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Highly Sensitive Poly-N-isopropylacrylamide Microgel-based Electrochemical Biosensor for the Detection of SARS-COV-2 Spike Protein

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Biomedical and Environmental Sciences 2023年第3期36卷 269-278页

作者： CHEN Hao HOU Zhi Yuan CHEN Die LI Ting WANG Yi Ming DE lima marcelo Andrade YANG Ying GUO Zhen Zhong Department of Anaesthesiology Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430030HubeiChina Hubei Province Key Laboratory of Occupational Hazard Identification and Control Wuhan University of Science and TechnologyWuhan 430065HubeiChina Department of Pharmacy Medical CollegeWuhan University of Science and Technology Wuhan 430065HubeiChina School of Public Health Medical CollegeWuhan University of Science and Technology Wuhan 430065HubeiChina School of Life Sciences Keele UniversityStaffordshire ST55BGUK School of Pharmacy and Bioengineering Keele UniversityStaffordshire ST47QBUK

Objective Late 2019 witnessed the outbreak and widespread transmission of coronavirus disease 2019(COVID-19),a new,highly contagious disease caused by novel severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).Consequently,considerable attention has been paid to the development of new diagnostic tools for the early detection of *** In this study,a new poly-N-isopropylacrylamide microgel-based electrochemical sensor was explored to detect the SARS-CoV-2 spike protein(S protein)in human *** microgel was composed of a copolymer of N-isopropylacrylamide and acrylic acid,and gold nanoparticles were encapsulated within the microgel through facile and economical *** electrochemical performance of the sensor was evaluated through differential pulse *** Under optimal experimental conditions,the linear range of the sensor was 10-13-10-9 mg/m L,whereas the detection limit was 9.55 fg/***,the S protein was instilled in artificial saliva as the infected human saliva model,and the sensing platform showed satisfactory detection *** The sensing platform exhibited excellent specificity and sensitivity in detecting spike protein,indicating its potential application for the time-saving and inexpensive detection of SARS-CoV-2.

关键词： Microgel SARS-CoV-2 Spike protein Detection

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Synthesis of highly fluorescent carbon dots from lemon and onion juices for determination of riboflavin in multivitamin/mineral supplements

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Journal of Pharmaceutical Analysis 2019年第3期9卷 209-216页

作者： Severino S. Monte-Filho Stefani I.E. Andrade marcelo B. lima Mario C.U. Araujo Universidade Federal da Paraíba CCEN Departamento de Química P.O. Box 5093 Zip Code 58051-970 Joao Pessoa PB Brazil Universidade Federal Rural de Pernambuco-Unidade Acad^emica de Serra Talhada UAST Zip Code 56909-535 Serra Talhada PE Brazil

In this work, lemon and onion biomasses commonly found in street markets are for the first time used to develop a facile, fast and low-cost one-step microwave-assisted carbonization method for synthesis of highly fluorescent carbon dots (CDs). The structure and optical properties of CDs were investigated by TEM, XRD, XRF, UV-Vis, FTIR, and fluorescence spectroscopy. CDs displayed satisfactory optical pro-prieties, a high quantum yield of 23.6%, and excellent water solubility, and the particle size was 4.23-8.22 nm with an average diameter of 6.15 nm. An efficient fluorescent resonance energy transfer (FRET) between the CDs and riboflavin was achieved with CDs acting as donor and riboflavin as acceptor. A linear relationship between FRET and the riboflavin concentration from 0.10 to 3.0 μg/mL was observed, allowing the development of an accurate and fast analytical method to determine this vitamin in multivitamin/mineral supplements. Despite the potential interferences in these supplements, CDs were selective for riboflavin under optimized conditions. A paired t-test at a 95% confidence level indicated no statistically significant difference between the proposed and the reference methods. Recovery test presented values ranged from 96.0% to 101.4%. The limit of detection and relative standard deviation were estimated at 1.0 ng/mL and <2.6% (n = 3), respectively. CDs were successfully synthesized in a domestic microwave oven (1450 W, 6 min), presenting satisfactory parameters when compared with results of other studies reported in the literature, suggesting that the proposed method is a potentially useful method for the synthesis of CDs and determination of riboflavin.

关键词： Carbon dots Microwave-assisted carbonization Lemon-onion juice Riboflavin Multivitamin/mineral supplements Fluorescence

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Epigenetic regulation of DNA repair machinery in Helicobacter pylori-induced gastric carcinogenesis

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World Journal of Gastroenterology 2015年第30期21卷 9021-9037页

作者： Juliana Carvalho Santos marcelo lima Ribeiro Sao Francisco University Medical School Clinical Pharmacology and Gastroenterology Unit Laboratory of Microbiology and Molecular Biology UNICAMP Universidade Estadual de CampinasGenetics and Molecular Biology

Although thousands of DNA damaging events occur in each cell every day,efficient DNA repair pathways have evolved to counteract them. The DNA repair machinery plays a key role in maintaining genomic stability by avoiding the maintenance of mutations. The DNA repair enzymes continuously monitor the chromosomes to correct any damage that is caused by exogenous and endogenous mutagens. If DNA damage in proliferating cells is not repaired because of an inadequate expression of DNA repair genes,it might increase the risk of cancer. In addition to mutations,which can be either inherited or somatically acquired,epigenetic silencing of DNA repair genes has been associated with carcinogenesis. Gastric cancer represents the second highest cause of cancer mortality worldwide. The disease develops from the accumulation of several genetic and epigenetic changes during the lifetime. Among the risk factors,Helicobacter pylori(H. pylori) infection is considered the main driving factor to gastric cancer development. Thus,in this review,we summarize the current knowledge of the role of H. pylori infection on the epigenetic regulation of DNA repair machinery in gastric carcinogenesis.

关键词： Helicobacter pylori DNA repair Epigenetic DNA methylation Gastric cancer Histone modification

Adenosine A1 receptor activation inhibits histamine release in gastric enterochromaffin-like cells

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BIOCELL 2015年第2期39卷 5-8页

作者： Rafael Martins de OLIVEIRA Carolina Bernardi STEFANI Angélica Aparecida Antoniellis SILVEIRA marcelo lima RIBEIRO Alessandra GAMBERO Clinical Pharmacology and Gastroenterology Unit São Francisco University Medical SchoolBragança PaulistaSPBrazil.

Adenosine acts as a gastroprotective factor decreasing inflammation and reducing gastric acid secretion. Quantitative RT-PCR was used to determine the expression of the adenosine receptor genes (A1AR, A2AAR, A2BAR and A3AR) and that of the gastrin receptor B gene (CCKBR) in isolated, short-term cultured enterochromaffin-like (ECL) cells. Both the A1AR and the CCKBR genes were expressed at a level high-er than the other genes. Also, the effect of 2-chloroadenosine, a stable agonist of A1 and A2A receptors, was explored on ECL cells, with a resulting inhibition of both basal and gastrin-stimulated histamine release. Also, dipropylcyclopentylxanthine (DPCPX), a selective A1 antagonist, prevented the inhibitory effects of 2-chloro-adenosine, suggesting the effect of 2-chloroadenosine is mediated by A1 receptors. It is concluded that isolated, short-term cultured ECL cells are a suitable model for studies relating gene expression and function, and that the gastroprotective actions of adenosine are at least partly mediated through A1 receptors.

关键词： Gastrin 2-chloroadenosine DPCPX

Downregulation of TNFR2 decreases survival gene expression,promotes apoptosis and affects the cell cycle of gastric cancer cells

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World Journal of Gastroenterology 2022年第24期28卷 2689-2704页

作者： Ana Flávia Teixeira Rossi Fernanda da Silva Manoel-Caetano Joice Matos Biselli Ágata Silva Cabral Marilia de Freitas Calmon Saiki marcelo lima Ribeiro Ana Elizabete Silva Department of Biological Sciences Sao Paulo State University(UNESP)São Josédo Rio Preto 15054-000São PauloBrazil Clinical Pharmacology and Gastroenterology Unit São Francisco University(USF)Bragança Paulista 12916-900São PauloBrazil

BACKGROUND Chronic inflammation due to Helicobacter pylori(***)infection promotes gastric *** necrosis factor-α(TNF-α),a key mediator of inflammation,induces cell survival or apoptosis by binding to two receptors(TNFR1 and TNFR2).TNFR1 can induce both survival and apoptosis,while TNFR2 results only in cell *** dysregulation of these processes may contribute to *** To evaluate the effects of TNFR1 and TNFR2 downregulation in AGS cells treated with *** extract on the TNF-α*** AGS cell lines containing TNFR1 and TNFR2 receptors downregulated by specific shRNAs and nonsilenced AGS cells were treated with *** extract for 6 ***,quantitative polymerase chain reaction with TaqMan®assays was used for the relative quantification of the mRNAs(TNFA,TNFR1,TNFR2,TRADD,TRAF2,CFLIP,NFKB1,NFKB2,CASP8,CASP3)and miRNAs(miR-19a,miR-34a,miR-103a,miR-130a,miR-181c)related to the TNF-αsignalling *** cytometry was employed for cell cycle analysis and apoptosis *** In nonsilenced AGS cells,*** extract treatment increased the expression of genes involved in cell survival and inhibited both apoptosis(NFKB1,NFKB2 and CFLIP)and the TNFR1 ***1 downregulation significantly decreased the expression of the TRADD and CFLIP genes,although no change was observed in the cellular process or miRNA *** contrast,TNFR2 downregulation decreased the expression of the TRADD and TRAF2 genes,which are both important downstream mediators of the TNFR1-mediated pathway,as well as that of the NFKB1 and CFLIP genes,while upregulating the expression of miR-19a and ***,a reduction in the number of cells in the G0/G1 phase and an increase in the number of cells in the S phase were observed,as well as the promotion of early *** Our findings mainly highlight the important role of TNFR2 in the TNF-αpathway in gastric cancer,indicating that silencing it can reduce the

关键词： Gastric cancer Helicobacter pylori Tumour necrosis factor-αsignalling pathway TNFR1 TNFR2 miRNAs

Hepcidin expression in colon during trinitrobenzene sulfonic acid-induced colitis in rats

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World Journal of Gastroenterology 2014年第15期20卷 4345-4352页

作者： Erica Martins Ferreira Gotardo Gilberto de Almeida Ribeiro Thayane Rodrigues Leite Clemente Camila Henrique Moscato Renata Bortolin Guerra Tome Thalita Rocha Jose Pedrazzoli Jr marcelo lima Ribeiro Alessandra Gambero Clinical Pharmacology and Gastroenterology Unit Sao Francisco University Medical SchoolBraganca PaulistaSP 12916-900Brazil

AIM:To investigate hepcidin expression,interleukin-6(IL-6)production and iron levels in the rat colon in the presence of trinitrobenzene sulfonic acid(TNBS)-induced ***:In rats,we evaluated the severity of colitis induced by repeated TNBS administration using macroscopic and microscopic scoring systems and myeloperoxidase activity *** colonic levels of hepcidin,tumor necrosis factor alpha(TNF-α),IL-10 and IL-6 were measured by Enzyme-Linked Immunosorbent Assay,and hepcidin-25 expression and iron deposition were analyzed by immunohistochemistry and the Prussian blue reaction,***-3 phosphorylation was assessed by Western blot *** parameters,iron and transferrin levels,and transferrin saturation were also ***,the ability of iron,pathogen-derived molecules and IL-6 to induce hepcidin expression in HT-29 cells was ***:Repeated TNBS administration to rats resulted in macroscopically and microscopically detectable colon lesions and elevated colonic myeloperoxidase ***-25 protein levels were increased in colonic surface epithelia in colitic rats(10.2±4.0pg/mg protein vs 71.0±8.4 pg/mg protein,P<0.01).Elevated IL-6 levels(8.2±1.7 pg/mg protein vs 14.7±0.7 pg/mg protein,P<0.05),TNF-αlevels(1.8±1.2pg/mg protein vs 7.4±2.1 pg/mg protein,P<0.05)and Stat-3 phosphorylation were also *** alterations in iron homeostasis,hepcidin levels and anemia were not detected in colitic *** deposition in the colon was only observed during *** gene expression was increased in HT-29 cells after IL-6 and lipopolysaccharide[a toll-like receptor 4(TLR-4)ligand]***,ferric citrate and peptidoglycan(a TLR-2 ligand)were unable to alter the in vitro expression of hepcidin in HT-29 ***:Colitis increased local hepcidin-25 expression,which was associated with the IL-6/Stat-3 signaling *** increase in local iron sequestration was also

关键词： Hepcidin-25, Interleukin-6, Iron, Stat-3, Anemia, Toll-like receptor 4

Role of pentoxifylline in non-alcoholic fatty liver disease in high-fat diet-induced obesity in mice

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World Journal of Hepatology 2015年第24期7卷 2551-2558页

作者： Simone Coghetto Acedo Cintia Rabelo e Paiva Caria érica Martins Ferreira Gotardo José Aires Pereira José Pedrazzoli marcelo lima Ribeiro Alessandra Gambero Clinical Pharmacology and Gastroenterology Unit Sao Francisco University Medical School

AIM:To study pentoxifylline effects in liver and adipose tissue inflammation in obese mice induced by high-fat diet(HFD).METHODS: Male swiss mice(6-wk old) were fed a highfat diet(HFD; 60% kcal from fat) or AIN-93(control diet; 15% kcal from fat) for 12 wk and received pentoxifylline intraperitoneally(100 mg/kg per day) for the last 14 d. Glucose homeostasis was evaluated by measurements of basal glucose blood levels and insulin tolerance test two days before the end of the protocol. Final body weight was assessed. Epididymal adipose tissue was collected and weighted for adiposity evaluation. Liver and adipose tissue biopsies were homogenized in solubilization buffer and cytokines were measured in supernatant by enzyme immunoassay or multiplex kit, respectively. Hepatic histopathologic analyses were performed in sections of paraformaldehyde-fixed, paraffin-embedded liver specimens stained with hematoxylin-eosin by an independent pathologist. Steatosis(macrovesicular and microvesicular), ballooning degeneration and inflammation were histopathologically determined. Triglycerides measurements were performed after lipid extraction in liver tissue. RESULTS: Pentoxifylline treatment reduced microsteatosis and tumor necrosis factor(TNF)-α in liver(156.3 ± 17.2 and 62.6 ± 7.6 pg/mL of TNF-α for non-treated and treated obese mice, respectively; P < 0.05). Serum aspartate aminotransferase levels were also reduced(23.2 ± 6.9 and 12.1 ± 1.6 U/L for nontreated and treated obese mice, respectively; P < 0.05) but had no effect on glucose homeostasis. In obese adipose tissue, pentoxifylline reduced TNF-α(106.1 ± 17.6 and 51.1 ± 9.6 pg/mL for non-treated and treated obese mice, respectively; P < 0.05) and interleukin-6(340.8 ± 51.3 and 166.6 ± 22.5 pg/mL for non-treated and treated obese mice, respectively; P < 0.05) levels; however, leptin(8.1 ± 0.7 and 23.1 ± 2.9 ng/mL for non-treated and treated lean mice, respectively; P < 0.05) and plasminogen activator inhibitor-1(600.2 ± 32.3

关键词： Pentoxifylline Steatosis Obesity Adipose tissue Adipokine Tumor necrosis factor-α

Multimodal brain monitoring in fulminant hepatic failure

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World Journal of Hepatology 2016年第22期8卷 915-923页

作者： Fernando Mendes Paschoal Jr Ricardo Carvalho Nogueira Karla De Almeida Lins Ronconi marcelo de lima Oliveira Manoel Jacobsen Teixeira Edson Bor-Seng-Shu Laboratory for Neurosonology and Cerebral Hemodynamics Department of Neurology Hospital das Clinicas Sao Paulo University Medical School Department of Neurology Division of Neurosurgery Hospital das Clinicas Sao Paulo University Medical School

Acute liver failure, also known as fulminant hepatic failure(FHF), embraces a spectrum of clinical entities characterized by acute liver injury, severe hepatocellular dysfunction, and hepatic encephalopathy. Cerebral edema and intracranial hypertension are common causes of mortality in patients with FHF. The management of patients who present acute liver failure starts with determining the cause and an initial evaluation of prognosis. Regardless of whether or not patients are listed for liver transplantation, they should still be monitored for recovery, death, or transplantation. In the past, neuromonitoring was restricted to serial clinical neurologic examination and, in some cases, intracranial pressure monitoring. Over the years, this monitoring has proven insufficient, as brain abnormalities were detected at late and irreversible stages. The need for real-time monitoring of brain functions to favor prompt treatment and avert irreversible brain injuries led to the concepts of multimodal monitoring and neurophysiological decision support. New monitoring techniques, such as brain tissue oxygen tension, continuous electroencephalogram, transcranial Doppler, and cerebral microdialysis, have been developed. These techniques enable early diagnosis of brain hemodynamic, electrical, and biochemical changes, allow brain anatomical and physiological monitoring-guided therapy, and have improved patient survival rates. The purpose of this review is to discuss the multimodality methods available for monitoring patients with FHF in the neurocritical care setting.

关键词： Fulminant hepatic failure Cerebral edema Multimodality methods Intracranial hypertension Liver transplantation

Inhibition of BACE1, the β-secretase implicated in Alzheimer’s disease, by a chondroitin sulfate extract from Sardina pilchardus

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Neural Regeneration Research 2020年第8期15卷 1546-1553页

作者： Courtney J.Mycroft-West Anthony J.Devlin Lynsay C.Cooper Patricia Procter Gavin J.Miller David G.Fernig Marco Guerrini Scott E.Guimond marcelo A.lima Edwin A.Yates Mark Andrew Skidmore Molecular&Structural Biosciences School of Life SciencesKeele UniversityHuxley BuildingKeeleStaffordshireST55BGUK Lennard-Jones Laboratory School of Chemical and Physical SciencesKeele UniversityKeeleStaffordshireST55BGUK Department of Biochemistry Institute of Integrative BiologyUniversity of LiverpoolCrown StreetLiverpoolL697ZBUK Istituto di Ricerche Chimiche e Biochimiche G.Ronzoni Via G.Colombo 8120133 MilanItaly School of Medicine KeeleStaffordshireST55BGUK

The pharmaceutical and anticoagulant agent heparin,a member of the glycosaminoglycan family of carbohydrates,has previously been identified as a potent inhibitor of a key Alzheimer’s disease drug target,the primary neuronalβ-secretase,β-site amyloid precursor protein cleaving enzyme 1(BACE1).The anticoagulant activity of heparin has,however,precluded the repurposing of this widely used pharmaceutical as an Alzheimer’s disease ***,a glycosaminoglycan extract,composed predominantly of 4-sulfated chondroitin sulfate,has been isolated from Sardina pilchardus,which possess the ability to inhibit BACE1(IC50[half maximal inhibitory concentration]=4.8μg/mL),while displaying highly attenuated anticoagulant activities(activated partial thromboplastin time EC50[median effective concentration]=403.8μg/mL,prothrombin time EC50=1.3 mg/mL).The marine-derived,chondroitin sulfate extract destabilizes BACE1,determined via differential scanning fluorimetry(ΔTm–5°C),to a similar extent as heparin,suggesting that BACE1 inhibition by glycosaminoglycans may occur through a common mode of action,which may assist in the screening of glycan-based BACE1 inhibitors for Alzheimer’s disease.

关键词： amyloid-β aspartyl protease carbohydrates galactosaminoglycans heparan sulfate heparin marine polysaccharide pilchards sardines therapeutics

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