Nonspecific Effects of Normal Aging on Taxonomic and Thematic Semantic Processing.

OBJECTIVE: This study aimed to assess the effect of normal aging on the processing of taxonomic and thematic semantic relations. METHOD: We used the Visual-World-Paradigm coupled with eye-movement recording. We compared performance of healthy younger and older adults on a word-to-picture matching task in which participants had to identify each target among semantically related (taxonomic or thematic) and unrelated distractors. RESULTS: Younger and older participants exhibited similar patterns of gaze fixations in the two semantic conditions. The effect of aging took the form of an overall reduction in sensitivity to semantic competitors, with no difference between the taxonomic and thematic conditions. Moreover, comparison of the proportions of fixations between the younger and older participants indicated that targets were identified equally quickly in both age groups. This was not the case when mouse-click reaction times were analyzed. CONCLUSIONS: Findings argue in favor of nonspecific effects of normal aging on semantic processing that similarly affect taxonomic and thematic processing. There are important clinical implications, as pathological aging has been repeatedly shown to selectively affect either taxonomic or thematic relations. Measuring eye-movements in a semantic task is also an interesting approach in the elderly, as these seem to be less impacted by aging than other motor responses.

Evaluation of the Bruker® MBT Sepsityper IVD module for the identification of polymicrobial blood cultures with MALDI-TOF MS.

Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) considerably reduces timeframe required from initial blood culture positivity towards complete bacterial identification. However, rapid identification of polymicrobial blood cultures remains challenging. We evaluated the performances of the Bruker® MBT Sepsityper IVD module on MALDI-TOF MS for the direct identification of polymicrobial blood culture bottles. This module has the ability to give a strong indication that a sample contains a mixture of organisms and to identify two of them. Blood culture bottles considered as polymicrobial using routine subculture were collected and processed using the Sepsityper kit. MALDI-TOF MS identification was performed using the MBT Compass IVD software including the Sepsityper module. From 143 polymicrobial blood culture bottles tested, 34.3% (49/143) were completely identified by the module. Both microorganisms were more easily detected by the module in samples containing two pathogens than in samples containing two contaminants (36.8% vs 29.4%). Additionally, in more than half of the samples, the module detected 1 of the different microorganisms contained in the same vial. In these cases, with a pathogen and contaminant in the same sample, the module detected the pathogen in more than 80%. The Sepsityper module identified 14 microorganisms which were not recovered by conventional culture methods. The Bruker® MBT Sepsityper IVD module contributed to a valuable identification of polymicrobial blood cultures in more than a third of all cases. Conventional culture methods are still required to complete the results and to carry on susceptibility testing.

Comparative Evaluation of Four Phenotypic Tests for Detection of Carbapenemase-Producing Gram-Negative Bacteria.

Four screening assays aimed for rapid detection of carbapenemase production from Gram-negative bacterial isolates, i.e., the Neo-Rapid Carb kit (Rosco Diagnostica A/S), the Rapidec Carba NP test (bioMérieux SA), the ß Carba test (Bio-Rad Laboratories N.V.), and a homemade electrochemical assay (BYG Carba test) were evaluated against a panel comprising 328 clinical isolates (Enterobacteriaceae [n = 198] and nonfermentative Gram-negative bacilli [n = 130]) with previously characterized resistance mechanisms to carbapenems. Among Enterobacteriaceae isolates, the BYG Carba test and the ß Carba test showed excellent sensitivities (respectively, 100% and 97.3%) and specificities (respectively, 98.9% and 97.7%). The two other assays yielded poorer performances with sensitivity and specificity of 91.9% and 83.9% for the Rapidec Carba NP test and of 89.2% and 89.7% for the Neo-Rapid Carb kit, respectively. Among Pseudomonas spp., sensitivities and specificities ranged, respectively, from 87.3% to 92.7% and from 88.2% to 94.1%. Finally, all tests performed poorly against Acinetobacter spp., with sensitivities and specificities, respectively, ranging from 27.3% to 75.8% and from 75 to 100%. Among commercially available assays, the ß Carba test appeared to be the most convenient for routine use and showed the best overall performances, especially against OXA-48-like producers. The excellent performance of the BYG Carba test against Enterobacteriaceae was confirmed (100% sensitivity and 98.9% specificity).

The Still Enigmatic Syndrome of Transient Global Amnesia: Interactions Between Neurological and Psychopathological Factors.

Transient global amnesia (TGA) is a neurological syndrome that usually occurs in middle-aged or older people. It is characterized by the abrupt onset of profound anterograde amnesia, associated with more variable retrograde amnesia and repetitive questioning. The whole episode lasts no more than 24 h. Almost 60 years after its first descriptions, the etiology of TGA remains unknown. Until now, TGA has been described exclusively as a memory disorder, but there is a growing body of evidence to show that emotional and psychological factors (as anxious and depressive symptoms) are present at different times of TGA. Their role therefore needs to be clarified. First, these factors seem to play a part in triggering TGA, at least for a subgroup of patients, suggesting the existence of an emotional TGA subtype. Second, recent research shows that almost all the TGA patients displayed modifications of their emotional state during the episode, possibly linked to sudden memory loss. The level of depressive and anxious symptoms could even reach a pathological threshold in patients with the so-called "emotional TGA subtype". Third, the persistence of these depressive and anxious symptoms after the end of the episode could account for lasting memory disorders in some patients. Finally, the analysis of these emotional syndrome and emotional factors and the recent data in neuroimaging could allow us to gain a better understanding of the pathophysiological mechanisms behind TGA. The aim of this review was thus to discuss whether the anxious and depressive symptoms are causative, resultant or coincidental of TGA.

Overreliance on thematic knowledge in semantic dementia: Evidence from an eye-tracking paradigm.

OBJECTIVE: The present study explored two types of semantic relationships in semantic dementia (SD), that rely on functionally and neuroanatomically distinct semantic systems (taxonomic vs. thematic). METHOD: We used the visual world paradigm coupled with eye-movement recordings, to gain an implicit, fine-grained and dynamic measure of semantic processing. Nine patients with SD and 15 healthy controls performed a simple word-to-picture matching task in which they had to identify each target among semantically related (taxonomic or thematic) competitors and unrelated distractors. RESULTS: We demonstrated different patterns of gaze fixations between patients with SD and controls: while patients with SD and controls were similarly sensitive to competition from taxonomically related pictures, patients with SD were far more sensitive than controls to thematically related competitors before identifying the targets. Moreover, most of the confusion errors made by patients with SD involved taxonomic distractors rather than thematic ones. CONCLUSIONS: We interpreted these findings as reflecting a semantic disequilibrium in SD, with increasing overreliance on thematic knowledge as taxonomic knowledge gradually deteriorates. We concluded that thematic relationships constitute a set of residual semantic knowledge and that their exaggerated activation in SD might certainly deserve further explorations to determine their specific role in this disease and notably, their influence on patients' abilities to deal with daily living activities. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

Identification of taxonomic and thematic relationships: Do the two semantic systems have the same status in semantic dementia?

Introduction: Disequilibrium between the taxonomic and thematic semantic systems was previously hypothesized in participants with semantic dementia (SD), without rigorously assessing their ability to identify the two types of semantic relationships. Therefore, the aim of the present study was to directly compare the ability of 10 participants with SD, 10 participants with Alzheimer's disease (AD), and 20 controls to identify thematic versus taxonomic relationships. Methods: Participants performed an explicit forced-choice picture-matching task in which they had to determine which of two pictures of choice was semantically related to the target picture. Target pictures could display natural or artifact objects. Each target was presented once with a taxonomically related picture and once with a thematically related picture. Results: Analyses of correct thematic and taxonomic matches as a function of target domain showed that the performance of the two groups of patients differed in the taxonomic conditions but not in the thematic conditions, demonstrating a relative preservation of thematic knowledge in SD. Additional correlation analyses further indicated that the particular status of thematic relationships in SD was even stronger for artifact concepts. Conclusions: Results provide evidence of the heterogeneous nature of semantic knowledge disruption in SD, and could be regarded as being consistent with the existence of two neuroanatomically and functionally distinct semantic systems. Results further stress the relevance of performing a more detailed and complete assessment of semantic performance in participants with SD, in order to capture the impaired but also preserved aspects of their knowledge.

Prevalence of multidrug-resistant organisms in nursing homes in Belgium in 2015.

OBJECTIVES: Following two studies conducted in 2005 and 2011, a third prevalence survey of multidrug-resistant microorganisms (MDRO) was organised in Belgian nursing homes (NHs) using a similar methodology. The aim was to measure the prevalence of carriage of methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), extended-spectrum ß-lactamase producing Enterobacteriaceae (ESBLE) and carbapenemase-producing Enterobacteriaceae (CPE) in NH residents. Risk factors for MDRO carriage were also explored. METHODS: Up to 51 randomly selected residents per NH were screened for MDRO carriage by trained local nurses between June and October 2015. Rectal swabs were cultured for ESBLE, CPE and VRE, while pooled samples of nose, throat and perineum and chronic wound swabs were obtained for culture of MRSA. Antimicrobial susceptibility testing, molecular detection of resistance genes and strain genotyping were performed. Significant risk factors for MDRO colonization MDRO was determined by univariate and multivariable analysis. RESULTS: Overall, 1447 residents from 29 NHs were enrolled. The mean weighted prevalence of ESBLE and MRSA colonization was 11.3% and 9.0%, respectively. Co-colonization occurred in 1.8% of the residents. VRE and CPE carriage were identified in only one resident each. Impaired mobility and recent treatment with fluoroquinolones or with combinations of sulphonamides and trimethoprim were identified as risk factors for ESBLE carriage, while for MRSA these were previous MRSA carriage/infection, a stay in several different hospital wards during the past year, and a recent treatment with nitrofuran derivatives. Current antacid use was a predictor for both ESBL and MRSA carriage. CONCLUSIONS: In line with the evolution of MRSA and ESBL colonization/infection in hospitals, a decline in MRSA carriage and an increase in ESBLE prevalence was seen in Belgian NHs between 2005 and 2015. These results show that a systemic approach, including surveillance and enhancement of infection control and antimicrobial stewardship programs is needed in both acute and chronic care facilities.

A recurrent and transesophageal echocardiography-associated outbreak of extended-spectrum ß-lactamase-producing Enterobacter cloacae complex in cardiac surgery patients.

Background: We report a recurrent outbreak of postoperative infections with extended-spectrum ß-lactamase (ESBL)-producing E. cloacae complex in cardiac surgery patients, describe the outbreak investigation and highlight the infection control measures. Methods: Cases were defined as cardiac surgery patients in Ghent University Hospital who were not known preoperatively to carry ESBL-producing E. cloacae complex and who postoperatively had a positive culture for this multiresistant organism between May 2017 and January 2018. An epidemiological investigation, including a case-control study, and environmental investigation were conducted to identify the source of the outbreak. Clonal relatedness of ESBL-producing E. cloacae complex isolates collected from case patients was assessed using whole-genome sequencing-based studies. Results: Three separate outbreak episodes occurred over the course of 9 months. A total of 8, 4 and 6 patients met the case definition, respectively. All but one patients developed a clinical infection with ESBL-producing E. cloacae complex, most typically postoperative pneumonia. Overall mortality was 22% (4/18). Environmental cultures were negative, but epidemiological investigation pointed to transesophageal echocardiography (TEE) as the outbreak source. Of note, four TEE probes showed a similar pattern of damage, which very likely impeded adequate disinfection. The first and second outbreak episode were caused by the same clone, whereas a different strain was responsible for the third episode. Conclusions: Health professionals caring for cardiac surgery patients and infection control specialists should be aware of TEE as possible infection source. Caution must be exercised to prevent and detect damage of TEE probes.

Influence of depressive symptoms on memory in transient global amnesia.

INTRODUCTION: Recent studies have shown that patients with transient global amnesia (TGA) experience a depressive mood during the episode. However, little evidence has been found of possible mood congruency effects on memory, which are probably masked by the massive anterograde amnesia. An implicit assessment could provide a means of settling this question. METHODS: First, we measured patients' emotional states on psychopathological scales. Second, we administered a lexical decision task to assess three priming effects: Semantic priming (SP; table-chair), emotional priming (EP; murder-garbage), and emotional plus semantic priming (ESP; cemetery-coffin). RESULTS: Patients displayed a more depressed mood than controls. For patients, we found a SP effect in the ESP condition and a striking inhibition effect (i.e., negative target recognized more slowly when preceded by a negative prime rather than a neutral one) in the EP condition. For controls, a priming effect was found in the SP and ESP conditions, but not the EP condition. Finally, whereas the priming effect was greater in SP than in the other two conditions for controls, for patients it was the EP condition that stood out from the other two, being the only condition that led to an inhibition effect. CONCLUSIONS: We highlighted a mood congruency effect in TGA which could impel patients to focus their attention on negative information. While the negative valence of items always led to a slowdown in reaction times for both patients and controls, attesting to a negativity bias, this bias was greater in patients, leading to an inhibition effect.

The relationship between working memory and episodic memory disorders in transient global amnesia.

In a previous study, we investigated the relationship between the disorders of both episodic memory and working memory in the acute phase of transient global amnesia (TGA). Since executive functions were spared, another dysfunction may be responsible for the binding and maintenance of multimodal informations and contribute to the encoding disorders observed in some patients [Quinette, P., Guillery, B., Desgranges, B., de la Sayette, V., Viader, F., & Eustache, F. (2003). Working memory and executive functions in transient global amnesia. Brain, 126, 1917-1934.]. The aim of this present study was to assess the functions of binding and maintenance of multimodal information during TGA and explore their involvement in episodic memory disorders. We therefore conducted a more thorough investigation of working memory in 16 new patients during the acute phase of TGA using two tasks designed to assess the binding process and both dimensions of the maintenance, namely the active storage and the memory load ability. We also investigated the nature of the episodic memory impairment in distinguishing between the performance of patients with preferential encoding deficits and those of patients with preferential storage disorders on the episodic memory task. This distinction was closely related to the severity of amnesia, i.e. an encoding disorder was observed rather in the early phase of TGA. The results showed that while the functions of binding and maintenance of multimodal information were intact in patients with storage disorders, they were impaired in the case of encoding deficits. These results are interpreted in the recent framework of episodic buffer proposed by Baddeley [Baddeley, A. D. (2000). The episodic buffer: A new component of working memory? Trends in Cognitive Sciences, 4, 417-423] that represents an interface between working memory and episodic memory.

Influence of patients' emotional state on the recovery processes after a transient global amnesia.

INTRODUCTION: Currently, there is no consensus on the delay necessary to a complete recovery after a transient global amnesia (TGA). However, it seems that slight episodic memory disorders extend beyond 24h. Although this impairment is probably a consequence of the TGA attack, other factors such as patients' emotional state can intervene in the slow recovery process. METHODS: In a first experiment, we studied the dynamic of recovery processes after a TGA. Thus, we assessed the anterograde and retrograde components of episodic memory in 19 patients one day, one month and one year after the attack. In a second experiment, we examined the impact of patients' emotional state on memory disorders, in using an original neuropsychological protocol (using material with emotional features) and an assessment of anxiety and depressive mood. This protocol was carried out in 19 other patients examined four months and one year after TGA. RESULTS: In the first experiment, we highlighted mild memory disorders affecting the anterograde component of episodic memory one day after the episode. In the second experiment, we showed these mild memory disorders could be detected several months after TGA. Moreover, patients who had the more depressive tendencies recognized the fewer items and those who displayed the highest level of anxiety supplied the fewer specific remote memories. CONCLUSIONS: Our results showed that patients displayed very mild memory disorders several months after the episode of TGA, not affecting the daily routine. This impairment was influenced by patients' emotional state, which could suggest that a high level of anxiety or depression can slow down the recovery. However, we cannot be sure that the deleterious effect of patients' emotional state on their cognitive performances is specific to TGA. Other investigations are necessary to unravel this issue.

Psychopathological factors, memory disorders and transient global amnesia.

BACKGROUND: Some studies have shown the presence of psychopathological disorders in transient global amnesia. AIMS: To determine whether transient global amnesia is associated with psychopathological disorders and to assess the influence of these psychopathological disorders on memory impairments. METHOD: Levels of anxiety and depression before and during transient global amnesia were rated. Memory performances were assessed by means of original episodic memory tasks and working memory tasks. These data were collected in 17 individuals observed during the very acute phase, 18 individuals examined in the peri-acute phase and 26 controls. RESULTS: During the acute phase, participants with transient global amnesia displayed a higher level of anxiety and a more depressed mood than controls. An alteration of emotional state, as measured by the Adjective Mood Scale, was correlated with deficits in anterograde memory. CONCLUSIONS: Transient global amnesia comprises sudden changes in people's emotional state, which has a major impact on and interacts with episodic memory impairment.