bluuebunny/crossref_metadata_2025_split huggingface dataset:
Activated carbon surface modifications by adsorption of bacteria and their effect on aqueous lead adsorption
Authors: Rivera‐Utrilla J , Bautista‐Toledo I , Ferro‐García M A , Moreno‐Castilla C 
Published: August 2002

AbstractThe adsorption of Escherichia coli on different activated carbons has been studied. The activated carbon samples used have been characterized, determining their surface area, pore size distribution, elemental analysis, mineral matter analysis and pH of the point of zero charge. The adsorption capacity of these carbons increased with their hydrophobicity and macropore volume. The number of bacteria adsorbed on the demineralized activated carbon in a solution of pH value equal to the iso‐electric point of the carbon was negligible. However, in the presence of cations the proportions of bacterial cells adsorbed were 87.8% (Fe3+), 54.7% (Ca2+) and 24.8% (Mg2+) respectively. This increase in adsorption capacity in the presence of electrolytes has been explained on the basis of both the reduction in electrostatic free energy and the increase in cell surface hydrophobicity due to the metal bound by some compounds of the cell membrane. When the solution pH was intermediate between the pH values of the point of zero charge of the carbon and bacteria the number of bacteria adsorbed increased due to the attractive interactions between the carbon and bacteria. The adsorption of bacteria on activated carbons decreased the porosity and increased the negative charge density of the latter. Depending on the experimental conditions used, the presence of bacteria can enhance the capacity of activated carbons to adsorb lead.© 2001 Society of Chemical Industry
Chemical removal of PCBs from water samples under ambient conditions
Authors: Nollet Hendrik , Lutgen Pierce , Verstraete Willy 
Published: August 2002

AbstractLiquids and sludges containing polychlorinated biphenyls (PCBs) can be treated to concentrate the PCBs in a solid residue. The latter can then be handled to destroy the PCBs. In the first part of this work, procedures are explored by which 2,3,4‐trichlorobiphenyl (TCB) and 2,2′,3,3′,4,5,6‐heptachlorobiphenyl (HeCB) are insolubilised, flocculated and removed from the water. The results demonstrate that application of Fe(III)‐oxyhydroxide precipitation permits effective and reversible co‐precipitation of TCB and HeCB. Fly ash from coal‐fired thermal powerplants and CaO can be used as well for the rapid removal of TCB and HeCB. In the second part of this work, rapid insolubilisation followed by the degradation of TCB and HeCB by zero‐valent iron powder in anaerobic batch systems is presented. Zero‐valent iron was also used for the reductive dechlorination/remediation of TCB and HeCB sorbed on the fly ash and CaO particles. Overall, this paper describes a methodology to rapidly concentrate the PCBs from water and to concomitantly detoxify them in the concentrate by a chemical reductive process under ambient conditions of pH and temperature.© 2002 Society of Chemical Industry
The fermentation of mixtures of D‐glucose and D‐xylose by Candida shehatae, Pichia stipitis or Pachysolen tannophilus to produce ethanol
Authors: Sánchez Sebastián , Bravo Vicente , Castro Eulogio , Moya Alberto J , Camacho Fernando 
Published: August 2002

AbstractThe fermentation of mixtures of D‐glucose and D‐xylose by three non‐traditional yeasts: Candida shehatae (ATCC 34887), Pachysolen tannophilus (ATCC 32691) and Pichia stipitis (ATCC 58376) have been studied to determine the optimal strain and initial culture conditions for the efficient production of ethanol. The comparison was made on the basis of maximum specific growth rate (µm), biomass productivity, the specific rates of total substrate consumption (qs) and ethanol production (qE) and the overall yields of ethanol and xylitol. All the experiments were performed in stirred‐tank batch reactors at a temperature of 30 °C. The initial pH of the culture medium was 4.5. The highest values of µm (above 0.5 h−1) were obtained with P stipitis in cultures containing high concentrations of D‐xylose. All three yeasts consumed the two monosaccharides in sequence, beginning with D‐glucose. The values of qs diminished during the course of each experiment with all of the yeasts. The highest values of the specific rates of total substrate consumption and ethanol production were obtained with C shehatae (for t = 10 h, qs and qE were above 5 g g−1 h−1 and 2 g g−1 h−1, respectively), although the highest overall ethanol yields were fairly similar with all three yeasts, at around 0.4 g g−1.© 2002 Society of Chemical Industry
Duplex sonographic criteria for measuring carotid stenoses
Authors: Staikov Ivan N. , Nedeltchev Krassen , Arnold Marcel , Remonda Luca , Schroth Gerhard , Sturzenegger Matthias , Herrmann Cornelia , Rivoir Anita , Mattle Heinrich P. 
Published: August 2002

AbstractPurposeThe aim of this retrospective study was to determine optimal duplex sonographic criteria for use in our institution for diagnosing severe carotid stenoses and to correlate those findings with angiographic measurements obtained by the European Carotid Surgery Trial (ECST), North American Symptomatic Carotid Endarterectomy Trial (NASCET), and Common Carotid (CC) methods of grading carotid stenoses.MethodsWe analyzed the angiographic data using the ECST, NASCET, and CC methods and compared the results with the duplex sonographic findings. We then calculated the sensitivity, specificity, positive and negative predictive values, and accuracy of the duplex sonographic method. Taking these parameters into account, the optimal intrastenotic peak systolic velocity (PSV) and end diastolic velocity (EDV) were derived for diagnosing severe stenoses according to the 3 angiographic methods.ResultsOptimal PSV and EDV values for diagnosing a 70% or greater stenosis in our laboratory were as follows: with the NASCET method of angiographic grading of stenoses, PSV 220 cm/second or greater and EDV 80 cm/second or greater, and with the ECST and CC methods, PSV 190 cm/second or greater, and EDV 65 cm/second or greater. The optimal PSV and EDV for diagnosing a stenosis of 80% or greater with the ECST grading method were 215 cm/second or greater and 90 cm/second or greater, respectively.ConclusionsDuplex sonography is a sensitive and accurate tool for evaluating severe carotid stenoses. Optimal PSVs and EDVs vary according to the angiographic method used to grade the stenosis. They are similar for stenoses 70% or greater with the NASCET method and for stenoses 80% or greater with the ECST method. © 2002 Wiley Periodicals, Inc. J Clin Ultrasound 30:275–281, 2002; Published online in Wiley InterScience (www. interscience.wiley.com). DOI: 10.1002/jcu.10078
Lymphatic networks in the periodontal tissue and dental pulp as revealed by histochemical study
Authors: Matsumoto Yuushi , Zhang Bi , Kato Seiji 
Published: August 2002

AbstractThe structural organization and fine distribution of the lymphatic networks in the periodontal tissues (gingiva, periodontal membrane, and alveolar process) and dental pulp of animals and humans were reviewed with special reference to histochemical examination by light and electron microscopy. The distinction between lymphatics and blood vessels was made on cryostat sections of undecalcified and calcified teeth treated with EDTA solution and whole mount preparations of periodontal membranes using 5′‐nucleotidase (5′‐Nase)‐alkaline phosphatase (ALPase) double staining. This staining procedure allowed lymphatic vessels in the periodontal tissue and dental pulp to be differentiated from blood vessels. The specificity and localization of the enzyme reactions were confirmed by comparative histochemical studies of the same specimen with light microscopy and scanning or transmission electron microscopy. Well‐developed 5′‐Nase‐positive lymphatic networks were observed on the tissue sections and whole mount preparations of the gingiva, periodontium, and dental pulp. More lymphatic vessels were seen in the root area of the periodontium than in the cervical area. In the dental pulp, lymphatic vessels were more numerous in the central part than in the peripheral odontoblastic layer. These distributions of the lymphatic capillary networks are discussed in relation to their ability to supply lymph to the teeth. Microsc. Res. Tech. 56:50–59, 2002. © 2002 Wiley‐Liss, Inc.
Adrenomedullin in the adrenal
Authors: Kapas Supriya , Hinson Joy P. 
Published: August 2002

AbstractAdrenomedullin (AM) was originally characterized in extracts of an adrenal medullary tumor. Since this original finding the peptide and its mRNA have also been found in the adrenal cortex, specifically, in the cells of the aldosterone‐secreting zona glomerulosa. It is clear that the synthesis of AM is actively regulated in both cortex and medulla. Much research effort has been focused on identifying a role for AM in the adrenal gland. To date, no consistent effect on medullary catecholamine biosynthesis has been demonstrated. In the cortex the actions of AM are controversial and appear to depend on both the tissue preparation used and on the specific receptor population expressed in the individual gland. The results of further studies on the long‐term actions of AM on adrenal growth and differentiation are awaited with interest. Microsc. Res. Tech. 57:91–97, 2002. © 2002 Wiley‐Liss, Inc.
Effects of Fragile X syndrome and an FMR1 knockout mouse model on forebrain neuronal cell biology
Authors: Churchill James D. , Beckel‐Mitchener Andrea , Weiler Ivan Jeanne , Greenough William T. 
Published: August 2002

AbstractThe neurological deficits exhibited by patients with Fragile X syndrome (FraX) have been attributed to the absence of the Fragile X Mental Retardation Protein (FMRP), the product of the FMR1 gene, which is nonfunctional in these individuals. While a great deal has been learned about FraX using non‐invasive techniques and autopsy tissue from humans, the limited availability of subjects and specimens severely restricts the rate at which such data can be collected and the types of experimental questions posed. In view of these limitations, a transgenic mouse model of FraX has been constructed in which the FMR1 gene is selectively knocked out (KO) [Bakker et al. (1994) Cell 78:23–33]. These mice show molecular, morphological, and behavioral alterations consistent with phenotypes observed in FraX patients, making them good models to study the absence of FMRP expression. Microsc. Res. Tech. 57:156–158, 2002. © 2002 Wiley‐Liss, Inc.
Modulation of podocyte phenotype in collapsing glomerulopathies
Authors: Barisoni Laura , Kopp Jeffrey B. 
Published: August 2002

AbstractPodocytes are well‐differentiated postmitotic cells whose function is largely based on their complex cytoskeletal architecture. In diseases with proteinuria, podocytes undergo morphologic changes. Podocytes react to an injurious stimulus by a reorganization of their foot process architecture that is independent of the primary injury and the cause of the proteinuria. Collapsing glomerulopathies, including the idiopathic and secondary forms due to HIV infection, have been previously considered a part of the focal sclerosing glomerulosclerosis (FSGS) spectrum. However, in contrast to FSGS, both forms of collapsing glomerulopathy are characterized by segmental and global collapse of the glomerular basement membrane (GBM) and by characteristic ultrastructural alterations in podocytes. These alterations include loss of the actin‐based cytoskeleton, a dysregulated/dedifferentiated phenotype, cellular hypertrophy, and cell proliferation. These observations raise the following questions: 1) What mechanism causes glomerular collapse and do podocytes have a role? We recently proposed that in collapsing glomerulopathies the composition of the GBM is altered and contains more immature forms of collagen IV. These observations suggest that dedifferentiated/dysregulated podocytes may participate in remodeling the GBM composition, producing fetal collagen isoforms. 2) What is the pathomechanism underlying podocyte dysregulation? Although it is still unclear which etiologic factors are responsible for the idiopathic forms of collapsing glomerulopathy, in situ hybridization studies in a transgenic mouse model of HIV‐associated collapsing glomerulopathy and on renal biopsies of patients with HIV‐associated collapsing glomerulopathy demonstrated the presence of the HIV‐1 RNA in podocytes and tubular epithelial cells. These findings suggest a direct link between viral gene expression and the dysregulation of the podocyte phenotype. 3) Another open question is how podocytes become infected in HIV‐associated collapsing glomerulopathy. HIV‐1 typically uses CD4 and a co‐receptor such as CCR5 or CXCR4 to enter cells. So far, there is no demonstration of the expression of these receptors in podocytes. These negative findings, however, do not exclude the possibility that in the kidney another, CD4 independent, co‐receptor may be used for viral cell entry. Finally, is it important to mention that collapsing glomerulopathies have a high prevalence in black patients, suggesting a link between racial background and the virus‐related podocyte injury. Microsc. Res. Tech. 57:254–262, 2002. Published 2002 Wiley‐Liss, Inc.
Calcium signalling in cells of oligodendroglial lineage
Authors: Soliven Betty 
Published: August 2002

AbstractIntracellular Ca2+ is the key signal that regulates the efficacy of neurotransmitter release and synaptic plasticity in neurons but is also an important second messenger involved in the signal transduction and modulation of gene expression in both excitable and non‐excitable cells. Glial cells, including cells of oligodendroglial (OLG) lineage, are capable of responding to extracellular stimuli via changes in the intracellular Ca2+. This review article focuses on the mechanisms of Ca2+ signalling in cells of OLG lineage with the goal of providing the basis for understanding the relevance of receptor‐ and non‐receptor‐mediated signalling to oligodendroglial development, myelination, and demyelination. Conclusions to date indicate that cells of OLG lineage exhibit remarkable plasticity with regard to the expression of ion channels and receptors linked to Ca2+ signalling and that perturbation of [Ca2+]i homeostasis contributes to the pathogenesis of demyelinating diseases. Microsc. Res. Tech. 52:672–679, 2001. © 2001 Wiley‐Liss, Inc.
Meningeal nociception: Electrophysiological studies related to headache and referred pain
Authors: Messlinger Karl , Ellrich Jens 
Published: August 2002

AbstractHeadaches, which are usually referred to characteristic sites of the skull, are believed to involve meningeal nociceptors located in the dura mater encephali. Animal experiments show that these meningeal nociceptors are polymodal and usually highly sensitive to mechanical stimulation. These properties are also characteristic for the second order neurons in the spinal trigeminal nucleus, most of which receive convergent input from facial receptive sites. Sensitization of primary and secondary neurons by chemical irritants to mechanical stimuli may be an important mechanism in the generation of headaches. The convergent input from extracranial structures, which seems to be differentially organized in rodents and man, may explain the typical features of referred headache. Targets for analgesics used in the therapy of headaches (non‐steroidal antiinflammatory drugs, 5‐HT1 receptor agonists) are probably meningeal nociceptors and different sites of the central trigeminal nociceptive and antinociceptive pathways. Microsc. Res. Tech. 53:129–137, 2001. © 2001 Wiley‐Liss, Inc.
Histological demonstration of increased vascular permeability in the dura mater of the rat
Authors: Dux Mária , Messlinger Karl 
Published: August 2002

AbstractNeurogenic inflammation of the dura mater encephali has been suggested to play an important role in the pathophysiology of headaches. Although functional studies using extravasation techniques indicate an enhanced permeability of blood vessels after chemical or electrical stimulation of C‐fibres supplying the dura mater, histological demonstration of leaky blood vessels is still a problem. We used the vascular labelling method combined with i.v. injection of colloidal silver solution to test the permeability increasing effect of intravenous administration of substance P, topical application of mustard oil or acidic phosphate buffer and local electrical stimulation of the exposed dura mater. Histological characteristics of increased vascular permeability were observed exclusively after mustard oil and acidic phosphate buffer. This observation may indicate different mechanisms of increased vascular permeability involving pinocytosis and formation of interendothelial gaps selectively visualized by the vascular labelling method. Microsc. Res. Tech. 53:229–231, 2001. © 2001 Wiley‐Liss, Inc.
Cell culture model for antiulcerogenic agents
Authors: Terano Akira , Hiraishi Hideyuki , Shimada Tadahito , Takahashi Morio , Yoshiura Kenta , Horie‐Sakata Kaori 
Published: August 2002

AbstractTo elucidate the mechanisms of antiulcerogenic agents, we established the cell culture model derived from rat gastric epithelium. The cultured cells were identified as mucus‐producing cells by using histological analysis. This culture model is useful for investigating the untiulcer effect of various agents and to reveal the mechanisms of the drug action. In particular, the ulcer‐healing model using the cultured monolayer is promising and convenient for the study of several growth factors such as HGF as well as antiulcerogenic agents. The effect of polaporezinc in the cultured model is introduced. Microsc. Res. Tech. 53:389–395, 2001. © 2001 Wiley‐Liss, Inc.
Immune response to autologous and heterologous Helicobacter pylori antigens in humans
Authors: Jakob Benjamin , Birkholz Sabine , Schneider Thomas , Duchmann Rainer , Zeitz Martin , Stallmach Andreas 
Published: August 2002

AbstractInfection of humans with Helicobacter pylori results in the development of chronic gastritis and plays an important role in gastric ulcer pathogenesis. Despite the infiltration of the mucosa with specific immunocompetent cells and production of specific antibodies, the infection usually persists for life. This study was performed to investigate if immunologic mechanisms exist which could contribute to the inability of the host to terminate the infection. Therefore, we compared the in vitro immunoreactivity of peripheral blood mononuclear cells (PBMC) from H. pylori‐infected patients after stimulation with sonicated H. pylori bacteria from the stomach of the patient (autologous bacterial strain) with stimulation by bacteria from other patients (heterologous bacteria). We measured cell proliferation, expression of T cell activation markers CD25, HLA‐DR, and CD71, as well as production of interleukin‐10 (IL‐10), an inhibitory cytokine. We found that the proliferative response of PBMC was significantly lower after autologous than after heterologous stimulation. Furthermore, secretion of IL‐10 in the culture supernatants was significantly higher when PBMC were incubated with autologous than with heterologous H. pylori antigens. No significant differences between autologous or heterologous stimulation were observed in the increased expression of T cell activation markers. These data indicate that systemic immunologic response to H. pylori are strain‐dependent. For further studies of the immune responses towards H. pylori, the use of an autologous stimulatory system seems necessary. Microsc. Res. Tech. 53:419–424, 2001. © 2001 Wiley‐Liss, Inc.
Ion channels in cultured microglia
Authors: Walz Wolfgang , Bekar Lane K. 
Published: August 2002

AbstractInward and, depending on activation state, outward potassium currents are the dominant ion channels in microglial cells in culture. During transition between resting and activated phases, there is also an upregulated expression of stretch/swelling‐activated chloride currents. Pharmacological blockade of the specific potassium channels does not prevent the transition, whereas blockade of chloride channels does, suggesting that this current may be involved in phase changes. Interestingly, this chloride current is far less studied than the potassium currents with regard to the different microglial phases. One puzzling finding when studying microglial state is that despite changes in current densities and membrane oscillations during transition, there is no evidence of an accompanying change in membrane potential. In other cells of the immune system, membrane oscillations and alterations in membrane potential are correlated with transitions in cellular phases. This discrepancy in microglia may be a result of the fact that almost all ion channel and membrane potential studies in culture are undertaken with concomitant dialysis of cytoplasm with pipette solution. Further complicating matters is that the few studies that use microglia in situ, find fundamental differences in ion channel current patterns of “resting” microglia as well as different temporal changes to pathological events or stimuli. Microsc. Res. Tech. 54:26–33, 2001. © 2001 Wiley‐Liss, Inc.
Phagocytic properties of microglia in vitro: Implications for a role in multiple sclerosis and EAE
Authors: Smith Marion E. 
Published: August 2002

AbstractThe microglial cell, after many years of neglect, has become recognized as the sole representative cell of the immune system that resides in the normal central nervous system. While normally dormant, microglia can be activated by secretory substances or signals associated with disease or injury, and becomes a phagocytic cell, which also produces its own injurious molecules. In the activating process, its morphology is changed from a resting process‐bearing cell, into a rounded amoebic form, and displays new or increased amounts of functional markers, such as receptors and Class I and Class II MHC molecules. Microglia prepared from newborn mice or rats for tissue culture are already activated, and can be used for studies of their phagocytic properties. Although they can phagocytize foreign substances, their uptake and metabolism of myelin are emphasized here, in keeping with their role in demyelinating diseases. A number of receptors have been implicated and appear to be important in the attachment to, and ingestion of, myelin particles in vitro, including the Fc, complement, macrophage scavenger, and the Galectin‐3/MAC‐2 receptors, although the α2‐macroglobulin/low‐density lipoprotein receptor and mannose receptors have also been suggested as participants in myelin phagocytosis. Certain cytokines and adhesion molecules also regulate the phagocytic activity of microglia. Comparative in vitro studies of phagocytosis by peritoneal macrophages and microglia have shown that the two kinds of cells respond differently to regulatory molecules, and it is concluded that they have different innate properties. The role of microglia in the demyelinative diseases experimental autoimmune encephalomyelitis and multiple sclerosis is emphasized here, and the possible means of intervention in the process leading to myelin destruction is discussed. Microsc. Res. Tech. 54:81–94, 2001. Published 2001 Wiley‐Liss, Inc.