to a detrimental effect. It is believed that sulfuric acid accelerates the decomposition of hydroperoxides in the presence of metallic salts such as Fe2+, inhibiting homopolymerization. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2348–2356, 2002
Graft copolymerization of acrylamide–methylacrylate comonomers onto cellulose using ceric ammonium nitrate
Authors: Gupta K. C. , Khandekar Keerti
Published: October 2002

The graft copolymerization of acrylamide–methylacrylate comonomers was carried out using ceric ammonium nitrate as initiator in the presence of nitric acid at 25 ± 1°C. The effects of feed molarity, feed composition, reaction time, and temperature on graft yield (%G) and other grafting parameters were investigated. The determination of rate of ceric (IV) ions disappearance as a function of feed molarity and reaction time was useful in the determination of the rate of ceric (IV) ions consumption during graft copolymerization. The graft yield (%G) in the presence of acrylamide increases because of the synergistic effect of acrylamide comonomer. The composition of the grafted chains (FAAm) varies on varying the feed composition and reaction temperature but is almost constant during feed molarity variation. The Mayo and Lewis method was used to determine the reactivity ratios of acrylamide (r1) and methylacrylate (r2), which are 0.65 and 1.07, respectively. The product of reactivity ratio (r1
r2) is less then unity; hence, an alternate arrangement of comonomer blocks in the grafted copolymer chain is proposed. The rate of graft copolymerization of comonomers onto cellulose is second power to the concentration of comonomers and square root to the concentration of ceric ammonium nitrate. Suitable reaction steps for graft copolymerization of comonomers onto cellulose are proposed. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2631–2642, 2002
Liposome immunoblotting assay using a substrate‐forming precipitate inside immunoliposomes
Authors: Kumada Yoichi , Maehara Masumi , Tomioka Kanji , Katoh Shigeo
Published: October 2002

A new immunoblotting assay which uses antibody‐coupled liposomes containing horseradish peroxidase is proposed. A substrate 4‐chloro‐1‐naphthol permeated through the phospholipid membrane of the antibody‐coupled liposomes and formed a colored product precipitating inside the liposomes. The precipitates accumulated in the liposomes and could be detected at the positions where the liposomes coupled with a target in blotted samples. Combination of liposomes with average diameter of 350 nm and a PVDF membrane with a pore size of 450 nm, 0.02 ng of IgM was detected, while the conventional immunoblotting using antibody‐HRP conjugates detected 2 ng of IgM. The sensitivity increased about two orders of magnitude by the liposome immunoblotting assay. This liposome immunoblotting assay gives a simple detection method of proteins with a high sensitivity, as well as a high sensitivity Western blotting assay. © 2002 Wiley Periodicals, Inc. Biotechnol Bioeng 80: 414–418, 2002.
Production of lovastatin examined by an integrated approach based on chemometrics and DOSY‐NMR
Authors: Bradamante Silvia , Barenghi Livia , Beretta Giangiacomo , Bonfa' Maria , Rollini Manuela , Manzoni Matilde
Published: October 2002

Microbial secondary metabolites are one of the sources of therapeutic molecules in the pharmaceutical industry. Product quality and high yields of secondary metabolites are the main goals for the commercial success of a fermentation process. Our novel approach was based on the decision‐tree algorithm to determine the key variables correlated with the process outcome and on DOSY‐NMR to identify both co‐metabolites and impurities, and it improves fermentation systems and speeds up bioprocess development. The approach has been validated in the case of lovastatin production from Aspergillus terreus. © 2002 Wiley Periodicals, Inc. Biotechnol Bioeng 80: 589–593, 2002.
Aortic arch variation analyzed by using plastination
Authors: Sora Mircea‐Constantin , Strobl Birgit , Förster‐Streffleur Sophie , Staykov Dimitre
Published: October 2002

Different ramification patterns can be observed during the development of the aortic arch. In this study a common trunk (CT), which subsequently branched into the brachiocephalic trunk (BT) and left common carotid artery (LCCA), arose from the aortic arch. The LCCA arose from the CT 10.27 mm above the aortic arch. After crossing the ventral aspect of the trachea and esophagus, the LCCA became situated on the left side of the esophagus. The caliber and length of the main branches of the aortic arch were determined and compared to reports in the literature. This variation was discovered in the context of producing transverse body slices using an E12 plastination process. Clin. Anat. 15:379–382, 2002. © 2002 Wiley‐Liss, Inc.
Assessment of contemporary stent deployment using intravascular ultrasound
Authors: Yoon Samuel C. , Laskey Warren K. , Assadourian Assadour , Kelly Debra , Gellman Joel , Herzog William , Stafford J. Lawrence
Published: October 2002

Four second‐ and third‐generation coronary stents were evaluated using QCA and intravascular ultrasound for adequacy of stent expansion, the influence of disease burden on adequacy of deployment, and postdeployment structural effects on the artery. Despite satisfactory stent deployment rates on angiography of 92 %, adequate stent deployment by IVUS ranged from 38% to 55%. There was no significant difference in deployment success across the four stent types. Lesions with significant plaque burden were associated with a lower rate of deployment success (P = 0.04). Twenty‐one edge dissections were demonstrated by IVUS; only six were detected by angiography. Observations made on first‐generation stents regarding adequacy of deployment still hold true for newer‐generation stents. Significant plaque burden is an independent negative predictor of stent deployment success. The presence of IVUS‐detected edge dissections indicates that the extent of injury during PCI extends beyond the physical length of the stent. Cathet Cardiovasc Intervent 2002;57:150–154. © 2002 Wiley‐Liss, Inc.
The disappearing coronary stenosis: Reemphasizing the importance of excluding coronary vasospasm before coronary intervention
Authors: Parham Walter A. , Kern Morton J.
Published: October 2002

We describe a case of resting angina with multiple angiographic stenoses that were highly suitable for stenting. These classic lesions resolved after intracoronary nitroglycerin while positioning a stent. This case reemphasizes the need to exclude vasospasm prior to any interventional coronary procedure. Cathet Cardiovasc Intervent 2002;57:224–228. © 2002 Wiley‐Liss, Inc.
Chiral synthesis of secondary alcohols using Geotrichum candidum
Authors: Nakamura Kaoru , Matsuda Tomoko , Harada Tadao
Published: October 2002

Chiral synthesis of secondary alcohols of both the (S)‐ and (R)‐enantiomer with extremely high enantioselectivities (up to >99% ee) using a biocatalyst, Geotrichum candidum, is reviewed. Resting cell and dried‐cell preparation using acetone were applied to oxidation, reduction, and deracemization reactions. Many methods to improve the reactivity and enantioselectivity of the reactions were developed. For example, additives such as secondary alcohols and hydrophobic resin (Amberlite™ XAD) were used in nonaqueous reaction media such as organic and supercritical solvents as well as in aqueous ones. As a result, optically pure alcohols of both enantiomers were synthesized on a gram scale. Chirality 14:703–708, 2002. © 2002 Wiley‐Liss, Inc.
Pulsed current gradient power supply for microcoil magnetic resonance imaging
Authors: Seeber D.A. , Hoftiezer J.H. , Pennington C.H.
Published: October 2002

Magnetic resonance imaging (MRI) microscopy requires very strong gradients (>10 T/m) that can be rapidly switched between positive and negative gradient fields. A gradient power supply is presented that is capable of pulsing a custom built triaxial microcoil gradient system to an excess of 15 T/m (and as high as 50 T/m), representing pulsed currents in excess of 150 A into loads of ∼200 mΩ (gradient coil plus cables). The gradient power supply is switchable (from positive to negative gradient fields) within a time of ∼10 μs. An H‐bridge design, consisting of four metal‐oxide semiconductor field‐effect transistors (MOSFETs), is used for changing both the current and magnetic field gradient directions. In series with the H bridge is an additional MOSFET that is optimized to be a voltage‐controlled (adjustable) resistor to send the current through the gradient coils. Because MOSFETS require special driving circuits to overcome parasitic capacitances, the MOSFET fundamental design parameters are also presented to complete the circuit schematics. The gradient power supply presented allows for the high gradient fields required for microcoil MRI of small samples. © 2002 Wiley Periodicals, Inc. Concepts in Magnetic Resonance (Magn Reson Engineering) 15: 189–200, 2002
Impact of undergoing prostate carcinoma screening on prostate carcinoma‐related knowledge and distress
Authors: Taylor Kathryn L. , Shelby Rebecca , Kerner Jon , Redd William , Lynch John
Published: October 2002

BACKGROUND

Despite the ongoing controversy regarding the utility of prostate carcinoma (PCa) screening, the prevalence of asymptomatic men who participate in free PCa screening programs is on the rise. However, this increased awareness has not been associated with increased knowledge about the potential limitations of PCa creening. We conducted a prospective assessment to delineate men's motivations for undergoing screening and to determine the impact of screening on psychological distress and on men's knowledge about PCa screening.

METHODS

We conducted two telephone interviews with a group of 136 men registered to undergo free PCa screening at two hospital‐based sites. The first interview was conducted before screening and the second interview followed receipt of the screening results. Interviews assessed demographics and screening history, reasons for undergoing the current screening, cancer‐related and general psychological distress, knowledge of risk factors for PCa, and knowledge of the benefits and limitations of screening. Only participants with normal screening results were included in these analyses.

RESULTS

“Seeking peace of mind about prostate cancer” was rated as the most important reason for undergoing screening. PCa‐related distress decreased following receipt of a negative result (P < 0.01). Stratified analyses indicated that this was particularly true among younger men and African American men (both Ps < 0.001). Awareness of the benefits of screening was very high, but awareness of limitations was low, with fewer limitations reported following screening compared with prescreening (P < 0.01). Although awareness of the established risk factors improved following screening, controversial risk factors (i.e., those with limited empirical support) and factors that were unrelated to PCa risk were also rated as more important in the development of PCa than they were before screening (all Ps < 0.05). Therefore, the results may reflect that following screening, participants were simply more likely to endorse plausible risk factors, rather than actually reflecting an increase in participants' knowledge.

CONCLUSIONS

These results suggest the importance of developing informed consent procedures and educational programs for the asymptomatic men who participate in free prostate screening programs each year, as the decision to be screened is being made without the benefit of a full understanding of the current state of medical knowledge about PCa screening. Until the definitive results of the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial are available, improved patient education is needed to assist men in making screening decisions consistent with their own preferences. Cancer 2002;95:1037–44. © 2002 American Cancer Society.

DOI 10.1002/cncr.10781
Morphology and therapeutic strategies for neuroendocrine tumors of the genitourinary tract
Authors: Helpap Burkhard
Published: October 2002

BACKGROUND

Although many articles have been published regarding neuroendocrine tumors (NET) and neuroendocrine carcinomas of both low‐ and high‐grade malignancy (NEC) of the genitourinary tract, the histologic diagnosis and therapeutic strategies for treating these entities remains difficult. In the current study the author discusses the significant differences between NET and NEC of the urinary bladder and the prostate, including therapeutic consequences.

METHODS

Four hundred eighty neoplasms of the urinary bladder and prostate with a small cell pattern were analyzed not only on slides stained with hematoxylin and eosin but also by means of immunohistochemical stains demonstrating a neuroendocrine origin. The avidin‐biotin complex method was used with the following markers: MIB‐1, chromogranin A (Chr A), synaptophysin (SNP), cytokeratin (CK) 34βE12, CK20, androgen receptor (AR), and prostate specific antigen (PSA).

RESULTS

Twenty tumors of the urinary bladder and 26 of the prostate demonstrated a diffuse neuroendocrine pattern. Only two patients were found to have a low‐grade NEC of the prostate with a low proliferative index but strong expression of neuroendocrine markers. All other patients with small cell neuroendocrine carcinomas of the bladder and prostate demonstrated extremely high proliferation activity (>80%) and expressed Chr A and SNP. CK34βE12, 20, PSA, and AR were not found to be expressed. The mean survival time was 6.9 months. Fourteen of 20 patients with NEC of the urinary bladder died of the disease and 19 of 24 patients with prostatic NEC died. The therapy for urinary bladder NEC was repeated transurethral resection and antiandrogen therapy was given for NEC of the prostate. Only one patient was treated with chemotherapy, which to the author's knowledge currently is the only treatment for NECs of the genitourinary tract.

CONCLUSIONS

Undifferentiated carcinomas of the urinary bladder and prostate should be analyzed not only by means of hematoxylin and eosin but also by immunohistochemical staining for Chr A and SNP to demonstrate a neuroendocrine origin. Because the prognosis of small cell NECs is very poor, pathologists should indicate in their final report the peculiarities of small cell NECs of the prostate and the urinary bladder with special emphasis on different therapeutic strategies. Cancer 2002;95:1415–20. © 2002 American Cancer Society.

DOI 10.1002/cncr.10840
A Phase II trial of gemcitabine and docetaxel in patients with chemotherapy‐naive, advanced nonsmall cell lung carcinoma
Authors: Popa Irina E. , Stewart Kathleen , Smith Frederick P. , Rizvi Naiyer A.
Published: October 2002

BACKGROUND

The goals of the current study were to determine the safety and efficacy of a nonplatinum‐containing doublet, gemcitabine and docetaxel, in the treatment of patients with chemotherapy‐naive nonsmall cell lung carcinoma (NSCLC).

METHODS

Thirty‐two patients with advanced, chemotherapy‐naive NSCLC were treated with gemcitabine (1000 mg/m2) and docetaxel (40 mg/m2) administered on Days 1 and 8 every 21 days. All patients were evaluable for toxicity and survival and 27 patients were evaluable for response.

RESULTS

This combination was extremely well tolerated with Grade 3 or 4 neutropenia occurring in 6 of 32 patients (19%) (grading was based on the National Cancer Institute Common Toxicity Criteria). There were two episodes of Grade 3 thrombocytopenia and no episodes of Grade 3 or 4 anemia. Grade 3 or 4 nonhematologic toxicities included nausea (occurring in 1 of 32 patients), diarrhea (occurring in 1 of 32 patients), fatigue (occurring in 10 of 32 patients), fluid retention (occurring in 2 of 32 patients), anorexia (occurring in 4 of 32 patients), and transaminitis (occurring in 2 of 32 patients). Six patients experienced Grade 3 pneumonitis that was at least possibly related to the combination of gemcitabine and docetaxel. There was 1 complete response and 7 partial responses for an overall response rate of 30%. The 1‐year and median survivals were 35% and 7.9 months, respectively.

CONCLUSIONS

In the current study, the regimen of gemcitabine (1000 mg/m2) and docetaxel (40 mg/m2) administered on Days 1 and 8 every 21 days was well tolerated with manageable hematologic and nonhematologic toxicities. The responses were comparable to those achieved with platinum‐based combination chemotherapy and the 2‐year survival was an encouraging 19%. These data would support the further study of this nonplatinum doublet in patients with advanced NSCLC. Cancer 2002;95:1714–19. © 2002 American Cancer Society.

DOI 10.1002/cncr.10843
Granule neurons generated during development extend divergent axon collaterals to hippocampal area CA3
Authors: Hastings Nicholas B. , Seth Malika I. , Tanapat Patima , Rydel Tracy A. , Gould Elizabeth
Published: October 2002

Most excitatory intrahippocampal pathways are characterized by significant, highly ordered projections into the long, or septotemporal, hippocampal axis. However, the mossy fiber system, the excitatory projection by which the dentate gyrus projects to hippocampal area CA3, is considered an exception, being organized to innervate exclusively transversely oriented cortical layers of the hippocampus. In the present study, the anatomy of the rat mossy fiber system was investigated using axonal tracing techniques, with an emphasis on determining its projection pattern into the long hippocampal axis. To this end, we used dual ipsilateral retrograde tracer injections to determine whether individual granule cells extend divergent axon collaterals to septotemporally distinct levels of hippocampal area CA3. We combined this technique with the fluorescent immunohistochemical detection of 5‐bromo‐2′‐deoxyuridine (BrdU), a marker of granule cell precursors and their progeny, to address whether the divergence of mossy fiber collaterals within area CA3 might by related to ontogenic gradients in granule cell genesis. We observed single granule neurons that had retrogradely transported both tracers, indicating that they had axon collaterals passing through or terminating within the distinct levels of area CA3 into which tracer had been injected. By using BrdU labeling, we identified divergent granule neurons that were produced during embryonic and postnatal development. We observed no adult‐generated granule neurons with significantly diverging mossy fiber collaterals. However, many fewer cells were labeled with BrdU in adult‐exposed animals. Because of this smaller sample, we cannot rule out the possibility that small numbers of divergent adult‐generated granule cells exist. We conclude that a proportion of the hippocampal mossy fiber projection extends septotemporally divergent axon collaterals to hippocampal area CA3. J. Comp. Neurol. 452:324–333, 2002. © 2002 Wiley‐Liss, Inc.
A multicolor, no‐lyse no‐wash assay for the absolute counting of CD34+ cells by flow cytometry
Authors: Alvarez‐Larran Alberto , Jover Lluis , Marin Pedro , Petriz Jordi
Published: October 2002

Background

We previously developed a method for counting CD34+ cells in unlysed whole blood. This method was applied to normal human bone marrow, peripheral blood after mobilization of progenitor cells, leukapheresis products, and cord blood and was validated with two different lyse‐no wash methods. However, the main advantage that we described, erythrocyte discrimination using nucleic acid staining, was also the main restriction because additional markers for the immunologic characterization of CD34+ cells cannot be included.

Methods

We used SYTO‐13 and fluorescein isothiocyanate (FITC)‐CD45 staining (FL1) instead of SYTO‐13 and phycoerythrin (PE)Cy5‐CD45 staining (FL3) to leave the third and fourth fluorescence parameters available for further characterization of CD34+ cells. The new method was validated by applying it to cord blood samples (n = 20).

Results

FITC‐CD45 antibody gave a 1.7‐fold increase in mean fluorescence intensity over SYTO‐13 alone. From absolute counts (CD34+ cells per microliter), we plotted the differences between the methods against their mean, showing that differences fell into acceptable ranges.

Conclusions

No‐lyse procedures may represent an advance for cell immunophenotyping and it could be applied to the measurement of additional markers. Cytometry (Clin. Cytometry) 50:249–253, 2002. © 2002 Wiley‐Liss, Inc.
Progress in the development of new treatments for combined Alzheimer's and Parkinson's diseases
Authors: Masliah Eliezer , Hansen Lawrence A. , Rockenstein Edward , Hashimoto Makoto
Published: October 2002

Misfolding of synaptic molecules such as amyloid β peptide and α‐synuclein has been proposed to play a key role in the mechanisms of neurodegeneration in Alzheimer's and Parkinson's disease, respectively. Notably, the majority of patients with Alzheimer's disease also have α‐synuclein‐immunoreactive Lewy bodies, and a substantial proportion of them develop a form of parkinsonism also known as Lewy body disease, that defies conventional therapies. Thus, factors involved in the pathogenesis of Alzheimer's disease might promote the development of particularly recalcitrant forms of Lewy body disease. We have shown that the amyloid β peptide 1‐42, of Alzheimer's disease, promotes the toxic conversion of α‐synuclein and accelerates α‐synuclein‐dependent deficits in transgenic mice. Understanding the mechanisms promoting the toxic conversion of α‐synuclein is of critical importance for the design of rationale treatments for Lewy body disease and transgenic models hold the promise for the development of such novel therapies. In this context therapies aimed at: (1) reducing amyloid β peptide 1‐42 production, (2) blocking toxic α‐synuclein oligomerization (e.g., β‐synuclein, antioxidants), (3) promoting α‐synuclein protofibril degradation, and (4) protecting neurons (e.g., anti‐oxidants, neurotrophic agents) against toxic α‐synuclein aggregates might prove to be significantly useful in the treatment of Lewy body disease. We characterized β‐synuclein, the non‐amyloidogenic homologue of α‐synuclein, as an inhibitor of aggregation of α‐synuclein. Our results raise the intriguing possibility that β‐synuclein might be a natural negative regulator of α‐synuclein aggregation, and that a similar class of endogenous factors might modulate the toxic conversion of other molecules involved in neurodegeneration. Such an anti‐amyloidogenic property of β‐synuclein in combination with other treatments might also provide a novel strategy for the treatment of neurodegenerative disorders. Drug Dev. Res. 56:282–292, 2002. © 2002 Wiley‐Liss, Inc.
From cyclooxygenase activities to Alzheimer's disease neuropathology:experimental approaches and therapeutic interventions
Authors: Pasinetti Giulio Maria
Published: October 2002

Several prospective and retrospective epidemiological studies have demonstrated a protective effect for antiinflammatory drugs in Alzheimer's disease (AD). However, despite this evidence therapeutic studies investigating nonsteroidal antiinflammatory drugs (NSAIDs), including cyclooxygenase (COX)‐1 and COX‐2 inhibitors and steroids, do not support this hypothesis. This discrepancy may be due to the fact that the bulk of epidemiological evidence has examined the likely incidence of AD prior to the onset of clinical symptoms of disease. In contrast, in therapeutic studies NSAIDs are administered to patients with illnesses severe enough to exceed the clinical detection threshold, suggesting that NSAID therapy administered following the onset of AD may not be optimally effective. Thus, patients at high risk for AD, e.g., those with mild cognitive impairment (MCI), may be more suitable for study in clinical trials of NSAIDs. Indeed, recent evidence suggests that different indices of classical inflammatory cascades have distinct associations with different phases of the clinical progression of AD. In this review, I discuss the potential role of inflammation in the clinical progression of AD and how this evidence relates to preventive use of antiinflammatory drugs for AD treatment. I then examine the importance of evidence for the potential role of inflammation in amyloidosis in the AD brain and experimental models. I consider the implications of inflammation in AD and recent evidence potentially supporting a negative role of inflammation in vaccination therapy trials. In conclusion, I examine cutting‐edge clinical studies investigating NSAID therapy for AD. Drug Dev. Res. 56:438–445, 2002. © 2002 Wiley‐Liss, Inc.
Role of insulin in Alzheimer's disease:approaches emerging from basic animal research and neurocognitive studies in humans
Authors: Kern Werner , Born Jan , Fehm Horst L.
Published: October 2002

Pancreatic insulin is transported across the blood–brain barrier to bind to central neurons receptors that can mediate actions of the hormone on cognitive function. In different animal models as well as in healthy humans, a beneficial influence of insulin on sensory processing, learning, and memory has been recently demonstrated. Additional support for this view derives from the investigation of the neuronal mechanisms of memory function. Recent findings of decreased levels of insulin in cerebrospinal fluid and a disturbance of insulin signaling in the brain of patients with Alzheimer's disease (AD) have raised interest in the role of insulin for cognitive impairment. Moreover, findings in cultured neurons hint at an influence of insulin on those cellular and molecular processes supposed to underlie AD pathology. Here, we briefly review the literature suggesting a link between disturbed insulin action in the brain and the development and progress of cognitive dysfunction as well as of neuropathological lesions in AD. Additionally, the potential therapeutic use of insulin in AD patients is discussed. Drug Dev. Res. 56:511–525, 2002. © 2002 Wiley‐Liss, Inc.
Effects of neonatal handling and maternal separation on rough‐and‐tumble play in the rat
Authors: Arnold Jennifer L. , Siviy Stephen M.
Published: October 2002

The extent to which brief daily handling and longer periods of separation from the mother during the first 2 weeks of life can affect play behavior in juvenile rats was assessed. Rat pups were separated from the mother for either 15 min daily (handling) or for 3 hr daily (maternal separation), and play was observed as juveniles. Overall levels of playfulness were not affected by either manipulation, although certain aspects of playful responsiveness were affected in males, but not females. In particular, the pattern of responsiveness to playful contacts was feminized in both handled and separated male rats. Activity in a novel open field at 15 days of age was increased in both males and females from the separated group, but not in the handled animals, as were the number of rears exhibited during the play bouts. These data suggest that early rearing experiences can have subtle gender‐dependent effects on some aspects of play in juvenile rats and that the underlying mechanism(s) responsible for these effects may differ from those associated with other effects reported for handling and maternal separation. © 2002 Wiley Periodicals, Inc. Dev Psychobiol 41: 205–215, 2002. Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/dev.10069