Biomedical subjects

Fang Du

Publications and source records attributed to Fang Du.

9 recordsLinked to original sources

PubMed2024

Uncovering essential anesthetics-induced exosomal miRNAs related to hepatocellular carcinoma progression: a bioinformatic investigation.

BACKGROUND: Anesthetic drugs may alter exosomal microRNA (miRNA) contents and mediate cancer progression and tumor microenvironment remodeling. Our study aims to explore how the anesthetics (sevoflurane and propofol) impact the miRNA makeup within exosomes in hepatocellular carcinoma (HCC), alongside the interconnected signaling pathways linked to the tumor immune microenvironment. METHODS: In this prospective study, we collected plasma exosomes from two groups of HCC patients (n = 5 each) treated with either propofol or sevoflurane, both before anesthesia and after hepatectomy. Exosomal miRNA profiles were assessed using next-generation sequencing (NGS). Furthermore, the expression data from The Cancer Genome Atlas-Liver Hepatocellular Carcinoma (TCGA-LIHC) was used to pinpoint the differentially expressed exosomal miRNAs (DEmiRNAs) attributed to the influence of propofol or sevoflurane in the context of HCC. Gene set enrichment analysis (GSEA) and gene set variation analysis (GSVA) were used to dissect the signaling pathways and biological activities associated with the identified DEmiRNAs and their corresponding target genes. RESULTS: A total of 35 distinct DEmiRNAs were exclusively regulated by either propofol (n = 9) or sevoflurane (n = 26). Through TCGA-LIHC database analysis, 8 DEmiRNAs were associated with HCC. These included propofol-triggered miR-452-5p and let-7c-5p, as well as sevoflurane-induced miR-24-1-5p, miR-122-5p, miR-200a-3p, miR-4686, miR-214-3p, and miR-511-5p. Analyses revealed that among these 8 DEmiRNAs, the upregulation of miR-24-1-5p consistently demonstrated a significant association with lower histological grades (p < 0.0001), early-stage tumors (p < 0.05) and higher survival (p = 0.029). Further analyses using GSEA and GSVA indicated that miR-24-1-5p, along with its target genes, were involved in governing the tumor immune microenvironment and potentially inhibiting tumor progression in HCC. CONCLUSIONS: This study provided bioinformatics evidence suggesting that sevoflurane-induced plasma exosomal miRNAs may have a potential impact on the immune microenvironment of HCC. These findings established a foundation for future research into mechanistic outcomes in cancer patients.

Carcinoma, Hepatocellular↗

PubMed2007

Ginkgolides protect primary cortical neurons from potassium cyanide-induced hypoxic injury.

In this study, we investigated the effects of ginkgolides (Gins A, B, C and J), the main constituent of the non-flavone fraction of EGb 761, on hypoxic injury induced by potassium cyanide (KCN) in primary cortical neurons. The neurons were pretreated with or without ginkgolides for 24 h before incubation with KCN for 4 h. Cell viability was then determined by a MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyletrazolium bromide] assay and lactate dehydrogenase (LDH) release from neurons into the medium was measured. The morphological changes of neurons were observed under inverse microscopy and electron microscopy. The results demonstrated that KCN (0.05 mmol/l) significantly decreased cell viability and increased LDH release (P < 0.05 versus the control). The characteristic changes of neuronal morphology induced by KCN were observed. However, pretreatment of neurons with 37.5 microg/ml of ginkgolides (ginkgolides + KCN group) led to a significant increase in cell viability, a decrease in LDH release (P < 0.05 versus the KCN group) and a remarkable improvement in cellular morphology in hypoxic neurons compared with the KCN group. The data suggested that ginkgolides have a significant role to protect the primary cortical neurons from hypoxic injury induced by KCN.

Animals↗

PubMed2006

Immunization with autologous T cells enhances in vivo anti-tumor immune responses accompanied by up-regulation of GADD45beta.

Immunization with inactivated autoreactive T cells may induce idiotype anti-idiotypic reactions to deplete autoreactive T cells, which are involved in autoimmune diseases. However, it is unknown whether attenuated activated healthy autologous T-cell immunization could increase anti-tumor immune responses. To this end, C57Bl/6 mice were immunized with attenuated activated autologous T cells. The splenocytes from immunized mice showed a higher proliferative ability than that from naive mice. The special phenotype analysis showed that there were more CD8+ T cells and CD62L+ T cells in immunized mice after 24 h of culture with 10% fetal calf serum complete medium in vitro (P<0.01). These results demonstrated that this immunization may activate T cells in vivo. Furthermore, the splenocytes from immunized mice revealed resistance to activation-induced cell death (AICD) in vitro. To further study the relative genes that are responsible for the higher proliferation and resistance to AICD, the expression of Fas/Fas ligand (FasL) and GADD45b was measured by real-time PCR. The results indicated that GADD45beta transcription was higher in the splenocytes from immunized mice than that in the naive mice. In addition, the Fas expression showed a parallel higher, but FasL did not change obviously. To investigate the biologic functions induced by immunization in vivo, a tumor model was established by EL-4 tumor cell inoculation in C57/Bl mice. Mice receiving autologous T-cell immunization had significantly inhibited tumor growth in vivo (P<0.01). This study implicated that immunization with attenuated activated autologous T cells enhances anti-tumor immune responses that participate in tumor growth inhibition.

Animals↗

PubMed2006

Epigallocatechin gallate protects dopaminergic neurons against 1-methyl-4- phenyl-1,2,3,6-tetrahydropyridine-induced neurotoxicity by inhibiting microglial cell activation.

OBJECTIVE: To observe whether the dopaminergic neuroprotective effect of (-)-epigallocatechin gallate (EGCG) is associated with its inhibition of microglial cell activation in vivo. METHODS: The effects of EGCG at different doses on dopaminergic neuronal survival were tested in a methyl-4-phenyl-pyridinium (MPP+)-induced dopaminergic neuronal injury model in the primary mesencephalic cell cultures. With unbiased stereological method, tyrosine hydroxylase-immunoreactive (TH-ir) cells were counted in the A8, A9 and A10 regions of the substantia nigra (SN) in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated C57BL/6 mice. The effect of EGCG on microglial activation in the SN was also investigated. RESULTS: Pretreatment with EGCG (1 to 100 micromol/L) significantly attenuated MPP+-induced TH-ir cell loss by 22.2% to 80.5% in the mesencephalic cell cultures. In MPTP-treated C57BL/6 mice, EGCG at a low concentration (1 mg/kg) provided significant protection against MPTP-induced TH-ir cell loss by 50.9% in the whole nigral area and by 71.7% in the A9 region. EGCG at 5 mg/kg showed more prominent protective effect than at 1 or 10 mg/kg. EGCG pretreatment significantly inhibited microglial activation and CD11b expression induced by MPTP. CONCLUSION: EGCG exerts potent dopaminergic neuroprotective activity by means of microglial inhibition, which shed light on the potential use of EGCG in treatment of Parkinson's disease.

Animals↗

PubMed2005

Variable optical attenuator with a polymer-stabilized dual-frequency liquid crystal.

A transmission-type variable optical attenuator (VOA) based on a polymer-stabilized dual-frequency liquid crystal (PSDFLC) is demonstrated at gamma = 1.55 microm. The VOA is highly transparent in the voltage-off state but scatters light in the voltage-on state. By using a birefringent beam displacer incorporated with half-wave plates, we can obtain a VOA that is polarization independent and that exhibits a 31 dB dynamic range. The polymer networks and dual-frequency effect together reduce the response time (rise + decay) of a 16 microm PSDFLC cell to 30 ms at room temperature and at a voltage of 24 Vrms.

Journal Article↗

PubMed2005

Topiramate therapy for paroxysmal kinesigenic choreoathetosis.

We observed the clinical efficacy of topiramate for paroxysmal kinesigenic choreoathetosis (PKC). Topiramate was administered as a monotherapy with titrated dosages to 8 patients with PKC. Target daily dose of topiramate was 100 to 200 mg; the follow-up period ranged from 8 months to 2 years. All of the patients became attack-free, and side effects were mild. The results show that topiramate is effective as a monotherapy for treating patients with PKC. The response to topiramate indicates that the disease may be caused by an ion channel defect.

Adolescent↗

PubMed2005

Dopamine D3 receptor-preferring agonists induce neurotrophic effects on mesencephalic dopamine neurons.

Anti-parkinsonian agents, pramipexole (PPX) and ropinirole (ROP), have been reported to possess neuroprotective properties, both in vitro and in vivo. The mechanisms underlying neuroprotection afforded by the D3-preferring receptor agonists remain poorly understood. The present study demonstrates that incubation of primary mesencephalic cultures with PPX and ROP or the conditioned medium from PPX- or ROP-treated primary cultures induced a marked increase in the number of dopamine (DA) neurons in the cultures. Similar effects can be observed after incubating with the conditioned medium derived from PPX- and ROP-treated substantia nigra astroglia. Meanwhile, PPX and ROP can protect the primary cells from insult of 1-methyl-4-phenylpyridinium (MPP+), the active metabolite of the neurotoxin 1-methyl-4-phenyl-1,2,5,6-tetrahydropyridine (MPTP). Furthermore, the neurotrophic effects of PPX and ROP on mesencephalic dopamine neurons could be significantly blocked by D3 receptor antagonist, but not by D2 receptor antagonist. Moreover, we found that the levels of glial cell line-derived neurotrophic factor (GDNF) and brain-derived neurotrophic factor (BDNF) in the conditioned medium of mesencephalic cultures treated with PPX and ROP were significantly increased. Blocking GDNF and BDNF with the neutralizing antibodies, the neurotrophic effects of PPX and ROP were greatly diminished. These results suggest that D3 dopamine receptor-preferring agonists, PPX and ROP, exert neurotrophic effects on cultured DA neurons by modulating the production of endogenous GDNF and BDNF, which may participate in their neuroprotection.

Animals↗

PubMed2005

[A study of making use of computer-aided projection fringe system to measure breast dimension].

OBJECTIVE: To measure breast basic dimension by using computer-aided projection fringe system. METHODS: A system has been developed for measuring breast basic dimension based on computer-aided projection fringe measurement and programming software. Plastic manikins breast's SN-N (sternal notch to nipple distance), N-ML (nipple to midline distance), N-N (internipple distance), MBW (base width of breast) and N-IMF (nipple to inframammary fold distance) are measured with this system. At the same time, these items are also measured with routine ruler. RESULTS: This study indicate that the system has some merits: (1) non-touching measurement; (2) it is very rapid, the patient measured need hold his breath only 0.5 second, and all the time it takes is about 2.5 minutes; (3) the measurement's sensitivity is as high as to 0.6 mm, which meets the clinic requirement entirely; (4) the measurement's accuracy of the system is not significantly when comparing to the routine ruler's. CONCLUSIONS: Computer-aided projection fringe system for measuring breast basic dimension is feasible and advanced.

Breast↗

PubMed2003

Adapting mini-mental state examination for dementia screening among illiterate or minimally educated elderly Chinese.

BACKGROUND: Illiteracy is prevalent among current elderly Chinese. There are few brief cognitive tests in Chinese designed to screen those possibly demented for more detailed evaluation in a clinical setting. OBJECTIVES: The present study adapted the Mini-Mental State Examination (MMSE) for screening dementia among illiterate or less educated elderly Chinese. METHODS: Literacy-dependent items of the MMSE were modified or substituted by equivalent items that are not literacy-dependment. Some items were modified to provide socio-cultural compatibility. After developing it, the Chinese adapted MMSE (CAMSE) was administered to 370 elderly outpatients from Xijing hospitals located in Xi'an, China, 93 of whom were found to be demented and 277 non-demented. Sensitivities and specificities for detecting dementia were evaluated by adjusting for different CAMSE cut-off points. The optimal cut-off points of 22 for literates and 20 for illiterates yielded a sensitivity of 83.87% and a specificity of 84.48%. Corresponding positive predictive value (PPV) was 0.65, and negative predictive value (NPV) was 0.94. The impact of literacy on CAMSE and individual test items was also evaluated. Illiterate subjects got a higher CAMSE total score than literate subjects (p < 0.05). Only one out of 12 test items, serial sevens, was negatively influenced by illiteracy (p < 0.01). After an interval of 4-6 weeks, 32 randomly selected subjects were retested with CAMSE. The test-retest reliability for total scores was 0.75 (p < 0.01). CONCLUSIONS: Results suggest that in the socio-cultural context for Chinese, irrespective of their literacy skills, CAMSE proved feasible for use in clinical settings for dementia screening.

Aged↗