Elevated fibrinogen in the healthy male relatives of patients with severe, premature coronary artery disease

Comparative study between zinc oxide nanoparticles synthesis by biogenic and wet chemical methods in vivo and in vitro against Staphylococcus aureus

ZnO nanoparticles (ZnO-NPs) can be used as nano medicine for Staphylococcus aureus infection, which causes deleterious effects on liver, kidney and lung tissue, as it causes catarrhal bronchitis, peri-bronchial oedema, lymphocytic granulomas, oedematous fluid and haemorrhage inside the bronchi, and interstitial pneumonia. In this research ZnO nanoparticle (ZnO-NPs) synthesis by biogenic method using green alga Ulva fasciata and by wet chemical method. Both of them tested in vitro and in vivo against Staphylococcus aureus. The characterization of ZnO-NPs was detected by U.V spectroscopy, Fourier-transform infrared (FTIR), Energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM). In vivo assessment eight groups, each group contain of five rats and the treatment as follow (1) an uninfected control group; (2) an infected group; groups (3), (4), and (5) were injected with biogenic or chemical ZnO-NPs or zinc acetate, as the bulk group, respectively; and groups (6), (7) and (8) were infected and then treated in the same manner as groups (3), (4), and (5), respectively. The blood profile, biochemical parameters, phagocytic activity and histological assessment of liver, kidney and lung tissue of each rat was investigated after 20 days. The rats treated with 5 mg/1 kg natural ZnO-NPs showed improved lung characteristics, and the number of platelets in the infected groups treated with ZnO-NPs from chemical and natural sources (G6 and G7) was close to those in the control group. However, the trend was reversed for regarding lymphocytes, which remained at higher levels in uninfected animals treated with synthetic ZnO-NPs (G4) than in infected rats treated with synthetic ZnO-NPs (G7). Moreover, a significant difference in phagocytic activity was found among all groups compared to that of controls. Compared to control group rats (G1), uninfected rats injected with only natural ZnO-NPs (G3) showed a significant (P < 0.05) improvement in the phagocytic index. We propose that ZnO-NPs produced from natural sources are preferable to those produced from chemical sources for use as nano medicine for the treatment of S. aureus infection in albino rats.

Platelet reactivity and endothelial function in children of patients with early acute myocardial infarction

AIMS

To assess whether platelet reactivity is increased in offspring of patients with early acute myocardial infarction (AMI) and its possible relation with endothelial dysfunction.

METHODS AND RESULTS

We studied 23 healthy children (15±3 years, 13 males) of patients with early AMI (≤50 years old; Group 1) and 21 healthy children of healthy subjects without any history of cardiovascular disease (14±3 years, 10 males; Group 2). Platelet reactivity was assessed by flow cytometry as the increase in monocyte-platelet aggregates (MPA) and CD41 and PAC-1 platelet expression in response to exercise stress test (EST), adenosine diphosphate (ADP) stimulation (10(-7) M), or both. Endothelial function was assessed by measuring brachial artery dilation during post-ischaemic forearm hyperaemia [flow-mediated dilation (FMD)]. Both EST and ADP induced a higher percentage increase in platelet receptor expression in Group 1, compared with Group 2, with the most significant difference being shown for the response to the combined stimuli (e.g. MPA, 23.1±12 vs. 5.63±8%, P<0.001; platelet PAC-1, 57.7±47 vs. 13.2±7%, P<0.001). Compared with Group 2, Group 1 children showed lower FMD (10.7±3.1 vs. 8.0±2.9%, respectively; P=0.007). However, no significant association was found between FMD and platelet reactivity.

CONCLUSION

Our results show increased platelet reactivity in children of patients with early AMI; the finding was not significantly correlated with endothelial dysfunction, suggesting that other mechanisms are mainly involved in the enhanced platelet response to agonistic stimuli.

[Von Willebrand factor, endothelial lesion, and ischemic heart disease]

OBJECTIVE

To analyze if the levels of von Willebrand factor (FvW) are higher in patients with ischemic heart disease than in healthy subjects and evaluate the relationship of these levels with clinical recurrence and coronary interventionism.

DESIGN

Observational prospective study.

PATIENTS

We analyzed the levels of FvW in 75 patients with ischemic heart disease who underwent coronary interventionism (Group I) and compared them with those of 30 healthy subjects with no cardiovascular risk factors and who, theoretically, had no coronary injuries (Group II).

MAIN VARIABLES

Levels of FvW before coronary interventionism (sample 0), 24 hours after (sample 1), and at three months of out-patient follow-up (sample 2). A single measurement was made of the FvW levels in Group II.

RESULTS

Subjects with ischemic heart disease had higher levels of FvW than healthy subjects (162+/-74% versus 95+/-33%; p=0.0001). FvW levels were significantly increased after coronary interventionism (162.4+/-74.9% in sample 0 versus 213+/-90% in sample 1; p=0.0001). Patients with clinical symptoms at three months have no significant difference regarding those with no symptoms in the FvW levels (125+/-63% versus 133+/-60%; p=0.57).

CONCLUSIONS

FvW levels reflect an endothelial alteration in patients with ischemic heart disease. The increase of the levels after coronary interventionism could be due to the endothelial aggression itself of the intervention. It was not possible to demonstrate higher levels of FvW in patients with symptoms in the three month follow-up.

Cardiovascular Actions of the Peroxisome Proliferator-Activated Receptor-Alpha (PPAR?) Agonist Wy14,643

This review examines the various effects of Wy14,643, a hypolipidemic agent that activates peroxisome proliferator-activated receptor-alpha (PPARalpha), on the cardiovascular system. An emphasis has been placed on the specific cellular processes affected by Wy14,643 as they relate to vascular and cardiac function. Although the topic of this discussion is limited to vascular and cardiac tissues, the importance of circulating lipids on cardiovascular disease requires that a description of the indirect actions of this compound on liver metabolism also be included. Finally, the pharmacology of Wy14,643 is discussed within the context of PPARalpha-dependent and -independent mechanisms.

Thrombin generation and fibrin clot structure

Generation of a hemostatic clot requires thrombin-mediated conversion of fibrinogen to fibrin. Previous in vitro studies have demonstrated that the thrombin concentration present at the time of gelation profoundly influences fibrin clot structure. Clots formed in the presence of low thrombin concentrations are composed of thick fibrin fibers and are highly susceptible to fibrinolysis; while, clots formed in the presence of high thrombin concentrations are composed of thin fibers and are relatively resistant to fibrinolysis. While most studies of clot formation have been performed by adding a fixed amount of purified thrombin to fibrinogen, clot formation in vivo occurs in a context of continuous, dynamic changes in thrombin concentration. These changes depend on the local concentrations of pro- and anti-coagulants and cellular activities. Recent studies suggest that patterns of abnormal thrombin generation produce clots with altered fibrin structure and that these changes are associated with an increased risk of bleeding or thrombosis. Furthermore, it is likely that clot structure also contributes to cellular events during wound healing. These findings suggest that studies explicitly evaluating fibrin formation during in situ thrombin generation are warranted to explain and fully appreciate mechanisms of normal and abnormal fibrin clot formation in vivo.

Atherothrombotic risk factor clustering in healthy male relatives of male patients with intermittent claudication

OBJECTIVE

Family history is an independent risk factor for premature acute myocardial infarction; in contrast, familial risk for peripheral arterial disease (PAD) has yet to be determined. Elevated levels of hemostatic proteins are consistently predictive for cardiovascular risk in "healthy" subjects, and may cluster with underlying insulin resistance. Atherothrombotic risk factor clustering occurs in first-degree relatives of subjects with coronary artery disease and type 2 diabetes. These may contribute to the enhanced cardiovascular risk in these subjects, and we hypothesised that familial clustering may occur in PAD. The objective of this study was to measure atherothrombotic risk factors in healthy male first-degree relatives of men with intermittent claudication, with emphasis on thrombotic risk.

METHODS

One hundred sixty-five healthy male first-degree relatives were compared with control subjects matched for age, sex, and race (n = 165), free from a personal or family history of premature cardiovascular disease. Primary outcome measures were fibrinogen, von Willebrand factor, factor VII clotting activity (FVII:C), and factor XIII levels. Atherosclerotic risk factors were measured, and subjects were genotyped for common functional polymorphisms (factor VII r353q and fibrinogen B beta-455).

RESULTS

Relatives had higher mean levels of fibrinogen (3.04 vs 2.89 g/L; P = .021), FVII:C (117% vs 104%; P = .000), factor XIII B subunit (1.11 vs 1.01 IU/mL; P = .000), and complex (A 2 B 2 ; 1.18 vs 1.11 IU/mL; P = .021). At multivariate analysis the association between relative status and fibrinogen, FVII:C, and factor XIII B subunit levels were independent of other variables.

CONCLUSIONS

The healthy male relatives of men with PAD have elevated levels of fibrinogen, factor VII, and factor XIII. Our results support the existence of thrombotic risk factor clustering in this population at "high risk."

Genetics of thrombophilia: impact on atherogenesis

PURPOSE OF REVIEW

The goal of this review is to present an update on basic and epidemiological findings associating variants in prothrombotic genes with atherogenesis and atherothrombotic disease.

RECENT FINDINGS

The relation between atherosclerosis and thrombosis has long been recognized but only recently has it been understood that certain hemostatic factors affect not only thrombus formation, but also have a direct atherogenic role. Atherosclerosis is a complex disorder that results from the interaction of multiple genetic and environmental factors. Numerous polymorphisms and mutations in genes related to the hemostatic system and to vascular redox determinants that modulate nitric oxide bioavailability have been identified in the past decade; their role in atherogenesis and the risk of cardiovascular disease, however, remain uncertain. We will discuss the functional implications and association with disease risk of polymorphisms in coagulation factors (fibrinogen, prothrombin, and factor V); fibrinolytic factors (plasminogen activator inhibitor 1 and lipoprotein(a)); platelet surface receptors; and vascular redox determinants (methylenetetrahydrofolate reductase, endothelial nitric oxide synthase, and the antioxidant enzymes cellular glutathione peroxidase and paraoxonase).

SUMMARY

Overall, these genetic variants have a modest effect on risk when considered individually but gain potency when acting synergistically with other genetic or environmental risk factors. We conclude that a better characterization of these interactions, in addition to the identification of potential novel genetic determinants, constitute key issues in the future understanding of the pathogenesis of atherothrombosis.

Family history, longevity, and risk of coronary heart disease: the PRIME Study

BACKGROUND

To assess the contribution of family history of coronary heart disease (CHD) and longevity in parents to 5-year incidence of coronary events in middle-aged men.

METHODS

A prospective study in men from Northern Ireland and the French cities and environs of Lille, Strasbourg, and Toulouse. A total of 10 600 men aged 50-59 years were examined between 1991 and 1994 and followed annually by questionnaire for incident cases of coronary disease. A detailed family history was taken and a quantitative family risk score for CHD was calculated for each subject. Five-year follow-up is complete; all coronary events (coronary deaths, myocardial infarction, and angina) documented by clinical records were reviewed by an independent medical committee.

RESULTS

At screening, 9758 subjects were free of clinical and historical evidence of CHD; in this group there were 317 coronary events by 5 years of follow-up. Subjects whose parents had both survived until >/=80 years showed a relative odds of 0.49 (95% CI: 0.31-0.77) for risk of a coronary event compared with subjects whose parents had not survived until >/=80 years old with adjustment for age and nine other risk factors including family history. The pattern of results was similar in France and Northern Ireland, although parental survival was longer in France. Likewise, subjects with a strong family history showed a relative odds of 1.93 (95% CI: 1.25-3.00) compared with subjects without such a history, after adjustment for age and the nine risk factors including parental longevity. The pattern of results was similar in France and Northern Ireland.

CONCLUSIONS

These results indicate that a family history of coronary disease and parental longevity, although related, act independently of one another and of other major cardiovascular risk factors in predicting 5-year risk of subsequent coronary events.