Development of a new synchronous fluorescence spectrometry combined with Al3+ sensitized for simultaneous and rapid determination of trace flumequine, ciprofloxacin and doxycycline hydrochloride residues in wastewater.

Antibiotics are a new type of environmental pollutants. Due to its wide application in many fields, antibiotic residues are ubiquitous in the wastewater environments. Given their potential threat on water ecosystem functioning and public health, the detection of antibiotic residues in wastewater environments has become very necessary. Based on the complexation of Al3+ with flumequine (FLU), ciprofloxacin (CIP) and doxycycline hydrochloride (DOX), their molecular conjugated area were increased and fluorescence intensity were enhanced, combined with synchronous fluorescence spectrometry (SFS) had good selectivity and high sensitivity, a novel method of Al3+ sensitized synchronous fluorescence spectrometry for the determination of FLU, CIP and DOX residues in wastewater was established. When the wavelength difference (Δλ) was selected 115.0 nm, synchronous fluorescence spectra of the three antibiotics could be well separated and the interference of wastewater matrix were eliminated primely. The new SFS made good use of spectral separation instead of conventional chemical separation, and the actual wastewater sample could be directly determined after simple filtration. The experiment results showed that the concentrations of FLU, CIP and DOX in the range of 0.5000-800.0 ng·mL-1, 0.5000-640.0 ng·mL-1 and 10.00-3500 ng·mL-1 had a good linear relationship with fluorescence intensity. The detection limits of three antibiotics were 0.02054 ng·mL-1, 0.03956 ng·mL-1 and 0.8524 ng·mL-1, respectively. Recovery rates of three antibiotics in wastewater samples were 90.72%-98.23%, 88.68%-95.08% and 85.94%-96.70%. The new SFS established in this experiment had the advantages of simple, rapid, sensitive, accurate and good selectivity. Simultaneous and rapid detection of FLU, CIP and DOX residues in wastewater was successfully realized. It had good application prospects in real-time water quality monitoring.

The Impact of Fitness Influencers on a Social Media Platform on Exercise Intention during the COVID-19 Pandemic: The Role of Parasocial Relationships.

In the context of COVID-19 pandemic lockdowns, fitness influencers on social media are greatly involved in people's home fitness processes, but there is limited research examining the role of fitness influencers on social media in exercise intention. This study aimed to explore whether people's perceptions of the personal attributes and content quality of fitness influencers can promote a strong emotional connection between the two, thereby influencing people's exercise intentions. Based on the theory of the parasocial relationship, we investigated the influence of social attractiveness (SA), physical attractiveness (PA), task attractiveness (TA), and content quality (CQ) of fitness influencers on the parasocial relationships (PSRs) between viewers and fitness influencers on social media and whether PSRs positively contribute to viewers' exercise intentions (EI). The results revealed that SA, PA, TA, and CQ have positive influences on PSRs and CQ; PSRs directly contribute to EI; and PSRs have a mediating effect between EI and CQ. This study provides new insights into understanding the relationship between fitness influencers and people's online fitness behaviors.

Rapid detection of four polycyclic aromatic hydrocarbons in drinking water by constant-wavelength synchronous fluorescence spectrometry.

Based on the advantages of the good selectivity and high sensitivity of the synchronous fluorescence method, an efficient method using constant-wavelength synchronous fluorescence spectrometry (CWSFS) for simultaneous and rapid determination of four polycyclic aromatic hydrocarbons (PAHs) (acenaphthene, phenanthrene, benzo[a]anthracene and fluoranthene) in drinking water was established in this study. When the difference in wavelength (Δλ) at 100 nm was chosen for CWSFS scanning, the synchronous fluorescence spectra of the four PAHs could be well separated with only one single scan. Different from conventional fluorescence analysis, the established method can avoid the interference among the four PAHs each other and the interference of the drinking water sample matrix, so the four PAHs in drinking water could be well distinguished and determined. The concentrations of four PAHs in the range of 0.05-100 µg/L, 0.1-400 µg/L, 0.05-100 µg/L and 0.5-2000 µg/L showed a good linear relationship with fluorescence intensity. The limits of detection were 0.0058 µg/L, 0.021 µg/L, 0.0061 µg/L and 0.056 µg/L, respectively. The recoveries were in the range of 86.55-98.74%. Overall, the established CWSFS had the characteristics of simple, rapid, sensitive and accuracy, and had been applied to the determination of the four PAHs in various drinking water with satisfactory results.

Synthesis and antitumor activity of benzophenone compound.

Seven benzophenone compounds were synthesized in one or two steps, then their antitumor activity was evaluated. The total yields ranged from 9% to 44%. Compounds 3c-5c exhibited obvious antitumor activity. Among them, compounds 3c and 4c exhibited excellent and broad-spectrum antitumor activity. Compound 3c exhibited much stronger inhibitory activities against fourteen cancer cells than cisplatin. In particular, compound 3c exhibited stronger cytotoxicity against hepatocarcinoma SMMC-7721 cells than Taxol, with a half maximal inhibitory concentration (IC50) of approximately 0.111 µM. These results demonstrated that compounds 3c, 4c and 5c were very promising antitumor leads for further structural modification.

MicroRNA-181b Serves as a Circulating Biomarker and Regulates Inflammation in Heart Failure.

Heart failure (HF) is the typical terminal stage of cardiac diseases involving inflammatory states. The function of microRNAs (miRNAs) in the progress of HF remains poorly understood. In this study, real-time PCR results showed a decreased expression of miRNA-181b (miR-181b) in HF patients compared with healthy individuals. Besides, miR-181b expressions were negatively correlated with hypersensitive C-reactive protein (hsCRP) levels in the serum of HF patients. Receiver operator characteristic (ROC) curve analysis showed that miR-181b was a diagnostic predictor of HF, and the area under the curve was 0.970 (DCM-induced HF group) and 0.962 (ICM-induced HF group). Strikingly, in HF rats induced by isoproterenol (ISO), the expression of miR-181b of heart tissue was suppressed before tumor necrosis factor-alpha (TNF-α), interleukin-1ß (IL-1ß), and interleukin-6 (IL-6) increase, as revealed by western blot and real-time PCR. Besides, the overexpression of miR-181b also decreased the expression of TNF-α, IL-1ß, and IL-6 in lipopolysaccharide- (LPS-) induced neonatal cardiomyocytes. In conclusion, our results revealed that miR-181b might be a potential biomarker for HF and provided a novel target for anti-inflammatory therapy.

Establishment and assessment of a nomogram model for predicting the risk of fulminant myocarditis: A STROBE compliant cross-sectional study.

ABSTRACT: We aimed to identify potential clinical predictors associated with the risk of fulminant myocarditis, and further to establish and assess a nomogram model based on significant attributes for clinical practicability.This is a retrospective, cross-sectional study, involving 28 patients with fulminant myocarditis and 35 age-, and sex-matched patients with non-fulminant myocarditis. Effect-size estimates are expressed as odds ratio (OR) and 95% confidence interval (CI).Fifteen factors were primarily identified to be associated with the significant risk of fulminant myocarditis after adjusting for confounders. Due to strong correlation, 6 factors were retained, including mean arterial pressure (OR, 95% CI, P: .82, .72-.94, .005), creatinine (2.15, 1.13-4.10, 0.020), blood urea nitrogen (1.45, 1.04-2.02, 0.028), aspartate aminotransferase (2.62, 1.16-5.91, 0.021), troponin I (1.43, 1.07-1.90, 0.015), and ventricular wall motion abnormality (25.81, 2.52-264.69, 0.006). The contribution of the 6 significant factors to predicting fulminant myocarditis risk was significant from multi-angle analyses, and regressing these factors in a nomogram model exhibited good predictive accuracy, as reflected by both C-index (>90%, P < .001).We have identified 6 clinical factors in significant association with fulminant myocarditis, and their prediction capability was more obvious in a nomogram model. Further investigations with larger sample sizes and longer follow-up intervals are warranted.

Discovery of Potent and Selective Methylenephosphonic Acid CD73 Inhibitors.

Solid tumors are often associated with high levels of extracellular ATP. Ectonucleotidases catalyze the sequential hydrolysis of ATP to adenosine, which potently suppresses T-cell and NK-cell functions via the adenosine receptors (A2a and A2b). The ectonucleotidase CD73 catalyzes the conversion of AMP to adenosine. Thus, increased CD73 enzymatic activity in the tumor microenvironment is a potential mechanism for tumor immune evasion and has been associated with poor prognosis in the clinic. CD73 inhibition is anticipated to restore immune function by skirting this major mechanism of adenosine generation. We have developed a series of potent and selective methylenephosphonic acid CD73 inhibitors via a structure-based design. Key binding interactions of the known inhibitor adenosine-5'-(α,ß-methylene)diphosphate (AMPCP) with hCD73 provided the foundation for our early designs. The structure-activity relationship study guided by this structure-based design led to the discovery of 4a, which exhibits excellent potency against CD73, exquisite selectivity against related ectonucleotidases, and a favorable pharmacokinetic profile.

Efficient synthesis, and antitumor and antioxidant activities of polyhydroxybenzophenone.

Five polyhydroxybenzophenones were synthesized, then their antitumor and antioxidant activities were evaluated. Compounds 1-3 and 5 exhibited obvious antitumor activity. Among them, compounds 1 and 2 exhibited stronger cytotoxicity against hepatocarcinoma SMMC-7721 cells than cisplatin, with half maximal inhibitory concentrations (IC50) of approximately 3.86 and 5.32 µM, respectively. Compounds 1, 2, and 3 exhibited stronger antioxidant activity than trolox, with IC50 values of 11.15, 10.15, and 8.91 µM, respectively, and the antioxidant mechanism and strength of all compounds were further verified using computational chemistry. These results demonstrated that compounds 1-3 and 5 were very promising leads for further structural modification.

Syntheses of xanthone derivatives and their bioactivity investigation.

Sixteen substituted 1-hydroxy-3-methylxanthones were synthesized in one step. The yields ranged from 33 to 76%. Then, the antitumor, antioxidant, anti-tyrosinase, anti-pancreatic lipase, and antifungal activities of compounds 1-16 were evaluated. Compounds 10-12 and 14 inhibited tyrosinase and pancreatic lipase activity to a certain extent, respectively. Compound 16 exhibited obvious cytotoxicity against fifteen cancer cells, moderate antioxidant activity, and moderate inhibitory activity against Candida albicans. In particular, compound 16 exhibited strong inhibitory activity against A-549 and A549/Taxol cells. These results demonstrated that compounds 10-12, 14, and 16 are promising leads for further structural modification.[Formula: see text].

Discovery of AB680: A Potent and Selective Inhibitor of CD73.

Extracellular adenosine (ADO), present in high concentrations in the tumor microenvironment (TME), suppresses immune function via inhibition of T cell and NK cell activation. Intratumoral generation of ADO depends on the sequential catabolism of ATP by two ecto-nucleotidases, CD39 (ATP → AMP) and CD73 (AMP → ADO). Inhibition of CD73 eliminates a major pathway of ADO production in the TME and can reverse ADO-mediated immune suppression. Extensive interrogation of structure-activity relationships (SARs), structure-based drug design, and optimization of pharmacokinetic properties culminated in the discovery of AB680, a highly potent (Ki = 5 pM), reversible, and selective inhibitor of CD73. AB680 is further characterized by very low clearance and long half-lives across preclinical species, resulting in a PK profile suitable for long-acting parenteral administration. AB680 is currently being evaluated in phase 1 clinical trials. Initial data show AB680 is well tolerated and exhibits a pharmacokinetic profile suitable for biweekly (Q2W) iv-administration in human.

Synthesis and antitumor, antityrosinase, and antioxidant activities of xanthone.

Ten substituted 1,3-dihydroxyxanthones were synthesized in one step. The yields ranged from 40 to 76%. Compounds 8-10 were first reported. Next, the compounds' in vitro anti-proliferative activities against nine human cancer cell lines, antityrosinase, and antioxidant activities were evaluated. Compounds 1, 4, 6-7, and 9-10 exhibited enhanced cytotoxicity against certain cancer cells. Compounds 2, 8, 9, and 10 inhibited tyrosinase activity to a certain extent. In addition, compound 4 exhibited the best antioxidant activity, which was consistent with theoretical calculations. These results demonstrated that compounds 1-2, 4, and 6-10 were promising leads for further investigation.

Serum microRNA-21 expression is significantly down-regulated in patients with dilated cardiomyopathy / 第二军医大学学报

Objective To address the levels of serum miR-21/155/181a/18b in dilated cardiomyopathy (DCM) patients at a progressive heart failure stage. Methods The serum miRNAs were measured by real-time reverse-transcription PCR in 40 DCM patients and in 30 healthy controls. Pearson’s correlation coefficient was used to calculate the potential correlation between miRNAs and other indicators, such as human Nterminal pro-brain natriuretic peptide (NT-proBNP), high-sensitivity C-reactive protein (hsCRP), left ventricular ejection fraction (LVEF%), and left ventricular end-diastolic diameter (LVEDD). Results Our findings revealed that serum miR-21 were significantly reduced in DCM patients compared with the healthy controls(P<0. 01). We also found that serum miR-21 was positively correlated with LVEF% and negatively correlated with LVEDD -<0. 001). Conclusion The serum level of cardiac remodeling-associated miR-21 is decreased in DCM patients at a progressive heart failure stage compared to the healthy controls, which may be also related to the disease severity.

A selective prostaglandin E2 receptor subtype 2 (EP2) antagonist increases the macrophage-mediated clearance of amyloid-beta plaques.

A high-throughput screen resulted in the discovery of benzoxazepine 1, an EP2 antagonist possessing low microsomal stability and potent CYP3A4 inhibition. Modular optimization of lead compound 1 resulted in the discovery of benzoxazepine 52, a molecule with single-digit nM binding affinity for the EP2 receptor and significantly improved microsomal stability. It was devoid of CYP inhibition and was ∼4000-fold selective against the other EP receptors. Compound 52 was shown to have good PK properties in CD-1 mice and high CNS permeability in C57Bl/6s mice and Sprague-Dawley rats. In an ex vivo assay, it demonstrated the ability to increase the macrophage-mediated clearance of amyloid-beta plaques from brain slices in a dose-dependent manner.

Pharmacokinetics and metabolism of AMG 232, a novel orally bioavailable inhibitor of the MDM2-p53 interaction, in rats, dogs and monkeys: in vitro-in vivo correlation.

1. AMG 232 is a novel inhibitor of the p53-MDM2 protein-protein interaction currently in Phase I clinical trials for multiple tumor indications. The objectives of the investigations reported in this article were to characterize the pharmacokinetic and drug metabolism properties of AMG 232 in pre-clinical species in vivo and in vitro, and in humans in vitro, and to predict its pharmacokinetics in humans through integrating PKDM data. 2. AMG 232 exhibited low clearance (<0.25 × Qh) and moderate to high oral bioavailability in mice, rats and monkeys (>42%), but high clearance (0.74 × Qh) and low oral exposure in dogs (18%). 3. Biotransformation was the major route of elimination of AMG 232 in rats, with only 7% of intravenously administered (14)C-labeled AMG 232 recovered as parent molecule in bile. The major metabolite was an acyl glucuronide as measured by in vivo rat studies and in vitro hepatocyte incubations in multiple species. 4. The in vitro-in vivo correlation of AMG 232 clearance was within 2-fold in pre-clinical species using hepatocytes. AMG 232 was predicted to exhibit low clearance, high volume distribution and long half-life in humans. The predictions are consistent with the preliminary human pharmacokinetic parameters of AMG 232 in clinical trials.

FLT3 and CDK4/6 inhibitors: signaling mechanisms and tumor burden in subcutaneous and orthotopic mouse models of acute myeloid leukemia.

FLT3(ITD) subtype acute myeloid leukemia (AML) has a poor prognosis with currently available therapies. A number of small molecule inhibitors of FLT3 and/or CDK4/6 are currently under development. A more complete and quantitative understanding of the mechanisms of action of FLT3 and CDK4/6 inhibitors may better inform the development of current and future compounds that act on one or both of the molecular targets, and thus may lead to improved treatments for AML. In this study, we investigated in both subcutaneous and orthotopic AML mouse models, the mechanisms of action of three FLT3 and/or CDK4/6 inhibitors: AMG925 (Amgen), sorafenib (Bayer and Onyx), and quizartinib (Ambit Biosciences). A composite model was developed to integrate the plasma pharmacokinetics of these three compounds on their respective molecular targets, the coupling between the target pathways, as well as the resulting effects on tumor burden reduction in the subcutaneous xenograft model. A sequential modeling approach was used, wherein model structures and estimated parameters from upstream processes (e.g. PK, cellular signaling) were fixed for modeling subsequent downstream processes (cellular signaling, tumor burden). Pooled data analysis was employed for the plasma PK and cellular signaling modeling, while population modeling was applied to the tumor burden modeling. The resulting model allows the decomposition of the relative contributions of FLT3(ITD) and CDK4/6 inhibition on downstream signaling and tumor burden. In addition, the action of AMG925 on cellular signaling and tumor burden was further studied in an orthotopic tumor mouse model more closely representing the physiologically relevant environment for AML.

Sphingosine kinase activity is not required for tumor cell viability.

Sphingosine kinases (SPHKs) are enzymes that phosphorylate the lipid sphingosine, leading to the formation of sphingosine-1-phosphate (S1P). In addition to the well established role of extracellular S1P as a mitogen and potent chemoattractant, SPHK activity has been postulated to be an important intracellular regulator of apoptosis. According to the proposed rheostat theory, SPHK activity shifts the intracellular balance from the pro-apoptotic sphingolipids ceramide and sphingosine to the mitogenic S1P, thereby determining the susceptibility of a cell to apoptotic stress. Despite numerous publications with supporting evidence, a clear experimental confirmation of the impact of this mechanism on tumor cell viability in vitro and in vivo has been hampered by the lack of suitable tool reagents. Utilizing a structure based design approach, we developed potent and specific SPHK1/2 inhibitors. These compounds completely inhibited intracellular S1P production in human cells and attenuated vascular permeability in mice, but did not lead to reduced tumor cell growth in vitro or in vivo. In addition, siRNA experiments targeting either SPHK1 or SPHK2 in a large panel of cell lines failed to demonstrate any statistically significant effects on cell viability. These results show that the SPHK rheostat does not play a major role in tumor cell viability, and that SPHKs might not be attractive targets for pharmacological intervention in the area of oncology.

Structure guided design of a series of sphingosine kinase (SphK) inhibitors.

Sphingosine-1-phosphate (S1P) signaling plays a vital role in mitogenesis, cell migration and angiogenesis. Sphingosine kinases (SphKs) catalyze a key step in sphingomyelin metabolism that leads to the production of S1P. There are two isoforms of SphK and observations made with SphK deficient mice show the two isoforms can compensate for each other's loss. Thus, inhibition of both isoforms is likely required to block SphK dependent angiogenesis. A structure based approach was used to design and synthesize a series of SphK inhibitors resulting in the identification of the first potent inhibitors of both isoforms of human SphK. Additionally, to our knowledge, this series of inhibitors contains the only sufficiently potent inhibitors of murine SphK1 with suitable physico-chemical properties to pharmacologically interrogate the role of SphK1 in rodent models and to reproduce the phenotype of SphK1 (-/-) mice.

Application of DBS sampling in combination with LC-MS/MS for pharmacokinetic evaluation of a compound with species-specific blood-to-plasma partitioning.

BACKGROUND: Dried blood spot (DBS) sampling in combination with LC-MS/MS has been used increasingly in drug discovery for quantitative analysis to support pharmacokinetic (PK) studies. In this study, we assessed the effect of blood-to-plasma (B:P) partitioning on the bioanalytical performance and PK data acquired by DBS for a compound AMG-1 with species and concentration-dependent B:P ratio. RESULTS: B:P partitioning did not adversely affect bioanalytical performance of DBS for AMG-1. For rat, (B:P ratio of 0.63), PK profiles from DBS and plasma methods were comparable. For dog, concentration-dependence of B:P ratio was observed both in vivo and in vitro. Additional studies demonstrated concentration-dependence of the compound's unbound fraction in plasma, which may contribute to the concentration-dependence of the B:P ratio. CONCLUSION: DBS is a promising sampling technique for preclinical pharmacokinetic studies. For compounds with high B:P ratio, caution needs to be applied for data comparison and interpretation between matrices.

Application of automated dried blood spot sampling and LC-MS/MS for pharmacokinetic studies of AMG 517 in rats.

BACKGROUND: The use of dried blood spot (DBS) sampling technique is of particular interest for drug discovery pharmacokinetic studies due to the small blood volume requirement. In addition, automated blood sampling is an attractive approach for rat pharmacokinetic studies as animal handling work is minimized. The goal of this study was to use an automated DBS sampler for automated blood collection and spotting onto DBS paper for pharmacokinetic studies in rats. AMG 517, a potent and selective vanilloid receptor antagonist, was dosed to rats (n = 3) intravenously and blood samples were collected at nine time points over a 24 h period using the automated DBS sampler. After drying, storage and shipment, the DBS samples were extracted and analyzed by LC-MS/MS. RESULTS: The developed bioanalytical method for the analysis of DBS samples had good accuracy and precision within the context of a discovery, non-GLP analysis. The concentration-time data and pharmacokinetic parameters generated from automated spotted samples were very similar to those derived from manually spotted DBS samples. The manual DBS data were also comparable to plasma data after correction for blood-to-plasma ratio. CONCLUSION: The automated DBS sampling is a promising technique for rodent pharmacokinetic studies and will improve the efficiency and quality of DBS sampling.

Discovery of amide replacements that improve activity and metabolic stability of a bis-amide smoothened antagonist hit.

A bis-amide antagonist of Smoothened, a seven-transmembrane receptor in the Hedgehog signaling pathway, was discovered via high throughput screening. In vitro and in vivo experiments demonstrated that the bis-amide was susceptible to N-acyl transferase mediated amide scission. Several bioisosteric replacements of the labile amide that maintained in vitro potency were identified and shown to be metabolically stable in vitro and in vivo.