Low end-tidal CO2 as a real-time severity marker of intra-anaesthetic acute hypersensitivity reactions.

BACKGROUND: Prompt diagnosis of intra-anaesthetic acute hypersensitivity reactions (AHR) is challenging because of the possible absence and/or difficulty in detecting the usual clinical signs and because of the higher prevalence of alternative diagnoses. Delayed epinephrine administration during AHR, because of incorrect/delayed diagnosis, can be associated with poor prognosis. Low end-tidal CO2 (etCO2) is known to be linked to low cardiac output. Yet, its clinical utility during suspected intra-anaesthetic AHR is not well documented. METHODS: Clinical data from the 86 patients of the Neutrophil Activation in Systemic Anaphylaxis (NASA) multicentre study were analysed. Consenting patients with clinical signs consistent with intra-anaesthetic AHR to a neuromuscular blocking agent were included. Severe AHR was defined as a Grade 3-4 of the Ring and Messmer classification. Causes of AHR were explored following recommended guidelines. RESULTS: Among the 86 patients, 50% had severe AHR and 69% had a confirmed/suspected IgE-mediated event. Occurrence and minimum values of arterial hypotension, hypocapnia and hypoxaemia increased significantly with the severity of AHR. Low etCO2 was the only factor able to distinguish mild [median 3.5 (3.2;3.9) kPa] from severe AHR [median 2.4 (1.6;3.0) kPa], without overlap in inter-quartile range values, with an area under the receiver operator characteristic curve of 0.92 [95% confidence interval: 0.79-1.00]. Among the 41% of patients who received epinephrine, only half received it as first-line therapy despite international guidelines. CONCLUSIONS: An etCO2 value below 2.6 kPa (20 mm Hg) could be useful for prompt diagnosis of severe intra-anaesthetic AHR, and could facilitate early treatment with titrated doses of epinephrine. CLINICAL TRIAL REGISTRATION: NCT01637220.

Anaphylactic bronchospasm during general anesthesia is not related to asthma.

In the general population, a history of asthma (HA) is associated with a higher risk of mortality of anaphylactic shock (AS), but it is unknown whether this association remains valid for intra-operative AS. The goal of this retrospective study was to investigate whether a HA was associated with a higher risk of bronchospasm during intra-operative AS. We analyzed 106 patients (January 2009-December 2012) with intra-operative AS: 57% of them had a confirmed IgE-mediated reaction and 27% had a HA. On logistic regression, the only factor statistically associated with bronchospasm was a neuromuscular blocking drug, with both IgE- or non-IgE-mediated reactions. These results suggest that the mechanisms of bronchospasm in AS may be different from those of asthma and that, in the presence of bronchospasm during anesthesia, AS should be considered to be the most likely cause.

[Nuclear magnetic resonance based metabolic phenotyping for patient evaluations in operating rooms and intensive care units]. / Phénotypage métabolique par résonance magnétique nucléaire pour l'évaluation périopératoire et en réanimation.

Metabolic phenotyping consists in the identification of subtle and coordinated metabolic variations associated with various pathophysiological stimuli. Different analytical methods, such as nuclear magnetic resonance, allow the simultaneous quantification of a large number of metabolites. Statistical analyses of these spectra thus lead to the discrimination between samples and the identification of a metabolic phenotype corresponding to the effect under study. This approach allows the extraction of candidate biomarkers and the recovery of perturbed metabolic networks, driving to the generation of biochemical hypotheses (pathophysiological mechanisms, diagnostic tests, therapeutic targets…). Metabolic phenotyping could be useful in anaesthesiology and intensive care medicine for the evaluation, monitoring or diagnosis of life-threatening situations, to optimise patient managements. This review introduces the physical and statistical fundamentals of NMR-based metabolic phenotyping, describes the work already achieved by this approach in anaesthesiology and intensive care medicine. Finally, potential areas of interest are discussed for the perioperative and intensive management of patients, from newborns to adults.

[Low monocytic HLA-DR expression and risk of secondary infection]. / Diminution de l'expression monocytaire de HLA-DR et risque d'infection hospitalière.

OBJECTIVES: The aim of this bibliographic review is to evaluate the usefulness of the measurement of HLA-DR expression on circulating monocytes (mHLA-DR) in predicting the development of nosocomial infections and unfavourable outcome in critically ill patients. DATA SOURCE: References obtained from the medical database PubMed in English and in French were reviewed. The keywords included separately or in combination were: HLA-DR antigens, sepsis, trauma, injuries, wounds, burns, stroke, pancreatitis, postoperative, prognostic, immunity, monocytic. DATA EXTRACTION: Data in selected articles were reviewed, clinical and basic science research relevant information were extracted. DATA SYNTHESIS: Low mHLA-DR expression appears as a marker for monocytic dysfunctions and immunosuppression, temporarily present in the majority of critically ill patients admitted to the ICU (sepsis, trauma injuries, postoperative, burns, pancreatitis and stroke). The decrease in mHLA-DR expression is a predictor of septic complications in all these clinical conditions. However, no predictive threshold value could be determined regarding unfavourable outcome. CONCLUSION: The monitoring of mHLA-DR expression could be a biomarker to detect ICU patients at high risk of developing secondary nosocomial infections. Those patients could probably benefit of preemptive strategies to prevent these infections.

[Acute pancreatitis and bradycardia]. / Pancréatite aiguë et bradycardie.

Acute pancreatitis is frequently associated with electrocardiographic abnormalities, including arrhythmias and repolarization. We briefly describe a male patient with a severe acute pancreatitis who presented several bradycardias during his hospitalization in our intensive care unit. The aim of this case report is to underline the probability of severe arrhythmias during acute pancreatitis, which can increase morbidity of this pathology. Despite many publications or reports, causes of increased EKG abnormalities during severe pancreatitis remained unclear and are probably multifactorial. To prevent accidents or complications, patients with severe acute pancreatitis should have a continuous EKG monitoring.

[Peroperative myocardial infarction, which treatment at the acute period?]. / Infarctus du myocarde peropératoire, quelle prise en charge à la phase aiguë?

We report the case of a patient who presented, during a hip replacement, a cardiogenic shock following a myocardial infarction. After a successful resuscitation of three cardiac arrests, an intra-aortic balloon pump was inserted, then the patient could have been transferred to the nearest cardiac catheterization laboratory for a percutaneous dilatation of the right coronary artery, allowing the patient to have favourable outcome. Treatment of perioperative myocardial infarction is not really standardized. This case report depicts that in such critical condition, insertion of an intra-aortic balloon pump with early percutaneous angioplasty for acute peroperative myocardial infarction is a valuable option.

Chromosome-specific single-locus FISH probes allow anchorage of an 1800-marker integrated radiation-hybrid/linkage map of the domestic dog genome to all chromosomes.

We present here the first fully integrated, comprehensive map of the canine genome, incorporating detailed cytogenetic, radiation hybrid (RH), and meiotic information. We have mapped a collection of 266 chromosome-specific cosmid clones, each containing a microsatellite marker, to all 38 canine autosomes by fluorescence in situ hybridization (FISH). A 1500-marker RH map, comprising 1078 microsatellites, 320 dog gene markers, and 102 chromosome-specific markers, has been constructed using the RHDF5000-2 whole-genome radiation hybrid panel. Meiotic linkage analysis was performed, with at least one microsatellite marker from each dog autosome on a panel of reference families, allowing one meiotic linkage group to be anchored to all 38 dog autosomes. We present a karyotype in which each chromosome is identified by one meiotic linkage group and one or more RH groups. This updated integrated map, containing a total of 1800 markers, covers >90% of the dog genome. Positional selection of anchor clones enabled us, for the first time, to orientate nearly all of the integrated groups on each chromosome and to evaluate the extent of individual chromosome coverage in the integrated genome map. Finally, the inclusion of 320 dog genes into this integrated map enhances existing comparative mapping data between human and dog, and the 1000 mapped microsatellite markers constitute an invaluable tool with which to perform genome scanning studies on pedigrees of interest.

Using the fluorogenic 5' nuclease assay for high-throughput detection of (CA)n repeats in radiation hybrid mapping.

Here, the power of the 5' nuclease assay to detect PCR products containing (CA)n repeats was compared with that of the classical electrophoretic analysis. This assay, which relies on the use of a unique (CA)10 energy transfer-labeled probe and the 5' nuclease activity of Taq DNA polymerase, was used to construct a dog radiation hybrid map consisting of microsatellite markers. Data from over 7000 PCRs were analyzed in parallel by the fluorogenic assay and the conventional ethidium bromide-stained, agarose gel-based assay. We show that the fluorogenic assay provides a sensitive, reliable and specific method for detecting (CA)n amplimers. Moreover, as no processing is required after the PCR, the risk of carryover contamination and the time required for sample analysis are greatly reduced. All radiation hyrid (RH) assays can be performed using a single PCR protocol, and a standard analysis method has been developed that enables numerically automated data processing. On the whole, using this strategy greatly enhanced the rapidity, throughput and accuracy of the RH mapping of microsatellite markers.

Microsatellite analysis using a two-step procedure for fluorescence labeling of PCR products.

A method for fluorescent labeling of PCR products has been developed. This method consists in a two-step procedure in which a first exponential classical PCR is followed by a "linear amplification". This second step relies on incorporation of fluorescent dNTP (dUTP or dCTP) in order to label the product on only one strand. The products can be applied without prior purification directly to a gel on a fluorescence-based automated DNA sequencer, for length and allele determination. The reliability of the results equals those of the classical 32P or fluorescent primer labeling methods, and the method is definitely less costly. Since the interpretation of the results is easier than with the method consisting in a fluorescent dNTP uptake in both strands in a single PCR, the present strategy should prove useful in mapping projects requiring analysis of a large number of microsatellites.

Toward a dog radiation hybrid map.

Dog fibroblasts grown from a biopsy performed in a male mongrel were fused after gamma irradiation with thymidine kinase-deficient hamster cells and cultivated in selection medium. A total of 148 clones were obtained and screened by means of PCR amplification using primers corresponding to a dog-specific short repetitive element and to dog microsatellites and genes. One hundred seven cell lines were selected and grown in roller bottles and the distribution of 39 markers was analyzed in the extracted DNA. The results clearly indicate that this panel of hybrid cell lines should prove invaluable for constructing a map of the canine genome. In parallel, for more than 500 microsatellites present in the databases or screened from two libraries of short inserts, we have determined PCR conditions favoring dog-specific products even in the presence of hamster DNA. These highly polymorphic microsatellites should be useful in further linkage studies. We have also characterized 254 markers: dog genes, human expressed sequenced tags (huESTs), and traced orthologous amplified sequenced tags (TOASTs). Once mapped, these will constitute powerful tools to detect regions of conserved synteny in human and other mammalian genomes.

[The importance of the canine model in medical genetics]. / Intérêt du modèle canin pour la génétique médicale.

Dog domestication dates back to as early as 100,000 years ago, or 10,000 years depending upon the data used, and nowadays more than 350 breeds are duly registered in the different kennel clubs around the world. Due to intensive selection in the course of breeding, dog presently comes in any shape, size, color one can imagine, in addition to displaying a wide panel of characters, capacities and behaviours. As a consequence of excessive breeding, numerous breeds are plagued by a large variety of genetic diseases, many of them resembling those observed in human. All this makes dog an attractive model to track down genes and alleles responsible for those phenotypic behavioural or pathological traits, provided a genome map with polymorphic markers, and genes is available.

Structure and expression of an asparaginyl-tRNA synthetase gene located on chromosome IV of Arabidopsis thaliana and adjacent to a novel gene of 15 exons.

The gene AtNS1 coding for an asparaginyl-tRNA synthetase and located on chromosome IV of Arabidopsis thaliana has been characterized. AtNS1 is the first asparaginyl-tRNA synthetase gene described in higher plants. The genomic environment of AtNS1 has been studied, as well as a partial cDNA of a second homologous asparaginyl-tRNA synthetase gene, AtNS2. Both AtNS1 and AtNS2 exhibit the highest similarity with prokaryotic homologues. A large novel gene of 15 exons, named AtG2484-1, is located adjacent to AtNS1. AtG2484-1 shows features rarely described in plants including large exons and one 3' non-coding exon. PCR and Northern analyses were carried out to obtain information about the expression of these genes in various A. thaliana tissues.

Analysis of a 14-kb fragment containing a putative cell wall gene and a candidate for the ARA1, arabinose kinase, gene from chromosome IV of Arabidopsis thaliana.

An Arabidopsis thaliana genomic DNA fragment of 14kb has been characterized in the framework of the E.S.S.A. programme. Computational and molecular approaches identified three novel gene sequences coding, respectively, for a protein of unknown function, a putative membrane-anchored cell wall protein and an arabinose kinase gene corresponding to the locus ARA1. The latter two genes named AtSEB1 and AtISA1 have been characterized in detail. They are very different in their organization, codon usage and level of expression. Homologues of AtSEB1 and AtISA1 have been identified. Sequence comparisons showed that the former genes contained a long 5' extension coding for an N-terminal domain probably specifying subcellular localization. Cloning and sequencing of the cognate cDNA for the AtISA1 homologue in A. thaliana, named GAL1, indicate that it encodes for a galactokinase-like protein. Our results highlight the integrative outcome of a systematic sequencing project in which links between biochemically and genetically characterized mutants, ESTs and genomic sequence data are generated.

A whole-genome radiation hybrid map of the dog genome.

A whole genome radiation hybrid (RH) map of the canine genome was constructed by typing 400 markers, including 218 genes and 182 microsatellites, on a panel of 126 radiation hybrid cell lines. Fifty-seven RH groups have been determined with lod scores greater than 6, and 180 framework landmarks were ordered with odds greater than 1000:1. Average spacing between adjacent markers is 23 cR5000, an estimated physical distance of 3.8 Mb. Fourteen groups have been assigned to 9 of the canine chromosomes, and a comparison of RH and genetic groups allowed the successful bridging of both types of data on one map composed of 31 RH and 13 syntenic RH groups. Comparison of canine, human, mouse, and pig maps underlined regions of conserved synteny. This integrated map, covering an estimated 80% of the dog genome, should prove a powerful tool for localizing and identifiying genes implicated in pathological and phenotypical traits.

Structure, organization and putative function of the genes identified within a 23.9-kb fragment from Arabidopsis thaliana chromosome IV.

In the framework of the complete genome sequencing programme of the crucifer Arabidopsis thaliana, a 23.9-kb fragment from the long arm of chromosome IV has been analysed. This paper presents a methodological approach, integrating computerized predictions, database screening, the sequencing of cognate cDNAs and a PCR-based detection of expression that allows the accumulation of an important amount of information from an anonymous sequence. This work revealed the organization of novel genes and the vestige of a copia-like retrotransposon. The gene AtRH1 encodes the first member of a new subfamily of the plant DEAD box RNA helicases. A recurrent and complete search of dbEST has been used to evaluate the number of different RNA helicases expressed in A. thaliana. On the 18 discriminated members of the family, only a small number seems to be expressed at a relatively high level. The putative gene AtTS1 encodes a novel terpene synthase in A. thaliana, and the genes G14587-5 and G14587-6 encode unknown proteins. This study illustrates most of the situations that could be encountered during the analysis of an anonymous sequence from A. thaliana.

Structure determination of two oligomannoside-type glycopeptides obtained from bovine lactotransferrin, by 500 MHz 1H-NMR spectroscopy.

The elucidation of the structures of two carbohydrate units, N-glycosidically linked to an asparagine residue of bovine lactotransferrin, is described. These carbohydrate structures are of the oligomannoside type and contain eight or nine mannose residues, respectively. The potency of 500 MHz 1H-NMR spectroscopy in primary structure determination of two closely related carbohydrate chains present in a mixture is demonstrated. This implies that 500 MHz 1H-NMR spectroscopy can disclose microheterogeneity which is almost untraceable using other approaches.

[Chromatographic fractionation and studies on microheterogenity of cow lactotransferrin prepared by an original procedure]. / Fractionnement chromatographique et études sur la microhétérogénété de la lactotransferrine de vache préparée par un procédé original

Authors describe an original procedure to prepare pure lactotransferrin from cow milk. Physicochemical properties of this lactotransferrin have been studied and compared with results from others. New data are presented: presence of fucose and N-acetylgalactosamine; C-terminal amino-acid identified with threonine. On the other hand, 4 fractions have been obtained by "DEAE-Sephadex" chromatography, study of which demonstrates that the microheterogeneity of the lactotransferrin depends on the carbohydrate moiety and especially on the N-acetylneuraminic acid content which varies from 0 to 2 residues.

[Structure of the carbohydrate groups of IgG1 immunoglobulins of cow colostrum]. / Structure des groupements glycanniques des immunoglobulines IgG1 du colostrum de Vache

Hydrolysis by chymotrypsin of bovine immunoglobulins (IgG1, type) isolated from colostral whey yields glycopeptides, structural studies of which lead to the following results. 1. IgG1 colostral immunoglobulins possess two glycan moieties which are linked to the peptidic chain by an N-(beta-aspartyl)-N-acetylglucosaminylamine bound. 2. The peptidic sequence is Asn (Glycan)-Ser-Thr-Tyr. 3. Application of partial acidic hydrolysis, periodic oxidation, hydrazinolysis-nitrous deamination, methylation and use of specific glycosidases lead to the determination of the following structure of the glycan moieties: (see article). These structures are related to the general glycan structure so-called of "N-acetyllactosamine type" because they possess the pentasaccharidic core common to numerous glycoproteins Man alpha (1 leads to 3) [Man alpha (1 leads to 6)] Man beta (1 leads to 4) GlcNAc beta (1 leads to 4) GlcNAc beta (leads to) Asn on which are conjugated two N-acetyllactosamine residues. They present a microheterogeneity which is due to the varying number of additional N-acetylneuraminic acid and fucose residues.