Identifying Long-range Synaptic Inputs Using Genetically Encoded Labels and Volume Electron Microscopy

Enzymes that facilitate the local deposition of electron dense reaction products have been widely used as labels in electron microscopy (EM). Peroxidases, in particular, can efficiently metabolize 3,3′-diaminobenzidine tetrahydrochloride hydrate (DAB) to produce precipitates with high contrast under EM following heavy metal staining, and can be genetically encoded to facilitate the labeling of specific cell-types or organelles. Nevertheless, the peroxidase/DAB method has so far not been reported to work in combination with 3D volume EM techniques (e.g. Serial blockface electron microscopy, SBEM; Focused ion beam electron microscopy, FIBSEM) because the surfactant treatment needed for efficient reagent penetration disrupts tissue ultrastructure and because these methods require the deposition of large amounts of heavy metals that can obscure DAB precipitates. However, a recently described peroxidase with enhanced enzymatic activity (dAPEX2) appears to successfully deposit EM-visible DAB products in thick tissue without surfactant treatment. Here we demonstrate that multiplexed dAPEX2/DAB tagging is compatible with both FIBSEM and SBEM volume EM approaches and use them to map long-range genetically identified synaptic inputs from the anterior cingulate cortex to the periaqueductal gray in the mouse brain.

Identifying long-range synaptic inputs using genetically encoded labels and volume electron microscopy

Enzymes that facilitate the local deposition of electron dense reaction products have been widely used as labels in electron microscopy (EM). Peroxidases, in particular, can efficiently metabolize 3,3′-diaminobenzidine tetrahydrochloride hydrate (DAB) to produce precipitates with high contrast under EM following heavy metal staining, and can be genetically encoded to facilitate the labeling of specific cell-types or organelles. Nevertheless, the peroxidase/DAB method has so far not been reported to work in combination with 3D volume EM techniques (e.g. Serial blockface electron microscopy, SBEM; Focused ion beam electron microscopy, FIBSEM) because the surfactant treatment needed for efficient reagent penetration disrupts tissue ultrastructure and because these methods require the deposition of large amounts of heavy metals that can obscure DAB precipitates. However, a recently described peroxidase with enhanced enzymatic activity (dAPEX2) appears to successfully deposit EM-visible DAB products in thick tissue without surfactant treatment. Here we demonstrate that multiplexed dAPEX2/DAB tagging is compatible with both FIBSEM and SBEM volume EM approaches and use them to map long-range genetically identified synaptic inputs from the anterior cingulate cortex to the periaqueductal gray in the mouse brain.

Computed Tomography-Guided Percutaneous Drainage of Pneumomediastinum in a Newborn: A Case Report

Background: Neonatal pneumomediastinum is seen in 2.5 per 1000 live births and mostly managed conservatively. An intervention is essential in cases with tension pneumomediastinum. Ultrasonography-guided (USG-guided) relief of pneumomediastinum has been reported in newborns. There are no reported cases of computed tomography-guided (CT-guided) drainage of pneumomediastinum in neonates. Case report: A newborn girl born at 34 week of gestation was intubated due to respiratory distress and received intratracheal surfactant treatment. Pneumomediastinum was detected at the chest X-ray on the 6th postnatal hour. On the second postnatal day, the patient's oxygen needs increased, tachypnea and subcostal retractions recurred, so it was decided to intervene. USG-guided drainage of the pneumomediastinum was attempted twice but was unsuccessful. Percutaneous drainage with CT guidance was performed successfully. Conclusion: This report aims to emphasize that CT-guided intervention of pneumomediastinum can be an effective alternative in a newborn if USG-guided intervention fails.

Preparation of Breathable Cellulose Based Polymeric Membranes with Enhanced Water Resistance for the Building Industry

This study focuses on the development of advanced water-resistant bio-based membranes with enhanced vapour permeability for use within building envelopes. Building walls are vulnerable to moisture damage and mold growth due to water penetration, built-in moisture, and interstitial condensation. In this work, breathable composite membranes were prepared using micro-fibrillated cellulose fiber (CF) and polylactic acid (PLA). The chemical composition and physical structure of CF is responsible for its hydrophilic nature, which affects its compatibility with polymers and consequently its performance in the presence of excessive moisture conditions. To enhance the dispersibility of CF in the PLA polymer, the fibers were treated with an organic phosphoric acid ester-based surfactant. The hygroscopic properties of the PLA-CF composites were improved after surfactant treatment and the membranes were resistant to water yet permeable to vapor. Morphological examination of the surface showed better interfacial adhesion and enhanced dispersion of CF in the PLA matrix. Thermal analysis revealed that the surfactant treatment of CF enhanced the glass transition temperature and thermal stability of the composite samples. These bio-based membranes have immense potential as durable, eco-friendly, weather resistant barriers for the building industry as they can adapt to varying humidity conditions, thus allowing entrapped water vapor to pass through and escape the building, eventually prolonging the building life.

Relation of asymmetric dimethylarginine with pulmonary morbidities in neonatal respiratory distress syndrome

BACKGROUND: Asymmetric Dimethyl Arginine (ADMA) is an endogenous inhibitor of nitric oxide synthase (NOS) is important in different diseases characterized by decreased nitric oxide (NO) availability. We aimed to assess the serum ADMA level in preterm infants suffering from respiratory distress syndrome (RDS) and its relationship with pulmonary outcomes. METHODS: This prospective study included 50 preterm neonates suffering from RDS aging≤32 weeks and weighing≤1500 gm. Serum ADMA levels were estimated in the 1st and 28th day of life by ELISA, and its correlation with surfactant requirement, duration of ventilation, and development of BPD was assessed. RESULTS: Fifty preterm infants with RDS were included, 30 infants were treated with surfactant within 12 hours after birth, the 1stday ADMA level was higher significantly in infants who required surfactant treatment than infants without surfactant treatment, At 36 weeks postmenstrual age, 16 infants were diagnosed with BPD, the 28th day ADMA level was significantly higher in infants with BPD than others without BPD. 1st-day ADMA level was significantly correlated with days on mechanical ventilation but there were no significant correlations between 1st day ADMA and days on CPAP and days on supplemental O2. CONCLUSION: Elevated serum ADMA level in preterm neonates with RDS estimated in the 1st and 28th day of life is a good predictor for pulmonary morbidities such as surfactant requirement, duration of mechanical ventilation, and development of BPD.

Pengaruh Perbandingan Minyak dan Surfaktan serta Suhu terhadap Karakteristik Sediaan Krim

This study aims to determine the effect of oil and surfactant comparisons and the temperature to the resultant dosage characteristics and determine the oil and surfactant ratio and the appropriate temperature for the preparation of cream. This study uses the group random two-factor design. The first factor is the comparison of oil that is mixture of cocoa fat and virgin coconut oil with surfactants that is mixture of tween 80 and span 80 consisting of 3 levels, which are 85% ; 15%, 80% ; 20% and 85% ; 25%. The second factor is temperature consisting of 3 levels, which are 60 º C, 70 º C and 80 º C. Results of this study showed the treatment of oil comparison and surfactants were had an strongly effect to the homogeneity, adhesive time, spread ability, separation ratio and viscosity, but had no effect on the pH of cream preparations. Temperature treatment had an strongly effect on homogeneity, adhesive time, spread ability, separation ratio and viscosity, while only had an effect on the pH of a basic cream. Interaction between the treatment had an effect on the ratio of separation, pH as well as the spread of cream preparations, but no had effect on adhesive time and the viscosity of the preparation of cream. Oil comparison and surfactant treatment of 80%: 20% and temperature 70ºC is the best treatment resulting in a cream preparations with homogenity characteristics, adhesive time 7.14 Second, ratio of separator 0.48, spread ability of 6.83 cm, viscosity of 37000 cps and pH 6.05. Keywords: oil, surfactans, temperature, cocoa fats, virgin coconut oil, tween 80 and span 80

Duration of and trends in respiratory support among extremely preterm infants

ObjectiveTo evaluate annual trends in the administration and duration of respiratory support among preterm infants.DesignRetrospective cohort study.SettingTertiary neonatal intensive care units in the Canadian Neonatal Network.Patients8881 extremely preterm infants born from 2010 to 2017 treated with endotracheal and/or non-invasive positive pressure support (PPS).Main outcome measuresCompeting risks methods were used to investigate the outcomes of mortality and time to first successful extubation, definitive extubation, weaning off PPS, and weaning PPS and/or low-flow oxygen, according to gestational age (GA). Cox proportional hazards and regression models were fitted to evaluate the trend in duration of respiratory support, survival and surfactant treatment over the study period.ResultsThe percentages of infants who died or were weaned from respiratory support were presented graphically over time by GA. Advancing GA was associated with ordinally earlier weaning from respiratory support. Year over year, infants born at 23 weeks were initially and definitively weaned from endotracheal and all PPS earlier (HR 1.06, 95% CI 1.01 to 1.11, for all outcomes), while survival simultaneously increased (OR 1.11, 95% CI 1.03 to 1.18). Infants born at 26 and 27 weeks remained on non-invasive PPS longer (HR 0.97, 95% CI 0.95 to 0.98 and HR 0.97, 95% CI 0.95 to 0.99, respectively). Early surfactant treatment declined among infants born at 24–27 weeks GA.ConclusionsInfants at the borderline of viability have experienced improved survival and earlier weaning from all forms of PPS, while those born at 26 and 27 weeks are spending more time on PPS in recent years. GA-based estimates of the duration of respiratory support and survival may assist in counselling, benchmarking, quality improvement and resource planning.

Synthetic Lung Surfactant Treatment for Covid-19 Pneumonia

: Covid-19 has led to millions of patients with morbidity ranging from mild flu-like symptoms to severe respiratory failure necessitating oxygen supplementation and mechanical ventilation, and ultimately death. The SARS-CoV-2 virus reacts with angiotensin-converting enzyme 2 (ACE2) molecules that are especially found in alveolar epithelial type 2 cells in the lungs and thereby causes a loss of lung surfactant, a protein-lipid mixture that is crucial for both native immunity and reduction of surface tension in the lung alveoli. Lung surfactant insufficiency results in atelectasis and loss of functional lung tissue amid an inflammatory storm and may be countered by treating Covid-19 pneumonia patients with exogenous lung surfactant, preferably by aerosol delivery of a novel dry powder synthetic lung surfactant. More research on timing, dosing and delivery of synthetic lung surfactant in patients with Covid-19 pneumonia is of crucial importance to implement this approach in clinical practice.