The effects of anagrelide on human megakaryocytopoiesis

Anagrelide, an inhibitor of platelet aggregation, decreases the number of platelets in normal subjects and in patients with myeloproliferative disorders. We describe studies aimed at discovering the general mechanism(s) by which anagrelide acts. We examined three hypotheses: (1) anagrelide shortens platelet survival, (2) anagrelide inhibits the proliferation of megakaryocytic-committed progenitor cells (CFU-M), and (3) anagrelide inhibits maturation of megakaryocytes. We observed that anagrelide did not shorten platelet survival. Proliferation of CFU-M in vivo was not affected by anagrelide, although high concentrations of anagrelide inhibited CFU-M in vitro . In-vivo and in-vitro anagrelide altered the maturation of megakaryocytes, causing a decrease in their size and changing other morphometric features. We conclude that anagrelide decreases the number of platelets primarily by interfering with the maturation of megakaryocytes.     

Electronmicroscopic cytochemical studies on lysosomes and peroxisomes of a rat cardiac muscle in the experimental alloxan diabetes.

The combined electronmicroscopic and cytochemical investigations of lysosomes and peroxisomes of a rat cardiac muscle were carried out in various duration time of the alloxan diabetes. The analysis of cytochemical reactions with DAB, confirming the existence of peroxisomes in rat heart muscle revealed that the state of experimental alloxan diabetes did not at all affect either cytochemical or morphological image of peroxisomes. In comparison with the control group, in all 3 experimental groups cytochemical reaction to acid phosphatase markedly pointed to the increase in number and size of electron-dense bodies (lysosomes) with positive reaction. This state may most probably result both from local and general organism disturbances in metabolism, induced by particular experimental conditions.     

Some histochemical observations on the myocardial metabolism in experimental conditions. Part I.

In the paper the author is concerned with the histochemical estimation of the metabolic adaptation of the heart muscle of albino rats during an early experimental alloxan diabetes. It has been found that the state of experimentally produced insulin deficiency directly influences metabolism of the heart muscle and the changes observed in the histochemical reactions prove this. An increase in the intensity of histochemical reactions concerns the PAS-positive reaction and the reactions to the NADH and NADPH tetrazole reductase activities. Alkaline phosphatase shows a decrease in the enzymatic activity, whose nature is transitional and reversible with regard to cytochrome oxidase and ATP-ase. The histochemical picture of metabolic changes depends on the duration time of experimental diabetes.     

Some histochemical observations on the myocardial metabolism in experimental conditions. Part II.

A histochemical evaluation of the activity of chosen oxido-reductive enzymes of the cardiac muscle connected with the citric acid cycle, glycolysis and pentose shunt in the early experimental alloxan diabetes period in white rats has been carried out. Dehydrogenases: succinate, isocitrate and glucose-6-phosphate indicated a decrease in the enzymatic activity while the lactate dehydrogenase activity did not undergo any change. An increase in the intensity of the histoenzymatic reaction only concerned glutamate dehydrogenase. The presented histoenzymatic evidence of changes in the enzymatic activities may speak for the possibility of an existence of a direct diabetes influence on the cardiac muscle metabolism.     

Peripheral blood lymphocyte apoptosis and its relationship with thyroid function tests in adolescents with hyperthyroidism due to Graves' disease

Introduction

Failures in apoptotic pathways can contribute to various autoimmune diseases, including autoimmune hyperthyroidism due to Graves’ disease (GD). The aim of the present research was to assess changes in the degree of peripheral blood (PB) lymphocyte apoptosis during methimazole (MMI) treatment in the group of teenage children, and to describe its relationship with thyroid function tests.

Material and methods

The percentage of PB apoptotic lymphocytes, assessed by the decrease in mitochondrial transmembrane potential (CMXRos staining), was measured in 30 adolescents at the time of diagnosis and after obtaining normalization of the thyroid hormone levels.

Results

The percentage of apoptotic lymphocytes in previously untreated patients with GD (5.16 ±2.81%) was significantly lower (p = 0.000001) than the percentage of apoptotic cells in the same group of patients after obtaining methimazole-induced euthyroidism (10.72 ±4.66%). There was a correlation between the increase of the mean percentages of apoptotic lymphocytes and the reduction of FT4 levels (R = 0.63, p < 0.0001), as well as the reduction of TT3 levels (R = 0.95, p < 0.0001). The more signs and symptoms accompanying the diagnosis of GD, the higher was the increment of the degree of lymphocyte apoptosis observed during the MMI-treatment (R = 0.74, p < 0.0000001). The methimazole dosage correlated (R = 0.85, p < 0.0001) with the percentage of apoptotic cells.

Conclusions

The use of methimazole in treatment of hyperthyroidism due to GD leads to an increment of apoptotic cells in PB. Higher doses of methimazole cause a higher increase of apoptotic lymphocytes. Apoptosis induction of human PB lymphocytes seems to be one of the indicators of proper hyperthyroidism treatment.     

Thyroid diseases in patients with acromegaly

Acromegaly often involves the presence of different pathologies of the thyroid gland. Long-lasting stimulation of the follicular epithelium by growth hormone (GH) and insulin-like growth factor 1 (IGF-1) can cause disorders in thyroid function, an increase in its mass and the development of goitre. Acromegalic patients present most frequently with non-toxic multinodular goitre. Nodules are more prevalent in patients with active acromegaly. It has been suggested that then thyroid size increases and it can be reduced through treatment with somatostatin analogues. The relationship between thyroid volume and the level of IGF-1 and the duration of the disease is unclear. Each acromegalic patient requires a hormonal and imaging evaluation of the thyroid when the diagnosis is made, and an accurate evaluation during further observation and treatment. Although the data concerning the co-occurrence of acromegaly and thyroid cancer still remain controversial, it is particularly important to diagnose the patient early and to rule out thyroid cancer.     

Ultrastructural Aspects of Leukaemic Cells in Acute Myeloblastic Leukaemia

Ultrastructural aspects of leukaemic cells in a case of myeloblastic leukaemia are described. Changes concerning of mitochondrial ultrastructure, but primarily the presence of vast numbers of fibrillar structures in the cytoplasm of the examined cells were observed. These structures were spreading through their gradual widening to cover almost the whole cell cytoplasm, damaging its organellae and internal architecture. The nature of the observed changes remains unknown.     

Autologous blood-derived stem cell transplantation in the treatment of hematopoietic malignant diseases (Part II)]

Autologous transplantation of circulating stem cells is potentially capable of creating a chance of normal hematopoietic reconstitution in the patients in which both allogeneic and autologous bone marrow transplantation was impossible. The authors have reviewed the possibilities for collection of adequate and sufficient numbers of peripheral blood stem cells as well as up-to-date results of their autografting especially in relation to hematopoietic malignant diseases. The advantages resulting from autologous transplantation of circulating stem cells depends on: 1. The lack of risk of GvH--disease. 2. early and rapid hematopoietic and lymphoid recovery, 3. probably, the low risk of graft contamination by tumor cells in early remission.     

Effect of Polymer Additives on the Microstructure and Mechanical Properties of Self-Leveling Rubberised Concrete

The materials based on concrete with an addition of rubber are well-known. The interaction between concrete components and rubber particles is in the majority cases insufficient. For this reason, different substances are introduced into concrete-rubber systems. The aim of this paper is to establish the influence of five different polymer additives, i.e., 1. an aqueous dispersion of a styrene-acrylic ester copolymer (silanised) (ASS), 2. water dispersion of styrene-acrylic copolymer (AS), 3. anionic copolymer of acrylic acid ester and styrene in the form of powder (AS.RDP), 4. water polymer dispersion produced from the vinyl acetate and ethylene monomers (EVA), 5. copolymer powder of vinyl acetate and ethylene (EVA.RDP)) on the properties of the self-leveling rubberised concrete. Scanning electron microscopy has allowed to establish the interaction between the cement paste and rubber aggregates. Moreover, the compressive strength and flexural strength of the studied materials were evaluated. The results indicate that the mechanical properties depend extensively on the type as well as the amount of the polymer additive introduced into the system.