Betaine-assisted recombinase polymerase assay for rapid hepatitis B virus detection.

Hepatitis B virus (HBV) is a worldwide epidemic pathogen that causes hepatitis B. On-site screening the HBV infection is of critical importance for preventing and diagnosing HBV infection. In this paper, a simple, visual, and rapid method for on-site detection of HBV-DNA has been developed. This method is based on betaine-assisted recombinase polymerase assay and followed with naked-eye detection via lateral flow assay (BRPA-LF). Result show that nonspecific amplification is prone to occur in recombinase polymerase amplification (RPA) if the assay was performed with serum sample without purification. This problem has been addressed by adding 0.8 M of betaine to the RPA reactions. It was demonstrated that BRPA-LF can detect 1,000 copies of HBV-DNA in 50 µL mixture, and achieved 90% sensitivity and 100% specificity for serum sample detection. These results demonstrated that BRPA-LF can resist serum interference and has great potential for on-site screening of HBV infection.

A survey of current practices, attitudes and demands of anaesthesiologists regarding the depth of anaesthesia monitoring in China.

BACKGROUND: In this study, we aimed to analyse survey data to explore two different hypotheses; and for this purpose, we distributed an online survey to Chinese anaesthesiologists. The hypothetical questions in this survey include: (1) Chinese anaesthesiologists mainly use the depth of anaesthesia (DoA) monitors to prevent intraoperative awareness and (2) the accuracy of these monitors is the most crucial performance factor during the clinical daily practice of Chinese anaesthesiologists. METHODS: We collected and statistically analysed the response of a total of 12,750 anesthesiologists who were invited to participate in an anonymous online survey. The Chinese Society of Anaesthesiologists (CSA) trial group provided the email address of each anaesthesiologist, and the selection of respondents was random from the computerized system. RESULTS: The overall response rate was 32.0% (4037 respondents). Only 9.1% (95% confidence interval, 8.2-10.0%) of the respondents routinely used DoA monitors. Academic respondents (91.5, 90.3-92.7%) most frequently used DoA monitoring to prevent awareness, whereas nonacademic respondents (88.8, 87.4-90.2%) most frequently used DoA monitoring to guide the delivery of anaesthetic agents. In total, the number of respondents who did not use a DoA monitor and whose patients experienced awareness (61.7, 57.8-65.6%) was significantly greater than those who used one or several DoA monitors (51.5, 49.8-53.2%). Overall, the crucial performance factor during DoA monitoring was considered by 61.9% (60.4-63.4%) of the respondents to be accuracy. However, most respondents (95.7, 95.1-96.3%) demanded improvements in the accuracy of the monitors for DoA monitoring. In addition, broad application in patients of all ages (86.3, 85.2-87.4%), analgesia monitoring (80.4, 79.2-81.6%), and all types of anaesthetic agents (75.6, 74.3-76.9%) was reported. In total, 65.0% (63.6-66.5%) of the respondents believed that DoA monitors should be combined with EEG and vital sign monitoring, and 53.7% (52.1-55.2%) believed that advanced DoA monitors should include artificial intelligence. CONCLUSIONS: Academic anaesthesiologists primarily use DoA monitoring to prevent awareness, whereas nonacademic anaesthesiologists use DoA monitoring to guide the delivery of anaesthetics. Anaesthesiologists demand high-accuracy DoA monitors incorporating EEG signals, multiple vital signs, and antinociceptive indicators. DoA monitors with artificial intelligence may represent a new direction for future research on DoA monitoring.

Betaine-assisted recombinase polymerase assay with enhanced specificity.

Recombinase polymerase amplification (RPA) is a widespread isothermal amplification method and regarded as an excellent candidate to replace polymerase chain reaction. However, the specificity of RPA is not always satisfactory when the sample contains amounts of background DNA. Herein, we report a novel RPA method named betaine-assisted RPA (B-RPA) that uses inexpensive betaine to avoid nonspecific amplification effectively. Result show that nonspecific amplification is prone to occur in RPA if the primers have not been rigorously refined, especially in detecting samples with large amounts of background DNA. This problem has been addressed by adding betaine to the RPA reactions. Our data show that the addition of 0.8 M betaine can significantly increase specificity and efficiency simultaneously. This B-RPA method is also used to detect hepatitis B virus DNA in clinical plasma samples, thereby demonstrating the clinical practicability of B-RPA.

[Oxidative mechanism of uric acid induced CRP expression in human umbilical vein endothelial cells].

OBJECTIVE: To explore the oxidative mechanism of uric acid (UA) induced CRP expression in human umbilical vein endothelial cells. METHODS: Different concentrations of UA (0 mg/dL, 4 mg/dL, 8 mg/dL, 12 mg/dL, 16 mg/dl) were incubated 12 h with HUVECs, and HUVECs were stimulated with 12 mg/dl. UA for different times (6 h, 12 h, 24 h, 48 h). CRP mRNA and protein expression were determined by real-time quantitative polymerase chain reaction (RT-qPCR) and Western blot, respectively; the effects of uric acid on the intracellular reactive oxygen species (ROS) production in HUVECs were measured by fluorescence microscope and flow cytometric analysis using a 2', 7'-Dichlorofluorescin diacetate (DCF-DA) fluorescence probe. The effects of N-acetyl cysteine (NAC) on UA-induced levels of ROS, mRNA and protein of CRP in HUVECs were also observed. RESULTS: The results demonstrated that UA could significantly increase the mRNA and protein expression of CRP in HUVECs in time- and concentration-dependent manners. HUVECs were stimulated with 12 mg/dL UA at 6 h, mRNA and protein levels of CRP significantly higher than that of control level (P<0.05), reached a peak at 12 h (P<0. 01). NAC reduced UA-induced levels of ROS, mRNA and protein of CRP in HUVECs compared with those of 12 mg/dL UA induced group(P<0. 05). CONCLUSION: Uric acid significantly increased mRNA and protein expression of CRP in HUVECs in time- and concentration-dependent manners. Its mechanism may be associated with uric acid induced increasing of ROS levels in endothelial cells, which suggested that the uric acid mediated oxidative stress and inflammation may be involved in the injury of endothelial cells.

Glycyrrhizic acid protects against temporal lobe epilepsy in young rats by regulating neuronal ferroptosis through the miR-194-5p/PTGS2 axis.

Temporal lobe epilepsy (TLE) leads to extensive degradation of the quality of life of patients. Glycyrrhizic acid (GA) has been reported to exert neuroprotective effects on status epilepticus. Herein, the current study set out to explore the functional mechanism of GA in TLE young rats. Firstly, TLE young rat models were established using the lithium chloride and pilocarpine regimen and then subjected to treatment with different doses of GA, miR-194-5p-antagomir, or/and sh-prostaglandin-endoperoxide synthase 2 (PTGS2) to observe changes in iron content, glutathione and malondialdehyde levels, and GPX4 (glutathione peroxidase 4) and PTGS2 protein levels in the hippocampus. Neuronal injury and apoptosis were assessed through HE, Nissl, and TUNEL staining. Additionally, the expression patterns of miR-194-5p were detected. The binding site of miR-194-5p and PTGS2 was verified with a dual-luciferase assay. Briefly, different doses of GA (20, 40, and 60 mg/kg) reduced the epileptic score, frequency, and duration in TLE young rats, along with reductions in iron content, lipid peroxidation, neuronal injury, and apoptosis in the hippocampus. Silencing of miR-194-5p partly annulled the action of GA on inhibiting ferroptosis and attenuating neuronal injury in TLE young rats. Additionally, PTGS2 was validated as a target of miR-194-5p. GA inhibited ferroptosis and ameliorated neuronal injury in TLE young rats via the miR-194-5p/PTGS2 axis. Overall, our findings indicated that GA exerts protective effects on TLE young rats against neuronal injury by inhibiting ferroptosis through the miR-194-5p/PTGS2 axis.

17ß-Estradiol promotes cell proliferation in rat osteoarthritis model chondrocytes via PI3K/Akt pathway.

Osteoarthritis (OA) is the most common cause of musculoskeletal pain and disability. The importance of chondrocytes in the pathogenesis of OA is unequivocal. 17ß-estradiol (E2) has a potential protective effect against OA. However, the mechanism of E2 in OA chondrocytes remains unclear. In this study, we investigated the regulative effect of E2 on cell growth and the relationship between E2 and the PI3K/Akt pathway in rat OA model chondrocytes (pretreated with interleukin-1ß). We found that E2 induced chondrocyte proliferation, and increased the expression level of Akt simultaneously, especially the expression level of P-Akt. Furthermore, the inhibition of P-Akt could block chondrocyte proliferation induced by E2. These results suggest that PI3K/Akt activation induced by E2 may be an important factor in the mechanism of E2 in cell proliferation in rat OA model chondrocytes, and help further understanding the role of E2 in OA progression.

[Effects of PTHrP and Notch signaling on the proliferation of epiphysis stem cells].

OBJECTIVE: To study the regulation of the proliferation of epiphysis stem cells by the PTHrP (parathyroid hormone related peptide) and Notch signaling systems. METHODS: An organ culture system of femurs of SD rat in 24 h after birth was employed. PTHrP (1 - 34) was used as the activator of the PTHrP signaling pathway and PTHrP (7 - 34) as the antagonist of PTH (parathyroid hormone)-receptor. For Notch signaling system, Jagged1/Fc was used as the activator and DAPT as its inhibitor. The femurs were cultured in DMEM (Dulbecco's modified Eagle's medium)/F12 medium while phosphate buffered saline was used for the control groups. Hematoxylin and eosin staining and bromodeoxyuridine analysis were used to analyze the length of the epiphysis stem cells zone and the proliferation of epiphysis stem cells. The expression of NICD (Notch intra-cellular domain) and Jagged1 were analyzed by immunohistochemistry. The epiphysis stem cells were transfected with the lentiviral vectors with rat PTHrP gene overexpression or inhibition properties, the cells transfected with the PGC-GFP-lentivirus or NC-GFP-lentivirus were used as control. Western blot was employed to detect the expression of NICD and Jagged1 genes. RESULTS: PTHrP (1 - 34) and Jagged1/Fc could dramatically elevate the rate of epiphysis stem cells zone by the whole growth plate length measurement while PTHrP (7 - 34) and DAPT could decrease the rate. Brdu analysis also showed that the number of proliferative epiphysis stem cells could be up-regulated by the PTHrP (1 - 34) or Jagged1/Fc signaling. By contrast, the treatment with PTHrP (7 - 34) or DAPT reduced the number of proliferative epiphysis stem cells. Immunohistochemistry and Western blot showed a significantly elevated expression of NICD and Jagged1 when PTHrP signaling was activated while a reductive expression of NICD and Jagged1 when PTHrP signaling was inactivated. CONCLUSION: Both of PTHrP and Notch signaling system could promote the proliferation of epiphysis stem cells. And the PTHrP signaling can stimulate Notch signaling to promote the proliferation of epiphysis stem cells.

Anti-influenza serum and mucosal antibody responses after administration of live attenuated or inactivated influenza vaccines to HIV-infected children.

BACKGROUND: Live-attenuated influenza vaccine (LAIV) prevents more cases of influenza in immune-competent children than the trivalent inactivated vaccine (TIV). We compared the antibody responses to LAIV or TIV in HIV-infected children. METHODS: Blood and saliva obtained at enrollment, 4 and 24 weeks postimmunization from 243 HIV-infected children randomly assigned to TIV or LAIV were analyzed. RESULTS: Both vaccines increased the anti-influenza neutralizing antibodies at 4 and 24 weeks postimmunization. At 4 weeks postimmunization, TIV recipients had 2-fold to 3-fold higher neutralizing antibody titers than LAIV recipients, but the proportions of subjects with protective titers (≥ 1:40) were similar between treatment groups (96%-100% for influenza A and 81%-88% for influenza B). Both vaccines increased salivary homotypic IgG antibodies, but not IgA antibodies. Both vaccines also increased serum heterosubtypic antibodies. Among HIV-specific characteristics, the baseline viral load correlated best with the antibody responses to either vaccine. We used LAIV-virus shedding as a surrogate of influenza infection. Influenza-specific humoral and mucosal antibody levels were significantly higher in nonshedders than in shedders. CONCLUSIONS: LAIV and TIV generated homotypic and heterosubtypic humoral and mucosal antibody responses in HIV-infected children. High titers of humoral or mucosal antibodies correlated with protection against viral shedding.