Biomedical subjects

Xiao-dong Ma

Publications and source records attributed to Xiao-dong Ma.

10 recordsLinked to original sources

PubMed2007

[Influence of bifidobacterium DNA on PKC and NF-kappaB in murine macrophages].

AIM: To explore the influence of DNA of bifidobacteriua adolescence on PKC and NK-kappaB of murine macrophages. METHODS: The fluorescent intensity of PKCalpha, PKCbetaI, PKCbetaII, PKCgamma, PKCepsilon and PKCzeta in murine peritoneal macrophages was detected by using laser confocal microscope. The density of NK-kappaB(+) macrophages was detected by immunocytochemical staining. RESULTS: The average fluorescent intensity of PKCalpha and PKCbetaII produced by mouse peritoneal macrophages in bifidobacterium DNA injection group was markedly higher than that in control group(P<0.01). There was no statistically significant difference of average fluorescent intensity of PKCbetaI, PKCgamma, PKCepsilon and PKCzeta between the two groups (P>0.05). The density of NK-kappaB(+) macrophages in bifidobacterium DNA injection group was markedly higher than that in control group (P<0.01). CONCLUSION: DNA of bifidobacteria adolescence could activate macrophages by promoting the activity of PKCalpha, PKCbetaII and NF-kappaB.

Animals↗

PubMed2006

[Resveratrol induces HepG2 cell apoptosis by depolarizing mitochondrial membrane].

OBJECTIVE: To investigate the effects of resveratrol on the proliferation, apoptosis, mitochondrial membrane potential and cell morphology of human liver cancer cell line HepG2. METHODS: The changes in HepG2 cell growth and proliferation in response to resveratrol treatment were evaluated by MTT assay, and resveratrol-induced apoptosis of HepG2 cells was investigated by flow cytometry. Inverted microscope and electron microscope were employed for observing morphological changes of the treated cells. The whole-cell mitochondrial membrane potential was measured in separate experiments using two fluorimetric probes, rhodamine123 and TMRE, respectively. HepG2 cells treated with rhodamine123 were analyzed by flow cytometry and cells treated with TMRE by confocal microscope. RESULTS: MTT assay showed that low concentrations of resveratrol produced no significant effect on the growth of HepG2 cells, whereas at high concentrations, resveratrol could obviously inhibit the cell growth in a time- and dose-dependent manner. Resveratrol also induced apoptosis of HepG2 cells, and after a 24-hour treatment, resveratrol caused sharp increment of the mitochondria membrane potential. CONCLUSION: Resveratrol is capable of inhibiting the proliferation of HepG2 cells and inducing cell apoptosis by depolarizing mitochondrial membrane potential.

Antineoplastic Agents, Phytogenic↗

PubMed2006

[Resveratrol promotes Ca2+-induced Ca2+ release from rat liver cell mitochondria mediated by Ca2+].

OBJECTIVE: To investigate the effects of resveratrol (Res) on mitochondrial opening and Ca(2+)-induced Ca(2+) release (CICR) from rat liver cell mitochondria mediated by Ca(2+). METHODS: Wistar rat liver cell mitochondria was extracted and Res-induced mitochondrial swelling was assessed spectrophotometrically at 540 nm to examine the permeability transition pore (PTP) opening. The membrane potential changes of Res-treated mitochondria were measured with fluorescence spectrophotometery. Ca(2+) uptake and release by the mitochondria was determined by absorbance change of arsenazo III at 685-675 nm monitored by dual wavelength spectrophotometry. RESULTS: Res promoted Ca(2+)-mediated PTP opening, and this effect was completely inhibited by CsA and lowered by trifluoperazine. CICR accelerated by Res treatment was completely blocked by ruthenium red and partly by trifluoperazine. CONCLUSION: Res can promote PTP opening by inducing CICR, which may be one of the pathways that Res induces cell apoptosis.

Animals↗

PubMed2006

[Effects of resveratrol on growth inhibition and gap-junctional intercellular communication of HepG2 cells].

OBJECTIVE: To investigate the effects of the resveratrol on proliferation and gap-junctional intercellular communication (GJIC) in human liver cancer cell line HepG2. METHODS: MTT assay was used to observe the effects of resveratrol on HepG2 cell growth, and the distribution of cell cycles was detected with flow cytometry (FCM). The effects of resveratrol on GJIC of HepG2 cells labeled with 5'-CFDA/AM was examined with fluorescence redistribution after photobleaching (FRAP) and confocal microscope. RESULTS: The results of MTT assay indicated that the proliferation of HepG2 cells was significantly inhibited by resveratrol in a time- and dose-dependent manner. Resveratrol could arrest HepG2 cell growth in S phase, inhibit DNA synthesis and induce cell apoptosis. Furthermore, the levels of GJIC increased sharply after resveratrol treatment of the cells. CONCLUSION: Resveratrol is capable of inhibiting HepG2 cell proliferation, causing cell growth arrest at S phase and inducing cell apoptosis. Increased GJIC level contributes to the effect of resveratrol in HepG2 cell proliferation inhibition and its cancer chemopreventive activity.

Antineoplastic Agents, Phytogenic↗

PubMed2005

[Effect of Liangge San on lipopolysaccharide-induced nuclear factor kappa B activation in cultured mouse macrophages].

OBJECTIVE: To investigate the effect of Liangge San, a recipe of traditional Chinese herbal medicine, on lipopolysaccharide (LPS)-induced nuclear factor kB (NF-kB) activation in mouse macrophages cultured in vitro and explore the signal transduction mechanism of the detoxifying effect of Liangge San. METHODS: The mice were given oral administration of concentrated decoction of Liangge San to obtain the drug-containing serum. Macrophages from mouse abdominal cavity were collected, incubated and subsequently re-incubated with LPS and the prepared serum at different doses. Immunofluorescence method was adopted to examine the expression of NF-kB subunit p65 in the nuclei of the macrophages, and the fluorescence intensity of p65 expression was measured by laser scanning confocal microscope (LSCM). RESULTS: The fluorescence intensity of p65 expression in the nuclei of macrophages incubated with LPS for 1 h was significantly increased compared with that in the cells without LPS stimulation and Liangge San serum-treated cells. The fluorescence intensities were significantly decreased in cells treated with the inhibitor TLCK and different doses of Liangge San serum in comparison with those in LPS-stimulated cells. The fluorescence intensities were the lowest in cells treated with TLCK and high-dose Liangge San serum, and the cells treated with moderate and low doses of the serum both showed lower intensity compared with that of LPS-stimulated cells. p65 expression was similar between the macrophages incubated with LPS and those treated with serum that contained no Liangge San. CONCLUSIONS: Mouse serum containing Liangge San can inhibit LPS-induced p65 expression in mouse macrophages in a dose-dependent manner, which may be one of the signal transduction mechanisms of the detoxifying effect of Liangge San.

Animals↗

PubMed2003

[Gene sequence analysis of SARS-associated coronavirus by nested RT-PCR].

OBJECTIVE: To explore an effective means for the detection of Severe Acute Respiratory Syndrome (SARS)- associated coronavirus. METHODS: The RNAs of the virus contained in the sputum samples from established SARS patients were extracted and reversely transcripted, followed by nested PCR using the reversely transcripted cDNA as the template. The PCR products were cloned then into the pMD18-T vectors, followed by sequence analysis. RESULTS: Specific fragments were amplified from the sputum samples of SARS patients, which were confirmed by DNA cloning and sequencing to belong to SARS-associated coronavirus. The Result of Blast shows only the difference in one nucleic acid from the TOR2 strain of SARS-associated coronavirus. CONCLUSION: Sequence analysis has confirmed the existence of SARS-associated coronavirus in the sputum samples of SARS patients, and nested RT-PCR is a quick, easy, and convenient way for the detection of the virus.

Base Sequence↗

PubMed2003

Rapid preparation of DNA microarray using PCR for hepatitis B and D virus detection.

OBJECTIVE: To prepare DNA microarray for detecting both hepatitis B and D virus as (HBV and HDV). METHODS: With the assistance of Oligo6.4 software, specific PCR primers targeting the conserved region of HBV and HDV were designed. The PCR products were purified and cloned into the pMD18-T vectors, followed by rapid identification. The recombinant plasmids were then extracted from positive clones and the target gene fragments underwent sequence analysis. RESULTS: The gene fragments of HBV and HDV were obtained by PCR, which were confirmed by sequence analysis to be specific gene fragments of HBV and HDV. CONCLUSION: Using PCR amplification products to prepare the DNA microarray is quick, simple and effective.

Hepatitis B virus↗

PubMed2003

[Preparation of gene chip probes for Bacillus anthracis protective antigen].

OBJECTIVE: To study the method for rapid preparation of the gene chip probes for Bacillus anthracis protective antigen (pag). METHODS: According to the sequences of pag published on PubMed, a pair of primers was designed to amplify the PA gene of Bacillus anthracis. Restriction enzyme digestion and AT clone were employed to rapidly screen out the recons of PA segments for the preparation of the gene chip probes. The DNA sequences of these segments were determined with 377 DNA Sequencer, and the resultant sequences analyzed with Bioinformatic software. RESULTS: With the designed primers, the pag 2,205 bp in length was amplified. After enzyme digestion and AT clone, 7 fragments of varied lengths were screened, which underwent analysis with the basic local alignment sequence tool (BLAST) and 377 DNA Sequencer. BLAST analysis showed that all the fragments cloned belonged to Bacillus anthracis. CONCLUSION: PCR in conjunction with restriction enzyme digestion and AT clone is rapid and simple to prepare the desired gene chip probes.

Antigens, Bacterial↗

PubMed2003

[Bioinformatic analysis of dengue virus cDNAs and design of oligonucleotide probes for microarray detection of the virus].

OBJECTIVE: To design oligonucleotide probes for microarray detection of dengue virus. METHODS: By analyzing the cDNAs of dengue viruses of 4 different serotypes with BLAST program, a group of specific sequences for the candidate probes was acquired. Oligo6.0 software was applied to analyze the candidates to select the probes with high specificity, identical length and similar melting temperature (Tm). RESULT: Altogether 48 oligonucleotide probes were designed, and deposited on oligonucleotide chips as the microarray for dengue virus detection. CONCLUSION: BLAST program and Oligo6.0 software are simple and effective means for designing the oligonucleotide probes.

Base Sequence↗

PubMed2003

Quick preparations of human parvovirus B19 microarray probes using PCR.

OBJECTIVE: To prepare DNA microarray probes for the detection of human parvovirus B19. Method Specific PCR primers were designed with the Primer Premier 5.0 to amplify the conserved regions of human parvovirus B19 genome. The PCR products were cloned into the pMD-18 T vector. METHOD: Sequences analysis showed the PCR products conformed to the sequences contained in the genome of human parvovirus B19. RESULT: Sequences analysis showed the PCR products conformed to the sequences contained in the genome of human parvovirus B19. CONCLUSION: PCR amplification of the conserved and specific human parvovirus B19 genes is simple and effective to prepare the desired probes.

DNA Probes↗