bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cadmium‐induced malignant transformation in rat liver cells: Role of aberrant oncogene expression and minimal role of oxidative stress
Authors: Qu Wei , Diwan Bhalchandra A. , Reece Jeffrey M. , Bortner Carl D. , Pi Jingbo , Liu Jie , Waalkes Michael P. 
Published: November 2004

AbstractOur study examined the role of oxidative stress and aberrant gene expression in malignant transformation induced by chronic, low‐level cadmium exposure in non‐tumorigenic rat liver epithelial cell line, TRL 1215. Cells were cultured in 1.0 μM cadmium (as CdCl2) for up to 28 weeks and compared to passage‐matched control cells. The level of cadmium used for transformation produced no evidence of increased superoxide (O2− ·) or hydrogen peroxide (H2O2) levels in the early stages of exposure (≤24 hr). The chronic cadmium exposed liver epithelial cells (CCE‐LE) were hyperproliferative with a growth rate about 3‐fold higher than control cells. CCE‐LE cells produced highly aggressive tumors upon inoculation into mice confirming malignant transformation. Analysis of cellular reactive oxygen species (ROS) showed that CCE‐LE cells possessed markedly lower basal levels of intracellular O2− ·and H2O2 and were very tolerant to high‐dose (50 μM) cadmium‐induced ROS. Time course studies showed the production of ROS by high‐dose cadmium was abolished well in advance of malignant transformation. In contrast, marked overexpression of the oncogenes c‐myc and c‐jun occurred in transformed CCE‐LE cells as evidenced by up to 10‐fold increases in both transcript and protein. A significant increase in DNA‐binding activity of the transcription factors AP‐1 and NF‐κB occurred in CCE‐LE cells. Increases in oncogene expression and transcription factor activity occurred concurrently with malignant transformation. Thus, cadmium‐induced ROS occurs as an early, high‐dose event but is abolished well in advance of malignant transformation. Low‐level chronic cadmium triggers oncogene overexpression possibly by altering critical transcription factor activity. Such changes in cellular gene expression likely culminate in the loss of growth control and cadmium‐induced neoplastic transformation in CCE‐LE cells, whereas generation of ROS by cadmium seemed to play a minimal role in this transformation. © 2004 Wiley‐Liss, Inc.
Direct determination of resin and fatty acids in process waters of paper industries by liquid chromatography/mass spectrometry
Authors: Rigol A. , Latorre A. , Lacorte S. , Barceló D. 
Published: November 2004

AbstractLiquid chromatography/mass spectrometry (LC/MS)‐based methods were developed for the analysis of 10 resin acids and five fatty acids in process waters of paper industries. No fragmentation of target compounds was observed using atmospheric pressure chemical ionization (APCI) with negative ionization. The [M − H]− ion permitted the individual quantification of fatty and aromatic resin acids, whereas the non‐aromatic resin acids presented a single and common ion at m/z 301. Separation with two columns of different polarity permitted peak confirmation. The method that used a C8 column with 2‐propanol in the mobile phase allowed a certain separation and identification of the non‐aromatic resin acids, whereas the method using a C18 column provided detection limits 10‐fold lower for fatty acids. Limits of detection were 0.10 ng for all compounds. Direct sample introduction was compared with liquid–liquid extraction, with similar recoveries (70–101%). Whereas slightly lower detection limits were obtained with liquid–liquid extraction, better reproducibility was observed for direct sample introduction. Resin and fatty acids were determined in process waters of several paper industries. Palmitic, dehydroabietic and non‐aromatic resin acids were encountered in most water samples, at levels between 22 and 403 µg l−1. LC/MS with direct sample introduction was found to be a good alternative to traditional liquid–liquid extraction and gas chromatography for the analysis of such compounds since no derivatization was required and sample manipulation was minimal. Copyright © 2003 John Wiley & Sons, Ltd.
Associative properties of perfluorooctyl end‐functionalized polystyrene–poly(ethylene oxide) diblock copolymers
Authors: Boschet Frédéric , Branger Catherine , Margaillan André , Hogen‐Esch Thieo E 
Published: November 2004

AbstractThe synthesis of 2,2,3,3‐tetrahydro‐perfluoroundecanoyl end‐functionalized polystyrene–poly(ethylene oxide) block (PS‐block‐PEO‐RF) copolymers and their matching PS‐block‐PEO diblock copolymers was carried out by sequential anionic polymerization. Viscometry and 19F NMR studies show that the PS‐block‐PEO copolymers, in contrast to their matching PS‐block‐PEO‐RF copolymers, exhibit a micellar rather than the associative behavior seen for the latter. However, the presence of an excess of fluorinated acid, used for end‐functionalization, produces a reduction of the associative behavior above the overlap concentration, with the fluorinated acid acting like a surfactant. A competition may also occur between PS—and RF—mediated micellization. Copyright © 2004 Society of Chemical Industry
Explosion of a railcar containing toluene diisocyanate waste
Authors: Ogle Russell A. , Carpenter Andrew R. , Morrison Delmar R. 
Published: November 2004

AbstractA railcar containing toluene diisocyanate (TDI) waste exploded during the unloading process at a hazardous waste‐treatment and disposal facility. The TDI waste material was to be used as a fuel at the RCRA‐permitted facility. Because of the viscous, almost solidlike consistency of the waste, the railcar was steam‐heated to facilitate unloading. The attempted unloading took place over a 5‐day period. The railcar was heated on two separate occasions and unloading was unsuccessfully attempted three times. The decision was made to reject the railcar shipment, but it remained at the unloading station. Approximately 2 days after the last heating cycle, the railcar exploded.This paper summarizes the accident investigation, with particular emphasis on the assessment of the reactivity hazards and self‐heating potential of the railcar contents. Under the circumstances of this accident, TDI should not undergo significant thermal decomposition. The evidence suggested the explosion was caused by the thermal decomposition of a contaminant that was not normally present in the TDI waste. © 2004 American Institute of Chemical Engineers Process Saf Prog, 2004
Expectation‐based, inference‐based, and bottom‐up software comprehension
Authors: O'Brien Michael P. , Buckley Jim , Shaft Teresa M. 
Published: November 2004

AbstractThe software comprehension process has been conceptualized as being either ‘top‐down’ or ‘bottom‐up’ in nature. We formally distinguish between two comprehension processes that have previously been grouped together as ‘top‐down’. The first is ‘expectation‐based’ comprehension, where the programmer has pre‐generated expectations of the code's meaning. The second is ‘inference‐based’ comprehension, where the programmer derives meaning from clichéd implementations in the code.We identify the distinguishing features of the two variants, and use these characteristics as the basis for an empirical study. This study establishes the existence of the above‐mentioned processes, in conjunction with ‘bottom‐up’ comprehension. It also illustrates the relationship between these processes and programmers' application domain familiarity. Copyright © 2004 John Wiley & Sons, Ltd.
The maturation‐dependent production of interleukin‐16 is impaired in monocyte‐derived dendritic cells from atopic dermatitis patients but is restored by inflammatory cytokines TNF‐α and IL‐1β
Authors: Reich Kristian , Hugo Sabine , Middel Peter , Blaschke Volker , Heine Andrea , Neumann Christine 
Published: November 2004

Background:  Maturation of dendritic cells (DCs) influences important DC functions such as production of cytokines. Recently, DCs were identified as a source of interleukin‐16 (IL‐16), a chemotactic factor for DCs themselves, CD4+ T cells, and eosinophils. There is evidence that DC‐derived IL‐16 may contribute to the pathogenesis of atopic dermatitis (AD).Objective:  To investigate the production of IL‐16 during differentiation of monocytes into DCs in healthy individuals and patients with AD.Methods:  IL‐16 production was investigated by quantitative real‐time RT‐PCR, intracellular cytokine staining, immunoblotting, and ELISA.Results:  DCs generated from peripheral monocytes by 5‐day culture in the presence of IL‐4 and granulocyte/macrophage colony‐stimulating factor acquired the capability to synthesize, store, and secrete IL‐16. Storage and release of IL‐16 was further enhanced during final DC maturation induced by additional 3‐day culture with tumor necrosis factor‐α (TNF‐α) and monocyte‐conditioned medium. Maturation, as determined by up‐regulation of CD83 and CD86 surface expression, and production of IL‐16, but not production of IL‐10 and IL‐12p40 was impaired in day 8 DCs derived from AD patients compared to those from healthy donors. Stimulation of day 8 DCs from AD patients with TNF‐α and IL‐1β enhanced the expression of CD83 and CD86 and restored the production of IL‐16.Conclusions:  Signals involved in the activation and maturation of DCs enhance their capacity to produce IL‐16. Functional abnormalities present in patients with AD at the monocyte level may account for impaired maturation and IL‐16 production of monocyte‐derived DCs.
Firm investment in transition
Authors: Rizov Marian 
Published: November 2004

AbstractIn this paper a model based on the Euler equation of optimal capital accumulation in the presence of convex adjustment costs is developed and estimated. The theoretical model explicitly allows for differential financial status across firms. The empirical analysis uses Romanian manufacturing firm panel data to estimate dynamic investment models with the generalized method of moments (GMM‐IV) technique and tests the derived hypotheses. The results indicate that the model based on the perfect market assumptions is rejected. The version of the model that allows for differential financial status of firms by using a theoretically derived sample selection rule is not rejected by the data. Controlling for soft budget constraints, common for transition economies, further improves the performance of the model.
Effective doses of vecuronium in a patient with myotonic dystrophy*
Authors: Nishi M. , Itoh H. , Tsubokawa T. , Taniguchi T. , Yamamoto K. 
Published: November 2004

SummaryOf the forms of muscular dystrophy, myotonic dystrophy has the greatest systemic involvement. Although most patients with myotonic dystrophy show normal sensitivity to non‐depolarising neuromuscular blocking drugs, some have been reported to show greatly increased sensitivity to these drugs, and little is known about the sensitivity of different muscles. We compared effective doses of vecuronium in a patient with myotonic dystrophy at the orbicularis oculi, adductor pollicis and flexor hallucis brevis muscles during total intravenous anaesthesia. The calculated ED50 for the orbicularis oculi (7.77 μg.kg−1 (95% CI 3.10–16.8 μg.kg−1)) was lower than for the adductor pollicis (25.3 μg.kg−1 (95% CI 20.7–43.3 μg.kg−1)) and flexor hallucis brevis muscles (29.5 μg.kg−1 (95% CI 11.0–85.6 μg.kg−1; p < 0.01)). The ED90 was also lower for the orbicularis oculi (35.7 μg.kg−1 (95% CI 14.8–66.5 μg.kg−1)) than for the other muscles (51.8 μg.kg−1 (95% CI 29.3–145.0 μg.kg−1) and 50.6 μg.kg−1 (95% CI 5.29–642.0 μg.kg−1), respectively) (p < 0.01)).
Severe lactic acidosis following alcohol related generalised seizures
Authors: Hulme J. , Sherwood N. 
Published: November 2004

SummaryA 45‐year‐old alcoholic man presented following several short grand‐mal seizures. He was not known to be epileptic. Initial investigations demonstrated a severe lactic acidosis. The rise in lactate was one of the highest levels reported in similar patients. The patient recovered within 4 h of management with oxygen, fluids and sodium bicarbonate. Lactic acidosis following convulsions is often associated with spontaneous resolution and a favourable outcome.
Pharmacokinetics of sevoflurane uptake into the brain
Authors: Turner M. J. , McCulloch T. J. , Kennedy R. R. , Baker A. B. 
Published: November 2004

SummaryTwo recent studies have examined the pharmacokinetics of sevoflurane in adults. Lu et al.(Pharmacokinetics of sevoflurane uptake into the brain and body, Anaesthesia 2003; 58: 951–6) observed that jugular bulb sevoflurane concentration initially rose unexpectedly rapidly and then approached arterial concentrations unexpectedly slowly, suggesting that a blood–brain diffusion barrier exists. They also observed a large alveolar‐arterial sevoflurane gradient, suggesting that an alveolar–arterial diffusion barrier exists. Nakamura et al. (Predicted sevoflurane partial pressure in the brain with an uptake and distribution model: Comparison with the measured value in internal jugular vein blood. Journal of Clinical Monitoring and Computing 1999; 15: 299–305) found no diffusion barriers. We used a computer model to analyse both data sets and show that the observations of Lu et al. can be explained by contamination of jugular samples with extracerebral blood. It is possible that the alveolar‐arterial gradients observed by Lu et al. are due to discrepancies in conversions between blood concentrations and gas partial pressures. Our study suggests that there is no blood–brain diffusion barrier for sevoflurane and that the data of Lu et al. must be interpreted with caution.
Characterization of T‐regulatory cells, induced by immature dendritic cells, which inhibit enteroantigen‐reactive colitis‐inducing T‐cell responses in vitro and in vivo
Authors: Gad Monika , Kristensen Nanna N. , Kury Evelyn , Claesson Mogens H. 
Published: November 2004

SummaryRegulatory T (Treg) cells, derived from co‐cultures of unfractionated CD4+ T cells and immature dendritic cells (DC), suppress enteroantigen‐induced proliferation of CD4+ CD25− T cells. The DC‐induced Treg cells are a mixture of CD25+ (10–20%) and CD25− (80–90%) T cells. However, all the suppressor activity in vitro and in vivo resides in the CD25+ T‐cell subset. The CD25+ DC‐induced Treg cells can inhibit enteroantigen‐induced proliferation in vitro through a transwell membrane, and their function does not appear to depend on previous activation. DC‐induced CD25+ Treg cells display a naïve phenotype, expressing high levels of CD45RB and l‐selectin (CD62L). In addition, the DC‐induced Treg cells mediate a stronger suppressive activity than prototype CD25+ regulatory T cells. The DC‐induced Treg cells, and hereof purified CD25+ and CD25− T‐cell fractions, were co‐injected into severe combined immunodeficiency (SCID) mice with colitis‐inducing CD4+ CD25− T cells. Both unfractionated CD4+ and purified CD25+ Treg cells fully protected the recipients against the development of colitis. In contrast, co‐transfer of fractionated CD25− T cells offered no protection against disease development. Enterobacterial antigen‐exposed CD4+ T cells of the protected mice secreted higher levels of interleukin‐10 and lower levels of interferon‐γ than the unprotected mice. The present data demonstrate DC‐induced CD4+ CD25+ Treg cells, which phenotypically and functionally differ from the generally accepted prototype of CD25+ Treg cells. These data may initiate new procedures for the expansion of Treg cells for clinical use.
Site‐specific regulation of tissue dendritic cell function by granulocyte–macrophage colony‐stimulating‐factor
Authors: Lees Joanne , Boam David , Proungvitaya Tanakorn , Wood Peter J. 
Published: November 2004

SummaryTissue dendritic cells (DC) are usually associated with phagocytic function but poor T‐cell immunostimulatory capacity. Following activation, dendritic cells are stimulated to leave tissue sites and migrate to lymphoid tissue, acquiring immunostimulatory capacity during the process. We provide evidence that the immunostimulatory capacity of tissue DC, but not spleen cells, can be affected in situ by granulocyte–macrophage colony‐stimulating‐factor (GM‐CSF). Initially it was found that islet cells from non‐obese diabetic and BALB/c mice, which produce GM‐CSF, showed significantly higher immunostimulatory capacity than islets from C3H and C57BL/6 mice, which do not produce GM‐CSF. Second, pretreatment of nonobese diabetic mice with anti‐GM‐CSF antibody significantly reduced the immunostimulatory capacity of islet cells, but not spleen cells, although it had no effect on the numbers of cells expressing DC‐associated antigens. Therefore the immunostimulatory function of islet DC is partially dependent on GM‐CSF. By contrast, spleen DC immunostimulatory function does not show the same dependence on GM‐CSF. This may affect the ability of dendritic cells to stimulate autoimmune responses or tolerance.
Assessment of a contrast medium as an adjunct to endodontic radiography
Authors: Bedford J. M. , Martin D. M. , Youngson C. C. 
Published: November 2004

AbstractAim  To assess if a contrast medium improved diagnostic yield of endodontic radiographs.Methodology  Forty‐five extracted mandibular premolar teeth were radiographed in bucco‐lingual and mesio‐distal planes. Access cavities were prepared, pulpal tissue extirpated and Ultravist® contrast medium introduced under pressure. Radiographs were retaken and the teeth cleared following perfusion with India ink. Three examiners assessed all the films for: number of roots, number of root canals, curvature of root and/or root canal, presence of lateral canals, presence of a single foramen or apical delta and the presence or absence of canal obstructions. The examiners’ interpretations were compared with the anatomy revealed by clearing.Results  Kappa scores were calculated for each of the examiners, for each set of radiographs, to assess the level of intra‐ and inter‐examiner agreement. Only moderate agreement was found throughout (κ = 0.40–0.61). For multiple root canals a false‐positive result was significantly more likely with contrast (P < 0.05). The use of contrast did not significantly improve the sensitivity of diagnosis of lateral canals or a single apical foramen. Contrast significantly increased the risk of falsely perceiving lateral canals (P < 0.002). Overall there was no statistically significant difference in the overall assessment of the anatomy of the root canals using contrast or plain radiographs (P > 0.2).Conclusions  Plain film radiographs confidently predict the presence of root or canal curvature but apical anatomy was assessed accurately in only 46% of cases. Plain radiographs were insensitive in assessing the number of root canals present, the presence of lateral canals and the occurrence of canal obstructions. The use of Ultravist® contrast medium to improve diagnosis of root canal morphology of premolars is not supported.
Role of cytosolic free calcium in the reorientation of pollen tube growth
Authors: Malhó Rui , Read Nick D. , Pais M. Salomé , Trewavas Anthony J. 
Published: November 2004

SummaryGrowing pollen tubes of Agapanthus umbellatus exhibited a tip‐to‐base gradient in cytosolic free calcium ([Ca2+]c). Although this gradient is believed to be involved in pollen tube growth, its role in specifying reorientation is unknown. The direction of pollen tube growth could be modified by iontophoretic micro‐injection, electrical fields (EFs) or photolysis of caged Ca2+. Iontophoretic injection resulted in a temporary cessation of growth, an increase in [Ca2+]c and, upon recovery, reoriented growth. Weak EFs also elevated [Ca2+]c, reduced growth rates and resulted in the reorientation of pollen tubes towards the cathode. Treatment with very low concentrations of the Ca2+‐channel blocker lanthanum chloride, prior to exposure to an EF, inhibited both the increase in [Ca2+]c and reorientation whilst only slightly affecting growth rates. The responses of growth inhibition and reorientation were mimicked when [Ca2+]c was artificially elevated by photoactivating caged Ca2+ (Nitr‐5). Our data suggest that [Ca2+]c is part of a transduction mechanism which enables growing pollen tubes to successfully reorient to directional signals in the style and thus accomplish eventual fertilization of the egg.
Purification, characterization, and cDNA sequence of glucose‐6‐phosphate dehydrogenase from potato (Solatium tuberosum L.)
Authors: Graeve Kerstin , von Schaewen Antje , Scheibe Renate 
Published: November 2004

SummaryGlucose‐6‐phosphate dehydrogenase (G6PDH, E.C. 1.1.1.49) has been purified from potato tuber at least 850‐fold to apparent homogeneity as judged by SDS‐PAGE. The enzyme was characterized by Km values of 260 μM for glucose‐6‐phosphate and 6 μM for NADP and a broad pH optimum between phi 7.5 and 9. NADPH, GTP, ATP, acetyl CoA and CoA inhibited G6PDH activity. Dithiothreitol (DTT) did not inactivate the enzyme. A highly specific antiserum was produced in a rabbit and used for immunodetection of G6PDH in Western blots.A cDNA library from potato leaves was screened with DNA probes produced by the polymerase chain reaction (PCR) in the presence of g6pdh‐specific primers. A full‐length cDNA clone was analyzed and the derived amino acid sequence compared with known G6PDH sequences from various sources. The homology of the plant sequence with G6PDH sequences from animals and yeast was found to be rather high (52%), whereas there was significantly lower homology with sequences of bacterial origin (37%). The lack of a plastidic signal sequence as well as the insensitivity of the recombinant enzyme towards reduced DTT, support the view that the cDNA sequence of a redox‐independent cytosolic isoform was obtained.
Transient transformation of Arabidopsis leaf protoplasts: a versatile experimental system to study gene expression
Authors: Abel Steffen , Theologis Athanasios 
Published: November 2004

SummaryAn improved protocol is reported to isolate and transiently transform mesophyll protoplasts of Arabidopsis thaliana. Transfected leaf protoplasts support high levels of expression of the bacterial reporter gene coding for β‐glucuronidase (GUS), under the control of the cauliflower mosaic virus (CaMV) 35S promoter. Transient expression of GUS activity was monitored spectrophotometrically and reached a maximum between 18 and 48 h after polyethylene glycol (PEG)‐mediated DNA uptake. Histochemical staining for GUS activity revealed reproducible transformation frequencies between 40 and 60%, based on the number of protoplasts survived. To demonstrate the applicability of the transient expression system, the subcellular localization of GUS proteins tagged with different nuclear polypeptides was studied in transfected mesophyll protoplasts, revealing nuclear compartmentalization of the chimeric GUS enzymes. Furthermore, Arabidopsis mesophyll protoplasts support auxin‐mediated induction of chloramphenicol acetyl‐transferase (CAT) activity when transfected with a transcriptional fusion between the CAT reporter gene and the early auxin‐inducible PS‐IAA4/5 promoter. Hence, the method allows in vivo analysis of promoter activity and subcellular localization of fusion proteins in a homologous transformation system.