Impact of medical practice guidelines on the assessment of patients with acute coronary syndrome without persistent ST segment elevation

Objective. To assess the impact of introducing clinical practice guidelines on acute coronary syndrome without persistent ST segment elevation (ACS) on patient initial assessment. Design. Prospective before-after evaluation over a 3-month period. Setting. The emergency ward of a tertiary teaching hospital. Patients. All consecutive patients with ACS evaluated in the emergency ward over the two 3-month periods. Intervention. Implementation of the practice guidelines, and the addition of a cardiology consultant to the emergency team. Main outcome measures. Diagnosis, electrocardiogram interpretation, and risk stratification after the initial evaluation. Results. The clinical characteristics of the 328 and 364 patients evaluated in the emergency ward for suspicion of ACS before and after guideline implementation were similar. Significantly more patients were classified as suffering from atypical chest pain (39.6% versus 47.0%; P = 0.006) after guideline implementation. Guidelines availability was associated with significantly more formal diagnoses (79.9% versus 92.9%; P < 0.0001) and risk stratification (53.7% versus 65.4%, P < 0.0001) at the end of initial assessment. Conclusion. Guidelines implementation, along with availability of a cardiology consultant in the emergency room had a positive impact on initial assessment of patients evaluated for suspicion of ACS. It led to increased confidence in diagnosis and stratification by risk, which are the first steps in initiating effective treatment for this common conditio

Gradient of Rigidity in the Lamellipodia of Migrating Cells Revealed by Atomic Force Microscopy

Changes in mechanical properties of the cytoplasm have been implicated in cell motility, but there is little information about these properties in specific regions of the cell at specific stages of the cell migration process. Fish epidermal keratocytes with their stable shape and steady motion represent an ideal system to elucidate temporal and spatial dynamics of the mechanical state of the cytoplasm. As the shape of the cell does not change during motion and actin network in the lamellipodia is nearly stationary with respect to the substrate, the spatial changes in the direction from the front to the rear of the cell reflect temporal changes in the actin network after its assembly at the leading edge. We have utilized atomic force microscopy to determine the rigidity of fish keratocyte lamellipodia as a function of time/distance from the leading edge. Although vertical thickness remained nearly constant throughout the lamellipodia, the rigidity exhibited a gradual but significant decrease from the front to the rear of the lamellipodia. The rigidity pro. le resembled closely the actin density pro. le, suggesting that the dynamics of rigidity are due to actin depolymerization. The decrease of rigidity may play a role in facilitating the contraction of the actin-myosin network at the lamellipodium/cell body transition zone

Structural basis and biophysical properties of synaptic plasticity studied by atomic force microscopy

In this thesis, we studied two systems important for synaptic plasticity, one presynaptic and another postsynaptic. The protein complex composed of VAMP 2, SNAP-25 and syntaxin 1 (SNARE complex) is essential for docking and fusion of neurotransmitter-filled synaptic vesicles with the presynaptic membrane. In order to better understand the fusion mechanisms, we reconstituted the synaptic SNARE complex in the imaging chamber of an atomic force microscope (AFM) and measured the interaction forces between its components. Each protein was tested against the two others, taken either individually or as binary complexes. This approach allowed us to determine specific interaction forces, dissociation kinetics of the SNAREs and led us to propose a sequence of formation for the complex. A theoretical model based on our measurements suggests that a minimum of four complexes is probably necessary for fusion to occur. We also showed that the regulatory protein nSec1 injected into the AFM chamber prevented the SNARE complex formation. Finally we measured the effect of tetanus toxin protease (TeTx) on the SNARE complex and its activity by on-line registration during TeTx injection. These experiments reveal that AFM is a valuable tool to investigate complicate interactions among a protein complex containing up to four components. Trafficking of glutamate receptors AMPA is closely related to postsynaptic induction of long-term potentiation. In a second part of this thesis, we used AFM to explore the distribution of AMPA receptors on-line at the surface of living cells in correlation with cellular viscoelastic properties. First, we showed that AFM permits to detect specifically AMPA receptors at the surface of living neurons and we proved that the specificity of detection is stable during time. Moreover, we were able to visualize variations in AMPA receptor density on surface in response to different stimulations. Finally, AFM also allowed us to study local viscoelastic properties of the cell and their modifications occurring during AMPA receptor trafficking. Our measurements reveal that AMPA receptors are situated at the cell surface on local stiffness maxima. We have noticed that an excitatory stimulation removes these stiffness maxima before producing internalization of receptors. Our results suggest also that AMPA receptors may be constituted of two subpopulations depending on the cell stiffness. A "hard" subpopulation may be preferentially internalized after an excitatory stimulation whereas a "soft" one seems to remain at the cell surface

Essais d'acclimatation des arbres à quinquina en Indochine. Sixième note

International audienceL'auteur s'est livré à des essais d'acclimatation de l'arbre à quinquina en diverses régions de la chaine annamitique et donnent le résultat de ses recherches

Question des quinquinas

Document numérisé par la Médiathèque scientifique de l'Institut PasteurGrand Conseil des intérêts économiques et financiers de l'Indochine. Séance plénière du 9 décembre 1931. Saïgon : Impr. J. Aspar, 1931, 9 p.Note présentée par Alexandre Yersin devant le Président du Grand Conseil des intérêts économiques et financiers de l'Indochine concernant la culture des quinquinas et en particulier de la nécessité d'une relation meilleure entre les Stations d'essais de l'Institut Pasteur de Saïgon et des services agricoles de l'Indochine

Note sur un cas de fièvre récurrente en Indochine

Document numérisé par la Médiathèque scientifique de l'Institut PasteurInternational audienceDiagnostic par Alexandre Yersin d'un premier cas de fièvre récurrente en Indochine

Expériences de culture de Cinchonas en Indochine

Document numérisé par la Médiathèque scientifique de l'Institut PasteurInternational audienceAnalyse sur la teneur en quinine d'échantillons d'écorces de quinquina prélevées dans les plantations de Dran et Djiring

Note sur les essais d'acclimatation des quinquinas entrepris en Indochine par l'Institut pasteur

International audienceAlexandre Yersin parle des essais d'acclimatation du quinquina effectués par l'Institut Pasteur de Saïgon dans la région du Sud-Annam

Note sur la fièvre bilieuse hématurique

Document numérisé par la Médiathèque scientifique de l'Institut PasteurInternational audienceEnvoyé par le Gouvernement français et l'Institut Pasteur, sur la petite île de Nossi-bé, proche de Madagascar, Alexandre Yersin autopsie des malades atteints de fièvre bilieuse hématurique. Ce texte est le bilan de ses observations

De Nha-Trang à Tourane par les pays moïs

Saïgon : Impr. coloniale, 1894. 35 p.Description du troisième voyage d'exploration d'Alexandre Yersin en pays Moïs