Results of a new platelet function test in various clinical diseases and in preserved blood]

In healthy persons, patients with thrombocytopenia and patients with arterial disturbances of blood flow with and without administration of Falithrom the pressure recording was carried out after the combined aggregation and adhesion of thrombocytes. The reaction time particularly observed after administration of ADP revealed marked differences in the groups examined, likewise the maximal pressure amplitude in front of the pumped through filter. When Falithrom was administered the thrombocyte functions were clearly impaired. The reduction of the capacity of platelets to obstruct filter pores can impressively be proved even in those thrombocytes stored in ACD-AG-plasma.     

Autoantibodies to the thrombocytes and erythrocytes in HIV-infected patients

In 48 patients with HIV infection were tested for the presence of autologous and allogenic antibodies to red blood cells with the use of Coombs' direct and indirect tests. 18 HIV-infected patients had IgG antibodies to thrombocytes, circulating in the blood (detected by the method of EIA) and bound to thrombocytes (detected by the method of RIA). In 5 out of 48 patients Coombs' direct test yielded positive results with red blood cells. 6 out of 18 examined patients had an elevated content of thrombocyte-bound antibodies. The presence of cross reactions between gp120 of human immunodeficiency virus and gp3a thrombocytes led to the formation of antithrombocyte antibodies and, consequently, to a decrease in the number of thrombocytes.     

Postoperative changes of the thrombocyte number and function]

In 30 patients the number of thrombocytes was determined 24-48 hours after surgical interventions and compared with the normal range. The function of thrombocytes was determined by the method of pressure registration in combined thrombocyte-aggregation-adhesion (DKTA method). In spite of the occurring thrombocytosis there is a tendency towards a decrease of response in most cases and thus of haemostatic function of blood platelets. The influence of the thrombocyte function caused by fibrinolytic split products or by a change of prostaglandine metabolism is discussed.     

Chicken thrombocytes in culture: lymphocyte-conditioned medium delays apoptosis.

Chicken thrombocytes are nucleated cells, analogs to mammalian platelets. These cells are involved in hemostasis, phagocytosis and secretion of specific products. Most of the properties of avian thrombocytes have been established in experiments that employed recently isolated blood cells. Attempts to cultivate these cells for a long period of time under optimal culture conditions for peripheral blood cells were unsuccessful; thrombocytes died after 24 h of cultivation unlike macrophages cocultured with them. Here we investigate the reasons and type of thrombocyte death in culture. Thrombocytes were separated from peripheral blood of roosters and cultured for 48 h. The influence of different culture conditions on thrombocyte viability was studied. Cells were cultured as adherent cell monolayers or under agitation (preventing adherence), in the presence or lack of lymphocytes or their soluble factors, and various concentrations of fetal bovine serum. After 24 h in standard culture thrombocytes displayed cytoplasm and chromatin condensation, DNA cleaved into oligonucleosomal fragments and unaltered mitochondria. These results strongly suggest that thrombocytes suffer an apoptotic cell death in culture. Apoptosis could be delayed by culturing thrombocytes in the presence of lymphocytes or their soluble factors.     

Modification of uremic thrombocytopathy by hemodialysis

By means of in vitro screen pressure measurement the functions of thrombocytes were detected in dialysis patients before and immediately after dialysis. Start values are below the normal region as a sign of uraemic thrombocytopathia. The expected improvement after dialysis was not to be seen. As a cause of deterioration an activation of the thrombocytes at the surfaces of the capillary kidney and an incomplete inhibition of this process by heparin is discussed.     

Blood morphology of the European eel (Anguilla anguilla). IV. Thrombocytes and their developmental stages]

By the aid of histological special stainings, cytochemical proofs, phase contrast and electron microscopical methods the thrombocytes (spindle cells) of the European ell (Anguilla anguilla) and their stages of development were described as an independent series of cells. After an artificial blood loss thrombocytoblasts, prothrombocytes and mature thrombocytes could distinctly be demonstrates. Besides the kidney the spleen was found to be the main place of the thrombopoiesis. Phase contrast investigations provided evidence for the relatively strong locomotion of these cells. By means of cytochemical proofs a further differentiation of the thrombocytes from other white blood cells can be made. Electron microscopical investigations of the thrombocytes yielded a great similarity to the thrombocytes of the amphibians. The endoplasmatic ring and particular inclusions could be shown to be characteritstic features of the fine structure.     

Examination of platelet aggregation and ultrastructure in patients with non-Hodgkin's lymphoma

Aggregation and secretion reaction of thrombocytes were studied in 54 patients suffering from Non-Hodgkin's++Lymphoma. Results were compared with electron-microscopic findings on thrombocytes of the same patients. Slight changes were found in stage II. In stage IV distinct therapy-resistant changes were noted in combination with storage pool disease syndrome which is to be considered as a consequence of impaired generation of thrombocytes in bone marrow.     

Ultrastructural distribution of peroxidase in thrombocytes of mammals and submammals

The localization and distribution of peroxidase (PPO) activity were studied ultracytochemically in thrombocytes from lampreys, carps, frogs, snakes, tortoises, rabbits, sheep, dogs, and monkeys. PPO activity was not detectable in the thrombocytes of lampreys, carps, frogs, and snakes. However, this enzyme activity was demonstrated in the nuclear envelope and endoplasmic reticulum of tortoise thrombocytes. Dog and monkey thrombocytes (blood platelets) exhibited PPO activity in the dense tubular system, but this enzyme activity was not detectable in rabbit and sheep thrombocytes. Our observations are interpreted to suggest that thrombocytes from animals lower than amphibia are peroxidase negative. Furthermore, it can be said that thrombocytes from animals higher than reptiles are generally positive, although there are exceptions. PPO activity was localized in the endoplasmic-reticulum system, but not in the cytoplasmic granules of thrombocytes common to submammals and mammals. In this study, we also compared the distribution of peroxidase activity in thrombocytes, neutrophils, and eosinophils and conclude that these are significant differences in the distribution of PPO and myeloperoxidase.     

Regulation of thrombocytopoiesis studied by a mathematical model

A mathematical model of thrombocytopoiesis is proposed which accounts for the recent data on its regulation. It is shown that the compensatory response of the system to a decrease in the level of thrombocytes in the blood is controlled by the total amount of thrombocytes and megakaryocytes. The proliferation intensity of megakaryocytes and the total number of thrombocytes reveal, respectively, a lineary and a logarithmical dependence on the total number of thrombocytes and megakaryocytes. The limits of the post-transfusion level of thrombocytes are defined, within which the thrombocytopoiesis is controlled only by the number of thrombocytes. The values of parameters characterizing the behaviour of the thrombocytopoiesis system are calculated.     

Ultrastructural distribution of peroxidase in thrombocytes of mammals and submammals

Summary The localization and distribution of peroxidase (PPO) activity were studied ultracytochemically in thrombocytes from lampreys, carps, frogs, snakes, tortoises, rabbits, sheep, dogs, and monkeys. PPO activity was not deteetable in the thrombocytes of lampreys, carps, frogs, and snakes. However, this enzyme activity was demonstrated in the nuclear envelope and endoplasmic reticulum of tortoise thrombocytes. Dog and monkey thrombocytes (blood platelets) exhibited PPO activity in the dense tubular system, but this enzyme activity was not detectable in rabbit and sheep thrombocytes. Our observations are interpreted to suggest that thrombocytes from animals lower than amphibia are peroxidase negative. Furthermore, it can be said that thrombocytes from animals higher than reptiles are generally positive, although there are exceptions. PPO activity was localized in the endoplasmic-reticulum system, but not in the cytoplasmic granules of thrombocytes common to submammals and mammals. In this study, we also compared the distribution of peroxidase activity in thrombocytes, neutrophils, and eosinophils and conclude that these are significant differences in the distribution of PPO and myeloperoxidase.     

The ultrastructure of the blood cells of the pike Esox lucius L.

The ultrastructure of pike peripheral blood cells, lymphocytes, thrombocytes, granulocytes, and monocytes is described. At present there are no reliable criteria for differentiating between round thrombocytes and small lymphocytes of fish on a routine basis. At the ultrastructural level thrombocytes could be clearly differentiated from lymphocytes by cytoplasmic canals and vesicles, marginal microtubules, and large glycogen deposits. Electron microscopic identification of thrombocytes was confirmed by examining the ultrastructural features of a purified thrombocyte fraction. In addition, a preliminary investigation of the structure of the haemopoietic cells in the thymus, anterior kidney, and spleen was carried out.     

Determination of the thrombocyte count in platelet-rich plasma]

A method is described according to which the number of thrombocytes may be calculated from the optical density of plasma enriched with platelets. The accuracy of the method is ensured by statistical calculations. Citrate venous blood of 60 surgical patients was used for the measurements.     

Glycolipid- and glycoprotein-based blood group A antigen expression in human thrombocytes. A1/A2 difference

Total non-acid glycolipid fractions and total sodium dodecylsulphate (SDS) solubilized protein fractions were isolated from human thrombocytes obtained from single human donors having different blood group A₁/A₂ phenotypes. The blood group A glycolipid antigens were characterized by immunostaining of thin layer plates with different monoclonal anti-A antibodies. The glycoproteins carrying blood group A epitopes were identified by SDS-PAGE and Western blot analysis using a monoclonal anti-A antibody. Blood group A glycolipid antigens were found in both A₁ and A₂ thrombocytes but the A₂ individuals expressed at least ten times less A glycolipids compared to the A₁ individuals. Expression of A type 3/4 chain and small amounts of A type 1 chain glycolipids were seen in thrombocytes of both A₁ and A₂ individuals, while the type 2 chain A glycolipids appeared to be missing from the A₂ thrombocytes. Blood group A reactive glycoproteins were only found in thrombocytes of A₁ individuals and could not be detected in A₂ individuals or a blood group O individual. The major blood group A glycoprotein were found as a double band migrating in the 130 kDa region.Abbreviations SDS sodium dodecyl sulfate - PAGE polyacrylamide gel electrophoresis - HPTLC high performance thin layer chromatography - CBB Coomassie brilliant blue - GVH graft versus host Part of this work was presented at the Xth International Symposium on Glycoconjugates, Jerusalem, Israel. September, 1989.In the short hand designation for glycolipids, the letter indicate blood group determinant, the first numeral, the number of sugar residues, and the second numeral, the type of carbohydrate chain. Thus, A-6-1 means a hexaglycosylceramide with a blood group A determinant based on the type 1 carbohydrate chain.     

The Breddin test in various forms of idiopathic thrombocytopenic purpura]

In 100 healthy persons and 38 patients with idiopathic thrombocytopenic purpura (ITP) the morphology of thrombocytes was examined according to BREDDIN. The survival time of the marked thrombocytes and their place of sequestration was determined in the patients and in 17 voluntary persons. A correlation was found to exist between the morphology of thrombocytes and those four forms of ITP which could be limited by means of radiometric methods. Moreover, a certain degree of dependence was found between the thrombocyte sequestration place and the presence of antibodies.     

The Effect of Contrast Medium SonoVue<Superscript>®</Superscript> on the Electric Charge Density of Blood Cells

The effect of contrast medium SonoVue® on the electric charge density of blood cells (erythrocytes and thrombocytes) was measured using a microelectrophoretic method. We examined the effect of adsorbed H⁺ and OH^? ions on the surface charge of erythrocytes or thrombocytes. Surface charge density values were determined from electrophoretic mobility measurements of blood cells performed at various pH levels. The interaction between solution ions and the erythrocyte’s or thrombocyte’s surface was described by a four-component equilibrium model. The agreement between the experimental and theoretical charge variation curves of the erythrocytes and thrombocytes was good at pH 2–9. The deviation observed at a higher pH may be caused by disregarding interactions between the functional groups of blood cells.     

Cell types in peripheral blood of the nurse shark: An approach to structure and function

Ultrastructural and functional studies were carried out on nurse shark (Ginglymostoma cirratum) peripheral blood cells in order to identify cells of definitive morphology and specific function. Along with erythrocytes and thrombocytes, four morphologically distinct leucocytes are recognized in peripheral blood: two types of granulocytes, the ‘eosiniphil’ and the ‘granulocyte’, and two mononuclear agranulocytic cells, one resembling mammalian macrophage and monocyte, the other resembling mammalian lymphocyte. Also present in peripheral circulation are blast-like cells and mitotic cells. In vitro phagocytosis was demonstrated by the monocyte-macrophage and the granulocyte while thrombocytes, eosinophils and lymphocytes showed no phagocytic activity in the system studied. It is stressed that care must be used in drawing functional analogies between blood cells of a mammal and an elasmobranch on the basis of morphological similarity alone.     

Hematologic complications in acute alcoholism]

The authors investigated the relations between cell anomalies (vacuolation, increasing sideroblastosis) caused by the uptake of alcohol and the dynamics of haematopoesis in the bone-marrow of 33 alcoholists who had been admitted in a comatose condition and who were neither affected with anaemia nor with chronic hepatitis. In all cases a maturation arrest of erythropoetic and granulopoetic cell elements which was not in accordance with the number of immature vacuolated cells could be observed. 12 test persons showed increased sideroblastic indices and a slightly diminished medullary reticulocytosis. The majority showed a very active thrombocytopoesis contrasting with the normal or even diminished number of thrombocytes in the peripheral blood. The authors come to the conclusion that alcohol will cause a general metabolic damage of haematopoesis and at the same time it will produce a direct toxic effect on the bone-marrow cells (proerythroblasts, promyelocytes) and the peripheral blood (thrombocytes).     

Separation of leucocytes in the dogfish (Scyliorhinus canicula) using density gradient centrifugation and differential adhesion to glass coverslips

Summary The blood of the dogfish, S. canicula, contains several types of leucocytes, namely thrombocytes, monocytes, lymphocytes and four populations of granulocytes. Three of these granulocyte types, G1, G3 and G4, are eosinophilic while G2 is heterophilic/neutrophilic. All of the leucocyte types, with the exception of G2 granulocytes and monocytes, can be separated by means of their differential adherent properties to glass and by density gradient centrifugation. Thrombocytes, G3 and G4 granulocytes can be separated in good purity by single-step methods while G1 granulocytes and lymphocytes require a combination of density gradient centrifugation followed by adherence to glass to remove contaminating thrombocytes. Depending on the cell type, between 11–45% of cells with consistently high viability can be recovered after separation. Separated populations of the thrombocytes and granulocytes will be especially useful for studies on the role of such cell types in inflammation.     

Haematological and haematopoietic responses to starvation in an air-breathing fish Channapunctatus Bloch

Changes in haematological values (RBC numbers, haemoglobin content, haematocrit value, MCV, MCH, MCHC, TLC and DLC) based on weekly samples from a group of starved fish were investigated. After 8 weeks of starvation, the effects of restoration to a normal diet was evaluated. Parallel studies on haematopoietic tissues were also made. Changes in some biochemical values such as blood glucose, liver and muscle glycogen were also examined to correlate biochemical effects with those of haematological changes. Erythrocytes, thrombocytes and neutrophils were found to be most sensitive to starvation. The initial response to deprivation of food was an increase in RBCs and related values and in total leukocyte population. However, from week 5 onwards a sharp decline in these cell populations was noted. The leukocytes and thrombocytes showed a change parallel to RBC and the total leukocyte counts. However, neutrophils were observed to show a consistent increase throughout the starvation period. A blood glucose level below SOmglOOmh¹ appeared critical in relation to blood cell population. Haematopoietic studies revealed that reticulocytes and mesomyelocytes were unable to keep pace with the changing peripheral blood picture. Other stages in development responded to the changes in the peripheral blood.     

Measurements of cell nuclei in blood smears from frogs]

In the blood-spread of frog size and extinction of nuclei of erythrocytes, thrombocytes and neutrophile leucocytes with segmental nucleus were investigated. The substance of nucleus was made visible by means of colouring in according to May-Grünwald and the DNA-content in according to Feulgen-reaction. The thickeness of layer and relief of the spread were recorded and measured with a touch-equipment. The nuclei and segments of nucleus, which are flat disks in the dry spread (nuclei of thrombocytes are about 0.75 mum thick), are considered to be rotational ellipsoids in the fluid blood; volume, surface and quantity of DNA are calculated. The erythrocytes have the smallest. the leucocytes the largest quantity of DNA in the nucleus. The concentration of the substance of nucleus and of the DNA increases with the dryness of the spread, to about the sixfold value at the nuclei of thrombocytes.