Angiojet Thrombo-aspiration Guided by Trans-Oesophageal Ultrasound.

INTRODUCTION: A 59 year old woman presented with acute right leg ischemia. On the computed tomography scan, thrombi were seen in the brachiocephalic trunk, in the descending aorta, in the infrarenal aorta, in the right deep femoral artery, and in the right crural arteries. TECHNIQUE: To remove the risk of cerebral emboli, thrombo-aspiration of the brachiocephalic trunk was planned, with associated thrombectomy of the infrarenal aorta, the right deep femoral artery, and the right crural arteries. Because the brachiocephalic thrombus could not be visualized with angiography, the anesthetists, who were performing a trans-oesophageal ultrasound of the heart, were asked to locate the thrombus, which was easily seen on the trans-oesophageal ultrasound. The aspiration catheter Angiojet (Boston Scientific, Marlborough, MA, USA) could be positioned under ultrasound guidance. Complete aspiration of the thrombus was then confirmed with the ultrasound (see video). The thrombectomy of the infrarenal aorta and right leg was then performed by open surgery. The patient's recovery was uneventful. Despite extensive investigations no etiology was found for the thrombi. DISCUSSION: Pre-operative trans-oesophageal ultrasound is routinely performed by anesthetists in patients with acute ischemia, to search for a cardiac source of emboli. In this case it had the added advantage of helping to locate and aspirate a thrombus in the brachiocephalic trunk.

Degradation pathway of homoserine lactone bacterial signal molecules by halogen antimicrobials identified by liquid chromatography with photodiode array and mass spectrometric detection.

The degradation pathway of acylated homoserine lactone bacterial signaling molecules by oxidizing hypochlorite and stabilized hypobromite antimicrobials has been characterized. A reversed-phase HPLC separation using a cyano column was developed to detect the parent lactones, lactone-hydrolysis products, and halogenation products. Elucidation of the structures of the reaction products was done with the aid of online photodiode array UV spectroscopy and atmospheric pressure chemical ionization mass spectrometry. Quantitative output of the HPLC method was also used to estimate the kinetics of the degradation pathway. The results of this work found that only beta-keto-amide signal molecules are halogenated, where normal amide signals are not, and may represent one possible mechanism for control of industrial biofilms.

Reaction of acylated homoserine lactone bacterial signaling molecules with oxidized halogen antimicrobials.

Oxidized halogen antimicrobials, such as hypochlorous and hypobromous acids, have been used extensively for microbial control in industrial systems. Recent discoveries have shown that acylated homoserine lactone cell-to-cell signaling molecules are important for biofilm formation in Pseudomonas aeruginosa, suggesting that biofouling can be controlled by interfering with bacterial cell-to-cell communication. This study was conducted to investigate the potential for oxidized halogens to react with acylated homoserine lactone-based signaling molecules. Acylated homoserine lactones containing a 3-oxo group were found to rapidly react with oxidized halogens, while acylated homoserine lactones lacking the 3-oxo functionality did not react. The Chromobacterium violaceum CV026 bioassay was used to determine the effects of such reactions on acylated homoserine lactone activity. The results demonstrated that 3-oxo acyl homoserine lactone activity was rapidly lost upon exposure to oxidized halogens; however, acylated homoserine lactones lacking the 3-oxo group retained activity. Experiments with the marine alga Laminaria digitata demonstrated that natural haloperoxidase systems are capable of mediating the deactivation of acylated homoserine lactones. This may illustrate a natural defense mechanism to prevent biofouling on the surface of this marine alga. The Chromobacterium violaceum activity assay illustrates that reactions between 3-oxo acylated homoserine lactone molecules and oxidized halogens do occur despite the presence of biofilm components at much greater concentrations. This work suggests that oxidized halogens may control biofilm not only via a cidal mechanism, but also by possibly interfering with 3-oxo acylated homoserine lactone-based cell signaling.