bluuebunny/crossref_metadata_2025_split huggingface dataset:
Degenerate solutions obtained from several variants of factor analysis
Authors: Zijlstra Bonne J. H. , Kiers Henk A. L. 
Published: November 2002

AbstractConsiderable research has been performed concerning degenerate solutions from the Parafac model. However, degenerate solutions have also been reported to occur with the shifted multiplicative model and a model for component analysis of multitrait multimethod matrices. Furthermore, we obtained similarly degenerate solutions for the directly fitted Parafac‐2 model, the indirectly fitted Parafac‐2 model and a constrained variant of the Tucker‐3 model. Comparing degenerate solutions reported in the literature with the degenerate solutions we obtained ourselves, we learned that for all the above‐mentioned models there are two‐factor degenerate solutions sharing the same properties. We distinguish three common features. Furthermore, the above‐mentioned models have in common that they are all variants of factor analysis producing component matrices with components that are rotationally unique. Underscoring the significance of this property, we show that all models for two‐way and three‐way factor analysis not resulting in solutions with rotationally unique components cannot produce degenerate solutions. Copyright © 2002 John Wiley & Sons, Ltd.
Distribution of brain‐derived neurotrophic factor and TrkB receptor proteins in the fetal and postnatal hippocampus and cerebellum of the guinea pig
Authors: Dieni Sandra , Rees Sandra 
Published: November 2002

AbstractThis study investigates the distribution of brain‐derived neurotrophic factor protein (BDNF) and its receptor, TrkB, during the development of hippocampus and cerebellum in a long‐gestation species, the guinea pig. In the granule cell populations of both structures, BDNF immunoreactivity (‐IR) was exclusive to postmigratory, mature neurons. In dentate granule cells, TrkB‐IR was coexpressed with BDNF‐IR, suggesting that the ligand‐receptor interaction could occur by means of an autocrine/paracrine mechanism. In cerebellar granule cells, TrkB‐IR was detected in both pre‐ and postmigratory cells, indicating that immature neurons are also BDNF‐responsive. With advancing gestational age an increase in the intensity of BDNF‐IR in granule cells was accompanied by concomitant increases in the staining and areal growth of the associated mossy fiber layer in the hippocampus, and the molecular layer in the cerebellum. The developmental increase in BDNF‐ and TrkB‐IR in the neuropil of both structures coincided with periods of significant growth in all strata, indicating a role for BDNF and TrkB in process outgrowth. In the hippocampus, CA2, CA3, and hilar, neurons demonstrated both BDNF‐ and TrkB‐IR during development and maturation, whereas CA1 neurons showed TrkB‐IR throughout this period but only transient BDNF‐IR in early gestation. In the fetal cerebellum, Purkinje cell bodies coexpressed BDNF‐IR and TrkB‐IR. In the postnatal period, BDNF‐IR was down‐regulated but TrkB‐IR persisted, indicating that mature Purkinje cells might retain their responsiveness to BDNF. Thus, we have demonstrated in both the hippocampus and cerebellum that the spatiotemporal distribution of BDNF‐IR and TrkB‐IR coincides with the maturation of granule cells prenatally and with significant periods of neuropil growth, both prenatally and in the immediate postnatal period. J. Comp. Neurol. 454:229–240, 2002. © 2002 Wiley‐Liss, Inc.
Morphology and differentiation of radial glia in the developing rat spinal cord
Authors: McMahon Siobhan S. , McDermott Kieran W. 
Published: November 2002

AbstractImportant events underlying the proper functioning of the central nervous system (CNS) include the production, assembly, and differentiation of appropriate types and numbers of cells during development. The mechanisms that control these events are difficult to unravel because of displacement of cells from their sites of origin to their permanent locations and because of the diverse cellular composition of the CNS. As in other regions of the mammalian CNS, the two major classes of neuroglial cells in the rat spinal cord are oligodendrocytes and astrocytes. In the developing spinal cord, radial glia are prominent. In this study, radial glia in the cervical region of the spinal cord were analysed. 1,1′Dioctadecyl‐3,3,3′‐tetramethylindocarbocyanine perchlorate (DiI) was used to determine the morphology and distribution of radial glia during spinal cord development. The DiI labelling technique enabled locating glial precursor cells during spinal cord development. Radial fibres that extended from the central canal to the pial surface were present at embryonic days 14, 16, and 18 in the developing spinal cord. Their distribution was restricted with increasing development, and by embryonic day 20 the only remaining evidence of radial glia were short radial processes in the white matter. J. Comp. Neurol. 454:263–271, 2002. © 2002 Wiley‐Liss, Inc.
Few intrinsic connections cross the hand‐face border of area 3b of New World monkeys
Authors: Fang Pei‐Chun , Jain Neeraj , Kaas Jon H. 
Published: November 2002

AbstractAfter long‐standing loss of afferents from the hand, the hand representation in area 3b of the somatosensory cortex of monkeys becomes responsive to touch on the face. Because the reactivation of deprived hand cortex by the face inputs could depend on axonal connections across the hand‐face border, we determined the extent of such connections in New World marmosets, owl monkeys, and squirrel monkeys. Small injections of anatomic tracers were placed in the hand or the face representations after these representations were identified by microelectrode recordings. The positions of retrogradely labeled neurons were plotted in processed brain sections cut parallel to the brain surface, and their locations were related to anatomic isomorphs of the hand and face representations revealed in adjacent brain sections stained for myelin. In these sections, the hand‐face border was clearly visualized as a myelin‐poor septum. The intrinsic connections of area 3b labeled by injections in either the hand or face representations were almost completely confined to their respective representation, and very few neurons projected across the border. In addition, neurons in the somatosensory thalamus labeled by injections in either face or hand representations were confined to either VPM, representing the face, or the hand subnucleus of VPL. Thus the reactivation of hand cortex by face stimulation does not depend on a previously existing network of intrinsic cortical connections across the hand‐face border, or mismatched thalamocortical projections. J. Comp. Neurol. 454:310–319, 2002. © 2002 Wiley‐Liss, Inc.
Localization of the Slack potassium channel in the rat central nervous system
Authors: Bhattacharjee Arin , Gan Li , Kaczmarek Leonard K. 
Published: November 2002

AbstractThe Slack gene encodes a voltage‐dependent K+ channel that has a unitary conductance of ∼60 pS. Evidence from heterologous expression studies suggests that Slack channel subunits can also combine with the Slo subunit to generate Ca2+‐activated K+ channels of larger conductances. Nonetheless, the function of Slack in the brain remains to be identified. We have now generated an affinity‐purified antibody against the N‐terminal of rat Slack, for biochemical and immunohistochemical studies. The antibody recognized Slack in transiently transfected CHO cells both by immunocytochemistry and by Western blot analysis. The antibody also detected a single band in rat brain membranes. The localization of Slack in rat brain slices was then determined using the antibody. Most prominent Slack immunoreactivity occurs in the brainstem, in particular the trigeminal system and reticular formation, where very intense staining was found in both cell bodies and axonal fibers of associated nuclei. Labeling was also very strong in the vestibular and oculomotor nuclei. Within the auditory system, the medial nucleus of the trapezoid had a robust signal consistent with staining of the giant presynaptic terminals. Strong Slack immunoreactivity was present in the olfactory bulb, red nucleus, and deep cerebellar nuclei. There was labeling also in the thalamus, substantia nigra, and amygdala. The only cortical region in which Slack immunoreactivity was detected was the frontal cortex. The subcellular and regional distribution of Slack differs from that previously reported for the Slo channel subunit and suggests that Slack may also have an autonomous role in regulating the firing properties of neurons. J. Comp. Neurol. 454:241–254, 2002. © 2002 Wiley‐Liss, Inc.
Odor‐stimulated glutamatergic neurotransmission in the zebrafish olfactory bulb
Authors: Edwards Jeffrey G. , Michel William C. 
Published: November 2002

AbstractThe role of glutamate as a neurotransmitter in the zebrafish olfactory bulb (OB) was established by examining neuronal activation following 1) glutamate receptor agonist stimulation of isolated olfactory bulbs and 2) odorant stimulation of intact fish. Four groups of neurons (mitral cells, projection neurons; granule cells, juxtaglomerular cells, and tyrosine hydroxylase‐containing cells; interneurons) were identified on the basis of cell size, cell location, ionotropic glutamate receptor (iGluR) agonist/odorant sensitivity, and glutamate, γ‐aminobutyric acid (GABA), and tyrosine hydroxylase immunoreactivity. Immunoreactive glutamate levels were highest in olfactory sensory neurons (OSNs) and mitral cells, the putative glutamatergic neurons. The sensitivity of bulbar neurons to iGluR agonists and odorants was established using a cationic channel permeant probe, agmatine (AGB). Agmatine that permeated agonist‐ or odor‐activated iGluRs was fixed in place with glutaraldehyde and detected immunohistochemically. N‐methyl‐D‐aspartic acid (NMDA) and α‐amino‐3‐hydroxyl‐5‐methylisoxazole‐4‐propionic acid (AMPA)/kainic acid (KA) iGluR agonists and odorants (glutamine, taurocholic acid) stimulated activity‐dependent labeling of bulbar neurons, which was blocked with a mixture of the iGluR antagonists, D‐2‐amino‐5‐phosphono‐valeric acid (APV) and 6‐cyano‐7‐nitroquinoxaline‐2,3‐dione (CNQX). The AMPA/KA antagonist CNQX completely blocked glutamine‐stimulated AGB labeling of granule cells and tyrosine hydroxylase‐containing cells, suggesting that, in these cell types, AMPA/KA receptor activation is essential for NMDA receptor activation. However, blocking AMPA/KA receptor activity failed to eliminate AGB labeling of mitral cells or juxtaglomerular cells. Collectively, these findings indicate that glutamate is the primary excitatory neurotransmitter in the zebrafish OB and that iGluR subtypes function heterogeneously in the bulbar neurons. J. Comp. Neurol. 454:294–309, 2002. © 2002 Wiley‐Liss, Inc.
Identification of cells expressing somatostatin receptor 2 in the gastrointestinal tract of Sstr2 knockout/lacZ knockin mice
Authors: Allen Jeremy P. , Canty Alison J. , Schulz Stefan , Humphrey Patrick P.A. , Emson Piers C. , Young Heather M. 
Published: November 2002

AbstractSomatostatin is found in neurons and endocrine cells in the gastrointestinal tract. The actions of somatostatin are mediated by a family of G‐protein–coupled receptors that compose five subtypes (SSTR1–5), each of which is encoded by a separate gene. lacZ “knockin” mice, in which the reporter gene lacZ was engineered into the genomic locus of Sstr2 by gene targeting, were used to examine the expression pattern of Sstr2 and identify potential targets for neurally released and hormonal somatostatin in the gastrointestinal tract. In the body of the stomach, a large proportion of epithelial cells and subpopulations of myenteric neurons expressed Sstr2. Double‐ or triple‐labeling with antisera to H+K+ATPase (to identify parietal cells) and/or histidine decarboxylase (to identify enterochromaffin‐like [ECL] cells) combined with β‐galactosidase staining revealed that both parietal cells and ECL cells expressed Sstr2, and these two cell types accounted for almost all of the Sstr2‐expressing epithelial cells. Somatostatin inhibits gastric acid secretion. The presence of SSTR2 on both parietal and ECL cells suggests that somatostatin acting on SSTR2 may reduce acid secretion by both acting directly on parietal cells and by reducing histamine release from ECL cells. In the small and large intestine, subpopulations of neurons in the myenteric and submucosal plexuses expressed Sstr2, and many of the Sstr2‐expressing myenteric neurons also showed SSTR2(a) immunostaining. Most of Sstr2‐expressing neurons in the myenteric plexus showed nitric oxide synthase (NOS) immunoreactivity. Previous studies have shown that NOS neurons are descending interneurons and anally projecting, inhibitory motor neurons. Thus, somatostatin acting at SSTR2 receptors on NOS neurons might modulate descending relaxation. J. Comp. Neurol. 454:329–340, 2002. © 2002 Wiley‐Liss, Inc.
Stakeholder excellence? Framing the evolution and complexity of a stakeholder perspective of the firm
Authors: Jonker Jan , Foster David 
Published: November 2002

AbstractAnalysing and dealing with the needs and demands of stakeholders is a major concern of modern business. This paper attempts to frame, systematize and conceptualize a number of the underlying issues related to the phenomenon. As a result, a vast array of unaddressed and unanswered questions emerges. What unites these is the implicit acceptance of an emerging (contemporary) stakeholder theory of the firm. This largely normative theory provides some understanding of what constitutes a stakeholder, what stakes they seek to protect and the way in which transactions between the stakeholder and the organizations are handled. While the brevity of the contribution necessitates a somewhat superficial treatment of the issues, the paper leads inevitably to the conclusion that the demonstrated complexity of really engaging with stakeholders means that both theory‐development and practice still have a long way to go. Copyright © 2002 John Wiley & Sons, Ltd. and ERP Environment.
Merocyanine 540 as a fluorescent probe of altered membrane phospholipid asymmetry in activated whole blood platelets
Authors: Watala Cezary , Waczulikova Iveta , Wieclawska Boguslawa , Rozalski Marcin , Gresner Peter , Gwoździński Krzysztof , Mateasik Anton , Śikurova Libuśa 
Published: November 2002

AbstractBackgroundPlatelet activation leads to the loss of a natural asymmetry of membrane phospholipids (PL) and the subsequent exposure of negatively charged PL in platelets with procoagulant activity that can be monitored routinely with annexin V (AN‐V).MethodsFlow cytometric analysis of merocyanine 540 (MC540) binding may be the alternate choice for the monitoring of platelet procoagulant activity. Due to the increased partition of negatively charged phosphatidylserine (PS) in the membrane outer leaflet of activated platelets, the interaction with MC540 is reduced.ResultsCollagen, which facilitated platelet PL bilayer symmetrization, vastly reduced MC540 fluorescence and augmented AN‐V binding to platelets. Such a collagen‐induced symmetrization was further augmented in the presence of thrombin receptor‐activating peptide (TRAP, SFLLRNPNDKYEPF). In the presence of VO4(−3) (the inhibitor of aminophospholipid translocase), the rebuilt of membrane asymmetry was attenuated, which resulted in further reduced MC540 fluorescence and enhanced AN‐V binding in activated cells. In platelets incubated with thapsigargin, the inhibitor of platelet tubular system Ca2+ ATP‐ase, which elevates intraplatelet Ca2+ concentration, TRAP increased AN‐V and reduced MC540 binding. The chelating of Ca2+ with EGTA outside of activated platelets reduced AN‐V binding, but did not affect MC540‐positive platelets. The fluctuations in reduced staining with MC540 paralleled enhanced AN‐V binding (r = −0.481, P < 0.01), especially for strong “procoagulant” activating agents.Conclusions(1) MC540 may be used in whole blood flow cytometry for the monitoring of platelet membrane symmetrization as an alternate or compounding method to AN‐V. (2) Platelet staining with MC540 is sensitive to the fluctuations in the intraplatelet [Ca2+] during platelet activation. (3) Use of MC540 is characterized by improved diagnostic precision and reliability compared with AN‐V. Cytometry 49:119–133, 2002. © 2002 Wiley‐Liss, Inc.
Antimycin A‐induced apoptosis of HL‐60 cells
Authors: King Malcolm A. , Radicchi‐Mastroianni Monica A. 
Published: November 2002

AbstractBackgroundPrevious experiments in our laboratory investigating apoptosis induced in HL‐60 cells by camptothecin (CAM) have revealed that the sequence and rapidity of the apoptotic phenomena in an individual cell depend on the proliferative state of that cell when it encounters CAM. The role of mitochondria in HL‐60 apoptosis was explored using an inhibitor of oxidative phosphorylation, antimycin A (AMA).MethodsChanges in cell light scatter, binding of annexin V‐fluorescein isothiocyanate (FITC), uptake of propidium iodide (PI), and DNA content after membrane fixation/permeabilization were monitored by flow cytometry. Z‐VAD‐FMK was used to inhibit caspases. Fluorescence microscopy was used to examine cell morphology.ResultsCells in the G1 phase of the cell cycle were the first to exhibit signs of apoptosis in response to 100 μM AMA and some of these cells disintegrated without exposing to phosphatidylserine (PS). Caspase inhibition prevented fragmentation of DNA, the nucleus, and the cell, but only delayed PS exposure and loss of plasma membrane integrity.ConclusionsThe highly active mitochondria of G1‐phase HL‐60 cells make them particularly sensitive to AMA. PS exposure and plasma membrane damage are mediated by noncaspase molecules released from mitochondria. We hypothesize that if mitochondria are subjected to a sufficiently severe insult, whether indirectly as a result of extensive CAM‐induced DNA damage or directly by the effect of AMA on electron transport, the nature and quantities of the proapoptotic molecules released are such that apoptosis proceeds to the point of cell disintegration before the PS exposure pathway is complete. Cytometry 49:106–112, 2002. © 2002 Wiley‐Liss, Inc.
Exposure of cells to static magnetic field accelerates loss of integrity of plasma membrane during apoptosis
Authors: Teodori Laura , Grabarek Jerzy , Smolewski Piotr , Ghibelli Lina , Bergamaschi Antonio , De Nicola Milena , Darzynkiewicz Zbigniew 
Published: November 2002

AbstractBackgroundMuch attention is being paid to the biologic effects of magnetic fields (MFs). Although MFs enhance tumorigenesis, they are neither mutagenic nor tumorigenic. The mechanism of their tumorigenic effect has not been elucidated.MethodsTo investigate the effect of MFs on apoptosis in HL‐60 cells, we exposed the cells to static MFs of 6 mT generated by a magnetic disk of known intensity. Apoptosis was triggered by the DNA topoisomerase I inhibitor, camptothecin (CPT). Activation of caspases in situ using the fluorochrome‐labeled inhibitor (FLICA) method and determination of plasma membrane integrity by excluding propidium iodide (PI) were measured by both laser scanning cytometry (LSC) and flow cytometry (FC). LSC and FC identified cells at three sequential stages of their demise: early apoptosis (cells with activated caspases and PI negative); late apoptosis (cells with activated caspases but unable to exclude PI); secondary necrosis (cells with apoptotic morphology no longer stained with FLICA, not excluding PI).ResultsMF alone did not induce any apoptogenic or necrogenic effect. CPT exposure led to the sequential appearance of apoptotic cells. In the presence of CPT and MF, the overall proportion of cells undergoing apoptosis was not significantly changed. However, we consistently observed a significant increase in the frequency of late apoptotic/necrotic cells when compared with samples treated with CPT alone (P < 0.001), as well as a decrease in the percentage of early apoptotic cells (P = 0.013). The data obtained by FC and LSC were consistent with each other, showing a similar phenomenon.ConclusionWhereas MF alone or with CPT did not affect overall cell viability, it accelerated the rate of cell transition from apoptosis to secondary necrosis after induction of apoptosis by the DNA‐damaging agent, CPT. Modulation of the kinetics of the transition from apoptosis to secondary necrosis by MF in vivo may play a role in inflammation and tumorigenesis. Cytometry 49:113–118, 2002. © 2002 Wiley‐Liss, Inc.
Detection of underlying characteristics of nuclear chromatin patterns of thyroid tumor cells using texture and factor analyses
Authors: Murata Shin‐ichi , Mochizuki Kunio , Nakazawa Tadao , Kondo Tetsuo , Nakamura Nobuki , Yamashita Hiroto , Urata Yoji , Ashihara Tsukasa , Katoh Ryohei 
Published: November 2002

AbstractBackgroundAspiration biopsy cytology of thyroid tumors has been used more frequently in recent times to differentiate between malignant and benign lesions. Chromatin patterns of the tumor cell nuclei are one of most important factors for cytologic diagnosis. The interpretation of nuclear chromatin patterns is subjective and more difficult than that of nuclear size or shape. In the present report, we investigated how to detect underlying chromatin characteristics of benign and malignant thyroid tumor cells by means of texture and factor analyses.MethodsWe employed a computer‐aided system in which light microscopy was combined with an image processor and monochrome camera. Using this system, 100 randomly selected cells in a Papanicolaou stained, aspiration biopsy cytologic smear in each case of 39 benign and malignant thyroid tumor cases were digitized. We applied two‐dimensional and higher texture analyses with the use of co‐occurrence and run‐length matrices to analyze the chromatin patterns. Factor analysis was used to determine whether a large number of independent variables actually measured one or more underlying common variables.ResultsAccording to parameters with high factor‐loading values, the morphologic chromatin characters were classified into three categories according to heterogeneity, contrast, and homogeneity of chromatin patterns. On the basis of analyses with these morphologic categories, nuclei of papillary carcinoma showed higher contrast of chromatin patterns than did those of the benign group. Moreover, there was a variety of contrasting chromatin patterns among cells in each papillary carcinoma case in comparison with the benign group. In contrast, follicular carcinomas showed a significant difference in the standard deviation of factor 3, which indicated more monotonous chromatin patterns among cells in each follicular carcinoma case than in each benign case.ConclusionWe believe that this technique, using texture and factor analyses, is useful in the detection of underlying characteristics of nuclear chromatin patterns in aspiration biopsy cytology. Cytometry 49:91–95, 2002. © 2002 Wiley‐Liss, Inc.