[An unexpected discovery of laryngeal neurofibroma during intubation for elective surgery]. / Le cas clinique du mois. Découverte fortuite d'un neurofibrome laryngé lors d'une intubation chez une patiente atteinte de neurofibromatose de type 1.

We report the unexpected discovery of a large laryngeal neurofibroma during a direct laryngoscopy for intubation in a 18-year old female with a medical history of neurofibromatosis type 1. The most striking feature of this case report is the discrepancy between the absence of clinical manifestations and the size and location of the neurofibroma. This case highlights the importance of a careful preoperative assessment, especially in the context of multisystemic disease. Knowledge of the disease, recognition of related complications and adequate preoperative evaluation are crucial to establish the safest anesthesia strategy.

Nous rapportons la découverte fortuite d'un volumineux neurofibrome laryngé lors de la laryngoscopie précédant une intubation endotrachéale chez une patiente de 18 ans atteinte d'une neurofibromatose de type 1, par ailleurs asymptomatique. Ce cas est remarquable par l'absence de toute manifestation clinique rapportée par la patiente malgré le volumineux neurofibrome présent dans le larynx. Il souligne l'importance d'une mise au point préopératoire approfondie, particulièrement dans le cas de maladies multisystémiques. Une bonne connaissance de cette maladie et de ses complications est indispensable pour réaliser un bilan préopératoire adéquat et déterminer la stratégie d'anesthésie la plus adaptée à ces patients.

Is the "in situ" simulation for teaching anesthesia residents a lower cost, feasible and satisfying alternative to simulation center ? A 24 months prospective observational study in a university hospital.

BACKGROUND: The value of simulation in medical education is increasingly obvious. Nevertheless, the high cost of running a simulation center and the time's availability for students to get to simulation center remain a major problem. Technological developments and miniaturization of computer systems now allow handling of simulation manikins. Therefore, "in situ" simulation seems a valuable alternative to center simulation. OBJECTIVE(S): To identify the costs and feasibility of "in situ" simulation. To conduct an evaluation of the sessions by participants in order to adapt the educational objectives. DESIGN: Observational study. SETTING: 118 "in situ" simulation sessions were organized between March 2011 and February 2013 in the university hospital of Université Catholique de Louvain. Sessions took place in OR facilities. At the end of each session, a questionnaire was given to each participant. PARTICIPANTS: 357 of 368 participants completed a questionnaire. For each session, one or two nurses and 2 residents in anesthesia were invited. MAIN OUTCOME MEASURES: Total costs for organizing the sessions. Number of realized sessions. Global satisfaction of participants. RESULTS: Total cost for organizing the sessions is 18 414 Euro. One hundred and one among the 118 scheduled sessions were performed, which corresponds to a rate of 85%. Three hundred and sixty-five people participated in training simulations. During the sessions, 357 questionnaires were completed. The global satisfaction was high with a median Likert scale of 5 (5-5) to the question "I would like to participate in other sessions in the future". CONCLUSION: The "in situ" simulation in anesthesia is feasible in a university hospital using the available facilities of the operating theater during the working hours of both participants and trainers. However, the number of annual sessions may be limited by the availability of the simulation room or staff.

Effect of pressure on decoupling of ionic conductivity from structural relaxation in hydrated protic ionic liquid, lidocaine HCl.

Broadband dielectric spectroscopy and pressure-temperature-volume methods are employed to investigate the effect of hydrostatic pressure on the conductivity relaxation time (τσ), both in the supercooled and glassy states of protic ionic liquid lidocaine hydrochloride monohydrate. Due to the decoupling between the ion conductivity and structural dynamics, the characteristic change in behavior of τσ(T) dependence, i.e., from Vogel-Fulcher-Tammann-like to Arrhenius-like behavior, is observed. This crossover is a manifestation of the liquid-glass transition of lidocaine HCl. The similar pattern of behavior was also found for pressure dependent isothermal measurements. However, in this case the transition from one simple volume activated law to another was noticed. Additionally, by analyzing the changes of conductivity relaxation times during isothermal densification of the sample, it was found that compression enhances the decoupling of electrical conductivity from the structural relaxation. Herein, we propose a new parameter, dlogRτ∕dP, to quantify the pressure sensitivity of the decoupling phenomenon. Finally, the temperature and volume dependence of τσ is discussed in terms of thermodynamic scaling concept.

Should the "in situ" simulation become the new way in Belgium? Experience of an academic hospital.

The place of simulation in medical education, particularly in anesthesia, appears to be more and more evident. However, the history of simulation in Belgium showed that the associated costs remain a barrier. The use of 'in situ' simulation, defined as the practice of simulation in the usual workplace, could solve the problem of providing access to this educational tool. Indeed, it allows reducing equipment and manpower costs: the needed equipment comes from the hospital, and supervision and organization are provided by staff members. It also provides access to simulation for a larger number of individuals on site. The environment is more realistic because the participants operate in their usual workplace, with their customary equipment and team. Furthermore, 'in situ' simulation allows participation of the paramedical staff. This allows developing skills related to teamwork and communication. Despite those numerous advantages, several difficulties persist. The associated logistic and organizational constraints can be cumbersome.

High pressure study of molecular dynamics of protic ionic liquid lidocaine hydrochloride.

In this paper, we investigate the effect of pressure on the molecular dynamics of protic ionic liquid lidocaine hydrochloride, a commonly used pharmaceutical, by means of dielectric spectroscopy and pressure-temperature-volume methods. We observed that near T(g) the pressure dependence of conductivity relaxation times reveals a peculiar behavior, which can be treated as a manifestation of decoupling between ion migration and structural relaxation times. Moreover, we discuss the validity of thermodynamic scaling in lidocaine HCl. We also employed the temperature-volume Avramov model to determine the value of pressure coefficient of glass transition temperature, dT(g)/dP|(P = 0.1). Finally, we investigate the role of thermal and density fluctuations in controlling of molecular dynamics of the examined compound.

Fundamentals of ionic conductivity relaxation gained from study of procaine hydrochloride and procainamide hydrochloride at ambient and elevated pressure.

The pharmaceuticals, procaine hydrochloride and procainamide hydrochloride, are glass-forming as well as ionically conducting materials. We have made dielectric measurements at ambient and elevated pressures to characterize the dynamics of the ion conductivity relaxation in these pharmaceuticals, and calorimetric measurements for the structural relaxation. Perhaps due to their special chemical and physical structures, novel features are found in the ionic conductivity relaxation of these pharmaceuticals. Data of conductivity relaxation in most ionic conductors when represented by the electric loss modulus usually show a single resolved peak in the electric modulus loss M(")(f) spectra. However, in procaine hydrochloride and procainamide hydrochloride we find in addition another resolved loss peak at higher frequencies over a temperature range spanning across T(g). The situation is analogous to many non-ionic glass-formers showing the presence of the structural α-relaxation together with the Johari-Goldstein (JG) ß-relaxation. Naturally the analogy leads us to name the slower and faster processes resolved in procaine hydrochloride and procainamide hydrochloride as the primary α-conductivity relaxation and the secondary ß-conductivity relaxation, respectively. The analogy of the ß-conductivity relaxation in procaine HCl and procainamide HCl with JG ß-relaxation in non-ionic glass-formers goes further by the finding that the ß-conductivity is strongly related to the α-conductivity relaxation at temperatures above and below T(g). At elevated pressure but compensated by raising temperature to maintain α-conductivity relaxation time constant, the data show invariance of the ratio between the ß- and the α-conductivity relaxation times to changes of thermodynamic condition. This property indicates that the ß-conductivity relaxation has fundamental importance and is indispensable as the precursor of the α-conductivity relaxation, analogous to the relation found between the Johari-Goldstein ß-relaxation and the structural α-relaxation in non-ionic glass-forming systems. The novel features of the ionic conductivity relaxation are brought out by presenting the measurements in terms of the electric modulus or permittivity. If presented in terms of conductivity, the novel features are lost. This warns against insisting that a log-log plot of conductivity vs. frequency is optimal to reveal and interpret the dynamics of ionic conductors.

Molecular dynamics studies on the water mixtures of pharmaceutically important ionic liquid lidocaine HCl.

In this paper the molecular dynamics of a common local-anesthetic drug, lidocaine hydrochloride (LD-HCl), and its water mixtures were investigated. By means of broadband dielectric spectroscopy and calorimetric measurements it was shown that even a small addition of water causes a significant effect on the relaxation dynamics of analyzed protic ionic liquid. Apart from the two well-resolved relaxations (σ- and γ-processes) and the ß-mode, identified as the JG-process, observed for anhydrous LD-HCl, a new relaxation peak (υ) is visible in the dielectric spectra of aqueous mixtures of this drug. Additionally, the significant effect of the water on the glass transition temperature of LD-HCl was found. The sample characterized with mole fraction of water X(w) = 0.44 reveals the glass transition temperature T(g), 42 K lower than that of anhydrous material (307 K). Finally, it was shown that by amorphization of the hydrochloride salt of lidocaine it is possible to obtain its room temperature ionic liquid form.

Anomalous electrical conductivity behavior at elevated pressure in the protic ionic liquid procainamide hydrochloride.

Using broadband dielectric spectroscopy, we investigated the effect of hydrostatic pressure on the conductivity relaxation time τ{σ} of the supercooled protic ionic liquid, procainamide hydrochloride, a common pharmaceutical. The pressure dependence of τ{σ} exhibited anomalous behavior in the vicinity of the glass transition T{g}, manifested by abrupt changes in activation volume. This peculiar behavior, paralleling the change in temperature dependence of τ{σ} near T{g}, is a manifestation of the decoupling between electrical conductivity and structural relaxation. Although the latter effectively ceases in the glassy state, free ions retain their mobility but with a reduced sensitivity to thermodynamic changes. This is the first observation of decoupling of ion migration from structural relaxation in a glassy conductor by isothermal densification.

Quantifying the Structural Dynamics of Pharmaceuticals in the Glassy State.

Structural dynamics in the glassy state of two protic ionic liquids, carvedilol phosphate and procaine hydrochloride, were characterized from analysis of changes in the conductivity relaxation times during physical aging. The obtained relaxation times, having a magnitude exceeding feasible experimental time scales and thus not directly measurable, are consistent with published data from a method that relies on the presence of a secondary relaxation. We also observe a narrowing of the relaxation dispersion, specific to higher frequencies, that is a consequence of the heterogeneous dynamics of deeply supercooled materials.

Efficient identification of point mutations by automated DNA sequencing of artificial heterozygote samples.

DNA sequencing templates of individual point mutants of the lacI target gene were amplified by polymerase chain reaction (PCR). By mixing the PCR fragments from two individual mutants in a defined ratio, samples of artificial heterozygous composition were prepared. These samples were then submitted to automated DNA sequencing. The simultaneous, visual comparison of the mixed mutant traces using a graphics program efficiently revealed all heterozygous positions. Based on the individual intensities of the heterozygous base signals the identified point mutations could be assigned to the corresponding mutants. This efficient approach doubles the sample throughput for both the sequencing reactions and the gel electrophoresis using an automated DNA sequencing system.

Stigmatella aurantiaca fruiting body formation is dependent on the fbfA gene encoding a polypeptide homologous to chitin synthases.

Stigmatella aurantiaca is a prokaryotic organism that undergoes a multicellular cycle of development resulting in the formation of a fruiting body. For analyzing this process, mutants defective in fruiting body formation have been induced by transposon mutagenesis using a Tn5-derived transposon. About 800 bp upstream of the transposon insertion of mutant AP182 which inactivates a gene (fbfB) involved in fruiting, a further gene (fbfA) needed for fruiting body formation was detected. Inactivation of fbfA leads to mutants which form only non-structured clumps instead of the wild-type fruiting body. The mutant phenotype of fbfA mutants can be partially suppressed by mixing the mutant cells with cells of some independent mutants defective in fruiting body formation. The fbfA gene is transcribed after 8 h of development as determined by measuring the induction of beta-galactosidase activity of a fbfA-delta(trp)-lacZ fusion gene and by Northern (RNA) analysis using an insertion encoding a stable mRNA. The predicted polypeptide FbfA shows a homology of about 30% to NodC of rhizobia, an N-acetylglucosamine-transferase which is involved in the synthesis of the sugar backbone of lipo-oligosaccharides. These induce the formation of the root nodules in the Papilionaceae. Besides the predicted molecular mass of 45.5 kDa, the hydropathy profile reveals a structural relationship to the NodC polypeptide.

A physical and genetic map of the Stigmatella aurantiaca DW4/3.1 chromosome.

A physical map of the myxobacterium Stigmatella aurantiaca DW4/3.1 chromosome was constructed by pulsed-field gel (PFG) long-range mapping. One-and two-dimensional pulsed-field gel analyses were used together with reciprocal double-restriction, cross-hybridization and hybridization fingerprint analysis. These PFG results were confirmed by Smith-Birnstiel analysis, by Southern hybridization using linking clones and clones of a lambda genomic library for the determination of adjacent restriction fragments and by transposon insertion mapping using defined genomic sequences for hybridization. It was thus possible to construct a circular restriction map of the single 9.35 Mbp chromosome of S. aurantiaca based on the endonucleases Asel and Spel. Genetic loci as well as the replication origin were located on the physical map by Southern hybridization using heterologous (derived from Myxococcus xanthus, Escherichia coli and Streptomyces lividans) and homologous probes that are mainly involved in development and cell motility.

Size and stability of the genomes of the myxobacteria Stigmatella aurantiaca and Stigmatella erecta.

Genomic DNA of Stigmatella aurantiaca DW 4/3.1 was restricted with the rare-cutting endonucleases AseI and SpeI. The restriction pattern derived is composed of 33 AseI and 25 SpeI fragments, whose total size amounts to approximately 9,350 kbp. Genomic fingerprint analysis of chromosomal DNA from several S. aurantiaca isolates further revealed five completely different SpeI and AseI fingerprints and one distinct fingerprint for Stigmatella erecta. In addition, minor variations between the genome sizes of these isolates were observed.