Predictors of left ventricular thrombus formation in patients with dilated cardiomyopathy: role of activated protein C resistance

OBJECTIVES: The aim of this study was to investigate the association between left ventricular thrombus formation and natural anticoagulant systems including the protein C, protein S and antithrombin in patients with dilated cardiomyopathy. MATERIALS AND METHODS: Sixty patients with dilated cardiomyopathy who met the inclusion criteria were included in the study. Patients were divided into two groups: group I consisted of 22 patients with left ventricular thrombus and group II consisted of 38 patients without left ventricular thrombus. Our main inclusion criteria were ejection fraction /= 6.0 cm. These two groups were compared for clinical and hematologic parameters (activated protein C resistance, protein S and antithrombin). RESULTS: There were no statistically significant differences between patients with or without left ventricular thrombi with respect to left ventricular end-diastolic and end-systolic dimensions, ejection fraction, fractional shortening and left atrial diameter. There were no statistically significant differences between patients with and without left ventricular thrombus with respect to platelet count (252 +/- 64/mm3 x 10(3) compared with 260 +/- 74/mm3 x 10(3) respectively, P=0.68), prothrombin time (12.94 +/- 1.9 s compared with 12.86 +/- 1.3 s respectively, P=0.82), activated partial thromboplastin time (32 +/- 5 compared with 30 +/- 4 s respectively, P=0.32) and fibrinogen levels (36 +/- 9 mg/dl compared with 34 +/- 8 mg/dl respectively, P=0.41). None of the patients had protein S and antithrombin deficiency. Activated protein C resistance was found in 12 patients (12 out of 22, 54%) in group I and four patients (four out of 38, 9.5%) in group II (P < 0.01). It was also shown to be an independent predictor of left ventricular thrombus (P < 0.05). CONCLUSION: Activated protein C resistance is found to be an independent predictor of left ventricular thrombus in patients with dilated cardiomyopathy who have ejection fractions less then 35% and left ventricular end-diastolic dimensions > 6.0 cm.     

Increased levels of somatostatin in rat ankles with adjuvant arthritis

Levels of somatostatin were investigated in the ankles and spinal cords of rats suffering from acute and chronic adjuvant arthritis. As measured by radioimmunoassay, somatostatin showed significantly higher concentrations only in chronic arthritic ankles. No significant difference was observed in somatostatin levels between the spinal cords of normal and arthritic groups. Using immunohistochemical labeling and electron microscopy, we observed increased somatostatin labeling in the mature bone matrix, monocytes, and polymorphonuclear cells of bone marrow and macrophage-like synovial cells of chronically arthritic rats. Understanding the mechanism(s) which lead to increased somatostatin in chronic arthritic joints may result in more effective treatment methods.     

Phosphorylation of troponin I controls cardiac twitch dynamics: evidence from phosphorylation site mutants expressed on a troponin I-null background in mice

The cardiac myofilament protein troponin I (cTnI) is phosphorylated by protein kinase C (PKC), a family of serine/threonine kinases activated within heart muscle by a variety of agonists. cTnI is also a substrate for cAMP-dependent protein kinase (PKA) activated during beta-adrenergic signaling. To investigate the role of cTnI phosphorylation in contractile regulation by these pathways, we generated transgenic mice harboring a mutated cTnI protein lacking phosphorylation sites for PKC (serine(43/45) and threonine(144) mutated to alanine) and for PKA (serine(23/24) mutated to alanine). Transgenic mice were interbred with cTnI-knockout mice to ensure the absence of endogenous phosphorylatable cTnI. Here, we report that regulation of myocyte twitch kinetics by beta-stimulation and by endothelin-1 was altered in myocytes containing mutant cTnI. In wild-type myocytes, the beta-agonist isoproterenol decreased twitch duration and relaxation time constant (tau) by 37% to 44%. These lusitropic effects of isoproterenol were reduced by about half in nonphosphorylatable cTnI mutant myocytes and were absent in cTnI mutants also lacking phospholamban (generated by crossing cTnI mutants with phospholamban-knockout mice). These observations are consistent with important roles for both cTnI and phospholamban phosphorylation in accelerating relaxation after beta-adrenergic stimulation. In contrast, endothelin-1 increased twitch duration by 32% and increased tau by 58%. These endothelin-1 effects were substantially blunted in nonphosphorylatable cTnI myocytes, indicating that PKC phosphorylation of cTnI slows cardiac relaxation and increases twitch duration. We propose that beta-agonists and endothelin-1 regulate cardiac twitch dynamics in opposite directions in part through phosphorylation of the myofilament protein cTnI on distinct sites.     

Cardiac involvement in childhood polyarteritis nodosa

In this report, we evaluated the cardiac findings of 15 children with polyarteritis nodosa. The age range of the patients was 4–14 years; with a mean of 10 years. All have had systemic involvement of the disease. The most common findings in cardiac evaluation were diminished left ventricular systolic functions and mild mitral and/or tricuspid valve regurgitation. One patient had pericardial thickening with no effusion. One had sinus tachycardia. There were no signs of myocardial infarction or ischemia clinically or electrocardiographically. In conclusion, we did not find cardiac complications, such as pericarditis or myocardial infarction, to be as frequent as in previous reports. However, even in asymptomatic patients, systolic dysfunction or valvular involvement were common findings in patients with polyarteritis nodosa, which were not reported previously. These findings may be due to the histological changes of the myocardium or atrioventricular valves. Although these were not severe and fatal lesions, long-term follow-up of these patients with echocardiography may help to determine the course of cardiac involvement.     

B‐mode and power Doppler sonographic findings in the long bicipital tendon in ankylosing spondylitis

Objectives: The aim of this study was to assess B‐mode and power Doppler ultrasound findings of long head of biceps tendon in patients with ankylosing spondylitis (AS). Methods: Anthropometric measurements were carried out and disease activity and functional status were evaluated with BASDAI, BASFI, Dougados Functional Index (DFI) and Articular Index (DAI) in 30 patients with AS. The Shoulder Disability Questionnaire (SDQ) was performed. Pressure pain threshold (PPT) was measured on bilateral long head of biceps tendon and B‐mode and power Doppler ultrasound were carried out. Focal changes (hypoechogenic areas within the tendon), calcification of the tendon, and fluid collection inside or outside the tendon sheath at bicipital groove (peritendinous hypoechoic rim) and vascularity of the peritendinous region were assessed. A cumulative ultrasound score (CUSS) was obtained. Results: Focal changes were present in five tendons of four patients. Calcification of the tendon was present in three tendons of three patients. Biceps tendon sheath effusion (peritendinous hypoechoic rim) was observed in 10 tendons of eight patients. Thirteen tendons of eight patients had discernible flow signals, six were inside the tendon sheath (within the hypoechoic rim) and seven were outside the tendon sheath. Cumulative US score correlated significantly with DFI and ESR. There was not a significant correlation between CUSS and total PPT. Conclusion: Ultrasound examination of the long head of biceps tendon gives detailed information of the tendon and PDUS has the potential to be able to show inflammatory activity of the tendon.     

Dicarbonyl Electrophiles Mediate Inflammation-Induced Gastrointestinal Carcinogenesis

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Beta3 integrin deficiency promotes atherosclerosis and pulmonary inflammation in high-fat-fed,hyperlipidemic mice

Hyperlipidemia promotes the chronic inflammatory disease atherosclerosis through poorly understood mechanisms. Atherogenic lipoproteins activate platelets, but it is unknown whether platelets contribute to early inflammatory atherosclerotic lesions. To address the role of platelet aggregation in diet-induced vascular disease, we studied beta3 integrin-deficient mice (lacking platelet integrin alphaIIbbeta3 and the widely expressed nonplatelet integrin alphavbeta3) in two models of atherosclerosis, apolipoprotein E (apoE)-null and low-density lipoprotein receptor (LDLR)-null mice. Unexpectedly, a high-fat, Western-type (but not a low-fat) diet caused death in two-thirds of the beta3-/-apoE-/- and half of the beta3-/-LDLR-/- mice due to noninfectious pneumonitis. In animals from both models surviving high-fat feeding, pneumonitis was absent, but aortic atherosclerosis was 2- to 6-fold greater in beta3-/- compared with beta+/+ littermates. Expression of CD36, CD40L, and CD40 was increased in lungs of beta3-/-LDLR-/- mice. Each was also increased in smooth muscle cells cultured from beta3-deficient mice and suppressed by retroviral reconstitution of beta3. These data show that the platelet defect caused by alphaIIbbeta3 deficiency does not impair atherosclerotic lesion initiation. They also suggest that alphavbeta3 has a suppressive effect on inflammation, the loss of which induces atherogenic mediators that are amplified by diet-induced hyperlipidemia.