JAK2 mutation status, hemostatic risk factors and thrombophilic factors in essential thrombocythemia (ET) patients

The recently discovered JAK2 V617F point mutation, found in 50–60% of ET patients, has been reported to be associated with a higher risk of thrombotic events. In this study, we explored if JAK2 V617F mutation, or coexisting thrombophilic and hemostatic risk factors, contributed to these complications. We examined 32 patients with ET, and looked for pathogenetic JAK2 V617F mutation and prothrombotic genes mutations: factor V Leiden, prothrombin and MTHFR. We also evaluated plasma levels of fibrinogen, factors VIII and XII, AT, protein C, protein S and serum level of homocysteine. Urokinase concentration was assessed in patients’ plasma as well as platelet lysates. There was no difference in the number of thrombotic complications between ET patients with and without JAK2 mutation. However, we found a number of thrombophilic and hemostatic risk factors that could contribute to thrombotic complications in ET patients. (Folia Histochemica et Cytobiologica 2011; Vol. 49, No. 2, pp. 267–271

Mild hyperhomocysteinemia in patients with essential thrombocythemia (ET) and its relation with MTHFR gene mutation and folic acid concentration

In this study we assessed homocysteine level in 106 patients with ET – 80 females and 26 males, mean age 54 (23–82) and in 20 healthy persons – 6 males and 14 females, mean age 41 (31–54). We also searched for a relation between homocysteine level and MTHFR gene mutation as well as vitamin B12 and folic acid concentration. Median homocysteine serum level was higher in ET patients than in control group. Elevated homocysteine level primarily stems from folic acid deficiency rather than from the presence of MTHFR gene mutation. Median folic acid level was lower in ET patients presenting thrombotic and bleeding complications than in ET patient without vascular episodes. We concluded that folic acid substitution may not only prevent hyperhomocysteinemia but also the development of vascular complications in ET patients

Nitric Oxide (NO) and Cyclooxygenase-2 (COX-2) Cross-Talk in Co-Cultures of Tumor Spheroids with Normal Cells

Cyclooxygenases (COX), prostaglandin E2 (PGE2) and nitric oxide (NO) are believed to be some of the most important factors related to colon cancer growth and metastasis. In this study, we aimed to investigate the associations between COX-2, PGE2 and NO in co-cultures of human colon cancer spheroids obtained from different tumor grades with normal human colonic epithelium and myofibroblast monolayers. L-arginine (2 mM), a substrate for nitric oxide synthases (NOS), decreased COX-2 and PGE2 levels, while NG-nitro-L-arginine methyl ester (L-NAME) (2 mM), a NOS inhibitor, had no influence on COX-2 and PGE2 levels but limited tumor cell motility. NS398 (75 μM), a selective COX-2 inhibitor, had no significant influence on NO level but decreased motility of tumor cells. COX-2, PGE2 and NO levels depended on the tumor grade of the cells, being the highest in Duke’s stage III colon carcinoma. Summing up, we showed that addition of L-arginine at doses which did not stimulate NO level caused a significant decrease in COX-2 and PGE2 amounts in co-cultures of colon tumor spheroids with normal epithelial cells and myofibroblasts. Any imbalances in NO level caused by exogenous factors influence COX-2 and PGE2 amounts depending on the kind of cells, their reciprocal interactions and the local microenvironmental conditions. The knowledge of these effects may be useful in limiting colon carcinoma progression and invasion

The Influence of Very Low Doses of Cisplatin on Tumor Cell Proliferation In Vitro and on Some Hematological and Enzymatic Parameters of Healthy Rats

Healthy rats had been treated for 2 or 6 weeks with 1.0 mL of 10−8 and 10−16 mg/mL of cisplatin. After 2 weeks of treatment, a significant increase in leukocyte and erythrocyte count and also in hematocrit was observed. Among leukocytes the number of neutrophils and eosinophils significantly increased. Biochemical analyses indicated a decrease in the glycogen content in the liver and kidneys after 2 weeks of treatment with low doses of cisplatin but at the end of the experiment (8th week of experiment) the stores of glycogen increased significantly. Biochemical analyses concerning the activity of some enzymes in the liver revealed a significant increase of peroxidase and acid phosphatase as well as catalase activities after 2 weeks of treatment. However, catalase was induced by a very low concentration of cisplatin, 10−16 mg/mL. After the cessation of cisplatin treatment the activity of enzymes returned to normal values

A comparison of cytokine production in 2-dimensional and 3-dimensional cultures of bone marrow stromal cells of multiple myeloma patients in response to RPMI8226 myeloma cells.

We examined cytokine production by bone marrow stromal cells (BMSCs) of patients with multiple myeloma (MM) in response to contact with myeloma RPMI8226 cells in standard 2-dimensional (2D) cultures and in 3-dimensional (3D) cultures on a gelatine sponge scaffold. It was detected that BMSCs in the 3D cultures produced more IL-11 and HGF and less IL-10 than in the 2D cultures. Moreover, RPMI8226 cells after contact with BMSCs in 3D cultures produced more sIL-6R than in the classic 2D cultures. We concluded that 3D cultures of BMSCs with myeloma cells offered a promising model for in vitro examination of interactions between myeloma cells and the bone marrow stroma and for examination of potent antimyeloma agents

Biologically and chemically important hydrazino-containing imidazolines as antioxidant agents

<p>Biologically and chemically useful hydrazinoimidazolines were evaluated as antioxidant and antihaemolytic agents. 1,1-Diphenyl-2-picrylhydrazyl radical (DPPH^•), galvinoxyl radical (GOR), nitric oxide (NO) and hydrogen peroxide (H₂O₂) scavenging assays, ferric ions reducing power assay, and <i>ex vivo</i> model of rat erythrocytes exposed to 2,2′-azobis(2-methylpropionamidine)dihydrochloride (AAPH) or H₂O₂ were used. The most potent DPPH^• scavengers proved to be hydrazinoimidazolines <b>3</b>, <b>2</b>, and <b>4</b>, revealing excellent antiradical effects – superior or comparable to that of all antioxidant standards used. Moreover, these molecules showed strong NO neutralising potencies – better to that of ascorbic acid (AA) (<b>3</b>), 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox) (<b>3</b> and <b>2)</b>, butylated hydroxytoluene (BHT) (<b>3</b> and <b>2</b>), and butylated hydroxyanisole (BHA) (<b>3</b>, <b>2</b>, and <b>4</b>). Compound <b>4</b> was also effective in GOR scavenging. The excellent scavenger of GOR, NO, and H₂O₂ proved to be structure <b>5</b>, with the potency superior or comparable to the majority of antioxidant standards used. In turn, compound <b>9</b> was effective in H₂O₂ and GOR neutralisation. All hydrazinoimidazolines revealed the reducing power that is higher than BHT. Moreover, the protective effects of most test compounds on oxidatively stressed erythrocytes were observed. Some structure–activity relationships were disclosed. A significance of the primary hydrazino group on antioxidant effects was confirmed. The most likely DPPH^• and GOR scavenging mechanisms for test compounds were propound. Among all the investigated molecules, hydrazinoimidazolines <b>5</b>, <b>3</b>, <b>2</b>, <b>4</b>, and <b>9</b>, due to their excellent or good antiradical activities, can represent promising antioxidant candidates with prospective utility for prevention of diseases related to reactive oxygen/nitrogen species.</p