bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation of fibrin glue: A study of chemical and physical methods
Authors: Silver Frederick H. , Wang Ming‐Che , Pins George D. 
Published: May 2005

AbstractConcentrated fibrinogen was prepared from whole blood by cryoprecipitation or chemical precipitation and combined with thrombin to make fibrin glue (FG). Surgical application of FG include control of bleeding, adhesion of tissues, and sealing of tissue defects. The purpose of this study was to compare cryoprecipitation (cryo) of fibrinogen to precipitation using ethanol, ammonium sulfate (AS), and poly(ethylene glycol) (PEG). Our results suggest that AS precipitation is as effective as cryo in yielding fibrin glues with high bond strengths and is more effective than ethanol and PEG precipitation. In addition, the volume of FG per milliliter of plasma is greater after AS precipitation than after a single freeze‐thaw cycle. It is concluded that AS is an efficient means for preparing FG from autologous blood. © 1995 John Wiley & Sons, Inc.
Foam fractionation of proteins: Concentration of aqueous solutions of bovine serum albumin
Authors: Schnepf Robert W. , Gaden Elmer L. 
Published: May 2005

AbstractThe effects of pH and concentration on foam separation of the protein bovine serum albumin (BSA) from solution has been studied. All results agree, at least qualitatively, with theory. BSA maximum enrichments were observed at the isoelectric pH and enrichment ratio was found to increase with decreasing protein concentrations.
The protection of some baked products against moulds by chemical and irradiation techniques
Authors: Axford D. W. E. , Ottaway F. J. H. 
Published: May 2005

AbstractThe nature of the problem of mould growth on baked products is discussed. Existing information on the reduction of this source of wastage by chemical and irradiation techniques is briefly reviewed, and new experimental evidence is presented relating to the use of these procedures. The effectiveness of ionizing radiations in preventing mould growth is indicated but there are many problems to be considered before it can be regarded as a satisfactorily established technique.
The course of bacterial population growth in batch and continuous culture according to the theory of Monod
Authors: Northam Jack I. 
Published: May 2005

AbstractThe equations of Monod that describe the course of bacterial population growth and substrate concentration during continuous culturing are usually analysed with reference to steady‐state conditions. These equations are analysed to give information on the course of bacterial population growth from inoculation to the achievement of a steady‐state condition. For common values of certain parameters occurring in Monod's development, growth is well approximated by an exponential law (logarithmic phase) which depends on: (a) the maximum specific growth‐rate constant for the organism and medium concerned, and (b) the constant dilution rate.
Transient and steady states in continuous fermentaion. Theory and experiment
Authors: Luedeking Robert , Piret Edgar L. 
Published: May 2005

AbstractSteady‐state and transient equations are derived for continuous‐flow fermentation processes. Analytical as well as graphical methods for predicting from batch data the performance of single‐ or multi‐stage continuous fermentations are developed. The criteria for stability are also examined. Actual experimental measurements of continuous lactic acid fermentations conducted at controlled pH levels agree with the theory developed.
Combined irradiation–heat processing of canned foods: Green peas inoculated with anaerobic bacterial spores
Authors: Kempe Lloyd L. , Graikoski John T. , Bonventre Peter F. 
Published: May 2005

AbstractCombined irradiation–heat processing is shown to be syner‐gistic for killing anaerobic bacterial spores inoculated into canned green peas. Following 1·2 megarad of gamma irradiation an F0 of 0·5 sterilized green peas inoculated with either 5,000,000 Clostridium botulinum 213 B or 300 PA 3679 spores per can. This processing schedule must be considered a minimum since it is based on a limited number of cans. Because sterilization by either irradiation or heat alone can damage the organoleptic properties of canned foods, the lowered schedules possible with combined processing may prove to be of value for preserving vegetables as well as meats.
The removal of nitrogen and phosphorus from sewage effluents through the use of algal culture
Authors: Witt V. , Borchardt J. A. 
Published: May 2005

AbstractThis study is designed to establish fundamental data which will permit the eventual application of algal culture to the removal of nutrients from sewage plant effluents. A test cell is described which gives reproducible data when environmental parameters are varied. The effect of changes in temperature, light intensity and culture density as reflected in the growth rate, are shown, and the influence of these parameters on the removal of nitrogen and phosphorus under the test conditions indicated. The importance of an adequate carbon source and proper pH control is demonstrated. The organisms used were Scenedesmus and Chlorella in mixed or unialgal cultures.
Sewage sludge conditioning with sulphur oxidizing bacteria
Authors: Johnston Wendye E. , Ives K. J. 
Published: May 2005

AbstractPrevious research has shown that a reduction in pH of digested sewage sludge considerably improves its filtration characteristics. Experiments with sulphur oxidizing bacteria (thiobacilli) have shown that under aerobic conditions with a supply of elemental sulphur the pH can be reduced by microbial sulphuric acid synthesis. A semi‐continuous process of sludge conditioning by this method was evolved, which would continue if the pH did not rise above pH 7 and if sufficient sulphur was supplied. Attempts to substitute sodium thiosulphate, or sulphide‐rich sludge, for elemental sulphur were unsuccessful. A note is appended on a method of enumerating the thiobacilli.
Purification process development using radioactive vitamin B12
Authors: Bungay H. R. , Marsh M. M. , Peterson R. C. 
Published: May 2005

AbstractThe use of low‐level radiotracer techniques permits rapid, precise estimation of yields and material balances for processing steps. This is a great advantage for development work with Vitamin B12 because the conventional methods using microbiological assays are slow and lack precision. Release of the vitamin from S. griseus cells, selection of absorbing resins, and screening of eluting agents were followed using cobalt‐60 cyanocobalamin. The method is most valuable when supplemented by microbiological assays because the yields of radioactivity are misleading in conditions which inactivate the vitamin.
Pilot plant studies on parboiling of rice—III. Effect of hot soaking and mechanical drying on the nutritive value of parboiled rice
Authors: Mazumder A. C. , Bose A. N. , Ganguli N. C. , Guha B. C. 
Published: May 2005

AbstractHot soaking of paddy in the parboiling process does not significantly affect the digestibility of rice compared to ‘raw’ rice. Mechanically dried parboiled rice appears to be slightly more digestible in vitro than sun‐dried parboiled rice. It is also significantly superior in thiamine value.
The formation of magnetic iron sulphide by bacterial reduction of iron solutions
Authors: Freke Anthony M. , Tate Donald 
Published: May 2005

AbstractLaboratory scale experiments have been carried out with sulphate‐reducing bacteria growing under anaerobic conditions to investigate the removal of iron from iron‐containing solutions. The complete removal of iron, as the insoluble sulphide, has been achieved from both ferrous and ferrous–ferric sulphate solutions. It has been found that under certain conditions a magnetic iron sulphide is produced. This aggregates under the influence of a magnetic field and settles at a rate of some 30 in./min. The magnetic sulphide has only been obtained from intermittent continuous cultures. With the system employed, rates of removal of up to 150 mg of iron per litre of culture vessel per hour have been obtained.
Modulation of extracellular‐matrix synthesized by cultured stromal cells from normal human breast tissue by epidermal growth factor
Authors: Baley Patricia , Lützelschwab Irene , Scott‐Burden Timothy , Küng Willy , Eppenberger Urs 
Published: May 2005

AbstractA routine, reproducible procedure was developed for the preparation and characterization of stromal cells from normal human breast tissue obtained by reduction mammaplasty. Isolates (n = 15) all exhibited enhanced rates of proliferation, even in the presence of 20% fetal calf serum, when exposed to epidermal growth factor or transforming growth factorα (both 10−8 M). Cellular responsiveness to these growth factors was consistent with expression of specific surface receptors for epidermal growth factor (∼104/cell). In cultures, stromal cells elaborated an extensive, crosslinked, insoluble extracellular matrix which remained firmly associated with the plastic surface of tissue culture ware upon lysis of cells. The insoluble matrix material was analyzed using enzymatic digestion procedures following incorporation of radio‐labelled precursors into macromolecular material prior to lysis and preparation. The relative proportion of glycoconjugate (glycopeptides and proteoglycans) and collage‐nous material present in matrix material was ∼45% and ∼55%, respectively, and this was modulated by inclusion of epidermal growth factor into culture medium to ∼60% and ∼40%, respectively. Under similar culture conditions stromal cells synthesized twice as much hyaluronate as was produced by control cultures. By use of specific antibody preparations we identified at least four species of glycopeptide present in stromal matrices (namely, fibronectin, laminin, tenascin, and thrombospon‐din) as well as three types of collagen (types I, III, and IV). The rapid and reproducible procedure for the preparation of radiolabelled insoluble matrix material from normal human breast tissue allows for the study of cellular interaction involving extracellular matrix turnover and degradation.
Suppression of protein kinase C and the stimulation of glucocorticoid receptor synthesis by dexamethasone in human fibroblasts derived from tumor tissue
Authors: Gadson Preston , McCoy Judy , Wikström Ann Charlotte , Gustafsson Jan‐Ake 
Published: May 2005

AbstractExposure of fibroblasts derived from keloid tissues, desmoid and dermal tissue from individuals with Gardner's syndrome ‐(GS) to dexamethasone resulted in the suppression of protein kinase C ‐(PKC) activity and [3H] thymidine incorporation into DNA, and a 20°fold induction of glutamine synthetase activity. Treatment of GS and keloid fibroblasts with 0.1 μM dexamethasone for 36 h increased glucocorticoid receptor ‐(GR) synthesis, as determined by [35S] methionine labeling and immunoprecipitation with a monoclonal antibody to the human GR. The suppression of PKC activity by dexmethasone was shown to result from a loss of protein mass as determined by immunoblotting using an antibody to PKC type III. In contrast to these results, exposure of fibroblasts isolated from normal tissues to dexamethasone did not result in the suppression PKC and [3H]thymidine incorporation, there was only a sixfold induction of glutamine synthetase, and a decrease of GR synthesis. As no primary receptor binding defect could be detected, the altered response of tumor cells to steroid‐occupied receptor indicates a partial post‐receptor binding defect in GS and keloid cells.
Growth and protein phosphorylation in the Nb2 lymphoma: Effect of prolactin, cAMP, and agents that activate adenylate cyclase
Authors: Rayhel Elizabeth J. , Hughes James P. , Svihla Doreen A. , Prentice David A. 
Published: May 2005

AbstractThe Nb2 T lymphoma is unique in that these lymphocytes proliferate in response to prolactin as well as in response to interleukin‐2. In this study, we have examined the responsiveness of the adenylate cyclase system in Nb2 cells and the role of this signaling system in regulating proliferation and protein phosphorylation. An analog of cAMP inhibited prolactin‐stimulated proliferation and blocked a prolactin‐induced decrease in protein phosphorylation. Forskolin, a potent activator of adenylate cyclase in T lymphocytes, did not elevate cAMP levels in Nb2 cells and was not an effective inhibitor of prolactin‐induced proliferation. In fact, one preparation of forskolin stimulated proliferation of quiescent Nb2 cells. Like forskolin, prostaglandin E2 did not stimulate cAMP production in Nb2 cells even though, it increased cAMP in a preparation of rat peripheral blood lymphocytes. Cholera toxin appeared to ADP‐ribosylate a stimulatory guanine nucleotide‐binding protein in Nb2 cells, but the toxin did not increase intracellular levels of cAMP nor was it a potent anti‐mitogenic agent. Pertussis toxin, an agent that can increase cAMP production through suppression of the inhibitory guanine nucleotide‐binding protein, exerted only minor anti‐proliferative actions on prolactin‐stimulated Nb2 cells. These data suggest that cAMP inhibits Nb2 cell proliferation and prolactin‐induced changes in protein phosphorylation but that the adenylate cyclase system in our clone of Nb2 cells responds poorly to agents that normally increase cAMP.
Alteration of lacto‐series glycolipid glycosyltransferase activities in human colonic adenocarcinoma DLD‐1 cells after culture in N,N‐dimethylformamide‐containing medium
Authors: Holmes Eric H. , Greene Thomas G. 
Published: May 2005

AbstractHuman colonic adenocarcinoma DLD‐1 cells were grown under conditions which induce characteristics of differentiated cells using medium containing 0.8% N,N‐dimethylformamide in order to study alterations in glycosphingolipid glycosyltransferase activities during this process. Analysis of biosynthetic reactions involved in lacto‐series antigen synthesis revealed no changes in the specific activities of either β1→4galactosyltransferase or α1→3/4fucosyltransferase with N,N‐dimethylformamide treatment. However, a dramatic decrease of from 14‐ to 20‐fold in the β1→3N‐acetylglucosaminyltransferase activity was observed in the treated cells. This enzyme catalyzes the rate‐limiting step in lacto‐series core chain synthesis. This is consistent with the pattern of regulation of lacto‐series antigen expression found to occur during oncogenesis in human colonic mucosa (Holmes EH, Hakomori S, Ostrander GK: J Biol Chem 262:15649, 1987). Total glycolipids from untreated and N,N‐dimethylformamide‐treated cells were isolated and subjected to TLC immunostain analysis and solid phase radioimmunoassay with a series of monoclonal antibodies specific for lacto‐series‐based carbohydrate antigens. A decrease of about 2‐fold or less in the quantity of lacto‐series antigens was observed as a consequence of N,N‐dimethylformamide treatment in both neutral glycolipid and ganglioside fractions. The results suggest that only very low levels of β1→3N‐acetylglucosaminyltransferase activity are required for the steady state expression of significant levels of lacto‐series based glycolipids and that modulation of its activity levels by N,N‐dimethylformamide treatment in DLD‐1 cells represents a convenient in vitro system for studying aspects of regulation of lacto‐series antigen expression.
Stimulation of a histone H4 protein kinase in Triton X‐100 lysates of rabbit peritoneal neutrophils pretreated with chemotactic factors: Lack of requirements of calcium mobilization and protein kinase C activation
Authors: Huang Chi‐Kuang , Laramee Gary R. , Yamazaki Munehiro , Sha'afi Ramadan I. 
Published: May 2005

AbstractThe characteristics of the activation of a histone H4 kinase activity in Triton X‐100 lysates of rabbit peritoneal neutrophils pretreated with fMet‐Leu‐Phe were studied: The activation of the kinase was (a) inhibited by the antagonist of formylpeptide, t‐Boc‐(Phe‐Leu)2−‐Phe, (b) completely inhibited by pertussis toxin pretreatment, (c) not affected by the pretreatment of neutrophils with an activator of protein kinase C, phorbol‐12‐myristate‐13‐acetate, or an inhibitor of protein kinase C, 1‐(5‐isoquinoline‐sulfonyl)‐2‐methyl‐piperazine, and (d) not inhibited in the cells preloaded with the intracellular calcium chelators, bis‐(o‐aminophenoxy)‐ethane‐N,N,N',N'‐tetra acetic acid acetoxymethyl‐ester (BAPTA/AM). These results suggest that the stimulus‐induced activation of H4 kinase requires functional receptor and GTP‐binding protein but neither calcium mobilization nor protein kinase C activation.
p53 Mutations: Gains or losses?
Authors: Michalovitz Dan , Halevy Orna , Oren Moshe 
Published: May 2005

AbstractAlthough the case for p53 as a tumor suppressor gene appears very strong, one should still keep an open eye for the possibility that mutations in p53 do not necessarily imply a mere loss of “suppressor” activity. It is still possible that the presence of a p53 mutation in a tumor contributes, in a dominant positive manner, to tumorigenesis. In other words, certain p53 mutants may well be oncogenic in their own right, and carry distinct activities that promote growth deregulation and malignant progression. Elucidating this issue also has practical implications, since the nature of the resident mutations may greatly dictate the consequences of attempts to reintroduce wild‐type (wt) p53 into particular types of tumor cells. There are two major obstacles along the road to meaningful answers: the limitations of the experimental systems used for evaluating the biological activities of Wt and mutant p53 and a fundamental lack of knowledge about the relevant biochemistry of the p53 protein. These two aspects constitute primary experimental challenges for investigators in the field.
Metal ion resistance in fungi: Molecular mechanisms and their regulated expression
Authors: Mehra Rajesh K. , Winge Dennis R. 
Published: May 2005

AbstractOne stress response in cells is the ability to survive in an environment containing excessive concentrations of metal ions. This paper reviews current knowledge about cellular and molecular mechanisms involved in the response and adaptation of various fungal species to metal stress. Most cells contain a repertoire of mechanisms to maintain metal homeostasis and prevent metal toxicity. Roles played by glutathione, related (γ‐EC)nG peptides, metallothionin‐like polypeptides, and sulfide ions are discussed. In response to cellular metal stress, the biosynthesis of some of these molecules are metalloregulated via intracellular metal sensors. The identity of the metal sensors and the role of metal ions in the regulation of biosynthesis of metallothionin and (γ‐EC)nG peptides are subjects of much current attention and are discussed herein.
Constitutively activated neu oncoprotein tyrosine kinase interferes with growth factor‐induced signals for gene activation
Authors: Lehtola Laura , Sistonen Lea , Koskinen Päivi , Lehväslaiho Heikki , Alitalo Kari , Renzo Maria Flavia Di , Comoglio Paolo M. 
Published: May 2005

AbstractThe neu receptor oncoprotein tyrosine kinase, capable of transforming cultured fibroblasts and causing mammary carcinomas in transgenic mice, carries a point mutation in its transmembrane domain and shows a constitutive tyrosine kinase activity. We analyzed the neu tyrosine kinase and its substrates in transfected NIH 3T3 fibroblasts by phosphotyrosine immunoblotting. Tyrosine phosphorylated proteins were similar but not identical in epidermal growth factor (EGF)‐stimulated cells expressing the human EGF receptor (EGFR) or a chimeric EGFR/neu receptor but differed from phosphotyrosyl proteins constitutively expressed in neu oncogene‐transformed cells. The neu oncoprotein in the latter cells was phosphorylated in tyrosine in a ligand‐independent manner and had a shortened half‐life in comparison with the normal neu protein. Tumor promoter pretreatment inhibited ligand‐induced receptor tyrosine phosphorylation and decreased tyrosine phosphorylated neu oncoprotein. Prolonged pretreatment with 12‐O‐tetradecanoyl‐phorbol‐13‐acetate (TPA) also prevented the induction of immediate early growth factor‐regulated genes in response to neu activation. Expression of the neu oncogene but not the protooncogene in NIH 3T3 cells was associated with enhanced levels of the jun and fos oncoproteins and loss of serum growth factor induction of immediate early mRNA responses. The constitutively activated neu oncoprotein tyrosine kinase thus deregulates cellular genomic responses to growth factors.
Estrogen‐stimulation of postconfluent cell accumulation and foci formation of human MCF‐7 breast cancer cells
Authors: Gierthy John F. , Lincoln David W. , Roth Karen E. , Bowser Samuel S. , Bradley Laurie , Dickerman Herbert W. , Bennett James A. 
Published: May 2005

AbstractFoci, nodules of cellular overgrowth, that appear after confluence are an in vitro characteristic of malignant transformation. A well‐studied in vitro model of estrogen‐dependent tumors is the MCF‐7 cell line, derived from a pleural metastasis of a human breast adenocarcinoma. We report that cultivation of MCF‐7 cells, using routine methods, results in extensive estrogen‐stimulated postconfluent cell accumulation characterized by discrete three‐dimensional arrays. Side view Nomarski optical sections revealed these to be principally multicellular foci with occasional domes and pseudoacinar vacuoles. This effect on MCF‐7 cell growth occurs in media containing fetal bovine serum but not with calf serum or charcoal‐dextran‐treated fetal bovine serum unless supplemented with estrogens. Foci formation starts 5–6 days after confluence, and the number of foci generated is a function of the concentration of added estrogens. Foci formation is suppressed by the antiestrogens Tamoxifen and LY 156758. Addition of progesterone, testosterone, or dexamethasone had little or no effect, while various estrogens (ethinyl estradiol, diethylstilbestrol, and moxestrol) induced foci development. Clones derived from single cells of the initial MCF‐7 population revealed a wide variance in estrogen‐induced foci formation, demonstrating heterogeneity of this tumor cell line. The postconfluent cell growth of the estrogen receptor‐deficient cell line, MDA‐MB‐231, contrasted with MCF‐7 by developing an extensive multilayer morphology devoid of discrete structures. The tumorigenic potential of the MCF‐7 cells used in our experiments was confirmed by their estrogen‐dependent growth in immunosuppressed male BDF1 mice.These data suggest an estrogen receptor‐based mechanism for the development of multicellular foci during postconfluent growth of MCF‐7 cells. After confluence, foci, in contrast to the quiescent surrounding monolayer, retain proliferating cells. Focus formation, therefore, reflects the heterogeneous responsiveness of these cells to estrogens and should provide a model permitting in vitro comparisons between the progenitor cells of multicellular foci and the monolayer population.
Antisense inhibition of c‐myc expression reveals common and distinct mechanisms of growth inhibition by TGFβ and TNFα
Authors: Robinson‐Benion Cheryl , Salhany Kevin E. , Hann Stephen R. , Holt Jeffrey T. 
Published: May 2005

AbstractDownregulation of the c‐myc gene in HL‐60 cells is associated with growth inhibition and induction of differentiation. Previous studies have reported that the growth inhibitors TGFβ and TNFα downregulate c‐myc mRNA levels, suggesting the possibility that these agents may exert some of their phenotypic effects via c‐myc downregulation. Our study demonstrates that although both growth inhibitors produce a similar decrease in c‐myc protein synthesis, TNFα produces a greater growth inhibition and differentiation induction in HL‐60 cells. Combined addition of anti‐myc oligomer with either growth inhibitor produces no additive effect. In fact, 4 μM anti‐myc oligomer produces the same growth and differentiation effects as does 10 ng/ml TGFβ1. We conclude that downregulation of c‐myc expression represents a common mechanism of growth inhibition by TGFβ and TNFα, but that TNFα possesses an additional effect that is independent of c‐myc expression.