bluuebunny/crossref_metadata_2025_split huggingface dataset:
Growth animation of human organs
Authors: Ďurikovič Roman , Czanner Silvester , Inoue Hirofumi 
Published: October 2002

AbstractThe growth of the organs of the human embryo changes significantly over a short period of time in the mother's body. The shape of the human organs is organic and has many folds that are difficult to model or animate using conventional techniques. Convolution surface and function representation are a good choice in modelling such organs as human embryo stomach and brain. Two approaches are proposed for animating organ growth: the first uses a simple line segment skeleton demonstrated on a stomach model and the other method uses a tubular skeleton calculated automatically from a 2D object outline. Growth speed varies with the position within the organ and thus the model is divided into multiple geometric primitives that are later glued by a blending operation. Animation of both the embryo stomach and brain is shown. Copyright © 2002 John Wiley & Sons, Ltd.
Lung metastasis detection and visualization on CT images: a knowledge‐based method
Authors: Archip Neculai , Erard Pierre‐Jean , Haefliger Jean‐Marie , Germond Jean‐Francois 
Published: October 2002

AbstractA solution to the problem of lung metastasis detection on computed tomography (CT) scans of the thorax is presented. A knowledge‐based top‐down approach for image interpretation is used. The method is inspired by the manner in which a radiologist and radiotherapist interpret CT images before radiotherapy is planned. A two‐dimensional followed by a three‐dimensional analysis is performed. The algorithm first detects the thorax contour, the lungs and the ribs, which further help the detection of metastases. Thus, two types of tumors are detected: nodules and metastases located at the lung extremities. A method to visualize the anatomical structures segmented is also presented. The system was tested on 20 patients (988 total images) from the Oncology Department of La Chaux‐de‐Fonds Hospital and the results show that the method is reliable as a computer‐aided diagnostic tool for clinical purpose in an oncology department. Copyright © 2002 John Wiley & Sons, Ltd.
Comparative material characterization of historical and industrial samples by using a compact micro‐XRF spectrometer
Authors: Bichlmeier S. , Janssens K. , Heckel J. , Hoffmann P. , Ortner H. M. 
Published: October 2002

AbstractAn experimental micro‐XRF set‐up was used for investigations in different application fields. In the archaeometric field, valuable 7th century gold objects were analysed with the aim of obtaining concentration data on well‐defined metal areas. The results revealed an insight into the gold manufacturing habits of early medieval times. In the industrial field, piezoelectric ceramics were investigated in order to identify small inclusions in the material. The aim was to identify possible contamination sources in the manufacturing process. Copyright © 2002 John Wiley & Sons, Ltd.
Role of phosphorylated MAPIB in neuritogenesis
Authors: Avila Jesus , Ulloa Luis , Diez‐Guerra Javier , Diaz‐Nido Javier 
Published: October 2002

ABSTRACTThe distribution of microtubule‐associated protein lB (MAPlB) phosphorylated by either proline‐directed protein kinase (PDPK) or casein kinase II (CK II) in neuroblastoma cells and hippocampal neurons has been studied by immunofluorescence using specific antibodies to distinct phosphorylation‐sensitive epitopes. A proximo‐distal gradient of increasing PDPK‐catalyzed phosphorylation of MAPlB is superimposed on a proximo distal gradient of decreasing CK II‐catalyzed MAPlB phosphorylation within growing axon‐like neurites. Additionally, CK II‐phosphorylated MAPlB is present in cell bodies and dendrites where no PDPK‐phosphorylated MAPlB is observed. These results suggest distinct roles for both types of modifications of MAPlB in developing neurons.
WHY DOES BONE MATRIX CONTAIN NON‐COLLAGENOUS PROTEINS? THE POSSIBLE ROLES OF OSTEOCALCIN, OSTEONECTIN, OSTEOPONTIN AND BONE SIALOPROTEIN IN BONE MINERALISATION AND RESORPTION
Authors: Roach H. I. 
Published: October 2002

ABSTRACTFour major non‐collagenous bone proteins were localised by single and double immuno‐histochemistry during de novo mineralisation and bone resorption. Both osteopontin and bone sialoprotein were localised ahead of the mineralisation front, suggesting that both proteins are necessary for the initiation of bone mineralisation. This supports previous suggestions that bone sialoprotein acts as a crystal nucleator. The role of osteopontin is less certain, but might be related to ensuring that only the right type of crystal is formed. Osteocalcin and osteonectin were not present in areas of first crystal formation, but were present in the fully mineralised matrix. Their role may be to control the size and speed of crystal formation.Osteopontin, bone sialoproteins and osteocalcin (but not osteonectin) were also present at reversal lines. Interpreting this localisation together with information from the literature, the following functions are suggested during resorption: Osteocalcin may act as a chemoattractant for osteoclasts, while both osteopontin and bone sialoprotein may facilitate the binding of osteoclasts via the arg‐gly‐asp motif.
GLUCOSE STRONGLY STIMULATES RATE OF THE RRNA SYNTHESIS IN EHRLICH ASCITES CARCINOMA CELLS
Authors: Buzhurina I. M. , Chernaya N. G. , Panov M. A. 
Published: October 2002

ABSTRACTA change in glucose concentration in an Ehrlich ascites carcinoma cell suspension from 0.1 mM to 20 mM causes a more than 50‐fold stimulation of the rate of ribosomal RNA synthesis. Such an effect occurs without any dramatic effect on the rate of protein synthesis in cells. This process parallels a decrease in intracellular pH which may be a reason of Na+/H+‐antiport activation.
A confocal microscopic evaluation of the effects of insulin imprinting on the binding of Concanavalin A by Tetrahymena pyriformis.
Authors: Kovcs Peter , Sundermann Christine , Estridge Barbara H. , Csaba György 
Published: October 2002

AbstractWith confocal microscopy it is possible to study the Concanavalin A (Con A) binding characteristics of the surface and interior of a single cell by viewing optical sections. It was observed in Tetrahymena pyriformis that Con A bound both to the plasma membrane and to intracellular structures. Incubation of cells with a competing sugar a‐methylmannopyranoside, decreased binding. Hormonal imprinting with insulin resulted in an increase in binding of Con A to the cell surface and a decrease in intracellular binding. It is possible that the intracellular binding sites may migrate to the plasma membrane.
EPR study of the sea anemone cytolysin, equinatoxin II, cytotoxicity on V‐79 cells
Authors: Batista Urška , Šentjurc Marjeta 
Published: October 2002

ABSTRACTElectron paramagnetic resonance (EPR) was used to study the effect of equinatoxin II (EqT II), a cytolytic protein isolated from the sea anemone Actinia equina L., on membrane fluidity and cell metabolism of V‐79 cells; the reduction of the spin probe incorporated into the cell membranes as well as the oxygen consumption in the cell suspension were measured. The results were compared with the results obtained by the cell viability study. Under the influence of EqT II (less than 37.5 μg/106 cells) no significant changes in cell membrane fluidity were observed, while reduction kinetics of the spin probe and the oxygen consumption decreased when the cells were kept in Tris buffer solution. However, in the presence of 10% fetal calf serum, which prevented cell lysis, the effects of EqT II were diminished. The oxygen consumption corresponds to the cell viability changes but the reduction kinetics alterations indicate that some oxidation‐reduction processes other than cell respiration are affected by EqT II in the absence of serum. The effect seems to be indirect, probably due to the formation of pores which are associated with changed permeability of plasmalemma for metabolites and ions.
Maternal nicotine exposure: reponse of type II pneumocytes of neonatal rat pups.
Authors: Maritz G. S. , Thomas R.‐A. 
Published: October 2002

ABSTRACTThe influence of maternal nicotine exposure during pregnancy and lactation on the Type II cells of lung tissue of one day old neonatal rat pups was investigated. The results clearly show that maternal nicotine exposure resulted in an increase in the type II cell count in the lungs of the offspring. In addition the lamellar body content of the type II cells of the nicotine exposed rat pups were significantly (P< 0.01) higher than that of the control animals. The type II cell mitochondria of lung tissue of nicotine exposed rat pups were swollen and no microvilli occurred on the alveolar surface. This clearly illustrates that nicotine interfered with type II cell integrity of tlte neonatal lung and may subsequently interfere with the normal development of the alveolar region of the lung.
Morphological alterations caused by lithium in various cell lines
Authors: Matthopoulos Demetrios P. , Tzaphlidou Margaret , Leontiou Ioannis 
Published: October 2002

AbstractLithium is being used for the treatment of mental diseases and for the attenuation of muelosuppression during chemotherapy. As during long term lithium treatment kidney damage has been reported, we studied morphological alterations in cells of kidney origin after exposure to lithium chloride. Above the level of 4 mmol, lithium has fatal effects in CV1 cells while HeLa cells that are not originating from kidneys, tolerate higher lithium concentrations. Cellular morphology alters during treatment duration. At early stages, cells become flatter on their substrate and upon longer than 4 days treatment begin to detach from their substrate and eventually cell death comes in a concentration dependent manner. The only morphological alteration observed in a lymphoblastoid cell line was a statistically significant cellular swelling.
A MOVING IMAGE OF FLAGELLA: NEWS AND VIEWS ON THE MECHANISMS INVOLVED IN AXONEMAL BEATING
Authors: COSSON J. 
Published: October 2002

AbstractBeating of cilia and flagellae allows movement of the fluid surrounding isolated cells (for example: protists) or epithelia (bronchial tissue) but is also responsible for the movement of unicellular organisms in this medium (such as spermatozoa or protists). This paper aims to describe: (1) the biochemical and structural elements of the ‘9 +2’ structure called the axoneme; (2) the mechanisms of wave generation and propagation along the axoneme of cilia and flagellae are then described, stating that in most models of wave propagation, a clear distinction is made between the dynein‐dependent microtubule sliding which represents the oscillatory motor and the bending mechanism which regulates wave propagation. In current models, the bending propagation is supported by a bind /relax cyclic mechanism which propagates in register, but frame‐shifted, with the powering action of the dynein motor along the axoneme. While a large amount of knowledge was accumulated about the motor, little is known about the resisting elements regulating the bending. (3) The present study also puts forward ideas as to how these organelles have been highly conserved throughout eucaryotic evolution, and concludes with suggestions for further fields of investigation into this unique mechanical device used for cell movement.
PROTEIN RETENTION IN THE ENDOPLASMIC RETICULUM OF INSECT CELLS IS NOT COMPROMISED BY BACULOVIRUS INFECTION
Authors: HENDERSON JANEY , MACDONALD HEATHER , LAZARUS COLIN M. , NAPIER RICHARD M. , HAWES CHRIS R. 
Published: October 2002

AbstractHigh level expression of the major auxin‐binding protein (ABP1) from maize (Zea maysL.) has been used to demonstrate that the machinery for retaining proteins in the endoplasmic reticulum (ER) of insect cells functions efficiently throughout the baculovirus infection cycle. Immuno‐localization showed wild‐type ABP1 (ABP1‐KDEL) to be targeted to the lumen of the ER, in accordance with its signal peptide and carboxyterminal KDEL ER‐retention signal. The protein accumulated in dilations of the ER, and none was detected at the cell surface. Immunoblotting of concentrated culture medium confirmed that ABP1‐KDEL was not secreted at a detectable level. In contrast, when the carboxyterminus was mutated to KEQL, secretion of the baculovirus‐expressed protein was readily detected. Immunolocalization and immunoblotting demonstrated that a high proportion of the ABP1‐KEQL protein was secreted at the cell surface and into the culture medium. The data demonstrate that the ER of insect cells has a great capacity to retain proteins and that this property is largely unaffected by the cellular disruption caused by baculovirus replication.
THE INTER‐SERTOLI CELL TIGHT JUNCTIONS IN GERM CELL‐FREE SEMINIFEROUS TUBULES FROM PRENATALLY IRRADIATED RATS: A FREEZE‐FRACTURE STUDY
Authors: RIBEIRO ALBERTO F. , DAVID‐FERREIRA JOSÉ F. 
Published: October 2002

AbstractThe tight junctions between Sertoli cells were examined by freeze‐fracture in 3‐month‐old prenatally irradiated rats, whose seminiferous tubules are devoid of germ cells. The replicas from irradiated tubules show elaborate interdigitations of the lateral membranes of Sertoli cells and very extensive tight junctions. These junctions are characterized by a great number of continuous parallel or complex interweaving strands of intramembranous particles, preferentially associated with E fracture faces. The presence of highly cross‐linked tight junctional strands is compatible with an epithelium deprived of germ cells, with a reduced need for flexibility. Anomalous ectoplasmic specializations, consisting of groups of cisternae arranged perpendicularly to the lateral surface, are found in the irradiated tubules. These structures may be involved in a storage mechanism of redundant lateral membrane resulting from the elimination of germ cells. Typical gap junctions, intercalated between the tight junctional strands, are larger and more frequently found in treated animals than in controls. These findings indicate that a very tight permeability barrier seems to be established in the irradiated testis even in the absence of germ cells. Thus, the formation and maintenance of Sertoli tight junctions do not appear to be directly dependent on the presence of germ cells. Nevertheless, the alterations detected in the tight junction architecture and in the ectoplasmic specializations indicate that maturing germ cells probably contribute to the functional organization of the blood—testis barrier in the normal testis.
POLYAMINE REGULATORY PROCESSES AND OXIDATIVE STRESS IN MONOCROTALINE‐TREATED PULMONARY ARTERY ENDOTHELIAL CELLS
Authors: AZIZ SHEWAN M. , TOBOREK MICHAL , HENNIG BERNHARD , ENDEAN ERIC , LIPKE DAVID W. 
Published: October 2002

AbstractAlterations in polyamine metabolism may be a critical mechanism of monocrotaline (MCT)‐induced structural remodeling of the pulmonary vasculature. In the present study, the hypothesis that MCT, through the induction of oxidative stress, modulates cellular polyamine regulatory mechanisms which in turn might be involved in the upregulation of fibronectin production in pulmonary artery endothelial cells (PAEC) was examined. A 24‐h treatment with MCT significantly increased PAEC polyamine concentrations as compared to vehicle‐treated cells. In addition, exposure to MCT caused an increase in abundance of ornithine decarboxylase (ODC) mRNA, upregulation of ODC activity and enhancement of spermidine import into PAEC. Inhibition ofde novopolyamine synthesis further increased spermidine uptake in MCT‐treated cells. The depletion of cellular polyamine contents through the blockade of bothde novopolyamine biosynthesis and polyamine transport prevented MCT‐induced increases in the medium level of fibronectin. In addition, PAEC treatment with MCT stimulated cellular oxidative stress as determined by increased levels of thiobarbituric acid reactive substances, enhanced dichlorofluorescein fluorescence and activation of NF‐KB. A co‐treatment with dimethylthiourea, an oxygen radical scavenger, prevented MCT‐induced increases in cellular oxidation and attenuated disturbances in polyamine metabolism. These data suggest that MCT can stimulate polyamine regulatory processes in PAEC possibly through an increase in cellular oxidative stress. The present study may have significant implication in understanding mechanisms of MCT‐induced pulmonary hypertension and remodeling of pulmonary vasculature.
EX VIVO APOPTOTIC POTENTIAL OF PERIPHERAL BLOOD MONONUCLEAR CELLS OF THE ELDERLY HUMAN SUBJECT
Authors: Szmit Ewa , Trzonkowski Piotr , Myśliwska Jolanta , Foerster Jerzy , Myśliwski Andrzej 
Published: October 2002

AbstractStudies of immunosenescence have led to a detailed knowledge of immune system dysfunctions in the ageing human being. Apoptosis seems to be one of the process regulating an immune response after the antigenic stimulation. We examined whether commonly used methods of assessing apoptosis in the elderly human subject produce comparable results to young subjects. PBMC of young and elderly volunteers were isolated from the venous blood and cultured for 6 or 24h with antigens of anti‐influenza vaccine or PMA. The intensity of apoptosis was measured using the annexinV test, flow cytometric evaluation of DNA content (sub‐G1 peak in DNA histograms), ‘ladder’ by DNA gel electrophoresis, and fluorescence microscope. Apoptosis in 6h‐lasting cultures of the elderly was more intense in annexinV test, while it was decreased assessing subG1 peak. Additionally, in the aged group, those changes were associated with cell cycle arrest. Our results suggest that the apoptosis after the stimulation with the vaccine antigens seems to be some kind of activation‐induced cell death (AICD). Different patterns of apoptosis after stimulation may be associated with the cell cycle arrest of the PBMC in the elderly.
Pollen and Macrofossils from Wisconsinan Interstadial Sediments in Northeastern Georgia
Authors: Jackson Stephen T. , Whitehead Donald R. 
Published: October 2002

AbstractPollen and plant macrofossil analyses and dating (both TAMS and conventional14C) of wetland sediments from the Nodoroc Site in the Piedmont region of northeastern Georgia identified two depositional episodes of interstadial (ca. 26,000-22,000 yr B.P.) and mid- to late Holocene (<3600 yr B.P.) age. Interstadial pollen assemblages were dominated byPinusandQuercus,withCarya, Picea,andAbiesalso present in significant amounts. The interstadial assemblages had lowerPinusand higherQuercuspollen percentages than apparently contemporaneous assemblages from sites in the southern Appalachians and Coastal Plain. Interstadial macrofossils included two needle morphotypes ofPinussubgenusPinus,possibly indicating local occurrence of twoPinusspecies. One of the needle morphotypes is consistent withPinus banksiana,but other species cannot be ruled out. Comparison of conventional and TAMS14C dates illustrates problems in obtaining accurate age models from wetlands and ponds characterized by shallow or fluctuating water levels, low sedimentation rates, and vegetation growing on the depositional surface.
Packrat Midden Evidence of Late Quaternary Vegetation Change in the White Mountains, California-Nevada
Authors: Jennings Steven A. , Elliott-Fisk Deborah L. 
Published: October 2002

AbstractPackrat (Neotomaspp.) middens from the White Mountains indicate climatic and plant community conditions for the last 19,000 yr. During full-glacial times (ca. 19,000 yr B.P.) and at the Pleistocene/Holocene boundary juniper woodlands were 600 m lower in elevation than at present. Midden assemblages and stable-isotope data suggest lower temperatures and increased precipitation relative to the present into the early Holocene. Two early Holocene middens (ca. 8000 yr B.P.) from lower elevations of the White Mountains contain fragments of pinyon pine and indicate that both pinyon and juniper grew at a site that today supports only a pinyon woodland. Two middle Holocene middens (ca. 5000 yr B.P.) indicate that there was an upward migration of pinyon-juniper woodlands along a high-elevation ecotone, but little change in the middle of the pinyon-juniper woodland. Middens from the late Holocene indicate that present-day plant communities were in place by ca. 2000 yr B.P. or before.
Stick-Nest Rat Middens as Sources of Paleoecological Data in Australian Deserts
Authors: Pearson Stuart , Dodson John R. 
Published: October 2002

AbstractThe existing paleoenvironmental data from the Australian arid zone lack sensitivity and come from only a few sites. Macrofossils and pollen from four dated middens of the stick-nest rat (Leporillus spp.) were analyzed from two sites in Western Australia. Animal and plant macrofossil remains were well preserved and provided evidence of change in species distribution within the last 1150 yr. Brush-tail possum and golden bandicoot have contracted their ranges in the recent past, possibly since the introduction of cats into Australia. An undescribed lacewing was also a significant find. Pollen preserved in parts of the same midden and in middens from different sites indicates that records are sensitive to the composition of the local vegetation when the midden was built. Pollen spectra are quite different from playa lakes, which record largely regional vegetation. Pollen preserved in the fecal pellets, desiccated urine, and grass mat nesting material provided similar information but some differences were apparent, suggesting dietary preferences were reflected in the fecal component. The pollen record suggested a trend to less-wooded vegetation cover in central Australia between 900 and 300 yr B.P.
Inverse Multiparameter Modeling of Paleoclimate Carbon Cycle Indices
Authors: Heinze C. , Hasselmann K. 
Published: October 2002

AbstractA simple linear response model describing the functional relationship between ocean carbon cycle parameters and paleoclimate tracers (atmospheric pCO2, δ13C, CaCO3 saturation) was derived from a set of sensitivity experiments performed previously using a three-dimensional carbon cycle model. The linear model is optimally fitted to ice and marine sediment core records for the last 120,000 yr to estimate the carbon cycle parameter changes that could have caused the observed reduction of atmospheric CO2 partial pressure during the last glaciation. The analysis indicates that the glacial pCO2 reduction was primarily caused by a strengthening of the biological POC pump and a retardation of the oceanic circulation. An increase in deep-sea alkalinity and a change in the advective pattern of the ocean circulation have a smaller impact on atmospheric CO2 but are necessary to explain the full set of paleoclimate tracers.