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Xiaowei Li

Publications and source records attributed to Xiaowei Li.

16 recordsLinked to original sources
PubMed2026

Enrichment Performance Assessment of Extracellular Vesicles Using Different Functionalized Magnetic Materials and Application in Urinary Proteomics of Prostate Cancer.

Extracellular vesicles (EVs) are lipid bilayer nanovesicles that mediate intercellular communication and hold significant potential for clinical applications. Although material-based isolation strategies offer promising alternatives to conventional methods, their relative performances have not been systematically evaluated. In this study, we conducted a comparative assessment of magnetic nanomaterials with distinct surface functionalities, including metal oxides (TiO2), metal-organic frameworks (UiO-66), biopolymeric materials (chitosan), and lipid probes (DSPE-PEG, DOPE-PEG, and CLS-PEG). A comprehensive evaluation across multiple dimensions including capture capacity, capture rate, sample volume, and product purity reveals that the bifunctional magnetic nanomaterial Fe3O4@UiO-66@DSPE material exhibits superior EV capture performance. This material enables the efficient and stable enrichment of high-purity EVs by synergizing Zr4+-phosphate coordination with lipid bilayer anchoring, and preserves EV biological integrity and activity. Meanwhile, this method could be highly compatible with proteomics, and over 1000 proteins are identified by proteomic analysis of urinary EVs, while 34 proteins are upregulated and 25 proteins are downregulated in prostate cancer patients relative to healthy donors. Notably, the differentially expressed proteins, such as AGT, ITIH4, and PGLYRP2, are associated with disease progression. Overall, this work highlights the superior performance of the Fe3O4@UiO-66@DSPE material for efficient and selective EV isolation. It provides a powerful tool for clinical liquid biopsy and proteomic biomarker discovery, enabling early diagnosis, prognostic evaluation, and precision therapy.

Humans↗
PubMed2025

Programmed ribosomal frameshifting during PLEKHM2 mRNA decoding generates a constitutively active proteoform that supports myocardial function.

Programmed ribosomal frameshifting is a process where a proportion of ribosomes change their reading frame on an mRNA. While frameshifting is commonly used by viruses, very few phylogenetically conserved examples are known in nuclear encoded genes. Here, we report a +1 frameshifting event during decoding of the human gene PLEKHM2 that provides access to a second internally overlapping ORF. The new carboxyl-terminal domain of this frameshift protein forms an α helix, which relieves PLEKHM2 from autoinhibition and allows it to move to the tips of cells without activation by ARL8. Reintroducing both the canonically translated and frameshifted protein are necessary to restore normal contractile function of PLEKHM2 knockout cardiomyocytes, demonstrating the necessity of frameshifting for normal cardiac activity.

Frameshifting, Ribosomal↗
PubMed2006

Residue depletion of florfenicol and its metabolite florfenicol amine in Swine tissues after intramuscular administration.

A study of the tissue depletion of florfenicol (FF) administered intramuscularly twice to swine at a dose rate of 20 mg per kg of body weight at 24 h intervals was carried out. Forty healthy cross swine were treated with the FF injection formulation. Five treated animals were selected randomly to be sacrificed at 1, 3, 6, 9, 12, 14, 17, and 21 days withdrawal. FF and florfenicol amine (FFa) residue concentrations in muscle, liver, and kidney were determined using high-performance liquid chromatography (HPLC) with photodiode array (PDA) detection at 225 nm. Liver samples showed the lowest FF and the highest FFa concentrations throughout the experiment period. However, the highest total concentrations of FF and FFa during the study were found in kidney, which indicated that kidney is the target tissue for FF. The sum of FF and FFa concentrations in all tissues analyzed was below the accepted maximum residue limits recommended by the Agriculture Ministry of People's Republic of China and the European Union at 8 days posttreatment.

Animals↗
PubMed2005

Dispersion behaviors of molybdena on titania (rutile and/or anatase).

Raman and FT-IR spectra were employed to investigate the dispersion of molybdena on mixed TiO2 (rutile and anatase, signed as R and A) with different BET surface ratios of rutile/TiO2(R + A). The results showed that (1) molybdena would preferentially disperse on the rutile surface in mixed TiO2; (2) for MoO3/rutile with low molybdena loading (e.g., 0.20 mmol/100 m2 rutile), a dispersed molybdena species existed on the rutile surface in an isolated tetrahedral coordination environment, while for MoO3/rutile with high molybdena loading (e.g. 0.82 mmol/100 m2 rutile), a polymeric molybdena species could be detected on the rutile surface; (3) for the MoO3/anatase sample, a dispersed molybdena species existed on the anatase surface in a polymeric coordination environment; and (4) the formation of the Bronsted acid site on the surface of rutile and anatase should be related to the polymeric molybdena species. All these results have been discussed via the interaction between OH groups of molybdena and OH groups of rutile and anatase, and it seems reasonable to suggest that, for the lower molybdena loading, the different states of the dispersed molybdena species should result from the different dehydration orders of OH groups of the molybdena and surface OH groups of rutile and anatase.

Molybdenum↗
PubMed2005

Thermosensitive N-isopropylacrylamide-N-propylacrylamide-vinyl pyrrolidone terpolymers: synthesis, characterization and preliminary application as embolic agents.

In this article, thermosensitive N-isopropylacrylamide (NIPAAm)-N-propylacrylamide (NPAAm)-vinyl pyrrolidone (VP) terpolymers (PNINAVP) were prepared by varying feed ratios with free radical copolymerization method. The composition ratios and molecular weights of PNINAVP were examined by NMR and GPC. The thermo-responsive behaviors of copolymer solutions in the absence and with addition of Iohexol, a radiopaque agent, were investigated by differential scanning calorimetry (DSC) and rheometer. The sol-gel transition of the copolymer solutions occurred reversibly within 1 min in response to temperature. Incorporation of Iohexol increased the transition time and transition temperature of PNINAVP solutions; the rheological properties were also influenced. It was observed that at body temperature, PNINAVP and Iohexol could form an integrated bulky hydrogel presumably due to the hydrogen bonding between them, which was favorable for the clinical follow-up and reducing toxic side effects. In vitro embolic model experiment indicated that 5 wt% 16:16:1H PNINAVP solution containing Iohexol displayed a satisfactory embolization effect. This solution was injected into the rete mirabiles (RM) of six swines through a microcatheter. The angiographical results obtained immediately after the operation showed a complete occlusion of the RM, and no recanalization was observed at postoperative month 1. The histological examination demonstrated no acute inflammatory reaction inside the RM and surrounding tissue. This work could provide a beneficial guidance for designing a new temperature-sensitive polymer-based embolic agent.

Acrylamides↗
PubMed2005

Pharmacokinetics of tilmicosin after oral administration in swine.

OBJECTIVE: To determine the pharmacokinetics of tilmicosin after oral administration of a single dose of tilmicosin base in swine. ANIMALS: 10 healthy swine. PROCEDURE: Tilmicosin base was administered via stomach tube at a single dose of 20 mg/kg (n = 5) or 40 mg/kg (5). Blood samples were obtained from a jugular vein immediately before and at 10, 20, and 30 minutes and 1, 2, 3, 4, 6, 8, 12, 24, 36, 48, 72, 96, and 120 hours after administration of tilmicosin. Tilmicosin concentrations in serum were quantified by use of a high-performance liquid chromatography procedure with UV light. Data for tilmicosin concentrations versus time were analyzed by use of compartmental and noncompartmental methods. RESULTS: Tilmicosin concentrations in serum decreased in a biexponential manner after oral administration. Mean +/- SD values for absorption half-lives were 1.49 +/- 0.23 hours and 1.64 +/- 0.40 hours, distribution half-lives were 2.96 +/- 0.58 hours and 3.20 +/- 0.76 hours, elimination half-lives were 25.26 +/- 8.25 and 20.69 +/- 5.07 hours, peak concentrations were 1.19 +/- 0.30 microg/mL and 2.03 +/- 0.28 microg/mL, and time to peak concentrations was 3.12 +/- 0.50 hours and 3.48 +/- 0.77 hours after oral administration of tilmicosin base at a single dose of 20 or 40 mg/kg, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: In swine, tilmicosin was rapidly absorbed and slowly eliminated after oral administration of a single dose of tilmicosin base powder.

Administration, Oral↗
PubMed2004

A rapid temperature-responsive sol-gel reversible poly(N-isopropylacrylamide)-g-methylcellulose copolymer hydrogel.

Poly(N-isopropylacrylamide) (PNIPAAm) was grafted to methylcellulose (MC) with various feeding ratios using ammonium persulfate and N,N,N',N'-tetramethyl ethylene diamine as an initiator. FTIR results confirm the formation of PNIPAAm-g-MC copolymers. The temperature responsiveness of copolymer gels was investigated by turbidimetry, dynamic contact angle (DCA), differential scanning calorimetry and dynamic mechanical analysis (DMA). The results indicate that PNIPAAm-g-MC hydrogels are strongly temperature responsive. At lower contents of MC, the lower critical solution temperature (LCST) is decreased, whereas further increasing MC contents raises the LCSTs. It is observed that the phase transition of the hydrogels occurs reversibly within 1 min, and near body temperature, a rigid gel can be generated in a certain range of MC content. What is more, the incorporation of MC prevents the syneresis of copolymer hydrogel. DMA measurement reveals that the storage moduli (E') of the gels increase upon increasing MC contents, and moreover the values of E' go up markedly above LCST. The copolymer hydrogels hold a promise as a blood vessel barrier by tuning gelation temperature, gelation time and mechanical strength.

Acrylic Resins↗
PubMed2003

[Study on the effect of NaFeEDTA on preventing lead poisoning in rats and its impact on zinc, copper].

In order to explore the effect of sodium iron ethylenediaminetetraacetate (NaFeEDTA) on preventing rats from lead poisoning and reducing the lead toxicity, and at the same time to explore its impact on zinc and copper, sixty Wistar rats were randomly divided into six groups including blank control group, model control group, positive control group and three different level NaFeEDTA (high, middle and low) groups. With the exception of the blank control group, which only received double distilled water treatment throughout the experiment, all the other rats were continuously treated with lead solution. At the same time, with the exception of the blank and model control groups, the other four groups were treated with acidi dimercaptosuccinici (DMSA), high, middle and low level NaFeEDTA solutions respectively. At the end of the study, several indicators were determined. The results showed that the hemoglobin levels in the three different level NaFeEDTA groups were significantly higher than those of the other four groups and at the same time the lead levels in blood and organs were lower than those of model group significantly. There were significant reverse correlations between iron supplement and the lead levels in liver, kidney and tibia among the three different level NaFeEDTA groups, and the correlation coefficients were -0.4432, -0.6134 and -0.3878 respectively. There were no significant differences in zinc levels and copper levels between the three level NaFeEDTA groups and the negative control group except the brain zinc levels in the middle and high level NaFeEDTA groups were lower and the kidney copper level in the low level NaFeEDTA group was higher than those of the model control group. It is concluded that the NaFeEDTA can effectively improve hemoglobin level, prevent rats from lead poisoning and reduce the lead toxicity. At the same time, NaFeEDTA does not have significant influence on zinc and copper levels in rats.

Animals↗
PubMed2002

[A novel alternative splicing isoform of vascular endothelial growth factor gene in human beings].

OBJECTIVE: To investigate a new alternative splicing isoform of vascular endothelial growth factor (VEGF) gene in human bejings. METHODS: The total RNA of the lung tissue of a legally aborted 4-month-old human fetus was isolated and then amplified by RT-PCR. The amplified product was cloned into the pMD18-T plasmid and pcDNA3.1(-). Then sequence analysis was conducted. RESULTS: The electrophoresis of the RT-PCR product showed one short band of VEGF121 comprising of 487 bp and a long band with two fragments: one normal VEGF165 comprising of 619 bp and one fragment comprising of 639 bp which was the same VEGF165 nucleotide sequence with a 20 bp fragment inserted between exon 3 and exon 4. Sequence analysis showed that this 20 bp long nucleotide was inserted from the 3' end of the third intron that contained splicing signal, thus causing shift mutation in reading frame of VEGF gene and early appearance of the stop code UAG in the middle of exon 4. CONCLUSION: A new alternative splicing isoform of VEGF has been identified in the lung tissue of a legally aborted human fetus. Its biological significance remains to be further investigated.

Alternative Splicing↗
PubMed2002

Diabetes in a Caribbean population: epidemiological profile and implications.

OBJECTIVE: To examine the distribution and impact of diabetes, glycaemic status, and related factors, in a predominantly black adult Caribbean population. METHODS: The study included 4709 people, or 84% of a simple random sample of Barbadian-born citizens aged 40-84 years, examined between 1988 and 1992 and re-assessed 4 years later. Diabetes was evaluated according to physician-diagnosis and glycosylated haemoglobin (GHb). Associations were assessed by logistic regression analyses, cumulative mortality by product-limit methods and death-rate ratios by Cox proportional hazards regression. RESULTS: Among the 4314 black participants, the prevalence of known diabetes, predominantly type 2, was 9.1% at 40-49 years of age and increased to 24.0% at 70-79 years. The overall prevalence was 17.5%, while it was 12.5% in mixed (black/ white; n = 184) and 6.0% in white/other participants (n = 133), only 0.3% had younger-onset. Additionally, 2% had GHb >10% (>2 SD over the mean) without diabetes history. Sulphonylureas were the most frequent treatment, while insulin use was infrequent. In black participants, diabetes was positively associated with age (OR = 1.03 per year; 95% CI : 1.02-1.04), diabetes family history (OR = 2.85, 95% CI : 2.39-3.40), hypertension (OR = 1.71, 95% CI : 1.42-2.05), obesity (BMI > or = 25 kg/m(2); OR = 1.74, 95% CI : 1.44-2.10), and high waist-hip ratio (WHR > or = 0.92; OR = 1.29, 95% CI : 1.09-1.53). Ocular co-morbidities were increased among people with diabetes, as was 4-year-mortality (death rate ratio = 1.42, 95% CI : 1.10-1.83). There was a 9% increase in mortality for each 1% increase in GHb (death rate ratio = 1.09, 95% CI : 1.04-1.15). CONCLUSIONS: A markedly high prevalence of diabetes existed in the adult black population, affecting almost one in five people and increasing morbidity and mortality. Prevention strategies are urgently needed to reduce the adverse implications of diabetes in this and similar populations.

Adult↗
PubMed2002

[Determination of heavy metal in Chinese herbs].

Microwave digestion system was used in digesting samples. Lead and cadmium were determined by graphite furnace atomic absorption spectrometry. Mercury was determined by cold vapor atomic absorption spectrometry. Standard reference material (NBS1570), spinach powder was used as analysis quality assurance in this method, and 264 Chinese herbs (23 species) and standard reference material were determined, and satisfactory results were obtained by using this method. Averages recovery of lead, cadmium and mercury is 95.0%, 97.5% and 99.2% respectively. Limit of detection (LOD) is 0.006 mg/kg, 0.208 microgram/kg and 0.026 microgram/kg respectively for lead, cadmium and mercury. Limit of quantity (LOQ) is 0.019 mg/kg, 0.694 microgram/kg and 0.087 microgram/kg respectively for lead, cadmium and mercury. This method is also suitable to determine lead, cadmium and mercury in food.

Cadmium↗
PubMedDate not supplied

Determination of four nitroimidazoles in poultry and swine muscle and eggs by liquid chromatography/tandem mass spectrometry.

A rapid method is presented for the determination of 4 nitroimidazoles in poultry and swine muscle and eggs by liquid chromatography/electrospray ionization-tandem mass spectrometry (LC/ESI-MS/MS). Samples were extracted with acetonitrile, then evaporated the organic phase. After filtration, the extract was directly injected into the LC/ESI-MS/MS system. The LC separation was made on a C8 column by applying a gradient composed of water and acetonitrile. Overall average recoveries ranged from 50-86% for egg, 66-115% for poultry muscle, and 79-111% for swine muscle. The decision limits ranged from 0.05-0.25 microg/kg for egg, 0.07-0.27 microg/kg for poultry muscle, and 0.07-0.26 microg/kg for swine muscle; and detection capabilities ranged from 0.51-0.68 microg/kg for egg, 0.41-0.75 microg/kg for poultry muscle, and 0.53-0.78 microg/kg for swine muscle.

Acetonitriles↗
PubMedDate not supplied

Multiresidue analysis of avermectins in cattle liver by liquid chromatography/tandem mass spectrometry.

A simple multiresidue analysis method was developed for the confirmation and quantification of eprinomectin, abamectin, doramectin, and ivermectin in cattle liver. The target analytes were extracted with acetonitrile and cleaned up with C18 and C8 solid-phase extraction cartridges before analysis by liquid chromatography combined with positive ion electrospray tandem mass spectrometry. The residue mean recoveries of the 4 drugs were 64.16-99.53%. The limit of detection was 2.5 ng/g for eprinomectin, abamectin, doramectin, and ivermectin.

Animals↗
PubMedDate not supplied

Determination of nitroimidazole residues in porcine urine by liquid chromatography/tandem mass spectrometry.

A reliable and sensitive method was developed for determination of nitroimidazoles in porcine urine. Sample preparation involves an extraction with ethyl acetate, followed by a solid-phase extraction cleanup step. The final extract is injected into the liquid chromatography/tandem mass spectrometry system in the positive-ion electrospray ionization mode. A C8 column with water and acetonitrile as the mobile phase is used for chromatographic separation under gradient conditions. Overall average recoveries ranged from 83 to 107%. The limits of detection ranged from 0.03 to 0.05 ng/mL, and the limits of quantitation, from 0.1 to 0.2 ng/mL.

Animals↗
PubMedDate not supplied

Multiresidue determination of zeranol and related compounds in bovine muscle by gas chromatography/mass spectrometry with immunoaffinity cleanup.

A gas chromatography/mass spectrometry (GC/MS) method with immunoaffinity cleanup was developed for the determination of zeranol and related compounds, taleranol, zearalanone, and alpha-zearalenol in bovine muscle. Muscle samples were extracted with methanol and cleaned up with immunoaffinity chromatography (IAC) columns containing monoclonal antibodies raised against zeranol coupled to CNBr-activated Sepharose 4B. After derivatization, the compounds were analyzed by GC/MS. The dynamic column capacities for zeranol, taleranol, zearalanone, and alpha-zearalenol were 2639.7, 2840.3, 2731.5, and 2736.3 ng/mL Sepharose gel, respectively. The limits of detection and quantification were 0.5 and 1.0 ng/g, respectively, for all 4 compounds. Mean recoveries were 79.6-110.7% with coefficients of variation of 3.2-11.4% at spiked levels of 1.0-5.0 ng/g. This IAC-GC/MS method may be used for the determination of zeranol, taleranol, zearalanone, and alpha-zearalenol residues in bovine muscle, and possibly other tissues.

Animals↗