Label-Free Direct Identification of MicroRNAs Based on a Narrow Constant-Inner-Diameter Emitter Mass Spectrometry Analysis.

MicroRNAs (miRNAs) are a class of endogenous noncoding small RNAs that play important roles in various biological processes and diseases. Direct determination of miRNAs is a cost-efficient and accurate method for analysis. Herein, we established a novel method for the analysis of miRNAs based on a narrow constant-inner-diameter mass spectrometry emitter. We utilized the gravity-assisted sleeving etching method to prepare a constant-inner-diameter mass spectrometry emitter with a capillary inner diameter of 5.5 µm, coupled it with a high-voltage power supply and a high-resolution mass spectrometer, and used it for miRNA direct detection. The method showed high sensitivity and reproducibility for the analysis of four miRNAs, with a limit of detection of 100 nmol/L (170 amol) for the Hsa-miR-1290 analysis. Compared with commercial ion sources, our method achieved higher sensitivity for miRNA detection. In addition, we analyzed the total miRNAs in the A549 cells. The result indicated that both spiked and endogenous miRNAs could be quantified with high accuracy. As a result, this method offers a promising platform for highly sensitive and accurate miRNA analysis. Furthermore, this approach can be extended to the analysis of other small oligonucleotides and holds the potential for studying clinical samples and facilitating disease diagnosis.

Single-Cell Metabolomics-Based Strategy for Studying the Mechanisms of Drug Action.

Studying the mechanisms of drug antitumor activity at the single-cell level can provide information about the responses of cell subpopulations to drug therapy, which is essential for the accurate treatment of cancer. Due to the small size of single cells and the low contents of metabolites, metabolomics-based approaches to studying the mechanisms of drug action at the single-cell level are lacking. Herein, we develop a label-free platform for studying the mechanisms of drug action based on single-cell metabolomics (sMDA-scM) by integrating intact living-cell electro-launching ionization mass spectrometry (ILCEI-MS) with metabolomics analysis. Using this platform, we reveal that non-small-cell lung cancer (NSCLC) cells treated by gefitinib can be clustered into two cell subpopulations with different metabolic responses. The glutathione metabolic pathway of the subpopulation containing 14.4% of the cells is not significantly affected by gefitinib, exhibiting certain resistance characteristics. The presence of these cells masked the judgment of whether cysteine and methionine metabolic pathway was remarkably influenced in the analysis of overall average results, revealing the heterogeneity of the response of single NSCLC cells to gefitinib treatment. The findings provide a basis for evaluating the early therapeutic effects of clinical medicines and insights for overcoming drug resistance in NSCLC subpopulations.

Successful application of continuous renal replacement therapy in a very low birth weight neonate with acute kidney injury.

Diagnosis and treatment process during hospitalization.

Intact living-cell electrolaunching ionization mass spectrometry for single-cell metabolomics.

While single-cell mass spectrometry can reveal cellular heterogeneity and the molecular mechanisms of intracellular biochemical reactions, its application is limited by the insufficient detection sensitivity resulting from matrix interference and sample dilution. Herein, we propose an intact living-cell electrolaunching ionization mass spectrometry (ILCEI-MS) method. A capillary emitter with a narrow-bore, constant-inner-diameter ensures that the entire living cell enters the MS ion-transfer tube. Inlet ionization improves sample utilization, and no solvent is required, preventing sample dilution and matrix interference. Based on these features, the detection sensitivity is greatly improved, and the average signal-to-noise (S/N) ratio is about 20 : 1 of single-cell peaks in the TIC of ILCEI-MS. A high detection throughput of 51 cells per min was achieved by ILCEI-MS for the single-cell metabolic profiling of multiple cell lines, and 368 cellular metabolites were identified. Further, more than 4000 primary single cells digested from the fresh multi-organ tissues of mice were detected by ILCEI-MS, demonstrating its applicability and reliability.

Effects of circular RNA Ttc3/miR-148a/Rcan2 axis on inflammation and oxidative stress in rats with acute kidney injury induced by sepsis.

Aim Increasing evidence demonstrated circular RNAs (circRNAs) are involved in the development of various diseases, including sepsis-induced AKI. Although CIRC-Ttc3 has been proved to regulate cardiac function after myocardial infarction, its role in sepsis-induced AKI remains unclear. MATERIALS AND METHODS: The AKI rat model was firstly induced by sepsis through cecal ligation puncture (CLP). Serum levels of creatinine, BUN, NGAL, TNF-α, IL-6, SOD, MDA and IL-1ß were measured through appropriate kits. The pathological alteration and renal microvascular permeability in renal tissues were determined by HE staining and Evans Blue assays. Cell apoptosis was detected by TUNEL assay. The expression levels of CIRC-Ttc3, miR-148a, TNF-α, IL-1ß and iNOS in rats' renal samples were tested by qRT-PCR or/and western blot. The binding ability between CIRC-Ttc3 and miR-148a was evaluated through luciferase reporter, RIP and RNA pull-down assays. KEY FINDINGS: Kidney injury was found in CLP-treated rats. CIRC-Ttc3 expression was down-regulated, and upregulation of CIRC-Ttc3 improved inflammatory responses and oxidative stress in AKI rats. Mechanismly, CIRC-Ttc3 was confirmed to bind to and negatively regulate miR-148a. Further rescue assays revealed that overexpression of miR-148a rescued the improvement of CIRC-Ttc3 on sepsis-induced AKI. Then, it was illustrated that CIRC-Ttc3 regulated Rcan2 expression by binding to miR-148a. Finally, knockdown of Rcan2 reversed the effects of miR-148a inhibition on sepsis-induced AKI. SIGNIFICANCE: CIRC-Ttc3 relieved inflammation and oxidative stress through regulating the miR-148a/Rcan2 axis in rats with AKI induced by sepsis. Therefore, CIRC-Ttc3 may be a potential therapeutic target for sepsis-induced AKI.

The absorbing filter Oxiris in severe coronavirus disease 2019 patients: A case series.

Hypercytokines cause acute respiratory distress syndrome (ARDS) in coronavirus disease 2019 (COVID-19) patients, which is the main reason for intensive care unit treatment and the leading cause of death in COVID-19 patients. Cytokine storm is a critical factor in the development of ARDS. This study evaluated the efficacy and safety of Oxiris filter in the treatment of COVID-19 patients. Five patients with COVID-19 who received continuous renal replacement therapy (CRRT) in Henan provincial people's hospital between January 23, 2019 and March 28, 2020, were enrolled in this study. Heart rate (HR), mean arterial pressure (MAP), oxygenation index (PaO2 /FiO2 ), renal function, C-reactive protein (CRP), cytokines, procalcitonin (PCT), acute physiology and chronic health evaluation II (APACHE II), sequential organ failure score (SOFA), and prognosis were compared after CRRT. Five COVID-19 patients, three males and two females, aged 70.2 ± 19.6 years, were enrolled. After treatment, HR (101.4 ± 14.08 vs. 83.8 ± 6.22 bpm/min), CRP (183 ± 25.21 vs. 93.78 ± 70.81 mg/L), IL-6 (3234.49 (713.51, 16038.36) vs. 181.29 (82.24, 521.39) pg/mL), IL-8 (154.86 (63.97, 1476.1) vs. 67.19 (27.84, 85.57) pg/mL), and IL-10 (17.43 (9.14, 41.22) vs. 4.97 (2.39, 8.70) pg/mL), APACHE II (29 ± 4.92 vs. 18.4 ± 2.07), and SOFA (17.2 ± 1.92 vs. 11.2 ± 3.4) significantly decreased (P < .05), while MAP (75.8 ± 4.92 vs. 85.8 ± 6.18 mm Hg), and PaO2 /FiO2 (101.2 ± 7.49 vs. 132.6 ± 26.15 mm Hg) significantly increased (P < .05). Among the five patients, negative conversion of nucleic acid test was found in three cases, while two cases died. No adverse events occurred during the treatment. Our study observed a reduced level of overexpressed cytokines, stabilization of hemodynamic status, and staged improvement of organ function during the treatment with Oxiris filter.

Does ligation of the dorsal branch of the cephalic vein affect the patency of a distal forearm arteriovenous fistula? A randomised study.

BACKGROUND: Whether ligation of the dorsal branch of the cephalic vein during the surgical establishment of the radiocephalic arteriovenous fistula (RCAVF) favorably or adversely affects the patency rate of the RCAVF remains controversial. We performed a randomized controlled trial to evaluate the effect of dorsal branch ligation on the patency rate of RCAVF. METHODS: A total of 115 patients who underwent surgical establishment were randomized to two groups treated with or without ligation of the dorsal branch of the cephalic vein during the surgical process. The primary patency rates of the RCAVF at 90, 270, and 360 days after the surgery and the secondary patency rates during a follow-up up to 1 year were compared. RESULTS: The patency rate did not differ significantly between the two groups at 3, 9, or 12 months after the procedure (P > 0.05). The combined primary patency rates of the RCAVF in patients from both groups at 3, 9 and 12 months after the procedure were 87.6, 82, and 74.5% respectively, while the combined secondary patency rate was 92.2% at the 1-year follow-up. The Log-rank test indicated that the initial patency rate and secondary patency rate did not differ significantly between the two groups (P = 0.674 and 0.759, respectively). CONCLUSION: This clinical study indicated that ligation of the dorsal branch of the cephalic vein does not significantly affect the patency of the arteriovenous fistula with a 1-year follow-up. TRIAL REGISTRATION: ISRCTN ISRCTN12288675, Registered 25 September 2019 in the ISRCTN registry. retrospectively registered.

Gas phase reaction between chromones and solvent in an electrospray ionization source.

Chromones were measured by using electrospray ionization mass spectrometry in negative mode. Interestingly, in addition to the deprotonated ion ([M - H]- ), unexpected [M + 17]- and [M + 31]- ions were observed in high intensity when water and methanol were used as the solvent. Chromones with different substitutes were tested. Compared with the deprotonated ion, [M + 17]- and [M + 31]- ions were observed with higher abundances when the C-3 site of chromones was substituted by electron withdrawing groups. Based on high performance liquid chromatography-mass spectrometry (LC-MS), deuterium-labeling and collisional-induced dissociation experiments, a covalent gas-phase nucleophilic addition reaction between chromone and water, and the formation of a noncovalent complex between chromone and methanol were proposed as the mechanism for the observed [M + 17]- and [M + 31]- ions, respectively. Understanding and using these unique gas phase reactions can avoid misannotation when analyzing chromones and their metabolites.

[The etiology and rescue modalities of 1692 cases of acute chemical poisoning].

OBJECTIVE: To investigate the etiology and characteristics of rescue of acute chemical poisoning. METHODS: A total of 1692 cases of acute chemical poisoning were analyzed retrospectively. The kinds of chemicals, the modes of exposure, the characteristics of poisoning and the methods of treatment were analyzed. RESULTS: Poisoning was due to occupational exposure to chemicals in 44.91%, daily life exposure to chemicals in 38.82% and environment chemical pollution in 16.25% of the cases. The total number of chemicals harming the patients was 173. The most common three of the chemicals were pesticides, harmful gases and organic solvents. Recently, the accidents of mass poisoning were increasing in number. CONCLUSIONS: To know the numerous chemicals responsible for acute chemical poisoning is essential for enhancing the pre-hospital care, emergency treatment and follow-up treatment. Further more, extensive clinical knowledge and numerous biologic laboratory tests are need to improve the diagnosis and rescue of acute chemical poisoning. In cases of chemical emergency that involves mass exposure, the majority of the affected persons are likely to be exposed to the poisoning chemicals, though some are exposed minimally. Moreover, resources to provide psychological support must be available both for the family member of casualties and the affected personnel.