Nanozyme-Based Colorimetric SARS-CoV-2 Nucleic Acid Detection by Naked Eye.

Fluorescence-based PCR and other amplification methods have been used for SARS-CoV-2 diagnostics, however, it requires costly fluorescence detectors and probes limiting deploying large-scale screening. Here, a cut-price colorimetric method for SARS-CoV-2 RNA detection by iron manganese silicate nanozyme (IMSN) is established. IMSN catalyzes the oxidation of chromogenic substrates by its peroxidase (POD)-like activity, which is effectively inhibited by pyrophosphate ions (PPi). Due to the large number of PPi generated by amplification processes, SARS-CoV-2 RNA can be detected by a colorimetric readout visible to the naked eye, with the detection limit of 240 copies mL-1 . This conceptually new method has been successfully applied to correctly distinguish positive and negative oropharyngeal swab samples of COVID-19. Colorimetric assay provides a low-cost and instrumental-free solution for nucleic acid detection, which holds great potential for facilitating virus surveillance.

Differential Expression of α-Enolase in Clinical Gastric Tissues and Cultured Normal/Cancer Cells in Response to Helicobacter pylori Infection and cagA Transfection.

Background and Objectives: The role of α-enolase (ENO1) in Helicobacter pylori-related gastric lesions might be a critical factor in the pathogenesis, but remains undefined. Materials and Methods: This study investigated the differential expression of α-enolase in clinical gastric specimens and cultured normal/cancer cells in response to H. pylori (cagA+) infection and cagA transfection using qPCR, Western blots and histochemical methods. Results: A total of 172 gastric specimens were collected from 142 patients, the former comprising chronic superficial gastritis (CSG), precancerous diseases (PCDs, including atrophic gastritis, intestinal metaplasia and dysplasia) and gastric cancer (GC) cases. Among the CSG and PCD cases, the H. pylori-infected group had significantly elevated ENO1 mRNA levels compared with the uninfected group. In the GC cases, differential ENO1 expressions were detected between the cancer tissues and the paracancerous tissues. Notably, significant difference was first detected between the GC cell (AGS) and the normal cell (GES-1) as a response of ENO1 to H. pylori infection and cagA transfection. Conclusions: This report reveals that ENO1 expression is associated with H. pylori infection, cagA transfection, co-culture duration, multiplicity of infection, gastric normal/cancerous cell lines and cellular differentiation. The findings may be crucial bases for further ascertaining H. pylori pathogenic mechanism and formulating novel therapeutic and diagnostic strategies.

Molecular dynamics simulation-guided toehold mediated strand displacement probe for single-nucleotide variants detection.

Single nucleotide variant (SNV) has become an emerging biomarker for various diseases such as cancers and infectious diseases. Toehold-mediated strand displacement (TMSD), the core reaction of DNA nanotechnology, has been widely leveraged to identify SNVs. However, inappropriate choice of mismatch location results in poor discrimination ability. Here, we comprehensively investigate the effect of mismatch location on TMSD kinetics by molecular dynamic simulation tool oxDNA through umbrella sampling and forward flux sampling disclosing that mismatches at the border of the toehold and branch migration domain yield the lowest TMSD reaction rate. Nine disease-related SNVs (SARS-CoV-2-D614G, EGFR-L858R, EGFR-T790M, KRAS-G12R, etc.) were tested experimentally showing a good agreement with simulation. The best choice of mismatch location enables high discrimination factor with a median of 124 for SNV and wild type. Coupling with a probe-sink system, a low variant allele frequency of 0.1% was detected with 3 S/N. We successfully used the probes to detect SNVs with high confidence in the PCR clones of constructed plasmids. This work provides mechanistic insights into TMSD process at the single-nucleotide level and can be a guidance for the design of TMSD system with fine-tuning kinetics for various applications in biosensors and nanotechnology.

Experimental study on Fenton oxidation regeneration of adsorbed toluene saturated activated carbon.

In this study, Fenton reagent has been adopted to oxidize and regenerate the resin based spherical activated carbon (SAC) adsorbed with toluene saturation. The effects of the mole ratio of Fe2+ and H2O2, the dosage of H2O2, pH value, temperature, regeneration time and the like on the regeneration rate of activated carbon have been exploited, the adsorbent used in the experiment is spherical activated carbon with a maximum adsorption capacity of 512.25 mg/g produced by Cui hong Taiyuan Science and Technology Co. The results show that the highest regeneration rate of activated carbon can reach 95.69%. The optimal regeneration condition is that the molar ratio of Fe2+ and H2O2 is 1/25, the concentration of H2O2 is 175 mmol/L, the pH is 2, the temperature is 20℃∼30℃, and the regeneration time is 180 min. The influence of regeneration process on the characterization of activated carbon has been studied by BET analysis as well as SEM analysis.

Combination of parathyroid hormone pretreatment and mechanical stretch promotes osteogenesis of periodontal ligament fibroblasts.

INTRODUCTION: Parathyroid hormone (PTH) potentiates the mechanical loading induced bone formation in fracture healing and orthodontics. This study aimed to gain insight into the underlying mechanisms in periodontal ligament fibroblasts (PDLFs). METHODS: Human PDLFs were cultured and subjected to uniaxial cyclic stretch at 0.5 Hz and 2000µ for 0, 6, 12, and 24 hours, respectively. 10 nM PTH was preadministered for 30 minutes before loading. The expression of PTH1R and osteogenic biomarkers Runx2, osteopontin, collagen type 1, alkaline phosphatase was assessed via immunofluorescence staining, quantitative polymerase chain reaction, or Western blot. Transfection of siPTH1R was applied, and alterations of osteogenic biomarkers were examined by Western blot. The expression of essential Wnt signal components Wnt3a, ß-catenin, low-density lipoprotein receptor-related protein 5, Wnt5a, receptor tyrosine kinase-like orphan receptor 2 were examined, and the influence of dickkopf-related protein 1 on osteogenic biomarkers was evaluated. RESULTS: The expression of PTH1R was instantaneously upregulated with PTH pretreatment and maintained a gradual increase until 24 hours. PTH synergistically enhanced the increase of Runx2, osteopontin, collagen type 1, and alkaline phosphatase under cyclic stretch, which was substantially attenuated by siPTH1R transfection. As for Wnt signal components, synergistic upregulation was detected on Wnt3a, ß-catenin, and low-density lipoprotein receptor-related protein 5, whereas Wnt5a and receptor tyrosine kinase-like orphan receptor 2 increased relatively mildly. Blockage of the canonical Wnt/ß-catenin pathway by dickkopf-related protein 1 impaired the boost of osteogenic biomarkers under the combined action of PTH and cyclic stretch. CONCLUSIONS: The combination of PTH pretreatment and cyclic stretch promotes osteogenesis of PDLFs synergistically, and the canonical Wnt/ß-catenin pathway is crucially involved in the underlying mechanism.

4-O-galloylalbiflorin inhibits the activity of CYP3A, 2C9, and 2D in human liver microsomes.

The effect of 4-O-galloylalbiflorin on the activity of cytochrome P450 enzymes (CYP450s) is an important factor that may induce drug-drug interaction.The effect of 4-O-galloylalbiflorin on the activity of CYP450s was evaluated in the presence of 0, 2.5, 5, 10, 25, 50, and 100 µM 4-O-galloylalbiflorin in pooled human liver microsomes. The inhibition model and corresponding parameters were assessed b fitting with Lineweaver-Burk plots. The time-dependent study was performed with the incubation time of 0, 5, 10, 15, and 30 min.4-O-galloylalbiflorin significantly inhibited the activity of CYP3A, 2C9, and 2 D in a concentration-dependent manner with the IC50 values of 8.2, 13, and 11 µM, respectively. The inhibition of CYP3A was found to be non-competitive and time-dependent with the Ki value of 4.0 µM and the KI/Kinact value of 2.2/0.030 (µM·min). The inhibition of CYP2C9 and 2 D was not affected by the incubation time but was found to be competitive with the Ki values of 6.7 and 6.6 µM, respectively.The inhibitory effect of 4-O-galloylalbiflorin on the activity of CYP3A, 2C9, and 2 D implying the potential drug-drug interaction between 4-O-galloylalbiflorin and the drugs metabolized by these CYP450s.

Evaluation of the prognostic value of CBXs in gastric cancer patients.

Chromobox (CBX) proteins were suggested to exert epigenetic regulatory and transcriptionally repressing effects on target genes and might play key roles in the carcinogenesis of a variety of carcinomas. Nevertheless, the functions and prognostic significance of CBXs in gastric cancer (GC) remain unclear. The current study investigated the roles of CBXs in the prognosis of GC using the Oncomine, The Gene Expression Profiling Interactive Analysis (GEPIA), UALCAN, The Cancer Genome Atlas (TCGA), and cBioPortal databases. CBX1/2/3/4/5 were significantly upregulated in GC tissues compared with normal tissues, and CBX7 was downregulated. Multivariate analysis showed that high mRNA expression levels of CBX3/8 were independent prognostic factors for prolonged OS in GC patients. In addition, the genetic mutation rate of CBXs was 37% in GC patients, and genetic alterations in CBXs showed no association with OS or disease-free survival (DFS) in GC patients. These results indicated that CBX3/8 can be prognostic biomarkers for the survival of GC patients.

MiRNA-214 promotes the pyroptosis and inhibits the proliferation of cervical cancer cells via regulating the expression of NLRP3.

Inflammasome mediates the maturation of interleukin-1ß (IL-1ß) and IL-18, triggers the pyroptosis and associates with multiple autoimmune diseases. In light of this, we hope to investigate the regulatory role of miRNA-214 in the inflammasome of cervical cancer. With the samples collected from 50 cervical cancer patients and 50 age-matched healthy subjects, real-time PCR and Western blotting were employed to detect the mRNA and/or protein expression profiles of the NOD-like receptor protein family, including NLRP1, NLRP3, NLRC4, Caspase-1, IL-1ß, IL-18 and miR-214. Corresponding plasmids were used to transfect the Hela, HCC94, Siha or HUCEL normal cell lines to upregulate or downregulate the expression of targeted genes and to construct the cervical cancer models on rats. In addition, RT-PCR and Western blot were also considered to detect the expression of miR-214 and pyroptosis-related genes, while the pyroptosis of cells was evaluated by using the caspase-1 activity detection kit. Downregulation of miR-214 was found in the cervical cancer patients and the cervical cancer cell lines (** P <0.01), while overexpression of miR-214 could induce the pyroptosis of cervical cancer cell by targeting NLRP3. In cervical cancer patients, miR-214 and NLRP3 are downregulated, while upregulation of miR-214, by enhancing the expression of NLRP3, can advance the pyroptosis of cervical cancer cells. In addition, we, for the first time, clarify the correlation of cervical cancer with the miR-214 and NLRP3.

Dose-response association between C-reactive protein and risk of all-cause and cause-specific mortality: a systematic review and meta-analysis of cohort studies.

PURPOSE: The purpose of the study is to quantitatively assess the association between C-reactive protein (CRP) and all-cause, cardiovascular disease (CVD), and cancer mortality; a dose-response meta-analysis was performed on data from cohort studies in general population. METHODS: The published relevant articles were searched for in PubMed, Web of Science, and Embase until September 21, 2019. The pooled relative risk (RR) was estimated by random effects of generalized least square regression models. The dose-response relationship was modeled using restricted cubic splines. RESULTS: Twenty-two articles were screened for the meta-analysis. Compared with the low CRP group, the pooled RR in the moderate CRP group was 1.30 (95% confidence interval (CI), 1.20-1.41) for all-cause mortality and 1.43 (95% CI, 1.22-1.68) for CVD mortality; the pooled RR in the high CRP group was 1.75 (95% CI, 1.59-1.92) for all-cause mortality, 2.02 (95% CI, 1.70-2.41) for CVD mortality, and 1.32 (95% CI, 1.21-1.45) for cancer mortality. CONCLUSIONS: This meta-analysis demonstrated the relationships between CRP and mortality were nonlinear for all-cause and CVD mortality and were linear for cancer and noncardiovascular mortality.

Prognostic Significance of ADAM17 for Gastric Cancer Survival: A Meta-Analysis.

Background and objectives: The prognostic role of a disintegrin and metalloproteinase (ADAM) 17 has been widely assessed in gastric cancer. However, the results are inconsistent. We performed a meta-analysis to evaluate the prognostic significance of ADAM17 and its association with clinicopathological parameters. Methods: The databases of PubMed, Web of Science, and Embase were searched for relevant articles published up to April 2020. The reported hazard ratios (HRs) and odds ratios (ORs) and their corresponding 95% confidence intervals (CIs) were pooled to evaluate the strength of the association. Stata 12.1 was used to perform statistical analyses. Results: Seven studies, including 1757 patients, were screened for the meta-analysis. Compared with the high ADAM17 expression group, the pooled HR was higher in the low ADAM17 expression group (HR = 2.04, 95% CI 1.66-2.50; I2 = 18.1%; p = 0.299). High ADAM17 expression was also related to the tumor node metastasis (TNM) stages (OR = 4.09, 95% CI 1.85-9.04; I2 = 84.1%; p = 0.000), lymph node metastasis (OR = 3.08, 95% CI 1.13-8.36; I2 = 79.7%; p = 0.007), and ages (OR = 1.65, 95% CI 1.24-2.21; I2 = 0%; p = 0.692) of the gastric patients. Conclusions: This meta-analysis revealed that ADAM17 is a significant biomarker for poor prognosis in gastric cancer.

[Expression of interleukin-37 in placenta and its relationship with the pathogenesis of severe preeclampsia].

OBJECTIVE: To investigate the expression of interleukin-37 (IL-37) in placenta tissue and its relationship with the pathogenesis of severe preeclampsia. METHODS: All the patients were recruited in Qilu Hospital of Shangdong University from November 2012 to November 2013. Among them, thirty patients with severe preeclampsia were assigned to the preeclampsia group, and thirty-one healthy pregnant women were assigned to the control group. Immunohistochemistry of SP was used to detect the IL-37 protein expression in placenta tissue of the two groups. The expression level of IL-37 in placenta tissue of the two groups was detected by western blot. Besides, reverse transcription (RT)-PCR was used to detect the expression of IL-37 mRNA. The correlation between the expression of IL-37 mRNA and the delivery gestational age, body mass index (BMI) was analyzed. RESULTS: (1) IL-37 were detected in the placenta of both the preeclampsia group and the control group, and the expression site mainly located in the syncytiotrophoblast, with a small amount in cytotrophoblast. (2) The expression levels of IL-37 protein in the preeclampsia group and the control group were 0.59 ± 0.39 and 0.88 ± 0.22, respectively. The IL-37 mRNA levels in the preeclampsia group and the control group were 0.55 ± 0.17 and 1.11 ± 0.21, respectively. Both decreased significantly when compared to the control group (P < 0.05). (3) Significant correlation between the expression of IL-37 mRNA and the delivery gestational weeks (r = 0.209, P > 0.05) was seen neither in the preeclampsia group nor in the control group (r = -0.053, P > 0.05). In the severe preeclampsia group, the pregnant women's BMI had no significant correlation with IL-37 mRNA expression of placenta tissue (r = 0.102, P > 0.05), neither did the control group(r = -0.115, P > 0.05). CONCLUSION: IL-37 expression is significantly lower in severe preeclampsia placenta tissue than that in the normal pregnant women, which may play a protective role in the course of severe preeclampsia.

[Expression of Gas6 in placenta and decidua tissues and its relationship with the pathogenesis of preeclampsia].

OBJECTIVE: To investigate the expression of growth arrest-specific protein 6 (Gas6) in the placenta and decidua tissues and its relationship with the pathogenesis of preeclampsia. METHODS: All the patients were recruited in Qilu Hospital of Shangdong University from October 2013 to June 2014. Among them, thirty-two women with early-onset severe preeclampsia who received cesarean section were assigned to the preeclampsia group, and thirty healthy pregnant women who received cesarean section were defined as the control group. Blood glucose, blood lipids, platelet count, D-dimer levels and other clinical indicators of the two groups were detected. Immunohistochemistry of SP was conducted to identify the localization of Gas6 protein in the placenta and decidua tissues. And reverse transcription (RT)-PCR was performed for quantitative analysis of Gas6 RNA expression in placentas. The correlations between placental Gas6 mRNA levels with clinical indicators were analyzed. RESULTS: (1) The gestational age at delivery, blood pressure, serum albumin, platelet count and birth weight of fetuses showed statistically significant differences between the two groups (P < 0.05). (2) The Gas6 protein expressed in the cytoplasm and nucleus of the syncytiotrophoblasts and decidual cells in the placenta and decidual tissues of the two groups. (3) The Gas6 mRNA expression elevated significantly in the placenta of preeclampsia group (0.60 ± 0.38) when compared to that of the control group (0.34 ± 0.22; P < 0.05). (4) The expression of Gas6 mRNA was positively related with body mass index, diastolic blood pressure, systolic blood pressure, free fatty acids and creatinine (P < 0.05), while it was negatively associated with serum albumin (P < 0.05). CONCLUSION: The high expression of Gas6 in the placenta and decidua tissues may be related to the pathogenesis of severe preeclampsia.