Identification of a Conserved, Linear Epitope on VP3 of Enterovirus A Species Recognized by a Broad-Spectrum Monoclonal Antibody.

Outbreaks of hand, foot and mouth disease (HFMD) have occurred frequently in the Asian-Pacific region over the last two decades, caused mainly by the serotypes in Enterovirus A species. High-quality monoclonal antibodies (mAbs) are needed to improve the accuracy and efficiency of the diagnosis of enteroviruses associated HFMD. In this study, a mAb 1A11 was generated using full particles of CV-A5 as an immunogen. In indirect immunofluorescence and Western blotting assays, 1A11 bound to the viral proteins of CV-A2, CV-A4, CV-A5, CV-A6, CV-A10, CV-A16, and EV-A71 of the Enterovirus A and targeted VP3. It has no cross-reactivity to strains of Enterovirus B and C. By mapping with over-lapped and truncated peptides, a minimal and linear epitope 23PILPGF28 was identified, located at the N-terminus of the VP3. A BLAST sequence search of the epitope in the NCBI genus Enterovirus (taxid: 12059) protein database indicates that the epitope sequence is highly conserved among the Enterovirus A species, but not among the other enterovirus species, first reported by us. By mutagenesis analysis, critical residues for 1A11 binding were identified for most serotypes of Enterovirus A. It may be useful for the development of a cost-effective and pan-Enterovirus A antigen detection for surveillance, early diagnosis and differentiation of infections caused by the Enterovirus A species.

Identification of specific and shared epitopes at the extreme N-terminal VP1 of Coxsackievirus A4, A2 and A5 by monoclonal antibodies.

Hand, foot and mouth disease (HFMD) is caused by a variety of serotypes in species A of the Enterovirus genus, including recently re-emerged Coxsackievirus A2 (CV-A2), CV-A4 and CV-A5. For development of diagnostic reagents, for surveillance, and the development of multivalent vaccines against HFMD, the antigenicity of HFMD-associated enteroviruses warrants investigation. The purified virions of CV-A4 were inoculated into Balb/c mice and hybridomas were obtained secreting monoclonal antibodies (mAbs) directed against CV-A4 and cross-reacting with other closely related species A enteroviruses. The mAbs were characterized by ELISA, Western blotting and in vitro neutralizing assays. The majority of mAbs was non-neutralizing, with only 2% of the mAbs neutralizing CV-A4 specifically. Most of mAbs bound to linear VP1 epitopes of CV-A4. Interestingly, four types of mAbs were obtained which bound specifically to CV-A4 or were broadly to CV-A4/-A2, CV-A4/-A5 and CV-A4/-A2/-A5, respectively. Mapping with overlapping or single-amino-acid mutant peptides revealed that the four types of mAbs all bound to the first 15 amino acids at the N-terminus of the VP1. This region of picornaviruses is functionally important as it is involved in uncoating and releasing of viral RNA into the cytosol. The binding footprints of four type mAbs are composed of conserved and variable residues and are different from each other. The newly discovered broadly cross-reactive mAbs reflect the high homology of CV-A4/ CV-A2/CV-A5. The results also demonstrate that it is possible and beneficial to develop the diagnostic reagents to detect rapidly the main pathogens of enteroviruses associated with HFMD cause by CV-A4/CV-A2/CV-A5.

The effectiveness and safety of linagliptin within elderly type 2 diabetes mellitus: a meta-analysis and systematic review.

BACKGROUND: Linagliptin is a convenient and effective drug approved for glycemic management in type 2 diabetes mellitus (T2DM). However, the effectiveness and safety evidence of linagliptin remains unclear with the increasing prevalence of T2DM in elderly patients. OBJECTIVE: For evaluating the effectiveness and safety of linagliptin within T2DM cases who aged ≥60 years. METHODS: The researchers pooled 4903 cases aged ≥60 years with T2DM from 5 published randomized clinical trials obtained from multiple databases. The safety was evaluated by the incidence and severity of adverse events (AEs) which mainly focused on hypoglycaemia. The major effectiveness end point was the change of glycated haemoglobin (HbA1c). Then the researchers made the qualitative and quantitative assessments of the investigation. RESULTS: The level of HbA1c and FPG was significantly reduced by linagliptin (WMD=-0.63%, 95% CI: -0.81, -0.44; p<0.00001; Z=6.70) and (WMD=-15.58 mg/dL, 95% CI: -22.34, -8.82; p<0.00001; Z=4.52) relative to that in the placebo cohort. The incidences of overall (OR=1.01, 95% CI: 0.82, 1.25; p=0.91) and severe negative events (OR=0.88, 95% CI: 0.61, 1.25; p=0.46) were not significant increased in linagliptin cohorts compared to the placebo cohorts. There is insignificant difference in hypoglycaemia between linagliptin and placebo cohorts for the 24 weeks' study(OR=1.12, 95% CI: 0.85, 1.48; p=0.41). Severe hypoglycemia had slightly descended incidence, whereas insignificant difference was shown in the linagliptin cohorts in contrast to placebo cohorts (OR=0.95, 95 % CI: 0.68, 1.32, p=0.76). CONCLUSIONS: Linagliptin is an effective drug with excellent safety for elderly T2DM.

Ultrafiltration for patients with acute decompensated heart failure: A systematic review and meta-analysis.

BACKGROUND: Ultrafiltration plays an indispensable role in relieving congestion and fluid retention in patients with acute decompensated heart failure (ADHF) in recent years. So far, there is no consistent agreement about whether early ultrafiltration (UF) is a first-line treatment for patients with ADHF. We, therefore, conducted a meta-analysis to assess the efficacy and safety of UF. METHODS: PubMed, Embase, and Cochrane Library databases were searched for randomized controlled trials (RCTs) that compared UF with diuretics in patients with ADHF and included our interested outcomes. The primary outcomes are heart failure rehospitalization, all-cause rehospitalization, and mortality. The second outcomes are fluid loss, weight loss, and adverse events. RevMan Version 5.4.1 was used to analyze the data of included studies. RESULTS: A total of 12 studies with 1197 patients were included. Our results showed a reduction in heart failure rehospitalization (risk ratio [RR] 0.67, 95% confidence interval [CI]: 0.52-0.87, P = .003) and all-cause rehospitalization (RR 0.62, 95% CI: 0.42-0.92; P = .02), an increase in fluid loss (1.47 L, 95% CI: 0.95-1.99 L, P < .001) and weight loss (1.65 kg, 95% CI: 0.90-2.41 kg; P < .001). There was no difference in mortality (RR 1.09, 95% CI: 0.78-1.51; P = .62). There were inconsistent agreements about which group have more total adverse events. Subgroup analysis showed that UF with larger mean fluid-remove rate (≥200 mL/h) could significantly remove more fluid, lose more weight, and decrease heart failure rehospitalization. Less weight loss for patients with ADHF may correlated to higher percent of ischemic etiology (ischemic etiology ≥50%). CONCLUSION: Although UF is more effective in removing fluid than diuretics and decrease rehospitalization of heart failure and all causes, there is not enough evidence to prove that UF is superior because of adverse events and mortality in the UF group. The mean fluid-removal rates should be set to ≥200 mL/h. Patient with different etiology may have different effects when treated with UF and it is a weak conclusion.Trial registration: The systematic review was registered with the International Prospective Registry of Systematic Reviews. (https://www.crd.york.ac.uk/prospero/, registration number CRD42021245049).

The glucagon-like peptide-1 (GLP-1) analog liraglutide attenuates renal fibrosis.

Renal fibrosis is recognized as the common route of all chronic kidney disease (CKD) progressing to end-stage renal disease (ESRD). Additionally, accumulating evidence suggests that epithelial-mesenchymal transition (EMT) plays a significant role in the process of renal fibrogenesis. Liraglutide is a long-acting glucagon-like peptide-1 (GLP-1) analog that has been widely used to treat type 2 diabetes. Recent studies have demonstrated that the GLP-1 analogs could also exert protective effects in cardiac fibrosis models. However, the effects of liraglutide on the progression of CKD remain largely unknown. In the present study, we investigated the effects of liraglutide on the progression to renal fibrosis induced by unilateral ureteral obstruction (UUO) and EMT of rat renal tubular epithelial cells (NRK-52E) induced with recombinant transforming growth factor-beta 1 (TGF-ß1). The results indicated that UUO increased collagen deposition and the mRNA expression of fibronectin (FN) and collagen type I alpha 1 (Col1α1) in the obstructed kidney tissues. The effects were blunted in liraglutide-treated UUO mice compared with control mice. The upregulation of Snail1 and alpha smooth muscle actin (α-SMA), and downregulation of E-cadherin revealed that EMT occurred in the UUO kidneys, and these effects were ameliorated following liraglutide treatment. Additionally, liraglutide treatment decreased the expression of TGF-ß1 and its receptor (TGF-ß1R) and inhibited the activation of its downstream signaling molecules (pSmad3 and pERK1/2). The in vitro results showed that the EMT and extracellular matrix (ECM) secretion of NRK-52E cells were induced by TGF-ß1. In addition, the Smad3 and ERK1/2 signaling pathways were highly activated in cells cultured with TGF-ß1. All these effects were attenuated by liraglutide treatment. However, the protective effects of liraglutide were abolished by co-incubation of the GLP-1 receptor (GLP-1R) antagonist exendin-3 (9-39). These results suggest that liraglutide attenuates the EMT and ECM secretion of NRK-52E cells induced by TGF-ß1 and EMT and renal fibrosis induced by UUO. The potential mechanism involves liraglutide binding to and activating GLP-1R, which prevents EMT by inhibiting the activation of TGF-ß1/Smad3 and ERK1/2 signaling pathways, thereby decreasing the ECM secretion and deposition. Therefore, liraglutide is a promising therapeutic agent that may halt the progression of renal fibrosis.

Characterizing the Blood Oxygen Level-Dependent Fluctuations in Musculoskeletal Tumours Using Functional Magnetic Resonance Imaging.

This study characterized the blood oxygen level-dependent (BOLD) fluctuations in benign and malignant musculoskeletal tumours via power spectrum analyses in pre-established low-frequency bands. BOLD MRI and T1-weighted imaging (T1WI) were collected for 52 patients with musculoskeletal tumours. Three ROIs were drawn on the T1WI image in the tumours' central regions, peripheral regions and neighbouring tissue. The power spectrum of the BOLD within each ROI was calculated and divided into the following four frequency bands: 0.01-0.027 Hz, 0.027-0.073 Hz, 0.073-0.198 Hz, and 0.198-0.25 Hz. ANOVA was conducted for each frequency band with the following two factors: the location of the region of interest (LoR, three levels: tumour "centre", "peripheral" and "healthy tissue") and tumour characteristic (TC, two levels: "malignant" and "benign"). There was a significant main effect of LoR in the frequencies of 0.073-0.198 Hz and 0.198-0.25 Hz. These data were further processed with post-hoc pair-wise comparisons. BOLD fluctuations at 0.073-0.198 Hz were stronger in the peripheral than central regions of the malignant tumours; however, no such difference was observed for the benign tumours. Our findings provide evidence that the BOLD signal fluctuates with spatial heterogeneity in malignant musculoskeletal tumours at the frequency band of 0.073-0.198 Hz.

[The Influence of Different Ionic Concentration in Cell Physiological Solution on Temperature Measurement by Near Infrared].

It is important to real-timely monitor and control the temperature of cell physiological solution in patch clamp experiments, which can eliminate the uncertainty due to temperature and improve the measurement accuracy. This paper studies the influence of different ions at different concentrations in the physiological solution on precision of a temperature model by using near infrared spectroscopy and chemometrics method. Firstly, we prepared twelve sample solutions respectively with the solutes of CaCl2, KCl and NaCl at four kinds of concentrations, and collected the spectra of different solutions at the setting temperature range 20-40 degrees C, the range of the spectra is 9 615-5 714 cm(-1). Then we divided the spectra of each solution at different temperatures into two parts (a training set and a prediction set) by three methods. Interval partial least squares method was used to select an effective wavelength range and develop calibration models between the spectra in the selected range and temperature velues. The experimental results show that RMSEP of CaCl2 solution with 0.25 g x mL(-1) is maximum, the result of the three tests are 0.386 3, 0.303 7 and 0.337 2 degrees C, RMSEP of NaCl with 0.005 g x mL(-1) solution is minimum, the result of the three tests are 0.220 8, 0.155 3 and 0.145 2 degrees C. The experimental results indicate that Ca2+ has the greatest influence on the accuracy of the temperature model of the cell physiological solution, then K+, and Na+ has the least influence. And with the ionic concentration increasing, the model accuracy decreases. Therefore; when we build the temperature model of cell physiological solution, it is necessary to change the proportion of the three kinds of main ions in cell physiological solution reasonably in order to correct the effects of different ionic concentrations in physiological solution and improve the accuracy of temperature measurements by near infrared spectroscopy.

Treeline dynamics in response to climate change in the Min Mountains, southwestern China.

BACKGROUND: Abies faxoniana is the dominant plant species of the forest ecosystem on the eastern edge of Qinghai-Tibet Plateau, where the treeline is strongly defined by climate. The tree-ring chronologies and age structure of Abies faxoniana were developed in the treeline ecotones on the northwestern and southeastern aspects of the Min Mountains in the Wanglang Nature Reserve to examine the treeline dynamics of recent decades in response to climate change. RESULTS: On the northwestern aspect, correlation analysis showed that the radial growth was significantly and positively correlated with precipitation in current January and monthly mean temperature in current April, but significantly and negatively correlated with monthly mean temperature in previous August. On the southeastern aspect, the radial growth was significantly negatively correlated with monthly mean temperature in previous July and August. CONCLUSIONS: The different responses of radial growth to climatic variability on both the aspects might be mainly due to the micro-environmental conditions. The recruitment benefited from the warm temperature in current April, July and September on the northwestern aspect. The responses of radial growth and recruitment to climatic variability were similar on the northwestern slope. Recruitment was greatly restricted by competition with dense bamboos on the southeastern aspect.

[Improving component analysis ability of the complex mixed solutions by multi-dimensional diffuse transmittance spectrometry].

The multi-dimensional diffuse transmittance spectrums were collected by the traditional near-infrared transmittance method combined with a scanning device, and then used for component analysis of the complex mixed solution. A xenon light, an electric control translation stage and a spectrometer were gathered to set up a device; Intralipid-20%, India-ink and C6H12O6 were used to prepare 225 kinds of complex mixed solutions; the diffuse transmittance spectrums were measured at 20 points off the transmission center distributed from 0-5 mm (interval 0.25 mm); the single and multi-point diffuse transmittance spectrums were analyzed by partial least squares regression for modeling and prediction. The results show that the modeling and prediction accuracy of the concentrations of the intralipid-20% and India-ink increased with the growing of the transmittance points, but the concentration of the C6H12O6 did not increase. It is proved that the spectrums collected by different points can raise the signal to noise radio of the strong absorption and scattering substance, and the signal to noise radio of the weak absorption and scattering substance would be improved by increasing the current system accuracy.

[D-value estimation of dynamic spectrum based on the statistical methods].

To realize the noninvasive concentration detection of blood components and improve the drawbacks existing in the time-domain single-trial estimation method of "dynamic spectrum" (DS), the D-value estimation method based on the statistical properties was proposed. We extracted the absolute difference between two corresponding values of each wavelength to make up the DS, selected the valid DSs from the DSs of different times by statistic method, and the valid DSs were superimposed and averaged as the final output of the DS. Data collected from 48 volunteers were processed by the D-value estimation and the single-trial estimation, respectively; and then the comparison was carried out between the two methods. Compared with the single-trial estimation, the valid DSs extracted by the D-value estimation were slightly better in denoising; And the average number of the remained valid DSs is improved from 48 to 130; the average of mean square error among the valid DSs is improved from 0.39 to 0.006; the speed of data processing is increased by nearly 20 times. The new method can significantly improve the quality of the extraction of DS.

[Response processes of Aralia elata photosynthesis and transpiration to light and soil moisture].

By using CIRAS-2 portable photosynthesis system, the light response processes of Aralia elata photosynthesis and transpiration under different soil moisture conditions were studied, aimed to understand the adaptability of A. elata to different light and soil moisture conditions. The results showed that the response processes of A. elata net photosynthetic rate (Pn), transpiration rate (Tr), and water use efficiency (WUE) to photon flux density (PFD) were different. With the increasing PFD in the range of 800-1800 micromol x m2(-2) x s(-1), Pn changed less, Tr decreased gradually, while WUE increased obviously. The light saturation point (LSP) and light compensation point (LCP) were about 800 and 30 micromol m(-2) x s(-1), respectively, and less affected by soil water content; while the apparent photosynthetic quantum yield (Phi) and dark respiratory rate (Rd) were more affected by the moisture content. The Pn and WUE had evident threshold responses to the variations of soil water content. When the soil relative water content (RWC) was in the range of 44%-79%, A. elata could have higher levels of Pn and WUE.

[Time shift invariant properties of commonly used growth models and their application].

Growth analysis is of significance in estimating the age of organisms, but in reality, the initial time for this estimation adopted by different authors is not always the same. For example, in the growth analysis of mammals, the age could be birth age or conceptional age. Such a discrepancy in time, the so-called time shift, may generate different results in parameter-simulating process. In this paper, the time-shift invariant properties of commonly used three-parameter growth models, i.e., Spillman, Logistic, Gompertz and Bertalanffy models, were analyzed, and the results showed that these four models all had the invariant characters under any time shift, namely, no matter which initial time (age) of estimation was adopted, the same fitness was obtained. A case study was made with the growth data of Phodopus roborovskii and by adopting both birth age and conceptional age.