Burkitt lymphoma in a child with atopic dermatitis and a 7-year history of regular topical tacrolimus use

We describe the case of a boy who presented with abdominal Burkitt lymphoma; he had been regularly using tacrolimus ointment 0.1% for severe recurrent atopic dermatitis for 7 years immediately prior to developing cancer. We present his medical history and review the current knowledge regarding a link between topical tacrolimus and malignancy risk.     

Noise Correlations for Faster and More Robust Learning

Distributed population codes are ubiquitous in the brain and pose a challenge to downstream neurons that must learn an appropriate readout. Here we explore the possibility that this learning problem is simplified through inductive biases implemented by stimulus-independent noise correlations that constrain learning to task-relevant dimensions. We test this idea in a set of neural networks that learn to perform a perceptual discrimination task. Correlations among similarly tuned units were manipulated independently of an overall population signal-to-noise ratio to test how the format of stored information affects learning. Higher noise correlations among similarly tuned units led to faster and more robust learning, favoring homogenous weights assigned to neurons within a functionally similar pool, and could emerge through Hebbian learning. When multiple discriminations were learned simultaneously, noise correlations across relevant feature dimensions sped learning, whereas those across irrelevant feature dimensions slowed it. Our results complement the existing theory on noise correlations by demonstrating that when such correlations are produced without significant degradation of the signal-to-noise ratio, they can improve the speed of readout learning by constraining it to appropriate dimensions.SIGNIFICANCE STATEMENT Positive noise correlations between similarly tuned neurons theoretically reduce the representational capacity of the brain, yet they are commonly observed, emerge dynamically in complex tasks, and persist even in well-trained animals. Here we show that such correlations, when embedded in a neural population with a fixed signal-to-noise ratio, can improve the speed and robustness with which an appropriate readout is learned. In a simple discrimination task such correlations can emerge naturally through Hebbian learning. In more complex tasks that require multiple discriminations, correlations between neurons that similarly encode the task-relevant feature improve learning by constraining it to the appropriate task dimension.     

Investigating the temporal dynamics of electroencephalogram (EEG) microstates using recurrent neural networks

Electroencephalogram (EEG) microstates that represent quasi‐stable, global neuronal activity are considered as the building blocks of brain dynamics. Therefore, the analysis of microstate sequences is a promising approach to understand fast brain dynamics that underlie various mental processes. Recent studies suggest that EEG microstate sequences are non‐Markovian and nonstationary, highlighting the importance of the sequential flow of information between different brain states. These findings inspired us to model these sequences using Recurrent Neural Networks (RNNs) consisting of long‐short‐term‐memory (LSTM) units to capture the complex temporal dependencies. Using an LSTM‐based auto encoder framework and different encoding schemes, we modeled the microstate sequences at multiple time scales (200–2,000 ms) aiming to capture stably recurring microstate patterns within and across subjects. We show that RNNs can learn underlying microstate patterns with high accuracy and that the microstate trajectories are subject invariant at shorter time scales (≤400 ms) and reproducible across sessions. Significant drop in the reconstruction accuracy was observed for longer sequence lengths of 2,000 ms. These findings indirectly corroborate earlier studies which indicated that EEG microstate sequences exhibit long‐range dependencies with finite memory content. Furthermore, we find that the latent representations learned by the RNNs are sensitive to external stimulation such as stress while the conventional univariate microstate measures (e.g., occurrence, mean duration, etc.) fail to capture such changes in brain dynamics. While RNNs cannot be configured to identify the specific discriminating patterns, they have the potential for learning the underlying temporal dynamics and are sensitive to sequence aberrations characterized by changes in metal processes. Empowered with the macroscopic understanding of the temporal dynamics that extends beyond short‐term interactions, RNNs offer a reliable alternative for exploring system level brain dynamics using EEG microstate sequences.     

Carcinoma presenting as idiopathic anterior glottic webs: A case series

An anterior glottic web is an abnormal fusion of the anterior aspect of the membranous vocal folds. Noncongenital glottic webs are usually iatrogenic from intubation or laryngeal surgery. We present six adult patients whose initial in‐office diagnoses were consistent with “idiopathic” benign anterior glottic webs as determined by three laryngologists (a.m.k. , j.m.b. , m.j.p. ). Further evaluation revealed the diagnoses of laryngeal squamous cell carcinoma in all cases. The high risk of malignancy in cases of idiopathic anterior glottic web necessitates biopsy for tissue diagnosis of all such lesions. Laryngoscope, 129:2118–2120, 2019     

The effect of various in-vitro and ex-vivo parameters on irrigant flow and apical pressure using manual syringe needle irrigation: Systematic review

BackgroundFluid dynamics is a majorly neglected aspect to be studied in root canal irrigation. The fundamental rule to understand mechanics is to observe patterns of flow during the process. Thus, this work is conducted to do a systemic assessment of the in-vitro and ex-vivo based studies to evaluate the effect of various parameters on the irrigant flow and apical pressure on using a manual syringe needle for root canal irrigation.MethodsThe literature search was conducted through libraries such as PubMed (Medline), CINAHL, Embase, Scopus and other hand literature from Google Scholar, the British medical library etc. The systematic review was reported following the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. As they include studies that were in-vitro and ex-vivo based, the risk of bias of the selected articles was assessed using a customized tool based on the previous literature and parameters evaluated in the studies included.ResultsThe literature search resulted in 101 items of which 19 records were included in this review. Results reported that multiple factors and parameters were assessed to evaluate the flow and apical pressures on using manual syringe needle irrigation.ConclusionsPresent systematic review gives insights in-depth about the irrigation dynamics of manual syringe needle irrigation. Besides, it is inconclusive to compile a single factor or a single parameter contributing to the enhanced irrigant flow and least apical pressures.     

Recognition of the critically ill patient and escalation of therapy

Critical illness often involves multiple organ failures and is associated with significant morbidity and mortality. In the vast majority of patients, there is a recognizable period of physiological deterioration which heralds the development of organ failure and critical illness. Despite efforts to improve the detection and management of critical illness, signs of deterioration are often missed and decisions to move patients to critical care units are delayed. Standardized approaches which implement an effective ‘chain of response’ are now utilized worldwide. They focus on attempting to reduce the incidence of serious adverse events (SAEs) such as in-hospital cardiac arrest and unplanned intensive care unit (ICU) admission using preventative measures. These systems should include: accurate recording and documentation of vital signs, recognition and interpretation of abnormal values, rapid bedside patient assessment by trained teams and appropriate interventions. Early warning systems (EWS) are an important part of this and can help identify patients at risk of deterioration and SAEs. Assessment of the critically ill patient should be undertaken by an appropriately trained clinician and follow a structured ABCDE (airway, breathing, circulation, disability and exposure) format. This facilitates correction of life-threatening problems by priority and provides a standardized approach between professionals. Lastly, timely support and input from members of the critical care team are vital to ensure optimal outcomes for critically ill patients.     

Relationship between flow cytometric features and clinical behavior of meningiomas

Meningiomas have a wide range of biological potential and clinical behavior. Histological findings are helpful in recognizing the malignant potential of a given tumor, but often fail to correlate with gross features, liability of recurrence, and extent of associated cerebral edema. To find alternate approaches to improve the correlation between biological and clinical behavior, 20 meningiomas were studied by flow cytometry (FC), an assessment that has been applied to meningiomas previously. Such FC features as DNA index (DI) and proliferative index (PI, %G2 + %S) were correlated with size, location, brain invasion, associated edema, and recurrence. Tumors with severe edema had significantly higher PIs (19.5 +/- 4.1) than those with moderate (12.6 +/- 4.5) or minimal (8 +/- 0) edema (P less than 0.05). The PI was greater than 16 in those tumors that recurred (n = 3) or invaded the brain (n = 3). Six tumors were aneuploid (DI, 1.33 +/- 0.17; PI, 17.1 +/- 5.3). These were uniformly large when compared with the diploid tumors, which were more variable in size. All of the aneuploid tumors were associated with moderate to severe cerebral edema. Two partly psammomatous tumors with high PIs and foci of high cellularity suggesting recent growth were associated with severe edema. One of these exhibited brain invasion. These preliminary data indicate that FC may have a potential use in the clinical management of meningiomas.