Browsing by Subject "Neutrophil"

Now showing 1 - 3 of 3
  • Thumbnail Image
    Publication
    Open Access
    An ultracytochemical study on the dynamics of alkaline phosphatase-positive granules in rat neutrophils
    (F. Hernández y Juan F. Madrid. Universidad de Murcia: Departamento de Biología Celular e Histología, 1998) Jiang, X.; Kobayashi, T.; Nahirney, P. C.; García del Saz, E.; Seguchi, H.
    Alkaline phosphatase (ALPase) activity was examined by cerium-based uitracytochemistry in isolated rat neutrophils following stimulation with phorbol myristate acetate (PMA) or N-formylmethionyl-leucyl-phenylalanine (fMLP). In control neutrophils, low levels of ALPase activity were detected in small tubular and spherical compartments distributed throughout the cytoplasm. Neutrophils stimulated for 2.5, 5, 15, and 30 min with 50 nglml PMA or 10-7 M fMLP displayed a time-dependent increase in ALPase activity. At 2.5 min, an increase in activity was first identified in compartments that were aggregated in the central regions of the cell. By 15 min, a dense precipitate was seen in tubular or elongated bead-like structures that extended to and made contact with the plasma membrane. Large enzyme-positive vacuoles were also observed in regions near the plasma membrane. At the longer stimulation times, a fine precipitate was present on the cell surface of the neutrophil in regions where subplasmalemmal ALPase activity was present. The results of this study indicate that an increase in activity and a redistribution of ALPase-positive structures occurs in neutrophils in response to stimulation with PMA and fMLP. It is likely that these compartments are latent pools of ALPase which, upon stimulation, fuse and mobilize the enzyme activity to the cell surface.
  • Thumbnail Image
    Publication
    Open Access
    ICAM-1 expression on endothelium and systemic cytokine production in cutaneous neutrophilic leukocytoclastic vasculitis in NZBxNZWF1 mice
    (Murcia : F. Hernández, 2005) Hayashi, T.; Hasegawa, K.; Ichinohe, N.
    The present study has examined relationship between cutaneous microvessel injury and adhesion molecule expression on the endothelium by cytokines in NZBxNZWF1 (B/WF1) mice, a model for human systemic lupus erythematosus. In advanced ages associated with overt clinical manifestation, but not in early ages, neutrophils with a minor proportion of monocytes and lymphocytes mainly adhered to the endothelium of capillary and the venule with fragmentation (leukocytoclasis), leading to the vascular injury (leukocytoclastic vasculitis). This was confirmed by the leak of monstral blue from the blood vessel. At this stage LFA-1+ leukocytes adhered to intensely expressed ICAM-1 on the endothelium, and this was paralleled with a significant rise in IL-1a and TNF-a in the circulation. The present study suggests that IL-1a and TNF-a may, at least in part, be responsible for the increased ICAM-1 expression on endothelium in cutaneous microvessels, resulting in the vascular injury characterized by neutrophilic leukocytoclasis in B/WF1 mice.
  • Thumbnail Image
    Publication
    Open Access
    The role of neutrophils and their immunosuppressive effects on prostate cancer
    (Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2025) Lou, Yihaoyun; Fan, Zhiguo; Ren, Shancheng; Biología Celular e Histología
    Over the past decade, there has been a significant increase in the incidence of prostate cancer on a global scale, establishing it as the second most prevalent malignant tumor among European and American males. Neutrophils are myeloid immune cells that constitute a crucial proportion of inflammatory cells within the human circulatory system and actively contribute to the composition of the prostate tumor microenvironment (TME). Recent investigations have revealed that neutrophils are influenced by the surrounding tumor environment and possess a dual capacity to either promote or suppress cancer within the TME. Nevertheless, the precise mechanisms of neutrophils in prostate cancer remain inadequately elucidated. In this review, we aimed to comprehensively outline the character of neutrophils in the development and progression of prostate cancer while also exploring the clinical prognostic significance of the neutrophil-to-lymphocyte ratio (NLR).