Sleep need driven oscillation of glutamate synaptic phenotype

Sleep loss increases AMPA-synaptic strength and number in the neocortex. However, this is only part of the synaptic sleep loss response. We report increased AMPA/NMDA EPSC ratio in frontal-cortical pyramidal neurons of layers 2-3. Silent synapses are absent, decreasing the plastic potential to convert silent NMDA to active AMPA synapses. These sleep loss changes are recovered by sleep. Sleep genes are enriched for synaptic shaping cellular components controlling glutamate synapse phenotype, overlap with autism risk genes and are primarily observed in excitatory pyramidal neurons projecting intra-telencephalically. These genes are enriched with genes controlled by the transcription factor, MEF2c and its repressor, HDAC4. Thus, sleep genes under the influence of MEF2c and HDAC4, can provide a framework within which motor learning and training occurs mediated by sleep-dependent oscillation of glutamate-synaptic phenotypes.

Label-free quantification of imaging features in the extracellular matrix of left and right-sided colon cancer tissues

The molecular pathogenesis of colorectal cancer is known to differ between the right and left side of the colon. Several previous studies have focussed on the differences in clinicopathological features, proteomic and genetic biomarkers, the composition of gut microbiota, response to therapy, and the characteristics of the tumour microenvironment. However, the morphology and density of collagen in the extracellular matrix (ECM) have not been studied intensively. In this study, we employed 2-photon laser scanning microscopy (2PLSM) to visualise the intrinsic second-harmonic generation (SHG) signal emitted by collagen fibres in the heterogeneous ECM of human colon tumour tissues. Through texture analysis of the SHG signal, we quantitatively distinguished the imaging features generated by structural differences of collagen fibres in healthy colon and cancers and found marked differences. The fibres inside of tumours exhibited a loss of organisation, particularly pronounced in right-sided colon cancer (RSCC), where the chaotic regions were significantly increased. In addition, a higher collagen content was found in left-sided colon cancer (LSCC). In future, this might aid in subclassification and therapeutic decisions or even in designing new therapy regimens by taking into account the differences between collagen fibres features between colon tumours located at different sides.

Building a Multidisciplinary Clinic Dedicated to Upper-Extremity Limb Loss

Complete care of the patient with upper limb loss mandates a long-term, multifaceted approach. Increased functionality and quality of life require collaborative efforts between the patient's surgeon, prosthetist, hand therapists, mental health professionals, and peers. An individual surgeon may find that initiating and maintaining a practice offering total integrated treatment for upper-extremity amputees is a formidable task, but with specific, actionable recommendations, the process can be demystified. The upper-extremity surgeon must be facile with operative techniques such as targeted muscle reinnervation (TMR), regenerative peripheral nerve interface (RPNI), and soft tissue reconstruction and focus on team recruitment strategy and promotion of the clinic within the community. Consistent communication and team decision-making shape each patient's preoperative and postoperative course. We aim to relay effective interventions at each step of recovery from each clinic member and describe clinic workflow designed to reinforce holistic care. We present a blueprint for creating a functional and comprehensive multidisciplinary center for patients with upper-extremity limb loss for those providers interested in providing care, but who are missing the logistical roadmap for how to do so.

Radial astrocyte synchronization modulates the visual system during behavioral-state transitions

Glial cells support the function of neurons. Recent evidence shows that astrocytes are also involved in brain computations. To explore whether and how their excitable nature affects brain computations and motor behaviors, we used two-photon Ca2+ imaging of zebrafish larvae expressing GCaMP in both neurons and radial astrocytes (RAs). We found that in the optic tectum, RAs synchronize their Ca2+ transients immediately after the end of an escape behavior. Using optogenetics, ablations, and a genetically encoded norepinephrine sensor, we observed that RA synchronous Ca2+ events are mediated by the locus coeruleus (LC)-norepinephrine circuit. RA synchronization did not induce direct excitation or inhibition of tectal neurons. Nevertheless, it modulated the direction selectivity and the long-distance functional correlations among neurons. This mechanism supports freezing behavior following a switch to an alerted state. These results show that LC-mediated neuro-glial interactions modulate the visual system during transitions between behavioral states.

Tendon Transfer to Treat Radial Nerve Palsy Following COVID-19 Infection

Multiple manifestations have been associated with the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus. Among them are mononeuritis multiplex (MNM) and other neurological complications, whose connection to coronavirus disease 2019 (COVID-19) is still unclear. One of the most common sites of nerve injury is the radial nerve, which can be treated with both nerve or tendon transfer. In this case report, a patient who was afflicted with severe COVID-19 infection and developed mono neuritis multiplex after prolonged mechanical ventilation with radial nerve palsy was treated with multiple tendon transfers. This is a way to use an established mechanism of resolving the manifestations of radial nerve palsy to aid in the recovery of COVID-19-related mononeuritis multiplex.

Should we abandon hormonal therapy in endometrial cancer? Outcomes of recurrent and metastatic endometrial cancer treated with systemic progestins

PURPOSE

The objective of this study is to determine primary survival endpoints in women with recurrent and metastatic endometrial carcinoma (RMEC) treated with progestins.

METHODS

A retrospective chart review was conducted at The Ottawa Hospital using electronic medical records. Inclusion criteria were a diagnosis of RMEC between 2000 and 2019, endometrioid histology, and ≥one line of progestin treatment. Progression-free survival (PFS) and overall survival (OS) were estimated using the Kaplan-Meier method.

RESULTS

Of 2342 cases reviewed, 74 met inclusion criteria. Sixty-six (88.0%) patients received megestrol acetate and 9 (12.0%) received a progestin alternative. The distribution of tumors by grade was: 1: 25 (33.3%), 2: 30 (40.0%), and 3: 20 (26.7%). The PFS and OS for the entire study sample was 14.3 months (95% CI 6.2-17.9) and 23.3 months (14.8-36.8), respectively. The PFS for patients with Grade 1-2 RMEC was 15.7 months (8.0, 19.5), compared to 5.0 months (3.0, 23.0) with Grade 3 disease. The OS for patients with Grade 1-2 versus Grade 3, was 25.9 months (15.3, 40.3) versus 12.5 months (5.7, 35.9), respectively. Thirty-four (45.9%) and 40 (54.1%) patients were treated with 0 and ≥1 line of chemotherapy. The PFS for chemotherapy-naïve patients was 17.9 months (14.3, 27.0), versus 6.2 months (3.9, 14.8) following ≥1 line of treatment. The OS was 29.1 months (17.9, 61.1) for chemotherapy-naïve patients versus 23.0 months (10.5, 37.6) for patients previously exposed.

CONCLUSIONS

This real-world data on RMEC suggests there is a role for progestins in select subgroups of women. The PFS for chemotherapy-naïve patients was 17.9 months (14.3, 27.0), versus 6.2 months (3.9, 14.8) following ≥1 line of treatment. The OS was 29.1 months (17.9, 61.1) for chemotherapy-OS was 29.1 months (17.9, 61.1) for chemotherapy-naïve patients versus 23.0 months (10.5, 37.6) for patients previously exposed.

The value of allied health professional research engagement on healthcare performance: a systematic review

BACKGROUND

Existing evidence suggests that clinician and organisation engagement in research can improve healthcare performance. With the increase in allied health professional (AHP) research activity, it is imperative for healthcare organisations, clinicians, managers, and leaders to understand research engagement specifically within allied health fields. This systematic review aims to examine the value of research engagement by allied health professionals and organisations on healthcare performance.

METHODS

This systematic review had a two-stage search strategy. Firstly, the papers from a previous systematic review examining the effect of research engagement in healthcare were screened to identify papers published pre-2012. Secondly, a multi-database search was used to conduct a re-focused update of the previous review, focusing specifically on allied health to identify publications from 2012-2021. Studies which examined the value of allied health research engagement on healthcare performance were included. All stages of the review were conducted by two reviewers independently. Each study was assessed using the appropriate Joanna Briggs Institute critical appraisal tool. A narrative synthesis was completed to analyse the similarities and differences between and within the different study types.

RESULTS

Twenty-two studies were included, comprising of mixed research designs, of which six were ranked as high importance. The findings indicated that AHP research engagement appears related to positive findings in improvements to processes of care. The review also identified the most common mechanisms which may link research engagement with these improvements.

DISCUSSION

This landmark systematic review and narrative synthesis suggests value in AHP research engagement in terms of both processes of care and more tentatively, of healthcare outcomes. While caution is required because of the lack of robust research studies, overall the findings support the agenda for growing AHP research. Recommendations are made to improve transparent reporting of AHP research engagement and to contribute essential evidence of the value of AHP research engagement.

TRIAL REGISTRATION

This systematic review protocol was registered with the international prospective register of systematic reviews, PROSPERO (registration number CRD42021253461 ).

Germline-focused analysis of tumour-detected variants in 49,264 cancer patients: ESMO Precision Medicine Working Group recommendations

BACKGROUND

The European Society for Medical Oncology Precision Medicine Working Group (ESMO PMWG) was reconvened to update its 2018/19 recommendations on follow-up of putative germline variants detected on tumour-only sequencing, which were based on an analysis of 17 152 cancers.

METHODS

We analysed an expanded dataset including 49 264 paired tumour-normal samples. We applied filters to tumour-detected variants based on variant allele frequency, predicted pathogenicity and population variant frequency. For 58 cancer-susceptibility genes, we then examined the proportion of filtered tumour-detected variants of true germline origin [germline conversion rate (GCR)]. We conducted subanalyses based on the age of cancer diagnosis, specific tumour types and 'on-tumour' status (established tumour-gene association).

RESULTS

Analysis of 45 472 nonhypermutated solid malignancy tumour samples yielded 21 351 filtered tumour-detected variants of which 3515 were of true germline origin. 3.1% of true germline pathogenic variants were absent from the filtered tumour-detected variants. For genes such as BRCA1, BRCA2 and PALB2, the GCR in filtered tumour-detected variants was >80%; conversely for TP53, APC and STK11 this GCR was <2%.

CONCLUSION

Strategic germline-focused analysis can prioritise a subset of tumour-detected variants for which germline follow-up will produce the highest yield of most actionable true germline variants. We present updated recommendations around germline follow-up of tumour-only sequencing including (i) revision to 5% for the minimum per-gene GCR, (ii) inclusion of actionable intermediate penetrance genes ATM and CHEK2, (iii) definition of a set of seven 'most actionable' cancer-susceptibility genes (BRCA1, BRCA2, PALB2, MLH1, MSH2, MSH6 and RET) in which germline follow-up is recommended regardless of tumour type.

An electrophysiological and kinematic model of Paramecium, the "swimming neuron"

Paramecium is a large unicellular organism that swims in fresh water using cilia. When stimulated by various means (mechanically, chemically, optically, thermally), it often swims backward then turns and swims forward again in a new direction: this is called the avoiding reaction. This reaction is triggered by a calcium-based action potential. For this reason, several authors have called Paramecium the "swimming neuron". Here we present an empirically constrained model of its action potential based on electrophysiology experiments on live immobilized paramecia, together with simultaneous measurement of ciliary beating using particle image velocimetry. Using these measurements and additional behavioral measurements of free swimming, we extend the electrophysiological model by coupling calcium concentration to kinematic parameters, turning it into a swimming model. In this way, we obtain a model of autonomously behaving Paramecium. Finally, we demonstrate how the modeled organism interacts with an environment, can follow gradients and display collective behavior. This work provides a modeling basis for investigating the physiological basis of autonomous behavior of Paramecium in ecological environments.

Reliability of Instant Messaging-Based Evaluation of Brain Imaging in Acute Stroke

BACKGROUND

The use of instant messenger applications among physicians has become common in acute stroke management, especially in developing countries. Photos or video sequences of brain computed tomography (CT) scans are being sent to receive real-time support in assessing radiological findings. We analyzed whether instant messaging-based evaluation is precise enough to extract relevant information from the images.

METHODS

In this prospective study, anonymized videos and photos of CT and CT angiography scans of patients with symptoms of acute stroke were recorded from the diagnostic monitor using a smartphone. Two neurologists and 2 neuroradiologists performed evaluation of the images using WhatsApp. The gold standard was set by 2 experienced neuroradiologists who evaluated the CT images with their full radiological equipment. Statistical analysis included the calculation of Cohen kappa (κ).

RESULTS

A total of 104 brain images (derived from 81 patients) were included. All 4 raters performed with a perfect (κ=1) interobserver reliability in diagnosing intracerebral hemorrhage. For subarachnoid hemorrhage, interobserver reliability was slightly lower (raters 1, 2, and 3, κ=1; rater 4, κ=0.88). For diagnosing stroke mimics, interobserver reliability showed considerable variations (κ between 0.32 and 1). Alberta Stroke Program Early CT Score differences overall were comparable between raters and did not exceed 3 to 4 points without noticeable outliers. All raters performed with a moderate-to-substantial interobserver reliability for detecting large vessel occlusions (κ=0.48 in rater 1, κ=0.62 in rater 2, and κ=0.63 in raters 3 and 4).

CONCLUSIONS

Stroke neurologists can reliably extract information on intracerebral hemorrhage from CT images recorded via smartphone and sent through instant messaging tools. Remote diagnosis of early infarct signs and stroke mimics was less reliable. We developed a standard for the acquisition of images, taking data protection into account.

Mechanical thrombectomy: Review

Large vessel occlusion stroke contributes to disability and mortality out of proportion to its incidence. Over time it was noted that intravenous thrombolysis alone was not sufficient for this stroke type. Slowly, endovascular approach and mechanical clot retrieval have come out to be the biggest advances in the field of neurology as well as modern medicine. Although the careful selection of patients is needed as standardized by landmark trials. At the same time, thrombectomy is now being studied in patients excluded by previous trials and is seemingly coming out be effective in the vast majority of patients with large vessel occlusions. Further, techniques and devices are getting refined day by day to achieve the maximum possible benefit.

Comparing Bridging Thrombolysis with Direct Thrombectomy in Stroke due to Large Vessel Occlusion- Indian Experience (LVO-Direct)

Objectives

Intravenous thrombolysis alone has poor recanalization rates in large vessel occlusion strokes. Bridging thrombolysis has evolved as a standard treatment approach in emergent large vessel occlusions. Patients who undergo thrombectomy have a higher probability of favorable outcomes irrespective of the use of prior intravenous thrombolysis. Our aim was to compare bridging thrombolysis with direct thrombectomy in ischemic stroke due to large vessel occlusion.

Methods

We included patients from our stroke registry, with large vessel occlusion strokes, presenting <4.5 hr from onset. Bridging thrombolysis was the standard approach. Direct thrombectomy was done in patients with contraindications to intravenous thrombolysis. The primary outcome was the modified Rankin scale at 3 months. Secondary outcomes were National Institute of Health Stroke Scale at 24 hr post-procedure, door to puncture time, puncture to recanalization time, the extent of recanalization, and the number of passes required. Safety outcomes were any occurrence of intracranial hemorrhage or other complications related to procedure or death. Logistic regression analysis was used to find the factors affecting the outcome.

Results

Total 76 patients were included, 29 underwent bridging thrombolysis and 47 underwent direct thrombectomy. A favorable outcome (mRS 0-2) was achieved in 19 (65.5%) patients in the bridging group and 25 (58.1%) patients in the direct group (P = 0.4, Chi-square test). There was no significant difference in any of the secondary outcomes as well. Symptomatic intracranial hemorrhage occurred in 2 (2.6%) patients and a total of 10 (13.9%) were dead at 3-month follow-up, comparable in both groups.

Conclusion

Direct thrombectomy has comparable outcomes to bridging thrombolysis in emergent large vessel occlusions.

Simulation model for Covid-19 pandemic

This paper outlines computer modeling algorithms designedto predict and forecast a COVID-19. In this paper, we considera deterministic model. Theongoing COVID-19 epidemic quicklyspread across the globe. Significant behavioural, social initiativesto limit city transport, case identification and touch tracking,quarantine, advice, and knowledge to the public, creationof detection kits, etc. and state measures were conducted toreduce the epidemic and eliminate coronavirus persistence inhumans around theworld from stopping the global coronavirusoutbreak. In this paper, we propose a basic SIR epidemic modelto show a simulation, the MATLAB algorithm using bouncingdots to depict safe and sick people to simulate infection spread.The graphical model shown here is implemented using MATLABpackage version 3.0.In this paper, we discuss the importance of models becausethey help one explore what could happen. They demonstratehow different possible futures might be shaped by what weare doing now. We can examine the effects of specific interventionsin different ways such as quarantine or a lockdown &explore how simulations may predict, how infectious diseasesadvanced to show the possible result of an outbreak, and betterguide initiatives in public health regarding the pandemicresponse andpandemic past including an overview of the keycharacteristics of adverse pandemic consequences and epidemicoutbreak.

Effect of visual input on syllable parsing in a computational model of a neural microcircuit for speech processing

Objective.Seeing a person talking can help us understand them, particularly in a noisy environment. However, how the brain integrates the visual information with the auditory signal to enhance speech comprehension remains poorly understood.Approach.Here we address this question in a computational model of a cortical microcircuit for speech processing. The model consists of an excitatory and an inhibitory neural population that together create oscillations in the theta frequency range. When stimulated with speech, the theta rhythm becomes entrained to the onsets of syllables, such that the onsets can be inferred from the network activity. We investigate how well the obtained syllable parsing performs when different types of visual stimuli are added. In particular, we consider currents related to the rate of syllables as well as currents related to the mouth-opening area of the talking faces.Main results.We find that currents that target the excitatory neuronal population can influence speech comprehension, both boosting it or impeding it, depending on the temporal delay and on whether the currents are excitatory or inhibitory. In contrast, currents that act on the inhibitory neurons do not impact speech comprehension significantly.Significance.Our results suggest neural mechanisms for the integration of visual information with the acoustic information in speech and make experimentally-testable predictions.

854 Mortality Associated with Conversion of Total Hip Arthroplasty for Failed Fixation/Hemiarthroplasty for Neck of Femur Fractures

Aim

To identify the mortality associated with failed internal fixation and hemiarthroplasty of neck of femur fractures.

Method

Patients undergoing conversion of internal fixation / hemi arthroplasty were identified from theatre records and surgical databases. Data was stored in Microsoft Excel spreadsheet. Clinical outcomes at 30 days, 1 year and 5 years post conversion total hip replacement.

Results

60 cases were collected between June 2006 and November 2016. 46 females and 14 males involved in the case. The mean age of male patients was 66.5 and for females 67.9. 32 patients had previous sliding hip screw fixation,12 had intra-medullary nails, 8 had cannulated screw fixation and 5 patients had hemiarthroplasty. The mean time to failure was 22 months (Range: 2 weeks to 60 months) and there were 6 cases of late posttraumatic arthritis (range 4 yrs to 23 yrs). Average time from documented failure to conversion THR was 2 months. There were 2 superficial wound infections which were successfully treated with antibiotics. There were 2 cases of deep infection which required multiple debridement, washout, and prolonged inpatient stay. Average duration of hospital stay was 5.7days. 18 patients died before 5 years for reasons unrelated to their hip. All had a functional prosthesis at time of last review. 42 patients alive at 5 years had a functional prosthesis at last review

Conclusions

Total Hip Arthroplasty is a successful procedure for failed fixation / hemiarthroplasty despite the technical challenges. A 3–5-year mortality rate of 33.33 % reflects well against the NHFD 1year mortality of 30 %.

Integrative sequencing discovers an ATF1-motif enriched molecular signature that differentiates hyalinizing clear cell carcinoma from mucoepidemoid carcinoma

OBJECTIVES

Salivary gland tumors are comprised of a diverse group of malignancies with widely varying prognoses. These cancers can be difficult to differentiate, especially in cases with limited potential for immunohistochemistry (IHC)-based characterization. Here, we sought to define the molecular profile of a rare salivary gland cancer called hyalinizing clear cell carcinoma (HCCC), and identify a molecular gene signature capable of distinguishing between HCCC and the histopathologically similar disease, mucoepidermoid carcinoma (MEC).

MATERIALS AND METHODS

We performed the first integrated full characterization of five independent HCCC cases.

RESULTS

We discovered insulin-like growth factor alterations and aberrant IGF2 and/or IGF1R expression in HCCC tumors, suggesting a potential dependence on this pathway. Further, we identified a 354 gene signature that differentiated HCCC from MEC, and was significantly enriched for genes with an ATF1 binding motif in their promoters, supporting a transcriptional pathogenic mechanism of the characteristic EWSR1-ATF1 fusion found in these tumors. Of the differentially expressed genes, IGF1R, SGK1 and SGK3 were found to be elevated in the HCCCs relative to MECs. Finally, analysis of immune checkpoints and subsequent IHC demonstrated that CXCR4 protein was elevated in several of the HCCC cases.

CONCLUSION

Collectively, our data identify an ATF1-motif enriched gene signature that may have clinical utility for molecular differentiation of HCCCs from other salivary gland tumors and discover potential actionable alterations that may benefit the clinical care of recurrent HCCC patients.

Global impact of COVID-19 on stroke care

Background

The COVID-19 pandemic led to profound changes in the organization of health care systems worldwide.

Aims

We sought to measure the global impact of the COVID-19 pandemic on the volumes for mechanical thrombectomy, stroke, and intracranial hemorrhage hospitalizations over a three-month period at the height of the pandemic (1 March–31 May 2020) compared with two control three-month periods (immediately preceding and one year prior).

Methods

Retrospective, observational, international study, across 6 continents, 40 countries, and 187 comprehensive stroke centers. The diagnoses were identified by their ICD-10 codes and/or classifications in stroke databases at participating centers.

Results

The hospitalization volumes for any stroke, intracranial hemorrhage, and mechanical thrombectomy were 26,699, 4002, and 5191 in the three months immediately before versus 21,576, 3540, and 4533 during the first three pandemic months, representing declines of 19.2% (95%CI, −19.7 to −18.7), 11.5% (95%CI, −12.6 to −10.6), and 12.7% (95%CI, −13.6 to −11.8), respectively. The decreases were noted across centers with high, mid, and low COVID-19 hospitalization burden, and also across high, mid, and low volume stroke/mechanical thrombectomy centers. High-volume COVID-19 centers (−20.5%) had greater declines in mechanical thrombectomy volumes than mid- (−10.1%) and low-volume (−8.7%) centers (p < 0.0001). There was a 1.5% stroke rate across 54,366 COVID-19 hospitalizations. SARS-CoV-2 infection was noted in 3.9% (784/20,250) of all stroke admissions.

Conclusion

The COVID-19 pandemic was associated with a global decline in the volume of overall stroke hospitalizations, mechanical thrombectomy procedures, and intracranial hemorrhage admission volumes. Despite geographic variations, these volume reductions were observed regardless of COVID-19 hospitalization burden and pre-pandemic stroke/mechanical thrombectomy volumes.

Decline in subarachnoid haemorrhage volumes associated with the first wave of the COVID-19 pandemic

Background

During the COVID-19 pandemic, decreased volumes of stroke admissions and mechanical thrombectomy were reported. The study’s objective was to examine whether subarachnoid haemorrhage (SAH) hospitalisations and ruptured aneurysm coiling interventions demonstrated similar declines.

Methods

We conducted a cross-sectional, retrospective, observational study across 6 continents, 37 countries and 140 comprehensive stroke centres. Patients with the diagnosis of SAH, aneurysmal SAH, ruptured aneurysm coiling interventions and COVID-19 were identified by prospective aneurysm databases or by International Classification of Diseases, 10th Revision, codes. The 3-month cumulative volume, monthly volumes for SAH hospitalisations and ruptured aneurysm coiling procedures were compared for the period before (1 year and immediately before) and during the pandemic, defined as 1 March–31 May 2020. The prior 1-year control period (1 March–31 May 2019) was obtained to account for seasonal variation.

Findings

There was a significant decline in SAH hospitalisations, with 2044 admissions in the 3 months immediately before and 1585 admissions during the pandemic, representing a relative decline of 22.5% (95% CI −24.3% to −20.7%, p<0.0001). Embolisation of ruptured aneurysms declined with 1170–1035 procedures, respectively, representing an 11.5% (95%CI −13.5% to −9.8%, p=0.002) relative drop. Subgroup analysis was noted for aneurysmal SAH hospitalisation decline from 834 to 626 hospitalisations, a 24.9% relative decline (95% CI −28.0% to −22.1%, p<0.0001). A relative increase in ruptured aneurysm coiling was noted in low coiling volume hospitals of 41.1% (95% CI 32.3% to 50.6%, p=0.008) despite a decrease in SAH admissions in this tertile.

Interpretation

There was a relative decrease in the volume of SAH hospitalisations, aneurysmal SAH hospitalisations and ruptured aneurysm embolisations during the COVID-19 pandemic. These findings in SAH are consistent with a decrease in other emergencies, such as stroke and myocardial infarction.

Synchronization, Stochasticity, and Phase Waves in Neuronal Networks With Spatially-Structured Connectivity

Oscillations in the beta/low gamma range (10–45 Hz) are recorded in diverse neural structures. They have successfully been modeled as sparsely synchronized oscillations arising from reciprocal interactions between randomly connected excitatory (E) pyramidal cells and local interneurons (I). The synchronization of spatially distant oscillatory spiking E–I modules has been well-studied in the rate model framework but less so for modules of spiking neurons. Here, we first show that previously proposed modifications of rate models provide a quantitative description of spiking E–I modules of Exponential Integrate-and-Fire (EIF) neurons. This allows us to analyze the dynamical regimes of sparsely synchronized oscillatory E–I modules connected by long-range excitatory interactions, for two modules, as well as for a chain of such modules. For modules with a large number of neurons (> 10⁵), we obtain results similar to previously obtained ones based on the classic deterministic Wilson-Cowan rate model, with the added bonus that the results quantitatively describe simulations of spiking EIF neurons. However, for modules with a moderate (~ 10⁴) number of neurons, stochastic variations in the spike emission of neurons are important and need to be taken into account. On the one hand, they modify the oscillations in a way that tends to promote synchronization between different modules. On the other hand, independent fluctuations on different modules tend to disrupt synchronization. The correlations between distant oscillatory modules can be described by stochastic equations for the oscillator phases that have been intensely studied in other contexts. On shorter distances, we develop a description that also takes into account amplitude modes and that quantitatively accounts for our simulation data. Stochastic dephasing of neighboring modules produces transient phase gradients and the transient appearance of phase waves. We propose that these stochastically-induced phase waves provide an explanative framework for the observations of traveling waves in the cortex during beta oscillations.

Non-immune fetal hydrops: etiology and outcome according to gestational age at diagnosis

OBJECTIVE

Fetal hydrops is associated with increased perinatal morbidity and mortality. The etiology and outcome of fetal hydrops may differ according to the gestational age at diagnosis. The aim of this study was to evaluate the cause, evolution and outcome of non-immune fetal hydrops (NIFH), according to the gestational age at diagnosis.

METHODS

This was a retrospective cohort study of all singleton pregnancies complicated by NIFH, at the Fetal Medicine Unit at St George's University Hospital, London, UK, between 2000 and 2018. All fetuses had detailed anomaly and cardiac ultrasound scans, karyotyping and infection screening. Prenatal diagnostic and therapeutic intervention, gestational age at diagnosis and delivery, as well as pregnancy outcome, were recorded. Regression analysis was used to test for potential association between possible risk factors and perinatal mortality.

RESULTS

We included 273 fetuses with NIFH. The etiology of the condition varied significantly in the three trimesters. Excluding 30 women who declined invasive testing, the cause of NIFH was defined as unknown in 62 of the remaining 243 cases (25.5%). Chromosomal aneuploidy was the most common cause of NIFH in the first trimester. It continued to be a significant etiologic factor in the second trimester, along with congenital infection. In the third trimester, the most common etiology was cardiovascular abnormality. Among the 152 (55.7%) women continuing the pregnancy, 48 (31.6%) underwent fetal intervention, including the insertion of pleuroamniotic shunts, fetal blood transfusion and thoracentesis. Fetal intervention was associated significantly with lower perinatal mortality (odds ratio (OR), 0.30 (95% CI, 0.14-0.61); P < 0.001); this association remained significant after excluding cases with a diagnosis of anemia or infection (OR, 0.29 (95% CI, 0.13-0.66); P = 0.003). In 104 fetuses not undergoing active fetal intervention, the gestational age at diagnosis was the only parameter that was significantly associated with the risk of perinatal mortality (OR, 0.92 (95% CI, 0.85-0.99); P = 0.035), while the affected body cavity and polyhydramnios were not (P > 0.05).

CONCLUSIONS

An earlier gestational age at diagnosis of NIFH was associated with an increased risk of aneuploidy and worse pregnancy outcome, including a higher risk of perinatal loss. Fetal therapy was associated significantly with lower perinatal mortality. © 2020 Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

State-wide utilization and performance of traditional and cell-free DNA-based prenatal testing pathways: the Victorian Perinatal Record Linkage (PeRL) study

OBJECTIVES

To perform individual record linkage of women undergoing screening with cell-free DNA (cfDNA), combined first-trimester screening (CFTS), second-trimester serum screening (STSS), and/or prenatal and postnatal cytogenetic testing with the aim to (1) obtain population-based estimates of utilization of prenatal screening and invasive diagnosis, (2) analyze the performance of different prenatal screening strategies, and (3) report the residual risk of any major chromosomal abnormality following a low-risk aneuploidy screening result.

METHODS

This was a retrospective study of women residing in the state of Victoria, Australia, who underwent prenatal screening or invasive prenatal diagnosis in 2015. Patient-funded cfDNA referrals from multiple providers were merged with state-wide results for government-subsidized CFTS, STSS and invasive diagnostic procedures. Postnatal cytogenetic results from products of conception and infants up to 12 months of age were obtained to ascertain cases of false-negative screening results and atypical chromosomal abnormalities. Individual record linkage was performed using LinkageWiz^TM .

RESULTS

During the study period, there were 79 140 births and 66 166 (83.6%) women underwent at least one form of aneuploidy screening. Linkage data were complete for 93.5% (n = 61 877) of women who underwent screening, and of these, 73.2% (n = 45 275) had CFTS alone, 20.2% (n = 12 486) had cfDNA alone; 5.3% (n = 3268) had STSS alone, 1.3% (n = 813) had both CFTS and cfDNA, and < 0.1% (n = 35) had both STSS and cfDNA. CFTS had a combined sensitivity for trisomies 21 (T21), 18 (T18) and 13 (T13) of 89.57% (95% CI, 82.64-93.93%) for a screen-positive rate (SPR) of 2.94%. There were 12 false-negative results in the CFTS pathway, comprising 10 cases of T21, one of T18 and one of T13. cfDNA had a combined sensitivity for T21, T18 and T13 of 100% (95% CI, 95.00-100%) for a SPR of 1.21%. When high-risk cfDNA results for any chromosome (including the sex chromosomes) and failed cfDNA tests were treated as screen positives, the SPR for cfDNA increased to 2.42%. The risk of any major chromosomal abnormality (including atypical abnormalities) detected on prenatal or postnatal diagnostic testing after a low-risk screening result was 1 in 1188 for CFTS (n = 37) and 1 in 762 for cfDNA (n = 16) (P = 0.13). The range of chromosomal abnormalities detected after a low-risk cfDNA result included pathogenic copy-number variants (n = 6), triploidy (n = 3), rare autosomal trisomies (n = 3) and monosomy X (n = 2).

CONCLUSIONS

Our state-wide record-linkage analysis delineated the utilization and clinical performance of the multitude of prenatal screening pathways available to pregnant women. The sensitivity of cfDNA for T21, T18 and T13 was clearly superior to that of CFTS. While there was no statistically significant difference in the residual risk of any major chromosomal abnormality after a low-risk CFTS or cfDNA result, there were fewer live infants diagnosed with a major chromosomal abnormality in the cfDNA cohort. These data provide valuable population-based evidence to inform practice recommendations and health policies. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

A simple device to immobilize protists for electrophysiology and microinjection

We present a simple device to mechanically immobilize motile cells such as ciliates. It can be used in particular for intracellular electrophysiology and microinjection. A transparent filter with holes smaller than the specimen is stretched over an outlet. A flow is induced by either a peristaltic pump or a depressurized tank, mechanically entraining cells to the bottom, where they are immobilized against the filter. The cells start swimming again as soon as the flow is stopped. We demonstrate the device by recording action potentials in Paramecium and injecting a fluorescent dye into the cytosol.

Germline-focussed analysis of tumour-only sequencing: recommendations from the ESMO Precision Medicine Working Group

It is increasingly common in oncology practice to perform tumour sequencing using large cancer panels. For pathogenic sequence variants in cancer susceptibility genes identified on tumour-only sequencing, it is often unclear whether they are of somatic or constitutional (germline) origin. There is wide-spread disparity regarding both the extent to which systematic 'germline-focussed analysis' is carried out upon tumour sequencing data and for which variants follow-up analysis of a germline sample is carried out. Here we present analyses of paired sequencing data from 17 152 cancer samples, in which 1494 pathogenic sequence variants were identified across 65 cancer susceptibility genes. From these analyses, the European Society of Medical Oncology Precision Medicine Working Group Germline Subgroup has generated (i) recommendations regarding germline-focussed analyses of tumour-only sequencing data, (ii) indications for germline follow-up testing and (iii) guidance on patient information-giving and consent.

Difficult Extubation: Calming the Sympathetic Storm

Tracheal extubation can evoke an equally strong haemodyamic stress response as tracheal intubation. We present a patient with myocardial infarction who repeatedly failed tracheal extubation. He developed acute pulmonary oedema following each attempt at tracheal extubation due to sympathetic overactivity. A change of approach with extubation under propofol sedation followed by continued sympatholysis with dexmedetomidine infusion allowed successful extubation.