Search results for " leukocyte"
showing 10 items of 364 documents
Microvascular in vivo assessment of reperfusion injury: significance of prostaglandin E1 and I2 in postischemic “no-reflow” and “reflow-paradox”
2004
Microvascular ischemia-reperfusion (I/R) injury is characterized by failure of capillary perfusion ("no-reflow") and reoxygenation-associated phenomena ("reflow-paradox"), including activation of leukocyte-endothelium interaction with cytotoxic mediator-induced loss of endothelial integrity. The objectives of this study were to elucidate the impact of both prostaglandins E(1) (PGE(1)) and I(2) (PGI(2)) in microvascular reperfusion injury, with special focus on the distinct pathophysiology of no-reflow- and reflow-paradox phenomena.By use of the hamster dorsal skinfold preparation and in vivo fluorescence microscopy, the microcirculation of a striated skin muscle was assessed before 4 h of p…
The global village of celiac disease
2004
In the last years our knowledge on epidemiology of celiac disease has increased: there is a wide spectrum of its clinical presentation (classical, atypical, silent and latent forms of celiac disease), and of its pathological mucosal intestinal features, which range from early and mild pictures to severe villous atrophy (Marsh stages). In addition, a strong genetic component, associated with the susceptibility to the disease (HLA and non HLA genes), has been found. This knowledge, together with the availability of new high sensitive and specific serological tests (antigliadin, antiendomysium and antitransglutaminase antibodies), has led us to the realization that celiac disease is the most c…
The “mode” of lymphocyte extravasation through HEV of Peyer's patches and its role in normal homing and inflammation
2007
The mode of lymphocyte transendothelial migration in the postcapillary high endothelial venules (HEVs) of Peyer's patches during normal homing and acute inflammation in the guinea pig was studied. It is common opinion that the lymphocyte transendothelial passage from the blood stream into the extravasal lymphoid tissue calls for a multistep process of endothelial and lymphocyte molecules favoring tethering, rolling, activation, arrest and its firm adhesion to the endothelial luminal surface. Ultrastructural serial pictures and the three-dimensional reconstruction of HEVs with lymphocytes during different moments of their transmigration through the endothelial wall enabled us to demonstrate …
Acquired IFNγ resistance impairs anti-tumor immunity and gives rise to T-cell-resistant melanoma lesions
2016
Melanoma treatment has been revolutionized by antibody-based immunotherapies. IFNγ secretion by CD8+ T cells is critical for therapy efficacy having anti-proliferative and pro-apoptotic effects on tumour cells. Our study demonstrates a genetic evolution of IFNγ resistance in different melanoma patient models. Chromosomal alterations and subsequent inactivating mutations in genes of the IFNγ signalling cascade, most often JAK1 or JAK2, protect melanoma cells from anti-tumour IFNγ activity. JAK1/2 mutants further evolve into T-cell-resistant HLA class I-negative lesions with genes involved in antigen presentation silenced and no longer inducible by IFNγ. Allelic JAK1/2 losses predisposing to …
Hla-Bb, Dr3 T Cell Impairhent is Completely Restored by in Vitho Treatment with Interleukin-2
1991
AbstractThe activity of recombinant interleukin-2 (rIL-2) on the in vitro lymphocyte proliferative response to phytohemagglutinin mitogen was investigated in healthy HLA-BB, DR3 positive and negative subjects. the response to mitogen, significantly decreased in HLA-BB, DR3 positive subjects, was completely restored by adding rIL-2. Moreover, in HLA-BB, DR3 positive subjects the in vitro treatment with rIL-2 significantly increased the reduced frequency of mitogen responsive T lymphocyte precursors, as assessed by limiting dilution analysis. These data suggest that a decrease in the size of the pool of T cell precursors able to produce IL-2 is responsible for the impairment of T cell functio…
Prostaglandin production by human polymorphnuclear leucocytes during phagocytosis in vitro.
1977
Human polymorphonuclear leukocytes were found to be able to synthetize and release substantial amounts of PGE2' when stimulated by a phagocytic stimulus such as zymosan particles coated with complement. Hydrocortisone, at a concentration of 10(-5) M, which proved to be effective in other biological systems, failed to inhibit phagocytosis and PG release.
Dynamic deformation of migratory efferent lymph-derived cells ?trapped? in the inflammatory microcirculation
2002
The cellular immune response depends on the delivery of lymphocytes from the lymph node to the peripheral site of antigenic challenge. During their passage through the inflammatory microcirculaton, the migratory cells can become transiently immobilized or "trapped" in small caliber vessels. In this report, we used intravital microscopy and temporal area mapping to define the dynamic deformation of efferent lymph-derived mononuclear cells trapped in the systemic inflammatory microcirculation. Mononuclear cells obtained from the efferent lymph draining the oxazolone-stimulated microcirculation were labeled with fluorescent dye and reinjected into the feeding arterial circulation. Intravital v…
Polymorphonuclear leukocyte membrane fluidity and cytosolic Ca2+ content in young adults with acute myocardial infarction. Evaluation at the initial …
2004
Our aim was to examine two aspects of polymorphonuclear leukocyte (PMN) rheology (membrane fluidity and cytosolic Ca2+ content), at baseline and after in vitro activation, in a group of young adults with acute myocardial infarction (AMI) at the initial stage and after 12 months. We enrolled 21 AMI subjects aged < or = 45 years (mean age 41.1 +/- 3.5 years) and evaluated PMN membrane fluidity, labelling intact PMN cells with the fluorescent probe 1,4-(trimethylamino)-phenyl-4-phenylhexatriene and the PMN cytosolic Ca2+ content marking PMN cells with the fluorescent probe Fura 2-AM, at baseline and after in vitro activation with 4-phorbol 12-myristate 13-acetate (PMA) and N-formyl-methionyl-l…
Granulocytenfunktionsdefekte bei granulomat�ser muco-cutaner candidiasis
1975
Es wird uber einen 12jahrigen Jungen mit einer rezidivierenden mucocutanen Candidiasis berichtet, der an einer Cryptococcose verstarb. Bei diesem Kind wurden Defekte der unspezifischen Immunitat in Form eines Chemotaxis- und Phagocytosedefizits der polymorphkernigen Neutrophilen nachgewiesen, wahrend Immunglobuline und Komplementfaktoren sowie insbesondere die lymphocytenvermittelten Reaktionen im Normbereich lagen. Die Heterogenitat hinsichtlich der Atiopathogenese der granulomatosen muco-cutanen Candidiasis machen auch Funktionsprufungen der Granulocytenfunktionen erforderlich, zumal solche Defekte inzwischen mehrfach beobachtet wurden.