bluuebunny/crossref_metadata_2025_split huggingface dataset:
Strategies To Stabilize New Oxides in the Srn+1(CoTa)nO3n+1 Ruddlesden–Popper Homologous Series
Authors: Boulahya Khalid , Parras Marina , González‐Calbet José María 
Published: October 2006

AbstractTwo new oxides of the Ruddlesden–Popper series have been isolated and structurally characterized in the Sr‐Co‐Ta‐O system. X‐ray and electron diffraction and high‐resolution electron microscopy show that polycrystalline Sr3CoTaO7 constitutes the n=2 member of a new Srn+1(CoTa)nO3n+1 homologous series, the essential feature of which is the existence of two connected Co/Ta octahedral layers, separated by Sr atoms. Sr2CoTaO6, the n=∞ member of the series, shows a particular short‐range ordering of Co and Ta at the octahedral sites leading, as shown by high‐resolution electron microscopy, to the disordered intergrowth of simple and double perovskite type domains. Strategies to stabilize new oxides of this series are discussed.
Microtransponders, the miniature RFID electronic chips, as platforms for cell growth in cytotoxicity assays
Authors: Mandecki Wlodek , Ardelt Barbara , Coradetti Thomas , Davidowitz Hanan , A. Flint James , Huang Zhili , M. Kopacka Wesley , Lin Xin , Wang Zhuying , Darzynkiewicz Zbigniew 
Published: October 2006

AbstractBackground:An electronic radio frequency (RF) microchip, the microtransponder (MTP), has been developed as a platform for assays in the fields of genomics and proteomics. Upon activation by light, each MTP provides a unique RF identification (ID) signal that matches a chip to the specific biological material attached to it. The MTP is powered by a photocell and has an antenna that transmits the signal. The aim of the present study was to explore utility of MTPs as a platform for cell growth in cytotoxicity assays.Methods:The MCF‐7, MCF‐116, A549, or T‐24 cells growing on MTPs placed in petri dishes or slide chambers were cultured untreated or exposed to antitumor drugs topotecan, mitoxantrone, or onconase for up to 4 days. Their attachment to‐ and growth on‐ MTPs was assessed by fluorescence microscopy and laser scanning cytometry (LSC) and compared with growth on the dish surface in the MTP neighborhood. The MTPs were fixed in ethanol, stained with propidium iodide (PI), and interrogated in flow in the instrument capable to rapidly (up to 103 MTPs/s) identify their ID signal and measure fluorescence.Results:The cells plated on MTPs exhibited similar attachment properties to those plated in culture dishes. When measured by LSC, they had similar mitotic activity, growth rate, and cell cycle distributions as the cells adhering to the culture dish in the neighborhood of MTPs. The fluorescence intensity of MTPs provided information about the cell number per MTP, which made it possible to assess cell growth rate and monitor the cytostatic/cytotoxic effects of the tested drugs.Conclusions:The MTP‐based system holds promise for the multiplexed cell assays in which numerous different cell lines can be screened for their growth rate or sensitivity while exposed to particular agents in the same vessel. Other advantages of the system are the rapidity of the screening and a very large number of ID codes. Because many cell lines/types can be assayed in a single dish, the system also offers cost savings on tissue culture reagents. © 2006 International Society for Analytical Cytology
Short circuit current of thermoionic energy converter by resonance light irradiation
Authors: Inaguma Takayuki , Tsuda Norio , Yamada Jun 
Published: October 2006

AbstractA thermoionic energy conversion is one of the methods of direct electricity generation. The space charge effect, which limits the space emission, is relaxed by enclosing cesium in the converter. In general, the converter is operated at high emitter temperature because of the production of cesium ion by contact thermal ionization. The high operating temperature causes short emitter lifetime which becomes a problem in terms of practical use. The converter is irradiated with the resonance light so that cesium ion is produced by photoionization. It is seen that the output resulting from the resonance light irradiation is much higher than that resulting from the visible light. Many cesium ions can be produced in the space between the electrodes since most of the resonance light is absorbed by cesium atoms. The maximum value of the short circuit current density is about 1kA/m2. It is found that resonance light irradiation is one of the effective methods suitable for practical application. © 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 158(1): 14–21, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10250
Potential role of CARMA1 in CD40‐induced splenic B cell proliferation and marginal zone B cell maturation
Authors: Pappu Bhanu P. , Lin Xin 
Published: October 2006

AbstractNF‐κB activation through B cell receptor (BCR) ligation is critical for B cell development, survival and antigen‐mediated activation of B cells. CARD domain and MAGUK‐domain containing protein‐1 (CARMA1), recently identified adaptor molecule, has been shown to play an essential role in BCR‐induced NF‐κB activation. CARMA1‐deficient B cells fail to proliferate upon BCR stimulation, leading to defective humoral responses. Surprisingly, CARMA1‐deficient B cells are also defective in CD40‐induced proliferation. The mechanisms responsible for CD40‐induced proliferation defect have not yet been characterized. In this study, we show that signaling cascades activated by CD40 stimulation are largely unaffected in CARMA1‐deficient B cells. Instead, we have found that the defective proliferation of CARMA1‐deficient B cells is due to two events. First, CARMA1‐deficient B cells show defective cell‐cycle progression. Secondly, the numbers of marginal zone (MZ) B cells, which are the main responders upon CD40 stimulation, are greatly diminished in CARMA1‐deficient mice. Since B cell maturation requires basal signaling through BCR and NF‐κB activation, we propose that impaired BCR signaling in CARMA1‐deficient mice leads to defective maturation of MZ B cell population, which in turn, contributes to impaired proliferation upon CD40 stimulation.
Salmonella typhimurium infection triggers dendritic cells and macrophages to adopt distinct migration patterns in vivo
Authors: Zhao Chunfang , Wood Michael W. , Galyov Edouard E. , Höpken Uta E. , Lipp Martin , Bodmer Helen C. , Tough David F. , Carter Robert W. 
Published: October 2006

AbstractThe presence of an anti‐bacterial T cell response and evidence of bacterial products in inflamed joints of reactive arthritis patients suggests an antigen transportation role in this disease for macrophages and dendritic cells. We have investigated the functional properties and in vivo migration of macrophages and DC after infection with Salmonella enterica serovar Typhimurium (S. typhimurium). BM‐derived macrophages and DC displayed enhanced expression of costimulatory molecules (CD40 and CD86) and increased production of pro‐inflammatory cytokines (TNF‐alpha, IL‐6 and IL‐12p40) and nitric oxide after infection. Upon adoptive transfer into mice, infected DC migrated to lymphoid tissues and induced an anti‐Salmonella T cell response, whereas infected macrophages did not. Infection of DC with S. typhimurium was associated with strong up‐regulation of the chemokine receptor CCR7 and acquisition of responsiveness to chemokines acting through this receptor. Moreover, S. typhimurium‐infected CCR7‐deficient DC were unable to migrate to lymph nodes after adoptive transfer, although they did reach the spleen. Our data demonstrate distinct roles for macrophages and DC as antigen transporters after S. typhimurium infection and a dependence on CCR7 for migration of DC to lymph nodes after bacterial infection.
Synthesis of 3‐Hydroxy‐ and 3‐Carboxy‐Δ2‐isoxazoline Amino Acids and Evaluation of Their Interaction with GABA Receptors and Transporters
Authors: Conti Paola , De Amici Marco , Pinto Andrea , Tamborini Lucia , Grazioso Giovanni , Frølund Bente , Nielsen Birgitte , Thomsen Christian , Ebert Bjarke , De Micheli Carlo 
Published: October 2006

AbstractA series of 3‐hydroxy‐ and 3‐carboxy‐Δ2‐isoxazoline amino acids, structurally related to the GABAA agonist THIP and to the GABA uptake inhibitors THPO and exo‐THPO, was prepared by means of synthetic strategies involving the 1,3‐dipolar cycloaddition of nitrile oxides. All derivatives were submitted to a pharmacological investigation at both GABA receptors and transporters. Unfortunately, all amino acids were devoid of activity except for a very low affinity at GABAA receptors, displayed by compounds 8 and 17. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Reproductive anomalies in stenoglossan snails related to pollution from marinas
Authors: Smith Blakeman S. 
Published: October 2006

AbstractOver 3090 snails of the dioecious intertidal species Nassarius absoletus Say were collected from a total of 71 localities. Their reproductive anatomy was examined for a superimposition of male characteristics on to the normal female anatomy, an abnormality called ‘imposex’. Imposex was rated numerically in terms of the fraction of the population affected and the intensity of expression in bearer snails. An initial survey of 22 localities in Fairfield and Westport, Connecticut, led to the hypothesis that imposex was related to a substance arising from marinas. This was tested at nine pairs of marina and control localities in Long Island Sound, as well as six pairs along a transect ranging from Rhode Island to Georgia. Imposex scores were significantly higher at the marina locality in every pair. Further confirmation was found in a detailed survey of the estuarine harbor at Southport, Connecticut, which showed that adjacent populations could differ in the amount of imposex to the extent that both the snails and the waters they lived in remained separated by natural or man‐made barriers. Imposex has been found in populations of N. obsoletus ranging from Damariscotta, Maine, to Savannah, Georgia, and it has been reported from San Francisco Bay, California. Similar anatomical abnormalities have been reported in at least 27 other species of taenioglossan and stenoglossan snails, extending the range to the Atlantic and Mediterranean coast of Europe and the British Isles. Concern is raised regarding the possible existence of another global pollutant with novel effects on marina biota.
Acute oral toxicity of butyl nitrite
Authors: Wood Ronald W. , Cox Christopher 
Published: October 2006

AbstractButyl nitrite is present in consumer products subject to abuse by inhalation. When inhaled, intense peripheral vasodilation and tachycardia ensue, described by users as a ‘rush’. When ingested, toxic sequelae include methemogloginemia and hypokinetic anoxia. The median lethal oral dose to rats of this compound is, with 95% confidence, 83 ± 3.5 mg kg−1.
Experimental conditions in GMR chronic inhalation studies of diesel exhaust
Authors: Schreck R. M. , Soderholm S. C. , Chan T. L. , Smiler K. L. , D'arcy J. B. 
Published: October 2006

AbstractA chronic inhalation exposure study was initiated to study the potential health effects of diesel exhaust on laboratory animals. Test atmospheres of clean air (control) or freshly diluted diesel exhaust at nominal particulate concentrations of 250, 750 and 1500 μg m−3 were supplied to four large volume inhalation chambers in which individually housed Fischer 344 albino rats (Rattus norvegicus) and Hartley guinea pigs (Cavia porcellus) were exposed for 20 h per day, 5 1/2 days per week. The diesel aerosol concentration, chamber temperature and relative humidity were continually monitored and controlled to maintain the exposure dose levels and an environment of 22 ± 2 °C and 50 ± 20% relative humidity. Animals were randomly sampled from the chambers for physiological, biochemical and pathological studies throughout the exposure period. The study was continued without interruption for 24 months with the mean diesel particle mass concentrations within 6% of the target values. The standard deviation of the mass concentration measurements was approximately 30% of the mean.
Electroencephalographic and evoked response correlates of trimethyltin induced neuronal damage in the rat hippocampus
Authors: Ray D. E. 
Published: October 2006

AbstractTrimethyltin produces localized neuronal damage in the rat hippocampus, amygdala and pyriform cortex when given systemically. In the present study the behavioural, electroencephalographic and auditory evoked responses of conscious rats were followed over an 11 day period after oral administration of trimethyltin. An early increase in hippocampal and, to a lesser extent, neocortical evoked response was seen, this preceding the behavioural symptoms. Development of symptoms (hyperactivity, tremor and fear) was accompanied by an increase in the incidence of theta rhythm in the electroencephalogram (EEG). Finally a fall in hippocampal evoked response and theta incidence was seen. It is suggested that a phase of neuronal excitability precedes neuronal damage, and that this is more pronounced in the hippocampus than in areas not developing subsequent neuronal loss.
The influence of selenium on mercury distribution in mice after exposure to low dose Hg° vapours
Authors: Hansen Jens C. , Kristensen Preben , Westergaard Ingrid 
Published: October 2006

AbstractThe influence of selenium administration on retention, elimination and organ distribution of mercury was studied in female mice exposed to 30 or 80 μg m−3 mercury vapour. The results demonstrated that, as after low doses of mercuric mercury, only excess selenium reduced the elimination of retained mercury vapour from the whole body. However, selenium was able to influence the organ distribution of mercury, even when the whole body burden of mercury was not affected. In mice, contrary to rats, selenium increased the lung and kidney concentrations of mercury without affecting its concentration in the liver.
The effect of daily oral dosing with ngaione for 7 weeks on the liver of the rat
Authors: Lee J. S. , Hrdlicka J. , Seawright A. A. 
Published: October 2006

AbstractThe present study was undertaken to see if rats could be made tolerant to normally lethal doses of the hepatotoxic, necrogenic myoporaceous essential oil ngaione, the single oral LD50 of which is 357 mg kg−1. Male Wistar rats weighing initially 90–100 g were dosed daily (for 7 weeks) by gavage with the oil dissolved in arachis oil, beginning at 50 mg kg−1 for the first 7 days and increased by 50% each week up to a final dose rate of 575 mg kg−1. Control rats were dosed with an equivalent amount of arachis oil. Groups of four animals were killed at the end of each week in order to study progressive morphological and chemical features of the livers. In the test rats there was marked liver enlargement after 3 weeks of dosing due mainly to increase in water levels. There were slight morphological liver changes indicative of mild toxic injury at this stage but no necrosis of the parenchymal cells or cirrhosis occurred even after 7 weeks of dosing. Cytochrome P‐450 levels in the liver microsomes were, however, reduced to some 2/3 that of controls after 3 weeks of dosing and to 1/4 after 7 weeks. Since ngaione requires activation by microsomal cytochrome P‐450 oxygenases for toxicity in the liver the markedly reduced levels of this enzyme is suggested as the cause of the decreased susceptibility of the rats to the oil after several weeks of treatment. It remains to be determined if the latter is the explanation of the tolerance shown by livestock continuously grazing plants containing the oils in the paddock.
Mammalian cell cytotoxicity of diesel engine emission fractions
Authors: Meltz Martin L. , Waugh Jane , Schneider Sandra , Greene Nathan D. , Rodriguez Charles , Hare Charles 
Published: October 2006

AbstractThe relative toxicity of extracted and fractionated diesel engine emission material was assessed with two in vitro mammalian cell culture systems, continously maintained Balb/c 3T3 cells and freshly‐isolated baboon peripheral blood lymphocytes. Particulate emission material from a two‐stroke cycle and a four‐stroke cycle diesel engine was collected on filters and then solvent extracted. The neutral material was fractionated chromatographically after an initial chemical fractionation of the emission material into acidic, neutral and basic fractions. Balb/c 3T3 cells treated with chemically and chromatographically‐differentiated fractions from both the two‐stroke cycle and the four‐stroke cycle diesel engines had different toxicities on a concentration dependent (μg ml−1) basis. Fractions from the four‐stroke cycle engine showed greater toxicity than those from the two‐stroke cycle engine. Toxicity comparisons were made on the basis of cloning efficiency measurements (indicative of effects on reproductive integrity) 8 days after a 72 h treatment interval, and on the basis of DNA, RNA and protein precursor incorporation rates (biochemical indices) during or immediately after 72 h of treatment. The Balb/c 3T3 system results were supported by similar results obtained when freshly isolated baboon peripheral blood lymphocytes were mitogen (concanavilin A) stimulated in the presence of the various fractions. The results in the in vitro lymphocyte system indicate a potential for altered immune defense capability if the cells were to be exposed to the fractions in vivo.
Medical survey techniques in the seveso TCDD exposure
Authors: Reggiani G 
Published: October 2006

AbstractThe release of TCDD in Seveso and the exposure of the people living in the contaminated territory has confronted the medical community responsible for the health surveillance of this population with a choice of techniques to be used for the task. Several methods of medical survey have been adopted: demographic and epidemiologic studies, prevalence surveys, retrospective and prospective cohort studies, cross‐sectional and case‐control studies, and short term tests of human monitoring. The techniques had to conform to the morbidity patterns to be examined; to the confounding variables to be considered; to the underlying disease conditions of the population; to the baseline data which were not always available or were insufficient; to the problem of non‐compliance; to the provision of appropriate control groups. Each technique contributed a different level of information in respect to the causal relationship with the suspected agent. None of the techniques could escape the limitations of the clinical toxicology studies where the number of exposed people entering the study is imposed by circumstances beyond the control of the investigators, and exposure is often poorly defined. At present, five years after the accident, chloracne has been the only clinical sign which can be causally related to a TCDD exposure in Seveso.
Electrochemical processes of nucleation and growth of hydroxyapatite on titanium supported by real‐time electrochemical atomic force microscopy
Authors: Eliaz Noam , Eliyahu Moshe 
Published: October 2006

AbstractRecently, interest in electrochemical formation of hydroxyapatite has evolved. In this work, highly crystalline hydroxyapatite is electrodeposited on pure titanium and Ti‐6Al‐4V alloy. In situ and ex situ imaging, coupled with potentiostatic and potentiodynamic measurements, is conducted by means of electrochemical atomic force microscopy. This allows for a study of the nucleation and growth of hydroxyapatite as well as of its near‐atomic structure. Electrodeposition of hydroxyapatite is shown to result from precipitation in solution, following two stages: (1) instantaneous nucleation, two‐dimensional growth; (2) progressive nucleation, three‐dimensional growth. Although some nucleation occurs already at −842 mV, potentials that are more negative than −1.26 V versus SCE are required for enhanced growth. Mass transport is found to have only secondary effect on the deposition process. The conclusions of this work have implications in optimization of coatings on implants as well as in enhancement of the understanding of bone mineralization in vivo. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
tert–butylhydroperoxide—Induced toxicity in isolated hepatocytes: Contribution of thiol oxidation and lipid peroxidation
Authors: Jewell Sarah A. , Monte Donato Di , Richelmi Plinio , Bellomo Giorgio , Orrenius Sten 
Published: October 2006

AbstractIncubation of isolated rat hepatocytes with tert‐butylhydroperoxide resulted in marked cytotoxicity preceded by intracellular glutathione depletion and extensive lipid peroxidation. Addition of antioxidants delayed, but did not prevent, this toxicity.A significant decrease in protein‐free sulfhydryl groups also, occurred in the presence of tert‐butylhydroperoxide; direct oxidation of protein thiols and mixed disulfide formation with glutathione were responsible for this decrease. The involvement of protein thiol depletion in tert‐butylhydroperoxide–induced cytotoxicity is suggested by our observation that administration of dithiothreitol, which caused re‐reduction of the oxidized sulfhydryl groups and mixed disulfides, efficiently protected the cells from toxicity. Moreover, depletion of intracellular glutathione by pretreatment of the hepatocytes with diethyl maleate accelerated and enhanced the depletion of protein thiols induced by tert‐butylhydroperoxide and potentiated cell toxicity even in the absence of lipid peroxidation.
Tricyclohexyltin hydroxide effects on cationic and substrate activation kinetics of beta‐adrenergic–stimulated cardiac Ca2+‐ATPase
Authors: Sahib Kabeer I. Ahammad , Desaiah Durisala 
Published: October 2006

AbstractPrevious studies from this laboratory have indicated that tricyclohexyltin hydroxide (Plictran) is a potent inhibitor of both basal‐ and isoproterenol‐stimulated cardiac sarcoplasmic reticulum (SR) Ca2+‐ATPase, with an estimated IC‐50 of 2.5 × 10−8M. The present studies were initiated to evaluate the mechanism of inhibition of Ca2+‐ATPase by Plictran. Data on substrate and cationic activation kinetics of Ca2+‐ATPase indicated alteration of Vmax and Km by Plictran (1 and 5×10−8M), suggesting a mixed type of inhibition. The beta‐adrenergic agonist isoproterenol increased Vmax of both ATP‐ and Ca2+‐dependent enzyme activities. However, the Km of enzyme was decreased only for Ca2+ Plictran inhibited isoproterenol‐stimulated Ca2+‐ATPase activity by altering both and Vmax and Km of ATP as well as Ca2+‐dependent enzyme activities, suggesting that after binding to a single independent site, Plictran inhibits enzyme catalysis by decreasing the affinity of enzyme for ATP as well as for Ca2+ Preincubation of enzyme with 15 μM cAMP or the addition of 2mM ATP to the reaction mixture resulted in slight activation of Plictran‐inhibited enzyme. Pretreatment of SR with 5 × 10−7M propranolol and 5 × 10−8M Plictran resulted in inhibition of basal activity in addition to the loss of stimulated activity. Preincubation of heart SR preparation with 5 × 10−5M coenzyme A in combination with 5 × 10−8M Plictran partly restored the beta‐adrenergic stimulation. These results suggest that some critical sites common to both basal‐ and beta‐adrenergic‐stimulated Ca2+‐ATPase are sensitive to binding by Plictran, and the resultant conformational change may lead to inhibition of beta‐adrenergic stimulation.