Resuscitation of Preterm Infants with Reduced Oxygen Results in Less Oxidative Stress than Resuscitation with 100% Oxygen

The objective of this study was to determine the effects of the level of inhaled oxygen during resuscitation on the levels of free radicals and anti-oxidative capacity in the heparinized venous blood of preterm infants. Forty four preterm infants <35 weeks of gestation with mild to moderate neonatal asphyxia were randomized into two groups. The first group of infants were resuscitated with 100% oxygen (100% O2 group), while in the other group (reduced O2 group), the oxygen concentration was titrated according to pulse oximeter readings. We measured total hydroperoxide (TH) and redox potential (RP) in the plasma within 60 min of birth. The integrated excessive oxygen (∑(FiO2-0.21) × Time(min)) was higher in the 100% O2 group than in the reduced O2 group (p<0.0001). TH was higher in the 100% O2 group than in the reduced O2 group (p<0.0001). RP was not different between the 100% O2 and reduced O2 groups (p = 0.399). RP/TH ratio was lower in the 100% O2 group than in the reduced O2 group (p<0.01). We conclude that in the resuscitation of preterm infants with mild to moderate asphyxia, oxidative stress can be reduced by lowering the inspired oxygen concentration using a pulse oximeter

Epidemiology of Coronavirus Disease Outbreak among Crewmembers on Cruise Ship, Nagasaki City, Japan, April 2020

In April 2020, a coronavirus disease (COVID-19) outbreak occurred on the cruise ship Costa Atlantica in Nagasaki, Japan. Our outbreak investigation included 623 multinational crewmembers onboard on April 20. Median age was 31 years; 84% were men. Each crewmember was isolated or quarantined in a single room inside the ship, and monitoring of health status was supported by a remote health monitoring system. Crewmembers with more severe illness were hospitalized. The investigation found that the outbreak started in late March and peaked in late April, resulting in 149 laboratory-confirmed and 107 probable cases of infection with severe acute respiratory syndrome coronavirus 2. Six case-patients were hospitalized for COVID-19 pneumonia, including 1 in severe condition and 2 who required oxygen administration, but no deaths occurred. Although the virus can spread rapidly on a cruise ship, we describe how prompt isolation and quarantine combined with a sensitive syndromic surveillance system can control a COVID-19 outbreak

Differentiation of human PNS and CNS neurons.

<p>(A) Phase-contrast image of pre-differentiated human induced pluripotent stem (iPS) cells under a feeder-free condition. (B) Phase-contrast image of embryonic bodies (EBs) before chemical induction on day 0. (C, D) Phase-contrast image of differentiated peripheral nervous system (PNS) neurons (C) and central nervous system (CNS) neurons (D). Induced neurites were detected on day 23 (C) and day 15 (D) in PNS and CNS neurons, respectively. (E, F) Immunofluorescent labeling with antibodies specific for class III beta-tubulin (TUJ1) and Peripherin in PNS (E) and CNS neurons (F) on day 22. Cell nuclei were counterstained with Hoechst 33342. Scale bar: 100 μm.</p

Structural and functional analysis of co-cultured neuronal networks.

<p>(A, B) Immunofluorescence images of co-cultured neurons 48 days after cell plating (bottom panel). Different regions indicated in the diagram are shown (top panel). Synapsin-1 staining was detected in the chamber with central nervous system (CNS) neurons, but not in the microtunnels. (C, D) Phase-contrast images of cells and the fluorescence images of a calcium probe on day 39. Fluorescence images before (pre stim) and 1 s after applying the electrical stimulation (post stim) are shown. Fluorescence was increased after the stimulus (arrowheads). (E) Calcium response after the stimulation normalized to the signal before the stimulation. The color bar shows fluorescence intensity. Neurites in the microtunnels were induced with electrical stimulation. (F) Kinetics of calcium transient onset during applying the electrical stimulation. Data of 6 peripheral nervous system (PNS) bundles were considered. (G) Identification of CNS neurons that responded to PNS bundle stimulation. Left, a co-culture sample at day 29 labelled with fluo-4. Right, normalized calcium response in CNS neurons following PNS bundle stimulation (dot-dashed line). The color bar indicates fluorescence intensity. White arrowheads identify CNS neurons that exhibited a calcium response to PNS bundle stimulation. (H) Kinetic plots of calcium transients in CNS neurons represented in panel G. The region highlighted by the yellow rectangle indicates the period of electrical stimulation of PNS bundles. (I) The effect of PNS bundle stimulation on the activity of CNS neurons. Calcium spiking in CNS neurons was averaged pre-, during and post-PNS bundle stimulation. Values are reported as mean±S.D. (<i>n</i> = 20 neurons from 3 samples). Statistical analyses using an unpaired t-test are shown here (ns not significant, * <i>p</i> < 0.001; Scale bar: 100 μm).</p

<i>In Vitro</i> Reconstruction of Neuronal Networks Derived from Human iPS Cells Using Microfabricated Devices

<div><p>Morphology and function of the nervous system is maintained via well-coordinated processes both in central and peripheral nervous tissues, which govern the homeostasis of organs/tissues. Impairments of the nervous system induce neuronal disorders such as peripheral neuropathy or cardiac arrhythmia. Although further investigation is warranted to reveal the molecular mechanisms of progression in such diseases, appropriate model systems mimicking the patient-specific communication between neurons and organs are not established yet. In this study, we reconstructed the neuronal network <i>in vitro</i> either between neurons of the human induced pluripotent stem (iPS) cell derived peripheral nervous system (PNS) and central nervous system (CNS), or between PNS neurons and cardiac cells in a morphologically and functionally compartmentalized manner. Networks were constructed in photolithographically microfabricated devices with two culture compartments connected by 20 microtunnels. We confirmed that PNS and CNS neurons connected via synapses and formed a network. Additionally, calcium-imaging experiments showed that the bundles originating from the PNS neurons were functionally active and responded reproducibly to external stimuli. Next, we confirmed that CNS neurons showed an increase in calcium activity during electrical stimulation of networked bundles from PNS neurons in order to demonstrate the formation of functional cell-cell interactions. We also confirmed the formation of synapses between PNS neurons and mature cardiac cells. These results indicate that compartmentalized culture devices are promising tools for reconstructing network-wide connections between PNS neurons and various organs, and might help to understand patient-specific molecular and functional mechanisms under normal and pathological conditions.</p></div

Schematic diagram showing the differentiation protocols from human iPS cells to mature neurons.

<p>Neurons of the peripheral nervous system (PNS; A) and the central nervous system (CNS; B) were induced from human induced pluripotent stem (iPS) cells with several compounds dissolved in serum-free media. Each medium and compound was added at the time indicated in (A) or (B).</p

Reconstruction of neuronal networks innervating the heart using iPS cells co-cultured in a microfabricated device.

<p>(A) Schematic diagram of the differentiation protocol for iPS cell-derived cardiomyocytes. (B) Calcium imaging of cardiomyocyte-aggregates on day 16. Contracting embryonic bodies (EBs) showed sustained calcium dynamics. The color bar shows fluorescence intensity, and the change in fluorescence signals confirms that these cell-aggregates contained cardiomyocytes. The graph is showing the kinetics of calcium transients during the recording. (C) Co-culture of peripheral nervous system (PNS) neurons and cardiomyocytes on day 44 after plating PNS neurons. PNS-derived bundles extended from left chamber (arrow) and reached a cardiomyocyte-aggregate, which was in the right chamber (within white dash line). (D) Immunostaining for the cardiomyocyte marker cTnT and the synaptic vesicle marker Synapsin-1 on day 24 after plating PNS neurons. Top, the positional relationship of the axon from PNS neurons and cardiomyocyte. Bottom, localization of Synapsin-1 on a cardiomyocyte (dot line region). Scale bar: 100 μm.</p

Schematic outline of the microfabrication process to manufacture the co-culturing device.

<p>(A) UV exposure of the photoresist through the photomask. (B) Development of micropatterns to fabricate the master mold. (C) Casting and curing of polydimethylsiloxane (PDMS) onto the maser mold. (D) Cutting, punching, and releasing of the PDMS chamber from the master mold.</p

Co-culturing of PNS and CNS neurons in the PDMS chamber device.

<p>(A) Schematic diagram of the polydimethylsiloxane (PDMS) co-culture chamber. Diameter of the chambers was 8 mm. Width of the microtunnels was 50 μm. Although the length of each microtunnel varied depending on its location, the length of each microtunnel was at least 1 mm. The neurites were able to pass through the 5-μm-high microtunnels. (B) Co-cultured neurons close to the microtunnels one day after cell plating. Peripheral nervous system (PNS) neurons were labeled with PKH26 (magenta), and central nervous system (CNS) neurons were labeled with PKH67 (green). (C) Most neurites of PNS neurons passed through the microtunnels 12 days after cell plating. Bundles (magenta) originating from PNS neurons reached the aggregated CNS neurons (green). (D) Phase-contrast images and immunofluorescent staining for class III beta-tubulin (TUJ1) and Peripherin. Neurites that passed through the microchannel originated from PNS neurons, which was confirmed by the expression of TUJ1 and Peripherin (arrowheads) 48 days after cell plating. (E) PNS neurites around the microtunnels 30 days after cell plating. Two different regions, indicated in the diagram, are shown at a high magnification. PNS neurites gathered together and made bundles before and during entering the tunnels. Scale bar: 100 μm.</p