Plasma membrane cyclic nucleotide gated calcium channels control land plant thermal sensing and acquired thermotolerance.

Typically at dawn on a hot summer day, land plants need precise molecular thermometers to sense harmless increments in the ambient temperature to induce a timely heat shock response (HSR) and accumulate protective heat shock proteins in anticipation of harmful temperatures at mid-day. Here, we found that the cyclic nucleotide gated calcium channel (CNGC) CNGCb gene from Physcomitrella patens and its Arabidopsis thaliana ortholog CNGC2, encode a component of cyclic nucleotide gated Ca(2+) channels that act as the primary thermosensors of land plant cells. Disruption of CNGCb or CNGC2 produced a hyper-thermosensitive phenotype, giving rise to an HSR and acquired thermotolerance at significantly milder heat-priming treatments than in wild-type plants. In an aequorin-expressing moss, CNGCb loss-of-function caused a hyper-thermoresponsive Ca(2+) influx and altered Ca(2+) signaling. Patch clamp recordings on moss protoplasts showed the presence of three distinct thermoresponsive Ca(2+) channels in wild-type cells. Deletion of CNGCb led to a total absence of one and increased the open probability of the remaining two thermoresponsive Ca(2+) channels. Thus, CNGC2 and CNGCb are expected to form heteromeric Ca(2+) channels with other related CNGCs. These channels in the plasma membrane respond to increments in the ambient temperature by triggering an optimal HSR, leading to the onset of plant acquired thermotolerance.

Acquired auditory agnosia in childhood and normal sleep electroencephalography subsequently diagnosed as Landau-Kleffner syndrome: a report of three cases.

Aim  We report three cases of Landau-Kleffner syndrome (LKS) in children (two females, one male) in whom diagnosis was delayed because the sleep electroencephalography (EEG) was initially normal. Method  Case histories including EEG, positron emission tomography findings, and long-term outcome were reviewed. Results  Auditory agnosia occurred between the age of 2 years and 3 years 6 months, after a period of normal language development. Initial awake and sleep EEG, recorded weeks to months after the onset of language regression, during a nap period in two cases and during a full night of sleep in the third case, was normal. Repeat EEG between 2 months and 2 years later showed epileptiform discharges during wakefulness and strongly activated by sleep, with a pattern of continuous spike-waves during slow-wave sleep in two patients. Patients were diagnosed with LKS and treated with various antiepileptic regimens, including corticosteroids. One patient in whom EEG became normal on hydrocortisone is making significant recovery. The other two patients did not exhibit a sustained response to treatment and remained severely impaired. Interpretation  Sleep EEG may be normal in the early phase of acquired auditory agnosia. EEG should be repeated frequently in individuals in whom a firm clinical diagnosis is made to facilitate early treatment.

Evaluation of MRSA-Screen, a simple anti-PBP 2a slide latex agglutination kit, for rapid detection of methicillin resistance in Staphylococcus aureus.

The MRSA-Screen test (Denka Seiken Co., Ltd., Tokyo, Japan), consisting of a slide latex agglutination kit that detects PBP 2a with a monoclonal antibody, was blindly compared to the oxacillin disk diffusion test, the oxacillin-salt agar screen, and PCR of the mecA gene for the detection of methicillin resistance in Staphylococcus aureus. A total of 120 methicillin-susceptible S. aureus (MSSA) and 80 methicillin-resistant S. aureus (MRSA) isolates, defined by the absence or presence of the mecA gene, respectively, were tested. The MRSA-Screen test, the oxacillin disk diffusion test, and the oxacillin-salt agar screening test showed sensitivities of 100, 61.3, and 82.5% and specificities of 99.2, 96.7, and 98.3%, respectively. We conclude that the MRSA-Screen is a very accurate, reliable, and fast test (15 min) for differentiation of MRSA from MSSA colonies on agar plates.

Estimating attributable mortality due to nosocomial infections acquired in intensive care units.

BACKGROUND: The strength of the association between intensive care unit (ICU)-acquired nosocomial infections (NIs) and mortality might differ according to the methodological approach taken. OBJECTIVE: To assess the association between ICU-acquired NIs and mortality using the concept of population-attributable fraction (PAF) for patient deaths caused by ICU-acquired NIs in a large cohort of critically ill patients. SETTING: Eleven ICUs of a French university hospital. DESIGN: We analyzed surveillance data on ICU-acquired NIs collected prospectively during the period from 1995 through 2003. The primary outcome was mortality from ICU-acquired NI stratified by site of infection. A matched-pair, case-control study was performed. Each patient who died before ICU discharge was defined as a case patient, and each patient who survived to ICU discharge was defined as a control patient. The PAF was calculated after adjustment for confounders by use of conditional logistic regression analysis. RESULTS: Among 8,068 ICU patients, a total of 1,725 deceased patients were successfully matched with 1,725 control patients. The adjusted PAF due to ICU-acquired NI for patients who died before ICU discharge was 14.6% (95% confidence interval [CI], 14.4%-14.8%). Stratified by the type of infection, the PAF was 6.1% (95% CI, 5.7%-6.5%) for pulmonary infection, 3.2% (95% CI, 2.8%-3.5%) for central venous catheter infection, 1.7% (95% CI, 0.9%-2.5%) for bloodstream infection, and 0.0% (95% CI, -0.4% to 0.4%) for urinary tract infection. CONCLUSIONS: ICU-acquired NI had an important effect on mortality. However, the statistical association between ICU-acquired NI and mortality tended to be less pronounced in findings based on the PAF than in study findings based on estimates of relative risk. Therefore, the choice of methods does matter when the burden of NI needs to be assessed.

Les staphylocoques résistants à la méthicilline (MRSA) : un nouveau risque professionnel chez les éleveurs de porcs

En 2004, en Hollande, une souche particulière de Staphylococcus aureus résistant à la méthicilline (MRSA2 pour Methicillin-Resistant Staphylococcus aureus) a été découverte chez des personnes en contact avec des porcs. Après investigations, il s'est avéré que 39 % des porcs hollandais et 23 % des éleveurs de porcs étaient porteurs (dans leur conduit nasal) de cette souche dont le profil génétique obtenu par la technique MLST3 (ST398) est différent des clones MRSA habituellement responsables des infections nosocomiales (Maugat et al. 2009 ; Lucet et al. 2005). Depuis, un nombre croissant d'études concernant l'émergence de cette souche dans d'autres pays (Canada, France, Allemagne, Angleterre, Belgique, Italie, Espagne, Danemark et Singapour) et chez d'autres animaux (chevaux, chiens, vaches et poulets) ont été publiées. En janvier 2009, une étude rapporte que cette souche vient d'être isolée aux USA lors du contrôle de deux très grands élevages de porcs. Les souches MRSA ST398 ont été retrouvées chez 70 % des animaux et chez 9 des 14 des employés de l'un des deux élevages concernés. En Hollande, la proportion des éleveurs de porcs colonisés par ces MRSA est passée de 23 % en 2004 à 50 % en 2008 (contre 0,03 % dans la population générale, c'est-à-dire sans contact avec des animaux de ferme). Dans plusieurs pays, la possibilité d'une transmission de l'animal à l'homme, puis inter-humaine a été confirmée par plusieurs études et concernerait en premier lieu les éleveurs, leur famille et les vétérinaires (Khanna et al. 2008 ; Smith et al. 2008 ; Wulf et al. 2008). Dès lors, les élevages de porcs sont susceptibles de constituer un réservoir4 important de MRSA qui peuvent se propager à d'autres animaux et à l'homme. L'apparition de cette nouvelle zoonose peut avoir de graves impacts sur la santé publique et constitue un risque professionnel émergent pour les éleveurs de porcs. En effet, si dans la très grande majorité des cas, la colonisation nasale de l'homme par ces MRSA reste asymptomatique, l'implication de ces MRSA ST398 dans des complications infectieuses (endocardite, pneumonie, septicémie et infection de la peau) a déjà été observée. Les deux articles proposés dans cette note traitent de la problématique de ces complications infectieuses. [Auteur]

Reversible acquired epileptic frontal syndrome and CSWS suppression in a child with congenital hemiparesis treated by hemispherotomy

Rapport de synthèse : Cette thèse a étudié en détail le cas d'un enfant souffrant d'une hémiplégie congénitale sur un infarctus prénatal étendu qui a développé une forme particulière d'épilepsie, le syndrome des pointes ondes continues du sommeil (POCS), associé à une régression mentale massive. Les caractéristiques de cette détérioration pointaient vers un dysfonctionnement de type frontal. Une chirurgie de l'épilepsie (hémisphérotomie) a, non seulement, permis la guérison de l'épilepsie mais une récupération rapide sur le plan comportemental et cognitif, suivie d'une reprise plus lente du développement, avec finalement à l'âge de 11 ans un niveau de déficience intellectuelle modérée. L'intérêt de cette étude réside dans le fait que l'enfant a pu être suivi prospectivement entre l'âge de 4.5 ans et 11 ans par des enregistrements électro-encéphalographiques (EEG) ainsi que des tests neuropsychologiques et des questionnaires de comportements sériés, permettant de comparer les périodes pré-, péri- et postopératoires, ce qui est rarement réalisable. Un enregistrement EEG de surface a même pu être effectué durant l'opération sur l'hémisphère non lésé, permettant de documenter l'arrêt des décharges épileptiformes généralisées dès la fin de l'intervention. L'hypothèse que nous avons- souhaité démontrer est que la régression comportementale et cognitive présentée par l'enfant après une période de développement précoce presque normale (retard de langage) était de nature épileptique : nous l'expliquons par la propagation de l'activité électrique anormale à partir de la lésion de l'hémisphère gauche vers les régions préservées, en particulier frontales bilatérales. L'hémisphérotomie a permis une récupération rapide en déconnectant l'hémisphère gauche lésé et épileptogène de l'hémisphère sain, qui a ainsi pu reprendre les fonctions cognitives les plus importantes. Les progrès plus lents par la suite et l'absence de rattrapage au delà d'un niveau de déficience mentale modérée sont plus difficiles à expliquer: on postule ici un effet de l'épilepsie sur le développement de réseaux neuronaux de l'hémisphère initialement non lésé, réseaux qui sont à la fois à un stade précoce de leur maturation et en cours de réorganisation suite à la lésion prénatale. La littérature sur les déficits cognitifs avant et après hemisphérotomie s'est surtout préoccupée du langage et de sa récupération possible. À notre connaissance, notre étude est la première à documenter la réversibilité d'une détérioration mentale avec les caractéristiques d'un syndrome frontal après hémisphérotomie. La chirurgie de l'épilepsie a offert ici une occasion unique de documenter le rôle de l'activité épileptique dans la régression cognitive puisqu'en interrompant brusquement la propagation de l'activité électrique anormale, on a pu comparer la dynamique du développement avant et après l'intervention. La mise en relation des multiples examens cliniques et EEG pratiqués chez un seul enfant sur plusieurs années a permis d'obtenir des informations importantes dans la compréhension des troubles cognitifs et du comportement associés aux épilepsies focales réfractaires. ABSTRACT : A boy with a right congenital hemiparesis due to a left pre-natal middle cerebral artery infarct developed focal epilepsy at 33 months and then an insidious and subsequently more rapid, massive cognitive and behavioural regression with a frontal syndrome between the ages of 4 and 5 years with continuous spike-waves during sleep (CSWS) on the EEG. Both the epilepsy and the CSWS were immediately suppressed by hemispherotomy at the age of 5 years and 4months. A behavioural-cognitive follow-up prior to hemispheratomy, an per-operative EEG and corticography and serial post-operative neuropsychological assessments were performed until the age of 11 years. The spread of the epileptic activity to the "healthy" frontal region was the cause of the reversible frontal syndrome. A later gradual long-term but incomplete cognitive recovery, with moderate mental disability was documented. T9ris outcome is probably explained by another facet of the epilepsy, namely the structural effects of prolonged epileptic dischazges in rapidly developing cerebral networks which are, at the same time undergoing the reorganization imposed by a unilateral early hemispheric lesion. Group studies on the outcome of children before and after hemispherectomy using only single IQ measures, pre- and postoperatively, may miss particular epileptic cognitive dysfunctions as they are likely to be different from case to case. Such detailed and rarely available complementary clinical and EEG data obtained in a single case at different time periods in relation to the epilepsy, including peroperative electrophysiological findings, may help to understand the different cognitive deficits and recovery profiles and the limits of full cognitive recovery.

Acquired oscillopsia: potential complication after multifocal IOL implantation

A healthy 60-year-old woman had uneventful bilateral sequential cataract surgery with diffractive multifocal intraocular lens (IOL) implantation. Immediately after surgery in the first eye, the patient complained of right monocular oscillopsia during motion. Surgery in the second eye was followed by the same symptoms. Ocular motility was normal. Any movement of head or eye was accompanied by oscillopsia, disappearing immediately upon cessation of movement. Slitlamp examination revealed pseudophacodonesis, without obvious zonular laxity. We postulate that the rapid oscillation of an unsteady multifocal IOL during head or eye movement caused the optical steps to pass in front of the visual axis. Cataract surgeons must be aware of this potential, but rare, complication before deciding to implant a multifocal IOL.

Selective acquired long QT syndrome (saLQTS) upon risperidone treatment.

ABSTRACT: BACKGROUND: Numerous structurally unrelated drugs, including antipsychotics, can prolong QT interval and trigger the acquired long QT syndrome (aLQTS). All of them are thought to act at the level of KCNH2, a subunit of the potassium channel. Although the QT-prolonging drugs are proscribed in the subjects with aLQTS, the individual response to diverse QT-prolonging drugs may vary substantially. CASE PRESENTATION: We report here a case of aLQTS in response to small doses of risperidone that was confirmed at three independent drug challenges in the absence of other QT-prolonging drugs. On the other hand, the patient did not respond with QT prolongation to some other antipsychotics. In particular, the administration of clozapine, known to be associated with higher QT-prolongation risk than risperidone, had no effect on QT-length. A detailed genetic analysis revealed no mutations or polymorphisms in KCNH2, KCNE1, KCNE2, SCN5A and KCNQ1 genes. CONCLUSIONS: Our observation suggests that some patients may display a selective aLQTS to a single antipsychotic, without a potassium channel-related genetic substrate. Contrasting with the idea of a common target of the aLQTS-triggerring drugs, our data suggests existence of an alternative target protein, which unlike the KCNH2 would be drug-selective.

Referral patterns and outcomes in noncritically ill patients with hospital-acquired acute kidney injury.

Background and objectives Despite modern treatment, the case fatality rate of hospital-acquired acute kidney injury (HA-AKI) is still high. We retrospectively described the prevalence and the outcome of HA-AKI without nephrology referral (nrHA-AKI) and late referred HA-AKI patients to nephrologists (lrHA-AKI) compared with early referral patients (erHA-AKI) with respect to renal function recovery, renal replacement therapy (RRT) requirement, and in-hospital mortality of HA-AKI. Design, setting, participants, & measurements Noncritically ill patients admitted to the tertiary care academic center of Lausanne, Switzerland, between 2004 and 2008 in the medical and surgical services were included. Acute kidney injury was defined using the Acute Kidney Injury Network (AKIN) classification. Results During 5 years, 4296 patients (4.12% of admissions) experienced 4727 episodes of HA-AKI during their hospital stay. The mean ± SD age of the patients was 61 ± 15 years with a 55% male predominance. There were 958 patients with nrHA-AKI (22.3%) and 2504 patients with lrHA-AKI (58.3%). RRT was required in 31% of the patients with lrHA-AKI compared with 24% of the patients with erHA-AKI. In the multiple risk factor analysis, compared with erHA-AKI, nrHA-AKI and lrHA-AKI were significantly associated with worse renal outcome and higher in-hospital mortality. Conclusions These data suggest that HA-AKI is frequent and the patients with nrHA-AKI or lrHA-AKI are at increased risk for in-hospital morbidity and mortality.

MAGE-A3 and MAGE-A4 specific CD4(+) T cells in head and neck cancer patients: detection of naturally acquired responses and identification of new epitopes.

Frequent expression of cancer testis antigens (CTA) has been consistently observed in head and neck squamous cell carcinomas (HNSCC). For instance, in 52 HNSCC patients, MAGE-A3 and -A4 CTA were expressed in over 75% of tumors, regardless of the sites of primary tumors such as oral cavity or hypopharynx. Yet, T-cell responses against these CTA in tumor-bearing patients have not been investigated in detail. In this study, we assessed the naturally acquired T-cell response against MAGE-A3 and -A4 in nonvaccinated HNSCC patients. Autologous antigen-presenting cells pulsed with overlapping peptide pools were used to detect and isolate MAGE-A3 and MAGE-A4 specific CD4(+) T cells from healthy donors and seven head and neck cancer patients. CD4(+) T-cell clones were characterized by cytokine secretion. We could detect and isolate MAGE-A3 and MAGE-A4 specific CD4(+) T cells from 7/7 cancer patients analyzed. Moreover, we identified six previously described and three new epitopes for MAGE-A3. Among them, the MAGE-A3(111-125) and MAGE-A3(161-175) epitopes were shown to be naturally processed and presented by DC in association with HLA-DP and DR, respectively. All of the detected MAGE-A4 responses were specific for new helper epitopes. These data suggest that naturally acquired CD4(+) T-cell responses against CT antigens often occur in vivo in HNSCC cancer patients and provide a rationale for the development of active immunotherapeutic approaches in this type of tumor.

Analyse des épisodes de bactériémies chez les patients nécessitant une prise en charge aux soins intensifs

Introduction : Bacteremia are among the leading forms of severe infections requiring ICU management, and have been reported to be associated with important morbidity and mortality. Bloodstream infection (BSI) can be classified as hospital-acquired (HA), healthcare-associated (HCA) and community-acquired (CA). Each type has its own characteristics and outcome. Methods : We analyzed all consecutive episodes of bacteremia occurring in patients hospitalized in our mixed 32-bed ICU over a 12 month period (01.10.2009-30.09.2010). HA BSI were prospectively included in a multicenter study (EUROBACT). We adapted the case report form to analyze retrospectively all other cases of BSI. Chi-square tests were used for the categorical variables and ANOVA tests for the continuous variables. Results : Bacteremia occurred in 103 patients (120 bacteria) for an incidence-density of 49.3 episodes/1000 admissions. Among HA episodes, about one quarter of episodes was related to vascular accesses, including two thirds acquired outside of the ICU. Concerning HCA BSI, two-thirds originated from the urinary tract. In contrast, a respiratory origin was found in one third of CA episodes. Multiresistant microorganisms were more frequent in HA and HCA BSI. The overall mortality was 32%, as compared to 7.9% and 13.6% for the overall ICU and hospital mortality of other ICU patients over the same period, respectively. In a multivariate model, age (1.06 [1.02-1.11]), septic shock (3.11 [1.16-8.33]) and renal remplacement (7.81 [1.50, 14.93]) were significantly associated with a fatal outcome. Conclusion : Two-thirds of bacteremia documented among ICU patients were nosocomial and in contrast to those community-acquired, Gram-negatives represented the majority of them. However, CA bacteremia were associated with a higher rate of septic shock and death. The microbiological characteristics of HCA episodes were more similar to those HA, that is why it is important to individualize this category in order to adapt the antibiotics.

Cost-effectiveness of full-course oral levofloxacin in severe community-acquired pneumonia.

Oral levofloxacin is as efficient as sequential antibiotic treatment in community-acquired pneumonia (CAP). The current authors assessed whether oral levofloxacin treatment of patients with severe CAP, followed-up for 30 days, would save money. Over a 12-month period, 129 hospitalised patients with severe non-intensive care unit CAP were randomly assigned to receive either oral levofloxacin or sequential antibiotic treatment. Direct and indirect costs were compared over a 30-day period from several perspectives. CAP resolved in 71 out of 77 oral levofloxacin (92%) and in 34 out of 37 sequential antibiotic treatment patients (92%). Patients' characteristics, treatment duration, hospital length of stay and mortality were similar in both groups. Drug acquisition costs were 1.7-times smaller in oral levofloxacin patients, who were less often transferred to rehabilitation centres, but they used more physicians' visits during follow-up and their total costs were lower. As only a minority of patients was still active, inability to work and, hence, indirect costs were similar in both groups. In this study, oral levofloxacin for severe non-intensive care unit community-acquired pneumonia was equally effective as sequential antibiotic treatment, but did not lead to major costs savings except for drug acquisition costs. External factors linked with patients' characteristics and/or medical practice are likely to play a role and should be addressed.

Rapid detection of MRSA in screening specimens during a hospital outbreak.

Objectives: To compare the results of rapid PCR screening for MRSA using the GeneXpert system with those of cultures in an outbreak setting. Methods: GeneXpert was used for screening MRSA in nose, throat, groin, and other clinical samples during a 6-month period. Samples were performed using a double-swab transystem. When >1 sample was found positive in a screening set, all second swabs of the set were analysed by culture. Results: From June to October 2009, 7568 rapid tests were performed, among which 432 (5.7%) were positive (nose: 149/2090, 7.1%; throat: 98/2078, 4.7%; groin: 152/2080, 7.3%; urine: 14/1090, 1.3%; wounds: 18/150, 12%; and others:1/27, 3.7%), and 84 (1.1%) were invalid. A total of 1517 samples were analyzed by both rapid PCR and culture. Rapid tests had a sensitivity of 0.896 compared to cultures, a specificity of 0.769, a PPV of 0.763, and a NPV of 0.899. The rapid test was found to be less sensitive in throat samples (0.81) than in nose or inguinal samples (0.93 for both). In 32/192 (16%) patients a positive rapid PCR result was not confirmed by culture, despite several subsequent screening samples in some patients. Cycle threshold (Ct) for SCCmec of these PCR positive reactions were all >30. Conclusions: GeneXpert MRSA was found to be suitable for the rapid detection in nose, inguinal, and throat samples, however with a lower sensitivity in the later. Negative cultures in 16% of our PCR-positive patients raised the question of false positivity or higher sensitivity of GeneXpert. Further work is needed to investigate these cases.

Characteristics and determinants of outcome of hospital-acquired bloodstream infections in intensive care units: the EUROBACT International Cohort Study.

PURPOSE: The recent increase in drug-resistant micro-organisms complicates the management of hospital-acquired bloodstream infections (HA-BSIs). We investigated the epidemiology of HA-BSI and evaluated the impact of drug resistance on outcomes of critically ill patients, controlling for patient characteristics and infection management. METHODS: A prospective, multicentre non-representative cohort study was conducted in 162 intensive care units (ICUs) in 24 countries. RESULTS: We included 1,156 patients [mean ± standard deviation (SD) age, 59.5 ± 17.7 years; 65 % males; mean ± SD Simplified Acute Physiology Score (SAPS) II score, 50 ± 17] with HA-BSIs, of which 76 % were ICU-acquired. Median time to diagnosis was 14 [interquartile range (IQR), 7-26] days after hospital admission. Polymicrobial infections accounted for 12 % of cases. Among monomicrobial infections, 58.3 % were gram-negative, 32.8 % gram-positive, 7.8 % fungal and 1.2 % due to strict anaerobes. Overall, 629 (47.8 %) isolates were multidrug-resistant (MDR), including 270 (20.5 %) extensively resistant (XDR), and 5 (0.4 %) pan-drug-resistant (PDR). Micro-organism distribution and MDR occurrence varied significantly (p < 0.001) by country. The 28-day all-cause fatality rate was 36 %. In the multivariable model including micro-organism, patient and centre variables, independent predictors of 28-day mortality included MDR isolate [odds ratio (OR), 1.49; 95 % confidence interval (95 %CI), 1.07-2.06], uncontrolled infection source (OR, 5.86; 95 %CI, 2.5-13.9) and timing to adequate treatment (before day 6 since blood culture collection versus never, OR, 0.38; 95 %CI, 0.23-0.63; since day 6 versus never, OR, 0.20; 95 %CI, 0.08-0.47). CONCLUSIONS: MDR and XDR bacteria (especially gram-negative) are common in HA-BSIs in critically ill patients and are associated with increased 28-day mortality. Intensified efforts to prevent HA-BSIs and to optimize their management through adequate source control and antibiotic therapy are needed to improve outcomes.