Monthlong Intubated Patient with Life-Threatening COVID-19 and Cerebral Microbleeds Suffers Only Mild Cognitive Sequelae at 8-Month Follow-up: A Case Report.

OBJECTIVE: To elaborate on possible cognitive sequelae related to COVID-19, associated cerebrovascular injuries as well as the general consequences from intensive care. COVID-19 is known to have several, serious CNS-related consequences, but neuropsychological studies of severe COVID-19 are still rare. METHODS: M., a 45-year-old man, who survived a severe COVID-19 disease course including Acute Respiratory Distress Syndrome (ARDS), cerebral microbleeds, and 35 days of mechanical ventilation, is described. We elaborate on M's recovery and rehabilitation process from onset to the 8-month follow-up. The cognitive functions were evaluated with a comprehensive screening battery at 4 weeks after extubation and at the 8-month follow-up. RESULTS: Following extubation, M. was delirious, reported visual hallucinations, and had severe sleeping difficulties. At about 3 months after COVID-19 onset, M. showed mild to moderate deficits on tests measuring processing speed, working memory, and attention. At assessments at 8 months, M. performed better, with results above average on tests measuring learning, memory, word fluency, and visuospatial functions. Minor deficits were still found regarding logical reasoning, attention, executive functioning, and processing speed. There were no lingering psychiatric symptoms. While M. had returned to a part-time job, he was not able to resume previous work-tasks. CONCLUSION: This case-study demonstrates possible cognitive deficits after severe COVID-19 and emphasizes the need of a neuropsychological follow-up, with tests sensitive to minor deficits. The main findings of this report provide some support that the long-term prognosis for cognition in severe COVID-19 may be hopeful

Gene dosage compensation calibrates four regulatory RNAs to control Vibrio cholerae quorum sensing

Quorum sensing is a mechanism of cell-to-cell communication that allows bacteria to coordinately regulate gene expression in response to changes in cell-population density. At the core of the Vibrio cholerae quorum-sensing signal transduction pathway reside four homologous small RNAs (sRNAs), named the quorum regulatory RNAs 1–4 (Qrr1–4). The four Qrr sRNAs are functionally redundant. That is, expression of any one of them is sufficient for wild-type quorum-sensing behaviour. Here, we show that the combined action of two feedback loops, one involving the sRNA-activator LuxO and one involving the sRNA-target HapR, promotes gene dosage compensation between the four qrr genes. Gene dosage compensation adjusts the total Qrr1–4 sRNA pool and provides the molecular mechanism underlying sRNA redundancy. The dosage compensation mechanism is exquisitely sensitive to small perturbations in Qrr levels. Precisely maintained Qrr levels are required to direct the proper timing and correct patterns of expression of quorum-sensing-regulated target genes

Mechanosensitive ATP Release Maintains Proper Mucus Hydration of Airways

The clearance of mucus from the airways protects the lungs from inhaled noxious and infectious materials. Proper hydration of the mucus layer enables efficient mucus clearance through beating of cilia on airway epithelial cells, and reduced clearance of excessively concentrated mucus occurs in patients with chronic obstructive pulmonary disease and cystic fibrosis. Key steps in the mucus transport process are airway epithelia sensing and responding to changes in mucus hydration. We reported that extracellular adenosine triphosphate (ATP) and adenosine were important luminal auto-crine and paracrine signals that regulated the hydration of the surface of human airway epithelial cultures through their action on apical membrane purinoceptors. Mucus hydration in human airway epithelial cultures was sensed by an interaction between cilia and the overlying mucus layer: Changes in mechanical strain, proportional to mucus hydration, regulated ATP release rates, adjusting fluid secretion to optimize mucus layer hydration. This system provided a feedback mechanism by which airways maintained mucus hydration in an optimum range for cilia propulsion. Understanding how airway epithelia can sense and respond to changes in mucus properties helps us to understand how the mucus clearance system protects the airways in health and how it fails in lung diseases such as cystic fibrosis

Statistical analysis plan for the Dex-CSDH trial: a randomised, double-blind, placebo-controlled trial of a 2-week course of dexamethasone for adult patients with a symptomatic chronic subdural haematoma

Abstract Background The incidence of chronic subdural haematoma (CSDH) is increasing. Although surgery remains the mainstay of management for symptomatic patients, uncertainty remains regarding the role of steroids. Hence, the Dex-CSDH trial was launched in the UK in 2015 aiming to determine whether, compared to placebo, dexamethasone can improve the 6-month functional outcome of patients with symptomatic CSDH by reducing the rate of surgical intervention and recurrence rate. Methods and design Dex-CSDH is a multi-centre, pragmatic, parallel group, double-blind, randomised trial assessing the clinical utility of a 2-week course of dexamethasone following a CSDH. Seven hundred fifty patients were randomised to either dexamethasone or placebo. The primary outcome is the modified Rankin Scale at 6 months which is dichotomised to favourable (a score of 0–3) versus unfavourable (a score of 4–6). Conclusions This paper and the accompanying additional material describe the statistical analysis plan for the trial. Trial registration ISRCTN, ISRCTN80782810. Registered on 7 November 2014. http://www.isrctn.com/ISRCTN80782810. EudraCT, 2014-004948-35. Registered on 20 March 2015. </jats:sec

Multiplexed, High Density Electrophysiology with Nanofabricated Neural Probes

Extracellular electrode arrays can reveal the neuronal network correlates of behavior with single-cell, single-spike, and sub-millisecond resolution. However, implantable electrodes are inherently invasive, and efforts to scale up the number and density of recording sites must compromise on device size in order to connect the electrodes. Here, we report on silicon-based neural probes employing nanofabricated, high-density electrical leads. Furthermore, we address the challenge of reading out multichannel data with an application-specific integrated circuit (ASIC) performing signal amplification, band-pass filtering, and multiplexing functions. We demonstrate high spatial resolution extracellular measurements with a fully integrated, low noise 64-channel system weighing just 330 mg. The on-chip multiplexers make possible recordings with substantially fewer external wires than the number of input channels. By combining nanofabricated probes with ASICs we have implemented a system for performing large-scale, high-density electrophysiology in small, freely behaving animals that is both minimally invasive and highly scalable

Preconditioning of mesenchymal stromal cells with low-intensity ultrasound: influence on chondrogenesis and directed SOX9 signaling pathways

Background: Continuous low-intensity ultrasound (cLIUS) facilitates the chondrogenic differentiation of human mesenchymal stromal cells (MSCs) in the absence of exogenously added transforming growth factor-beta (TGFβ) by upregulating the expression of transcription factor SOX9, a master regulator of chondrogenesis. The present study evaluated the molecular events associated with the signaling pathways impacting SOX9 gene and protein expression under cLIUS. Methods: Human bone marrow-derived MSCs were exposed to cLIUS stimulation at 14 kPa (5 MHz, 2.5 Vpp) for 5 min. The gene and protein expression of SOX9 was evaluated. The specificity of SOX9 upregulation under cLIUS was determined by treating the MSCs with small molecule inhibitors of select signaling molecules, followed by cLIUS treatment. Signaling events regulating SOX9 expression under cLIUS were analyzed by gene expression, immunofluorescence staining, and western blotting. Results: cLIUS upregulated the gene expression of SOX9 and enhanced the nuclear localization of SOX9 protein when compared to non-cLIUS-stimulated control. cLIUS was noted to enhance the phosphorylation of the signaling molecule ERK1/2. Inhibition of MEK/ERK1/2 by PD98059 resulted in the effective abrogation of cLIUS-induced SOX9 expression, indicating that cLIUS-induced SOX9 upregulation was dependent on the phosphorylation of ERK1/2. Inhibition of integrin and TRPV4, the upstream cell-surface effectors of ERK1/2, did not inhibit the phosphorylation of ERK1/2 and therefore did not abrogate cLIUS-induced SOX9 expression, thereby suggesting the involvement of other mechanoreceptors. Consequently, the effect of cLIUS on the actin cytoskeleton, a mechanosensitive receptor regulating SOX9, was evaluated. Diffused and disrupted actin fibers observed in MSCs under cLIUS closely resembled actin disruption by treatment with cytoskeletal drug Y27632, which is known to increase the gene expression of SOX9. The upregulation of SOX9 under cLIUS was, therefore, related to cLIUS-induced actin reorganization. SOX9 upregulation induced by actin reorganization was also found to be dependent on the phosphorylation of ERK1/2. Conclusions: Collectively, preconditioning of MSCs by cLIUS resulted in the nuclear localization of SOX9, phosphorylation of ERK1/2 and disruption of actin filaments, and the expression of SOX9 was dependent on the phosphorylation of ERK1/2 under cLIUS

Elevated Intracellular Calcium Stimulates NHE3 Activity by an IKEPP (NHERF4) Dependent Mechanism

The ileal brush border (BB) contains four evolutionarily related multi-PDZ domain proteins including NHERF1, NHERF2, PDZK1 (NHERF3) and IKEPP (NHERF4). Why multiple related PDZ proteins are in a similar location in the same cell is unknown. However, some specificity in regulation of NHE3 activity has been identified. For example, elevated intracellular Ca2+ ([Ca2+]i) inhibition of NHE3 is reconstituted by NHERF2 but not NHERF1, and involves the formation of large NHE3 complexes. To further evaluate the specificity of the NHERF family in calcium regulation of NHE3 activity, the current study determined whether the four PDZ domain containing protein IKEPP reconstitutes elevated [Ca2+]i regulation of NHE3. In vitro, IKEPP bound to the F2 region (aa 590-667) of NHE3 in overlay assays, which is the same region where NHERF1 and NHERF2 bind. PS120 cells lack endogenous NHE3 and IKEPP. Treatment of PS120/NHE3/IKEPP cells (stably transfected with NHE3 and IKEPP) with the Ca2+ ionophore, 4-Br-{"type":"entrez-nucleotide","attrs":{"text":"A23187","term_id":"833253","term_text":"A23187"}}A23187 (0.5μM), stimulated NHE3 Vmax activity by ∼40%. This was associated with an increase in plasma membrane expression of NHE3 by a similar amount. NHE3 activity and surface expression were unaffected by {"type":"entrez-nucleotide","attrs":{"text":"A23187","term_id":"833253","term_text":"A23187"}}A23187 in PS120/NHE3 cells lacking IKEPP. Based on sucrose density gradient centrifugation, IKEPP was also shown to exist in large complexes, some of which overlap in size with NHE3, and the size of both NHE3 and IKEPP complexes decreased in parallel after [Ca2+]i elevation. FRET experiments on fixed cells demonstrated that IKEPP and NHE3 directly associated at an intracellular site. Elevating [Ca2+]i decreased this intracellular NHE3 and IKEPP association. In summary: (1) In the presence of IKEPP, elevated [Ca2+]i stimulates NHE3 activity. This was associated with increased expression of NHE3 in the plasma membrane as well as a shift to smaller sizes of NHE3 and IKEPP containing complexes. (2) IKEPP directly binds NHE3 at its F2 C-terminal domain and directly associates with NHE3 in vivo (FRET). (3) Elevated [Ca2+]i decreased the association of IKEPP and NHE3 in an intracellular compartment. Based on which NHERF family member is expressed in PS120 cells, elevated [Ca2+]i stimulates (IKEPP), inhibits (NHERF2) or does not affect (NHERF1) NHE3 activity. This demonstrates that regulation of NHE3 depends on the nature of the NHERF family member associating with NHE3 and the accompanying NHE3 complexes