The Circulating Platelet

The Circulating Platelet focuses on the biochemistry and physiology of platelets. Composed of contributions of authors, the compilation starts with the discussions on the origin, discovery, production, and life span of blood platelets. The discussions continue with the morphology of platelets. Concerns include peripheral, sol-gel, and organelle zones and the membrane systems. The book also looks at the energy metabolism of thrombocytes and highlights the presence of glycoproteins in blood platelets. These include polysaccharides, glucosaminoglycans, and glycoproteins. The text also discusses the properties, functions, and the physiological value of thrombosthenin. The compilation further discusses platelet aggregation and functions of platelets. Concerns include collection and processing of platelets; preparation of homogenates; and the agents that influence platelet aggregation. The role of platelets in blood clots and fibrinolysis is emphasized. The selection ends with discussions on the immunological reactions of platelets; the clinical diseases related to blood platelets; and blood transfusion and preservation. The text is vital for researchers interested in studying blood platelets.

1. 1 Platelets in Hemostasis and Thrombosis: A Brief Overview For more than 100 years the dominant role of blood platelets in hemostasis and thrombosis has been well documented. Seven years before their identification as a distinct class of blood corpuscles by Bizzozero (1882), Zahn (1875), using intravital microscopic observations, described the growth of an arterial thrombus as the result of "continued apposition of colorless blood corpuscles along the direction of blood flow. " A hallmark still valid today was set by Eberth and Schimmel busch (1888), who clearly divided the formation of the hemostatic plug into the result of the "conglutination of preformed blood corpuscles," followed by the "plasmatic coagulation as the formation of fibrin from substances dissolved in blood," as two distinct processes taking place in the described order. In spite of technical shortcomings, by approaching the limits of the light microscopic techniques of their time, Eberth and Schimmel busch discovered a change in the morphology of the platelets, paralleled by a presumptive change in their functional state, which was a prerequisite for the formation of a platelet plug. Their meticulous description implicitly anticipated the modern terminology of the "smooth disk" as the resting form of the circulating platelet and the activated "spiny sphere" as a result of a change in shape following stimulation.

Battle is a practical and sometimes lasting way of solving man's problems. It relies on the strength of the combatants and ignores the truth of the dispute. Discussion face to face can dissolve attitudes which have incorrectly determined judgements. The most striking example of this that I know is a Battle in Ireland in the eleventh century, where the king of Leinster fought a Viking prince. The Icelanders had raided Ireland for several generations in search of women, which they lacked since most of the population of Iceland were men who had arrived there by rowing long-boats from Norway. The prince was leading such a raid for the first time. Standing in the prow of the leading boat he saw Irish cavalry galloping along the beach to meet them. As they approached the shore the Irish king rode out of the band to challenge single combat. The Icelander jumped into the surf to meet him. As they raised their swords each realized that the other's face was like his own. When the Irish king spoke the other recognized the language. It had been spoken in Iceland by his grandmother who had been captured and taken there from Ireland. Swords were dropped and replaced by drinking horns. It was soon established that they were cousins. The battle gave way to a life-time of close co-operation.

12 The average human body has on the order of 10 circulating platelets. They are crucial for hemostasis, and yet excessive platelet activation is a major cause of m- bidity and mortality in Western societies. It is therefore not surprising that platelets have become one of the most extensively investigated biological cell types. We are, however, far from understanding precisely how platelets become activated under physiological and pathophysiological conditions. In addition, there are large gaps in our knowledge of platelet production from their giant precursor cell, the megakar- cyte. Understanding megakaryocyte biology will be crucial for the development of platelet gene targeting. The aim of Platelets and Megakaryocytes is therefore to bring together established and recently developed techniques to provide a comprehensive guide to the study of both the platelet and the megakaryocyte. It consists of five s- tions split between two volumes. The more functional assays appear in Volume 1, whereas Volume 2 includes signaling techniques, postgenomic methods, and a n- ber of key perspectives chapters. Part I of Volume 1, Platelets and Megakaryocytes: Functional Assays, describes many well-established approaches to the study of platelet function, including aggregometry, secretion, arachidonic acid metabolism, procoagulant responses, pla- let adhesion under static or flow conditions, flow cytometry, and production of microparticles. Although one would ideally wish to perform experiments with human platelets, studies within the circulation using intravital microscopy require the use of animal models, which are described in Chapter 16, vol. 1.

The second edition of Transfusion Medicine and Hemostasis continues to be the only "pocket-size" quick reference for pathology residents and transfusion medicine fellows. It covers all topics in blood banking, transfusion medicine, and clinical and laboratory based coagulation. Short, focused chapters, organized by multiple hierarchical headings, are supplemented with up to 10 suggested reading citations. This single reference covers essentially all the topics required to meet the goals and objectives of a major program in transfusion medicine and clinical coagulation. New chapters in the coagulation testing section reflect the development of new tests available and their incorporation into clinical practice. Coverage includes essential updates on the importance of new cellular therapies, peripheral blood and bone marrow hematopoietic progenitor cells, as well as cord blood banking and regenerative medicine. The authors also examine advances in the understanding of molecular testing and pathogen reduction in two separate quality control chapters (one for blood centers and one for hospitals). Updated content covers new coagulation tests, cellular therapies, and quality control issues Easy to use, with focused, well-defined chapters in a standardized format throughout Offers quick "cross-reference" lists at the end of each chapter Includes lists of common abbreviations and indexes that cross reference diagnostic, clinical and therapeutic commonalities

New updated edition first published with Cambridge University Press. This new edition includes 29 chapters on topics as diverse as pathophysiology of atherosclerosis, vascular haemodynamics, haemostasis, thrombophilia and post-amputation pain syndromes.

Platelets play a key role in thrombosis and haemostasis. However recent evidence clearly demonstrates that the functional role of platelets extends to many other processes in the body. With an internationally recognised list of contributing authors, The Non-Thrombotic Role of Platelets in Health and Disease, is a unique and definitive source of state-of-the-art knowledge about the additional role of platelets outside thrombosis and haemostasis. The intended audience for The Non-Thrombotic Role of Platelets in Health and Disease includes platelet biologists, microbiologists, immunologists, haematologists, oncologists, respiratory physicians, cardiologists, neurobiologists, tissue engineers, as well as students and fellows in these areas.