[Microangiopathic hemolytic anemia in patients with diseases of the hematopoietic and lymphatic systems]

Microangiopathic haemolytic anaemia was diagnosed in the course of haematopoietic and lymphatic disorders such as chronic granulocytic leukemia, chronic myelofibrosis, chronic lymphatic leukemia, Osler's disease, chronic monocytic leukemia, and lymphoplasmocytic lymphoma, in 11 patients (6 women and 5 men) aged between 33 and 81 years (mean age 58.8 years) treated at the Haematological Out-Patient Clinic of the Postgraduate Medical Education Centre within 1977-1987. The following laboratory tests were carried out: 1) morphology of the peripheral blood and bone marrow, especially some haematological parameters concerning erythrocytes and blood platelets; 2) biochemical tests reflecting erythrocytes disintegration; 3) haemostasis. All examined patients suffered from haemolytic anaemia of various degree with characteristic changes in erythrocyte shape (helmets, tear-drops etc.). Haemolytic origin of anaemia was confirmed by the increased LDH activity. In the majority of patients no compensative stimulation of haematopoiesis (reticulocytosis, red blood cells hyperproliferation in bone marrow) was seen. Clinical symptoms of haemostatic disorders such as haemorrhagic diathesis and vein thrombosis were diagnosed in 50% of the patients. Blood platelet counts ranged from markedly decreased to significantly increased. Bone marrow smears did not show increased number of megacariocytes. Bleeding time was prolonged in the majority of examined patients while prothrombin index--decreased). Abnormal fibrinogen levels (decreased or increased) were found in the majority of patients with fibrin degradation products. Microangiopathic haemolytic anaemia in these patients differ from the typical Moschowitz's disease clinically probably due to the lack of compensative stimulation of erythropoiesis and lower thrombocytopenia.

Synthesis and antitumor properties of pyrazolo [3,4-D] pyrimidine derivatives

Several new 5-substituted 1-phenylpyrazole [3,4-d] pyrimidine derivatives were synthesized and tested for antitumor activity. Compound 17, which has 3,4-dichlorophenyl moiety at N5 of the pyrazole pyrimidine ring, shows a strong activity against L-1210 leukemia (152%). On the other hand, compounds 15, 17 and 21 were the most active against sarcoma Sa-180. It was observed that many derivatives of pyrazole [3,4-d] pyrimidine possess different biological, especially antitumor properties [1-6, 9, 10].

Purification and properties of hamamelosekinase

Hamamelosekinase (ATP:hamamelose 2(1)-phosphotransferase) was purified from a crude extract of Kluyvera citrophila 627 (Enterobacteriaeceae) which has been grown on D-hamamelose. Ammonium-sulfate fractionation and twofold chromatography on DEAE-cellulose resulted in a 51-fold purification of the enzyme. Neither glucosekinase nor significant ATPase activity could be detected in the pure preparation. Besides D-hamamelose only D-hamamelitol was utilized as a substrate; however, the latter was phosphorylated at a very low rate. The molecular weight of the enzyme as estimated by gel chromatography is 21 000. The Km values for hamamelose and ATP were 3 mM nd 2.5 mM, respectively. The pH optimum was found at 7.5. In contrast to hexokinase, purified hamamelosekinase is very labile and could only be stabilized by addition of its substrate D-hamamelose. The most unusual property with respect to yeast hexokinase is a pronounced substrate inhibiton by hamamelose (> 5mM) and ATP (> 7mM), respectively, which could be interpreted as due to an economic utilization of the nutrient. Hamamelosekinase as well as glucosekinase are inducible by growing the microorganisms on the corresponding monosaccharides.

Properties of penicillin amidase immobilized by copolymerization with acrylamide

An enzyme preparation in a spherical granule form was obtained by copolymerization of penicillin amidase (EC 3.5.1.11) (previously modified with maleic anhydride) and acrylamide via a crosslinking agent. As compared with the native enzyme, immobilized amidase is more resistant to heating, has a lower affinity to benzylpenicillin, and is less inhibited by phenylacetate. Its substrate specificity and optimum pH remain unchanged.