Formation of intracellular vesicles within the Gram+ Lactococcus lactis induced by the overexpression of Caveolin-1ß.

BACKGROUND: Caveolae are invaginated plasma membrane domains of 50-100 nm in diameter involved in many important physiological functions in eukaryotic cells. They are composed of different proteins, including the membrane-embedded caveolins and the peripheric cavins. Caveolin-1 has already been expressed in various expression systems (E. coli, insect cells, Toxoplasma gondii, cell-free system), generating intracellular caveolin-enriched vesicles in E. coli, insect cells and T. gondii. These systems helped to understand the protein insertion within the membrane and its oligomerization. There is still need for fundamental insights into the formation of specific domains on membrane, the deformation of a biological membrane driven by caveolin-1, the organization of a caveolar coat, and the requirement of specific lipids and proteins during the process. The aim of this study was to test whether the heterologously expressed caveolin-1ß was able to induce the formation of intracellular vesicles within a Gram+ bacterium, Lactococcus lactis, since it displays a specific lipid composition different from E. coli and appears to emerge as a good alternative to E. coli for efficient overexpression of various membrane proteins. RESULTS: Recombinant bacteria transformed with the plasmid pNZ-HTC coding for the canine isoform of caveolin-1ß were shown to produce caveolin-1ß, in its functional oligomeric form, at a high expression level unexpected for an eukaryotic membrane protein. Electron microscopy revealed several intracellular vesicles from 30 to 60 nm, a size comparable to E. coli h-caveolae, beneath the plasma membrane of the overexpressing bacteria, showing that caveolin-1ß is sufficient to induce membrane vesiculation. Immunolabelling studies showed antibodies on such neo-formed intracellular vesicles, but none on plasma membrane. Density gradient fractionation allowed the correlation between detection of oligomers on Western blot and appearance of vesicles measurable by DLS, showing the requirement of caveolin-1ß oligomerization for vesicle formation. CONCLUSIONS: Lactococcus lactis cells can heterologously overexpress caveolin-1ß, generating caveolin-1ß enriched intracellular neo-formed vesicles. These vesicles might be useful for potential co-expression of membrane proteins of pharmaceutical interest for their simplified functional characterization.

[Diagnosis and treatment of cardiac transthyretin amyloidosis. Innovative therapy with tafamidis.] / Le médicament du mois. Diagnostic et traitement d'une amyloïdose cardiaque à transthyrétine. Thérapeutique innovante avec le tafamidis.

Cardiac amyloidosis is a rare and severe disease with worse prognosis than classic cardiac insufficiency. Transthyretin amyloïdosis is an underdiagnosed cause of amyloidosis. Technetium scintigraphy allows to confirm diagnosis of transthyretin amyloidosis with great specificity. A new hope is brought by tafamidis, a novel therapeutic option for this specific condition. This medication is the first one that proved a risk reduction in mortality among patients with cardiac amyloidosis in class NYHA I and II. In this article, we review across a clinical case the modalities for the diagnosis and treatment of transthyretin amyloidosis.

L'amyloïdose cardiaque est une maladie rare et sévère. En cas d'insuffisance cardiaque, le pronostic est pire que pour les autres étiologies. L'amyloïdose à transthyrétine est une des formes d'amyloïdose dont le diagnostic peut être posé avec une grande spécificité grâce à la scintigraphie au technétium. Une lueur d'espoir est apportée par l'arrivée du tafamidis, une nouvelle classe thérapeutique. Ce médicament est le premier à avoir démontré une réduction de mortalité parmi les patients en classe NYHA I et II. Dans cet article, nous décrivons, à partir d'un cas clinique, les démarches diagnostiques et thérapeutiques nécessaires à la prise en charge d'un patient présentant une insuffisance cardiaque sur amyloïdose à transthyrétine.

Surface plasmons in suspended graphene: launching with in-plane gold nanoantenna and propagation properties.

Graphene physics and plasmonics are two fields which, once combined, promise a variety of exciting applications. One of those applications is the integration of active nano-optoelectronic devices in electronic systems, using the fact that plasmons in graphene are tunable, highly confined and weakly damped. A crucial challenge remains before achieving these active devices: finding a platform enabling a high propagation of Graphene Plasmons Polaritons (GPPs). Suspended graphene presenting ultrahigh electron mobility has given rise to increasing interest. We numerically studied the plasmonic properties of suspended graphene. We propose a hybrid configuration and a set of conditions to launch graphene plasmons via an in-plane gold nanoantenna, for micrometric propagation of surface plasmons in suspended graphene. Finally, we propose a realistic optoelectronic device based on the use of suspended graphene.

Independent evaluation of tolerance of therapeutic plasma inactivated by amotosalen-HCl-UVA (Intercept ™) over a 5-year period of extensive delivery.

Amotosalen-HCl-UVA (AI) is a process to inactivate pathogens in therapeutic plasma (FFP). Tolerance is the main residual issue in FFP transfusion, and only large series observations are powered enough to identify significantly elevated levels of hazards. We report here on 15,133 new transfusions of AI-FFP, over the previously published 36,035, which in all represents one of the largest series observed by means of a highly standardized surveillance (51.168 observations). There is no noticeable difference in terms of tolerance of AI-FFP compared to 5875 transfusions of Quarantine (Q)-FFP. There was no significant difference in terms of advance events, between the two types of FFP (P = 0.98); further, no difference was recorded either when the total number of AI-FFP (51,168) was compared to the corresponding number of Q-FFP (5875; P = 0.62).

[Clinical case of the month. Tetanus still exists!]. / Le cas clinique du mois. Le tétanos existe toujours !

We report the dramatic story of a 81 year old patient admitted to the intensive care unit following the development of tetanus. This man, perfectly autonomous, used to workin his garden without anti-tetanus immunization coverage. In this article, we report the therapeutic management of tetanus. We emphasize the importance of vaccination which permits to avoid the disease, the mortality and morbidity of which remain high.

[Clinical case of the month. Spontaneous hematoma and acquired hemophilia]. / Le cas clinique du mois. Hématomes spontanés et hémophilie acquise.

Acquired haemophilia is a rare disease, 50% of the cases are idiopathic. We report a case admitted in cardiology for spontaneous hematoma. Observation of isolated prolonged activated partial thromboplastin time (aPPT) without anticoagulation treatment and the absence of correction with normal plasma suggested diagnosis. Confirmation of inhibitors to FVIII allowed perfusions of activated prothrombin complex concentrates.

[2011 European guidelines for the management of cardiovascular diseases during pregnancy. Part II: management of hypertension]. / Recommandations Européennes 2011 pour la prise en charge des maladies cardiovasculaires pendant la grossesse. Partie 2: Prise en charge de l'hypertension artérielle.

In this article, we report the 2011 European guidelines on the management of cardiovascular diseases during pregnancy, with particular attention to the management of hypertension as hypertensive disorders are the most frequent cardiovascular complications in pregnancy.

[2011 European Society of Cardiology guidelines for the management of cardiovascular diseases during pregnancy. Part 1]. / Recommandations Européennes 2011 pour la prise en charge des maladies cardiovasculaires pendant la grossesse. Partie 1: valvulopathies et anticoagulation.

In this article, we describe the 2011 European guidelines on the management of cardiovascular diseases during pregnancy, with particular attention to the management of valvular heart disease and anticoagulation.We will also describe cardiologic conditions in which pregnancy is contraindicated and the preferred way of delivery.

[A left intraventricular mass]. / Le cas clinique du mois. A propos d'une masse intra-ventriculaire gauche.

We report the case of a 29-years-old male presenting with a large mass inserted at the hypokinetic apex of the left ventricle. Without any early regression under anticoagulant therapy and taking into account recent neurological manifestations, surgical extraction was decided. The mass corresponded to a chronic thrombus lying on a non-transmural myocardial necrosis. This case gives us the opportunity to review all causes of intracardiac masses.

Inter-island divergence within Drosophila mauritiana, a species of the D. simulans complex: Past history and/or speciation in progress?

Speciation with gene flow may be more common than generally thought, which makes detailed understanding of the extent and pattern of genetic divergence between geographically isolated populations useful. Species of the Drosophila simulans complex provide a good model for speciation and evolutionary studies, and hence understanding their population genetic structure will increase our understanding of the context in which speciation has occurred. Here, we describe genetic diversity and genetic differentiation of two distant populations of D. mauritiana (Mauritius and Rodrigues Islands) at mitochondrial and nuclear loci. We surveyed the two populations for their mitochondrial haplotypes, eight nuclear genes and 18 microsatellite loci. A new mitochondrial type is fixed in the Rodrigues population of D. mauritiana. The two populations are highly differentiated, their divergence appears relatively ancient (100,000 years) compared to the origin of the species, around 0.25MYA, and they exhibit very limited gene flow. However, they have similar levels of divergence from their sibling, D. simulans. Both nuclear genes and microsatellites revealed contrasting demographic histories between the two populations, expansion for the Mauritius population and stable population size for the Rodrigues Island population. The discovery of pronounced geographic structure within D. mauritiana combined to genetic structuring and low gene flow between the two island populations illuminates the evolutionary history of the species and clearly merits further attention in the broad context of speciation.

Magma pressure discharge induces very long period seismicity.

Volcano seismicity is one of the key parameters to understand magma dynamics of erupting volcanoes. However, the physical process at the origin of the resulting complex and broadband seismic signals remains unclear. Syn-eruptive very long period (VLP) seismic signals have been explained in terms of the sudden expansion of gas pockets rising in the liquid melt. Their origin is linked to a magma dynamics which triggers the explosive process occurring before the explosive onset. We provide evidence based on acoustic, thermal, and ground deformation data to demonstrate that VLP signals at Stromboli are generated at the top of the magma column mainly after the explosion onset. We show that VLP amplitude and duration scale with the eruptive flux which induces a decompression of 103-104 Pa involving the uppermost ~ 250 m of the feeding conduit. The seismic VLP source represents the final stage of a ~ 200 s long charge and discharge mechanism the magma column has to release excess gas accumulated at the base of a denser and degassed magma mush. The position of the VLP seismic source coincides with the centroid of the shallow mush plug and tracks elevation changes of the magma free surface.

[Adherence to antiplatelet therapy in patients with coronary artery disease]. / Adhésion thérapeutique aux antiagrégants chez le patient coronarien.

Clinical benefit of antiplatelet therapy is established for cardiovascular disease and percutaneous coronary intervention (PCI). Dual antiplatelet therapy is used to optimize platelet inhibition. However, cardiovascular events still occur. Aspirin/clopidogrel resistance and poor compliance are the main factors implied in recurrent events. Compliance to dual antiplatelet therapy is particularly relevant during the first 6 months following acute coronary syndromes and PCI. Furthermore, several studies have shown association between antiplatelet resistance and poor compliance. Additionally, late (1 month to 1 year) and very late (> 1 year) stent thromboses are intimately linked to interruption of antiplatelet treatment. In this article we review the latest data about compliance, resistance and recommendations regarding antiplatelet therapy.

[Operational qualification of the computer-based information system and electronic data interchanges in a hospital blood bank]. / Qualification opérationnelle du système informatique d'un dépôt de sang et de ses échanges de données.

Since 1985, a Council Resolution defines a new approach to technical harmonization and standards. The directives resulting from this new approach establish the essential safety requirements with which products put on the market must conform, and which should therefore enjoy free movement throughout the European Union, owing to a presumption of conformity. However, if the manufacturer is responsible for the conformity of its product in terms of safety, it is the end-user who must make sure that its requirements for a specific use or a considered application are satisfied and that the product meets its needs. It is the objective of the procedure of validation, which calls upon protocols of qualification intended to show the aptitude of a material, a system, a device, of an installation, to meet the requirements of specified quality and safety. This concept of qualification applies to the data-processing software of the hospital blood banks. Only the stage of operational qualification will be developed here. It involves scenarios made up of test files which make it possible to check the electronic data interchanges between the hospital blood bank and the blood establishment (transmission of the results of analysis, transmission of the data of traceability), as well as the functions of assistance to the issuing of the labile blood products.

[Structural or functional relationship between immunohematology and distribution - Which elements for controlling risks?] / Lien immunohématologie-délivrance structurel ou fonctionnel ­ Quels éléments pour la maîtrise des risques ?

OBJECTIVE: Transfusion safety is based on the availability of safe and compatible blood products at the right time and to the right patient, and requires close monitoring in order to detect possible incidents. The decree of June 20th 2018, which establishes the national blood transfusion's guiding plan, states that the organization that prevails throughout the national territory is built around an inseparable link between the implementation of erythrocyte immunohematology and the labile blood products delivery by authorised structures. METHOD: The article describes the two types of the link's organization, structural or functional, used to develop the comparative risk-benefit analysis. RESULTS: The structural link, which has fewer interfaces, reduces risk situations that lead to delays in release by default of a compatible product. The cases in which a functional link may have a greater benefit than the risks generated are those related to a geographical distance between the delivery site and the patient's place of care. In these cases, a functional link is possible provided that certain organizational points are mastered. CONCLUSION: The comparative analysis shows that the structural link is to be favoured since that the coherence of the patient's care and his care path is ensured. In certain situations, mainly geographical, the functional link can have a benefit that offsets the risks generated by the new interfaces; provided that the system is secured by a real tripartite collaboration between health care institution, biology laboratory and delivery site.

Polyphasic characterization of Xanthomonas axonopodis pv. allii associated with outbreaks of bacterial blight on three Allium species in the Mascarene archipelago.

Based on the number of new reports during the last two decades, bacterial blight of onion (Allium cepa) is considered an emerging disease. The causal agent, Xanthomonas axonopodis pv. allii, is pathogenic to several Allium species after inoculation, but outbreaks worldwide have been primarily reported on onion. We describe a unique epidemiological situation in Réunion Island, France, with concomitant outbreaks on three Allium species, onion, leek (A. porrum), and garlic (A. sativum). There was no host specialization within Allium spp. among strains associated with the three host species. Based on amplified fragment length polymorphism (AFLP) and restriction fragment length polymorphism, strains associated with these outbreaks in Réunion Island were highly related genetically to strains isolated from diseased plant samples and contaminated seed lots in the neighboring island of Mauritius, where the disease has occurred since 1984. All AFLP haplotypes were identified as X. axonopodis pv. allii based on polymerase chain reaction analysis using specific primers, biochemical tests, and/or pathogenicity tests. Two genetically related groups of strains (A and B) that can be distinguished by AFLP, differential utilization of three carbon sources, and xanthomonadin pigment production were detected initially after establishment of the pathogen. In less than 10 years after the establishment of the pathogen there was nearly an extinction of group A strains in Réunion Island, suggesting differences in fitness between strains in the two groups.

[Update on regulatory framework and certification process]. / Le point sur la réglementation et la procédure d'autorisation.

Patients receiving blood transfusion must benefit from the same quality of care, no matter where they are treated. In an effort to enhance transfusion safety, regulations applicable to blood depot facilities have been considerably reinforced over the last few years. At the present time, facilities authorized to store and distribute labile blood products are subject to the same principles of good practice as transfusion centers. A series of regulations published in 2007 established the duties and responsibilities of depot facilities according to category (emergency, intermediary or distribution) and set out the conditions for certification.

[Lessons learned from a distribution incident at the Alps-Mediterranean Division of the French Blood Establishment]. / Exemple d'un incident de délivrance à l'EFS Alpes-Méditerranée.

The Alps-Mediterranean division of the French blood establishment (EFS Alpes-Mediterranée) has implemented a risk management program. Within this framework, the labile blood product distribution process was assessed to identify critical steps. Subsequently, safety measures were instituted including computer-assisted decision support, detailed written instructions and control checks at each step. Failure of these measures to prevent an incident underlines the vulnerability of the process to the human factor. Indeed root cause analysis showed that the incident was due to underestimation of the danger by one individual. Elimination of this type of risk will require continuous training, testing and updating of personnel. Identification and reporting of nonconformities will allow personnel at all levels (local, regional, and national) to share lessons and implement appropriate risk mitigation strategies.

[Acute intermittent porphyria: a rare contra-indication to acute myocardial infarction treatment]. / La porphyrie intermittente aiguë: une contre-indication rare au traitement de l'infarctus du myocarde.

The treatment of acute myocardial infarction as described in guidelines, generaly meets with few contra-indications. In our clinical practice, we have met an exceptional one: acute intermittent porphyria. This disease is characterized by acute abdominal pain, neurologic disturbances and cardiac arrhythmias related to different stimuli such as some drugs. Among these drugs, several molecules are usually used for treatment of acute coronary syndromes. Knowledge of these the therapies is crucial to avoid some dangerous consequences.

[What is the purpose of dual or triple inhibition of the renin-angiotensin-aldosterone system?]. / Quelle place pour une double ou triple inhibition du système rénine-angiotensine-aldostérone ?

The blockade of the renin-angiotensin-aldosterone system (RAAS) is helpful in the management of arterial hypertension, congestive heart failure, post-myocardial infarction and diabetic nephropathy. Such blockade can be obtained with an angiotensin converting enzyme inhibitor, a specific antagonist of angiotensin II AT1 receptors, an aldosterone receptor antagonist and/or a direct inhibitor of renin such as aliskiren. Various studies have demonstrated that a dual or even triple RAAS inhibition may offer a better cardiorenal protection, in refractory congestive heart failure and in nephropathy with proteinuria. However, in the ONTARGET study, the dual inhibition with ramipril plus telmisartan did not provide any additional benefit compared to ramipril alone in high-risk cardiovascular patients, but showed a worse tolerance profile.