Adhesive ability and biofilm metabolic activity of Listeria monocytogenes strains before and after cold stress

2012 ◽  
Vol 11 (61) ◽  
Author(s):  
Rihab BEN SLAMA
Keyword(s):  
Listeria Monocytogenes ◽  
Cold Stress ◽  
Metabolic Activity ◽  
Before And After ◽  
Adhesive Ability

scholarly journals Synergism between calcium nitrate applications and fungal endophytes to increase sugar concentration in Festuca sinensis under cold stress

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10568
Author(s):  
Lianyu Zhou ◽  
Chunjie Li ◽  
James F. White ◽  
Richard D. Johnson
Keyword(s):  
Cold Stress ◽  
Metabolic Activity ◽  
Soluble Sugars ◽  
Fungal Endophytes ◽  
Calcium Nitrate ◽  
Soluble Carbohydrates ◽  
Total Chlorophyll ◽  
Endophyte Infection ◽  
Before And After ◽  
The Impact

Epichloë endophytes have been shown to increase tolerance to biotic and abiotic stresses in many cool-season grasses. We investigated the impact of endophyte infection of Festuca sinensis, on root metabolic activity, photosynthetic pigments, leaf relative water content (RWC) and soluble carbohydrates in a field experiment carried out during chilling and irrigation with Ca(NO3)2. A highly significant (P < 0.001) correlation for Epichloë endophytes was observed for root metabolic activity. Ca(NO3)2affectedverysignificantly root metabolic activity and total chlorophyll (P < 0.001). Low temperature led to highly significant (P < 0.001) reductions in root metabolic activity, RWC, total chlorophyll, chlorophyll a/b ratio, and carotenoid contents. In addition, the fructose concentrations of shoots were greater on the 14th day than on the 28th day and before treatment, whilst the glucose concentration of roots was much higher on the 28th day than before and after 14 days treatment. Moreover, our results indicated that the addition of calcium nitrate contributed to higher levels of total chlorophylls, soluble sugars, sucrose, fructose or glucose in the shoots and roots in both E+ and E- plants during long periods of chilling. These results suggest that Epichloë endophyte infection and/or exogenous calcium nitrate can confer better tolerance to cold stress.

Acute cold stress in rheumatoid arthritis inadequately activates stress responses and induces an increase of interleukin 6

2008 ◽  
Vol 68 (4) ◽  
pp. 572-578 ◽  
Author(s):  
R H Straub ◽  
G Pongratz ◽  
H Hirvonen ◽  
T Pohjolainen ◽  
M Mikkelsson ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Stress Response ◽  
Cold Stress ◽  
Stress Responses ◽  
Plasma Levels ◽  
Acute Stress ◽  
Whole Body ◽  
Cold Therapy ◽  
Before And After ◽  
Sympathetic Stress

Objective:Acute stress in patients with rheumatoid arthritis (RA) should stimulate a strong stress response. After cryotherapy, we expected to observe an increase of hormones of the adrenal gland and the sympathetic nervous system.Methods:A total of 55 patients with RA were recruited for whole-body cryotherapy at −110°C and −60°C, and local cold therapy between −20°C and −30°C for 7 days. We measured plasma levels of steroid hormones, neuropeptide Y (sympathetic marker), and interleukin (IL)6 daily before and after cryotherapy.Results:In both therapy groups with/without glucocorticoids (GC), hormone and IL6 levels at baseline and 5 h after cold stress did not change over 7 days of cryotherapy. In patients without GC, plasma levels of cortisol and androstenedione were highest after −110°C cold stress followed by −60°C or local cold stress. The opposite was found in patients under GC therapy, in whom, unexpectedly, −110°C cold stress elicited the smallest responses. In patients without GC, adrenal cortisol production increased relative to other adrenal steroids, and again the opposite was seen under GC therapy with a loss of cortisol and an increase of dehydroepiandrosterone. Importantly, there was no sympathetic stress response in both groups. Patients without GC and −110°C cold stress demonstrated higher plasma IL6 compared to the other treatment groups (not observed under GC), but they showed the best clinical response.Conclusions:We detected an inadequate stress response in patients with GC. It is further shown that the sympathetic stress response was inadequate in patients with/without GC. Paradoxically, plasma levels of IL6 increased under strong cold stress in patients without GC. These findings confirm dysfunctional stress axes in RA.

Influence of different concentrations of fibrinogen on the properties of a fibrin matrix for vascular tissue engineering

2021 ◽  
Vol 29 (1) ◽  
pp. 21-34
Author(s):  
Vera G. Matveeva ◽  
Mariam Yu. Khanova ◽  
Tatyana V. Glushkova ◽  
Larisa V. Antonova
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Metabolic Activity ◽  
Vascular Tissue ◽  
Physical And Mechanical Properties ◽  
Vascular Tissue Engineering ◽  
Test Machine ◽  
Fibrin Matrix ◽  
Before And After ◽  
The Difference

Aim. To evaluate the potential utility of fibrin matrices containing 10, 20, and 25 mg/ml of fibrinogen (fibrin-10, fibrin-20, and fibrin-30, respectively) in vascular tissue engineering (VTE). Materials and Methods. Fibrinogen was isolated using the method of ethanol cryoprecipitation and polymerized using a solution of thrombin and CaCl2. The fibrin structure was studied in a scanning electron microscope, and the physical and mechanical properties of the material were tested on a Zwick/Roell test machine. The metabolic activity of endothelial cells (EC) on the fibrin surface was evaluated by the MTT assay, and the viability of fibroblasts in the thickness of fibrin and possibility for migration by in fluorescent and light microscopy. Percent of fibrin shrinkage was determined from the difference in the sample volumes before and after removal of moisture. Results. The fiber diameter did not differ among all fibrin samples, but the pore diameter in fibrin-30 was smaller than those in fibrin-10 and fibrin-20. A possibility for migration of fibroblasts into the depth of the fibrin matrix and preservation of 97-100% viability of cells at a depth 5 mm was confirmed. The metabolic activity of EC on the surface of fibrin-20 and fibrin-30 exceeded that on collagen, fibronectin, and fibrin-10. All fibrin samples shrank in volume to 95.5-99.5%, and the highest shrinkage was seen in fibrin-10. The physical and mechanical properties of fibrin were inferior to those of human A. mammaria by a factor of 10. Conclusion. Fibrin with fibrinogen concentrations of 20 and 30 mg/ml maintains a high metabolic and proliferative activity of EC on the surface and also a high viability of fibroblasts in the matrix. Its availability, ease of preparation, and a number of other favorable properties make fibrin a promising material for VTE. However, the problem of insufficient strength requires further investigations.

scholarly journals Strand specific RNA-sequencing and membrane lipid profiling reveals growth phase-dependent cold stress response mechanisms in Listeria monocytogenes

PLoS ONE ◽  
2017 ◽  
Vol 12 (6) ◽  
pp. e0180123 ◽  
Author(s):  
Patricia Hingston ◽  
Jessica Chen ◽  
Kevin Allen ◽  
Lisbeth Truelstrup Hansen ◽  
Siyun Wang
Keyword(s):  
Listeria Monocytogenes ◽  
Stress Response ◽  
Cold Stress ◽  
Rna Sequencing ◽  
Growth Phase ◽  
Membrane Lipid ◽  
Lipid Profiling

Phagocyte Metabolic Activity during Hemodialysis with Different Dialyzers Not Affecting the Number of Circulating Phagocytes

1992 ◽  
Vol 15 (2) ◽  
pp. 89-92 ◽  
Author(s):  
R. Vanholder ◽  
N. Van Landschoot ◽  
M.A. Waterloos ◽  
J. Delanghe ◽  
G. Van Maele ◽  
...  
Keyword(s):  
Metabolic Activity ◽  
Whole Blood ◽  
Metabolic Function ◽  
Phagocytic Capacity ◽  
Phagocytic Process ◽  
Before And After ◽  
Leukocyte Counts ◽  
Membrane Type ◽  
Phagocytic Reaction

Overall leukocyte counts decrease during certain forms of hemodialysis, but little information is available on the intradialytic evolution of phagocytic metabolic function, especially during dialysis with dialyzers not affecting the number of circulating phagocytes. This study evaluated the phagocytic capacity of granulocytes and monocytes to generate CO2 out of glucose under basic unchallenged conditions and after stimulation with latex or zymosan, before and after 15, 60 and 240 minutes of dialysis with reused cuprophan, AN69S, polysulphone, polymethylmethacrylate and hemophan hemodialyzers. Phagocytic metabolic function was assessed in whole blood on the basis of 14CO2-production from labelled glucose during the phagocytic process. There were no changes in basic unchallenged CO2-production with any of the dialyzers. Reactivity to latex and zymosan, expressed per number of phagocytes, showed no decrease, irrespective of the membrane type. For polymethylmethacrylate and reused cuprophan, a slight but significant increase in metabolic reactivity was observed in response to latex and zymosan. The test employed may give a screening picture of the phagocytic reaction to contact with dialyzers and membranes and thus of their degree of biocompatibility towards the phagocyte system.

INFLUENCE OF EXPOSURE TO COLD AND ASCORBIC ACID ADMINISTRATION ON THE WEIGHT AND THE METABOLIC ACTIVITY OF THE ADRENAL GLAND OF HYPO- PHYSECTOMIZED RATS GIVEN ACTH

1955 ◽  
Vol 33 (1) ◽  
pp. 677-680
Author(s):  
L.-P. Dugal ◽  
A. Desmarais ◽  
P. M. Gagnon
Keyword(s):  
Ascorbic Acid ◽  
Adrenal Gland ◽  
Metabolic Activity ◽  
Standard Dose ◽  
Exposure To Cold ◽  
Before And After ◽  
Hypophysectomized Rats ◽  
Adrenal Response ◽  
The Right ◽  
Acid Administration

Modification of the response of the adrenal gland to ACTH was observed in hypophysectomized rats exposed to cold with or without ascorbic acid treatment. Changes in weight and metabolic activity of the gland were used to measure the adrenal response. All comparisons were made between the left and the right adrenal of each animal before and after treatment. The results obtained show that cold stress increases the response of the adrenal to a standard dose of two units of ACTH; they also indicate that ascorbic acid administration increases so much the responsiveness of the adrenal gland to ACTH at room temperature that such a response is not enhanced by exposure to cold.

Evaluation of Third-Party Deep Cleaning as a Listeria monocytogenes Control Strategy in Retail Delis

2017 ◽  
Vol 80 (11) ◽  
pp. 1913-1923 ◽  
Author(s):  
Susan R. Hammons ◽  
Andrea J. Etter ◽  
Jingjin Wang ◽  
Tongyu Wu ◽  
Thomas Ford ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Standard Operating Procedure ◽  
Third Party ◽  
Food Marketing ◽  
High Prevalence ◽  
Standard Operating ◽  
Before And After ◽  
Contact Surfaces ◽  
Very High

ABSTRACT The objective of this study was to develop and assess the efficacy of an aggressive deep cleaning sanitation standard operating procedure (DC-SSOP) in nine retail delicatessens to reduce persistent Listeria monocytogenes environmental contamination. The DC-SSOP was developed from combined daily SSOPs recommended by the Food Marketing Institute and input from experts in Listeria control from food manufacturing and sanitation. The DC-SSOP was executed by a trained professional cleaning service during a single 12-h shutdown period. A modified protocol from the U.S. Food and Drug Administration Bacteriological Analytical Manual was used to detect L. monocytogenes in samples from 28 food and nonfood contact surfaces that were collected immediately before and after each cleaning and in samples collected monthly for 3 months. The DC-SSOP significantly reduced L. monocytogenes prevalence overall during the 3-month follow-up period and produced variable results for persistent L. monocytogenes isolates. Six delis with historically low to moderate L. monocytogenes prevalence had no significant changes in the number of samples positive for L. monocytogenes after deep cleaning. Deep cleaning in very high prevalence delis (20 to 30% prevalence) reduced L. monocytogenes by 25.6% (Padj &lt; 0.0001, n = 294) overall during the follow-up period. Among delis with extremely high prevalence (&gt;30%), positive samples from nonfood contact surfaces were reduced by 19.6% (Padj = 0.0002, n = 294) during the follow-up period. The inability of deep cleaning to completely eliminate persistent L. monocytogenes was likely due to the diverse infrastructures in each deli, which may require more individualized intervention strategies.

Exogenous protein affects developmental competence and metabolic activity of bovine pre-implantation embryos in vitro

1998 ◽  
Vol 10 (4) ◽  
pp. 327 ◽  
Author(s):  
J. Eckert ◽  
P. A. Pugh ◽  
J. G. Thompson ◽  
H. Niemann ◽  
H. R. Tervit
Keyword(s):  
Metabolic Activity ◽  
Production Systems ◽  
Lactate Production ◽  
Developmental Competence ◽  
Morphological Development ◽  
Bovine Embryo ◽  
In Vitro Production ◽  
Exogenous Protein ◽  
Before And After

The role of exogenous protein during bovine pre-implantation embryo development in two in vitro production systems was investigated. Morphological development, survival after vitrification and metabolic activity before and after vitrification were recorded in blastocysts generated in vitro in synthetic oviduct fluid (SOF) medium in the presence of either bovine serum albumin (BSA) or polyvinyl-alcohol (PVA). Metabolic activity was determined by measuring oxygen consumption, glucose and pyruvate uptake as well as lactate production. Development to blastocysts and survival after vitrification were reduced significantly in medium lacking protein. Of the metabolic parameters measured, only pyruvate uptake was increased significantly in embryos cultured in medium supplemented with PVA. Whereas in BSA-supplemented medium pyruvate uptake was correlated with lactate production, in PVA-supplemented medium glucose uptake was correlated with lactate production. Lactate production increased significantly after vitrification as compared with fresh embryos. Thus, exogenously added protein significantly alters oxidative metabolism. In medium lacking protein, the additional pyruvate may be used for the maintenance of intracellular amino acid pools. Vitrification appears to alter glycolytic metabolic profiles indicating a stress-response. In conclusion, the perturbed metabolism corresponding to reduced developmental capacity of embryos produced under protein-free conditions emphasizes the ambiguity between maximum develop-ment, technical and hygienic requirements and physiological demands of the early bovine embryo in vitro. The use of well-defined recombinant proteins might assist in closing this gap.

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