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M Mosorin

Publications and source records attributed to M Mosorin.

9 recordsLinked to original sources
PubMed2002

Increased amount of type III pN-collagen in AAA when compared with AOD.

OBJECTIVE: the extent of the processing of type III procollagen to type III collagen was determined in nine human abdominal aortic aneurysms (AAA), and compared with ten samples of aortoiliac occlusive disease (AOD). METHODS: the aminoterminal propeptide (PIIINP) and telopeptide (IIINTP) of type III procollagen and collagen, respectively, were immunologically measured in the soluble and insoluble fractions of the extracellular matrix. The assay for PIIINP in the insoluble matrix was further validated. RESULTS: the insoluble matrices of AAAs contained at least 12 times more incompletely processed type III pN-collagen than AOD specimens (0.74% and 0.061%, respectively). Also, the soluble extracts of AAAs tended to contain more non-processed type III pN-collagen than free, properly cleaved aminoterminal propeptide. CONCLUSIONS: the larger amount of type III pN-collagen suggests an alteration in the metabolism of type III collagen in AAAs. This may partially explain the decreased tensile strength of the aortic tissue.

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PubMed2001

Use of doxycycline to decrease the growth rate of abdominal aortic aneurysms: a randomized, double-blind, placebo-controlled pilot study.

OBJECTIVE: Eradication of Chlamydia pneumoniae infection and inhibition of elastolytic matrix metalloproteinases with doxycycline have been suggested to reduce the growth rates of small abdominal aortic aneurysms (AAA). We designed a study to investigate the efficacy of doxycycline in reducing the expansion of small AAAs. SUBJECTS AND METHODS: This was a prospective, double-blind, randomized, placebo-controlled study that was set in a university referral hospital. The study group consisted of 32 of 34 initially eligible patients who had an AAA diameter perpendicular to the aortic axis of 30 mm or more in size or a ratio of infrarenal to suprarenal aortic diameter of 1.2 or more and a diameter less than 55 mm. Patients were randomly assigned to receive either doxycycline (150 mg daily) or placebo during a 3-month period and underwent ultrasound surveillance during an 18-month period. Outcome measures included aneurysm expansion rates, the number of patients who had AAA rupture or repair, C pneumoniae antibody titers, and serum concentrations of C-reactive protein. RESULTS: The aneurysm expansion rate in the doxycycline group was significantly lower than that in the placebo group during the 6- to 12-month (P = .01) and the 12- to 18-month periods (P =.01). Five patients (41%) in the placebo group and 1 patient (7%) in the doxycycline group had an overall expansion of the aneurysm of 5 mm or more during the 18-month follow-up. Among the placebo group patients, a higher expansion rate was observed in those with enhanced C pneumoniae immunoglobulin G antibody titers (> 128) than in those with lower titers (P = .03). Doxycycline treatment had no clear effect on antibody titers. However, at 6-month follow-up, C-reactive protein levels in the doxycycline group were significantly lower than the baseline levels (P = .01). CONCLUSIONS: The results of this small pilot study suggest that doxycycline may favorably alter the outcome of patients with small AAA. However, because of the small size of this randomized study and of the potentially confounding effect of pretreatment risk factors, doxycycline-based treatment cannot be justified only on the ground of the current results. Because of the high prevalence of this disorder and its clinical, social, and economic relevance, a multicenter study should be performed to further investigate whether there is any place for medical treatment of small AAAs.

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PubMed2000

Detection of Chlamydia pneumoniae-reactive T lymphocytes in human atherosclerotic plaques of carotid artery.

Linkage between Chlamydia pneumoniae infection and atherosclerosis has been confirmed in several studies, but the precise role of this organism in the disease process is not known. We investigated the relation and reactivity of T lymphocytes of human carotid plaques to C pneumoniae antigens. Tissue specimens were obtained from 17 patients who underwent carotid endarterectomy. Immunohistological staining and/or in situ hybridization revealed the presence of C pneumoniae in 11 (64%) of the 17 of the cases. Inflammatory infiltration seen in the vessel walls consisted primarily of CD45RO+ T-memory lymphocytes (median 80%, range 50% to 90%), whereas CD20+ B cells and monocytes were in minor proportion. In vivo activated T lymphocytes were propagated from the specimens with interleukin-2, and the antigen specificity of the established T-cell lines (TLLs) was analyzed against C pneumoniae elementary body antigen. TLLs were established from all 17 carotid tissues but none from the control specimens of ascending aorta. C pneumoniae was recognized as a specific T-cell-stimulating antigen in 7 (41%) of 17 cases. Further analyses of the C pneumoniae-reactive TLLs showed that chlamydial 60-kDa heat-shock protein induced specific proliferation in 5 (71%) of 7 cases and revealed 2 haplotype (DRB1*1502 and DQB1*06) binding motifs in human 60-kDa heat-shock protein. C pneumoniae was identified as a specific microbial antigen recognized by 41% of TLLs propagated from in vivo activated plaque T cells. Our results suggests that cell-mediated immunity to C pneumoniae plays a role in the atherosclerotic process and that this response may involve autoimmunity.

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PubMed1999

Chlamydia pneumoniae reactive T lymphocytes in the walls of abdominal aortic aneurysms.

BACKGROUND: The presence of Chlamydia pneumoniae in the walls of abdominal aortic aneurysms (AAAs) has been demonstrated recently, but its role in the cause and/or maintenance of aortic wall inflammation is not known. In the present study, we have investigated the possible relationship between C. pneumoniae and the antigen specificity of T lymphocytes mediating inflammation in AAA tissue. MATERIALS AND METHODS: Tissue specimens were obtained from 22 consecutive AAA patients undergoing elective surgery (mean age 67 +/- 1 year). Immunohistochemical analysis of the formalin-fixed tissue was performed using the streptavidin-biotin-peroxidase method. In vivo activated T lymphocytes were propagated from the specimens with interleukin (IL) 2, and antigen specificity of the established T-cell lines was analysed in the presence of autologous antigen-presenting cells using radioactive thymidine labelling. RESULTS: Immunohistological staining of AAA tissue showed the presence of C. pneumoniae antigen in 55% (6/11) of the samples studied. The inflammatory cell infiltrate of the AAA tissue contained 60-90% T (CD45RO) and 0-10% B (CD20) cells. When the tissue specimens were cultured without antigen in the presence of IL-2, lymphocyte propagation was achieved in 17 out of the 22 samples. Chlamydia pneumoniae antigen was found to induce a positive proliferative response in 8 of the 17 lines. CONCLUSIONS: The presence of C. pneumoniae specific T lymphocytes among in vivo activated cells from the AAA tissue specimens suggests that C. pneumoniae participates in the maintenance of the inflammatory response in the tissue and may thus be involved in the progression of the disease.

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PubMed1999

Complete processing of type III collagen in atherosclerotic plaques.

The extent of processing of type III collagen is assessed, and the proportions of type I and III collagens are estimated in atherosclerotic plaques obtained from the carotid artery, common femoral artery, and aorta. The fraction of type III collagen that had retained its amino-terminal propeptide (pN-collagen) was 42% in the soluble extract but only 0.0081% in the insoluble residue. Taken together, only 0.011% of the type III collagen in whole plaques was in the form of type III pN-collagen. Together with the small amounts of the free propeptides of type I procollagen, this finding indicates a low rate of collagen turnover. The amounts of solubilized telopeptides of type I and III collagens were measured, after heat denaturation and trypsin digestion of the collagenous helix, by specific immunoassays for the corresponding trypsin-generated antigens. The mean proportion of type III collagen was 61% (95% confidence interval, 58% to 65%) in the carotid and femoral artery plaques and 56% (95% confidence interval, 44% to 68%) in the aortic specimens. The completely processed and cross-linked type III collagen seems to be the major collagen type in atherosclerotic plaques.

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PubMed1998

Angiogenesis is associated with mononuclear inflammatory cells in abdominal aortic aneurysms.

BACKGROUND AND AIMS: To evaluate the extent of neovascularisation in abdominal aortic aneurysms, specimens from the aneurysm walls of 17 consecutive patients (14 men, mean age 69 years, range 59 to 79 years) were studied and compared with specimens from patients with aortoiliac occlusive disease (n = 8, five men, mean age 53 years; range 40 to 71 years). Routine histology was performed after haematoxylin and eosin, Verhoeff's elastic and periodic acid-Schiff stainings. For immunophenotypic analysis of inflammatory cells four monoclonal mouse antibodies (UCHL1, L26, PG-M1 and KP1) were used. RESULTS: The histological sections through the walls of the AAAs showed extensive destruction of elastin and variable inflammation. Dense neovascularisation was seen throughout the aortic wall in the AAA cases compared to a mild angiogenetic response seen only occasionally in the AODs. CONCLUSIONS: Angiogenesis may play a significant role in the AAA process by recruiting and carrying a macrophage-rich infiltrate to the aortic wall.

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PubMed1997

Surgical and long-term outcome of graft replacement of aneurysms of the descending thoracic aorta. Analysis of 28 consecutive cases.

A consecutive series of 28 patients operated on at the Oulu University Hospital during the years 1974-1994 for aneurysms of the descending thoracic aorta is presented. Twenty-five cases were elective and three were operated on as emergencies. Their mean age was 58 years. During the aortic cross-clamp, circulatory support of the lower body, was used in 27 cases as follows: a direct aorto-femoral shunt without a pump (12/28), left-heart bypass (11/28) or femoro-femoral perfusion (4/28). Hospital mortality was 14% (4/28). One patient with a ruptured aneurysm died of renal failure, but there were no other renal complications. None had paraplegia postoperatively. Three had symptoms of paraparesis, but only one of them had a slight permanent discomfort while walking. The mean follow-up time was 100 months, range 2-242 months. Late actuarial survival including hospital mortality, was 65% at 5 years and 41% at 10 years, reflecting the generalized aortic disease with a high risk of very late rupture (4) and other manifestations of atherosclerosis with myocardial infarction (6) or cerebral atherosclerosis (1), the remaining late deaths being unrelated. The efficacy of lower body circulatory support in avoiding peroperative renal and spinal cord ischaemic complications is demonstrated.

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