bluuebunny/crossref_metadata_2025_split huggingface dataset:
Polymerization of methylmethacrylate monomer in the presence of dithizone and carbazone complexes
Authors: Hanna Wageih G. , Mekewi Mohamed A. , El‐Mosallamy El‐Said H. 
Published: September 2002

AbstractIt has been proved that lead dithizone and carbazone complexes act as adequate initiators for radical polymerization of methylmethacrylate and also as reliable indicators for the free‐radical mechanism. Lead dithizone complex, in particular, exhibited the phenomenon of color change during the polymerization process, suggesting the use of this complex as a free‐radical indicator and also as a coloring material for acrylic polymers in situ. The color change observed during the polymerization process was attributed to the change in the structure of complex compounds according to a tautomerization mechanism. The presence of lead dithizone and carbazone complexes as initiators exhibited reduced molecular mass compared to those prepared in their absence, indicating their role as regulating agents during the polymerization process. The polydispersity and tacticity parameters were measured through the present work using GPC and 1H–NMR techniques, respectively. The amorphous nature of polymer chains in both the absence and the presence of the lead dithizone and carbazone was studied using X‐ray diffraction, where an increased crystallinity was observed. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 562–568, 2001
Graft copolymerization of hydroxyethyl methacrylate onto chitosan
Authors: El‐Tahlawy Khaled , Hudson Samuel M. 
Published: September 2002

AbstractChitosan is a polysaccharide derived from chitin, which is commonly found in shellfish waste materials. The present work is concerned with the graft copolymerization of 2‐hydroxyethylmethacrylate (HEMA) onto chitosan using thiocarbonation–potassium bromate for redox initiation. The combined effects of the principal reaction variables for the grafting reaction were studied systematically. This grafting reaction was studied with respect to percentages of graft yield (%G.Y.), homopolymer (%H.P.), and total conversion (%T.C.). A tentative polymerization mechanism is proposed. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 683–702, 2001
Glial fibrillary acidic protein‐positive cells of the kidney are capable of raising a protective biochemical barrier similar to astrocytes: Expression of metallothionein in podocytes
Authors: Buniatian Gayane Hrachia , Hartmann Hans‐Jürgen , Traub Peter , Wiesinger Heinrich , Albinus Margitta , Nagel Wolfgang , Shoeman Robert , Mecke Dieter , Weser Ulrich 
Published: September 2002

AbstractBlood–tissue exchange and homeostasis within the organs depend on various interactions between endothelial and perivascular cells (Buniatian, 2001). Podocytes possess anatomical and cellular features intermediate between those of astrocytes and hepatic stellate cells (HSCs). Podocytes, like HSCs, are associated with fenestrated capillaries and, similar to astrocytes, interact with the capillaries via the basement membrane and participate in permeability‐limiting ultrafiltration. The fact that podocytes come in direct contact with xenobiotics prompted us to investigate whether they express metallothionein (MT), an anticytotoxic system characteristic of astrocytes. In comparative studies, cryosections of 1‐ and 3‐month‐old rat kidney and adult rat brain, as well as podocytes and astrocytes from early and prolonged primary cultures of glomerular explants and newborn rat brain, respectively, were investigated. The cells were double‐labeled with antiserum against glial fibrillary acidic protein (GFAP) and monoclonal antibody (MAb) against the lysine‐containing epitope of Cd/Zn‐MT‐I (MAb MT) or MAb against alpha‐actin. In kidney sections, MT immunoreactivity was detected in GFAP‐positive glomerular cells and in interstitial fibroblasts. The pattern of staining for MT and GFAP in glomerular cells was similar to that of astrocytes in vivo. In glomerular cell cultures, MT was expressed in cobblestone‐like podocytes which contained Wilms' tumor protein and lacked desmin. MT was upregulated at later culture periods, during which podocytes acquired features typical of undifferentiated astrocytes. This study hints at the existence of common regulatory mechanisms of blood–tissue interactions by neural and non‐neural perivascular cells. These mechanisms appear to be used in an organ‐specific manner. Anat Rec 267:296–306, 2002. © 2002 Wiley‐Liss, Inc.
Intraorbital anatomy of the koala (Phascolarctos cinereus)
Authors: Kempster R.C. , Bancroft B.J. , Hirst L.W. 
Published: September 2002

AbstractThis is the first documented study of the anatomical details of the contents of the normal koala orbit, excluding the bulbus oculi. Baseline data were established which are necessary for understanding and treating ocular disease in the koala (Phascolarctos cinereus). The anatomy of the orbital contents of the koala were examined and described from animals that presented dead or were euthanized for humane reasons. Dissections of the orbital cavity were performed under magnification. Polymethyl methacrylate (PMMA) casts of the nasolacrimal system and the vascular supply of the orbit were also made in order to study these systems. The superficial lymphatic drainage of the conjunctival tissues was studied by subcutaneous injection of Evan's Blue into the palpebral conjunctiva of a freshly deceased animal, and by Microfil casts of the efferent lymphatics. In general, the orbital contents of the koala are consistent with those of other carnivorous polyprotodont and herbivorous diprotodont marsupials. Anat Rec 267:277–287, 2002. © 2002 Wiley‐Liss, Inc.
Size and shape changes during late fetal growth (137–157 gestational days) in the pigtailed macaque (Macaca nemestrina) craniofacial complex: An application using three‐dimensional coordinate data and finite element scaling analysis
Authors: Zumpano Michael P. 
Published: September 2002

AbstractForm changes within the fetal pigtailed macaque (Macaca nemestrina) craniofacial complex was documented using finite element scaling analysis (FESA) and three‐dimensional (3D) coordinate data for 35 craniofacial landmarks. Coordinate data were digitized from 3D reconstructions of computed tomography (CT) images and 2D axial slices. Twenty‐two fetal pigtailed macaques ranging in age from 137 to 157 gestational days were included (in this species, birth is estimated at 170 gestational days). The null hypothesis that the craniofacial complex grows with isometry during late fetal growth of the craniofacial complex was tested (P < 0.05), and the prediction that morphological change along an anteroposterior axis dominates late fetal growth was also investigated. The null hypothesis was rejected, indicating that allometric growth is present during late fetal growth. Growth along an anteroposterior axis is localized in the palate and mandible. The neurocranium grows along a superoinferior axis, while the neurofacial junction displays growth along both the anteroposterior and superoinferior axes. Mediolateral changes are localized between asterions, the external auditory meati, and maxillary and mandibular alveolar points. Finally, a 3D model of craniofacial growth for this species was created, localizing size and shape changes that occur during late fetal growth for each of the 35 craniofacial landmarks defined in this study. Anat Rec 267:307–320, 2002. © 2002 Wiley‐Liss, Inc.
Immunohistochemical localization of heat shock protein 25 (HSP 25) during root formation of the rat molar
Authors: Onishi Tomoyuki , Tsubone Hanako , Ooshima Takashi , Sobue Shizuo , El‐Sharaby Ashraf , Wakisaka Satoshi 
Published: September 2002

AbstractThe present study investigated the immunohistochemical localization of heat shock protein 25 (HSP 25) of rat molar teeth during root formation. Most, probably all, cells of the epithelial rest of Malassez (ERM cells) had immunoreaction for laminin, a marker protein for basement membrane. During root formation, HSP 25 immunoreactivity was observed in odontoblasts, cells at the subodontoblastic layer, and those in close proximity to the acellular cementum. HSP 25‐immunopositive cells at the subodontoblastic layer were present only at the apical region. Most HSP 25‐immunoreactive cells in close proximity to the cementum lacked laminin immunoreactivity. However, at postnatal day 28 a small number of cells showed immunoreaction for both HSP 25 and laminin at the cervical and bifurcational regions. Under the electron microscope, most HSP 25‐immunoreactive cells along the surface of the cementum were round and contained rich organelles such as mitochondria and rough endoplasmic reticulum. They lay between fiber bundles of the periodontal ligament. The localization and morphological features of these HSP 25‐immunoreactive cells resemble those of cementoblasts. On the other hand, HSP 25‐immunoreactive cells at the cervical region were oval and contained few cell organelles. They were closely apposed to each other, and separated from the surrounding tissues with basal lamina. These features were similar to those of mature ERM cells. In contrast, cells with microvillus‐like processes and relatively rich mitochondoria, which were similar to immature ERM cells, had no immunoreaction for HSP 25. These results suggest that HSP 25 may be involved in shape alterations of ERM cells, cementoblasts, and odontoblasts during differentiation. Anat Rec 267:321–329, 2002. © 2002 Wiley‐Liss, Inc.
Comparison of seismic reflection and ground‐penetrating radar imaging at the controlled archaeological test site, Champaign, Illinois
Authors: Hildebrand J. A. , Wiggins S. M. , Henkart P. C. , Conyers L. B. 
Published: September 2002

AbstractShallow seismic reflection and ground‐penetrating radar images were collected at a replicated burial mound in the Controlled Archaeological Test Site (CATS) in Champaign, Illinois. The CATS mound contains a pig burial within a wood‐lined crypt at a depth of 1.6–2.4 m. Seismic reflection data were collected from two different energy sources: a small (0.5 kg) hammer for an impulsive source, and a vibrator for a frequency swept source. Seismic data were collected at densely spaced points (5 cm) along a line of 48 geophone receivers. These data were stacked in a common mid‐point gather, band‐pass filtered, and processed with frequency–wavenumber migration. The seismic image produced by the hammer source was dominated by bodywaves at 120 Hz, whereas the vibrator source image was dominated by surface waves at 70 Hz. Both seismic sources revealed clear reflections from the burial crypt, and placed the top of the crypt at the correct depth with a seismic velocity of 120 m s−1. The bottom of the crypt was poorly defined by the seismic data owing to multiple reflections within the crypt. The vibrator source also revealed a high‐frequency (360 Hz) reflector at 2.7 m depth within the mound, perhaps due to a resonant cavity within the pig's body. Single channel ground‐penetrating radar data were processed with the same approach, including band‐pass filtering and migration. The radar data reveal clear reflections from the burial crypt. Extremely fast radar velocities (260 mm ns−1) are required in the upper portion of the burial mound to place the top of the crypt at its correct depth. The bottom of the crypt was well defined by ground‐penetrating radar, and was located accurately with respect to the top of the crypt with a moderate radar velocity (170 mm ns−1). The application of both seismic reflection and ground‐penetrating radar to the same site may be beneficial for improved understanding of their abilities for shallow subsurface imaging. Copyright © 2002 John Wiley & Sons, Ltd.
Atherosclerosis in rheumatoid arthritis: Morphologic evidence obtained by carotid ultrasound
Authors: Park Yong‐Beom , Ahn Chul‐Woo , Choi Hyon K. , Lee Seung‐Hoon , In Byung‐Hyun , Lee Hyun‐Chul , Nam Chung‐Mo , Lee Soo‐Kon 
Published: September 2002

AbstractObjectiveRecent studies have suggested increased cardiovascular disease among patients with rheumatoid arthritis (RA). We undertook this study to obtain morphologic evidence of subclinical atherosclerosis in RA patients.MethodsWe used high‐resolution B‐mode ultrasound to compare carotid artery intima‐media wall thickness (IMT) between 53 postmenopausal women with RA and 53 controls matched by age, sex, and menopause status. No subject in either group had a history of atherosclerosis or its complications. We investigated the association between IMT and relevant clinical and therapeutic variables, including the impact of low‐dose corticosteroid therapy (≤10 mg/day prednisolone).ResultsThe mean ± SD IMT of the left and right common carotid arteries in RA patients was significantly greater than that in controls (0.77 ± 0.09 mm versus 0.68 ± 0.14 mm; P < 0.001). Early RA (duration ≤1 year) was associated with lesser IMT than was RA of longer duration (0.72 ± 0.03 mm versus 0.78 ± 0.01 mm; P < 0.04). Prednisolone use was not associated with increased IMT (0.78 ± 0.02 mm in nonusers versus 0.76 ± 0.01 mm in users; P = 0.38).ConclusionOur data indicate that RA patients have an ultrasonic marker of early atherosclerosis consistent with an increased risk for atherosclerosis.
Hormonal and reproductive risk factors for development of systemic lupus erythematosus: Results of a population‐based, case–control study
Authors: Cooper Glinda S. , Dooley Mary Anne , Treadwell Edward L. , St.Clair E. William , Gilkeson Gary S. 
Published: September 2002

AbstractObjectiveEstrogen and prolactin may accelerate the progression of murine systemic lupus erythematosus (SLE). In humans, 85% of lupus patients are women, which also suggests the importance of hormonal factors in disease pathogenesis. The purpose of this study was to examine hormonal and reproductive risk factors for lupus among women.MethodsThis population‐based, case–control study included 240 female SLE patients diagnosed between January 1, 1995 and July 31, 1999 who fulfilled the American College of Rheumatology classification criteria. Female controls (n = 321) were identified through driver's license records. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (95% CIs) as measures of association, adjusting for age, state, race, and education. Analyses were limited to exposures before diagnosis.ResultsBreast‐feeding was associated with a decreased risk of developing SLE (OR 0.6, 95% CI 0.4–0.9), with a statistically significant trend for number of babies breast‐fed and total weeks of breast‐feeding. There were no associations with number of pregnancies or live births. Natural menopause occurred earlier in women with subsequent development of SLE compared with controls (P < 0.001). There was little association between SLE and current use or duration of use of hormone replacement therapy or oral contraceptives, and no association with previous use of fertility drugs.ConclusionWe found little evidence that estrogen‐ or prolactin‐related exposures are associated with an increased risk of lupus. The reduced risk observed among women who had breast‐fed one or more babies should be examined in other studies. Early natural menopause, rather than decreasing risk of SLE because of reduced estrogen exposure, may be a marker of susceptibility to development of SLE.
Finer linkage mapping of primary hip osteoarthritis susceptibility on chromosome 11q in a cohort of affected female sibling pairs
Authors: Chapman Kay , Mustafa Zehra , Dowling Barbara , Southam Lorraine , Carr Andrew , Loughlin John 
Published: September 2002

AbstractObjectiveTo finer linkage‐map a primary osteoarthritis (OA) susceptibility locus as a prerequisite to linkage disequilibrium/association analysis.MethodsA 50‐cM interval of chromosome 11q that we had previously identified as harboring susceptibility to hip OA in a female sibling‐pair cohort was subjected to finer linkage mapping. Thirty‐five microsatellite markers with a mean marker interval of 1.4 cM were genotyped in 146 families containing female sibling pairs who were concordant for hip OA, as ascertained by total hip replacement.ResultsTwo‐point and multipoint linkage analysis revealed 2 distinct regions of linkage within the 50‐cM interval. The first locus had a linkage interval of 11.9 cM and was centered at 81.5 cM from the 11p telomere, with a maximum multipoint logarithm of odds (LOD) score of 2.4. The second region had a linkage interval of 6.5 cM and was centered at 93.1 cM from the 11p telomere, with a maximum multipoint LOD score of 1.8.ConclusionDense linkage mapping has highlighted the presence of 2 loci on chromosome 11q, each conferring susceptibility to hip OA. Both loci are sufficiently narrow for association analysis to be undertaken.
Empirical modelling of the DEM/USD and DEM/JPY foreign exchange rate: Structural shifts in GARCH‐models and their implications
Authors: Herwartz Helmut , Reimers Hans‐Eggert 
Published: September 2002

AbstractWe analyse daily changes of two log foreign exchange (FX) rates involving the Deutsche Mark (DEM) for the period 1975–1998, namely FX‐rates measured against the US dollar (USD) and the Japanese yen (JPY). To account for volatility clustering we fit a GARCH(1,1)‐model with leptokurtic innovations. Its parameters are not stable over the sample period and two separate variance regimes are selected for both exchange rate series. The identified points of structural change are close to a change of the monetary policies in the US and Japan, the latter of which is followed by a long period of decreasing asset prices. Having identified subperiods of homogeneous volatility dynamics we concentrate on stylized facts to distinguish these volatility regimes. The bottom level of estimated volatility turns out be considerably higher during the second part of the sample period for both exchange rates. A similar result holds for the average level of volatility and for implied volatility of heavily traded at the money options. Copyright © 2002 John Wiley & Sons, Ltd.
Effect of two methods of introducing foods during feeding treatment on acceptance of previously rejected items
Authors: Ahearn William H. 
Published: September 2002

AbstractThe effects of using a single food item (e.g. bread) versus using multiple items (e.g. bread, pasta, and rice) when establishing food acceptance via an escape prevention procedure were investigated with six children who presented with food selectivity. Eating was exposed to a differential reinforcement of food acceptance treatment package but food acceptance did not improve. Criterion levels of appropriate eating (> 80% acceptance, < 20% expulsion, and < 20% disruption) were subsequently established with either nonremoval of the spoon or physical guidance for each of the participants. Three of the children were presented with only one food item during acquisition of acceptance. The other children were presented with three different food items from the same food group. It was found that acquisition of acceptance was more rapid for the single‐item group but that food acceptance was more likely to generalize to previously rejected items for the multi‐item group. The implications for clinical intervention are discussed. Copyright © 2002 John Wiley & Sons, Ltd.
Identifying operant functions for tics in children with mental retardation
Authors: Richman David M. , Lindauer Steve E. 
Published: September 2002

AbstractFunctional analyses were used to assess the effects of environmental consequences on occurrences of repetitive vocal behavior that had been diagnosed as chronic vocal tics in two adolescent males with mental retardation. The functional analyses indicated that one participant's tics were sensitive to positive reinforcement in the form of caregiver attention, while the second participant's tics occurred independent of social consequences. The results are discussed in terms of using functional analysis methodology during assessment, diagnosis, and treatment selection for suspected tics. Copyright © 2002 John Wiley & Sons, Ltd.
Conformational dynamics of helix S6 from Shaker potassium channel: Simulation studies
Authors: Bright Joanne N. , Shrivastava Indira H. , Cordes Frank S. , Sansom Mark S. P. 
Published: September 2002

AbstractProlines in transmembrane (TM) α‐helices are believed to play an important structural and/or functional role in membrane proteins. At a structural level a proline residue distorts α‐helical structure due to the loss of at least one stabilizing backbone hydrogen bond, and introduces flexibility in the helix that may result in substantial kink and swivel motions about the effective “hinge.” At a functional level, for example in Kv channels, it is believed that proline‐induced molecular hinges may have a direct role in gating, i.e., the conformational change linked to opening/closing the channel to movement of ions. In this article we study the conformational dynamics of the S6 TM helix from of the Kv channel Shaker, which possesses the motif PVP—a motif that is conserved in Kv channels. We perform multiple molecular dynamics simulations of single S6 helices in a membrane‐mimetic environment in order to effectively map the kink–swivel conformational space of the protein, exploiting the ability of multiple simulations to achieve greater sampling. We show that the presence of proline locally perturbs the helix, disrupting local dihedral angles and producing local twist and unwinding in the region of the hinge—an effect that is relaxed with distance from the PVP motif. We furthermore show that motions about the hinge are highly anisotropic, reflecting a preferred region of kink–swivel conformation space that may have implications for the gating process. © 2002 Wiley Periodicals, Inc. Biopolymers 64: 303–313, 2002
Self‐aggregation properties of spin‐labeled zervamicin IIA as studied by PELDOR spectroscopy
Authors: Milov A. D. , Tsvetkov Yu. D. , Gorbunova E. Yu. , Mustaeva L. G. , Ovchinnikova T. V. , Raap J. 
Published: September 2002

AbstractIn this article, the pulsed double electron–electron resonance in electron spin‐echo (PELDOR) technique is applied to study the self‐aggregation of spin‐labeled zervamicin IIA, a hexadecapeptide antibiotic of fungal origin, which is known to form ion channels in a phospholipid double layer. Measurements of the ion channel forming properties and the antibiotic activity of the analog indicate that replacement of the C‐terminal phenylalaninol by the amino‐2,2,6,6‐tetramethylpiperidinyloxy (TEMPO) residue does not influence the biophysical and biological properties. The dipole–dipole interaction between the spin labels of the fully biologically active peptide analog was studied in frozen (77 K) glassy solutions in different ratios of toluene–methanol. The spin‐labeled zervamicin IIA molecules were shown to form aggregates. An average distance between the spin labels in the aggregates was estimated to be in the range of 25–35 Å (depending on the solvent composition), indicating that the amphiphilic helical peptide molecules are oriented in an antiparallel fashion. Increasing of methanol content in the solution results in a loosening of the aggregate structure. It was shown that the fraction of aggregated zervamicin IIA molecules is less than 44–67% depending on the solvent composition. The general usefulness of the method to obtain structural long‐range information in a range of several tens of angstroms is demonstrated by comparison with the peptide cluster of trichogin GA IV. © 2002 Wiley Periodicals, Inc. Biopolymers 64: 328–336, 2002