1,721,091 research outputs found
CARATTERIZZAZIONE IN VITRO DELLA RISPOSTA A STIMOLI INFETTIVI DELLE CELLULE EPITELIALI MAMMARIE BOVINE (BME-UV)
No full textIn vitro assessment of bovine mammary epithelial cells response to infectious stimuli
Non-specific (innate) immune response plays a major role in defending the udder from bacterial invasion. Moreover, recent investigations suggest that mammary gland epithelial cells could have a large and important role as a source of soluble components of immune defenses.
An experimental model was developed based on BME-UV cell line, Staphylococcus aureus as a challenge to assess the interactions among epithelial cells and bacteria by measuring cytokine and three lysosomal enzymes, lysozyme lactoferrin and N-acetyl-b-D-glucosaminidase (NAGase), in S. aureus-stimulated MGEC. S.aureus strains invading epithelial cells elicited an immunological response with levels related to strain characteristics. We found that BME-UV cells didn’t produce lactoferrin. NAGase and Lysozyme have a similar substrate as a target, but our results suggest different secretion mechanisms . These data confirms that epithelial cells could play an important role in udder innate defenses.
Besides we investigate the expression of the bovine cathelicidins BMAP-27, BMAP-28, Bac5, and indolicidin in lipopolysaccharide (LPS)-treated cells to examine their potentials to trigger defense responses in bovine mammary cells. Our results indicate multiple roles for the bovine cathelicidins with complementary and mutually enhanced antimicrobial activities.
We also investigate the potential effects of tylosin, a macrolide antimicrobial on the immune system. The results of this study confirmed that tylosin could have a significant effect on the release of Lysozyme, NAGase and cytokines by bovine epithelial cells without affecting cell functions. This study showed that an in-vitro model based on S. aureus challenge on epithelial cells could be helpful in assessing both the intracellular and extracellular activity of antimicrobials and their influence on epithelial cell immune and inflammatory response
Bovine mammary gland epithelial cells innate immune response to S. Aureus
No full textRecently, epithelial cells (EC) has been recognized as a major source of innate immune components useful to protect mammary gland from infections. A study was designed to investigate the response induced by different S.aureus strains on EC. Ten S.aureus isolated from subclinical mastitis cases in dairy cows of different herds were selected based on their genetic characteristics and antimicrobial susceptibility. A clonal cell line (BME-UV) established from udder primary epithelial cell synthesizing several milk components was used as an in vitro model. Previous studies showed that this cell line can express several cytokines and immune components when stimulated by bacteria or toxins. Bacteria count, lysozyme (LYZ) and NAGase (NAG) concentration were used to assess cellular response, while the strains were classified in two groups by TLR expression: high rate (HR) and low rate (LR).
As expected S.aureus growth both intracellularly and extracellularly. However, extracellular S.aureus showed similar curves when isolates expressing TLRs in high rate and in low rate were considered, while intracellular curves were different. Indeed, in this latter case LR isolates peaked at 10 h PI, then the concentration decreased, while increased around 2 logs in the HR group.
The results of the study confirmed the capability of EC to produce component of innate immunity. However the response was triggered only when bacteria concentration was over 0.5 log10 μg/ml. When LYZ concentration in relation to TLR expression was considered, data showed as extracellular LYZ increased more rapidly in HR than in LR isolates until 10h PI, when the two curves stated to overlap. Intracellular LYZ concentration showed to have a very similar pattern both in HR and LR groups. However, LYZ level were always higher in HR group when compared with LR one.
Extracellular NAG was always very low, while intracellular NAG concentrations were higher than extracellular ones, as expected. Also when TLR expression were considered, a similar pattern for both LR and HR isolates were observed, even if at different mean levels up 10 h PI. Then, the concentration decreased at intracellular level and increased extracellularly.
S.aureus to have different capability to induce innate immune response. However, these difference were influenced by the growth rate and by the site of infection (intracellular/extracellular). The production of innate immune parameters from EC in response to S.aureus infections suggest that these cells could be a target of choice in developing immune-modulators to be used to control bovine mastiti
Analisi citofluorimetrica del pattern antigenico su aspirati linfonodali in corso di linfoma canino
No full textLe lesioni del Legamento Crociato Anteriore nel basket femminile
No full textLe strutture osteoarticolari del ginocchio sono tra le più colpite dagli infortuni nel basket, sport nel quale i gesti tecnico-specifici portano le atlete a dover effettuare cambi di direzione, cambi di senso e movimenti torsionali eseguiti ad alta velocità oltre a salti
ed atterraggi. È da sottolineare, talvolta, la gravità degli infortuni riscontrati
al livello del LCA poiché spesso può comportare un allontanamento
dai campi da gioco per diversi mesi.
In questo articolo esamineremo i più probabili meccanismi di lesione del LCA che colpiscono maggiormente il genere femminile rispetto a quello maschile.
È fondamentale impostare sedute di prevention training che abbiano come obiettivo quello di rinforzare il più possibile le strutture che possano migliorare la stabilità dell’intera articolazione del ginocchio e non solo.
I programmi devono essere presenti già durante le fasi di preparazione pre-campionato, proseguendo poi durante la stagione agonistica.
Infine, ma non per minore importanza, è importante sottolineare che la letteratura suggerisce di attuare programmi preventivi specialmente nelle giovani atlete
Innate immune response of mammary gland epithelial cells to intracellular Staphylococcus aureus
No full textBackground. Non-specific (innate) immune
response plays a major role in defending udder from bacteria invasion. Innate soluble immune defenses are all involved in preventing bacteria adhesion, multiplication and in bacteria killing.
Recent investigations suggested that epithelial cells could have a large and important role as a source for soluble components of immune defenses's. Methods. Ten S.aureus isolates from subclinical mastitis cases in dairy cows of different herds were considered. These isolates
were characterized by different virulence genes patterns. A clonal cell line established from udder epithelial cells (BME-UV), synthesizing several milk components, was used as an in vitro model. Cell line was exposed to S.aureus and the intracellular and extracellular release of Lysozyme and NAGase were assessed from 4 h until 24 h by a fluorescence-based procedure on a microplate fluorimeter. Results. The
preliminary results of this study showed that
S.aureus strains invading epithelial cells elicited an immunological response with levels related to strain characteristics. The pattern of lysozyme concentration was time-dependent and showed an extracellular increase at 24h after exposure to S.aureus. Moreover, it was detectable intracellularly starting at 4h, but not in the surnatant before 24 h. NAGase is a glycosidase and showed a release pattern different from lysozyme, even if it is also considered a lysosomial enzyme. Its extracellular concentration increased at 24h, when cells showed dysfunction, but at cell level
it decreased over the 24 h. Conclusions. These data confirms that epithelial cells could play an important role in udder innate defenses. Moreover, they suggest that the release pattern of the two enzymes considered is different. Lysozyme is involved in antibacterial activity
and could be considered as a marker of
bacteria-induced inflammation. About NAGase,
it could be hypotesized that it is more a marker of cellular damage and an extracellular increase is a sign of cellular dysfunction and/or disruption rather than of inflammation
Assessment of epithelial cells’ immune and inflammatory response to Staphylococcus aureus when exposed to a macrolide
No full textNon-specific (innate) immune response plays a major role in defending the udder from bacterial
invasion. Moreover, recent investigations suggest that mammary gland epithelial cells (MGEC)
could have a large and important role as a source of soluble components of immune defences.
Despite many attempts to find other ways to control/prevent mastitis (i.e. vaccine) antimicrobial
therapy is still the most used and effective means of curing clinical and subclinical mastitis.
However, drug concentrations and therapy durations are far from the optimal in order to reduce
costs. Therefore, efficacy of antimicrobial therapy is dependent not only on the substance
activity but also on the positive interactions with the host innate immune response. Surprisingly,
information on these interactions is rather scarce in the mastitis field. A simple experimental
model was developed based on BME-UV cell line, Staphylococcus aureus as a challenge and a
macrolide as an antimicrobial to assess the interactions among epithelial cells, Staph. aureus
and the potential effects of antimicrobials on the immune system. The results of this study
confirmed that tylosin has good antimicrobial activity against both intracellular and extracellular
Staph. aureus in bovine MGEC without affecting cell functions. In this study, a significant downregulation
of IL-1 and IL-6 was observed, while TNF and IL-8 expression rate numerically
increased, but differences were not significant. To our knowledge, this is the first paper assessing
the concentration of two lysosomal enzymes, lysozyme and N-acetyl-b-D-glucosaminidase
(NAGase), in Staph. aureus-stimulated MGEC. The results of this study confirmed that tylosin
could have a significant effect on the release of these enzymes. Moreover, even if both enzymes
have a similar substrate as a target, the results suggest different secretion mechanisms and an
influence of antimicrobial treatment on these mechanisms. Successful mastitis cure is the result
of achieving the optimal efficiency of both innate immune defences and therapeutical activities,
by means of killing bacteria without eliciting an excessive inflammatory response. Therefore,
antimicrobials for mastitis therapy should be selected not only on bacterial sensitivity, but also
for their positive interactions with the innate immune response of the mammary gland. This
study showed that an in-vitro model based on Staph. aureus challenge on MGEC could be
helpful in assessing both the intracellular and extracellular activity of antimicrobials and their
influence on epithelial cell immune and inflammatory response
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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