Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Production”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 289 records · Page 16Linked to original sources
PubMed1996

Stimulation of gelatinase B and tissue inhibitors of metalloproteinase (TIMP) production in co-culture of human osteosarcoma cells and human fibroblasts: gelatinase B production was stimulated via up-regulation of fibroblast growth factor (FGF) receptor.

Co-cultures of human osteosarcoma Takase (OST) cells with various human fibroblasts derived from surgical specimens stimulated production of gelatinase B (92-kDa type-IV collagenase, MMP-9), tissue inhibitors of metalloproteinase (TIMP)-1, and TIMP-2 when compared to cultures of individual cells. The maximum stimulation of gelatinase-B production occurred at a cellular ratio of 1:1. Conditioned media from several fibroblast cultures stimulated OST cells to produce gelatinase B, TIMP-1 and TIMP-2, but not vice versa. Among various recombinant growth factors or cytokines, tumor necrosis factor (TNF)-alpha stimulated gelatinase-B production in cultures of OST cells alone, while recombinant basic fibroblast growth factor (bFGF) stimulated gelatinase-B production in co-cultures of OST cells with skin fibroblasts but not in individual cultures of each cell type. In the co-cultures, gelatinase-B production was inhibited by anti-bFGF monoclonal antibody (MAb), but not by anti TNF-alpha MAb. This co-culture-specific stimulation of gelatinase-B production by bFGF was associated with increased expression of the FGF receptor in the co-culture.

Animals↗
PubMed2003

Outdoor helical tubular photobioreactors for microalgal production: modeling of fluid-dynamics and mass transfer and assessment of biomass productivity.

The production of the microalga Phaeodactylum tricornutum in an outdoor helical reactor was analyzed. First, fluid dynamics, mass-transfer capability, and mixing of the reactor was evaluated at different superficial gas velocities. Performance of the reactor was controlled by power input per culture volume. A maximum liquid velocity of 0.32 m s(-1) and mass transfer coefficient of 0.006 s(-1) were measured at 3200 W m(-3). A model of the influence of superficial gas velocity on the following reactor parameters was proposed: gas hold-up, induced liquid velocity, and mass transfer coefficient, with the accuracy of the model being demonstrated. Second, the influence of superficial gas velocity on the yield of the culture was evaluated in discontinuous and continuous cultures. Mean daily values of culture parameters, including dissolved oxygen, biomass concentration, chlorophyll fluorescence (F(v)/F(m) ratio), growth rate, biomass productivity, and photosynthetic efficiency, were determined. Different growth curves were measured when the superficial gas velocity was modified-the higher the superficial gas velocity, the higher the yield of the system. In continuous mode, biomass productivity increased by 35%, from 1.02 to 1.38 g L(-1) d(-1), when the superficial gas velocity increased from 0.27 to 0.41 m s(-1). Maximal growth rates of 0.068 h(-1), biomass productivities up to 1.4 g L(-1) d(-1), and photosynthetic efficiency of up to 15% were obtained at the higher superficial gas velocity of 0.41 m s(-1). The fluorescence parameter, F(v)/F(m), which reflects the maximal efficiency of PSII photochemistry, showed that the cultures were stressed at average irradiances within the culture higher than 280 microE m(-2) s(-1) at every superficial gas velocity. For nonstressed cultures, the yield of the system was a function of average irradiance inside the culture, with the superficial gas velocity determining this relationship. When superficial gas velocity was increased, higher growth rates, biomass productivities, and photosynthetic efficiencies were obtained for similar average irradiance values. The higher the superficial gas velocity, the higher the liquid velocity, with this increase enhancing the movement of the cells inside the culture. In this way the efficiency of the cells increased and higher biomass concentrations and productivities were reached for the same solar irradiance.

Bioreactors↗
PubMed2004

Process strategies to enhance pyruvate production with recombinant Escherichia coli: from repetitive fed-batch to in situ product recovery with fully integrated electrodialysis.

Using the pyruvate production strain Escherichia coli YYC202 ldhA::Kan different process alternatives are studied with the aim of preventing potential product inhibition by appropriate product separation. This strain is completely blocked in its ability to convert pyruvate into acetyl-CoA or acetate, resulting in acetate auxotrophy during growth in glucose minimal medium. Continuous experiments with cell retention, repetitive fed-batch, and an in situ product recovery (ISPR) process with fully integrated electrodialysis were tested. Although the continuous approach achieved a high volumetric productivity (QP) of 110 g L(-1) d(-1), this approach was not pursued because of long-term production strain instabilities. The highest pyruvate/glucose molar yield of up to 1.78 mol mol(-1) together with high QP 145 g L(-1) d(-1) and high pyruvate titers was achieved by the repetitive fed-batch approach. To separate pyruvate from fermentation broth a fully integrated continuous process was developed. In this process electrodialysis was used as a separation unit. Under optimum conditions a (calculated) final pyruvate titer of >900 mmol L(-1) (79 g L(-1)) was achieved.

Bioreactors↗
PubMed1996

Characterization of cytokine production in murine Trypanosoma cruzi infection by in situ immunocytochemistry: lack of association between susceptibility and type 2 cytokine production.

Cytokine production in the spleens of mice infected with the protozoan parasite Trypanosoma cruzi was analyzed in three models which differ in the outcome of the infection. Using immunocytochemical techniques to detect cytokine-producing cells, the production of type 1 [interleukin-2 (IL-2) and interferon (IFN)-gamma], type 2 (IL-4, IL-5, IL-10), inflammatory [tumor necrosis factor (TNF)-alpha, IL-1 alpha, IL-6] and regulatory (transforming growth factor-beta) cytokines were examined. With the exception of IL-4 and IL-5, cells producing all of the cytokines assayed were detected in both the resistant and susceptible models of T. cruzi infection. Cells producing IL-4 and IL-5 were not detected until later in infection in the resistant mice (> 34 days), at about the time animals of the susceptible strain succumb to the infection. Mice of the susceptible model showed a slight delay in the appearance of cells producing the type 1 cytokines IL-2 and IFN-gamma and an earlier appearance of TNF-producing cells, in comparison to resistant mice. Cells producing IL-2 or IL-10 were transient in their appearance in the spleen while cells producing IL-1, IL-4, IL-5, IL-6, IFN-gamma, TNF, or TGF-beta were first detectable in either the acute or post-acute stage of the infection and persisted up to 700 days post infection in two different resistant models of the infection. Cells producing IFN-gamma, TNF-alpha and TGF-beta were particularly numerous even very late in the infection. Double-staining techniques were used to show that the vast majority of the IFN-gamma-producing cells in the spleen were CD4-, CD8- alpha/beta TCR+T cells. This study confirms the transience of IL-2 production in the acute stage of T. cruzi infection and the persistent and simultaneous production of type 1 and type 2 cytokines during the late-acute and chronic stages of the infection. Susceptibility or resistance to T. cruzi infection does not associate with a Th2 pattern of cytokine production in the three models examined in this study. The overlapping pattern of type 1 and type 2 cytokine-producing cells in both the acute and chronic stages of T. cruzi infection demonstrates that longterm infections do not necessarily lead to a dominance of either type 1 or type 2 cytokine production.

Animals↗
PubMed1985

Regulated production of an influenza virus spliced mRNA mediated by virus-specific products.

The influenza virus NS2 mRNA is generated through processing by cellular enzymes of a transcript (the NS1 mRNA) of virion RNA segment 8. Production of this mRNA is altered in cells infected with a mutant of influenza A (fowl plague) virus. The proportion of segment 8 transcripts which accumulated in a spliced form was found to be considerably lower in mutant virus-infected cells than in cells infected with wild-type virus, and the amplification in production of NS2 mRNA relative to that of the NS1 mRNA, which normally occurs during infection with wild-type virus, was not observed with the mutant. The NS1 mRNA specified by the mutant virus has unaltered splice recognition sites and was apparently processed normally during a mixed infection with a strain of virus which is wild-type for production of NS2 mRNA. These results suggest that the production of NS2 mRNA is regulated by virus-specific products; these products may act by increasing the efficiency of splicing of NS1 mRNA.

Animals↗
PubMed1996

Production of granulocyte colony-stimulating factor by THP-1 cells in response to retinoic acid and phorbol ester is mediated through the autocrine production of interleukin-1.

The human monocytic leukemic cell line, THP-1, which differentiates toward macrophages in response to phorbol 12-myristate 13-acetate (PMA) was investigated for its ability to produce granulocyte colony-stimulating factor (G-CSF). G-CSF protein was neither produced during PMA-induced differentiation nor in response to retinoic acid (RA) alone. However, when combined, PMA and RA synergistically stimulated G-CSF production with optimal effect observed at 10(-7)M for both PMA and RA. The synergistic interaction between PMA and RA on G-CSF production appeared to be mediated primarily through production of interleukin-1 beta (IL-1 beta) since neutralization of IL-1 beta activity inhibited about 80% of G-CSF production. It has been previously reported that IL-1 potently synergizes with RA to stimulate G-CSF production by THP-1 cells pretreated with PMA Using synthetic ligands to RA receptors (RAR) and retinoid X receptors (RXR) that selectively bind and activate RAR-RXR and RXR-RXR dimers respectively, we showed that the ability of RA to synergize with IL-1 was signaled through RAR-RXR heterodimer pathway. Finally, we demonstrated that RA can also enhance IL-1-induced G-CSF production in primary monocytes of human peripheral blood.

Drug Synergism↗
PubMed1995

Interleukin 1 induces prostacyclin-dependent increases in cyclic AMP production and does not affect cyclic GMP production in human vascular smooth muscle cells.

Interleukin 1 (IL-1) is a pro-inflammatory cytokine which has direct vasorelaxant effects on vascular smooth muscle cells (VSMC). In the present study, IL-1 markedly increased intracellular levels of the vasodilatory mediator, cAMP, in human saphenous and human aortic VSMC. IL-1-induced cAMP was associated with a marked increase in prostacyclin (PGI2) production, and was reversed by indomethacin and tranylcypromine, inhibitors of cyclooxygenase and PGI2 synthetase respectively. Furthermore, PGI2, but not PGE2, was a potent inducer of cAMP production in HSVSMC, implicating a role for PGI2 in mediating IL-1-induced cAMP production. In previous studies, IL-1 increased immunoreactive cGMP production in human saphenous VSMC through a pathway inhibitable by soluble guanylate cyclase inhibitors, methylene blue and LY83583, but not by nitric oxide (NO) synthase inhibitors, suggesting a role of NO-independent activation of soluble guanylate cyclase. However, in the present study, it was found that cAMP cross-reacted significantly in cGMP radioimmunoassays employing three out of four commercial antisera, that IL-1 did not affect cGMP production in human saphenous or human aortic VSMC as determined by an RIA having low cAMP cross-reactivity, and that both LY83583 and methylene blue inhibited IL-1-induced increases in cAMP. The results implicate prostacyclin-dependent cAMP production as a mediator of the vasodilatory effects of IL-1 in humans.

Aminoquinolines↗
PubMed2005

Biological effects of Maillard browning products that may affect acrylamide safety in food: biological effects of Maillard products.

The heat-induced reaction of amino groups of amino acids, peptides, and proteins with carbonyl groups of reducing sugars such as glucose results in the concurrent formation of so-called Maillard browning products and acrylamide. For this reason, reported studies of adverse biological effects of pure acrylamide may not always be directly relevant to acrylamide in processed food, which may contain Maillard and other biologically active products. These may either antagonize or potentiate the toxicity of acrylamide. To stimulate progress, this paper presents an overview of selected reported studies on the antiallergenic/allergenic, antibiotic, anticarcinogenic/carcinogenic antimutagenic/mutagenic, antioxidative/oxidative, clastogenic (chromosome-damaging), and cytotoxic activities of Maillard products, which may adversely or beneficially impact the toxicity of acrylamide. The evaluation of biological activities of Maillard products and of other biologically active food ingredients suggests that they could both enhance and/or ameliorate acrylamide toxicity, especially carcinogenicity, but less so neurological or reproductive manifestations. Future studies should be directed to differentiate the individual and combined toxicological relationships among acrylamide and the Maillard products, define individual and combined potencies, and develop means to prevent the formation of both acrylamide and the most toxic Maillard products. Such studies should lead to safer foods.

Acrylamide↗
PubMed1991

Enhancing effect of mouse peritoneal exudate cells and their products on antibody productivity of hybridoma cells: application of in vivo factors to in vitro culture.

Mouse peritoneal exudate cells induced by casein enhanced in vitro antibody production rate per cell of a hybridoma in co-culture. Culture supernatant of the exudate cells also enhanced three-fold the antibody productivity when added to cultures of a hybridoma at 10% (v/v). Hence the enhancement of antibody productivity by the exudate cells seemed to be caused by soluble enhancing factors secreted by the exudate cells. The exudate cells maximally secreted the enhancing factors when harvested from mice on day 4 of the induction period following the injection of casein. A semi-continuous culture of the hybridoma demonstrated the applicability of the culture supernatant to enhance antibody production by producing a two-fold increase over the control for seven days when supplemented with the supernatant at 5%. Significant amounts of interleukin-6 were detected in culture supernatant of the exudate cells. Interleukin-6 obtained from other sources enhanced the antibody productivity two-fold when added to the hybridoma culture at the concentration of 5 unit/ml. Interleukin-6, therefore, is expected to be one of the principal antibody enhancing factors secreted by the exudate cells. Other interleukins examined, that is, interleukin-1 to -5 did not enhance the antibody productivity.

Animals↗
PubMed1995

Increased hyaluronan production in the glomeruli from diabetic rats: a link between glucose-induced prostaglandin production and reduced sulphated proteoglycan.

Exposure in vivo or in vitro to elevated glucose increases production of vasoactive prostaglandins by glomeruli and mesangial cells. This study aimed to determine whether this increased prostaglandin production could provide a link with later structural changes in diabetic nephropathy. Glomerular cores were prepared from control rats and streptozotocin-diabetic rats (3 weeks' duration). Over 24 h in culture hyaluronan production from diabetic glomerular cores was higher than production from control glomerular cores whether maintained in 5.6 mmol/l glucose (105.6 +/- 15.5 vs 53.6 +/- 8.5 ng hyaluronan per 250 glomerular cores, p < 0.001); in 25 mmol/l glucose (149.3 +/- 34.8 vs 62.7 +/- 7.8 ng hyaluronan per 250 glomerular cores, p < 0.01); or in 45 mmol/l glucose (176.8 +/- 23.3 vs 102.0 +/- 17.9 ng hyaluronan per 250 glomerular cores, p < 0.01). At 5.6 mmol/l glucose, exposure in vitro to prostaglandin E2 caused an increase in hyaluronan production [maximal at 10(-9) mol/l prostaglandin E2, 237 +/- 19 vs 42 +/- 4, ng hyaluronan per 250 glomerular cores, p < 0.001 (control) and 195 +/- 7 vs 103 +/- 5, ng hyaluronan per 250 glomerular cores, p < 0.001 (diabetic)]. In both control and diabetic glomerular cores hyaluronan production was reduced significantly by the cyclooxygenase inhibitor indomethacin (10(-5) mol/l) [24.7 +/- 3.33 vs. 40.25 +/- 4.11 ng hyaluronan per 250 glomerular cores, p < 0.05 (control) and 36.5 +/- 6.25 vs 118.0 +/- 22.6, p < 0.01 (diabetic)]. A direct spectrophotometric microassay was used to determine the concentration of sulphated glycosaminoglycans derived from papain-digested glomerular core proteoglycans.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

Oxygen radical production by neutrophils from patients with bacterial infection and rheumatoid arthritis. Measurement of hydrogen peroxide may most accurately represent enhancement of oxygen radical production during infection.

The production of three kinds of oxygen radicals (superoxide, hydrogen peroxide, and hydroxyl radicals) by neutrophils from patients with bacterial infection or rheumatoid arthritis was measured. The stimulators used in this study were opsonized zymosan (1 mg/ml), phorbol myristate acetate (20 ng/ml), A23187 (1 microM), and platelet activating factor (1 microM). Oxygen radical production by neutrophils from patients with rheumatoid arthritis was not significantly different from that of the control group. Hydrogen peroxide production by the neutrophils from patients with bacterial infection was significantly enhanced by only opsonized zymosan, but the production of the other kinds of oxygen radicals was not. Cytochalasin B reduced the production of hydrogen peroxide induced by opsonized zymosan more markedly than that of any other kind of oxygen radical. The measurement of hydrogen peroxide is suggested to be the most accurate indicator of the enhancement of intracellular production of oxygen radicals by neutrophils during infection.

Arthritis, Rheumatoid↗
PubMed2002

The production of human papillomavirus type 16 L1 vaccine product from Escherichia coli inclusion bodies.

The major capsid protein L1 of the human papillomavirus type 16 (HPV16) has been previously expressed recombinantly in Escherichia coli cells as inclusion bodies (IBs). The HPV16 L1 protein offers potential as a vaccine candidate against cervical cancer, but the reported E. coli process is limited in its ability to economically produce significant quantities of material. In this study, a scaleable laboratory process for the purification of recombinant His-tagged L1 protein and its processing to give an immunogenic product is developed. The performances of ion-exchange chromatography (IEX) and immobilised metal affinity chromatography (IMAC) for the purification of L1 protein in the presence of concentrated denaturant are compared. IEX was found to be superior to IMAC when taking into account the complexity of operation, cost of adsorbent, selectivity and purity of the final product. Following purification, reduction of denaturant concentration was performed by dilution to yield a product suitable for formulation. The simplicity and ease of scale-up of dilution makes it an attractive option for process scale production and superior to the existing approach employing dialysis. It was found that direct dilution of denaturant into suitable buffer can give rise to products which have neutralising conformational epitopes identified by strong antibody-binding properties, as assessed by ELISA with a conformational monoclonal antibody. Analysis of the results showed negative main effects of protein concentration and PEG addition on antibody-binding yields, but positive main effects of the addition of detergent and L-arginine to the buffer. The diluted product had antigenic properties as assessed by ELISA and may be formulated easily for use by diafiltration and the addition of adjuvant. This work demonstrates the feasibility of producing viral vaccines using E. coli and scaleable unit operations.

Journal Article↗
PubMed1993

The hydrolysis product of ICRF-187 promotes iron-catalysed hydroxyl radical production via the Fenton reaction.

d-1,2-Bis(3,5-dioxopiperazine-1-yl)propane (ICRF-187) (ADR-529) is a drug that ameliorates the cardiotoxicity of Adriamycin. The drug enters cells where hydrolysis leads to its diacid diamide product, dl-N,N'-dicarboxamidomethyl-N,N'-dicarboxymethyl-1,2-diamino propane (ICRF-198) (ADR-925), which is structurally similar to ethylenediaminetetraacetic acid (EDTA). The protective mechanism of ICRF-187 is unknown, but a plausible explanation is that ICRF-198 chelates iron intracellularly to prevent iron-dependent free radical reactions such as hydroxyl radical (.OH) production. We have compared Fe(ICRF-198) with Fe(EDTA) in its ability to promote .OH formation in several Fenton reaction systems. The Fenton reaction was studied with H2O2 and Fe2+ chelates or catalytic amounts of the iron chelates in the presence of Adriamycin radicals, paraquat radicals, superoxide anion radicals (O2-), and ascorbate as reducing species. .OH was detected with deoxyribose and dimethyl sulfoxide. The two methods gave comparable results. Fe(ICRF-198) was 80-100% as effective as Fe(EDTA) at promoting .OH production in the presence of the organic radicals and ascorbate, 30-70% in the presence of O2-, and 150% with non-cycling Fe2+. Fe(EDTA) is a more efficient catalyst of .OH production than physiological chelates such as ADP, ATP and citrate. Therefore, by comparing previous work which examined physiological chelates and Fe(EDTA) with the present work, Fe(ICRF-198) appears to be a better .OH catalyst than the physiological chelates. These results suggest that ICRF-198 generated in vivo from ICRF-187 would not protect against intracellular .OH production. They also imply that .OH production may not be as important in Adriamycin cardiotoxicity as other radical reactions, such as lipid peroxidation and thiol oxidation, that are inhibited by ICRF-198.

Ascorbic Acid↗
PubMed1995

Regulation of prostaglandin H synthase 2 expression in human monocytes by the marine natural products manoalide and scalaradial. Novel effects independent of inhibition of lipid mediator production.

The marine natural products manoalide and scalaradial are potent anti-inflammatory agents that inactivate the enzyme phospholipase A2 (PLA2) in vitro. To study the mechanism of inhibition of prostaglandin E2 (PGE2) production in human monocytes by manoalide and scalaradial, lipopolysaccharide (LPS)-induced prostaglandin biosynthesis and induction of prostaglandin H synthase (PGHS) were evaluated. LPS (10 ng/mL) and interleukin-1 beta (IL-1 beta, 50-1000 ng/mL) but not tumor necrosis factor alpha (TNF alpha, 300 ng/mL) induced the expression of the PGHS-2 isoform as determined by immunoblot analysis with a specific polyclonal antibody for PGHS-2. Manoalide and scalaradial (1-10 microM) inhibited LPS-induced endogeneous PGE2 production, reduced the LPS-induced PGHS activity, and reduced the expression of PGHS-2. Indomethacin [a PGHS inhibitor (0.01 to 0.1 microM)], zileuton [a 5-lipoxygenase inhibitor (3-10 microM)], and WEB-2806 [a platelet-activating factor (PAF) antagonist (30 microM)] did not affect the LPS-induced expression of PGHS-2 in human monocytes. These results suggest that modulation of lipid mediator production by manoalide or scalaradial may not be involved in the observed effects on the expression of PGHS-2. Manoalide and scalaradial also inhibited the release of IL-1 beta and TNF alpha from LPS-stimulated monocytes. Expression of PGHS-2 induced by either LPS or IL-1 beta was blocked by the IL-1 receptor antagonist (IL-1ra, 2 micrograms/mL) but not by rolipram, a phosphodiesterase IV inhibitor that inhibits TNF alpha but not IL-1 beta release. Similar to LPS, IL-1 beta-induced PGHS-2 expression was apparently not regulated by lipid mediators such as prostaglandins, leukotrienes or PAF as determined with specific inhibitors and antagonists. Scalaradial and to some extent manoalide were capable of blocking the IL-1 beta-induced expression of PHGS-2. These results indicate that IL-1 beta is the predominant cytokine responsible for the induction of PGHS-2 in the human monocyte. Furthermore, marine natural products such as scalaradial have novel effects on the IL-1 beta-mediated induction of PGHS-2 in human monocytes, which appears to be independent of effects on lipid mediator production.

Anti-Inflammatory Agents, Non-Steroidal↗