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1.
Med Klin Intensivmed Notfmed ; 119(6): 465-469, 2024 Sep.
Artículo en Alemán | MEDLINE | ID: mdl-39120610

RESUMEN

End-stage liver disease is a life-threatening clinical syndrome combined with a state of immune dysfunction. In this constellation patients are prone to bacterial, fungal and viral infections associated with markedly increased morbidity and mortality rates. Bacterial infections are the most prevalent kind of infection in patients with end-stage liver disease accounting for nearly 30%. The evolving rates of multidrug resistant organisms present enormous challenges in treatment strategies. Therefore, the urgent needs for prevention, early detection strategies and widespread treatment options are a necessity to handle the rising incidence of infection complications in end-stage liver disease.


Asunto(s)
Infecciones Bacterianas , Cirrosis Hepática , Humanos , Cirrosis Hepática/complicaciones , Cirrosis Hepática/mortalidad , Cirrosis Hepática/diagnóstico , Infecciones Bacterianas/diagnóstico , Micosis/diagnóstico , Micosis/etiología , Estudios Transversales , Infecciones Oportunistas/mortalidad , Infecciones Oportunistas/diagnóstico , Infecciones Oportunistas/inmunología , Factores de Riesgo , Enfermedad Hepática en Estado Terminal/mortalidad , Enfermedad Hepática en Estado Terminal/diagnóstico , Virosis/complicaciones , Virosis/diagnóstico , Trasplante de Hígado , Huésped Inmunocomprometido , Tasa de Supervivencia
2.
Psychol Sci ; 35(9): 995-1009, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38913829

RESUMEN

Working memory (WM) is a goal-directed memory system that actively maintains a limited amount of task-relevant information to serve the current goal. By this definition, WM maintenance should be terminated after the goal is accomplished, spontaneously removing no-longer-relevant information from WM. Past studies have failed to provide direct evidence of spontaneous removal of WM content by allowing participants to engage in a strategic reallocation of WM resources to competing information within WM. By contrast, we provide direct neural and behavioral evidence that visual WM content can be largely removed less than 1 s after it becomes obsolete, in the absence of a strategic allocation of resources (total N = 442 adults). These results demonstrate that visual WM is intrinsically a goal-directed system, and spontaneous removal provides a means for capacity-limited WM to keep up with ever-changing demands in a dynamic environment.


Asunto(s)
Memoria a Corto Plazo , Percepción Visual , Humanos , Memoria a Corto Plazo/fisiología , Adulto , Masculino , Femenino , Adulto Joven , Percepción Visual/fisiología
3.
Viruses ; 16(3)2024 03 08.
Artículo en Inglés | MEDLINE | ID: mdl-38543784

RESUMEN

(1) Background: Critically ill patients are frequently diagnosed with pulmonary Herpes simplex virus-1 (HSV) reactivation, which then can lead to HSV bronchopneumonitis and is associated with higher mortality and longer mechanical ventilation. For the particular subgroup of critically ill patients with acute on chronic liver failure (ACLF), however, the impact of HSV reactivation is unknown. We investigated the impact of HSV reactivation in these patients. (2) Methods: We conducted a retrospective analysis, evaluating data from 136 mechanically ventilated patients with ACLF between January 2016 and August 2023. Clinical parameters were compared between patients with and without HSV bronchopneumonitis. (3) Results: 10.3% were diagnosed with HSV bronchopneumonitis (HSV group). Mortality did not differ between the HSV and non-HSV group (85.7% vs. 75.4%, p = 0.52). However, the clinical course in the HSV group was more complicated as patients required significantly longer mechanical ventilation (14 vs. 21 days, p = 0.04). Furthermore, fungal superinfections were significantly more frequent in the HSV group (28.6% vs. 6.6%, p = 0.006). (4) Conclusions: Mortality of critically ill patients with ACLF with HSV bronchopneumonitis was not increased in spite of the cirrhosis-associated immune dysfunction. Their clinical course, however, was more complicated with significantly longer mechanical ventilation.


Asunto(s)
Insuficiencia Hepática Crónica Agudizada , Herpes Simple , Herpesvirus Humano 1 , Humanos , Estudios Retrospectivos , Enfermedad Crítica , Progresión de la Enfermedad
4.
Endosc Int Open ; 12(3): E361-E366, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38464982

RESUMEN

Background and study aims The prognosis for pancreatic cancer remains poor. Molecular diagnostics and customized therapies are becoming increasingly important in clinical routine. Patient-derived, predictive model systems such as organoids have the potential to substantially increase the depth of information from biopsy material by functional and molecular characterization. We compared the extent to which the use of fine-needle aspiration needles (FNA, 22G) or fine-needle biopsy needles (FNB, 22G) influences the generation of pancreatic cancer patient-derived organoids (PDOs) to establish endoscopic standards of organoid technology. Patients and methods Endoscopic ultrasound (EUS)-guided punctures by EUS-FNA and EUS-FNB of pancreatic masses highly suspicious for adenocarcinoma (detected by computed tomography and/or magnetic resonance imaging) were prospectively evaluated. Consecutive patients received EUS-FNA and EUS-FNB in a randomized order without the need to exchange the needle shaft (only the inner needle type (FNA/-B) was exchanged) between the passes. With each needle type, the specimens for histological analysis and for PDOs were obtained separately. Results Fifty patients were enrolled in the study. Histology revealed malignancy in 42 of 50 cases (84%). In total PDOs were generated from 17 patients (34%). Of these, nine were established by FNB only, two by FNA only, and six by both FNA and FNB. Histology revealed malignancy in 13 of 17 PDO cases (76%). In two histologically false-negative cases, PDOs could be established. Conclusions EUS-FNB was superior to EUS-FNA in terms of successful generation of PDOs, although it failed to show statistical significance.

5.
Clin Transl Gastroenterol ; 15(2): e00660, 2024 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-38088370

RESUMEN

INTRODUCTION: The identification of risk factors for precursor lesions of colorectal cancer (CRC) holds great promise in the context of prevention. With this study, we aimed to identify patient characteristics associated with colorectal polyps (CPs) and polyp features of potential malignant progression. Furthermore, a potential association with gut microbiota in this context was investigated. METHODS: In this single-center study, a total of 162 patients with CPs and 91 control patients were included. Multiple variables including information on lifestyle, diet, serum parameters, and gut microbiota, analyzed by 16S-rRNA gene amplicon sequencing and functional imputations (Picrust2), were related to different aspects of CPs. RESULTS: We observed that elevated serum alkaline phosphatase (AP) levels were significantly associated with the presence of high-grade dysplastic polyps. This association was further seen for patients with CRC. Thereby, AP correlated with other parameters of liver function. We did not observe significant changes in the gut microbiota between patients with CP and their respective controls. However, a trend toward a lower alpha-diversity was seen in patients with CRC. Interestingly, AP was identified as a possible clinical effect modifier of stool sample beta diversity. DISCUSSION: We show for the first time an increased AP in premalignant CP. Furthermore, AP showed a significant influence on the microbial composition of the intestine. Relatively elevated liver enzymes, especially AP, may contribute to the detection of precancerous dysplastic or neoplastic changes in colorectal lesions. The association between elevated AP, premalignant CP, and the microbiome merits further study.


Asunto(s)
Pólipos del Colon , Neoplasias Colorrectales , Microbioma Gastrointestinal , Humanos , Neoplasias Colorrectales/genética , Pólipos del Colon/diagnóstico , Pólipos del Colon/patología , Bacterias , Heces , Microbioma Gastrointestinal/genética , Hiperplasia
6.
Curr Opin Psychol ; 55: 101782, 2024 02.
Artículo en Inglés | MEDLINE | ID: mdl-38160572

RESUMEN

A growing body of research suggests that prosocial behavior increases across adulthood. Yet, whether these age differences reflect "pure altruistic" or selfish motives, or the developmental mechanisms that underlie them, are largely unknown. Within a value-based decision framework, pure altruistic tendencies can be measured and distinguished from impure altruistic motives through neural-level information. Indeed, age differences in donations appear to be driven by a genuine concern for the well-being of others. Candidate mechanisms behind such pure altruistic changes need to show documented age differences and evidence of causal links to prosocial behavior. As examples, we discuss how three factors that meet these criteria--social norms, mood, and cognitive functioning--might explain age differences in pure altruistic tendencies.


Asunto(s)
Altruismo , Motivación , Humanos , Adulto , Cognición , Afecto
7.
Cognition ; 239: 105578, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37541029

RESUMEN

Hierarchical control is often thought to dissect a complex task space into isolated subspaces in order to eliminate interference. Yet, there is also evidence from serial-order control tasks that our cognitive system can make use of abstract relationships between different parts (chunks) of a sequence. Past evidence in this regard was limited to situations with ordered stimuli (e.g., numbers or positions) that may have aided the detection of relationships and allowed gradual learning and hypothesis testing. Therefore, we used a modified task-span paradigm (with no ordered elements between tasks) in which participants performed memorized sequences of tasks that were encoded in terms of separate chunks of three tasks each. To allow examination of learning effects, each sequence was "cycled" through repeatedly. Importantly, we compared sequences whose chunks were governed by a common, abstract grammar with sequences whose chunks were governed by different grammars. Experiment 1 examined the effect of relationships between shared-element chunks (e.g., ABB-BAA vs. ABB-BAB), Experiment 2 and 3 between different-element chunks (e.g., ABA-CDC vs. ABA-CCD), and Experiment 4 examined second-order relationships (e.g., ABA-ABB--CDC-CDD vs. ABA-ABB--CDC-CCD). Robust evidence in favor of beneficial effects of abstract inter-chunk relationships was obtained across all four experiments. Importantly, these effects were at least as strong in initial cycles of performing a given sequence as during later cycles, suggesting that the cognitive system operates with an "expectation of abstract relationships," rather than benefitting from them through gradual learning. We discuss the implications of these results for models of hierarchical control.


Asunto(s)
Aprendizaje , Memoria , Humanos
8.
Digestion ; 104(5): 391-399, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37331350

RESUMEN

INTRODUCTION: Cold snare polypectomy (CSP) is a safe and effective procedure for small colorectal polyps ≤9 mm. There are only limited data regarding CSP of larger neoplastic lesions. This study evaluated the efficacy and safety of CSP for polyps between 10 and 15 mm in size. METHODS: In this prospective single-arm observational pilot study, patients with a least one polyp 10-15 mm were included. These polyps were preferably removed by CSP using a dedicated hybrid snare. The primary outcome was the histological complete resection rate (CRR) determined by pathologically negative margins of the specimen and no neoplastic tissue obtained from biopsies of the resection site margin. Secondary outcomes were en bloc resection rate, failure of CSP, and incidence of adverse events. RESULTS: A total of 61 neoplastic polyps were removed from 39 patients. Overall CRR was 80.3% (49/61). CSP was feasible in 78.7% (48/61) of polyps and the CRR in this group was 85.4% (41/48). When CSP failed (13/61; 21.3%), lesions were successfully resected by immediate HSP using the same snare with a CRR of 61.5% (8/13) in this group. One patient presented delayed hemorrhage after HSP of a polyp but successful hemostasis was achieved with two hemoclips. No other adverse events occurred. No recurrence was seen on follow-up colonoscopy in cases with incomplete resected polyps. CONCLUSION: CSP seems to be efficient and safe in removing colorectal polyps up to 15 mm. A hybrid snare seems to be particularly advantageous for these polyps as it allows immediate conversion to HSP if CSP might fail in larger polyps. This trial is registered at ClinicalTrials.gov (NCT04464837).


Asunto(s)
Pólipos del Colon , Neoplasias Colorrectales , Humanos , Colonoscopía/efectos adversos , Colonoscopía/métodos , Pólipos del Colon/cirugía , Pólipos del Colon/patología , Estudios Prospectivos , Proyectos Piloto , Resultado del Tratamiento , Márgenes de Escisión , Neoplasias Colorrectales/patología
9.
Eur Radiol ; 33(11): 7380-7387, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37284864

RESUMEN

OBJECTIVE: For transjugular intrahepatic portosystemic shunt (TIPS) creation, ultrasound guidance for portal vein puncture is strongly recommended. However, outside regular hours of service, a skilled sonographer might be lacking. Hybrid intervention suites combine CT imaging with conventional angiography allowing to project 3D information into the conventional 2D imaging and further CT-fluoroscopic puncture of the portal vein. The purpose of this study was to assess whether TIPS using angio-CT facilitates the procedure for a single interventional radiologist. METHODS: All TIPS procedures from 2021 and 2022 which took place outside regular working hours were included (n = 20). Ten TIPS procedures were performed with just fluoroscopy guidance and ten procedures using angio-CT. For the angio-CT TIPS, a contrast-enhanced CT was performed on the angiography table. From the CT, a 3D volume was created using virtual rendering technique (VRT). The VRT was blended with the conventional angiography image onto the live monitor and used as guidance for the TIPS needle. Fluoroscopy time, area dose product, and interventional time were assessed. RESULTS: Hybrid intervention with angio-CT did lead to a significantly shorter fluoroscopy time and interventional time (p = 0.034 for both). Mean radiation exposure was significantly reduced, too (p = 0.04). Furthermore, the mortality rate was lower in patients who underwent the hybrid TIPS (0% vs 33%). CONCLUSION: TIPS procedure in angio-CT performed by only one interventional radiologist is quicker and reduces radiation exposure for the interventionalist compared to mere fluoroscopy guidance. The results further indicate increased safety using angio-CT. CLINICAL RELEVANCE STATEMENT: This study aimed to evaluate the feasibility of using angio-CT in TIPS procedures during non-standard working hours. Results indicated that the use of angio-CT significantly reduced fluoroscopy time, interventional time, and radiation exposure, while also leading to improved patient outcomes. KEY POINTS: • Image guiding such as ultrasound is recommended for transjugular intrahepatic portosystemic shunt creation but might be not available for emergency cases outside of regular working hours. • Transjugular intrahepatic portosystemic shunt creation using an angio-CT with image fusion is feasible for only one physician under emergency settings and results in lower radiation exposure and faster procedures. • Transjugular intrahepatic portosystemic shunt creation using an angio-CT with image fusion seems to be safer than using mere fluoroscopy guidance.


Asunto(s)
Derivación Portosistémica Intrahepática Transyugular , Humanos , Derivación Portosistémica Intrahepática Transyugular/métodos , Vena Porta/diagnóstico por imagen , Vena Porta/cirugía , Angiografía , Ultrasonografía , Tomografía Computarizada por Rayos X , Resultado del Tratamiento , Estudios Retrospectivos
10.
Cogn Psychol ; 144: 101582, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37352807

RESUMEN

Most task spaces require a hierarchical structure, where decisions on one level are contingent on previous decisions made on one or more higher levels. While it is a truism that increasing the number of hierarchical levels makes it harder to solve a given task, the exact nature of this "number-of-levels" effect is not clear. On the one hand, processing costs might be strictly "local," incurred only when higher-level settings need to be updated, while otherwise lower-level decisions are insulated from the presence of higher-level settings (local updating costs with ballistic control). On the other hand, maintaining and integrating more complex hierarchical structures could require overall greater representational resources, negatively affecting each individual decision within the represented task space (global integration/maintenance costs). Further, navigation through hierarchical structures can be guided either through prompts in the environment (cue-based), or through sequential plans (serial-order based), with potentially distinct maintenance and updating demands. In two experiments, we assessed performance as a function of hierarchical level and format (serial-order vs. cue-based). Model comparisons showed that the pattern of costs in the serial-order format was consistent with a global maintenance/integration account. In contrast, in the cue-based format, costs arose at updating points and when one additional relevant level beyond the current decision was relevant, while additional levels produced no further costs. This overall constellation of costs can be explained by assuming that each decision requires checking the immediately relevant higher-level context for that decision. For cue-based control, this context involves the "next-level-up" rule, whereas in the serial-order format, each trial requires updating of the current position within the sequence, which in turn requires integration across all relevant hierarchical levels.


Asunto(s)
Cognición , Señales (Psicología) , Humanos
11.
J Clin Med ; 12(7)2023 Mar 28.
Artículo en Inglés | MEDLINE | ID: mdl-37048641

RESUMEN

Acute-on-chronic liver failure (ACLF) is associated with high mortality. Objective prognostic scores are important for treatment decisions. EASIX (Endothelial Activation and Stress Index) is a simple biomarker consisting of LDH, platelets, and creatinine, reflecting endothelial dysfunction after allogeneic stem cell transplantation. Considering endothelial dysfunction in the pathogenesis of ACLF, this study aimed to test the discriminative ability of EASIX in advanced liver disease. We retrospectively analysed the prognostic potential of EASIX to predict 28-day and 3-month mortality in a total of 188 liver cirrhotic patients requiring treatment at the intensive care unit. We evaluated the ability of EASIX to rule out early infections and predict the need for hemodialysis. EASIX performed moderately better than established scores in predicting 28-day mortality (AUC = 0.771) and was nearly equivalent (AUC = 0.791) to SOFA and APACHE-II in the prediction of 3-month mortality. Importantly, EASIX showed better diagnostic potential in ruling out clinically apparent infections than common proinflammatory markers (AUC = 0.861, p < 0.001) and showed suitable accuracy in predicting the need for hemodialysis (AUC = 0.833). EASIX is an accurate, objective and easily assessable biomarker for predicting mortality and complications in patients with advanced liver disease.

12.
Diagnostics (Basel) ; 13(5)2023 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-36900138

RESUMEN

Ascitic fluid infection is a serious complication of liver cirrhosis. The distinction between the more common spontaneous bacterial peritonitis (SBP) and the less common secondary peritonitis in patients with liver cirrhosis is crucial due to the varying treatment approaches. This retrospective multicentre study was conducted in three German hospitals and analysed 532 SBP episodes and 37 secondary peritonitis episodes. Overall, >30 clinical, microbiological, and laboratory parameters were evaluated to identify key differentiation criteria. Microbiological characteristics in ascites followed by severity of illness and clinicopathological parameters in ascites were the most important predictors identified by a random forest model to distinguish between SBP and secondary peritonitis. To establish a point-score model, a least absolute shrinkage and selection operator (LASSO) regression model selected the ten most promising discriminatory features. By aiming at a sensitivity of 95% either to rule out or rule in SBP episodes, two cut-off scores were defined, dividing patients with infected ascites into a low-risk (score ≥ 45) and high-risk group (score < 25) for secondary peritonitis. Overall, the discrimination of secondary peritonitis from SBP remains challenging. Our univariable analyses, random forest model, and LASSO point score may help clinicians with the crucial differentiation between SBP and secondary peritonitis.

13.
J Intensive Care Med ; 38(8): 717-726, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-36872888

RESUMEN

Introduction: Septic shock is associated with high mortality and hemodynamic impairment. The use of corticoids is a common therapeutic tool in critically ill patients. However, data on the mechanisms and prognostic ability of hemodynamic improvement by adjunctive steroids are rare. This study primarily aimed to evaluate short-term effects of hydrocortisone therapy on catecholamine requirement and hemodynamics derived from transpulmonary thermodilution (TPTD) in 30 critically ill patients with septic shock and a 28 days mortality rate of 50%. Methods: Hydrocortisone was administered with an intravenous bolus of 200 mg, followed by a continuous infusion of 200 mg per 24 h. Hemodynamic assessment was performed immediately before as well as 2, 8, 16, and 24 h after the initiation of corticoids. For primary endpoint analysis, we evaluated the impact of hydrocortisone on vasopressor dependency index (VDI) and cardiac power index (CPI). Results: Adjunctive hydrocortisone induced significant decreases of VDI from 0.41 (0.29-0.49) mmHg-1 at baseline to 0.35 (0.25-0.46) after 2 h (P < .001), 0.24 (0.12-0.35) after 8 h (P < .001), 0.18 (0.09-0.24) after 16 h (P < .001) and 0.11 (0.06-0.20) mmHg-1 after 24 h (P < .001). In parallel, we found an improvement in CPI from 0.63 (0.50-0.83) W/m2 at baseline to 0.68 (0.54-0.85) after 2 h (P = .208), 0.71 (0.60-0.90) after 8 h (P = .033), 0.82 (0.6-0.98) after 16 h (P = .004) and 0.90 (0.67-1.07) W/m2 after 24 h (P < .001). Our analyses revealed a significant reduction in noradrenaline requirement in parallel with a moderate increase in mean arterial pressure, systemic vascular resistance index, and cardiac index. As a secondary endpoint, our results showed a significant decrease in lung water parameters. Moreover, changes in CPI (ΔCPI) and VDI (ΔVDI) after 24 h of hydrocortisone therapy revealed accurate prognostic ability to predict 28 days mortality (AUC = 0.802 vs 0.769). Conclusion: Adjunctive hydrocortisone leads to a rapid decrease in catecholamine requirement and a substantial circulatory improvement in critically ill patients with septic shock.


Asunto(s)
Choque Séptico , Humanos , Hidrocortisona/uso terapéutico , Termodilución/métodos , Enfermedad Crítica/terapia , Hemodinámica , Norepinefrina , Vasoconstrictores/uso terapéutico , Vasoconstrictores/farmacología
14.
Endoscopy ; 55(5): 415-422, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-36323331

RESUMEN

BACKGROUND: Risk stratification and recommendation for surgery for intraductal papillary mucinous neoplasm (IPMN) are currently based on consensus guidelines. Risk stratification from presurgery histology is only potentially decisive owing to the low sensitivity of fine-needle aspiration. In this study, we developed and validated a deep learning-based method to distinguish between IPMN with low grade dysplasia and IPMN with high grade dysplasia/invasive carcinoma using endoscopic ultrasound (EUS) images. METHODS: For model training, we acquired a total of 3355 EUS images from 43 patients who underwent pancreatectomy from March 2015 to August 2021. All patients had histologically proven IPMN. We used transfer learning to fine-tune a convolutional neural network and to classify "low grade IPMN" from "high grade IPMN/invasive carcinoma." Our test set consisted of 1823 images from 27 patients, recruiting 11 patients retrospectively, 7 patients prospectively, and 9 patients externally. We compared our results with the prediction based on international consensus guidelines. RESULTS: Our approach could classify low grade from high grade/invasive carcinoma in the test set with an accuracy of 99.6 % (95 %CI 99.5 %-99.9 %). Our deep learning model achieved superior accuracy in prediction of the histological outcome compared with any individual guideline, which have accuracies between 51.8 % (95 %CI 31.9 %-71.3 %) and 70.4 % (95 %CI 49.8-86.2). CONCLUSION: This pilot study demonstrated that deep learning in IPMN-EUS images can predict the histological outcome with high accuracy.


Asunto(s)
Adenocarcinoma Mucinoso , Carcinoma Ductal Pancreático , Aprendizaje Profundo , Neoplasias Intraductales Pancreáticas , Neoplasias Pancreáticas , Humanos , Carcinoma Ductal Pancreático/patología , Estudios Retrospectivos , Neoplasias Intraductales Pancreáticas/diagnóstico por imagen , Proyectos Piloto , Adenocarcinoma Mucinoso/patología , Neoplasias Pancreáticas/patología
15.
Antibiotics (Basel) ; 11(11)2022 Nov 12.
Artículo en Inglés | MEDLINE | ID: mdl-36421254

RESUMEN

This study is aimed at assessing the distinctive features of patients with infected ascites and liver cirrhosis and developing a scoring system to allow for the accurate identification of patients not requiring abdominocentesis to rule out infected ascites. A total of 700 episodes of patients with decompensated liver cirrhosis undergoing abdominocentesis between 2006 and 2020 were included. Overall, 34 clinical, drug, and laboratory features were evaluated using machine learning to identify key differentiation criteria and integrate them into a point-score model. In total, 11 discriminatory features were selected using a Lasso regression model to establish a point-score model. Considering pre-test probabilities for infected ascites of 10%, 15%, and 25%, the negative and positive predictive values of the point-score model for infected ascites were 98.1%, 97.0%, 94.6% and 14.9%, 21.8%, and 34.5%, respectively. Besides the main model, a simplified model was generated, containing only features that are fast to collect, which revealed similar predictive values. Our point-score model appears to be a promising non-invasive approach to rule out infected ascites in clinical routine with high negative predictive values in patients with hydropic decompensated liver cirrhosis, but further external validation in a prospective study is needed.

16.
Elife ; 112022 10 31.
Artículo en Inglés | MEDLINE | ID: mdl-36314769

RESUMEN

For flexible goal-directed behavior, prioritizing and selecting a specific action among multiple candidates are often important. Working memory has long been assumed to play a role in prioritization and planning, while bridging cross-temporal contingencies during action selection. However, studies of working memory have mostly focused on memory for single components of an action plan, such as a rule or a stimulus, rather than management of all of these elements during planning. Therefore, it is not known how post-encoding prioritization and selection operate on the entire profile of representations for prospective actions. Here, we assessed how such control processes unfold over action representations, highlighting the role of conjunctive representations that nonlinearly integrate task-relevant features during maintenance and prioritization of action plans. For each trial, participants prepared two independent rule-based actions simultaneously, then they were retro-cued to select one as their response. Prior to the start of the trial, one rule-based action was randomly assigned to be high priority by cueing that it was more likely to be tested. We found that both full action plans were maintained as conjunctive representations during action preparation, regardless of priority. However, during output selection, the conjunctive representation of the high-priority action plan was more enhanced and readily selected as an output. Furthermore, the strength of the high-priority conjunctive representation was associated with behavioral interference when the low-priority action was tested. Thus, multiple alternate upcoming actions were maintained as integrated representations and served as the target of post-encoding attentional selection mechanisms to prioritize and select an action from within working memory.


Asunto(s)
Atención , Memoria a Corto Plazo , Humanos , Estudios Prospectivos , Memoria a Corto Plazo/fisiología , Atención/fisiología , Señales (Psicología)
17.
Psychol Aging ; 37(7): 816-826, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-36074581

RESUMEN

We tested the hypothesis that there is an age-related deficit in the recovery from interruptions. This hypothesis is based on the idea that it is more difficult for old than for young adults to establish a focused state after working memory has been "opened up" through an interruption. Old (N = 95) and young adults (N = 94) performed competing nondominant and dominant primary tasks (selecting either exogenously or endogenously cued targets) in alternating, single-task blocks that were occasionally interrupted through trials with unrelated math tasks. As predicted, after interruptions, older adults showed increased and prolonged recovery costs, as well as generally larger endogenous/exogenous and conflict effects in blocks that contained interruptions. Individual differences in working memory (WM) capacity did not produce comparable results, suggesting that the interruption-based deficits were specific to aging. In addition, the theoretically important, paradoxical cost asymmetry (i.e., larger interruption costs for the dominant exogenous than for the nondominant endogenous task) was stronger in old than in young adults. These results provide novel insights about the interplay between WM and long-term memory during task control, as well as the origin of age differences in task-set selection. (PsycInfo Database Record (c) 2022 APA, all rights reserved).


Asunto(s)
Envejecimiento , Memoria a Corto Plazo , Humanos , Anciano , Memoria a Largo Plazo , Individualidad
18.
EMBO Mol Med ; 14(4): e14876, 2022 04 07.
Artículo en Inglés | MEDLINE | ID: mdl-35119792

RESUMEN

Despite the advance and success of precision oncology in gastrointestinal cancers, the frequency of molecular-informed therapy decisions in pancreatic ductal adenocarcinoma (PDAC) is currently neglectable. We present a longitudinal precision oncology platform based on functional model systems, including patient-derived organoids, to identify chemotherapy-induced vulnerabilities. We demonstrate that treatment-induced tumor cell plasticity in vivo distinctly changes responsiveness to targeted therapies, without the presence of a selectable genetic marker, indicating that tumor cell plasticity can be functionalized. By adding a mechanistic layer to precision oncology, adaptive processes of tumors under therapy can be exploited, particularly in highly plastic tumors, such as pancreatic cancer.


Asunto(s)
Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Carcinoma Ductal Pancreático/tratamiento farmacológico , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/patología , Humanos , Organoides/patología , Neoplasias Pancreáticas/tratamiento farmacológico , Neoplasias Pancreáticas/patología , Medicina de Precisión , Neoplasias Pancreáticas
19.
Psychol Sci ; 33(2): 325-338, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-35108148

RESUMEN

Action selection appears to rely on conjunctive representations that nonlinearly integrate task-relevant features. Here, we tested a corollary of this hypothesis: that such representations are also intricately involved during attempts to stop an action-a key aspect of action regulation. We tracked both conjunctive representations and those of constituent rule, stimulus, or response features through trial-by-trial representational similarity analysis of the electroencephalogram signal in a combined rule-selection and stop-signal paradigm. Across two experiments with student participants (N = 57), we found (a) that the strength of decoded conjunctive representations prior to the stop signal uniquely predicted trial-by-trial stopping success (Experiment 1) and (b) that these representations were selectively suppressed following the onset of the stop signal (Experiments 1 and 2). We conclude that conjunctive representations are key to successful action execution and therefore need to be suppressed when an intended action is no longer appropriate.


Asunto(s)
Electroencefalografía , Electroencefalografía/métodos , Humanos , Tiempo de Reacción/fisiología
20.
J Pers Soc Psychol ; 123(4): 693-716, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35201818

RESUMEN

Testosterone has been theorized to direct status-seeking behaviors, including competitive behavior. However, most human studies to date have adopted correlational designs, and findings across studies are inconsistent. This experiment (n = 115) pharmacologically manipulated men's testosterone levels prior to a mixed-gender math competition and examined basal cortisol (a hormone implicated in stress and social avoidance) and context cues related to an opponent's perceived status (an opponent's gender or a win/loss in a prior competition) as factors that may moderate testosterone's impact on competitive behavior. We test and find support for the hypothesis that testosterone given to low-cortisol men evokes status-seeking behavior, whereas testosterone given to high-cortisol men evokes status-loss avoidance. In the initial rounds of competition, testosterone's influence on competitive decisions depended on basal cortisol and opponent gender. After providing opponent-specific win-lose feedback, testosterone's influence on decisions to reenter competitions depended on basal cortisol and this objective cue to status, not gender. Compared to placebo, men given exogenous testosterone who were low in basal cortisol showed an increased tendency to compete against male and high-status opponents relative to female and low-status opponents (status-seeking). Men given exogenous testosterone who were high in basal cortisol showed the opposite pattern-an increased tendency to compete against female and low-status opponents relative to male and high-status opponents (status-loss avoidance). These results provide support for a context-dependent dual-hormone hypothesis: Testosterone flexibly directs men's competitive behavior contingent on basal cortisol levels and cues that signal an opponent's status. (PsycInfo Database Record (c) 2022 APA, all rights reserved).


Asunto(s)
Hidrocortisona , Testosterona , Conducta Competitiva , Señales (Psicología) , Femenino , Humanos , Masculino , Saliva
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