bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

AbstractIntrinsic 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

AbstractHypoxia 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

AbstractAdult 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

AbstractAcoustic 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

AbstractTwo 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

AbstractThe 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

AbstractThe 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

AbstractThe 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

AbstractThe 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

AbstractAn 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

AbstractHigh 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

AbstractSimulated 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

AbstractTrihalomethanes (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

AbstractExtraction 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

AbstractIn 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