Chronic infection and inflammation have recently been implicated as important etiologic agents for atherosclerosis in general and, in particular, ischemic heart disease. Several agents have been suggested as possible candidates for the chronic inflammation including cytomegalovirus, Helicobacter pylori and Chlamydia pneumoniae. We hypothesized that a vascular infection with C. pneumoniae may induce a chronic inflammatory reaction in the host vascular tissue and activated inflammatory cells may express inflammatory mediators such as cyclooxygenase-2 (COX-2) and matrix metalloproteinases (MMPs). At first, we evaluated the relationship between C. pneumoniae infection and atherosclerosis indirectly by serologic study, and then, to confirm our hypothesis, we performed an immunohistochemical study of atherosclerotic plaques. The seropositive rate of anti-Chlamydia pneumoniae IgG was higher in the disease group (Group I, 59.8%, n = 254) than in the negative control group (Group III, 47.4%, n = 97) (p = 0.041), but the anti-Chlamydia pneumoniae IgA was not different in seropositivity between the two groups (Group I, 64.6%; Group III, 57.7%). The simultaneous seropositive rates of both IgG and IgA were 56.7% in Group I and 43.3% in Group III (p = 0.033). In subgroups without the conventional risk factors of atherosclerosis, these findings were more prominent. Furthermore, we performed immunohistochemical staining on the atherosclerotic aortic tissues obtained from patients that were seropositive to C. pneumoniae (n = 5), by using antibodies to C. pneumoniae, COX-2, and MMP-9. The immunoreactivity for COX-2 and MMP-9 increased in the atherosclerotic plaques itself, predominantly in the surrounding area of immunoreactive C. pneumoniae. These findings support our hypothesis and C. pneumoniae may participate in a pathogenetic mechanism for atherogenesis or progression of atherosclerosis. The present study may open a promising perspective concerning future therapeutic trials of chronic inflammation related atherogenesis under pathophysiological conditions.
Aged ; Arteriosclerosis/pathology* ; Arteriosclerosis/microbiology* ; Arteriosclerosis/metabolism ; Chlamydia Infections/complications* ; Chlamydophila pneumoniae ; Female ; Gelatinase B/metabolism ; Human ; Isoenzymes/metabolism ; Male ; Middle Age ; Prostaglandin-Endoperoxide Synthase/metabolism ; Serologic Tests*

OBJECTIVENanobacteria, a new kind of bacteria found by a Finnish scholar, is considered to relate to many human diseases like nephrolithiasis. However, there are no data available on nanobacteria infection in Chinese people.

METHODSNanobacteria was detected in serum of 336 cases of healthy adults in Southern China by enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry stain. The monoclonal antibody of nanobacterum was supplied by Kuipio University of Finland.

RESULTSNanobacteria infection rates were 27 (8.0%), 19 (5.7%) in the healthy adults by ELISA and immunohistochemistry stain respectively. No difference was shown between the 2 methods and between male and female, statistically. Age and sex did not seem to be related to the infectious risk of nanobacteria. However, the infectious rate was lower in those below 30-year-old than that of people over 60-year-old (P < 0.05).

CONCLUSIONNanobacteria was existed in the serum of Chinese healthy people with an infectious rate of 8.0%.

Adult ; Arteriosclerosis ; microbiology ; China ; epidemiology ; Enzyme-Linked Immunosorbent Assay ; Female ; Gram-Negative Bacteria ; isolation & purification ; Gram-Negative Bacterial Infections ; blood ; epidemiology ; microbiology ; Humans ; Immunohistochemistry ; Kidney Calculi ; microbiology ; Male

Chlamydia pneumoniae infection implicated as an important etiologic factor of atherosclerosis, especially in coronary artery disease (CAD), was found in vitro to be associated with the induction of matrix metalloproteinases (MMPs). An extracellular matrix metalloproteinase inducer (EMMPRIN)/membrane-type 1 matrix metalloproteinase (MT1-MMP) system which induces and activates MMPs,is suggested to be functional and were upregulated in the failing myocardium. However, the upstream regulation of MMPs by C. pneumoniae within atheroma itself remains unclear. We evaluated the seroepidemiologic study of C. pneumoniae infection in CAD patients (n = 391) and controls (n = 97) and performed histopathological and in vitro analysis in atherosclerotic vascular tissues obtained from patients with seropositive to C. pneumoniae (n = 20), by using immunochemistry for C. pneumoniae, EMMPRIN/MT1-MMP, MMP-2, and MMP-9. The seropositive rates of both anti-C. pneumoniae IgG and IgA were 56.7% in CAD group and 43.3% in control group (P =0.033). Seropositive rate was increased in subgroups of CAD patients without conventional coronary risk factors compared to those with conventional risk factors. Immunoreactivities of EMMPRIN, MT1-MMP, MMP-2, and MMP-9 were increased in the atheromatous plaque itself, predominantly in immunoreactive macrophages/mononuclear cells to C. pneumoniae. Furthermore, Western blot analysis showed that EMMPRIN and MMP-2 were detected more prominently in atherosclerotic tissues infected with C. pneumoniae compared to control tissues. Zymographic analysis revealed that activities of MMP-2 and MMP-9 were more increased in atherosclerotic tissues infected with C. pneumoniae compared to control tissues. The present study demonstrated upstream regulation of MMPs can be induced by C. pneumoniae within atheromatous plaque itself. These findings help to understand the potential role of C. pneumoniae in the progression of atherosclerosis.
Aged ; Animals ; Arteriosclerosis/complications/enzymology/*microbiology/*pathology ; Blotting, Western ; Chlamydia Infections/*complications/enzymology/epidemiology/immunology ; Chlamydophila pneumoniae/immunology/*pathogenicity ; Disease Progression ; Extracellular Matrix/enzymology ; Female ; Gelatinases/*metabolism ; Human ; Immunohistochemistry ; Male ; Matrix Metalloproteinases/*metabolism ; Membrane Glycoproteins/*metabolism ; Middle Aged ; Up-Regulation