Dual-target nucleic acid sequences responsive electrochemiluminescence biosensor using single type carbon dots as probe for SARS-CoV-2 detection based on series catalytic hairpin assembly amplification.

Severe acute respiratory syndrome coronavirus (SARS-CoV-2) is rampant all over the world, and rapid and effective virus detection is the best auxiliary to curb the spread of the epidemic. A diagnosis can only be made if two or more different nucleic acid sequences are confirmed at the same time, and in most of traditional detection technologies, these target sequences have been detected separately. In this work, an electrochemiluminescent (ECL) biosensor employing a single ECL probe as signal output and responding to dual-target simultaneously is proposed for the first time. Taking the two sequences located in ORF 1ab region and N region of SARS-CoV-2 gene sequence as the model target and nitrogen doped carbon quantum dots (CDs) as ECL beacon, supplemented with catalytic hairpin assembly (CHA) reaction for signal amplification, the presented strategy has been successfully applied to the rapid detection of SARS-CoV-2. The developed SARS-CoV-2 biosensor based on the series CHA systems can realize the quantitative determination of SARS-CoV-2 in the range of 50 fM to 200 pM within 40 min. Moreover, the clinical validity of this method has been verified by the high consistency between the detection results of using this method and those using RT-qPCR for seven clinical pharyngeal swab samples.

Circ_0000284: A risk factor and potential biomarker for prehypertension and hypertension.

CircRNAs have been shown to be involved in the development of certain diseases, but their application in prehypertension and hypertension remains unclear. We aimed to explore the potential role of circ_0000284 in revealing the molecular regulatory mechanisms of prehypertension and hypertension. We enrolled a total of 100 patients with normal blood pressure, 100 patients with prehypertension and 100 patients with hypertension. The expression of circ_0000284 among the groups was detected by real-time fluorescence quantitative polymerase chain reaction (qRT‒PCR). Multivariate logistic models were constructed combining conventional risk factors with circ_0000284. A receiver operating characteristic curve (ROC) was used to analyze the diagnostic value of circRNAs in the clinical model. Spearman correlation was used to analyze the correlation of circ_0000284 and the biochemical characteristics of all subjects. The results showed that circ_0000284 was differentially expressed among the normal blood pressure group, prehypertensive group and hypertensive group and showed a significantly upregulated trend in the progression to hypertension (P < 0.05). The ROC curve revealed a high diagnostic ability of circ_0000284 in hypertension in the clinical model (AUC = 0.812). Circ_0000284 also presented a certain ability for early diagnosis of prehypertension (AUC = 0.628). Spearman correlation showed that circ_0000284 was positively correlated with Na and CKMB. Our study suggested that upregulated expression of circ_0000284 was an independent risk factor for prehypertension and hypertension. Circ_0000284 was a potential fingerprint for the early diagnosis of hypertension and distinguished the intermediate stage of hypertension development. Moreover, our study provided new insight into the correlation between circ_0000284 and cardiac injury in the progression to hypertension.

A Ratiometric Fluorescence Probe for Selective Detection of ex vivo Methylglyoxal in Diabetic Mice.

Accurate monitoring of methylglyoxal (MGO) at cell and living level was crucial to reveal its role in the pathogenesis of diabetes since MGO was closely related to diabetes. Herein, a ratiometric fluorescence strategy was constructed based on the capture probe 2,3-diaminonaphthalene (DAN) for the specific detection of MGO. Compared to the fluorescent probes with a single emission wavelength, the ratiometric mode by monitoring two emissions can effectively avoid the interference from the biological background, and provided additional self-calibration ability, which can realize accurate detection of MGO. The proposed method showed a good linear relationship in the range of 0-75 µm for MGO detection, and the limit of detection was 0.33 µm. DAN responded to MGO with good specificity and was successfully applied for detecting the ex vivo MGO level in plasma of KK-Ay mice as a type II diabetes model. Besides, the prepared DAN test strip can be visualized for rapid semi-quantitative analysis of MGO using the naked eye. Furthermore, human skin fibroblasts and HeLa cells were utilized for exogenous MGO imaging, and ex vivo MGO imaging was performed on tissues of KK-Ay mice. All results indicated that the DAN-based ratiometric fluorescence probe can be used as a potential method to detect the level of MGO, thus enabling indications for the occurrence of diabetes and its complications.

Exhausting T Cells During HIV Infection May Improve the Prognosis of Patients with COVID-19.

T-cell reduction is an important characteristic of coronavirus disease 2019 (COVID-19), and its immunopathology is a subject of debate. It may be due to the direct effect of the virus on T-cell exhaustion or indirectly due to T cells redistributing to the lungs. HIV/AIDS naturally served as a T-cell exhaustion disease model for recognizing how the immune system works in the course of COVID-19. In this study, we collected the clinical charts, T-lymphocyte analysis, and chest CT of HIV patients with laboratory-confirmed COVID-19 infection who were admitted to Jin Yin-tan Hospital (Wuhan, China). The median age of the 21 patients was 47 years [interquartile range (IQR) = 40-50 years] and the median CD4 T-cell count was 183 cells/µl (IQR = 96-289 cells/µl). Eleven HIV patients were in the non-AIDS stage and 10 were in the AIDS stage. Nine patients received antiretroviral treatment (ART) and 12 patients did not receive any treatment. Compared to the reported mortality rate (nearly 4%-10%) and severity rate (up to 20%-40%) among COVID-19 patients in hospital, a benign duration with 0% severity and mortality rates was shown by 21 HIV/AIDS patients. The severity rates of COVID-19 were comparable between non-AIDS (median CD4 = 287 cells/µl) and AIDS (median CD4 = 97 cells/µl) patients, despite some of the AIDS patients having baseline lung injury stimulated by HIV: 7 patients (33%) were mild (five in the non-AIDS group and two in the AIDS group) and 14 patients (67%) were moderate (six in the non-AIDS group and eight in the AIDS group). More importantly, we found that a reduction in T-cell number positively correlates with the serum levels of interleukin 6 (IL-6) and C-reactive protein (CRP), which is contrary to the reported findings on the immune response of COVID-19 patients (lower CD4 T-cell counts with higher levels of IL-6 and CRP). In HIV/AIDS, a compromised immune system with lower CD4 T-cell counts might waive the clinical symptoms and inflammatory responses, which suggests lymphocyte redistribution as an immunopathology leading to lymphopenia in COVID-19.

Clinical characteristics of non-ICU hospitalized patients with coronavirus disease 2019 and liver injury: A retrospective study.

BACKGROUND & AIMS: Coronavirus disease 2019 (COVID-19) has raised world concern for global epidemic since December, 2019. Limited data are available for liver function in COVID-19 patients. We aimed to investigate the risk factors related to liver injury in the COVID-19 patients. METHODS: A retrospective study was performed in non-ICU Ward at Jinyintan Hospital from February 2, 2020 to February 23, 2020. Consecutively confirmed COVID-19 discharged cases were enrolled. The clinical characteristics of patients with liver injury and without liver injury were compared. RESULTS: A total of 79 COVID-19 patients were included. 31.6%, 35.4% and 5.1% COVID-19 patients had elevated levels of alanine transaminase (ALT), aspartate aminotransferase (AST) and bilirubin respectively. Median value of ALT, AST and bilirubin for entire cohort was 36.5 (17.5 ~ 71.5) U/L, 34.5 (25.3 ~ 55.3) U/L and 12.7 (8.1 ~ 15.4) mmol/L respectively. There were no significant differences in age, previous medical history and symptoms between the two groups. Males were more likely to have liver injury when infected with COVID-19 (P < .05); compared with patients without liver injury, patients with liver injury had increased levels of white blood cell counts, neutrophils, CRP and CT score (P < .05) and had a longer length of stay (P < .05). Logistic regression analyses suggested that the extent of pulmonary lesions on CT was a predictor of liver function damage (P < .05). CONCLUSIONS: Liver injury is common in non-ICU hospitalized COVID-19 patients. It may be related to systemic inflammation. Intense monitoring and evaluation of liver function in patients with severe pulmonary imaging lesions should be considered.

Relationship between components of metabolic syndrome and arterial stiffness in Chinese hypertensives.

Background: Subjects with metabolic syndrome showed increased risk of cardiovascular events. We investigated the relationship between components of metabolic syndrome and arterial stiffness in Chinese hypertensives.Method: 680 subjects (aged 58.44 ± 11.67 years, male 63.53%, hypertension 65.00%) were divided into five groups based on the number of known components of metabolic syndrome (MSCs) according to the criteria of 2010 Chinses Guidelines for Prevention and Management of Hypertension (0MSCs: n= 86; 1MSCs: n= 153; 2MSCs: n= 201; 3MSCs: n= 148; 4/5MSCs: n= 92.). Body weight, height, waist circumference, blood pressure and clinical biochemical tests were measured. Carotid-femoral pulse wave velocity (cfPWV) was measured using a non-invasive automatic device (Complior Analysis, France).Results: The level of cfPWV was significantly increased with the increasing number of MSCs (8.20 ± 1.54 vs 8.72 ± 1.48 vs 9.34 ± 1.77 vs 9.64 ± 1.86 vs 9.91 ± 2.19 m/s, P<0.05). In subjects with hypertension (n= 442), cfPWV was higher than those without hypertension (n= 238) (9.59 ± 1.90 vs 8.49 ± 1.50 m/s, P<0.05) . Stepwise multiple regression analysis revealed that age, gender, the number of MSCs, heart rate as well as serum uric acid level were determinants for cfPWV (P<0.05). In the subgroups stratified by age, systolic blood pressure correlated with cfPWV in hypertensives under 55 years old, while in non-hypertensives the correlation was found after 60 years old.Conclusion: The arterial stiffness became significant with the increasing of the metabolic components numbers, which was independent of age, gender and blood pressure. And the presence of hypertension played the most important role in the progress of arterial stiffness even compared with age.

Electrochemiluminescence biosensor for miRNA-21 based on toehold-mediated strand displacement amplification with Ru(phen)32+ loaded DNA nanoclews as signal tags.

A novel electrochemiluminescence (ECL) biosensor was developed for high sensitive and selective detection of miRNA-21 based on the efficient and specific toehold-mediated strand displacement (TMSD) amplification with Ru(phen)32+ loaded DNA nanoclews (NCs-Ru(phen)32+) as signal tags. The stable DNA nanoclews, synthesized by a simple rolling circle amplification reaction, were employed to load with Ru(phen)32+ efficiently as ECL signal tags to amplify the signals. As for TMSD, the substrate strand (Sub) was initially hybridized with P1 and P2 to form DNA duplex structures with a toehold 1. miRNA-21 could hybridize with the toehold 1 and trigger the TMSD amplification with the help of assist strand, releasing lots of P1 stands from DNA duplex structures. The TMSD technique realized the converting and amplification of the single miRNA-21 input to lots of output DNA (namely P1) with good selectivity, simultaneously. Output P1 were designed to expand the stem-locked region of HP, which were immobilized on the Au electrodes firstly. Subsequently, the opened HP could hybridize with the Ru(phen)32+, capturing the ECL signal tags closed to the sensing surface. The ECL intensity of the system had a linear relationship with the logarithm of the miRNA-21 concentration in the range of 1.0 fM to 100 pM with a limit of detection of 0.65 fM. The strategy was further applied to detect miRNA-21 in complex samples, and the result was consistent with the qRT-PCR.

Association of homocysteine with carotid-femoral pulse wave velocity in a southern Chinese population.

This study aimed to investigate whether plasma homocysteine levels were associated with carotid-femoral pulse wave velocity (cfPWV), a golden standard of arterial stiffness, in a population from southern China. A cross-sectional study was conducted on 713 patients admitted to the First Affiliated Hospital of Fujian Medical University from February 2016 to August 2017. They were divided into four groups based on gender-specific quartile of homocysteine levels. Age, cfPWV, uric acid levels, and percentage of hypertension increased with ascending quartiles. The duration of hypertension and systolic blood pressure were higher in the highest quartile than in the lowest quartile. Pearson's correlation analysis and multivariate regression showed a correlation of homocysteine levels with cfPWV. A nearly twofold increased risk of cfPWV ≥10 m/s was observed in the highest quartile compared with the lowest quartile (in the highest quartile: odds ratio = 2.917, 95% confidence interval: 1.635-5.202, P < 0.001). After stratification, this correlation was present in both sexes, in patients aged over 65 years, and those with hypertension. The plasma homocysteine levels were independently associated with cfPWV in the population from southern China, especially in the elderly and those with hypertension.

A sensitive fluorescent sensor for quantification of alpha-fetoprotein based on immunosorbent assay and click chemistry.

A novel fluoresencent immunosensor for determination of cancer biomarkers such as alpha-fetoprotein (AFP) was designed by utilizing both the high specificity of antigen-antibody sandwich structure and the high sensitivity of the click chemistry based fluorescence detection. Instead of an enzyme or fluorophore, the CuO nanoparticles are labeled on the detection antibody, which was not susceptible to the change of the external environments. The CuO nanoparticles which were modified on the sandwich structure can be dissolved to produce Cu(2+) ions with the help of HCl and then the Cu(2+) ions were reduced by sodium ascorbate to produce Cu(+) ions which triggered the Cu(+) catalyzed alkyne-azide cycloaddition (CuAAC) reaction between the weak fluorescent compound (3-azido-7-hydroxycoumarin) and propargyl alcohol to form a strong fluorescent compound. A good linear relationship was observed between the fluorescence increase factor of the system and the concentration of AFP in the range of 0.025-5.0 ng/mL with a detection limit of 12 pg/mL (S/N=3). The proposed fluorescent sensor had been applied to detect AFP in the human serum samples and gave satisfactory results.