bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sample preparation of animal tissues and cell cultures for secondary ion mass spectrometry (SIMS) microscopy
Authors: Chandra Subhash , Morrison George H. 
Published: August 2004

Summary—Sample preparation is a critical step in the elemental analysis of animal tissues and cell cultures with ion microscopy. Since live cells cannot be analyzed with ion microscopy, a careful sample fixation is necessary which preserves the native structural and chemical integrity of a specimen. The evaluation of morphological and chemical integrity of a fixed specimen is necessary before any physiological explanation of ion fluxes is interpreted based on ion microscopy. For diffusible ion localization studies, strict cryogenic procedures are recommended. Examples are shown for diffusible ion microanalysis in frozen‐freeze‐dried tissues and cell cultures. Ion microscopy studies of tightly bound elements/molecules may be conducted in chemically fixed and/or plastic embedded specimens. Since it is not generally known which elements/molecules are tightly bound to the tissue matrix, a confirmation of elemental distribution with cryogenic procedures is desirable. A recent approach of combining laser scanning confocal fluorescence microscopy and ion microscopy on the same frozen freeze‐dried cell is also discussed for recognizing smaller cytoplasmic structures in ion microscopy images.
Scanning secondary ion analytical microscopy with parallel detection
Authors: Slodzian Georges , Daigne Bernard , Girard François , Boust Fabrice , Hillion François 
Published: August 2004

Summary—The secondary ion microscope described here allows to obtain the simultaneous registration of chemical and isotopic distribution maps of several elements composing the sample. The instrument has been specially designed to optimize both sensitivity and selectivity: bombardment with primary Cs+ ions to increase the ionization yields of negative secondary ions, efficient collection of secondary ions at the target surface, matching of the secondary ion beam etendue with the acceptance of the mass spectrometer working at high mass resolution, spectrometer with parallel detection capabilities. The probe diameter can be made as low as 30 nm and ion induced electron images registered at the same time as ion images. Presently, four ion micrographs are obtained simultaneously over a field of view up to 20 × 20 μm2 containing up to 512 × 512 pixels. Examples are shown with an ion probe diameter of 0.1 μm.
SIMS microscopy: a tool to measure the intracellular concentration of carbon 14‐labelled molecules
Authors: Hindie Elif , Coulomb Bernard , Galle Pierre 
Published: August 2004

Summary—Monolayer cultures of human fibroblasts were incubated for 24 h with 14C‐arginine and observed by means of SIMS microscopy (ion microscopy). Carbon 14 imaging showed the intracellular distribution of labelled arginine which featured high nuclear incorporation. The local concentration of this amino acid in different cells and intracellular structures was assessed through local isotopic 14C/12C ratio measurement. This relates the signal intensity of the labelling isotope carbon 14 to that of the corresponding natural isotope (carbon 12) of known tissular concentration. Using this method we were able to measure minor variations in the molecular concentration of arginine (expressed as μmol/g of tissue) between different fibroblasts. Results of this study indicate that SIMS microscopy is well adapted to carbon 14 detection and can provide quantitative maps of the cellular and subcellular distribution of 14C‐labelled molecules.
Mapping of intracellular halogenous molecules by low and high resolution SIMS microscopy
Authors: Berry Jean‐Pierre , Galle Pierre , Chassoux Danièle , Escaig Françoise , Linarez‐Cruz L. Gustavo , Lespinats Genevieve 
Published: August 2004

Summary—The subcellular distribution of halogenous molecules has been studied by SIMS microscopy in cultured cells of a human breast carcinoma (MCF‐7 cell line). Two instruments of microanalysis were used. A low lateral resolution ion microscope (SMI 300 CAMECA) and a prototype scanning ion microscope equipped with a cesium gun that gives high lateral resolution images. This apparatus has been developed by G Slodzian, in Onera Laboratories (Office National d'Etudes et de Recherches Aérospatiales). Molecules studied by low lateral resolution ion microscope were halogenous steroids: fluorometholone, triamcinolone, bromocriptine and bromoandrosterone. Analytical images show that the first two compounds are mainly localized in the nuclear structure of MCF‐7 cells whereas the last two molecules are localized in cytoplasm of these cells. Images were obtained with a resolution of 1 μm. With the scanning ion microscope, it is now possible to obtain images at the ultrastructural level. Four analytical images can be simultaneously obtained by a single scan of the imaged area, corresponding to a depth of erosion of the section of ten nm. The intranuclear distributions of three pyrimidine analogs, 5‐bromo‐2′‐deoxyuridine, 5‐iodo‐2′‐deoxyuridine and 5‐fluorouracil have been studied in phase S and M of MCF‐7 cells and these images have been compared to the distribution of sulfur, nitrogen and phosphorus. All these images have been obtained with a lateral resolution better that 100 nm.
Intracellular boron localization and uptake in cell cultures using imaging secondary ion mass spectrometry (ion microscopy) for neutron capture therapy for cancer
Authors: Bennett Brian D. , Zha Xiaohui , Gay Isabelle , Morrison George H. 
Published: August 2004

Summary—Quantitative ion microscopy of freeze‐fractured, freeze‐dried cultured cells is a technique for single cell and subcellular elemental analysis [1–3]. This review describes the technique and its usefulness in determining the uptake and subcellular distribution of the boron from boron neutron capture therapy drugs.
SIMS determination of the distribution of the main mineral cations in the depth of the cuticle and the pecto‐cellulosic wall of epidermal cells of flax stems: problems encountered with SIMS depth profiling
Authors: Ripoll Camille , Jauneau Alain , Lefèbvre Fabrice , Demarty Maurice , Thellier Michel 
Published: August 2004

Summary—Depth profiles of C, Na, Mg, Al, K and Ca were performed in the cuticle and wall of epidermal cells of flax hypocotyls, with current densities ranging from 0.2 to 1 pA μm−2. The crater bottoms were never flat, but exhibited fairly complex, filiform or alveolar structures. The profiles of K, Ca and Mg were reasonably parallel to one another. The Ca/Mg signal ratio was in the magnitude of 3.5 in the cuticle. The Na profile, except perhaps in the cuticle, did not parallel the K, Ca and Mg profiles, but rather paralleled the C profile. At the outset of the depth profiles, ie in the cuticle, the intensity of the Na signal, although fairly variable, was usually above that of K; then there was an abrupt decrease of the Na signal, possibly at the border of the cuticle and of the wall. The Al signal usually began to increase, thus revealing the occurrence of perforations through the epidermis sample, after 80 min sputtering at a current density of 1 pA μm−2; the mean sputtering rate was thus estimated to be in the order of 1 μm h−1.
The role of secondary ion mass spectrometry (SIMS) in biological microanalysis: technique comparisons and prospects
Authors: Linton Richard W. , Goldsmith Jack G. 
Published: August 2004

Summary—The virtues and limitations of SIMS ion microscopy are compared with other spectroscopic techniques applicable to biological microanalysis, with a special emphasis on techniques for elemental localization in biological tissue (electron, X‐ray, laser, nuclear, ion microprobes). Principal advantages of SIMS include high detection sensitivity, high depth resolution, isotope specificity, and possibilities for three‐dimensional imaging. Current limitations, especially in comparison to X‐ray microanalysis, center on lateral spatial resolution and quantification. Recent SIMS instrumentation advances involving field emission liquid metal ion sources and laser post‐ionization will help to minimize these limitations in the future. The molecular surface analysis capabilities of static SIMS, especially with the new developments in commercial time‐of‐flight spectrometers, are promising for application to biomimetic, biomaterials, and biological tissue or cell surfaces. However, the direct microchemical imaging of biomolecules in tissue samples using SIMS will be hindered by limited concentrations, small analytical volumes, and the inefficiencies of converting surface molecules to structurally significant gas phase ions. Indirect detection using elemental or isotopically tagged molecules, however, shows considerable promise for molecular imaging studies using SIMS ion microscopy.
The ultrastructural study of the interphase cell nucleus of Lacandonia schismatica (Lacandoniaceae: Triuridales) reveals a non‐typical extranucleolar particle
Authors: Jiménez‐Garcia Luis Felipe , Agredano‐Moreno Lourdes Teresa , de Segura‐Valdez Maria Lourdes , Echeverria Olga Margarita , Martinez Esteban , Ramos Clara Hilda , Vázquez‐Nin Gerardo Hebert 
Published: August 2004

Summary—By light and electron microscope cytochemistry we characterized the interphase nucleus of Lacandonia schismatica, the only known species of the new plant family Lacandoniaceae, whose most peculiar feature is the inverted position of the sexual organs, an aspect never found before among flowering plants. Furthermore, we compare it to Triuris alata, a related species, to Voyria aphylla (a dicotyledon), to Gymnosiphon divaricatus (a monocotyledon) and also to saprophytes. The reticulated chromatin of L schismatica and T alata is similar to that of other monocotyledons. In addition, we describe a unique type of RNP granules in the interchromatin space which are about 32 ± 3 nm SD in diameter and occur as huge clusters. They are intermediate in size and spatial distribution between inter‐ and peri‐chromatin granules. We term them ‘Lacandonia granules’. The granules were also found in T alata. They are 31 ± 2 nm in diameter. No significant differences in size were observed between them (P > 0.05). Synaptonemallike complexes and ring‐shaped structures were seen in interphase nuclei of somatic cells of these species. Coiled and nucleolus‐associated bodies, as well as centromeres were also found in these two organisms. On the contrary, Vaphylla and G divaricatus display a chromocentric nuclear organization. The nuclear similarities between L schismatica and T alata suggest extremely close phylogenetic relationships between them.
The association of microtubules with the plasmalemma in epidermal tendon cells of the river crab
Authors: Nakazawa Eiko , Katoh Kazuo , Ishikawa Harunori 
Published: August 2004

Summary—The mode of association of microtubules (MTs) with the plasmalemma in epidermal tendon cells of the river crab, Potamon dehaani was studied by thin‐section electron microscopy. In the leg muscle, the tendon cells connect striated muscle cells with the cuticle, forming specialized junctions at both ends. At the muscle‐tendon cell junction, the apposed plasmalemmas are interdigitated in a zig‐zag pattern separated by a uniform space of about 50 nm, where the basal lamina is shared by two cells. At the tendon cell‐cuticle junction, the plasmalemma of the tendon cell forms many conical invaginations, into which dense fibrous material extends from the cuticle. Inside the tendon cell, numerous microtubules run parallel to the direction of tension transmission and are arranged into parallel bundles of various sizes. Within such bundles, fine filamentous structures cross‐link adjacent MTs. MTs span the entire length of the cell and attach at their both ends to the junctional domains of the plasmalemma. The junctional plasmalemma is characterized by formation of an electron‐dense undercoat, through which MTs are connected with the plasmalemma proper. The ultrastructural features of MT association with the plasmalemma are basically the same at both junctions. At the junctions, MTs usually terminate with free ends and are linked laterally to the plasmalemmal undercoat with fine filamentous structures. These observations emphasize the role of the plasmalemmal undercoat as a device of the attachment of MTs to the plasmalemma.
Alterations in erythrocyte membrane fluidity in children with trisomy 21: a fluorescence study
Authors: Kantar A. , Giorgi PL , Curatola G. , Fiorini R. 
Published: August 2004

Summary—Membrane fluidity of erythrocytes obtained from 15 children with trisomy 21 and 20 healthy controls were studied by measuring steady‐state fluorescence anisotropy and fluorescence lifetime of 1,6‐diphenyl‐1,3,5‐hexatriene (DPH) and 1‐(4‐trimethylammoniumphenyl)‐6‐phenyl‐1,3,5‐hexatriene (TMA‐DPH) incorporated in hemoglobin‐free erythrocyte membranes. Our results demonstrate a significant decrease in DPH fluorescence anisotropy and a significant increase in TMA‐DPH fluorescence anistropy in erythrocytes from subjects with trisomy 21. No significant differences between the two groups were observed in the fluorescence lifetime of DPH and TMA‐DPH. These data suggest an increase in membrane fluidity in the interior part of the membrane and a decrease in fluidity at the lipid‐water interface region. This could be in part attributed to an increased oxidative damage in trisomy 21.
Opposing effects of heparin with TGF‐β or aFGF during repair of a mechanical wound of human endothelium. Influence of cAMP on cell migration
Authors: Klein‐Soyer Claudine , Archipoff Gisèle , Beretz Alain , Cazenave Jean‐Pierre 
Published: August 2004

Summary—The effects on vascular wound repair in vitro of aFGF and TGF‐β, growth factors having opposite influences on endothelial cell growth and angiogenesis, were studied using as a model a mechanical lesion of confluent endothelium. Modulation by heparin of the activities of these growth factors during the repair process was also examined. Whereas heparin alone inhibited repair by lowering both cell proliferation and cell migration, TGF‐β alone mainly inhibited cell proliferation. When added together, TGF‐β and heparin exerted a combined inhibitory effect resulting in a residual lesion 50% larger than in controls. aFGF alone accelerated lesion coverage and this effect was enhanced by 40% over control values when heparin was added with aFGF. This acceleration was slightly (less than 10%) but consistently diminished by TGF‐β. Cell density in confluent unwounded areas was increased by 40% in the presence of aFGF, but TGF‐β diminished cell density by 20%. A small (30%) increase in intracellular cAMP was measured whenever aFGF was present during the repair process. In comparison, intracellular cAMP inducing agents (forskolin, dbcAMP) accelerated cell migration by 20% during lesion recovery without affecting cell proliferation or density. The present results show that the inhibitory effects of TGF‐β during vascular wound repair are opposed by aFGF. Furthermore, heparin (or heparan sulfates in vivo) modulates growth factors having activating or inhibiting functions and thus plays a regulatory role during the repair process. cAMP‐inducing substances other than growth factors are able to accelerate cell migration.
African swine fever virus interaction with microtubules
Authors: de Matos Antonio Pedro Alves , Carvalho Zilda G. 
Published: August 2004

Summary—The role of microtubules in intracellular transport of African swine fever virus (ASFV) and virus‐induced inclusions was studied by immunofluorescence using anti‐ASFV and anti‐tubulin antibodies, by electron microscopy of infected Vero cells and by in vitro binding of virions to purified microtubules. MTC, a reversible colchicine analogue, was used to depolymerize microtubules. In cells treated with MTC multiple large inclusions containing ASFV antigens and particles were observed in the cytoplasm. Removal of the drug lead to migration and fusion of the inclusions at a perinuclear location. To study the effect of microtubule repolymerization on virus particle distribution, the particles were counted in thin sections of MTC treated cells and at different times after removal of the drug. In cells treated with MTC 6.8% and 3.6% of the virus particles were found respectively in the cytoplasm and at the cell membrane while 38% of the particles were located around the virosome. With reversal of the drug effect the number of virus particles around the virosomes progressively decreased to 10% at 2 h while the number of particles in the cytoplasm and at the cell membrane increased. At 2 h after removal of the drug 33.5% of the particles were found budding from the cell membrane. Virus particles were found closely associated with microtubules in cytoskeletons obtained by Triton X‐100 extraction of taxol treated cells. The association of virus particles with microtubules was also observed in vitro using purified microtubules and virus particles. The results show that microtubules are involved in the transport of African swine fever virus particles from the assembly site to the cell surface and in the movement and fusion of the virus inclusions.
Total positivity in the De Concini-Procesi Compactification
Authors: He Xuhua 
Published: August 2004

We study the nonnegative part

G

>
0

¯

\overline {G_{>0}}

of the De Concini-Procesi compactification of a semisimple algebraic group

G
G

, as defined by Lusztig. Using positivity properties of the canonical basis and parametrization of flag varieties, we will give an explicit description of

G

>
0

¯

\overline {G_{>0}}

. This answers the question of Lusztig in Total positivity and canonical bases, Algebraic groups and Lie groups (ed. G.I. Lehrer), Cambridge Univ. Press, 1997, pp. 281-295. We will also prove that

G

>
0

¯

\overline {G_{>0}}

has a cell decomposition which was conjectured by Lusztig.
Goodbye Father
Authors: Schoenherr Richard A. , Yamane David 
Published: August 2004

Abstract
A single unavoidable fact looms large in the future of Catholicism – in the last half‐century the number of priests has plummeted by 40% while the number of Catholics has increased by 65%. The specter of a faith defined by full pews and empty altars confronts the church. The root cause of this priest shortage is the church's insistence on mandatory celibacy, a requirement in place since the 1100s. Today, one in three ordained American priests under the age of 35 says he would marry if permitted. Given the potential recruiting advantages of abandoning the celibacy requirement, Richard Schoenherr asks why the conservative coalition – headed by the Pope – is so adamantly opposed to a married clergy. The answer is that acceptance of married priests is but the first step toward a gender inclusivity that will result in ordained women – a move that will not only alter the structure of the Catholic church forever but also will destabilize patriarchy in the wider society. Combining demographic data, historical analysis, and theoretical reflection, Schoenherr argues that such change is not only necessary if the church is to thrive but unavoidable if it is to survive. Currently, the priesthood exercises sacramental, sacerdotal, male, celibate monopoly over the Catholic means of salvation, but of these four characteristics, only sacramental sacerdotalism constitutes the deep structure of the priesthood. Priest shortage is the ‘linchpin’ in a powerful matrix of forces for change – pluralism over dogmatism in worldviews, personalist over transcendentalist views of sexuality, egalitarianism over inequality in gender relations – that are driving the church toward abandoning the celibate male exclusivity that now threatens authentic ministry in the church. The book is arranged in five parts (I. Celibacy, patriarchy, and the priest shortage; II. Social change in organized religion; III. Conflict and paradox; IV. Coalitions in the Catholic Church; and V. Continuity and change), and has an introduction by the editor David Yamane, who prepared the book for publication after Schoenherr's death in 1996. It is a companion work to Full Pews And Empty Altars: Demographics of the Priest Shortage in United States Catholic Dioceses (Richard Schoenherr and Lawrence Young, 1993), an analysis of the drop‐off in numbers of priests in the USA dating from the 1960s.
Compulsory Celibacy and the Priest Shortage
Authors: Schoenherr Richard A. 
Published: August 2004

Abstract
Since the priest shortage in the Catholic Church is the core of the theoretical model of social change in organized religion presented in Part II of the book, this chapter summarizes the major findings of the author's demographic investigations of the diocesan priesthood population in the USA, and treats the major cause of priest shortage – mandatory celibacy. It reviews the empirical research on the issue and considers whether dissatisfaction with compulsory celibacy stems from short‐ or long‐term attitudinal (social) change. It also examines the impact of homosexuality in the priesthood on attitudes to mandatory celibacy.
Unity and Diversity
Authors: Schoenherr Richard A. 
Published: August 2004

Abstract
The first trend in the matrix of social forces affecting the Catholic Church is the decline in the priest population combined with growth in church membership, and this dual force bears a catalytic relationship to the other six trends, so must be treated separately – in effect, priest shortage is the key to understanding why other social forces are reaching a critical threshold simultaneously. Thus, in Chs. 7–9, it is first shown that each of the other trends is reaching a state of balanced tension and then, at the end of Ch. 9, that priest shortage is a catalyst creating convergence among them.
This chapter addresses the second and third trends in the matrix: the decline of dogmatism coupled with the rise of pluralism; and the decline of Eurocentrism (the Western Church) coupled with the emergence of the Church inculturated in six continents (world Church); these have a direct bearing on the tension between unity and diversity in the Catholic Church. First, it is shown that the increasing tensions between dogmatism and pluralism help account for changes in expressive social forces, i.e., the cultural and motivational transformations occurring in Catholicism. Then it is shown how conflict between organizational centrism and localism helps account for changes in utilitarian social forces, i.e., the internal political–economic transformations facing the Church.
Priestly Coalition
Authors: Schoenherr Richard A. 
Published: August 2004

Abstract
This chapter continues the discussion on coalitions in the Catholic Church by describing the conservative or priestly coalition. The strength of the conservative coalition is structurally determined by the centralized papacy, and to bolster its own structurally (hierarchically) based power, the current papacy is closely allied with the Roman curia, certain conservative segments of national hierarchies, and key theologians. In addition, organized lay groups such as Opus Dei, Comunione e Liberazione, and the Knights of Malta play an important role in the papal coalition. Thus, as the new millennium dawns, the papal coalition is dominant, priestly, conservative – and formidable. The chapter exemplifies this power by accounts of the aborted reforms of the Roman curia, the growing pains of the newly established Synod of Bishops, retrenchment in the appointment and promotion of bishops, and constraints on the autonomy of bishops, scholars, lower clergy, and nuns.