Hairpin DNA-based electrochemical amplification strategy for miRNA sensing by using single gold nanoelectrodes.

A new sensor has been developed to detect miRNA-15 using nanoelectrodes and a hairpin DNA-based electrochemical amplification technique. By utilizing a complex DNA cylinder connected with hairpin DNA1, the sensor is able to absorb more methylene blue (MB) than simple double-stranded DNA. Another hairpin DNA2 is modified on an Au nanoelectrode surface and, when miRNA-15 is introduced, it triggers a chain reaction. This reaction unlocks two hairpins alternatively to polymerize into a complex structure that attaches more MB. The miRNA-15 is then replaced by DNA1 due to strand displacement reactions and continues to react with the next DNA2 to achieve circular amplification. The electrochemical signal from MB oxidation has a linear relationship with the miRNA-15 concentrations, making it possible to detect miRNA-15. Moreover, this method can be readily adapted for the detection of various other miRNA species. The newly devised nanosensor holds promising applications for the in vivo detection of miRNA-15 within biological systems, which is achieved by leveraging the advantageous characteristics of nanoelectrodes, including their low resistance-capacitance time constant, rapid mass transfer kinetics, and small diameter.

Outcome of neonatal hypoxemic respiratory failure: a livebirth population-based retrospective survey.

BACKGROUND: To explore the prevalence, outcome and perinatal risks of neonatal hypoxemic respiratory failure (NRF) in a survey of all livebirths from a regional network of perinatal-neonatal care during the transition period after 5-year universal health insurance implemented in China. METHODS: Clinical data of all neonatal respiratory morbidities in Huai'an were retrospectively collected in the regional perinatal network database of all livebirths as vital statistics in 2015. NRF was defined as hypoxemia requiring continuous positive airway pressure (CPAP) and/or mechanical ventilation (MV) for at least 24 h. Mortality risks of antenatal and perinatal morbidities, major respiratory therapies and complications were analyzed by multivariable logistic regression model. RESULTS: There were 788 NRF cases identified in 9.9% (7960) hospitalized, or 13.3‰ (59056) livebirths, in which 6.7% received intensive care and 93.0% critical care. The major underlying morbidities were respiratory distress syndrome (RDS, 36.4%) and pneumonia/sepsis (35.3%), treated mainly by CPAP, MV and surfactant. Significantly improved outcomes by surfactant in RDS were in patients with birthweight (BW) < 1500 g or gestational age (GA) < 32 weeks. The overall mortality rate in NRF was 18.4% whereas for those of BW < 1000 g and GA < 28 weeks, 70% and 54%, respectively. The multivariable regression analysis showed the highest odds for NRF death among meconium aspiration syndrome, congenital anomalies, BW < 1500 g and necrotizing enterocolitis, whereas born in level III hospitals, cesarean delivery, CPAP and MV were associated with markedly reduced death odds. CONCLUSIONS: The salient findings with associated risk estimates reflected efficiency of respiratory support as critical care in a prefectural regional network infrastructure for annual livebirths in 5.6 million inhabitants. It implicated the representativeness of contemporaneous perinatal-neonatal care standard at medium to medium-high level, in one/fourth of the population of China, aiming at saving more life of very critical and preterm infants for better survival.

[A population-based epidemiological survey of neonatal respiratory failure in Huai'an City of Jiangsu Province, in 2010].

OBJECTIVE: To investigate the prevalence, clinical characteristics, treatment, and prognosis of neonatal respiratory failure (NRF) in Huai'an, Jiangsu Province, China, in 2010. METHODS: The clinical data of all NRF cases in the hospitals of Huai'an in 2010 were prospectively collected and analyzed using descriptive epidemiological methods. RESULTS: Among 60,986 live births in Huai'an in 2010, there were 556 (0.91%) cases of NRF. The average birth weight of newborns with NRF was 2,433±789 g, with 53.8% determined as low birth weight and 64.1% as preterm. The major causes of NRF were respiratory distress syndrome, pneumonia, asphyxia, sepsis, and pulmonary hemorrhage. Among the newborns with NRF, 23.7% were accompanied by certain birth defects. Fourteen percent of newborns with NRF received pulmonary surfactant (PS) therapy, and the median time of the first dose of PS was 5 hours (range: 0-51 hours). Nasal continuous positive airway pressure treatment, conventional mechanical ventilation, and high-frequency ventilation were used in 67.9%, 33.3%, and 13.7% of patients, respectively. The cure and improvement rate of NRF patients was 73.9% (411/556), and the mortality rate was 22.5% (125/556). The average hospitalization expenses were 9,270 (range: 196-38182) Yuan. CONCLUSIONS: High morbidity, high mortality and high medical costs make NRF a serious challenge in Huai'an. It is essential to improve the quality of perinatal care and develop new techniques and new models in neonatal respiratory therapy in order to reduce the morbidity and mortality of NRF.

Expression profile of plasma microRNAs in premature infants with respiratory distress syndrome.

As well-known regulators of gene expression, microRNAs (miRNAs) are important not only in cell proliferation and differentiation, but also in tumorigenesis and organ development. It has been estimated that miRNAs may be responsible for regulating the expression of almost one third of the human genome. Simultaneously, with advances in neonatal care in the clinic, an increased number of premature infants are being saved and, thus, respiratory distress syndrome (RDS) has become more common. However, previous non-miRNA studies have suggested their connection with RDS. In the present study, a miRNA microarray, including >1,891 capture probes was used to compared the expression profiles of plasma miRNAs between RDS and control groups. miRNAs, which were observed to have consistent fold-changes (fold-change ≥ 1.3) between the two groups were selected and validated using reverse transcription-quantitative polymerase chain reaction. As a result, 171 differentially expressed miRNAs were identified, including two upregulated and seven downregulated miRNAs. Of these miRNAs, four were selected as having higher fold-changes between the two groups. This is the first time, to the best of our knowledge, that these nine miRNAs have been reported in RDS. It was hypothesized that these novel miRNAs may be important in RDS, and may provide meaningful biomarkers for the diagnosis of RDS.