sP- and sE-selectin in stroke patients with metabolic disorders

Background Activation of platelets and endothelial cells plays an important role in the pathogenesis of atherosclerosis and thrombotic disorders. The aim of our study was to assess the relationship between the metabolic disorders and markers of platelet activity and vascular injury in patient with acute ischemic stroke. Material and methods The study group consisted of 84 patients with acute non-lacunar ischemic stroke divided into four subgroups with: (1) normolipidemia and normoglycemia, (2) normolipidemia and hyperglycemia, (3) hyperlipidemia and normoglycemia, (4) hyperlipidemia and hyperglycemia. 21 healthy subjects served as controls. We analyzed the concentration of adhesion molecules sP-selectin and sE-selectin in serum collected from all studied groups using ELISA method. Results We observed significantly higher sE- and sP-selectin concentration in patients with hyperglycemia and hyperlipidemia compared to both control subjects and patients with normolipidemia and normoglycemia. We did not observe additional effect of comorbid hyperlipidemia and hyperglycemia on studied markers. Soluble E- and P-selectin concentration correlated positively with LDL, TC and HbA1c level in all stroke patients. Conclusion Soluble E- and P-selectin, blood markers of vascular injury and platelet activation, could be useful in the assessment of atherothrombotic properties of hyperglycemia and hyperlipidemia in stroke patients

Fibrinogen concentrations in ischaemic stroke patients with metabolic disorders

Background. Hyperfibrinogenemia plays a crucial role in the coagulation cascade leading to the formation of clots. It is involved in the process of platelet aggregation, primary haemostasis, and leukocyte-endothelial cell interactions. The aim of our study was to assess the correlations between fibrinogen concentration and particular risk factors for vascular diseases and atherosclerotic changes in stroke patients. Methods. The study group consisted with 94 patients with acute ischaemic stroke with normo- or hyperglycaemia and normoor hyperlipidemia. 21 healthy subjects served as a control group. Fibrinogen level, HbA1c, and lipid profile were measured in all patients. Using a flow cytometer, we assessed CD61 positive microparticles which were defined as platelet-derived microparticles (PDMPs). The level of sP-selectin in serum was measured using the ELISA method. Results. A significant positive correlation was observed between fibrinogen concentration and sP-selectin (p = 0.001), HbA1c (p < 0.05) level, and percentage of PDMPs (p < 0.05) in the study patients. Furthermore, we noticed a significant negative correlation between fibrinogen concentration and the level of HDL (p < 0.05). No correlation was observed between fibrinogen and TC, LDL and TG levels. Conclusions and clinical implications. Our findings suggest that an elevated fibrinogen level may represent a marker of prothrombotic condition exacerbated in the state of hyperglycaemia and activation of platelets and endothelial cells. This suggests an important role played by fibrinogen in the process of thrombogenesis

Evaluation of DNA primase DnaG as a potential target for antibiotics

Mycobacteria contain genes for several DNA-dependent RNA primases, including dnaG, which encodes an essential replication enzyme that has been proposed as a target for antituberculosis compounds. An in silico analysis revealed that mycobacteria also possess archaeo-eukaryotic superfamily primases (AEPs) of unknown function. Using a homologous recombination system, we obtained direct evidence that wild-type dnaG cannot be deleted from the chromosome of Mycobacterium smegmatis without disrupting viability, even in backgrounds in which mycobacterial AEPs are overexpressed. In contrast, single-deletion AEP mutants or mutants defective for all four identified M. smegmatis AEP genes did not exhibit growth defects under standard laboratory conditions. Deletion of native dnaG in M. smegmatis was tolerated only after the integration of an extra intact copy of the M. smegmatis or Mycobacterium tuberculosis dnaG gene, under the control of chemically inducible promoters, into the attB site of the chromosome. M. tuberculosis and M. smegmatis DnaG proteins were overproduced and purified, and their primase activities were confirmed using radioactive RNA synthesis assays. The enzymes appeared to be sensitive to known inhibitors (suramin and doxorubicin) of DnaG. Notably, M. smegmatis bacilli appeared to be sensitive to doxorubicin and resistant to suramin. The growth and survival of conditional mutant mycobacterial strains in which DnaG was significantly depleted were only slightly affected under standard laboratory conditions. Thus, although DnaG is essential for mycobacterial viability, only low levels of protein are required for growth. This suggests that very efficient inhibition of enzyme activity would be required for mycobacterial DnaG to be useful as an antibiotic target

The impact of hyperglycemia and hyperlipidemia on plasma P-selectin and platelet markers after ischemic stroke

Introduction Platelet activation plays a key role in the pathogenesis of ischemic cerebrovascular diseases. Thus, it is very important to identify novel pharmacological targets for platelet inhibition to improve ischemic stroke treatment. The aim of the study was to assess the relationship between metabolic disorders and platelet activity markers in patients with acute ischemic stroke. Material and methods : Ninety-four patients with acute ischemic stroke were divided into four groups with: normolipidemia and normoglycemia (NL/NG), n = 25; normolipidemia and hyperglycemia (NL/HG), n = 21; hyperlipidemia and normoglycemia (HL/NG), n = 27; hyperlipidemia and hyperglycemia (NL/NG), n = 21. Twenty-one healthy subjects served as controls. We assessed the CD62P expression on resting and thrombin-activated blood platelets using the flow cytometer and anti-CD61 and anti-CD62P monoclonal antibodies. CD61-positive microparticles were defined as platelet-derived microparticles. The level of sP-selectin in serum was measured by the ELISA method. Results: We observed a significant influence of hyperlipidemia and hyperglycemia on sP-selectin concentration. A strong correlation between higher sP-selectin concentration and enhanced LDL (p = 0.001), total cholesterol (p = 0.02), HbA 1c level (p < 0.001) was noticed. The level of sP-selectin and PDMPs (p < 0.001) were significantly higher in all groups of stroke patients compared with the controls. CD62P expression on resting and thrombin activated platelets were significantly lower in groups of patients with stroke. Conclusions : Hyperlipidemia and hyperglycemia exert an equal stimulatory effect on tested platelet markers but with no synergistic action in stroke patients with both of the metabolic comorbidities. sP-selectin concentration in stroke patients best reflects the impact of hyperglycemia and hyperlipidemia on vascular lesions and platelet activation

Expression of TNF-alpha, OPG, IL-1 beta and the presence of the measles virus RNA in the stapes of the patients with otosclerosis

Persistent measles virus infections play a crucial role in the pathomechanism of otosclerosis. The study was undertaken to investigate the role of tumor necrosis factor-α (TNF-α), interleukin 1β (IL-1β) and osteoprotegerin (OPG) in otosclerotic bone remodeling and to assess the relation of TNF-α, OPG and IL-1β expression levels in otosclerotic stape footplates to the occurrence of measles virus infection. 61 patients with otosclerosis were treated surgically. Thirty-one stapes obtained from cadavers of people, who had died from a sudden cause were used as a control group. The presence of measles virus RNA and the expression levels of TNF-α, IL-1β and OPG in otosclerotic foci were assessed using one-step RT-PCR. The presence of measles virus RNA was noted in 80.3 % of otosclerotic stapes (49 out of 61) and 9.7 % of normal tissues (3 out of 31). Transcript of TNF-α, IL-1β and OPG was detected in 40, 46 and 18 virus-positive stapes, respectively. The transcript level of TNF-α and IL-1β was significantly higher in otosclerotic tissues comparing to normal tissue. The OPG expression level was significantly lower in otosclerotic tissues comparing to controls. The presence of measles virus RNA in the stapes may indicate its role in the pathogenesis of otosclerosis. The presence of TNF-α and IL-1β mRNA in the virus-positive stapes could be the result of viral antigen stimulation and may be a marker of inflammation the otosclerotic focus. The lack of OPG mRNA and the presence of TNF-α and IL-1β mRNA in the majority of otosclerotic tissues reflect the bone remodeling process occurring in the stapes