Blood cellular elements

Platelets are the smallest cellular elements of blood of 2.5 pm in average normal diameter. They fulfill an essential role in hemostasis and thrombosis. Thrombosis is a complex phenomenon, involving interaction of endothelial cells and blood cellular elements like platelets, leukocytes and red blood cells. Moreover, platelets influence both thrombosis formation and fibrinolysis. 

Symp. Radiolabellea Blood Cellular Elements, New York, 1980. 

Serious and sometimes fatal blood dyscrasias (patiiologic condition of blood disorder of cellular elements of blood) are die chief adverse reaction seen witii the adiniiiistration of chloramphenicol, hi addition to blood dyscrasias superinfection, hypersensitivity reactions, nausea, vomiting, and headache may be seen. It is recommended that patients receiving oral chloramphenicol be hospitalized so that patient observation and frequent blood studies can be performed during treatment witii this drug. 

O The acute leukemias are diseases of bone marrow resulting from aberrant proliferation of hematopoietic precursors. The hallmark of these malignancies is the leukemic blast cell, a visibly immature and abnormal cell in the peripheral blood that often replaces the bone marrow and interferes with normal hematopoiesis. These blast cells proliferate in the marrow and inhibit normal cellular elements, resulting in anemia, neutropenia, and thrombocytopenia. Leukemia also may infiltrate other organs, including the liver, spleen, bone, skin, lymph nodes, and central nervous system (CNS). Virtually anywhere there is blood flow, the potential for extramedullary (outside the bone marrow) leukemia exists. 

Blood consists of cellular elements (red blood cells, white blood cells, and platelets) as well as plasma, the fluid in which the blood cells are suspended. Normally, total circulating blood volume is about 8% of body weight (about 5 1 in women and 5.5 1 in men). Adipose tissue is relatively avascular and therefore contains little blood compared to other tissues. 

The cellular elements of the blood have a short life span and must be continuously replaced. The formation of red blood cells, white blood cells, and platelets, collectively, is referred to as hematopoiesis. This process takes place in the red bone marrow. In adults, red bone marrow is found in the pelvis, ribs, and sternum. 

The most numerous of the cellular elements in the blood are the erythrocytes (red blood cells). On average, there are 5 million red blood cells per microliter (pi) of blood, or a total of about 25 to 30 trillion red blood cells in the adult human body. The percentage of the blood made up of red blood cells is referred to as hematocrit. An average hematocrit is about 45% (42% females, 47% males). As such, the viscosity of the blood is determined primarily by these elements. 

The third of the cellular elements within the blood are the platelets (thrombocytes). Platelets are actually small, round or oval cell fragments. They are about 2 to 4 pm in diameter and have no nuclei. Platelets are formed in the red bone marrow as pinched-off portions of the very large megakaryocytes. Each megakaryocyte, which is confined to the bone marrow, can produce... 

The blood is collected using an aseptic technique into sterile containers. It can then be allowed to clot with subsequent recovery of the antibody-containing antisera by centrifugation. Alternatively, the blood may be collected in the presence of heparin, or another suitable anticoagulant, with subsequent removal of the suspended cellular elements, again by centrifugation. In this case, the resultant antibody-containing solution is termed plasma . 

Blood is the transport medium of the body. Plasma, which accounts for approximately 60% of the total volume, carries a wide range of small and medium-sized metabolites some are simply dissolved in solution (93% of the plasma is water), others are carried by specific carrier proteins. The chemical composition of the plasma is complex and reflects the chemical composition inside cells, which is why blood tests are so commonly used in diagnosis to see the biochemical events occurring in tissues. The formed cellular elements of the blood perform several functions defence against blood loss from bleeding (platelets, also called thrombocytes), defence against infection and immune surveillance (white cells, leucocytes), and gas transport and pH buffering (red cells, erythrocytes). 

Human blood constitutes about 8% of the body s weight. It consists of cells and cell fragments in an aqueous medium, the blood plasma. The proportion of cellular elements, known as hematocrit, in the total volume is approximately 45%. 

Arterial thrombosis. The formation of an aggregate of blood factors (thrombus), primarily platelets and fibrin, with entrapment of cellular elements in the arteries. Arthritis. Inflammation of a joint. 

LJ Hatam, HJ Kayden. A high-performance liquid chromatographic method for the determination of tocopherol in plasma and cellular elements of the blood. J Lipid Res 20 639-645, 1979. 

Blood dyscrasia A pathologic condition of the blood, usually referring to a defect in one or more of the blood s cellular elements. 

Hemostasis as defined by Virchow in the last century is a fine balance between blood flow, humoral factors, and cellular elements of the vascular system. Today, molecular and... 

The various components of the nervous system can be further differentiated into three basic cellular elements (1) neurons, (2) interstitial cells, and (3) connective tissue, blood vessels, and microglia. The neuron is the only cell type in the nervous system involved in information processing. Each neuron is, in its own right, a receiver, an integrator, and a transmitter of information. Neurons are always in contact with other neurons so that they create simple or complex channels through which many different responses can be transmitted. All behavior, no matter how complex, results from the interactive function of the billions of neurons. 

Studies on the origin and development of the cellular elements of the blood and the so-called endothelial cells which line the blood vessels in the normal embryo are peculiarly difficult on account of the important r61e that wandering mesenchyme cells play in these processes. The problem is also further confused by the perplexing mixture of cells of different origin brought about by the early established circulation of the body fluids. The development of no other embryonic tissue is so disturbed by mechanical and physical conditions. 

Know the general properties of blood the functions of its cellular elements and the meaning of the terms plasma, serum, hematocrit, plasma proteins, hemoglobin, coagulation. 

Normal values for total blood volume vary depending on the methods used for its determination and the basis of reference (sex, age, weight, surface area). In a healthy adult or normal body habitus, the circulating blood comprises 6-8% of the body weight, or 63-80 mL/kg. Blood consists of cellular elements suspended in a solution containing a host of proteins and low molecular weight substances. There are three types of cells in blood the red cells (erythrocytes), the white cells (leukocytes), and platelets (thrombocytes). Only the white cells possess... 

Auranofin is a triethylphosphine gold derivative for oral administration. It is in some respects strikingly different from the rest. Some 25% of an oral dose is absorbed through the intestinal wall and blood concentrations are some 15-25% of those reached with parenteral therapy. Auranofin is bound to cellular elements of the blood, is excreted mainly in the feces, and exhibits less tissue retention and total body gold accumulation than parenteral forms. It is more effective in acute inflammatory models and is a potent inhibitor of lysosomal enzyme release, antibody-dependent cellular toxicity, and superoxide production. Auranofin also affects humoral and cellular immune reactions. However, some have found auranofin to be rather less effective than parenteral gold. Auranofin is used in doses of 2-9 mg/day (generally 6 mg/day), which is less than the dose originally recommended. 

As a result of the contact of blood with none-ndothelial surfaces, several humoral and cellular systems can be activated. Exposure of blood proteins and cells to blood contacting medical devices can activate plasma proteolytic systems (coagulation (blood clotting system), fibrinolysis (process by which clot is broken down), complement cascade (a system of soluble proteins involved in microbiocidal activity and the release of inflammatory components), Kallekrein-kinin and contact systems) and at least three cellular elements (leukocytes, endothelial cells, and platelets). Contrary to the normal situations whereby these mechanisms are localized and intended to promote wound healing, activation of these systems by medical devices can result in nonlocalized systemic reactions. The preclinical and clinical assessments of hemocompatibility are designed to minimize modification of these systems. 

Remove cellular elements from blood to provide cell-free plasma or serum for analysis (see Chapter 2). 

Methods for Determining Parent Compounds and Metabolites in Biological Materials. NDMA is equally distributed in the cellular elements of the blood and in the plasma and serum (Lakritz et al. 1980). Therefore, it is advantageous to analyze whole blood for the quantification of NDMA. 

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