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1.
J Neurosci ; 43(15): 2767-2781, 2023 04 12.
Artículo en Inglés | MEDLINE | ID: mdl-36894317

RESUMEN

To better understand how prefrontal networks mediate forms of cognitive control disrupted in schizophrenia, we translated a variant of the AX continuous performance task that measures specific deficits in the human disease to 2 male monkeys and recorded neurons in PFC and parietal cortex during task performance. In the task, contextual information instructed by cue stimuli determines the response required to a subsequent probe stimulus. We found parietal neurons encoding the behavioral context instructed by cues that exhibited nearly identical activity to their prefrontal counterparts (Blackman et al., 2016). This neural population switched their preference for stimuli over the course of the trial depending on whether the stimuli signaled the need to engage cognitive control to override a prepotent response. Cues evoked visual responses that appeared in parietal neurons first, whereas population activity encoding contextual information instructed by cues was stronger and more persistent in PFC. Increasing cognitive control demand biased the representation of contextual information toward the PFC and augmented the temporal correlation of task-defined information encoded by neurons in the two areas. Oscillatory dynamics in local field potentials differed between cortical areas and carried as much information about task conditions as spike rates. We found that, at the single-neuron level, patterns of activity evoked by the task were nearly identical between the two cortical areas. Nonetheless, distinct population dynamics in PFC and parietal cortex were evident. suggesting differential contributions to cognitive control.SIGNIFICANCE STATEMENT We recorded neural activity in PFC and parietal cortex of monkeys performing a task that measures cognitive control deficits in schizophrenia. This allowed us to characterize computations performed by neurons in the two areas to support forms of cognitive control disrupted in the disease. Subpopulations of neurons in the two areas exhibited parallel modulations in firing rate; and as a result, all patterns of task-evoked activity were distributed between PFC and parietal cortex. This included the presence in both cortical areas of neurons reflecting proactive and reactive cognitive control dissociated from stimuli or responses in the task. However, differences in the timing, strength, synchrony, and correlation of information encoded by neural activity were evident, indicating differential contributions to cognitive control.


Asunto(s)
Señales (Psicología) , Corteza Prefrontal , Humanos , Masculino , Corteza Prefrontal/fisiología , Lóbulo Parietal/fisiología , Neuronas/fisiología , Cognición/fisiología
2.
Neuroimage ; 298: 120792, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39147294

RESUMEN

BACKGROUND: Executive dysfunction such as inattention or forgetfulness can lead to disruptions in a person's daily functioning and quality of life. OBJECTIVE/HYPOTHESIS: This triple-blinded randomized clinical trial assessed the efficacy of bifrontal (over the forehead) transcranial direct current stimulation (tDCS) concurrent with cognitive training to improve cognitive performance in a healthy sample. METHODS: Fifty-eight participants were randomly assigned to one of three stimulation conditions (2 mA left anode-right cathode, 2 mA right anode-left cathode, or sham), which was administered with cognitive training tasks 3x/week over 12 weeks with assessments at baseline, midpoint (6 weeks), and post-training (12 weeks). We assessed cognitive performance, functional connectivity, and the influence of individual differences in training advancement. RESULTS: Forty participants completed training. We found that at midpoint and post, all groups improved significantly on overall cognitive performance. The left anode group's attention & vigilance score improved significantly at post, but the other two groups did not. Greater attention training advancement predicted attention improvement by post, most notably in the left anode group. Finally, within-network connectivity decreased in the control network and increased in the somatomotor network across all groups. CONCLUSIONS: These results suggest that, given cognitive training, the left anode montage is more effective at improving attention than the right anode montage and sham. Future research may focus on the application of the left anode montage during cognitive training to assess its effectiveness in improving cognition in neuropsychiatric disorders.


Asunto(s)
Atención , Estimulación Transcraneal de Corriente Directa , Humanos , Masculino , Femenino , Estimulación Transcraneal de Corriente Directa/métodos , Adulto , Atención/fisiología , Adulto Joven , Imagen por Resonancia Magnética , Red Nerviosa/diagnóstico por imagen , Red Nerviosa/fisiología , Cognición/fisiología , Función Ejecutiva/fisiología , Entrenamiento Cognitivo
3.
Cogn Affect Behav Neurosci ; 23(1): 203-215, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36418846

RESUMEN

Cognitive control deficits are associated with impaired executive functioning in schizophrenia. The Dual Mechanisms of Control framework suggests that proactive control requires sustained dorsolateral prefrontal activity, whereas reactive control marshals a larger network. However, primate studies suggest these processes are maintained by dual-encoding regions. To distinguish between these theories, we compared the distinctiveness of proactive and reactive control functional neuroanatomy. In a reanalysis of data from a previous study, 47 adults with schizophrenia and 56 controls completed the Dot Pattern Expectancy task during an fMRI scan examining proactive and reactive control in frontoparietal and medial temporal regions. Areas suggesting specialized control or between-group differences were tested for association with symptoms and task performance. Elastic net models additionally explored these areas' predictive abilities regarding performance. Most regions were active in both reactive and proactive control. However, evidence of specialized proactive control was found in the left middle and superior frontal gyri. Control participants showed greater proactive control in the left middle and right inferior frontal gyri. Elastic net models moderately predicted task performance and implicated various frontal gyri regions in control participants, with additional involvement of anterior cingulate and posterior parietal regions for reactive control. Elastic nets for patient participants implicated the inferior and superior frontal gyri, and posterior parietal lobe. Specialized cognitive control was unassociated with either performance or schizophrenia symptomatology. Future work is needed to clarify the distinctiveness of proactive and reactive control, and its role in executive deficits in severe psychopathology.


Asunto(s)
Neuroanatomía , Esquizofrenia , Humanos , Esquizofrenia/diagnóstico por imagen , Lóbulo Frontal , Corteza Prefrontal/diagnóstico por imagen , Lóbulo Temporal , Imagen por Resonancia Magnética
4.
Psychol Med ; 52(6): 1115-1125, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-32799938

RESUMEN

BACKGROUND: Schizophrenia is a disorder characterized by pervasive deficits in cognitive functioning. However, few well-powered studies have examined the degree to which cognitive performance is impaired even among individuals with schizophrenia not currently on antipsychotic medications using a wide range of cognitive and reinforcement learning measures derived from cognitive neuroscience. Such research is particularly needed in the domain of reinforcement learning, given the central role of dopamine in reinforcement learning, and the potential impact of antipsychotic medications on dopamine function. METHODS: The present study sought to fill this gap by examining healthy controls (N = 75), unmedicated (N = 48) and medicated (N = 148) individuals with schizophrenia. Participants were recruited across five sites as part of the CNTRaCS Consortium to complete tasks assessing processing speed, cognitive control, working memory, verbal learning, relational encoding and retrieval, visual integration and reinforcement learning. RESULTS: Individuals with schizophrenia who were not taking antipsychotic medications, as well as those taking antipsychotic medications, showed pervasive deficits across cognitive domains including reinforcement learning, processing speed, cognitive control, working memory, verbal learning and relational encoding and retrieval. Further, we found that chlorpromazine equivalency rates were significantly related to processing speed and working memory, while there were no significant relationships between anticholinergic load and performance on other tasks. CONCLUSIONS: These findings add to a body of literature suggesting that cognitive deficits are an enduring aspect of schizophrenia, present in those off antipsychotic medications as well as those taking antipsychotic medications.


Asunto(s)
Antipsicóticos , Esquizofrenia , Humanos , Antipsicóticos/uso terapéutico , Dopamina , Cognición , Memoria a Corto Plazo , Pruebas Neuropsicológicas
5.
Colorectal Dis ; 24(3): 257-263, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-34797583

RESUMEN

AIM: Provisional research on the faecal immunohistochemical test (FIT) for symptomatic colorectal patients has shown a high negative predictive value but has lacked long-term patient follow-up, raising the possibility of missed diagnoses of colorectal cancer (CRC). The aim of this work is to describe the long-term diagnostic accuracy of the FIT for CRC and significant bowel disease (SBD) in a symptomatic population in NHS Lanarkshire. METHOD: From October 2016 to February 2019, all primary care referrals of symptomatic colorectal patients in NHS Lanarkshire were asked to provide a FIT. The baseline demographics, investigations and diagnoses for each patient were prospectively completed until February 2021. A FIT result of ≥10 µg haemoglobin (Hb)/g faeces was considered to be positive. RESULTS: A total of 5250 patients were identified (median age 62 years; 46% male; median follow-up 31 months) with 65.1% (3418) being FIT negative. The SBD rate was 6.2% and the CRC rate was 2.9% (151). The SBD rate was significantly higher in the FIT-positive group (13.8% vs. 2.2%; p < 0.001) and 32.9% of patients with FIT ≥ 400 µg Hb/g had SBD. The sensitivity of FIT ≥ 10 µg Hb/g for CRC was 87.4% and for SBD it was 76.9%. Specificity was 66.6% and 66.7%, and the negative-predictive value was 99.4% and 97.7%, respectively. Sensitivity for CRC could theoretically be increased to 94.8% if FIT-negative patients were to undergo flexible sigmoidoscopy. CONCLUSION: A FIT-only referral pathway for symptomatic colorectal patients will miss over 12% of cancers and over 23% of SBD. Theoretically, combining FIT-negative patients with flexible sigmoidoscopy increases the sensitivity for CRC. The FIT offers a mechanism for prioritizing patient access to investigations, particularly in resource-limited areas; however, further work to identify FIT-negative patients diagnosed with CRC is required.


Asunto(s)
Neoplasias Colorrectales , Enfermedades Intestinales , Colonoscopía , Neoplasias Colorrectales/diagnóstico , Detección Precoz del Cáncer , Heces/química , Femenino , Hemoglobinas/análisis , Humanos , Masculino , Persona de Mediana Edad , Sangre Oculta , Sensibilidad y Especificidad
6.
Clin Anat ; 35(4): 421-427, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-34535937

RESUMEN

The precaecocolic fascia, previously known as Jackson's membrane, is a variable vascular peritoneal fold between the ascending colon and the right posterolateral abdominal wall. First described in 1913, it was originally thought to be of developmental or inflammatory origin and associated with abdominal pain. This investigation aimed to review its frequency, form and structure and look for evidence of association with malformation of the bowel, or previous inflammation. 26 dissecting room cadavers were studied to identify the precaecocolic fascia, any malrotation of the colon or signs of previous inflammation: adhesions, surgical scars, or absence of the appendix. Its structure was examined histologically and latex injections were used to trace the arteries. Membranes comparable with previous descriptions of the precaecocolic fascia occurred in 12 of 26 abdomens. They varied in form and size from long and translucent to short, thick, and opaque. In structure, the fascia resembled a fold of peritoneum containing a thickened fibrous lamina. Large thin-walled arteries in the fascia crossed the arteries in the wall of the colon at the point of attachment. No significant association with colonic malrotation or markers of previous inflammation were found. Attention should be paid to the definition of the precaecocolic fascia and "membrane" seems a more appropriate term than "fascia". It is one of a recognized group of peritoneal folds/bands, doubtful in origin but unlikely to be post-inflammatory. It may modify colonic mobility or complicate colonic operations.


Asunto(s)
Colon Ascendente , Colon , Fascia , Humanos , Inflamación , Peritoneo
7.
J Neurosci ; 40(8): 1650-1667, 2020 02 19.
Artículo en Inglés | MEDLINE | ID: mdl-31941665

RESUMEN

The mediodorsal nucleus of the thalamus (MD) is reciprocally connected with the prefrontal cortex (PFC), and although the MD has been implicated in a range of PFC-dependent cognitive functions (Watanabe and Funahashi, 2012; Mitchell and Chakraborty, 2013; Parnaudeau et al., 2018), little is known about how MD neurons in the primate participate specifically in cognitive control, a capability that reflects the ability to use contextual information (such as a rule) to modify responses to environmental stimuli. To learn how the MD-PFC thalamocortical network is engaged to mediate forms of cognitive control that are selectively disrupted in schizophrenia, we trained male monkeys to perform a variant of the AX continuous performance task, which reliably measures cognitive control deficits in patients (Henderson et al., 2012) and used linear multielectrode arrays to record neural activity in the MD and PFC simultaneously. We found that the two structures made clearly different contributions to distributed processing for cognitive control: MD neurons were specialized for decision-making and response selection, whereas prefrontal neurons were specialized to preferentially encode the environmental state on which the decision was based. In addition, we observed that functional coupling between MD and PFC was strongest when the decision as to which of the two responses in the task to execute was being made. These findings delineate unique contributions of MD and PFC to distributed processing for cognitive control and characterized neural dynamics in this network associated with normative cognitive control performance.SIGNIFICANCE STATEMENT Cognitive control is fundamental to healthy human executive functioning (Miller and Cohen, 2001) and deficits in patients with schizophrenia relate to decreased functional activation of the MD thalamus and the prefrontal cortex (Minzenberg et al., 2009), which are reciprocally linked (Goldman-Rakic and Porrino, 1985; Xiao et al., 2009). We carry out simultaneous neural recordings in the MD and PFC while monkeys perform a cognitive control task translated from patients with schizophrenia to relate thalamocortical dynamics to cognitive control performance. Our data suggest that state representation and decision-making computations for cognitive control are preferentially performed by PFC and MD, respectively. This suggests experiments to parse decision-making and state representation deficits in patients while providing novel computational targets for future therapies.


Asunto(s)
Cognición/fisiología , Toma de Decisiones/fisiología , Núcleo Talámico Mediodorsal/fisiopatología , Corteza Prefrontal/fisiopatología , Esquizofrenia/fisiopatología , Animales , Electrodos Implantados , Macaca mulatta , Masculino , Vías Nerviosas/fisiología , Neuronas/fisiología
8.
Hum Brain Mapp ; 42(16): 5244-5263, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34331484

RESUMEN

Perceptions of spiteful behavior are common, distinct from rational fear, and may undergird persecutory ideation. To test this hypothesis and investigate neural mechanisms of persecutory ideation, we employed a novel economic social decision-making task, the Minnesota Trust Game (MTG), during neuroimaging in patients with schizophrenia (n = 30) and community monozygotic (MZ) twins (n = 38; 19 pairs). We examined distinct forms of mistrust, task-related brain activation and connectivity, and investigated relationships with persecutory ideation. We tested whether co-twin discordance on these measurements was correlated to reflect a common source of underlying variance. Across samples persecutory ideation was associated with reduced trust only during the suspiciousness condition, which assessed spite sensitivity given partners had no monetary incentive to betray. Task-based activation contrasts for specific forms of mistrust were limited and unrelated to persecutory ideation. However, task-based connectivity contrasts revealed a dorsal cingulate anterior insula network sensitive to suspicious mistrust, a left frontal-parietal (lF-P) network sensitive to rational mistrust, and a ventral medial/orbital prefrontal (vmPFC/OFC) network that was sensitive to the difference between these forms of mistrust (all p < .005). Higher persecutory ideation was predicted only by reduced connectivity between the vmPFC/OFC and lF-P networks (p = .005), which was only observed when the intentions of the other player were relevant. Moreover, co-twin differences in persecutory ideation predicted co-twin differences in both spite sensitivity and in vmPFC/OFC-lF-P connectivity. This work found that interconnectivity may be particularly important to the complex neurobiology underlying persecutory ideation, and that unique environmental variance causally linked persecutory ideation, decision-making, and brain connectivity.


Asunto(s)
Corteza Cerebral/fisiopatología , Conectoma , Toma de Decisiones/fisiología , Esquizofrenia/fisiopatología , Percepción Social , Confianza , Adolescente , Adulto , Corteza Cerebral/diagnóstico por imagen , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Esquizofrenia/diagnóstico por imagen , Gemelos Monocigóticos , Adulto Joven
9.
Psychol Med ; 51(15): 2610-2619, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-32366335

RESUMEN

BACKGROUND: Generalization of conditioned-fear, a core feature of post-traumatic stress disorder (PTSD), has been the focus of several recent neuroimaging studies. A striking outcome of these studies is the frequency with which neural correlates of generalization fall within hubs of well-established functional networks including salience (SN), central executive (CEN), and default networks (DN). Neural substrates of generalization found to date may thus reflect traces of large-scale brain networks that form more expansive neural representations of generalization. The present study includes the first network-based analysis of generalization and PTSD-related abnormalities therein. METHODS: fMRI responses in established intrinsic connectivity networks (ICNs) representing SN, CEN, and DN were assessed during a generalized conditioned-fear task in male combat veterans (N = 58) with wide-ranging PTSD symptom severity. The task included five rings of graded size. Extreme sizes served as conditioned danger-cues (CS+: paired with shock) and safety-cues (CS-), and the three intermediate sizes served as generalization stimuli (GSs) forming a continuum-of-size between CS+ and CS-. Generalization-gradients were assessed as behavioral and ICN response slopes from CS+, through GSs, to CS-. Increasing PTSD symptomatology was predicted to relate to less-steep slopes indicative of stronger generalization. RESULTS: SN, CEN, and DN responses fell along generalization-gradients with levels of generalization within and between SN and CEN scaling with PTSD symptom severity. CONCLUSIONS: Neural substrates of generalized conditioned-fear include large-scale networks that adhere to the functional organization of the brain. Current findings implicate levels of generalization in SN and CEN as promising neural markers of PTSD.


Asunto(s)
Miedo/psicología , Red Nerviosa/diagnóstico por imagen , Red Nerviosa/fisiopatología , Trastornos por Estrés Postraumático/diagnóstico por imagen , Trastornos por Estrés Postraumático/fisiopatología , Trastornos por Estrés Postraumático/psicología , Campaña Afgana 2001- , Conflictos Armados/psicología , Señales (Psicología) , Miedo/fisiología , Generalización Psicológica , Humanos , Imagen por Resonancia Magnética , Masculino , Personal Militar , Estados Unidos , Veteranos
10.
Mol Biol Rep ; 48(3): 2083-2092, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33660094

RESUMEN

Rising seawater temperatures cause coral bleaching. The molecular responses of the coral holobiont under stress conditions, determine the success of the symbiosis. Anomastraea irregularis is a hard coral commonly found in the harsh intertidal zones of the south coast of KwaZulu-Natal (KZN), South Africa, where it thrives at the very margins of hard coral distribution in the Western Indian Ocean. To identify the possible molecular and cellular mechanisms underlying its resilience to heat stress, experimental and control nubbins were exposed to temperatures of 29 and 19 °C respectively for 24 h. The transcriptome was assembled de novo from 42.8 million quality controlled 63 bp paired-end short sequence reads obtained via RNA sequencing (RNA-seq). The assembly yielded 333,057 contigs (> 500 bp = 55,626, Largest = 6341 bp N50 = 747 bp). 1362 (1.23%) of the transcripts were significantly differentially expressed between heat stressed and control samples. Log fold change magnitudes among individual genes ranged from - 4.6 to 7.2. Overall, the heat stress response in the A. irregularis constituted a protective response involving up regulation of apoptosis and SUMOylation. Gene ontology (GO) analyses revealed that heat stress in the coral affected the metabolism, protein synthesis, photosynthesis, transport and cytoskeleton. This is the first study to produce a reference transcriptome of this coral species and analyze its response to heat stress. The assembled transcriptome also presents a valuable resource for further transcriptomic and genomic studies.


Asunto(s)
Antozoos/genética , Antozoos/fisiología , Respuesta al Choque Térmico/genética , Análisis de Secuencia de ARN , Transcriptoma/genética , Animales , Perfilación de la Expresión Génica , Regulación de la Expresión Génica , Ontología de Genes , Anotación de Secuencia Molecular , Análisis de Componente Principal
11.
Cogn Affect Behav Neurosci ; 20(1): 76-90, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31811557

RESUMEN

Higher cognitive functioning is supported by adaptive reconfiguration of large-scale functional brain networks. Cognitive control (CC), which plays a vital role in flexibly guiding cognition and behavior in accordance with our goals, supports a range of executive functions via distributed brain networks. These networks process information dynamically and can be represented as functional connectivity changes between network elements. Using graph theory, we explored context-dependent network reorganization in 56 healthy adults performing fMRI tasks from two cognitive domains that varied in CC and episodic-memory demands. We examined whole-brain modular structure during the DPX task, which engages proactive CC in the frontal-parietal cognitive-control network (FPN), and the RiSE task, which manipulates CC demands at encoding and retrieval during episodic-memory processing, and engages FPN, the medial-temporal lobe and other memory-related networks in a context dependent manner. Analyses revealed different levels of network integration and segregation. Modularity analyses revealed greater brain-wide integration across tasks in high CC conditions compared to low CC conditions. Greater network reorganization occurred in the RiSE memory task, which is thought to require coordination across multiple brain networks, than in the DPX cognitive-control task. Finally, FPN, ventral attention, and visual systems showed within network connectivity effects of cognitive control; however, these cognitive systems displayed varying levels of network reorganization. These findings provide insight into how brain networks reorganize to support differing task contexts, suggesting that the FPN flexibly segregates during focused proactive control and integrates to support control in other domains such as episodic memory.


Asunto(s)
Encéfalo/fisiología , Cognición/fisiología , Función Ejecutiva/fisiología , Memoria Episódica , Red Nerviosa/fisiología , Adulto , Encéfalo/fisiopatología , Mapeo Encefálico , Humanos , Masculino , Memoria a Corto Plazo , Red Nerviosa/fisiopatología , Vías Nerviosas/fisiología , Vías Nerviosas/fisiopatología
12.
J Sex Med ; 17(9): 1751-1760, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32653392

RESUMEN

BACKGROUND: A number of studies have found that hypersexuality is associated with a high propensity for sexual excitation. In comparison, less is known about the relationship between hypersexuality and sexual arousal at the state level. Also, previous research has revealed a relationship between hypersexuality and negative mood. However, the possibility that sexual response might not be as negatively impacted by negative mood in hypersexual individuals has, as yet, not been tested. AIM: The purpose of this study was to investigate sexual responsivity and the effects of negative mood on sexual arousal in hypersexual men who have sex with men (MSM). METHODS: A total of 211 MSM were assigned to a hypersexuality (N = 81) or a control (N = 130) group using an interview patterned with a semi-structured Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders format. Participants filled out questionnaires and were shown neutral, sexual, and anxiety- and sadness-inducing films. OUTCOMES: Changes in penile circumference and self-reported sexual arousal were the primary outcomes analyzed in this study. RESULTS: Controlling for age and HIV status, no differences were found in genital response between hypersexual and non-hypersexual men. Also, the 2 groups did not differ in subjective sexual arousal. Moreover, no effects of negative mood were found. Time series clustering analyses revealed 3 groups-low responders and slow and fast high responders. Sexual excitation, but not sexual compulsivity or pornography use, predicted cluster membership. CLINICAL TRANSLATION: Hypersexual MSM may benefit more from an exploration of motivational and behavioral, as compared to psychophysiological, mechanisms underlying possible links between (negative) mood and sexual behavior. STRENGTHS & LIMITATIONS: Strengths of the study include its sample size, making it one of the larger psychophysiological sex studies; the use of clinical interviews for group assignment; the inclusion of genital response measures; and the application of time series clustering to examine differences among participants. Limitations include possible sample heterogeneity and the reliance on researcher-selected stimuli. CONCLUSION: Given the lack of any effects of negative mood on sexual response in hypersexual MSM, future studies could explore in more depth possible motivational and behavioral effects, including, for example, the impact of negative mood on the tendency to seek out sex as a form of distraction or for validation or emotional support. Janssen E, Prause N, Romine RS, et al. Sexual Responsivity and the Effects of Negative Mood on Sexual Arousal in Hypersexual Men Who Have Sex With Men (MSM). J Sex Med 2020;17:1751-1760.


Asunto(s)
Trastornos Parafílicos , Minorías Sexuales y de Género , Homosexualidad Masculina , Humanos , Masculino , Excitación Sexual , Conducta Sexual
13.
J Wound Ostomy Continence Nurs ; 47(1): 32-38, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-31929442

RESUMEN

PURPOSE: The aim of this study was to evaluate both surgical and patient-centered stomal complications after stoma formation, with emphasis on underreported symptoms and complaints. DESIGN: Prospective, single-group study. SUBJECTS AND SETTING: Patients undergoing emergency and elective ostomy surgery between January 1, 1999, and June 1, 2016, in 3 acute care hospitals were followed up by stoma care nurse specialists in NHS Lanarkshire, Scotland. METHODS: Data were collected on surgery type (emergency or elective), stoma type (ileostomy or colostomy), stoma-related complications including surgical complications (stenosis, retractions, hernia, and prolapse) and so-called "patient-centered" complications (skin changes, odor, leakage, soiling, and nighttime emptying) at 5 time points: 10 days, 3 months, 6 months, 1 year, and 2 years postoperatively. For this study, we report comparisons at 10 days and 2 years, using frequencies reported as percentages. RESULTS: Data from 3509 consecutive stoma surgeries were analyzed. Complication rates were similar in both emergency and elective cases. The nighttime symptoms of leakage and soiling were significantly greater in the ileostomy group and worsened over the 2-year period. The parastomal hernia rate was 34.5% at 2 years, a finding more common in the colostomy group (46.4% vs 20.1%, P < .001). However, the rate of clinically significant hernia was similar when comparing the colostomy group with the ileostomy group (3.6% vs 2.2%, P = .38). Emergency stoma surgeries (40.2%) were preoperatively sited compared with 95.9% of elective cases. CONCLUSIONS: Our prospective multicenter study demonstrated that stoma-related complications are similar irrespective of whether the stoma was formed via an elective surgery or emergency surgery. Nighttime symptoms of leakage, soiling, and emptying were high post-stoma formation, particularly in the ileostomy group, and worsened over the 2-year period. Findings from our study highlight the presence and persistence of complications. We believe our work highlights the importance of having frequent discussions with patients about making decisions about approaches to reduce complications to enhance patient outcomes.


Asunto(s)
Estomas Quirúrgicos/efectos adversos , Adulto , Anciano , Estudios de Cohortes , Procedimientos Quirúrgicos del Sistema Digestivo/efectos adversos , Procedimientos Quirúrgicos del Sistema Digestivo/métodos , Procedimientos Quirúrgicos del Sistema Digestivo/estadística & datos numéricos , Femenino , Hospitales/estadística & datos numéricos , Humanos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/clasificación , Complicaciones Posoperatorias/epidemiología , Estudios Prospectivos , Escocia/epidemiología
14.
Hum Brain Mapp ; 40(18): 5397-5411, 2019 12 15.
Artículo en Inglés | MEDLINE | ID: mdl-31471938

RESUMEN

Deficits in response inhibition have been observed in schizophrenia and bipolar disorder; however, the neural origins of the abnormalities and their relevance to genetic liability for psychosis are unknown. We used a stop-signal task to examine motor inhibition and associated neural processes in schizophrenia patients (n = 57), bipolar disorder patients (n = 21), first-degree biological relatives of patients with schizophrenia (n = 34), and healthy controls (n = 56). Schizophrenia patients demonstrated motor control deficits reflected in longer stop-signal reaction times and elongated reaction times. With the possibility of needing to inhibit a button press, both schizophrenia and bipolar disorder patients showed diminished reductions of the P300 brain response and only the healthy controls demonstrated adjustments in response execution time, as measured by response-locked lateralized readiness potentials. Schizotypal traits in the biological relatives were associated with less P300 modulation consistent with the motor-related anomalies being associated with subtle schizophrenia-spectrum symptomatology in family members. The two patient groups had elongated response selection processes as manifest in the delayed onset of the stimulus-locked lateralized readiness potential. The bipolar disorder group was unique in showing significantly diminished neural responses to the stop-signal to inhibit a response. Antipsychotic medication dosage was related to worse motor inhibition, thus motor inhibition deficits in schizophrenia may be partially explained by the effect of pharmacological agents. Failed modulation of brain processes in relation to response inhibition probability and the lengthening of motor response selection appear to be transdiagnostic abnormalities spanning schizophrenia and bipolar disorder.


Asunto(s)
Trastorno Bipolar/diagnóstico por imagen , Inhibición Psicológica , Desempeño Psicomotor/fisiología , Tiempo de Reacción/fisiología , Esquizofrenia/diagnóstico por imagen , Adulto , Trastorno Bipolar/fisiopatología , Trastorno Bipolar/psicología , Potenciales Relacionados con Evento P300/fisiología , Femenino , Humanos , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Esquizofrenia/fisiopatología , Psicología del Esquizofrénico
15.
Cogn Affect Behav Neurosci ; 19(6): 1492-1508, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31209734

RESUMEN

Humans have a remarkable capacity to mentally project themselves far ahead in time. This ability, which entails the mental simulation of events, is thought to be fundamental to deliberative decision making, as it allows us to search through and evaluate possible choices. Many decisions that humans make are foraging decisions, in which one must decide whether an available offer is worth taking, when compared to unknown future possibilities (i.e., the background). Using a translational decision-making paradigm designed to reveal decision preferences in rats, we found that humans engaged in deliberation when making foraging decisions. A key feature of this task is that preferences (and thus, value) are revealed as a function of serial choices. Like rats, humans also took longer to respond when faced with difficult decisions near their preference boundary, which was associated with prefrontal and hippocampal activation, exemplifying cross-species parallels in deliberation. Furthermore, we found that voxels within the visual cortices encoded neural representations of the available possibilities specifically following regret-inducing experiences, in which the subject had previously rejected a good offer only to encounter a low-valued offer on the subsequent trial.


Asunto(s)
Toma de Decisiones/fisiología , Hipocampo/fisiología , Corteza Prefrontal/fisiología , Pensamiento/fisiología , Corteza Visual/fisiología , Adulto , Emociones/fisiología , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Neuroimagen , Estimulación Luminosa , Tiempo de Reacción , Recompensa , Adulto Joven
16.
Surgeon ; 17(5): 277-283, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-30314957

RESUMEN

BACKGROUND: The Montgomery ruling has had a wide-ranging impact on the consent process and has been the subject of new guidelines by bodies, including the Royal College of Surgeons (RCSEng). This is the first study to examine the current standard of consent for surgical procedures at a national level. METHOD: A national collaborative research model was used, with prospective data collection performed across hospitals in Scotland. Variables associated with the consent process were audited across three surgical specialities (general surgery, urology and orthopaedics) and measured against standards set by RCSEng, the Scottish Public Services Ombudsman and medical defence organisations. RESULTS: A total of 289 cases were identified from 12 hospitals. The majority of patients were reviewed by a consultant surgeon in clinic (79.9%) or on the day of surgery (55.4%). The clinic consent rate was 27.0%, while a copy of the documented discussion was only provided to 4.2% of patients. On the day of surgery, the benefits, risks and alternatives to the planned procedure were discussed in less than half of cases. This rate was similar across different clinician grades, while marked variation was seen across hospitals. CONCLUSION: In this prospective multi-centre study we have demonstrated wide variation in the consent processes in many surgical specialities across Scotland. Following the Montgomery ruling, we have demonstrated the current consent process in elective surgery is likely to be substandard, and may require additional steps to be taken by clinicians to ensure patients are fully informed to make decisions regarding their treatment.


Asunto(s)
Procedimientos Quirúrgicos Electivos/legislación & jurisprudencia , Consentimiento Informado/legislación & jurisprudencia , Consentimiento Informado/normas , Toma de Decisiones , Procedimientos Quirúrgicos Electivos/normas , Encuestas de Atención de la Salud , Humanos , Internet , Estudios Prospectivos , Escocia
17.
Behav Res Methods ; 51(3): 1360-1370, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-30076533

RESUMEN

The change detection task is a common method for assessing the storage capacity of working memory, but estimates of memory capacity from this task can be distorted by lapses of attention. When combined with appropriate mathematical models, some versions of the change detection task make it possible to separately estimate working memory and the probability of attentional lapses. In principle, these models should allow researchers to isolate the effects of experimental manipulations, group differences, and individual differences on working memory capacity and on the rate of attentional lapses. However, the present research found that two variants of a widely accepted model of the change detection task are not mathematically identified.


Asunto(s)
Atención , Memoria a Corto Plazo , Humanos , Individualidad , Percepción Visual
18.
Hum Brain Mapp ; 39(9): 3574-3585, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-29691946

RESUMEN

Conscientiousness is a personality trait associated with many important life outcomes, but little is known about the mechanisms that underlie it. We investigated its neural correlates using functional connectivity analysis in fMRI, which identifies brain regions that act in synchrony. We tested the hypothesis that a broad network resembling a combination of the salience and ventral attention networks, which we provisionally label the goal priority network (GPN), is a neural correlate of Conscientiousness. Self- and peer-ratings of Conscientiousness were collected in a community sample of adults who underwent a resting-state fMRI scan (N = 218). An independent components analysis yielded five components that overlapped substantially with the GPN. We examined synchrony within and between these GPN subcomponents. Synchrony within one of the components-mainly comprising regions of anterior insula, dorsal anterior cingulate cortex, and dorsolateral prefrontal cortex-was significantly associated with Conscientiousness. Connectivity between this component and the four other GPN components was also significantly associated with Conscientiousness. Our results support the hypothesis that variation in a network that enables prioritization of multiple goals may be central to Conscientiousness.


Asunto(s)
Conectoma , Conciencia , Imagen por Resonancia Magnética , Red Nerviosa/fisiopatología , Adulto , Atención/fisiología , Sincronización Cortical/fisiología , Femenino , Objetivos , Humanos , Inteligencia , Masculino , Modelos Neurológicos , Modelos Psicológicos , Inventario de Personalidad , Análisis de Componente Principal , Descanso , Adulto Joven
19.
Int J Colorectal Dis ; 33(1): 65-69, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-29101452

RESUMEN

AIMS: Scottish Intercollegiate Guidelines Network (SIGN) guidelines require patients with colorectal cancer to wait no longer than 62 days from first referral to initiation of definitive treatment. We previously demonstrated that failure to meet with these guidelines did not appear to lead to poor outcomes in the short term. This study investigates whether this holds true over a longer period. METHODS: The survival status of 1,012 patients treated for colorectal cancer between January 1999 and June 2005 was reviewed. As in the previous audit, patients were placed into four groups, standard met (elective), standard met (emergency), standard failed (elective) and standard failed (emergency). Parameters analysed were pathological staging, 30-day mortality, long-term survival and cause of death. Data was analysed using log rank and chi-squared tests. RESULTS: Operative mortality was higher in patients meeting the standard (7% elective, 20% emergency) compared to those who did not meet the standard (4% elective, 7% emergency). The proportion of early stage disease (Dukes' A and B) was highest in elective patients who failed the standard (50%) and lowest in emergencies meeting the standard (30%). Long-term survival was greatest in elective patients who failed the standard with 52% alive in October 2011 compared to 34% of elective cases meeting the standard. The most common cause of recorded death was colorectal cancer in all groups. CONCLUSIONS: Patients who were not treated within the time frame set by the SIGN guidelines survived for longer following surgery. Reasons for this are likely to be multifactorial and include pathological cancer stage.


Asunto(s)
Neoplasias Colorrectales/mortalidad , Cooperación del Paciente , Adulto , Anciano , Anciano de 80 o más Años , Causas de Muerte , Humanos , Persona de Mediana Edad , Análisis de Supervivencia , Factores de Tiempo
20.
Surg Radiol Anat ; 40(12): 1343-1348, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30173375

RESUMEN

PURPOSE: Controversy exists as to whether a high or low tie ligation of the inferior mesenteric artery (IMA) is the preferred technique in surgeries of the left colon and rectum. This study aims to contribute to the discussion as to which is the more beneficial technique by investigating the neurovasculature at each site. METHODS: Ten embalmed cadaveric donors underwent division of the inferior mesenteric artery at the level of the low tie. The artery was subsequently ligated at the root to render a section of tissue for histological analysis of the proximal (high tie), mid and distal (low tie) segments. RESULTS: Ganglia observed in the proximal end of seven specimens in the sample imply that there would be disruption to the innervation in a high tie procedure. CONCLUSION: This study suggests that a high tie should be avoided if the low tie is oncologically viable.


Asunto(s)
Colectomía/métodos , Arteria Mesentérica Inferior/inervación , Arteria Mesentérica Inferior/cirugía , Anciano de 80 o más Años , Anastomosis Quirúrgica , Cadáver , Femenino , Humanos , Ligadura/métodos , Masculino
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