bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ultrastructural and permeability features of microvessels in the periventricular area of senescence‐accelerated mice (SAM)
Authors: Ueno Masaki , Sakamoto Haruhiko , Kanenishi Kenji , Onodera Masayuki , Akiguchi Ichiro , Hosokawa Masanori 
Published: August 2002

AbstractBrain transfer of intravenously injected horseradish peroxidase (HRP) and the ultrastructural features of the vessels were examined in periventricular areas in senescence‐accelerated mice (SAMP8), which show age‐related deficits in learning and memory, and senescence‐accelerated resistant mice (SAMR1), which do not show age‐related deficits. In all mice examined with light microscopy, staining reaction for HRP was seen in the periventricular area adjacent to the medial side of the lateral ventricle. Electron microscopic examination in the periventricular area of young and old mice of both strains showed that the staining reaction for HRP appeared in the vesicular profiles of the endothelial cytoplasm, the cytoplasm of the perivascular cells, the basal lamina, and the adjoining extracellular spaces of the white matter, suggesting an incomplete blood–brain barrier (BBB) in the periventricular white matter. In addition, irregularly thickened endothelial cell cytoplasm, membranous inclusions within the basal lamina, and electron‐dense endothelial cell cytoplasm were occasionally seen in aged SAMP8 mice. These findings were not observed in 3‐month‐old SAMP8 mice and 3‐ and 13‐month‐old SAMR1 mice. Perivascular collagen deposits were also frequently seen in aged SAMP8 mice. These findings indicate that the endothelial cells and pericytes in the periventricular white matter in aged SAMP8 mice have an ultrastructure with damaged BBB function. Intravascular substances can easily penetrate the periventricular white matter and the BBB of the vessels in the area can be deteriorated with aging in SAMP8 mice. Microsc. Res. Tech. 53:232–238, 2001. © 2001 Wiley‐Liss, Inc.
III. Chemokines and other mediators, 8. Chemokines and their receptors in cell‐mediated immune responses in the lung
Authors: Matsukawa Akihiro , Lukacs Nicholas W. , Hogaboam Cory M. , Chensue Stephen W. , Kunkel Steven L. 
Published: August 2002

AbstractChemokines constitute a large family of chemotactic cytokines that belong to a super‐gene family of 8–10 kDa proteins. The chemokines are considered to be primarily beneficial in host defense against invading pathogens. However, the reactions induced by chemokines can be occasionally excessive, resulting in a harmful response to the host. Recent studies in chemokine biology have elucidated that chemokines are involved in the initiation, development, and maintenance of numbers of diseases including lung diseases. In addition to its chemotactic activity, evidence suggests that chemokines can modify the outcome of the cell‐mediated immune responses by altering the Th1/Th2 cytokine profile. Chemokines are also capable of dictating the direction of specific immune responses. Chemokine action is mediated by a large super‐family of G‐protein coupled receptors, and the receptors are preferentially expressed on Th1/Th2 cells. Certain chemokine receptors are constitutively expressed in immune surveying cells such as dendritic cells and naive T cells. The corresponding chemokines are present in normal lymphoid tissues, suggesting a role of chemokines/receptors in cell homing and cell‐cell communication in lymphoid tissue that can be an initial step for immune recognition. Thus, comprehension of the chemokine biology in immune responses appears to be fundamental for understanding the pathogenesis of T cell–mediated immune responses. The following review will highlight the current insight into the role of chemokines and their receptors in the cell‐mediated immune response, with a special focus on lung diseases. Microsc. Res. Tech. 53:298–306, 2001. © 2001 Wiley‐Liss, Inc.
IV. Clinical aspects of delayed hypersensitivity in lungs: Pathophysiology of hypersensitivity disorders in clinics
Authors: Hirata Kazuto , Kanazawa Hiroshi , Kamoi Hiroshi 
Published: August 2002

AbstractHypersensitivity pneumonitis (HP) is an immunologically mediated lung disease of inhaled antigens. HP is not a uniform disease but rather a clinical complex syndrome characterized by varying intensities of responsiveness to different organic antigens. The main aetiological agents include thermophilic bacteria, fungi, animal proteins, and chemical compounds. A combination of host and environmental factors should be considered as a requisite to developing this disease. Although the antigens differ widely, the clinical syndromes that results are very similar. HP occurs mainly in non‐smokers, and clinically it may be in acute, subacute, or chronic forms. The diagnosis of HP requires a constellation of clinic, radiographic, physiologic, pathologic, and immunologic criteria. HP is characterized by a diffuse and predominantly mononuclear cell inflammation, a partly granulomatous, immune disorder of alveolar regions that often involves the small airway. A strong evidence supports that delayed cell‐mediated hypersensitivity mechanisms play a role in pathogenesis of HP. Studies performed on lung cells have demonstrated that cells bearing suppressor/cytotoxic phenotype characterize the lymphocytic alveolitis in patients with hypersensitivity pneumonitis. And also recently evidence has been provided indicating that a prominent role of T‐helper 1 cell‐mediated hypersensitivity with an imbalance in T‐lymphocyte subsets, although the deposit of immune complex may participate in an acute form of the disease as well as in the early phase of the chronic form. Microsc. Res. Tech. 53:307–312, 2001. © 2001 Wiley‐Liss, Inc.
Dynamics and plasticity of peptidergic control centres in the retino‐brain‐pituitary system of Xenopus laevis
Authors: Kramer B.M.R. , Kolk S.M. , Berghs C.A.F.M. , Tuinhof R. , Ubink R. , Jenks B.G. , Roubos E.W. 
Published: August 2002

AbstractThis review deals particularly with the recent literature on the structural and functional aspects of the retino‐brain‐pituitary system that controls the physiological process of background adaptation in the aquatic toad Xenopus laevis. Taking together the large amount of multidisciplinary data, a consistent picture emerges of a highly plastic system that efficiently responds to changes in the environmental light condition by releasing POMC‐derived peptides, such as the peptide α‐melanophore‐stimulating hormone (α‐MSH), into the circulation. This plasticity is exhibited by both the central nervous system and the pituitary pars intermedia, at the level of molecules, subcellular structures, synapses, and cells. Signal transduction in the pars intermedia of the pituitary gland of Xenopus laevis appears to be a complex event, involving various environmental factors (e.g., light and temperature) that act via distinct brain centres and neuronal messengers converging on the melanotrope cells. In the melanotropes, these messages are translated by specific receptors and second messenger systems, in particular via Ca2+ oscillations, controlling main secretory events such as gene transcription, POMC‐precursor translation and processing, posttranslational peptide modifications, and release of a bouquet of POMC‐derived peptides. In conclusion, the Xenopus hypothalamo‐hypophyseal system involved in background adaptation reveals how neuronal plasticity at the molecular, cellular and organismal levels, enable an organism to respond adequately to the continuously changing environmental factors demanding physiological adaptation. Microsc. Res. Tech. 54:188–199, 2001. © 2001 Wiley‐Liss, Inc.
Free‐floating cryostat sections for immunoelectron microscopy: Bridging the gap from light to electron microscopy
Authors: Kan Robert K. , Pleva Christina M. , Backof Daniel R. , Hamilton Tracey A. , Petrali John P. 
Published: August 2002

AbstractFrozen skin sections are routinely used for light microscopic immunohistochemical study of the skin basement membrane zone for two reasons: some skin basement membrane zone proteins are labile to routine chemical fixation, and skin is not amenable to vibratome sectioning. However, inherent limitations of conventional frozen sections, including compromised morphology and a requirement for glass slide‐mounting, usually limit immunohistochemical study to the light microscopy level. In the present study, we introduce use of unfixed, free‐floating cryostat sections for characterization of immunolocalizations of selected skin basement membrane proteins at both the light and electron microscopy level. The new procedure employs free‐floating cryostat sections that can be processed as routine tissue specimens and can be subjected to a variety of special staining procedures including immunohistochemistry. Especially useful is the ease of progressive processing of the same tissue specimen from light microscopy to electron microscopy. In this regard, the method renders itself useful when results of immunolabeling experiments need to be elucidated quickly at histological and ultrastructural levels as required for diagnostic and accelerated investigative strategies. Microsc. Res. Tech. 54:246–253, 2001. © 2001 Wiley‐Liss, Inc.
Capillary plexus development in the day five to day six chick chorioallantoic membrane is inhibited by cytochalasin D and suramin
Authors: Melkonian Goar , Munoz Nicole , Chung Jeanne , Tong Cathy , Marr Rebecca , Talbot P. 
Published: August 2002

AbstractThe chick chorioallantoic membrane (CAM) is a valuable model for evaluating angiogenesis and vasculogenesis. Our purpose was to characterize the formation of the CAM vasculature, in particular the capillary plexus, between days five and six after fertilization and to examine the mode of action of cytochalasin D and suramin on vascular development during this interval. The CAM increased 20‐fold in size between days five and six, during which time the capillary plexus forms by both migration of mesodermal blood vessels toward the ectoderm and by the formation of new vessels from angioblasts near the ectoderm. Between days five and six, the CAM becomes thinner, and the density of the mesodermal cells decreases. To determine the mode of action of anti‐angiogenic drugs on the day five to day six CAM, various concentrations of cytochalasin D or suramin were added directly to day five CAMs, and their effects were evaluated on day six. Both drugs significantly inhibited CAM growth, altered branching patterns of the major vessels, decreased area of the major vessels, and inhibited the formation of the capillary plexus by inhibiting both vasculogenesis and the migration of mesodermal blood vessels to the ectoderm. Cytochalasin D also inhibited compartmentalization of the plexus. Cytochalasin D and suramin were inhibitory at similar doses. This study provides new information on early CAM development, establishes the mode of action and dose dependency of cytochalasin D and suramin on day five to day six CAMs, and demonstrates that the day five to day six CAM provides a useful assay to examine the effect of anti‐angiogenic drugs on blood vessel development, including capillary plexus formation. J. Exp. Zool. 292:241–254, 2001. © 2002 Wiley‐Liss, Inc.
When bad things happen to good trees*
Authors: Aivaliotis Manuel , Gordon Gary , Graveman William 
Published: August 2002

AbstractWhen the edges in a tree or rooted tree fail with a certain fixed probability, the (greedoid) rank may drop. We compute the expected rank as a polynomial in p and as a real number under the assumption of uniform distribution. We obtain several different expressions for this expected rank polynomial for both trees and rooted trees, one of which is especially simple in each case. We also prove two extremal theorems that determine both the largest and smallest values for the expected rank of a (rooted or unrooted) tree, and precisely when these extreme bounds are achieved. We conclude with directions for further study. © 2001 John Wiley & Sons, Inc. J Graph Theory 37: 79–99, 2001
Counting 5‐connected planar triangulations
Authors: Gao Zhicheng J. , Wanless Ian M. , Wormald Nicholas C. 
Published: August 2002

AbstractLet tn be the number of rooted 5‐connected planar triangulations with 2n faces. We find tn exactly for small n, as well as an asymptotic formula for n → ∞. Our results are found by compositions of lower connectivity maps whose faces are triangles or quadrangles. We also find the asymptotic number of cyclically 5‐edge connected cubic planar graphs. © 2001 John Wiley & Sons, Inc. J Graph Theory 38: 18–35, 2001
Adaptive technology strategies and technical efficiency: Evidence from the Sri Lankan agricultural machinery industry
Authors: Deraniyagala Sonali 
Published: August 2002

AbstractRecent research has highlighted the importance of technology strategies in influencing the economic performance of firms in developing countries. Attention has focused on two types of strategies: the first involves adopting technologies developed elsewhere without undertaking any modifications and the second involves investing in such technologies but adapting them to suit firm‐specific needs and circumstances. Whilst it has been indicated that the second type of adaptive strategy is likely to lead to higher productivity gains than the first, this hypothesis has not been tested econometrically. Using survey data, this paper undertakes an econometric analysis of the effects of these alternative technology strategies on firm‐level technical efficiency in the agricultural machinery industry in Sri Lanka. Controlling for other possible determinants, it finds that adaptive strategies have a significant positive effect on efficiency in this industry. © 2001 John Wiley & Sons, Ltd.
Mineralized dermal layer of the Brazilian tree‐frog Corythomantis greeningi
Authors: Katchburian E. , Antoniazzi M.M. , Jared C. , Faria F.P. , Souza Santos H. , Freymüller E. 
Published: August 2002

AbstractSome species of anuran amphibians possess a calcified dermal layer (the Eberth‐Kastschenko layer) located between the “stratum spongiosum” and the “stratum compactum.” This layer consists of calcium phosphate deposits, proteoglycans, and glycosaminoglycans. Although regarded as a protective layer against desiccation, a calcium reservoir, or possibly a remnant of a dermal skeleton present in anuran ancestors, very little is known about its origin, structure, and function. Thus, we studied the structure and composition of the mineralized dermal layer of Corythomantis greeningi, a peculiar hylid from the Brazilian semiarid region (caatinga), using conventional and cryosubstitution methods combined with transmission, scanning, and analytical electron microscopy. Results show that the dermal layer consists of dense, closely juxtaposed, globular structures. Although the electron opacity of the globules was variable, depending on the type of preparation, crystal‐like inclusions were present in all of them, as confirmed by dark field microscopy. Electron probe X‐ray microanalysis showed calcium, phosphorus, and oxygen, and electron diffraction revealed a crystalline structure comparable to that of a hydroxyapatite. J. Morphol. 248:56–63, 2001. © 2001 Wiley‐Liss, Inc.
Histological study of Goniodoris castanea Alder and Hancock, 1845 (Nudibranchia, Doridoidea, Goniodorididae)
Authors: Wägele Heike , Cervera Juan Lucas 
Published: August 2002

AbstractThe major organ systems of Goniodoris castanea were investigated by histological means, with an emphasis on those structures that are difficult to see by dissection. The species is characterized by some peculiar features that are unique or seldom within the Nudibranchia, such as the complete absence of specialized vacuolated cells, the presence of globular salivary glands, the presence of cuticular structures in the proximal intestine, a muscular sphincter around the distal vaginal duct, and the position of the blood gland closer to the pericardium than to the nervous system. Some of these characters are discussed in a phylogenetic context, although a thorough phylogenetic analysis is preliminary, due to lack of knowledge of probably related species. J. Morphol. 250:61–69, 2001. © 2001 Wiley‐Liss, Inc.
Segmentation with gray‐scale connectedness can separate arteries and veins in MRA
Authors: Tizon Xavier , Smedby Örjan 
Published: August 2002

AbstractPurposeTo describe and present some preliminary results for a novel algorithm for segmentation with gray‐scale connectedness as a means to separate arteries and veins in magnetic resonance angiography (MRA).Materials and MethodsThe proposed algorithm, SeparaSeed, uses the gray‐scale degree of connectedness as a tool to find the zone surrounding each vessel, in order to split the original volume into its different vessel components. In contrast to traditional segmentation methods, no gray‐scale information is lost in the process. The segmentation is performed in one step, resulting in a partition of the initial volume into a chosen number of regions of interest (ROIs). Finally, visualization is achieved by projecting the 3D vessel trees to 2D using the common maximum intensity projection (MIP). The algorithm was tested in two MRA data sets of the vessels of the pelvis acquired after injection of an intravascular contrast agent and in one data set of the vessels of the neck with gadolinium.ResultsIn all data sets, a large proportion of the venous signal was removed while preserving that of the arteries, thus improving visualization of the relevant vessels.ConclusionSeparation of arteries and veins is feasible with the proposed algorithm with a moderate amount of interaction. J. Magn. Reson. Imaging 2002;15:438–445. © 2002 Wiley‐Liss, Inc.
Advances in human cardiac 31P‐MR spectroscopy: SLOOP and clinical applications
Authors: von Kienlin Markus , Beer Meinrad , Greiser Andreas , Hahn Dietbert , Harre Kerstin , Köstler Herbert , Landschütz Wilfried , Pabst Thomas , Sandstede Jörn , Neubauer Stefan 
Published: August 2002

AbstractPhosphorus magnetic resonance spectroscopy (31P‐MRS) has revealed a lot about the biochemistry of physiological and pathological processes in the heart. Nevertheless, until today, cardiac 31P‐MRS has not had any clinical impact, albeit some pioneering studies demonstrated that 31P‐MRS can indeed provide diagnostic information. In this paper, the development of techniques for human cardiac 31P‐MRS over the past decade is reviewed, and the requirements for a reliable clinical measurement protocol are discussed. Spatial localization with optimal pointspread function (SLOOP) is a new method to achieve spatial localization and absolute quantitation. Its properties are detailed, and preliminary findings in patients with dilated cardiomyopathy or myocardial infarction are presented. J. Magn. Reson. Imaging 2001;13:521–527. © 2001 Wiley‐Liss, Inc.
Laser‐induced interstitial thermotherapy of liver metastases in an interventional 0.5 Tesla MRI system: Technique and first clinical experiences
Authors: Fiedler Volkhard Ulrich , Schwarzmaier Hans‐Joachim , Eickmeyer Frank , Müller Frank Peter , Schoepp Christian , Verreet Patrick Robert 
Published: August 2002

AbstractLaser‐induced interstitial thermotherapy (LITT) surveyed by magnetic resonance imaging (MRI) has been shown to be effective in various applications. The laser treatment of colorectal liver metastases usually requires a separate device (e.g., ultrasound or CT) to position the laser applicator. In this study, we used an interventional 0.5 T MRI system, allowing both the navigation to the target tissue and on‐line thermometry. Laser irradiation was performed using a near‐infrared laser source combined with a cooled laser light guide. We treated 20 patients exhibiting a total of 58 colorectal liver metastases. Clinically relevant complications did not occur. No residual tumor was observed after laser irradiation in all metastases with a diameter below 2 cm. Metastases with a mean diameter between 2 and 3 cm demonstrated total necrosis in 71%, while in larger tumors this proportion decreased to 46% (diameter, 3–4 cm) and 30% (diameter, >4 cm), respectively. We conclude that LITT, guided by the employed interventional MRI system, is feasible and safe. The results suggest a more aggressive treatment, especially for larger metastases. J. Magn. Reson. Imaging 2001;13:729–737. © 2001 Wiley‐Liss, Inc.
Three‐dimensional adaptive filtering in magnetic resonance angiography
Authors: Westin Carl‐Fredrik , Wigström Lars , Loock Tomas , Sjöqvist Lars , Kikinis Ron , Knutsson Hans 
Published: August 2002

AbstractIn order to enhance 3D image data from magnetic resonance angiography (MRA), a novel method based on the theory of multidimensional adaptive filtering has been developed. The purpose of the technique is to suppress image noise while enhancing important structures. The method is based on local structure estimation using six 3D orientation selective filters, followed by an adaptive filtering step controlled by the local structure information. The complete filtering procedure requires approximately 3 minutes of computational time on a standard workstation for a 256 × 256 × 64 data set. The method has been evaluated using a mathematical vessel model and in vivo MRA data (both phase contrast and time of flight (TOF)). 3D adaptive filtering results in a better delineation of small blood vessels and efficiently reduces the high‐frequency noise. Depending on the data acquisition and the original data type, contrast‐to‐noise ratio (CNR) improvements of up to 179% (8.9 dB) were observed. 3D adaptive filtering may provide an alternative to prolonging the scan time or using contrast agents in MRA when the CNR is low. J. Magn. Reson. Imaging 2001;14:63–71. © 2001 Wiley‐Liss, Inc.
Quadrupole time‐of‐flight versus triple‐quadrupole mass spectrometry for the determination of phosphopeptides by precursor ion scanning
Authors: Steen Hanno , Küster Bernhard , Mann Matthias 
Published: August 2002

AbstractAn API 3000 triple‐quadrupole instrument and a QSTAR Pulsar quadrupole time‐of‐flight (TOF) mass spectrometer were compared for the determination of phosphopeptides by precursor ion scanning in both the positive and negative nanoelectrospray ionization modes. The limits of detection for synthetic phosphopeptides were similar (500 amol µl−1) for both types of instruments when monitoring precursors of −79 Da (PO3−). However, the quadrupole TOF system was approximately fivefold more sensitive (1 fmol µl−1) than the triple‐quadrupole instrument (5 fmol µl−1) when monitoring precursors of 216 Da (immonium ion of phosphotyrosine). The recently introduced Q2‐pulsing function, which enhances the transmission of fragment ions of a selected m/z window from the collision cell into the TOF part, improved the sensitivity of precursor ion scans on a quadrupole TOF instrument. The selectivity of precursor ion scans is much better on quadrupole TOF systems than on triple quadrupoles because the high resolving power of the reflectron‐TOF mass analyzer permits high‐accuracy fragment ion selection at no expense of sensitivity. This minimizes interferences from other peptide fragment ions (a‐, b‐, and y‐ type) of the same nominal mass but with sufficient differences in their exact masses. As a result, the characteristic immonium ion of phosphotyrosine at m/z 216.043 can be utilized for the selective detection of tyrosine phosphorylated peptides. Our data suggest that, in addition to their superior performance for peptide sequencing, quadrupole TOF instruments also offer a very viable alternative to triple quadrupoles for precursor ion scanning, thus combining high sensitivity and selectivity for both MS and MS/MS experiments in one instrument. Copyright © 2001 John Wiley & Sons, Ltd.