Revised recommendations from the CSO-HNS taskforce on performance of tracheotomy during the COVID-19 pandemic - what a difference a year makes.

BACKGROUND: During the early part of the COVID-19 pandemic, the Canadian Society of Otolaryngology - Head & Neck Surgery (CSO-HNS) task force published recommendations on performance of tracheotomy. Since then, our understanding of the virus has evolved with ongoing intensive research efforts. New literature has helped us better understand various aspects including patient outcomes and health care worker (HCW) risks associated with tracheotomy during the COVID-19 pandemic. Accordingly, the task force has re-evaluated and revised some of the previous recommendations. MAIN BODY: Based on recent evidence, a negative reverse transcription polymerase chain reaction (RT-PCR) COVID-19 swab status is no longer the main deciding factor in the timing of tracheotomy. Instead, tracheotomy may be considered as soon as COVID-19 swab positive patients are greater than 20 days beyond initial symptoms and 2 weeks of mechanical ventilation. Furthermore, both open and percutaneous surgical techniques may be considered with both techniques showing similar safety and outcome profiles. Additional recommendations with discussion of current evidence are presented. CONCLUSION: These revised recommendations apply new evidence in optimizing patient and health care system outcomes as well as minimizing risks of COVID-19 transmission during aerosol-generating tracheotomy procedures. As previously noted, additional evidence may lead to further evolution of these and other similar recommendations.

Recommendations from the CSO-HNS taskforce on performance of tracheotomy during the COVID-19 pandemic.

INTRODUCTION: The performance of tracheotomy is a common procedural request by critical care departments to the surgical services of general surgery, thoracic surgery and otolaryngology - head & neck surgery. A Canadian Society of Otolaryngology - Head & Neck Surgery (CSO-HNS) task force was convened with multi-specialty involvement from otolaryngology-head & neck surgery, general surgery, critical care and anesthesiology to develop a set of recommendations for the performance of tracheotomies during the COVID-19 pandemic. MAIN BODY: The tracheotomy procedure is highly aerosol generating and directly exposes the entire surgical team to the viral aerosol plume and secretions, thereby increasing the risk of transmission to healthcare providers. As such, we believe extended endotracheal intubation should be the standard of care for the entire duration of ventilation in the vast majority of patients. Pre-operative COVID-19 testing is highly recommended for any non-emergent procedure. CONCLUSION: The set of recommendations in this document highlight the importance of avoiding tracheotomy procedures in patients who are COVID-19 positive if at all possible. Recommendations for appropriate PPE and environment are made for COVID-19 positive, negative and unknown patients requiring consideration of tracheotomy. The safety of healthcare professionals who care for ill patients and who keep critical infrastructure operating is paramount.

Depression and survival of glioma patients: A systematic review and meta-analysis.

INTRODUCTION: There is currently a lack of a well-formed consensus regarding the effects of depression on the survival of glioma patients. A more thorough understanding of such effects may better highlight the importance of recognizing depressive symptoms in this patient population and guide treatment plans in the future. OBJECTIVE: The aim of this meta-analysis was to study the effect of depression on glioma patients' survival. METHODS: A meta-analysis was conducted according to the PRISMA guidelines. PubMed, Embase, and Cochrane databases were searched for studies that reported depression and survival among glioma patients through 11/06/2016. Both random-effects (RE) and fixed-effect (FE) models were used to compare survival outcomes in glioma patients with and without depression. RESULTS: Out of 619 identified articles, six were selected for the meta-analysis. Using RE model, the various measures for survival outcomes displayed worsened outcomes for both high and low-grade glioma patients with depression compared to those without depression. For binary survival outcomes, the overall pooled risk ratio for survival was 0.70 (95% CI: 0.47, 1.04; 6 studies; I2 = 54.9%, P-heterogeneity = 0.05) for high grade gliomas (HGG) and 0.28 (95% CI: 0.04, 1.78; I2 = 0%, P-heterogeneity = 1.00; one study) for low grade gliomas (LGG) was. A sub-group analysis in the HGG group by depression timing (pre- versus post-operative) revealed no differences between depression and survival outcomes (P-interaction = 0.47). For continuous survival outcomes, no statistically significant difference was found among the high and low-grade glioma groups (P-interaction = 0.31). The standardized mean difference (SMD) in survival outcomes was -0.56 months (95%CI: -1.13, 0.02; 4 studies, I2 = 89.4%, P-heterogeneity < 0.01) for HGG and -1.69 months (95%CI: -3.26, -0.13; one study; I2 = 0%, P-heterogeneity = 1.00) for LGG. In patients with HGG, the pooled HR of death also showed a borderline significant increased risk of death among depressive patients (HR 1.42, 95% CI: 1.00, 2.01). Results using the FE model were not materially different. CONCLUSIONS: Depression was associated with significantly worsened survival regardless of time of diagnosis, especially among patients with high-grade glioma.

Abdominal Organ Transplant Center Tobacco Use Policies Vary by Organ Program Type.

BACKGROUND: Smoking is a modifiable risk factor for cardiovascular disease, malignancy, and surgical complications. Transplant center practices toward smokers vary widely and evoke the classic tension between the ethical principles of justice and utility. We sought to assess current smoking policy variation in U.S. kidney, liver, and pancreas transplant centers. METHODS: An online survey was sent to program directors of all United Network for Organ Sharing-approved solid abdominal organ transplant programs regarding their policies toward prior and current tobacco use. RESULTS: Responses were received from 26% of kidney, 31% of liver, and 37% of pancreas transplant centers. Across organ programs, virtually all centers (97% to 100%) reported transplantations for former smokers, whereas 59% of kidney, 62% of liver, and 33% of pancreas programs reported transplantations for current smokers. Organ programs reported similar rates of having smoking cessation programs (74% to 77%) and performing serum cotinine testing (31% to 38%). Smoking was an absolute contraindication to transplantation at 38% of kidney, 15% of liver, and 50% of pancreas programs. Programs with absolute contraindication policies were less likely to perform transplantations in current smokers and more likely to check serum cotinine levels, but no more likely to have smoking cessation programs. CONCLUSIONS: There is variation in tobacco use policies among abdominal organ transplant programs and centers. Balancing equity and justice when deciding which patients to waitlist requires an individualized approach to the tobacco-using patient, consideration of organ-specific factors, tobacco-related disease burden, and overall patient health. Such multifaceted assessments might be favorable to inflexible tobacco use policies.

Effects of isoflurane and ethanol administration on c-Fos immunoreactivity in mice.

Noninvasive functional imaging holds great promise for the future of translational research, due to the ability to directly compare between preclinical and clinical models of psychiatric disorders. Despite this potential, concerns have been raised regarding the necessity to anesthetize rodent and monkey subjects during these procedures, because anesthetics may alter neuronal activity. For example, in studies on drugs of abuse and alcohol, it is not clear to what extent anesthesia can interfere with drug-induced neural activity. Therefore, the current study investigated whole-brain c-Fos activation following isoflurane anesthesia as well as ethanol-induced activation of c-Fos in anesthetized mice. In the first experiment, we examined effects of one or three sessions of gaseous isoflurane on c-Fos activation across the brain in male C57BL/6J mice. Isoflurane administration led to c-Fos activation in several areas, including the piriform cortex and lateral septum. Lower or similar levels of activation in these areas were detected after three sessions of isoflurane, suggesting that multiple exposures may eliminate some of the enhanced neuronal activation caused by acute isoflurane. In the second experiment, we investigated the ability of ethanol injection (1.5 or 2.5g/kgi.p.) to induce c-Fos activation under anesthesia. Following three sessions of isoflurane, 1.5g/kg of ethanol induced c-Fos in the central nucleus of amygdala and the centrally-projecting Edinger-Westphal nucleus (EWcp). This induction was lower after 2.5g/kg of ethanol. These results demonstrate that ethanol-induced neural activation can be detected in the presence of isoflurane anesthesia. They also suggest, that while habituation to isoflurane helps reduce neuronal activation, interaction between effects of anesthesia and alcohol can occur. Studies using fMRI imaging could benefit from using habituated animals and dose-response analyses.

Phase-gradient contrast in thick tissue with a scanning microscope.

It is well known that the principle of reciprocity is valid for light traveling even through scattering or absorptive media. This principle has been used to establish an equivalence between conventional widefield microscopes and scanning microscopes. We make use of this principle to introduce a scanning version of oblique back-illumination microscopy, or sOBM. This technique provides sub-surface phase-gradient and amplitude images from unlabeled tissue, in an epi-detection geometry. That is, it may be applied to arbitrarily thick tissue. sOBM may be implemented as a simple, cost-effective add-on with any scanning microscope, requiring only the availability of an extra input channel in the microscope electronics. We demonstrate here its implementation in combination with two-photon excited fluorescence (TPEF) microscopy and with coherent anti-Stokes Raman scattering (CARS) microscopy, applied to brain or spinal cord tissue imaging. In both cases, sOBM provides information on tissue morphology complementary to TPEF or CARS contrast. This information is obtained simultaneously and is automatically co-registered. Finally, we show that sOBM can be operated at video rate.

Coopération OMS - Côte d’Ivoire 2012 – 2013 : rapport biennal

Le rapport du biennium 2012-2013 montre la contribution que l’OMS a apporté au secteur de la santé en Côte d’Ivoire à travers la mise en oeuvre de programme de coopération avec le pays (OMS/Côte d’Ivoire) qui vise à soutenir les efforts du gouvernement afin d’améliorer la santé des populations. Il est important de noter que 2013 marque la fin du programme de coopération et également la fin de la Stratégie de Coopération avec le Pays (2009-2013). Le rapport passe en revue les réalisations majeures par les programmes prioritaires de coopération, les défis auxquels nous avons dû faire face et les perspectives pour le prochain biennium (2014-2015).

Towards generalised reference condition models for environmental assessment: a case study on rivers in Atlantic Canada.

Evaluation of the ecological status of river sites in Canada is supported by building models using the reference condition approach. However, geography, data scarcity and inter-operability constraints have frustrated attempts to monitor national-scale status and trends. This issue is particularly true in Atlantic Canada, where no ecological assessment system is currently available. Here, we present a reference condition model based on the River Invertebrate Prediction and Classification System approach with regional-scale applicability. To achieve this, we used biological monitoring data collected from wadeable streams across Atlantic Canada together with freely available, nationally consistent geographic information system (GIS) environmental data layers. For the first time, we demonstrated that it is possible to use data generated from different studies, even when collected using different sampling methods, to generate a robust predictive model. This model was successfully generated and tested using GIS-based rather than local habitat variables and showed improved performance when compared to a null model. In addition, ecological quality ratio data derived from the model responded to observed stressors in a test dataset. Implications for future large-scale implementation of river biomonitoring using a standardised approach with global application are presented.

In vivo evaluation of demyelination and remyelination in a nerve crush injury model.

Nerves of the peripheral nervous system have, to some extent, the ability to regenerate after injury, particularly in instances of crush or contusion injuries. After a controlled crush injury of the rat sciatic nerve, demyelination and remyelination are followed with functional assessments and imaged both ex vivo and in vivo over the course of 4 weeks with video-rate coherent anti-Stokes Raman scattering (CARS) microscopy. A new procedure compatible with live animal imaging is developed for performing histomorphometry of myelinated axons. This allows quantification of demyelination proximal and remyelination distal to the crush site ex vivo and in vivo respectively.

Wide-field multiphoton imaging of cellular dynamics in thick tissue by temporal focusing and patterned illumination.

Wide-field temporal focusing is a novel technique that provides optical sectioning for imaging without the need for beam scanning. However, illuminating over large areas greatly reduces the photon density which limits the technique applicability to small regions, precluding functional imaging of cellular networks. Here we present a strategy that combines beam shaping and temporal focusing of amplified pulses (>1 µJ/pulse) for fast imaging of cells from the central nervous system in acute slices. Multiphoton video-rate imaging over total areas as wide as 4800 µm(2) with an optical sectioning under 10 µm at 800 nm is achieved with our setup, leading to imaging of calcium dynamics of multiple cells simultaneously in thick tissue.

Dissection of corticotropin-releasing factor system involvement in locomotor sensitivity to methamphetamine.

Sensitivity to the euphoric and locomotor-activating effects of drugs of abuse may contribute to risk for excessive use and addiction. Repeated administration of psychostimulants such as methamphetamine (MA) can result in neuroadaptive consequences that manifest behaviorally as a progressive escalation of locomotor activation, termed psychomotor sensitization. The present studies addressed the involvement of specific components of the corticotropin-releasing factor (CRF) system in locomotor activation and psychomotor sensitization induced by MA (1, 2 mg/kg) by utilizing pharmacological approaches, as well as a series of genetic knockout (KO) mice, each deficient for a single component of the CRF system: CRF-R1, CRF-R2, CRF, or the CRF-related peptide Urocortin 1 (Ucn1). CRF-R1 KO mice did not differ from wild-type mice in sensitization to MA, and pharmacological blockade of CRF-R1 with CP-154,526 (15, 30 mg/kg) in DBA/2J mice did not selectively attenuate either the acquisition or expression of MA-induced sensitization. Deletion of either of the endogenous ligands of CRF-R1 (CRF, Ucn1) either enhanced or had no effect on MA-induced sensitization, providing further evidence against a role for CRF-R1 signaling. Interestingly, deletion of CRF-R2 attenuated MA-induced locomotor activation, elucidating a novel contribution of the CRF system to MA sensitivity, and suggesting the participation of the endogenous urocortin peptides Ucn2 and Ucn3. Immunohistochemistry for Fos was used to visualize neural activation underlying CRF-R2-dependent sensitivity to MA, identifying the basolateral and central nuclei of the amygdala as neural substrates involved in this response. Our results support further examination of CRF-R2 involvement in neural processes associated with MA addiction.

Differential sensitivity of the perioculomotor urocortin-containing neurons to ethanol, psychostimulants and stress in mice and rats.

The perioculomotor urocortin-containing population of neurons (pIIIu: otherwise known as the non-preganglionic Edinger-Westphal nucleus) is sensitive to alcohol and is involved in the regulation of alcohol intake. A recent study indicated that this brain region is also sensitive to psychostimulants. Since pIIIu has been shown to respond to stress, we investigated how psychostimulant-induced pIIIu activation compares to stress- and ethanol-induced activation, and whether it is independent from a generalized stress response. Several experiments were performed to test how the pIIIu responds to psychostimulants by quantifying the number of Fos immunoreactive nuclei after acute i.p. injections of saline, 10-30 mg/kg cocaine, 5 mg/kg methamphetamine, 5 mg/kg amphetamine, 2.5 g/kg ethanol, 2 h of restraint stress, 10 min of swim stress, or six applications of mild foot shock in male C57BL/6 J mice. We also compared Fos immunoreactivity in pIIIu after acute (20 mg/kg cocaine) and repeated cocaine exposure (7 days of 20 mg/kg cocaine) injections in male C57BL/6 J mice in order to investigate the potential habituation of this response. Finally, we quantified the number of Fos immunoreactive nuclei in pIIIu after administration of saline, 2.5 g/kg ethanol, 20 mg/kg cocaine, or 2 h of restraint stress in male Sprague-Dawley rats. We found that exposure to psychostimulants and ethanol induced significantly higher Fos levels in pIIIu compared to stress in mice. Furthermore, repeated cocaine injections did not decrease Fos immunoreactivity as would be expected if this response were due to stress. In rats, exposure to ethanol, psychostimulant and restraint stress all induced pIIIu Fos immunoreactivity compared to saline-injected controls. In both mice and rats, ethanol- and cocaine-induced Fos immunoreactivity occurred exclusively in urocortin 1-positive, but not in tyrosine hydroxylase-positive, cells. These results provide evidence that the pIIIu Fos-response to psychostimulants is independent of a generalized stress in mice, but not rats. They additionally show that the pIIIu response to stress differs significantly between species.

Quantitative myelin imaging with coherent anti-Stokes Raman scattering microscopy: alleviating the excitation polarization dependence with circularly polarized laser beams.

The use of coherent anti-Stokes Raman scattering microscopy tuned to the lipid vibration for quantitative myelin imaging suffers from the excitation polarization dependence of this third-order nonlinear optical effect. The contrast obtained depends on the orientation of the myelin membrane, which in turn affects the morphometric parameters that can be extracted with image analysis. We show how circularly polarized laser beams can be used to avoid this complication, leading to images free of excitation polarization dependence. The technique promises to be optimal for in vivo imaging and the resulting images can be used for coherent anti-Stokes Raman scattering optical histology on native state tissue.

Purely axial compression of fiber Bragg gratings embedded in a highly deformable polymer.

We demonstrate a tuning device for fiber Bragg gratings with a wavelength tuning range in excess of 65 nm. A purely axial tuning technique using a highly deformable polymer molded in a cylinder shape is used to embed a fiber Bragg grating and to achieve a wavelength tuning range from 1551.7 to 1485.5 nm. The tuning curve is highly linear with a tuning rate of 9.6 nm for every percent of applied strain. The insertion losses of the device, the variations of the full width at half maximum, and the stability of the Bragg wavelength over a working day have been studied and shown to be less than 0.02 dB, 0.14, and 0.2 nm, respectively.

Retinal flow cytometer.

The in vivo flow cytometer is an instrument capable of continuous, real-time monitoring of fluorescently labeled cells in the circulation without the need to draw blood samples. However, the original system probes a single vessel in the mouse ear; the small sample volume limits the sensitivity of the technique. We describe an in vivo retinal flow cytometer that simultaneously probes five artery-vein pairs in the mouse eye by circularly scanning a small laser spot rapidly around the optic nerve head. We demonstrate that the retinal flow cytometer detects about five times more cells per minute than the original in vivo flow cytometer does in the ear.

Single molecule study of DNA conductivity in aqueous environment.

The dc electrical conductivity of double stranded DNA is investigated experimentally. Single DNA molecules are manipulated with subpiconewton force and deposited on gold nanoelectrodes by optical traps. The DNA is modified at its ends for specific bead attachments and along the chain to favor charge transfer between the DNA base pair stack and the electrodes. For an electrode separation of 70 nm we find, in aqueous environment, electrical resistances above 100 G Omega indicating that even for weak stretching the double helix is almost insulating at this length scale.

Probing DNA and RNA single molecules with a double optical tweezer.

A double-tweezer setup is used to induce mechanical stress in systems of molecular biology. A double strand of DNA is first stretched and the data is compared to precedent experiments to check the experimental setup. Then a short foldable fragment of RNA is probed; the typical unfolding/refolding hysteresis behaviour of this kind of construction is shown and followed by a study of its elasticity and a comparison to a worm-like chain model. Eventually, we describe the unfolding of a larger RNA structure, which unfolds by multiple steps. We show that this unfolding is not reversible and that it presents numerous unfolding pathways.