10 research outputs found
CD40L is selectively expressed on platelets from thrombocytopenic septic patients
Introduction It has been recently hypothesized that septic microangio-
pathy is caused or at least promoted by the interaction between endo-
thelial surface receptor CD40 and its ligand CD40L, expressed by activated
platelets. This interaction produces procoagulative changes in endothelial
cells, endothelial apoptosis, subendothelial matrix exposition and microthrombi formation. Since virtually all septic patients show a certain degree of coagulation abnormalities, we hypothesized that low platelet count is associated with a diff erent degree of CD40L expression and that this could correlate with the severity of disease.
Methods To determine the infl uence of sepsis on levels of platelet-derived
CD40L expression, we performed a prospective observational study in a
polyvalent university hospital ICU. Eighteen consecutively septic patients
were enrolled in the study, independently of the platelet count and the severity of disease (SOFA score). Flow cytometry of fresh blood from septic
patients (n = 18) and age-matched controls (n = 8) was performed for membrane-bound CD40L and CD62P on circulating platelets.
Results Flow cytometry demonstrated low levels of CD62P in controls
while the levels in patients were high. CD40L+ platelets were selectively
found from patients with thrombocytopenia (platelet count ≤60,000/mm3). Furthermore a direct correlation between CD40L expression and the SOFA score was found in patients with sepsis and thrombocytopenia compared to patients with sepsis without thrombocytopenia.
Conclusions These results suggest that CD40L expression on platelets is
somehow related to the degree of thrombocytopenia and possibly can
be a marker of the severity of sepsis. Although the role of endothelial-
derived CD40/platelet-derived CD40L interaction is not fully understood
during sepsis, the expression of CD40L on platelets could be related to
the severity of organ disease due to the possible bursting of endothelial
damage through this pathway. Further investigation is needed to
determine whether platelets CD40L contributes to endothelial and
subsequent organ damage, its role in thrombocytopenia and its correlation with the outcome of sepsis. The microvascular injury seems to be a central event in sepsis, so understanding the mechanisms
underlying its development is crucial for the individuation of new and
specifi c therapeutic strategies
LFA-1 and ICAM-1 expression induced during melanoma-endothelial cell co-culture favors the transendothelial migration of melanoma cell lines in vitro
<p>Abstract</p> <p>Background</p> <p>Patients with metastatic melanoma have a poor median rate of survival. It is therefore necessary to increase our knowledge about melanoma cell dissemination which includes extravasation, where cancer cells cross the endothelial barrier. Extravasation is well understood during travelling of white blood cells, and involves integrins such as LFA-1 (composed of two chains, CD11a and CD18) expressed by T cells, while ICAM-1 is induced during inflammation by endothelial cells. Although melanoma cell lines cross endothelial cell barriers, they do not express LFA-1. We therefore hypothesized that melanoma-endothelial cell co-culture might induce the LFA-1/ICAM ligand/receptor couple during melanoma transmigration.</p> <p>Methods</p> <p>A transwell approach has been used as well as blocking antibodies against CD11a, CD18 and ICAM-1. Data were analyzed with an epifluorescence microscope. Fluorescence intensity was quantified with the ImageJ software.</p> <p>Results</p> <p>We show here that HUVEC-conditioned medium induce cell-surface expression of LFA-1 on melanoma cell lines. Similarly melanoma-conditioned medium activates ICAM-1 expression in endothelial cells. Accordingly blocking antibodies of ICAM-1, CD11a or CD18 strongly decrease melanoma transmigration. We therefore demonstrate that melanoma cells can cross endothelial monolayers in vitro due to the induction of ICAM-1 and LFA-1 occurring during the co-culture of melanoma and endothelial cells. Our data further suggest a role of LFA-1 and ICAM-1 in the formation of melanoma cell clumps enhancing tumor cell transmigration.</p> <p>Conclusion</p> <p>Melanoma-endothelial cell co-culture induces LFA-1 and ICAM-1 expression, thereby favoring in vitro melanoma trans-migration.</p
Significance of Plasma Cytokine Levels in Melanoma Patients With Histologically Negative Sentinel Lymph Nodes
Nanobiocide Based-Silver Nanomaterials Upon Coronaviruses: Approaches for Preventing Viral Infections
Respiratory viruses in foods and their potential transmission through the diet: A review of the literature
The Medial Septum Is Insulin Resistant in the AD Presymptomatic Phase: Rescue by Nerve Growth Factor-Driven IRS1 Activation
Long-Term Seasonal and Interannual Patterns of Marine Mammal Strandings in Subtropical Western South Atlantic
Understanding temporal patterns of marine mammal occurrence is useful for establishing
conservation strategies. We used a 38 yr-long dataset spanning 1976 to 2013 to describe
temporal patterns and trends in marine mammal strandings along a subtropical stretch of
the east coast of South America. This region is influenced by a transitional zone between
tropical and temperate waters and is considered an important fishing ground off Brazil. Generalized
Additive Models were used to evaluate the temporal stranding patterns of the most
frequently stranded species. Forty species were documented in 12,540 stranding events.
Franciscana (n = 4,574), South American fur seal, (n = 3,419), South American sea lion (n =
2,049), bottlenose dolphins (n = 293) and subantarctic fur seal (n = 219) were the most frequently
stranded marine mammals. The seasonality of strandings of franciscana and bottlenose
dolphin coincided with periods of higher fishing effort and strandings of South
American and subantarctic fur seals with post-reproductive dispersal. For South American
sea lion the seasonality of strandings is associated with both fishing effort and post-reproductive
dispersal. Some clear seasonal patterns were associated with occurrence of cold-
(e.g. subantarctic fur seal) and warm-water (e.g. rough-toothed dolphin) species in winter
and summer, respectively. Inter-annual increases in stranding rate were observed for franciscana
and South American fur seal and these are likely related to increased fishing effort
and population growth, respectively. For subantarctic fur seal the stranding rate showed a
slight decline while for bottlenose dolphin it remained steady. No significant year to year variation
in stranding rate was observed for South American sea lion. The slight decrease in
frequency of temperate/polar marine mammals and the increased occurrence of subtropical/tropical
species since the late 1990s might be associated with environmental changes
linked to climate change. This long-term study indicates that temporal stranding patterns of
marine mammals might be explained by either fishing-related or environmental factors