bluuebunny/crossref_metadata_2025 huggingface dataset:
In vitro exposure to quercetin and genistein alters lipid peroxides and prevents the loss of glutathione in human progenitor mononuclear (U937) cells
Authors: Boadi William Y. , Iyere Peter A. , Adunyah Samuel E.
Published: January 2005

The effects of ßavonoids quercetin and genistein were investigated according to their potency to inhibit the oxidation of U937 cells via Fenton's pathway through the analysis of lipid peroxides and glutathione (GSH) levels. Human leukemia (U937) cells from the American Type Culture Collection were maintained at 37 °C for 24 h under 5% CO2 tension in RPMI‐1640 medium containing 10% fetal bovine serum and 50 units ml−1 each of penicillin and streptomycin. Cells were oxidized with iron 50 µM) or copper (50 µM) in H2O2 (0.01 mM) without or with a ßavonoid sample (10 or 20 µM) for the lipid peroxidation studies. The GSH levels were measured (GSH Kit) before and after oxidation as above with different concentrations of ßavonoids (0–40 µM). Lipid peroxide was measured by the thiobarbituric acid assay. Both quercetin and genistein at either the 10 or 20 µM level decreased lipid peroxidation signicantly compared with their respective controls (P < 0.01). Lipid peroxides by Fe compared to the Cu‐treated samples did not differ signicantly from each other. However, the combination of ßavonoids at the doses tested signicantly (P < 0.001) decreased lipid peroxides, the effect being the same for both metal ions. The GSH levels increased signicantly before exposure to the metal ions (for the different doses for the differences between the ßavonoid samples and their respective untreated levels). For quercetin and genistein the increases in GSH above their untreated levels were 4.5, 8.3, 11.7 and 15 and 3.8, 7.9, 12.5 and 14.6 nmol 10−6 cells, respectively, for the 5–40 µM levels tested for each ßavonoid. Following the exposure to the metal ions, GSH levels remained almost the same for the different concentrations for each of the ßavonoids tested but signicantly above all of the controls and same for those of the untreated samples. The results indicate that both ßavonoids inhibited lipid peroxides and the inhibition may be attributed to the prevention of loss of intracellular GSH levels in U937 cells. Copyright © 2005 John Wiley & Sons, Ltd.
Radioprotective and locomotor responses of mice treated with nimodipine alone and in combination with WR‐151327
Authors: Landauer M. R. , Castro C. A. , Benson K. A. , Hogan J. B. , Weiss J. F.
Published: January 2005

The effect of combining a radiation‐protective phosphorothioate with another agent was investigated in an attempt to increase radioprotection and reduce toxicity. The calcium channel blocker nimodipine (NIMO) was administered alone (1 or 10 mg kg−1) or in combination with 200 mg kg−1 of the phosphorothioate radioprotector WR‐151327 (WR) (S‐3‐(3‐methylaminopropylamino)propylphosphorothioic acid). Radioprotection as measured (30‐day survival) of mice treated i.p. 30 min before 60Co irradiation at a dose rate of 1 Gy min−1) was evaluated in CD2F1 male mice. The effects of nimodipine and WR‐151327 on locomotor activity were investigated also in a separate group of non‐irradiated mice. The LD50/30 for the Emulphor vehicle control group was 8.56. For nimodipine alone (1 or 10 mg kg−1) the LD50/30was 8.39 and 10.21 Gy, respectively, yielding dose modification factors (DMFs) of 0.98 and 1.19, respectively. When WR‐151327 was given alone, the <LD50/30 was 12.48 Gy (DMF = 1.46; P < 0.05 from vehicle). WR‐151327 combined with 1 or 10 mg kg−1 nimodipine resulted in an LD50/30 of 12.73 Gy (DMF 1.49, P < 0.05 from vehicle), and when WR‐151327 was combined with 10 mg kg−1 nimodipine the LD50/30 was 14.29 Gy (DMF = 1.67, P < 0.001 from WR‐151327). For either dose of nimodipine, locomotor activity did not differ from vehicle. WR‐151327 and WR‐151327 + 1 mg kg−1 nimodipine resulted in locomotor decrements for up to 4 h post‐administration (P < 0.05 from vehicle), and WR‐151327 + 10 mg kg−1 nimodipine for up to 6 h (P < 0.05 from WR‐151327). Therefore, although there was an additive radioprotective effect when the higher dose of nimodipine was combined with WR‐151327, the locomotor decrement was also enhanced. These results demonstrate that a combination of nimodipine and a phosphorothioate such as WR‐151327 may be useful as a clinical setting where behavioral and physiological side‐effects can be monitored. Published in 2001 by John Wiley & Sons, Ltd.
Uncoupling effect of mercuric chloride on mitochondria isolated from an hepatic cell line
Authors: Königsberg Mina , López‐Díazguerrero Norma Edith , Bucio Leticia , Gutiérrez‐Ruiz María Concepción
Published: January 2005

A human fetal hepatic cell line (WRL‐68) was used as a model to study the damage produced by mercury. The Hg(II) uptake by WRL‐68 cells was found to be in a biphasic manner with a rapid initial uptake phase lasting about 5 min, followed by a sustained phase of slower accumulation. Distribution of mercury was studied and mitochondria were found to be the major target for mercury in this cell line (48%), followed by nuclei (38%), cytosol (8%) and microsomes (7%). Mitochondrial morphological damage after mercury treatment was observed by transmission electron microscopy. To determine if the toxic effect of mercury on mitochondrial bioenergetics was direct or indirect, mitochondria were isolated from WRL‐68 cells after 1 h of pre‐incubation with 0.5 µM HgCl2. Oxygen consumption was quantified in two sets of experiments: in the presence of classical mitochondrial respiratory inhibitors; and in the presence of oligomycin. No significant difference was found in respiration with classical inhibitors, indicating that mercury does not affect directly the mitochondrial respiratory chain. However, mitochondria of Hg‐treated cells were not inhibited when oligomycin was added, probably due to an uncoupling effect. This effect was prevented with dithiothreitol (DTT) treatment. A possible explanation for mercury's effect on mitochondria and its relation with oxidative stress is presented. Copyright © 2001 John Wiley & Sons, Ltd.
Quantification of the kinetics and thermodynamics of protein adsorption using atomic force microscopy
Authors: Gettens Robert T. T. , Bai Zhijun , Gilbert Jeremy L.
Published: January 2005

Both in situ and ex situ methods for quantifying area fraction coverage of protein on a surface using atomic force microscopy were developed. The in situ method used a continuous fluid flow system to observe the kinetics of adsorption in real time. The ex situ method required immersing the sample in solution, drying the sample, and imaging in an ambient environment to obtain kinetic and isothermal data. These methods were developed using the plasma protein fibrinogen in a phosphate‐buffered saline solution on grade IV muscovite mica and highly ordered pyrolytic graphite (HOPG) substrates. Kinetic and quasiisothermal data were obtained and a Langmuir model was fit to the data. An adsorption rate constant of 2.2 × 10−4 mL · μg−1s−1 and a desorption rate constant of 8.3 × 10−5 s−1 were found on an HOPG surface. Completely irreversible adsorption was found on the mica surface with an adsorption rate constant of 2.7 × 10−4 mL · μg−1s−1. Additionally, protein conformation and assembly orientation on these surfaces were documented where fibrinogen on HOPG formed a network‐like structure, whereas fibrinogen on mica was more random. Also, nano‐topographical factors (ledges) were seen as sites of preferential adsorption. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res 72A: 246–257, 2005
Three‐dimensional chemical structures by protein functionalized micron‐sized beads bound to polylysine‐coated silicone surfaces
Authors: Lateef Syed S. , Boateng Samuel , Ahluwalia Neil , Hartman Thomas J. , Russell Brenda , Hanley Luke
Published: January 2005

A novel method is described here that allows three‐dimensional (3D) control of both chemistry and morphology by a series of wet chemical steps: the attachment of protein functionalized micron‐sized beads onto a flat silicone surface that has been functionalized with a distinct chemical modification. Bovine serum albumin (BSA), laminin, or polylysine is covalently bound to 6.5‐μm‐diameter spherical beads. A chemical method is then used to bind these beads to a flat silicone surface that is subsequently functionalized with polylysine. This process leads to a nonspecific cell adhesive background on the flat surface (polylysine) with the option of differing chemistry on the third‐dimension due to the protein BSA or laminin on the bead protruding from the surface. The beads do not detach during cyclic stretching in vitro. Neo‐natal rat cardiac fibroblasts are cultured on the beaded surfaces and compared with fibroblasts cultured on nonbeaded, flat polylysine surfaces. Fibroblast plating density, integrin, and physical responses are examined as a function of varying the ligands on the beads. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res 72A: 373–380, 2005
Potential pitfalls of radiolabel adsorption to ceramic biomaterials
Authors: Parker Tony , Upton Zee , Vellinga Douwe , Wei Mei , Leavesley David
Published: January 2005

The use of radiolabeled precursor molecules for the metabolic analysis of cell functions is commonplace. Tritiated thymidine, in particular, has been used to quantitate cellular proliferation in numerous cells, including osteoblasts, when cultured on various biomaterials. Our aim was to assess cellular protein synthesis and proliferation, on a range of fluoride ion‐substituted hydroxyapatites. Initially, we used a classical metabolic analysis strategy with radiolabeled tracer molecules. Our results suggested that these materials supported enhanced protein synthesis and proliferation of SaOS‐2 human osteoblast‐like cells. However, control samples also revealed enhanced adsorption of the radiolabeled tracer. We have shown that this arises because partially fluoride ion‐substituted hydroxyapatite exhibits enhanced adsorptive characteristics of radiolabeled leucine and thymidine over tissue culture plastic, hydroxyapatite, and fluoroapatite. Moreover, manual cell count data obtained through SEM analysis showed no significant difference in cell proliferation between any of the materials, further indicating that our initial results were artifacts. These results highlight the use and reporting of appropriate cell‐free controls are critical in bioassays examining functional responses of cells to biomaterials, and if absent, may confound accurate data interpretation. Our findings have general implications for investigations of cell function on other novel ceramic biomaterials. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res 72A: 363–372, 2005
Effect of poly‐L‐lysine coating on macrophage activation by alginate‐based microcapsules: Assessment using a new in vitro method
Authors: Juste Sandy , Lessard Mélanie , Henley Nathalie , Ménard Martin , Hallé Jean‐Pierre
Published: January 2005

The characteristics of the microcapsule surface, which interacts directly with the host macrophages, may have a role in the biocompatibility of alginate‐poly‐L‐lysine (PLL)‐alginate (APA) microcapsule. The objectives of the study were: 1) to develop and validate a simple, rapid, and sensitive in vitro method for assessing microcapsule biocompatibility, based on microcapsule coincubation with macrophages and measurement, by reverse transcriptase‐polymerase chain reaction, of cytokine mRNA expression, and 2) to evaluate the effect of alginate purification and PLL coating on macrophage activation. The mRNA expression of tumor necrosis factor‐α and interleukin‐1β was significantly higher when macrophages were coincubated with beads made with nonpurified compared with purified alginate (p < 0.01, p < 0.05, respectively) and negative control (p < 0.001) or with APA microcapsules compared with non‐PLL‐coated alginate beads and negative control (p < 0.001). The mRNA expression of interleukin‐6 differed significantly only when APA microcapsules were compared with a negative control (p < 0.05). These results confirm that alginate purification improves microcapsule biocompatibility, and suggest that PLL is not completely covered and/or neutralized by the second alginate incubation and thus has a role in the host macrophage activation. The assay is sensitive to both alginate contaminants and microcapsule surface characteristics and may be a useful tool for the development of biocompatible microcapsules. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res 72A: 389–398, 2005
Insulin‐like growth factor‐1 increases endothelin receptor A levels and action in cultured rat aortic smooth muscle cells
Authors: Kwok Ching Fai , Juan Chi‐Chang , Shih Kuang‐Chung , Hwu Chii‐Min , Jap Tjin‐Shing , Ho Low‐Tone
Published: January 2005

Insulin is known to cause an increase in endothelin‐1 (ET‐1) receptors in vascular smooth muscle cells (SMCs), but the effect of insulin‐like growth factor 1 (IGF‐1) on ET‐1 receptor expression is not known. We therefore carried out the present study to determine the effect of IGF‐1 on the binding of ET‐1 to, and ET type A receptor (ETAR) expression and ET‐1‐induced 3H‐thymidine incorporation in, vascular SMCs. In serum‐free medium, IGF‐1 treatment increased the binding of 125I‐ET‐1 to SMC cell surface ET receptors from a specific binding of 20.1% ± 3.1% per mg of protein in control cells to 45.1% ± 8.6% per mg of protein in cells treated with IGF‐1 (10 nM). The effect of IGF‐1 was dose‐related, with a significant effect (1.4‐fold) being seen at 1 nM. The minimal time for IGF‐1 treatment to be effective was 30 min and the maximal effect was reached at 6 h. Immunoblotting analysis showed that ETAR expression in IGF‐1‐treated cells was increased by 1.7‐fold compared to controls. Levels of ETAR mRNA measured by the RT‐PCR method and Northern blotting were also increased by 2‐fold in IGF‐1‐treated SMCs. These effects of IGF‐1 were abolished by cycloheximide or genistein. Finally, ET‐1‐stimulated thymidine uptake and cell proliferation were enhanced by IGF‐1 treatment, with a maximal increase of 3.2‐fold compared to controls. In conclusion, in vascular SMCs, IGF‐1 increases the expression of the ET‐1 receptor in a dose‐ and time‐related manner. This effect is associated with increased thymidine uptake and involves tyrosine kinase activation and new protein synthesis. These findings support the role of IGF‐1 in the development of atherosclerotic, hypertensive, and diabetic vascular complications. © 2004 Wiley‐Liss, Inc.
Construction and characterization of multiple human colon cancer cell lines for inducibly regulated gene expression
Authors: Welman Arkadiusz , Cawthorne Christopher , Barraclough Jane , Smith Nigel , Griffiths Gareth J. , Cowen Rachel L. , Williams Judith C. , Stratford Ian J. , Dive Caroline
Published: January 2005

Validation of targets for cancer drug discovery requires robust experimental models. Systems based on inducible gene expression are well suited to this purpose but are difficult to establish in several epithelial cell types. Using the recently discovered transcriptional transactivator (rtTA2S‐M2), we developed a strategy for fast and efficient generation of Tet On cells. Multiple clones of HCT116, SW480, and HT29 human colon cancer cells for doxycycline‐regulated gene expression were constructed that constitutively express green fluorescent protein (GFP) for selection/maintenance purposes. The cell lines displayed good fold inducibility (49–124× HCT116; 178–621× SW480; 261–787× HT29) and minimal leakiness after transient transfection with a luciferase reporter or with vectors driving inducible expression of red fluorescent protein (dsRed2), constitutively active c‐Src or dominant negative K‐Ras4B. The clones preserved their transformed phenotype as demonstrated by comparing their properties to respective wild type cells, in terms of growth in vitro and in vivo (as tumor xenografts), cell cycle traverse, and sensitivity to drugs used in chemotherapy. These engineered cell lines enabled tightly controlled inducible gene expression both in vitro and in vivo, and proved well suited for construction of double‐stable cell lines inducibly expressing a protein of interest. As such they represent a useful research tool for example, to dissect oncogene function(s) in colon cancer. Supplementary material for this article be found at http://www.mrw.interscience.wiley.com/suppmat/0730‐2312/suppmat/94/suppmat_welman.doc. © 2005 Wiley‐Liss, Inc.
Effects of cell cycle status on early events in retroviral replication
Authors: Katz Richard A. , Greger James G. , Skalka Anna Marie
Published: January 2005

The study of retroviruses over the last century has revealed a wide variety of disease‐producing mechanisms, as well as apparently harmless interactions with animal hosts. Despite their potential pathogenic properties, the intrinsic features of retroviruses have been harnessed to create gene transfer vectors that may be useful for the treatment of disease. Retroviruses, as all viruses, have evolved to infect specific cells within the host, and such specificities are relevant to both pathogenesis and retrovirus‐based vector design. The majority of cells of an animal host are not progressing rapidly through the cell cycle, and such a cellular environment appears to be suboptimal for replication of all retroviruses. Retrovirus‐based vectors can therefore be restricted in many important target cells, such as post‐mitotic differentiated cells or stem cells that may divide only infrequently. Despite intense interest, our understanding of how cell cycle status influences retroviral infection is still quite limited. In this review, we focus on the importance of the cell cycle as it relates to the early steps in retroviral replication. Retroviruses have been categorized based on their abilities to complete these early steps in non‐cycling cells. However, all retroviruses are subject to a variety of cell cycle restrictions. Here, we discuss such restrictions, and how they may block retroviral replication, be tolerated, or overcome. J. Cell. Biochem. 94: 880–889, 2005. © 2005 Wiley‐Liss, Inc.
Cellular transformation of NIH3T3 fibroblasts by CIZ/NMP4 fusions
Authors: Corveleyn Anniek , Janssen Hilde , Martini Alessandra , Somers Riet , Cools Jan , Marynen Peter
Published: January 2005

Molecular cloning of the translocations t(12;22)(p13;q12) and t(12;17)(p13;q11) in acute leukaemia showed that either EWSR1 or its homologue TAF15 are fused to the transcription factor CIZ. EWSR1 and TAF15 belong to the TET family (TLS/FUS, EWSR1 and TAF15) of proteins. TET fusions have been identified in both solid tumours and acute myeloid leukaemia. The novel 12p translocations directly implicated TET fusions in acute lymphoblastic leukaemia as well, and demonstrated the involvement of CIZ in haematopoietic malignancies. In addition, a new fusion E2A‐CIZ was recently cloned as a result of a t(12;19)(p13;p13) in a patient with acute lymphoblastic leukaemia. NIH3T3 cells stably expressing TET‐CIZ fusions display a transformed phenotype in a focus formation assay. We show here that E2A‐CIZ also transforms 3T3 fibroblasts, suggesting that the addition of a transactivation domain to the CIZ protein is involved in this phenotype. An artificial VP16‐CIZ construct reveals similar transforming properties, supporting this. We have then analysed the domains within TAF15‐CIZ that are necessary for 3T3 fibroblast transformation. Deletion of the zinc fingers of CIZ resulted in loss of both DNA‐binding and transforming properties of TAF15‐CIZ, whereas deletion of the other functional domains of CIZ had no effect. Fusion of a transactivation domain to CIZ is suggestive for a transactivating function in transformation. Luciferase experiments indeed showed that E2A‐CIZ as well as VP16‐CIZ transactivates the MMP7 promoter. Taken together, our results reported here suggest that transformation of 3T3 fibroblasts by CIZ fusions is dependent on DNA‐binding and might involve transactivation of CIZ target genes. © 2004 Wiley‐Liss, Inc.
Dexamethasone upregulates the expression of the nuclear cofactor p300 and its interaction with C/EBPβ in cultured myotubes
Authors: Yang Hongmei , Menconi Michael J. , Wei Wei , Petkova Victoria , Hasselgren Per‐Olof
Published: January 2005

Muscle wasting during sepsis and other catabolic conditions is, at least in part, mediated by glucocorticoids and is associated with upregulated transcription of multiple genes in the ubiquitin‐proteasome proteolytic pathway. In addition to transcription factors, nuclear cofactors, including p300, regulate gene transcription. We tested the hypothesis that glucocorticoids upregulate the expression of p300 in muscle cells. Treatment of cultured L6 myotubes, a rat skeletal muscle cell line, with dexamethasone resulted in a dose‐ and time‐dependent increase in p300 protein and mRNA levels. Surprisingly, the effect of dexamethasone on p300 levels was not inhibited by the glucocorticoid receptor (GR) antagonist RU38486 and RU38486 exerted an agonist effect on p300, increasing its expression. Co‐immunoprecipitation showed that treatment of the myotubes with dexamethasone resulted in protein–protein interaction between p300 and C/EBPβ, but not C/EBPδ. The present results suggest that glucocorticoids upregulate the expression of p300 and its interaction with C/EBPβ in skeletal muscle. Increased expression and activity of p300 may be involved in the regulation of gene transcription in glucocorticoid‐dependent muscle wasting. J. Cell. Biochem. 94: 1058–1067, 2005. © 2005 Wiley‐Liss, Inc.
Expression of p16INK4A variants in senescent human fibroblasts independent of protein phosphorylation
Authors: Weebadda Wineeta K.C. , Jackson Tonya J. , Lin Athena W.
Published: January 2005

Upregulation of the p16 tumor suppressor is a hallmark of senescence in human fibroblasts. In this study, we investigated potential protein modification of p16 in senescent human fibroblasts using 2D SDS–PAGE analysis. Three distinct p16 variants with isoelectric points of 5.2, 5.4, and 5.6, were consistently detected in normal human IMR90 fibroblasts that had undergone senescence due to forced expression of oncogenic H‐ras or culture passage. Moreover, in contrast to short‐term serum starvation, which induces quiescence, IMR90 fibroblasts cultured in low serum for a prolonged period exhibited senescent phenotypes and expression of the three p16 variants. All three p16 variants are unlikely phosphoproteins since they failed to react with antibodies against phospho‐serine, and were resistant to the treatment with phosphatases. Functionally, co‐immunoprecipitation assays using antibodies against cdk4 and/or cdk6 revealed that only the two most acidic p16 variants associated with cdk4/6. Moreover, senescence induced by the forced expression of p16 in early passage IMR90 fibroblasts or osteosarcoma U2OS cells was accompanied by expression of the two most acidic p16 variants, which also associated with cdk4/6. In summary, we report that prolonged serum starvation‐induced senescence may provide an additional model for studying biochemical changes in senescence, including p16 regulation. Furthermore, induction of endogenous p16 in senescent human fibroblasts correlates with the expression of three distinct p16 variants independent of protein phosphorylation. Lastly, expression of the two cdk‐bound variants is sufficient to induce senescence in human cells. © 2004 Wiley‐Liss, Inc.
Passive osmotic properties of in situ human articular chondrocytes within non‐degenerate and degenerate cartilage
Authors: Bush Peter G. , Hall Andrew C.
Published: January 2005

Osteoarthritis is characterized by many factors, including proteoglycan loss, decreased collagen stiffness, and increased cartilage hydration. Chondrocyte swelling also occurs, and correlates with the degree of osteoarthritis, however, the cause is unknown but might be related to alterations to their passive osmotic properties. We have used two‐photon confocal laser scanning microscopy to measure the passive osmotic characteristics of in situ chondrocytes within relatively non‐degenerate and degenerate human tibial plateau cartilage, and in chondrocytes isolated from relatively non‐degenerate cartilage. Explants with bone attached were taken from a total of 42 patients undergoing arthroplasty and graded macroscopically and microscopically into two groups, grade 0 + 1 and grade 2 + 3. There was a significant increase in cartilage hydration between these two groups (P < 0.05), however, there was no change when medium osmolarity was varied over ∼0–480 mOsm. The passive osmotic behavior of in situ chondrocytes (at 4°C) was identical over a range of culture medium osmolarities (∼0–515 mOsm), however, the maximum swelling of cells within degenerate cartilage and isolated chondrocytes was greater compared to those in non‐degenerate cartilage. The swelling in the majority of in situ chondrocytes was accounted for by the reduced interstitial osmolarity occurring with cartilage degeneration. There was, however, a small population of in situ chondrocytes whose volume was in excess (≥2,500 μm3) of that predicted from the decreased interstitial osmotic pressure. These results show that for the majority of cells studied, the differences in passive chondrocyte volume between relatively non‐degenerate, degenerate, and isolated cells were entirely accounted for by changes to the extracellular osmolarity (180–515 mOsm). © 2005 Wiley‐Liss, Inc.
Nitric oxide stimulated vascular smooth muscle cells undergo apoptosis induced in part by arachidonic acid derived eicosanoids
Authors: Pilane Cyril M. , LaBelle Edward F.
Published: January 2005

The role of eicosanoids in atherogenesis has not been thouroughly explained. This is partly due to the numerous eicosanoids and the variable effects that each has on different systems. Apoptosis of vascular smooth muscle cells has been shown to play a role in the atherosclerotic disease leading to lesion formation and further destabilization of the formed lesion. In this study, we have investigated the role of arachidonic acid derived eicosanoids in nitric oxide (NO)‐stimulated vascular smooth muscle cells. We have shown previously that the nitric oxide (NO)‐induced apoptosis of vascular smooth muscle cells was accompanied by arachidonic acid release via cytoplasmic phospholipase A2 (cPLA2) activation. Also, arachidonic acid, but not oleic acid, induced apoptosis of these cells at low concentrations (5–10 μM). Our results revealed that the cPLA2 specific inhibitor, arachidonyl trifluoromethyl ketone (AACOCF3), blocked NO‐induced eicosanoid production, while the presence of arachidonic acid enhanced the ability of the cells to make prostaglandin E2 (PGE2). Also, inhibitors of the cyclo‐oxygenase (Cox) enzymes, such as N‐[2‐cyclohexyloxy)‐4‐nitrophenyl]‐methanesulfonamide (NS‐398), a specific Cox‐2 inhibitor, or indomethacin, a non‐specific Cox inhibitor, blocked NO‐induced PGE2 production and apoptosis of vascular smooth muscle cells to the same extent, indicating that apoptosis might be induced by a Cox‐2 metabolic product. In addition to these observations, the eicosanoids investigated, namely, PGE2, PGI2 LTB4, and PGJ2, showed different effects on vascular smooth muscle cells. Both PGJ2 and LTB4 decreased the percentage of viable cells and induced apoptosis of vascular smooth muscle cells, while PGE2 and PGI2 had no effect on cell viability and failed to induce apoptosis. These data suggest that eicosanoids, such as PGJ2, but not PGE2 or PGI2, are involved in NO‐induced apoptosis of vascular smooth muscle cells and that the eicosanoid synthesis pathways might be utilized for vascular therapeutic strategies. © 2005 Wiley‐Liss, Inc.
Captopril and its synthesis from chiral intermediates
Authors: Chirumamilla R R , Marchant R , Nigam P
Published: January 2005

Captopril is an antihypertensive agent that inhibits the angiotensin‐converting enzyme of the renin–angiotensin system. Chiral intermediates are used in the synthesis of the drug. These intermediates are obtained by resolution of racemic compounds or by chemical, biocatalytic methods and or by asymmetric synthesis by biocatalytic process. This article reviews the various chemical and biochemical processes involved in the synthesis of the chiral drug, including the pharmacological action of captopril.

© 2001 Society of Chemical Industry
Some catalytic properties of silica‐supported base and metal porphyrins for hydrocarbon cracking and hydrogenation
Authors: Caga I T , Carnell I D , Winterbottom J M
Published: January 2005

A base porphyrin, etioporphyrin (EPI), has been synthesised and a number of metal–etioporphyrin compounds have been derived from EPI by metal insertion, these being nickel, vanadyl, palladium and platinum. The metal–etioporphyrins were supported on silica gel with loadings of 0.5–5.0% (w/w) to be employed as catalysts for hydrocarbon cracking and to a minor extent for hydrogenation. The porphyrins themselves were characterised using temperature programmed decomposition (TPD), temperature programmed reduction (TPR), mass spectroscopy (MS) and infra‐red (IR) spectroscopy. TPD studies up to 550 °C indicated complete stability and TPR studies (20–500 °C) showed interaction with hydrogen, nickel–EPI and Pd–EPI especially showing strong interaction. MS studies showed that metal insertion had occurred for VO–EPI and Ni–EPI and Pd insertion was demonstrated to have occurred using an analytical method. IR spectroscopy carried out on VO–EPI and Ni–EPI showed an absence of NH linkages, again confirming metal insertion. The behaviour of the catalysts for hydrocarbon cracking was studied using 2,2‐dimethylbutane (2,2‐DMB) as the model reactant in the temperature range 440–550 °C and thermally in the temperature range 440–600 °C and at 1 at, m (101.3 kPa) pressure. All porphyrins, even the base porphyrin, exhibited cracking activity and the catalysed reaction had an energy of activation, depending on the porphyrin, in the range 78–113 kJ/mol−1, compared with a value of 210 kJ mol−1 for the thermal reaction. The product distribution was dominated by C1 and C2 hydrocarbons and is typical of a free radical reaction, the thermal reaction giving a similar product distribution, so that the porphyrin catalyst acts as a free radical initiator. Hydrogenation studies using hex‐1‐ene at 150 °C and at 1 atm. pressure showed that Pd–EPI/SiO2 was an active and possibly stable hydrogenation catalyst, whereas Ni–EPI/SiO2 while of only slightly lower activity initially, lost that activity so that the Pd–EPI catalyst was over 16 times more active at the end of a 2 h period.

© 2001 Society of Chemical Industry
Low energy steam explosion treatment of plant biomass
Authors: Sawada Tatsuro , Nakamura Yoshitoshi
Published: January 2005

The rational operational condition for maximizing the pretreatment effect on plant biomass while minimizing heat required was investigated. Eucalyptus globulus chips were used to evaluate the operational method for the most efficient conversion of plant biomass into useful materials by steam explosion. The energy consumption required to carry out the steam explosion was calculated by considering the mass balances of the water, the wood component, and the heat balance in the steam explosion apparatus. The energy consumption increased significantly with the increase of steam pressure and steaming time, and decreased rapidly with increase of the thickness of the heat‐insulating material in the steam explosion apparatus. The amount of methanol‐soluble lignin, a low molecular weight lignin, was measured experimentally under various operational conditions such as steam pressure and steaming time. The steam explosion at the steam pressure of 3.9 MPa and steaming time of 1.1 min was the most effective method for maximizing the delignification with low energy consumption.

© 2001 Society of Chemical Industry
The preparation of D‐glucaric acid by oxidation of molasses in packed beds
Authors: Pamuk Vecihi , Yılmaz Murat , Alıcılar Ahmet
Published: January 2005

An attempt has been made to prepare glucaric acid by oxidation of sugar beet molasses in packed beds. In the first part, a suitable oxidizing medium was sought. Experiments were performed in a cylindrical Pyrex‐glass reactor with air–molasses cocurrent downflow. Spherical glass and cylindrical vanadium pentoxide particles were used as an inert packing and catalyst respectively. The addition of catalyst, sodium nitrite, nitric and sulfuric acids to the medium resulted in an improvement in glucaric acid yield. The presence of nitric acid in the oxidizing medium and the use of vanadium pentoxide catalyst were the most effective factors as regards the yield. In the second part, the effects of temperature, molasses concentration, amount of catalyst and air flow rate on the yield were studied; each of these variables increased the yield. The use of a longer catalyst bed, however, resulted in a decrease in the yield. The highest rate of conversion of glucose to glucaric acid was 63.9% at optimum conditions.

© 2001 Society of Chemical Industry
Adsorption behaviour of metal ions on imprinted chitosan resin
Authors: Tianwei Tan , Xiaojing He , Weixia Du
Published: January 2005

A new method for preparation of metal ion imprinted chitosan resin, which can considerably enhance the adsorption capacity and selectivity of the metal ion is presented in this paper. The conditions influencing the preparation of chitosan imprinted resin such as the cross‐linking agent, epichlororohydrin and ethylene glycol diglycidyl ether, and metal ion concentration are optimized. The chemical and the physical stability are also discussed and the imprinted chitosan resin can be used many times without losing adsorption capacity. The adsorption isotherms were studied and a new model was suggested to correlate the relationship of adsorption with pH and metal ion concentration.

© 2001 Society of Chemical Industry
Oxidation of benzothiazole, 2‐mercaptobenzothiazole and 2‐hydroxybenzothiazole in aqueous solution by means of H2O2/UV or photoassisted Fenton systems
Authors: Andreozzi R , Caprio V , Marotta R
Published: January 2005

Oxidative treatments of benzothiazole and benzothiazole derivatives (2‐mercaptobenzothiazole, 2‐hydroxybenzothiazole) in aqueous solution have been studied by using H2O2/UV and iron(III) photoassisted Fenton techniques. Experimental runs have been carried out in the pH range 3.0 –8.0 by means of annular reactors and proper UV lamps. The effect of pH, the initial concentration of hydrogen peroxide, the substrate, and the iron(III) concentrations have been investigated. A suitable model has been developed and used for the best estimation of kinetic constants for HO radical attack on the target molecules with the H2O2/UV system. The values obtained with this model are consistent with those reported in the literature for other heterocyclic compounds.

© 2001 Society of Chemical Industry
Growth‐promoting properties of yeast extracts produced at different pH values, with different autolysis promoters and bacterial populations
Authors: Barrette Julie , Champagne Claude P , Goulet Jacques
Published: January 2005

The effect of the autolysis conditions of bakers' yeast on the growth‐promoting properties of the resulting yeast extracts (YE) were examined on cultures of Lactococcus lactis ssp lactis D25 and of Lactococcus lactis ssp cremoris R2. The various YE were produced by conducting autolysis at four pH levels (pH 4.0, 5.5, 7.0 or 8.5) and with or without the autolysis promoters (AP) ethyl acetate or chitosan. To determine if the presence of contaminating bacteria during autolysis affected the YE characteristics, one series of YE was also prepared with the bakers' yeast cell suspension contaminated with 108 CFU/cm−3 of typical yeast plant bacteria (mostly of the Bacillus genus) at the beginning of autolysis. The growth curves of the lactococci in media supplemented with the various YE were analyzed to determine the maximum optical density (ODmax), the maximum growth rate (µmax) and the fermentation time (F‐time) at which ODmax was reached. The addition of bacterial contaminants (at 108 CFUcm−3) did not significantly influence the growth‐promoting properties of YE. The lactococci had higher ODmax and µmax values when the media contained YE produced at pH 4.0 or 5.5, and these YE contained 40% more total nitrogen than those obtained at pH 7.0 or 8.5. There was no major effect of AP on the biological value of the resulting YE, but a significant interaction between pH and AP was found for L lactis D25. Thus the ODmax of YE produced at pH 7.0 and 8.5 were highest when ethyl acetate was used as autolysis promoter, as compared with control and chitosan at pH 7.0–8.5, while the opposite was obtained with products produced at pH 4.0 and 5.5. This study shows that parameters used to produce YE influence their biological value with respect to the growth‐promoting properties of lactococci.

© 2001 Society of Chemical Industry
The effect of fermentation parameters on the production of Mucor miehei acid protease in a chemically defined medium
Authors: Ayhan F , Çelebi Serdar S , Tanyolaç A
Published: January 2005

Batch shake flask experiments were carried out with a fungal strain of Mucor miehei ATCC 3420 to study the effects of five fermentation parameters; initial D‐glucose concentration, temperature, initial pH, agitation rate and inoculum ratio, on the production of rennin in a chemically defined medium. A statistical design was used to assign the experimental levels of five fermentation parameters for the determination of optimum conditions. The highest concentration of milk‐clotting activity (MCA) obtained was 2286 SU cm−3 (without concentration of the broth) at 29.6 g dm−3 initial D‐glucose concentration, 6.8 initial pH, 37.6 °C temperature, 81 stroke per min agitation rate and 5.2% (v/v) inoculum ratio. Although enzyme secretion was a function of all the operational parameters investigated, the pH range (4.6–5.2) reached at the time of enzyme production had a profound effect on milk‐clotting activity levels. In the fermentation sample at maximum milk‐clotting activity the R factor, the ratio of milk‐clotting activity to proteolytic activity, was determined as 1 SU PU−1, denoting similar characteristics to a commercial animal rennet.

© 2001 Society of Chemical Industry
Electrochemical removal of cadmium using a batch undivided reactor with a rotating cylinder electrode
Authors: Grau Javier M , Bisang José M
Published: January 2005

The performance of an undivided electrochemical batch reactor with a rotating cylinder electrode under potentiostatic control is examined for the removal of cadmium from a sodium sulfate solution containing 500 ppm Cd(II) at pH ≅ 7. The effect of hydrogen evolution as a side cathodic reaction on the figures of merit of the reactor is analysed. The best results were obtained for a cathode potential of −0.9 V against the saturated calomel electrode. With an angular velocity of 1500 rpm the space time yield and the normalized space velocity were 0.66 mol m−3 s−1 and 3.9 h−1 respectively, while the fractional conversion was 67.3% with a current efficiency of 66.7%. The surface morphology of the deposits as a function of the applied potential is also reported.

© 2001 Society of Chemical Industry
Study of alternatives for the design of a mobile unit for wastewater treatment by supercritical water oxidation
Authors: Cocero M José , Sanz M Teresa , Fernández‐Polanco Fernando
Published: January 2005

Supercritical water oxidation (SCWO) has been shown to be an appropriate technology for the treatment of water containing toxic and hazardous substances, because it provides high destruction efficiencies. This paper reports a study of alternatives, and optimisation of various parameters and conditions, which are applied to the design of a mobile treatment unit. Phenol was selected as a model organic compound present in the feed stream and NaCl was selected as a model polar compound for solid separation. Pilot plant results show that efficiencies above 99.9% in phenol destruction are reached, at an operation temperature of about 650 °C, with stoichiometric amounts of air. Feed streams with a wide range of heating values (lower limit 530 and upper limit 930 kJ kg−1) can be handled, because these values allow both thermal and mechanical energy recoveries, which are the key factor for economic feasibility. The unit is capable of handling wastewater containing toxic, recalcitrant or non‐biodegradable compounds that cannot be treated with global streams at the wastewater treatment plant of a factory. It is specifically proposed for use in industries in which wastewater contains solvent mixtures of fine chemicals and pharmaceuticals.

© 2001 Society of Chemical Industry
Dynamic enzymatic resolution of Naproxen methyl ester in a membrane bioreactor
Authors: Xin Jia‐ying , Li Shu‐ben , Xu Yi , Chui Jun‐ru , Xia Chun‐gu
Published: January 2005

A lipase‐catalyzed enantioselective continuous hydrolysis process under in situ racemization of substrate using sodium hydroxide as catalyst was developed for the production of (S)‐Naproxen from racemic Naproxen methyl ester in an aqueous–organic biphase system. Use of a tubular silicone rubber membrane in the stirred tank reactor to separate the chemical catalytic racemization and biocatalytic resolution processes, served to avoid the key problem associated with conventional dynamic resolution, viz the incompatibility of in situ chemical racemization with the presence of a biocatalyst. To overcome product inhibition and to facilitate product recovery from the aqueous–organic emulsion containing substrate and lipase, a hydrophilic porous semipermeable membrane was used in the stirred tank reactor. Greater than 60% conversion of the racemate with an enantiomeric excess of product (eep) greater than 96% was obtained. In addition, transformation of Candida rugosa lipase (CRL) isoenzymes was observed in the reaction process.

© 2001 Society of Chemical Industry
Adsorption of selected toxic metals by modified peanut shells
Authors: Chamarthy Srinath , Seo Chung W , Marshall Wayne E
Published: January 2005

The objective of this study was to modify peanut shells to enhance their adsorptive properties toward the metal ions cadmium (Cd2+), copper (Cu2+), nickel (Ni2+), lead (Pb2+) and zinc (Zn2+). Milled peanut shells were initially washed with water or 0.1 N NaOH or left unwashed. Following these treatments or lack of treatment, the shells were either left unmodified or modified by a heat treatment in the presence of either 1.0 M phosphoric acid or 0.6 M citric acid. Modified peanut shells were evaluated either for adsorption efficiency or for adsorption capacity using the five metal ions listed above. Adsorption efficiencies and capacities were compared with efficiencies and/or capacities for the commercial chelating or cation exchange resins Amberlite 200, Amberlite IRC‐718, Duolite GT‐73, and carboxymethylcellulose. For the adsorption efficiencies of individual metal ions, modified peanut shells met or exceeded the adsorption values for cadmium, copper, nickel or zinc ions compared with the commercial resins Duolite GT‐73 and carboxymethylcellulose. In a solution containing all five metal ions, modified peanut shells met or exceeded the adsorption efficiencies for cadmium, copper and lead ions compared with Duolite GT‐73, Amberlite IRC‐718 and carboxymethylcellulose. Adsorption capacities of modified peanut shells met or exceeded the adsorption capacity of Duolite GT‐73 for lead ions only. Citric or phosphoric acid‐modified peanut shells showed a preference for Cu2+ and Pb2+ and appear promising as potentially inexpensive adsorbents for selected metal ions.

© 2001 Society of Chemical Industry
The effect of recycle ratio on nitrogen removal in the combined pre‐denitrification/nitrification biofilter system
Authors: Chiou Ren‐Jie , Ouyang Chaio‐Fuei
Published: January 2005

Previous research has shown that nitrogen in municipal wastewater could be eliminated by a biofilter system. This study investigates the effect of the recycle ratio on total nitrogen removal and the nitrogen component in the effluent. In this study, a system combining pre‐denitrification/nitrification biofilters was set up. The experiments which varied the recycle ratio of the nitrifying solution to the influent were carried out in order to determine the amount of the total nitrogen removal and the form of nitrogen in the effluent. These experimental results show that total nitrogen removal might be dependent on nitrification but not on denitrification. Although the operation at a low recycle ratio would result in a lower value of total nitrogen removal, the NH3‐N content of the effluent would be lower and the flow condition would be more stable. In comparison, operation at a higher recycle ratio would result in a lower NO3−‐N content in the effluent, while the NH3‐N content in the effluent would be higher. At a recycle ratio of 2.5, the total nitrogen removal is at its maximum. The relationship between specific nitrification rate and recycle ratio is also discussed.

© 2001 Society of Chemical Industry
Effects of polyacrylamide on microbial density levels and biodegradability in waste‐activated sludge
Authors: Chu Ching‐Ping , Lee Duu‐Jong , Chang Bea‐Ven , Liao Chian‐Sen
Published: January 2005

This study addressed the possible role of polyelectrolyte flocculation on microbial density levels in a waste‐activated sludge. Such an effect is commonly ignored. Applying polyelectrolyte reduced the density level of coliform bacteria in the flocculated sludge. Polyelectrolyte also reduced the 5‐day biochemical oxygen demand of sludge, possibly retarding the subsequent biodegradation processes.

© 2001 Society of Chemical Industry
Modelling shock loadings and starvation in the biofiltration of toluene and xylene
Authors: Métris Aline , Gerrard A Mark , Cumming Robert H , Weigner Pavel , Paca Jan
Published: January 2005

The response of biofilters to varying periods of starvation and to changes in inlet concentrations of a mixture of toluene and xylene have been tested in laboratory‐scale biofilters packed with a mixture of Perlite and compost. These results have been mathematically modelled taking the emission of carbon dioxide as a proxy for kinetics measurements. The use of CO2 is a more practical approach than that of kinetics based upon batch experiments on pure cultures. A simplification of Zarook's method, our model produced good outlet predictions given small changes in the inlet concentration of toluene and xylene. But for more stressful situations, like the resumption of the feed after periods of starvation, the use of carbon dioxide proved to be inappropriate as an indicator of the biomass activity, greatly overestimating biofilter performance. This suggested either the occurrence of cryptic growth (as a result of the stress inflicted on the biomass) or perhaps the utilisation of the compost as a carbon source.

© 2001 Society of Chemical Industry
Biodegradation of quinoline in crude oil
Authors: Sugaya Kazuo , Nakayama Osamu , Hinata Naoyuki , Kamekura Koichi , Ito Akira , Yamagiwa Kazuaki , Ohkawa Akira
Published: January 2005

Removal of quinoline, which is typical of nitrogen‐containing compounds in crude oil, was achieved by a biodegradation reaction by Comamonas sp TKV3‐2‐1. The aerobic strain, Comamonas sp TKV3‐2‐1, which can grow utilizing quinoline as the sources of both carbon and nitrogen, degraded quinoline to 2‐hydroxyquinoline, finally to water‐soluble substances. The degradation reaction of 2‐hydroxyquinoline was revealed to be regarded as a rate‐limiting step controlling the overall reaction of biodenitrogenation process of quinoline in crude oil. The degradation rate of 2‐hydroxyquinoline in a stirred fermenter had a maximum of 211 mg 2‐hydroxyquinoline g‐cell−1 h−1 when the portion of crude oil in the reaction mixture, the cell concentration and the rotational speed of agitation impeller were 83.3%(v/v), 28.5 gdm−3 and 11.7 s−1, respectively. After the reaction was completed, the crude oil and the cell suspension could be separated efficiently by centrifuging. The possibility of constructing a bioprocess for removing quinoline in crude oil under storage is also discussed.

© 2001 Society of Chemical Industry