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 1,027 records · Page 57Linked to original sources
PubMed1978

Effect of halothane on the rate of acid production, lactate production and pyruvate dehydrogenase activity of malignant hyperpyrexia human muscle.

The rates of acid production were compared in thin strips of muscle biopsy samples isolated from malignant hyperpyrexia and control vastus internus human muscle. Halothane doubled the rate of acid production by malignant hyperpyrexia susceptible muscle but had no effect on control samples. This increased rate of release of acid from muscle was not from lactate. In addition, the pyruvate dehydrogenase activity of both control and malignant hyperpyrexia muscle samples was not stimulated by halothane.

Acids↗
PubMed1998

Thiopental attenuates relaxation and cyclic GMP production in vascular smooth muscle of endotoxin-treated rat aorta, independent of nitric oxide production.

As thiopental (thiopentone) suppresses cyclic GMP (cGMP) formation produced by nitric oxide donor drugs, we have tested if it suppresses cGMP formation and increases vascular tone after induction of calcium-calmodulin-independent nitric oxide synthase (iNOS). Rat aortic rings were treated with Escherichia coli lipopolysaccharide (LPS) 1 microgram ml-1 for 4 h, and the effects of thiopental on tension, cGMP concentrations and nitrite accumulation were determined. Thiopental 0.3 mmol litre-1 reduced the tension of phenylephrine-precontracted aortic rings before LPS treatment, but caused no significant effects on tension in the presence of L-arginine 10 mumol litre-1 after LPS treatment. L-Arginine 1 mumol litre-1 to 1 mmol litre-1 increased concentrations of cGMP in LPS-treated aorta in a concentration-dependent manner. This was reduced by thiopental 0.3-1 mmol litre-1. Treatment with L-arginine 1 mmol litre-1 increased concentrations of nitrite, the end product of nitric oxide; this was not affected by thiopental 1 mmol litre-1. We conclude that thiopental suppressed cGMP formation in iNOS-induced vascular smooth muscle without affecting nitric oxide production.

Anesthetics, Intravenous↗
PubMedDate not supplied

Impact of the ampD gene and its product on beta-lactamase production in Enterobacter cloacae.

In an investigation of the influence of the ampD gene on beta-lactamase production and induction in Enterobacter cloacae, the ampR-ampC gene region cloned into a plasmid and the ampD gene cloned into another vector were transferred to a strain of Escherichia coli. The genetically manipulated E. coli strains served as a model for study of the inducibility of beta-lactamases in E. cloacae. In addition, beta-lactamase induction in E. cloacae bearing the previously mentioned plasmids was studied. After induction of the beta-lactamase with cefoxitin, the specific hydrolytic activity, the viable cell count, and the degradation of cefoxitin were determined. beta-Lactamase expression decreased with an increasing amount of the ampD gene product. The cefoxitin concentration decreased in proportion to the amount of enzyme, but the induction of beta-lactamase seemed not to be an important factor influencing the viable cell count of E. cloacae as long as cefoxitin concentrations exceeded the MIC. Despite different beta-lactamase concentrations, the decrease in the viable cell count was nearly identical in all experiments.

Cefoxitin↗
PubMed1999

CD4(+) T cells induced by virus-like particles expressing a major T cell epitope down-regulate IL-5 production in an ongoing immune response to Der p 1 independently of IFN-gamma production.

It has been previously demonstrated that hybrid Ty virus-like particles (VLP) prime effective CD8(+) and CD4(+) T cell responses. In this study, we investigated the effect of treating mice with Ty VLP carrying the immunodominant epitope of Der p 1 after sensitizing them to the group 1 allergen of the house dust mite Dermatophagoides pteronyssinus (Der p 1), under conditions that induce T(h)2 immunity. We show that i.p. treatment with the hybrid VLP abrogated allergen-specific IL-5 production and reduced allergen-specific cell proliferation. This suppression of the response was mediated by CD4(+) T cells and was not accompanied by an increase in IFN-gamma production.

Allergens↗
PubMed1993

Bioavailable level and source of cysteine determine protein quality of a commercial enteral product: adequacy of tryptophan but deficiency of cysteine for rats fed an enteral product prepared fresh or stored beyond shelf life.

Young rats were used in bioassays designed to assess the protein quality and tryptophan as well as cystine adequacy of the enteral product TwoCal-HN that was either freshly prepared or had been stored (nonrefrigerated) in a warehouse for 10 mo (i.e., beyond shelf life). Based upon supplementation studies, cystine was observed to be the first-limiting amino acid in both fresh and expired TwoCal-HN, and tryptophan was not second limiting. Protein efficiency ratio (PER) of expired, but not fresh, TwoCal-HN was lower than that of the casein control diet, but with cystine supplementation, PER of the TwoCal-HN products was equal to or greater than the PER of the casein control. With a diet containing 10 g protein/100 g that also contained energy-furnishing ingredients simulating TwoCal-HN, maximal growth enhancement occurred with a supplement of 1 g cystine/kg diet. Both glutathione and N-acetyl-L-cysteine were observed to be equivalent to an isomolar level of L-cystine in stimulating growth. Using a chemically defined amino acid diet that was singly deficient in tryptophan, bioavailability of tryptophan was determined for casein, fresh TwoCal-HN, expired TwoCal-HN and D-tryptophan. Slope-ratio bioefficacy values relative to L-tryptophan (weight gain regressed on supplemental tryptophan intake) indicated that none of the experimental sources of tryptophan had bioavailabilities different from 100%. The results indicated that tryptophan did not deteriorate, as measured analytically or biologically, as a result of storing TwoCal-HN beyond shelf life.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1998

Net primary production of forests: a constant fraction of gross primary production?

Considerable progress has been made in our ability to model and measure annual gross primary production (GPP) by terrestrial vegetation. But challenges remain in estimating maintenance respiration (R(m)) and net primary production (NPP). To search for possible common relationships, we assembled annual carbon budgets from six evergreen and one deciduous forest in Oregon, USA, three pine plantations in New South Wales, Australia, a deciduous forest in Massachusetts, USA, and a Nothofagus forest on the South Island of New Zealand. At all 12 sites, a standard procedure was followed to estimate annual NPP of foliage, branches, stems, and roots, the carbon expended in synthesis of these organs (R(g)), their R(m), and that of previously produced foliage and sapwood in boles, branches, and large roots. In the survey, total NPP ranged from 120 to 1660 g C m(-2) year(-1), whereas the calculated fraction allocated to roots varied from 0.22 to 0.63. Comparative analysis indicated that the total NPP/GPP ratio was conservative (0.47 +/- 0.04 SD). This finding supports the possibility of greatly simplifying forest growth models. The constancy of the NPP/GPP ratio also provides an incentive to renew efforts to understand the environmental factors affecting partitioning of NPP above and belowground.

Journal Article↗
PubMedDate not supplied

Syringomycin production among strains of Pseudomonas syringae pv. syringae: conservation of the syrB and syrD genes and activation of phytotoxin production by plant signal molecules.

The syrB and syrD genes of Pseudomonas syringae pv. syringae are predicted to encode proteins that function in the synthesis and export of syringomycin, respectively. Using portions of the syr genes as DNA probes, both genes were shown to be conserved as single copies within a 15-kb or smaller DNA region among a broad spectrum of P. s. pv. syringae strains that produce syringomycin or one of its amino acid analogs, syringotoxin and syringostatin. Strains representative of P. viridiflava and six pathovars of P. syringae failed to hybridize with the gene probes, demonstrating that syr sequences are highly specific to P. s. pv. syringae and related nonpathogenic strains. Maximum parsimony analysis of restriction fragment length polymorphism profiles was used to evaluate relatedness among strains within the syrB and syrD gene region. A tree, conveying the smallest number of evolutionary changes among strains, revealed considerable diversity within the syr gene region; subclusters of strains were identified that appear to share specific qualities relevant to the plant-pathogen interaction. Because both the syrB gene and syringomycin production can be induced in response to plant signal molecules, 42 strains containing homologous syr sequences were tested for signal-mediated induction of toxin production. Over 90% of the toxigenic strains produced larger quantities of toxin when the plant signal molecules, arbutin and D-fructose, were added to syringomycin-minimal medium; 13 of the strains produced > or = 10-fold higher toxin levels. Some strains, such as 5D428, produced toxin only in the presence of these signals.(ABSTRACT TRUNCATED AT 250 WORDS)

ATP-Binding Cassette Transporters↗
PubMed2004

Pleiotrophin mRNA is highly expressed in neural stem (progenitor) cells of mouse ventral mesencephalon and the product promotes production of dopaminergic neurons from embryonic stem cell-derived nestin-positive cells.

Neural stem cells are promising candidates for donor cells in neural transplantation. However, the mechanism by which neural stem cells differentiate into neurons is not well understood. In the present study, a serial analysis of gene expression (SAGE) was carried out to generate a gene file of neural stem (progenitor) cells from the mouse ventral mesencephalon. Among the 15,815 tags investigated, the mRNA of the housekeeping genes (elongation factor 1-alpha, ATPase subunit 6, GAPDH, actin), laminin receptor 1, HSP 70, pleiotrophin, and nestin were highly expressed. Because pleiotrophin (PTN) exhibits mitogenic and trophic effects on neural development and exhibits trophic effects on survival of dopaminergic (DAergic) neurons, we investigated the role of PTN in neurogenesis, especially to DAergic neurons. Here, we show that PTN increased the production of tyrosine hydroxylase (TH)-positive neurons from embryonic stem (ES) cell-derived nestin-positive cells. The expression of Nurr1 mRNA was enhanced by PTN. L-dopa in the culture medium was increased by PTN. This effect was as strong as with sonic hedgehog. Data suggest that PTN mRNA is highly expressed in neural stem (progenitor) cells of mouse ventral mesencephalon, and PTN promotes the production of DAergic neurons from ES cell-derived nestin-positive cells.

Animals↗
PubMed2000

Reconstruction of radionuclide contamination of the Techa River caused by liquid waste discharge from radiochemical production at the Mayak Production Association.

Because of its importance to reconstructing radiation doses for ongoing epidemiological studies, a feasibility study was undertaken to determine if the source term of radioactive materials released to the Techa River from the Mayak Production Association, the first facility in the former Soviet Union for the production of plutonium, could be reconstructed from historical measurements made at a limited number of downriver locations. The feasibility study used historically measured water flow rates and total-beta radioactivity measurements, and considered the processes of radioactive decay and of sorption/desorption. A simple radionuclide mass balance approach was used. To determine the rate of input of radionuclides to the Techa River system, the Techa River was depicted as a series of segments for which measurements are available. For each segment of the river, a system of recurrent (with time) equations was compiled for radioactivity balance accounting for the radioactivity inflow at the inflowing end, activity discharge with water at the outflowing end, and the reduction of activity because of radioactive decay. The equations change with time to account for the changing nature of the river regime. Effective sorption constants for 90Sr and 137Cs, which characterize the transport of radionuclides among the river system components (water and bottom sediments), were defined based on the inventory of these radionuclides deposited at each of the studied river segments and data on water concentration and radioactive removal. All the information on radioactive contamination of the river system components during the period 1949-1996 was used. Solution of the series of equations provided information on the rate of input of these radionuclides into the upper end of the river. The pilot study indicated that it is possible to determine the historical releases of a wider suite of radionuclides using the historical monitoring data from numerous locations along the river, rather than relying on a more uncertain reconstruction of quantities released at the point of discharge. Radionuclides considered include 90Sr, 106Ru, 137Cs, and 144Ce. Estimated concentrations of selected radionuclides at various times are presented.

Feasibility Studies↗
PubMed2003

Lost productive work time costs from health conditions in the United States: results from the American Productivity Audit.

The American Productivity Audit (APA) is a telephone survey of a random sample of 28,902 U.S. workers designed to quantify the impact of health conditions on work. Lost productive time (LPT) was measured for personal and family health reasons and expressed in hours and dollars. Health-related LPT cost employers 225.8 billion US dollars/year (1685 US dollars/employee per year); 71% is explained by reduced performance at work. Personal health LPT was 30% higher in females and twice as high in smokers (> or =1 pack/day) versus nonsmokers. Workers in high-demand, low-control jobs had the lowest average LPT/week versus the highest LPT for those in low-demand, high-control jobs. Family health-related work absence accounted for 6% of all health-related LPT. Health-related LPT costs are substantial but largely invisible to employers. Costs vary significantly by worker characteristics, suggesting that intervention needs vary by specific subgroups.

Absenteeism↗
PubMed1990

Hydrolytic enzyme production by Clostridium difficile and its relationship to toxin production and virulence in the hamster model.

Thirty isolates of Clostridium difficile expressing different degrees of toxigenicity and virulence in an animal model were assayed for the production of chondroitin-4-sulphatase, hyaluronidase, heparinase, collagenase and protease. All strains demonstrated some hydrolytic enzyme activity. There was no direct correlation between toxigenic status, or virulence, and hydrolytic enzyme production. However, all five strains known to be highly virulent in the hamster model had hyaluronidase, chondroitin-4-sulphatase and collagenase activity whereas only three of five toxigenic but poorly virulent strains had these activities, the collagenase activity being weak in all three cases. The only two proteolytic strains are also highly virulent. The potential tissue damaging properties of these hydrolytic enzymes may help to explain the differences in virulence of C. difficile strains seen in the Syrian hamster model of antibiotic-associated colitis, and may contribute to the spectrum of disease seen in man. It is also possible that chondroitin-4-sulphatase, hyaluronidase and collagenase activity may release essential nutrients, promoting establishment of C. difficile in the gut.

Animals↗
PubMed1989

Regulated expression at high copy number allows production of a growth-inhibitory oncogene product in Drosophila Schneider cells.

The Drosophila metallothionein promoter (Mtn) was used to obtain efficient, regulated expression of foreign gene products inserted in high copy numbers into Drosophila melanogaster Schneider 2 cells. An expression unit comprised of a reporter gene [Escherichia coli galactokinase (galK)] fused to the Mtn promoter was stably introduced into Schneider 2 cells in up to several hundred copies per cell in a single transfection-selection event. This system contrasts dramatically with other eukaryotic systems that permit only a few copies of a gene to be stably inserted in a single transfection-selection event. The transfected Drosophila S2 cell lines expressed high levels of both galK mRNA and protein in response to metal induction. Most important, and in contrast to mammalian cells, expression remained fully regulated even at high copy number, with low basal expression maintained in the absence of inducer. This regulated system was used to obtain efficient expression in Drosophila cells of an otherwise lethal or growth-inhibitory gene product, the human H-ras oncogene. The ability to obtain regulated high-level expression of potentially lethal foreign proteins is unique to the Drosophila cell system.

Animals↗
PubMed2002

Crystal structures of a meta-cleavage product hydrolase from Pseudomonas fluorescens IP01 (CumD) complexed with cleavage products.

2-Hydroxy-6-oxo-7-methylocta-2,4-dienoate hydrolase (CumD) from Pseudomonas fluorescens IP01 hydrolyzes a meta-cleavage product generated in the cumene (isopropylbenzene) degradation pathway. The crystal structures of the inactive S103A mutant of the CumD enzyme complexed with isobutyrate and acetate ions were determined at 1.6 and 2.0 A resolution, respectively. The isobutyrate and acetate ions were located at the same position in the active site, and occupied the site for a part of the hydrolysis product with CumD, which has the key determinant group for the substrate specificity of related hydrolases. One of the oxygen atoms of the carboxyl group of the isobutyrate ion was hydrogen bonded with a water molecule and His252. Another oxygen atom of the carboxyl group was situated in an oxyanion hole formed by the two main-chain N atoms. The isopropyl group of the isobutyric acid was recognized by the side-chains of the hydrophobic residues. The substrate-binding pocket of CumD was long, and the inhibition constants of various organic acids corresponded well to it. In comparison with the structure of BphD from Rhodococcus sp. RHA1, the structural basis for the substrate specificity of related hydrolases, is revealed.

Amino Acid Sequence↗
PubMed1980

Pyomelanin production by Pseudomonas aeruginosa. I. Transformation of pyomelanin productivity.

Pseudomonas aeruginosa was successfully transformed from a pyomelanin-producing strain to a non-pyomelanin-producing strain by genetic transformation, with an average frequency of 1.17 X 10-3/recipient. Although the transformation frequency was not affected by doses of DNA between 17 and 51 microgram/ml, it was influenced by the growth phase of the recipient bacteria, i.e., it was highest in the late logarithmic phase. Biochemical functions of the transformants were the same as those of the recipient strain except for pyomelanin production. Some of them, however, showed an intermediate growth behavior and cell arrangement between the donor and recipient. The serological type of the donor strain was sometimes contransduced although a few transformants became nonagglutinable with either donor or recipient type antiserum. The pyomelanin producing activity and serological type gained of some transformants were eliminated by either subculturing in nutrient broth or acridine treatment. The results obtained suggested that the pyomelanin productivity of P. aeruginosa is controlled by a plasmid.

Acridine Orange↗
PubMed2005

IgE production after four routes of injections of Japanese cedar pollen allergen without adjuvant: crucial role of resident cells at intraperitoneal or intranasal injection site in the production of specific IgE toward the allergen.

The production of specific IgE antibodies directed toward cedar pollen correlates well with the onset of allergic rhinitis; but the mechanisms of allergen recognition as nonself and Ig class switch to IgE by the immune system are still not fully understood. In the present study, we injected cedar pollen into mice through 4 different routes (intranasal (i.n.), intraperitoneal (i.p.), intravenous (i.v.), and subcutaneous (s.c.)) without adjuvant 1 to 3 times, and determined time-dependent changes in the total and specific serum IgE levels compared with those in the serum levels of other isotype Igs. After an i.p. or i.n. injection of allergen into the mice, they produced a 1.5-to 1.7-fold increase in total IgE, but none in IgG, IgM, or IgA antibodies in their serum, whereas an i.v. or s.c. injection of allergen was inactive as an inducer of total IgE antibodies. Upon a 2nd (s.c.) injection of the allergen into the i.p. or i.n. sensitized mice, a large amount of allergen-specific IgE antibodies was found in the serum. In the case of i.v. or s.c. sensitized mice, however, they produced total, but not specific, IgE antibodies; and a 3rd (s.c.) injection of the allergen resulted in a large amount of specific IgE antibodies in the serum. These results imply that resident cells at the i.p. or i.n. injection site may play a crucial role in the efficient production of total and specific IgE antibodies toward the allergen.

Administration, Intranasal↗
PubMed1994

The sss gene product, which affects pyoverdin production in Pseudomonas aeruginosa 7NSK2, is a site-specific recombinase.

Pyoverdin production by Pseudomonas aeruginosa strain 7NSK2 was induced by Zn(II) in the presence of iron. A mutant was isolated in which Zn(II) no longer induced pyoverdin production. The sss gene which was inactivated in this mutant was cloned and sequenced. Its protein sequence showed 50% identity to the XerC protein of Escherichia coli, which is a member of the lambda integrase family of site-specific recombinases. An open reading frame was found upstream of sss whose protein sequence showed strong identity to DapF, the diaminopimelate epimerase. In E. coli, xerC is part of a multicistronic unit that also contains dapF. The sss gene of P. aeruginosa could restore site-specific recombination at cer in an E. coli xerC mutant and the E. coli xerC gene could complement a genomic sss mutation in P. aeruginosa.

Amino Acid Sequence↗
PubMed1991

Divergent effect of the anaerobic bacteria by-product butyric acid on the immune response: suppression of T-lymphocyte proliferation and stimulation of interleukin-1 beta production.

The effects of short-chain fatty acids (SCFA) produced by anaerobic bacteria, namely propionic, butyric and iso-butyric on T-cell proliferation was investigated. A dose-dependent inhibition of both phytohemagglutinin-induced blastogenesis and mixed lymphocyte culture was observed in the millimolar range of SCFA concentrations. The tested SCFA displayed different levels of suppression. The degree of activity was in the following order: butyrate greater than propionate greater than isobutyrate. T-cell inhibition was partially reversed, at least for propionic and isobutyric acids, by increasing the concentration of macrophages in the assay system. Furthermore, butyric acid displayed an interesting biphasic stimulation of monocyte interleukin-1 beta production, a cytokine with a powerful bone-resorbing activity. Since millimolar concentrations of SCFA are present in gingival fluid from periodontal pockets, the observed results support the role of these by-products of anaerobic metabolism in the pathogenesis of periodontal diseases.

Alveolar Bone Loss↗
PubMed1991

Production and identification of natural monocyte chemotactic protein from virally infected murine fibroblasts. Relationship with the product of the mouse competence (JE) gene.

Primary cultures of mouse embryonic fibroblasts and confluent monolayers of mouse fibroblastoid cells (L929) were found to secrete a chemotactic factor specific for monocytes. It biological activity was deduced from both the migration distance under agarose and the number of migrated monocytes in the micropore filter method. The monocyte chemotactic protein (MCP) was inducible in these cells by double-stranded RNA and by infection with virus. In embryonic fibroblasts MCP was also produced in response to the cytokines interleukin-1 (IL-1) and tumor necrosis factor (TNF). Under all conditions for induction of MCP tested no production of chemotactic activity for granulocytes could be detected. MCP activity from virally infected L929 cells was concentrated and purified by sequential adsorption to controlled pore glass, heparin-Sepharose chromatography, ion-exchange FPLC and reversed-phase HPLC. Pure MCP was found to occur mainly as a 7-8-kDa protein. Although the mature protein possessed a blocked NH2-terminus, it was identified by enzymatic cleavage and sequence analysis of an internal fragment. The sequence obtained corresponded to a part of the cDNA-derived protein sequence of the murine 'competence' (JE) gene, inducible in fibroblasts by cytokines and virus. In all probability the 7-8-kDa MCP form represents the natural product of the mouse gene JE. Murine MCP can thus be classified in the novel family of small inducible inflammatory proteins.

Amino Acid Sequence↗