bluuebunny/crossref_metadata_2025 huggingface dataset:
EGF receptor‐mediated, c‐Src‐dependent, activation of Stat5b is downregulated in mitogenically responsive hepatocytes
Authors: Guren Tormod K. , Ødegård John , Abrahamsen Hilde , Thoresen G. Hege , Susa Mira , Andersson Yvonne , Østby Eva , Christoffersen Thoralf
Published: May 2003

Signal transducer and activator of transcription (STAT) proteins may be activated by epidermal growth factor (EGF), but their role in EGF receptor‐mediated mitogenic signaling is not clear. We previously showed that Stat5b was activated by EGF in rat hepatocytes in primary monolayer culture. In the present study, we found that EGF induced tyrosine phosphorylation of Stat5b both on Tyr‐699, which correlated with specific DNA binding activity, and also on other tyrosine residues. The Src tyrosine kinase inhibitor CGP77675 blocked the EGF‐induced activation of Stat5b, but did not affect the Stat5b activation by growth hormone (GH) or prolactin (PRL). The Stat5b response to EGF was most pronounced soon (3 h) after plating (early G1) and at high cell density (50,000 hepatocytes per cm2). However, at this cell density EGF did not stimulate DNA synthesis. In hepatocytes at 24 h of culturing (mid/late G1) with 20,000 cells per cm2, EGF induced strong phosphorylation of the EGF receptor, as well as Shc and ERK, and stimulated DNA synthesis, but did not activate Stat5b, although the Stat5b response to GH or PRL was retained. A strong GH‐induced Stat5b activation neither influenced the DNA synthesis alone nor enhanced the mitogenic effect of EGF. The results show that EGF induces tyrosine phosphorylation and DNA‐binding activity of Stat5b in a manner different from GH and PRL, apparently by a Src‐dependent mechanism. The data also provide further evidence that Stat5b is not required for mitogenic signaling from the EGF receptor. © 2003 Wiley‐Liss, Inc.
Post‐transcriptional expression of DMT1 in the heart of rat
Authors: Ke Ya , Chen Yin Yin , Chang Yan Zhong , Duan Xiang Lin , Ho Kwok Ping , Jiang De He , Wang Kui , Qian Zhong Ming
Published: May 2003

Non‐transferrin‐bound iron (NTBI) overtaken by heart cells might be a key cause leading to iron‐mediated injury in heart disorders. NTBI uptake by heart cells might be mediated by divalent metal transporter 1 (DMT1). The understanding of the role of DMT1 in heart iron metabolism is fundamental for elucidating the cause resulting in excessive iron in the heart. The study was to evaluate effects of age and dietary iron on DMT1 mRNA expression and protein synthesis in rat heart. DMT1 mRNA expression was determined by RT‐PCR and sequence analysis, and DMT1 protein by Western blot analysis. DMT1 mRNAs with or without iron‐responsive element (IRE) both were found in rat heart. Expression of two forms of DMT1 mRNAs was the lowest at the age of post‐natal day (PND) 7, and then increased with the age, reaching the highest at PND196 (non‐IRE form) and PND63 (IRE form), respectively. During different ages, the levels of DMT1 (IRE) mRNA were higher than those of DMT1 (non‐IRE) mRNA and were significantly correlated with the non‐heme iron contents in the heart. After fed a high iron for 6 weeks, the rats had a sixfold elevation in heart iron and 22% (non‐IRE from) and 40% (IRE from) reduction in DMT1 protein compared to the controls. A low iron diet for 6‐weeks caused cardiac hypertrophy and heart iron deficiency and also an increase in levels of two forms of DMT1 proteins. However, iron status had no significant effect on DMT1 (IRE) and DMT1 (non‐IRE) mRNAs expression in the heart, although it can significantly influence heart transferrin receptor (TfR) mRNA expression. The results demonstrated that DMT1 mRNAs expression in the heart is age‐dependent and that two forms of DMT1 mRNAs both are regulated by iron on the post‐transcriptional level only. © 2003 Wiley‐Liss, Inc.
Induction of leukotriene C4 synthase after the differentiation of rat basophilic leukemia cells with retinoic acid and a low dose of actinomycin D and its suppression with methylprednisolone
Authors: Abe Masayoshi , Shibata Kazuhiko , Urata Hidenori , Sakata Noriyuki , Katsuragi Takeshi
Published: May 2003

Leukotriene C4 synthase (LTC4 S) is a pivotal enzyme for generation of cysteinyl‐leukotrienes (cysLTs). LTC4 S activity in rat basophilic leukemia‐1 (RBL‐1) cells increased after culture in the presence of retinoic acid (RA) analogues, which was inhibited by cycloheximide or actinomycin D (ACD). Unexpectedly, the co‐addition of a low dose of ACD with RA further potentiated the upregulation of the LTC4 S activity. Daunorubicin and mitomycin C also had a similar effect. When stimulated with calcium ionophore A23187, control cells did not produce cysLTs, but RA‐treated cells generated cysLTs and the co‐addition of ACD further increased. While LTC4 S mRNA and protein increased in the cells treated with RA, the co‐addition of ACD further potentiated both in proportion to the LTC4 S activity. The effect of ACD was considered to enhance the transcription rate of LTC4 S gene, but not the mRNA‐stability. The addition of methylprednisolone (MP) inhibited generation of cysLTs from the cells with A23187‐stimulation and also did LTC4 S activity, but did not inhibit 5‐lipoxygenase (5‐LOX). The suppression of LTC4 S with MP showed a dependent manner on the time‐point and duration of MP‐treatment after RA‐addition which was correlated with reduction in LTC4 S mRNA and protein. The cells cultured with RA plus ACD contained more histamine, chymase activity, and granules in the cytoplasm than the control cells, suggesting differentiation to mature mast cells. In consideration of RA‐differentiation therapy, it may be of pathophysiological relevance that the antineoplastic agents potentiate RA‐induced, steroid‐sensitive, induction of LTC4 S in RBL‐1 cells. © 2003 Wiley‐Liss, Inc.
Functional activity of serotoninergic and melatoninergic systems expressed in the skin
Authors: Slominski Andrzej , Pisarchik Alexander , Zbytek Blazej , Tobin Desmond J. , Kauser Söbia , Wortsman Jacobo
Published: May 2003

We tested the expression of genes coding receptors of a cutaneous serotoninergic/melatoninergic system in whole human skin and in normal and pathologic cultured skin cells. Evaluation of serotonin (5HT), melatonin (MT), and melatonin‐related receptors (MRR) showed expression of the isoforms 5HT2B, 5HT7, and MT1 genes in almost all the tested samples. Expression of other isoforms was less prevalent; 5HT2C, MRR, and MT2 were rarely detected. We also found novel isoforms for MT2, MRR, and 5HT2B and documented the process of RNA editing for 5HT2C. Testing for functional activity of these receptors with serotonin and melatonin (10−14 to 10−10 M) showed variable effects depending on cell type and culture conditions. Thus, serotonin stimulated proliferation of melanocytes in medium deprived of growth factors, while inhibiting cell growth in the presence of growth factors. Melatonin inhibited both apoptosis of HaCaT keratinocytes incubated in serum‐free media, and proliferation of cells cultured in medium supplemented with serum. Melatonin also increased the numbers of viable fibroblasts incubated in serum free medium. N‐acetylserotonin (NAS) and 5 methoxytryptamine (5MTT) were generally without effect on cell proliferation, with the exception of an inhibition of melanocyte proliferation at the higher 5MTT concentration of 10−10 M. Thus, skin cells represent a true target for the products of the serotoninergic/melatoninergic cutaneous pathway with their actions modulating cell proliferation or viability. © 2003 Wiley‐Liss, Inc.
Modulation of human fibroblast gap junction intercellular communication by hyaluronan
Authors: Moyer K.E. , Ehrlich H.P.
Published: May 2003

The composition of the extracellular matrix changes during dermal repair. Initially, hyaluronan (HA) concentration is high, however, by day 3, HA is eliminated. HA optimizes collagen organization within granulation tissue. One possible mechanism of HA modulation of collagen packing is through the promotion of gap junction intercellular communication (GJIC). Gap junctions are gated channels that allow rapid intercellular communication and synchronization of coupled cell activities. The gap junction channel is composed of connexin (Cx) proteins that form a gated channel between coupled cells. HA is reported to enhance Cx43 expression in transformed fibroblasts. GJIC was quantified by the scrape loading technique and reported as a coupling index. The coupling index for human dermal fibroblasts was 4.6 ± 0.2, while the coupling index for fibroblasts treated with HA more than doubled to 10.6 ± 0.7. By Western blot analysis no differences were appreciated in the protein levels of Cx43 or β‐catenin, a protein involved in the translocation of Cx to the cell surface. By immuno‐histology Cx43 and β‐catenin were evenly distributed throughout the cell in controls, but in cells treated with HA these proteins were co‐localized to the cell surface. Coupled fibroblasts are reported to enhance the organization of collagen fibrils. It is proposed that HA increases the accumulation of Cx43 and β‐catenin on the cell surface, leading to greater GJIC and enhanced collagen organization. © 2003 Wiley‐Liss, Inc.
Modulation of metabolic control by angiotensin converting enzyme (ACE) inhibition
Authors: Henriksen Erik J. , Jacob Stephan
Published: May 2003

Angiotensin converting enzyme (ACE) inhibitors are a widely used intervention for blood pressure control, and are particularly beneficial in hypertensive type 2 diabetic subjects with insulin resistance. The hemodynamic effects of ACE inhibitors are associated with enhanced levels of the vasodilator bradykinin and decreased production of the vasoconstrictor and growth factor angiotensin II (ATII). In insulin‐resistant conditions, ACE inhibitors can also enhance whole‐body glucose disposal and glucose transport activity in skeletal muscle. This review will focus on the metabolic consequences of ACE inhibition in insulin resistance. At the cellular level, ACE inhibitors acutely enhance glucose uptake in insulin‐resistant skeletal muscle via two mechanisms. One mechanism involves the action of bradykinin, acting through bradykinin B2 receptors, to increase nitric oxide (NO) production and ultimately enhance glucose transport. A second mechanism involves diminution of the inhibitory effects of ATII, acting through AT1 receptors, on the skeletal muscle glucose transport system. The acute actions of ACE inhibitors on skeletal muscle glucose transport are associated with upregulation of insulin signaling, including enhanced IRS‐1 tyrosine phosphorylation and phosphatidylinositol‐3‐kinase activity, and ultimately with increased cell‐surface GLUT‐4 glucose transporter protein. Chronic administration of ACE inhibitors or AT1 antagonists to insulin‐resistant rodents can increase protein expression of GLUT‐4 in skeletal muscle and myocardium. These data support the concept that ACE inhibitors can beneficially modulate glucose control in insulin‐resistant states, possibly through a NO‐dependent effect of bradykinin and/or antagonism of ATII action on skeletal muscle. © 2003 Wiley‐Liss, Inc.
1–40 β‐amyloid protein fragment modulates the expression of CD44 and CD71 on the astrocytoma cell line in the presence of IL1β and TNFα
Authors: Speciale Livianna , Ruzzante Stefania , Calabrese Elena , Saresella Marina , Taramelli Donatella , Mariani Claudio , Bava Laura , Longhi Renato , Ferrante Pasquale
Published: May 2003

The modulation of CD44, VCAM‐1 and CD71 expression was analysed by flow cytometry in the 1321N1 astrocytoma cell line in the presence of interleukin‐1β (IL1β), tumour necrosis factor‐α (TNFα) and 1–40 or 25–35 β‐amyloid (Aβ) fragments. The percentage of 1321N1 astrocytoma cell line expressing these markers increased significantly after treatment with TNFα or IL1β. The presence of Aβ 1–40 fragment, alone or in combination with IL1β, induced an increase in the percentage of cells expressing CD44, but not VCAM‐1. However, the concomitant presence of Aβ 1–40 fragment and of IL1β or TNFα caused an increase in the percentage of CD71 positive cells. In contrast, the shorter Aβ 25–35 fragment was always inactive. These results indicates that Aβ 1–40 fragment, in association with cytokines, can activate this astrocyte‐derived cell line and add further elements in favour of the hypothesis that β‐amyloid can act as immunological mediator. © 2003 Wiley‐Liss, Inc.
Cdc42 and RhoA are differentially regulated during arachidonate‐mediated HeLa cell adhesion
Authors: Roberts Louis A. , Glenn Honor , Hahn Chang S. , Jacobson Bruce S.
Published: May 2003

Cell adhesion to extracellular matrix requires stimulation of an eicosanoid signaling pathway through the metabolism of arachidonate by 5‐lipoxygenase to leukotrienes and cyclooxygenase‐1/2 to prostaglandins, as well as activation of the small GTPase signaling pathway involving Cdc42 and Rho. These signaling pathways direct remodeling of the actin cytoskeleton during the adhesion process, specifically the polymerization of actin during cell spreading and the bundling of actin filaments when cells migrate. However, few studies linking these signaling pathways have been described in the literature. We have previously shown that HeLa cell adhesion to collagen requires oxidation of arachidonic acid (AA) by lipoxygenase for actin polymerization and cell spreading, and cyclooxygenase for bundling actin filaments during cell migration. We demonstrate that small GTPase activity is required for HeLa cell spreading upon gelatin, and that Cdc42 is activated while Rho is downregulated during the spreading process. Using constitutively active and dominant negative expression studies, we show that Cdc42 is required for HeLa cell spreading and migration, while activated RhoA is antagonistic towards spreading. Constitutively active RhoA promotes cell migration and increases the degree of actin bundling in HeLa cells. Further, we demonstrate that activation of either the AA oxidation pathway or the small GTPase pathway cannot rescue inhibition of spreading when the alternate pathway is blocked. Our results suggest (1) both the eicosanoid signaling pathway and small GTPase activation are required during HeLa cell adhesion, and (2) these signaling pathways converge to properly direct remodeling of the actin cytoskeleton during HeLa cell spreading and migration upon collagen. © 2003 Wiley‐Liss, Inc.
Expression of connective tissue growth factor in bone: Its role in osteoblast proliferation and differentiation in vitro and bone formation in vivo
Authors: Safadi Fayez F. , Xu Jie , Smock Steven L. , Kanaan Reem A. , Selim Abdul‐Hafez , Odgren Paul R. , Marks Sandy C. , Owen Thomas A. , Popoff Steven N.
Published: May 2003

Connective tissue growth factor (CTGF) is a secreted, extracellular matrix‐associated signaling protein that regulates diverse cellular functions. In vivo, CTGF is expressed in many tissues with highest levels in the kidney and brain. The purpose of this study was twofold; first, to localize CTGF in normal bone in vivo during growth and repair, and second, to examine CTGF expression and function in primary osteoblast cultures in vitro and test its effect on bone formation in vivo. Northern and Western blot analyses confirmed that CTGF is expressed in normal long bones during the period of growth or modeling. In situ hybridization and immunohistochemical analysis demonstrated intense staining for CTGF mRNA and protein in osteoblasts lining metaphyseal trabeculae. Examination of CTGF expression in the fracture callus demonstrated that it was primarily localized in osteoblasts lining active, osteogenic surfaces. In primary osteoblast cultures, CTGF mRNA levels demonstrated a bimodal pattern of expression, being high during the peak of the proliferative period, abating as the cells became confluent, and increasing to peak levels and remaining high during mineralization. This pattern suggests that CTGF may play a role in osteoblast proliferation and differentiation as previously demonstrated for fibroblasts and chondrocytes. Treatment of primary osteoblast cultures with anti‐CTGF neutralizing antibody caused a dose‐dependent inhibition of nodule formation and mineralization. Treatment of primary osteoblast cultures with recombinant CTGF (rCTGF) caused an increase in cell proliferation, alkaline phosphatase activity, and calcium deposition, thereby establishing a functional connection between CTGF and osteoblast differentiation. In vivo delivery of rCTGF into the femoral marrow cavity induced osteogenesis that was associated with increased angiogenesis. This study clearly shows that CTGF is important for osteoblast development and function both in vitro and in vivo. © 2003 Wiley‐Liss, Inc.
Codominance of cisplatin resistance in somatic cell hybrids
Authors: Ying Yu‐Lan Mary , Shen Ding‐Wu , Liang Xing‐Jie , Gottesman Michael M.
Published: May 2003

Intrinsic or acquired resistance to cisplatin in cancer cells remains a major obstacle to successful chemotherapy. The clinically relevant genetic and molecular mechanisms of resistance have not yet been identified. Cisplatin‐resistant (CP‐r) human KB epidermoid carcinoma cell lines (HeLa) resistant to varying levels of cisplatin after single and multiple selection steps are cross‐resistant to other platinum compounds and to methotrexate. Intraspecies hybrids of the sensitive and KB CP‐r cells were fused with HeLa D98OR CP‐s, hypoxanthine‐aminopterin‐thymidine (HAT) sensitive, ouabain resistant, to determine whether cisplatin resistance is dominant or recessive. Cell–cell hybridization between the sensitive cells and single‐step or two‐step KB CP‐r cells both indicated codominance of cisplatin resistance compared to hybrids between sensitive cell lines (D98ORxKB). The hybrids between sensitive cell lines (D98xKB) and a single‐step CP‐r KB cell line (D98xKB‐CP.5) also were cross‐resistant to carboplatin and methotrexate. In addition, the relatively slower growth rate of CP‐r cells appears to be dominant. In the two‐step CP‐r KB cell line, KB‐CP1, resistance is no more dominant than in the single‐step CP‐r KB cell line, KB‐CP.5, suggesting that one of the two steps of resistance in KB‐CP1 may not be dominant. These dominance data suggest that it might be possible to identify one or more genes responsible for cisplatin resistance by gene transfer from a resistant cell line to a sensitive cell line. © 2003 Wiley‐Liss, Inc.
Hypoxia is a major stimulator of osteoclast formation and bone resorption
Authors: Arnett Timothy R. , Gibbons Daniel C. , Utting Jennifer C. , Orriss Isabel R. , Hoebertz Astrid , Rosendaal Martin , Meghji Sajeda
Published: May 2003

Hypoxia is known to act as a general stimulator of cells derived from marrow precursors. We investigated the effect of oxygen tension on the formation and function of osteoclasts, the cells responsible for bore resorption, which are of promonocytic origin. Using 7‐ and 13‐day cultures of mouse marrow cells on ivory discs, we found that reducing oxygen tension from the ambient atmospheric level of 20% by increasing the proportion of nitrogen caused progressive increases in the formation of multinucleated osteoclasts and resorption pits. Peak effects occurred in 2% oxygen, where stimulations of resorption up to 21‐fold were measured. Significant stimulations of osteoclast formation and resorption were observed even in severely hypoxic cultures gassed with 0.2% oxygen. Short‐term cultures of cells disaggregated from rat bones indicated that hypoxia did not alter the resorptive activity of mature osteoclasts, but reduced their survival or adherence. In 3‐day organ cultures of mouse calvarial bones, exposure to 2% oxygen resulted in maximal, fivefold stimulation of osteoclast‐mediated calcium release, an effect equivalent to that of prostaglandin E2 (PGE2), a reference osteolytic agent. Hypoxia also caused a moderate acidosis in calvarial cultures, presumably as a result of increased anaerobic metabolism; this observation is significant because osteoclast activation is dependent on extracellular acidification. Our experiments reveal a previously‐overlooked mechanism of considerable potential importance for the regulation of bone destruction. These findings may help explain the bone loss associated with a wide range of pathological states involving local or systemic hypoxia, and emphasize the importance of the vasculature in bone. © 2003 Wiley‐Liss, Inc.
Characterization of proliferating human skeletal muscle‐derived cells in vitro: Differential modulation of myoblast markers by TGF‐β2
Authors: Stewart Jeffrey D. , Masi Terése L. , Cumming Andrew E. , Molnar Gyongyi M. , Wentworth Bruce M. , Sampath Kuber , McPherson John M. , Yaeger Peter C.
Published: May 2003

Adult human skeletal muscle‐derived cells (HuSkMC) propagated in vitro are under investigation as a cell‐based therapy for the treatment of myocardial infarction. We have characterized HuSkMC with respect to cell identity and state of differentiation as a prerequisite to their clinical use. Flow cytometric analysis of propagated HuSkMC revealed a population of cells that expressed the myoblast markers CD56 and desmin. The presence of myoblasts in these cultures was further confirmed by their capacity to form myotubes and increase creatine kinase activity when cultured in low serum conditions. The non‐myoblast fraction of these propagated cells expressed TE7, a marker associated with the fibroblast phenotype. Spontaneous differentiation of myoblasts occurred during serial propagation of HuSkMC, as judged by myotube formation, thereby reducing the myoblast representative fraction with continued cell expansion. We examined transforming growth factor β2 (TGF‐β2) for its utility in controlling this spontaneous differentiation of adult human myoblasts in vitro. Propagation of HuSkMC in the presence of 1 ng/ml TGF‐β2 for 5 days decreased desmin expression within the myoblast population and caused a parallel reduction of creatine kinase activity. CD56 expression was unaffected, indicating a differential regulation of these myoblast markers. The reduction in desmin expression and creatine kinase activity was, however, reversible upon the removal of TGF‐β. These data collectively indicate that TGF‐β2 restrained differentiation of adult human skeletal myoblasts during propagation without causing irreversible loss of the myoblast phenotype, demonstrating the potential utility of using TGF‐β2 during cultivation and expansion of HuSkMC intended for therapeutic implantation. © 2003 Wiley‐Liss, Inc.
Large‐scale sonochemical reactors for process intensification: design and experimental validation
Authors: Gogate Parag R , Mujumdar Sukti , Pandit Aniruddha B
Published: May 2003

Acoustic cavitation results in substantial enhancement in the rates of various chemical reactions but the existing knowledge about the application of reactors based on acoustic cavitation is limited to very small capacities (of the order of few millilitres). In the present work, an overview of the application of acoustic cavitation for the intensification of chemical reactions has been presented briefly, discussing the causes for the observed enhancement and highlighting some of the typical examples. A novel reactor has been developed operating at a capacity of 7 dm3 and tested with two reactions, ie liberation of iodine from aqueous potassium iodide and degradation of formic acid. The energy efficiency of the reactor has been calculated and compared with the conventional sonochemical reactors. The effect of frequency of irradiation on the percentage conversion of the reactants has been studied. Due to quite low conversions in the case of formic acid degradation, further intensification was attempted using aeration, addition of hydrogen peroxide, and the presence of solid particles (TiO2). Compared with conventional reactors the novel reactor gives excellent results and it can be said that the future of using acoustic cavitation for process intensification lies in the development of large‐scale multiple frequency multiple transducer reactors. Copyright © 2003 Society of Chemical Industry
Capacity of activated carbon derived from pistachio shells by H3PO4 in the removal of dyes and phenolics
Authors: Attia Amina A , Girgis Badie S , Khedr Soheir A
Published: May 2003

Two activated carbons were obtained from pistachio shells by impregnation with H3PO4 under standard conditions of acid concentration (50 wt%) and heat treatment at 773 K for 2 h. The soaking time was 24 and 72 h for the two samples before thermal pyrolysis. Analysis of the N2/77 K adsorption isotherms proved that both were highly adsorbing carbons with considerable microporosity, and that the prolonged contact with activant enhanced total porosity (surface area and pore volume) and increased the amount of mesoporosity. Adsorption isotherms of probe molecules, viz methylene blue (MB), rhodamine B (RB), phenol (P) and p‐nitrophenol (PNP), were determined at room temperature, from aqueous solutions. Both the Langmuir and Freundlich model adsorption equations show satisfactory fit to experimental data. Both carbons exhibit similar adsorption parameters irrespective of their porosity characteristics. The sequence of uptake per unit weight was: PNP > MB > RB > P. Low affinity towards phenol may be associated with its competition with water molecules which are more favourably attracted to the acid surface which has a high oxygen functionality. Preferred adsorption in the order PNP > MB > RB is proposed to be a function of carbon porosity, related to the increased molecular dimensions of the solutes. Adsorption from a binary mixture of equal concentrations of MB and RB showed reduced uptake for both sorbates in comparison to the single component experiments. RB removal surpasses that of MB in the binary test and may be attributed to lower water solubility and higher molecular dimensions. Copyright © 2003 Society of Chemical Industry
Impact of the presence of solids on peroxidase‐catalyzed treatment of aqueous phenol
Authors: Wagner Monika , Nicell James A
Published: May 2003

The impact of the presence of solids on the treatment of aqueous solutions of phenol using horseradish peroxidase (HRP) and hydrogen peroxide was investigated. The solids studied were silica gel, kaolin, bentonite, cellulose and peat moss. Kaolin, bentonite, cellulose and peat moss enhanced phenol transformation at pH 5.0 and 7.0 starting at concentrations of 100, 1000 or 10 000 mg dm−3. At pH 9.0, bentonite and kaolin had negative impacts when present at 10 000 mg dm−3 and peat moss when present at 1000 mg dm−3 and 10 000 mg dm−3. In the case of bentonite and peat moss, the enhancing effects at pH 7.0 were associated with the dissolved or colloidal constituents, while in the case of kaolin, the enhancing effects were due to the solid material. Freshly made bentonite suspensions inactivated the peroxidase enzyme; however aged bentonite suspensions and their supernatants did not affect enzyme stability. H2O2 was unstable in solutions containing peat moss constituents. Phenolic solutions treated in the presence of bentonite, kaolin and peat moss were significantly less toxic than the controls, indicating that these materials were able to interact with and partially neutralize precursors of toxic reaction products. Copyright © 2003 Society of Chemical Industry
A study of antifungal antibiotic production by Thermomonospora sp MTCC 3340 using full factorial design
Authors: Gupte Monali , Kulkarni Pushpa
Published: May 2003

The three independent variables, viz concentration of carbon source (glucose), concentration of nitrogen source (soybean meal) and temperature of incubation were found to be the most important for production of antifungal antibiotic by the isolate Thermomonospora sp MTCC 3340 from one‐factor‐at‐a‐time study. These variables were varied at three levels in a total number of 27 experiments designed using full factorial design. The results on analysis using the statistical software SPSS (version 6.0) indicated that the optimum combination of the three factors for the maximum yield of the antibiotic was concentration of carbon source (glucose) 2%, concentration of nitrogen source (soybean meal) 1% and temperature of incubation 30 °C. A close fit between experimental and predicted values of the antifungal yield was obtained using one of the modes derived from the statistical analysis, indicating that this model was applicable to this production. Copyright © 2003 Society of Chemical Industry
Biotransformation of l‐menthol by twelve isolates of soil‐borne plant pathogenic fungi (Rhizoctonia solani) and classification of fungi
Authors: Miyazawa Mitsuo , Kawazoe Hideki , Hyakumachi Mitsuro
Published: May 2003

The microbial transformation of l‐menthol (1) was investigated by using 12 isolates of soil‐borne plant pathogenic fungi, Rhizoctonia solani (AG‐1‐IA Rs24, Joichi‐2, RRG97‐1; AG‐1‐IB TR22, R147, 110.4; AG‐1‐IC F‐1, F‐4, P‐1; AG‐1‐ID RCP‐1, RCP‐3, and RCP‐7) as a biocatalyst. Rhizoctonia solani F‐1, F‐4 and P‐1 showed 89.7–99.9% yields of converted product from 1, RCP‐1, RCP‐3, and RCP‐7 26.0–26.9% and the other isolates 0.1–12.0%. In the cases of F‐1, F‐4 and P‐1, substrate 1 was converted to (−)‐(1S,3R,4S,6S)‐6‐hydroxymenthol (2), (−)‐(1S,3R,4S)‐1‐hydroxymenthol (3) and (+)‐(1S,3R,4R,6S)‐6,8‐dihydroxymenthol (4), which was a new compound. Substrate 1 was converted to 2 and/or 3 by RRG97‐1, 110.4, RCP‐1, RCP‐3 and RCP‐7. The structures of the metabolic products were elucidated on the basis of their spectral data. In addition, metabolic pathways of the biotransformation of 1 by Rhizoctonia solani are discussed. Finally, from the main component analysis and the differences in the yields of converted product from 1, the 12 isolates of Rhizoctonia solani were divided into three groups based on an analysis of the metabolites. Copyright © 2003 Society of Chemical Industry
Kinetic and equilibrium modeling of liquid‐phase adsorption of lead and lead chelates on activated carbons
Authors: Krishnan K Anoop , Sheela A , Anirudhan TS
Published: May 2003

The sawdust (SD) waste generated in the timber industry was converted to a low‐cost activated carbon (SDAC) using a simpler and cheaper activation process, single‐step steam pyrolysis activation. The possibility of utilizing SDAC for the removal of lead (Pb(II)) in the absence of ligands and nitrilotriacetic acid (NTA) and ethylenediaminetetraacetic acid (EDTA) chelated Pb(II) complexes from the liquid phase was examined and the results were compared with those for commercial activated carbon (CAC). SDAC shows a high adsorption capacity for Pb(II) and Pb(II) chelates compared with CAC. The extent of adsorption of Pb(II) and Pb(II) chelates on activated carbons was found to be a function of solution pH and species distribution of Pb(II) and Pb(II) chelates. The optimum pH range for the removal of Pb(II) in the absence of ligands by SDAC was 6.5–8.0, whereas its maximum removal by CAC was observed at pH 6.5. In the presence of ligands, the extent of Pb(II) adsorption was enhanced in the pH range 2.0–5.0 and was reduced significantly in the pH range 6.0–8.0. The maximum uptake of Pb(II) chelates for both carbons was observed at pH 5.0. Kinetic models such as pseudo‐first‐order, pseudo‐second‐order and pore diffusion were tested to investigate the adsorption mechanism. Batch kinetic studies showed that the adsorption of Pb(II) from aqueous solutions with and without ligands could be best described by a psuedo‐first‐order model for both carbons. The effect of pH on the adsorption isotherms of Pb(II) and Pb(II) chelates was also investigated. The applicability of the Langmuir and Freundlich isotherms, established for various initial concentrations of the adsorbate and for different pH values, was tested at 30 °C. Copyright © 2003 Society of Chemical Industry
Isolation of ethylenediamine from industrial solution of ethylenediamine hydrochloride by electrodialysis
Authors: Jayaraman Krishnamoorthy , Velayutham David , Srinivasan Ramanujam Kanakam , Chidambaram Sankaranarayanan
Published: May 2003

An industrial solution of ethylenediamine hydrochloride which contains about 18% chloride and 12% amine was electrodialysed in a five‐compartment cell to obtain pure ethylenediamine. Different parameters such as alkali concentration and current density were studied to optimise conditions of maximum current efficiency for amine recovery and chloride removal from the feed solution. The Suitabilities of different ion‐exchange membranes for electrodialysis were compared. Variation in current efficiency for amine recovery with increases in the concentration of amine during electrodialysis was also studied. Current efficiency for amine recovery and chloride removal is about 78% and 91% respectively under optimum conditions. The amount of electrical energy consumed is 12.1 kWh kg−1 for ethylenediamine recovery and 8.6 kWh kg−1 for chloride removal. The concentration of pure amine obtained after the electrodialysis was around 20%. The results are encouraging for industrial applications whereby ethylenediamines free from chlorides can be isolated. Copyright © 2003 Society of Chemical Industry
Calcium removal from industrial wastewater by bio‐catalytic CaCO3 precipitation
Authors: Hammes Frederik , Seka Arsène , Van Hege Kris , Van de Wiele Tom , Vanderdeelen Jan , Siciliano Steven D , Verstraete Willy
Published: May 2003

High concentrations of soluble calcium in industrial wastewater present problems due to the calcification of downstream processing. The current trend towards circuit closure and increased water re‐use will escalate this problem. We investigated ureolytic microbial carbonate precipitation as a novel process for removing excess calcium from industrial effluents. Two laboratory‐scale reactors, both with a hydraulic retention time of 8 h, were fed with 1.8 dm3 of anaerobic effluent (about 11 mM Ca2+) from a paper recycling plant. Both reactors were inoculated with pre‐cultivated calcareous sludge and the treatment reactor was additionally dosed with urea to a final concentration of 8.3 mM. Even though the anaerobic wastewater was saturated as such with respect to CaCO3, urea addition and hydrolysis was shown to be a pre‐requisite for precipitation. Almost all (85–90% w/v) of the soluble calcium was precipitated as CaCO3 and removed through sedimentation in the treatment reactor. This bio‐catalytic process presents an uncomplicated and efficient method for the removal of calcium from industrial wastewater. Copyright © 2003 Society of Chemical Industry
Treatment of wastewater using a combined biological and electrochemical technique
Authors: Doan Huu D , Wu Jianning , Boithi Edwin , Storrar Megan
Published: May 2003

Simulated wastewater containing propylene glycol methyl ether, Ni2+ and Zn2+ was treated using an aerated packed column. An electrochemical cell was also installed beneath the packing support in the bottom section of the column. The flowrate of water through the column was maintained at 8.94 kg m−2 s−1. For 72 h of treatment using aeration alone, the BOD5 was reduced by 43%, 56%, and 54% for air flowrates of 0.00094, 0.00141, and 0.00188 kg m−2 s−1 respectively. On the other hand, when the electrochemical cell was activated without aeration, the BOD5 was reduced by 15%, 17%, and 23% at the applied voltages of 8, 16, and 25 V respectively. When both aeration of the wastewater and a voltage of 25 V were used, the percentage removal of BOD5, on the average, was about 65% for all air flowrates used. The concentrations of Ni2+ and Zn2+ were also reduced by 57% and 61% respectively, in the absence of the supporting electrolyte. The addition of potassium chloride (100 ppm) as the supporting electrolyte enhanced the metal removal by 30%. Copyright © 2003 Society of Chemical Industry
Dehalogenation of trihalomethanes in drinking water on Pd–Fe° bimetallic surface
Authors: Guasp Edwin , Wei Robert
Published: May 2003

Trihalomethanes (THMs), water disinfection‐byproducts, in potable water are of public health concern. Degradation of THMs by palladium‐treated iron granules (Pd–Fe° ) has been studied in a flow‐through column system. Laboratory‐scale columns of approximately 628 cm2 were loaded with Torpedo and Silica sands plus anthracite mixed with Pd–Fe° at a 10 : 1 ratio (w/w). The column setup in regard to composition and flow rate was aimed at simulating real rapid‐sand filtration conditions. A single passage of THM samples with concentration range 50–200 ppb through the column resulted in greater than 90% disappearance of parent THMs with one or more bromine atoms (CHCl2Br, CHClBr2 CHBr3), but the degradation of CHCl3 occurred much more slowly. Only 4–11% of the degradation of THMs resulted in the formation of dihalogenated products, indicating that they are degraded to form products other than dihalomethanes. The dehalogenation of brominated THMs decreased by less than 6% when the column temperature was lowered from 23° to 4 °C. Within the pH range of 4.0–6.5, there was little change in the dehalogenation, however the substantial decrease in the degradation occurred at pH 10. The Pd–Fe° also contributed significantly to the degradation of other halogenated and some nonhalogenated volatile compounds. Dehalogenation efficiency of the column was decreased by about 38% following 3 weeks of daily operation but could be regenerated with simple acid washing. No measurable Pd and iron concentrations (<300 ppb) were detected in the column effluents over a period of 3–4 weeks, indicating that the Pd–Fe° is fairly stable in the column. Copyright © 2003 Society of Chemical Industry
Removal of arsenic(III) and arsenic(V) from sulfuric acid solution by liquid–liquid extraction
Authors: Iberhan Lucyna , Wiśniewski Maciej
Published: May 2003

Extraction of arsenic(III) and arsenic(V) from sulfuric acid solution was studied. Cyanex® 923, Cyanex® 925, dialkyldithiophosphinic acids (Cyanex® 301), hydrophobic glycol (2‐ethylhexane‐1,3‐diol), and hydroxamic acids were used as extractants. The efficiency of extraction depended on extractant, diluent, valency of arsenic, and sulfuric acid concentration. Acidic reagents extracted As(III) better than As(V), while the opposite order of extraction efficiency was observed for the solvating extractants. The use of an aromatic diluent (toluene) was preferred. Toluene was found to be a better diluent for the Cyanex® 923 and Cyanex® 925 than Exxsol D 220/230 and octane. In the case of neo‐decanohydroxamic acids, the type of diluent had no significant effect on extraction of arsenic. The extraction of both As(III) and As(V) increased when the concentration of the sulfuric acid in the feed increased. The co‐extraction of sulfuric acid was observed. The extraction with hydroxamic acids was significantly slower in comparison to the extraction with other reagents. Extractant: arsenic species: sulfuric acid molar ratios were determined and they confirmed the composition of extracted species. Copyright © 2003 Society of Chemical Industry
Combined mode of operation for thermal parametric pumping
Authors: Ghasem Nayef Mohamed
Published: May 2003

In thermal parametric pumping, the temperature change can be imposed through the bed jacket (direct mode) or through temperature change of the fluid stream (recuperative mode). The process to be addressed here is thermal parametric pumping operating in a combined mode of operation by changing the temperature of the fluid stream before entering the packed bed through a heat exchanger (recuperative mode) at the same time as imposing a temperature change through the bed jacket (direct mode). Axial dispersion and the general non‐linear form of the equilibrium isotherm were taken into account in the mathematical model used to verify the experimental results of separating a binary liquid mixture of a benzene/n‐hexane/silica gel system. Copyright © 2003 Society of Chemical Industry
Biofiltration of waste gases in a reactor with a split‐feed
Authors: Mendoza JA , Veiga MC , Kennes C
Published: May 2003

The efficiency of using different feed strategies was evaluated in the case of a gas‐phase biofilter packed with an inert carrier material. During a preliminary control‐period, the biofilter was first fed with a single downflow feed of toluene. Reactor performance and biomass distribution were evaluated. The feed was then split into two flows before entering the reactor. Different feed ratios were tested during a 6‐month period, following the preliminary control stage. Splitting the feed into equal flow rates through the upper and middle part of the biofilter (in a 50 : 50 ratio) improved the performance compared with the single‐feed period. Such a high performance could also be maintained when using a higher flow rate for the upper port than for the middle port, with a feed‐ratio of approximately 70 : 30, when more biomass was formed in the upper half of the filter bed. However, performance decreased when inverting this ratio from 70 : 30 to 30 : 70, ie when the highest flow rate was fed through the middle port of the biofilter. Copyright © 2003 Society of Chemical Industry
Feasibility studies onin‐situbiological treatment of drilling muds at an abandoned site in Sicily
Authors: McDonald Jason A , Portier Ralph J
Published: May 2003

The ongoing production and bioaccumulation of drilling fluids and muds has resulted in an increased concern for reducing the environmental impact of contaminated sites. The use of bioremediation as a treatment option is an important focus of research. Objectives of this study were: (i) to assess initial toxicity of drilling mud from an agricultural setting in Galliano, Sicily (Italy) and (ii) to develop a low intervention bioremediation approach to ensure that US and international soil/ground water quality standards have been met. Total petroleum hydrocarbon content of the drilling mud was reduced to 617.0 ± 176.0, 446.0 ± 195.0, and 533.0 ± 138.0 mg kg−1, respectively, from 5000.0 ± 530.0 mg kg−1after treatment via conventionalex‐situsoil slurry reactor mixing (84.2–95% reduction). Using anin‐situapproach with bioreactors placed vertically into the zone of contamination, hydrocarbon concentrations went from 217.12 ± 43.38 and 149.68 ± 45.51 mg kg−1to 15.16 ± 3.35 and 34.27 ± 15.86 mg kg−1for control test beds (85.1 ± 11.2% reduction), and from 89.20 ± 67.42, 141.71 ± 64.80, and 197.87 ± 77.38 mg kg−1to 5.24 ± 6.15, 15.02 ± 10.20, and 9.65 ± 9.37 mg kg−1for experimental test beds (92.9 ± 3.0% reduction), respectively. Cadmium (Cd) and Selenium (Se) had exceeded Italian and state soil leachability standards (0.005 mg dm−3Cd) and (0.010, 0.050 mg dm−3Se), at the conclusion of the study.In‐situtreatment of drilling mud provided a framework for monitoring the fate of organic and residual metals toxicity in soils. Copyright © 2003 Society of Chemical Industry
Hydrogen production from sucrose using an anaerobic sequencing batch reactor process
Authors: Lin Chiu‐Yue , Jo Chia‐Hong
Published: May 2003

Studies on hydrogen production in an anaerobic sequencing batch reactor (AnSBR) indicated that the anaerobic acidogenic conversion of sucrose could produce hydrogen. The hydrogen production of acclimated sewage sludge depended on hydraulic retention time (HRT) and reaction period/settling period (R/S) ratio. A short equivalent HRT, even up to 4 h, gave good hydrogen productivity and high hydrogen production rate (HPR) values. For each equivalent HRT, R/S ratio control also increased the hydrogen productivity and HPR. Reactor operation at an intimate control of HRT and R/S ratio was preferable for hydrogen production. At HRT 8 h, R/S ratio 5.6 and an organic loading rate of 0.23 mol‐sucrose dm−3 day−1, each mole of sucrose in the mesophilic hydrogenic reactor yielded 2.6 mole of hydrogen; each gram of biomass produced 0.069 mole of hydrogen per day. Copyright © 2003 Society of Chemical Industry
Approach to a pulse photoelectrocatalytic process for the degradation of organic pollutants
Authors: He Chun , Xiong Ya , Zha Changhong , Wang Ximei , Zhu Xihai
Published: May 2003

Ag–TiO2 composite film was supported on indium–tin oxide glass (ITO) by a dip‐coating and subsequent photodeposition procedure. The composite film was employed as the photoanode for photoelectrocatalytic (PEC) degradation of Acid Orange II. The degradation efficiency for the PEC process on the Ag–TiO2/ITO electrode with a 0.8 V anodic bias is significantly higher than that for a photocatalytic process on Ag–TiO2/ITO film or for a PEC process on a neat TiO2/ITO photoanode. A new PEC technology with a pulse anodic bias was also proposed in order to solve the problem of the loss of deposited Ag from the Ag–TiO2/ITO. It was found that the PEC process with a 4.2 V pulse anodic bias could much more efficiently degrade Acid Orange II than that with a constant anodic bias of 0.8 V or 4.2 V. Moreover, when the duration of the open and close circuit time was identical, the treatment efficiency was observed to be optimal. Copyright © 2003 Society of Chemical Industry
Pseudoaneurysm of the dorsalis pedis artery: Color Doppler sonographic and angiographic findings
Authors: Özdemir Hüseyin , Mahmutyazıcıoğlu Kamran , Özkökeli Mehmet , Savranlar Ahmet , Özer Tülay , Demirel Fatma
Published: May 2003

Pseudoaneurysm of the dorsalis pedis artery is an uncommon condition that is usually caused by a traumatic injury or an iatrogenic intervention. The patient usually complains of an enlarging painless, pulsatile mass. A tentative diagnosis may be made by palpation of the pulsatile mass and detection of an associated systolic bruit. Color Doppler sonographic and arteriographic examinations can be used to confirm the diagnosis. We report the case of a 17‐year‐old patient with a posttraumatic pseudoaneurysm of the dorsalis pedis artery. Sonographic examinations revealed pulsatile flow into and out of a cystic structure surrounded by a thick hypoechoic wall and a “to‐and‐fro” pattern in the neck of the vascular mass; these findings were consistent with the diagnosis of a pseudoaneurysm. Angiography confirmed the diagnosis. The patient was treated with ligation of the artery and resection of the pseudoaneurysm. He recovered well after surgery and remained free of symptoms 3 months postoperatively. We believe that color Doppler sonography should be the procedure of choice for use in diagnosing pseudoaneurysms; arteriography can then be used to evaluate the alternative blood supply before surgery is undertaken. © 2003 Wiley Periodicals, Inc. J Clin Ultrasound 31:283–287, 2003
Intraoperative transesophageal sonographic monitoring of tumor thrombus in the inferior vena cava during radical nephrectomy and thrombectomy for renal cell carcinoma
Authors: Tomita Yoshihiko , Kurumada Shigenori , Takahashi Kota , Ohzeki Hajime
Published: May 2003

We report the case of a 58‐year‐old woman with renal cell carcinoma in whom real‐time transesophageal sonographic monitoring of the tumor thrombus in the inferior vena cava provided dynamic information, allowing us to determine the appropriate operative procedure to use. Observation of the thrombus throughout the operation showed that mobilization of the liver resulted in compression of the inferior vena cava against the spine, increasing the risk of migration of the tumor thrombus and reinforcing the need to maintain adequate positioning of the liver to prevent such compression. The surgery was completed successfully, and the patient's postoperative course was uneventful. We recommend the use of real‐time transesophageal sonographic monitoring of the tumor thrombus during such surgical procedures. © 2003 Wiley Periodicals, Inc. J Clin Ultrasound 31:274–277, 2003