Leucocyte Populations (leucocyte + population)

Distribution by Scientific Domains


Selected Abstracts


Leucocyte populations in respiratory syncytial virus-induced bronchiolitis

JOURNAL OF PAEDIATRICS AND CHILD HEALTH, Issue 2 2001
PK Smith
Objectives: To enumerate the cellular composition of the airways in infants with acute bronchiolitis. Methodology: Cells were obtained by airway lavage from the upper and lower airway and the peripheral blood of infants with respiratory syncytial virus (RSV)+ bronchiolitis, RSV, bronchiolitis and age-matched controls. Results: Neutrophils are the predominant cells present in the upper and lower airway. Neutrophils are present at a higher number/unit volume in the airway than in the peripheral blood. Conclusions: Neutrophils, being the dominant cellular infiltrate into the airway, are likely to contribute to the pathophysiology of bronchiolitis. Therapies targeted at limiting neutrophil influx or neutrophil-mediated damage in the airway may have a therapeutic role. [source]


Neutrophils: key mediators of tumour angiogenesis

INTERNATIONAL JOURNAL OF EXPERIMENTAL PATHOLOGY, Issue 3 2009
Simon Tazzyman
Summary It is now well known that most malignant tumours contain a significant amount of leucocytic infiltrates the presence of which has, on many occasions, been linked to poor patient prognosis. These leucocyte populations are recruited to tumours by chemotactic factors released by either viable or necrotic tumour cells, or by cells within the tumour stroma. In recent times, most studies have analysed the role that tumour-associated macrophages (TAM) have on tumour progression. However, there is now increasing evidence to show that neutrophils also actively participate in this process. Whilst there are some data to suggest that neutrophil-derived factors can promote genetic mutations leading to tumourigenesis, or secrete factors that promote tumour cell proliferation; there is now substantial evidence to show that neutrophils, like TAM, significantly affect tumour angiogenesis. In this review, we discuss the likely mechanisms by which neutrophils are recruited into the tumour and then elaborate on how these cells may induce tumour vascularization by the secretion of powerful pro-angiogenic factors. We also discuss possible future chemotherapeutic strategies that are aimed at limiting tumour angiogenesis by inhibiting neutrophil recruitment. [source]


An optimized method to separate reticulocytes from peripheral blood for molecular analysis

INTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 3 2009
R. PETRUZZELLI
Summary A method based on immunomagnetic sorting of reticulocytes from peripheral blood was set up and combined to a commercial extraction kit for the isolation of total RNA from whole blood. This procedure resulted in high-quality RNA samples suitable for molecular analysis. We used this procedure to analyse erythroid-specific transcripts, starting from peripheral blood samples, to search for differently expressed mRNAs in patients with hereditary persistence of foetal haemoglobin. After erythrocyte lysis, CD15+and CD45+ peripheral cells were negatively sorted to remove leucocyte populations that could have affected the subsequent screening procedure. The cell sorting and RNA extraction procedure was completed within 1,2 h of erythrocyte lysis, which represents a consistent saving of time compared with other procedures. Moreover, it produced 1 ,g of total RNA per ml of blood samples, which is sufficient for molecular analysis. Therefore, our method is a reliable and efficient tool to isolate RNA from specific cell subpopulations poorly represented in peripheral blood, particularly when accurate detection and characterization of highly unstable and poorly expressed molecules is required. [source]


Haematological and biochemical alterations in Korean catfish, Silurus asotus, experimentally infected with Edwardsiella tarda

AQUACULTURE RESEARCH, Issue 2 2010
Jin Ha Yu
Abstract This study determined the haematological changes in Korean catfish, Silurus asotus, experimentally infected with Edwardsiella tarda. Twenty-four or 48 h after infection with 1 × 104 colony-forming units (CFU) mL,1 of E. tarda, the fish were anaesthetized and the blood was collected. The haematological and biochemical tests included haematocrit (Ht), haemoglobin (Hb), leucocyte counts (Lc), total calcium (Ca), total protein (TP) concentration, alkaline phosphatase (ALP), glucose (GLU), aspartate aminotransferase, lysozyme and differential leucocyte populations. After 24- and 48-h infection, the values of Ht, Hb, Lc, TP, ALP and GLU were significantly decreased with respect to the control. Aspartate aminotransferase and lysozyme activity in both the 24- and 48-h groups exhibited higher levels compared with those in the control. However, the bacterial infection did not induce any significant alteration in the Ca concentration. After the 48-h infection, neutrophils and macrophage populations were reduced whereas lymphocytes were increased with respect to those in the control and the 24-h infection groups. The present study demonstrates that E. tarda infection causes haemato-biochemical responses that are related to the general physiological condition and defence system in catfish. [source]


Modelling parasite dissemination: host cell subversion and immune evasion by Toxoplasma gondii

CELLULAR MICROBIOLOGY, Issue 3 2010
Henrik Lambert
Summary Protozoan parasites belong to the most widespread and devastating human pathogens. Their ability to manipulate host responses and establish infection in their hosts continues to puzzle researchers. Recent developments of experimental model systems are contributing to the discovery of new aspects of the biology of parasite dissemination. Here, we review current knowledge on strategies utilized by the apicomplexan parasite Toxoplasma gondii to disseminate and establish infection in its host. Recent findings have revealed intricate mechanisms by which this obligate intracellular protozoan sequesters cellular functions of the immune system to assure propagation. These mechanisms include the hijacking of migratory leucocytes, modulation of migratory properties of infected cells and rapid transfer of parasites between different leucocyte populations by cytotoxicity-induced parasite egress. Collectively, Toxoplasma strikes a delicate balance, assuring efficient dissemination and establishment of asymptomatic lifelong infection in its host while protecting its intracellular entity and limiting host pathology. [source]


Identification of wild type and variants of oestrogen receptors in polymorphonuclear and mononuclear leucocytes

CLINICAL ENDOCRINOLOGY, Issue 1 2006
Denis Stygar
Summary Objective, ,Leucocytes play an important role in the pathogenesis of autoimmune and cardiovascular diseases. Clinical and epidemiological observations indicate that the sex steroid hormones, particularly oestrogens, may regulate leucocyte functions. The assumption that oestrogens have a direct effect on leucocytes has to be supported by identification of functional oestrogen receptors (ER) in leucocytes. This study aimed at investigating the presence of ER subtypes in different types of leucocytes isolated from peripheral blood of female and male donors. Design and patients, ,A total of nine men (age range 18,43 years) and nine women (age range 19,42 years) all healthy blood donors, were recruited for the study. The donors did not receive any medication or hormonal contraceptives for the last three months. Ten millilitres of peripheral blood was collected from each donor. Polymorphonuclear leucocytes (PMN) and peripheral blood mononuclear cells (PBMC) were purified by density gradient centrifugation. Measurements, ,ER, and ER, mRNA expression was measured by real-time reverse transcriptase,polymerase chain reaction (RT-PCR), and ER proteins were analysed by Western blot in the PBMC and PMN leucocyte populations. In addition, expression profiles of ER variant isoforms were characterized by conventional PCR using the splice-targeted primer approach. Results, ,Although we detected wild-type ER, and ER, mRNAs in PBMC but not in PMN cells, the ER, and ER, proteins were found in both cell types using Western blot. We observed that both ER, and ER, proteins differ in size between PMN and PBMC, suggesting that the two leucocyte populations contain diverse variant isoforms of ER, and ER,. RT-PCR analysis of exon-deleted ER splice variants revealed that PBMC express several exon-deleted variants of ER, and ER,, along with wild-type receptor, whereas the PMN cells only express exon-deleted variant isoforms and no wild-type ER, or ER,. Conclusions, ,Our study demonstrates the presence of ER, and ER, in PBMC and PMN cells from female and male donors. The ER, and ER, genes have complex transcriptional profiles, with many receptor variant isoforms being expressed. Considering the diversity of ER isoforms in leucocyte subtypes, we conclude that the expected effect of oestrogen would be highly cell type-specific. Further studies are needed to test the functional activity of ER isoforms and their relation to disease. [source]