Leukocyte Disorders
Leukocyte Rolling
Leukocytes
Bipolar Disorder
Leukocyte-Adhesion Deficiency Syndrome
Antigens, CD18
Encyclopedias as Topic
Guanosine Diphosphate Fucose
Receptors, Leukocyte-Adhesion
Varying expression levels of colony stimulating factor receptors in disease states and different leukocytes. (1/31)
Administration of G-CSF may not always respond in rise of neutrophil counts in different patient population. In order to understand a possible inter-relationship between the G-CSF and GM-CSF induced leukocyte responses and expression levels of receptors for G-CSF (G-CSFr) and GM-CSF (GM-CSFr), the levels of each receptor and CSF were measured in patients with basophilia (8), eosinophilia (14) and bacterial infection showing neutrophilia (12) in comparison with normal healthy adults (12) and children (14). G-CSFr was expressed in neutrophils in the largest amount followed by monocytes, but GM-CSFr was expressed more in monocytes than neutrophils. Lymphocytes and basophils did not express G-CSFr or GM-CSFr. The amount of GM-CSFr in neutrophils was present less in patients with infection than normal control (P = 0.031). The neutrophils expressed more G-CSFr than GM-CSFr. The quantity of G-CSFr in eosinophil showed marked interval change, higher in acute stage. The plasma concentrations of G-CSF in patients with infection were much higher than normal adults or children (117.95 +/- 181.16 pg/ml, P < 0.05). Binding assay with excess amount of CSFs could discriminate the patient who did not show any response to G-CSF or GM-CSF administration. After incubation with excess CSFs, more receptors were blocked in children than in adults (G-CSF P = 0.024, GM-CSF P = 0.006). These results indicate that the amount of CSFr in leukocyte varies in different types of leukocyte, and changes according to the patients' condition even in the same type of leukocyte, and the CSFrs of children bind to CSFs more than those of adults. (+info)Sebastian syndrome: report of the first case in a South American family. (2/31)
The Sebastian syndrome (SS) is a MYH9-related disorders, which are an extremely infrequent group of four autosomal dominant illnesses. SS consist of giant platelets, leukocyte inclusions and thrombocytopenia. To our knowledge, there are no case reports of this syndrome in South America. The propositus was a 35-year-old Argentine woman with a history of purpuric lesions in her lower limbs and thrombocytopenia. Idiopathic thrombocytopenia purpura (ITP) was previously diagnosed, but she did not respond to treatment with steroids. Family history failed to provide any evidence of hearing loss, easy bruising, nephritis, renal failure or cataracts. The patient and 11 members of her family were evaluated. The diagnosis of SS was established by demonstrating giant platelets, thrombocytopenia and leukocyte inclusions in peripheral smear in two relatives and by peripheral smear and electronic microscopy in the propositus. MYH9-related disorders should be suspected whenever a patient has a low platelet count or a bleeding diathesis of unknown origin. In these cases, the history, carefully peripheral smear exam, immunocytochemistry and electronic microscopy will be of great help. Differentiation ITP with SS is important to avoid unnecessary diagnostic studies and treatments. (+info)Infections in patients with inherited defects in phagocytic function. (3/31)
Patients with defects in phagocytic function are predisposed to intracellular microorganisms and typically have early dissemination of the infection. Recognition of the underlying disorder and aggressive antimicrobial therapy has been beneficial for the patients. Improved understanding of the pathophysiology has also affected patient management by allowing specific, targeted immunomodulatory intervention. The disorders described in this review are not common but have had a significant impact on our understanding of the role of phagocytic cells in host defense. Conversely, understanding the role of the neutrophil and macrophage in infection has benefited not just the patients described in this review but also other patients with similar disease processes. (+info)Polymorphonuclear neutrophil dysfunctions in streptozotocin-induced type 1 diabetic rats. (4/31)
Since conflicting results have been reported on non-specific immune response in type 1 diabetes, this study evaluates polymorphonuclear neutrophil (PMN) functions in the infection free Long Evan diabetic rats (type 1) by using tests that include: polarization assay, phagocytosis of baker\'s yeasts (Saccharomyces cerevisiae) and nitroblue tetrazolium (NBT) dye reduction. Polarization assay showed that neutrophils from diabetic rats were significantly activated at the basal level compared to those from the controls (p < 0.001). After PMN activation with N-formylmethionyl-leucyl-phenylalanine (FMLP), control neutrophils were found to be more polarized than those of the diabetic neutrophils and the highest proportions of polarization were found to be 67 % and 57 % at 10(-7) M FMLP, respectively. In the resting state, neutrophils from the diabetic rats reduced significantly more NBT dye than that of the controls (p < 0.001). The percentages of phagocytosis of opsonized yeast cells by the neutrophils from control and diabetic rats were 87 % and 61 %, respectively and the difference was statistically significant (p < 0.001). Evaluation of the phagocytic efficiency of PMNs revealed that control neutrophils could phagocytose 381 +/- 17 whereas those from the diabetic rats phagocytosed 282 +/- 16 yeast cells, and the efficiency of phagocytosis varied significantly (p < 0.001). Further, both the percentages of phagocytosis and the efficiency of phagocytosis by the diabetic neutrophils were inversely related with the levels of their corresponding plasma glucose (p = 0.02; r = -0.498 and p < 0.05; r = -0.43, respectively), which indicated that increased plasma glucose reduced the phagocytic ability of neutrophils. Such relationship was not observed with the control neutrophils. These data clearly indicate that PMN functions are altered in the streptozotocin (STZ)-induced diabetic rats, and hyperglycemia may be the cause for the impairment of their functions leading to many infectious episodes. (+info)Reversal in fatigued athletes of a defect in interferon gamma secretion after administration of Lactobacillus acidophilus. (5/31)
BACKGROUND: Fatigue and impaired performance in athletes is well recognised and has been loosely linked to "overtraining". Reduced concentration of IgA in the saliva and increased shedding of Epstein Barr virus (EBV) have been associated with intense training in elite athletes. OBJECTIVE: To determine whether athletes presenting with fatigue and impaired performance had an immune defect relevant to defective containment of EBV infection, and whether a probiotic preparation (Lactobacillus acidophilus) shown to enhance mucosal immunity in animal models could reverse any detected abnormality. RESULTS: The fatigued athletes had clinical characteristics consistent with re-activation of EBV infection and significantly (p = 0.02) less secretion of interferon (IFN) gamma from blood CD4 positive T cells. After one month of daily capsules containing 2 x 10(10) colony forming units of L acidophilus, secretion of IFNgamma from T cells had increased significantly (p = 0.01) to levels found in healthy control athletes. A significant (p = 0.03) increase in salivary IFNgamma concentrations in healthy control athletes after the one month course of L acidophilus demonstrated in man the capacity for this probiotic to enhance the mucosal IFNgamma concentration. CONCLUSION: This is the first evidence of a T cell defect in fatigued athletes, and of its reversal following probiotic therapy. (+info)Both influenza-induced neutrophil dysfunction and neutrophil-independent mechanisms contribute to increased susceptibility to a secondary Streptococcus pneumoniae infection. (6/31)
Since secondary Streptococcus pneumoniae infections greatly increase the mortality of influenza infections, we determined the relative roles of neutrophil-dependent and -independent mechanisms in increased susceptibility to S. pneumoniae during influenza infection. Mice infected with influenza for 6 days, but not 3 days, showed a significant increase in susceptibility to S. pneumoniae infection compared to mice not infected with influenza. There was significant neutrophil accumulation in the lungs of S. pneumoniae-infected mice regardless of whether or not they were infected with influenza for 3 or 6 days. Depletion of neutrophils in these mice resulted in increased susceptibility to S. pneumoniae in both the non-influenza-infected mice and mice infected with influenza for 3 days but not in the mice infected with influenza for 6 days, indicating that a prior influenza infection of 6 days may compromise neutrophil function, resulting in increased susceptibility to a S. pneumoniae infection. Neutrophils from the lungs of mice infected with influenza for 3 or 6 days exhibited functional impairment in the form of decreased phagocytosis and intracellular reactive oxygen species generation in response to S. pneumoniae. In addition, neutrophil-depleted mice infected with influenza for 6 days were more susceptible to S. pneumoniae than neutrophil-depleted mice not infected with influenza, indicating that neutrophil-independent mechanisms also contribute to influenza-induced increased susceptibility to S. pneumoniae. Pulmonary interleukin-10 levels were increased in coinfected mice infected with influenza for 6 days but not 3 days. Thus, an influenza infection of 6 days increases susceptibility to S. pneumoniae by both suppression of neutrophil function and by neutrophil-independent mechanisms such as enhanced cytokine production. (+info)Best practice in primary care pathology: review 7. (7/31)
This seventh best-practice review examines four series of common primary care questions in laboratory medicine: (1) blood count abnormalities 2; (2) cardiac troponins; (3) high-density lipoprotein cholesterol; and (4) viral diseases 2. The review is presented in a question-answer format, with authorship attributed for each question series. The recommendations are a precis of guidance found using a standardised literature search of national and international guidance notes, consensus statements, health policy documents and evidence-based medicine reviews, supplemented by Medline Embase searches to identify relevant primary research documents. The recommendations are not standards, but form a guide to be set in the clinical context. Most are consensus based rather than evidence based. They will be updated periodically to take account of new information. (+info)Functional characterization of natural killer cells in type I leukocyte adhesion deficiency. (8/31)
In this study, we analyzed IL-2-activated polyclonal natural killer (NK) cells derived from 2 patients affected by leukocyte adhesion deficiency type I (LAD1), an immunodeficiency characterized by mutations of the gene coding for CD18, the beta subunit shared by major leukocyte integrins. We show that LAD1 NK cells express normal levels of various triggering NK receptors (and coreceptors) and that mAb-mediated engagement of these receptors results in the enhancement of both NK cytolytic activity and cytokine production. Moreover, these activating NK receptors were capable of recognizing their specific ligands on target cells. Thus, LAD1 NK cells, similarly to normal NK cells, were capable of killing most human tumor cells analyzed and produced high amounts of IFN-gamma when cocultured in presence of target cells. Murine target cells represented a common exception, as they were poorly susceptible to LAD1 NK cells. Finally, LAD1 NK cells could efficiently kill or induce maturation of monocyte-derived immature dendritic cells (DCs). Altogether our present study indicates that in LAD1 patients, 3 important functions of NK cells (eg, cytotoxicity, IFN-gamma production, and DC editing) are only marginally affected and provides new insight on the cooperation between activating receptors and LFA-1 in the induction of NK cell activation and function. (+info)Leukocyte disorders, also known as white blood cell disorders, refer to a group of conditions that affect the production, function, or number of leukocytes (white blood cells) in the body. Leukocytes play a crucial role in protecting the body against infection and disease. Therefore, disorders that affect these cells can significantly impact an individual's immune system and overall health.
There are several types of leukocyte disorders, including:
1. Leukopenia: A condition characterized by abnormally low levels of white blood cells in the blood. This can increase the risk of infection.
2. Leukocytosis: A condition characterized by an elevated number of white blood cells in the blood. While this can be a normal response to infection or inflammation, it can also indicate an underlying medical condition such as leukemia.
3. Neutropenia: A condition characterized by abnormally low levels of neutrophils, a type of white blood cell that helps fight bacterial infections. This can increase the risk of infection.
4. Neutrophilia: A condition characterized by an elevated number of neutrophils in the blood. This can be a normal response to infection or inflammation, but it can also indicate an underlying medical condition such as an acute bacterial infection.
5. Lymphocytosis: A condition characterized by an elevated number of lymphocytes, a type of white blood cell that helps fight viral infections and cancer cells. This can be a normal response to infection or vaccination, but it can also indicate an underlying medical condition such as chronic lymphocytic leukemia.
6. Lymphopenia: A condition characterized by abnormally low levels of lymphocytes in the blood. This can increase the risk of infection and indicate an underlying medical condition such as HIV/AIDS or autoimmune disorders.
7. Monocytosis: A condition characterized by an elevated number of monocytes, a type of white blood cell that helps fight chronic infections and cancer cells. This can be a normal response to infection or inflammation, but it can also indicate an underlying medical condition such as chronic inflammatory diseases.
8. Monocytopenia: A condition characterized by abnormally low levels of monocytes in the blood. This can increase the risk of infection and indicate an underlying medical condition such as bone marrow disorders or autoimmune diseases.
These conditions can be caused by various factors, including infections, inflammation, cancer, autoimmune disorders, medications, and genetic disorders. Proper diagnosis and treatment require a thorough evaluation of the patient's medical history, physical examination, laboratory tests, and imaging studies.
Leukocyte rolling is a crucial step in the process of leukocytes (white blood cells) migrating from the bloodstream to the site of infection or inflammation, which is known as extravasation. This phenomenon is mediated by the interaction between selectins on the surface of endothelial cells and their ligands on leukocytes.
The multi-step adhesion cascade begins with leukocyte rolling, where leukocytes move along the vessel wall in a slow, rolling motion. This is facilitated by the transient interactions between selectins (P-selectin, E-selectin, and L-selectin) on endothelial cells and their ligands (PSGL-1, CD44, and others) on leukocytes. These interactions are weak and short-lived but sufficient to reduce the leukocyte's velocity and enable it to roll along the vessel wall.
Leukocyte rolling allows the leukocytes to come in close contact with the endothelium, where they can receive further signals that promote their activation and firm adhesion. This process is critical for the immune response to infection and inflammation, as it enables the recruitment of effector cells to the site of injury or infection.
Leukocytes, also known as white blood cells (WBCs), are a crucial component of the human immune system. They are responsible for protecting the body against infections and foreign substances. Leukocytes are produced in the bone marrow and circulate throughout the body in the bloodstream and lymphatic system.
There are several types of leukocytes, including:
1. Neutrophils - These are the most abundant type of leukocyte and are primarily responsible for fighting bacterial infections. They contain enzymes that can destroy bacteria.
2. Lymphocytes - These are responsible for producing antibodies and destroying virus-infected cells, as well as cancer cells. There are two main types of lymphocytes: B-lymphocytes and T-lymphocytes.
3. Monocytes - These are the largest type of leukocyte and help to break down and remove dead or damaged tissues, as well as microorganisms.
4. Eosinophils - These play a role in fighting parasitic infections and are also involved in allergic reactions and inflammation.
5. Basophils - These release histamine and other chemicals that cause inflammation in response to allergens or irritants.
An abnormal increase or decrease in the number of leukocytes can indicate an underlying medical condition, such as an infection, inflammation, or a blood disorder.
Bipolar disorder, also known as manic-depressive illness, is a mental health condition that causes extreme mood swings that include emotional highs (mania or hypomania) and lows (depression). When you become depressed, you may feel sad or hopeless and lose interest or pleasure in most activities. When your mood shifts to mania or hypomania (a less severe form of mania), you may feel euphoric, full of energy, or unusually irritable. These mood swings can significantly affect your job, school, relationships, and overall quality of life.
Bipolar disorder is typically characterized by the presence of one or more manic or hypomanic episodes, often accompanied by depressive episodes. The episodes may be separated by periods of normal mood, but in some cases, a person may experience rapid cycling between mania and depression.
There are several types of bipolar disorder, including:
* Bipolar I Disorder: This type is characterized by the occurrence of at least one manic episode, which may be preceded or followed by hypomanic or major depressive episodes.
* Bipolar II Disorder: This type involves the presence of at least one major depressive episode and at least one hypomanic episode, but no manic episodes.
* Cyclothymic Disorder: This type is characterized by numerous periods of hypomania and depression that are not severe enough to meet the criteria for a full manic or depressive episode.
* Other Specified and Unspecified Bipolar and Related Disorders: These categories include bipolar disorders that do not fit the criteria for any of the other types.
The exact cause of bipolar disorder is unknown, but it appears to be related to a combination of genetic, environmental, and neurochemical factors. Treatment typically involves a combination of medication, psychotherapy, and lifestyle changes to help manage symptoms and prevent relapses.
Leukocyte Adhesion Deficiency Syndrome (LAD) is a group of rare inherited disorders that affect the ability of white blood cells, specifically neutrophils, to adhere to and migrate into tissues, particularly those involved in immune responses. This results in recurrent bacterial and fungal infections starting in infancy.
There are three types of LAD, each caused by different genetic mutations:
1. LAD I: This is the most common and severe form, caused by a deficiency in the CD18 protein which is crucial for neutrophil adhesion. Symptoms include delayed separation of the umbilical cord, severe periodontal disease, and recurrent skin, lung and gastrointestinal infections.
2. LAD II: Also known as congenital disorder of glycosylation, type Ib, it is caused by a deficiency in the enzyme glucosyltransferase, leading to abnormal sugar chains on cell surfaces. Symptoms are similar to LAD I but less severe, and also include mental retardation and impaired growth.
3. LAD III: This is the least common form, caused by a defect in the integrin-linked kinase (ILK) gene. It results in a more complex phenotype with muscular and cardiac abnormalities, in addition to immune dysfunction.
Treatment typically involves prophylactic antibiotics, granulocyte-colony stimulating factor (G-CSF) to increase neutrophil counts, and sometimes bone marrow transplantation.
CD18 is a type of protein called an integrin that is found on the surface of many different types of cells in the human body, including white blood cells (leukocytes). It plays a crucial role in the immune system by helping these cells to migrate through blood vessel walls and into tissues where they can carry out their various functions, such as fighting infection and inflammation.
CD18 forms a complex with another protein called CD11b, and together they are known as Mac-1 or CR3 (complement receptor 3). This complex is involved in the recognition and binding of various molecules, including bacterial proteins and fragments of complement proteins, which help to trigger an immune response.
CD18 has been implicated in a number of diseases, including certain types of cancer, inflammatory bowel disease, and rheumatoid arthritis. Mutations in the gene that encodes CD18 can lead to a rare disorder called leukocyte adhesion deficiency (LAD) type 1, which is characterized by recurrent bacterial infections and impaired wound healing.
An encyclopedia is a comprehensive reference work containing articles on various topics, usually arranged in alphabetical order. In the context of medicine, a medical encyclopedia is a collection of articles that provide information about a wide range of medical topics, including diseases and conditions, treatments, tests, procedures, and anatomy and physiology. Medical encyclopedias may be published in print or electronic formats and are often used as a starting point for researching medical topics. They can provide reliable and accurate information on medical subjects, making them useful resources for healthcare professionals, students, and patients alike. Some well-known examples of medical encyclopedias include the Merck Manual and the Stedman's Medical Dictionary.
Guanosine diphosphate fucose (GDP-fucose) is a nucleotide sugar that plays a crucial role in the process of protein glycosylation, specifically the addition of fucose residues to proteins and lipids. It is formed from GDP-mannose through the action of the enzyme GDP-mannose 4,6-dehydratase, which converts GDP-mannose to GDP-4-keto-6-deoxymannose, which is then reduced by GDP-4-keto-6-deoxymannose reductase to form GDP-fucose.
GDP-fucose serves as a donor substrate for various glycosyltransferases that catalyze the transfer of fucose residues to specific acceptor molecules, such as proteins and lipids. Fucosylation is involved in many biological processes, including cell adhesion, inflammation, and cancer metastasis. Therefore, understanding the regulation of GDP-fucose biosynthesis and fucosylation has important implications for the development of therapies for various diseases.
Cell adhesion refers to the binding of cells to extracellular matrices or to other cells, a process that is fundamental to the development, function, and maintenance of multicellular organisms. Cell adhesion is mediated by various cell surface receptors, such as integrins, cadherins, and immunoglobulin-like cell adhesion molecules (Ig-CAMs), which interact with specific ligands in the extracellular environment. These interactions lead to the formation of specialized junctions, such as tight junctions, adherens junctions, and desmosomes, that help to maintain tissue architecture and regulate various cellular processes, including proliferation, differentiation, migration, and survival. Disruptions in cell adhesion can contribute to a variety of diseases, including cancer, inflammation, and degenerative disorders.
Leukocyte adhesion receptors are a type of cell surface molecules found on the white blood cells (leukocytes), which play a crucial role in the immune system's response to infection and inflammation. These receptors mediate the adhesion of leukocytes to the endothelial cells that line the blood vessels, allowing them to migrate out of the bloodstream and into the surrounding tissues where they can carry out their immune functions.
There are several types of leukocyte adhesion receptors, including selectins, integrins, and immunoglobulin-like receptors. Selectins are involved in the initial capture and rolling of leukocytes along the endothelium, while integrins mediate their firm adhesion and subsequent transmigration into the tissues. Immunoglobulin-like receptors can either enhance or inhibit leukocyte activation and function.
Dysregulation of leukocyte adhesion receptors has been implicated in various inflammatory and immune-related diseases, such as atherosclerosis, arthritis, and cancer metastasis. Therefore, targeting these receptors with therapeutic agents has emerged as a promising strategy for the treatment of these conditions.
Neutrophils are a type of white blood cell that are part of the immune system's response to infection. They are produced in the bone marrow and released into the bloodstream where they circulate and are able to move quickly to sites of infection or inflammation in the body. Neutrophils are capable of engulfing and destroying bacteria, viruses, and other foreign substances through a process called phagocytosis. They are also involved in the release of inflammatory mediators, which can contribute to tissue damage in some cases. Neutrophils are characterized by the presence of granules in their cytoplasm, which contain enzymes and other proteins that help them carry out their immune functions.