Identification of novel serum metabolic signatures to predict chronic kidney disease among Chinese elders using UPLC-Orbitrap-MS.

BACKGROUND: Chronic kidney disease (CKD) is a major public health concern. However, validated and broadly applicable biomarkers for early CKD diagnosis are currently not available. We aimed to identify serum metabolic signatures at an early stage of CKD to provide a reference for future investigations into the early diagnostic biomarkers. METHODS: Serum metabolites were extracted from 65 renal dysfunction (RD) patients and 121 healthy controls (discovery cohort: 12 RD patients and 55 health participants; validation cohort: 53 RD patients and 66 health participants). Metabolite extracts were analyzed by ultraperformance liquid chromatography coupled with quadrupole-electrostatic field orbital trap mass spectrometry (UPLC-QE-Orbitrap MS) for untargeted metabolomics. Orthogonal partial least squares-discriminant analysis (OPLS-DA) was performed to detect different compounds between groups. Receiver operating characteristic (ROC) curve analysis was carried out to determine the diagnostic value of the validated differential metabolites between groups. We referred to the Kyoto Encyclopedia of Gene and Genomes (KEGG) to elucidate the metabolic pathways of the validated differential metabolites. RESULTS: A total of 22 and 23 metabolites had significantly different abundances in the discovery and validation cohort, respectively. Six of them (creatinine, L-proline, citrulline, butyrylcarnitine, 1-methylhistidine, and valerylcarnitine) in the RD group was more abundant than that of the health group in both cohorts. The combination of the six validated differential metabolites were able to accurately detect RD (AUC 0.86). Three of the six metabolites are involved in the metabolism of arginine and proline. CONCLUSIONS: The present study highlights that creatinine, L-proline, citrulline, butyrylcarnitine, 1-methylhistidine, and valerylcarnitine are metabolite indicators with potential predictive value for CKD.

Study on the adverse effect of acid-corrosion on the dentin in terms of degradation of fracture resistance.

Human dentin is known for its hierarchical structure through long-term evolution. Dental caries, embodied by dentin demineralization, is ascribed to a different reaction between peritubular dentin (PTD) and intertubular dentin (ITD) to acid dissolution. This study sheds light on the adverse effect of acid on dentin in terms of degradation of its fracture toughness (FT) due to the acid dissolution-induced corrosion of PTD. A scanning electronic microscope (SEM) is utilized to visualize the difference between normal and acid-treated dentin subjected to the same loading method in terms of crack propagation performance. 3D simulative representative volume elements (RVEs) are developed to analyze the effect of PTD missing on the performance of dentin fracture resistance (FR). The results indicate PTD plays a significant role in enhancing dentin FR capability and thus reveals the importance of structural integrity for dentin.

Analysis of the suitable thawing endpoint of the frozen chicken breast using video recording analysis, shear force, and bioelectrical impedance measurement.

This study focuses on analyzing the texture properties and bioelectrical impedance characteristics of frozen chicken breasts during low-temperature thawing, meanwhile, we also compared the differences in physiochemical properties. Frozen chicken breasts were thawed at 4 ± 2°C for 2, 4, 6, 8, and 10 h separately, then the physiochemical properties (color, pH, water-holding capacity, water distribution), the texture properties (easy-to-cut level), and the bioelectrical impedance were determined and analyzed. The easy-to-cut level of the samples was evaluated by the sensory panel and two indexes, one is Warner-Bratzler shear force measured by texture analysis machine, and the other is cutting speed value calculated by the consumer-oriented cutting behavior analysis using frame-by-frame video recording analysis method. These two methods were used to characterize the easy-to-cut level of the frozen samples during thawing from the industrial processing and home cooking standpoint. Strong correlations were observed between the easy-to-cut level and the bioelectrical impedance of the frozen chicken breasts during thawing. The impedance magnitude at 100 kHz showed a high correlation coefficient (R2 = .9417) with Warner-Bratzler shear force, and the impedance magnitude at 50 Hz showed a high correlation coefficient (R2 = .8658) with cutting speed. Our results indicated the acceptability of using bioelectrical impedance to evaluate the easy-to-cut thawing endpoint for both industry processing and home cooking.

Predicting of elderly population structure and density by a novel grey fractional-order model with theta residual optimization: a case study of Shanghai City, China.

BACKGROUND: Accurately predicting the future development trend of population aging is conducive to accelerating the development of the elderly care industry. This study constructed a combined optimization grey prediction model to predict the structure and density of elderly population. METHODS: In this paper, a GT-FGM model is proposed, which combines Theta residual optimization with fractional-order accumulation operator. Fractional-order accumulation can effectively weaken the randomness of the original data sequence. Meanwhile, Theta residual optimization can adjust parameter by minimizing the mean absolute error. And the population statistics of Shanghai city from 2006 to 2020 were selected for prediction analysis. By comparing with the other traditional grey prediction methods, three representative error indexes (MAE, MAPE, RMSE) were conducting for error analysis. RESULTS: Compared with the FGM model, GM (1,1) model, Verhulst model, Logistic model, SES and other classical prediction methods, the GT-FGM model shows significant forecasting advantages, and its multi-step rolling prediction accuracy is superior to other prediction methods. The results show that the elderly population density in nine districts in Shanghai will exceed 0.5 by 2030, among which Huangpu District has the highest elderly population density, reaching 0.6825. There has been a steady increase in the elderly population over the age of 60. CONCLUSIONS: The GT-FGM model can improve the prediction accuracy effectively. The elderly population in Shanghai shows a steady growth trend on the whole, and the differences between districts are obvious. The government should build a modern pension industry system according to the aging degree of the population in each region, and promote the balanced development of each region.

Possible sarcopenia and its risk factors in a home for seniors in Shanghai.

BACKGROUND AND OBJECTIVES: The Asian Working Group for Sarcopenia (AWGS) recommended various measures for identifying patients with possible sarcopenia in its 2019 consensus. The present survey aimed to assess older adults in a senior home to determine the prevalence and associated factors for possible sarcope-nia and to compare the differences between various assessment pathways based on AWGS 2019 criteria. METHODS AND STUDY DESIGN: This cross-sectional study examined 583 participants of a senior home. Patients with possible sarcopenia were determined through the following four pathways: [I] calf circumference (CC) + handgrip strength (HGS); [II] SARC-F+HGS; (III) SARC-CalF+HGS; and (IV) CC, SARC-F, and/or SARC-CalF+HGS. RESULTS: The four assessment pathways revealed a high prevalence of possible sarcopenia in the older adults in the senior home ([I]=50.6%; [II]=46.8%; [III]=48.2%; [IV]=65.9%). There is significant difference in prevalence between pathway IV and the other pathways (p<0.001). A multivariate analysis revealed that advanced age, risk of malnutrition, malnutrition, high level of care, an exercise frequency of <3 times per week, and osteoporosis were correlated with a higher risk of possible sarcopenia. By contrast, oral nutritional supplements (ONS) reduced the risk of possible sarcopenia. CONCLUSIONS: This survey reported a high prevalence of possible sarcopenia in the older adults of the senior home and determined the associated influencing factors. Furthermore, our findings suggested that pathway IV is the most suitable pathway for the examined older adults which enabled the detection and early intervention of more possible sarcopenia.

Malnutrition and its risk factors in a home for seniors in Shanghai.

BACKGROUND AND OBJECTIVES: Older adults residing in senior homes are at a high risk of malnutrition. In this study, we investigated the nutritional status of these individuals and factors associated with malnutrition in this population. METHODS AND STUDY DESIGN: This cross-sectional study (September 2020-January 2021) included a total of 583 older adults residing in a senior home in Shanghai (mean age, 85.0±6.6 years). The Mini Nutritional Assessment Short Form (MNA-SF) questionnaire was administered to assess the nutritional status of the participants. Patients with possible sarcopenia were identified according to the guidelines recommended by the Asian Working Group for Sarcopenia in its 2019 consensus (AWGS 2019). Moreover, the factors influencing malnutrition were determined through multivariate analyses. RESULTS: The likelihoods of having malnutrition and being at a risk of malnutrition were noted in 10.5% and 37.4% of the participants, respectively. In both male and female participants, handgrip strength (HGS) and calf circumference (CC) increased significantly with increasing scores on the aforementioned questionnaire (p<0.001). Among the participants, 44.6% had ≥3 chronic diseases and 48.2% used multiple medicines. Multivariate analyses revealed that dys-phagia (OR, 3.8; 95% CI, 1.7-8.5), possible sarcopenia (OR, 3.6; 95% CI, 2.2-5.6), and dementia (OR, 4.5; 95% CI, 2.8-7.0) were correlated with a relatively high prevalence of malnutrition/malnutrition risk. Exercise (at least thrice a week) reduced malnutrition risk. CONCLUSIONS: Malnutrition is common among older adults residing in senior homes; therefore, the associated factors must be identified, and appropriate interventions should be administered.

Atomic force microscopy-based assessment of multimechanical cellular properties for classification of graded bladder cancer cells and cancer early diagnosis using machine learning analysis.

Cellular mechanical properties (CMPs) have been frequently reported as biomarkers for cell cancerization to assist objective cytology, compared to the current subjective method dependent on cytomorphology. However, single or dual CMPs cannot always successfully distinguish every kind of malignant cell from its benign counterpart. In this work, we extract 4 CMPs of four different graded bladder cancer (BC) cell lines by AFM (atomic force microscopy)-based nanoindentation to generate a CMP database, which is used to train a cancerization-grade classifier by machine learning. The classifier is tested on 4 categories of BC cells at different cancer grades. The classification shows split-independent robustness and an accuracy of 91.25% with an AUC-ROC (ROC stands for receiver operating characteristic, and ROC curve is a graphical plot which illustrates the performance of a binary classifier system as its discrimination threshold is varied) value of 97.98%. Finally, we also compare our proposed method with traditional invasive diagnosis and noninvasive cancer diagnosis relying on cytomorphology, in terms of accuracy, sensitivity and specificity. Unlike former studies focusing on the discrimination between normal and cancerous cells, our study fulfills the classification of 4 graded cell lines at different cancerization stages, and thus provides a potential method for early detection of cancerization. STATEMENT OF SIGNIFICANCE: We measured four cellular mechanical properties (CMPs) of 4 graded bladder cancer (BC) cell lines using AFM (atomic force microscopy). We found that single or dual CMPs cannot fulfill the task of BC cell classification. Instead, we employ MLA (Machine Learning Algorithm)-based analysis whose inputs are BC CMPs. Compared with traditional cytomorphology-based prognoses, the non-invasive method proposed in this study has higher accuracy but with many fewer cellular properties as inputs. The proposed non-invasive prognosis is characterized with high sensitivity and specificity, and thus provides a potential tumor-grading means to identify cancer cells with different metastatic potential. Moreover, our study proposes an objective grading method based on quantitative characteristics desirable for avoiding misdiagnosis induced by ambiguous subjectivity.

Comprehensive bioinformatics analysis of the E2F family in human clear cell renal cell carcinoma.

Clear cell renal cell carcinoma (ccRCC) originates from renal tubular epithelial cells and is the most common pathological renal cell carcinoma type with the worst prognosis. The relationship between the expression, prognosis and mechanism of ccRCC and the E2F family remains challenging. In the present study, RNA sequencing and clinical data of ccRCC from The Cancer Genome Atlas and two datasets, GSE36895 and GSE53757, from the Gene Expression Omnibus were used to identify the role of the E2F family in ccRCC. A total of 10 groups of tumor tissues and paired-normal tissues from patients with ccRCC were verified by reverse transcription-quantitative PCR. the expression, tumor grade and stage, prognosis and regulatory mechanism of the E2F family in ccRCC were analyzed. It was found that the expression levels of E2F1 to 4 and 6 to 8 were higher in ccRCC tissues than in normal tissues, whereas the expression level of E2F5 was lower in the former than in the latter. The expression levels of E2F1 to 8 were correlated with tumor stage and grade. Low expression of E2F1 to 5 and 7 to 8 was significantly associated with longer overall survival, disease-specific survival and progression-free survival times. The data revealed that the E2F family rarely has genetic mutations. The expression of E2F1, E2F2, E2F5, E2F7 and E2F8 was significantly correlated with DNA methylation, and E2F1 to E2F7 were significantly correlated with copy number and the data showed that the expression of E2Fs was significantly correlated with the cell cycle. The results of the present study suggested that E2F family genes may be potential targets for ccRCC molecular diagnosis and targeted therapy.

Insights into cell classification based on combination of multiple cellular mechanical phenotypes by using machine learning algorithm.

Although cellular elastic property (CEP, also known as cellular elastic modulus) has been frequently reported as a biomarker to distinguish some cancerous cells from their benign counterparts, it cannot be adopted as a universal hallmark to be applied to every kind cell. In the present study, we report that insignificant difference is observed between normal gastric cell and its cancer counterpart which is one of the common human malignancies, in terms of CEP statistical distribution. In this regard, we propose multiple cellular mechanical phenotypes (CMPs) to differentiate the above two cell types, which is realized by machine learning algorithm (MLA). The results show that the cellular classification effect proves better with more CMPs adopted, regardless of the exact MLA employed. Moreover, the MLA-based method remains effective if we add two more cell lines to the above two cell categories. Our study indicates that MLA-based cellular classification can potentially serve as an efficient and objective means to assist or even validate cancer prognostics.

Analysis of Colchicine-Induced Effects on Hepatoma and Hepatocyte Cells by Atomic Force Microscopy.

Biomechanical properties of cells are altered by many diseases. Cancer cell metastasis is related to the properties such as the cell stiffness that influences cell proliferation, differentiation and migration. In this paper, we used an atomic force microscope to analyze the colchicine-induced effects on the mechanical properties of hepatocyte (HL-7702 cells) and hepatoma cells (SMCC-7721 cells) in culture at the nanoscale. The cells were exposed to a solution with a normal dose of colchicine for two, four and six hours. Surface topographic images showed that colchicine decreased the stability of the cytoskeleton. After the same six-hour treatment in a solution with a normal dose of colchicine, the biomechanical properties of HL-7702 cells were almost unchanged. However, the stiffness and the adhesion force of the SMCC-7721 cells were clearly increased (more than twofold of the normal values), especially after four hours. The deformability of SMCC-7721 cancer cells was significantly decreased within the six-hour treatment in the solution with a normal dose of colchicine. Analysis of the biomechanical properties of post-treatment hepatoma cells provided a complementary explanation for the mechanism of action of colchicine on cells at the nanoscale. This method is expected to allow the monitoring of potential metastatic cancer cell changes, thus preventing the emergence and the transmission of disease, and improving the diagnosis of cancer.

Biomechanical measurement and analysis of colchicine-induced effects on cells by nanoindentation using an atomic force microscope.

Colchicine is a drug commonly used for the treatment of gout, however, patients may sometimes encounter side-effects induced by taking colchicine, such as nausea, vomiting, diarrhea and kidney failure. In this regard, it is imperative to investigate the mechanism effects of colchicine on biological cells. In this paper, we present a method for the detection of mechanical properties of nephrocytes (VERO cells), hepatocytes (HL-7702 cells) and hepatoma cells (SMCC-7721 cells) in culture by atomic force microscope (AFM) to analyze the 0.1 µg/mL colchicine-induced effects on the nanoscale for two, four and six hours. Compared to the corresponding control cells, the biomechanical properties of the VERO and SMCC-7721 cells changed significantly and the HL-7702 cells did not considerably change after the treatment when considering the same time period. Based on biomechanical property analyses, the colchicine solution made the VERO and SMCC-7721 cells harder. We conclude that it is possible to reduce the division rate of the VERO cells and inhibit the metastasis of the SMCC-7721 cells. The method described here can be applied to study biomechanics of many other types of cells with different drugs. Therefore, this work provides an accurate and rapid method for drug screening and mechanical analysis of cells in medical research.

Investigation of fullerenol-induced changes in poroelasticity of human hepatocellular carcinoma by AFM-based creep tests.

In this study, atomic force microscopy (AFM) is used to investigate the alterations of the poroelastic properties of hepatocellular carcinoma (SMMC-7721) cells treated with fullerenol. The SMMC-7721 cells were subject to AFM-based creep tests, and a corresponding poroelastic indentation model was used to determine the poroelastic parameters by curve fitting. Comparative analyses indicated that the both permeability and diffusion of fullerenol-treated cells increased significantly while their elastic modulus decreased by a small amount. From the change in the trend of the determined parameter, we verified the corresponding alternations of cytoskeleton (mainly filaments actin), which was reported by the previous study using confocal imaging method. Our investigation on SMMC-7721 cell reveals that the poroelastic properties could provide a better understanding how the cancer cells are affected by fullerenol or potentially other drugs which could find possible applications in drug efficacy test, cancer diagnosis and secure therapies.

Axisymmetric Contact Problem for a Flattened Cell: Contributions of Substrate Effect and Cell Thickness to the Determination of Viscoelastic Properties by Using AFM Indentation.

Nanoindentation technology has proven to be an effective method to investigate the viscoelastic properties of biological cells. The experimental data obtained by nanoindentation are frequently interpreted by Hertz contact model. However, in order to validate Hertz contact model, some studies assume that cells have infinite thickness which does not necessarily represent the real situation. In this study, a rigorous contact model based upon linear elasticity is developed for the interpretation of indentation tests of flattened cells. The cell, normally bonded to the Petri dish, is initially treated as an elastic layer of finite thickness perfectly fixed to a rigid substrate. The theory of linear elasticity is utilized to solve this contact issue and then the solutions are extended to viscoelastic situation which is regarded as a good indicator for mechanical properties of biological cells. To test the present model, AFM-based creep test has been conducted on living human hepatocellular carcinoma cell (SMMC-7721 cell) and its fullerenol-treated counterpart. The results indicate that the present model could not only describe very well the creep behavior of SMMC-7721 cells, but also curb overestimation of the mechanical properties due to substrate effect.

Determination of work of adhesion of biological cell under AFM bead indentation.

Hertz contact theory has been widely used for the determination of cell elasticity based on AFM indentation experiments. In light of the adhesive contact between AFM tip and cell, this study applied Johnson-Kendall-Roberts (JKR) model to fit the indentation force-displacement (F-D) curves reported previously. A MIN6 cell has been modeled as first a sphere and then a flattened cell with different thicknesses. The results have shown that both basic JKR model and "generalized" JKR model can best describe the unloading force-displacement behaviors of the indentation curves. The Young׳s modulus of the cell and the work of adhesion of the cell-indenter interface are obtained. In comparison to the Hertzian contact model, the JKR model provides obviously better fitting to the experimental results, indicating that the adhesion is significant in the cell interaction.

Investigation of work of adhesion of biological cell (human hepatocellular carcinoma) by AFM nanoindentation.

In this study, we presented an investigation of mechanical properties by AFM nanoindentation on human hepatocellular carcinoma cells treated with fullerenol for 24, 48 and 72 h. AFM nanoindentation was routinely applied to investigate the morphology and biomechanical properties of living carcinoma cells, and adhesion phenomena (negative force) were detected in the obtained force-displacement curves. Conventionally, Hertz contact model has been widely used for determination of cell elasticity, however this contact model cannot account for adhesion. Alternatively, JKR contact model, as expected for adhesion circumstance, has been applied to fit the obtained force-displacement curves. In this investigation, we have derived both the work of adhesion and the elastic modulus of biological cells (human hepatocellular carcinoma) under fullerenol treatment. The results show that the chosen JKR model can provide better fitting results than Hertz contact model. The results show that both Young's modulus and work of adhesion exhibit significant variation as the treatment time increases. The calculated mechanical properties of elastic modulus and work of adhesion can be used as an effective bio-index to evaluate the effects of fullerenol or other anticancer agents on cancer cells and thus to provide insight into cancer progression in the treatment.

[Comparison of HBV persistent infection mice models by different serotypes of AAVs carrying HBV genomes].

In recent years, Hepatitis B virus (HBV) persistent infection mouse model with recombinant adeno-associated virus 8 carrying 1.3 copies of HBV genome (rAAV8-1.3HBV) is concerned. We studied and compared the efficacy among HBV persistent infection mice models by other serotypes except AAV8. First, we prepared and purified five viruses: rAAV1-1.3HBV, rAAV2-1.3HBV, rAAV5-1.3HBV, rAAV8-1.3HBV and rAAV9-1.3HBV. Then we injected each virus into 3 C57BL/6J mice with the dose of lx 1011 vg (Viral genome, vg) per mouse. We detected HBsAg and HBeAg in sera by enzyme-linked immunosorbent assay (ELISA) at different time points post injection. We killed mice 8 weeks post injection and took blood and livers for assay. We detected copies of HBV DNA by real-time quantitative PCR in sera and livers. Meantime, we detected HBcAg in the livers of mice by immunohistochemistry and further performed pathology analysis of these livers. The five groups of mice, HBeAg and HBsAg expression sustained 8 weeks in serological detection and HBV DNA was both detected in sera and livers at the time of 8 weeks post injection. HBeAg, HBsAg, HBV DNA copies expression levels in descending order were AAV8>AAV9>AAV1>AAV5>AAV2. HBcAg expression was detected in livers as well. Varied degrees of liver damage were shown in five groups of mice. This study provides more alternative AAV vector species to establish a persistent infection with hepatitis B model.