bluuebunny/crossref_metadata_2025 huggingface dataset:
Syntheses and magnetic properties of novel bithiazole‐containing polymeric complexes
Authors: Weng Jian , Sun Weilin , Jiang Liming , Shen Zhiquan
Published: August 2002

Three novel bithiazole‐containing polymers were synthesized from 2,2′‐diamino‐4, 4′‐bithiazole (DABT) condensed with bismaleimide, bis(methyloxycarbonyl ethyl)tin dichloride (BETD), and 4,4′‐diphenylmethane diisocyanate (DPDI), respectively. A new series of polymeric complexes were prepared from Fe2+ and the three polymers. These polymers and their complexes were characterized through FTIR, 1H‐NMR, and related techniques. The chemical compositions of the complexes were determined by XPS. The presence of the exchange interaction between the unpaired electrons was investigated by ESR spectroscopy. The magnetic behavior of these complexes was measured as a function of the magnetic field strength (0–40 kOe) at 5 K and as a function of temperature (5–300 K) at a magnetic field strength of 30 kOe. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1353–1359, 2001
Solid‐phase extraction of phenolic compounds with poly[metalloprotoporphyrin IX]
Authors: Lo Balbo Alfredo , Hurst Jorge , Campo Dall'Orto Viviana , Rezzano Irene
Published: August 2002

A highly insoluble metalloporphyrin polymeric material was used as sorbent for the solid‐phase extraction of phenolic compounds. Substantial quantities of phenols (40 to 60 mg/g polymer) were absorbed from aqueous solution comparing satisfactorily with other extraction methods. The polymeric phase presented similar KSPE values for the hydrophobic compounds tested such as p‐chlorophenol, BPA, p‐nitrophenol, and a significant lower value for the more hydrophilic p‐aminophenol and cresol. Several metallic complexes of protoporphyrin IX (Co2+, Cu2+, Ni2+, Zn2+, and Fe3+) have been tested. The analytes were extracted with high recoveries at acid and neutral pH values, whereas at pH 10 low recoveries were obtained. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 3038–3043, 2001
Cellulose/casein blend membranes from NaOH/urea solution
Authors: Yang Guang , Zhang Lina , Han Hongwei , Zhou Jinping
Published: August 2002

Cellulose membranes and cellulose/casein blend membranes were successfully prepared from a new solvent system (6 wt % NaOH/4 wt % urea aqueous solution) by coagulation with a sulfuric acid aqueous solution. The structures and properties of the membranes were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy (SEM), wide‐angle X‐ray diffraction, differential scanning calorimetry, and a tensile test. The experimental results showed that the suitable coagulation condition was 5 wt % H2SO4 for 5 min. When the casein content of the mixture was less than 15 wt %, the blend membranes were miscible because of the interactions between the hydroxyl groups of cellulose and the peptide bonds of casein. The blend membranes with 10 wt % casein had good miscibility, higher crystallinity, and the highest mechanical properties and thermal stability. In this case, the tensile strength and breaking elongation of the blend membranes were 109 MPa and 16%, respectively, and its pore size, obtained by SEM, was 290 nm, which suggests that the blend membranes provide a potential application for the field of separation technology. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 3260–3267, 2001
Water‐soluble polymers. LXXXIII. Correlation of experimentally determined drag reduction efficiency and extensional viscosity of high molecular weight polymers in dilute aqueous solution
Authors: Cowan Martin E. , Garner Chad , Hester Roger D. , McCormick Charles L.
Published: August 2002

The extensional viscosity for aqueous solutions of high molecular weight poly(acrylamide) copolymers and poly(ethylene oxide) homopolymers was measured using a laboratory‐designed screen extensional rheometer. A Bingham model was developed to estimate the average local polymer coil extensional viscosity (ηcoil). A strong correlation was found between the measured ηcoil values and the polymer extensional viscosity predicted by a bead‐spring model. The dilute aqueous solution drag reduction was measured with a rotating disk instrument under conditions minimizing the effects of shear degradation. Extensional viscosity and drag reduction measurements were performed in deionized water and in 0.514M sodium chloride. The relative drag reduction efficiency values (Δ) in both solvents were found to strongly correlate with measured ηcoil values. This is the first report of the accurate prediction of drag reduction behavior for a wide range of polymer types in various solvents from the independently measured molecular parameters ηcoil and [η]C. The often‐used relative drag reduction efficiency expressed as the product of [η]C and Δ can now be replaced by the absolute drag reduction efficiency [η]Cηcoil. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1222–1231, 2001
Isotactic polypropylene morphology–Raman spectra correlations
Authors: Wang Xueqin , Michielsen Stephen
Published: August 2002

Isotactic polypropylene (iPP) is used in a wide variety of products, including the rapidly growing area of nonwoven fabrics. A new method based on Raman microspectroscopy is developed to determine the morphology of iPP fibers in complex structures through correlations with specific features of the Raman spectra and the birefringence and Lorentz density of a series of fibers. A good correlation is found between the fourth Legendre polynomial (P4) of the principle axis of the Raman tensor of the 841 cm−1 band and the birefringence. Only vibrations that include the CCC backbone stretch correlate well with the birefringence. There is a second, empirical correlation between the birefringence and the depolarization ratios of the 841 and 809 cm−1 Raman bands when the fiber axis is oriented parallel to the laser polarization. The experimental protocol for this empirical correlation is much simpler than for the P4 correlation while simultaneously yielding improved accuracy. There is another empirical correlation between the Lorentz density and the depolarization ratios of the 841 and 1330 cm−1 Raman bands. Thus, the birefringence and Lorentz density of iPP fibers could be determined quantitatively using polarized Raman microspectroscopy. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1330–1338, 2001
Flow visualization and extrudate swell of natural rubber in a capillary rheometer: Effect of die/barrel system
Authors: Sombatsompop N. , Dangtungee R.
Published: August 2002

An investigation was carried out to examine the effect of die/barrel system on the flow patterns and extrudate swell of natural rubber in the barrel of a capillary rheometer, using a colored tracer as the visualization technique. The capillary rheometer used in this work had two dies located along the barrel, which is novel in rheometer design. The flow of the rubber in the upper barrel was dependent on the piston/barrel action and changed with piston displacement, whereas the complexity of the flow in the lower barrel was dependent not only on the piston displacement, but also on the geometry of the upper die design. The flow patterns that developed in the whole barrel were independent of the die located at the bottom of the barrel. In addition, the change in extrudate swell was associated with the flow occurring in the barrel, residence time, elastic characteristic, and the temperature rise during the flow. It was concluded that the general style of the flow patterns of natural rubber was greatly dependent on the die geometry that the material had previously moved past. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2525–2533, 2001
Atomic force microscopy (AFM) study of poly(ethylene terephthalate‐co‐4,4′‐bibenzoate): A polymer of intermediate structure
Authors: Schiraldi D. A. , Occelli M. L. , Gould S. A. C.
Published: August 2002

An atomic force microscope (AFM) operating in both tapping and contact modes was used to study the surface topography and the molecular organization of a molded flexural test bar prepared from a poly(ethylene terephthalate‐co‐4,4'‐bibenzoate) copolymer containing a terephthalate:4,4′‐bibenzoate molar ratio of 45:55 (PETBB‐55). Micrometer‐scale (15 × 15 μm) contact‐mode AFM images revealed that the PETBB surface contains a deep indentation that forms trenches that extend over the entire surface examined. In addition, the surface may appear as an overlay of fibrils having different orientation. At greater magnification (1 × 1 μm), it is possible to observe the existence of micropores. These results were also observed in images obtained while operating the AFM in the tapping mode. The side of the part is more homogeneous and ordered than is its top surface. It has the appearance of a stacked lamellar structure in which missing fibrils can originate cracks ∼0.5‐μm wide. Fine surface details were observed in nanometer‐scale images, showing the presence of chains of white spots that could represent molecules or a cluster of molecules. These chains can form domains in which they are almost parallel to each other and have a preferred orientation; this structural organization was generated without any orientation other than that produced during a mold flow. Alternatively, chain lengths are interrupted and white spots form, distorted by easily recognizable hexagonal arrangements. The degree of lamellar order observed in the side of the bar, the area of greatest flow orientation in the part, was not been observed for the PET homopolymer in the past and bears some resemblance to previously imaged liquid crystalline polyester (LCP) structures. Combined with some previously reported LCP‐like mechanical properties, we propose that this PETBB copolymer is, in fact, a “frustrated LCP,” one that with some driving force could be converted to liquid crystallinity. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2616–2623, 2001
Synthesis and characterization of thermoplastic polyurethanes as binder for novel thermoplastic propellant
Authors: Duo Yingquan , Tan Huimin , Chen Futai
Published: August 2002

Two series of thermoplastic polyurethanes (TPUs), which used nitroester plasticiable tetrahydrofuran‐ethylene oxide random copolyether as soft segment and adduction products of isophorone diisocyanate (IPDI) and toluene diisocyanate (TDI) with 1,4‐butanediol as hard segments respectively, were successfully synthesized as binders for novel thermoplastic propellant. Mechanical tests and DSC techniques were applied to make characterizations of the polymers in order to choose candidate materials. Results shown that the TPU based on IPDI with fraction of the hard segment around 45% will meet requirements of propellant in terms of mechanical properties and glass transition of the soft segment phase. The results were further manifested in detail by quantitative studies of the degree of microphase separation as well as hydrogen bonding within the hard segment domain based on the equations established through FTIR and DSC analyses. It was found that mixing of two phases, which mainly referred to the mount of the hard segment dissolving into the soft segment phase, was as little as 10% in IPDI series TPUs, whereas it was almost up to 30% in TDI series. This indicated that better phase separation was achieved in IPDI series TPU. By contrast, studies of hydrogen bonding in domain revealed that the domain of TPUs prepared with TDI was much oriented in comparison with that with IPDI, which indicated higher processing temperatures. The results were raised by the melting index results under required conditions. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2961–2966, 2002; DOI 10.1002/app.2324
Biomonitoring of heavy metal contamination along the Salento coast (Italy) by metallothionein evaluation in Mytilus galloprovincialis and Mullus barbatus
Authors: Lionetto M.G. , Giordano M.E. , Caricato R. , Pascariello M.F. , Marinosci L. , Schettino T.
Published: August 2002

1. The aim of the present study was to identify possible ecotoxicological risk of heavy metal contamination along the coast of the Salento Peninsula (South of Italy) evaluating levels of metallothioneins (Mts), by a spectrophotometric method, in two bioindicator species: Mytilus galloprovincialis and Mullus barbatus.

2. Cellular stress response to heavy metals, indicated by increased levels of Mt, measured in marine organisms can represent an early warning of heavy metal contamination along the Salento coast particularly at the hot spot of Brindisi and act as an alert for possible toxic effects on higher level organisms. Copyright © 2001 John Wiley & Sons, Ltd.
The human cadaver in the age of biomedical informatics
Authors: Aziz M. Ashraf , Mckenzie James C. , Wilson James S. , Cowie Robert J. , Ayeni Sylvanus A. , Dunn Barbara K.
Published: August 2002

Major national and international critiques of the medical curriculum in the 1980s noted the following significant flaws: (1) over‐reliance on learning by rote memory, (2) insufficient exercise in analysis and synthesis/conceptualization, and (3) failure to connect the basic and clinical aspects of training. It was argued that the invention of computers and related imaging techniques called to question the traditional instruction based on the faculty‐centered didactic lecture. In the ensuing reform, which adopted case‐based, small group, problem‐based learning, time allotted to anatomical instruction was severely truncated. Many programs replaced dissection with prosections and computer‐based learning. We argue that cadaver dissection is still necessary for (1) establishing the primacy of the patient, (2) apprehension of the multidimensional body, (3) touch‐mediated perception of the cadaver/patient, (4) anatomical variability, (5) learning the basic language of medicine, (6) competence in diagnostic imaging, (7) cadaver/patient‐centered computer‐assisted learning, (8) peer group learning, (9) training for the medical specialties. Cadaver‐based anatomical education is a prerequisite of optimal training for the use of biomedical informatics. When connected to dissection, medical informatics can expedite and enhance preparation for a patient‐based medical profession. Actual dissection is equally necessary for acquisition of scientific skills and for a communicative, moral, ethical, and humanistic approach to patient care. Anat Rec (New Anat) 269:20–32, 2002. © 2002 Wiley‐Liss, Inc.
Ultrastructure of canine type II pneumocytes during hypothermic ischemia of the lung: A study by means of conventional and energy filtering transmission electron microscopy and stereology
Authors: Ochs Matthias , Fehrenbach Heinz , Richter Joachim
Published: August 2002

Alterations in pulmonary surfactant have been reported to be associated with ischemia/reperfusion injury in experimental and clinical lung transplantation. It is unknown whether these alterations are due to damage to surfactant synthesizing type II pneumocytes during hypothermic ischemic storage. The aim of the present study was to examine the effects of hypothermic ischemic storage of the lung on canine type II pneumocytes by means of conventional (CTEM) and energy filtering TEM (EFTEM) and stereology. The lungs of 18 dogs were fixed for TEM immediately after cardiac arrest (6 double lungs) and after storage in Tutofusin® at 4°C for 20 min, 4 hr, 8 hr, and 12 hr (6 single lungs, respectively). Using a systematic uniform random sampling scheme, type II pneumocytes were analyzed qualitatively and stereologically. The relative phosphorus content of cell organelles, especially the surfactant containing lamellar bodies, was investigated by EFTEM. By CTEM, no major qualitative alterations could be observed in type II pneumocytes of the experimental groups. Stereologically, no significant changes in the volume densities or the volume‐to‐surface ratios of type II pneumocytes and their lamellar bodies were found. By EFTEM, the highest intracellular phosphorus signals were recorded over lamellar bodies in all experimental groups. No changes in the phosphorus signals were observed during ischemia. These results indicate that the ultrastructure of canine type II pneumocytes and their lamellar bodies is not affected by hypothermic ischemia of the lung up to 12 hr. Structural preservation of intracellular surfactant is possible during prolonged ischemic lung storage. Anat Rec 263:118–126, 2001. © 2001 Wiley‐Liss, Inc.
Contributions of intercalated duct cells to the normal parenchyma of submandibular glands of adult rats
Authors: Man Yan‐Gao , Ball William D. , Marchetti Luigi , Hand Arthur R.
Published: August 2002

The parenchyma of the submandibular gland in the adult male rat is self‐renewing, with most newly formed acinar and granular duct cells believed to differentiate from the rapidly proliferating intercalated duct (ID) compartment. Since the ID cells are phenotypically diverse, based on their different expression of perinatal secretory proteins, we systemically injected tritiated thymidine for 24 hours, and followed the pattern of thymidine distribution in cells by autoradiography and immunocytochemistry of defined cellular phenotypes over a 1‐month chase period. Proliferating cells were found within all parenchymal cell compartments; they were most numerous in ID, and primarily in those cells lacking immunoreactivity for the perinatal proteins SMG‐B1, ‐C, and ‐D. The labeling index (LI) of the ID cells reached a peak at 7 days postinjection, and then decreased over the next 3 weeks. Concurrently, the LI increased significantly in those cells at the junctions of ID with both acini and granular ducts, and also within these larger parenchymal elements. We conclude that the ID cells not reactive for perinatal proteins proliferate to expand the ID compartment, and that ID cells at the ends of the ducts differentiate into both acinar and granular duct cells. Our data provide no evidence for the differentiation of ID cells into cells of striated ducts (SD); however, the small number of excretory duct (ED) profiles seen in our preparations showed extremely high LI (>25%), suggesting that more extensive data might reveal a precursor role for the ED in replacement of SD cells. In addition to the stepwise passage of cells from ID to other parenchymal elements at their junctions, the reported occurrence of occasional clusters of B1‐positive acini (BAC) among the typical B1‐negative acini had suggested an alternate pathway, in which entire segments of newly expanded ID might develop directly into a recapitulated perinatal stage of B1‐reactive cell, pursuant to becoming mature acinar cells. Consistent with this suggestion, the BAC had a fourfold greater LI than typical adult acini; moreover, when analyzed by electron microscopic immunocytochemistry, they appeared similar to the novel perinatal Type III cells both ultrastructurally and in their pattern of B1‐immunogold labeling. In contrast, the less common acini showing a sublingual gland phenotype had no significant difference in LI from typical acinar cells. Overall, our results emphasize the importance of the nonimmunoreactive ID cells in normal cellular replacement, and the possibility that ID can undergo en bloc differentiation into replacement acini as well as incremental addition of single cells at the boundaries of ID with acini and with granular ducts. Anat Rec 263:202–214, 2001. © 2001 Wiley‐Liss, Inc.
Proteinase inhibitors in Nauphoeta cinerea midgut
Authors: Elpidina Elena N. , Vinokurov Konstantin S. , Rudenskaya Yuliya A. , Dunaevsky Yakov E. , Zhuzhikov Dmitry P.
Published: August 2002

Proteinase inhibitors were studied in the midgut of Nauphoeta cinerea Oliv. (Blattoptera: Blaberidae) in experimental conditions, excluding their nutritional origin. One trypsin inhibitor (TI) with Mr 8,000 and two subtilisin inhibitors (SI1 and SI2) with Mr 13,000 and 8,000 were detected after fractionation of total protein preparation on Sephadex G‐50. Ninety‐four percent of both types of inhibitors was located in anterior midgut (AM). TI was 120‐fold purified by FPLC‐chromatography on Mono Q. Its isoelectric point was 4.3. TI lost a large part of activity in acidic and especially in alkaline medium. TI, SI1, and SI2 effectively inhibited activities of endogenous proteinases from posterior midgut (PM) of the cockroach. A search for inhibitor of endogenous unusual SH‐dependent proteinase from AM revealed in AM a new inhibitor with Mr 18,000. It was also inactivated in alkaline medium and was effective against proteinases from PM along with unusual SH‐dependent proteinase from AM. A mechanism of regulation of activity of midgut proteinases is proposed based on pH‐stability of inhibitors. Arch. Insect Biochem. Physiol. 48:217–222, 2001. © 2001 Wiley‐Liss, Inc.
Comparative assessment of leflunomide and methotrexate for the treatment of rheumatoid arthritis, by dynamic enhanced magnetic resonance imaging
Authors: Reece Richard J. , Kraan Maarten C. , Radjenovic Aleksandra , Veale Douglas J. , O'Connor P. J. , Ridgway John P. , Gibbon W. W. , Breedveld Ferdinand C. , Tak Paul P. , Emery Paul
Published: August 2002

Objective

Ethical constraints on the conduct of placebo‐controlled trials evaluating new therapies for serious chronic diseases, such as rheumatoid arthritis (RA), indicate the need for discerning methods to assess treatment effect in active‐controlled clinical trials. Dynamic gadolinium‐enhanced magnetic resonance imaging (DEMRI) is a sensitive technique for the detection of synovial inflammation in RA. Therefore, this investigation was undertaken to evaluate DEMRI as an efficacy assessment tool for differentiating treatment effect in a randomized, active‐controlled trial comparing leflunomide and methotrexate.

Methods

Patients with active RA (n = 39) were randomized in a 2‐center, prospective, double‐blind clinical trial to receive either leflunomide (n = 18) or methotrexate (n = 21) therapy for 4 months. DEMRI scans were obtained at baseline and at 4 months, and the initial rate of enhancement (IRE) and the maximal signal intensity (SI) enhancement (ME) were calculated from the SI curves. Clinical improvement was assessed by conventional outcome measures.

Results

Thirty‐four patients (17 treated with leflunomide and 17 with methotrexate) had usable baseline and end point DEMRI scans. Leflunomide treatment was associated with a significantly greater improvement in IRE compared with methotrexate treatment (P < 0.05). Average values of ME indicated reduction of inflammation with both leflunomide and methotrexate. The improvement in clinical signs and symptoms, as measured by traditional assessments, was comparable for both active treatments.

Conclusion

Results of this study validate the sensitivity of DEMRI in detecting inflammatory changes in active RA in response to treatment. Improvement in synovial inflammation as measured by IRE was significantly better with leflunomide than with methotrexate over 4 months of therapy.
Presence of microchimerism in labial salivary glands in systemic sclerosis but not in Sjögren's syndrome
Authors: Aractingi Sélim , Sibilia Jean , Meignin Véronique , Launay David , Hachulla Eric , Le Danff Caroline , Janin Anne , Mariette Xavier
Published: August 2002

Objective

To determine whether microchimerism can be implicated in Sjögren's syndrome (SS) by studying minor salivary glands, one of the targets of the disease.

Methods

Labial salivary gland (LSG) biopsy specimens from 16 female patients with primary SS and 11 with systemic sclerosis (SSc) (a disease in which microchimerism is frequently detected) were analyzed. All 27 women had a history of pregnancy with a male baby. Specimens were microdissected, and polymerase chain reaction (PCR) was performed using the unique sex‐determining region Y gene probe.

Results

The sensitivity of PCR for detecting male cells in LSG was high; the presence of 3 male cells was consistently detected in DNA extracted from a normal female LSG specimen to which male DNA had been added, and 1 male cell was detected in 50% of specimens analyzed. Male DNA was not found in any of the specimens from the 16 SS patients but was detected in 5 (45%) of 11 SSc specimens (P = 0.006). No differences in the rate of detection were found between patients with diffuse and limited SSc (male DNA detected in 2 of 3 and 3 of 8, respectively; P = 0.55) or between patients with and those without secondary SS (1 of 6 and 4 of 5, respectively; P = 0.08).

Conclusion

The results of our study strengthen the possibility that microchimerism is implicated in SSc. This is the first study to demonstrate the presence of chimeric cells in LSG from 45% of SSc patients, independent of the presence of secondary SS. However, microchimerism was not detected in LSG from patients with primary SS, suggesting that the pathogenesis of the 2 diseases is different.
Antiphospholipid syndrome: Clinical and immunologic manifestations and patterns of disease expression in a cohort of 1,000 patients
Authors: Cervera Ricard , Piette Jean‐Charles , Font Josep , Khamashta Munther A. , Shoenfeld Yehuda , Camps María Teresa , Jacobsen Soren , Lakos Gabriella , Tincani Angela , Kontopoulou‐Griva Irene , Galeazzi Mauro , Meroni Pier Luigi , Derksen Ronald H. W. M. , de Groot Philip G. , Gromnica‐Ihle Erika , Baleva Marta , Mosca Marta , Bombardieri Stefano , Houssiau Frédéric , Gris Jean‐Christophe , Quéré Isabelle , Hachulla Eric , Vasconcelos Carlos , Roch Beate , Fernández‐Nebro Antonio , Boffa Marie‐Claire , Hughes Graham R. V. , Ingelmo Miguel
Published: August 2002

Objective

To analyze the clinical and immunologic manifestations of antiphospholipid syndrome (APS) in a large cohort of patients and to define patterns of disease expression.

Methods

The clinical and serologic features of APS (Sapporo preliminary criteria) in 1,000 patients from 13 European countries were analyzed using a computerized database.

Results

The cohort consisted of 820 female patients (82.0%) and 180 male patients (18.0%) with a mean ± SD age of 42 ± 14 years at study entry. “Primary” APS was present in 53.1% of the patients; APS was associated with systemic lupus erythematosus (SLE) in 36.2%, with lupus‐like syndrome in 5.0%, and with other diseases in 5.9%. A variety of thrombotic manifestations affecting the majority of organs were recorded. A catastrophic APS occurred in 0.8% of the patients. Patients with APS associated with SLE had more episodes of arthritis and livedo reticularis, and more frequently exhibited thrombocytopenia and leukopenia. Female patients had a higher frequency of arthritis, livedo reticularis, and migraine. Male patients had a higher frequency of myocardial infarction, epilepsy, and arterial thrombosis in the lower legs and feet. In 28 patients (2.8%), disease onset occurred before age 15; these patients had more episodes of chorea and jugular vein thrombosis than the remaining patients. In 127 patients (12.7%), disease onset occurred after age 50; most of these patients were men. These patients had a higher frequency of stroke and angina pectoris, but a lower frequency of livedo reticularis, than the remaining patients.

Conclusion

APS may affect any organ of the body and display a broad spectrum of manifestations. An association with SLE, the patient's sex, and the patient's age at disease onset can modify the disease expression and define specific subsets of APS.
Arthritis in MRL/lpr mice is under the control of multiple gene loci with an allelic combination derived from the original inbred strains
Authors: Kamogawa Junji , Terada Miho , Mizuki Shinichi , Nishihara Miyuki , Yamamoto Haruyasu , Mori Shiro , Abe Yoriko , Morimoto Koji , Nakatsuru Syuichi , Nakamura Yusuke , Nose Masato
Published: August 2002

Objective

To clarify the mode of inheritance and the genome origins of arthritis in a lupus‐prone strain of mice, MRL/MpJ, bearing a Fas deletion mutant gene, lpr (MRL/lpr).

Methods

Using non–lupus‐prone strains of mice, C3H/HeJ‐lpr/lpr (C3H/lpr), (MRL/lpr × C3H/lpr)F1 intercross and MRL/lpr × (MRL/lpr × C3H/lpr)F1 backcross mice were prepared. Arthritis in individual mice was analyzed by histopathologic grading, and the genomic DNA of the backcross mice was examined by simple sequence‐length polymorphism analysis to determine the polymorphic microsatellite markers highly associated with arthritis.

Results

Arthritis‐susceptibility loci with significant linkage were mapped between D15Mit111 and D15Mit18 (map position 17.8–18.7 cM) on chromosome 15 and between D19Mit112 and D19Mit72 (map position 43.0–55.0) on chromosome 19 (logarithm of odds scores 3.5 and 4.3, respectively). Three other loci, one mapped to each of chromosomes 1, 2, and 7, showed suggestive linkage. Loci homozygous for MRL alleles on chromosomes 1 and 19 enhanced arthritis in both sexes, whereas other loci on chromosomes 2 and 15 selectively affected males. A locus homozygous for MRL alleles on chromosome 7 inhibited arthritis in both sexes. Three of these loci were found to originate from an LG/J strain and 1 from an AKR/J strain. Some combinations of these loci showed an additive effect in a hierarchical manner on the development of arthritis.

Conclusion

Arthritis in MRL/lpr mice is a complex pathologic manifestation resulting from the cumulative effect of multiple gene loci with an allelic combination derived from the original inbred strains.
Suppression of collagen‐induced arthritis by single administration of poly(lactic‐co‐glycolic acid) nanoparticles entrapping type II collagen: A novel treatment strategy for induction of oral tolerance
Authors: Kim Wan‐Uk , Lee Woo‐Kyoung , Ryoo Jae‐Woong , Kim Seung‐Hoon , Kim Jin , Youn Jeehee , Min So‐Youn , Bae Eui‐Young , Hwang Sue‐Yun , Park Sung‐Hwan , Cho Chul‐Soo , Park Jong‐Sang , Kim Ho‐Youn
Published: August 2002

Objective

Poly(lactic‐co‐glycolic acid) (PLGA), a biodegradable polymer, is a carrier for drug delivery systems. This study was undertaken to investigate the tolerogenic effect of single administration of PLGA entrapping type II collagen (CII) on the development of collagen‐induced arthritis (CIA).

Methods

The biophysical properties of PLGA nanoparticles entrapping CII (PLGA‐CII) were investigated by in vitro release testing of CII, immunohistochemistry analysis, and electron microscopy. PLGA‐CII was fed singly to animals 14 days before immunization, and the effect on joint inflammation was assessed. Circulating IgG anti‐CII antibodies and T cell responses to CII in draining lymph nodes were assayed by enzyme‐linked immunosorbent assay and 3H‐thymidine incorporation assay, respectively. The expression of messenger RNA (mRNA) for transforming growth factor β (TGFβ) and tumor necrosis factor α (TNFα) was determined by reverse transcriptase–polymerase chain reaction.

Results

The in vitro release test showed that CII was slowly discharged from PLGA‐CII over a period of a month. After single administration of PLGA‐CII, numerous particles ∼300 nm in size were detectable in Peyer's patches, by electron microscopy and immunohistochemical staining for CII, 14 days after the original feeding. Mice fed a single dose of PLGA containing 40 μg of CII had significantly reduced values for incidence and severity of arthritis, serum IgG anti‐CII antibodies, and CII‐specific T cell proliferation as compared with mice fed solvent alone, those fed 6 doses of 20 μg CII alone, and those fed a single dose of PLGA alone. PLGA‐CII was also able to suppress CIA after disease onset. Moreover, PLGA‐CII–fed mice showed a higher level of TGFβ mRNA expression in Peyer's patches, but a lower level of TNFα mRNA expression in draining lymph nodes, compared with the other groups of mice.

Conclusion

Our data show that PLGA may serve as a powerful vehicle to promote the tolerance effect of oral CII and that single administration of PLGA‐CII may hold promise as a new treatment strategy in rheumatoid arthritis.
Laboratory testing in rheumatoid arthritis patients taking disease‐modifying antirheumatic drugs: Clinical evaluation and cost analysis
Authors: Aletaha Daniel , Smolen Josef S.
Published: August 2002

Objective

To develop and validate evidence‐based recommendations for routine laboratory tests in patients with rheumatoid arthritis (RA) receiving traditional disease‐modifying antirheumatic drugs (DMARDs), and to calculate the monitoring costs.

Methods

Outpatient charts of 362 RA patients taking DMARDs were reviewed, and all laboratory abnormalities recorded. Recommendations on monitoring DMARD therapy were derived and then tested in an independent validation cohort of 231 patients. Cost analysis was performed using a cost catalog.

Results

Laboratory abnormalities were seen in 10% of treatment courses; relevant abnormalities were seen only during the first 4 months of therapy. Laboratory tests should be performed in week 2 and 4, then monthly for the first 4 months of therapy, then 2 to 4 times per year. These were capable of detecting 98.3% of laboratory abnormalities in a timely manner in another RA cohort. Up to 78% of costs can be saved when the presented recommendations are compared with those of international rheumatology societies.

Conclusion

Laboratory tests can be reduced substantially in patients receiving DMARD therapy. In consequence, costs can decrease significantly without oversight of adverse events.
Web page change and persistence—A four‐year longitudinal study
Authors: Koehler Wallace
Published: August 2002

Changes in the topography of the Web can be expressed in at least four ways: (1) more sites on more servers in more places, (2) more pages and objects added to existing sites and pages, (3) changes in traffic, and (4) modifications to existing text, graphic, and other Web objects. This article does not address the first three factors (more sites, more pages, more traffic) in the growth of the Web. It focuses instead on changes to an existing set of Web documents. The article documents changes to an aging set of Web pages, first identified and “collected” in December 1996 and followed weekly thereafter. Results are reported through February 2001. The article addresses two related phenomena: (1) the life cycle of Web objects, and (2) changes to Web objects. These data reaffirm that the half‐life of a Web page is approximately 2years. There is variation among Web pages by top‐level domain and by page type (navigation, content). Web page content appears to stabilize over time; aging pages change less often than once they did.
Research anxiety and students' perceptions of research: An experiment. Part I. Effect of teaching Kuhlthau's ISP model
Authors: Kracker Jacqueline
Published: August 2002

This two‐part study investigates the effect of a 30‐minute presentation of Carol Kuhlthau's Information Search Process (ISP) model on students' perceptions of research and research paper anxiety. An experiment was designed to collect both quantitative and qualitative data during a semester. An upper division undergraduate course, Technical and Professional Writing, with four sections participated in the experiment in fall 1999. A survey instrument, the Research Process Survey (RPS), was developed to collect data about students' feelings and thoughts at the onset of their course research project (pretest) and at the completion of the project (posttest). A standard anxiety test (STAI Y‐1) was adopted to measure anxiety levels during pretest and posttest sessions and at two additional points between. Two of the four sections heard a guest presentation of the ISP model as treatment after the pretest; the other two sections heard a different guest speak about career experiences as a technical writer (a placebo talk). The results of this experiment are reported in two articles according to the nature of the collected data. This article reports on results of the quantitative analysis. Four hypotheses were proposed to examine the effects on awareness of cognitive aspects, awareness of affective aspects, level of anxiety, and satisfaction with research. One hypothesis was supported. A significant change in anxiety levels was measured (p = 0.5). Although statistical tests did not reject three null hypotheses, positive trends in change as a result of the ISP model were identified. A second article reports on results of qualitative analysis of the texts that participants wrote about a memorable past research experience and about the current research experience.
Hyperlink–affiliation network structure of top web sites: Examining affiliates with hyperlink in Korea
Authors: Park Han Woo , Barnett George A. , Nam In‐Yong
Published: August 2002

This article argues that individual Web sites form hyperlink–affiliations with others for the purpose of strengthening their individual trust, expertness, and safety. It describes the hyperlink–affiliation network structure of Korea's top 152 Web sites. The data were obtained from their Web sites for October 2000. The results indicate that financial Web sites, such as credit card and stock Web sites, occupy the most central position in the network. A cluster analysis reveals that the structure of the hyperlink–affiliation network is influenced by the financial Web sites with which others are affiliated. These findings are discussed from the perspective of Web site credibility.
A new method for analyzing scientific productivity
Authors: Huber John C.
Published: August 2002

Previously, a new method for measuring scientific productivity was demonstrated for authors in mathematical logic and some subareas of 19th‐century physics. The purpose of this article is to apply this new method to other fields to support its general applicability. We show that the method yields the same results for modern physicists, biologists, psychologists, inventors, and composers. That is, each individual's production is constant over time, and the time‐period fluctuations follow the Poisson distribution. However, the productivity (e.g., papers per year) varies widely across individuals. We show that the distribution of productivity does not follow the normal (i.e., bell curve) distribution, but rather follows the exponential distribution. Thus, most authors produce at the lowest rate and very few authors produce at the higher rates. We also show that the career duration of individuals follows the exponential distribution. Thus, most authors have a very short career and very few have a long career. The principal advantage of the new method is that the detail structure of author productivity can be examined, such as trends, etc. Another advantage is that information science studies have guidance for the length of time interval being examined and estimating when an author's entire body of work has been recorded.
Analysis of regression in game theory approach
Authors: Lipovetsky Stan , Conklin Michael
Published: August 2002

Working with multiple regression analysis a researcher usually wants to know a comparative importance of predictors in the model. However, the analysis can be made difficult because of multicollinearity among regressors, which produces biased coefficients and negative inputs to multiple determination from presum ably useful regressors. To solve this problem we apply a tool from the co‐operative games theory, the Shapley Value imputation. We demonstrate the theoretical and practical advantages of the Shapley Value and show that it provides consistent results in the presence of multicollinearity. Copyright © 2001 John Wiley & Sons, Ltd.
In Vitro/in Vivo scaling of alprazolam metabolism by CYP3A4 and CYP3A5 in humans
Authors: Hirota Noriko , Ito Kiyomi , Iwatsubo Takafumi , Green Carol E. , Tyson Charles A. , Shimada Noriaki , Suzuki Hiroshi , Sugiyama Yuichi
Published: August 2002

We attempted to predict the in vivo metabolic clearance of alprazolam from in vitro metabolic studies using human liver microsomes and human CYP recombinants. Good correlations were observed between the intrinsic clearance (CLint) for 4‐hydroxylation and CYP3A4 content and between the CLint for α‐hydroxylation and CYP3A5 content in ten human liver microsomal samples. Using the recombinant CYP isoforms expressed in insect cells, the CLint for CYP3A4 was about 2‐fold higher than the CLint for CYP3A5 in the case of 4‐hydroxylation. However, the CLint for CYP3A5 was about 3‐fold higher than the CLint for CYP3A4 in the case of α‐hydroxylation. The metabolic rates for 4‐ and α‐hydroxylation increased as the added amount of cytochrome b5 increased, and their maximum values were 3‐ to 4‐fold higher than those without cytochrome b5. The values of CLint, in vivo predicted from in vitro studies using human liver microsomes and CYP3A4 and CYP3A5 recombinants were within 2.5 times of the observed value calculated from literature data. The average CLint value (sum of 4‐ and α‐hydroxylation) obtained using three human liver microsomal samples was 4‐fold higher than that obtained using three small intestinal microsomal samples from the same donors, indicating the minor contribution of intestinal metabolism to alprazolam disposition. The area under the plasma concentration‐time curve (AUC) of alprazolam is reported to increase following co‐administration of ketoconazole and the magnitude of the increase predicted from the in vitro Ki values and reported pharmacokinetic parameters of ketoconazole was 2.30–2.45, which is close to the value observed in vivo (3.19). A quantitative prediction of the AUC increase by cimetidine was also successful (1.73–1.79 vs 1.58–1.64), considering the active transport of cimetidine into the liver. In conclusion, we have succeeded in carrying out an in vitro/in vivo scaling of alprazolam metabolism using human liver microsomes and human CYP3A4 and CYP3A5 recombinants. Copyright © 2001 John Wiley & Sons, Ltd.
Electrorotation of axolotl embryos
Authors: Abou‐Ali Ghalia , Kaler Karan V.I.S. , Paul Reginald , Björklund Natalie K. , Gordon Richard
Published: August 2002

The frequency dependent dielectric properties of individual axolotl embryos (Ambystoma mexicanum) were investigated experimentally utilizing the technique of electrorotation. Individual axolotl embryos, immersed in low conductivity media, were subjected to a known frequency and fixed amplitude rotating AC electric field and the ensuing rotational motion of the embryo was monitored using a conventional optical microscope. None of the embryos in the pregastrulation or neurulation stages of development exhibited any rotational motion over the field frequency range (10 Hz–5 MHz). Over the same frequency range, the embryos in the gastrulation stage of development exhibited both co‐field and counterfield rotation over different ranges of the applied field frequency. Typically, the counterfield rotation exhibited a peak in the rotation spectrum at ∼ 1 KHz while the co‐field peak was located at ∼ 1–2 MHz. The rotational spectral data was analyzed using a multishelled spherical embryo model to determine the electrical character of embryos during the early development stages (Stages 5–16; i.e., 16 cell through open neural plate stages). Bioelectromagnetics 23:214–223, 2002. © 2002 Wiley‐Liss, Inc.
Partial‐body exposure of human volunteers to 2450 MHz pulsed or CW fields provokes similar thermoregulatory responses*
Authors: Adair Eleanor R. , Mylacraine Kevin S. , Cobb Brenda L.
Published: August 2002

Many reports describe data showing that continuous wave (CW) and pulsed (PW) radiofrequency (RF) fields, at the same frequency and average power density (PD), yield similar response changes in the exposed organism. During whole‐body exposure of squirrel monkeys at 2450 MHz CW and PW fields, heat production and heat loss responses were nearly identical. To explore this question in humans, we exposed two different groups of volunteers to 2450 MHz CW (two females, five males) and PW (65 μs pulse width, 104 pps; three females, three males) RF fields. We measured thermophysiological responses of heat production and heat loss (esophageal and six skin temperatures, metabolic heat production, local skin blood flow, and local sweat rate) under a standardized protocol (30 min baseline, 45 min RF or sham exposure, 10 min baseline), conducted in three ambient temperatures (Ta = 24, 28, and 31°C). At each Ta, average PDs studied were 0, 27, and 35 mW/cm2 (Specific absorption rate (SAR) = 0, 5.94, and 7.7 W/kg). Mean data for each group showed minimal changes in core temperature and metabolic heat production for all test conditions and no reliable differences between CW and PW exposure. Local skin temperatures showed similar trends for CW and PW exposure that were PD‐dependent; only the skin temperature of the upper back (facing the antenna) showed a reliably greater increase (P = .005) during PW exposure than during CW exposure. Local sweat rate and skin blood flow were both Ta‐ and PD‐dependent and showed greater variability than other measures between CW and PW exposures; this variability was attributable primarily to the characteristics of the two subject groups. With one noted exception, no clear evidence for a differential response to CW and PW fields was found. Bioelectromagnetics 22:246–259, 2001. © 2001 Wiley‐Liss, Inc.
Influence of a stationary magnetic field on water relations in lettuce seeds. Part II: Experimental results
Authors: Reina Francisco Garcìa , Pascual Luis Arza , Fundora Ilvelisse Almanza
Published: August 2002

An experimental study on water absorption by lettuce seeds previously treated in a stationary magnetic field of 0–10 mT is presented. A significant increase in the rate with which the seeds absorb water is observed in the interval 0–10 mT of magnetic treatment. An increment in the total mass of absorbed water in this interval is also observed. These results are consistent with the reports on the increase of germination rate of the seeds, and the theoretical calculation of the variations induced by magnetic fields in the ionic currents across the cellular membrane. The fields originate in changes in the ionic concentration and thus in the osmotic pressure which regulates the entrance of water to the seeds. The good correlation between the theoretical approach and experimental results provides strong evidence that the magnetic field alters the water relations in seeds, and this effect may be the explanation of the reported alterations in germination rate of seeds by the magnetic field. Bioelectromagnetics 22:596–602, 2001. © 2001 Wiley‐Liss, Inc.
Can molecular mechanisms of biological processes be extracted from expression profiles? Case study: endothelial contribution to tumor‐induced angiogenesis
Authors: Novatchkova Maria , Eisenhaber Frank
Published: August 2002

Whereas the genome contains all potential developmental programs, expression profiles permit the determination of genes that are actively transcribed under defined physiological conditions. In this article, the idea of extracting biological mechanisms from expression data is tested. Molecular processes of the endothelial contribution to angiogenesis are derived from recently published expression profiles. The analysis reveals the sensitivity limits of experimental detection of transcriptional changes and how sequence‐analytic techniques can help to identify the function of genes in question. We conclude that the transcripts (http://mendel.imp.univie.ac.at/SEQUENCES/TEMS/) found to be up‐regulated in angiogenesis are involved in extracellular matrix remodeling, cellular migration, adhesion, cell‐cell communication rather than in angiogenesis initiation or integrative control. Comparison with tissue‐specific patterns of EST occurrence shows that, indeed, the presumptive tumor‐specific endothelial markers are more generally expressed by cell types involved in migration and matrix remodeling processes. This exemplary study demonstrates how bioinformatics approaches can be helpful in deriving mechanistic information from diverse sources of experimental data. BioEssays 23:1159–1175, 2001. © 2001 John Wiley & Sons, Inc.