Left Brachiocephalic Venous Aneurysm: A Rare Clinical Finding.

Brachiocephalic venous aneurysm is an extremely rare condition, with <20 cases reported in the literature. We present a case of a 72-year-old man who was referred to our department owing to a large aneurysm of the left brachiocephalic vein that was incidentally discovered on computed tomography. Further workup confirmed an isolated saccular aneurysm of the left brachiocephalic vein. The patient underwent aneurysmectomy via sternotomy with no requirement for a vascular graft or cardiopulmonary bypass. The postoperative course and follow-up were uneventful.

Genome Sequence of a Hyperthermophilic Archaeon, Thermococcus nautili 30-1, That Produces Viral Vesicles.

Thermococcus nautili 30-1 (formerly Thermococcus nautilus), an anaerobic hyperthermophilic marine archaeon, was isolated in 1999 from a deep-sea hydrothermal vent during the Amistad campaign. Here, we present the complete sequence of T. nautili, which is able to produce membrane vesicles containing plasmid DNA. This property makes T. nautili a model organism to study horizontal gene transfer.

Finding a needle in the common carotid artery 3 years after ingestion.

A woman presented with an ischemic stroke involving the right middle cerebral artery. Investigations revealed a foreign body in the cervical area. It was identified as a metal needle, perforating the posterior pharyngeal wall and migrating into the right common carotid artery (CCA). Three years previously, this patient had complained of odynophagia, brought on by needle ingestion. Three days before her stroke, she had hematemesis, caused by migration of the needle into the CCA. The stroke was caused by migration of the thrombus. This type of event is rarely encountered in Europe. Early recognition could avoid dangerous vascular complications.

Extracellular membrane vesicles harbouring viral genomes.

Cells from the three domains of life produce extracellular membrane vesicles (MVs), suggesting that MV production is a fundamental aspect of cellular physiology. We have recently shown that MVs produced by the hyperthermophilic archaeon Thermococcus kodakaraensis can be used as vehicles to transfer exogenous recombinant plasmid DNA from cell to cell. Here, we show that Thermococcus nautilus, which harbours three plasmids, pTN1, pTN2 and pTN3, produces MVs, and that some of them selectively incorporate pTN1 and pTN3. Interestingly, pTN3 represents the genome of a defective virus, which encodes signature proteins common to a large group of viruses infecting hosts from all three cellular domains. However, preparations of MVs produced by T. nautilus have a protein composition similar to that of classical MVs from Thermococcales and do not contain the viral major capsid protein encoded by pTN3. Our results suggest that MVs can serve as vehicles for the intercellular transport of viral genomes and facilitate recombination between viral, plasmid and/or cellular chromosomes in the absence of viral infection.

Is it mandatory to carry out completion arteriography after carotid endarterectomy with patch angioplasty?

BACKGROUND: This study compares the neurologic evolution and number of restenoses between 2 groups of patients who underwent internal carotid endarterectomy with patch angioplasty (CEP): one group with systematic intraoperative completion arteriography (CA) and another group without. METHODS: This monocentric retrospective study was performed from January 2000 to December 2008 on 559 consecutive CEPs; 179 were controlled with CA and 380 were not. Surgery was chosen for patients with greater than 50% symptomatic or greater than 60% asymptomatic stenosis (North American Symptomatic Carotid Endarterectomy Trial criteria). Each patient's neurologic and ultrasound status was followed-up postoperatively, and at 3 months in the presence of neurologic symptoms, and at the end of the follow-up. Residual stenosis and restenosis were defined by a reduction in diameter of greater than 50% or a maximal systolic velocity greater than 150 cm/s. The surgical team included 4 vascular surgeons: 2 experienced surgeons who did not perform CA, 1 experienced surgeon monitoring surgical trainees, and 1 who had little experience performing CA. RESULTS: In both groups, the patients were comparable in terms of cardiovascular risks, except for age, gender, statin treatment, and neoplastic medical history. During the first 30 postoperative days, the mean rate of cerebrovascular accident (CVA) and death was 0.4%. In the CA group, 1 incidence (0.6%) of partial monocular blindness occurred, and in the no-CA group, 1 incidence (0.2%) of hemorrhagic CVA and 3 (0.5%) transient ischemic attacks (TIAs) occurred. One of these TIAs resulted from a residual stenosis. Mean follow-up was 41 months. During this time, 6 ipsilateral neurologic accidents occurred in the CA group (1 ischemic CVA, 3 TIAs, 1 partial monocular blindness, and 1 hemorrhagic CVA), whereas 10 occurred in the no CA group (1 ischemic CVA, 4 TIAs, 3 hemorrhagic CVAs, 1 partial monocular blindness, and 1 recurrence of vertebrobasilar insufficiency). The combined morbidity and mortality rates in the 2 groups were 3.3% and 2.8%, respectively (P > 0.05). Two residual stenoses (0.5%) and 6 significant restenoses (1.6%) were diagnosed in the no-CA group; 4 significant restenoses (2.2%) occurred in the CA group (P > 0.05). CONCLUSIONS: When performed by experienced surgeons, systematic intraoperative CA does not reduce the incidence of ipsilateral neurologic complications after CEP. Systematic intraoperative arteriography enables surgical trainees to obtain results as satisfactory as those of experienced surgeons.

Hyperthermophilic archaea produce membrane vesicles that can transfer DNA.

Thermococcales are hyperthermophilic archaea found in deep-sea hydrothermal vents. They have been recently reported to produce membrane vesicles (MVs) into their culture medium. Here, we have characterized the mode of production and determined the biochemical composition of MVs from two species of Thermococcales, Thermococcus gammatolerans and Thermococcus kodakaraensis. We observed that MVs are produced by a budding process from the cell membrane reminiscent of ectosome (microparticle) formation in eukaryotes. MVs and cell membranes from the same species have a similar protein and lipid composition, confirming that MVs are produced from cell membranes. The major protein present in cell membranes and MVs of both species is the oligopeptide binding protein OppA. This protein is also abundant in MVs from cells grown in minimal medium, suggesting that OppA could be involved in processes other than peptides scavenging. We have previously shown that MVs from Thermococcales harbour DNA and protect DNA against thermodegradation. Here, we show that T. kodakaraensis cells transformed with the shuttle plasmid pLC70 release MVs harbouring this plasmid. Notably, these MVs can be used to transfer pLC70 into plasmid-free cells, suggesting that MVs could be involved in DNA transfer between cells at high temperature.

Membrane vesicles, nanopods and/or nanotubes produced by hyperthermophilic archaea of the genus Thermococcus.

Thermococcus species produce MVs (membrane vesicles) into their culture medium. These MVs are formed by a budding process from the cell envelope, similar to ectosome formation in eukaryotic cells. The major protein present in MVs of Thermococci is a peptide-binding receptor of the OppA (oligopeptide-binding protein A) family. In addition, some of them contain a homologue of stomatin, a universal membrane protein involved in vesiculation. MVs produced by Thermococcus species can recruit endogenous or exogenous plasmids and plasmid transfer through MVs has been demonstrated in Thermococcus kodakaraensis. MVs are frequently secreted in clusters surrounded by S-layer, producing either big protuberances (nanosphere) or tubular structures (nanotubes). Thermococcus gammatolerans and T. kodakaraensis produce nanotubes containing strings of MVs, resembling the recently described nanopods in bacteria, whereas Thermococcus sp. 5-4 produces filaments whose internal membrane is continuous. These nanotubes can bridge neighbouring cells, forming cellular networks somehow resembling nanotubes recently observed in Firmicutes. As suggested for bacteria, archaeal nanopods and/or nanotubes could be used to expand the metabolic sphere around cells and/or to promote intercellular communication.

Plasmids, viruses and virus-like membrane vesicles from Thermococcales.

Several families of plasmids and viruses (PVs) have now been described in hyperthermophilic archaea of the order Thermococcales. One family of plasmids replicates by the rolling circle mechanism, whereas most other PVs probably replicate by the θ mode. PVs from Thermococcales encode novel families of DNA replication proteins that have only detectable homologues in other archaeal PVs. PVs from different families share a common gene pool and co-evolve with their hosts. Most Thermococcales also produce virus-like membrane vesicles similar to eukaryotic microparticles (ectosomes). Some membrane vesicles of Thermococcus nautilus harbour the plasmid pTN1, suggesting that vesicles can be involved in plasmid transfer between species.

Exploring plant endomembrane dynamics using the photoconvertible protein Kaede.

Photoactivatable and photoconvertible fluorescent proteins capable of pronounced light-induced spectral changes are a powerful addition to the fluorescent protein toolbox of the cell biologist. They permit specific tracking of one subcellular structure (organelle or cell subdomain) within a differentially labelled population. They also enable pulse-chase analysis of protein traffic. The Kaede gene codes for a tetrameric protein found in the stony coral Trachyphyllia geoffroyi, which emits green fluorescence that irreversibly shifts to red following radiation with UV or violet light. We report here the use of Kaede to explore the plant secretory pathway. Kaede versions of the Golgi marker sialyl-transferase (ST-Kaede) and of the vacuolar pathway marker cardosin A (cardA-Kaede) were engineered. Several optical devices enabling photoconversion and observation of Kaede using these two constructs were assessed to optimize Kaede-based imaging protocols. Photoconverted ST-Kaede red-labelled organelles can be followed within neighbouring populations of non-converted green Golgi stacks, by their gradual development of orange/yellow coloration from de novo synthesis of Golgi proteins (green). Results highlight some aspects on the dynamics of the plant Golgi. For plant bio-imaging, the photoconvertible Kaede offers a powerful tool to track the dynamic behaviour of designated subpopulations of Golgi within living cells, while visualizing the de novo formation of proteins and structures, such as a Golgi stack.