16 research outputs found
Effect of electrical activity of the diaphragm waveform patterns on SpO₂ for extremely preterm infants ventilated with neurally adjusted ventilatory assist
[Objective] This study aimed to evaluate the association between electrical activity of the diaphragm (Edi) waveform patterns and peripheral oxygen saturation (SpO2) in extremely preterm infants who are ventilated with neurally adjusted ventilatory assist (NAVA). [Study Design] We conducted a retrospective cohort study at a level III neonatal intensive care unit. Extremely preterm infants born at our hospital between November 2019 and November 2020 and ventilated with NAVA were included. We collected Edi waveform data and classified them into four Edi waveform patterns, including the phasic pattern, central apnea pattern, irregular low-voltage pattern, and tonic burst pattern. We analyzed the Edi waveform pattern for the first 15 h of collectable data in each patient. To investigate the association between Edi waveform patterns and SpO2, we analyzed the dataset every 5 min as one data unit. We compared the proportion of each waveform pattern between the desaturation (Desat [+]) and non-desaturation (Desat [–]) groups. [Results] We analyzed collected data for 105 h (1260 data units). The proportion of the phasic pattern in the Desat (+) group was significantly lower than that in the Desat (–) group (p < .001). However, the proportions of the central apnea, irregular low-voltage, and tonic burst patterns in the Desat (+) group were significantly higher than those in the Desat (–) group (all p < .05). [Conclusion] Our results indicate that proportions of Edi waveform patterns have an effect on desaturation of SpO2 in extremely preterm infants who are ventilated with NAVA
Mouse Hair Significantly Lightened Through Replacement of the Cysteine Residue in the N-Terminal Domain of Mc1r Using the CRISPR/Cas9 System
A loss-of-function mutation in the melanocortin 1 receptor gene (MC1R), which switches off the eumelanin production, causes yellowish coat color variants in mammals. In a wild population of sables (Martes zibellina) in Hokkaido, Japan, the mutation responsible for a bright yellow coat color variant was inferred to be a cysteine replacement at codon 35 of the N-terminal extracellular domain of the Mc1r receptor. In the present study, we validated these findings by applying genome editing on Mc1r in mouse strains C3H/HeJ and C57BL/6N, altering the codon for cysteine (Cys33Phe). The resulting single amino acid substitution (Cys33Phe) and unintentionally generated frameshift mutations yielded a color variant exhibiting substantially brighter body color, indicating that the Cys35 replacement produced sufficient MC1R loss of function to confirm that this mutation is responsible for producing the Hokkaido sable yellow color variant. Notably, the yellowish mutant mouse phenotype exhibited brown coloration in subapical hair on the dorsal side in both the C3H/HeJ and C57BL/6N strains, despite the inability of the latter to produce the agouti signaling protein (Asip). This darker hair and body coloration was not apparent in the Hokkaido sable variant, implying the presence of an additional genetic system shaping yellowish hair variability
Thermal- and pH-Dependent Size Variable Radical Nanoparticles and Its Water Proton Relaxivity for Metal-free MRI Functional Contrast Agents
For development of the metal-free MRI contrast agents, we prepared the supra-molecular organic radical, TEMPO-UBD, carrying TEMPO radical, as well as the urea, alkyl group, and phenyl ring, which demonstrate self-assembly behaviors using noncovalent bonds in an aqueous solution. In addition, TEMPO-UBD has the tertiary amine and the oligoethyleneglycol chains (OEGs) for the function of pH and thermal responsiveness. By DLS and TEM imaging, the resulting self-assembly was seen to form the spherical nano-particles 10 – 150 nm in size. On heating, interestingly, the nano-particles showed a lower critical solution temperature (LCST) behavior having two-step variation. This double-LCST behavior is the first such example among the supra-molecules. To evaluate of the ability as MRI contrast agents, the values of proton (1H) longitudinal relaxivity (r1) were determined using MRI apparatus. In conditions below and above CAC at pH 7.0, the distinguishable r1 values were estimated to be 0.17 and 0.21 mM(-1)s(1), indicating the suppression of fast tumbling motion of TEMPO moiety in a nano-particle. Furthermore, r1 values became larger in the order of pH 7.0 > 9.0 > 5.0. Those thermal and pH dependencies indicated the possibility of metal-fee MRI functional contrast agents in the future
Thermal- and pH-Dependent Size Variable Radical Nanoparticles and Its Water Proton Relaxivity for Metal-free MRI Functional Contrast Agents
Self-Assembly Behavior of Emissive Urea Benzene Derivatives Enables Heat-Induced Accumulation in Tumor Tissue.
In this study we describe the construction of a system composed of thermally responsive molecules that can be induced to accumulate in tumor tissues by heating. EgX molecules consisting of an urea-benzene framework and oligoethylene glycol (OEG) functional groups with an emissive aminoquinoline formed nanoparticles (NPs) ∼10 nm in size at 23 °C with a fluorescence quantum yield of 7-10%. At higher temperatures, additional self-assembly occurred as a result of OEG dehydration, and the NPs grew to over 1000 nm in size; this was accompanied by low critical solution temperature behavior. EgXs accumulated in tumor tissues of mice at a body temperature of around 33-35 °C, an effect that was accelerated by external heating around the tumor to approximately 40 °C as a result of increased particle size and enhanced retention in tissue. These EgX NPs can serve as a tool for in vivo monitoring of tumor progression and response to treatment
Mouse Hair Significantly Lightened Through Replacement of the Cysteine Residue in the N-Terminal Domain of Mc1r Using the CRISPR/Cas9 System
Self-Assembly Behavior of Emissive Urea Benzene Derivatives Enables Heat-Induced Accumulation in Tumor Tissue.
Fluorescence Tumor-Imaging Using a Thermo-Responsive Molecule with an Emissive Aminoquinoline Derivative.
Thermal- and pH-Dependent Size Variable Radical Nanoparticles and Its Water Proton Relaxivity for Metal-Free MRI Functional Contrast Agents
For
development of the metal-free MRI contrast agents, we prepared
the supra-molecular organic radical, <b>TEMPO-UBD</b>, carrying
TEMPO radical, as well as the urea, alkyl group, and phenyl ring,
which demonstrate self-assembly behaviors using noncovalent bonds
in an aqueous solution. In addition, <b>TEMPO-UBD</b> has the
tertiary amine and the oligoethylene glycol chains (OEGs) for the
function of pH and thermal responsiveness. By dynamic light scattering
and transmission electron microscopy imaging, the resulting self-assembly
was seen to form the spherical nanoparticles 10–150 nm in size.
On heating, interestingly, the nanoparticles showed a lower critical
solution temperature (LCST) behavior having two-step variation. This
double-LCST behavior is the first such example among the supra-molecules.
To evaluate of the ability as MRI contrast agents, the values of proton
(<sup>1</sup>H) longitudinal relaxivity (<i>r</i><sub>1</sub>) were determined using MRI apparatus. In conditions below and above
CAC at pH 7.0, the distinguishable <i>r</i><sub>1</sub> values
were estimated to be 0.17 and 0.21 mM<sup>–1</sup> s<sup>1</sup>, indicating the suppression of fast tumbling motion of TEMPO moiety
in a nanoparticle. Furthermore, <i>r</i><sub>1</sub> values
became larger in the order of pH 7.0 > 9.0 > 5.0. Those thermal
and
pH dependencies indicated the possibility of metal-fee MRI functional
contrast agents in the future