Biomedical subjects

Sigitas Urbonavicius

Publications and source records attributed to Sigitas Urbonavicius.

4 recordsLinked to original sources

PubMed2006

Expression of matrix metalloproteinases, their tissue inhibitors, and osteopontin in the wall of thoracic and abdominal aortas with dilatative pathology.

Matrix metalloproteinases (MMPs) degrade extracellular matrix and may play a central role in the pathogenesis of aortic aneurysms. We studied 2 groups of patients: 15 with dilatative pathology of the ascending thoracic aorta and 17 with aneurysm of the abdominal aortic wall (AAA). We compared the expression of MMPs, tissue inhibitors of matrix metalloproteinases (TIMPs), and osteopontin in the wall of thoracic and abdominal aneurysms. In AAA, MMP-9 and TIMP-1 expression in inflammatory cells was higher than in smooth muscle cells (SMCs) (median score: 3.5 versus 1, P < .0001; 2 versus 1, P < .04, respectively), whereas MMP-2 demonstrated higher expression in SMCs than in inflammatory cells (median score: 0 versus 4, P < .0001). In ATA, MMP-2, MMP-9, TIMP-1, TIMP-2, TIMP-3, and osteopontin expression in SMCs was higher than in inflammatory cells (median score: 3 versus 0, P < .0001; 4 versus 1, P < .0005; 2 versus 0, P < .001; 5 versus 2, P < .0001; 2 versus 0, P < .005; and 5 versus 1.5, P < .0001, respectively), when both inflammatory cells of the media and the adventitia were considered together. The cellular expression of MMP-9 and their tissue inhibitors TIMP-1, TIMP-2, and TIMP-3 differs in the dilatative pathology of abdominal and thoracic aortas, so the hypothetical model of morphogenesis of AAA cannot completely explain the formation of dilatative pathology of the ascending thoracic aorta.

Adult↗

PubMed2005

Predictors of post-operative mortality following treatment for non-ruptured abdominal aortic aneurysm.

The aim of this prospective study of patients undergoing repair of non-ruptured abdominal aortic aneurysm between 1999 and 2003 was to evaluate and compare risk factors for mortality after surgery, to determine a complex of informative factors for lethal outcome, and to define patient risk groups. Logistic regression analysis revealed a complex of informative factors, including female gender, previous myocardial infarction, age greater than 75 years, and clinical course of abdominal aortic aneurysm as important indicators for lethal outcome. A risk score model identified low-, moderate- and high-risk groups with mortality rates of 2.9%, 8.0% and 44.4%, respectively.

Journal Article↗

PubMed2004

Serum antibodies against Chlamydia pneumoniae outer membrane protein cross-react with the heavy chain of immunoglobulin in the wall of abdominal aortic aneurysms.

BACKGROUND: Chlamydia pneumoniae (Cp) has been demonstrated in arteries and abdominal aortic aneurysms (AAAs). However, the validity of the methods used is questioned, and antibiotic treatment trials have thus far shown disappointing results. Nevertheless, antibodies against the Cp outer membrane proteins (OMPs) have been associated with progression of atherosclerosis and AAAs. The aim of this study was to detect Cp OMPs in the wall of AAA patients by use of purified serum antibodies directed against Cp OMP and to assess potential cross-reacting proteins in AAA walls. METHODS AND RESULTS: Seventeen patients undergoing infrarenal AAA repair were studied. Full AAA thickness tissue was collected from the anterior wall of the aneurysm. Anti-OMP was extracted from seropositive AAA patients by use of an ELISA kit (Labsystems). Analysis was performed by use of 2D polyacrylamide gel electrophoresis, immunoblotting, and mass spectrometric protein identification. OMP antigens were not detected in 16 of 17 AAA walls. However, 3 major AAA proteins cross-reacted with anti-OMP. The proteins were all identified as heavy chains of human immunoglobulin. CONCLUSIONS: We could not find evidence of Cp OMP in 16 of 17 AAA walls, but instead, all samples showed a strong cross-reaction between Cp OMP antibodies and human immunoglobulin. This might indicate that AAA is an autoimmune disease, perhaps triggered by an initial Cp infection.

Aged↗

PubMed2002

[Ruptured abdominal aortic aneurysm].

Rupture of the abdominal aortic aneurysm is a high lethal risk pathology, which requires precise diagnosis and urgent and efficient surgical treatment. Despite improved diagnostic capabilities (echoscopy, in specialized departments--angiography, computed tomography, magnetic nucleus resonance), mortality related to this pathology remains high in intensive care units. In the present article data concerning prevalence and clinical outcomes of the rupture of the abdominal aortic aneurysm for 1999-2001 is presented in detail. During this period 22 patients have undergone surgery due to abdominal aortic aneurysm rupture. Described are most prevalent complications, mortality rates and causes, analyzed are treatment strategy and tactics.

Aged↗