bluuebunny/crossref_metadata_2025 huggingface dataset:
Isolation of a stromal cell line from an early passage of a mouse mammary tumor line: A model for stromal parenchymal interactions
Authors: Lamb Caroline A. , Fabris Victoria , Gorostiaga María Alicia , Helguero Luisa A. , Efeyan Alejo , Bottino María Cecilia , Simian Marina , Soldati Rocío , Sanjuan Norberto , Molinolo Alfredo , Lanari Claudia
Published: September 2004

We have developed a murine mammary tumor cell line, MC4‐L4, and after 15 passages, a spindle‐shaped population became evident. The cuboidal cells, MC4‐L4E, cloned by limit dilution, proved to be epithelial tumor cells. When inoculated in syngeneic mice, they gave rise to invasive metastatic carcinomas expressing estrogen and progesterone receptors. These tumors regressed after anti‐progestin treatment and stopped growing after 17‐β‐estradiol administration. In vitro, they were insensitive to medroxyprogesterone acetate (MPA), 17‐β‐estradiol, and EGF and were inhibited by TGFβ1. They expressed mutated p53 and estrogen receptors α; progesterone receptors were undetectable. Cells were polyploid and shared the same four common marker chromosomes present in the parental tumor in addition to an exclusive marker. Spindle‐shaped cells, MC4‐L4F, were selected by differential attachment and detachment and proved to be non‐epithelial non‐tumorigenic cells. They were cytokeratin negative, showed mesenchymal features by electron microscopy, differentiated to adipocytes when treated with an adipogenic cocktail, were stimulated by TGFβ1 and EGF, showed a wild‐type p53, and did not exhibit the marker chromosomes of the parental tumor. Although they expressed estrogen receptors α, they were insensitive to 17‐β‐estradiol in proliferation assays. Co‐cultures of both cell types had a synergic effect on progesterone receptors expression and on cell proliferation, being the epithelial cells, the most responsive ones, and 17‐β‐estradiol increased cell proliferation only in co‐cultures. Cytogenetic studies and data on p53 mutations rule out the possibility of an epithelial mesenchymal transition. Their unique characteristics make them an excellent model to be used in studies of epithelial–stromal interactions in the context of hormone responsiveness in hormone related tumors. © 2004 Wiley‐Liss, Inc.
Induction of mitochondrial fusion by cysteine‐alkylators ethacrynic acid and N‐ethylmaleimide
Authors: Bowes Timothy J. , Gupta Radhey S.
Published: September 2004

Mitochondrial fusion and fission are important aspects of eukaryotic cell function that permit the adoption of varied mitochondrial morphologies depending upon cellular physiology. We previously observed that ethacrynic acid (EA) induced mitochondrial fusion in cultured BSC‐1 and CHO/wt cells. However, the mechanism responsible for it was not clear since EA has a number of known cellular effects including glutathione (GSH) depletion and alkylation of cysteine residues. To gain insight, we have tested the effects of a variety of compounds on EA induced cellular toxicity and mitochondrial fusion. N‐acetyl cysteine (NAC), a GSH precursor, was found to abrogate both the toxic and fusion‐inductive effects, whereas diethylmaleate (dEM), a GSH depletor, potentiated both these effects in a dose‐dependent manner. However, treatment with dEM alone, which depleted GSH to the same degree as EA, did not induce mitochondrial fusion. These results indicate that although detoxification of EA via formation of GSH conjugates is dependant upon GSH levels, the depletion of GSH by EA is not responsible for its effect on mitochondrial fusion. Dihydro‐EA (DH‐EA), a saturated EA analogue, lacked EA's toxicity and effect on fusion, indicating that the α,β‐unsaturated ketone is central to its observed effects. N‐ethylmaleimide (NEM), another well‐known cysteine‐alkylator, also induced mitochondrial fusion at near toxic concentrations. These data suggests that cysteine‐alkylation is the causative factor for fusion and toxicity. In live BSC‐1 cells, EA induced fusion of mitochondria occurred very rapidly (<20 min), which suggests that it is inducing fusion by modifying certain critical cysteine residue(s) in proteins involved in the process. © 2004 Wiley‐Liss, Inc.
Regulation of Fas (CD95)‐induced apoptotic and necrotic cell death by reactive oxygen species in macrophages
Authors: Medan Djordje , Wang Liying , Toledo David , Lu Bin , Stehlik Christian , Jiang Bing‐Hua , Shi Xianglin , Rojanasakul Yon
Published: September 2004

Although reactive oxygen species (ROS) have long been suspected to play a key role in Fas (CD95)‐induced cell death, the identity of specific ROS involved in this process and the relationship between apoptotic and necrotic cell death induced by Fas are largely unknown. Using electron spin resonance (ESR) spectroscopy, we showed that activation of Fas receptor by its ligand (FasL) in macrophages resulted in a rapid and transient production of hydrogen peroxide (H2O2) and hydroxyl radicals (·OH). The response was visible as early as 5 min and peaked at approximately 45 min post‐treatment. Morphological analysis of total death response (apoptosis vs. necrosis) showed dose and time dependency with apoptosis significantly increased at 6 h after the treatment, while necrosis remained at a baseline level. Only at a 35‐fold increase in apoptosis did necrosis become significant. Inhibition of apoptosis by a pan‐caspase inhibitor, benzyloxycarbonyl‐Val‐Ala‐Asp‐(OMe) fluoromethyl ketone (zVAD‐fmk), significantly inhibited cell necrosis, indicating the linkage between the two events. Catalase (H2O2 scavenger) and deferoxamine (·OH scavenger) effectively inhibited the total death response as well as the ESR signals, while superoxide dismutase (SOD) (O scavenger) had minimal effects. These results established the role for H2O2 and ·OH as key participants in Fas‐induced cell death and indicated apoptosis as a primary mode of cell death preceding necrosis. Because the Fas death pathway is implicated in various inflammatory and immunologic disorders, utilization of antioxidants and apoptosis inhibitors as potential therapeutic agents may be advantageous. © 2004 Wiley‐Liss, Inc.
Cell type‐specific regulation of the TGF‐β‐responsive α2(I) collagen gene by CpG methylation
Authors: Yamane Kenichi , Suzuki Hiroyuki , Ihn Hironobu , Kato Mitsuyasu , Yoshikawa Hirohide , Tamaki Kunihiko
Published: September 2004

The α2(I) collagen gene shows cell type‐specific expression, however, the mechanism behind this specificity remains to be determined. We demonstrate here that transforming growth factor‐beta (TGF‐β)‐mediated induction of α2(I) collagen gene is regulated by DNA methylation in a cell type‐specific manner. Human α2(I) collagen mRNA and type I collagen protein were expressed in normal human fibroblasts (NHF), and also strongly enhanced by TGF‐β; they were not detected in HaCaT, HeLa, or HepG2 cells (termed “collagen‐induction resistant (CIR) cells”) even following stimulation with TGF‐β. On the other hand, the transcriptional activity of exogenously transfected α2(I) collagen promoter was clearly up‐regulated by TGF‐β in the CIR cells as well as in NHF. In the CIR cells, CpG clusters around the transcription start site of the α2(I) collagen gene were heavily methylated, whereas no methylation was detected in NHF. Moreover, α2(I) collagen gene was reactivated in the CIR cells by 5‐Aza‐2‐deoxycytidine (5‐AdC) treatment to some extent. However, demethylation by 5‐AdC was limited and it was unable to recover the TGF‐β responsiveness. In NHF, the α2(I) collagen gene has a Smad3‐accessible chromatin structure and acetylated histones in the promoter regions. By contrast, in the CIR cells, Smad3 failed to bind to the chromatin and histones were not acetylated in this area. Furthermore, in vitro methylation of the reporter gene containing the α2(I) collagen promoter significantly reduced both basal and TGF‐β‐induced enhancement of the transcriptional activity in NHF. Thus, we propose that α2(I) collagen gene provides the first example of the TGF‐β responsive gene whose cell type‐specificity is regulated by CpG methylation. © 2004 Wiley‐Liss, Inc.
Endotoxin disrupts the leucine‐signaling pathway involving phosphorylation of mTOR, 4E‐BP1, and S6K1 in skeletal muscle
Authors: Lang Charles H. , Frost Robert A.
Published: September 2004

Endotoxin (i.e., lipopolysaccharide, LPS) impairs skeletal muscle protein synthesis. Although this impairment is not acutely associated with a decreased plasma concentration of total amino acids, LPS may blunt the anabolic response to amino acids. To examine this hypothesis, rats were injected intraperitoneally with LPS or saline (Sal) and 4 h thereafter were orally administered either leucine (Leu) or Sal. The gastrocnemius was removed 20 min later to assess signaling components important in the translational control of protein synthesis. In the Sal‐Leu group phosphorylation of 4E‐BP1 in muscle was markedly increased, compared to values from time‐matched saline‐treated control rats. This change was associated with a redistribution of eukaryotic initiation factor (eIF) 4E from the inactive eIF4E · 4E‐BP1 complex to the active eIF4E · eIF4G complex. In LPS‐treated rats, the Leu‐induced phosphorylation of 4E‐BP1 and changes in eIF4E distribution were partially or completely abrogated. LPS also antagonized the Leu‐induced increase in phosphorylation of S6K1, ribosomal protein S6 and mTOR. Neither LPS nor leu altered the total amount or phosphorylation of TSC2 in muscle. The ability of LPS to blunt the anabolic effects of Leu could not be attributed to differences in the plasma concentrations of insulin or Leu between groups. Furthermore, the replacement of plasma insulin‐like growth factor (IGF)‐I in LPS‐treated rats to basal levels also did not ameliorate the defect in leucine‐induced phosphorylation of S6K1 or S6, although it did reverse the LPS‐induced decrease in the constitutive phosphorylation of mTOR, S6 and 4E‐BP1. Pretreatment with the glucocorticoid receptor antagonist RU486 was unable to prevent the LPS‐induced leucine resistance. In contrast, to the abovementioned results with leucine, LPS did not prevent the ability of pharmacological levels of IGF‐I to phosphorylate 4E‐BP1, S6K1, mTOR or alter the availability of eIF4E. Hence, LPS working via a glucocorticoid‐independent mechanism produces a leucine resistance in skeletal muscle that might be expected to impair the ability of this amino acid to stimulate translation intiation and protein synthesis. © 2004 Wiley‐Liss, Inc.
Phospholipase A2 activating protein (PLAA) is required for 1α,25(OH)2D3 signaling in growth plate chondrocytes
Authors: Schwartz Z. , Graham E.J. , Wang L. , Lossdörfer S. , Gay I. , Johnson‐Pais T.L. , Carnes D.L. , Sylvia V.L. , Boyan B.D.
Published: September 2004

Phospholipase A2 (PLA2) is pivotal in the rapid membrane‐mediated actions of 1,25‐dihydroxyvitamin D3 [1α,25(OH)2D3]. Microarray analysis indicated that PLA2 activating protein (PLAA) mRNA is upregulated 6‐fold before rat growth plate cells exhibit 1α,25(OH)2D3‐dependent protein kinase C (PKC) increases, suggesting that it plays an important role in 1α,25(OH)2D3's mechanism of action. PLAA mRNA was confirmed in 1α,25(OH)2D3‐responsive growth zone (prehypertrophic and upper hypertrophic cell zones) chondrocytes by RT‐PCR and Northern blot in vitro and by in situ hybridization in vivo. PLAA protein was shown by Western blot and immunohistochemistry. PLAAs role in 1α,25(OH)2D3 signaling was evaluated in growth zone cell cultures using PLAA peptide. Arachidonic acid release was increased as was PLA2‐specific activity in plasma membranes and matrix vesicles. PKCα, but not PKCβ, PKCε, or PKCζ, was increased. PLAAs effect was comparable to that of 1α,25(OH)2D3 and was additive with 1α,25(OH)2D3. PLA2 inhibitors quinacrine and AACOCF3, and cyclooxygenase inhibitor indomethacin blocked the effect of PLAA peptide on PKC, indicating arachidonic acid and its metabolites were involved. This was confirmed using exogenous arachidonic acid. Prostaglandin acted via EP1 based on inhibition by SC19220 and not via EP2 since AH6809 had no effect. Like 1α,25(OH)2D3, PLAA peptide also increased activity of phospholipase C‐specific activity via beta‐1 and beta‐3 isoforms, but not delta‐1 or gamma‐1; the effect of PLAA was via lysophospholipid but not via arachidonic acid. PLAA peptide decreased [3H]‐thymidine incorporation to 50% of the decrease caused by 1α,25(OH)2D3. In contrast, PLAA peptide increased alkaline phosphatase‐specific activity and proteoglycan production in a manner similar to 1α,25(OH)2D3. This indicates that PLAA is a specific activator of PLA2 in growth plate chondrocytes, and suggests that it mediates the membrane effect of 1α,25(OH)2D3, thereby modulating physiological response. © 2004 Wiley‐Liss, Inc.
Expression of PDGF and their receptors in human retinal pigment epithelial cells and fibroblasts: Regulation by TGF‐β
Authors: Nagineni Chandrasekharam N. , Kutty Veena , Detrick Barbara , Hooks John J.
Published: September 2004

Platelet derived growth factors (PDGF) are known to be associated with vitreoretinal disorders such as proliferative vitreoretinopathy (PVR). We have studied the expression of PDGF and their receptors in human retinal pigment epithelial cells (HRPE) and choroid fibroblasts (HCHF), and the regulation of PDGF and its receptors by various cytokines and growth factors. RT‐PCR analyses showed enhanced expression of PDGF‐A and PDGF‐B mRNA in HRPE treated with TGF‐β, but not with other cytokines. A minimal increase was observed in PDGF‐A mRNA in TGF‐β treated HCHF cells. PDGF‐Rα mRNA, which was expressed prominently in HCHF and at very low levels in HRPE, was not affected by any of the agents. PDGF‐Rβ was not detectable in either HRPE or HCHF. HRPE secreted PDGF‐AA and AB constitutively, and this secretion was significantly enhanced by TGF‐β. In contrast, HCHF cultures did not secrete detectable levels of any of the three isoforms of PDGF (AA, AB, BB). All three human recombinant PDGF isoforms enhanced HCHF cell proliferation significantly, while only a minimal increase was observed in HRPE. PDGF isoforms also induced HCHF cell elongation and promoted migration of HCHF in an in vitro wound assay. The results presented in this study demonstrate that TGF‐β activated RPE cells produce PDGF that may act on fibroblasts and other mesenchyme derived cells which express PDGF receptors. These studies indicate that the promotion of the proliferation and migration of mesenchymal cells by RPE cell derived PDGF may facilitate the formation of fibrovascular tissues associated with PVR. © 2004 Wiley‐Liss, Inc.
A thermal study on the use of immobilized penicillin G acylase in the formation of 7‐amino‐3‐deacetoxy cephalosporanic acid from cephalosporin G
Authors: Pan Jian‐Liang , Syu Mei‐Jywan
Published: September 2004

Penicillin G acylase (PGA) is an important enzyme for the industrial production of 7‐amino‐3‐deacetoxy cephalosporanic acid (7‐ADCA) from cephalosporin G (Ceph‐G), and 6‐aminopenicillanic acid (6‐APA) from penicillin G (Pen‐G). These products are used for the manufacture of semi‐synthetic cephalosporins and penicillins. In this study, immobilized PGA was utilized to catalyze the conversion of Ceph‐G to 7‐ADCA. The optimal conditions were found to be an operating temperature of 45 °C, 0.2 M phosphate buffer, a substrate concentration of 30 mg cm−3 and a catalyst particle concentration of 0.01 g cm−3 (specific activity of 623.2 U g−1). Up to 45 °C the reaction was characterized by an activation energy of 38.66 kJ mol−1. Beyond 57.5 °C there was a sharp decline of activity, characterized by a deactivation energy of 235.88 kJ mol−1. Copyright © 2004 Society of Chemical Industry
Kinetics of esterification of palmitic acid with isopropanol using p‐toluene sulfonic acid and zinc ethanoate supported over silica gel as catalysts
Authors: Aafaqi Roomana , Mohamed Abdul Rahman , Bhatia Subhash
Published: September 2004

Kinetic data on the esterification of palmitic acid with isopropanol were obtained using homogeneous (para‐toluene sulfonic acid, p‐TSA) and heterogeneous (zinc ethanoate coated on silica gel, ZnA/SG) catalysts in a batch reactor. The ZnA/SG catalyst was prepared using a sol–gel technique. The esterification reaction was studied at different reaction temperatures (373–443 K), initial reactants molar ratio (1–5), catalyst loading (1–5 gcat dm−3) and water concentration in feed (0–15 vol%). A power law rate equation was used for homogeneous kinetics analysis. The Langmuir Hinshelwood Hougen Watson (LHHW) model was used for heterogeneous kinetics. The kinetic parameters of both models were obtained using Polymath software. The reaction parameters were used to obtain simulated values of conversion for both catalytic systems. The simulated values were compared with the experimental values and were in good agreement. Copyright © 2004 Society of Chemical Industry
The effect of raw glycerol concentration on the production of 1,3‐propanediol by Clostridium butyricum
Authors: Papanikolaou Seraphim , Fick Michel , Aggelis George
Published: September 2004

Raw glycerol, the main by‐product of the bio‐diesel production process, was converted to 1,3‐propanediol by Clostridium butyricum F2b. In batch cultures, 47.1 g dm−3 of 1,3‐propanediol were produced. Continuous cultures were conducted at a constant dilution rate (= 0.04 h−1) and various inlet glycerol concentrations with 1,3‐propanediol produced at levels up to 44.0 g dm−3. At increasing glycerol concentrations in the inlet medium, biomass yield decreased. This decrease was attributed to the microbial metabolism being directed towards the biosynthesis of organic acids (and hence carbon losses as CO2) instead of biochemical anabolic reactions. An autonomous analytical model was developed, and quantified the effect of inlet glycerol concentration on the production of biomass and metabolites. Indeed, high inlet substrate concentrations positively affected the biosynthesis, principally of butyric acid and to a lesser extent that of acetic acid. In contrast, at increased glycerol concentrations, the relative increase of 1,3‐propanediol production per unit of substrate consumed was lower as compared with that of acetic and, mainly, butyric acid. This could be explained by the fact that the butyric acid pathway represents an alternative and competitive one to that of 1,3‐propanediol for re‐generation of NADH2 equivalents in the microbial cell. Copyright © 2004 Society of Chemical Industry
Treatment of textile dye wastewater by using an electrochemical bipolar disc stack reactor
Authors: Muthukumar Karuppan , Sundaram P Shunmuga , Anantharaman N , Basha C Ahmed
Published: September 2004

Textile dye house wastewater from a reactive dye processing unit was treated by using an electrochemical oxidation technique. The experiments were carried out in an electrochemical bipolar disc reactor using RuO2 coated on titanium as anode and titanium as cathode. The sodium chloride present in the effluent was used as supporting electrolyte. Operating parameters such as current density, reservoir hold‐up and electrolysis time were studied for maximum Chemical Oxygen Demand (COD) reduction and other relevant parameters such as current efficiency and power consumption per kg of COD removal were calculated. The higher flow rate and lower reservoir hold‐up resulted in improved COD removal. The applied current density was also found to significantly influence the reduction of COD. A suitable mathematical model is also proposed to illustrate the relationship between the basic parameters. Pseudo mass transfer coefficients were also evaluated for different experimental conditions. Copyright © 2004 Society of Chemical Industry
Monitoring of cell growth using the focused beam reflectance method
Authors: Pearson Alan P , Glennon Brian , Kieran Patricia M
Published: September 2004

In this paper the use of a focused beam reflectance measurement (FBRM) particle characterisation probe was investigated as a tool for monitoring the growth of the filamentous bacteria Streptomyces natalensis. The optimum operating parameters of the probe were identified, and it was found that the sample agitation rate had the largest effect on the mean value of a number of statistics of the chord length distribution (CLD) measured by the FBRM probe. A series of fractions of the particle size distribution was generated by sieving. It was found that the mean chord length measured by the probe responded to changes in the size distribution examined, increasing from 57.2 µm to 69.9 µm with an increase in the upper particle size from 180 µm to 300 µm. It was also found that the average total counts measured by the probe also increased with increasing sample concentration. This relationship was further investigated and it was found that in the normal range of biomass levels experienced in a fermentation (up to 4.0 g dm−3) there was an apparently linear relationship between counts and concentration. However, as concentration was increased further the relationship became increasingly non‐linear. Copyright © 2004 Society of Chemical Industry
Efficient purification and morphology characterization of paclitaxel from cell cultures of Taxus chinensis
Authors: Pyo Sang‐Hyun , Kim Moon‐Suk , Cho Jin‐Suk , Song Bong‐Kyu , Han Byung‐Hee , Choi Ho‐Joon
Published: September 2004

Paclitaxel was purified from cell cultures of Taxus chinensis by a combination of extraction, low‐pressure chromatography, precipitation and HPLC. A crude extract (purity 6.9%) was obtained by methanol extraction of plant cell cultures, followed by liquid–liquid extraction using dichloromethane. The extract was purified to greater than 32% with a 97% step yield by low‐pressure chromatography. After acetone/pentane precipitation, the resulting purity and step yield were 75.8% and 97.4%, respectively. High performance liquid chromatography steps, which were composed of an HPLC step with column‐packed ODS and an HPLC step with column‐packed silica, were applied to give over 99.5% purity with high yield. Amorphous paclitaxel with a fine particle size, which has a solubility advantage compared with the stable crystalline form, was obtained by dissolving in dichloromethane, followed by spray‐drying. Copyright © 2004 Society of Chemical Industry
Investigating the use of cooling surfaces in solid‐state fermentation tray bioreactors: modelling and experimentation
Authors: Khanahmadi Morteza , Roostaazad Reza , Safekordi Aliakbar , Bozorgmehri Ramin , Mitchell David A
Published: September 2004

The effect of wall cooling in tray‐type solid‐state fermenters was investigated by cultivation of Aspergillus niger ATCC 10 864 on wheat bran. Temperature, moisture, pH and glucoamylase activity in the bed were monitored. Application of the heat exchanger plate reduced the overall water loss but increased the heterogeneity of moisture distribution in the bed. Moisture content increased markedly close to the heat transfer plate while the upper regions of the bed dried out. The thermal conductivity of the bed was measured to be 0.19 W m−1 K−1. At these conditions and depending on the air flow rate, 58–82% of the metabolic heat was removed via conduction towards the plate. A mathematical model was developed to describe the behaviour of the system. Model predictions were in good agreement with the experimental results. Diffusion coefficients of water vapour and oxygen in the bed were estimated to be around 1.3 × 10−5 m2 s−1 and 1 × 10−5 m2 s−1 respectively. Based on these values the mathematical model describes the way oxygen and water vapour diffusion influences biomass growth and moisture distribution in the bed. Copyright © 2004 Society of Chemical Industry
An anion exchange resin from soybean hulls
Authors: Marshall Wayne E , Wartelle Lynda H
Published: September 2004

Agricultural by‐products are generally poor adsorbents of anions in solution. Therefore, modification of the by‐product could enhance its anion exchange capabilities. The objective of this study was to increase the anion exchange properties of the agricultural by‐product, soybean hulls, by chemical modification. Soybean hulls were quaternized with the quaternizing agent, N‐(3‐chloro‐2‐hydroxypropyl) trimethylammonium chloride, in the presence of a strongly alkaline environment. This modification increased the amount of positive charge on the hulls as evidenced by increased nitrogen content and increased uptake of anions compared with the unmodified hulls. A method to optimize the anion exchange properties of the hulls was developed. Ion exchange properties of the hulls toward anions of environmental significance, namely arsenate (As), chromate (Cr), dichromate (Cr2), phosphate (P) and selenate (Se) were determined. The modified hulls were also compared with commercial cellulose‐based and synthetic anion exchange resins in their ability to remove these anions from solution. The experimental and commercial resins were also compared for their ability to remove a mixture of arsenate, chromate, dichromate and selenate from laboratory prepared solutions to levels below the maximum contaminant levels for these anions in drinking water as specified by the US Environmental Protection Agency (US EPA). Our results demonstrate that the soy hull resin is more efficient in anion removal than the commercial cellulose‐based resin but not as effective as the commercial synthetic resin. Published in 2003 for SCI by John Wiley & Sons, Ltd.
Characteristics of photocatalytic oxidation of gaseous 2‐propanol using thin‐film TiO2 photocatalyst
Authors: Chang Chiu‐Ping , Chen Jong‐Nan , Lu Ming‐Chun
Published: September 2004

This work presents a photocatalysis‐based method to treat and purify air because of its broad applicability to common, oxidizable, air contaminants. The effect of oxygen content, temperature, water vapor, and 2‐propanol concentration on the TiO2 surface was investigated. The rate of 2‐propanol decomposition increased with increasing the oxygen content, but was reduced at temperatures higher than 100°C. When water vapor concentration was in the range of 10–355 mmol m−3, the rate of 2‐propanol decomposition was proportional to the water content. However, an opposite result was observed at a higher concentration of water vapor. 2‐Propanol was photooxidized to acetone, and eventually to carbon dioxide and water. The kinetic model of 2‐propanol photooxidation was successfully developed by the competitive Langmuir–Hinshelwood rate form, incorporating the inhibition effect coming from the formation of acetone. Copyright © 2004 Society of Chemical Industry
Solvent extraction of zirconium(IV) from acidic chloride solutions using the thiosubstituted organophosphorus acids Cyanex 301 and 302
Authors: Ramachandra Reddy B , Rajesh Kumar J , Varada Reddy A
Published: September 2004

Solvent extraction of zirconium(IV) from acidic chloride solutions has been carried out with the thiosubstituted organophosphorus acids Cyanex 301 and Cyanex 302. The extraction follows an ion exchange mechanism: MO2+(aq) + 2 HA(org) ↔ MOA2(org) + 2 H+(aq), where, M = Zr(IV); HA = Cyanex 301 or Cyanex 302. The plots of log D (distribution ratio) vs log [HA], are linear with slopes of 2, indicating the association of two moles of extractant with the extracted metal species. The plots of log D vs log [H+] gave straight lines with a negative slope of 1.7 for Cyanex 301 and 1.8 for Cyanex 302, indicating the exchange of two moles of hydrogen ions for every mole of Zr(IV). Addition of sodium salts enhanced the extraction of metal. The stripping behavior of metal from the loaded organic (LO) with HCl and H2SO4 was studied. Increase of temperature during the extraction and the stripping stage increases the metal transfer, showing the process is exothermic. Mixed extractants, the extraction behavior of associated elements such as Hf(IV), Ti(IV), Al(III), Fe(III) and the IR spectra of the metal complexes were studied. Copyright © 2004 Society of Chemical Industry
Use of keratin fiber for separation of heavy metals from water
Authors: Kar P , Misra M
Published: September 2004

Nano‐porous keratin fiber is effective in removing heavy metals from solutions. The biosorption of heavy metals from solutions is dependent upon the solution pH, the contact time, surface area and temperature. The intrinsic properties of the keratin fiber, ie stability over a wide range of pH, structural toughness and high surface area, are the positive factors. Alkaline ultrasonic treatment of the keratin fiber resulted in a multi‐fold increase in metal uptake. Adsorption of heavy metals using both batch and column operations was conducted. Multiple elution and adsorption tests indicated that it is possible to reuse keratin fiber as a biosorbent for a number of cycles. Copyright © 2004 Society of Chemical Industry
Determination of the efficiency and removal mechanism of cobalt by crab shell particles
Authors: Lee Moo‐Yeal , Hong Kyung‐Jin , Kajiuchi Toshio , Yang Ji‐Won
Published: September 2004

The effects of contact time, solution pH and ionic strength on interactions between cobalt (59Co) ions in synthetic liquid waste and particles of raw crab shell, Portunus trituberculatus, in batch reactions were studied. Approximately 19.5 mg dm−3 Co was removed within 6 h after contact with 1.0 g dm−3 crab shell at an initial concentration of 20 mg dm−3 Co. Due to the dissolution of calcium carbonate in the crab shell, the solution pH changed spontaneously to 10, leading to precipitation of cobalt ions. The efficiency of cobalt removal depended on solution pH, but was less pH sensitive than for controls without crab shell. The maximum uptake of Co at an initial pH value of 5.0 was 510 mg g−1 crab shell. The removal efficiency was affected slightly by ionic strength up to 2.0 mol dm−3 of NaCl. Scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS) indicated that the removal mechanism of Co by crab shell resulted primarily from the dissolution of calcium carbonate followed by precipitation of cobalt on the surface of the shell. Compared with commonly used ion‐exchange resins such as natural zeolite, Durasil 70, and Durasil 230, the efficiency of Co removal by a column of mixture of crab shell and activated carbon was at least three‐fold greater, indicating that crab shell is a suitable biosorbent for the removal of cobalt from liquid waste. Copyright © 2004 Society of Chemical Industry
Titration methodologies for monitoring of anaerobic digestion in developing countries—a review
Authors: Lahav O , Morgan BE
Published: September 2004

An increase in volatile fatty acids (VFA) concentration (or the proportional decrease in carbonate alkalinity concentration) is the first practical measurable indication that an anaerobic treatment system is in a state of stress. If the system is not rectified at this early stage, failure is likely. Current methods for VFA measurement include distillation, colorimetry, gas chromatography and various titration techniques. In terms of simplicity, speed and cost‐effectiveness it is generally accepted that titration methods are superior for the purpose of on‐site routine monitoring and control, particularly in developing countries. This paper reviews the methods published in the last four decades concerning on‐site titration measurement of VFA and carbonate alkalinity concentrations. The review encompasses the following: aquatic chemistry related to the theory on which most of the methods are based, and a detailed description of each of the principal methods published followed by critical and comparative evaluation. Copyright © 2004 Society of Chemical Industry
Twin reversed arterial perfusion: Report of four cases
Authors: Malhotra Neena , Sinha Alka , Deka Deepika , Roy Kallol K.
Published: September 2004

Twin reversed arterial perfusion (TRAP sequence), or acardiaus, is a rare and serious complication of monozygotic multiple gestation. The acardiac fetus suffers from lethal anomalies. The normal co‐twin also runs a high risk of perinatal morbidity and mortality due to heart failure and prematurity. Four cases of acardius are presented. The role of sonography in the condition's diagnosis and management is discussed. © 2004 Wiley Periodicals, Inc. J Clin Ultrasound 32:411–414, 2004
Multiseptate gallbladder with acute acalculous cholecystitis
Authors: Erdogmus Besir , Yazici Burhan , Safak Alp Alper , Ozdere Betul Ayca
Published: September 2004

Multiseptate gallbladder is a rare congenital malformation of the gallbladder. In some cases, right upper quadrant pain, recurrent abdominal pain, and gallstones were present. We present the sonographic findings in a case of multiseptate gallbladder with acute cholecystitis, which (to our knowledge) has not been reported before. We hypothesize that bile sludge accumulated and subsequent cholecystitis developed as a result of bile stasis in our case because the classic predisposing factors that have been described were absent. © 2004 Wiley Periodicals, Inc. J Clin Ultrasound 32:423–424, 2004
Expression of VEGFR‐3 and 5′‐Nase in regenerating lymphatic vessels of the cutaneous wound healing
Authors: Ji Rui‐Cheng , Miura Masahiro , Qu Peng , Kato Seiji
Published: September 2004

The vascular endothelial growth factor‐C (VEGF‐C), a specific lymphangiogenic growth factor, raises new questions and perspectives in studying lymphatic development and regeneration. Wound healing skins in mice were processed for 5′‐nucleotidase (5′‐Nase) and VEGFR‐3 (the receptor of VEGF‐C) histochemical staining to distinguish lymphatics from blood capillaries and to analyze lymphangiogenesis. In the wounds of 3–5 days after injury, anti‐VEGFR‐3 immunopositive signals unevenly appeared in 5′‐Nase‐positive lymphatic vessels in the subcutaneous tissue. A few small circular and irregular lymphatic‐like structures with VEGFR‐3 expression scattered in the dermal and subcutaneous tissues. Between days 7 and 15 of the wounds, numerous accumulated vasculatures were stained for 5′‐Nase and PECAM‐1, extending irregularly along the wound edge. Von Willebrand factor was expressed in the endothelial cells of blood vessels and lymphatics in the subcutaneous tissue. Ultrastructural changes of lymphatic vessels developed at different stages, from lymphatic‐like structures to newly formed lymphatic vessels with an extremely thin and indented wall. Endothelial cells of the lymphatic vessel were eventually featured by typical intercellular junctions, which deposited with reaction products of VEGFR‐3 and 5′‐Nase‐cerium but lacked VEGF‐C expression. The present findings indicate that VEGF‐C‐induced lymphangiogenesis occurs from the subcutaneous to the dermis along the wound healing edge, especially in the dermal‐subcutaneous transitional area, favorable to growth of regenerating lymphatic vessels. Microsc. Res. Tech. 64:279–286, 2004. © 2004 Wiley‐Liss, Inc.
The switch mechanism of the cell death mode from apoptosis to necrosis in menadione‐treated human osteosarcoma cell line 143B cells
Authors: Kamiński Marcin , Niemczyk Edyta , Masaoka Makoto , Karbowski Mariusz , Hallmann Anna , Kędzior Jakub , Majczak Anna , Knap Dorota , Nishizawa Yuji , Usukura Jiro , Woźniak Michał , Klimek Jerzy , Wakabayashi Takashi
Published: September 2004

Time‐dependent changes in the cell death mode from apoptosis to necrosis were studied in cultured 143B cells treated with menadione, an anti‐cancerous drug, excluding a possible involvement of “secondary necrosis.” The population of apoptotic cells judged by FITC‐Annexin V and propidium iodide (PI) double staining reached its maximum at 6 hours after 100 μM menadione treatment followed by an abrupt decrease thereafter, while that of necrotic cells continuously increased reaching 90% at 24 hours. Electron microscopically, cells attached to the culture dish at 6 hours after the treatment consisted of two different types of cells: cells with typical apoptotic features occupying the major population and those with condensed nuclei and swollen cytoplasm. Cells attached to the culture dish at 8 hours after the treatment consisted exclusively of those with condensed nuclei and swollen cytoplasm. Mitochondria in these cells showed various structural changes: those swollen to various degrees with deposition of flocculent densities, or those with highly condensed matrix. Distinct decreases both in intracellular levels of ATP and caspase‐3‐like activities and remarkable elevations of intracellular levels of superoxide, which were partly suppressed by NAD(P)H oxidase inhibitors, occurred at 6 hours after the treatment. These results may suggest that distinct increases of the intracellular level of superoxide derived from plasma membrane NAD(P)H oxidase besides that from mitochondria have triggered the transition of cell death mode from apoptosis to necrosis. Transition of highly condensed mitochondria to extremely swollen ones may reflect necrotic processes in menadione‐treated cells. The present study strongly suggests that time‐dependent study is essential using the electron microscopic technique to analyze detailed processes in the changes of the cell death mode. Microsc. Res. Tech. 64:255–268, 2004. © 2004 Wiley‐Liss, Inc.
New satellite DNA in Lacerta s. str. lizards (Sauria: Lacertidae): Evolutionary pathways and phylogenetic impact
Authors: Ciobanu Doina , Grechko Vernata V. , Darevsky Ilya S. , Kramerov Dmitri A.
Published: September 2004

A new tandemly repeated (satellite) DNA family namely Agi160, from Lacerta agilis and Lacerta strigata (Lacerta sensu stricto (s. str.), Linnaeus 1758) have been cloned and sequenced. Agi160 is found in the above two species, as well as two other representatives of the same genus, L. viridis and L. media. DNA hybridization did not reveal it in Darevskia, Podarcis, Zootoca, Eremias, Ophisops, and Gallotia – the other genera of the family Lacertidae. The results suggest that Agi160 is a Lacerta s. str. specific family of tandem DNA repeats. However, a comparison between sequences of Agi160 and CLsat repeat units revealed 60 bp regions 62–74% identical. The latter is a satellite DNA family typical for Darevskia (syn. “L. saxicola complex”) (Grechko et al., Molecular‐genetic classification and phylogenetic relatedness of some species of Lacertidae lizards by taxonoprint data. Mol Biol 32:172–183, 1988.). Both Agi160 and CLsat tandem repeats share several common features (e.g., the same AT content and distribution of multiple short A‐T runs, internal structure of repeated units, the presence of conservative regions). These data are indicative of their common origin and a possibly strong selective pressure upon conserving both satellites. A comparative analysis of structure, organization, and abundance of these two families of satDNA reveals evolutionary pathways that led to their formation and divergence. The data are consistent with the hypotheses of the concerted evolution of satellite DNA families. The possibility of use of Agi160 as a phylogenetic tool, defining relationships within Lacerta s. str., as well as within the whole family of Lacertidae is discussed. J. Exp. Zool. (Mol. Dev. Evol.) 000:1–12, 2004. © 2004 Wiley‐Liss, Inc.
Evaluation of tissue‐specific promoters in carcinomas of the cervix uteri
Authors: Rein Daniel T. , Breidenbach Martina , Nettelbeck Dirk M. , Kawakami Yosuke , Siegal Gene P. , Huh Warner K. , Wang Minghui , Hemminki Akseli , Bauerschmitz Gerd J. , Yamamoto Masato , Adachi Yasuo , Takayama Koichi , Dall Peter , Curiel David T.
Published: September 2004

Background

Gene therapy is a novel approach for treatment of patients with advanced, recurrent, or metastatic cervical cancer. One effective way to direct transgene expression to specific tissues or tumors is the use of tissue‐specific‐promoters (TSPs). In the context of adenovirus (Ad)‐mediated cancer gene therapy it is rational to choose a TSP which is highly expressed in the tumor but has potentially low activity in non‐tumor cells, especially the liver. In this study, we have investigated several promoters which fulfill these criteria. Candidate cervical cancer specific TSPs include promoters of the genes for secretory leukoprotease inhibitor (SLPI), cyclooxygenase‐2 (COX‐2), Midkine (MK), vascular endothelial growth factor receptor type 1 (flt‐1), vascular endothelial growth factor (VEGF), Survivin and the receptor for chemokine SDS‐1 (CXCR4).

Methods

To evaluate the specific gene expression of the different promoters in the context of cervical cancer, we constructed a panel of E1‐deleted Ads that express luciferase under the control of the promoters of interest. We investigated various established cervical cancer cell lines, as well as purified primary cancer cells and normal control cells from the cervix uteri.

Results

In all cell lines tested, promoters for MK, VEGF and CXCR4 showed the highest activity. Both MK and VEGF promoters also resulted in a high activity in primary cervical cancer cells. Interestingly, gene expression profiles correlate with luciferase activity in both cell lines and primary cancer samples.

Conclusions

Our study demonstrates that the promoters for MK and VEGF are active in cervical cancer. We believe that both promoters can be successfully employed as TSPs for gene therapy targeted to cervical cancer. Copyright © 2004 John Wiley & Sons, Ltd.
Synthesis of carbon‐14 labelled gemifloxacin
Authors: Shin Hyun Il , Rim Jong Gill , Lee Ki Seung , Kim Young Seok , Nam Do Hyun , Shin Hyun Ik , Chang Jay Hyok , Oh Chang Young , Ham Won Hun
Published: September 2004

A new antibacterial agent gemifloxacin was labelled with carbon‐14 for studies of pharmacokinetics and metabolism, the label was located in position 3 of the quinolone ring system. The overall radiochemical yield of the 14‐step synthesis, starting from [2‐14C]sodium acetate was 16.6%, and the radiochemical purity 97.5%. Copyright © 2004 John Wiley & Sons, Ltd.
Modeling of the gas‐phase ion chemistry of protonated arginine
Authors: Csonka István Pál , Paizs Béla , Suhai Sándor
Published: September 2004

Arginine is often involved at the C‐terminus of peptides obtained from tryptic digests of proteins. The very basic guanidine group of the side‐chain of arginine has a large effect on the backbone fragmentation of protonated peptides. Furthermore, arginine exhibits specific fragmentation reactions involving its side‐chain. Various tautomerization states, conformers and side‐chain dissociation channels of protonated arginine were studied using theoretical methods. The guanidine loss of protonated arginine is proved to be an SN2 substitution on the δ‐carbon of the side‐chain, starting from species containing the NεH—C+(NηH2)(Nη′H2) or —Nε+H2—C(NηH)(Nη′H2) moieties and leads to formation to either protonated guanidine or protonated proline. In the corresponding transition structures the proline moiety is protonated. Under low‐energy collision conditions the extra proton transfers to the guanidine moiety, leading to the formation of C+(NH2)3. On the other hand, the lifetime of the fragmenting species under high‐energy collision conditions is shorter, resulting in enhanced formation of protonated proline and its dissociation products. The first step of ammonia loss is the leaving of a preformed NH3 from tautomers containing the —NεH—C(NηH3+)(Nη′H) or —Nε—C(NηH3+)(Nη′H2) moieties. The resulting protonated carbodiimide group can be stabilized by intramolecular nucleophilic attack, leading to ring formation. Overall, reactions involved in the ammonia loss from protonated arginine can be considered as an SN1 substitution on the central ζ‐carbon of the guanidine group. Copyright © 2004 John Wiley & Sons, Ltd.
Entropy considerations in kinetic method experiments
Authors: Wesdemiotis Chrys
Published: September 2004

In extended kinetic method experiments, relative binding enthalpies (‘affinities’) and relative entropies are obtained based on unimolecular dissociation kinetics. A series of ion‐bound dimers AXBi is formed, in which the sample (A) and structurally similar reference molecules (Bi) are bridged by a central cation or anion (X). The branching ratios of the AXBi set to AX and BiX are determined at different internal energies, usually by subjecting AXBi to collisionally activated dissociation at various collision energies. The dependence of the natural logarithm of the branching ratios on the corresponding BiX bond enthalpies (X affinities of Bi) is evaluated as a function of internal energy to thereby deduce the AX bond enthalpy (X affinity of A) as well as an apparent relative entropy of the competitive dissociation channels, Δ(ΔSapp). Experiments with proton‐ and Na+‐bound dimers show that this approach can yield accurate binding enthalpies. In contrast, the derived Δ(ΔSapp) values do not correlate with the corresponding thermodynamic entropy differences between the channels leading to AX and BiX, even after scaling. The observed trends are reconciled by the transition state switching model. According to this model, the kinetics of barrierless dissociations, such as those encountered in kinetic method studies, are dominated by a family of tight transition states (‘entropy bottlenecks’) lying lower in energy than the corresponding dissociation thresholds. In general, the relative energies of these tight transition states approximately match those of the dissociation products, but their relative entropies tend to be much smaller, as observed experimentally. Copyright © 2004 John Wiley & Sons, Ltd.
Systematic and random errors in ion affinities and activation entropies from the extended kinetic method
Authors: Ervin Kent M. , Armentrout P. B.
Published: September 2004

An evaluation of the extended kinetic method with full entropy analysis was conducted using RRKM theory to simulate data for collision‐induced dissociation under single‐collision conditions. A rigorous method for analyzing kinetic method data, orthogonal distance regression, is introduced and compared with previous methods in the literature. The results demonstrate that the use of the extended kinetic method is definitely superior to the standard kinetic method, but final ion affinities and activation entropies differ intrinsically from the correct values. Considering the effects of both systematic and random error in Monte Carlo simulations of the full entropy analysis, error distributions of ±4 to ±12 kJ mol−1 for ion affinities and of ±9 to ±30 J mol−1 K−1 for activation entropy differences are found (±2 standard deviations of the sample populations). The systematic errors in ion affinities are larger for systems with large activation entropy differences. These uncertainties do not include any error in the absolute calibration of the reference ion affinity scale. We argue that application of an empirical correction factor is inadvisable. Copyright © 2004 John Wiley & Sons, Ltd.
Phylogenetic analysis of the full‐length SARS‐CoV sequences: Evidence for phylogenetic discordance in three genomic regions
Authors: Magiorkinis G. , Magiorkinis E. , Paraskevis D. , Vandamme A.M. , Van Ranst M. , Moulton V. , Hatzakis A.
Published: September 2004

The origin of the severe acute respiratory syndrome‐coronavirus (SARS‐CoV) remains unclear. Evidence based on Bayesian scanning plots and phylogenetic analysis using maximum likelihood (ML) and Bayesian methods indicates that SARS‐CoV, for the largest part of the genome (∼80%), is more closely related to Group II coronaviruses sequences, whereas in three regions in the ORF1ab gene it shows no apparent similarity to any of the previously characterized groups of coronaviruses. There is discordant phylogenetic clustering of SARS‐CoV and coronaviruses sequences, throughout the genome, compatible with either ancient recombination events or altered evolutionary rates in different lineages, or a combination of both. J. Med. Virol. 74:369–372, 2004. © 2004 Wiley‐Liss, Inc.