A new method for the determination of thrombocyte function in patients and in preserved blood]

In a circulating thrombocytic plasma the pressure in front of a defined mesh filter depends on the combined capacity of adhesion and aggregation of thrombocytes. A new clinical in vitro test is based on this principle which comes nearest to the conditions to be found in hemostasis dependent on thrombocytes. Judging from the preliminary results of investigations performed on stored blood, blood donors, patients with thrombocytopenia, disturbances of blood flow and patients under anticoagulant therapy, the time until the pressure rise after administering ADP and the maximal pressure amplitude proved to be the most significant parameters of the new procedure.     

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.     

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.     

Antithrombotic effect of preparations from the leeches Hirudo medicinalis

Antithrombotic effect of leech salivary gland secretion was maximal after intravenous administration into rats and was slightly decreased in cases of peroral administration. Blood from leech intestinal tract and leech homogenate exhibited less distinct antithrombotic action. Effect of these preparations was maintained after peroral administration. The antithrombotic effect of the leech preparations did not depend on their antithrombic activity caused by hirudin. These leech preparations appear to elongate a period of blood plasma recalcification caused by kallikrein inhibitor as well as apparently due to their capacity to inhibit aggregation of the thrombocytes.     

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.     

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.     

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.     

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.     

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.     

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.     

Results in the treatment of immune thrombocytolytic purpura (ITP)]

The late results in the treatment of 43 patients (adults) with chronic idiopathic thrombocytopenic purpura (ITP) are represented. Steroid treatment proved to be excellent and well-efficient in 20% of all cases and splenectomy in 70% of all cases. The good, but temporary increase of thrombocytes observed after the preceding steroid medication and the thrombocytosis after splenectomy can be explained as a favourable prognostic sign for a lasting success after the operation.     

Effects of Capsaicin and Isoflavone on Blood Pressure and Serum Levels of Insulin-Like Growth Factor-I in Normotensive and Hypertensive Volunteers with Alopecia

Insulin-like growth factor-I (IGF-I) reduces arterial blood pressure. Since administration of capsaicin and isoflavone increases serum levels of IGF-I by sensory neuron stimulation in subjects with alopecia, it is possible that administration of capsaicin and isoflavone reduces arterial blood pressure in patients with hypertension. Systolic and diastolic blood pressure (BP) and serum levels of IGF-I were determined before and at 1, 3, and 5 months after administration of capsaicin and isoflavone in 42 volunteers with alopecia, 29 normotensive and 13 hypertensive volunteers. Neither systolic nor diastolic BP changed in the normotensive volunteers after combined administration of capsaicin and isoflavone. In contrast, systolic and diastolic BP was significantly reduced in hypertensive volunteers after administration of capsaicin and isoflavone. Serum levels of IGF-I significantly increased in both normotensive and hypertensive volunteers after administration of capsaicin and isoflavone. These observations suggest that administration of capsaicin and isoflavone might reduce BP in hypertensive, but not in normotensive subjects, probably by increasing serum levels of IGF-I.     

Decreased first-pass metabolism of labetalol in chronic liver disease.

The effect of chronic liver disease on the rate of elimination and extent of "first-pass" metabolism of labetalol was studied. Pharmacokinetic measurements were made after both oral and intravenous administration to seven healthy subjects and to 10 patients with chronic liver disease. Plasma half life was similar in the two groups. Plasma concentrations were considerably higher in the patients than in the healthy subjects after oral administration but similar after intravenous injection. Thus the bioavailability of labetalol was increased in liver disease due to reduced first-pass metabolism. Bioavailability in the group of patients correlated negatively with serum albumin concentration. There were falls in supine heart rate and blood pressure which tended to be greater after oral administration in the patients with liver disease, suggesting an exaggerated response related to the increased bioavailability. Oral dosage requirements of labetalol and possibly other drugs susceptible to first-pass metabolism are reduced in the presence of liver disease.     

Adenine nucleotides in thrombocytes of birds

Analysis of free nucleotide composition of both avian thrombocytes and pig platelets showed quantitative differences in the level of adenine nucleotides. 3H-adenine taken up by turkey thrombocytes was metabolized mainly to adenine nucleotides was not released after thrombin action. Thrombin liberated non-radioactive adenine nucleotides (18.2 +/- 1.5%, 20.6 +/- 1.9%) of the total, probably localized in a storage pool. Malonyldialdehyhyde (MDA) production due to thrombin was observed in both platelets and thrombocytes.     

Adrenergic and dopaminergic regulation of circulating beta-endorphin-like immunoreactivity in hypertension.

The central alpha-2-adrenergic receptor agonist, clonidine (300 micrograms daily) significantly increased the plasma beta-endorphin-like immunoreactivity (beta ELI) in 12 patients with mild to moderate essential hypertension in a randomized, crossover study. A significant linear correlation between the increase in plasma beta ELI and the decrease in blood pressure (both systolic and diastolic) was found after clonidine administration. The role of the reduced central sympathetic tone, induced by alpha-2-adrenoceptor stimulation, in the elevation of circulating beta ELI can be suggested. The plasma beta ELI increased also significantly after the dopaminergic D-2 receptor agonist, bromocryptine treatment, (5 mg, daily) in 13 patients with borderline and mild essential hypertension in a randomized, crossover study. A significant drop in circulating noradrenaline and in arterial blood pressure and a significant linear correlation between the changes of plasma noradrenaline level and blood pressure was found after bromocryptine administration. There was no correlation between the rise in plasma beta ELI and the decrease in blood pressure after bromocryptine. The importance of the central sympathetic activity and not only a direct pituitary dopaminergic agonist effect on the beta-endorphin secretion can be stressed in the effect of bromocryptine on the immunoreactive beta-endorphin level.     

Intravenous diazoxide in treatment of hypertension associated with recent myocardial infarction

Twenty patients with blood pressure over 180/110 mm Hg one hour after admission to a coronary care unit with recent acute myocardial infarction were given intravenous diazoxide in a bolus of 300 mg. The average blood pressure before diazoxide was 194/122 mm Hg. Blood pressure fell considerably in all patients, though six patients required two injections. The average fall was 58 mm Hg systolic and 40 mm Hg diastolic. No patient became severely hypotensive. The heart rate increased by an average of 10 beats/min. In nine patients the electrocardiographic changes immediately after the administration of diazoxide suggested an increase in myocardial injury. Though none of the patients seemed to deteriorate clinically from the diazoxide the electrocardiographic changes suggested that the use of intravenous diazoxide to lower blood pressure in patients with acute myocardial infarction might possibly be deleterious.     

Composition of main haematopoietic compartments in normal and bled channel catfish

Differential cell counts showed that the head and trunk kidney of control and bled channel catfish Ictalurus punctatus had myeloid characteristics. They contained lymphoid and granuloid cells, thrombocytes, erythroid and agranular cells in decreasing order of abundance (%). Among the blast and precursor cells, the most numerous erythroid ones were followed by granuloid, lymphoid and agranular ones. The main changes after blood withdrawal were the decrease of thrombocytes and the increase of precursor cells in both kidney parts. In the group examined 7 days after bleeding the head kidney had a higher percentage of erythroid cells and lymphocyte precursors than the trunk kidney while the latter had more granuloid cells and their precursors. Basophils were present ( c . 1%) in both regions of the kidney of all groups. The spleen was predominantly a lymphatic organ. It contained c . 80% lymphoid cells, a higher incidence of granulated lymphocytes than in kidneys, 15% thrombocytes and 1.4% agranular cells. Blood withdrawal caused an increase of thrombocytes, a decrease of lymphoid cells and an increase of erythroid precursors in the spleen. The last probably stemmed from the circulation. While haematocrit values failed to indicate the anaemic state in the bled groups, the differential red blood cell count showed dramatic differences between the control and bled groups as well as between the two groups in different stages of recuperation from the blood loss.     

Evaluation of clinical efficacy of platelet substitution in acute leukemia using resonance thrombography

For evaluating the clinical effectiveness of thrombocyte substitution, the resonance thrombogram was registered before and after thrombocyte substitution in 50 patients with acute leukemia and the increase of thrombocytes (corrected increment) determined. Thrombocyte substitution led to a significant diminution of the platelet amplitude (p less than 0.01) and platelet value. The highest value of these alterations of parameters was reached 1 hour after transfusion, it was somewhat lower after 24 hours, yet the initial value was not reached again. Correlations could be found to exist between the platelet amplitude and the corrected thrombocyte increase 1 hour and 24 hours after transfusion. The resonance thrombography enables the successful control of thrombocyte substitution to be made and it is suitable for monitoring hemostasis in severe thrombocytopenia due to production.     

Quantitative analysis of shape and volume changes in activated thrombocytes in real time by single‐shot spatial light modulator‐based differential interference contrast imaging

We suggest to use a combination of optical tweezers and single‐image quantitative differential interference contrast (DIC) emulated by a spatial light modulator (SLM) to study physiological shape changes in thrombocytes after activation and demonstrate the effectiveness of this system for the given task. A specially designed phase mask displayed at the SLM enables quantitative phase calculation from only a single recording. The optical tweezers stabilize trapped thrombocytes for long‐time monitoring of changes in the optical thickness profile of thrombocytes during activation by adenosine diphosphate (ADP). (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Embolisms in the embryo

Artificial embolisms were produced in chick embryos by injecting small mouse liver cell particles in an extraembryonal vein. 1-10 h after the injection the embryos were fixed, and serial sections were examined by light microscope. Most of the obstructed vessels were later recanalized. All of the emboli were surrounded by thrombocytes and partly fixed on the vessel wall. The smaller of the injected particles were lying outside the vessels in the neighboring mesenchyme. The significance of thrombocytes for this transport mechanism is discussed.