Longitudinal variations of characteristic frequencies of skeletal muscle fibre potentials detected by a bipolar electrode or multi-electrode

We aimed to reveal reasons for longitudinal variations of characteristic frequencies of electromyographic signals detected by surface longitudinal multi-electrodes. Since the terminal phases were reduced in bipolar recordings, wetested whether the frequency variations reflected the effects of the excitation origin and extinction as in monopolar recordings. A precise and fast convolution method to calculate the signals detected by a multielectrode was suggested. The contribution of different electrode poles was introduced in the impulse response. When a longitudinal multi-electrode with an even number of poles was positioned above the end-plate of asymmetrical fibres, the signal mainly reflected the processes of the excitation extinction. This increased the signal mean and median frequencies. Although the effects of origin and extinction of the excitation were significantly reduced in the spatially filtered signals, the frequency variations along the fibre reflected these intrinsic features of any skeletal muscle fibre of finite length.     

Noticeable Decreased Expression of Tenascin-X in Calcific Aortic Valves

Calcification of aortic valves results in valvular aortic stenosis and is becoming a common valvular condition in elderly populations. An understanding of the molecular mechanisms of this valve lesion is important for revealing potential biomarkers associated with the development and progression of this disease. In order to identify proteins that are differentially expressed in calcific aortic valves (CAVs) compared with those in adjacent normal valvular tissues, comprehensive analysis of differentially expressed proteins in the tissues was done by a quantitative proteomic approach with isobaric tag for absolute and relative quantitation labeling followed by nanoliquid chromatography matrix-assisted laser desorption/ionization time-of-flight tandem mass spectrometry. The proteomic analysis revealed 105 proteins differentially expressed in CAVs in contrast to adjacent normal valvular tissues with high confidence. Significantly increased expression (>_1.3-fold) was found in 34 proteins, whereas decreased expression (<0.77-fold) was found in 39 proteins in CAVs. Among them, α-2-HS-glycoprotein showed the greatest increase in expression (6.54-fold) and tenascin-X showed the greatest decrease in expression (0.37-fold). Numerous extracellular matrix proteins such as collagens were identified as proteins with significantly decreased expression. Panther pathway analysis showed that some of the identified proteins were linked to blood coagulation and integrin signaling pathways. Cluster analysis of the 105 proteins differentially expressed in CAVs based on the expression pattern revealed that tenascin-X was clustered with proteins controlling collagen structure and function, especially collagen fibrillogenesis, such as decorin and fibromodulin. We confirmed decreased levels of these proteins in CAVs by Western blot analyses. These results indicated that massive destruction of the extracellular matrix occurs in CAVs.     

Pericardial Effusion Masquerading as an Aortic Dissection

A 24‐year‐old woman with a history of recurrent syncope underwent an echocardiogram that was suspicious for an ascending aortic dissection. Cardiac magnetic resonance imaging was performed which showed no evidence of aortic dissection. However, it did demonstrate a pericardial effusion that extended to the aortic arch. This case shows how pericardial effusions can simulate the appearance of an aortic dissection because of its extension to the aortic arch. (Echocardiography 2011;28:E16‐E18)     

Mycotic Aneurysm of the Descending Thoracic Aorta Review and Case Report

A 74-year-old male presented with bilateral invalidating claudication. A bilateral percutaneous transluminal angioplasty (PTA) with stenting of both superficial femoral arteries was performed but complicated by an urosepsis with Escherichia coli and a septic phlebitis at the site of an intravenous line. The phlebitis was complicated by a local abcedation for which incision and drainage were performed. One month after discharge he was readmitted at our hospital with septic fever and positive hemocultures for Escherichia coli. Positron emission tomography-computed tomographic scan (PET/CT-scan) showed a mycotic aneurysm of the thoracic aorta. Because no cryopreserved donor aorta was available and the aneurysm size rapidly increased, an open in situ repair was performed with a Dacron silver prosthesis soaked in rifampicin. His recovery was further complicated by a perforated toxic megacolon for which a subtotal colectomy was performed. Further recovery was uncomplicated and 10 months after the aortic repair patient is still free from infection.     

Autosomal dominant polycystic kidney disease and coronary artery dissection or aneurysm: a systematic review

Importance Autosomal dominant polycystic kidney disease (ADPKD) has been associated with cardiovascular abnormalities such as intracranial and aortic aneurysms. Objective To systematically review the case reports and case series of ADPKD patients with coronary artery dissection or aneurysm. Evidence review Systematic review registration number: CRD42015015723. Data sources: MEDLINE, Web of Science and OpenGrey, reference lists of studies. Study selection: Published case reports and case series. Data extraction: Two parties analyzed the studies. Disagreements were solved by consensus or by a third party. Funding: none. Findings The reports of 23 patients (22 from 17 studies – six with coronary artery dissection and 16 with coronary artery aneurysm – and one with coronary dissection) were analyzed and reported here. Most patients were symptomatic. Coronary dissection showed female and left descending anterior artery predominance, features similar to non-ADPKD patients, but a median diagnostic age below expected (41 vs. 50 years old). Coronary aneurysms had male and right coronary artery predominance but lower median diagnostic age (44 years old) and higher rate of multiple vessel affection than reported for non-ADPKD patients. Conclusion and relevance Clinical disparities may suggest a different mechanism of aneurysm formation compared to the population without ADPKD. Nevertheless, lack of access to data of one patient and text of one article limited our conclusions. Coronary aneurysms and dissections represent a source of coronary syndromes and death in ADPKD. Mutation of ADPKD-related genes may predispose to coronary abnormalities, especially aneurysms. Further analysis regarding this association is necessary.     

Massive organ embolization from primary aortic thrombosis

A 49-year-old woman was hospitalized for acute left foot arterial ischemia. Arterial Doppler revealed occlusion of the dorsalis pedis and posterior tibial arteries. A computed tomography angiography performed to assess abdominal pain showed hepatic, splenic, renal and pancreatic infarctions. A splenic artery embolism and a small aortic wall thrombus at the celiac trunk were identified. No radiological signs of aortic atherosclerosis were found. No predisposing conditions for secondary aortic thrombosis or intracardiac embolic sources were detected. It was determined that primary aortic thrombosis, a rare though potentially serious condition, was to blame. Isolated aortic mural thrombosis therapy is not well established, although systemic anticoagulation, thrombolysis, thromboaspiration, endovascular stent grafting and surgical thrombectomy have been attempted with varying success. In our patient, systemic anticoagulation therapy was initiated and resulted in aortic thrombus resolution. Close clinical follow-up is crucial, as the aortic thrombus can recur despite anticoagulation and aggressive control of the atherosclerotic risk factors.