Helicobacter pylori Infection Impairs Endothelial Function Through an Exosome-Mediated Mechanism.

Background Epidemiological studies have suggested an association between Helicobacter pylori (H pylori) infection and atherosclerosis through undefined mechanisms. Endothelial dysfunction is critical to the development of atherosclerosis and related cardiovascular diseases. The present study was designed to test the hypothesis that H pylori infection impaires endothelial function through exosome-mediated mechanisms. Methods and Results Young male and female patients (18-35 years old) with and without H pylori infection were recruited to minimize the chance of potential risk factors for endothelial dysfunction for the study. Endothelium-dependent flow-mediated vasodilatation of the brachial artery was evaluated in the patients and control subjects. Mouse infection models with CagA+H pylori from a gastric ulcer patient were created to determine if H pylori infection-induced endothelial dysfunction could be reproduced in animal models. H pylori infection significantly decreased endothelium-dependent flow-mediated vasodilatation in young patients and significantly attenuated acetylcholine-induced endothelium-dependent aortic relaxation without change in nitroglycerin-induced endothelium-independent vascular relaxation in mice. H pylori eradication significantly improved endothelium-dependent vasodilation in both patients and mice with H pylori infection. Exosomes from conditioned media of human gastric epithelial cells cultured with CagA+H pylori or serum exosomes from patients and mice with H pylori infection significantly decreased endothelial functions with decreased migration, tube formation, and proliferation in vitro. Inhibition of exosome secretion with GW4869 effectively preserved endothelial function in mice with H pylori infection. Conclusions H pylori infection impaired endothelial function in patients and mice through exosome-medicated mechanisms. The findings indicated that H pylori infection might be a novel risk factor for cardiovascular diseases.

Endovascular Treatment of Infected Brachial Pseudoaneurysm in an Intravenous Drug Abuser: A Case Report.

We report the case of a 36-year-old male, admitted in the emergency room with a nonruptured brachial pseudoaneurysm after buprenorphine injection, with no signs of distal acute ischemia. After endovascular treatment with a nitinol covered stent associated with adapted antibiotherapy and 35 days of hospitalizations, the patient was discharged with good short results but stent need to be removed at 6 months for thrombosis and partial exposure through the wound.

Radial mycotic aneurysm complicated with infective endocarditis caused by Streptococcus sanguinis.

Peripheral mycotic aneurysm is a rare complication of infective endocarditis. We herein report the case of a 61-year-old man with a mycotic aneurysm in the left brachial artery, that appeared during treatment with antibiotics against infective endocarditis caused by Streptococcus sanguinis. After confirming the collateral blood flow on arteriography, we resected the aneurysm and performed valvuloplasty, annuloplasty and coronary artery bypass grafting. The patient has been in good condition without complications, such as motor dysfunction or neuropathy.

Successful treatment of a mycotic pseudoaneurysm of the brachial artery with percutaneous ultrasound-guided thrombin injection and antibiotics.

We report the case of a 48 year old male with human immuno-deficiency virus and hepatitis C virus infection and previous grafting of a thoracic aortic aneurysm. He returned from a trip to India with fever and in a poor physical condition. Diagnostic work-up revealed septicaemia with staphylococcus aureus, infection of the aortic graft with covered rupture of the proximal anastomosis and mitral valve endocarditis. Following antibiotic therapy, implantation of a transcutaneous endovascular aortic prosthesis and mitral valve repair were performed. During the postoperative period, the patient complained of pain and a palpable pulsating mass in the right cubital fossa. Ultrasound scan revealed a pseudoaneurysm at the brachial artery bifurcation. Since there were no signs of venous puncture in this area, we assumed this to be a mycotic pseudoaneurysm resulting from septic embolism. In the absence of clinical signs of inflammation, this pseudoaneurysm was successfully treated by ultrasound-guided thrombin injection. Irrespective of the cause for this mycotic pseudoaneurysm of the brachial artery, percutaneous ultrasound-guided thrombin closure in combination with antibiotic therapy might be a feasible, safe, cheap and minimally-invasive alternative to surgery.

Mycotic aneurysm of the brachial artery secondary to hospital-acquired methicillin-resistant Staphylococcus epidermidis in a complicated case of infective endocarditis.

We present a case of brachial artery mycotic aneurysm caused by methicillin-resistant Staphylococcus epidermidis in a patient with infective endocarditis. A 66-year-old woman suffered two transient ischemic attacks over an 8-week period secondary to septic emboli from mitral valve endocarditis. Following valve replacement surgery, the patient was troubled by persisting paresthesia in the right hand. A mycotic aneurysm of the brachial artery was diagnosed, and surgical repair was successfully undertaken. The purpose of this case report is to highlight an unusual causative organism for mycotic aneurysm and to underline the increasing threat of multi-drug-resistant bacteria as a cause of vascular disease.

Determination of site of infection in endocarditis.

Medical-surgical treatment of antibiotic refractory endocarditis requires determination of the site of infection, which is not always possible with conventional cardiac catheterization. The cases of two patients with right-sided endocarditis who survived after combined medical-surgical therapy are presented. One had persistent Pseudomonas aeruginosa bacteremia and three possible sites of infection. Multiple quantitative blood cultures proximal and distal to each suspected site indicated the pulmonary valve alone was infected. The second had sustained bacteremia with three enteric organisms and no apparent valvular abnormality. Quantitative cultures excluded the abdomen as the continuing source of bacteremia and suggested the tricuspid valve was infected. This was confirmed by a second catheterization using multiple cultures in conjuction with dye dilution studies, intracardiac phonocardiography, and angiography. These bacteriologic and cardiologic techniques may be especially useful in detecting right-sided endocarditis and may also be helpful in detecting concomitant infection of both sides of the heart.

Localization of endovascular infection by selective catheterization with serial cultures.

Pseudomonas infection developed at the suture line of an aortic graft in a patient 13 years after the operation. The site of the infection was localized by quantitative blood cultures taken with the aid of selective arterial catheterization. This technique may be of great help in localizing the source of endovascular infection in difficult cases.