Correlation of bacterial coinfection versus matrix metalloproteinase 9 and tissue inhibitor of metalloproteinase 1 expression in aortic aneurysm and atherosclerosis

Real-Time Evaluation of Blood Flow Patterns Using AneurysmFlow for an in vivo Abdominal Aortic Aneurysm Model

BACKGROUND

Many new tools for abdominal aortic aneurysm (AAA) rupture risk evaluation have been developed. These new tools need detailed hemodynamic information in AAA. However, hemodynamic data obtained from in vivo research are lacking. Thus, the objective of this study was to analyze blood flow patterns in an in vivo AAA model to acquire real-time hemodynamic information using AneurysmFlow, a novel flow evaluation system.

METHODS

Digital subtraction angiography images of patients who underwent endovascular aneurysm repair were analyzed using the visualization function of the AneurysmFlow to classify blood flow patterns as laminar or turbulent flow. The presence of boundary layer separation was also evaluated. The time taken for contrast medium to travel from the infrarenal aortic neck to aortic bifurcation was acquired to calculate the flow velocity. Associations between characteristics of aneurysm including lumen occupying ratio of intraluminal thrombus (ILT) and the hemodynamic flow pattern were evaluated.

RESULTS

A total of 37 AAA patients was enrolled. Their blood flow patterns were evaluated using the AneurysmFlow. Logistic regression analyses with lumen occupying ratio of ILT as an independent variable showed that the larger the lumen occupying ratio of ILT, the more likely the aneurysm was to show a laminar pattern (P = 0.03) and the more likely the boundary layer separation would not exist (P = 0.04). The flow velocity from the infrarenal aortic neck to the aortic bifurcation showed a positive association with the lumen occupying ratio of the ILT in linear regression analysis (P < 0.001).

CONCLUSION

Hemodynamic analysis of AAA with the AneurysmFlow using real-time individual patient models showed different flow patterns and flow velocities depending on ILT. This novel analytic approach using AneurysmFlow has potential to play an important role in obtaining clinically meaningful hemodynamic information of AAA.

Thrombosis associated with mycoplasma pneumoniae infection (Review)

Mycoplasma pneumoniae is a common pathogen causing respiratory infections in children and adults. In addition to respiratory diseases, Mycoplasma pneumoniae is also involved in numerous extrapulmonary diseases. Thrombosis is an extrapulmonary manifestation associated with Mycoplasma pneumoniae infection. In recent years, an increasing number of case reports have been published identifying thrombosis secondary to Mycoplasma pneumoniae infection. In the present study, the available relevant literature in English available on PubMed, Medline and Web of Science was consulted. The results of the present study demonstrated that in patients with thrombosis caused by Mycoplasma pneumoniae infection, some of the factors causing thrombosis are transient and some are due to hereditary thrombophilia. Following timely treatment, the majority of patients recovered completely but some patients had a poor prognosis. The present review focuses on the pathogenesis, clinical features, treatment and prognosis of this crucial issue, which contributes toward the understanding of the disease.

TIMP‑3 suppresses the proliferation and migration of SMCs from the aortic neck of atherosclerotic AAA in rabbits, via decreased MMP‑2 and MMP‑9 activity, and reduced TNF‑α expression

The present study investigated the role of tissue inhibitor of matrix metalloproteinase‑3 (TIMP‑3) in regulating the proliferation, migration, apoptosis and activity of matrix metalloproteinase (MMP)‑2 and ‑9, during the development of an atherosclerotic abdominal artery aneurysm (AAA). Experiments were conducted using rabbit AAA neck (NA) smooth muscle cells (SMCs), to investigate the potential for TIMP‑3 to be used as a novel stent coating in preventing aortic dilation adjacent to the AAA. The atherosclerotic AAA model was induced in New Zealand white rabbits via a 6‑week high‑cholesterol diet, followed by incubation of the targeted aortic region with elastase. SMCs were isolated from the aorta adjacent to the aneurysm 30 days after AAA model induction, and stimulated with 3, 10, 30 or 100 ng/ml TIMP‑3. Cell proliferation was investigated using Cell Counting Kit‑8 reagent, migration was examined using a Boyden chamber assay and apoptotic rate was analyzed using the Annexin V‑fluorescein isothiocyanate Apoptosis Detection kit. Gelatin zymography and ELISA were used to measure the activity of MMP‑2 and MMP‑9, and the expression of tumor necrosis factor‑α (TNF‑α), respectively. Analysis of cell proliferation indicated that 10, 30 and 100 ng/ml TIMP‑3 reduced cell viability. Cell migration was decreased by 10, 30 and 100 ng/ml TIMP‑3. MMP‑2 activity was inhibited by 10, 30 and 100 ng/ml TIMP‑3, and MMP‑9 activity was suppressed by 30 and 100 ng/ml TIMP‑3. The protein levels of secreted TNF‑α were reduced by 10, 30 and 100 ng/ml TIMP‑3. The present study demonstrated the ability of 30 and 100 ng/ml TIMP‑3 to attenuate migration and proliferation, and to inhibit the activity of MMP‑2, MMP‑9 and TNF‑α secretion of NA SMCs. In conclusion, TIMP‑3 may be considered a potential therapeutic drug for use in a novel drug‑eluting stent, to attenuate the progressive dilation of the aortic NA.

Mycoplasma pneumoniae infection presenting as stroke and meningoencephalitis with aortic and subclavian aneurysms without pulmonary involvement

A 39-year-old Philipino man presented with acute onset fever and headache. Neurological examination was normal except for neck stiffness. There was no history of chest pain, cough or breathlessness. Cerebrospinal fluid (CSF) showed a mild increase in protein with normal sugar and lymphocytic pleocytosis. CSF PCR for herpes simplex and varicella zoster virus was negative. He developed acute right haemiplegia a week after hospitalisation. MRI showed acute infarct in the left centrum semiovale. His angiogram showed aneurysm in the left subclavian artery and aortic arch. The mycoplasma antibody test came positive with very high titres, while rest of the workup was negative. He was treated with azithromycin and his symptoms improved completely.

He was asymptomatic on follow-up after a month. His repeat immunoglobulin G mycoplasma antibody titre showed elevation. Mycoplasma infection is a treatable cause of meningoencephalitis and stroke secondary to vasculitis. Arterial aneurysms are known to occur with mycoplasma infection although rare.

Infectious agents is a risk factor for myxomatous mitral valve degeneration: A case control study

BACKGROUND

The etiology of myxomatous mitral valve degeneration (MVD) is not fully understood and may depend on time or environmental factors for which the interaction of infectious agents has not been documented. The purpose of the study is to analyze the effect of Mycoplasma pneumoniae (Mp), Chlamydophila pneumoniae (Cp) and Borrelia burgdorferi (Bb) on myxomatous mitral valve degeneration pathogenesis and establish whether increased in inflammation and collagen degradation in myxomatous mitral valve degeneration etiopathogenesis.

METHODS

An immunohistochemical test was performed to detect the inflammatory cells (CD20, CD45, CD68) and Mp, Bb and MMP9 antigens in two groups. The in situ hybridization was performed to detect Chlamydophila pneumoniae and the bacteria study was performed using transmission electron microscopy. Group 1 (n = 20), surgical specimen composed by myxomatous mitral valve degeneration, and group 2 (n = 20), autopsy specimen composed by normal mitral valve. The data were analyzed using SigmaStat version 20 (SPSS Inc., Chicago, IL, USA). The groups were compared using Student's t test, Mann-Whitney test. A correlation analysis was performed using Spearman's correlation test. P values lower than 0.05 were considered statistically significant.

RESULTS

By immunohistochemistry, there was a higher inflammatory cells/mm2 for CD20 and CD45 in group 1, and CD68 in group 2. Higher number of Mp and Cp antigens was observed in group 1 and more Bb antigens was detected in group 2. The group 1 exhibited a positive correlation between the Bb and MVD percentage, between CD45 and Mp, and between MMP9 with Mp. These correlations were not observed in the group 2. Electron microscopy revealed the presence of structures compatible with microorganisms that feature Borrelia and Mycoplasma characteristics.

CONCLUSIONS

The presence of infectious agents, inflammatory cells and collagenases in mitral valves appear to contribute to the pathogenesis of MVD. Mycoplasma pneumoniae was strongly related with myxomatous mitral valve degeneration. Despite of low percentage of Borrelia burgdorferi in MD group, this agent was correlated with myxomatous degeneration and this may occour due synergistic actions between these infectious agents likely contribute to collagen degradation.

Pleural Empyema and Aortic Aneurysm: A Retrospective National Population-Based Cohort Study

Pleural empyema (PE) may evolve into necrosis, fistula in the thorax, and sepsis; thus, it is also associated with high mortality.We investigated and analyzed the risk of aortic aneurysm (AA) in a cohort study of patients with PE.A total of 34,250 patients diagnosed with PE were identified as the PE cohort, and 137,000 patients without PE were selected randomly as the control group and matched by sex, age, and index year of PE diagnosis. Patients ages 20 years and younger with a history of AA were excluded. The risk of AA was analyzed using a Cox proportional hazards regression model.Excess risk of AA development was 1.69-fold higher in PE patients (adjusted hazard ratio [aHR] = 1.69; 95% confidence interval [CI] = 1.39-2.05) compared with non-PE patients. The patients with PE exhibited a greater adjusted risk of AA (aHR = 2.01; CI = 1.44-2.81) even if they did not have any of the 9 comorbidities included in our analysis (diabetes, hypertension, hyperlipidemia, chronic obstructive pulmonary disease, heart failure, cardiac artery disease, stroke, bacterial endocarditis, and rheumatic endocarditis). Compared with the patients without any of the 9 comorbidities or PE, the patients with only PE had a greater risk of developing AA (aHR = 2.00; CI = 1.43-2.79). The PE cohort had a significantly higher cumulative incidence of AA than the non-PE cohort did during 12 years of follow-up.In a large-scale cohort, patients with PE are linked with an increased risk of AA.