MyMedR

Displaying publications 21 - 40 of 51 in total

Abstract:

Sort:

Soluble dietary fiber from Prunus persica dregs alleviates gut microbiota dysfunction through lead excretion

Yao M, Guo X, Shao X, Wei Y, Zhang X, Wang H, et al.

Food Chem Toxicol, 2023 May;175:113725.
PMID: 36925041 DOI: 10.1016/j.fct.2023.113725

Lead (Pb) can pollute the environment and food through air, water and other means, resulting in human exposure to lead pollution, and there is no threshold level of lead toxicity, even small doses of lead will have a range of harmful effects in humans. This study demonstrates for the first time that dietary addition of soluble dietary fiber (SDF) from Prunus persica dregs reduces lead bioaccumulation in mice, and eliminates lead through feces. Compared with lead-exposed mice, SDF supplementation effectively prevented lead-induced changes in colon tissue, and increased expression of tight junction proteins (ZO-1 and occludin). We analyzed the effects of SDF on gut microbiota and metabolites by a combination of 16S rRNA high-throughput sequencing and untargeted metabolomics. The results showed that SDF altered lead-induced perturbations in the layout and structure of the gut microbiota, including increased Desulfovibrio and Alistipes abundance and decreased Bacteroidetes abundance. Meanwhile, we also provide evidence that SDF supplementation alters the levels of amino acids, bile acids, and lipids in the gut, and that these metabolites are closely associated with microbiota with good lead binding capacity. Therefore, we speculate that SDF has the potential to provide a protective effect against intestinal damage by promoting lead excretion.
Fulltext Effects of tai chi on postural balance and quality of life among the elderly with gait disorders: A systematic review

Xu F, Soh KG, Chan YM, Bai XR, Qi F, Deng N

PLoS One, 2023;18(9):e0287035.
PMID: 37768953 DOI: 10.1371/journal.pone.0287035

BACKGROUND: Tai Chi is good for improving the physical fitness of older adults. But few studies have reported the effects of Tai Chi on the postural balance and quality of life of older adults with gait disorders.
OBJECTIVE: This review aimed to assess the influence of tai chi on postural stability and quality of life in older adults with abnormal gait.
METHOD: According to the literature retrieval principles, the works published from the inception date to May 2023 were retrieved, including the following databases: PubMed, Scopus, Web of Science, China National Knowledge Infrastructure, EBSCOhost, and Google Scholar. Subsequently, literature screening and quality assessment were performed.
RESULTS: A total of 16 randomized controlled trials were included in this study, Tai Chi intervention can affect populations with Parkinson's disease (PD), no exercise, mild cognitive impairment (MCI), chronic stroke, sedentary, fear of falling, or history of falling. Postural instability is associated with balance, gait, the Unified Parkinson's Disease Rating Scale Motor Subscale 3 (UPDRS III), mobility, lower body strength, and falls. Only two articles looked at quality of life. The Yang style is the most commonly used in the intervention. Nonetheless, most studies were performed on female participants, hence, more research on older male populations is needed.
CONCLUSION: Tai Chi intervention benefits postural balance in patients with gait disorders. 12 weeks is the most common intervention period for patients with gait disorders. The frequency of intervention is seven articles twice a week, and the intervention time is about 60 minutes. The Tai Chi intervention methods in this study involve Yang Style, Sun Style, Taoist Tai Chi, and Health Qigong Tai Chi, but the Yang Style Tai Chi intervention is the most widely used.
Influences of flavonoids from Sedum aizoon L. on biofilm formation of Pseudomonas fragi

Wang H, Ge Q, Shao X, Wei Y, Zhang X, Wang H, et al.

Appl Microbiol Biotechnol, 2023 Apr 20.
PMID: 37079063 DOI: 10.1007/s00253-023-12526-z

Pseudomonas fragi (P. fragi) is one of the main categories of bacteria responsible for the spoilage of chilled meat. In the processing and preservation of chilled meat, it is easy to form biofilms on the meat, leading to the development of slime on the meat, which becomes a major quality defect. Flavonoids, as one of the critical components of secondary plant metabolites, are receiving increasing attention for their antibacterial activity. Flavonoids in Sedum aizoon L. (FSAL), relying on its prominent antibacterial activity, are of research importance in food preservation and other applications. This article aims to investigate the effect of FSAL on the biofilm formation of P. fragi, to better apply FSAL to the processing and preservation of meat products. The disruption of cellular structure and aggregation properties by FSAL was demonstrated by the observation of the cellular state within the biofilm. The amount of biofilm formation was determined by crystal violet staining, and the content of polysaccharides and proteins in the extracellular wrapped material was determined. It was shown that the experimental concentrations of FSAL (1.0 MIC) was able to inhibit biofilm formation and reduce the main components in the extracellular secretion. The swimming motility assay and the downregulation of flagellin-related genes confirmed that FSAL reduced cell motility and adhesion. The downregulation of cell division genes and the lowering of bacterial metabolic activity suggested that FSAL could hinder bacterial growth and reproduction within P. fragi biofilms. KEY POINTS: • FSAL inhibited the activity of Pseudomonas fragi in the dominant meat strain • The absence of EPS components affected the formation of P. fragi biofilms • P. fragi has reduced adhesion capacity due to impaired flagellin function.
Inhibitory Mechanism of Flavonoids from Sedum aizoon L. on Rhizopus nigricans

Ge Q, Wang K, Shao X, Wei Y, Zhang X, Liu Y, et al.

Foodborne Pathog Dis, 2023 May;20(5):197-208.
PMID: 37172299 DOI: 10.1089/fpd.2022.0083

Rhizopus nigricans is a widespread phytopathogen in fruits and vegetables that can cause considerable economic effects and resource waste. Flavonoids from Sedum aizoon L. (FSAL) have specific antifungal activities. This study selected FSAL as an antifungal to prolong the preservation of fruits and vegetables. The results showed that the mycelial morphology and ultrastructure were damaged by the FSAL treatment (1.0 minimum inhibitory concentration), led to the increase of reactive oxygen species and malondialdehyde, and affected the activity of key enzymes in the glycolytic pathway, such as lactic dehydrogenase, pyruvate kinase, and hexokinase of R. nigricans. Key genes in glycolysis were upregulated or downregulated. In addition, in the treatment and control groups, 221 differentially expressed genes were found, including 89 that were upregulated and 32 that were downregulated, according to the transcriptome results. The differential genes were mainly enriched in glycolysis, pyruvate metabolism, and citrate cycle pathways. The results revealed some insights into the antifungal mechanism of FSAL against R. nigricans and offered a theoretical foundation for its advancement as a novel plant-derived antifungal agent.
PpBZR1, a BES/BZR transcription factor, enhances cold stress tolerance by suppressing sucrose degradation in peach fruit

Zhang S, Cao K, Wei Y, Jiang S, Ye J, Xu F, et al.

Plant Physiol Biochem, 2023 Sep;202:107972.
PMID: 37611487 DOI: 10.1016/j.plaphy.2023.107972

Brassinosteroids (BRs) are phytohormones that play numerous roles in a plant's response to environmental stress. While BES/BZR transcription factors are essential components in BR signaling, their role in regulating postharvest fruit responses to cold stress is largely unknown. In this study, the application of 24-epibrassinolide (EBR) to peaches alleviated chilling injury (CI) during postharvest cold storage. We further characterized a key BES/BZR gene, PpBZR1, which regulates peach cold resistance. Transient expression PpBZR1 in peaches showed that PpBZR1 inhibits PpVIN2 expression and VIN activity, resulting in an elevated level of sucrose, which protects fruit from CI. Arabidopsis thaliana expressing PpBZR1 that had a high germination and seedling survival rate at low temperatures, which may be due to higher level of sucrose and lower oxidative damage. Mechanistically, we confirmed that PpBZR1 directly binds to the PpVIN2 promoter and functions as a negative regulator for sucrose metabolism. In addition, PpCBF1/5/6 were induced by EBR treatment and AtCBFs were upregulated in PpBZR1 transgenic Arabidopsis thaliana. Combined with previous findings, we hypothesize that PpBZR1 regulates PpVIN2 and may also be mediated by CBF. In conclusion, PpBZR1 expression is induced by EBR treatment during cold storage, which futher inhibite sucrose degradation gene PpVIN2 transcription via direct binding its promoter and indirectly regulating PpVIN2, resulting in slower sucrose degradation and higher chilling tolerance of peach.
Tryptophol Improves the Biocontrol Efficacy of Scheffersomyces spartinae against the Gray Mold of Strawberries by Quorum Sensing

Zhao Z, Wei Y, Zou X, Jiang S, Chen Y, Ye J, et al.

J Agric Food Chem, 2023 Dec 02.
PMID: 38041637 DOI: 10.1021/acs.jafc.3c06676

Previously, we reported that marine yeast Scheffersomyces spartinae exhibited biocontrol efficacy against the gray mold of strawberries caused by Botrytis cinerea. Herein, tryptophol, a quorum-sensing molecule, was identified in the metabolites of S. spartinae. Subsequently, we found that 25 μM tryptophol promoted population density, biofilm formation, and cell aggregation of S. spartinae. Furthermore, 25 μM tryptophol improved the biocontrol efficacy of S. spartinae against B. cinerea in vitro and in the strawberry fruit. Under a scanning electronic microscope, tryptophol facilitated colonization and biofilm formation on strawberry wounds, showing that tryptophol increased the biocontrol efficacy of S. spartinae via quorum sensing. Transcriptome analysis revealed that tryptophol upregulated the gene expression of SDS3, DAL81, DSE1, SNF5, SUN41, FLO8, and HOP1, which was associated with cell adhesion or biofilm formation. Thus, to the best of our knowledge, this study was the first to report that tryptophol improved the biocontrol efficacy of S. spartinae via quorum sensing.
Glutamate application maintains quality and antioxidant capacity of fresh-cut carrots by modulating GABA shunt, phenylpropanoid and ROS metabolism

Zhang J, Zhao J, Zuo X, You W, Ru X, Xu F, et al.

Food Chem, 2024 Jun 15;443:138545.
PMID: 38306904 DOI: 10.1016/j.foodchem.2024.138545

The effects of exogenous glutamate treatment on the quality attributes, γ-aminobutyric acid (GABA) shunt, phenylpropanoid pathway, and antioxidant capacity of fresh-cut carrots were investigated. Results showed that glutamate treatment suppressed the increases in lightness and whiteness values, inhibited the degradation of total carotenoids and maintained better flavor and taste in fresh-cut carrots. Moreover, glutamate treatment rapidly promoted the activities of glutamate decarboxylase and GABA transaminase, thus improving the GABA content. It also significantly enhanced the activities of phenylalanine ammonia-lyase, cinnamate-4-hydroxylase, and 4-coumarate coenzyme A ligase and promoted the accumulation of total phenolics as well as the main individual phenolic compounds, including chlorogenic and caffeic acid. In addition, glutamate application activated the reactive oxygen system-related enzyme including peroxidase, superoxide dismutase, ascorbate peroxidase, and catalase activities to maintain higher antioxidant capacity in fresh-cut carrots. These results demonstrated that exogenous glutamate treatment maintained better nutritional quality and alleviated color deterioration by accelerating the accumulation of GABA and phenolics and enhancing the antioxidant capacity in fresh-cut carrots.
CmCML11 interacts with CmCAMTA5 to enhance γ-aminobutyric acid (GABA) accumulation by regulating GABA shunt in fresh-cut cantaloupe

You W, Zhang J, Ru X, Xu F, Wu Z, Jin P, et al.

Plant Physiol Biochem, 2024 Jan;206:108217.
PMID: 38039581 DOI: 10.1016/j.plaphy.2023.108217

The effect of calcium chloride (CaCl2) treatment on γ-aminobutyric acid (GABA) accumulation in fresh-cut cantaloupe and the involved mechanisms were investigated. The result showed that 1% (w/v) CaCl2 treatment increased GABA content and activities of glutamate decarboxylase (GAD) and succinate semialdehyde dehydrogenase (SSADH), while decreased glutamate (Glu) content and GABA transaminase (GABA-T) activities in fresh-cut cantaloupe. CmCML11 and CmCAMTA5 expressions of CaCl2-treated fruit increased by 187.4% and 165.6% than control fruit in the initial 6 h. Besides, expressions of GABA shunt genes, including CmGAD1, CmGAD2, CmGABA-T and CmSSADH were also up-regulated by CaCl2 treatment during early storage. Moreover, acting as a transcriptional activator, CmCAMTA5 could bind to the CG-box in promoters of CmGAD1, CmGABA-T and CmSSADH and activate their transcription. Furthermore, the interaction between CmCML11 and CmCAMTA5 could enhance the transcriptional activation on GABA shunt genes which were regulated by CmCAMTA5. Collectively, our findings revealed that CaCl2 treatment promoted GABA accumulation in fresh-cut cantaloupe via the combined effect of CmCML11 and CmCAMTA5 in the regulation of expressions of CmGAD1, CmGABA-T, and CmSSADH in GABA shunt.
Ethyl cinnamate suppresses tumor growth through anti-angiogenesis by attenuating VEGFR2 signal pathway in colorectal cancer

Wang S, Yang J, Kuang X, Li H, Du H, Wu Y, et al.

J Ethnopharmacol, 2024 May 23;326:117913.
PMID: 38360380 DOI: 10.1016/j.jep.2024.117913

ETHNOPHARMACOLOGICAL RELEVANCE: Kaempferia galanga Linn. is an aromatic medicinal herb with extensively applied in India, China, Malaysia and other South Asia countries for thousands of years. It has been mentioned to treat abdominal tumors. Ethyl cinnamate (EC), one of the main chemical constituents of the rhizome of K. galanga, exhibited nematocidal, sedative and vasorelaxant activities. However, its anti-angiogenic activity, and anti-tumor effect have not been investigated.
AIM OF THE STUDY: To investigate the anti-angiogenic mechanism of EC and its anti-tumor effect by suppressing angiogenesis.
MATERIALS AND METHODS: The in vitro anti-angiogenic effect was evaluated using HUVECs model induced by VEGF and zebrafish model in vivo. The influence of the EC on phosphorylation of VEGFR2 and its downstream signaling pathways were evaluated by western blotting assay. Molecule docking technology was conducted to explore the interaction between EC and VEGFR2. SPR assay was used for detecting the binding affinity between EC and VEGFR2. To further investigate the molecular mechanism of EC on anti-angiogenesis, VEGFR2 knockdown in HUVECs and examined the influence of the EC. Anti-tumor activity of EC was evaluated using colony formation assay and apoptosis assay. The inhibitory effect of EC on tumor growth was explored using HT29 colon cancer xenograft model.
RESULTS: EC obviously inhibited proliferation, migration, invasion and tube formation of VEGF-induced HUVECs. EC also induced apoptosis of HUVECs. Moreover, it inhibited the development of vessel formation in zebrafish. Further investigations demonstrated that EC could suppress the phosphorylation of VEGFR2, and its downstream signaling pathways were altered in VEGF-induced HUVECs. EC formed a hydrogen bond to bind with the ATP binding site of the VEGFR2, and EC-VEGFR2 interaction was shown in SPR assay. The suppressive effect of EC on angiogenesis was abrogated after VEGFR2 knockdown in HUVECs. EC inhibited the colon cancer cells colony formation and induced apoptosis. In addition, EC suppressed tumor growth in colon cancer xenograft model, and no detectable hepatotoxicity and nephrotoxicity. In addition, it inhibited the phosphorylation of VEGFR2, and its downstream signal pathways in tumor.
CONCLUSIONS: EC could inhibit tumor growth in colon cancer by suppressing angiogenesis via VEGFR2 signaling pathway, and suggested EC as a promising candidate for colon cancer treatment.
Exogenous chlorogenic acid inhibits quality deterioration in fresh-cut potato slices

You W, Wang C, Zhang J, Ru X, Xu F, Wu Z, et al.

Food Chem, 2024 Jul 15;446:138866.
PMID: 38430769 DOI: 10.1016/j.foodchem.2024.138866

Fresh-cut potatoes are prone to surface browning and physiological degradation. Chlorogenic acid (CGA), a natural phenolic antioxidant, has demonstrated preservative properties in various postharvest products. However, the underlying mechanisms of its application on maintaining quality remain unclear. Therefore, the effect of exogenous CGA treatment on quality deterioration of potato slices and the mechanisms involved were investigated. Results revealed CGA treatment retarded the browning coloration, suppressed microbial growth and inhibited the declines in starch, and ascorbic acid contents in potato slices. Meanwhile, the treatment activated the phenylpropanoid pathway but decreased the activities of phenolic decomposition-related enzymes such as polyphenol oxidase (PPO) and tyrosinase and downregulated StPPO expression. Moreover, the treated slices exhibited reduced accumulation of reactive oxygen species and increased activity of antioxidant enzymes. Additionally, they displayed enhanced 2,2-diphenyl-1-picrylhydrazyl radicals scavenging capacity and higher ATP levels. Therefore, these findings indicated that CGA treatment was effective for quality maintenance and antioxidant capacity enhancement in fresh-cut potatoes, thereby providing potential strategies for the preservation and processing of fresh-cut produce.
The regulation of Cytochrome f by mannose treatment in broccoli and its relationship with programmed cell death in tobacco BY-2 cells

Zhao S, Chen J, Cao S, Wang H, Chen H, Wei Y, et al.

Plant Physiol Biochem, 2024 Mar;208:108480.
PMID: 38437751 DOI: 10.1016/j.plaphy.2024.108480

It is well established that programmed cell death (PCD) occurred in broccoli during postharvest senescence, but no studies have been conducted on the regulation of broccoli cytochrome f by mannose treatment and its relationship with PCD. In this study, we treated broccoli buds with mannose to investigate the changes in color, total chlorophyll content, gene expression related to chlorophyll metabolism, chloroplast structure, and cytochrome f determination during postharvest storage. In addition, to investigate the effect of cytochrome f on PCD, we extracted cytochrome f from broccoli and treated Nicotiana tabacum L. cv Bright Yellow 2 (BY-2) cells with extracted cytochrome f from broccoli at various concentrations. The results showed that cytochrome f can induce PCD in tobacco BY-2 cells, as evidenced by altered cell morphology, nuclear chromatin disintegration, DNA degradation, decreased cell viability, and increased caspase-3-like protease production. Taken together, our study indicated that mannose could effectively delay senescence of postharvest broccoli by inhibiting the expression of gene encoding cytochrome f which could induce PCD.
Influence of flavonoids from Sedum aizoon L. on mitochondrial function of Rhizopus nigricans in strawberry

Ge Q, Zhao S, Shao X, Wei Y, Chen J, Wang H, et al.

World J Microbiol Biotechnol, 2024 Apr 13;40(5):161.
PMID: 38613738 DOI: 10.1007/s11274-024-03967-3

Rhizopus nigricans (R. nigricans), one of the fungi that grows the fastest, is frequently discovered in postharvest fruits, it's the main pathogen of strawberry root rot. Flavonoids in Sedum aizoon L. (FSAL) is a kind of green and safe natural substance extracted from Sedum aizoon L. which has antifungal activity. In this study, the minimum inhibitory concentration (MIC) of FSAL on R. nigricans and cell apoptosis tests were studied to explore the inhibitory effect of FSAL on R. nigricans. The effects of FSAL on mitochondria of R. nigricans were investigated through the changes of mitochondrial permeability transition pore(mPTP), mitochondrial membrane potential(MMP), Ca2+ content, H2O2 content, cytochrome c (Cyt c) content, the related enzyme activity and related genes of mitochondria. The results showed that the MIC of FSAL on R. nigricans was 1.800 mg/mL, with the addition of FSAL (1.800 mg/mL), the mPTP openness of R. nigricans increased and the MMP reduced. Resulting in an increase in Ca2+ content, accumulation of H2O2 content and decrease of Cyt c content, the activity of related enzymes was inhibited and related genes were up-regulated (VDAC1, ANT) or down-regulated (SDHA, NOX2). This suggests that FSAL may achieve the inhibitory effect of fungi by damaging mitochondria, thereby realizing the postharvest freshness preservation of strawberries. This lays the foundation for the development of a new plant-derived antimicrobial agent.
Fulltext High-Throughput Non-Contact Vitrification of Cell-Laden Droplets Based on Cell Printing

Shi M, Ling K, Yong KW, Li Y, Feng S, Zhang X, et al.

Sci Rep, 2015 Dec 14;5:17928.
PMID: 26655688 DOI: 10.1038/srep17928

Cryopreservation is the most promising way for long-term storage of biological samples e.g., single cells and cellular structures. Among various cryopreservation methods, vitrification is advantageous by employing high cooling rate to avoid the formation of harmful ice crystals in cells. Most existing vitrification methods adopt direct contact of cells with liquid nitrogen to obtain high cooling rates, which however causes the potential contamination and difficult cell collection. To address these limitations, we developed a non-contact vitrification device based on an ultra-thin freezing film to achieve high cooling/warming rate and avoid direct contact between cells and liquid nitrogen. A high-throughput cell printer was employed to rapidly generate uniform cell-laden microdroplets into the device, where the microdroplets were hung on one side of the film and then vitrified by pouring the liquid nitrogen onto the other side via boiling heat transfer. Through theoretical and experimental studies on vitrification processes, we demonstrated that our device offers a high cooling/warming rate for vitrification of the NIH 3T3 cells and human adipose-derived stem cells (hASCs) with maintained cell viability and differentiation potential. This non-contact vitrification device provides a novel and effective way to cryopreserve cells at high throughput and avoid the contamination and collection problems.
Fulltext Engineering artificial machines from designable DNA materials for biomedical applications

Qi H, Huang G, Han Y, Zhang X, Li Y, Pingguan-Murphy B, et al.

Tissue Eng Part B Rev, 2015 Jun;21(3):288-97.
PMID: 25547514 DOI: 10.1089/ten.TEB.2014.0494

Deoxyribonucleic acid (DNA) emerges as building bricks for the fabrication of nanostructure with complete artificial architecture and geometry. The amazing ability of DNA in building two- and three-dimensional structures raises the possibility of developing smart nanomachines with versatile controllability for various applications. Here, we overviewed the recent progresses in engineering DNA machines for specific bioengineering and biomedical applications.
Engineering physical microenvironment for stem cell based regenerative medicine

Han YL, Wang S, Zhang X, Li Y, Huang G, Qi H, et al.

Drug Discov Today, 2014 Jun;19(6):763-73.
PMID: 24508818 DOI: 10.1016/j.drudis.2014.01.015

Regenerative medicine has rapidly evolved over the past decade owing to its potential applications to improve human health. Targeted differentiations of stem cells promise to regenerate a variety of tissues and/or organs despite significant challenges. Recent studies have demonstrated the vital role of the physical microenvironment in regulating stem cell fate and improving differentiation efficiency. In this review, we summarize the main physical cues that are crucial for controlling stem cell differentiation. Recent advances in the technologies for the construction of physical microenvironment and their implications in controlling stem cell fate are also highlighted.
Improved sensitivity of lateral flow assay using paper-based sample concentration technique

Tang R, Yang H, Choi JR, Gong Y, Hu J, Feng S, et al.

Talanta, 2016 May 15;152:269-76.
PMID: 26992520 DOI: 10.1016/j.talanta.2016.02.017

Lateral flow assays (LFAs) hold great promise for point-of-care testing, especially in resource-poor settings. However, the poor sensitivity of LFAs limits their widespread applications. To address this, we developed a novel device by integrating dialysis-based concentration method into LFAs. The device successfully achieved 10-fold signal enhancement in Human Immunodeficiency Virus (HIV) nucleic acid detection with a detection limit of 0.1nM and 4-fold signal enhancement in myoglobin (MYO) detection with a detection limit of 1.56ng/mL in less than 25min. This simple, low-cost and portable integrated device holds great potential for highly sensitive detection of various target analytes for medical diagnostics, food safety analysis and environmental monitoring.
Paper-based capacitive sensors for identification and quantification of chemicals at the point of care

Hu J, Yew CT, Chen X, Feng S, Yang Q, Wang S, et al.

Talanta, 2017 Apr 01;165:419-428.
PMID: 28153277 DOI: 10.1016/j.talanta.2016.12.086

The identification and quantification of chemicals play a vital role in evaluation and surveillance of environmental health and safety. However, current techniques usually depend on costly equipment, professional staff, and/or essential infrastructure, limiting their accessibility. In this work, we develop paper-based capacitive sensors (PCSs) that allow simple, rapid identification and quantification of various chemicals from microliter size samples with the aid of a handheld multimeter. PCSs are low-cost parallel-plate capacitors (~$0.01 per sensor) assembled from layers of aluminum foil and filter paper via double-sided tape. The developed PCSs can identify different kinds of fluids (e.g., organic chemicals) and quantify diverse concentrations of substances (e.g., heavy metal ions) based on differences in dielectric properties, including capacitance, frequency spectrum, and dielectric loss tangent. The PCS-based method enables chemical identification and quantification to take place much cheaply, simply, and quickly at the point-of-care (POC), holding great promise for environmental monitoring in resource-limited settings.
Lateral Flow Assay Based on Paper-Hydrogel Hybrid Material for Sensitive Point-of-Care Detection of Dengue Virus

Choi JR, Yong KW, Tang R, Gong Y, Wen T, Yang H, et al.

Adv Healthc Mater, 2017 Jan;6(1).
PMID: 27860384 DOI: 10.1002/adhm.201600920

Paper-based devices have been broadly used for the point-of-care detection of dengue viral nucleic acids due to their simplicity, cost-effectiveness, and readily observable colorimetric readout. However, their moderate sensitivity and functionality have limited their applications. Despite the above-mentioned advantages, paper substrates are lacking in their ability to control fluid flow, in contrast to the flow control enabled by polymer substrates (e.g., agarose) with readily tunable pore size and porosity. Herein, taking the benefits from both materials, the authors propose a strategy to create a hybrid substrate by incorporating agarose into the test strip to achieve flow control for optimal biomolecule interactions. As compared to the unmodified test strip, this strategy allows sensitive detection of targets with an approximately tenfold signal improvement. Additionally, the authors showcase the potential of functionality improvement by creating multiple test zones for semi-quantification of targets, suggesting that the number of visible test zones is directly proportional to the target concentration. The authors further demonstrate the potential of their proposed strategy for clinical assessment by applying it to their prototype sample-to-result test strip to sensitively and semi-quantitatively detect dengue viral RNA from the clinical blood samples. This proposed strategy holds significant promise for detecting various targets for diverse future applications.
Fulltext Calcium Involved in the Enrichment of γ-Aminobutyric Acid (GABA) in Broccoli Sprouts under Fructose Treatment

Wei Q, Xie K, Wang H, Shao X, Wei Y, Chen Y, et al.

Plants (Basel), 2023 Jan 04;12(2).
PMID: 36678938 DOI: 10.3390/plants12020224

The effect of fructose on γ-aminobutyric acid (GABA) content and its metabolic pathway in broccoli sprouts was investigated. The results demonstrated that the fructose treatment not only significantly increased the fresh weight, GABA, and glutamate contents in sprouts, but also promoted the activity of glutamic acid decarboxylase (GAD) and the expressions of BoGAD1 and BoGAD2. Meanwhile, fructose treatment inhibited the stem length of broccoli sprouts and enhanced the abscisic acid (ABA) production in comparison with the control. Ca2+, CaM contents, and BoCaM2 expression in broccoli sprouts were also stimulated after fructose treatment. Exogenous fructose increased inositol trisphosphate (IP3) content and activated the activity of phosphatidylinositol-specific phospholipase C (PI-PLC) and the expression of BoPLC2, contributing to Ca2+ influx into the cells. These results suggested that Ca2+ played an essential role in GABA enrichment under fructose treatment, which may be associated with GAD and PI-PLC.
Fulltext In situ normoxia enhances survival and proliferation rate of human adipose tissue-derived stromal cells without increasing the risk of tumourigenesis

Choi JR, Pingguan-Murphy B, Wan Abas WA, Yong KW, Poon CT, Noor Azmi MA, et al.

PLoS One, 2015;10(1):e0115034.
PMID: 25615717 DOI: 10.1371/journal.pone.0115034

Adipose tissue-derived stromal cells (ASCs) natively reside in a relatively low-oxygen tension (i.e., hypoxic) microenvironment in human body. Low oxygen tension (i.e., in situ normoxia), has been known to enhance the growth and survival rate of ASCs, which, however, may lead to the risk of tumourigenesis. Here, we investigated the tumourigenic potential of ASCs under their physiological condition to ensure their safe use in regenerative therapy. Human ASCs isolated from subcutaneous fat were cultured in atmospheric O2 concentration (21% O2) or in situ normoxia (2% O2). We found that ASCs retained their surface markers, tri-lineage differentiation potential, and self-renewal properties under in situ normoxia without altering their morphology. In situ normoxia displayed a higher proliferation and viability of ASCs with less DNA damage as compared to atmospheric O2 concentration. Moreover, low oxygen tension significantly up-regulated VEGF and bFGF mRNA expression and protein secretion while reducing the expression level of tumour suppressor genes p16, p21, p53, and pRb. However, there were no significant differences in ASCs telomere length and their relative telomerase activity when cultured at different oxygen concentrations. Collectively, even with high proliferation and survival rate, ASCs have a low tendency of developing tumour under in situ normoxia. These results suggest 2% O2 as an ideal culture condition for expanding ASCs efficiently while maintaining their characteristics.

Filters

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links