bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tyrosine protein kinase expression in long‐term quiescent WI‐38 cells following growth factor simulation
Authors: Korcz Aleksandra , Soprano Dianne Robert , Soprano Kenneth J. 
Published: May 2005

AbstractWe have used the WI‐38 cell long‐term quiescent model system to study the regulation of cell cycle progression at the molecular level. By modulating the length of time that WI‐38 cells are density arrested, it is possible to proportionately alter the length of the prereplicative or G‐1 phase which the cell traverses after growth factor stimulation in preparation for entry into DNA synthesis. Stimulation of long‐and short‐term density arrested WI‐38 cells with different growth factors or higher concentrations of individual growth factors does not alter the time required by long‐term cells to enter S after stimulation. However, the time during the prereplicative period for which these growth factors are needed is different. Long‐term quiescent WI‐38 cells require EGF to traverse the G‐0/G‐1 border but do not need and apparently cannot respond to IGF‐1 during the first 10 h after EGF stimulation, the length of the prolongation of the prereplicative phase. This suggests that EGF stimulation of long‐term quiescent WI‐38 cells initiates a series of molecular events which make these cells “competent” to respond to the “progression” growth factor, IGF‐1. In light of the well‐established role of protein tyrosine kinases in signal transduction, we set out to identify, clone, and analyze the expression of receptor and non‐receptor tyrosine kinases which potentially could play a role during the prolongation of the prereplicative phase in making the long‐term quiescent WI‐38 cells competent to respond to IGF‐1. We obtained 49 clones representing 11 different receptor and non‐receptor type protein tyrosine kinases. Analysis of expression of these clones revealed a variety of different patterns of expression. However, the most striking pattern was exhibited by IGF‐1 receptor. Our results suggest that induction of IGF‐1 receptor mRNA by EGF may be an important event in the establishment of competence by EGF in long‐term density arrested WI‐38 cells. © 1995 Wiley‐Liss, Inc.
Steroid‐hormone regulation of myosin subunit expression in smooth and cardiac muscle
Authors: Calovini Tanja , Haase Hannelore , Morano Ingo 
Published: May 2005

AbstractWe investigated the effects of ovarectomy and the steroid hormones estrogen and testosterone on the in vivo expression of heavy (MHC) and light (MLC) chains of myosin in the heart, uterus, and aorta of rats. In the heart, ovarectomy decreased alpha‐MHC expression, while both steroid hormones normalized it. Differential steroid hormone effects could be observed on myosin subunit expression of smooth muscle. Testosterone but not estrogen normalized the ovarectomy‐induced decreased expression of SM1 and strongly increased the expression of 5′‐inserted MHC in the uterus. Estrogen but not testosterone normalized the ovarectomy‐induced diminished MLC17a expression. In contrast to the uterus, no steroid hormone effects on myosin subunit expression could be observed in the aorta. © 1995 Wiley‐Liss, Inc.
Bone marrow interface: Preferential attachment of an osteoblastic marrow stromal cell line
Authors: Benayahu D. , Fried A. , Efraty M. , Robey P. Gehron , Wientroub S. 
Published: May 2005

AbstractIn this study, we report on the cell adhesion properties of marrow stromal cells to extracellular matrix components such as collagen and noncollagenous proteins. The osteoblastic cells and their non‐osteoblastic counter‐parts (MBA series) from the marrow stroma differentially recognized a spectrum of extracellular matrix proteins. The osteoblastic cells, MBA‐15, preferentially attached to bone matrix proteins, whereas fibroendothelial MBA‐2.1 and adipocytic 14F1.1 cells did not. The MBA‐15 cells demonstrated a preference in their attachment to fibronectin > mixture of collagens > bone matrix extracts > collagen type 1 > noncollagenous proteins. Clonal subpopulations derived from the MBA‐15 cell line representing various stages along the osteogenic lineage expressed differential attachment preference. MBA‐15.4, a less differentiated clonal line, was compared to MBA‐15.6, a mature cell line. © 1995 Wiley‐Liss, Inc.
Evidence for a single pool of myo‐inositol in hormone‐responsive WRK‐1 cells
Authors: Monaco Marie E. , Moldover Nancy H. 
Published: May 2005

AbstractPrevious reports have suggested the existence of at least two pools of cellular myo‐inositol (Ins); it has been further hypothesized that only one of these pools is utilized during hormone‐activated, cyclic phosphatidylinositol (PtdIns) resynthesis. In an effort to investigate this possibility, we have undertaken kinetic studies of Ins metabolism in WRK‐1 cells. Our results indicate that a single pool of Ins is involved in both basal and activated PtdIns synthesis. Ins generated by the hydrolysis of phosphatidylinositol 4,5‐bisphosphate (PtdInsP2) mixes with the existing pool of free Ins and is not used exclusively for resynthesis of PtdIns. © 1995 Wiley‐Liss, Inc.
Identification of functional insulin‐like growth factor‐II/mannose‐6‐phosphate receptors in isolated bone cells
Authors: Martinez D. A. , Zuscik M. J. , Ishibe M. , Rosier R. N. , Romano P. R. , Cushing J. E. , Puzas J. E. 
Published: May 2005

AbstractThe role of the IGF‐II/cation independent mannose‐6‐phosphate (IGF‐II/M6P) receptor in the transduction of cellular effects evoked by IGF‐II has been extensively debated in the literature. Many reports suggest that IGF‐II transduces its effects through the IGF‐I receptor, while others show that IGF‐II utilizes the type II receptor to affect cellular activity. This study (1) verifies the presence of the IGF‐II/M6P receptor in rat calvarial osteoblasts, and (2) evaluates the ability of the receptor to initiate intracellular single. Using conventional receptor binding assays, it was found that osteoblasts bind IGF‐II with high affinity. Scatchard analyses indicated that there are 5.08 × 104 IGF‐II/M6P receptor per osteoblast with a Kd near (2.0 nM). The receptor protein was further identified by cross‐linking with 125I‐IGF‐II. Northern analysis was used to identify an mRNA transcript for the IGF‐II/M6P receptor protein. To examine if the IGF‐II/M6P receptor can initiate second messenger signals, the ability of IGF‐II to evoke Ca2+ transients was evaluated. Osteoblasts pretreated with IGF‐I did not lose their ability to respond to IGF‐II. Further, a polyclonal antibody against the rat IGF‐II/M6P receptor (R‐II‐PAB1) (1) was able to evoke its own Ca2+ response, and (2) was able to block the generation of Ca2+ transients caused by IGF‐II. The data in this report show that the osteoblastic Ca2+ response to IGF‐II appears to be caused by an intracellular release of Ca2+ which is mediated by the IGF‐II/M6P receptor making it possible to envision how the receptor may be an important modulator of osteoblast mediated osteogenesis. © 1995 Wiley‐Liss, Inc.
Cultured AIDS‐related kaposi's sarcoma (AIDS‐KS) cells demonstrate impaired bioenergetic adaptation to oxidant challenge: Implication for oxidant stress in AIDS‐KS pathogenesis
Authors: Mallery S. R. , Bailer R. T. , Hohl C. M. , Ng‐Bautista C. L. , Ness G. M. , Livingston B. E. , Hout B. L. , Stephens R. E. , Brierley G. P. 
Published: May 2005

AbstractDespite its recognition as the most prevalent HIV associated cancer, speculation still abounds regarding the pathogenesis of AIDS‐related Kaposi's sarcoma (AIDS‐KS). However, it has been established that both cytokines, e.g. IL‐6, and HIV‐associated products, e.g., Tat, are integral in AIDS‐KS cellular proliferation. Further, both experimental and clinical evidence is accumulating to link reactive oxygen intermediates (ROI) with both cytokine induction (primarily via nuclear factor‐κB [NF‐κB] dependent routes) as well as the subsequent cytokine, tumor necrosis factor α (TNFα) stimulation of HIV replication. Features of AIDS‐KS patients, such as retention of phagocytes, presence of sustained immunostimulation, and a frequent history of KS lesions arising at traumatized sites, make oxidant stress a viable clinical factor in AIDS‐KS development. Time course nucleotide profile analyses show that AIDS‐KS cells have an inherent, statistically significant, biochemical deficit, even prior to oxidant stress, due to (1) a more glycolytic bioenergetic profile, resulting in lower levels of high energy phosphates (impairing capacity for glutathione [GSH] synthesis and DNA repair); (2) lower levels of NADPH (compromising the activities of GSSG reductase and peroxidase function of catalase); and (3) reduced levels of GSH (impeding both GSH peroxidase and GSH‐S‐transferases). Following exposure to physiologically relevant levels of H2O2 only the human microvascular endothelial cells (a putative AIDS‐KS progenitor cell) responded with bioenergetic adaptations that reflected co‐ordination of energy generating and cytoprotective pathways, e.g., retention of the cellular energy charge, increased NAD+, and an accentuation of the ATP, NADPH, and total adenine nucleotide differences relative to AIDS‐KS cells. Also, some of the AIDS‐KS strains retained intracellular GSSG subsequent to oxidant challenge, inviting the formation of deleterious protein mixed disulfides. While the results of our study address some AIDS‐KS issues, they also raise an etiological question, i.e., Does the inability to tolerate oxidant stress arise in conjunction with AIDS‐KS neoplastic development, or is it pre‐existing in the population at risk? Regardless, use of antioxidant therapy (low risk/potentially high benefit) in both the “at risk” population as well as in those individuals with active disease may prove a useful preventative and/or treatment modality. © 1995 Wiley‐Liss, Inc.
Microbial metabolism of xenobiotics: Fundamental and applied research
Authors: Singleton Ian 
Published: May 2005

AbstractThe ability of microorganisms to metabolise xenobiotic compounds has received much attention due to the environmental persistence and toxicity of these chemicals. The microbial degradation of xenobiotics is seen as a cost effective method of removing these pollutants from the environment by a process now known as bioremediation. Microbial treatment of industrial effluents is also possible. Fundamental work has revealed that a wide variety of microorganisms are capable of degrading an equally wide range of organic pollutants. Pure and mixed cultures of microorganisms have been studied and degradation is observed under both aerobic and anaerobic conditions. Breakdown products have been found during work on the degradative pathways involved and toxicological assessments using bacteria and higher organisms (fish, plants) have been used to determine the toxicity of these intermediates. Many of the degradative genes responsible for xenobiotic metabolism are present on plasmids, transposons or are grouped in clusters on chromosomes. This provides clues to the evolution of degradative pathways and makes the task of genetic manipulation easier such that new microbial strains capable of efficiently degrading pollutants can be developed. Several enzymes involved in xenobiotic metabolism have been isolated and factors affecting their activity investigated. Genetically manipulated strains or naturally isolated organisms may be used in the treatment of industrial wastes or as inocula to enhance degradation in the environment. Environmental factors, including pH, temperature, bioavailability, nutrient supply and oxygen availability have been shown to affect xenobiotic biodegradation. These factors must be optimised to obtain a satisfactory microbial treatment process. Using information gained from fundamental research, bioremediation technology has been used to detoxify different contaminated environments and the results of field studies are very encouraging.
The isomerization kinetics of lactose to lactulose in the presence of borate
Authors: Kozempel Michael , Kurantz Michael 
Published: May 2005

AbstractThe kinetics of the isomerization of lactose to lactulose in the presence of boric acid and NaOH was studied. A first order equation fits the data for the rate controlling reaction—the formation of a boric acid–lactulose complex. Since the reaction is optimum at a molar ratio of boric acid to lactose of 1·0 and pH 11, a model was developed for application at these reaction conditions.
Immobilization of hydrophobic lipase derivatives on to organic polymer beads
Authors: Basri Mahiran , Ampon Kamaruzaman , Yunus W. M. Zin Wan , Razak Che Nyonya A. , Salleh A. Bakar 
Published: May 2005

AbstractA simple and effective method of lipase immobilization is described. Lipase from Candida rugosa was first modified with several hydrophobic modifiers before being adsorbed on to organic polymer beads. The soluble hydrophobic lipase derivatives adsorbed more strongly on to the various polymers as compared with the native lipase. The optimal adsorption temperature of the native and modified lipases on all the polymers was 40°C. The optimal pH of adsorption was between 6 and 7. Lipase immobilized in this manner produced high catalytic recoveries which were affected by the type of modifiers, degree of modification and type of supports used. Monomethoxypolyethylene glycol (1900) activated with p‐nitrophenyl chloroformate was found to be the best modifier of the enzyme at 95% modification, for adsorption to the polymers. Increasing the degree of modification of the enzyme increased the activity which was immobilized. Generally, both native and hydrophobic lipase derivatives showed higher specific activities when immobilized on polar polymers compared with non‐polar polymers.
An affinity adsorbent derived from aminopropyl silica for serine protease chromatography
Authors: Chang Ru‐Mu , Lee Wen‐Chien 
Published: May 2005

AbstractA silica‐based adsorbent for affinity chromatography of serine protease was prepared by bonding p‐aminobenzamidine (pABZ) to aminopropyl silica. Silanization of silica with both γ‐aminopropyltrimethoxysilane and γ‐amino‐propyltriethoxysilane under anhydrous conditions led to a monolayer density of primary amino groups. The aminopropyl silica was converted to primary hydroxylcontaining silica via diazotization, and consequently activated with p‐nitrophenyl chloroformate and immobilized with ligand pABZ. The resultant silica–pABZ has a ligand density of 13.8 μmol g−1. Pyridine was indicated by the data to increase the reactivity of the chloroformate toward the hydroxyl group more efficiently than 4‐dimethylaminopyridine. Two stages of adsorption were found in batch adsorption of trypsin with an equilibrium adsorption isotherm of the Langmuir type. When the chromatographic column packed with this silica–p ABZ was operated under a higher flow rate (2·33 cm3 min−1) and with 3 g dm−3 of crude urokinase as the influence, the yield was 55%. Both the flow rate and the concentration of the crude protein were shown, by measuring the dynamic binding capacity from chromatographic experiments, to be the factors which influenced the chromatographic efficiency.
Physicochemical factors affecting the formation of the biological response modifier scleroglucan
Authors: Taurhesia Shelly , McNeil Brian 
Published: May 2005

AbstractThe use of phosphate as the limiting nutrient for scleroglucan formation by Sclerotium glucanicum led to stimulation of glucan formation. Final exopolysaccharide concentrations achieved in phosphate‐limited (18·9 kg m−3) cultures were much higher than in the usual nitrogen‐limited fermentations (11·4 kg m−3). The mechanism by which phosphate limitation engendered glucan formation may be largely non‐specific, involving a generalised diversion of the carbon source away from biomass formation and towards glucan synthesis. The effect of stirrer speed was examined in a fermenter fitted with a 6‐bladed Rushton turbine impeller of 0·5 vessel diameter. It was noted that biomass and scleroglucan formation showed different optima. This may have been due to the markedly different oxygen requirements of the two processes.
1,4‐Dihydroxyanthraquinone‐2‐carboxamides and 2,3‐dicarboximides. Orange dyes for synthetic polymer fibres
Authors: Peters Arnold T. 
Published: May 2005

AbstractHydrolysis of 1,4‐dihydroxy‐2,3‐dicyanoanthraquinone gives 1,4‐dihydroxyanthraquinone‐2,3‐dicarboxylic anhydride, reaction of which with alkylamines and arylamines gives either the 2‐carboxamide or 2,3‐dicarboximide derivatives. These compounds colour polyester in brownish‐orange hues having good light fastness. The colour of the dyes is discussed in relation to other 2‐substituted derivatives of 1,4‐dihydroxyanthraquinone.
A comparative study of effects of soy and corn flours on the evolution of alcohol fermentation in successive batches
Authors: Maia Amazile B. R. A. , Nelson David L. 
Published: May 2005

AbstractThe evolution of alcohol fermentation in ten successive batches was analysed using three distinct media, all containing commercial sucrose as substrate. The first medium contained mineral salts and yeast extract, the second contained only soy flour as the nutrient source and the third only corn flour. The alcohol contents and yeast viabilities were determined during ten successive batches with each medium. There was no significant differentiation in ethanol yield during the total period of tests (60 h with each medium). However, the medium containing soy flour showed the best evolution of yeast viability. The best specific productivity of ethanol was obtained with the medium containing corn flour, which justifies the traditional and empirical use of the component in the fermentation step by the small producers of sugar cane spirits in Brazil.
Rational design of metal mesh particles for biological fluidized bed reactors
Authors: Kargi Fikret , Toprak Hikmet 
Published: May 2005

AbstractUtilization of metal mesh particles as a support material in biological waste treatment and fermentation technology offers special advantages over other immobilization methods. A theoretical analysis of fluidized bed bioreactors utilizing metal mesh support particles is presented and optimization of important parameters for rational design of metal mesh particles is discussed.
Selectivity aspects in the multi‐phase hydrogenation of α,β‐unsaturated aldehydes over supported noble metal catalysts: Part I
Authors: Satagopan V. , Chandalia Sampatraj B. 
Published: May 2005

AbstractThe selective hydrogenation of cinnamaldehyde and other unsaturated aliphatic aldehydes under a two‐phase liquid system using toluene and aqueous alkaline solution over supported palladium catalysts has been investigated with a view to obtaining the corresponding saturated aldehydes with sufficiently high selectivities. In the case of cinnamaldehyde, the effects of various process parameters on the reaction rate and selectivity with respect to the aldehyde have been investigated. The results obtained are likely to be useful for the rational design of the process for the production of industrially relevant products, such as hydrocinnamaldehyde and citronellal using cinnamaldehyde and citral as the starting materials.
Activity of ruthenium hydrogenation catalysts in copper(II) formate decomposition
Authors: Kluson Petr , Cerveny Libor , Krivska Marie , Had Jiri , Laurentova Simona 
Published: May 2005

AbstractCharcoal‐, silica‐, alumina‐ and titanium(IV) oxide‐supported ruthenium catalysts, prepared by conventional impregnation and incipient wetness methods from a ruthenium(III) oxide precursor were tested in copper(II) formate decomposition in aqueous solution. Such a reaction was found to be an efficient and simple activity test of charcoal‐supported catalysts. The application of this reaction for a bimetallic ruthenium–copper catalyst preparation was also suggested. Experimental results were compared with those obtained using commercial catalysts and ruthenium black.
Kinetic model for substrate utilization and methane production during the anaerobic digestion of olive mill wastewater and condensation water waste
Authors: Martín Antonio , Borja Rafael , Banks Charles J. 
Published: May 2005

AbstractA kinetic model to describe the anaerobic digestion of olive mill wastewater (OMW) and condensation water from thermally‐concentrated OMW has been developed. Two complementary kinetic descriptions, for substrate utilization and methane production, were derived. The model equations accounted for extracellular hydrolysis of complex substrates (OMW) and considered the hydrolysed products as the limiting substrates for cell growth and product formation according to Monod kinetics. Predicted relationships agreed well with experimental data. When extracellular hydrolysis was required and rate limiting, as in the case of the OMW, the equations were reduced to a Contois‐type form. However, if no extracellular hydrolysis of the substrate was involved, as in the case of the condensation water from thermally‐concentrated OMW, the equations were in the form of a Monod‐type relationship. Thus, the equations represented a generalized kinetic expression for anaerobic fermentation relating the Monod and Contois equations, which held in the two extreme cases.
Enzymatic resolution of 1‐hydroxy‐2,3‐dihydroindene and 1‐hydroxy‐1,2,3,4‐tetrahydronaphthalene derivatives using lipases
Authors: Izumi Taeko , Murakami Satoshi 
Published: May 2005

Abstract1‐Hydroxy‐3‐methyl‐2,3‐dihydroindene and 1‐hydroxy‐1,2,3,4‐tetrahydronaphthalene derivatives were kinetically resolved with lipases by transesterification using vinyl esters or butyric anhydride as acyl donors. These results are discussed in considering the influence of acyl donors and with reference to Prelog's proposal that certain enzymes exhibit ‘product stereospecificity’.
Use of INT to determine the respiratory activity of immobilised and free Penicillium chrysogenum
Authors: Mussenden Paul J. , Bucke Christopher , Saunders Gunter , Keshavarz Tajalli 
Published: May 2005

AbstractThe specific oxygen uptake rates (OUR) of k‐carrageenan‐immobilised and free cell cultures of Penicillium chrysogenum were determined using an oxygen electrode in a closed chamber. This was compared with the respiratory activity determined by the extent of staining with iodonitrophenyl tetrazolium chloride (INT). The degree of INT staining correlated with the OUR; an increase in INT deposition corresponding to an increase in the measured OUR. The INT staining technique could therefore be used to determine cell respiratory activity. In this way a profile of fungal cell activity throughout immobilised cell aggregates and free cell pellets was determined. In both types of cell culture, after the initial growth period only the peripheral biomass was observed to be active.
Characterization of extracellular thermostable xylanase from Chaetomium globosum
Authors: Gandhi Jagruti P. , Rao K. Koteswara , Dave Prafulla J. 
Published: May 2005

AbstractThis paper deals with the characterization of extracellular thermostable xylanase produced by Chaetomium globosum, an ascomycete fungus. The crude extracellular enzyme was found to have temperature and pH optima of 60°C and 5·0 respectively. The enzyme hydrolyses xylan to a mixture of xylo‐oligomers. Xylobiose and xylose are the major breakdown products.