scholarly journals Role of Phosphorylcholine in Streptococcus Pyogenes Adherence to Epithelial Cells

2021 ◽  
Author(s):  
Hiroyuki Iuchi ◽  
Junichiro Ohori ◽  
Takeshi Tokushige ◽  
Satoshi Kiyama
Keyword(s):  
Epithelial Cells ◽  
Streptococcus Pyogenes ◽  
Negative Correlation ◽  
Platelet Activating Factor ◽  
Significant Negative Correlation ◽  
Inhibitory Effects ◽  
Polymerase Chain ◽  
Intracellular Invasion ◽  
Adhesion And Invasion

Abstract Background: This study aimed to evaluate the influence of Phosphorylcholine (PC) expression on the adherence and invasion of Streptococcus pyogenes (S. pyogenes) to epithelial cells to clarify the potential effectiveness of a vaccine targeting PC. Methods: Eight clinical strains of S. pyogenes were cultured overnight, and PC expression was evaluated by fluorescence-activated cell sorting. Bacterial adherence and invasion were examined using Detroit 562 cells. An anti-PC-specific monoclonal antibody (TEPC-15) was used to inhibit bacterial PC, and a platelet-activating factor receptor (PAF-R) antagonist (ABT-491) was used to inhibit cellular PAF-R. Additionally, amplification of the emm gene was performed using polymerase chain reaction with the standard primers. Results: The level of PC expressed on the S. pyogenes surfaces differed in each strain. Furthermore, PC expression was different even in the same emm type. Adherence assay experiments showed that there was a significant negative correlation between TEPC-15 and ABT-491 inhibitory effects and PC expression in S. pyogenes. Similarly, intracellular invasion assay experiments showed that there was a significant negative correlation between TEPC-15 and ABT-491 inhibitory effects and PC expression in S. pyogenes. Conclusion: The present study suggests that PC is involved in the cell adhesion and invasion of S. pyogenes, regardless of the emm type.

scholarly journals Nurses Burnout, Resilience, and Its Association With Socio-Demographic Factors During COVID-19 Pandemic

2022 ◽  
Vol 12 ◽  
Author(s):  
Majid Heidari Jamebozorgi ◽  
Ali Karamoozian ◽  
Tayebe Ilaghinezhad Bardsiri ◽  
Hojjat Sheikhbardsiri
Keyword(s):  
Negative Correlation ◽  
Maslach Burnout Inventory ◽  
Significant Negative Correlation ◽  
Cross Sectional Study ◽  
Stressful Events ◽  
Personal Accomplishment ◽  
Cross Sectional ◽  
Work Related ◽  
Socio Demographic Factors

BackgroundIn the recent pandemic, nurses have faced workload and being exposed to burnout. Resilience helps address work-related psychological problems such as stressful events and burnout. According to the roles of nurses in the healthcare system, we investigated the relationship between resiliency and burnout in nurses.Material and MethodsIn this descriptive analytical cross-sectional study, 364 nurses participated from April to June 2021. Census sampling was used to recruit participants. Maslach burnout inventory (MBI), Connor-Davidson Resiliency Scale (CDRISC), and a demographic check-list were utilized to collect data. Data analysis was done using SPSS version 22. Shapiro-Wilk, Kruskal–Wallis test, Mann–Whitney U-test, correlation analysis, and generalized linear model were applied accordingly.ResultsOverall, the findings showed that nurses had severe symptoms of burnout and a moderate level of resilience. The two domains of burnout, emotional exhaustion and personal accomplishment had a significantly negative correlation with resilience (r = −0.442, p < 0.001 and r = −0.351, p = 0.03, respectively). Linear regression showed that demographic characteristics (Hospital type, ward type, gender, and overtime) were the major predictors of the 3 sub-categories of burnout. A significant negative correlation was observed between burnout and resilience highlighting the role of resilience in reducing burnout (P < 0.05).ConclusionIn order to help nurses to tackle and endure burnout in pandemic times, there is a need to implement national and local policies to help them accordingly.

scholarly journals Role of insulin during the development of oligofructose (OF)-induced equine laminitis

2015 ◽  
Vol 59 (2) ◽  
pp. 303-309
Author(s):  
Renli Jiang ◽  
Li Gao ◽  
Guanying Wang ◽  
Xinran Li ◽  
Yue Li ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Glucose Oxidase ◽  
Negative Correlation ◽  
Significant Negative Correlation ◽  
Control Group ◽  
Endothelin 1 ◽  
Limulus Amoebocyte Lysate ◽  
And Control ◽  
Over Time

Abstract Horses (n = 20) were divided into 2 groups: oligofructose (OF)-induced equine laminitis group (group OF; n = 11) which received 10 g/kg b.w. of OF dissolved in 4 L water via nasogastric intubation, and control group (NS; n = 9) which received 4 L of saline. Blood was collected at 4 h intervals over 72 h study period and analysed by ELISA, kinetic limulus amoebocyte lysate assay, and glucose-oxidase methods. The level of insulin changed significantly in horses which received OF (P < 0.01); there was a significant negative correlation between the level of adiponectin and insulin over time. The results suggested that insulin may play an important role in the development of OF-induced equine laminitis by altering the level of endothelin-1 and nitric oxide.

Correlates and Mediators of Dissociation: Towards a Transtheoretical Perspective

2020 ◽  
pp. 027623662095628
Author(s):  
Damla E. Aksen ◽  
Craig Polizzi ◽  
Steven Jay Lynn
Keyword(s):  
Negative Affect ◽  
Negative Correlation ◽  
Emotion Dysregulation ◽  
Sleep Disturbances ◽  
Significant Negative Correlation ◽  
Unique Variance ◽  
Positive Correlations ◽  
Bidirectional Relations ◽  
Mediational Role

We evaluated variables important to understanding dissociation ( N = 379 undergraduates). We investigated: (a) the correlations among dissociation and impulsivity, alexithymia, mindfulness, negative affect, neuroticism, sleep disturbances, and emotion dysregulation; (b) unique variance of these variables in statistically predicting dissociation scores; and (c) the statistical mediational role of emotion dysregulation and sleep in explaining dissociation. We found significant positive correlations between dissociation and emotion dysregulation, sleep, alexithymia, negative affect, impulsivity, and neuroticism as well as a significant negative correlation between mindfulness and dissociation, consistent with Lynn et al . Sleep, impulsivity, emotion dysregulation, and negative affect uniquely related to and explained significant variance in dissociation, in order from most to least variance accounted for. Sleep partially mediated the relation between emotion dysregulation and dissociation and the relation between impulsivity and dissociation. Emotion dysregulation partially mediated the relation between sleep and dissociation and the relation between impulsivity and dissociation. Additional findings provided support for bidirectional relations between sleep experiences and dissociation and emotion dysregulation and dissociation.

scholarly journals Signaling in TRPV1-induced platelet activating factor (PAF) in human esophageal epithelial cells

2010 ◽  
Vol 298 (2) ◽  
pp. G233-G240 ◽  
Author(s):  
Jie Ma ◽  
Karen M. Harnett ◽  
Jose Behar ◽  
Piero Biancani ◽  
Weibiao Cao
Keyword(s):  
Epithelial Cells ◽  
Western Blot ◽  
Transient Receptor Potential ◽  
Platelet Activating Factor ◽  
Calcium Ionophore ◽  
Transferase Activity ◽  
Ionophore A23187 ◽  
Acetyl Coa ◽  
Coa Transferase

Transient receptor potential channel, vanilloid subfamily member 1 (TRPV1) receptors were identified in human esophageal squamous epithelial cell line HET-1A by RT-PCR and by Western blot. In fura-2 AM-loaded cells, the TRPV1 agonist capsaicin caused a fourfold cytosolic calcium increase, supporting a role of TRPV1 as a capsaicin-activated cation channel. Capsaicin increased production of platelet activating factor (PAF), an important inflammatory mediator that acts as a chemoattractant and activator of immune cells. The increase was reduced by the p38 MAP kinase (p38) inhibitor SB203580, by the cytosolic phospholipase A2 (cPLA2) inhibitor AACOCF3, and by the lyso-PAF acetyltransferase inhibitor sanguinarin, indicating that capsaicin-induced PAF production may be mediated by activation of cPLA2, p38, and lyso-PAF acetyltransferase. To establish a sequential signaling pathway, we examined the phosphorylation of p38 and cPLA2 by Western blot. Capsaicin induced phosphorylation of p38 and cPLA2. Capsaicin-induced p38 phosphorylation was not affected by AACOCF3. Conversely, capsaicin-induced cPLA2 phosphorylation was blocked by SB203580, indicating that capsaicin-induced PAF production depends on sequential activation of p38 and cPLA2. To investigate how p38 phosphorylation may result from TRPV1-mediated calcium influx, we examined a possible role of calmodulin kinase (CaM-K). p38 phosphorylation was stimulated by the calcium ionophore A23187 and by capsaicin, and the response to both agonists was reduced by a CaM inhibitor and by CaM-KII inhibitors, indicating that calcium induced activation of CaM and CaM-KII results in P38 phosphorylation. Acetyl-CoA transferase activity increased in response to capsaicin and was inhibited by SB203580, indicating that p38 phosphorylation in turn causes activation of acetyl-CoA transferase to produce PAF. Thus epithelial cells produce PAF in response to TRPV1-mediated calcium elevation.

scholarly journals Role of Endogenous Allelochemicals in Host Plant Resistance to Japanese Beetles

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 767E-767
Author(s):  
Thomas G. Ranney ◽  
James D. Burton ◽  
James F. Walgenbach ◽  
D. Mason Pharr ◽  
Cindy A. Patton ◽  
...  
Keyword(s):  
Negative Correlation ◽  
Chemical Constituents ◽  
Soluble Sugars ◽  
Significant Negative Correlation ◽  
Mechanisms Of Resistance ◽  
Feeding Intensity ◽  
Prunus Virginiana ◽  
Feeding Trials ◽  
Choice Feeding

No-choice feeding trials were conducted with adult Japanese beetles on leaves from 14 taxa of rosaceous trees. Feeding intensity (leaf area consumption) ranged from 0.08 to 6.1 cm2/day for Prunus virginiana and P. sargentii, respectively. Analysis of endogenous chemical constituents suggested that the mechanisms of resistance varied for the different plant genera. Among the Prunus taxa there was a significant negative correlation between cyanide potential and feeding intensity (r = –0.56). Tissue toughness (resistance to tearing) was also negatively correlated with feeding intensity (r = –0.39) for all taxa. Soluble sugars (glucose, fructose, sucrose, and sorbitol) had no significant phagostimulatory effect, separately or in combination.

Uraemic Bleeding : Contributory Role Of Red Cells

1981 ◽  
Author(s):  
M Livio ◽  
D Marchesi ◽  
G Mecca ◽  
G Remuzzi ◽  
M B Donati ◽  
...  
Keyword(s):  
Blood Cell ◽  
Cell Volume ◽  
Negative Correlation ◽  
Packed Cell Volume ◽  
Significant Negative Correlation ◽  
T Test ◽  
Red Cells ◽  
Student’S T ◽  
Student’S T Test

The bleeding times (B.T.) of 65 patients with chronic uraemia were determined inmediately before a routine haonodialysis session. A significant negative correlation (r=0.67, p < 0.01) was found between B.T. and packed cell volume (PCV) values. When the patients with bleeding times longer than 15 min were excluded frcm the analysis, a negative correlation with PCV was still apparent (r = 0.55; p<0.01 ) .in addition, X2 analysis showed a significant association between PCV values <30% and B.T. longer than 260 sec(p<0.001) . Fourteen uraemic patients with PC/ values between 13% and 27% and B.T. longer than 15 min, required washed blood cell transfusions, after which PCV values increased variably but no shortening of B.T. was observed unless PCV rose to at least 30%. In particular, 2 uraemic patients with B.T. >15 min and PCV values of 21% and 19% were transfused on several occasions. PCV rose to 23%, 30% and 35% in the first patient and to 25% and 34% in the second one. The corresponding B.T. were >15 min,>15 min and 0 min 30 sec and > 15 and 9 min 30 sec. In a group of 15 patients with uraemia-unrelated anemias (PCV between 20% and 34%) the median B.T. was 300 sec (range 120-450 sec) whereas in a group of 15 uraemic patients with comparable PCV values, the median B.T. was 390 sec (range 180 - 900 sec) (p<0.05, paired student's t test) . It is concluded that among other factors red cells may contribute to the defective haemostasis in uraemic patients.

scholarly journals A Role of Epithelial Cells and Virulence Factors in Biofilm Formation by Streptococcus pyogenes In Vitro

2020 ◽  
Vol 88 (10) ◽  
Author(s):  
Feiruz Alamiri ◽  
Yashuan Chao ◽  
Maria Baumgarten ◽  
Kristian Riesbeck ◽  
Anders P. Hakansson
Keyword(s):  
Antibiotic Resistance ◽  
Epithelial Cells ◽  
Virulence Factors ◽  
Streptococcus Pyogenes ◽  
Biofilm Formation ◽  
Model Systems ◽  
Respiratory Epithelial Cells ◽  
Abiotic Surfaces ◽  
Respiratory Epithelial

ABSTRACT Biofilm formation by Streptococcus pyogenes (group A streptococcus [GAS]) in model systems mimicking the respiratory tract is poorly documented. Most studies have been conducted on abiotic surfaces, which poorly represent human tissues. We have previously shown that GAS forms mature and antibiotic-resistant biofilms on physiologically relevant epithelial cells. However, the roles of the substratum, extracellular matrix (ECM) components, and GAS virulence factors in biofilm formation and structure are unclear. In this study, biofilm formation was measured on respiratory epithelial cells and keratinocytes by determining biomass and antibiotic resistance, and biofilm morphology was visualized using scanning electron microscopy. All GAS isolates tested formed biofilms that had similar, albeit not identical, biomass and antibiotic resistance for both cell types. Interestingly, functionally mature biofilms formed more rapidly on keratinocytes but were structurally denser and coated with more ECM on respiratory epithelial cells. The ECM was crucial for biofilm integrity, as protein- and DNA-degrading enzymes induced bacterial release from biofilms. Abiotic surfaces supported biofilm formation, but these biofilms were structurally less dense and organized. No major role for M protein, capsule, or streptolysin O was observed in biofilm formation on epithelial cells, although some morphological differences were detected. NAD-glycohydrolase was required for optimal biofilm formation, whereas streptolysin S and cysteine protease SpeB impaired this process. Finally, no correlation was found between cell adherence or autoaggregation and GAS biofilm formation. Combined, these results provide a better understanding of the role of biofilm formation in GAS pathogenesis and can potentially provide novel targets for future treatments against GAS infections.

Acetylcholine and substance P stimulate bronchial epithelial cells to release eosinophil chemotactic activity

1998 ◽  
Vol 84 (5) ◽  
pp. 1528-1534 ◽  
Author(s):  
Sekiya Koyama ◽  
Etsuro Sato ◽  
Hiroshi Nomura ◽  
Keishi Kubo ◽  
Sonoko Nagai ◽  
...  
Keyword(s):  
Substance P ◽  
Epithelial Cells ◽  
Receptor Antagonist ◽  
Platelet Activating Factor ◽  
Bronchial Epithelial Cells ◽  
Chemotactic Activity ◽  
Dependent Manner ◽  
Bronchial Epithelial ◽  
Lipoxygenase Inhibitors

We investigated a role of neuroregulation in the release of eosinophil chemotactic activity (ECA) from bovine bronchial epithelial cells (BBEC). BBEC were stimulated with acetylcholine (ACh) and substance P (SP), and the supernatant fluids were tested for ECA by a blind-well chemotactic chamber technique. BBEC released ECA in response to ACh and SP in a dose- and time-dependent manner. Checkerboard analysis showed that ECA in regard to ACh and SP was chemotactic rather than chemokinetic. Partial characterization revealed that ECA involved both lipids and peptides. The release of ECA in response to ACh and SP was inhibited by nonspecific and 5-specific lipoxygenase inhibitors and by cycloheximide ( P < 0.01). Molecular-sieve column chromatography revealed that these mediators induced three molecular mass peaks (near 25 kDa, 9 kDa, and 400 Da, respectively). The lowest peak, which represented the predominant activity, was blocked by leukotriene B4-receptor antagonist ( P < 0.01) but not by platelet-activating factor-receptor antagonist. The release of leukotriene B4 in the supernatant fluids was increased in response to ACh and SP stimulation ( P < 0.01). Platelet-activating factor was not detected. These results raise the possibility of a role of neuroregulation for the elaboration of ECA in the airway.

scholarly journals Role of Lipooligosaccharide in Opa-Independent Invasion of Neisseria gonorrhoeae into Human Epithelial Cells

2000 ◽  
Vol 191 (6) ◽  
pp. 949-960 ◽  
Author(s):  
Wenxia Song ◽  
Lang Ma ◽  
Ruiwu Chen ◽  
Daniel C. Stein
Keyword(s):  
Epithelial Cells ◽  
Neisseria Gonorrhoeae ◽  
Outer Membrane ◽  
Actin Filaments ◽  
Direct Interaction ◽  
Host Cells ◽  
Bacterial Outer Membrane ◽  
Isogenic Strains ◽  
Adhesion And Invasion

Lipooligosaccharide (LOS) has been implicated in the adhesion and invasion of host epithelial cells. We examined the adhesive and invasive abilities of isogenic gonococcal opacity-associated outer membrane protein–negative, pilus-positive (Opa−Pil+) Neisseria gonorrhoeae strains expressing genetically defined LOS. Strain F62 (Opa−Pil+), expressing the lacto-N-neotetraose and the galNac-lacto-N-neotetraose LOS, and its isogenic derivative that expressed only the lacto-N-neotetraose LOS (F62ΔlgtD), adhered to, and invaded, to the same extent the human cervical epidermoid carcinoma cell line, ME180. While the adhesive abilities of Opa−Pil+ isogenic strains that express LOS molecules lacking the lacto-N-neotetraose structure were similar to that seen for F62, their invasive abilities were much lower than the strains expressing lacto-N-neotetraose. Fluorescence microscopy studies showed that the adherence of F62, but not the strains lacking lacto-N-neotetraose, induced the rearrangement of actin filaments under the adherent sites. Electron microscopy studies demonstrated that F62, but not the strains lacking lacto-N-neotetraose, formed extensive and intimate associations with epithelial cell membranes. Thus, in the absence of detectable Opa protein, the lacto-N-neotetraose LOS promotes gonococcal invasion into ME180 cells. The data also suggest that LOS is involved in the mobilization of actin filaments in host cells, and in the formation of a direct interaction between the bacterial outer membrane and the plasma membrane of ME180 cells.

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