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BACKGROUND: Rectovaginal fistulae (RVF) are notoriously challenging to treat. Martius flap (MF) is a technique employed to manage RVF, among various others, with none being universally successful. We aimed to assess the outcomes of RVF managed with MF interposition. METHODS: A PRISMA-compliant meta-analysis searching for all studies specifically reporting on the outcomes of MF for RVF was performed. The primary objective was the mean success rate, whilst secondary objectives included complications and recurrence. The MedCalc software (version 20.118) was used to conduct proportional meta-analyses of data. Weighted mean values with 95% CI are presented and stratified according to aetiology where possible. RESULTS: Twelve non-randomized (11 retrospective, 1 prospective) studies, assessing 137 MF were included. The mean age of the study population was 42.4 (±15.7), years. There were 44 primary and 93 recurrent RVF. The weighted mean success rate for MF when performed for primary RVF was 91.4% (95% CI: 79.45-98.46; I2 = 32.1%; P = 0.183) and that for recurrent RVF was 77.5% (95% CI: 62.24-89.67; I2 = 58.1%; P = 0.008). The weighted mean complication rate was 29% (95% CI: 8.98-54.68; I2 = 85.4%; P < 0.0001) and the overall recurrence rate was 12.0% (95% CI: 5.03-21.93; I2 = 52.3%; P = 0.021). When purely radiotherapy-induced RVF were evaluated, the mean overall success rate was 94.6% (95% CI: 83.33-99.75; I2 = 0%; P = 0.350). CONCLUSIONS: MF interposition appears to be more effective for primary than recurrent RVF. However, the poor quality of the data limits definitive conclusions being drawn and demands further assessment with randomized studies.
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Single-cell technologies have transformed our understanding of human tissues. Yet, studies typically capture only a limited number of donors and disagree on cell type definitions. Integrating many single-cell datasets can address these limitations of individual studies and capture the variability present in the population. Here we present the integrated Human Lung Cell Atlas (HLCA), combining 49 datasets of the human respiratory system into a single atlas spanning over 2.4 million cells from 486 individuals. The HLCA presents a consensus cell type re-annotation with matching marker genes, including annotations of rare and previously undescribed cell types. Leveraging the number and diversity of individuals in the HLCA, we identify gene modules that are associated with demographic covariates such as age, sex and body mass index, as well as gene modules changing expression along the proximal-to-distal axis of the bronchial tree. Mapping new data to the HLCA enables rapid data annotation and interpretation. Using the HLCA as a reference for the study of disease, we identify shared cell states across multiple lung diseases, including SPP1+ profibrotic monocyte-derived macrophages in COVID-19, pulmonary fibrosis and lung carcinoma. Overall, the HLCA serves as an example for the development and use of large-scale, cross-dataset organ atlases within the Human Cell Atlas.
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COVID-19 , Neoplasias Pulmonares , Fibrose Pulmonar , Humanos , Pulmão , Neoplasias Pulmonares/genética , MacrófagosRESUMO
BACKGROUND: Anastomotic leaks (AL) remain a devastating complication following intestinal anastomoses resulting in increased morbidity and mortality. Wrapping the anastomosis with omentum may be protective although data are conflicting. We performed a meta-analysis to assess the effect of omentoplasty on colorectal anastomoses. METHODS: PubMed, EMBASE and Cochrane databases were searched for relevant articles from inception until August 2021. All randomized controlled trials (RCT) that reported on the use of omentoplasty in colon and rectal surgery were included. The primary outcome was rate of overall AL while secondary outcomes included clinical and radiological AL, overall reoperation and mortality. Random effects models were used to calculate pooled effect size estimates. Sensitivity analyses were also performed. RESULTS: Four RCTs were included capturing 1067 patients. The mean (SD) age of the cohort was 61.5 (±14.8) years. On random effects analysis, omentoplasty reduced rate of overall (OR 0.43, 95% CI = 0.21-0.87, p = 0.02) and clinical AL (OR = 0.35, 95% CI = 0.15-0.81, p = 0.01). However, there was no difference in radiological AL (OR = 0.77, 95% CI = 0.40-1.47, p = 0.42), overall reoperations (OR 0.48, 95% CI = 0.18-1.32, p = 0.16) or mortality (OR 0.52, 95% CI = 0.12 to-2.18, p = 0.37). On sensitivity analysis, assessing rectal anastomoses only, the results for overall AL remained similar (OR 0.28, 95% CI = 0.12-0.61, p = 0.002). CONCLUSION: Although omentoplasty appears to reduce the rate of overall and clinical AL, the heterogeneity in the data prevents definitive recommendations from being made. Further well-designed trials are needed to investigate this technique.
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Fístula Anastomótica , Cirurgia Colorretal , Idoso , Anastomose Cirúrgica/efeitos adversos , Anastomose Cirúrgica/métodos , Fístula Anastomótica/etiologia , Fístula Anastomótica/prevenção & controle , Fístula Anastomótica/cirurgia , Esofagectomia/efeitos adversos , Humanos , Pessoa de Meia-Idade , Omento/cirurgiaRESUMO
Modern electrophysiological recordings simultaneously capture single-unit spiking activities of hundreds of neurons spread across large cortical distances. Yet, this parallel activity is often confined to relatively low-dimensional manifolds. This implies strong coordination also among neurons that are most likely not even connected. Here, we combine in vivo recordings with network models and theory to characterize the nature of mesoscopic coordination patterns in macaque motor cortex and to expose their origin: We find that heterogeneity in local connectivity supports network states with complex long-range cooperation between neurons that arises from multi-synaptic, short-range connections. Our theory explains the experimentally observed spatial organization of covariances in resting state recordings as well as the behaviorally related modulation of covariance patterns during a reach-to-grasp task. The ubiquity of heterogeneity in local cortical circuits suggests that the brain uses the described mechanism to flexibly adapt neuronal coordination to momentary demands.
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Potenciais de Ação/fisiologia , Modelos Neurológicos , Córtex Motor , Rede Nervosa , Neurônios , Animais , Eletrofisiologia , Feminino , Macaca mulatta , Masculino , Córtex Motor/citologia , Córtex Motor/fisiologia , Rede Nervosa/citologia , Rede Nervosa/fisiologia , Neurônios/citologia , Neurônios/fisiologiaRESUMO
The Human Cell Atlas (HCA) consortium aims to establish an atlas of all organs in the healthy human body at single-cell resolution to increase our understanding of basic biological processes that govern development, physiology and anatomy, and to accelerate diagnosis and treatment of disease. The Lung Biological Network of the HCA aims to generate the Human Lung Cell Atlas as a reference for the cellular repertoire, molecular cell states and phenotypes, and cell-cell interactions that characterise normal lung homeostasis in healthy lung tissue. Such a reference atlas of the healthy human lung will facilitate mapping the changes in the cellular landscape in disease. The discovAIR project is one of six pilot actions for the HCA funded by the European Commission in the context of the H2020 framework programme. discovAIR aims to establish the first draft of an integrated Human Lung Cell Atlas, combining single-cell transcriptional and epigenetic profiling with spatially resolving techniques on matched tissue samples, as well as including a number of chronic and infectious diseases of the lung. The integrated Human Lung Cell Atlas will be available as a resource for the wider respiratory community, including basic and translational scientists, clinical medicine, and the private sector, as well as for patients with lung disease and the interested lay public. We anticipate that the Human Lung Cell Atlas will be the founding stone for a more detailed understanding of the pathogenesis of lung diseases, guiding the design of novel diagnostics and preventive or curative interventions.
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Pneumopatias , Pulmão , Humanos , Proteômica , TóraxRESUMO
INTRODUCTION: The purpose of a loop ileostomy is to temporarily divert faeces away from a distal anastomosis, to reduce the consequences of anastomotic leak. This ultimately requires a second procedure to restore bowel continuity, which confers risk of complications including the development of Clostridioides difficile infection (CDI). It is hypothesized that patients who undergo loop ileostomy reversal are at increased risk of CDI when compared with other patients undergoing elective colorectal surgical procedures, and that these patients also experience an increased length of stay (LOS). METHODS: A retrospective cohort study was performed on all patients who underwent loop ileostomy reversal at the Gold Coast Hospital and Health Service between 1 January 2012 and 31 December 2019. RESULTS: Two hundred and twenty-eight patients were identified. Eight tested positive for CDI on faecal PCR (3.51%), a higher incidence than that in patients who underwent an elective colorectal surgical procedure during the same period (0.83%) (RR = 4.23). Additionally, median LOS for ileostomy reversal patients was significantly increased in those who also had CDI when compared with those without CDI (11 versus 4 days; P = 0.0003). CONCLUSION: The study confirmed that the incidence of CDI was higher in those who underwent ileostomy reversal when compared with an otherwise comparable hospital population (elective colorectal surgery patients). Additionally, those patients who underwent ileostomy reversal and had CDI experienced an increased LOS which translates to increased cost to the healthcare system. Further investigation into pre-operative screening and prophylactic antibiotics should be considered as a measure to mitigate this post-operative complication.
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Clostridioides difficile , Infecções por Clostridium , Neoplasias Colorretais , Austrália/epidemiologia , Clostridioides , Infecções por Clostridium/complicações , Infecções por Clostridium/etiologia , Neoplasias Colorretais/complicações , Humanos , Ileostomia/efeitos adversos , Ileostomia/métodos , Incidência , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Estudos Retrospectivos , Centros de Atenção TerciáriaRESUMO
BACKGROUND: Diverting ileostomy is utilized to protect high-risk anastomoses, though it is not shown to reduce the leak rate it may reduce the severe consequences of an anastamotic leak. In recent years mesh development has advanced to allow placement of meshes into potentially contaminated fields, such as an ostomy closure site. METHOD: A retrospective review of all ileostomy closure procedures in Gold Coast from 1st January 2011 until 31st December 2018 were included. Patient demographics and surgical outcomes and follow up reviewed to identify any cases of incisional hernia relating to ostomy closure. RESULTS: A total of 193 patients were identified, after exclusions 171 were suitable for analysis within the study, a total of 25 incisional hernia detected radiologically or clinically. Two independent risk factors were identified BMI >30 and ASA 3-4. Both had significant association with development of incisional hernia with a 3- and 2-fold RR increase, respectively. This was also reflected in a subset analysis of BMI ranges demonstrating increased risk in the obese and severely obese group. DISCUSSION: The high-risk group in our population was elevated BMI and ASA, these are the patients we would expect to benefit the most from targeted therapy to reduce the incidence of incisional hernia. Future studies to look at whether reducing BMI or prophylactic mesh placement are effective.
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Hérnia Incisional , Humanos , Ileostomia/efeitos adversos , Ileostomia/métodos , Hérnia Incisional/epidemiologia , Hérnia Incisional/etiologia , Hérnia Incisional/prevenção & controle , Estudos Retrospectivos , Fatores de Risco , Telas Cirúrgicas/efeitos adversosRESUMO
Resting state has been established as a classical paradigm of brain activity studies, mostly based on large-scale measurements such as functional magnetic resonance imaging or magneto- and electroencephalography. This term typically refers to a behavioral state characterized by the absence of any task or stimuli. The corresponding neuronal activity is often called idle or ongoing. Numerous modeling studies on spiking neural networks claim to mimic such idle states, but compare their results with task- or stimulus-driven experiments, or to results from experiments with anesthetized subjects. Both approaches might lead to misleading conclusions. To provide a proper basis for comparing physiological and simulated network dynamics, we characterize simultaneously recorded single neurons' spiking activity in monkey motor cortex at rest and show the differences from spontaneous and task- or stimulus-induced movement conditions. We also distinguish between rest with open eyes and sleepy rest with eyes closed. The resting state with open eyes shows a significantly higher dimensionality, reduced firing rates, and less balance between population level excitation and inhibition than behavior-related states.
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BACKGROUND: A large evidence-practice gap exists regarding provision of nutrition to patients following surgery. The aim of this study was to evaluate the processes supporting the implementation of an intervention designed to improve the timing and adequacy of nutrition following bowel surgery. METHODS: A mixed-method pilot study, using an integrated knowledge translation (iKT) approach, was undertaken at a tertiary teaching hospital in Australia. A tailored, multifaceted intervention including ten strategies targeted at staff or patients were co-developed with knowledge users at the hospital and implemented in practice. Process evaluation outcomes included reach, intervention delivery and staffs' responses to the intervention. Quantitative data, including patient demographics and surgical characteristics, intervention reach, and intervention delivery were collected via chart review and direct observation. Qualitative data (responses to the intervention) were sequentially collected from staff during one-on-one, semi-structured interviews. Quantitative data were summarized using median (IQR), mean (SD) or frequency(%), while qualitative data were analysed using content analysis. RESULTS: The intervention reached 34 patients. Eighty-four percent of nursing staff received an awareness and education session, while 0% of medical staff received a formal orientation or awareness and education session, despite the original intention to deliver these sessions. Several strategies targeted at patients had high fidelity, including delivery of nutrition education (92%); and prescription of oral nutrition supplements (100%) and free fluids immediately post-surgery (79%). Prescription of a high energy high protein diet on postoperative day one (0%) and oral nutrition supplements on postoperative day zero (62%); and delivery of preoperative nutrition handout (74%) and meal ordering education (50%) were not as well implemented. Interview data indicated that staff regard nutrition-related messages as important, however, their acceptance, awareness and perceptions of the intervention were mixed. CONCLUSIONS: Approximately half the patient-related strategies were implemented well, which is likely attributed to the medical and nursing staff involved in intervention design championing these strategies. However, some strategies had low delivery, which was likely due to the varied awareness and acceptance of the intervention among staff on the ward. These findings suggest the importance of having buy-in from all staff when using an iKT approach to design and implement interventions.
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Terapia Nutricional , Pesquisa Translacional Biomédica , Austrália , Humanos , Estado Nutricional , Projetos PilotoRESUMO
OBJECTIVES: Timely and adequate nutrition after surgery is important. The aim of this study was to evaluate the effects of an intervention, developed using an integrated knowledge translation approach, designed to improve oral intake among postoperative colorectal patients. METHODS: A pre/post, mixed-methods pilot study was undertaken at a tertiary teaching hospital in Australia. Patients who had undergone elective colorectal surgery and were admitted to the ward where 10 nutrition-related strategies had been implemented were included. Quantitative data, including patient demographics, timing and type of nutrition consumed, and protein and energy intake were collected pre- and post-intervention via chart audits, direct observations, and verbal clarification. Qualitative data on patient (n = 18) responses to the intervention were collected through one-on-one, semistructured interviews and analyzed using inductive content analysis. RESULTS: Sixty-four patients were observed (30 pre- and 34 post-intervention). Significant improvements were seen for the following outcomes (presented as median [interquartile range], pre- versus post-intervention): time (h) to first dietary intake (15.7 [7.4-22.5] versus 4.9 [3.7-14.2]); patient energy intakes (kJ) on day 1 (1719 [947-2200] versus 3530 [2192-5169]) and day 2 (2506 [1071-3749] versus 4144 [2987-5889]); and patient protein intake (g) on day 1 (3.3 [1.8-11.2] versus 30.3 [20-45]) and day 2 (10.8 [3.5-29.9] versus 39.6 [30.7-59]). Prescription of free fluids as first diet type increased from 13% to 79% pre- and post-intervention, respectively. There were no significant differences in time (h) to first solid dietary intake (86.1 [60.1-104] versus 69.2 [46.1-115.5]) and overall proportion of patients who met both their estimated energy and protein requirements while in hospital pre- and post-intervention (22 versus 37%). Patients reported positive experiences with the intervention. CONCLUSION: A multifaceted intervention developed using an integrated knowledge translation approach has the potential to improve oral intake in patients who undergo colorectal surgery. A larger-scale trial is required to confirm these findings and assess the effects of the intervention on clinical outcomes and costs.
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Cirurgia Colorretal , Austrália , Ingestão de Alimentos , Ingestão de Energia , Humanos , Estado Nutricional , Projetos PilotoRESUMO
BACKGROUND: In Australia, colorectal cancer (CRC) is the third most common cancer and the second leading cause of cancer death. It is more common in patients over 50 years, with previous evidence showing patients under 50 years account for only 9% of CRC. However, recent Australian and International studies have shown an increase in CRC incidence in patients under 50 years of age. The main aim of this study was to analyse the incidence of CRC in patients under 50 and to determine if screening would be beneficial in this population. METHODS: A retrospective cohort study was performed on all patients under 50 years of age who underwent a colonoscopy, performed by a colorectal surgeon, at the Gold Coast Hospital and Health Service between January 2013 and December 2017. RESULTS: A total of 557 patients were included in the study; 120 (21.5%) colonoscopies had a significant finding (CRC or adenoma with malignant potential). 1.9% of patients were diagnosed with CRC, all were symptomatic at time of diagnosis, the majority were stage 3 or 4. CONCLUSION: A total of 1.9% of patients under 50 who underwent colonoscopy were diagnosed with CRC, whilst 21.5% of patients had significant findings. These rates are greater than previously quoted figures and data for patients under 50, and provides evidence to support lowering of the CRC faecal occult blood testing screening age.
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Neoplasias Colorretais , Detecção Precoce de Câncer , Austrália/epidemiologia , Colonoscopia , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/epidemiologia , Humanos , Programas de Rastreamento , Estudos RetrospectivosRESUMO
BACKGROUND: Laparoscopic and open techniques in rectal cancer are well-published, however, technical challenges remain for mid to low rectal cancer resections in the narrow pelvis. Transanal total mesorectal excision (taTME) has been pioneered to potentially circumvent these challenges. The aims of this study were to evaluate the learning curve associated with our first cases of taTME as well as compare outcomes to that of conventionally performed rectal resections. METHODS: This was a single-centre retrospective study with data collated from all elective resections by the colorectal unit from 2015 to 2017. Primary outcome was completeness of total mesorectal excision and secondary outcomes were intra- and post-operative morbidity and mortality. RESULTS: A total of 43 patients were identified. Of which, 20 underwent taTME. Mesorectal completeness was obtained in only 47.4% in the taTME group compared to 78.3% in the anterior resection group (p = 0.115). 5.9% of patients in our taTME group had positive circumferential resection margin compared to nil in the anterior resection. Conversion rates were greater in the taTME group (15% versus 0%; 0.028). Operative time, length of stay and clavien IV and V complications were greater in the taTME group. CONCLUSION: This study highlights the difficulty in introducing a novel technique given the learning curve. Our results would expect to improve with increased caseload.
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Laparoscopia , Neoplasias Retais , Cirurgia Endoscópica Transanal , Humanos , Curva de Aprendizado , Duração da Cirurgia , Complicações Pós-Operatórias/epidemiologia , Neoplasias Retais/cirurgia , Reto/cirurgia , Estudos Retrospectivos , Resultado do TratamentoRESUMO
Despite advances in symptomatic treatment options the pathomechanism of idiopathic Parkinson's disease (PD) remains poorly understood. Animal studies from recent years suggest pathological information processing in the basal ganglia network to be responsible for major movement deficits observed in patients, which, according to the information lesion hypothesis, might also explain the mechanism of action of deep brain stimulation (DBS). Using novel measures from information theory we characterize the information content, storage and transfer of intraoperatively recorded local field potentials (LFP) from the subthalamic area of n â= â19 PD patients undergoing surgery for implantation of electrodes for deep brain stimulation. In agreement with recent animal studies we demonstrate a significant positive correlation of subthalamic information content and movement deficits (ρ â> â0.48). Analysis of information storage reveals a larger processing memory in the zona incerta (ZI) than in the subthalamic nucleus (STN). We discuss possible implications for the efficiency of high frequency DBS. Further, we estimate the information transfer between forearm muscles and ZI/STN. Here, we show that the bidirectional information flow with respect to the STN is larger compared to the ZI. In contrast to the STN, however, the bidirectional information flow in the ZI is modulated, namely increased, by movement. The results of our study may help to understand the mechanism of action of deep brain stimulation and further explain recent studies claiming efficiency of ZI stimulation for certain motor symptoms.
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Fenômenos Eletrofisiológicos/fisiologia , Músculo Esquelético/fisiopatologia , Doença de Parkinson/fisiopatologia , Núcleo Subtalâmico/fisiopatologia , Zona Incerta/fisiopatologia , Adulto , Idoso , Estimulação Encefálica Profunda , Eletrocorticografia , Eletrodos Implantados , Eletromiografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doença de Parkinson/cirurgia , Núcleo Subtalâmico/cirurgiaRESUMO
Radiological evidence of inflammation, using computed tomography (CT), is needed to diagnose the first occurrence of diverticulitis. CT is also warranted when the severity of symptoms suggests that perforation or abscesses have occurred. Diverticulitis is classified as complicated or uncomplicated based on CT scan, severity of symptoms and patient history; this classification is used to direct management. Outpatient treatment is recommended in afebrile, clinically stable patients with uncomplicated diverticulitis. For patients with uncomplicated diverticulitis, antibiotics have no proven benefit in reducing the duration of the disease or preventing recurrence, and should only be used selectively. For complicated diverticulitis, non-operative management, including bowel rest and intravenous antibiotics, is indicated for small abscesses; larger abscesses of 3-5 cm should be drained percutaneously. Patients with peritonitis and sepsis should receive fluid resuscitation, rapid antibiotic administration and urgent surgery. Surgical intervention with either Hartmann procedure or primary anastomosis, with or without diverting loop ileostomy, is indicated for peritonitis or in failure of non-operative management. Colonoscopy is recommended for all patients with complicated diverticulitis 6 weeks after CT diagnosis of inflammation, and for patients with uncomplicated diverticulitis who have suspicious features on CT scan or who otherwise meet national bowel cancer screening criteria.
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Abscesso/terapia , Antibacterianos/uso terapêutico , Procedimentos Cirúrgicos do Sistema Digestório/métodos , Doença Diverticular do Colo/terapia , Hidratação/métodos , Peritonite/terapia , Sepse/terapia , Abscesso/diagnóstico por imagem , Assistência Ambulatorial , Anastomose Cirúrgica , Colectomia , Colonoscopia/métodos , Doença Diverticular do Colo/diagnóstico , Doença Diverticular do Colo/diagnóstico por imagem , Drenagem , Hospitalização , Humanos , Ileostomia , Guias de Prática Clínica como Assunto , Índice de Gravidade de Doença , Tomografia Computadorizada por Raios XRESUMO
Computational neuroscience relies on simulations of neural network models to bridge the gap between the theory of neural networks and the experimentally observed activity dynamics in the brain. The rigorous validation of simulation results against reference data is thus an indispensable part of any simulation workflow. Moreover, the availability of different simulation environments and levels of model description require also validation of model implementations against each other to evaluate their equivalence. Despite rapid advances in the formalized description of models, data, and analysis workflows, there is no accepted consensus regarding the terminology and practical implementation of validation workflows in the context of neural simulations. This situation prevents the generic, unbiased comparison between published models, which is a key element of enhancing reproducibility of computational research in neuroscience. In this study, we argue for the establishment of standardized statistical test metrics that enable the quantitative validation of network models on the level of the population dynamics. Despite the importance of validating the elementary components of a simulation, such as single cell dynamics, building networks from validated building blocks does not entail the validity of the simulation on the network scale. Therefore, we introduce a corresponding set of validation tests and present an example workflow that practically demonstrates the iterative model validation of a spiking neural network model against its reproduction on the SpiNNaker neuromorphic hardware system. We formally implement the workflow using a generic Python library that we introduce for validation tests on neural network activity data. Together with the companion study (Trensch et al., 2018), the work presents a consistent definition, formalization, and implementation of the verification and validation process for neural network simulations.
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Transfer entropy (TE) provides a generalized and model-free framework to study Wiener-Granger causality between brain regions. Because of its nonparametric character, TE can infer directed information flow also from nonlinear systems. Despite its increasing number of applications in neuroscience, not much is known regarding the influence of common electrophysiological preprocessing on its estimation. We test the influence of filtering and downsampling on a recently proposed nearest neighborhood based TE estimator. Different filter settings and downsampling factors were tested in a simulation framework using a model with a linear coupling function and two nonlinear models with sigmoid and logistic coupling functions. For nonlinear coupling and progressively lower low-pass filter cut-off frequencies up to 72% false negative direct connections and up to 26% false positive connections were identified. In contrast, for the linear model, a monotonic increase was only observed for missed indirect connections (up to 86%). High-pass filtering (1 Hz, 2 Hz) had no impact on TE estimation. After low-pass filtering interaction delays were significantly underestimated. Downsampling the data by a factor greater than the assumed interaction delay erased most of the transmitted information and thus led to a very high percentage (67-100%) of false negative direct connections. Low-pass filtering increases the number of missed connections depending on the filters cut-off frequency. Downsampling should only be done if the sampling factor is smaller than the smallest assumed interaction delay of the analyzed network.
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Algoritmos , Encéfalo/fisiologia , Conectoma/estatística & dados numéricos , Processamento de Sinais Assistido por Computador , Eletroencefalografia , Entropia , Humanos , Modelos Lineares , Dinâmica não LinearRESUMO
Microbial pathogens have developed several mechanisms to modulate and interfere with host cell cycle progression. In this study, we analyzed the effect of the human pathogen Neisseria meningitidis on the cell cycle of epithelial cells. Two pathogenic isolates, as well as two carrier isolates, were tested for their ability to adhere to and invade into the epithelial cell lines Detroit 562 and NP69 and to modulate the cell cycle. We found that all isolates adhered equally well to both Detroit 562 and NP69 cells, whereas the carrier isolates were significantly less invasive. Using propidium iodide staining and 5-ethynyl-2'-deoxyuridine pulse-labeling, we provide evidence that meningococcal infection arrested cells in the G1 phase of the cell cycle at 24 h postinfection. In parallel, a significant decrease of cells in the S phase was observed. Interestingly, G1-phase arrest was only induced after infection with live bacteria but not with heat-killed bacteria. By Western blotting we demonstrate that bacterial infection resulted in a decreased protein level of the cell cycle regulator cyclin D1, whereas cyclin E expression levels were increased. Furthermore, N. meningitidis infection induced an accumulation of the cyclin-dependent kinase inhibitor (CKI) p21(WAF1/CIP1) that was accompanied by a redistribution of this CKI to the cell nucleus, as shown by immunofluorescence analysis. Moreover, the p27(CIP1) CKI was redistributed and showed punctate foci in infected cells. In summary, we present data that N. meningitidis can interfere with the processes of host cell cycle regulation.
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Pontos de Checagem do Ciclo Celular , Células Epiteliais/microbiologia , Interações Hospedeiro-Patógeno , Infecções Meningocócicas/microbiologia , Neisseria meningitidis/fisiologia , Aderência Bacteriana/fisiologia , Western Blotting , Núcleo Celular/metabolismo , Ciclina D1/metabolismo , Ciclina E/metabolismo , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Células Epiteliais/fisiologia , Humanos , Infecções Meningocócicas/metabolismo , Neisseria meningitidis/metabolismoRESUMO
BACKGROUND: Secretion of ADP and ATP is an essential prerequisite for platelet aggregation. Impaired nucleotide secretion can cause aggregation defects and increased bleeding risk. Quantitative determination of platelet nucleotide content and exocytosis is thus of importance for the characterization and diagnosis of bleeding phenotypes. For transgenic animal models with hemostatic defects analysis of potential secretion defects is as well imperative. METHODS: Supernatants of washed platelets and platelet-rich plasma were analyzed by HPLC for ADP and ATP concentration. Calibration of the HPLC data was accomplished with an internal standard compensating for loss of analyte, detection sensitivity, and interference of the biomatrix. RESULTS: HPLC analysis of nucleotide secretion was carried out with human and mouse platelets. Detection limits were determined for washed platelet and platelet-rich plasma samples. In the physiological concentration range linearity with respect to the peak area is maintained. CONCLUSION: The method combines reasonable sensitivity with robustness. The internal standard ensures reliable quantification of nucleotide concentrations even in presence of otherwise interfering substances. The low sample consumption renders possible the application to analysis of small samples like in mouse experiments.
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PURPOSE: This study was designed to assess the role of laparoscopic resection rectopexy for symptomatic rectal intussusception in patients who failed medical treatment. The functional outcomes of laparoscopic resection rectopexy were evaluated. METHODS: Patients who underwent laparoscopic resection rectopexy for rectal intussusception between July 1998 and November 2004 were identified. All patients with obstructed defecation failing medical treatment were included. Data were prospectively collected for the perioperative period. A follow-up questionnaire was used to assess functional outcome. RESULTS: Between 1998 and 2004, a total of 56 patients (53 females (95 percent); age range, 23-83 years) underwent laparoscopic resection rectopexy for rectal intussusception. The median operative time was 123 minutes. Morbidity was 7 percent, and there was no mortality. Fifty-two patients were available for follow-up, and of these 33 (63 percent) reported an overall improvement in their function after surgery. Of 28 patients suffering constipation, 15 (53 percent) reported an improvement in bowel frequency. Sixty-seven percent of patients incontinent before surgery improved. Symptoms of incomplete evacuation resolved in 38 percent of affected patients. Thirty-six percent of patients needing to strain at stool did not have this problem after surgery. Median follow-up was 44 (range, 15-92) months. CONCLUSIONS: The management of patients with rectal intussusception and obstructed defecation failing medical treatment is challenging. Laparoscopic resection rectopexy is an option that might offer symptomatic relief and improved function. Further studies are required to define the selection criteria to optimize the outcome in this patient group.